1//===--- SemaChecking.cpp - Extra Semantic Checking -----------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file implements extra semantic analysis beyond what is enforced
11//  by the C type system.
12//
13//===----------------------------------------------------------------------===//
14
15#include "clang/Sema/SemaInternal.h"
16#include "clang/AST/ASTContext.h"
17#include "clang/AST/CharUnits.h"
18#include "clang/AST/DeclCXX.h"
19#include "clang/AST/DeclObjC.h"
20#include "clang/AST/EvaluatedExprVisitor.h"
21#include "clang/AST/Expr.h"
22#include "clang/AST/ExprCXX.h"
23#include "clang/AST/ExprObjC.h"
24#include "clang/AST/ExprOpenMP.h"
25#include "clang/AST/StmtCXX.h"
26#include "clang/AST/StmtObjC.h"
27#include "clang/Analysis/Analyses/FormatString.h"
28#include "clang/Basic/CharInfo.h"
29#include "clang/Basic/TargetBuiltins.h"
30#include "clang/Basic/TargetInfo.h"
31#include "clang/Lex/Lexer.h" // TODO: Extract static functions to fix layering.
32#include "clang/Sema/Initialization.h"
33#include "clang/Sema/Lookup.h"
34#include "clang/Sema/ScopeInfo.h"
35#include "clang/Sema/Sema.h"
36#include "llvm/ADT/STLExtras.h"
37#include "llvm/ADT/SmallBitVector.h"
38#include "llvm/ADT/SmallString.h"
39#include "llvm/Support/Format.h"
40#include "llvm/Support/Locale.h"
41#include "llvm/Support/ConvertUTF.h"
42#include "llvm/Support/raw_ostream.h"
43#include <limits>
44
45using namespace clang;
46using namespace sema;
47
48SourceLocation Sema::getLocationOfStringLiteralByte(const StringLiteral *SL,
49                                                    unsigned ByteNo) const {
50  return SL->getLocationOfByte(ByteNo, getSourceManager(), LangOpts,
51                               Context.getTargetInfo());
52}
53
54/// Checks that a call expression's argument count is the desired number.
55/// This is useful when doing custom type-checking.  Returns true on error.
56static bool checkArgCount(Sema &S, CallExpr *call, unsigned desiredArgCount) {
57  unsigned argCount = call->getNumArgs();
58  if (argCount == desiredArgCount) return false;
59
60  if (argCount < desiredArgCount)
61    return S.Diag(call->getLocEnd(), diag::err_typecheck_call_too_few_args)
62        << 0 /*function call*/ << desiredArgCount << argCount
63        << call->getSourceRange();
64
65  // Highlight all the excess arguments.
66  SourceRange range(call->getArg(desiredArgCount)->getLocStart(),
67                    call->getArg(argCount - 1)->getLocEnd());
68
69  return S.Diag(range.getBegin(), diag::err_typecheck_call_too_many_args)
70    << 0 /*function call*/ << desiredArgCount << argCount
71    << call->getArg(1)->getSourceRange();
72}
73
74/// Check that the first argument to __builtin_annotation is an integer
75/// and the second argument is a non-wide string literal.
76static bool SemaBuiltinAnnotation(Sema &S, CallExpr *TheCall) {
77  if (checkArgCount(S, TheCall, 2))
78    return true;
79
80  // First argument should be an integer.
81  Expr *ValArg = TheCall->getArg(0);
82  QualType Ty = ValArg->getType();
83  if (!Ty->isIntegerType()) {
84    S.Diag(ValArg->getLocStart(), diag::err_builtin_annotation_first_arg)
85      << ValArg->getSourceRange();
86    return true;
87  }
88
89  // Second argument should be a constant string.
90  Expr *StrArg = TheCall->getArg(1)->IgnoreParenCasts();
91  StringLiteral *Literal = dyn_cast<StringLiteral>(StrArg);
92  if (!Literal || !Literal->isAscii()) {
93    S.Diag(StrArg->getLocStart(), diag::err_builtin_annotation_second_arg)
94      << StrArg->getSourceRange();
95    return true;
96  }
97
98  TheCall->setType(Ty);
99  return false;
100}
101
102/// Check that the argument to __builtin_addressof is a glvalue, and set the
103/// result type to the corresponding pointer type.
104static bool SemaBuiltinAddressof(Sema &S, CallExpr *TheCall) {
105  if (checkArgCount(S, TheCall, 1))
106    return true;
107
108  ExprResult Arg(TheCall->getArg(0));
109  QualType ResultType = S.CheckAddressOfOperand(Arg, TheCall->getLocStart());
110  if (ResultType.isNull())
111    return true;
112
113  TheCall->setArg(0, Arg.get());
114  TheCall->setType(ResultType);
115  return false;
116}
117
118static bool SemaBuiltinOverflow(Sema &S, CallExpr *TheCall) {
119  if (checkArgCount(S, TheCall, 3))
120    return true;
121
122  // First two arguments should be integers.
123  for (unsigned I = 0; I < 2; ++I) {
124    Expr *Arg = TheCall->getArg(I);
125    QualType Ty = Arg->getType();
126    if (!Ty->isIntegerType()) {
127      S.Diag(Arg->getLocStart(), diag::err_overflow_builtin_must_be_int)
128          << Ty << Arg->getSourceRange();
129      return true;
130    }
131  }
132
133  // Third argument should be a pointer to a non-const integer.
134  // IRGen correctly handles volatile, restrict, and address spaces, and
135  // the other qualifiers aren't possible.
136  {
137    Expr *Arg = TheCall->getArg(2);
138    QualType Ty = Arg->getType();
139    const auto *PtrTy = Ty->getAs<PointerType>();
140    if (!(PtrTy && PtrTy->getPointeeType()->isIntegerType() &&
141          !PtrTy->getPointeeType().isConstQualified())) {
142      S.Diag(Arg->getLocStart(), diag::err_overflow_builtin_must_be_ptr_int)
143          << Ty << Arg->getSourceRange();
144      return true;
145    }
146  }
147
148  return false;
149}
150
151static void SemaBuiltinMemChkCall(Sema &S, FunctionDecl *FDecl,
152		                  CallExpr *TheCall, unsigned SizeIdx,
153                                  unsigned DstSizeIdx) {
154  if (TheCall->getNumArgs() <= SizeIdx ||
155      TheCall->getNumArgs() <= DstSizeIdx)
156    return;
157
158  const Expr *SizeArg = TheCall->getArg(SizeIdx);
159  const Expr *DstSizeArg = TheCall->getArg(DstSizeIdx);
160
161  llvm::APSInt Size, DstSize;
162
163  // find out if both sizes are known at compile time
164  if (!SizeArg->EvaluateAsInt(Size, S.Context) ||
165      !DstSizeArg->EvaluateAsInt(DstSize, S.Context))
166    return;
167
168  if (Size.ule(DstSize))
169    return;
170
171  // confirmed overflow so generate the diagnostic.
172  IdentifierInfo *FnName = FDecl->getIdentifier();
173  SourceLocation SL = TheCall->getLocStart();
174  SourceRange SR = TheCall->getSourceRange();
175
176  S.Diag(SL, diag::warn_memcpy_chk_overflow) << SR << FnName;
177}
178
179static bool SemaBuiltinCallWithStaticChain(Sema &S, CallExpr *BuiltinCall) {
180  if (checkArgCount(S, BuiltinCall, 2))
181    return true;
182
183  SourceLocation BuiltinLoc = BuiltinCall->getLocStart();
184  Expr *Builtin = BuiltinCall->getCallee()->IgnoreImpCasts();
185  Expr *Call = BuiltinCall->getArg(0);
186  Expr *Chain = BuiltinCall->getArg(1);
187
188  if (Call->getStmtClass() != Stmt::CallExprClass) {
189    S.Diag(BuiltinLoc, diag::err_first_argument_to_cwsc_not_call)
190        << Call->getSourceRange();
191    return true;
192  }
193
194  auto CE = cast<CallExpr>(Call);
195  if (CE->getCallee()->getType()->isBlockPointerType()) {
196    S.Diag(BuiltinLoc, diag::err_first_argument_to_cwsc_block_call)
197        << Call->getSourceRange();
198    return true;
199  }
200
201  const Decl *TargetDecl = CE->getCalleeDecl();
202  if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl))
203    if (FD->getBuiltinID()) {
204      S.Diag(BuiltinLoc, diag::err_first_argument_to_cwsc_builtin_call)
205          << Call->getSourceRange();
206      return true;
207    }
208
209  if (isa<CXXPseudoDestructorExpr>(CE->getCallee()->IgnoreParens())) {
210    S.Diag(BuiltinLoc, diag::err_first_argument_to_cwsc_pdtor_call)
211        << Call->getSourceRange();
212    return true;
213  }
214
215  ExprResult ChainResult = S.UsualUnaryConversions(Chain);
216  if (ChainResult.isInvalid())
217    return true;
218  if (!ChainResult.get()->getType()->isPointerType()) {
219    S.Diag(BuiltinLoc, diag::err_second_argument_to_cwsc_not_pointer)
220        << Chain->getSourceRange();
221    return true;
222  }
223
224  QualType ReturnTy = CE->getCallReturnType(S.Context);
225  QualType ArgTys[2] = { ReturnTy, ChainResult.get()->getType() };
226  QualType BuiltinTy = S.Context.getFunctionType(
227      ReturnTy, ArgTys, FunctionProtoType::ExtProtoInfo());
228  QualType BuiltinPtrTy = S.Context.getPointerType(BuiltinTy);
229
230  Builtin =
231      S.ImpCastExprToType(Builtin, BuiltinPtrTy, CK_BuiltinFnToFnPtr).get();
232
233  BuiltinCall->setType(CE->getType());
234  BuiltinCall->setValueKind(CE->getValueKind());
235  BuiltinCall->setObjectKind(CE->getObjectKind());
236  BuiltinCall->setCallee(Builtin);
237  BuiltinCall->setArg(1, ChainResult.get());
238
239  return false;
240}
241
242static bool SemaBuiltinSEHScopeCheck(Sema &SemaRef, CallExpr *TheCall,
243                                     Scope::ScopeFlags NeededScopeFlags,
244                                     unsigned DiagID) {
245  // Scopes aren't available during instantiation. Fortunately, builtin
246  // functions cannot be template args so they cannot be formed through template
247  // instantiation. Therefore checking once during the parse is sufficient.
248  if (!SemaRef.ActiveTemplateInstantiations.empty())
249    return false;
250
251  Scope *S = SemaRef.getCurScope();
252  while (S && !S->isSEHExceptScope())
253    S = S->getParent();
254  if (!S || !(S->getFlags() & NeededScopeFlags)) {
255    auto *DRE = cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
256    SemaRef.Diag(TheCall->getExprLoc(), DiagID)
257        << DRE->getDecl()->getIdentifier();
258    return true;
259  }
260
261  return false;
262}
263
264static inline bool isBlockPointer(Expr *Arg) {
265  return Arg->getType()->isBlockPointerType();
266}
267
268/// OpenCL C v2.0, s6.13.17.2 - Checks that the block parameters are all local
269/// void*, which is a requirement of device side enqueue.
270static bool checkOpenCLBlockArgs(Sema &S, Expr *BlockArg) {
271  const BlockPointerType *BPT =
272      cast<BlockPointerType>(BlockArg->getType().getCanonicalType());
273  ArrayRef<QualType> Params =
274      BPT->getPointeeType()->getAs<FunctionProtoType>()->getParamTypes();
275  unsigned ArgCounter = 0;
276  bool IllegalParams = false;
277  // Iterate through the block parameters until either one is found that is not
278  // a local void*, or the block is valid.
279  for (ArrayRef<QualType>::iterator I = Params.begin(), E = Params.end();
280       I != E; ++I, ++ArgCounter) {
281    if (!(*I)->isPointerType() || !(*I)->getPointeeType()->isVoidType() ||
282        (*I)->getPointeeType().getQualifiers().getAddressSpace() !=
283            LangAS::opencl_local) {
284      // Get the location of the error. If a block literal has been passed
285      // (BlockExpr) then we can point straight to the offending argument,
286      // else we just point to the variable reference.
287      SourceLocation ErrorLoc;
288      if (isa<BlockExpr>(BlockArg)) {
289        BlockDecl *BD = cast<BlockExpr>(BlockArg)->getBlockDecl();
290        ErrorLoc = BD->getParamDecl(ArgCounter)->getLocStart();
291      } else if (isa<DeclRefExpr>(BlockArg)) {
292        ErrorLoc = cast<DeclRefExpr>(BlockArg)->getLocStart();
293      }
294      S.Diag(ErrorLoc,
295             diag::err_opencl_enqueue_kernel_blocks_non_local_void_args);
296      IllegalParams = true;
297    }
298  }
299
300  return IllegalParams;
301}
302
303/// OpenCL C v2.0, s6.13.17.6 - Check the argument to the
304/// get_kernel_work_group_size
305/// and get_kernel_preferred_work_group_size_multiple builtin functions.
306static bool SemaOpenCLBuiltinKernelWorkGroupSize(Sema &S, CallExpr *TheCall) {
307  if (checkArgCount(S, TheCall, 1))
308    return true;
309
310  Expr *BlockArg = TheCall->getArg(0);
311  if (!isBlockPointer(BlockArg)) {
312    S.Diag(BlockArg->getLocStart(),
313           diag::err_opencl_enqueue_kernel_expected_type) << "block";
314    return true;
315  }
316  return checkOpenCLBlockArgs(S, BlockArg);
317}
318
319static bool checkOpenCLEnqueueLocalSizeArgs(Sema &S, CallExpr *TheCall,
320                                            unsigned Start, unsigned End);
321
322/// OpenCL v2.0, s6.13.17.1 - Check that sizes are provided for all
323/// 'local void*' parameter of passed block.
324static bool checkOpenCLEnqueueVariadicArgs(Sema &S, CallExpr *TheCall,
325                                           Expr *BlockArg,
326                                           unsigned NumNonVarArgs) {
327  const BlockPointerType *BPT =
328      cast<BlockPointerType>(BlockArg->getType().getCanonicalType());
329  unsigned NumBlockParams =
330      BPT->getPointeeType()->getAs<FunctionProtoType>()->getNumParams();
331  unsigned TotalNumArgs = TheCall->getNumArgs();
332
333  // For each argument passed to the block, a corresponding uint needs to
334  // be passed to describe the size of the local memory.
335  if (TotalNumArgs != NumBlockParams + NumNonVarArgs) {
336    S.Diag(TheCall->getLocStart(),
337           diag::err_opencl_enqueue_kernel_local_size_args);
338    return true;
339  }
340
341  // Check that the sizes of the local memory are specified by integers.
342  return checkOpenCLEnqueueLocalSizeArgs(S, TheCall, NumNonVarArgs,
343                                         TotalNumArgs - 1);
344}
345
346/// OpenCL C v2.0, s6.13.17 - Enqueue kernel function contains four different
347/// overload formats specified in Table 6.13.17.1.
348/// int enqueue_kernel(queue_t queue,
349///                    kernel_enqueue_flags_t flags,
350///                    const ndrange_t ndrange,
351///                    void (^block)(void))
352/// int enqueue_kernel(queue_t queue,
353///                    kernel_enqueue_flags_t flags,
354///                    const ndrange_t ndrange,
355///                    uint num_events_in_wait_list,
356///                    clk_event_t *event_wait_list,
357///                    clk_event_t *event_ret,
358///                    void (^block)(void))
359/// int enqueue_kernel(queue_t queue,
360///                    kernel_enqueue_flags_t flags,
361///                    const ndrange_t ndrange,
362///                    void (^block)(local void*, ...),
363///                    uint size0, ...)
364/// int enqueue_kernel(queue_t queue,
365///                    kernel_enqueue_flags_t flags,
366///                    const ndrange_t ndrange,
367///                    uint num_events_in_wait_list,
368///                    clk_event_t *event_wait_list,
369///                    clk_event_t *event_ret,
370///                    void (^block)(local void*, ...),
371///                    uint size0, ...)
372static bool SemaOpenCLBuiltinEnqueueKernel(Sema &S, CallExpr *TheCall) {
373  unsigned NumArgs = TheCall->getNumArgs();
374
375  if (NumArgs < 4) {
376    S.Diag(TheCall->getLocStart(), diag::err_typecheck_call_too_few_args);
377    return true;
378  }
379
380  Expr *Arg0 = TheCall->getArg(0);
381  Expr *Arg1 = TheCall->getArg(1);
382  Expr *Arg2 = TheCall->getArg(2);
383  Expr *Arg3 = TheCall->getArg(3);
384
385  // First argument always needs to be a queue_t type.
386  if (!Arg0->getType()->isQueueT()) {
387    S.Diag(TheCall->getArg(0)->getLocStart(),
388           diag::err_opencl_enqueue_kernel_expected_type)
389        << S.Context.OCLQueueTy;
390    return true;
391  }
392
393  // Second argument always needs to be a kernel_enqueue_flags_t enum value.
394  if (!Arg1->getType()->isIntegerType()) {
395    S.Diag(TheCall->getArg(1)->getLocStart(),
396           diag::err_opencl_enqueue_kernel_expected_type)
397        << "'kernel_enqueue_flags_t' (i.e. uint)";
398    return true;
399  }
400
401  // Third argument is always an ndrange_t type.
402  if (!Arg2->getType()->isNDRangeT()) {
403    S.Diag(TheCall->getArg(2)->getLocStart(),
404           diag::err_opencl_enqueue_kernel_expected_type)
405        << S.Context.OCLNDRangeTy;
406    return true;
407  }
408
409  // With four arguments, there is only one form that the function could be
410  // called in: no events and no variable arguments.
411  if (NumArgs == 4) {
412    // check that the last argument is the right block type.
413    if (!isBlockPointer(Arg3)) {
414      S.Diag(Arg3->getLocStart(), diag::err_opencl_enqueue_kernel_expected_type)
415          << "block";
416      return true;
417    }
418    // we have a block type, check the prototype
419    const BlockPointerType *BPT =
420        cast<BlockPointerType>(Arg3->getType().getCanonicalType());
421    if (BPT->getPointeeType()->getAs<FunctionProtoType>()->getNumParams() > 0) {
422      S.Diag(Arg3->getLocStart(),
423             diag::err_opencl_enqueue_kernel_blocks_no_args);
424      return true;
425    }
426    return false;
427  }
428  // we can have block + varargs.
429  if (isBlockPointer(Arg3))
430    return (checkOpenCLBlockArgs(S, Arg3) ||
431            checkOpenCLEnqueueVariadicArgs(S, TheCall, Arg3, 4));
432  // last two cases with either exactly 7 args or 7 args and varargs.
433  if (NumArgs >= 7) {
434    // check common block argument.
435    Expr *Arg6 = TheCall->getArg(6);
436    if (!isBlockPointer(Arg6)) {
437      S.Diag(Arg6->getLocStart(), diag::err_opencl_enqueue_kernel_expected_type)
438          << "block";
439      return true;
440    }
441    if (checkOpenCLBlockArgs(S, Arg6))
442      return true;
443
444    // Forth argument has to be any integer type.
445    if (!Arg3->getType()->isIntegerType()) {
446      S.Diag(TheCall->getArg(3)->getLocStart(),
447             diag::err_opencl_enqueue_kernel_expected_type)
448          << "integer";
449      return true;
450    }
451    // check remaining common arguments.
452    Expr *Arg4 = TheCall->getArg(4);
453    Expr *Arg5 = TheCall->getArg(5);
454
455    // Fith argument is always passed as pointers to clk_event_t.
456    if (!Arg4->getType()->getPointeeOrArrayElementType()->isClkEventT()) {
457      S.Diag(TheCall->getArg(4)->getLocStart(),
458             diag::err_opencl_enqueue_kernel_expected_type)
459          << S.Context.getPointerType(S.Context.OCLClkEventTy);
460      return true;
461    }
462
463    // Sixth argument is always passed as pointers to clk_event_t.
464    if (!(Arg5->getType()->isPointerType() &&
465          Arg5->getType()->getPointeeType()->isClkEventT())) {
466      S.Diag(TheCall->getArg(5)->getLocStart(),
467             diag::err_opencl_enqueue_kernel_expected_type)
468          << S.Context.getPointerType(S.Context.OCLClkEventTy);
469      return true;
470    }
471
472    if (NumArgs == 7)
473      return false;
474
475    return checkOpenCLEnqueueVariadicArgs(S, TheCall, Arg6, 7);
476  }
477
478  // None of the specific case has been detected, give generic error
479  S.Diag(TheCall->getLocStart(),
480         diag::err_opencl_enqueue_kernel_incorrect_args);
481  return true;
482}
483
484/// Returns OpenCL access qual.
485static OpenCLAccessAttr *getOpenCLArgAccess(const Decl *D) {
486    return D->getAttr<OpenCLAccessAttr>();
487}
488
489/// Returns true if pipe element type is different from the pointer.
490static bool checkOpenCLPipeArg(Sema &S, CallExpr *Call) {
491  const Expr *Arg0 = Call->getArg(0);
492  // First argument type should always be pipe.
493  if (!Arg0->getType()->isPipeType()) {
494    S.Diag(Call->getLocStart(), diag::err_opencl_builtin_pipe_first_arg)
495        << Call->getDirectCallee() << Arg0->getSourceRange();
496    return true;
497  }
498  OpenCLAccessAttr *AccessQual =
499      getOpenCLArgAccess(cast<DeclRefExpr>(Arg0)->getDecl());
500  // Validates the access qualifier is compatible with the call.
501  // OpenCL v2.0 s6.13.16 - The access qualifiers for pipe should only be
502  // read_only and write_only, and assumed to be read_only if no qualifier is
503  // specified.
504  switch (Call->getDirectCallee()->getBuiltinID()) {
505  case Builtin::BIread_pipe:
506  case Builtin::BIreserve_read_pipe:
507  case Builtin::BIcommit_read_pipe:
508  case Builtin::BIwork_group_reserve_read_pipe:
509  case Builtin::BIsub_group_reserve_read_pipe:
510  case Builtin::BIwork_group_commit_read_pipe:
511  case Builtin::BIsub_group_commit_read_pipe:
512    if (!(!AccessQual || AccessQual->isReadOnly())) {
513      S.Diag(Arg0->getLocStart(),
514             diag::err_opencl_builtin_pipe_invalid_access_modifier)
515          << "read_only" << Arg0->getSourceRange();
516      return true;
517    }
518    break;
519  case Builtin::BIwrite_pipe:
520  case Builtin::BIreserve_write_pipe:
521  case Builtin::BIcommit_write_pipe:
522  case Builtin::BIwork_group_reserve_write_pipe:
523  case Builtin::BIsub_group_reserve_write_pipe:
524  case Builtin::BIwork_group_commit_write_pipe:
525  case Builtin::BIsub_group_commit_write_pipe:
526    if (!(AccessQual && AccessQual->isWriteOnly())) {
527      S.Diag(Arg0->getLocStart(),
528             diag::err_opencl_builtin_pipe_invalid_access_modifier)
529          << "write_only" << Arg0->getSourceRange();
530      return true;
531    }
532    break;
533  default:
534    break;
535  }
536  return false;
537}
538
539/// Returns true if pipe element type is different from the pointer.
540static bool checkOpenCLPipePacketType(Sema &S, CallExpr *Call, unsigned Idx) {
541  const Expr *Arg0 = Call->getArg(0);
542  const Expr *ArgIdx = Call->getArg(Idx);
543  const PipeType *PipeTy = cast<PipeType>(Arg0->getType());
544  const QualType EltTy = PipeTy->getElementType();
545  const PointerType *ArgTy = ArgIdx->getType()->getAs<PointerType>();
546  // The Idx argument should be a pointer and the type of the pointer and
547  // the type of pipe element should also be the same.
548  if (!ArgTy ||
549      !S.Context.hasSameType(
550          EltTy, ArgTy->getPointeeType()->getCanonicalTypeInternal())) {
551    S.Diag(Call->getLocStart(), diag::err_opencl_builtin_pipe_invalid_arg)
552        << Call->getDirectCallee() << S.Context.getPointerType(EltTy)
553        << ArgIdx->getType() << ArgIdx->getSourceRange();
554    return true;
555  }
556  return false;
557}
558
559// \brief Performs semantic analysis for the read/write_pipe call.
560// \param S Reference to the semantic analyzer.
561// \param Call A pointer to the builtin call.
562// \return True if a semantic error has been found, false otherwise.
563static bool SemaBuiltinRWPipe(Sema &S, CallExpr *Call) {
564  // OpenCL v2.0 s6.13.16.2 - The built-in read/write
565  // functions have two forms.
566  switch (Call->getNumArgs()) {
567  case 2: {
568    if (checkOpenCLPipeArg(S, Call))
569      return true;
570    // The call with 2 arguments should be
571    // read/write_pipe(pipe T, T*).
572    // Check packet type T.
573    if (checkOpenCLPipePacketType(S, Call, 1))
574      return true;
575  } break;
576
577  case 4: {
578    if (checkOpenCLPipeArg(S, Call))
579      return true;
580    // The call with 4 arguments should be
581    // read/write_pipe(pipe T, reserve_id_t, uint, T*).
582    // Check reserve_id_t.
583    if (!Call->getArg(1)->getType()->isReserveIDT()) {
584      S.Diag(Call->getLocStart(), diag::err_opencl_builtin_pipe_invalid_arg)
585          << Call->getDirectCallee() << S.Context.OCLReserveIDTy
586          << Call->getArg(1)->getType() << Call->getArg(1)->getSourceRange();
587      return true;
588    }
589
590    // Check the index.
591    const Expr *Arg2 = Call->getArg(2);
592    if (!Arg2->getType()->isIntegerType() &&
593        !Arg2->getType()->isUnsignedIntegerType()) {
594      S.Diag(Call->getLocStart(), diag::err_opencl_builtin_pipe_invalid_arg)
595          << Call->getDirectCallee() << S.Context.UnsignedIntTy
596          << Arg2->getType() << Arg2->getSourceRange();
597      return true;
598    }
599
600    // Check packet type T.
601    if (checkOpenCLPipePacketType(S, Call, 3))
602      return true;
603  } break;
604  default:
605    S.Diag(Call->getLocStart(), diag::err_opencl_builtin_pipe_arg_num)
606        << Call->getDirectCallee() << Call->getSourceRange();
607    return true;
608  }
609
610  return false;
611}
612
613// \brief Performs a semantic analysis on the {work_group_/sub_group_
614//        /_}reserve_{read/write}_pipe
615// \param S Reference to the semantic analyzer.
616// \param Call The call to the builtin function to be analyzed.
617// \return True if a semantic error was found, false otherwise.
618static bool SemaBuiltinReserveRWPipe(Sema &S, CallExpr *Call) {
619  if (checkArgCount(S, Call, 2))
620    return true;
621
622  if (checkOpenCLPipeArg(S, Call))
623    return true;
624
625  // Check the reserve size.
626  if (!Call->getArg(1)->getType()->isIntegerType() &&
627      !Call->getArg(1)->getType()->isUnsignedIntegerType()) {
628    S.Diag(Call->getLocStart(), diag::err_opencl_builtin_pipe_invalid_arg)
629        << Call->getDirectCallee() << S.Context.UnsignedIntTy
630        << Call->getArg(1)->getType() << Call->getArg(1)->getSourceRange();
631    return true;
632  }
633
634  return false;
635}
636
637// \brief Performs a semantic analysis on {work_group_/sub_group_
638//        /_}commit_{read/write}_pipe
639// \param S Reference to the semantic analyzer.
640// \param Call The call to the builtin function to be analyzed.
641// \return True if a semantic error was found, false otherwise.
642static bool SemaBuiltinCommitRWPipe(Sema &S, CallExpr *Call) {
643  if (checkArgCount(S, Call, 2))
644    return true;
645
646  if (checkOpenCLPipeArg(S, Call))
647    return true;
648
649  // Check reserve_id_t.
650  if (!Call->getArg(1)->getType()->isReserveIDT()) {
651    S.Diag(Call->getLocStart(), diag::err_opencl_builtin_pipe_invalid_arg)
652        << Call->getDirectCallee() << S.Context.OCLReserveIDTy
653        << Call->getArg(1)->getType() << Call->getArg(1)->getSourceRange();
654    return true;
655  }
656
657  return false;
658}
659
660// \brief Performs a semantic analysis on the call to built-in Pipe
661//        Query Functions.
662// \param S Reference to the semantic analyzer.
663// \param Call The call to the builtin function to be analyzed.
664// \return True if a semantic error was found, false otherwise.
665static bool SemaBuiltinPipePackets(Sema &S, CallExpr *Call) {
666  if (checkArgCount(S, Call, 1))
667    return true;
668
669  if (!Call->getArg(0)->getType()->isPipeType()) {
670    S.Diag(Call->getLocStart(), diag::err_opencl_builtin_pipe_first_arg)
671        << Call->getDirectCallee() << Call->getArg(0)->getSourceRange();
672    return true;
673  }
674
675  return false;
676}
677// \brief OpenCL v2.0 s6.13.9 - Address space qualifier functions.
678// \brief Performs semantic analysis for the to_global/local/private call.
679// \param S Reference to the semantic analyzer.
680// \param BuiltinID ID of the builtin function.
681// \param Call A pointer to the builtin call.
682// \return True if a semantic error has been found, false otherwise.
683static bool SemaOpenCLBuiltinToAddr(Sema &S, unsigned BuiltinID,
684                                    CallExpr *Call) {
685  if (Call->getNumArgs() != 1) {
686    S.Diag(Call->getLocStart(), diag::err_opencl_builtin_to_addr_arg_num)
687        << Call->getDirectCallee() << Call->getSourceRange();
688    return true;
689  }
690
691  auto RT = Call->getArg(0)->getType();
692  if (!RT->isPointerType() || RT->getPointeeType()
693      .getAddressSpace() == LangAS::opencl_constant) {
694    S.Diag(Call->getLocStart(), diag::err_opencl_builtin_to_addr_invalid_arg)
695        << Call->getArg(0) << Call->getDirectCallee() << Call->getSourceRange();
696    return true;
697  }
698
699  RT = RT->getPointeeType();
700  auto Qual = RT.getQualifiers();
701  switch (BuiltinID) {
702  case Builtin::BIto_global:
703    Qual.setAddressSpace(LangAS::opencl_global);
704    break;
705  case Builtin::BIto_local:
706    Qual.setAddressSpace(LangAS::opencl_local);
707    break;
708  default:
709    Qual.removeAddressSpace();
710  }
711  Call->setType(S.Context.getPointerType(S.Context.getQualifiedType(
712      RT.getUnqualifiedType(), Qual)));
713
714  return false;
715}
716
717ExprResult
718Sema::CheckBuiltinFunctionCall(FunctionDecl *FDecl, unsigned BuiltinID,
719                               CallExpr *TheCall) {
720  ExprResult TheCallResult(TheCall);
721
722  // Find out if any arguments are required to be integer constant expressions.
723  unsigned ICEArguments = 0;
724  ASTContext::GetBuiltinTypeError Error;
725  Context.GetBuiltinType(BuiltinID, Error, &ICEArguments);
726  if (Error != ASTContext::GE_None)
727    ICEArguments = 0;  // Don't diagnose previously diagnosed errors.
728
729  // If any arguments are required to be ICE's, check and diagnose.
730  for (unsigned ArgNo = 0; ICEArguments != 0; ++ArgNo) {
731    // Skip arguments not required to be ICE's.
732    if ((ICEArguments & (1 << ArgNo)) == 0) continue;
733
734    llvm::APSInt Result;
735    if (SemaBuiltinConstantArg(TheCall, ArgNo, Result))
736      return true;
737    ICEArguments &= ~(1 << ArgNo);
738  }
739
740  switch (BuiltinID) {
741  case Builtin::BI__builtin___CFStringMakeConstantString:
742    assert(TheCall->getNumArgs() == 1 &&
743           "Wrong # arguments to builtin CFStringMakeConstantString");
744    if (CheckObjCString(TheCall->getArg(0)))
745      return ExprError();
746    break;
747  case Builtin::BI__builtin_stdarg_start:
748  case Builtin::BI__builtin_va_start:
749    if (SemaBuiltinVAStart(TheCall))
750      return ExprError();
751    break;
752  case Builtin::BI__va_start: {
753    switch (Context.getTargetInfo().getTriple().getArch()) {
754    case llvm::Triple::arm:
755    case llvm::Triple::thumb:
756      if (SemaBuiltinVAStartARM(TheCall))
757        return ExprError();
758      break;
759    default:
760      if (SemaBuiltinVAStart(TheCall))
761        return ExprError();
762      break;
763    }
764    break;
765  }
766  case Builtin::BI__builtin_isgreater:
767  case Builtin::BI__builtin_isgreaterequal:
768  case Builtin::BI__builtin_isless:
769  case Builtin::BI__builtin_islessequal:
770  case Builtin::BI__builtin_islessgreater:
771  case Builtin::BI__builtin_isunordered:
772    if (SemaBuiltinUnorderedCompare(TheCall))
773      return ExprError();
774    break;
775  case Builtin::BI__builtin_fpclassify:
776    if (SemaBuiltinFPClassification(TheCall, 6))
777      return ExprError();
778    break;
779  case Builtin::BI__builtin_isfinite:
780  case Builtin::BI__builtin_isinf:
781  case Builtin::BI__builtin_isinf_sign:
782  case Builtin::BI__builtin_isnan:
783  case Builtin::BI__builtin_isnormal:
784    if (SemaBuiltinFPClassification(TheCall, 1))
785      return ExprError();
786    break;
787  case Builtin::BI__builtin_shufflevector:
788    return SemaBuiltinShuffleVector(TheCall);
789    // TheCall will be freed by the smart pointer here, but that's fine, since
790    // SemaBuiltinShuffleVector guts it, but then doesn't release it.
791  case Builtin::BI__builtin_prefetch:
792    if (SemaBuiltinPrefetch(TheCall))
793      return ExprError();
794    break;
795  case Builtin::BI__assume:
796  case Builtin::BI__builtin_assume:
797    if (SemaBuiltinAssume(TheCall))
798      return ExprError();
799    break;
800  case Builtin::BI__builtin_assume_aligned:
801    if (SemaBuiltinAssumeAligned(TheCall))
802      return ExprError();
803    break;
804  case Builtin::BI__builtin_object_size:
805    if (SemaBuiltinConstantArgRange(TheCall, 1, 0, 3))
806      return ExprError();
807    break;
808  case Builtin::BI__builtin_longjmp:
809    if (SemaBuiltinLongjmp(TheCall))
810      return ExprError();
811    break;
812  case Builtin::BI__builtin_setjmp:
813    if (SemaBuiltinSetjmp(TheCall))
814      return ExprError();
815    break;
816  case Builtin::BI_setjmp:
817  case Builtin::BI_setjmpex:
818    if (checkArgCount(*this, TheCall, 1))
819      return true;
820    break;
821
822  case Builtin::BI__builtin_classify_type:
823    if (checkArgCount(*this, TheCall, 1)) return true;
824    TheCall->setType(Context.IntTy);
825    break;
826  case Builtin::BI__builtin_constant_p:
827    if (checkArgCount(*this, TheCall, 1)) return true;
828    TheCall->setType(Context.IntTy);
829    break;
830  case Builtin::BI__sync_fetch_and_add:
831  case Builtin::BI__sync_fetch_and_add_1:
832  case Builtin::BI__sync_fetch_and_add_2:
833  case Builtin::BI__sync_fetch_and_add_4:
834  case Builtin::BI__sync_fetch_and_add_8:
835  case Builtin::BI__sync_fetch_and_add_16:
836  case Builtin::BI__sync_fetch_and_sub:
837  case Builtin::BI__sync_fetch_and_sub_1:
838  case Builtin::BI__sync_fetch_and_sub_2:
839  case Builtin::BI__sync_fetch_and_sub_4:
840  case Builtin::BI__sync_fetch_and_sub_8:
841  case Builtin::BI__sync_fetch_and_sub_16:
842  case Builtin::BI__sync_fetch_and_or:
843  case Builtin::BI__sync_fetch_and_or_1:
844  case Builtin::BI__sync_fetch_and_or_2:
845  case Builtin::BI__sync_fetch_and_or_4:
846  case Builtin::BI__sync_fetch_and_or_8:
847  case Builtin::BI__sync_fetch_and_or_16:
848  case Builtin::BI__sync_fetch_and_and:
849  case Builtin::BI__sync_fetch_and_and_1:
850  case Builtin::BI__sync_fetch_and_and_2:
851  case Builtin::BI__sync_fetch_and_and_4:
852  case Builtin::BI__sync_fetch_and_and_8:
853  case Builtin::BI__sync_fetch_and_and_16:
854  case Builtin::BI__sync_fetch_and_xor:
855  case Builtin::BI__sync_fetch_and_xor_1:
856  case Builtin::BI__sync_fetch_and_xor_2:
857  case Builtin::BI__sync_fetch_and_xor_4:
858  case Builtin::BI__sync_fetch_and_xor_8:
859  case Builtin::BI__sync_fetch_and_xor_16:
860  case Builtin::BI__sync_fetch_and_nand:
861  case Builtin::BI__sync_fetch_and_nand_1:
862  case Builtin::BI__sync_fetch_and_nand_2:
863  case Builtin::BI__sync_fetch_and_nand_4:
864  case Builtin::BI__sync_fetch_and_nand_8:
865  case Builtin::BI__sync_fetch_and_nand_16:
866  case Builtin::BI__sync_add_and_fetch:
867  case Builtin::BI__sync_add_and_fetch_1:
868  case Builtin::BI__sync_add_and_fetch_2:
869  case Builtin::BI__sync_add_and_fetch_4:
870  case Builtin::BI__sync_add_and_fetch_8:
871  case Builtin::BI__sync_add_and_fetch_16:
872  case Builtin::BI__sync_sub_and_fetch:
873  case Builtin::BI__sync_sub_and_fetch_1:
874  case Builtin::BI__sync_sub_and_fetch_2:
875  case Builtin::BI__sync_sub_and_fetch_4:
876  case Builtin::BI__sync_sub_and_fetch_8:
877  case Builtin::BI__sync_sub_and_fetch_16:
878  case Builtin::BI__sync_and_and_fetch:
879  case Builtin::BI__sync_and_and_fetch_1:
880  case Builtin::BI__sync_and_and_fetch_2:
881  case Builtin::BI__sync_and_and_fetch_4:
882  case Builtin::BI__sync_and_and_fetch_8:
883  case Builtin::BI__sync_and_and_fetch_16:
884  case Builtin::BI__sync_or_and_fetch:
885  case Builtin::BI__sync_or_and_fetch_1:
886  case Builtin::BI__sync_or_and_fetch_2:
887  case Builtin::BI__sync_or_and_fetch_4:
888  case Builtin::BI__sync_or_and_fetch_8:
889  case Builtin::BI__sync_or_and_fetch_16:
890  case Builtin::BI__sync_xor_and_fetch:
891  case Builtin::BI__sync_xor_and_fetch_1:
892  case Builtin::BI__sync_xor_and_fetch_2:
893  case Builtin::BI__sync_xor_and_fetch_4:
894  case Builtin::BI__sync_xor_and_fetch_8:
895  case Builtin::BI__sync_xor_and_fetch_16:
896  case Builtin::BI__sync_nand_and_fetch:
897  case Builtin::BI__sync_nand_and_fetch_1:
898  case Builtin::BI__sync_nand_and_fetch_2:
899  case Builtin::BI__sync_nand_and_fetch_4:
900  case Builtin::BI__sync_nand_and_fetch_8:
901  case Builtin::BI__sync_nand_and_fetch_16:
902  case Builtin::BI__sync_val_compare_and_swap:
903  case Builtin::BI__sync_val_compare_and_swap_1:
904  case Builtin::BI__sync_val_compare_and_swap_2:
905  case Builtin::BI__sync_val_compare_and_swap_4:
906  case Builtin::BI__sync_val_compare_and_swap_8:
907  case Builtin::BI__sync_val_compare_and_swap_16:
908  case Builtin::BI__sync_bool_compare_and_swap:
909  case Builtin::BI__sync_bool_compare_and_swap_1:
910  case Builtin::BI__sync_bool_compare_and_swap_2:
911  case Builtin::BI__sync_bool_compare_and_swap_4:
912  case Builtin::BI__sync_bool_compare_and_swap_8:
913  case Builtin::BI__sync_bool_compare_and_swap_16:
914  case Builtin::BI__sync_lock_test_and_set:
915  case Builtin::BI__sync_lock_test_and_set_1:
916  case Builtin::BI__sync_lock_test_and_set_2:
917  case Builtin::BI__sync_lock_test_and_set_4:
918  case Builtin::BI__sync_lock_test_and_set_8:
919  case Builtin::BI__sync_lock_test_and_set_16:
920  case Builtin::BI__sync_lock_release:
921  case Builtin::BI__sync_lock_release_1:
922  case Builtin::BI__sync_lock_release_2:
923  case Builtin::BI__sync_lock_release_4:
924  case Builtin::BI__sync_lock_release_8:
925  case Builtin::BI__sync_lock_release_16:
926  case Builtin::BI__sync_swap:
927  case Builtin::BI__sync_swap_1:
928  case Builtin::BI__sync_swap_2:
929  case Builtin::BI__sync_swap_4:
930  case Builtin::BI__sync_swap_8:
931  case Builtin::BI__sync_swap_16:
932    return SemaBuiltinAtomicOverloaded(TheCallResult);
933  case Builtin::BI__builtin_nontemporal_load:
934  case Builtin::BI__builtin_nontemporal_store:
935    return SemaBuiltinNontemporalOverloaded(TheCallResult);
936#define BUILTIN(ID, TYPE, ATTRS)
937#define ATOMIC_BUILTIN(ID, TYPE, ATTRS) \
938  case Builtin::BI##ID: \
939    return SemaAtomicOpsOverloaded(TheCallResult, AtomicExpr::AO##ID);
940#include "clang/Basic/Builtins.def"
941  case Builtin::BI__builtin_annotation:
942    if (SemaBuiltinAnnotation(*this, TheCall))
943      return ExprError();
944    break;
945  case Builtin::BI__builtin_addressof:
946    if (SemaBuiltinAddressof(*this, TheCall))
947      return ExprError();
948    break;
949  case Builtin::BI__builtin_add_overflow:
950  case Builtin::BI__builtin_sub_overflow:
951  case Builtin::BI__builtin_mul_overflow:
952    if (SemaBuiltinOverflow(*this, TheCall))
953      return ExprError();
954    break;
955  case Builtin::BI__builtin_operator_new:
956  case Builtin::BI__builtin_operator_delete:
957    if (!getLangOpts().CPlusPlus) {
958      Diag(TheCall->getExprLoc(), diag::err_builtin_requires_language)
959        << (BuiltinID == Builtin::BI__builtin_operator_new
960                ? "__builtin_operator_new"
961                : "__builtin_operator_delete")
962        << "C++";
963      return ExprError();
964    }
965    // CodeGen assumes it can find the global new and delete to call,
966    // so ensure that they are declared.
967    DeclareGlobalNewDelete();
968    break;
969
970  // check secure string manipulation functions where overflows
971  // are detectable at compile time
972  case Builtin::BI__builtin___memcpy_chk:
973  case Builtin::BI__builtin___memmove_chk:
974  case Builtin::BI__builtin___memset_chk:
975  case Builtin::BI__builtin___strlcat_chk:
976  case Builtin::BI__builtin___strlcpy_chk:
977  case Builtin::BI__builtin___strncat_chk:
978  case Builtin::BI__builtin___strncpy_chk:
979  case Builtin::BI__builtin___stpncpy_chk:
980    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 2, 3);
981    break;
982  case Builtin::BI__builtin___memccpy_chk:
983    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 3, 4);
984    break;
985  case Builtin::BI__builtin___snprintf_chk:
986  case Builtin::BI__builtin___vsnprintf_chk:
987    SemaBuiltinMemChkCall(*this, FDecl, TheCall, 1, 3);
988    break;
989  case Builtin::BI__builtin_call_with_static_chain:
990    if (SemaBuiltinCallWithStaticChain(*this, TheCall))
991      return ExprError();
992    break;
993  case Builtin::BI__exception_code:
994  case Builtin::BI_exception_code:
995    if (SemaBuiltinSEHScopeCheck(*this, TheCall, Scope::SEHExceptScope,
996                                 diag::err_seh___except_block))
997      return ExprError();
998    break;
999  case Builtin::BI__exception_info:
1000  case Builtin::BI_exception_info:
1001    if (SemaBuiltinSEHScopeCheck(*this, TheCall, Scope::SEHFilterScope,
1002                                 diag::err_seh___except_filter))
1003      return ExprError();
1004    break;
1005  case Builtin::BI__GetExceptionInfo:
1006    if (checkArgCount(*this, TheCall, 1))
1007      return ExprError();
1008
1009    if (CheckCXXThrowOperand(
1010            TheCall->getLocStart(),
1011            Context.getExceptionObjectType(FDecl->getParamDecl(0)->getType()),
1012            TheCall))
1013      return ExprError();
1014
1015    TheCall->setType(Context.VoidPtrTy);
1016    break;
1017  // OpenCL v2.0, s6.13.16 - Pipe functions
1018  case Builtin::BIread_pipe:
1019  case Builtin::BIwrite_pipe:
1020    // Since those two functions are declared with var args, we need a semantic
1021    // check for the argument.
1022    if (SemaBuiltinRWPipe(*this, TheCall))
1023      return ExprError();
1024    break;
1025  case Builtin::BIreserve_read_pipe:
1026  case Builtin::BIreserve_write_pipe:
1027  case Builtin::BIwork_group_reserve_read_pipe:
1028  case Builtin::BIwork_group_reserve_write_pipe:
1029  case Builtin::BIsub_group_reserve_read_pipe:
1030  case Builtin::BIsub_group_reserve_write_pipe:
1031    if (SemaBuiltinReserveRWPipe(*this, TheCall))
1032      return ExprError();
1033    // Since return type of reserve_read/write_pipe built-in function is
1034    // reserve_id_t, which is not defined in the builtin def file , we used int
1035    // as return type and need to override the return type of these functions.
1036    TheCall->setType(Context.OCLReserveIDTy);
1037    break;
1038  case Builtin::BIcommit_read_pipe:
1039  case Builtin::BIcommit_write_pipe:
1040  case Builtin::BIwork_group_commit_read_pipe:
1041  case Builtin::BIwork_group_commit_write_pipe:
1042  case Builtin::BIsub_group_commit_read_pipe:
1043  case Builtin::BIsub_group_commit_write_pipe:
1044    if (SemaBuiltinCommitRWPipe(*this, TheCall))
1045      return ExprError();
1046    break;
1047  case Builtin::BIget_pipe_num_packets:
1048  case Builtin::BIget_pipe_max_packets:
1049    if (SemaBuiltinPipePackets(*this, TheCall))
1050      return ExprError();
1051    break;
1052  case Builtin::BIto_global:
1053  case Builtin::BIto_local:
1054  case Builtin::BIto_private:
1055    if (SemaOpenCLBuiltinToAddr(*this, BuiltinID, TheCall))
1056      return ExprError();
1057    break;
1058  // OpenCL v2.0, s6.13.17 - Enqueue kernel functions.
1059  case Builtin::BIenqueue_kernel:
1060    if (SemaOpenCLBuiltinEnqueueKernel(*this, TheCall))
1061      return ExprError();
1062    break;
1063  case Builtin::BIget_kernel_work_group_size:
1064  case Builtin::BIget_kernel_preferred_work_group_size_multiple:
1065    if (SemaOpenCLBuiltinKernelWorkGroupSize(*this, TheCall))
1066      return ExprError();
1067  }
1068
1069  // Since the target specific builtins for each arch overlap, only check those
1070  // of the arch we are compiling for.
1071  if (Context.BuiltinInfo.isTSBuiltin(BuiltinID)) {
1072    switch (Context.getTargetInfo().getTriple().getArch()) {
1073      case llvm::Triple::arm:
1074      case llvm::Triple::armeb:
1075      case llvm::Triple::thumb:
1076      case llvm::Triple::thumbeb:
1077        if (CheckARMBuiltinFunctionCall(BuiltinID, TheCall))
1078          return ExprError();
1079        break;
1080      case llvm::Triple::aarch64:
1081      case llvm::Triple::aarch64_be:
1082        if (CheckAArch64BuiltinFunctionCall(BuiltinID, TheCall))
1083          return ExprError();
1084        break;
1085      case llvm::Triple::mips:
1086      case llvm::Triple::mipsel:
1087      case llvm::Triple::mips64:
1088      case llvm::Triple::mips64el:
1089        if (CheckMipsBuiltinFunctionCall(BuiltinID, TheCall))
1090          return ExprError();
1091        break;
1092      case llvm::Triple::systemz:
1093        if (CheckSystemZBuiltinFunctionCall(BuiltinID, TheCall))
1094          return ExprError();
1095        break;
1096      case llvm::Triple::x86:
1097      case llvm::Triple::x86_64:
1098        if (CheckX86BuiltinFunctionCall(BuiltinID, TheCall))
1099          return ExprError();
1100        break;
1101      case llvm::Triple::ppc:
1102      case llvm::Triple::ppc64:
1103      case llvm::Triple::ppc64le:
1104        if (CheckPPCBuiltinFunctionCall(BuiltinID, TheCall))
1105          return ExprError();
1106        break;
1107      default:
1108        break;
1109    }
1110  }
1111
1112  return TheCallResult;
1113}
1114
1115// Get the valid immediate range for the specified NEON type code.
1116static unsigned RFT(unsigned t, bool shift = false, bool ForceQuad = false) {
1117  NeonTypeFlags Type(t);
1118  int IsQuad = ForceQuad ? true : Type.isQuad();
1119  switch (Type.getEltType()) {
1120  case NeonTypeFlags::Int8:
1121  case NeonTypeFlags::Poly8:
1122    return shift ? 7 : (8 << IsQuad) - 1;
1123  case NeonTypeFlags::Int16:
1124  case NeonTypeFlags::Poly16:
1125    return shift ? 15 : (4 << IsQuad) - 1;
1126  case NeonTypeFlags::Int32:
1127    return shift ? 31 : (2 << IsQuad) - 1;
1128  case NeonTypeFlags::Int64:
1129  case NeonTypeFlags::Poly64:
1130    return shift ? 63 : (1 << IsQuad) - 1;
1131  case NeonTypeFlags::Poly128:
1132    return shift ? 127 : (1 << IsQuad) - 1;
1133  case NeonTypeFlags::Float16:
1134    assert(!shift && "cannot shift float types!");
1135    return (4 << IsQuad) - 1;
1136  case NeonTypeFlags::Float32:
1137    assert(!shift && "cannot shift float types!");
1138    return (2 << IsQuad) - 1;
1139  case NeonTypeFlags::Float64:
1140    assert(!shift && "cannot shift float types!");
1141    return (1 << IsQuad) - 1;
1142  }
1143  llvm_unreachable("Invalid NeonTypeFlag!");
1144}
1145
1146/// getNeonEltType - Return the QualType corresponding to the elements of
1147/// the vector type specified by the NeonTypeFlags.  This is used to check
1148/// the pointer arguments for Neon load/store intrinsics.
1149static QualType getNeonEltType(NeonTypeFlags Flags, ASTContext &Context,
1150                               bool IsPolyUnsigned, bool IsInt64Long) {
1151  switch (Flags.getEltType()) {
1152  case NeonTypeFlags::Int8:
1153    return Flags.isUnsigned() ? Context.UnsignedCharTy : Context.SignedCharTy;
1154  case NeonTypeFlags::Int16:
1155    return Flags.isUnsigned() ? Context.UnsignedShortTy : Context.ShortTy;
1156  case NeonTypeFlags::Int32:
1157    return Flags.isUnsigned() ? Context.UnsignedIntTy : Context.IntTy;
1158  case NeonTypeFlags::Int64:
1159    if (IsInt64Long)
1160      return Flags.isUnsigned() ? Context.UnsignedLongTy : Context.LongTy;
1161    else
1162      return Flags.isUnsigned() ? Context.UnsignedLongLongTy
1163                                : Context.LongLongTy;
1164  case NeonTypeFlags::Poly8:
1165    return IsPolyUnsigned ? Context.UnsignedCharTy : Context.SignedCharTy;
1166  case NeonTypeFlags::Poly16:
1167    return IsPolyUnsigned ? Context.UnsignedShortTy : Context.ShortTy;
1168  case NeonTypeFlags::Poly64:
1169    if (IsInt64Long)
1170      return Context.UnsignedLongTy;
1171    else
1172      return Context.UnsignedLongLongTy;
1173  case NeonTypeFlags::Poly128:
1174    break;
1175  case NeonTypeFlags::Float16:
1176    return Context.HalfTy;
1177  case NeonTypeFlags::Float32:
1178    return Context.FloatTy;
1179  case NeonTypeFlags::Float64:
1180    return Context.DoubleTy;
1181  }
1182  llvm_unreachable("Invalid NeonTypeFlag!");
1183}
1184
1185bool Sema::CheckNeonBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
1186  llvm::APSInt Result;
1187  uint64_t mask = 0;
1188  unsigned TV = 0;
1189  int PtrArgNum = -1;
1190  bool HasConstPtr = false;
1191  switch (BuiltinID) {
1192#define GET_NEON_OVERLOAD_CHECK
1193#include "clang/Basic/arm_neon.inc"
1194#undef GET_NEON_OVERLOAD_CHECK
1195  }
1196
1197  // For NEON intrinsics which are overloaded on vector element type, validate
1198  // the immediate which specifies which variant to emit.
1199  unsigned ImmArg = TheCall->getNumArgs()-1;
1200  if (mask) {
1201    if (SemaBuiltinConstantArg(TheCall, ImmArg, Result))
1202      return true;
1203
1204    TV = Result.getLimitedValue(64);
1205    if ((TV > 63) || (mask & (1ULL << TV)) == 0)
1206      return Diag(TheCall->getLocStart(), diag::err_invalid_neon_type_code)
1207        << TheCall->getArg(ImmArg)->getSourceRange();
1208  }
1209
1210  if (PtrArgNum >= 0) {
1211    // Check that pointer arguments have the specified type.
1212    Expr *Arg = TheCall->getArg(PtrArgNum);
1213    if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg))
1214      Arg = ICE->getSubExpr();
1215    ExprResult RHS = DefaultFunctionArrayLvalueConversion(Arg);
1216    QualType RHSTy = RHS.get()->getType();
1217
1218    llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch();
1219    bool IsPolyUnsigned = Arch == llvm::Triple::aarch64;
1220    bool IsInt64Long =
1221        Context.getTargetInfo().getInt64Type() == TargetInfo::SignedLong;
1222    QualType EltTy =
1223        getNeonEltType(NeonTypeFlags(TV), Context, IsPolyUnsigned, IsInt64Long);
1224    if (HasConstPtr)
1225      EltTy = EltTy.withConst();
1226    QualType LHSTy = Context.getPointerType(EltTy);
1227    AssignConvertType ConvTy;
1228    ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS);
1229    if (RHS.isInvalid())
1230      return true;
1231    if (DiagnoseAssignmentResult(ConvTy, Arg->getLocStart(), LHSTy, RHSTy,
1232                                 RHS.get(), AA_Assigning))
1233      return true;
1234  }
1235
1236  // For NEON intrinsics which take an immediate value as part of the
1237  // instruction, range check them here.
1238  unsigned i = 0, l = 0, u = 0;
1239  switch (BuiltinID) {
1240  default:
1241    return false;
1242#define GET_NEON_IMMEDIATE_CHECK
1243#include "clang/Basic/arm_neon.inc"
1244#undef GET_NEON_IMMEDIATE_CHECK
1245  }
1246
1247  return SemaBuiltinConstantArgRange(TheCall, i, l, u + l);
1248}
1249
1250bool Sema::CheckARMBuiltinExclusiveCall(unsigned BuiltinID, CallExpr *TheCall,
1251                                        unsigned MaxWidth) {
1252  assert((BuiltinID == ARM::BI__builtin_arm_ldrex ||
1253          BuiltinID == ARM::BI__builtin_arm_ldaex ||
1254          BuiltinID == ARM::BI__builtin_arm_strex ||
1255          BuiltinID == ARM::BI__builtin_arm_stlex ||
1256          BuiltinID == AArch64::BI__builtin_arm_ldrex ||
1257          BuiltinID == AArch64::BI__builtin_arm_ldaex ||
1258          BuiltinID == AArch64::BI__builtin_arm_strex ||
1259          BuiltinID == AArch64::BI__builtin_arm_stlex) &&
1260         "unexpected ARM builtin");
1261  bool IsLdrex = BuiltinID == ARM::BI__builtin_arm_ldrex ||
1262                 BuiltinID == ARM::BI__builtin_arm_ldaex ||
1263                 BuiltinID == AArch64::BI__builtin_arm_ldrex ||
1264                 BuiltinID == AArch64::BI__builtin_arm_ldaex;
1265
1266  DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
1267
1268  // Ensure that we have the proper number of arguments.
1269  if (checkArgCount(*this, TheCall, IsLdrex ? 1 : 2))
1270    return true;
1271
1272  // Inspect the pointer argument of the atomic builtin.  This should always be
1273  // a pointer type, whose element is an integral scalar or pointer type.
1274  // Because it is a pointer type, we don't have to worry about any implicit
1275  // casts here.
1276  Expr *PointerArg = TheCall->getArg(IsLdrex ? 0 : 1);
1277  ExprResult PointerArgRes = DefaultFunctionArrayLvalueConversion(PointerArg);
1278  if (PointerArgRes.isInvalid())
1279    return true;
1280  PointerArg = PointerArgRes.get();
1281
1282  const PointerType *pointerType = PointerArg->getType()->getAs<PointerType>();
1283  if (!pointerType) {
1284    Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer)
1285      << PointerArg->getType() << PointerArg->getSourceRange();
1286    return true;
1287  }
1288
1289  // ldrex takes a "const volatile T*" and strex takes a "volatile T*". Our next
1290  // task is to insert the appropriate casts into the AST. First work out just
1291  // what the appropriate type is.
1292  QualType ValType = pointerType->getPointeeType();
1293  QualType AddrType = ValType.getUnqualifiedType().withVolatile();
1294  if (IsLdrex)
1295    AddrType.addConst();
1296
1297  // Issue a warning if the cast is dodgy.
1298  CastKind CastNeeded = CK_NoOp;
1299  if (!AddrType.isAtLeastAsQualifiedAs(ValType)) {
1300    CastNeeded = CK_BitCast;
1301    Diag(DRE->getLocStart(), diag::ext_typecheck_convert_discards_qualifiers)
1302      << PointerArg->getType()
1303      << Context.getPointerType(AddrType)
1304      << AA_Passing << PointerArg->getSourceRange();
1305  }
1306
1307  // Finally, do the cast and replace the argument with the corrected version.
1308  AddrType = Context.getPointerType(AddrType);
1309  PointerArgRes = ImpCastExprToType(PointerArg, AddrType, CastNeeded);
1310  if (PointerArgRes.isInvalid())
1311    return true;
1312  PointerArg = PointerArgRes.get();
1313
1314  TheCall->setArg(IsLdrex ? 0 : 1, PointerArg);
1315
1316  // In general, we allow ints, floats and pointers to be loaded and stored.
1317  if (!ValType->isIntegerType() && !ValType->isAnyPointerType() &&
1318      !ValType->isBlockPointerType() && !ValType->isFloatingType()) {
1319    Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer_intfltptr)
1320      << PointerArg->getType() << PointerArg->getSourceRange();
1321    return true;
1322  }
1323
1324  // But ARM doesn't have instructions to deal with 128-bit versions.
1325  if (Context.getTypeSize(ValType) > MaxWidth) {
1326    assert(MaxWidth == 64 && "Diagnostic unexpectedly inaccurate");
1327    Diag(DRE->getLocStart(), diag::err_atomic_exclusive_builtin_pointer_size)
1328      << PointerArg->getType() << PointerArg->getSourceRange();
1329    return true;
1330  }
1331
1332  switch (ValType.getObjCLifetime()) {
1333  case Qualifiers::OCL_None:
1334  case Qualifiers::OCL_ExplicitNone:
1335    // okay
1336    break;
1337
1338  case Qualifiers::OCL_Weak:
1339  case Qualifiers::OCL_Strong:
1340  case Qualifiers::OCL_Autoreleasing:
1341    Diag(DRE->getLocStart(), diag::err_arc_atomic_ownership)
1342      << ValType << PointerArg->getSourceRange();
1343    return true;
1344  }
1345
1346  if (IsLdrex) {
1347    TheCall->setType(ValType);
1348    return false;
1349  }
1350
1351  // Initialize the argument to be stored.
1352  ExprResult ValArg = TheCall->getArg(0);
1353  InitializedEntity Entity = InitializedEntity::InitializeParameter(
1354      Context, ValType, /*consume*/ false);
1355  ValArg = PerformCopyInitialization(Entity, SourceLocation(), ValArg);
1356  if (ValArg.isInvalid())
1357    return true;
1358  TheCall->setArg(0, ValArg.get());
1359
1360  // __builtin_arm_strex always returns an int. It's marked as such in the .def,
1361  // but the custom checker bypasses all default analysis.
1362  TheCall->setType(Context.IntTy);
1363  return false;
1364}
1365
1366bool Sema::CheckARMBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
1367  llvm::APSInt Result;
1368
1369  if (BuiltinID == ARM::BI__builtin_arm_ldrex ||
1370      BuiltinID == ARM::BI__builtin_arm_ldaex ||
1371      BuiltinID == ARM::BI__builtin_arm_strex ||
1372      BuiltinID == ARM::BI__builtin_arm_stlex) {
1373    return CheckARMBuiltinExclusiveCall(BuiltinID, TheCall, 64);
1374  }
1375
1376  if (BuiltinID == ARM::BI__builtin_arm_prefetch) {
1377    return SemaBuiltinConstantArgRange(TheCall, 1, 0, 1) ||
1378      SemaBuiltinConstantArgRange(TheCall, 2, 0, 1);
1379  }
1380
1381  if (BuiltinID == ARM::BI__builtin_arm_rsr64 ||
1382      BuiltinID == ARM::BI__builtin_arm_wsr64)
1383    return SemaBuiltinARMSpecialReg(BuiltinID, TheCall, 0, 3, false);
1384
1385  if (BuiltinID == ARM::BI__builtin_arm_rsr ||
1386      BuiltinID == ARM::BI__builtin_arm_rsrp ||
1387      BuiltinID == ARM::BI__builtin_arm_wsr ||
1388      BuiltinID == ARM::BI__builtin_arm_wsrp)
1389    return SemaBuiltinARMSpecialReg(BuiltinID, TheCall, 0, 5, true);
1390
1391  if (CheckNeonBuiltinFunctionCall(BuiltinID, TheCall))
1392    return true;
1393
1394  // For intrinsics which take an immediate value as part of the instruction,
1395  // range check them here.
1396  unsigned i = 0, l = 0, u = 0;
1397  switch (BuiltinID) {
1398  default: return false;
1399  case ARM::BI__builtin_arm_ssat: i = 1; l = 1; u = 31; break;
1400  case ARM::BI__builtin_arm_usat: i = 1; u = 31; break;
1401  case ARM::BI__builtin_arm_vcvtr_f:
1402  case ARM::BI__builtin_arm_vcvtr_d: i = 1; u = 1; break;
1403  case ARM::BI__builtin_arm_dmb:
1404  case ARM::BI__builtin_arm_dsb:
1405  case ARM::BI__builtin_arm_isb:
1406  case ARM::BI__builtin_arm_dbg: l = 0; u = 15; break;
1407  }
1408
1409  // FIXME: VFP Intrinsics should error if VFP not present.
1410  return SemaBuiltinConstantArgRange(TheCall, i, l, u + l);
1411}
1412
1413bool Sema::CheckAArch64BuiltinFunctionCall(unsigned BuiltinID,
1414                                         CallExpr *TheCall) {
1415  llvm::APSInt Result;
1416
1417  if (BuiltinID == AArch64::BI__builtin_arm_ldrex ||
1418      BuiltinID == AArch64::BI__builtin_arm_ldaex ||
1419      BuiltinID == AArch64::BI__builtin_arm_strex ||
1420      BuiltinID == AArch64::BI__builtin_arm_stlex) {
1421    return CheckARMBuiltinExclusiveCall(BuiltinID, TheCall, 128);
1422  }
1423
1424  if (BuiltinID == AArch64::BI__builtin_arm_prefetch) {
1425    return SemaBuiltinConstantArgRange(TheCall, 1, 0, 1) ||
1426      SemaBuiltinConstantArgRange(TheCall, 2, 0, 2) ||
1427      SemaBuiltinConstantArgRange(TheCall, 3, 0, 1) ||
1428      SemaBuiltinConstantArgRange(TheCall, 4, 0, 1);
1429  }
1430
1431  if (BuiltinID == AArch64::BI__builtin_arm_rsr64 ||
1432      BuiltinID == AArch64::BI__builtin_arm_wsr64)
1433    return SemaBuiltinARMSpecialReg(BuiltinID, TheCall, 0, 5, true);
1434
1435  if (BuiltinID == AArch64::BI__builtin_arm_rsr ||
1436      BuiltinID == AArch64::BI__builtin_arm_rsrp ||
1437      BuiltinID == AArch64::BI__builtin_arm_wsr ||
1438      BuiltinID == AArch64::BI__builtin_arm_wsrp)
1439    return SemaBuiltinARMSpecialReg(BuiltinID, TheCall, 0, 5, true);
1440
1441  if (CheckNeonBuiltinFunctionCall(BuiltinID, TheCall))
1442    return true;
1443
1444  // For intrinsics which take an immediate value as part of the instruction,
1445  // range check them here.
1446  unsigned i = 0, l = 0, u = 0;
1447  switch (BuiltinID) {
1448  default: return false;
1449  case AArch64::BI__builtin_arm_dmb:
1450  case AArch64::BI__builtin_arm_dsb:
1451  case AArch64::BI__builtin_arm_isb: l = 0; u = 15; break;
1452  }
1453
1454  return SemaBuiltinConstantArgRange(TheCall, i, l, u + l);
1455}
1456
1457bool Sema::CheckMipsBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
1458  unsigned i = 0, l = 0, u = 0;
1459  switch (BuiltinID) {
1460  default: return false;
1461  case Mips::BI__builtin_mips_wrdsp: i = 1; l = 0; u = 63; break;
1462  case Mips::BI__builtin_mips_rddsp: i = 0; l = 0; u = 63; break;
1463  case Mips::BI__builtin_mips_append: i = 2; l = 0; u = 31; break;
1464  case Mips::BI__builtin_mips_balign: i = 2; l = 0; u = 3; break;
1465  case Mips::BI__builtin_mips_precr_sra_ph_w: i = 2; l = 0; u = 31; break;
1466  case Mips::BI__builtin_mips_precr_sra_r_ph_w: i = 2; l = 0; u = 31; break;
1467  case Mips::BI__builtin_mips_prepend: i = 2; l = 0; u = 31; break;
1468  }
1469
1470  return SemaBuiltinConstantArgRange(TheCall, i, l, u);
1471}
1472
1473bool Sema::CheckPPCBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
1474  unsigned i = 0, l = 0, u = 0;
1475  bool Is64BitBltin = BuiltinID == PPC::BI__builtin_divde ||
1476                      BuiltinID == PPC::BI__builtin_divdeu ||
1477                      BuiltinID == PPC::BI__builtin_bpermd;
1478  bool IsTarget64Bit = Context.getTargetInfo()
1479                              .getTypeWidth(Context
1480                                            .getTargetInfo()
1481                                            .getIntPtrType()) == 64;
1482  bool IsBltinExtDiv = BuiltinID == PPC::BI__builtin_divwe ||
1483                       BuiltinID == PPC::BI__builtin_divweu ||
1484                       BuiltinID == PPC::BI__builtin_divde ||
1485                       BuiltinID == PPC::BI__builtin_divdeu;
1486
1487  if (Is64BitBltin && !IsTarget64Bit)
1488      return Diag(TheCall->getLocStart(), diag::err_64_bit_builtin_32_bit_tgt)
1489             << TheCall->getSourceRange();
1490
1491  if ((IsBltinExtDiv && !Context.getTargetInfo().hasFeature("extdiv")) ||
1492      (BuiltinID == PPC::BI__builtin_bpermd &&
1493       !Context.getTargetInfo().hasFeature("bpermd")))
1494    return Diag(TheCall->getLocStart(), diag::err_ppc_builtin_only_on_pwr7)
1495           << TheCall->getSourceRange();
1496
1497  switch (BuiltinID) {
1498  default: return false;
1499  case PPC::BI__builtin_altivec_crypto_vshasigmaw:
1500  case PPC::BI__builtin_altivec_crypto_vshasigmad:
1501    return SemaBuiltinConstantArgRange(TheCall, 1, 0, 1) ||
1502           SemaBuiltinConstantArgRange(TheCall, 2, 0, 15);
1503  case PPC::BI__builtin_tbegin:
1504  case PPC::BI__builtin_tend: i = 0; l = 0; u = 1; break;
1505  case PPC::BI__builtin_tsr: i = 0; l = 0; u = 7; break;
1506  case PPC::BI__builtin_tabortwc:
1507  case PPC::BI__builtin_tabortdc: i = 0; l = 0; u = 31; break;
1508  case PPC::BI__builtin_tabortwci:
1509  case PPC::BI__builtin_tabortdci:
1510    return SemaBuiltinConstantArgRange(TheCall, 0, 0, 31) ||
1511           SemaBuiltinConstantArgRange(TheCall, 2, 0, 31);
1512  }
1513  return SemaBuiltinConstantArgRange(TheCall, i, l, u);
1514}
1515
1516bool Sema::CheckSystemZBuiltinFunctionCall(unsigned BuiltinID,
1517                                           CallExpr *TheCall) {
1518  if (BuiltinID == SystemZ::BI__builtin_tabort) {
1519    Expr *Arg = TheCall->getArg(0);
1520    llvm::APSInt AbortCode(32);
1521    if (Arg->isIntegerConstantExpr(AbortCode, Context) &&
1522        AbortCode.getSExtValue() >= 0 && AbortCode.getSExtValue() < 256)
1523      return Diag(Arg->getLocStart(), diag::err_systemz_invalid_tabort_code)
1524             << Arg->getSourceRange();
1525  }
1526
1527  // For intrinsics which take an immediate value as part of the instruction,
1528  // range check them here.
1529  unsigned i = 0, l = 0, u = 0;
1530  switch (BuiltinID) {
1531  default: return false;
1532  case SystemZ::BI__builtin_s390_lcbb: i = 1; l = 0; u = 15; break;
1533  case SystemZ::BI__builtin_s390_verimb:
1534  case SystemZ::BI__builtin_s390_verimh:
1535  case SystemZ::BI__builtin_s390_verimf:
1536  case SystemZ::BI__builtin_s390_verimg: i = 3; l = 0; u = 255; break;
1537  case SystemZ::BI__builtin_s390_vfaeb:
1538  case SystemZ::BI__builtin_s390_vfaeh:
1539  case SystemZ::BI__builtin_s390_vfaef:
1540  case SystemZ::BI__builtin_s390_vfaebs:
1541  case SystemZ::BI__builtin_s390_vfaehs:
1542  case SystemZ::BI__builtin_s390_vfaefs:
1543  case SystemZ::BI__builtin_s390_vfaezb:
1544  case SystemZ::BI__builtin_s390_vfaezh:
1545  case SystemZ::BI__builtin_s390_vfaezf:
1546  case SystemZ::BI__builtin_s390_vfaezbs:
1547  case SystemZ::BI__builtin_s390_vfaezhs:
1548  case SystemZ::BI__builtin_s390_vfaezfs: i = 2; l = 0; u = 15; break;
1549  case SystemZ::BI__builtin_s390_vfidb:
1550    return SemaBuiltinConstantArgRange(TheCall, 1, 0, 15) ||
1551           SemaBuiltinConstantArgRange(TheCall, 2, 0, 15);
1552  case SystemZ::BI__builtin_s390_vftcidb: i = 1; l = 0; u = 4095; break;
1553  case SystemZ::BI__builtin_s390_vlbb: i = 1; l = 0; u = 15; break;
1554  case SystemZ::BI__builtin_s390_vpdi: i = 2; l = 0; u = 15; break;
1555  case SystemZ::BI__builtin_s390_vsldb: i = 2; l = 0; u = 15; break;
1556  case SystemZ::BI__builtin_s390_vstrcb:
1557  case SystemZ::BI__builtin_s390_vstrch:
1558  case SystemZ::BI__builtin_s390_vstrcf:
1559  case SystemZ::BI__builtin_s390_vstrczb:
1560  case SystemZ::BI__builtin_s390_vstrczh:
1561  case SystemZ::BI__builtin_s390_vstrczf:
1562  case SystemZ::BI__builtin_s390_vstrcbs:
1563  case SystemZ::BI__builtin_s390_vstrchs:
1564  case SystemZ::BI__builtin_s390_vstrcfs:
1565  case SystemZ::BI__builtin_s390_vstrczbs:
1566  case SystemZ::BI__builtin_s390_vstrczhs:
1567  case SystemZ::BI__builtin_s390_vstrczfs: i = 3; l = 0; u = 15; break;
1568  }
1569  return SemaBuiltinConstantArgRange(TheCall, i, l, u);
1570}
1571
1572/// SemaBuiltinCpuSupports - Handle __builtin_cpu_supports(char *).
1573/// This checks that the target supports __builtin_cpu_supports and
1574/// that the string argument is constant and valid.
1575static bool SemaBuiltinCpuSupports(Sema &S, CallExpr *TheCall) {
1576  Expr *Arg = TheCall->getArg(0);
1577
1578  // Check if the argument is a string literal.
1579  if (!isa<StringLiteral>(Arg->IgnoreParenImpCasts()))
1580    return S.Diag(TheCall->getLocStart(), diag::err_expr_not_string_literal)
1581           << Arg->getSourceRange();
1582
1583  // Check the contents of the string.
1584  StringRef Feature =
1585      cast<StringLiteral>(Arg->IgnoreParenImpCasts())->getString();
1586  if (!S.Context.getTargetInfo().validateCpuSupports(Feature))
1587    return S.Diag(TheCall->getLocStart(), diag::err_invalid_cpu_supports)
1588           << Arg->getSourceRange();
1589  return false;
1590}
1591
1592bool Sema::CheckX86BuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
1593  int i = 0, l = 0, u = 0;
1594  switch (BuiltinID) {
1595  default:
1596    return false;
1597  case X86::BI__builtin_cpu_supports:
1598    return SemaBuiltinCpuSupports(*this, TheCall);
1599  case X86::BI__builtin_ms_va_start:
1600    return SemaBuiltinMSVAStart(TheCall);
1601  case X86::BI__builtin_ia32_extractf64x4_mask:
1602  case X86::BI__builtin_ia32_extracti64x4_mask:
1603  case X86::BI__builtin_ia32_extractf32x8_mask:
1604  case X86::BI__builtin_ia32_extracti32x8_mask:
1605  case X86::BI__builtin_ia32_extractf64x2_256_mask:
1606  case X86::BI__builtin_ia32_extracti64x2_256_mask:
1607  case X86::BI__builtin_ia32_extractf32x4_256_mask:
1608  case X86::BI__builtin_ia32_extracti32x4_256_mask:
1609    i = 1; l = 0; u = 1;
1610    break;
1611  case X86::BI_mm_prefetch:
1612  case X86::BI__builtin_ia32_extractf32x4_mask:
1613  case X86::BI__builtin_ia32_extracti32x4_mask:
1614  case X86::BI__builtin_ia32_extractf64x2_512_mask:
1615  case X86::BI__builtin_ia32_extracti64x2_512_mask:
1616    i = 1; l = 0; u = 3;
1617    break;
1618  case X86::BI__builtin_ia32_insertf32x8_mask:
1619  case X86::BI__builtin_ia32_inserti32x8_mask:
1620  case X86::BI__builtin_ia32_insertf64x4_mask:
1621  case X86::BI__builtin_ia32_inserti64x4_mask:
1622  case X86::BI__builtin_ia32_insertf64x2_256_mask:
1623  case X86::BI__builtin_ia32_inserti64x2_256_mask:
1624  case X86::BI__builtin_ia32_insertf32x4_256_mask:
1625  case X86::BI__builtin_ia32_inserti32x4_256_mask:
1626    i = 2; l = 0; u = 1;
1627    break;
1628  case X86::BI__builtin_ia32_sha1rnds4:
1629  case X86::BI__builtin_ia32_shuf_f32x4_256_mask:
1630  case X86::BI__builtin_ia32_shuf_f64x2_256_mask:
1631  case X86::BI__builtin_ia32_shuf_i32x4_256_mask:
1632  case X86::BI__builtin_ia32_shuf_i64x2_256_mask:
1633  case X86::BI__builtin_ia32_insertf64x2_512_mask:
1634  case X86::BI__builtin_ia32_inserti64x2_512_mask:
1635  case X86::BI__builtin_ia32_insertf32x4_mask:
1636  case X86::BI__builtin_ia32_inserti32x4_mask:
1637    i = 2; l = 0; u = 3;
1638    break;
1639  case X86::BI__builtin_ia32_vpermil2pd:
1640  case X86::BI__builtin_ia32_vpermil2pd256:
1641  case X86::BI__builtin_ia32_vpermil2ps:
1642  case X86::BI__builtin_ia32_vpermil2ps256:
1643    i = 3; l = 0; u = 3;
1644    break;
1645  case X86::BI__builtin_ia32_cmpb128_mask:
1646  case X86::BI__builtin_ia32_cmpw128_mask:
1647  case X86::BI__builtin_ia32_cmpd128_mask:
1648  case X86::BI__builtin_ia32_cmpq128_mask:
1649  case X86::BI__builtin_ia32_cmpb256_mask:
1650  case X86::BI__builtin_ia32_cmpw256_mask:
1651  case X86::BI__builtin_ia32_cmpd256_mask:
1652  case X86::BI__builtin_ia32_cmpq256_mask:
1653  case X86::BI__builtin_ia32_cmpb512_mask:
1654  case X86::BI__builtin_ia32_cmpw512_mask:
1655  case X86::BI__builtin_ia32_cmpd512_mask:
1656  case X86::BI__builtin_ia32_cmpq512_mask:
1657  case X86::BI__builtin_ia32_ucmpb128_mask:
1658  case X86::BI__builtin_ia32_ucmpw128_mask:
1659  case X86::BI__builtin_ia32_ucmpd128_mask:
1660  case X86::BI__builtin_ia32_ucmpq128_mask:
1661  case X86::BI__builtin_ia32_ucmpb256_mask:
1662  case X86::BI__builtin_ia32_ucmpw256_mask:
1663  case X86::BI__builtin_ia32_ucmpd256_mask:
1664  case X86::BI__builtin_ia32_ucmpq256_mask:
1665  case X86::BI__builtin_ia32_ucmpb512_mask:
1666  case X86::BI__builtin_ia32_ucmpw512_mask:
1667  case X86::BI__builtin_ia32_ucmpd512_mask:
1668  case X86::BI__builtin_ia32_ucmpq512_mask:
1669  case X86::BI__builtin_ia32_vpcomub:
1670  case X86::BI__builtin_ia32_vpcomuw:
1671  case X86::BI__builtin_ia32_vpcomud:
1672  case X86::BI__builtin_ia32_vpcomuq:
1673  case X86::BI__builtin_ia32_vpcomb:
1674  case X86::BI__builtin_ia32_vpcomw:
1675  case X86::BI__builtin_ia32_vpcomd:
1676  case X86::BI__builtin_ia32_vpcomq:
1677    i = 2; l = 0; u = 7;
1678    break;
1679  case X86::BI__builtin_ia32_roundps:
1680  case X86::BI__builtin_ia32_roundpd:
1681  case X86::BI__builtin_ia32_roundps256:
1682  case X86::BI__builtin_ia32_roundpd256:
1683    i = 1; l = 0; u = 15;
1684    break;
1685  case X86::BI__builtin_ia32_roundss:
1686  case X86::BI__builtin_ia32_roundsd:
1687  case X86::BI__builtin_ia32_rangepd128_mask:
1688  case X86::BI__builtin_ia32_rangepd256_mask:
1689  case X86::BI__builtin_ia32_rangepd512_mask:
1690  case X86::BI__builtin_ia32_rangeps128_mask:
1691  case X86::BI__builtin_ia32_rangeps256_mask:
1692  case X86::BI__builtin_ia32_rangeps512_mask:
1693  case X86::BI__builtin_ia32_getmantsd_round_mask:
1694  case X86::BI__builtin_ia32_getmantss_round_mask:
1695    i = 2; l = 0; u = 15;
1696    break;
1697  case X86::BI__builtin_ia32_cmpps:
1698  case X86::BI__builtin_ia32_cmpss:
1699  case X86::BI__builtin_ia32_cmppd:
1700  case X86::BI__builtin_ia32_cmpsd:
1701  case X86::BI__builtin_ia32_cmpps256:
1702  case X86::BI__builtin_ia32_cmppd256:
1703  case X86::BI__builtin_ia32_cmpps128_mask:
1704  case X86::BI__builtin_ia32_cmppd128_mask:
1705  case X86::BI__builtin_ia32_cmpps256_mask:
1706  case X86::BI__builtin_ia32_cmppd256_mask:
1707  case X86::BI__builtin_ia32_cmpps512_mask:
1708  case X86::BI__builtin_ia32_cmppd512_mask:
1709  case X86::BI__builtin_ia32_cmpsd_mask:
1710  case X86::BI__builtin_ia32_cmpss_mask:
1711    i = 2; l = 0; u = 31;
1712    break;
1713  case X86::BI__builtin_ia32_xabort:
1714    i = 0; l = -128; u = 255;
1715    break;
1716  case X86::BI__builtin_ia32_pshufw:
1717  case X86::BI__builtin_ia32_aeskeygenassist128:
1718    i = 1; l = -128; u = 255;
1719    break;
1720  case X86::BI__builtin_ia32_vcvtps2ph:
1721  case X86::BI__builtin_ia32_vcvtps2ph256:
1722  case X86::BI__builtin_ia32_rndscaleps_128_mask:
1723  case X86::BI__builtin_ia32_rndscalepd_128_mask:
1724  case X86::BI__builtin_ia32_rndscaleps_256_mask:
1725  case X86::BI__builtin_ia32_rndscalepd_256_mask:
1726  case X86::BI__builtin_ia32_rndscaleps_mask:
1727  case X86::BI__builtin_ia32_rndscalepd_mask:
1728  case X86::BI__builtin_ia32_reducepd128_mask:
1729  case X86::BI__builtin_ia32_reducepd256_mask:
1730  case X86::BI__builtin_ia32_reducepd512_mask:
1731  case X86::BI__builtin_ia32_reduceps128_mask:
1732  case X86::BI__builtin_ia32_reduceps256_mask:
1733  case X86::BI__builtin_ia32_reduceps512_mask:
1734  case X86::BI__builtin_ia32_prold512_mask:
1735  case X86::BI__builtin_ia32_prolq512_mask:
1736  case X86::BI__builtin_ia32_prold128_mask:
1737  case X86::BI__builtin_ia32_prold256_mask:
1738  case X86::BI__builtin_ia32_prolq128_mask:
1739  case X86::BI__builtin_ia32_prolq256_mask:
1740  case X86::BI__builtin_ia32_prord128_mask:
1741  case X86::BI__builtin_ia32_prord256_mask:
1742  case X86::BI__builtin_ia32_prorq128_mask:
1743  case X86::BI__builtin_ia32_prorq256_mask:
1744  case X86::BI__builtin_ia32_psllwi512_mask:
1745  case X86::BI__builtin_ia32_psllwi128_mask:
1746  case X86::BI__builtin_ia32_psllwi256_mask:
1747  case X86::BI__builtin_ia32_psrldi128_mask:
1748  case X86::BI__builtin_ia32_psrldi256_mask:
1749  case X86::BI__builtin_ia32_psrldi512_mask:
1750  case X86::BI__builtin_ia32_psrlqi128_mask:
1751  case X86::BI__builtin_ia32_psrlqi256_mask:
1752  case X86::BI__builtin_ia32_psrlqi512_mask:
1753  case X86::BI__builtin_ia32_psrawi512_mask:
1754  case X86::BI__builtin_ia32_psrawi128_mask:
1755  case X86::BI__builtin_ia32_psrawi256_mask:
1756  case X86::BI__builtin_ia32_psrlwi512_mask:
1757  case X86::BI__builtin_ia32_psrlwi128_mask:
1758  case X86::BI__builtin_ia32_psrlwi256_mask:
1759  case X86::BI__builtin_ia32_psradi128_mask:
1760  case X86::BI__builtin_ia32_psradi256_mask:
1761  case X86::BI__builtin_ia32_psradi512_mask:
1762  case X86::BI__builtin_ia32_psraqi128_mask:
1763  case X86::BI__builtin_ia32_psraqi256_mask:
1764  case X86::BI__builtin_ia32_psraqi512_mask:
1765  case X86::BI__builtin_ia32_pslldi128_mask:
1766  case X86::BI__builtin_ia32_pslldi256_mask:
1767  case X86::BI__builtin_ia32_pslldi512_mask:
1768  case X86::BI__builtin_ia32_psllqi128_mask:
1769  case X86::BI__builtin_ia32_psllqi256_mask:
1770  case X86::BI__builtin_ia32_psllqi512_mask:
1771  case X86::BI__builtin_ia32_fpclasspd128_mask:
1772  case X86::BI__builtin_ia32_fpclasspd256_mask:
1773  case X86::BI__builtin_ia32_fpclassps128_mask:
1774  case X86::BI__builtin_ia32_fpclassps256_mask:
1775  case X86::BI__builtin_ia32_fpclassps512_mask:
1776  case X86::BI__builtin_ia32_fpclasspd512_mask:
1777  case X86::BI__builtin_ia32_fpclasssd_mask:
1778  case X86::BI__builtin_ia32_fpclassss_mask:
1779    i = 1; l = 0; u = 255;
1780    break;
1781  case X86::BI__builtin_ia32_palignr:
1782  case X86::BI__builtin_ia32_insertps128:
1783  case X86::BI__builtin_ia32_dpps:
1784  case X86::BI__builtin_ia32_dppd:
1785  case X86::BI__builtin_ia32_dpps256:
1786  case X86::BI__builtin_ia32_mpsadbw128:
1787  case X86::BI__builtin_ia32_mpsadbw256:
1788  case X86::BI__builtin_ia32_pcmpistrm128:
1789  case X86::BI__builtin_ia32_pcmpistri128:
1790  case X86::BI__builtin_ia32_pcmpistria128:
1791  case X86::BI__builtin_ia32_pcmpistric128:
1792  case X86::BI__builtin_ia32_pcmpistrio128:
1793  case X86::BI__builtin_ia32_pcmpistris128:
1794  case X86::BI__builtin_ia32_pcmpistriz128:
1795  case X86::BI__builtin_ia32_pclmulqdq128:
1796  case X86::BI__builtin_ia32_vperm2f128_pd256:
1797  case X86::BI__builtin_ia32_vperm2f128_ps256:
1798  case X86::BI__builtin_ia32_vperm2f128_si256:
1799  case X86::BI__builtin_ia32_permti256:
1800    i = 2; l = -128; u = 255;
1801    break;
1802  case X86::BI__builtin_ia32_palignr128:
1803  case X86::BI__builtin_ia32_palignr256:
1804  case X86::BI__builtin_ia32_palignr128_mask:
1805  case X86::BI__builtin_ia32_palignr256_mask:
1806  case X86::BI__builtin_ia32_palignr512_mask:
1807  case X86::BI__builtin_ia32_alignq512_mask:
1808  case X86::BI__builtin_ia32_alignd512_mask:
1809  case X86::BI__builtin_ia32_alignd128_mask:
1810  case X86::BI__builtin_ia32_alignd256_mask:
1811  case X86::BI__builtin_ia32_alignq128_mask:
1812  case X86::BI__builtin_ia32_alignq256_mask:
1813  case X86::BI__builtin_ia32_vcomisd:
1814  case X86::BI__builtin_ia32_vcomiss:
1815  case X86::BI__builtin_ia32_shuf_f32x4_mask:
1816  case X86::BI__builtin_ia32_shuf_f64x2_mask:
1817  case X86::BI__builtin_ia32_shuf_i32x4_mask:
1818  case X86::BI__builtin_ia32_shuf_i64x2_mask:
1819  case X86::BI__builtin_ia32_dbpsadbw128_mask:
1820  case X86::BI__builtin_ia32_dbpsadbw256_mask:
1821  case X86::BI__builtin_ia32_dbpsadbw512_mask:
1822    i = 2; l = 0; u = 255;
1823    break;
1824  case X86::BI__builtin_ia32_fixupimmpd512_mask:
1825  case X86::BI__builtin_ia32_fixupimmpd512_maskz:
1826  case X86::BI__builtin_ia32_fixupimmps512_mask:
1827  case X86::BI__builtin_ia32_fixupimmps512_maskz:
1828  case X86::BI__builtin_ia32_fixupimmsd_mask:
1829  case X86::BI__builtin_ia32_fixupimmsd_maskz:
1830  case X86::BI__builtin_ia32_fixupimmss_mask:
1831  case X86::BI__builtin_ia32_fixupimmss_maskz:
1832  case X86::BI__builtin_ia32_fixupimmpd128_mask:
1833  case X86::BI__builtin_ia32_fixupimmpd128_maskz:
1834  case X86::BI__builtin_ia32_fixupimmpd256_mask:
1835  case X86::BI__builtin_ia32_fixupimmpd256_maskz:
1836  case X86::BI__builtin_ia32_fixupimmps128_mask:
1837  case X86::BI__builtin_ia32_fixupimmps128_maskz:
1838  case X86::BI__builtin_ia32_fixupimmps256_mask:
1839  case X86::BI__builtin_ia32_fixupimmps256_maskz:
1840  case X86::BI__builtin_ia32_pternlogd512_mask:
1841  case X86::BI__builtin_ia32_pternlogd512_maskz:
1842  case X86::BI__builtin_ia32_pternlogq512_mask:
1843  case X86::BI__builtin_ia32_pternlogq512_maskz:
1844  case X86::BI__builtin_ia32_pternlogd128_mask:
1845  case X86::BI__builtin_ia32_pternlogd128_maskz:
1846  case X86::BI__builtin_ia32_pternlogd256_mask:
1847  case X86::BI__builtin_ia32_pternlogd256_maskz:
1848  case X86::BI__builtin_ia32_pternlogq128_mask:
1849  case X86::BI__builtin_ia32_pternlogq128_maskz:
1850  case X86::BI__builtin_ia32_pternlogq256_mask:
1851  case X86::BI__builtin_ia32_pternlogq256_maskz:
1852    i = 3; l = 0; u = 255;
1853    break;
1854  case X86::BI__builtin_ia32_pcmpestrm128:
1855  case X86::BI__builtin_ia32_pcmpestri128:
1856  case X86::BI__builtin_ia32_pcmpestria128:
1857  case X86::BI__builtin_ia32_pcmpestric128:
1858  case X86::BI__builtin_ia32_pcmpestrio128:
1859  case X86::BI__builtin_ia32_pcmpestris128:
1860  case X86::BI__builtin_ia32_pcmpestriz128:
1861    i = 4; l = -128; u = 255;
1862    break;
1863  case X86::BI__builtin_ia32_rndscalesd_round_mask:
1864  case X86::BI__builtin_ia32_rndscaless_round_mask:
1865    i = 4; l = 0; u = 255;
1866    break;
1867  }
1868  return SemaBuiltinConstantArgRange(TheCall, i, l, u);
1869}
1870
1871/// Given a FunctionDecl's FormatAttr, attempts to populate the FomatStringInfo
1872/// parameter with the FormatAttr's correct format_idx and firstDataArg.
1873/// Returns true when the format fits the function and the FormatStringInfo has
1874/// been populated.
1875bool Sema::getFormatStringInfo(const FormatAttr *Format, bool IsCXXMember,
1876                               FormatStringInfo *FSI) {
1877  FSI->HasVAListArg = Format->getFirstArg() == 0;
1878  FSI->FormatIdx = Format->getFormatIdx() - 1;
1879  FSI->FirstDataArg = FSI->HasVAListArg ? 0 : Format->getFirstArg() - 1;
1880
1881  // The way the format attribute works in GCC, the implicit this argument
1882  // of member functions is counted. However, it doesn't appear in our own
1883  // lists, so decrement format_idx in that case.
1884  if (IsCXXMember) {
1885    if(FSI->FormatIdx == 0)
1886      return false;
1887    --FSI->FormatIdx;
1888    if (FSI->FirstDataArg != 0)
1889      --FSI->FirstDataArg;
1890  }
1891  return true;
1892}
1893
1894/// Checks if a the given expression evaluates to null.
1895///
1896/// \brief Returns true if the value evaluates to null.
1897static bool CheckNonNullExpr(Sema &S, const Expr *Expr) {
1898  // If the expression has non-null type, it doesn't evaluate to null.
1899  if (auto nullability
1900        = Expr->IgnoreImplicit()->getType()->getNullability(S.Context)) {
1901    if (*nullability == NullabilityKind::NonNull)
1902      return false;
1903  }
1904
1905  // As a special case, transparent unions initialized with zero are
1906  // considered null for the purposes of the nonnull attribute.
1907  if (const RecordType *UT = Expr->getType()->getAsUnionType()) {
1908    if (UT->getDecl()->hasAttr<TransparentUnionAttr>())
1909      if (const CompoundLiteralExpr *CLE =
1910          dyn_cast<CompoundLiteralExpr>(Expr))
1911        if (const InitListExpr *ILE =
1912            dyn_cast<InitListExpr>(CLE->getInitializer()))
1913          Expr = ILE->getInit(0);
1914  }
1915
1916  bool Result;
1917  return (!Expr->isValueDependent() &&
1918          Expr->EvaluateAsBooleanCondition(Result, S.Context) &&
1919          !Result);
1920}
1921
1922static void CheckNonNullArgument(Sema &S,
1923                                 const Expr *ArgExpr,
1924                                 SourceLocation CallSiteLoc) {
1925  if (CheckNonNullExpr(S, ArgExpr))
1926    S.DiagRuntimeBehavior(CallSiteLoc, ArgExpr,
1927           S.PDiag(diag::warn_null_arg) << ArgExpr->getSourceRange());
1928}
1929
1930bool Sema::GetFormatNSStringIdx(const FormatAttr *Format, unsigned &Idx) {
1931  FormatStringInfo FSI;
1932  if ((GetFormatStringType(Format) == FST_NSString) &&
1933      getFormatStringInfo(Format, false, &FSI)) {
1934    Idx = FSI.FormatIdx;
1935    return true;
1936  }
1937  return false;
1938}
1939/// \brief Diagnose use of %s directive in an NSString which is being passed
1940/// as formatting string to formatting method.
1941static void
1942DiagnoseCStringFormatDirectiveInCFAPI(Sema &S,
1943                                        const NamedDecl *FDecl,
1944                                        Expr **Args,
1945                                        unsigned NumArgs) {
1946  unsigned Idx = 0;
1947  bool Format = false;
1948  ObjCStringFormatFamily SFFamily = FDecl->getObjCFStringFormattingFamily();
1949  if (SFFamily == ObjCStringFormatFamily::SFF_CFString) {
1950    Idx = 2;
1951    Format = true;
1952  }
1953  else
1954    for (const auto *I : FDecl->specific_attrs<FormatAttr>()) {
1955      if (S.GetFormatNSStringIdx(I, Idx)) {
1956        Format = true;
1957        break;
1958      }
1959    }
1960  if (!Format || NumArgs <= Idx)
1961    return;
1962  const Expr *FormatExpr = Args[Idx];
1963  if (const CStyleCastExpr *CSCE = dyn_cast<CStyleCastExpr>(FormatExpr))
1964    FormatExpr = CSCE->getSubExpr();
1965  const StringLiteral *FormatString;
1966  if (const ObjCStringLiteral *OSL =
1967      dyn_cast<ObjCStringLiteral>(FormatExpr->IgnoreParenImpCasts()))
1968    FormatString = OSL->getString();
1969  else
1970    FormatString = dyn_cast<StringLiteral>(FormatExpr->IgnoreParenImpCasts());
1971  if (!FormatString)
1972    return;
1973  if (S.FormatStringHasSArg(FormatString)) {
1974    S.Diag(FormatExpr->getExprLoc(), diag::warn_objc_cdirective_format_string)
1975      << "%s" << 1 << 1;
1976    S.Diag(FDecl->getLocation(), diag::note_entity_declared_at)
1977      << FDecl->getDeclName();
1978  }
1979}
1980
1981/// Determine whether the given type has a non-null nullability annotation.
1982static bool isNonNullType(ASTContext &ctx, QualType type) {
1983  if (auto nullability = type->getNullability(ctx))
1984    return *nullability == NullabilityKind::NonNull;
1985
1986  return false;
1987}
1988
1989static void CheckNonNullArguments(Sema &S,
1990                                  const NamedDecl *FDecl,
1991                                  const FunctionProtoType *Proto,
1992                                  ArrayRef<const Expr *> Args,
1993                                  SourceLocation CallSiteLoc) {
1994  assert((FDecl || Proto) && "Need a function declaration or prototype");
1995
1996  // Check the attributes attached to the method/function itself.
1997  llvm::SmallBitVector NonNullArgs;
1998  if (FDecl) {
1999    // Handle the nonnull attribute on the function/method declaration itself.
2000    for (const auto *NonNull : FDecl->specific_attrs<NonNullAttr>()) {
2001      if (!NonNull->args_size()) {
2002        // Easy case: all pointer arguments are nonnull.
2003        for (const auto *Arg : Args)
2004          if (S.isValidPointerAttrType(Arg->getType()))
2005            CheckNonNullArgument(S, Arg, CallSiteLoc);
2006        return;
2007      }
2008
2009      for (unsigned Val : NonNull->args()) {
2010        if (Val >= Args.size())
2011          continue;
2012        if (NonNullArgs.empty())
2013          NonNullArgs.resize(Args.size());
2014        NonNullArgs.set(Val);
2015      }
2016    }
2017  }
2018
2019  if (FDecl && (isa<FunctionDecl>(FDecl) || isa<ObjCMethodDecl>(FDecl))) {
2020    // Handle the nonnull attribute on the parameters of the
2021    // function/method.
2022    ArrayRef<ParmVarDecl*> parms;
2023    if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(FDecl))
2024      parms = FD->parameters();
2025    else
2026      parms = cast<ObjCMethodDecl>(FDecl)->parameters();
2027
2028    unsigned ParamIndex = 0;
2029    for (ArrayRef<ParmVarDecl*>::iterator I = parms.begin(), E = parms.end();
2030         I != E; ++I, ++ParamIndex) {
2031      const ParmVarDecl *PVD = *I;
2032      if (PVD->hasAttr<NonNullAttr>() ||
2033          isNonNullType(S.Context, PVD->getType())) {
2034        if (NonNullArgs.empty())
2035          NonNullArgs.resize(Args.size());
2036
2037        NonNullArgs.set(ParamIndex);
2038      }
2039    }
2040  } else {
2041    // If we have a non-function, non-method declaration but no
2042    // function prototype, try to dig out the function prototype.
2043    if (!Proto) {
2044      if (const ValueDecl *VD = dyn_cast<ValueDecl>(FDecl)) {
2045        QualType type = VD->getType().getNonReferenceType();
2046        if (auto pointerType = type->getAs<PointerType>())
2047          type = pointerType->getPointeeType();
2048        else if (auto blockType = type->getAs<BlockPointerType>())
2049          type = blockType->getPointeeType();
2050        // FIXME: data member pointers?
2051
2052        // Dig out the function prototype, if there is one.
2053        Proto = type->getAs<FunctionProtoType>();
2054      }
2055    }
2056
2057    // Fill in non-null argument information from the nullability
2058    // information on the parameter types (if we have them).
2059    if (Proto) {
2060      unsigned Index = 0;
2061      for (auto paramType : Proto->getParamTypes()) {
2062        if (isNonNullType(S.Context, paramType)) {
2063          if (NonNullArgs.empty())
2064            NonNullArgs.resize(Args.size());
2065
2066          NonNullArgs.set(Index);
2067        }
2068
2069        ++Index;
2070      }
2071    }
2072  }
2073
2074  // Check for non-null arguments.
2075  for (unsigned ArgIndex = 0, ArgIndexEnd = NonNullArgs.size();
2076       ArgIndex != ArgIndexEnd; ++ArgIndex) {
2077    if (NonNullArgs[ArgIndex])
2078      CheckNonNullArgument(S, Args[ArgIndex], CallSiteLoc);
2079  }
2080}
2081
2082/// Handles the checks for format strings, non-POD arguments to vararg
2083/// functions, and NULL arguments passed to non-NULL parameters.
2084void Sema::checkCall(NamedDecl *FDecl, const FunctionProtoType *Proto,
2085                     ArrayRef<const Expr *> Args, bool IsMemberFunction,
2086                     SourceLocation Loc, SourceRange Range,
2087                     VariadicCallType CallType) {
2088  // FIXME: We should check as much as we can in the template definition.
2089  if (CurContext->isDependentContext())
2090    return;
2091
2092  // Printf and scanf checking.
2093  llvm::SmallBitVector CheckedVarArgs;
2094  if (FDecl) {
2095    for (const auto *I : FDecl->specific_attrs<FormatAttr>()) {
2096      // Only create vector if there are format attributes.
2097      CheckedVarArgs.resize(Args.size());
2098
2099      CheckFormatArguments(I, Args, IsMemberFunction, CallType, Loc, Range,
2100                           CheckedVarArgs);
2101    }
2102  }
2103
2104  // Refuse POD arguments that weren't caught by the format string
2105  // checks above.
2106  if (CallType != VariadicDoesNotApply) {
2107    unsigned NumParams = Proto ? Proto->getNumParams()
2108                       : FDecl && isa<FunctionDecl>(FDecl)
2109                           ? cast<FunctionDecl>(FDecl)->getNumParams()
2110                       : FDecl && isa<ObjCMethodDecl>(FDecl)
2111                           ? cast<ObjCMethodDecl>(FDecl)->param_size()
2112                       : 0;
2113
2114    for (unsigned ArgIdx = NumParams; ArgIdx < Args.size(); ++ArgIdx) {
2115      // Args[ArgIdx] can be null in malformed code.
2116      if (const Expr *Arg = Args[ArgIdx]) {
2117        if (CheckedVarArgs.empty() || !CheckedVarArgs[ArgIdx])
2118          checkVariadicArgument(Arg, CallType);
2119      }
2120    }
2121  }
2122
2123  if (FDecl || Proto) {
2124    CheckNonNullArguments(*this, FDecl, Proto, Args, Loc);
2125
2126    // Type safety checking.
2127    if (FDecl) {
2128      for (const auto *I : FDecl->specific_attrs<ArgumentWithTypeTagAttr>())
2129        CheckArgumentWithTypeTag(I, Args.data());
2130    }
2131  }
2132}
2133
2134/// CheckConstructorCall - Check a constructor call for correctness and safety
2135/// properties not enforced by the C type system.
2136void Sema::CheckConstructorCall(FunctionDecl *FDecl,
2137                                ArrayRef<const Expr *> Args,
2138                                const FunctionProtoType *Proto,
2139                                SourceLocation Loc) {
2140  VariadicCallType CallType =
2141    Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply;
2142  checkCall(FDecl, Proto, Args, /*IsMemberFunction=*/true, Loc, SourceRange(),
2143            CallType);
2144}
2145
2146/// CheckFunctionCall - Check a direct function call for various correctness
2147/// and safety properties not strictly enforced by the C type system.
2148bool Sema::CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall,
2149                             const FunctionProtoType *Proto) {
2150  bool IsMemberOperatorCall = isa<CXXOperatorCallExpr>(TheCall) &&
2151                              isa<CXXMethodDecl>(FDecl);
2152  bool IsMemberFunction = isa<CXXMemberCallExpr>(TheCall) ||
2153                          IsMemberOperatorCall;
2154  VariadicCallType CallType = getVariadicCallType(FDecl, Proto,
2155                                                  TheCall->getCallee());
2156  Expr** Args = TheCall->getArgs();
2157  unsigned NumArgs = TheCall->getNumArgs();
2158  if (IsMemberOperatorCall) {
2159    // If this is a call to a member operator, hide the first argument
2160    // from checkCall.
2161    // FIXME: Our choice of AST representation here is less than ideal.
2162    ++Args;
2163    --NumArgs;
2164  }
2165  checkCall(FDecl, Proto, llvm::makeArrayRef(Args, NumArgs),
2166            IsMemberFunction, TheCall->getRParenLoc(),
2167            TheCall->getCallee()->getSourceRange(), CallType);
2168
2169  IdentifierInfo *FnInfo = FDecl->getIdentifier();
2170  // None of the checks below are needed for functions that don't have
2171  // simple names (e.g., C++ conversion functions).
2172  if (!FnInfo)
2173    return false;
2174
2175  CheckAbsoluteValueFunction(TheCall, FDecl, FnInfo);
2176  if (getLangOpts().ObjC1)
2177    DiagnoseCStringFormatDirectiveInCFAPI(*this, FDecl, Args, NumArgs);
2178
2179  unsigned CMId = FDecl->getMemoryFunctionKind();
2180  if (CMId == 0)
2181    return false;
2182
2183  // Handle memory setting and copying functions.
2184  if (CMId == Builtin::BIstrlcpy || CMId == Builtin::BIstrlcat)
2185    CheckStrlcpycatArguments(TheCall, FnInfo);
2186  else if (CMId == Builtin::BIstrncat)
2187    CheckStrncatArguments(TheCall, FnInfo);
2188  else
2189    CheckMemaccessArguments(TheCall, CMId, FnInfo);
2190
2191  return false;
2192}
2193
2194bool Sema::CheckObjCMethodCall(ObjCMethodDecl *Method, SourceLocation lbrac,
2195                               ArrayRef<const Expr *> Args) {
2196  VariadicCallType CallType =
2197      Method->isVariadic() ? VariadicMethod : VariadicDoesNotApply;
2198
2199  checkCall(Method, nullptr, Args,
2200            /*IsMemberFunction=*/false, lbrac, Method->getSourceRange(),
2201            CallType);
2202
2203  return false;
2204}
2205
2206bool Sema::CheckPointerCall(NamedDecl *NDecl, CallExpr *TheCall,
2207                            const FunctionProtoType *Proto) {
2208  QualType Ty;
2209  if (const auto *V = dyn_cast<VarDecl>(NDecl))
2210    Ty = V->getType().getNonReferenceType();
2211  else if (const auto *F = dyn_cast<FieldDecl>(NDecl))
2212    Ty = F->getType().getNonReferenceType();
2213  else
2214    return false;
2215
2216  if (!Ty->isBlockPointerType() && !Ty->isFunctionPointerType() &&
2217      !Ty->isFunctionProtoType())
2218    return false;
2219
2220  VariadicCallType CallType;
2221  if (!Proto || !Proto->isVariadic()) {
2222    CallType = VariadicDoesNotApply;
2223  } else if (Ty->isBlockPointerType()) {
2224    CallType = VariadicBlock;
2225  } else { // Ty->isFunctionPointerType()
2226    CallType = VariadicFunction;
2227  }
2228
2229  checkCall(NDecl, Proto,
2230            llvm::makeArrayRef(TheCall->getArgs(), TheCall->getNumArgs()),
2231            /*IsMemberFunction=*/false, TheCall->getRParenLoc(),
2232            TheCall->getCallee()->getSourceRange(), CallType);
2233
2234  return false;
2235}
2236
2237/// Checks function calls when a FunctionDecl or a NamedDecl is not available,
2238/// such as function pointers returned from functions.
2239bool Sema::CheckOtherCall(CallExpr *TheCall, const FunctionProtoType *Proto) {
2240  VariadicCallType CallType = getVariadicCallType(/*FDecl=*/nullptr, Proto,
2241                                                  TheCall->getCallee());
2242  checkCall(/*FDecl=*/nullptr, Proto,
2243            llvm::makeArrayRef(TheCall->getArgs(), TheCall->getNumArgs()),
2244            /*IsMemberFunction=*/false, TheCall->getRParenLoc(),
2245            TheCall->getCallee()->getSourceRange(), CallType);
2246
2247  return false;
2248}
2249
2250static bool isValidOrderingForOp(int64_t Ordering, AtomicExpr::AtomicOp Op) {
2251  if (!llvm::isValidAtomicOrderingCABI(Ordering))
2252    return false;
2253
2254  auto OrderingCABI = (llvm::AtomicOrderingCABI)Ordering;
2255  switch (Op) {
2256  case AtomicExpr::AO__c11_atomic_init:
2257    llvm_unreachable("There is no ordering argument for an init");
2258
2259  case AtomicExpr::AO__c11_atomic_load:
2260  case AtomicExpr::AO__atomic_load_n:
2261  case AtomicExpr::AO__atomic_load:
2262    return OrderingCABI != llvm::AtomicOrderingCABI::release &&
2263           OrderingCABI != llvm::AtomicOrderingCABI::acq_rel;
2264
2265  case AtomicExpr::AO__c11_atomic_store:
2266  case AtomicExpr::AO__atomic_store:
2267  case AtomicExpr::AO__atomic_store_n:
2268    return OrderingCABI != llvm::AtomicOrderingCABI::consume &&
2269           OrderingCABI != llvm::AtomicOrderingCABI::acquire &&
2270           OrderingCABI != llvm::AtomicOrderingCABI::acq_rel;
2271
2272  default:
2273    return true;
2274  }
2275}
2276
2277ExprResult Sema::SemaAtomicOpsOverloaded(ExprResult TheCallResult,
2278                                         AtomicExpr::AtomicOp Op) {
2279  CallExpr *TheCall = cast<CallExpr>(TheCallResult.get());
2280  DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
2281
2282  // All these operations take one of the following forms:
2283  enum {
2284    // C    __c11_atomic_init(A *, C)
2285    Init,
2286    // C    __c11_atomic_load(A *, int)
2287    Load,
2288    // void __atomic_load(A *, CP, int)
2289    LoadCopy,
2290    // void __atomic_store(A *, CP, int)
2291    Copy,
2292    // C    __c11_atomic_add(A *, M, int)
2293    Arithmetic,
2294    // C    __atomic_exchange_n(A *, CP, int)
2295    Xchg,
2296    // void __atomic_exchange(A *, C *, CP, int)
2297    GNUXchg,
2298    // bool __c11_atomic_compare_exchange_strong(A *, C *, CP, int, int)
2299    C11CmpXchg,
2300    // bool __atomic_compare_exchange(A *, C *, CP, bool, int, int)
2301    GNUCmpXchg
2302  } Form = Init;
2303  const unsigned NumArgs[] = { 2, 2, 3, 3, 3, 3, 4, 5, 6 };
2304  const unsigned NumVals[] = { 1, 0, 1, 1, 1, 1, 2, 2, 3 };
2305  // where:
2306  //   C is an appropriate type,
2307  //   A is volatile _Atomic(C) for __c11 builtins and is C for GNU builtins,
2308  //   CP is C for __c11 builtins and GNU _n builtins and is C * otherwise,
2309  //   M is C if C is an integer, and ptrdiff_t if C is a pointer, and
2310  //   the int parameters are for orderings.
2311
2312  static_assert(AtomicExpr::AO__c11_atomic_init == 0 &&
2313                    AtomicExpr::AO__c11_atomic_fetch_xor + 1 ==
2314                        AtomicExpr::AO__atomic_load,
2315                "need to update code for modified C11 atomics");
2316  bool IsC11 = Op >= AtomicExpr::AO__c11_atomic_init &&
2317               Op <= AtomicExpr::AO__c11_atomic_fetch_xor;
2318  bool IsN = Op == AtomicExpr::AO__atomic_load_n ||
2319             Op == AtomicExpr::AO__atomic_store_n ||
2320             Op == AtomicExpr::AO__atomic_exchange_n ||
2321             Op == AtomicExpr::AO__atomic_compare_exchange_n;
2322  bool IsAddSub = false;
2323
2324  switch (Op) {
2325  case AtomicExpr::AO__c11_atomic_init:
2326    Form = Init;
2327    break;
2328
2329  case AtomicExpr::AO__c11_atomic_load:
2330  case AtomicExpr::AO__atomic_load_n:
2331    Form = Load;
2332    break;
2333
2334  case AtomicExpr::AO__atomic_load:
2335    Form = LoadCopy;
2336    break;
2337
2338  case AtomicExpr::AO__c11_atomic_store:
2339  case AtomicExpr::AO__atomic_store:
2340  case AtomicExpr::AO__atomic_store_n:
2341    Form = Copy;
2342    break;
2343
2344  case AtomicExpr::AO__c11_atomic_fetch_add:
2345  case AtomicExpr::AO__c11_atomic_fetch_sub:
2346  case AtomicExpr::AO__atomic_fetch_add:
2347  case AtomicExpr::AO__atomic_fetch_sub:
2348  case AtomicExpr::AO__atomic_add_fetch:
2349  case AtomicExpr::AO__atomic_sub_fetch:
2350    IsAddSub = true;
2351    // Fall through.
2352  case AtomicExpr::AO__c11_atomic_fetch_and:
2353  case AtomicExpr::AO__c11_atomic_fetch_or:
2354  case AtomicExpr::AO__c11_atomic_fetch_xor:
2355  case AtomicExpr::AO__atomic_fetch_and:
2356  case AtomicExpr::AO__atomic_fetch_or:
2357  case AtomicExpr::AO__atomic_fetch_xor:
2358  case AtomicExpr::AO__atomic_fetch_nand:
2359  case AtomicExpr::AO__atomic_and_fetch:
2360  case AtomicExpr::AO__atomic_or_fetch:
2361  case AtomicExpr::AO__atomic_xor_fetch:
2362  case AtomicExpr::AO__atomic_nand_fetch:
2363    Form = Arithmetic;
2364    break;
2365
2366  case AtomicExpr::AO__c11_atomic_exchange:
2367  case AtomicExpr::AO__atomic_exchange_n:
2368    Form = Xchg;
2369    break;
2370
2371  case AtomicExpr::AO__atomic_exchange:
2372    Form = GNUXchg;
2373    break;
2374
2375  case AtomicExpr::AO__c11_atomic_compare_exchange_strong:
2376  case AtomicExpr::AO__c11_atomic_compare_exchange_weak:
2377    Form = C11CmpXchg;
2378    break;
2379
2380  case AtomicExpr::AO__atomic_compare_exchange:
2381  case AtomicExpr::AO__atomic_compare_exchange_n:
2382    Form = GNUCmpXchg;
2383    break;
2384  }
2385
2386  // Check we have the right number of arguments.
2387  if (TheCall->getNumArgs() < NumArgs[Form]) {
2388    Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
2389      << 0 << NumArgs[Form] << TheCall->getNumArgs()
2390      << TheCall->getCallee()->getSourceRange();
2391    return ExprError();
2392  } else if (TheCall->getNumArgs() > NumArgs[Form]) {
2393    Diag(TheCall->getArg(NumArgs[Form])->getLocStart(),
2394         diag::err_typecheck_call_too_many_args)
2395      << 0 << NumArgs[Form] << TheCall->getNumArgs()
2396      << TheCall->getCallee()->getSourceRange();
2397    return ExprError();
2398  }
2399
2400  // Inspect the first argument of the atomic operation.
2401  Expr *Ptr = TheCall->getArg(0);
2402  Ptr = DefaultFunctionArrayLvalueConversion(Ptr).get();
2403  const PointerType *pointerType = Ptr->getType()->getAs<PointerType>();
2404  if (!pointerType) {
2405    Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer)
2406      << Ptr->getType() << Ptr->getSourceRange();
2407    return ExprError();
2408  }
2409
2410  // For a __c11 builtin, this should be a pointer to an _Atomic type.
2411  QualType AtomTy = pointerType->getPointeeType(); // 'A'
2412  QualType ValType = AtomTy; // 'C'
2413  if (IsC11) {
2414    if (!AtomTy->isAtomicType()) {
2415      Diag(DRE->getLocStart(), diag::err_atomic_op_needs_atomic)
2416        << Ptr->getType() << Ptr->getSourceRange();
2417      return ExprError();
2418    }
2419    if (AtomTy.isConstQualified()) {
2420      Diag(DRE->getLocStart(), diag::err_atomic_op_needs_non_const_atomic)
2421        << Ptr->getType() << Ptr->getSourceRange();
2422      return ExprError();
2423    }
2424    ValType = AtomTy->getAs<AtomicType>()->getValueType();
2425  } else if (Form != Load && Form != LoadCopy) {
2426    if (ValType.isConstQualified()) {
2427      Diag(DRE->getLocStart(), diag::err_atomic_op_needs_non_const_pointer)
2428        << Ptr->getType() << Ptr->getSourceRange();
2429      return ExprError();
2430    }
2431  }
2432
2433  // For an arithmetic operation, the implied arithmetic must be well-formed.
2434  if (Form == Arithmetic) {
2435    // gcc does not enforce these rules for GNU atomics, but we do so for sanity.
2436    if (IsAddSub && !ValType->isIntegerType() && !ValType->isPointerType()) {
2437      Diag(DRE->getLocStart(), diag::err_atomic_op_needs_atomic_int_or_ptr)
2438        << IsC11 << Ptr->getType() << Ptr->getSourceRange();
2439      return ExprError();
2440    }
2441    if (!IsAddSub && !ValType->isIntegerType()) {
2442      Diag(DRE->getLocStart(), diag::err_atomic_op_bitwise_needs_atomic_int)
2443        << IsC11 << Ptr->getType() << Ptr->getSourceRange();
2444      return ExprError();
2445    }
2446    if (IsC11 && ValType->isPointerType() &&
2447        RequireCompleteType(Ptr->getLocStart(), ValType->getPointeeType(),
2448                            diag::err_incomplete_type)) {
2449      return ExprError();
2450    }
2451  } else if (IsN && !ValType->isIntegerType() && !ValType->isPointerType()) {
2452    // For __atomic_*_n operations, the value type must be a scalar integral or
2453    // pointer type which is 1, 2, 4, 8 or 16 bytes in length.
2454    Diag(DRE->getLocStart(), diag::err_atomic_op_needs_atomic_int_or_ptr)
2455      << IsC11 << Ptr->getType() << Ptr->getSourceRange();
2456    return ExprError();
2457  }
2458
2459  if (!IsC11 && !AtomTy.isTriviallyCopyableType(Context) &&
2460      !AtomTy->isScalarType()) {
2461    // For GNU atomics, require a trivially-copyable type. This is not part of
2462    // the GNU atomics specification, but we enforce it for sanity.
2463    Diag(DRE->getLocStart(), diag::err_atomic_op_needs_trivial_copy)
2464      << Ptr->getType() << Ptr->getSourceRange();
2465    return ExprError();
2466  }
2467
2468  switch (ValType.getObjCLifetime()) {
2469  case Qualifiers::OCL_None:
2470  case Qualifiers::OCL_ExplicitNone:
2471    // okay
2472    break;
2473
2474  case Qualifiers::OCL_Weak:
2475  case Qualifiers::OCL_Strong:
2476  case Qualifiers::OCL_Autoreleasing:
2477    // FIXME: Can this happen? By this point, ValType should be known
2478    // to be trivially copyable.
2479    Diag(DRE->getLocStart(), diag::err_arc_atomic_ownership)
2480      << ValType << Ptr->getSourceRange();
2481    return ExprError();
2482  }
2483
2484  // atomic_fetch_or takes a pointer to a volatile 'A'.  We shouldn't let the
2485  // volatile-ness of the pointee-type inject itself into the result or the
2486  // other operands. Similarly atomic_load can take a pointer to a const 'A'.
2487  ValType.removeLocalVolatile();
2488  ValType.removeLocalConst();
2489  QualType ResultType = ValType;
2490  if (Form == Copy || Form == LoadCopy || Form == GNUXchg || Form == Init)
2491    ResultType = Context.VoidTy;
2492  else if (Form == C11CmpXchg || Form == GNUCmpXchg)
2493    ResultType = Context.BoolTy;
2494
2495  // The type of a parameter passed 'by value'. In the GNU atomics, such
2496  // arguments are actually passed as pointers.
2497  QualType ByValType = ValType; // 'CP'
2498  if (!IsC11 && !IsN)
2499    ByValType = Ptr->getType();
2500
2501  // The first argument --- the pointer --- has a fixed type; we
2502  // deduce the types of the rest of the arguments accordingly.  Walk
2503  // the remaining arguments, converting them to the deduced value type.
2504  for (unsigned i = 1; i != NumArgs[Form]; ++i) {
2505    QualType Ty;
2506    if (i < NumVals[Form] + 1) {
2507      switch (i) {
2508      case 1:
2509        // The second argument is the non-atomic operand. For arithmetic, this
2510        // is always passed by value, and for a compare_exchange it is always
2511        // passed by address. For the rest, GNU uses by-address and C11 uses
2512        // by-value.
2513        assert(Form != Load);
2514        if (Form == Init || (Form == Arithmetic && ValType->isIntegerType()))
2515          Ty = ValType;
2516        else if (Form == Copy || Form == Xchg)
2517          Ty = ByValType;
2518        else if (Form == Arithmetic)
2519          Ty = Context.getPointerDiffType();
2520        else {
2521          Expr *ValArg = TheCall->getArg(i);
2522          unsigned AS = 0;
2523          // Keep address space of non-atomic pointer type.
2524          if (const PointerType *PtrTy =
2525                  ValArg->getType()->getAs<PointerType>()) {
2526            AS = PtrTy->getPointeeType().getAddressSpace();
2527          }
2528          Ty = Context.getPointerType(
2529              Context.getAddrSpaceQualType(ValType.getUnqualifiedType(), AS));
2530        }
2531        break;
2532      case 2:
2533        // The third argument to compare_exchange / GNU exchange is a
2534        // (pointer to a) desired value.
2535        Ty = ByValType;
2536        break;
2537      case 3:
2538        // The fourth argument to GNU compare_exchange is a 'weak' flag.
2539        Ty = Context.BoolTy;
2540        break;
2541      }
2542    } else {
2543      // The order(s) are always converted to int.
2544      Ty = Context.IntTy;
2545    }
2546
2547    InitializedEntity Entity =
2548        InitializedEntity::InitializeParameter(Context, Ty, false);
2549    ExprResult Arg = TheCall->getArg(i);
2550    Arg = PerformCopyInitialization(Entity, SourceLocation(), Arg);
2551    if (Arg.isInvalid())
2552      return true;
2553    TheCall->setArg(i, Arg.get());
2554  }
2555
2556  // Permute the arguments into a 'consistent' order.
2557  SmallVector<Expr*, 5> SubExprs;
2558  SubExprs.push_back(Ptr);
2559  switch (Form) {
2560  case Init:
2561    // Note, AtomicExpr::getVal1() has a special case for this atomic.
2562    SubExprs.push_back(TheCall->getArg(1)); // Val1
2563    break;
2564  case Load:
2565    SubExprs.push_back(TheCall->getArg(1)); // Order
2566    break;
2567  case LoadCopy:
2568  case Copy:
2569  case Arithmetic:
2570  case Xchg:
2571    SubExprs.push_back(TheCall->getArg(2)); // Order
2572    SubExprs.push_back(TheCall->getArg(1)); // Val1
2573    break;
2574  case GNUXchg:
2575    // Note, AtomicExpr::getVal2() has a special case for this atomic.
2576    SubExprs.push_back(TheCall->getArg(3)); // Order
2577    SubExprs.push_back(TheCall->getArg(1)); // Val1
2578    SubExprs.push_back(TheCall->getArg(2)); // Val2
2579    break;
2580  case C11CmpXchg:
2581    SubExprs.push_back(TheCall->getArg(3)); // Order
2582    SubExprs.push_back(TheCall->getArg(1)); // Val1
2583    SubExprs.push_back(TheCall->getArg(4)); // OrderFail
2584    SubExprs.push_back(TheCall->getArg(2)); // Val2
2585    break;
2586  case GNUCmpXchg:
2587    SubExprs.push_back(TheCall->getArg(4)); // Order
2588    SubExprs.push_back(TheCall->getArg(1)); // Val1
2589    SubExprs.push_back(TheCall->getArg(5)); // OrderFail
2590    SubExprs.push_back(TheCall->getArg(2)); // Val2
2591    SubExprs.push_back(TheCall->getArg(3)); // Weak
2592    break;
2593  }
2594
2595  if (SubExprs.size() >= 2 && Form != Init) {
2596    llvm::APSInt Result(32);
2597    if (SubExprs[1]->isIntegerConstantExpr(Result, Context) &&
2598        !isValidOrderingForOp(Result.getSExtValue(), Op))
2599      Diag(SubExprs[1]->getLocStart(),
2600           diag::warn_atomic_op_has_invalid_memory_order)
2601          << SubExprs[1]->getSourceRange();
2602  }
2603
2604  AtomicExpr *AE = new (Context) AtomicExpr(TheCall->getCallee()->getLocStart(),
2605                                            SubExprs, ResultType, Op,
2606                                            TheCall->getRParenLoc());
2607
2608  if ((Op == AtomicExpr::AO__c11_atomic_load ||
2609       (Op == AtomicExpr::AO__c11_atomic_store)) &&
2610      Context.AtomicUsesUnsupportedLibcall(AE))
2611    Diag(AE->getLocStart(), diag::err_atomic_load_store_uses_lib) <<
2612    ((Op == AtomicExpr::AO__c11_atomic_load) ? 0 : 1);
2613
2614  return AE;
2615}
2616
2617/// checkBuiltinArgument - Given a call to a builtin function, perform
2618/// normal type-checking on the given argument, updating the call in
2619/// place.  This is useful when a builtin function requires custom
2620/// type-checking for some of its arguments but not necessarily all of
2621/// them.
2622///
2623/// Returns true on error.
2624static bool checkBuiltinArgument(Sema &S, CallExpr *E, unsigned ArgIndex) {
2625  FunctionDecl *Fn = E->getDirectCallee();
2626  assert(Fn && "builtin call without direct callee!");
2627
2628  ParmVarDecl *Param = Fn->getParamDecl(ArgIndex);
2629  InitializedEntity Entity =
2630    InitializedEntity::InitializeParameter(S.Context, Param);
2631
2632  ExprResult Arg = E->getArg(0);
2633  Arg = S.PerformCopyInitialization(Entity, SourceLocation(), Arg);
2634  if (Arg.isInvalid())
2635    return true;
2636
2637  E->setArg(ArgIndex, Arg.get());
2638  return false;
2639}
2640
2641/// SemaBuiltinAtomicOverloaded - We have a call to a function like
2642/// __sync_fetch_and_add, which is an overloaded function based on the pointer
2643/// type of its first argument.  The main ActOnCallExpr routines have already
2644/// promoted the types of arguments because all of these calls are prototyped as
2645/// void(...).
2646///
2647/// This function goes through and does final semantic checking for these
2648/// builtins,
2649ExprResult
2650Sema::SemaBuiltinAtomicOverloaded(ExprResult TheCallResult) {
2651  CallExpr *TheCall = (CallExpr *)TheCallResult.get();
2652  DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
2653  FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
2654
2655  // Ensure that we have at least one argument to do type inference from.
2656  if (TheCall->getNumArgs() < 1) {
2657    Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least)
2658      << 0 << 1 << TheCall->getNumArgs()
2659      << TheCall->getCallee()->getSourceRange();
2660    return ExprError();
2661  }
2662
2663  // Inspect the first argument of the atomic builtin.  This should always be
2664  // a pointer type, whose element is an integral scalar or pointer type.
2665  // Because it is a pointer type, we don't have to worry about any implicit
2666  // casts here.
2667  // FIXME: We don't allow floating point scalars as input.
2668  Expr *FirstArg = TheCall->getArg(0);
2669  ExprResult FirstArgResult = DefaultFunctionArrayLvalueConversion(FirstArg);
2670  if (FirstArgResult.isInvalid())
2671    return ExprError();
2672  FirstArg = FirstArgResult.get();
2673  TheCall->setArg(0, FirstArg);
2674
2675  const PointerType *pointerType = FirstArg->getType()->getAs<PointerType>();
2676  if (!pointerType) {
2677    Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer)
2678      << FirstArg->getType() << FirstArg->getSourceRange();
2679    return ExprError();
2680  }
2681
2682  QualType ValType = pointerType->getPointeeType();
2683  if (!ValType->isIntegerType() && !ValType->isAnyPointerType() &&
2684      !ValType->isBlockPointerType()) {
2685    Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer_intptr)
2686      << FirstArg->getType() << FirstArg->getSourceRange();
2687    return ExprError();
2688  }
2689
2690  switch (ValType.getObjCLifetime()) {
2691  case Qualifiers::OCL_None:
2692  case Qualifiers::OCL_ExplicitNone:
2693    // okay
2694    break;
2695
2696  case Qualifiers::OCL_Weak:
2697  case Qualifiers::OCL_Strong:
2698  case Qualifiers::OCL_Autoreleasing:
2699    Diag(DRE->getLocStart(), diag::err_arc_atomic_ownership)
2700      << ValType << FirstArg->getSourceRange();
2701    return ExprError();
2702  }
2703
2704  // Strip any qualifiers off ValType.
2705  ValType = ValType.getUnqualifiedType();
2706
2707  // The majority of builtins return a value, but a few have special return
2708  // types, so allow them to override appropriately below.
2709  QualType ResultType = ValType;
2710
2711  // We need to figure out which concrete builtin this maps onto.  For example,
2712  // __sync_fetch_and_add with a 2 byte object turns into
2713  // __sync_fetch_and_add_2.
2714#define BUILTIN_ROW(x) \
2715  { Builtin::BI##x##_1, Builtin::BI##x##_2, Builtin::BI##x##_4, \
2716    Builtin::BI##x##_8, Builtin::BI##x##_16 }
2717
2718  static const unsigned BuiltinIndices[][5] = {
2719    BUILTIN_ROW(__sync_fetch_and_add),
2720    BUILTIN_ROW(__sync_fetch_and_sub),
2721    BUILTIN_ROW(__sync_fetch_and_or),
2722    BUILTIN_ROW(__sync_fetch_and_and),
2723    BUILTIN_ROW(__sync_fetch_and_xor),
2724    BUILTIN_ROW(__sync_fetch_and_nand),
2725
2726    BUILTIN_ROW(__sync_add_and_fetch),
2727    BUILTIN_ROW(__sync_sub_and_fetch),
2728    BUILTIN_ROW(__sync_and_and_fetch),
2729    BUILTIN_ROW(__sync_or_and_fetch),
2730    BUILTIN_ROW(__sync_xor_and_fetch),
2731    BUILTIN_ROW(__sync_nand_and_fetch),
2732
2733    BUILTIN_ROW(__sync_val_compare_and_swap),
2734    BUILTIN_ROW(__sync_bool_compare_and_swap),
2735    BUILTIN_ROW(__sync_lock_test_and_set),
2736    BUILTIN_ROW(__sync_lock_release),
2737    BUILTIN_ROW(__sync_swap)
2738  };
2739#undef BUILTIN_ROW
2740
2741  // Determine the index of the size.
2742  unsigned SizeIndex;
2743  switch (Context.getTypeSizeInChars(ValType).getQuantity()) {
2744  case 1: SizeIndex = 0; break;
2745  case 2: SizeIndex = 1; break;
2746  case 4: SizeIndex = 2; break;
2747  case 8: SizeIndex = 3; break;
2748  case 16: SizeIndex = 4; break;
2749  default:
2750    Diag(DRE->getLocStart(), diag::err_atomic_builtin_pointer_size)
2751      << FirstArg->getType() << FirstArg->getSourceRange();
2752    return ExprError();
2753  }
2754
2755  // Each of these builtins has one pointer argument, followed by some number of
2756  // values (0, 1 or 2) followed by a potentially empty varags list of stuff
2757  // that we ignore.  Find out which row of BuiltinIndices to read from as well
2758  // as the number of fixed args.
2759  unsigned BuiltinID = FDecl->getBuiltinID();
2760  unsigned BuiltinIndex, NumFixed = 1;
2761  bool WarnAboutSemanticsChange = false;
2762  switch (BuiltinID) {
2763  default: llvm_unreachable("Unknown overloaded atomic builtin!");
2764  case Builtin::BI__sync_fetch_and_add:
2765  case Builtin::BI__sync_fetch_and_add_1:
2766  case Builtin::BI__sync_fetch_and_add_2:
2767  case Builtin::BI__sync_fetch_and_add_4:
2768  case Builtin::BI__sync_fetch_and_add_8:
2769  case Builtin::BI__sync_fetch_and_add_16:
2770    BuiltinIndex = 0;
2771    break;
2772
2773  case Builtin::BI__sync_fetch_and_sub:
2774  case Builtin::BI__sync_fetch_and_sub_1:
2775  case Builtin::BI__sync_fetch_and_sub_2:
2776  case Builtin::BI__sync_fetch_and_sub_4:
2777  case Builtin::BI__sync_fetch_and_sub_8:
2778  case Builtin::BI__sync_fetch_and_sub_16:
2779    BuiltinIndex = 1;
2780    break;
2781
2782  case Builtin::BI__sync_fetch_and_or:
2783  case Builtin::BI__sync_fetch_and_or_1:
2784  case Builtin::BI__sync_fetch_and_or_2:
2785  case Builtin::BI__sync_fetch_and_or_4:
2786  case Builtin::BI__sync_fetch_and_or_8:
2787  case Builtin::BI__sync_fetch_and_or_16:
2788    BuiltinIndex = 2;
2789    break;
2790
2791  case Builtin::BI__sync_fetch_and_and:
2792  case Builtin::BI__sync_fetch_and_and_1:
2793  case Builtin::BI__sync_fetch_and_and_2:
2794  case Builtin::BI__sync_fetch_and_and_4:
2795  case Builtin::BI__sync_fetch_and_and_8:
2796  case Builtin::BI__sync_fetch_and_and_16:
2797    BuiltinIndex = 3;
2798    break;
2799
2800  case Builtin::BI__sync_fetch_and_xor:
2801  case Builtin::BI__sync_fetch_and_xor_1:
2802  case Builtin::BI__sync_fetch_and_xor_2:
2803  case Builtin::BI__sync_fetch_and_xor_4:
2804  case Builtin::BI__sync_fetch_and_xor_8:
2805  case Builtin::BI__sync_fetch_and_xor_16:
2806    BuiltinIndex = 4;
2807    break;
2808
2809  case Builtin::BI__sync_fetch_and_nand:
2810  case Builtin::BI__sync_fetch_and_nand_1:
2811  case Builtin::BI__sync_fetch_and_nand_2:
2812  case Builtin::BI__sync_fetch_and_nand_4:
2813  case Builtin::BI__sync_fetch_and_nand_8:
2814  case Builtin::BI__sync_fetch_and_nand_16:
2815    BuiltinIndex = 5;
2816    WarnAboutSemanticsChange = true;
2817    break;
2818
2819  case Builtin::BI__sync_add_and_fetch:
2820  case Builtin::BI__sync_add_and_fetch_1:
2821  case Builtin::BI__sync_add_and_fetch_2:
2822  case Builtin::BI__sync_add_and_fetch_4:
2823  case Builtin::BI__sync_add_and_fetch_8:
2824  case Builtin::BI__sync_add_and_fetch_16:
2825    BuiltinIndex = 6;
2826    break;
2827
2828  case Builtin::BI__sync_sub_and_fetch:
2829  case Builtin::BI__sync_sub_and_fetch_1:
2830  case Builtin::BI__sync_sub_and_fetch_2:
2831  case Builtin::BI__sync_sub_and_fetch_4:
2832  case Builtin::BI__sync_sub_and_fetch_8:
2833  case Builtin::BI__sync_sub_and_fetch_16:
2834    BuiltinIndex = 7;
2835    break;
2836
2837  case Builtin::BI__sync_and_and_fetch:
2838  case Builtin::BI__sync_and_and_fetch_1:
2839  case Builtin::BI__sync_and_and_fetch_2:
2840  case Builtin::BI__sync_and_and_fetch_4:
2841  case Builtin::BI__sync_and_and_fetch_8:
2842  case Builtin::BI__sync_and_and_fetch_16:
2843    BuiltinIndex = 8;
2844    break;
2845
2846  case Builtin::BI__sync_or_and_fetch:
2847  case Builtin::BI__sync_or_and_fetch_1:
2848  case Builtin::BI__sync_or_and_fetch_2:
2849  case Builtin::BI__sync_or_and_fetch_4:
2850  case Builtin::BI__sync_or_and_fetch_8:
2851  case Builtin::BI__sync_or_and_fetch_16:
2852    BuiltinIndex = 9;
2853    break;
2854
2855  case Builtin::BI__sync_xor_and_fetch:
2856  case Builtin::BI__sync_xor_and_fetch_1:
2857  case Builtin::BI__sync_xor_and_fetch_2:
2858  case Builtin::BI__sync_xor_and_fetch_4:
2859  case Builtin::BI__sync_xor_and_fetch_8:
2860  case Builtin::BI__sync_xor_and_fetch_16:
2861    BuiltinIndex = 10;
2862    break;
2863
2864  case Builtin::BI__sync_nand_and_fetch:
2865  case Builtin::BI__sync_nand_and_fetch_1:
2866  case Builtin::BI__sync_nand_and_fetch_2:
2867  case Builtin::BI__sync_nand_and_fetch_4:
2868  case Builtin::BI__sync_nand_and_fetch_8:
2869  case Builtin::BI__sync_nand_and_fetch_16:
2870    BuiltinIndex = 11;
2871    WarnAboutSemanticsChange = true;
2872    break;
2873
2874  case Builtin::BI__sync_val_compare_and_swap:
2875  case Builtin::BI__sync_val_compare_and_swap_1:
2876  case Builtin::BI__sync_val_compare_and_swap_2:
2877  case Builtin::BI__sync_val_compare_and_swap_4:
2878  case Builtin::BI__sync_val_compare_and_swap_8:
2879  case Builtin::BI__sync_val_compare_and_swap_16:
2880    BuiltinIndex = 12;
2881    NumFixed = 2;
2882    break;
2883
2884  case Builtin::BI__sync_bool_compare_and_swap:
2885  case Builtin::BI__sync_bool_compare_and_swap_1:
2886  case Builtin::BI__sync_bool_compare_and_swap_2:
2887  case Builtin::BI__sync_bool_compare_and_swap_4:
2888  case Builtin::BI__sync_bool_compare_and_swap_8:
2889  case Builtin::BI__sync_bool_compare_and_swap_16:
2890    BuiltinIndex = 13;
2891    NumFixed = 2;
2892    ResultType = Context.BoolTy;
2893    break;
2894
2895  case Builtin::BI__sync_lock_test_and_set:
2896  case Builtin::BI__sync_lock_test_and_set_1:
2897  case Builtin::BI__sync_lock_test_and_set_2:
2898  case Builtin::BI__sync_lock_test_and_set_4:
2899  case Builtin::BI__sync_lock_test_and_set_8:
2900  case Builtin::BI__sync_lock_test_and_set_16:
2901    BuiltinIndex = 14;
2902    break;
2903
2904  case Builtin::BI__sync_lock_release:
2905  case Builtin::BI__sync_lock_release_1:
2906  case Builtin::BI__sync_lock_release_2:
2907  case Builtin::BI__sync_lock_release_4:
2908  case Builtin::BI__sync_lock_release_8:
2909  case Builtin::BI__sync_lock_release_16:
2910    BuiltinIndex = 15;
2911    NumFixed = 0;
2912    ResultType = Context.VoidTy;
2913    break;
2914
2915  case Builtin::BI__sync_swap:
2916  case Builtin::BI__sync_swap_1:
2917  case Builtin::BI__sync_swap_2:
2918  case Builtin::BI__sync_swap_4:
2919  case Builtin::BI__sync_swap_8:
2920  case Builtin::BI__sync_swap_16:
2921    BuiltinIndex = 16;
2922    break;
2923  }
2924
2925  // Now that we know how many fixed arguments we expect, first check that we
2926  // have at least that many.
2927  if (TheCall->getNumArgs() < 1+NumFixed) {
2928    Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least)
2929      << 0 << 1+NumFixed << TheCall->getNumArgs()
2930      << TheCall->getCallee()->getSourceRange();
2931    return ExprError();
2932  }
2933
2934  if (WarnAboutSemanticsChange) {
2935    Diag(TheCall->getLocEnd(), diag::warn_sync_fetch_and_nand_semantics_change)
2936      << TheCall->getCallee()->getSourceRange();
2937  }
2938
2939  // Get the decl for the concrete builtin from this, we can tell what the
2940  // concrete integer type we should convert to is.
2941  unsigned NewBuiltinID = BuiltinIndices[BuiltinIndex][SizeIndex];
2942  const char *NewBuiltinName = Context.BuiltinInfo.getName(NewBuiltinID);
2943  FunctionDecl *NewBuiltinDecl;
2944  if (NewBuiltinID == BuiltinID)
2945    NewBuiltinDecl = FDecl;
2946  else {
2947    // Perform builtin lookup to avoid redeclaring it.
2948    DeclarationName DN(&Context.Idents.get(NewBuiltinName));
2949    LookupResult Res(*this, DN, DRE->getLocStart(), LookupOrdinaryName);
2950    LookupName(Res, TUScope, /*AllowBuiltinCreation=*/true);
2951    assert(Res.getFoundDecl());
2952    NewBuiltinDecl = dyn_cast<FunctionDecl>(Res.getFoundDecl());
2953    if (!NewBuiltinDecl)
2954      return ExprError();
2955  }
2956
2957  // The first argument --- the pointer --- has a fixed type; we
2958  // deduce the types of the rest of the arguments accordingly.  Walk
2959  // the remaining arguments, converting them to the deduced value type.
2960  for (unsigned i = 0; i != NumFixed; ++i) {
2961    ExprResult Arg = TheCall->getArg(i+1);
2962
2963    // GCC does an implicit conversion to the pointer or integer ValType.  This
2964    // can fail in some cases (1i -> int**), check for this error case now.
2965    // Initialize the argument.
2966    InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
2967                                                   ValType, /*consume*/ false);
2968    Arg = PerformCopyInitialization(Entity, SourceLocation(), Arg);
2969    if (Arg.isInvalid())
2970      return ExprError();
2971
2972    // Okay, we have something that *can* be converted to the right type.  Check
2973    // to see if there is a potentially weird extension going on here.  This can
2974    // happen when you do an atomic operation on something like an char* and
2975    // pass in 42.  The 42 gets converted to char.  This is even more strange
2976    // for things like 45.123 -> char, etc.
2977    // FIXME: Do this check.
2978    TheCall->setArg(i+1, Arg.get());
2979  }
2980
2981  ASTContext& Context = this->getASTContext();
2982
2983  // Create a new DeclRefExpr to refer to the new decl.
2984  DeclRefExpr* NewDRE = DeclRefExpr::Create(
2985      Context,
2986      DRE->getQualifierLoc(),
2987      SourceLocation(),
2988      NewBuiltinDecl,
2989      /*enclosing*/ false,
2990      DRE->getLocation(),
2991      Context.BuiltinFnTy,
2992      DRE->getValueKind());
2993
2994  // Set the callee in the CallExpr.
2995  // FIXME: This loses syntactic information.
2996  QualType CalleePtrTy = Context.getPointerType(NewBuiltinDecl->getType());
2997  ExprResult PromotedCall = ImpCastExprToType(NewDRE, CalleePtrTy,
2998                                              CK_BuiltinFnToFnPtr);
2999  TheCall->setCallee(PromotedCall.get());
3000
3001  // Change the result type of the call to match the original value type. This
3002  // is arbitrary, but the codegen for these builtins ins design to handle it
3003  // gracefully.
3004  TheCall->setType(ResultType);
3005
3006  return TheCallResult;
3007}
3008
3009/// SemaBuiltinNontemporalOverloaded - We have a call to
3010/// __builtin_nontemporal_store or __builtin_nontemporal_load, which is an
3011/// overloaded function based on the pointer type of its last argument.
3012///
3013/// This function goes through and does final semantic checking for these
3014/// builtins.
3015ExprResult Sema::SemaBuiltinNontemporalOverloaded(ExprResult TheCallResult) {
3016  CallExpr *TheCall = (CallExpr *)TheCallResult.get();
3017  DeclRefExpr *DRE =
3018      cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
3019  FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
3020  unsigned BuiltinID = FDecl->getBuiltinID();
3021  assert((BuiltinID == Builtin::BI__builtin_nontemporal_store ||
3022          BuiltinID == Builtin::BI__builtin_nontemporal_load) &&
3023         "Unexpected nontemporal load/store builtin!");
3024  bool isStore = BuiltinID == Builtin::BI__builtin_nontemporal_store;
3025  unsigned numArgs = isStore ? 2 : 1;
3026
3027  // Ensure that we have the proper number of arguments.
3028  if (checkArgCount(*this, TheCall, numArgs))
3029    return ExprError();
3030
3031  // Inspect the last argument of the nontemporal builtin.  This should always
3032  // be a pointer type, from which we imply the type of the memory access.
3033  // Because it is a pointer type, we don't have to worry about any implicit
3034  // casts here.
3035  Expr *PointerArg = TheCall->getArg(numArgs - 1);
3036  ExprResult PointerArgResult =
3037      DefaultFunctionArrayLvalueConversion(PointerArg);
3038
3039  if (PointerArgResult.isInvalid())
3040    return ExprError();
3041  PointerArg = PointerArgResult.get();
3042  TheCall->setArg(numArgs - 1, PointerArg);
3043
3044  const PointerType *pointerType = PointerArg->getType()->getAs<PointerType>();
3045  if (!pointerType) {
3046    Diag(DRE->getLocStart(), diag::err_nontemporal_builtin_must_be_pointer)
3047        << PointerArg->getType() << PointerArg->getSourceRange();
3048    return ExprError();
3049  }
3050
3051  QualType ValType = pointerType->getPointeeType();
3052
3053  // Strip any qualifiers off ValType.
3054  ValType = ValType.getUnqualifiedType();
3055  if (!ValType->isIntegerType() && !ValType->isAnyPointerType() &&
3056      !ValType->isBlockPointerType() && !ValType->isFloatingType() &&
3057      !ValType->isVectorType()) {
3058    Diag(DRE->getLocStart(),
3059         diag::err_nontemporal_builtin_must_be_pointer_intfltptr_or_vector)
3060        << PointerArg->getType() << PointerArg->getSourceRange();
3061    return ExprError();
3062  }
3063
3064  if (!isStore) {
3065    TheCall->setType(ValType);
3066    return TheCallResult;
3067  }
3068
3069  ExprResult ValArg = TheCall->getArg(0);
3070  InitializedEntity Entity = InitializedEntity::InitializeParameter(
3071      Context, ValType, /*consume*/ false);
3072  ValArg = PerformCopyInitialization(Entity, SourceLocation(), ValArg);
3073  if (ValArg.isInvalid())
3074    return ExprError();
3075
3076  TheCall->setArg(0, ValArg.get());
3077  TheCall->setType(Context.VoidTy);
3078  return TheCallResult;
3079}
3080
3081/// CheckObjCString - Checks that the argument to the builtin
3082/// CFString constructor is correct
3083/// Note: It might also make sense to do the UTF-16 conversion here (would
3084/// simplify the backend).
3085bool Sema::CheckObjCString(Expr *Arg) {
3086  Arg = Arg->IgnoreParenCasts();
3087  StringLiteral *Literal = dyn_cast<StringLiteral>(Arg);
3088
3089  if (!Literal || !Literal->isAscii()) {
3090    Diag(Arg->getLocStart(), diag::err_cfstring_literal_not_string_constant)
3091      << Arg->getSourceRange();
3092    return true;
3093  }
3094
3095  if (Literal->containsNonAsciiOrNull()) {
3096    StringRef String = Literal->getString();
3097    unsigned NumBytes = String.size();
3098    SmallVector<UTF16, 128> ToBuf(NumBytes);
3099    const UTF8 *FromPtr = (const UTF8 *)String.data();
3100    UTF16 *ToPtr = &ToBuf[0];
3101
3102    ConversionResult Result = ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes,
3103                                                 &ToPtr, ToPtr + NumBytes,
3104                                                 strictConversion);
3105    // Check for conversion failure.
3106    if (Result != conversionOK)
3107      Diag(Arg->getLocStart(),
3108           diag::warn_cfstring_truncated) << Arg->getSourceRange();
3109  }
3110  return false;
3111}
3112
3113/// Check the arguments to '__builtin_va_start' or '__builtin_ms_va_start'
3114/// for validity.  Emit an error and return true on failure; return false
3115/// on success.
3116bool Sema::SemaBuiltinVAStartImpl(CallExpr *TheCall) {
3117  Expr *Fn = TheCall->getCallee();
3118  if (TheCall->getNumArgs() > 2) {
3119    Diag(TheCall->getArg(2)->getLocStart(),
3120         diag::err_typecheck_call_too_many_args)
3121      << 0 /*function call*/ << 2 << TheCall->getNumArgs()
3122      << Fn->getSourceRange()
3123      << SourceRange(TheCall->getArg(2)->getLocStart(),
3124                     (*(TheCall->arg_end()-1))->getLocEnd());
3125    return true;
3126  }
3127
3128  if (TheCall->getNumArgs() < 2) {
3129    return Diag(TheCall->getLocEnd(),
3130      diag::err_typecheck_call_too_few_args_at_least)
3131      << 0 /*function call*/ << 2 << TheCall->getNumArgs();
3132  }
3133
3134  // Type-check the first argument normally.
3135  if (checkBuiltinArgument(*this, TheCall, 0))
3136    return true;
3137
3138  // Determine whether the current function is variadic or not.
3139  BlockScopeInfo *CurBlock = getCurBlock();
3140  bool isVariadic;
3141  if (CurBlock)
3142    isVariadic = CurBlock->TheDecl->isVariadic();
3143  else if (FunctionDecl *FD = getCurFunctionDecl())
3144    isVariadic = FD->isVariadic();
3145  else
3146    isVariadic = getCurMethodDecl()->isVariadic();
3147
3148  if (!isVariadic) {
3149    Diag(Fn->getLocStart(), diag::err_va_start_used_in_non_variadic_function);
3150    return true;
3151  }
3152
3153  // Verify that the second argument to the builtin is the last argument of the
3154  // current function or method.
3155  bool SecondArgIsLastNamedArgument = false;
3156  const Expr *Arg = TheCall->getArg(1)->IgnoreParenCasts();
3157
3158  // These are valid if SecondArgIsLastNamedArgument is false after the next
3159  // block.
3160  QualType Type;
3161  SourceLocation ParamLoc;
3162  bool IsCRegister = false;
3163
3164  if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Arg)) {
3165    if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(DR->getDecl())) {
3166      // FIXME: This isn't correct for methods (results in bogus warning).
3167      // Get the last formal in the current function.
3168      const ParmVarDecl *LastArg;
3169      if (CurBlock)
3170        LastArg = CurBlock->TheDecl->parameters().back();
3171      else if (FunctionDecl *FD = getCurFunctionDecl())
3172        LastArg = FD->parameters().back();
3173      else
3174        LastArg = getCurMethodDecl()->parameters().back();
3175      SecondArgIsLastNamedArgument = PV == LastArg;
3176
3177      Type = PV->getType();
3178      ParamLoc = PV->getLocation();
3179      IsCRegister =
3180          PV->getStorageClass() == SC_Register && !getLangOpts().CPlusPlus;
3181    }
3182  }
3183
3184  if (!SecondArgIsLastNamedArgument)
3185    Diag(TheCall->getArg(1)->getLocStart(),
3186         diag::warn_second_arg_of_va_start_not_last_named_param);
3187  else if (IsCRegister || Type->isReferenceType() ||
3188           Type->isPromotableIntegerType() ||
3189           Type->isSpecificBuiltinType(BuiltinType::Float)) {
3190    unsigned Reason = 0;
3191    if (Type->isReferenceType())  Reason = 1;
3192    else if (IsCRegister)         Reason = 2;
3193    Diag(Arg->getLocStart(), diag::warn_va_start_type_is_undefined) << Reason;
3194    Diag(ParamLoc, diag::note_parameter_type) << Type;
3195  }
3196
3197  TheCall->setType(Context.VoidTy);
3198  return false;
3199}
3200
3201/// Check the arguments to '__builtin_va_start' for validity, and that
3202/// it was called from a function of the native ABI.
3203/// Emit an error and return true on failure; return false on success.
3204bool Sema::SemaBuiltinVAStart(CallExpr *TheCall) {
3205  // On x86-64 Unix, don't allow this in Win64 ABI functions.
3206  // On x64 Windows, don't allow this in System V ABI functions.
3207  // (Yes, that means there's no corresponding way to support variadic
3208  // System V ABI functions on Windows.)
3209  if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86_64) {
3210    unsigned OS = Context.getTargetInfo().getTriple().getOS();
3211    clang::CallingConv CC = CC_C;
3212    if (const FunctionDecl *FD = getCurFunctionDecl())
3213      CC = FD->getType()->getAs<FunctionType>()->getCallConv();
3214    if ((OS == llvm::Triple::Win32 && CC == CC_X86_64SysV) ||
3215        (OS != llvm::Triple::Win32 && CC == CC_X86_64Win64))
3216      return Diag(TheCall->getCallee()->getLocStart(),
3217                  diag::err_va_start_used_in_wrong_abi_function)
3218             << (OS != llvm::Triple::Win32);
3219  }
3220  return SemaBuiltinVAStartImpl(TheCall);
3221}
3222
3223/// Check the arguments to '__builtin_ms_va_start' for validity, and that
3224/// it was called from a Win64 ABI function.
3225/// Emit an error and return true on failure; return false on success.
3226bool Sema::SemaBuiltinMSVAStart(CallExpr *TheCall) {
3227  // This only makes sense for x86-64.
3228  const llvm::Triple &TT = Context.getTargetInfo().getTriple();
3229  Expr *Callee = TheCall->getCallee();
3230  if (TT.getArch() != llvm::Triple::x86_64)
3231    return Diag(Callee->getLocStart(), diag::err_x86_builtin_32_bit_tgt);
3232  // Don't allow this in System V ABI functions.
3233  clang::CallingConv CC = CC_C;
3234  if (const FunctionDecl *FD = getCurFunctionDecl())
3235    CC = FD->getType()->getAs<FunctionType>()->getCallConv();
3236  if (CC == CC_X86_64SysV ||
3237      (TT.getOS() != llvm::Triple::Win32 && CC != CC_X86_64Win64))
3238    return Diag(Callee->getLocStart(),
3239                diag::err_ms_va_start_used_in_sysv_function);
3240  return SemaBuiltinVAStartImpl(TheCall);
3241}
3242
3243bool Sema::SemaBuiltinVAStartARM(CallExpr *Call) {
3244  // void __va_start(va_list *ap, const char *named_addr, size_t slot_size,
3245  //                 const char *named_addr);
3246
3247  Expr *Func = Call->getCallee();
3248
3249  if (Call->getNumArgs() < 3)
3250    return Diag(Call->getLocEnd(),
3251                diag::err_typecheck_call_too_few_args_at_least)
3252           << 0 /*function call*/ << 3 << Call->getNumArgs();
3253
3254  // Determine whether the current function is variadic or not.
3255  bool IsVariadic;
3256  if (BlockScopeInfo *CurBlock = getCurBlock())
3257    IsVariadic = CurBlock->TheDecl->isVariadic();
3258  else if (FunctionDecl *FD = getCurFunctionDecl())
3259    IsVariadic = FD->isVariadic();
3260  else if (ObjCMethodDecl *MD = getCurMethodDecl())
3261    IsVariadic = MD->isVariadic();
3262  else
3263    llvm_unreachable("unexpected statement type");
3264
3265  if (!IsVariadic) {
3266    Diag(Func->getLocStart(), diag::err_va_start_used_in_non_variadic_function);
3267    return true;
3268  }
3269
3270  // Type-check the first argument normally.
3271  if (checkBuiltinArgument(*this, Call, 0))
3272    return true;
3273
3274  const struct {
3275    unsigned ArgNo;
3276    QualType Type;
3277  } ArgumentTypes[] = {
3278    { 1, Context.getPointerType(Context.CharTy.withConst()) },
3279    { 2, Context.getSizeType() },
3280  };
3281
3282  for (const auto &AT : ArgumentTypes) {
3283    const Expr *Arg = Call->getArg(AT.ArgNo)->IgnoreParens();
3284    if (Arg->getType().getCanonicalType() == AT.Type.getCanonicalType())
3285      continue;
3286    Diag(Arg->getLocStart(), diag::err_typecheck_convert_incompatible)
3287      << Arg->getType() << AT.Type << 1 /* different class */
3288      << 0 /* qualifier difference */ << 3 /* parameter mismatch */
3289      << AT.ArgNo + 1 << Arg->getType() << AT.Type;
3290  }
3291
3292  return false;
3293}
3294
3295/// SemaBuiltinUnorderedCompare - Handle functions like __builtin_isgreater and
3296/// friends.  This is declared to take (...), so we have to check everything.
3297bool Sema::SemaBuiltinUnorderedCompare(CallExpr *TheCall) {
3298  if (TheCall->getNumArgs() < 2)
3299    return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
3300      << 0 << 2 << TheCall->getNumArgs()/*function call*/;
3301  if (TheCall->getNumArgs() > 2)
3302    return Diag(TheCall->getArg(2)->getLocStart(),
3303                diag::err_typecheck_call_too_many_args)
3304      << 0 /*function call*/ << 2 << TheCall->getNumArgs()
3305      << SourceRange(TheCall->getArg(2)->getLocStart(),
3306                     (*(TheCall->arg_end()-1))->getLocEnd());
3307
3308  ExprResult OrigArg0 = TheCall->getArg(0);
3309  ExprResult OrigArg1 = TheCall->getArg(1);
3310
3311  // Do standard promotions between the two arguments, returning their common
3312  // type.
3313  QualType Res = UsualArithmeticConversions(OrigArg0, OrigArg1, false);
3314  if (OrigArg0.isInvalid() || OrigArg1.isInvalid())
3315    return true;
3316
3317  // Make sure any conversions are pushed back into the call; this is
3318  // type safe since unordered compare builtins are declared as "_Bool
3319  // foo(...)".
3320  TheCall->setArg(0, OrigArg0.get());
3321  TheCall->setArg(1, OrigArg1.get());
3322
3323  if (OrigArg0.get()->isTypeDependent() || OrigArg1.get()->isTypeDependent())
3324    return false;
3325
3326  // If the common type isn't a real floating type, then the arguments were
3327  // invalid for this operation.
3328  if (Res.isNull() || !Res->isRealFloatingType())
3329    return Diag(OrigArg0.get()->getLocStart(),
3330                diag::err_typecheck_call_invalid_ordered_compare)
3331      << OrigArg0.get()->getType() << OrigArg1.get()->getType()
3332      << SourceRange(OrigArg0.get()->getLocStart(), OrigArg1.get()->getLocEnd());
3333
3334  return false;
3335}
3336
3337/// SemaBuiltinSemaBuiltinFPClassification - Handle functions like
3338/// __builtin_isnan and friends.  This is declared to take (...), so we have
3339/// to check everything. We expect the last argument to be a floating point
3340/// value.
3341bool Sema::SemaBuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs) {
3342  if (TheCall->getNumArgs() < NumArgs)
3343    return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
3344      << 0 << NumArgs << TheCall->getNumArgs()/*function call*/;
3345  if (TheCall->getNumArgs() > NumArgs)
3346    return Diag(TheCall->getArg(NumArgs)->getLocStart(),
3347                diag::err_typecheck_call_too_many_args)
3348      << 0 /*function call*/ << NumArgs << TheCall->getNumArgs()
3349      << SourceRange(TheCall->getArg(NumArgs)->getLocStart(),
3350                     (*(TheCall->arg_end()-1))->getLocEnd());
3351
3352  Expr *OrigArg = TheCall->getArg(NumArgs-1);
3353
3354  if (OrigArg->isTypeDependent())
3355    return false;
3356
3357  // This operation requires a non-_Complex floating-point number.
3358  if (!OrigArg->getType()->isRealFloatingType())
3359    return Diag(OrigArg->getLocStart(),
3360                diag::err_typecheck_call_invalid_unary_fp)
3361      << OrigArg->getType() << OrigArg->getSourceRange();
3362
3363  // If this is an implicit conversion from float -> double, remove it.
3364  if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(OrigArg)) {
3365    Expr *CastArg = Cast->getSubExpr();
3366    if (CastArg->getType()->isSpecificBuiltinType(BuiltinType::Float)) {
3367      assert(Cast->getType()->isSpecificBuiltinType(BuiltinType::Double) &&
3368             "promotion from float to double is the only expected cast here");
3369      Cast->setSubExpr(nullptr);
3370      TheCall->setArg(NumArgs-1, CastArg);
3371    }
3372  }
3373
3374  return false;
3375}
3376
3377/// SemaBuiltinShuffleVector - Handle __builtin_shufflevector.
3378// This is declared to take (...), so we have to check everything.
3379ExprResult Sema::SemaBuiltinShuffleVector(CallExpr *TheCall) {
3380  if (TheCall->getNumArgs() < 2)
3381    return ExprError(Diag(TheCall->getLocEnd(),
3382                          diag::err_typecheck_call_too_few_args_at_least)
3383                     << 0 /*function call*/ << 2 << TheCall->getNumArgs()
3384                     << TheCall->getSourceRange());
3385
3386  // Determine which of the following types of shufflevector we're checking:
3387  // 1) unary, vector mask: (lhs, mask)
3388  // 2) binary, scalar mask: (lhs, rhs, index, ..., index)
3389  QualType resType = TheCall->getArg(0)->getType();
3390  unsigned numElements = 0;
3391
3392  if (!TheCall->getArg(0)->isTypeDependent() &&
3393      !TheCall->getArg(1)->isTypeDependent()) {
3394    QualType LHSType = TheCall->getArg(0)->getType();
3395    QualType RHSType = TheCall->getArg(1)->getType();
3396
3397    if (!LHSType->isVectorType() || !RHSType->isVectorType())
3398      return ExprError(Diag(TheCall->getLocStart(),
3399                            diag::err_shufflevector_non_vector)
3400                       << SourceRange(TheCall->getArg(0)->getLocStart(),
3401                                      TheCall->getArg(1)->getLocEnd()));
3402
3403    numElements = LHSType->getAs<VectorType>()->getNumElements();
3404    unsigned numResElements = TheCall->getNumArgs() - 2;
3405
3406    // Check to see if we have a call with 2 vector arguments, the unary shuffle
3407    // with mask.  If so, verify that RHS is an integer vector type with the
3408    // same number of elts as lhs.
3409    if (TheCall->getNumArgs() == 2) {
3410      if (!RHSType->hasIntegerRepresentation() ||
3411          RHSType->getAs<VectorType>()->getNumElements() != numElements)
3412        return ExprError(Diag(TheCall->getLocStart(),
3413                              diag::err_shufflevector_incompatible_vector)
3414                         << SourceRange(TheCall->getArg(1)->getLocStart(),
3415                                        TheCall->getArg(1)->getLocEnd()));
3416    } else if (!Context.hasSameUnqualifiedType(LHSType, RHSType)) {
3417      return ExprError(Diag(TheCall->getLocStart(),
3418                            diag::err_shufflevector_incompatible_vector)
3419                       << SourceRange(TheCall->getArg(0)->getLocStart(),
3420                                      TheCall->getArg(1)->getLocEnd()));
3421    } else if (numElements != numResElements) {
3422      QualType eltType = LHSType->getAs<VectorType>()->getElementType();
3423      resType = Context.getVectorType(eltType, numResElements,
3424                                      VectorType::GenericVector);
3425    }
3426  }
3427
3428  for (unsigned i = 2; i < TheCall->getNumArgs(); i++) {
3429    if (TheCall->getArg(i)->isTypeDependent() ||
3430        TheCall->getArg(i)->isValueDependent())
3431      continue;
3432
3433    llvm::APSInt Result(32);
3434    if (!TheCall->getArg(i)->isIntegerConstantExpr(Result, Context))
3435      return ExprError(Diag(TheCall->getLocStart(),
3436                            diag::err_shufflevector_nonconstant_argument)
3437                       << TheCall->getArg(i)->getSourceRange());
3438
3439    // Allow -1 which will be translated to undef in the IR.
3440    if (Result.isSigned() && Result.isAllOnesValue())
3441      continue;
3442
3443    if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2)
3444      return ExprError(Diag(TheCall->getLocStart(),
3445                            diag::err_shufflevector_argument_too_large)
3446                       << TheCall->getArg(i)->getSourceRange());
3447  }
3448
3449  SmallVector<Expr*, 32> exprs;
3450
3451  for (unsigned i = 0, e = TheCall->getNumArgs(); i != e; i++) {
3452    exprs.push_back(TheCall->getArg(i));
3453    TheCall->setArg(i, nullptr);
3454  }
3455
3456  return new (Context) ShuffleVectorExpr(Context, exprs, resType,
3457                                         TheCall->getCallee()->getLocStart(),
3458                                         TheCall->getRParenLoc());
3459}
3460
3461/// SemaConvertVectorExpr - Handle __builtin_convertvector
3462ExprResult Sema::SemaConvertVectorExpr(Expr *E, TypeSourceInfo *TInfo,
3463                                       SourceLocation BuiltinLoc,
3464                                       SourceLocation RParenLoc) {
3465  ExprValueKind VK = VK_RValue;
3466  ExprObjectKind OK = OK_Ordinary;
3467  QualType DstTy = TInfo->getType();
3468  QualType SrcTy = E->getType();
3469
3470  if (!SrcTy->isVectorType() && !SrcTy->isDependentType())
3471    return ExprError(Diag(BuiltinLoc,
3472                          diag::err_convertvector_non_vector)
3473                     << E->getSourceRange());
3474  if (!DstTy->isVectorType() && !DstTy->isDependentType())
3475    return ExprError(Diag(BuiltinLoc,
3476                          diag::err_convertvector_non_vector_type));
3477
3478  if (!SrcTy->isDependentType() && !DstTy->isDependentType()) {
3479    unsigned SrcElts = SrcTy->getAs<VectorType>()->getNumElements();
3480    unsigned DstElts = DstTy->getAs<VectorType>()->getNumElements();
3481    if (SrcElts != DstElts)
3482      return ExprError(Diag(BuiltinLoc,
3483                            diag::err_convertvector_incompatible_vector)
3484                       << E->getSourceRange());
3485  }
3486
3487  return new (Context)
3488      ConvertVectorExpr(E, TInfo, DstTy, VK, OK, BuiltinLoc, RParenLoc);
3489}
3490
3491/// SemaBuiltinPrefetch - Handle __builtin_prefetch.
3492// This is declared to take (const void*, ...) and can take two
3493// optional constant int args.
3494bool Sema::SemaBuiltinPrefetch(CallExpr *TheCall) {
3495  unsigned NumArgs = TheCall->getNumArgs();
3496
3497  if (NumArgs > 3)
3498    return Diag(TheCall->getLocEnd(),
3499             diag::err_typecheck_call_too_many_args_at_most)
3500             << 0 /*function call*/ << 3 << NumArgs
3501             << TheCall->getSourceRange();
3502
3503  // Argument 0 is checked for us and the remaining arguments must be
3504  // constant integers.
3505  for (unsigned i = 1; i != NumArgs; ++i)
3506    if (SemaBuiltinConstantArgRange(TheCall, i, 0, i == 1 ? 1 : 3))
3507      return true;
3508
3509  return false;
3510}
3511
3512/// SemaBuiltinAssume - Handle __assume (MS Extension).
3513// __assume does not evaluate its arguments, and should warn if its argument
3514// has side effects.
3515bool Sema::SemaBuiltinAssume(CallExpr *TheCall) {
3516  Expr *Arg = TheCall->getArg(0);
3517  if (Arg->isInstantiationDependent()) return false;
3518
3519  if (Arg->HasSideEffects(Context))
3520    Diag(Arg->getLocStart(), diag::warn_assume_side_effects)
3521      << Arg->getSourceRange()
3522      << cast<FunctionDecl>(TheCall->getCalleeDecl())->getIdentifier();
3523
3524  return false;
3525}
3526
3527/// Handle __builtin_assume_aligned. This is declared
3528/// as (const void*, size_t, ...) and can take one optional constant int arg.
3529bool Sema::SemaBuiltinAssumeAligned(CallExpr *TheCall) {
3530  unsigned NumArgs = TheCall->getNumArgs();
3531
3532  if (NumArgs > 3)
3533    return Diag(TheCall->getLocEnd(),
3534             diag::err_typecheck_call_too_many_args_at_most)
3535             << 0 /*function call*/ << 3 << NumArgs
3536             << TheCall->getSourceRange();
3537
3538  // The alignment must be a constant integer.
3539  Expr *Arg = TheCall->getArg(1);
3540
3541  // We can't check the value of a dependent argument.
3542  if (!Arg->isTypeDependent() && !Arg->isValueDependent()) {
3543    llvm::APSInt Result;
3544    if (SemaBuiltinConstantArg(TheCall, 1, Result))
3545      return true;
3546
3547    if (!Result.isPowerOf2())
3548      return Diag(TheCall->getLocStart(),
3549                  diag::err_alignment_not_power_of_two)
3550           << Arg->getSourceRange();
3551  }
3552
3553  if (NumArgs > 2) {
3554    ExprResult Arg(TheCall->getArg(2));
3555    InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
3556      Context.getSizeType(), false);
3557    Arg = PerformCopyInitialization(Entity, SourceLocation(), Arg);
3558    if (Arg.isInvalid()) return true;
3559    TheCall->setArg(2, Arg.get());
3560  }
3561
3562  return false;
3563}
3564
3565/// SemaBuiltinConstantArg - Handle a check if argument ArgNum of CallExpr
3566/// TheCall is a constant expression.
3567bool Sema::SemaBuiltinConstantArg(CallExpr *TheCall, int ArgNum,
3568                                  llvm::APSInt &Result) {
3569  Expr *Arg = TheCall->getArg(ArgNum);
3570  DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
3571  FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
3572
3573  if (Arg->isTypeDependent() || Arg->isValueDependent()) return false;
3574
3575  if (!Arg->isIntegerConstantExpr(Result, Context))
3576    return Diag(TheCall->getLocStart(), diag::err_constant_integer_arg_type)
3577                << FDecl->getDeclName() <<  Arg->getSourceRange();
3578
3579  return false;
3580}
3581
3582/// SemaBuiltinConstantArgRange - Handle a check if argument ArgNum of CallExpr
3583/// TheCall is a constant expression in the range [Low, High].
3584bool Sema::SemaBuiltinConstantArgRange(CallExpr *TheCall, int ArgNum,
3585                                       int Low, int High) {
3586  llvm::APSInt Result;
3587
3588  // We can't check the value of a dependent argument.
3589  Expr *Arg = TheCall->getArg(ArgNum);
3590  if (Arg->isTypeDependent() || Arg->isValueDependent())
3591    return false;
3592
3593  // Check constant-ness first.
3594  if (SemaBuiltinConstantArg(TheCall, ArgNum, Result))
3595    return true;
3596
3597  if (Result.getSExtValue() < Low || Result.getSExtValue() > High)
3598    return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
3599      << Low << High << Arg->getSourceRange();
3600
3601  return false;
3602}
3603
3604/// SemaBuiltinARMSpecialReg - Handle a check if argument ArgNum of CallExpr
3605/// TheCall is an ARM/AArch64 special register string literal.
3606bool Sema::SemaBuiltinARMSpecialReg(unsigned BuiltinID, CallExpr *TheCall,
3607                                    int ArgNum, unsigned ExpectedFieldNum,
3608                                    bool AllowName) {
3609  bool IsARMBuiltin = BuiltinID == ARM::BI__builtin_arm_rsr64 ||
3610                      BuiltinID == ARM::BI__builtin_arm_wsr64 ||
3611                      BuiltinID == ARM::BI__builtin_arm_rsr ||
3612                      BuiltinID == ARM::BI__builtin_arm_rsrp ||
3613                      BuiltinID == ARM::BI__builtin_arm_wsr ||
3614                      BuiltinID == ARM::BI__builtin_arm_wsrp;
3615  bool IsAArch64Builtin = BuiltinID == AArch64::BI__builtin_arm_rsr64 ||
3616                          BuiltinID == AArch64::BI__builtin_arm_wsr64 ||
3617                          BuiltinID == AArch64::BI__builtin_arm_rsr ||
3618                          BuiltinID == AArch64::BI__builtin_arm_rsrp ||
3619                          BuiltinID == AArch64::BI__builtin_arm_wsr ||
3620                          BuiltinID == AArch64::BI__builtin_arm_wsrp;
3621  assert((IsARMBuiltin || IsAArch64Builtin) && "Unexpected ARM builtin.");
3622
3623  // We can't check the value of a dependent argument.
3624  Expr *Arg = TheCall->getArg(ArgNum);
3625  if (Arg->isTypeDependent() || Arg->isValueDependent())
3626    return false;
3627
3628  // Check if the argument is a string literal.
3629  if (!isa<StringLiteral>(Arg->IgnoreParenImpCasts()))
3630    return Diag(TheCall->getLocStart(), diag::err_expr_not_string_literal)
3631           << Arg->getSourceRange();
3632
3633  // Check the type of special register given.
3634  StringRef Reg = cast<StringLiteral>(Arg->IgnoreParenImpCasts())->getString();
3635  SmallVector<StringRef, 6> Fields;
3636  Reg.split(Fields, ":");
3637
3638  if (Fields.size() != ExpectedFieldNum && !(AllowName && Fields.size() == 1))
3639    return Diag(TheCall->getLocStart(), diag::err_arm_invalid_specialreg)
3640           << Arg->getSourceRange();
3641
3642  // If the string is the name of a register then we cannot check that it is
3643  // valid here but if the string is of one the forms described in ACLE then we
3644  // can check that the supplied fields are integers and within the valid
3645  // ranges.
3646  if (Fields.size() > 1) {
3647    bool FiveFields = Fields.size() == 5;
3648
3649    bool ValidString = true;
3650    if (IsARMBuiltin) {
3651      ValidString &= Fields[0].startswith_lower("cp") ||
3652                     Fields[0].startswith_lower("p");
3653      if (ValidString)
3654        Fields[0] =
3655          Fields[0].drop_front(Fields[0].startswith_lower("cp") ? 2 : 1);
3656
3657      ValidString &= Fields[2].startswith_lower("c");
3658      if (ValidString)
3659        Fields[2] = Fields[2].drop_front(1);
3660
3661      if (FiveFields) {
3662        ValidString &= Fields[3].startswith_lower("c");
3663        if (ValidString)
3664          Fields[3] = Fields[3].drop_front(1);
3665      }
3666    }
3667
3668    SmallVector<int, 5> Ranges;
3669    if (FiveFields)
3670      Ranges.append({IsAArch64Builtin ? 1 : 15, 7, 7, 15, 15});
3671    else
3672      Ranges.append({15, 7, 15});
3673
3674    for (unsigned i=0; i<Fields.size(); ++i) {
3675      int IntField;
3676      ValidString &= !Fields[i].getAsInteger(10, IntField);
3677      ValidString &= (IntField >= 0 && IntField <= Ranges[i]);
3678    }
3679
3680    if (!ValidString)
3681      return Diag(TheCall->getLocStart(), diag::err_arm_invalid_specialreg)
3682             << Arg->getSourceRange();
3683
3684  } else if (IsAArch64Builtin && Fields.size() == 1) {
3685    // If the register name is one of those that appear in the condition below
3686    // and the special register builtin being used is one of the write builtins,
3687    // then we require that the argument provided for writing to the register
3688    // is an integer constant expression. This is because it will be lowered to
3689    // an MSR (immediate) instruction, so we need to know the immediate at
3690    // compile time.
3691    if (TheCall->getNumArgs() != 2)
3692      return false;
3693
3694    std::string RegLower = Reg.lower();
3695    if (RegLower != "spsel" && RegLower != "daifset" && RegLower != "daifclr" &&
3696        RegLower != "pan" && RegLower != "uao")
3697      return false;
3698
3699    return SemaBuiltinConstantArgRange(TheCall, 1, 0, 15);
3700  }
3701
3702  return false;
3703}
3704
3705/// SemaBuiltinLongjmp - Handle __builtin_longjmp(void *env[5], int val).
3706/// This checks that the target supports __builtin_longjmp and
3707/// that val is a constant 1.
3708bool Sema::SemaBuiltinLongjmp(CallExpr *TheCall) {
3709  if (!Context.getTargetInfo().hasSjLjLowering())
3710    return Diag(TheCall->getLocStart(), diag::err_builtin_longjmp_unsupported)
3711             << SourceRange(TheCall->getLocStart(), TheCall->getLocEnd());
3712
3713  Expr *Arg = TheCall->getArg(1);
3714  llvm::APSInt Result;
3715
3716  // TODO: This is less than ideal. Overload this to take a value.
3717  if (SemaBuiltinConstantArg(TheCall, 1, Result))
3718    return true;
3719
3720  if (Result != 1)
3721    return Diag(TheCall->getLocStart(), diag::err_builtin_longjmp_invalid_val)
3722             << SourceRange(Arg->getLocStart(), Arg->getLocEnd());
3723
3724  return false;
3725}
3726
3727/// SemaBuiltinSetjmp - Handle __builtin_setjmp(void *env[5]).
3728/// This checks that the target supports __builtin_setjmp.
3729bool Sema::SemaBuiltinSetjmp(CallExpr *TheCall) {
3730  if (!Context.getTargetInfo().hasSjLjLowering())
3731    return Diag(TheCall->getLocStart(), diag::err_builtin_setjmp_unsupported)
3732             << SourceRange(TheCall->getLocStart(), TheCall->getLocEnd());
3733  return false;
3734}
3735
3736namespace {
3737class UncoveredArgHandler {
3738  enum { Unknown = -1, AllCovered = -2 };
3739  signed FirstUncoveredArg;
3740  SmallVector<const Expr *, 4> DiagnosticExprs;
3741
3742public:
3743  UncoveredArgHandler() : FirstUncoveredArg(Unknown) { }
3744
3745  bool hasUncoveredArg() const {
3746    return (FirstUncoveredArg >= 0);
3747  }
3748
3749  unsigned getUncoveredArg() const {
3750    assert(hasUncoveredArg() && "no uncovered argument");
3751    return FirstUncoveredArg;
3752  }
3753
3754  void setAllCovered() {
3755    // A string has been found with all arguments covered, so clear out
3756    // the diagnostics.
3757    DiagnosticExprs.clear();
3758    FirstUncoveredArg = AllCovered;
3759  }
3760
3761  void Update(signed NewFirstUncoveredArg, const Expr *StrExpr) {
3762    assert(NewFirstUncoveredArg >= 0 && "Outside range");
3763
3764    // Don't update if a previous string covers all arguments.
3765    if (FirstUncoveredArg == AllCovered)
3766      return;
3767
3768    // UncoveredArgHandler tracks the highest uncovered argument index
3769    // and with it all the strings that match this index.
3770    if (NewFirstUncoveredArg == FirstUncoveredArg)
3771      DiagnosticExprs.push_back(StrExpr);
3772    else if (NewFirstUncoveredArg > FirstUncoveredArg) {
3773      DiagnosticExprs.clear();
3774      DiagnosticExprs.push_back(StrExpr);
3775      FirstUncoveredArg = NewFirstUncoveredArg;
3776    }
3777  }
3778
3779  void Diagnose(Sema &S, bool IsFunctionCall, const Expr *ArgExpr);
3780};
3781
3782enum StringLiteralCheckType {
3783  SLCT_NotALiteral,
3784  SLCT_UncheckedLiteral,
3785  SLCT_CheckedLiteral
3786};
3787} // end anonymous namespace
3788
3789static void CheckFormatString(Sema &S, const StringLiteral *FExpr,
3790                              const Expr *OrigFormatExpr,
3791                              ArrayRef<const Expr *> Args,
3792                              bool HasVAListArg, unsigned format_idx,
3793                              unsigned firstDataArg,
3794                              Sema::FormatStringType Type,
3795                              bool inFunctionCall,
3796                              Sema::VariadicCallType CallType,
3797                              llvm::SmallBitVector &CheckedVarArgs,
3798                              UncoveredArgHandler &UncoveredArg);
3799
3800// Determine if an expression is a string literal or constant string.
3801// If this function returns false on the arguments to a function expecting a
3802// format string, we will usually need to emit a warning.
3803// True string literals are then checked by CheckFormatString.
3804static StringLiteralCheckType
3805checkFormatStringExpr(Sema &S, const Expr *E, ArrayRef<const Expr *> Args,
3806                      bool HasVAListArg, unsigned format_idx,
3807                      unsigned firstDataArg, Sema::FormatStringType Type,
3808                      Sema::VariadicCallType CallType, bool InFunctionCall,
3809                      llvm::SmallBitVector &CheckedVarArgs,
3810                      UncoveredArgHandler &UncoveredArg) {
3811 tryAgain:
3812  if (E->isTypeDependent() || E->isValueDependent())
3813    return SLCT_NotALiteral;
3814
3815  E = E->IgnoreParenCasts();
3816
3817  if (E->isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull))
3818    // Technically -Wformat-nonliteral does not warn about this case.
3819    // The behavior of printf and friends in this case is implementation
3820    // dependent.  Ideally if the format string cannot be null then
3821    // it should have a 'nonnull' attribute in the function prototype.
3822    return SLCT_UncheckedLiteral;
3823
3824  switch (E->getStmtClass()) {
3825  case Stmt::BinaryConditionalOperatorClass:
3826  case Stmt::ConditionalOperatorClass: {
3827    // The expression is a literal if both sub-expressions were, and it was
3828    // completely checked only if both sub-expressions were checked.
3829    const AbstractConditionalOperator *C =
3830        cast<AbstractConditionalOperator>(E);
3831
3832    // Determine whether it is necessary to check both sub-expressions, for
3833    // example, because the condition expression is a constant that can be
3834    // evaluated at compile time.
3835    bool CheckLeft = true, CheckRight = true;
3836
3837    bool Cond;
3838    if (C->getCond()->EvaluateAsBooleanCondition(Cond, S.getASTContext())) {
3839      if (Cond)
3840        CheckRight = false;
3841      else
3842        CheckLeft = false;
3843    }
3844
3845    StringLiteralCheckType Left;
3846    if (!CheckLeft)
3847      Left = SLCT_UncheckedLiteral;
3848    else {
3849      Left = checkFormatStringExpr(S, C->getTrueExpr(), Args,
3850                                   HasVAListArg, format_idx, firstDataArg,
3851                                   Type, CallType, InFunctionCall,
3852                                   CheckedVarArgs, UncoveredArg);
3853      if (Left == SLCT_NotALiteral || !CheckRight)
3854        return Left;
3855    }
3856
3857    StringLiteralCheckType Right =
3858        checkFormatStringExpr(S, C->getFalseExpr(), Args,
3859                              HasVAListArg, format_idx, firstDataArg,
3860                              Type, CallType, InFunctionCall, CheckedVarArgs,
3861                              UncoveredArg);
3862
3863    return (CheckLeft && Left < Right) ? Left : Right;
3864  }
3865
3866  case Stmt::ImplicitCastExprClass: {
3867    E = cast<ImplicitCastExpr>(E)->getSubExpr();
3868    goto tryAgain;
3869  }
3870
3871  case Stmt::OpaqueValueExprClass:
3872    if (const Expr *src = cast<OpaqueValueExpr>(E)->getSourceExpr()) {
3873      E = src;
3874      goto tryAgain;
3875    }
3876    return SLCT_NotALiteral;
3877
3878  case Stmt::PredefinedExprClass:
3879    // While __func__, etc., are technically not string literals, they
3880    // cannot contain format specifiers and thus are not a security
3881    // liability.
3882    return SLCT_UncheckedLiteral;
3883
3884  case Stmt::DeclRefExprClass: {
3885    const DeclRefExpr *DR = cast<DeclRefExpr>(E);
3886
3887    // As an exception, do not flag errors for variables binding to
3888    // const string literals.
3889    if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
3890      bool isConstant = false;
3891      QualType T = DR->getType();
3892
3893      if (const ArrayType *AT = S.Context.getAsArrayType(T)) {
3894        isConstant = AT->getElementType().isConstant(S.Context);
3895      } else if (const PointerType *PT = T->getAs<PointerType>()) {
3896        isConstant = T.isConstant(S.Context) &&
3897                     PT->getPointeeType().isConstant(S.Context);
3898      } else if (T->isObjCObjectPointerType()) {
3899        // In ObjC, there is usually no "const ObjectPointer" type,
3900        // so don't check if the pointee type is constant.
3901        isConstant = T.isConstant(S.Context);
3902      }
3903
3904      if (isConstant) {
3905        if (const Expr *Init = VD->getAnyInitializer()) {
3906          // Look through initializers like const char c[] = { "foo" }
3907          if (const InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
3908            if (InitList->isStringLiteralInit())
3909              Init = InitList->getInit(0)->IgnoreParenImpCasts();
3910          }
3911          return checkFormatStringExpr(S, Init, Args,
3912                                       HasVAListArg, format_idx,
3913                                       firstDataArg, Type, CallType,
3914                                       /*InFunctionCall*/false, CheckedVarArgs,
3915                                       UncoveredArg);
3916        }
3917      }
3918
3919      // For vprintf* functions (i.e., HasVAListArg==true), we add a
3920      // special check to see if the format string is a function parameter
3921      // of the function calling the printf function.  If the function
3922      // has an attribute indicating it is a printf-like function, then we
3923      // should suppress warnings concerning non-literals being used in a call
3924      // to a vprintf function.  For example:
3925      //
3926      // void
3927      // logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...){
3928      //      va_list ap;
3929      //      va_start(ap, fmt);
3930      //      vprintf(fmt, ap);  // Do NOT emit a warning about "fmt".
3931      //      ...
3932      // }
3933      if (HasVAListArg) {
3934        if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(VD)) {
3935          if (const NamedDecl *ND = dyn_cast<NamedDecl>(PV->getDeclContext())) {
3936            int PVIndex = PV->getFunctionScopeIndex() + 1;
3937            for (const auto *PVFormat : ND->specific_attrs<FormatAttr>()) {
3938              // adjust for implicit parameter
3939              if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
3940                if (MD->isInstance())
3941                  ++PVIndex;
3942              // We also check if the formats are compatible.
3943              // We can't pass a 'scanf' string to a 'printf' function.
3944              if (PVIndex == PVFormat->getFormatIdx() &&
3945                  Type == S.GetFormatStringType(PVFormat))
3946                return SLCT_UncheckedLiteral;
3947            }
3948          }
3949        }
3950      }
3951    }
3952
3953    return SLCT_NotALiteral;
3954  }
3955
3956  case Stmt::CallExprClass:
3957  case Stmt::CXXMemberCallExprClass: {
3958    const CallExpr *CE = cast<CallExpr>(E);
3959    if (const NamedDecl *ND = dyn_cast_or_null<NamedDecl>(CE->getCalleeDecl())) {
3960      if (const FormatArgAttr *FA = ND->getAttr<FormatArgAttr>()) {
3961        unsigned ArgIndex = FA->getFormatIdx();
3962        if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
3963          if (MD->isInstance())
3964            --ArgIndex;
3965        const Expr *Arg = CE->getArg(ArgIndex - 1);
3966
3967        return checkFormatStringExpr(S, Arg, Args,
3968                                     HasVAListArg, format_idx, firstDataArg,
3969                                     Type, CallType, InFunctionCall,
3970                                     CheckedVarArgs, UncoveredArg);
3971      } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
3972        unsigned BuiltinID = FD->getBuiltinID();
3973        if (BuiltinID == Builtin::BI__builtin___CFStringMakeConstantString ||
3974            BuiltinID == Builtin::BI__builtin___NSStringMakeConstantString) {
3975          const Expr *Arg = CE->getArg(0);
3976          return checkFormatStringExpr(S, Arg, Args,
3977                                       HasVAListArg, format_idx,
3978                                       firstDataArg, Type, CallType,
3979                                       InFunctionCall, CheckedVarArgs,
3980                                       UncoveredArg);
3981        }
3982      }
3983    }
3984
3985    return SLCT_NotALiteral;
3986  }
3987  case Stmt::ObjCStringLiteralClass:
3988  case Stmt::StringLiteralClass: {
3989    const StringLiteral *StrE = nullptr;
3990
3991    if (const ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(E))
3992      StrE = ObjCFExpr->getString();
3993    else
3994      StrE = cast<StringLiteral>(E);
3995
3996    if (StrE) {
3997      CheckFormatString(S, StrE, E, Args, HasVAListArg, format_idx,
3998                        firstDataArg, Type, InFunctionCall, CallType,
3999                        CheckedVarArgs, UncoveredArg);
4000      return SLCT_CheckedLiteral;
4001    }
4002
4003    return SLCT_NotALiteral;
4004  }
4005
4006  default:
4007    return SLCT_NotALiteral;
4008  }
4009}
4010
4011Sema::FormatStringType Sema::GetFormatStringType(const FormatAttr *Format) {
4012  return llvm::StringSwitch<FormatStringType>(Format->getType()->getName())
4013  .Case("scanf", FST_Scanf)
4014  .Cases("printf", "printf0", FST_Printf)
4015  .Cases("NSString", "CFString", FST_NSString)
4016  .Case("strftime", FST_Strftime)
4017  .Case("strfmon", FST_Strfmon)
4018  .Cases("kprintf", "cmn_err", "vcmn_err", "zcmn_err", FST_Kprintf)
4019  .Case("freebsd_kprintf", FST_FreeBSDKPrintf)
4020  .Case("os_trace", FST_OSTrace)
4021  .Default(FST_Unknown);
4022}
4023
4024/// CheckFormatArguments - Check calls to printf and scanf (and similar
4025/// functions) for correct use of format strings.
4026/// Returns true if a format string has been fully checked.
4027bool Sema::CheckFormatArguments(const FormatAttr *Format,
4028                                ArrayRef<const Expr *> Args,
4029                                bool IsCXXMember,
4030                                VariadicCallType CallType,
4031                                SourceLocation Loc, SourceRange Range,
4032                                llvm::SmallBitVector &CheckedVarArgs) {
4033  FormatStringInfo FSI;
4034  if (getFormatStringInfo(Format, IsCXXMember, &FSI))
4035    return CheckFormatArguments(Args, FSI.HasVAListArg, FSI.FormatIdx,
4036                                FSI.FirstDataArg, GetFormatStringType(Format),
4037                                CallType, Loc, Range, CheckedVarArgs);
4038  return false;
4039}
4040
4041bool Sema::CheckFormatArguments(ArrayRef<const Expr *> Args,
4042                                bool HasVAListArg, unsigned format_idx,
4043                                unsigned firstDataArg, FormatStringType Type,
4044                                VariadicCallType CallType,
4045                                SourceLocation Loc, SourceRange Range,
4046                                llvm::SmallBitVector &CheckedVarArgs) {
4047  // CHECK: printf/scanf-like function is called with no format string.
4048  if (format_idx >= Args.size()) {
4049    Diag(Loc, diag::warn_missing_format_string) << Range;
4050    return false;
4051  }
4052
4053  const Expr *OrigFormatExpr = Args[format_idx]->IgnoreParenCasts();
4054
4055  // CHECK: format string is not a string literal.
4056  //
4057  // Dynamically generated format strings are difficult to
4058  // automatically vet at compile time.  Requiring that format strings
4059  // are string literals: (1) permits the checking of format strings by
4060  // the compiler and thereby (2) can practically remove the source of
4061  // many format string exploits.
4062
4063  // Format string can be either ObjC string (e.g. @"%d") or
4064  // C string (e.g. "%d")
4065  // ObjC string uses the same format specifiers as C string, so we can use
4066  // the same format string checking logic for both ObjC and C strings.
4067  UncoveredArgHandler UncoveredArg;
4068  StringLiteralCheckType CT =
4069      checkFormatStringExpr(*this, OrigFormatExpr, Args, HasVAListArg,
4070                            format_idx, firstDataArg, Type, CallType,
4071                            /*IsFunctionCall*/true, CheckedVarArgs,
4072                            UncoveredArg);
4073
4074  // Generate a diagnostic where an uncovered argument is detected.
4075  if (UncoveredArg.hasUncoveredArg()) {
4076    unsigned ArgIdx = UncoveredArg.getUncoveredArg() + firstDataArg;
4077    assert(ArgIdx < Args.size() && "ArgIdx outside bounds");
4078    UncoveredArg.Diagnose(*this, /*IsFunctionCall*/true, Args[ArgIdx]);
4079  }
4080
4081  if (CT != SLCT_NotALiteral)
4082    // Literal format string found, check done!
4083    return CT == SLCT_CheckedLiteral;
4084
4085  // Strftime is particular as it always uses a single 'time' argument,
4086  // so it is safe to pass a non-literal string.
4087  if (Type == FST_Strftime)
4088    return false;
4089
4090  // Do not emit diag when the string param is a macro expansion and the
4091  // format is either NSString or CFString. This is a hack to prevent
4092  // diag when using the NSLocalizedString and CFCopyLocalizedString macros
4093  // which are usually used in place of NS and CF string literals.
4094  SourceLocation FormatLoc = Args[format_idx]->getLocStart();
4095  if (Type == FST_NSString && SourceMgr.isInSystemMacro(FormatLoc))
4096    return false;
4097
4098  // If there are no arguments specified, warn with -Wformat-security, otherwise
4099  // warn only with -Wformat-nonliteral.
4100  if (Args.size() == firstDataArg) {
4101    Diag(FormatLoc, diag::warn_format_nonliteral_noargs)
4102      << OrigFormatExpr->getSourceRange();
4103    switch (Type) {
4104    default:
4105      break;
4106    case FST_Kprintf:
4107    case FST_FreeBSDKPrintf:
4108    case FST_Printf:
4109      Diag(FormatLoc, diag::note_format_security_fixit)
4110        << FixItHint::CreateInsertion(FormatLoc, "\"%s\", ");
4111      break;
4112    case FST_NSString:
4113      Diag(FormatLoc, diag::note_format_security_fixit)
4114        << FixItHint::CreateInsertion(FormatLoc, "@\"%@\", ");
4115      break;
4116    }
4117  } else {
4118    Diag(FormatLoc, diag::warn_format_nonliteral)
4119      << OrigFormatExpr->getSourceRange();
4120  }
4121  return false;
4122}
4123
4124namespace {
4125class CheckFormatHandler : public analyze_format_string::FormatStringHandler {
4126protected:
4127  Sema &S;
4128  const StringLiteral *FExpr;
4129  const Expr *OrigFormatExpr;
4130  const unsigned FirstDataArg;
4131  const unsigned NumDataArgs;
4132  const char *Beg; // Start of format string.
4133  const bool HasVAListArg;
4134  ArrayRef<const Expr *> Args;
4135  unsigned FormatIdx;
4136  llvm::SmallBitVector CoveredArgs;
4137  bool usesPositionalArgs;
4138  bool atFirstArg;
4139  bool inFunctionCall;
4140  Sema::VariadicCallType CallType;
4141  llvm::SmallBitVector &CheckedVarArgs;
4142  UncoveredArgHandler &UncoveredArg;
4143
4144public:
4145  CheckFormatHandler(Sema &s, const StringLiteral *fexpr,
4146                     const Expr *origFormatExpr, unsigned firstDataArg,
4147                     unsigned numDataArgs, const char *beg, bool hasVAListArg,
4148                     ArrayRef<const Expr *> Args,
4149                     unsigned formatIdx, bool inFunctionCall,
4150                     Sema::VariadicCallType callType,
4151                     llvm::SmallBitVector &CheckedVarArgs,
4152                     UncoveredArgHandler &UncoveredArg)
4153    : S(s), FExpr(fexpr), OrigFormatExpr(origFormatExpr),
4154      FirstDataArg(firstDataArg), NumDataArgs(numDataArgs),
4155      Beg(beg), HasVAListArg(hasVAListArg),
4156      Args(Args), FormatIdx(formatIdx),
4157      usesPositionalArgs(false), atFirstArg(true),
4158      inFunctionCall(inFunctionCall), CallType(callType),
4159      CheckedVarArgs(CheckedVarArgs), UncoveredArg(UncoveredArg) {
4160    CoveredArgs.resize(numDataArgs);
4161    CoveredArgs.reset();
4162  }
4163
4164  void DoneProcessing();
4165
4166  void HandleIncompleteSpecifier(const char *startSpecifier,
4167                                 unsigned specifierLen) override;
4168
4169  void HandleInvalidLengthModifier(
4170                           const analyze_format_string::FormatSpecifier &FS,
4171                           const analyze_format_string::ConversionSpecifier &CS,
4172                           const char *startSpecifier, unsigned specifierLen,
4173                           unsigned DiagID);
4174
4175  void HandleNonStandardLengthModifier(
4176                    const analyze_format_string::FormatSpecifier &FS,
4177                    const char *startSpecifier, unsigned specifierLen);
4178
4179  void HandleNonStandardConversionSpecifier(
4180                    const analyze_format_string::ConversionSpecifier &CS,
4181                    const char *startSpecifier, unsigned specifierLen);
4182
4183  void HandlePosition(const char *startPos, unsigned posLen) override;
4184
4185  void HandleInvalidPosition(const char *startSpecifier,
4186                             unsigned specifierLen,
4187                             analyze_format_string::PositionContext p) override;
4188
4189  void HandleZeroPosition(const char *startPos, unsigned posLen) override;
4190
4191  void HandleNullChar(const char *nullCharacter) override;
4192
4193  template <typename Range>
4194  static void
4195  EmitFormatDiagnostic(Sema &S, bool inFunctionCall, const Expr *ArgumentExpr,
4196                       const PartialDiagnostic &PDiag, SourceLocation StringLoc,
4197                       bool IsStringLocation, Range StringRange,
4198                       ArrayRef<FixItHint> Fixit = None);
4199
4200protected:
4201  bool HandleInvalidConversionSpecifier(unsigned argIndex, SourceLocation Loc,
4202                                        const char *startSpec,
4203                                        unsigned specifierLen,
4204                                        const char *csStart, unsigned csLen);
4205
4206  void HandlePositionalNonpositionalArgs(SourceLocation Loc,
4207                                         const char *startSpec,
4208                                         unsigned specifierLen);
4209
4210  SourceRange getFormatStringRange();
4211  CharSourceRange getSpecifierRange(const char *startSpecifier,
4212                                    unsigned specifierLen);
4213  SourceLocation getLocationOfByte(const char *x);
4214
4215  const Expr *getDataArg(unsigned i) const;
4216
4217  bool CheckNumArgs(const analyze_format_string::FormatSpecifier &FS,
4218                    const analyze_format_string::ConversionSpecifier &CS,
4219                    const char *startSpecifier, unsigned specifierLen,
4220                    unsigned argIndex);
4221
4222  template <typename Range>
4223  void EmitFormatDiagnostic(PartialDiagnostic PDiag, SourceLocation StringLoc,
4224                            bool IsStringLocation, Range StringRange,
4225                            ArrayRef<FixItHint> Fixit = None);
4226};
4227} // end anonymous namespace
4228
4229SourceRange CheckFormatHandler::getFormatStringRange() {
4230  return OrigFormatExpr->getSourceRange();
4231}
4232
4233CharSourceRange CheckFormatHandler::
4234getSpecifierRange(const char *startSpecifier, unsigned specifierLen) {
4235  SourceLocation Start = getLocationOfByte(startSpecifier);
4236  SourceLocation End   = getLocationOfByte(startSpecifier + specifierLen - 1);
4237
4238  // Advance the end SourceLocation by one due to half-open ranges.
4239  End = End.getLocWithOffset(1);
4240
4241  return CharSourceRange::getCharRange(Start, End);
4242}
4243
4244SourceLocation CheckFormatHandler::getLocationOfByte(const char *x) {
4245  return S.getLocationOfStringLiteralByte(FExpr, x - Beg);
4246}
4247
4248void CheckFormatHandler::HandleIncompleteSpecifier(const char *startSpecifier,
4249                                                   unsigned specifierLen){
4250  EmitFormatDiagnostic(S.PDiag(diag::warn_printf_incomplete_specifier),
4251                       getLocationOfByte(startSpecifier),
4252                       /*IsStringLocation*/true,
4253                       getSpecifierRange(startSpecifier, specifierLen));
4254}
4255
4256void CheckFormatHandler::HandleInvalidLengthModifier(
4257    const analyze_format_string::FormatSpecifier &FS,
4258    const analyze_format_string::ConversionSpecifier &CS,
4259    const char *startSpecifier, unsigned specifierLen, unsigned DiagID) {
4260  using namespace analyze_format_string;
4261
4262  const LengthModifier &LM = FS.getLengthModifier();
4263  CharSourceRange LMRange = getSpecifierRange(LM.getStart(), LM.getLength());
4264
4265  // See if we know how to fix this length modifier.
4266  Optional<LengthModifier> FixedLM = FS.getCorrectedLengthModifier();
4267  if (FixedLM) {
4268    EmitFormatDiagnostic(S.PDiag(DiagID) << LM.toString() << CS.toString(),
4269                         getLocationOfByte(LM.getStart()),
4270                         /*IsStringLocation*/true,
4271                         getSpecifierRange(startSpecifier, specifierLen));
4272
4273    S.Diag(getLocationOfByte(LM.getStart()), diag::note_format_fix_specifier)
4274      << FixedLM->toString()
4275      << FixItHint::CreateReplacement(LMRange, FixedLM->toString());
4276
4277  } else {
4278    FixItHint Hint;
4279    if (DiagID == diag::warn_format_nonsensical_length)
4280      Hint = FixItHint::CreateRemoval(LMRange);
4281
4282    EmitFormatDiagnostic(S.PDiag(DiagID) << LM.toString() << CS.toString(),
4283                         getLocationOfByte(LM.getStart()),
4284                         /*IsStringLocation*/true,
4285                         getSpecifierRange(startSpecifier, specifierLen),
4286                         Hint);
4287  }
4288}
4289
4290void CheckFormatHandler::HandleNonStandardLengthModifier(
4291    const analyze_format_string::FormatSpecifier &FS,
4292    const char *startSpecifier, unsigned specifierLen) {
4293  using namespace analyze_format_string;
4294
4295  const LengthModifier &LM = FS.getLengthModifier();
4296  CharSourceRange LMRange = getSpecifierRange(LM.getStart(), LM.getLength());
4297
4298  // See if we know how to fix this length modifier.
4299  Optional<LengthModifier> FixedLM = FS.getCorrectedLengthModifier();
4300  if (FixedLM) {
4301    EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
4302                           << LM.toString() << 0,
4303                         getLocationOfByte(LM.getStart()),
4304                         /*IsStringLocation*/true,
4305                         getSpecifierRange(startSpecifier, specifierLen));
4306
4307    S.Diag(getLocationOfByte(LM.getStart()), diag::note_format_fix_specifier)
4308      << FixedLM->toString()
4309      << FixItHint::CreateReplacement(LMRange, FixedLM->toString());
4310
4311  } else {
4312    EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
4313                           << LM.toString() << 0,
4314                         getLocationOfByte(LM.getStart()),
4315                         /*IsStringLocation*/true,
4316                         getSpecifierRange(startSpecifier, specifierLen));
4317  }
4318}
4319
4320void CheckFormatHandler::HandleNonStandardConversionSpecifier(
4321    const analyze_format_string::ConversionSpecifier &CS,
4322    const char *startSpecifier, unsigned specifierLen) {
4323  using namespace analyze_format_string;
4324
4325  // See if we know how to fix this conversion specifier.
4326  Optional<ConversionSpecifier> FixedCS = CS.getStandardSpecifier();
4327  if (FixedCS) {
4328    EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
4329                          << CS.toString() << /*conversion specifier*/1,
4330                         getLocationOfByte(CS.getStart()),
4331                         /*IsStringLocation*/true,
4332                         getSpecifierRange(startSpecifier, specifierLen));
4333
4334    CharSourceRange CSRange = getSpecifierRange(CS.getStart(), CS.getLength());
4335    S.Diag(getLocationOfByte(CS.getStart()), diag::note_format_fix_specifier)
4336      << FixedCS->toString()
4337      << FixItHint::CreateReplacement(CSRange, FixedCS->toString());
4338  } else {
4339    EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
4340                          << CS.toString() << /*conversion specifier*/1,
4341                         getLocationOfByte(CS.getStart()),
4342                         /*IsStringLocation*/true,
4343                         getSpecifierRange(startSpecifier, specifierLen));
4344  }
4345}
4346
4347void CheckFormatHandler::HandlePosition(const char *startPos,
4348                                        unsigned posLen) {
4349  EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard_positional_arg),
4350                               getLocationOfByte(startPos),
4351                               /*IsStringLocation*/true,
4352                               getSpecifierRange(startPos, posLen));
4353}
4354
4355void
4356CheckFormatHandler::HandleInvalidPosition(const char *startPos, unsigned posLen,
4357                                     analyze_format_string::PositionContext p) {
4358  EmitFormatDiagnostic(S.PDiag(diag::warn_format_invalid_positional_specifier)
4359                         << (unsigned) p,
4360                       getLocationOfByte(startPos), /*IsStringLocation*/true,
4361                       getSpecifierRange(startPos, posLen));
4362}
4363
4364void CheckFormatHandler::HandleZeroPosition(const char *startPos,
4365                                            unsigned posLen) {
4366  EmitFormatDiagnostic(S.PDiag(diag::warn_format_zero_positional_specifier),
4367                               getLocationOfByte(startPos),
4368                               /*IsStringLocation*/true,
4369                               getSpecifierRange(startPos, posLen));
4370}
4371
4372void CheckFormatHandler::HandleNullChar(const char *nullCharacter) {
4373  if (!isa<ObjCStringLiteral>(OrigFormatExpr)) {
4374    // The presence of a null character is likely an error.
4375    EmitFormatDiagnostic(
4376      S.PDiag(diag::warn_printf_format_string_contains_null_char),
4377      getLocationOfByte(nullCharacter), /*IsStringLocation*/true,
4378      getFormatStringRange());
4379  }
4380}
4381
4382// Note that this may return NULL if there was an error parsing or building
4383// one of the argument expressions.
4384const Expr *CheckFormatHandler::getDataArg(unsigned i) const {
4385  return Args[FirstDataArg + i];
4386}
4387
4388void CheckFormatHandler::DoneProcessing() {
4389  // Does the number of data arguments exceed the number of
4390  // format conversions in the format string?
4391  if (!HasVAListArg) {
4392      // Find any arguments that weren't covered.
4393    CoveredArgs.flip();
4394    signed notCoveredArg = CoveredArgs.find_first();
4395    if (notCoveredArg >= 0) {
4396      assert((unsigned)notCoveredArg < NumDataArgs);
4397      UncoveredArg.Update(notCoveredArg, OrigFormatExpr);
4398    } else {
4399      UncoveredArg.setAllCovered();
4400    }
4401  }
4402}
4403
4404void UncoveredArgHandler::Diagnose(Sema &S, bool IsFunctionCall,
4405                                   const Expr *ArgExpr) {
4406  assert(hasUncoveredArg() && DiagnosticExprs.size() > 0 &&
4407         "Invalid state");
4408
4409  if (!ArgExpr)
4410    return;
4411
4412  SourceLocation Loc = ArgExpr->getLocStart();
4413
4414  if (S.getSourceManager().isInSystemMacro(Loc))
4415    return;
4416
4417  PartialDiagnostic PDiag = S.PDiag(diag::warn_printf_data_arg_not_used);
4418  for (auto E : DiagnosticExprs)
4419    PDiag << E->getSourceRange();
4420
4421  CheckFormatHandler::EmitFormatDiagnostic(
4422                                  S, IsFunctionCall, DiagnosticExprs[0],
4423                                  PDiag, Loc, /*IsStringLocation*/false,
4424                                  DiagnosticExprs[0]->getSourceRange());
4425}
4426
4427bool
4428CheckFormatHandler::HandleInvalidConversionSpecifier(unsigned argIndex,
4429                                                     SourceLocation Loc,
4430                                                     const char *startSpec,
4431                                                     unsigned specifierLen,
4432                                                     const char *csStart,
4433                                                     unsigned csLen) {
4434  bool keepGoing = true;
4435  if (argIndex < NumDataArgs) {
4436    // Consider the argument coverered, even though the specifier doesn't
4437    // make sense.
4438    CoveredArgs.set(argIndex);
4439  }
4440  else {
4441    // If argIndex exceeds the number of data arguments we
4442    // don't issue a warning because that is just a cascade of warnings (and
4443    // they may have intended '%%' anyway). We don't want to continue processing
4444    // the format string after this point, however, as we will like just get
4445    // gibberish when trying to match arguments.
4446    keepGoing = false;
4447  }
4448
4449  StringRef Specifier(csStart, csLen);
4450
4451  // If the specifier in non-printable, it could be the first byte of a UTF-8
4452  // sequence. In that case, print the UTF-8 code point. If not, print the byte
4453  // hex value.
4454  std::string CodePointStr;
4455  if (!llvm::sys::locale::isPrint(*csStart)) {
4456    UTF32 CodePoint;
4457    const UTF8 **B = reinterpret_cast<const UTF8 **>(&csStart);
4458    const UTF8 *E =
4459        reinterpret_cast<const UTF8 *>(csStart + csLen);
4460    ConversionResult Result =
4461        llvm::convertUTF8Sequence(B, E, &CodePoint, strictConversion);
4462
4463    if (Result != conversionOK) {
4464      unsigned char FirstChar = *csStart;
4465      CodePoint = (UTF32)FirstChar;
4466    }
4467
4468    llvm::raw_string_ostream OS(CodePointStr);
4469    if (CodePoint < 256)
4470      OS << "\\x" << llvm::format("%02x", CodePoint);
4471    else if (CodePoint <= 0xFFFF)
4472      OS << "\\u" << llvm::format("%04x", CodePoint);
4473    else
4474      OS << "\\U" << llvm::format("%08x", CodePoint);
4475    OS.flush();
4476    Specifier = CodePointStr;
4477  }
4478
4479  EmitFormatDiagnostic(
4480      S.PDiag(diag::warn_format_invalid_conversion) << Specifier, Loc,
4481      /*IsStringLocation*/ true, getSpecifierRange(startSpec, specifierLen));
4482
4483  return keepGoing;
4484}
4485
4486void
4487CheckFormatHandler::HandlePositionalNonpositionalArgs(SourceLocation Loc,
4488                                                      const char *startSpec,
4489                                                      unsigned specifierLen) {
4490  EmitFormatDiagnostic(
4491    S.PDiag(diag::warn_format_mix_positional_nonpositional_args),
4492    Loc, /*isStringLoc*/true, getSpecifierRange(startSpec, specifierLen));
4493}
4494
4495bool
4496CheckFormatHandler::CheckNumArgs(
4497  const analyze_format_string::FormatSpecifier &FS,
4498  const analyze_format_string::ConversionSpecifier &CS,
4499  const char *startSpecifier, unsigned specifierLen, unsigned argIndex) {
4500
4501  if (argIndex >= NumDataArgs) {
4502    PartialDiagnostic PDiag = FS.usesPositionalArg()
4503      ? (S.PDiag(diag::warn_printf_positional_arg_exceeds_data_args)
4504           << (argIndex+1) << NumDataArgs)
4505      : S.PDiag(diag::warn_printf_insufficient_data_args);
4506    EmitFormatDiagnostic(
4507      PDiag, getLocationOfByte(CS.getStart()), /*IsStringLocation*/true,
4508      getSpecifierRange(startSpecifier, specifierLen));
4509
4510    // Since more arguments than conversion tokens are given, by extension
4511    // all arguments are covered, so mark this as so.
4512    UncoveredArg.setAllCovered();
4513    return false;
4514  }
4515  return true;
4516}
4517
4518template<typename Range>
4519void CheckFormatHandler::EmitFormatDiagnostic(PartialDiagnostic PDiag,
4520                                              SourceLocation Loc,
4521                                              bool IsStringLocation,
4522                                              Range StringRange,
4523                                              ArrayRef<FixItHint> FixIt) {
4524  EmitFormatDiagnostic(S, inFunctionCall, Args[FormatIdx], PDiag,
4525                       Loc, IsStringLocation, StringRange, FixIt);
4526}
4527
4528/// \brief If the format string is not within the funcion call, emit a note
4529/// so that the function call and string are in diagnostic messages.
4530///
4531/// \param InFunctionCall if true, the format string is within the function
4532/// call and only one diagnostic message will be produced.  Otherwise, an
4533/// extra note will be emitted pointing to location of the format string.
4534///
4535/// \param ArgumentExpr the expression that is passed as the format string
4536/// argument in the function call.  Used for getting locations when two
4537/// diagnostics are emitted.
4538///
4539/// \param PDiag the callee should already have provided any strings for the
4540/// diagnostic message.  This function only adds locations and fixits
4541/// to diagnostics.
4542///
4543/// \param Loc primary location for diagnostic.  If two diagnostics are
4544/// required, one will be at Loc and a new SourceLocation will be created for
4545/// the other one.
4546///
4547/// \param IsStringLocation if true, Loc points to the format string should be
4548/// used for the note.  Otherwise, Loc points to the argument list and will
4549/// be used with PDiag.
4550///
4551/// \param StringRange some or all of the string to highlight.  This is
4552/// templated so it can accept either a CharSourceRange or a SourceRange.
4553///
4554/// \param FixIt optional fix it hint for the format string.
4555template <typename Range>
4556void CheckFormatHandler::EmitFormatDiagnostic(
4557    Sema &S, bool InFunctionCall, const Expr *ArgumentExpr,
4558    const PartialDiagnostic &PDiag, SourceLocation Loc, bool IsStringLocation,
4559    Range StringRange, ArrayRef<FixItHint> FixIt) {
4560  if (InFunctionCall) {
4561    const Sema::SemaDiagnosticBuilder &D = S.Diag(Loc, PDiag);
4562    D << StringRange;
4563    D << FixIt;
4564  } else {
4565    S.Diag(IsStringLocation ? ArgumentExpr->getExprLoc() : Loc, PDiag)
4566      << ArgumentExpr->getSourceRange();
4567
4568    const Sema::SemaDiagnosticBuilder &Note =
4569      S.Diag(IsStringLocation ? Loc : StringRange.getBegin(),
4570             diag::note_format_string_defined);
4571
4572    Note << StringRange;
4573    Note << FixIt;
4574  }
4575}
4576
4577//===--- CHECK: Printf format string checking ------------------------------===//
4578
4579namespace {
4580class CheckPrintfHandler : public CheckFormatHandler {
4581  bool ObjCContext;
4582
4583public:
4584  CheckPrintfHandler(Sema &s, const StringLiteral *fexpr,
4585                     const Expr *origFormatExpr, unsigned firstDataArg,
4586                     unsigned numDataArgs, bool isObjC,
4587                     const char *beg, bool hasVAListArg,
4588                     ArrayRef<const Expr *> Args,
4589                     unsigned formatIdx, bool inFunctionCall,
4590                     Sema::VariadicCallType CallType,
4591                     llvm::SmallBitVector &CheckedVarArgs,
4592                     UncoveredArgHandler &UncoveredArg)
4593    : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg,
4594                         numDataArgs, beg, hasVAListArg, Args,
4595                         formatIdx, inFunctionCall, CallType, CheckedVarArgs,
4596                         UncoveredArg),
4597      ObjCContext(isObjC)
4598  {}
4599
4600  bool HandleInvalidPrintfConversionSpecifier(
4601                                      const analyze_printf::PrintfSpecifier &FS,
4602                                      const char *startSpecifier,
4603                                      unsigned specifierLen) override;
4604
4605  bool HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier &FS,
4606                             const char *startSpecifier,
4607                             unsigned specifierLen) override;
4608  bool checkFormatExpr(const analyze_printf::PrintfSpecifier &FS,
4609                       const char *StartSpecifier,
4610                       unsigned SpecifierLen,
4611                       const Expr *E);
4612
4613  bool HandleAmount(const analyze_format_string::OptionalAmount &Amt, unsigned k,
4614                    const char *startSpecifier, unsigned specifierLen);
4615  void HandleInvalidAmount(const analyze_printf::PrintfSpecifier &FS,
4616                           const analyze_printf::OptionalAmount &Amt,
4617                           unsigned type,
4618                           const char *startSpecifier, unsigned specifierLen);
4619  void HandleFlag(const analyze_printf::PrintfSpecifier &FS,
4620                  const analyze_printf::OptionalFlag &flag,
4621                  const char *startSpecifier, unsigned specifierLen);
4622  void HandleIgnoredFlag(const analyze_printf::PrintfSpecifier &FS,
4623                         const analyze_printf::OptionalFlag &ignoredFlag,
4624                         const analyze_printf::OptionalFlag &flag,
4625                         const char *startSpecifier, unsigned specifierLen);
4626  bool checkForCStrMembers(const analyze_printf::ArgType &AT,
4627                           const Expr *E);
4628
4629  void HandleEmptyObjCModifierFlag(const char *startFlag,
4630                                   unsigned flagLen) override;
4631
4632  void HandleInvalidObjCModifierFlag(const char *startFlag,
4633                                            unsigned flagLen) override;
4634
4635  void HandleObjCFlagsWithNonObjCConversion(const char *flagsStart,
4636                                           const char *flagsEnd,
4637                                           const char *conversionPosition)
4638                                             override;
4639};
4640} // end anonymous namespace
4641
4642bool CheckPrintfHandler::HandleInvalidPrintfConversionSpecifier(
4643                                      const analyze_printf::PrintfSpecifier &FS,
4644                                      const char *startSpecifier,
4645                                      unsigned specifierLen) {
4646  const analyze_printf::PrintfConversionSpecifier &CS =
4647    FS.getConversionSpecifier();
4648
4649  return HandleInvalidConversionSpecifier(FS.getArgIndex(),
4650                                          getLocationOfByte(CS.getStart()),
4651                                          startSpecifier, specifierLen,
4652                                          CS.getStart(), CS.getLength());
4653}
4654
4655bool CheckPrintfHandler::HandleAmount(
4656                               const analyze_format_string::OptionalAmount &Amt,
4657                               unsigned k, const char *startSpecifier,
4658                               unsigned specifierLen) {
4659  if (Amt.hasDataArgument()) {
4660    if (!HasVAListArg) {
4661      unsigned argIndex = Amt.getArgIndex();
4662      if (argIndex >= NumDataArgs) {
4663        EmitFormatDiagnostic(S.PDiag(diag::warn_printf_asterisk_missing_arg)
4664                               << k,
4665                             getLocationOfByte(Amt.getStart()),
4666                             /*IsStringLocation*/true,
4667                             getSpecifierRange(startSpecifier, specifierLen));
4668        // Don't do any more checking.  We will just emit
4669        // spurious errors.
4670        return false;
4671      }
4672
4673      // Type check the data argument.  It should be an 'int'.
4674      // Although not in conformance with C99, we also allow the argument to be
4675      // an 'unsigned int' as that is a reasonably safe case.  GCC also
4676      // doesn't emit a warning for that case.
4677      CoveredArgs.set(argIndex);
4678      const Expr *Arg = getDataArg(argIndex);
4679      if (!Arg)
4680        return false;
4681
4682      QualType T = Arg->getType();
4683
4684      const analyze_printf::ArgType &AT = Amt.getArgType(S.Context);
4685      assert(AT.isValid());
4686
4687      if (!AT.matchesType(S.Context, T)) {
4688        EmitFormatDiagnostic(S.PDiag(diag::warn_printf_asterisk_wrong_type)
4689                               << k << AT.getRepresentativeTypeName(S.Context)
4690                               << T << Arg->getSourceRange(),
4691                             getLocationOfByte(Amt.getStart()),
4692                             /*IsStringLocation*/true,
4693                             getSpecifierRange(startSpecifier, specifierLen));
4694        // Don't do any more checking.  We will just emit
4695        // spurious errors.
4696        return false;
4697      }
4698    }
4699  }
4700  return true;
4701}
4702
4703void CheckPrintfHandler::HandleInvalidAmount(
4704                                      const analyze_printf::PrintfSpecifier &FS,
4705                                      const analyze_printf::OptionalAmount &Amt,
4706                                      unsigned type,
4707                                      const char *startSpecifier,
4708                                      unsigned specifierLen) {
4709  const analyze_printf::PrintfConversionSpecifier &CS =
4710    FS.getConversionSpecifier();
4711
4712  FixItHint fixit =
4713    Amt.getHowSpecified() == analyze_printf::OptionalAmount::Constant
4714      ? FixItHint::CreateRemoval(getSpecifierRange(Amt.getStart(),
4715                                 Amt.getConstantLength()))
4716      : FixItHint();
4717
4718  EmitFormatDiagnostic(S.PDiag(diag::warn_printf_nonsensical_optional_amount)
4719                         << type << CS.toString(),
4720                       getLocationOfByte(Amt.getStart()),
4721                       /*IsStringLocation*/true,
4722                       getSpecifierRange(startSpecifier, specifierLen),
4723                       fixit);
4724}
4725
4726void CheckPrintfHandler::HandleFlag(const analyze_printf::PrintfSpecifier &FS,
4727                                    const analyze_printf::OptionalFlag &flag,
4728                                    const char *startSpecifier,
4729                                    unsigned specifierLen) {
4730  // Warn about pointless flag with a fixit removal.
4731  const analyze_printf::PrintfConversionSpecifier &CS =
4732    FS.getConversionSpecifier();
4733  EmitFormatDiagnostic(S.PDiag(diag::warn_printf_nonsensical_flag)
4734                         << flag.toString() << CS.toString(),
4735                       getLocationOfByte(flag.getPosition()),
4736                       /*IsStringLocation*/true,
4737                       getSpecifierRange(startSpecifier, specifierLen),
4738                       FixItHint::CreateRemoval(
4739                         getSpecifierRange(flag.getPosition(), 1)));
4740}
4741
4742void CheckPrintfHandler::HandleIgnoredFlag(
4743                                const analyze_printf::PrintfSpecifier &FS,
4744                                const analyze_printf::OptionalFlag &ignoredFlag,
4745                                const analyze_printf::OptionalFlag &flag,
4746                                const char *startSpecifier,
4747                                unsigned specifierLen) {
4748  // Warn about ignored flag with a fixit removal.
4749  EmitFormatDiagnostic(S.PDiag(diag::warn_printf_ignored_flag)
4750                         << ignoredFlag.toString() << flag.toString(),
4751                       getLocationOfByte(ignoredFlag.getPosition()),
4752                       /*IsStringLocation*/true,
4753                       getSpecifierRange(startSpecifier, specifierLen),
4754                       FixItHint::CreateRemoval(
4755                         getSpecifierRange(ignoredFlag.getPosition(), 1)));
4756}
4757
4758//  void EmitFormatDiagnostic(PartialDiagnostic PDiag, SourceLocation StringLoc,
4759//                            bool IsStringLocation, Range StringRange,
4760//                            ArrayRef<FixItHint> Fixit = None);
4761
4762void CheckPrintfHandler::HandleEmptyObjCModifierFlag(const char *startFlag,
4763                                                     unsigned flagLen) {
4764  // Warn about an empty flag.
4765  EmitFormatDiagnostic(S.PDiag(diag::warn_printf_empty_objc_flag),
4766                       getLocationOfByte(startFlag),
4767                       /*IsStringLocation*/true,
4768                       getSpecifierRange(startFlag, flagLen));
4769}
4770
4771void CheckPrintfHandler::HandleInvalidObjCModifierFlag(const char *startFlag,
4772                                                       unsigned flagLen) {
4773  // Warn about an invalid flag.
4774  auto Range = getSpecifierRange(startFlag, flagLen);
4775  StringRef flag(startFlag, flagLen);
4776  EmitFormatDiagnostic(S.PDiag(diag::warn_printf_invalid_objc_flag) << flag,
4777                      getLocationOfByte(startFlag),
4778                      /*IsStringLocation*/true,
4779                      Range, FixItHint::CreateRemoval(Range));
4780}
4781
4782void CheckPrintfHandler::HandleObjCFlagsWithNonObjCConversion(
4783    const char *flagsStart, const char *flagsEnd, const char *conversionPosition) {
4784    // Warn about using '[...]' without a '@' conversion.
4785    auto Range = getSpecifierRange(flagsStart, flagsEnd - flagsStart + 1);
4786    auto diag = diag::warn_printf_ObjCflags_without_ObjCConversion;
4787    EmitFormatDiagnostic(S.PDiag(diag) << StringRef(conversionPosition, 1),
4788                         getLocationOfByte(conversionPosition),
4789                         /*IsStringLocation*/true,
4790                         Range, FixItHint::CreateRemoval(Range));
4791}
4792
4793// Determines if the specified is a C++ class or struct containing
4794// a member with the specified name and kind (e.g. a CXXMethodDecl named
4795// "c_str()").
4796template<typename MemberKind>
4797static llvm::SmallPtrSet<MemberKind*, 1>
4798CXXRecordMembersNamed(StringRef Name, Sema &S, QualType Ty) {
4799  const RecordType *RT = Ty->getAs<RecordType>();
4800  llvm::SmallPtrSet<MemberKind*, 1> Results;
4801
4802  if (!RT)
4803    return Results;
4804  const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl());
4805  if (!RD || !RD->getDefinition())
4806    return Results;
4807
4808  LookupResult R(S, &S.Context.Idents.get(Name), SourceLocation(),
4809                 Sema::LookupMemberName);
4810  R.suppressDiagnostics();
4811
4812  // We just need to include all members of the right kind turned up by the
4813  // filter, at this point.
4814  if (S.LookupQualifiedName(R, RT->getDecl()))
4815    for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
4816      NamedDecl *decl = (*I)->getUnderlyingDecl();
4817      if (MemberKind *FK = dyn_cast<MemberKind>(decl))
4818        Results.insert(FK);
4819    }
4820  return Results;
4821}
4822
4823/// Check if we could call '.c_str()' on an object.
4824///
4825/// FIXME: This returns the wrong results in some cases (if cv-qualifiers don't
4826/// allow the call, or if it would be ambiguous).
4827bool Sema::hasCStrMethod(const Expr *E) {
4828  typedef llvm::SmallPtrSet<CXXMethodDecl*, 1> MethodSet;
4829  MethodSet Results =
4830      CXXRecordMembersNamed<CXXMethodDecl>("c_str", *this, E->getType());
4831  for (MethodSet::iterator MI = Results.begin(), ME = Results.end();
4832       MI != ME; ++MI)
4833    if ((*MI)->getMinRequiredArguments() == 0)
4834      return true;
4835  return false;
4836}
4837
4838// Check if a (w)string was passed when a (w)char* was needed, and offer a
4839// better diagnostic if so. AT is assumed to be valid.
4840// Returns true when a c_str() conversion method is found.
4841bool CheckPrintfHandler::checkForCStrMembers(
4842    const analyze_printf::ArgType &AT, const Expr *E) {
4843  typedef llvm::SmallPtrSet<CXXMethodDecl*, 1> MethodSet;
4844
4845  MethodSet Results =
4846      CXXRecordMembersNamed<CXXMethodDecl>("c_str", S, E->getType());
4847
4848  for (MethodSet::iterator MI = Results.begin(), ME = Results.end();
4849       MI != ME; ++MI) {
4850    const CXXMethodDecl *Method = *MI;
4851    if (Method->getMinRequiredArguments() == 0 &&
4852        AT.matchesType(S.Context, Method->getReturnType())) {
4853      // FIXME: Suggest parens if the expression needs them.
4854      SourceLocation EndLoc = S.getLocForEndOfToken(E->getLocEnd());
4855      S.Diag(E->getLocStart(), diag::note_printf_c_str)
4856          << "c_str()"
4857          << FixItHint::CreateInsertion(EndLoc, ".c_str()");
4858      return true;
4859    }
4860  }
4861
4862  return false;
4863}
4864
4865bool
4866CheckPrintfHandler::HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier
4867                                            &FS,
4868                                          const char *startSpecifier,
4869                                          unsigned specifierLen) {
4870  using namespace analyze_format_string;
4871  using namespace analyze_printf;
4872  const PrintfConversionSpecifier &CS = FS.getConversionSpecifier();
4873
4874  if (FS.consumesDataArgument()) {
4875    if (atFirstArg) {
4876        atFirstArg = false;
4877        usesPositionalArgs = FS.usesPositionalArg();
4878    }
4879    else if (usesPositionalArgs != FS.usesPositionalArg()) {
4880      HandlePositionalNonpositionalArgs(getLocationOfByte(CS.getStart()),
4881                                        startSpecifier, specifierLen);
4882      return false;
4883    }
4884  }
4885
4886  // First check if the field width, precision, and conversion specifier
4887  // have matching data arguments.
4888  if (!HandleAmount(FS.getFieldWidth(), /* field width */ 0,
4889                    startSpecifier, specifierLen)) {
4890    return false;
4891  }
4892
4893  if (!HandleAmount(FS.getPrecision(), /* precision */ 1,
4894                    startSpecifier, specifierLen)) {
4895    return false;
4896  }
4897
4898  if (!CS.consumesDataArgument()) {
4899    // FIXME: Technically specifying a precision or field width here
4900    // makes no sense.  Worth issuing a warning at some point.
4901    return true;
4902  }
4903
4904  // Consume the argument.
4905  unsigned argIndex = FS.getArgIndex();
4906  if (argIndex < NumDataArgs) {
4907    // The check to see if the argIndex is valid will come later.
4908    // We set the bit here because we may exit early from this
4909    // function if we encounter some other error.
4910    CoveredArgs.set(argIndex);
4911  }
4912
4913  // FreeBSD kernel extensions.
4914  if (CS.getKind() == ConversionSpecifier::FreeBSDbArg ||
4915      CS.getKind() == ConversionSpecifier::FreeBSDDArg) {
4916    // We need at least two arguments.
4917    if (!CheckNumArgs(FS, CS, startSpecifier, specifierLen, argIndex + 1))
4918      return false;
4919
4920    // Claim the second argument.
4921    CoveredArgs.set(argIndex + 1);
4922
4923    // Type check the first argument (int for %b, pointer for %D)
4924    const Expr *Ex = getDataArg(argIndex);
4925    const analyze_printf::ArgType &AT =
4926      (CS.getKind() == ConversionSpecifier::FreeBSDbArg) ?
4927        ArgType(S.Context.IntTy) : ArgType::CPointerTy;
4928    if (AT.isValid() && !AT.matchesType(S.Context, Ex->getType()))
4929      EmitFormatDiagnostic(
4930        S.PDiag(diag::warn_format_conversion_argument_type_mismatch)
4931        << AT.getRepresentativeTypeName(S.Context) << Ex->getType()
4932        << false << Ex->getSourceRange(),
4933        Ex->getLocStart(), /*IsStringLocation*/false,
4934        getSpecifierRange(startSpecifier, specifierLen));
4935
4936    // Type check the second argument (char * for both %b and %D)
4937    Ex = getDataArg(argIndex + 1);
4938    const analyze_printf::ArgType &AT2 = ArgType::CStrTy;
4939    if (AT2.isValid() && !AT2.matchesType(S.Context, Ex->getType()))
4940      EmitFormatDiagnostic(
4941        S.PDiag(diag::warn_format_conversion_argument_type_mismatch)
4942        << AT2.getRepresentativeTypeName(S.Context) << Ex->getType()
4943        << false << Ex->getSourceRange(),
4944        Ex->getLocStart(), /*IsStringLocation*/false,
4945        getSpecifierRange(startSpecifier, specifierLen));
4946
4947     return true;
4948  }
4949
4950  // Check for using an Objective-C specific conversion specifier
4951  // in a non-ObjC literal.
4952  if (!ObjCContext && CS.isObjCArg()) {
4953    return HandleInvalidPrintfConversionSpecifier(FS, startSpecifier,
4954                                                  specifierLen);
4955  }
4956
4957  // Check for invalid use of field width
4958  if (!FS.hasValidFieldWidth()) {
4959    HandleInvalidAmount(FS, FS.getFieldWidth(), /* field width */ 0,
4960        startSpecifier, specifierLen);
4961  }
4962
4963  // Check for invalid use of precision
4964  if (!FS.hasValidPrecision()) {
4965    HandleInvalidAmount(FS, FS.getPrecision(), /* precision */ 1,
4966        startSpecifier, specifierLen);
4967  }
4968
4969  // Check each flag does not conflict with any other component.
4970  if (!FS.hasValidThousandsGroupingPrefix())
4971    HandleFlag(FS, FS.hasThousandsGrouping(), startSpecifier, specifierLen);
4972  if (!FS.hasValidLeadingZeros())
4973    HandleFlag(FS, FS.hasLeadingZeros(), startSpecifier, specifierLen);
4974  if (!FS.hasValidPlusPrefix())
4975    HandleFlag(FS, FS.hasPlusPrefix(), startSpecifier, specifierLen);
4976  if (!FS.hasValidSpacePrefix())
4977    HandleFlag(FS, FS.hasSpacePrefix(), startSpecifier, specifierLen);
4978  if (!FS.hasValidAlternativeForm())
4979    HandleFlag(FS, FS.hasAlternativeForm(), startSpecifier, specifierLen);
4980  if (!FS.hasValidLeftJustified())
4981    HandleFlag(FS, FS.isLeftJustified(), startSpecifier, specifierLen);
4982
4983  // Check that flags are not ignored by another flag
4984  if (FS.hasSpacePrefix() && FS.hasPlusPrefix()) // ' ' ignored by '+'
4985    HandleIgnoredFlag(FS, FS.hasSpacePrefix(), FS.hasPlusPrefix(),
4986        startSpecifier, specifierLen);
4987  if (FS.hasLeadingZeros() && FS.isLeftJustified()) // '0' ignored by '-'
4988    HandleIgnoredFlag(FS, FS.hasLeadingZeros(), FS.isLeftJustified(),
4989            startSpecifier, specifierLen);
4990
4991  // Check the length modifier is valid with the given conversion specifier.
4992  if (!FS.hasValidLengthModifier(S.getASTContext().getTargetInfo()))
4993    HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
4994                                diag::warn_format_nonsensical_length);
4995  else if (!FS.hasStandardLengthModifier())
4996    HandleNonStandardLengthModifier(FS, startSpecifier, specifierLen);
4997  else if (!FS.hasStandardLengthConversionCombination())
4998    HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
4999                                diag::warn_format_non_standard_conversion_spec);
5000
5001  if (!FS.hasStandardConversionSpecifier(S.getLangOpts()))
5002    HandleNonStandardConversionSpecifier(CS, startSpecifier, specifierLen);
5003
5004  // The remaining checks depend on the data arguments.
5005  if (HasVAListArg)
5006    return true;
5007
5008  if (!CheckNumArgs(FS, CS, startSpecifier, specifierLen, argIndex))
5009    return false;
5010
5011  const Expr *Arg = getDataArg(argIndex);
5012  if (!Arg)
5013    return true;
5014
5015  return checkFormatExpr(FS, startSpecifier, specifierLen, Arg);
5016}
5017
5018static bool requiresParensToAddCast(const Expr *E) {
5019  // FIXME: We should have a general way to reason about operator
5020  // precedence and whether parens are actually needed here.
5021  // Take care of a few common cases where they aren't.
5022  const Expr *Inside = E->IgnoreImpCasts();
5023  if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(Inside))
5024    Inside = POE->getSyntacticForm()->IgnoreImpCasts();
5025
5026  switch (Inside->getStmtClass()) {
5027  case Stmt::ArraySubscriptExprClass:
5028  case Stmt::CallExprClass:
5029  case Stmt::CharacterLiteralClass:
5030  case Stmt::CXXBoolLiteralExprClass:
5031  case Stmt::DeclRefExprClass:
5032  case Stmt::FloatingLiteralClass:
5033  case Stmt::IntegerLiteralClass:
5034  case Stmt::MemberExprClass:
5035  case Stmt::ObjCArrayLiteralClass:
5036  case Stmt::ObjCBoolLiteralExprClass:
5037  case Stmt::ObjCBoxedExprClass:
5038  case Stmt::ObjCDictionaryLiteralClass:
5039  case Stmt::ObjCEncodeExprClass:
5040  case Stmt::ObjCIvarRefExprClass:
5041  case Stmt::ObjCMessageExprClass:
5042  case Stmt::ObjCPropertyRefExprClass:
5043  case Stmt::ObjCStringLiteralClass:
5044  case Stmt::ObjCSubscriptRefExprClass:
5045  case Stmt::ParenExprClass:
5046  case Stmt::StringLiteralClass:
5047  case Stmt::UnaryOperatorClass:
5048    return false;
5049  default:
5050    return true;
5051  }
5052}
5053
5054static std::pair<QualType, StringRef>
5055shouldNotPrintDirectly(const ASTContext &Context,
5056                       QualType IntendedTy,
5057                       const Expr *E) {
5058  // Use a 'while' to peel off layers of typedefs.
5059  QualType TyTy = IntendedTy;
5060  while (const TypedefType *UserTy = TyTy->getAs<TypedefType>()) {
5061    StringRef Name = UserTy->getDecl()->getName();
5062    QualType CastTy = llvm::StringSwitch<QualType>(Name)
5063      .Case("NSInteger", Context.LongTy)
5064      .Case("NSUInteger", Context.UnsignedLongTy)
5065      .Case("SInt32", Context.IntTy)
5066      .Case("UInt32", Context.UnsignedIntTy)
5067      .Default(QualType());
5068
5069    if (!CastTy.isNull())
5070      return std::make_pair(CastTy, Name);
5071
5072    TyTy = UserTy->desugar();
5073  }
5074
5075  // Strip parens if necessary.
5076  if (const ParenExpr *PE = dyn_cast<ParenExpr>(E))
5077    return shouldNotPrintDirectly(Context,
5078                                  PE->getSubExpr()->getType(),
5079                                  PE->getSubExpr());
5080
5081  // If this is a conditional expression, then its result type is constructed
5082  // via usual arithmetic conversions and thus there might be no necessary
5083  // typedef sugar there.  Recurse to operands to check for NSInteger &
5084  // Co. usage condition.
5085  if (const ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
5086    QualType TrueTy, FalseTy;
5087    StringRef TrueName, FalseName;
5088
5089    std::tie(TrueTy, TrueName) =
5090      shouldNotPrintDirectly(Context,
5091                             CO->getTrueExpr()->getType(),
5092                             CO->getTrueExpr());
5093    std::tie(FalseTy, FalseName) =
5094      shouldNotPrintDirectly(Context,
5095                             CO->getFalseExpr()->getType(),
5096                             CO->getFalseExpr());
5097
5098    if (TrueTy == FalseTy)
5099      return std::make_pair(TrueTy, TrueName);
5100    else if (TrueTy.isNull())
5101      return std::make_pair(FalseTy, FalseName);
5102    else if (FalseTy.isNull())
5103      return std::make_pair(TrueTy, TrueName);
5104  }
5105
5106  return std::make_pair(QualType(), StringRef());
5107}
5108
5109bool
5110CheckPrintfHandler::checkFormatExpr(const analyze_printf::PrintfSpecifier &FS,
5111                                    const char *StartSpecifier,
5112                                    unsigned SpecifierLen,
5113                                    const Expr *E) {
5114  using namespace analyze_format_string;
5115  using namespace analyze_printf;
5116  // Now type check the data expression that matches the
5117  // format specifier.
5118  const analyze_printf::ArgType &AT = FS.getArgType(S.Context,
5119                                                    ObjCContext);
5120  if (!AT.isValid())
5121    return true;
5122
5123  QualType ExprTy = E->getType();
5124  while (const TypeOfExprType *TET = dyn_cast<TypeOfExprType>(ExprTy)) {
5125    ExprTy = TET->getUnderlyingExpr()->getType();
5126  }
5127
5128  analyze_printf::ArgType::MatchKind match = AT.matchesType(S.Context, ExprTy);
5129
5130  if (match == analyze_printf::ArgType::Match) {
5131    return true;
5132  }
5133
5134  // Look through argument promotions for our error message's reported type.
5135  // This includes the integral and floating promotions, but excludes array
5136  // and function pointer decay; seeing that an argument intended to be a
5137  // string has type 'char [6]' is probably more confusing than 'char *'.
5138  if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
5139    if (ICE->getCastKind() == CK_IntegralCast ||
5140        ICE->getCastKind() == CK_FloatingCast) {
5141      E = ICE->getSubExpr();
5142      ExprTy = E->getType();
5143
5144      // Check if we didn't match because of an implicit cast from a 'char'
5145      // or 'short' to an 'int'.  This is done because printf is a varargs
5146      // function.
5147      if (ICE->getType() == S.Context.IntTy ||
5148          ICE->getType() == S.Context.UnsignedIntTy) {
5149        // All further checking is done on the subexpression.
5150        if (AT.matchesType(S.Context, ExprTy))
5151          return true;
5152      }
5153    }
5154  } else if (const CharacterLiteral *CL = dyn_cast<CharacterLiteral>(E)) {
5155    // Special case for 'a', which has type 'int' in C.
5156    // Note, however, that we do /not/ want to treat multibyte constants like
5157    // 'MooV' as characters! This form is deprecated but still exists.
5158    if (ExprTy == S.Context.IntTy)
5159      if (llvm::isUIntN(S.Context.getCharWidth(), CL->getValue()))
5160        ExprTy = S.Context.CharTy;
5161  }
5162
5163  // Look through enums to their underlying type.
5164  bool IsEnum = false;
5165  if (auto EnumTy = ExprTy->getAs<EnumType>()) {
5166    ExprTy = EnumTy->getDecl()->getIntegerType();
5167    IsEnum = true;
5168  }
5169
5170  // %C in an Objective-C context prints a unichar, not a wchar_t.
5171  // If the argument is an integer of some kind, believe the %C and suggest
5172  // a cast instead of changing the conversion specifier.
5173  QualType IntendedTy = ExprTy;
5174  if (ObjCContext &&
5175      FS.getConversionSpecifier().getKind() == ConversionSpecifier::CArg) {
5176    if (ExprTy->isIntegralOrUnscopedEnumerationType() &&
5177        !ExprTy->isCharType()) {
5178      // 'unichar' is defined as a typedef of unsigned short, but we should
5179      // prefer using the typedef if it is visible.
5180      IntendedTy = S.Context.UnsignedShortTy;
5181
5182      // While we are here, check if the value is an IntegerLiteral that happens
5183      // to be within the valid range.
5184      if (const IntegerLiteral *IL = dyn_cast<IntegerLiteral>(E)) {
5185        const llvm::APInt &V = IL->getValue();
5186        if (V.getActiveBits() <= S.Context.getTypeSize(IntendedTy))
5187          return true;
5188      }
5189
5190      LookupResult Result(S, &S.Context.Idents.get("unichar"), E->getLocStart(),
5191                          Sema::LookupOrdinaryName);
5192      if (S.LookupName(Result, S.getCurScope())) {
5193        NamedDecl *ND = Result.getFoundDecl();
5194        if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(ND))
5195          if (TD->getUnderlyingType() == IntendedTy)
5196            IntendedTy = S.Context.getTypedefType(TD);
5197      }
5198    }
5199  }
5200
5201  // Special-case some of Darwin's platform-independence types by suggesting
5202  // casts to primitive types that are known to be large enough.
5203  bool ShouldNotPrintDirectly = false; StringRef CastTyName;
5204  if (S.Context.getTargetInfo().getTriple().isOSDarwin()) {
5205    QualType CastTy;
5206    std::tie(CastTy, CastTyName) = shouldNotPrintDirectly(S.Context, IntendedTy, E);
5207    if (!CastTy.isNull()) {
5208      IntendedTy = CastTy;
5209      ShouldNotPrintDirectly = true;
5210    }
5211  }
5212
5213  // We may be able to offer a FixItHint if it is a supported type.
5214  PrintfSpecifier fixedFS = FS;
5215  bool success = fixedFS.fixType(IntendedTy, S.getLangOpts(),
5216                                 S.Context, ObjCContext);
5217
5218  if (success) {
5219    // Get the fix string from the fixed format specifier
5220    SmallString<16> buf;
5221    llvm::raw_svector_ostream os(buf);
5222    fixedFS.toString(os);
5223
5224    CharSourceRange SpecRange = getSpecifierRange(StartSpecifier, SpecifierLen);
5225
5226    if (IntendedTy == ExprTy && !ShouldNotPrintDirectly) {
5227      unsigned diag = diag::warn_format_conversion_argument_type_mismatch;
5228      if (match == analyze_format_string::ArgType::NoMatchPedantic) {
5229        diag = diag::warn_format_conversion_argument_type_mismatch_pedantic;
5230      }
5231      // In this case, the specifier is wrong and should be changed to match
5232      // the argument.
5233      EmitFormatDiagnostic(S.PDiag(diag)
5234                               << AT.getRepresentativeTypeName(S.Context)
5235                               << IntendedTy << IsEnum << E->getSourceRange(),
5236                           E->getLocStart(),
5237                           /*IsStringLocation*/ false, SpecRange,
5238                           FixItHint::CreateReplacement(SpecRange, os.str()));
5239    } else {
5240      // The canonical type for formatting this value is different from the
5241      // actual type of the expression. (This occurs, for example, with Darwin's
5242      // NSInteger on 32-bit platforms, where it is typedef'd as 'int', but
5243      // should be printed as 'long' for 64-bit compatibility.)
5244      // Rather than emitting a normal format/argument mismatch, we want to
5245      // add a cast to the recommended type (and correct the format string
5246      // if necessary).
5247      SmallString<16> CastBuf;
5248      llvm::raw_svector_ostream CastFix(CastBuf);
5249      CastFix << "(";
5250      IntendedTy.print(CastFix, S.Context.getPrintingPolicy());
5251      CastFix << ")";
5252
5253      SmallVector<FixItHint,4> Hints;
5254      if (!AT.matchesType(S.Context, IntendedTy))
5255        Hints.push_back(FixItHint::CreateReplacement(SpecRange, os.str()));
5256
5257      if (const CStyleCastExpr *CCast = dyn_cast<CStyleCastExpr>(E)) {
5258        // If there's already a cast present, just replace it.
5259        SourceRange CastRange(CCast->getLParenLoc(), CCast->getRParenLoc());
5260        Hints.push_back(FixItHint::CreateReplacement(CastRange, CastFix.str()));
5261
5262      } else if (!requiresParensToAddCast(E)) {
5263        // If the expression has high enough precedence,
5264        // just write the C-style cast.
5265        Hints.push_back(FixItHint::CreateInsertion(E->getLocStart(),
5266                                                   CastFix.str()));
5267      } else {
5268        // Otherwise, add parens around the expression as well as the cast.
5269        CastFix << "(";
5270        Hints.push_back(FixItHint::CreateInsertion(E->getLocStart(),
5271                                                   CastFix.str()));
5272
5273        SourceLocation After = S.getLocForEndOfToken(E->getLocEnd());
5274        Hints.push_back(FixItHint::CreateInsertion(After, ")"));
5275      }
5276
5277      if (ShouldNotPrintDirectly) {
5278        // The expression has a type that should not be printed directly.
5279        // We extract the name from the typedef because we don't want to show
5280        // the underlying type in the diagnostic.
5281        StringRef Name;
5282        if (const TypedefType *TypedefTy = dyn_cast<TypedefType>(ExprTy))
5283          Name = TypedefTy->getDecl()->getName();
5284        else
5285          Name = CastTyName;
5286        EmitFormatDiagnostic(S.PDiag(diag::warn_format_argument_needs_cast)
5287                               << Name << IntendedTy << IsEnum
5288                               << E->getSourceRange(),
5289                             E->getLocStart(), /*IsStringLocation=*/false,
5290                             SpecRange, Hints);
5291      } else {
5292        // In this case, the expression could be printed using a different
5293        // specifier, but we've decided that the specifier is probably correct
5294        // and we should cast instead. Just use the normal warning message.
5295        EmitFormatDiagnostic(
5296          S.PDiag(diag::warn_format_conversion_argument_type_mismatch)
5297            << AT.getRepresentativeTypeName(S.Context) << ExprTy << IsEnum
5298            << E->getSourceRange(),
5299          E->getLocStart(), /*IsStringLocation*/false,
5300          SpecRange, Hints);
5301      }
5302    }
5303  } else {
5304    const CharSourceRange &CSR = getSpecifierRange(StartSpecifier,
5305                                                   SpecifierLen);
5306    // Since the warning for passing non-POD types to variadic functions
5307    // was deferred until now, we emit a warning for non-POD
5308    // arguments here.
5309    switch (S.isValidVarArgType(ExprTy)) {
5310    case Sema::VAK_Valid:
5311    case Sema::VAK_ValidInCXX11: {
5312      unsigned diag = diag::warn_format_conversion_argument_type_mismatch;
5313      if (match == analyze_printf::ArgType::NoMatchPedantic) {
5314        diag = diag::warn_format_conversion_argument_type_mismatch_pedantic;
5315      }
5316
5317      EmitFormatDiagnostic(
5318          S.PDiag(diag) << AT.getRepresentativeTypeName(S.Context) << ExprTy
5319                        << IsEnum << CSR << E->getSourceRange(),
5320          E->getLocStart(), /*IsStringLocation*/ false, CSR);
5321      break;
5322    }
5323    case Sema::VAK_Undefined:
5324    case Sema::VAK_MSVCUndefined:
5325      EmitFormatDiagnostic(
5326        S.PDiag(diag::warn_non_pod_vararg_with_format_string)
5327          << S.getLangOpts().CPlusPlus11
5328          << ExprTy
5329          << CallType
5330          << AT.getRepresentativeTypeName(S.Context)
5331          << CSR
5332          << E->getSourceRange(),
5333        E->getLocStart(), /*IsStringLocation*/false, CSR);
5334      checkForCStrMembers(AT, E);
5335      break;
5336
5337    case Sema::VAK_Invalid:
5338      if (ExprTy->isObjCObjectType())
5339        EmitFormatDiagnostic(
5340          S.PDiag(diag::err_cannot_pass_objc_interface_to_vararg_format)
5341            << S.getLangOpts().CPlusPlus11
5342            << ExprTy
5343            << CallType
5344            << AT.getRepresentativeTypeName(S.Context)
5345            << CSR
5346            << E->getSourceRange(),
5347          E->getLocStart(), /*IsStringLocation*/false, CSR);
5348      else
5349        // FIXME: If this is an initializer list, suggest removing the braces
5350        // or inserting a cast to the target type.
5351        S.Diag(E->getLocStart(), diag::err_cannot_pass_to_vararg_format)
5352          << isa<InitListExpr>(E) << ExprTy << CallType
5353          << AT.getRepresentativeTypeName(S.Context)
5354          << E->getSourceRange();
5355      break;
5356    }
5357
5358    assert(FirstDataArg + FS.getArgIndex() < CheckedVarArgs.size() &&
5359           "format string specifier index out of range");
5360    CheckedVarArgs[FirstDataArg + FS.getArgIndex()] = true;
5361  }
5362
5363  return true;
5364}
5365
5366//===--- CHECK: Scanf format string checking ------------------------------===//
5367
5368namespace {
5369class CheckScanfHandler : public CheckFormatHandler {
5370public:
5371  CheckScanfHandler(Sema &s, const StringLiteral *fexpr,
5372                    const Expr *origFormatExpr, unsigned firstDataArg,
5373                    unsigned numDataArgs, const char *beg, bool hasVAListArg,
5374                    ArrayRef<const Expr *> Args,
5375                    unsigned formatIdx, bool inFunctionCall,
5376                    Sema::VariadicCallType CallType,
5377                    llvm::SmallBitVector &CheckedVarArgs,
5378                    UncoveredArgHandler &UncoveredArg)
5379    : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg,
5380                         numDataArgs, beg, hasVAListArg,
5381                         Args, formatIdx, inFunctionCall, CallType,
5382                         CheckedVarArgs, UncoveredArg)
5383  {}
5384
5385  bool HandleScanfSpecifier(const analyze_scanf::ScanfSpecifier &FS,
5386                            const char *startSpecifier,
5387                            unsigned specifierLen) override;
5388
5389  bool HandleInvalidScanfConversionSpecifier(
5390          const analyze_scanf::ScanfSpecifier &FS,
5391          const char *startSpecifier,
5392          unsigned specifierLen) override;
5393
5394  void HandleIncompleteScanList(const char *start, const char *end) override;
5395};
5396} // end anonymous namespace
5397
5398void CheckScanfHandler::HandleIncompleteScanList(const char *start,
5399                                                 const char *end) {
5400  EmitFormatDiagnostic(S.PDiag(diag::warn_scanf_scanlist_incomplete),
5401                       getLocationOfByte(end), /*IsStringLocation*/true,
5402                       getSpecifierRange(start, end - start));
5403}
5404
5405bool CheckScanfHandler::HandleInvalidScanfConversionSpecifier(
5406                                        const analyze_scanf::ScanfSpecifier &FS,
5407                                        const char *startSpecifier,
5408                                        unsigned specifierLen) {
5409
5410  const analyze_scanf::ScanfConversionSpecifier &CS =
5411    FS.getConversionSpecifier();
5412
5413  return HandleInvalidConversionSpecifier(FS.getArgIndex(),
5414                                          getLocationOfByte(CS.getStart()),
5415                                          startSpecifier, specifierLen,
5416                                          CS.getStart(), CS.getLength());
5417}
5418
5419bool CheckScanfHandler::HandleScanfSpecifier(
5420                                       const analyze_scanf::ScanfSpecifier &FS,
5421                                       const char *startSpecifier,
5422                                       unsigned specifierLen) {
5423  using namespace analyze_scanf;
5424  using namespace analyze_format_string;
5425
5426  const ScanfConversionSpecifier &CS = FS.getConversionSpecifier();
5427
5428  // Handle case where '%' and '*' don't consume an argument.  These shouldn't
5429  // be used to decide if we are using positional arguments consistently.
5430  if (FS.consumesDataArgument()) {
5431    if (atFirstArg) {
5432      atFirstArg = false;
5433      usesPositionalArgs = FS.usesPositionalArg();
5434    }
5435    else if (usesPositionalArgs != FS.usesPositionalArg()) {
5436      HandlePositionalNonpositionalArgs(getLocationOfByte(CS.getStart()),
5437                                        startSpecifier, specifierLen);
5438      return false;
5439    }
5440  }
5441
5442  // Check if the field with is non-zero.
5443  const OptionalAmount &Amt = FS.getFieldWidth();
5444  if (Amt.getHowSpecified() == OptionalAmount::Constant) {
5445    if (Amt.getConstantAmount() == 0) {
5446      const CharSourceRange &R = getSpecifierRange(Amt.getStart(),
5447                                                   Amt.getConstantLength());
5448      EmitFormatDiagnostic(S.PDiag(diag::warn_scanf_nonzero_width),
5449                           getLocationOfByte(Amt.getStart()),
5450                           /*IsStringLocation*/true, R,
5451                           FixItHint::CreateRemoval(R));
5452    }
5453  }
5454
5455  if (!FS.consumesDataArgument()) {
5456    // FIXME: Technically specifying a precision or field width here
5457    // makes no sense.  Worth issuing a warning at some point.
5458    return true;
5459  }
5460
5461  // Consume the argument.
5462  unsigned argIndex = FS.getArgIndex();
5463  if (argIndex < NumDataArgs) {
5464      // The check to see if the argIndex is valid will come later.
5465      // We set the bit here because we may exit early from this
5466      // function if we encounter some other error.
5467    CoveredArgs.set(argIndex);
5468  }
5469
5470  // Check the length modifier is valid with the given conversion specifier.
5471  if (!FS.hasValidLengthModifier(S.getASTContext().getTargetInfo()))
5472    HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
5473                                diag::warn_format_nonsensical_length);
5474  else if (!FS.hasStandardLengthModifier())
5475    HandleNonStandardLengthModifier(FS, startSpecifier, specifierLen);
5476  else if (!FS.hasStandardLengthConversionCombination())
5477    HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
5478                                diag::warn_format_non_standard_conversion_spec);
5479
5480  if (!FS.hasStandardConversionSpecifier(S.getLangOpts()))
5481    HandleNonStandardConversionSpecifier(CS, startSpecifier, specifierLen);
5482
5483  // The remaining checks depend on the data arguments.
5484  if (HasVAListArg)
5485    return true;
5486
5487  if (!CheckNumArgs(FS, CS, startSpecifier, specifierLen, argIndex))
5488    return false;
5489
5490  // Check that the argument type matches the format specifier.
5491  const Expr *Ex = getDataArg(argIndex);
5492  if (!Ex)
5493    return true;
5494
5495  const analyze_format_string::ArgType &AT = FS.getArgType(S.Context);
5496
5497  if (!AT.isValid()) {
5498    return true;
5499  }
5500
5501  analyze_format_string::ArgType::MatchKind match =
5502      AT.matchesType(S.Context, Ex->getType());
5503  if (match == analyze_format_string::ArgType::Match) {
5504    return true;
5505  }
5506
5507  ScanfSpecifier fixedFS = FS;
5508  bool success = fixedFS.fixType(Ex->getType(), Ex->IgnoreImpCasts()->getType(),
5509                                 S.getLangOpts(), S.Context);
5510
5511  unsigned diag = diag::warn_format_conversion_argument_type_mismatch;
5512  if (match == analyze_format_string::ArgType::NoMatchPedantic) {
5513    diag = diag::warn_format_conversion_argument_type_mismatch_pedantic;
5514  }
5515
5516  if (success) {
5517    // Get the fix string from the fixed format specifier.
5518    SmallString<128> buf;
5519    llvm::raw_svector_ostream os(buf);
5520    fixedFS.toString(os);
5521
5522    EmitFormatDiagnostic(
5523        S.PDiag(diag) << AT.getRepresentativeTypeName(S.Context)
5524                      << Ex->getType() << false << Ex->getSourceRange(),
5525        Ex->getLocStart(),
5526        /*IsStringLocation*/ false,
5527        getSpecifierRange(startSpecifier, specifierLen),
5528        FixItHint::CreateReplacement(
5529            getSpecifierRange(startSpecifier, specifierLen), os.str()));
5530  } else {
5531    EmitFormatDiagnostic(S.PDiag(diag)
5532                             << AT.getRepresentativeTypeName(S.Context)
5533                             << Ex->getType() << false << Ex->getSourceRange(),
5534                         Ex->getLocStart(),
5535                         /*IsStringLocation*/ false,
5536                         getSpecifierRange(startSpecifier, specifierLen));
5537  }
5538
5539  return true;
5540}
5541
5542static void CheckFormatString(Sema &S, const StringLiteral *FExpr,
5543                              const Expr *OrigFormatExpr,
5544                              ArrayRef<const Expr *> Args,
5545                              bool HasVAListArg, unsigned format_idx,
5546                              unsigned firstDataArg,
5547                              Sema::FormatStringType Type,
5548                              bool inFunctionCall,
5549                              Sema::VariadicCallType CallType,
5550                              llvm::SmallBitVector &CheckedVarArgs,
5551                              UncoveredArgHandler &UncoveredArg) {
5552  // CHECK: is the format string a wide literal?
5553  if (!FExpr->isAscii() && !FExpr->isUTF8()) {
5554    CheckFormatHandler::EmitFormatDiagnostic(
5555      S, inFunctionCall, Args[format_idx],
5556      S.PDiag(diag::warn_format_string_is_wide_literal), FExpr->getLocStart(),
5557      /*IsStringLocation*/true, OrigFormatExpr->getSourceRange());
5558    return;
5559  }
5560
5561  // Str - The format string.  NOTE: this is NOT null-terminated!
5562  StringRef StrRef = FExpr->getString();
5563  const char *Str = StrRef.data();
5564  // Account for cases where the string literal is truncated in a declaration.
5565  const ConstantArrayType *T =
5566    S.Context.getAsConstantArrayType(FExpr->getType());
5567  assert(T && "String literal not of constant array type!");
5568  size_t TypeSize = T->getSize().getZExtValue();
5569  size_t StrLen = std::min(std::max(TypeSize, size_t(1)) - 1, StrRef.size());
5570  const unsigned numDataArgs = Args.size() - firstDataArg;
5571
5572  // Emit a warning if the string literal is truncated and does not contain an
5573  // embedded null character.
5574  if (TypeSize <= StrRef.size() &&
5575      StrRef.substr(0, TypeSize).find('\0') == StringRef::npos) {
5576    CheckFormatHandler::EmitFormatDiagnostic(
5577        S, inFunctionCall, Args[format_idx],
5578        S.PDiag(diag::warn_printf_format_string_not_null_terminated),
5579        FExpr->getLocStart(),
5580        /*IsStringLocation=*/true, OrigFormatExpr->getSourceRange());
5581    return;
5582  }
5583
5584  // CHECK: empty format string?
5585  if (StrLen == 0 && numDataArgs > 0) {
5586    CheckFormatHandler::EmitFormatDiagnostic(
5587      S, inFunctionCall, Args[format_idx],
5588      S.PDiag(diag::warn_empty_format_string), FExpr->getLocStart(),
5589      /*IsStringLocation*/true, OrigFormatExpr->getSourceRange());
5590    return;
5591  }
5592
5593  if (Type == Sema::FST_Printf || Type == Sema::FST_NSString ||
5594      Type == Sema::FST_FreeBSDKPrintf || Type == Sema::FST_OSTrace) {
5595    CheckPrintfHandler H(S, FExpr, OrigFormatExpr, firstDataArg,
5596                         numDataArgs, (Type == Sema::FST_NSString ||
5597                                       Type == Sema::FST_OSTrace),
5598                         Str, HasVAListArg, Args, format_idx,
5599                         inFunctionCall, CallType, CheckedVarArgs,
5600                         UncoveredArg);
5601
5602    if (!analyze_format_string::ParsePrintfString(H, Str, Str + StrLen,
5603                                                  S.getLangOpts(),
5604                                                  S.Context.getTargetInfo(),
5605                                            Type == Sema::FST_FreeBSDKPrintf))
5606      H.DoneProcessing();
5607  } else if (Type == Sema::FST_Scanf) {
5608    CheckScanfHandler H(S, FExpr, OrigFormatExpr, firstDataArg, numDataArgs,
5609                        Str, HasVAListArg, Args, format_idx,
5610                        inFunctionCall, CallType, CheckedVarArgs,
5611                        UncoveredArg);
5612
5613    if (!analyze_format_string::ParseScanfString(H, Str, Str + StrLen,
5614                                                 S.getLangOpts(),
5615                                                 S.Context.getTargetInfo()))
5616      H.DoneProcessing();
5617  } // TODO: handle other formats
5618}
5619
5620bool Sema::FormatStringHasSArg(const StringLiteral *FExpr) {
5621  // Str - The format string.  NOTE: this is NOT null-terminated!
5622  StringRef StrRef = FExpr->getString();
5623  const char *Str = StrRef.data();
5624  // Account for cases where the string literal is truncated in a declaration.
5625  const ConstantArrayType *T = Context.getAsConstantArrayType(FExpr->getType());
5626  assert(T && "String literal not of constant array type!");
5627  size_t TypeSize = T->getSize().getZExtValue();
5628  size_t StrLen = std::min(std::max(TypeSize, size_t(1)) - 1, StrRef.size());
5629  return analyze_format_string::ParseFormatStringHasSArg(Str, Str + StrLen,
5630                                                         getLangOpts(),
5631                                                         Context.getTargetInfo());
5632}
5633
5634//===--- CHECK: Warn on use of wrong absolute value function. -------------===//
5635
5636// Returns the related absolute value function that is larger, of 0 if one
5637// does not exist.
5638static unsigned getLargerAbsoluteValueFunction(unsigned AbsFunction) {
5639  switch (AbsFunction) {
5640  default:
5641    return 0;
5642
5643  case Builtin::BI__builtin_abs:
5644    return Builtin::BI__builtin_labs;
5645  case Builtin::BI__builtin_labs:
5646    return Builtin::BI__builtin_llabs;
5647  case Builtin::BI__builtin_llabs:
5648    return 0;
5649
5650  case Builtin::BI__builtin_fabsf:
5651    return Builtin::BI__builtin_fabs;
5652  case Builtin::BI__builtin_fabs:
5653    return Builtin::BI__builtin_fabsl;
5654  case Builtin::BI__builtin_fabsl:
5655    return 0;
5656
5657  case Builtin::BI__builtin_cabsf:
5658    return Builtin::BI__builtin_cabs;
5659  case Builtin::BI__builtin_cabs:
5660    return Builtin::BI__builtin_cabsl;
5661  case Builtin::BI__builtin_cabsl:
5662    return 0;
5663
5664  case Builtin::BIabs:
5665    return Builtin::BIlabs;
5666  case Builtin::BIlabs:
5667    return Builtin::BIllabs;
5668  case Builtin::BIllabs:
5669    return 0;
5670
5671  case Builtin::BIfabsf:
5672    return Builtin::BIfabs;
5673  case Builtin::BIfabs:
5674    return Builtin::BIfabsl;
5675  case Builtin::BIfabsl:
5676    return 0;
5677
5678  case Builtin::BIcabsf:
5679   return Builtin::BIcabs;
5680  case Builtin::BIcabs:
5681    return Builtin::BIcabsl;
5682  case Builtin::BIcabsl:
5683    return 0;
5684  }
5685}
5686
5687// Returns the argument type of the absolute value function.
5688static QualType getAbsoluteValueArgumentType(ASTContext &Context,
5689                                             unsigned AbsType) {
5690  if (AbsType == 0)
5691    return QualType();
5692
5693  ASTContext::GetBuiltinTypeError Error = ASTContext::GE_None;
5694  QualType BuiltinType = Context.GetBuiltinType(AbsType, Error);
5695  if (Error != ASTContext::GE_None)
5696    return QualType();
5697
5698  const FunctionProtoType *FT = BuiltinType->getAs<FunctionProtoType>();
5699  if (!FT)
5700    return QualType();
5701
5702  if (FT->getNumParams() != 1)
5703    return QualType();
5704
5705  return FT->getParamType(0);
5706}
5707
5708// Returns the best absolute value function, or zero, based on type and
5709// current absolute value function.
5710static unsigned getBestAbsFunction(ASTContext &Context, QualType ArgType,
5711                                   unsigned AbsFunctionKind) {
5712  unsigned BestKind = 0;
5713  uint64_t ArgSize = Context.getTypeSize(ArgType);
5714  for (unsigned Kind = AbsFunctionKind; Kind != 0;
5715       Kind = getLargerAbsoluteValueFunction(Kind)) {
5716    QualType ParamType = getAbsoluteValueArgumentType(Context, Kind);
5717    if (Context.getTypeSize(ParamType) >= ArgSize) {
5718      if (BestKind == 0)
5719        BestKind = Kind;
5720      else if (Context.hasSameType(ParamType, ArgType)) {
5721        BestKind = Kind;
5722        break;
5723      }
5724    }
5725  }
5726  return BestKind;
5727}
5728
5729enum AbsoluteValueKind {
5730  AVK_Integer,
5731  AVK_Floating,
5732  AVK_Complex
5733};
5734
5735static AbsoluteValueKind getAbsoluteValueKind(QualType T) {
5736  if (T->isIntegralOrEnumerationType())
5737    return AVK_Integer;
5738  if (T->isRealFloatingType())
5739    return AVK_Floating;
5740  if (T->isAnyComplexType())
5741    return AVK_Complex;
5742
5743  llvm_unreachable("Type not integer, floating, or complex");
5744}
5745
5746// Changes the absolute value function to a different type.  Preserves whether
5747// the function is a builtin.
5748static unsigned changeAbsFunction(unsigned AbsKind,
5749                                  AbsoluteValueKind ValueKind) {
5750  switch (ValueKind) {
5751  case AVK_Integer:
5752    switch (AbsKind) {
5753    default:
5754      return 0;
5755    case Builtin::BI__builtin_fabsf:
5756    case Builtin::BI__builtin_fabs:
5757    case Builtin::BI__builtin_fabsl:
5758    case Builtin::BI__builtin_cabsf:
5759    case Builtin::BI__builtin_cabs:
5760    case Builtin::BI__builtin_cabsl:
5761      return Builtin::BI__builtin_abs;
5762    case Builtin::BIfabsf:
5763    case Builtin::BIfabs:
5764    case Builtin::BIfabsl:
5765    case Builtin::BIcabsf:
5766    case Builtin::BIcabs:
5767    case Builtin::BIcabsl:
5768      return Builtin::BIabs;
5769    }
5770  case AVK_Floating:
5771    switch (AbsKind) {
5772    default:
5773      return 0;
5774    case Builtin::BI__builtin_abs:
5775    case Builtin::BI__builtin_labs:
5776    case Builtin::BI__builtin_llabs:
5777    case Builtin::BI__builtin_cabsf:
5778    case Builtin::BI__builtin_cabs:
5779    case Builtin::BI__builtin_cabsl:
5780      return Builtin::BI__builtin_fabsf;
5781    case Builtin::BIabs:
5782    case Builtin::BIlabs:
5783    case Builtin::BIllabs:
5784    case Builtin::BIcabsf:
5785    case Builtin::BIcabs:
5786    case Builtin::BIcabsl:
5787      return Builtin::BIfabsf;
5788    }
5789  case AVK_Complex:
5790    switch (AbsKind) {
5791    default:
5792      return 0;
5793    case Builtin::BI__builtin_abs:
5794    case Builtin::BI__builtin_labs:
5795    case Builtin::BI__builtin_llabs:
5796    case Builtin::BI__builtin_fabsf:
5797    case Builtin::BI__builtin_fabs:
5798    case Builtin::BI__builtin_fabsl:
5799      return Builtin::BI__builtin_cabsf;
5800    case Builtin::BIabs:
5801    case Builtin::BIlabs:
5802    case Builtin::BIllabs:
5803    case Builtin::BIfabsf:
5804    case Builtin::BIfabs:
5805    case Builtin::BIfabsl:
5806      return Builtin::BIcabsf;
5807    }
5808  }
5809  llvm_unreachable("Unable to convert function");
5810}
5811
5812static unsigned getAbsoluteValueFunctionKind(const FunctionDecl *FDecl) {
5813  const IdentifierInfo *FnInfo = FDecl->getIdentifier();
5814  if (!FnInfo)
5815    return 0;
5816
5817  switch (FDecl->getBuiltinID()) {
5818  default:
5819    return 0;
5820  case Builtin::BI__builtin_abs:
5821  case Builtin::BI__builtin_fabs:
5822  case Builtin::BI__builtin_fabsf:
5823  case Builtin::BI__builtin_fabsl:
5824  case Builtin::BI__builtin_labs:
5825  case Builtin::BI__builtin_llabs:
5826  case Builtin::BI__builtin_cabs:
5827  case Builtin::BI__builtin_cabsf:
5828  case Builtin::BI__builtin_cabsl:
5829  case Builtin::BIabs:
5830  case Builtin::BIlabs:
5831  case Builtin::BIllabs:
5832  case Builtin::BIfabs:
5833  case Builtin::BIfabsf:
5834  case Builtin::BIfabsl:
5835  case Builtin::BIcabs:
5836  case Builtin::BIcabsf:
5837  case Builtin::BIcabsl:
5838    return FDecl->getBuiltinID();
5839  }
5840  llvm_unreachable("Unknown Builtin type");
5841}
5842
5843// If the replacement is valid, emit a note with replacement function.
5844// Additionally, suggest including the proper header if not already included.
5845static void emitReplacement(Sema &S, SourceLocation Loc, SourceRange Range,
5846                            unsigned AbsKind, QualType ArgType) {
5847  bool EmitHeaderHint = true;
5848  const char *HeaderName = nullptr;
5849  const char *FunctionName = nullptr;
5850  if (S.getLangOpts().CPlusPlus && !ArgType->isAnyComplexType()) {
5851    FunctionName = "std::abs";
5852    if (ArgType->isIntegralOrEnumerationType()) {
5853      HeaderName = "cstdlib";
5854    } else if (ArgType->isRealFloatingType()) {
5855      HeaderName = "cmath";
5856    } else {
5857      llvm_unreachable("Invalid Type");
5858    }
5859
5860    // Lookup all std::abs
5861    if (NamespaceDecl *Std = S.getStdNamespace()) {
5862      LookupResult R(S, &S.Context.Idents.get("abs"), Loc, Sema::LookupAnyName);
5863      R.suppressDiagnostics();
5864      S.LookupQualifiedName(R, Std);
5865
5866      for (const auto *I : R) {
5867        const FunctionDecl *FDecl = nullptr;
5868        if (const UsingShadowDecl *UsingD = dyn_cast<UsingShadowDecl>(I)) {
5869          FDecl = dyn_cast<FunctionDecl>(UsingD->getTargetDecl());
5870        } else {
5871          FDecl = dyn_cast<FunctionDecl>(I);
5872        }
5873        if (!FDecl)
5874          continue;
5875
5876        // Found std::abs(), check that they are the right ones.
5877        if (FDecl->getNumParams() != 1)
5878          continue;
5879
5880        // Check that the parameter type can handle the argument.
5881        QualType ParamType = FDecl->getParamDecl(0)->getType();
5882        if (getAbsoluteValueKind(ArgType) == getAbsoluteValueKind(ParamType) &&
5883            S.Context.getTypeSize(ArgType) <=
5884                S.Context.getTypeSize(ParamType)) {
5885          // Found a function, don't need the header hint.
5886          EmitHeaderHint = false;
5887          break;
5888        }
5889      }
5890    }
5891  } else {
5892    FunctionName = S.Context.BuiltinInfo.getName(AbsKind);
5893    HeaderName = S.Context.BuiltinInfo.getHeaderName(AbsKind);
5894
5895    if (HeaderName) {
5896      DeclarationName DN(&S.Context.Idents.get(FunctionName));
5897      LookupResult R(S, DN, Loc, Sema::LookupAnyName);
5898      R.suppressDiagnostics();
5899      S.LookupName(R, S.getCurScope());
5900
5901      if (R.isSingleResult()) {
5902        FunctionDecl *FD = dyn_cast<FunctionDecl>(R.getFoundDecl());
5903        if (FD && FD->getBuiltinID() == AbsKind) {
5904          EmitHeaderHint = false;
5905        } else {
5906          return;
5907        }
5908      } else if (!R.empty()) {
5909        return;
5910      }
5911    }
5912  }
5913
5914  S.Diag(Loc, diag::note_replace_abs_function)
5915      << FunctionName << FixItHint::CreateReplacement(Range, FunctionName);
5916
5917  if (!HeaderName)
5918    return;
5919
5920  if (!EmitHeaderHint)
5921    return;
5922
5923  S.Diag(Loc, diag::note_include_header_or_declare) << HeaderName
5924                                                    << FunctionName;
5925}
5926
5927static bool IsFunctionStdAbs(const FunctionDecl *FDecl) {
5928  if (!FDecl)
5929    return false;
5930
5931  if (!FDecl->getIdentifier() || !FDecl->getIdentifier()->isStr("abs"))
5932    return false;
5933
5934  const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(FDecl->getDeclContext());
5935
5936  while (ND && ND->isInlineNamespace()) {
5937    ND = dyn_cast<NamespaceDecl>(ND->getDeclContext());
5938  }
5939
5940  if (!ND || !ND->getIdentifier() || !ND->getIdentifier()->isStr("std"))
5941    return false;
5942
5943  if (!isa<TranslationUnitDecl>(ND->getDeclContext()))
5944    return false;
5945
5946  return true;
5947}
5948
5949// Warn when using the wrong abs() function.
5950void Sema::CheckAbsoluteValueFunction(const CallExpr *Call,
5951                                      const FunctionDecl *FDecl,
5952                                      IdentifierInfo *FnInfo) {
5953  if (Call->getNumArgs() != 1)
5954    return;
5955
5956  unsigned AbsKind = getAbsoluteValueFunctionKind(FDecl);
5957  bool IsStdAbs = IsFunctionStdAbs(FDecl);
5958  if (AbsKind == 0 && !IsStdAbs)
5959    return;
5960
5961  QualType ArgType = Call->getArg(0)->IgnoreParenImpCasts()->getType();
5962  QualType ParamType = Call->getArg(0)->getType();
5963
5964  // Unsigned types cannot be negative.  Suggest removing the absolute value
5965  // function call.
5966  if (ArgType->isUnsignedIntegerType()) {
5967    const char *FunctionName =
5968        IsStdAbs ? "std::abs" : Context.BuiltinInfo.getName(AbsKind);
5969    Diag(Call->getExprLoc(), diag::warn_unsigned_abs) << ArgType << ParamType;
5970    Diag(Call->getExprLoc(), diag::note_remove_abs)
5971        << FunctionName
5972        << FixItHint::CreateRemoval(Call->getCallee()->getSourceRange());
5973    return;
5974  }
5975
5976  // Taking the absolute value of a pointer is very suspicious, they probably
5977  // wanted to index into an array, dereference a pointer, call a function, etc.
5978  if (ArgType->isPointerType() || ArgType->canDecayToPointerType()) {
5979    unsigned DiagType = 0;
5980    if (ArgType->isFunctionType())
5981      DiagType = 1;
5982    else if (ArgType->isArrayType())
5983      DiagType = 2;
5984
5985    Diag(Call->getExprLoc(), diag::warn_pointer_abs) << DiagType << ArgType;
5986    return;
5987  }
5988
5989  // std::abs has overloads which prevent most of the absolute value problems
5990  // from occurring.
5991  if (IsStdAbs)
5992    return;
5993
5994  AbsoluteValueKind ArgValueKind = getAbsoluteValueKind(ArgType);
5995  AbsoluteValueKind ParamValueKind = getAbsoluteValueKind(ParamType);
5996
5997  // The argument and parameter are the same kind.  Check if they are the right
5998  // size.
5999  if (ArgValueKind == ParamValueKind) {
6000    if (Context.getTypeSize(ArgType) <= Context.getTypeSize(ParamType))
6001      return;
6002
6003    unsigned NewAbsKind = getBestAbsFunction(Context, ArgType, AbsKind);
6004    Diag(Call->getExprLoc(), diag::warn_abs_too_small)
6005        << FDecl << ArgType << ParamType;
6006
6007    if (NewAbsKind == 0)
6008      return;
6009
6010    emitReplacement(*this, Call->getExprLoc(),
6011                    Call->getCallee()->getSourceRange(), NewAbsKind, ArgType);
6012    return;
6013  }
6014
6015  // ArgValueKind != ParamValueKind
6016  // The wrong type of absolute value function was used.  Attempt to find the
6017  // proper one.
6018  unsigned NewAbsKind = changeAbsFunction(AbsKind, ArgValueKind);
6019  NewAbsKind = getBestAbsFunction(Context, ArgType, NewAbsKind);
6020  if (NewAbsKind == 0)
6021    return;
6022
6023  Diag(Call->getExprLoc(), diag::warn_wrong_absolute_value_type)
6024      << FDecl << ParamValueKind << ArgValueKind;
6025
6026  emitReplacement(*this, Call->getExprLoc(),
6027                  Call->getCallee()->getSourceRange(), NewAbsKind, ArgType);
6028}
6029
6030//===--- CHECK: Standard memory functions ---------------------------------===//
6031
6032/// \brief Takes the expression passed to the size_t parameter of functions
6033/// such as memcmp, strncat, etc and warns if it's a comparison.
6034///
6035/// This is to catch typos like `if (memcmp(&a, &b, sizeof(a) > 0))`.
6036static bool CheckMemorySizeofForComparison(Sema &S, const Expr *E,
6037                                           IdentifierInfo *FnName,
6038                                           SourceLocation FnLoc,
6039                                           SourceLocation RParenLoc) {
6040  const BinaryOperator *Size = dyn_cast<BinaryOperator>(E);
6041  if (!Size)
6042    return false;
6043
6044  // if E is binop and op is >, <, >=, <=, ==, &&, ||:
6045  if (!Size->isComparisonOp() && !Size->isEqualityOp() && !Size->isLogicalOp())
6046    return false;
6047
6048  SourceRange SizeRange = Size->getSourceRange();
6049  S.Diag(Size->getOperatorLoc(), diag::warn_memsize_comparison)
6050      << SizeRange << FnName;
6051  S.Diag(FnLoc, diag::note_memsize_comparison_paren)
6052      << FnName << FixItHint::CreateInsertion(
6053                       S.getLocForEndOfToken(Size->getLHS()->getLocEnd()), ")")
6054      << FixItHint::CreateRemoval(RParenLoc);
6055  S.Diag(SizeRange.getBegin(), diag::note_memsize_comparison_cast_silence)
6056      << FixItHint::CreateInsertion(SizeRange.getBegin(), "(size_t)(")
6057      << FixItHint::CreateInsertion(S.getLocForEndOfToken(SizeRange.getEnd()),
6058                                    ")");
6059
6060  return true;
6061}
6062
6063/// \brief Determine whether the given type is or contains a dynamic class type
6064/// (e.g., whether it has a vtable).
6065static const CXXRecordDecl *getContainedDynamicClass(QualType T,
6066                                                     bool &IsContained) {
6067  // Look through array types while ignoring qualifiers.
6068  const Type *Ty = T->getBaseElementTypeUnsafe();
6069  IsContained = false;
6070
6071  const CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
6072  RD = RD ? RD->getDefinition() : nullptr;
6073  if (!RD || RD->isInvalidDecl())
6074    return nullptr;
6075
6076  if (RD->isDynamicClass())
6077    return RD;
6078
6079  // Check all the fields.  If any bases were dynamic, the class is dynamic.
6080  // It's impossible for a class to transitively contain itself by value, so
6081  // infinite recursion is impossible.
6082  for (auto *FD : RD->fields()) {
6083    bool SubContained;
6084    if (const CXXRecordDecl *ContainedRD =
6085            getContainedDynamicClass(FD->getType(), SubContained)) {
6086      IsContained = true;
6087      return ContainedRD;
6088    }
6089  }
6090
6091  return nullptr;
6092}
6093
6094/// \brief If E is a sizeof expression, returns its argument expression,
6095/// otherwise returns NULL.
6096static const Expr *getSizeOfExprArg(const Expr *E) {
6097  if (const UnaryExprOrTypeTraitExpr *SizeOf =
6098      dyn_cast<UnaryExprOrTypeTraitExpr>(E))
6099    if (SizeOf->getKind() == clang::UETT_SizeOf && !SizeOf->isArgumentType())
6100      return SizeOf->getArgumentExpr()->IgnoreParenImpCasts();
6101
6102  return nullptr;
6103}
6104
6105/// \brief If E is a sizeof expression, returns its argument type.
6106static QualType getSizeOfArgType(const Expr *E) {
6107  if (const UnaryExprOrTypeTraitExpr *SizeOf =
6108      dyn_cast<UnaryExprOrTypeTraitExpr>(E))
6109    if (SizeOf->getKind() == clang::UETT_SizeOf)
6110      return SizeOf->getTypeOfArgument();
6111
6112  return QualType();
6113}
6114
6115/// \brief Check for dangerous or invalid arguments to memset().
6116///
6117/// This issues warnings on known problematic, dangerous or unspecified
6118/// arguments to the standard 'memset', 'memcpy', 'memmove', and 'memcmp'
6119/// function calls.
6120///
6121/// \param Call The call expression to diagnose.
6122void Sema::CheckMemaccessArguments(const CallExpr *Call,
6123                                   unsigned BId,
6124                                   IdentifierInfo *FnName) {
6125  assert(BId != 0);
6126
6127  // It is possible to have a non-standard definition of memset.  Validate
6128  // we have enough arguments, and if not, abort further checking.
6129  unsigned ExpectedNumArgs = (BId == Builtin::BIstrndup ? 2 : 3);
6130  if (Call->getNumArgs() < ExpectedNumArgs)
6131    return;
6132
6133  unsigned LastArg = (BId == Builtin::BImemset ||
6134                      BId == Builtin::BIstrndup ? 1 : 2);
6135  unsigned LenArg = (BId == Builtin::BIstrndup ? 1 : 2);
6136  const Expr *LenExpr = Call->getArg(LenArg)->IgnoreParenImpCasts();
6137
6138  if (CheckMemorySizeofForComparison(*this, LenExpr, FnName,
6139                                     Call->getLocStart(), Call->getRParenLoc()))
6140    return;
6141
6142  // We have special checking when the length is a sizeof expression.
6143  QualType SizeOfArgTy = getSizeOfArgType(LenExpr);
6144  const Expr *SizeOfArg = getSizeOfExprArg(LenExpr);
6145  llvm::FoldingSetNodeID SizeOfArgID;
6146
6147  for (unsigned ArgIdx = 0; ArgIdx != LastArg; ++ArgIdx) {
6148    const Expr *Dest = Call->getArg(ArgIdx)->IgnoreParenImpCasts();
6149    SourceRange ArgRange = Call->getArg(ArgIdx)->getSourceRange();
6150
6151    QualType DestTy = Dest->getType();
6152    QualType PointeeTy;
6153    if (const PointerType *DestPtrTy = DestTy->getAs<PointerType>()) {
6154      PointeeTy = DestPtrTy->getPointeeType();
6155
6156      // Never warn about void type pointers. This can be used to suppress
6157      // false positives.
6158      if (PointeeTy->isVoidType())
6159        continue;
6160
6161      // Catch "memset(p, 0, sizeof(p))" -- needs to be sizeof(*p). Do this by
6162      // actually comparing the expressions for equality. Because computing the
6163      // expression IDs can be expensive, we only do this if the diagnostic is
6164      // enabled.
6165      if (SizeOfArg &&
6166          !Diags.isIgnored(diag::warn_sizeof_pointer_expr_memaccess,
6167                           SizeOfArg->getExprLoc())) {
6168        // We only compute IDs for expressions if the warning is enabled, and
6169        // cache the sizeof arg's ID.
6170        if (SizeOfArgID == llvm::FoldingSetNodeID())
6171          SizeOfArg->Profile(SizeOfArgID, Context, true);
6172        llvm::FoldingSetNodeID DestID;
6173        Dest->Profile(DestID, Context, true);
6174        if (DestID == SizeOfArgID) {
6175          // TODO: For strncpy() and friends, this could suggest sizeof(dst)
6176          //       over sizeof(src) as well.
6177          unsigned ActionIdx = 0; // Default is to suggest dereferencing.
6178          StringRef ReadableName = FnName->getName();
6179
6180          if (const UnaryOperator *UnaryOp = dyn_cast<UnaryOperator>(Dest))
6181            if (UnaryOp->getOpcode() == UO_AddrOf)
6182              ActionIdx = 1; // If its an address-of operator, just remove it.
6183          if (!PointeeTy->isIncompleteType() &&
6184              (Context.getTypeSize(PointeeTy) == Context.getCharWidth()))
6185            ActionIdx = 2; // If the pointee's size is sizeof(char),
6186                           // suggest an explicit length.
6187
6188          // If the function is defined as a builtin macro, do not show macro
6189          // expansion.
6190          SourceLocation SL = SizeOfArg->getExprLoc();
6191          SourceRange DSR = Dest->getSourceRange();
6192          SourceRange SSR = SizeOfArg->getSourceRange();
6193          SourceManager &SM = getSourceManager();
6194
6195          if (SM.isMacroArgExpansion(SL)) {
6196            ReadableName = Lexer::getImmediateMacroName(SL, SM, LangOpts);
6197            SL = SM.getSpellingLoc(SL);
6198            DSR = SourceRange(SM.getSpellingLoc(DSR.getBegin()),
6199                             SM.getSpellingLoc(DSR.getEnd()));
6200            SSR = SourceRange(SM.getSpellingLoc(SSR.getBegin()),
6201                             SM.getSpellingLoc(SSR.getEnd()));
6202          }
6203
6204          DiagRuntimeBehavior(SL, SizeOfArg,
6205                              PDiag(diag::warn_sizeof_pointer_expr_memaccess)
6206                                << ReadableName
6207                                << PointeeTy
6208                                << DestTy
6209                                << DSR
6210                                << SSR);
6211          DiagRuntimeBehavior(SL, SizeOfArg,
6212                         PDiag(diag::warn_sizeof_pointer_expr_memaccess_note)
6213                                << ActionIdx
6214                                << SSR);
6215
6216          break;
6217        }
6218      }
6219
6220      // Also check for cases where the sizeof argument is the exact same
6221      // type as the memory argument, and where it points to a user-defined
6222      // record type.
6223      if (SizeOfArgTy != QualType()) {
6224        if (PointeeTy->isRecordType() &&
6225            Context.typesAreCompatible(SizeOfArgTy, DestTy)) {
6226          DiagRuntimeBehavior(LenExpr->getExprLoc(), Dest,
6227                              PDiag(diag::warn_sizeof_pointer_type_memaccess)
6228                                << FnName << SizeOfArgTy << ArgIdx
6229                                << PointeeTy << Dest->getSourceRange()
6230                                << LenExpr->getSourceRange());
6231          break;
6232        }
6233      }
6234    } else if (DestTy->isArrayType()) {
6235      PointeeTy = DestTy;
6236    }
6237
6238    if (PointeeTy == QualType())
6239      continue;
6240
6241    // Always complain about dynamic classes.
6242    bool IsContained;
6243    if (const CXXRecordDecl *ContainedRD =
6244            getContainedDynamicClass(PointeeTy, IsContained)) {
6245
6246      unsigned OperationType = 0;
6247      // "overwritten" if we're warning about the destination for any call
6248      // but memcmp; otherwise a verb appropriate to the call.
6249      if (ArgIdx != 0 || BId == Builtin::BImemcmp) {
6250        if (BId == Builtin::BImemcpy)
6251          OperationType = 1;
6252        else if(BId == Builtin::BImemmove)
6253          OperationType = 2;
6254        else if (BId == Builtin::BImemcmp)
6255          OperationType = 3;
6256      }
6257
6258      DiagRuntimeBehavior(
6259        Dest->getExprLoc(), Dest,
6260        PDiag(diag::warn_dyn_class_memaccess)
6261          << (BId == Builtin::BImemcmp ? ArgIdx + 2 : ArgIdx)
6262          << FnName << IsContained << ContainedRD << OperationType
6263          << Call->getCallee()->getSourceRange());
6264    } else if (PointeeTy.hasNonTrivialObjCLifetime() &&
6265             BId != Builtin::BImemset)
6266      DiagRuntimeBehavior(
6267        Dest->getExprLoc(), Dest,
6268        PDiag(diag::warn_arc_object_memaccess)
6269          << ArgIdx << FnName << PointeeTy
6270          << Call->getCallee()->getSourceRange());
6271    else
6272      continue;
6273
6274    DiagRuntimeBehavior(
6275      Dest->getExprLoc(), Dest,
6276      PDiag(diag::note_bad_memaccess_silence)
6277        << FixItHint::CreateInsertion(ArgRange.getBegin(), "(void*)"));
6278    break;
6279  }
6280}
6281
6282// A little helper routine: ignore addition and subtraction of integer literals.
6283// This intentionally does not ignore all integer constant expressions because
6284// we don't want to remove sizeof().
6285static const Expr *ignoreLiteralAdditions(const Expr *Ex, ASTContext &Ctx) {
6286  Ex = Ex->IgnoreParenCasts();
6287
6288  for (;;) {
6289    const BinaryOperator * BO = dyn_cast<BinaryOperator>(Ex);
6290    if (!BO || !BO->isAdditiveOp())
6291      break;
6292
6293    const Expr *RHS = BO->getRHS()->IgnoreParenCasts();
6294    const Expr *LHS = BO->getLHS()->IgnoreParenCasts();
6295
6296    if (isa<IntegerLiteral>(RHS))
6297      Ex = LHS;
6298    else if (isa<IntegerLiteral>(LHS))
6299      Ex = RHS;
6300    else
6301      break;
6302  }
6303
6304  return Ex;
6305}
6306
6307static bool isConstantSizeArrayWithMoreThanOneElement(QualType Ty,
6308                                                      ASTContext &Context) {
6309  // Only handle constant-sized or VLAs, but not flexible members.
6310  if (const ConstantArrayType *CAT = Context.getAsConstantArrayType(Ty)) {
6311    // Only issue the FIXIT for arrays of size > 1.
6312    if (CAT->getSize().getSExtValue() <= 1)
6313      return false;
6314  } else if (!Ty->isVariableArrayType()) {
6315    return false;
6316  }
6317  return true;
6318}
6319
6320// Warn if the user has made the 'size' argument to strlcpy or strlcat
6321// be the size of the source, instead of the destination.
6322void Sema::CheckStrlcpycatArguments(const CallExpr *Call,
6323                                    IdentifierInfo *FnName) {
6324
6325  // Don't crash if the user has the wrong number of arguments
6326  unsigned NumArgs = Call->getNumArgs();
6327  if ((NumArgs != 3) && (NumArgs != 4))
6328    return;
6329
6330  const Expr *SrcArg = ignoreLiteralAdditions(Call->getArg(1), Context);
6331  const Expr *SizeArg = ignoreLiteralAdditions(Call->getArg(2), Context);
6332  const Expr *CompareWithSrc = nullptr;
6333
6334  if (CheckMemorySizeofForComparison(*this, SizeArg, FnName,
6335                                     Call->getLocStart(), Call->getRParenLoc()))
6336    return;
6337
6338  // Look for 'strlcpy(dst, x, sizeof(x))'
6339  if (const Expr *Ex = getSizeOfExprArg(SizeArg))
6340    CompareWithSrc = Ex;
6341  else {
6342    // Look for 'strlcpy(dst, x, strlen(x))'
6343    if (const CallExpr *SizeCall = dyn_cast<CallExpr>(SizeArg)) {
6344      if (SizeCall->getBuiltinCallee() == Builtin::BIstrlen &&
6345          SizeCall->getNumArgs() == 1)
6346        CompareWithSrc = ignoreLiteralAdditions(SizeCall->getArg(0), Context);
6347    }
6348  }
6349
6350  if (!CompareWithSrc)
6351    return;
6352
6353  // Determine if the argument to sizeof/strlen is equal to the source
6354  // argument.  In principle there's all kinds of things you could do
6355  // here, for instance creating an == expression and evaluating it with
6356  // EvaluateAsBooleanCondition, but this uses a more direct technique:
6357  const DeclRefExpr *SrcArgDRE = dyn_cast<DeclRefExpr>(SrcArg);
6358  if (!SrcArgDRE)
6359    return;
6360
6361  const DeclRefExpr *CompareWithSrcDRE = dyn_cast<DeclRefExpr>(CompareWithSrc);
6362  if (!CompareWithSrcDRE ||
6363      SrcArgDRE->getDecl() != CompareWithSrcDRE->getDecl())
6364    return;
6365
6366  const Expr *OriginalSizeArg = Call->getArg(2);
6367  Diag(CompareWithSrcDRE->getLocStart(), diag::warn_strlcpycat_wrong_size)
6368    << OriginalSizeArg->getSourceRange() << FnName;
6369
6370  // Output a FIXIT hint if the destination is an array (rather than a
6371  // pointer to an array).  This could be enhanced to handle some
6372  // pointers if we know the actual size, like if DstArg is 'array+2'
6373  // we could say 'sizeof(array)-2'.
6374  const Expr *DstArg = Call->getArg(0)->IgnoreParenImpCasts();
6375  if (!isConstantSizeArrayWithMoreThanOneElement(DstArg->getType(), Context))
6376    return;
6377
6378  SmallString<128> sizeString;
6379  llvm::raw_svector_ostream OS(sizeString);
6380  OS << "sizeof(";
6381  DstArg->printPretty(OS, nullptr, getPrintingPolicy());
6382  OS << ")";
6383
6384  Diag(OriginalSizeArg->getLocStart(), diag::note_strlcpycat_wrong_size)
6385    << FixItHint::CreateReplacement(OriginalSizeArg->getSourceRange(),
6386                                    OS.str());
6387}
6388
6389/// Check if two expressions refer to the same declaration.
6390static bool referToTheSameDecl(const Expr *E1, const Expr *E2) {
6391  if (const DeclRefExpr *D1 = dyn_cast_or_null<DeclRefExpr>(E1))
6392    if (const DeclRefExpr *D2 = dyn_cast_or_null<DeclRefExpr>(E2))
6393      return D1->getDecl() == D2->getDecl();
6394  return false;
6395}
6396
6397static const Expr *getStrlenExprArg(const Expr *E) {
6398  if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
6399    const FunctionDecl *FD = CE->getDirectCallee();
6400    if (!FD || FD->getMemoryFunctionKind() != Builtin::BIstrlen)
6401      return nullptr;
6402    return CE->getArg(0)->IgnoreParenCasts();
6403  }
6404  return nullptr;
6405}
6406
6407// Warn on anti-patterns as the 'size' argument to strncat.
6408// The correct size argument should look like following:
6409//   strncat(dst, src, sizeof(dst) - strlen(dest) - 1);
6410void Sema::CheckStrncatArguments(const CallExpr *CE,
6411                                 IdentifierInfo *FnName) {
6412  // Don't crash if the user has the wrong number of arguments.
6413  if (CE->getNumArgs() < 3)
6414    return;
6415  const Expr *DstArg = CE->getArg(0)->IgnoreParenCasts();
6416  const Expr *SrcArg = CE->getArg(1)->IgnoreParenCasts();
6417  const Expr *LenArg = CE->getArg(2)->IgnoreParenCasts();
6418
6419  if (CheckMemorySizeofForComparison(*this, LenArg, FnName, CE->getLocStart(),
6420                                     CE->getRParenLoc()))
6421    return;
6422
6423  // Identify common expressions, which are wrongly used as the size argument
6424  // to strncat and may lead to buffer overflows.
6425  unsigned PatternType = 0;
6426  if (const Expr *SizeOfArg = getSizeOfExprArg(LenArg)) {
6427    // - sizeof(dst)
6428    if (referToTheSameDecl(SizeOfArg, DstArg))
6429      PatternType = 1;
6430    // - sizeof(src)
6431    else if (referToTheSameDecl(SizeOfArg, SrcArg))
6432      PatternType = 2;
6433  } else if (const BinaryOperator *BE = dyn_cast<BinaryOperator>(LenArg)) {
6434    if (BE->getOpcode() == BO_Sub) {
6435      const Expr *L = BE->getLHS()->IgnoreParenCasts();
6436      const Expr *R = BE->getRHS()->IgnoreParenCasts();
6437      // - sizeof(dst) - strlen(dst)
6438      if (referToTheSameDecl(DstArg, getSizeOfExprArg(L)) &&
6439          referToTheSameDecl(DstArg, getStrlenExprArg(R)))
6440        PatternType = 1;
6441      // - sizeof(src) - (anything)
6442      else if (referToTheSameDecl(SrcArg, getSizeOfExprArg(L)))
6443        PatternType = 2;
6444    }
6445  }
6446
6447  if (PatternType == 0)
6448    return;
6449
6450  // Generate the diagnostic.
6451  SourceLocation SL = LenArg->getLocStart();
6452  SourceRange SR = LenArg->getSourceRange();
6453  SourceManager &SM = getSourceManager();
6454
6455  // If the function is defined as a builtin macro, do not show macro expansion.
6456  if (SM.isMacroArgExpansion(SL)) {
6457    SL = SM.getSpellingLoc(SL);
6458    SR = SourceRange(SM.getSpellingLoc(SR.getBegin()),
6459                     SM.getSpellingLoc(SR.getEnd()));
6460  }
6461
6462  // Check if the destination is an array (rather than a pointer to an array).
6463  QualType DstTy = DstArg->getType();
6464  bool isKnownSizeArray = isConstantSizeArrayWithMoreThanOneElement(DstTy,
6465                                                                    Context);
6466  if (!isKnownSizeArray) {
6467    if (PatternType == 1)
6468      Diag(SL, diag::warn_strncat_wrong_size) << SR;
6469    else
6470      Diag(SL, diag::warn_strncat_src_size) << SR;
6471    return;
6472  }
6473
6474  if (PatternType == 1)
6475    Diag(SL, diag::warn_strncat_large_size) << SR;
6476  else
6477    Diag(SL, diag::warn_strncat_src_size) << SR;
6478
6479  SmallString<128> sizeString;
6480  llvm::raw_svector_ostream OS(sizeString);
6481  OS << "sizeof(";
6482  DstArg->printPretty(OS, nullptr, getPrintingPolicy());
6483  OS << ") - ";
6484  OS << "strlen(";
6485  DstArg->printPretty(OS, nullptr, getPrintingPolicy());
6486  OS << ") - 1";
6487
6488  Diag(SL, diag::note_strncat_wrong_size)
6489    << FixItHint::CreateReplacement(SR, OS.str());
6490}
6491
6492//===--- CHECK: Return Address of Stack Variable --------------------------===//
6493
6494static const Expr *EvalVal(const Expr *E,
6495                           SmallVectorImpl<const DeclRefExpr *> &refVars,
6496                           const Decl *ParentDecl);
6497static const Expr *EvalAddr(const Expr *E,
6498                            SmallVectorImpl<const DeclRefExpr *> &refVars,
6499                            const Decl *ParentDecl);
6500
6501/// CheckReturnStackAddr - Check if a return statement returns the address
6502///   of a stack variable.
6503static void
6504CheckReturnStackAddr(Sema &S, Expr *RetValExp, QualType lhsType,
6505                     SourceLocation ReturnLoc) {
6506
6507  const Expr *stackE = nullptr;
6508  SmallVector<const DeclRefExpr *, 8> refVars;
6509
6510  // Perform checking for returned stack addresses, local blocks,
6511  // label addresses or references to temporaries.
6512  if (lhsType->isPointerType() ||
6513      (!S.getLangOpts().ObjCAutoRefCount && lhsType->isBlockPointerType())) {
6514    stackE = EvalAddr(RetValExp, refVars, /*ParentDecl=*/nullptr);
6515  } else if (lhsType->isReferenceType()) {
6516    stackE = EvalVal(RetValExp, refVars, /*ParentDecl=*/nullptr);
6517  }
6518
6519  if (!stackE)
6520    return; // Nothing suspicious was found.
6521
6522  SourceLocation diagLoc;
6523  SourceRange diagRange;
6524  if (refVars.empty()) {
6525    diagLoc = stackE->getLocStart();
6526    diagRange = stackE->getSourceRange();
6527  } else {
6528    // We followed through a reference variable. 'stackE' contains the
6529    // problematic expression but we will warn at the return statement pointing
6530    // at the reference variable. We will later display the "trail" of
6531    // reference variables using notes.
6532    diagLoc = refVars[0]->getLocStart();
6533    diagRange = refVars[0]->getSourceRange();
6534  }
6535
6536  if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(stackE)) {
6537    // address of local var
6538    S.Diag(diagLoc, diag::warn_ret_stack_addr_ref) << lhsType->isReferenceType()
6539     << DR->getDecl()->getDeclName() << diagRange;
6540  } else if (isa<BlockExpr>(stackE)) { // local block.
6541    S.Diag(diagLoc, diag::err_ret_local_block) << diagRange;
6542  } else if (isa<AddrLabelExpr>(stackE)) { // address of label.
6543    S.Diag(diagLoc, diag::warn_ret_addr_label) << diagRange;
6544  } else { // local temporary.
6545    S.Diag(diagLoc, diag::warn_ret_local_temp_addr_ref)
6546     << lhsType->isReferenceType() << diagRange;
6547  }
6548
6549  // Display the "trail" of reference variables that we followed until we
6550  // found the problematic expression using notes.
6551  for (unsigned i = 0, e = refVars.size(); i != e; ++i) {
6552    const VarDecl *VD = cast<VarDecl>(refVars[i]->getDecl());
6553    // If this var binds to another reference var, show the range of the next
6554    // var, otherwise the var binds to the problematic expression, in which case
6555    // show the range of the expression.
6556    SourceRange range = (i < e - 1) ? refVars[i + 1]->getSourceRange()
6557                                    : stackE->getSourceRange();
6558    S.Diag(VD->getLocation(), diag::note_ref_var_local_bind)
6559        << VD->getDeclName() << range;
6560  }
6561}
6562
6563/// EvalAddr - EvalAddr and EvalVal are mutually recursive functions that
6564///  check if the expression in a return statement evaluates to an address
6565///  to a location on the stack, a local block, an address of a label, or a
6566///  reference to local temporary. The recursion is used to traverse the
6567///  AST of the return expression, with recursion backtracking when we
6568///  encounter a subexpression that (1) clearly does not lead to one of the
6569///  above problematic expressions (2) is something we cannot determine leads to
6570///  a problematic expression based on such local checking.
6571///
6572///  Both EvalAddr and EvalVal follow through reference variables to evaluate
6573///  the expression that they point to. Such variables are added to the
6574///  'refVars' vector so that we know what the reference variable "trail" was.
6575///
6576///  EvalAddr processes expressions that are pointers that are used as
6577///  references (and not L-values).  EvalVal handles all other values.
6578///  At the base case of the recursion is a check for the above problematic
6579///  expressions.
6580///
6581///  This implementation handles:
6582///
6583///   * pointer-to-pointer casts
6584///   * implicit conversions from array references to pointers
6585///   * taking the address of fields
6586///   * arbitrary interplay between "&" and "*" operators
6587///   * pointer arithmetic from an address of a stack variable
6588///   * taking the address of an array element where the array is on the stack
6589static const Expr *EvalAddr(const Expr *E,
6590                            SmallVectorImpl<const DeclRefExpr *> &refVars,
6591                            const Decl *ParentDecl) {
6592  if (E->isTypeDependent())
6593    return nullptr;
6594
6595  // We should only be called for evaluating pointer expressions.
6596  assert((E->getType()->isAnyPointerType() ||
6597          E->getType()->isBlockPointerType() ||
6598          E->getType()->isObjCQualifiedIdType()) &&
6599         "EvalAddr only works on pointers");
6600
6601  E = E->IgnoreParens();
6602
6603  // Our "symbolic interpreter" is just a dispatch off the currently
6604  // viewed AST node.  We then recursively traverse the AST by calling
6605  // EvalAddr and EvalVal appropriately.
6606  switch (E->getStmtClass()) {
6607  case Stmt::DeclRefExprClass: {
6608    const DeclRefExpr *DR = cast<DeclRefExpr>(E);
6609
6610    // If we leave the immediate function, the lifetime isn't about to end.
6611    if (DR->refersToEnclosingVariableOrCapture())
6612      return nullptr;
6613
6614    if (const VarDecl *V = dyn_cast<VarDecl>(DR->getDecl()))
6615      // If this is a reference variable, follow through to the expression that
6616      // it points to.
6617      if (V->hasLocalStorage() &&
6618          V->getType()->isReferenceType() && V->hasInit()) {
6619        // Add the reference variable to the "trail".
6620        refVars.push_back(DR);
6621        return EvalAddr(V->getInit(), refVars, ParentDecl);
6622      }
6623
6624    return nullptr;
6625  }
6626
6627  case Stmt::UnaryOperatorClass: {
6628    // The only unary operator that make sense to handle here
6629    // is AddrOf.  All others don't make sense as pointers.
6630    const UnaryOperator *U = cast<UnaryOperator>(E);
6631
6632    if (U->getOpcode() == UO_AddrOf)
6633      return EvalVal(U->getSubExpr(), refVars, ParentDecl);
6634    return nullptr;
6635  }
6636
6637  case Stmt::BinaryOperatorClass: {
6638    // Handle pointer arithmetic.  All other binary operators are not valid
6639    // in this context.
6640    const BinaryOperator *B = cast<BinaryOperator>(E);
6641    BinaryOperatorKind op = B->getOpcode();
6642
6643    if (op != BO_Add && op != BO_Sub)
6644      return nullptr;
6645
6646    const Expr *Base = B->getLHS();
6647
6648    // Determine which argument is the real pointer base.  It could be
6649    // the RHS argument instead of the LHS.
6650    if (!Base->getType()->isPointerType())
6651      Base = B->getRHS();
6652
6653    assert(Base->getType()->isPointerType());
6654    return EvalAddr(Base, refVars, ParentDecl);
6655  }
6656
6657  // For conditional operators we need to see if either the LHS or RHS are
6658  // valid DeclRefExpr*s.  If one of them is valid, we return it.
6659  case Stmt::ConditionalOperatorClass: {
6660    const ConditionalOperator *C = cast<ConditionalOperator>(E);
6661
6662    // Handle the GNU extension for missing LHS.
6663    // FIXME: That isn't a ConditionalOperator, so doesn't get here.
6664    if (const Expr *LHSExpr = C->getLHS()) {
6665      // In C++, we can have a throw-expression, which has 'void' type.
6666      if (!LHSExpr->getType()->isVoidType())
6667        if (const Expr *LHS = EvalAddr(LHSExpr, refVars, ParentDecl))
6668          return LHS;
6669    }
6670
6671    // In C++, we can have a throw-expression, which has 'void' type.
6672    if (C->getRHS()->getType()->isVoidType())
6673      return nullptr;
6674
6675    return EvalAddr(C->getRHS(), refVars, ParentDecl);
6676  }
6677
6678  case Stmt::BlockExprClass:
6679    if (cast<BlockExpr>(E)->getBlockDecl()->hasCaptures())
6680      return E; // local block.
6681    return nullptr;
6682
6683  case Stmt::AddrLabelExprClass:
6684    return E; // address of label.
6685
6686  case Stmt::ExprWithCleanupsClass:
6687    return EvalAddr(cast<ExprWithCleanups>(E)->getSubExpr(), refVars,
6688                    ParentDecl);
6689
6690  // For casts, we need to handle conversions from arrays to
6691  // pointer values, and pointer-to-pointer conversions.
6692  case Stmt::ImplicitCastExprClass:
6693  case Stmt::CStyleCastExprClass:
6694  case Stmt::CXXFunctionalCastExprClass:
6695  case Stmt::ObjCBridgedCastExprClass:
6696  case Stmt::CXXStaticCastExprClass:
6697  case Stmt::CXXDynamicCastExprClass:
6698  case Stmt::CXXConstCastExprClass:
6699  case Stmt::CXXReinterpretCastExprClass: {
6700    const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr();
6701    switch (cast<CastExpr>(E)->getCastKind()) {
6702    case CK_LValueToRValue:
6703    case CK_NoOp:
6704    case CK_BaseToDerived:
6705    case CK_DerivedToBase:
6706    case CK_UncheckedDerivedToBase:
6707    case CK_Dynamic:
6708    case CK_CPointerToObjCPointerCast:
6709    case CK_BlockPointerToObjCPointerCast:
6710    case CK_AnyPointerToBlockPointerCast:
6711      return EvalAddr(SubExpr, refVars, ParentDecl);
6712
6713    case CK_ArrayToPointerDecay:
6714      return EvalVal(SubExpr, refVars, ParentDecl);
6715
6716    case CK_BitCast:
6717      if (SubExpr->getType()->isAnyPointerType() ||
6718          SubExpr->getType()->isBlockPointerType() ||
6719          SubExpr->getType()->isObjCQualifiedIdType())
6720        return EvalAddr(SubExpr, refVars, ParentDecl);
6721      else
6722        return nullptr;
6723
6724    default:
6725      return nullptr;
6726    }
6727  }
6728
6729  case Stmt::MaterializeTemporaryExprClass:
6730    if (const Expr *Result =
6731            EvalAddr(cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr(),
6732                     refVars, ParentDecl))
6733      return Result;
6734    return E;
6735
6736  // Everything else: we simply don't reason about them.
6737  default:
6738    return nullptr;
6739  }
6740}
6741
6742///  EvalVal - This function is complements EvalAddr in the mutual recursion.
6743///   See the comments for EvalAddr for more details.
6744static const Expr *EvalVal(const Expr *E,
6745                           SmallVectorImpl<const DeclRefExpr *> &refVars,
6746                           const Decl *ParentDecl) {
6747  do {
6748    // We should only be called for evaluating non-pointer expressions, or
6749    // expressions with a pointer type that are not used as references but
6750    // instead
6751    // are l-values (e.g., DeclRefExpr with a pointer type).
6752
6753    // Our "symbolic interpreter" is just a dispatch off the currently
6754    // viewed AST node.  We then recursively traverse the AST by calling
6755    // EvalAddr and EvalVal appropriately.
6756
6757    E = E->IgnoreParens();
6758    switch (E->getStmtClass()) {
6759    case Stmt::ImplicitCastExprClass: {
6760      const ImplicitCastExpr *IE = cast<ImplicitCastExpr>(E);
6761      if (IE->getValueKind() == VK_LValue) {
6762        E = IE->getSubExpr();
6763        continue;
6764      }
6765      return nullptr;
6766    }
6767
6768    case Stmt::ExprWithCleanupsClass:
6769      return EvalVal(cast<ExprWithCleanups>(E)->getSubExpr(), refVars,
6770                     ParentDecl);
6771
6772    case Stmt::DeclRefExprClass: {
6773      // When we hit a DeclRefExpr we are looking at code that refers to a
6774      // variable's name. If it's not a reference variable we check if it has
6775      // local storage within the function, and if so, return the expression.
6776      const DeclRefExpr *DR = cast<DeclRefExpr>(E);
6777
6778      // If we leave the immediate function, the lifetime isn't about to end.
6779      if (DR->refersToEnclosingVariableOrCapture())
6780        return nullptr;
6781
6782      if (const VarDecl *V = dyn_cast<VarDecl>(DR->getDecl())) {
6783        // Check if it refers to itself, e.g. "int& i = i;".
6784        if (V == ParentDecl)
6785          return DR;
6786
6787        if (V->hasLocalStorage()) {
6788          if (!V->getType()->isReferenceType())
6789            return DR;
6790
6791          // Reference variable, follow through to the expression that
6792          // it points to.
6793          if (V->hasInit()) {
6794            // Add the reference variable to the "trail".
6795            refVars.push_back(DR);
6796            return EvalVal(V->getInit(), refVars, V);
6797          }
6798        }
6799      }
6800
6801      return nullptr;
6802    }
6803
6804    case Stmt::UnaryOperatorClass: {
6805      // The only unary operator that make sense to handle here
6806      // is Deref.  All others don't resolve to a "name."  This includes
6807      // handling all sorts of rvalues passed to a unary operator.
6808      const UnaryOperator *U = cast<UnaryOperator>(E);
6809
6810      if (U->getOpcode() == UO_Deref)
6811        return EvalAddr(U->getSubExpr(), refVars, ParentDecl);
6812
6813      return nullptr;
6814    }
6815
6816    case Stmt::ArraySubscriptExprClass: {
6817      // Array subscripts are potential references to data on the stack.  We
6818      // retrieve the DeclRefExpr* for the array variable if it indeed
6819      // has local storage.
6820      const auto *ASE = cast<ArraySubscriptExpr>(E);
6821      if (ASE->isTypeDependent())
6822        return nullptr;
6823      return EvalAddr(ASE->getBase(), refVars, ParentDecl);
6824    }
6825
6826    case Stmt::OMPArraySectionExprClass: {
6827      return EvalAddr(cast<OMPArraySectionExpr>(E)->getBase(), refVars,
6828                      ParentDecl);
6829    }
6830
6831    case Stmt::ConditionalOperatorClass: {
6832      // For conditional operators we need to see if either the LHS or RHS are
6833      // non-NULL Expr's.  If one is non-NULL, we return it.
6834      const ConditionalOperator *C = cast<ConditionalOperator>(E);
6835
6836      // Handle the GNU extension for missing LHS.
6837      if (const Expr *LHSExpr = C->getLHS()) {
6838        // In C++, we can have a throw-expression, which has 'void' type.
6839        if (!LHSExpr->getType()->isVoidType())
6840          if (const Expr *LHS = EvalVal(LHSExpr, refVars, ParentDecl))
6841            return LHS;
6842      }
6843
6844      // In C++, we can have a throw-expression, which has 'void' type.
6845      if (C->getRHS()->getType()->isVoidType())
6846        return nullptr;
6847
6848      return EvalVal(C->getRHS(), refVars, ParentDecl);
6849    }
6850
6851    // Accesses to members are potential references to data on the stack.
6852    case Stmt::MemberExprClass: {
6853      const MemberExpr *M = cast<MemberExpr>(E);
6854
6855      // Check for indirect access.  We only want direct field accesses.
6856      if (M->isArrow())
6857        return nullptr;
6858
6859      // Check whether the member type is itself a reference, in which case
6860      // we're not going to refer to the member, but to what the member refers
6861      // to.
6862      if (M->getMemberDecl()->getType()->isReferenceType())
6863        return nullptr;
6864
6865      return EvalVal(M->getBase(), refVars, ParentDecl);
6866    }
6867
6868    case Stmt::MaterializeTemporaryExprClass:
6869      if (const Expr *Result =
6870              EvalVal(cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr(),
6871                      refVars, ParentDecl))
6872        return Result;
6873      return E;
6874
6875    default:
6876      // Check that we don't return or take the address of a reference to a
6877      // temporary. This is only useful in C++.
6878      if (!E->isTypeDependent() && E->isRValue())
6879        return E;
6880
6881      // Everything else: we simply don't reason about them.
6882      return nullptr;
6883    }
6884  } while (true);
6885}
6886
6887void
6888Sema::CheckReturnValExpr(Expr *RetValExp, QualType lhsType,
6889                         SourceLocation ReturnLoc,
6890                         bool isObjCMethod,
6891                         const AttrVec *Attrs,
6892                         const FunctionDecl *FD) {
6893  CheckReturnStackAddr(*this, RetValExp, lhsType, ReturnLoc);
6894
6895  // Check if the return value is null but should not be.
6896  if (((Attrs && hasSpecificAttr<ReturnsNonNullAttr>(*Attrs)) ||
6897       (!isObjCMethod && isNonNullType(Context, lhsType))) &&
6898      CheckNonNullExpr(*this, RetValExp))
6899    Diag(ReturnLoc, diag::warn_null_ret)
6900      << (isObjCMethod ? 1 : 0) << RetValExp->getSourceRange();
6901
6902  // C++11 [basic.stc.dynamic.allocation]p4:
6903  //   If an allocation function declared with a non-throwing
6904  //   exception-specification fails to allocate storage, it shall return
6905  //   a null pointer. Any other allocation function that fails to allocate
6906  //   storage shall indicate failure only by throwing an exception [...]
6907  if (FD) {
6908    OverloadedOperatorKind Op = FD->getOverloadedOperator();
6909    if (Op == OO_New || Op == OO_Array_New) {
6910      const FunctionProtoType *Proto
6911        = FD->getType()->castAs<FunctionProtoType>();
6912      if (!Proto->isNothrow(Context, /*ResultIfDependent*/true) &&
6913          CheckNonNullExpr(*this, RetValExp))
6914        Diag(ReturnLoc, diag::warn_operator_new_returns_null)
6915          << FD << getLangOpts().CPlusPlus11;
6916    }
6917  }
6918}
6919
6920//===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===//
6921
6922/// Check for comparisons of floating point operands using != and ==.
6923/// Issue a warning if these are no self-comparisons, as they are not likely
6924/// to do what the programmer intended.
6925void Sema::CheckFloatComparison(SourceLocation Loc, Expr* LHS, Expr *RHS) {
6926  Expr* LeftExprSansParen = LHS->IgnoreParenImpCasts();
6927  Expr* RightExprSansParen = RHS->IgnoreParenImpCasts();
6928
6929  // Special case: check for x == x (which is OK).
6930  // Do not emit warnings for such cases.
6931  if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LeftExprSansParen))
6932    if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RightExprSansParen))
6933      if (DRL->getDecl() == DRR->getDecl())
6934        return;
6935
6936  // Special case: check for comparisons against literals that can be exactly
6937  //  represented by APFloat.  In such cases, do not emit a warning.  This
6938  //  is a heuristic: often comparison against such literals are used to
6939  //  detect if a value in a variable has not changed.  This clearly can
6940  //  lead to false negatives.
6941  if (FloatingLiteral* FLL = dyn_cast<FloatingLiteral>(LeftExprSansParen)) {
6942    if (FLL->isExact())
6943      return;
6944  } else
6945    if (FloatingLiteral* FLR = dyn_cast<FloatingLiteral>(RightExprSansParen))
6946      if (FLR->isExact())
6947        return;
6948
6949  // Check for comparisons with builtin types.
6950  if (CallExpr* CL = dyn_cast<CallExpr>(LeftExprSansParen))
6951    if (CL->getBuiltinCallee())
6952      return;
6953
6954  if (CallExpr* CR = dyn_cast<CallExpr>(RightExprSansParen))
6955    if (CR->getBuiltinCallee())
6956      return;
6957
6958  // Emit the diagnostic.
6959  Diag(Loc, diag::warn_floatingpoint_eq)
6960    << LHS->getSourceRange() << RHS->getSourceRange();
6961}
6962
6963//===--- CHECK: Integer mixed-sign comparisons (-Wsign-compare) --------===//
6964//===--- CHECK: Lossy implicit conversions (-Wconversion) --------------===//
6965
6966namespace {
6967
6968/// Structure recording the 'active' range of an integer-valued
6969/// expression.
6970struct IntRange {
6971  /// The number of bits active in the int.
6972  unsigned Width;
6973
6974  /// True if the int is known not to have negative values.
6975  bool NonNegative;
6976
6977  IntRange(unsigned Width, bool NonNegative)
6978    : Width(Width), NonNegative(NonNegative)
6979  {}
6980
6981  /// Returns the range of the bool type.
6982  static IntRange forBoolType() {
6983    return IntRange(1, true);
6984  }
6985
6986  /// Returns the range of an opaque value of the given integral type.
6987  static IntRange forValueOfType(ASTContext &C, QualType T) {
6988    return forValueOfCanonicalType(C,
6989                          T->getCanonicalTypeInternal().getTypePtr());
6990  }
6991
6992  /// Returns the range of an opaque value of a canonical integral type.
6993  static IntRange forValueOfCanonicalType(ASTContext &C, const Type *T) {
6994    assert(T->isCanonicalUnqualified());
6995
6996    if (const VectorType *VT = dyn_cast<VectorType>(T))
6997      T = VT->getElementType().getTypePtr();
6998    if (const ComplexType *CT = dyn_cast<ComplexType>(T))
6999      T = CT->getElementType().getTypePtr();
7000    if (const AtomicType *AT = dyn_cast<AtomicType>(T))
7001      T = AT->getValueType().getTypePtr();
7002
7003    // For enum types, use the known bit width of the enumerators.
7004    if (const EnumType *ET = dyn_cast<EnumType>(T)) {
7005      EnumDecl *Enum = ET->getDecl();
7006      if (!Enum->isCompleteDefinition())
7007        return IntRange(C.getIntWidth(QualType(T, 0)), false);
7008
7009      unsigned NumPositive = Enum->getNumPositiveBits();
7010      unsigned NumNegative = Enum->getNumNegativeBits();
7011
7012      if (NumNegative == 0)
7013        return IntRange(NumPositive, true/*NonNegative*/);
7014      else
7015        return IntRange(std::max(NumPositive + 1, NumNegative),
7016                        false/*NonNegative*/);
7017    }
7018
7019    const BuiltinType *BT = cast<BuiltinType>(T);
7020    assert(BT->isInteger());
7021
7022    return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger());
7023  }
7024
7025  /// Returns the "target" range of a canonical integral type, i.e.
7026  /// the range of values expressible in the type.
7027  ///
7028  /// This matches forValueOfCanonicalType except that enums have the
7029  /// full range of their type, not the range of their enumerators.
7030  static IntRange forTargetOfCanonicalType(ASTContext &C, const Type *T) {
7031    assert(T->isCanonicalUnqualified());
7032
7033    if (const VectorType *VT = dyn_cast<VectorType>(T))
7034      T = VT->getElementType().getTypePtr();
7035    if (const ComplexType *CT = dyn_cast<ComplexType>(T))
7036      T = CT->getElementType().getTypePtr();
7037    if (const AtomicType *AT = dyn_cast<AtomicType>(T))
7038      T = AT->getValueType().getTypePtr();
7039    if (const EnumType *ET = dyn_cast<EnumType>(T))
7040      T = C.getCanonicalType(ET->getDecl()->getIntegerType()).getTypePtr();
7041
7042    const BuiltinType *BT = cast<BuiltinType>(T);
7043    assert(BT->isInteger());
7044
7045    return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger());
7046  }
7047
7048  /// Returns the supremum of two ranges: i.e. their conservative merge.
7049  static IntRange join(IntRange L, IntRange R) {
7050    return IntRange(std::max(L.Width, R.Width),
7051                    L.NonNegative && R.NonNegative);
7052  }
7053
7054  /// Returns the infinum of two ranges: i.e. their aggressive merge.
7055  static IntRange meet(IntRange L, IntRange R) {
7056    return IntRange(std::min(L.Width, R.Width),
7057                    L.NonNegative || R.NonNegative);
7058  }
7059};
7060
7061IntRange GetValueRange(ASTContext &C, llvm::APSInt &value, unsigned MaxWidth) {
7062  if (value.isSigned() && value.isNegative())
7063    return IntRange(value.getMinSignedBits(), false);
7064
7065  if (value.getBitWidth() > MaxWidth)
7066    value = value.trunc(MaxWidth);
7067
7068  // isNonNegative() just checks the sign bit without considering
7069  // signedness.
7070  return IntRange(value.getActiveBits(), true);
7071}
7072
7073IntRange GetValueRange(ASTContext &C, APValue &result, QualType Ty,
7074                       unsigned MaxWidth) {
7075  if (result.isInt())
7076    return GetValueRange(C, result.getInt(), MaxWidth);
7077
7078  if (result.isVector()) {
7079    IntRange R = GetValueRange(C, result.getVectorElt(0), Ty, MaxWidth);
7080    for (unsigned i = 1, e = result.getVectorLength(); i != e; ++i) {
7081      IntRange El = GetValueRange(C, result.getVectorElt(i), Ty, MaxWidth);
7082      R = IntRange::join(R, El);
7083    }
7084    return R;
7085  }
7086
7087  if (result.isComplexInt()) {
7088    IntRange R = GetValueRange(C, result.getComplexIntReal(), MaxWidth);
7089    IntRange I = GetValueRange(C, result.getComplexIntImag(), MaxWidth);
7090    return IntRange::join(R, I);
7091  }
7092
7093  // This can happen with lossless casts to intptr_t of "based" lvalues.
7094  // Assume it might use arbitrary bits.
7095  // FIXME: The only reason we need to pass the type in here is to get
7096  // the sign right on this one case.  It would be nice if APValue
7097  // preserved this.
7098  assert(result.isLValue() || result.isAddrLabelDiff());
7099  return IntRange(MaxWidth, Ty->isUnsignedIntegerOrEnumerationType());
7100}
7101
7102QualType GetExprType(const Expr *E) {
7103  QualType Ty = E->getType();
7104  if (const AtomicType *AtomicRHS = Ty->getAs<AtomicType>())
7105    Ty = AtomicRHS->getValueType();
7106  return Ty;
7107}
7108
7109/// Pseudo-evaluate the given integer expression, estimating the
7110/// range of values it might take.
7111///
7112/// \param MaxWidth - the width to which the value will be truncated
7113IntRange GetExprRange(ASTContext &C, const Expr *E, unsigned MaxWidth) {
7114  E = E->IgnoreParens();
7115
7116  // Try a full evaluation first.
7117  Expr::EvalResult result;
7118  if (E->EvaluateAsRValue(result, C))
7119    return GetValueRange(C, result.Val, GetExprType(E), MaxWidth);
7120
7121  // I think we only want to look through implicit casts here; if the
7122  // user has an explicit widening cast, we should treat the value as
7123  // being of the new, wider type.
7124  if (const auto *CE = dyn_cast<ImplicitCastExpr>(E)) {
7125    if (CE->getCastKind() == CK_NoOp || CE->getCastKind() == CK_LValueToRValue)
7126      return GetExprRange(C, CE->getSubExpr(), MaxWidth);
7127
7128    IntRange OutputTypeRange = IntRange::forValueOfType(C, GetExprType(CE));
7129
7130    bool isIntegerCast = CE->getCastKind() == CK_IntegralCast ||
7131                         CE->getCastKind() == CK_BooleanToSignedIntegral;
7132
7133    // Assume that non-integer casts can span the full range of the type.
7134    if (!isIntegerCast)
7135      return OutputTypeRange;
7136
7137    IntRange SubRange
7138      = GetExprRange(C, CE->getSubExpr(),
7139                     std::min(MaxWidth, OutputTypeRange.Width));
7140
7141    // Bail out if the subexpr's range is as wide as the cast type.
7142    if (SubRange.Width >= OutputTypeRange.Width)
7143      return OutputTypeRange;
7144
7145    // Otherwise, we take the smaller width, and we're non-negative if
7146    // either the output type or the subexpr is.
7147    return IntRange(SubRange.Width,
7148                    SubRange.NonNegative || OutputTypeRange.NonNegative);
7149  }
7150
7151  if (const auto *CO = dyn_cast<ConditionalOperator>(E)) {
7152    // If we can fold the condition, just take that operand.
7153    bool CondResult;
7154    if (CO->getCond()->EvaluateAsBooleanCondition(CondResult, C))
7155      return GetExprRange(C, CondResult ? CO->getTrueExpr()
7156                                        : CO->getFalseExpr(),
7157                          MaxWidth);
7158
7159    // Otherwise, conservatively merge.
7160    IntRange L = GetExprRange(C, CO->getTrueExpr(), MaxWidth);
7161    IntRange R = GetExprRange(C, CO->getFalseExpr(), MaxWidth);
7162    return IntRange::join(L, R);
7163  }
7164
7165  if (const auto *BO = dyn_cast<BinaryOperator>(E)) {
7166    switch (BO->getOpcode()) {
7167
7168    // Boolean-valued operations are single-bit and positive.
7169    case BO_LAnd:
7170    case BO_LOr:
7171    case BO_LT:
7172    case BO_GT:
7173    case BO_LE:
7174    case BO_GE:
7175    case BO_EQ:
7176    case BO_NE:
7177      return IntRange::forBoolType();
7178
7179    // The type of the assignments is the type of the LHS, so the RHS
7180    // is not necessarily the same type.
7181    case BO_MulAssign:
7182    case BO_DivAssign:
7183    case BO_RemAssign:
7184    case BO_AddAssign:
7185    case BO_SubAssign:
7186    case BO_XorAssign:
7187    case BO_OrAssign:
7188      // TODO: bitfields?
7189      return IntRange::forValueOfType(C, GetExprType(E));
7190
7191    // Simple assignments just pass through the RHS, which will have
7192    // been coerced to the LHS type.
7193    case BO_Assign:
7194      // TODO: bitfields?
7195      return GetExprRange(C, BO->getRHS(), MaxWidth);
7196
7197    // Operations with opaque sources are black-listed.
7198    case BO_PtrMemD:
7199    case BO_PtrMemI:
7200      return IntRange::forValueOfType(C, GetExprType(E));
7201
7202    // Bitwise-and uses the *infinum* of the two source ranges.
7203    case BO_And:
7204    case BO_AndAssign:
7205      return IntRange::meet(GetExprRange(C, BO->getLHS(), MaxWidth),
7206                            GetExprRange(C, BO->getRHS(), MaxWidth));
7207
7208    // Left shift gets black-listed based on a judgement call.
7209    case BO_Shl:
7210      // ...except that we want to treat '1 << (blah)' as logically
7211      // positive.  It's an important idiom.
7212      if (IntegerLiteral *I
7213            = dyn_cast<IntegerLiteral>(BO->getLHS()->IgnoreParenCasts())) {
7214        if (I->getValue() == 1) {
7215          IntRange R = IntRange::forValueOfType(C, GetExprType(E));
7216          return IntRange(R.Width, /*NonNegative*/ true);
7217        }
7218      }
7219      // fallthrough
7220
7221    case BO_ShlAssign:
7222      return IntRange::forValueOfType(C, GetExprType(E));
7223
7224    // Right shift by a constant can narrow its left argument.
7225    case BO_Shr:
7226    case BO_ShrAssign: {
7227      IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth);
7228
7229      // If the shift amount is a positive constant, drop the width by
7230      // that much.
7231      llvm::APSInt shift;
7232      if (BO->getRHS()->isIntegerConstantExpr(shift, C) &&
7233          shift.isNonNegative()) {
7234        unsigned zext = shift.getZExtValue();
7235        if (zext >= L.Width)
7236          L.Width = (L.NonNegative ? 0 : 1);
7237        else
7238          L.Width -= zext;
7239      }
7240
7241      return L;
7242    }
7243
7244    // Comma acts as its right operand.
7245    case BO_Comma:
7246      return GetExprRange(C, BO->getRHS(), MaxWidth);
7247
7248    // Black-list pointer subtractions.
7249    case BO_Sub:
7250      if (BO->getLHS()->getType()->isPointerType())
7251        return IntRange::forValueOfType(C, GetExprType(E));
7252      break;
7253
7254    // The width of a division result is mostly determined by the size
7255    // of the LHS.
7256    case BO_Div: {
7257      // Don't 'pre-truncate' the operands.
7258      unsigned opWidth = C.getIntWidth(GetExprType(E));
7259      IntRange L = GetExprRange(C, BO->getLHS(), opWidth);
7260
7261      // If the divisor is constant, use that.
7262      llvm::APSInt divisor;
7263      if (BO->getRHS()->isIntegerConstantExpr(divisor, C)) {
7264        unsigned log2 = divisor.logBase2(); // floor(log_2(divisor))
7265        if (log2 >= L.Width)
7266          L.Width = (L.NonNegative ? 0 : 1);
7267        else
7268          L.Width = std::min(L.Width - log2, MaxWidth);
7269        return L;
7270      }
7271
7272      // Otherwise, just use the LHS's width.
7273      IntRange R = GetExprRange(C, BO->getRHS(), opWidth);
7274      return IntRange(L.Width, L.NonNegative && R.NonNegative);
7275    }
7276
7277    // The result of a remainder can't be larger than the result of
7278    // either side.
7279    case BO_Rem: {
7280      // Don't 'pre-truncate' the operands.
7281      unsigned opWidth = C.getIntWidth(GetExprType(E));
7282      IntRange L = GetExprRange(C, BO->getLHS(), opWidth);
7283      IntRange R = GetExprRange(C, BO->getRHS(), opWidth);
7284
7285      IntRange meet = IntRange::meet(L, R);
7286      meet.Width = std::min(meet.Width, MaxWidth);
7287      return meet;
7288    }
7289
7290    // The default behavior is okay for these.
7291    case BO_Mul:
7292    case BO_Add:
7293    case BO_Xor:
7294    case BO_Or:
7295      break;
7296    }
7297
7298    // The default case is to treat the operation as if it were closed
7299    // on the narrowest type that encompasses both operands.
7300    IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth);
7301    IntRange R = GetExprRange(C, BO->getRHS(), MaxWidth);
7302    return IntRange::join(L, R);
7303  }
7304
7305  if (const auto *UO = dyn_cast<UnaryOperator>(E)) {
7306    switch (UO->getOpcode()) {
7307    // Boolean-valued operations are white-listed.
7308    case UO_LNot:
7309      return IntRange::forBoolType();
7310
7311    // Operations with opaque sources are black-listed.
7312    case UO_Deref:
7313    case UO_AddrOf: // should be impossible
7314      return IntRange::forValueOfType(C, GetExprType(E));
7315
7316    default:
7317      return GetExprRange(C, UO->getSubExpr(), MaxWidth);
7318    }
7319  }
7320
7321  if (const auto *OVE = dyn_cast<OpaqueValueExpr>(E))
7322    return GetExprRange(C, OVE->getSourceExpr(), MaxWidth);
7323
7324  if (const auto *BitField = E->getSourceBitField())
7325    return IntRange(BitField->getBitWidthValue(C),
7326                    BitField->getType()->isUnsignedIntegerOrEnumerationType());
7327
7328  return IntRange::forValueOfType(C, GetExprType(E));
7329}
7330
7331IntRange GetExprRange(ASTContext &C, const Expr *E) {
7332  return GetExprRange(C, E, C.getIntWidth(GetExprType(E)));
7333}
7334
7335/// Checks whether the given value, which currently has the given
7336/// source semantics, has the same value when coerced through the
7337/// target semantics.
7338bool IsSameFloatAfterCast(const llvm::APFloat &value,
7339                          const llvm::fltSemantics &Src,
7340                          const llvm::fltSemantics &Tgt) {
7341  llvm::APFloat truncated = value;
7342
7343  bool ignored;
7344  truncated.convert(Src, llvm::APFloat::rmNearestTiesToEven, &ignored);
7345  truncated.convert(Tgt, llvm::APFloat::rmNearestTiesToEven, &ignored);
7346
7347  return truncated.bitwiseIsEqual(value);
7348}
7349
7350/// Checks whether the given value, which currently has the given
7351/// source semantics, has the same value when coerced through the
7352/// target semantics.
7353///
7354/// The value might be a vector of floats (or a complex number).
7355bool IsSameFloatAfterCast(const APValue &value,
7356                          const llvm::fltSemantics &Src,
7357                          const llvm::fltSemantics &Tgt) {
7358  if (value.isFloat())
7359    return IsSameFloatAfterCast(value.getFloat(), Src, Tgt);
7360
7361  if (value.isVector()) {
7362    for (unsigned i = 0, e = value.getVectorLength(); i != e; ++i)
7363      if (!IsSameFloatAfterCast(value.getVectorElt(i), Src, Tgt))
7364        return false;
7365    return true;
7366  }
7367
7368  assert(value.isComplexFloat());
7369  return (IsSameFloatAfterCast(value.getComplexFloatReal(), Src, Tgt) &&
7370          IsSameFloatAfterCast(value.getComplexFloatImag(), Src, Tgt));
7371}
7372
7373void AnalyzeImplicitConversions(Sema &S, Expr *E, SourceLocation CC);
7374
7375bool IsZero(Sema &S, Expr *E) {
7376  // Suppress cases where we are comparing against an enum constant.
7377  if (const DeclRefExpr *DR =
7378      dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()))
7379    if (isa<EnumConstantDecl>(DR->getDecl()))
7380      return false;
7381
7382  // Suppress cases where the '0' value is expanded from a macro.
7383  if (E->getLocStart().isMacroID())
7384    return false;
7385
7386  llvm::APSInt Value;
7387  return E->isIntegerConstantExpr(Value, S.Context) && Value == 0;
7388}
7389
7390bool HasEnumType(Expr *E) {
7391  // Strip off implicit integral promotions.
7392  while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
7393    if (ICE->getCastKind() != CK_IntegralCast &&
7394        ICE->getCastKind() != CK_NoOp)
7395      break;
7396    E = ICE->getSubExpr();
7397  }
7398
7399  return E->getType()->isEnumeralType();
7400}
7401
7402void CheckTrivialUnsignedComparison(Sema &S, BinaryOperator *E) {
7403  // Disable warning in template instantiations.
7404  if (!S.ActiveTemplateInstantiations.empty())
7405    return;
7406
7407  BinaryOperatorKind op = E->getOpcode();
7408  if (E->isValueDependent())
7409    return;
7410
7411  if (op == BO_LT && IsZero(S, E->getRHS())) {
7412    S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison)
7413      << "< 0" << "false" << HasEnumType(E->getLHS())
7414      << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
7415  } else if (op == BO_GE && IsZero(S, E->getRHS())) {
7416    S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison)
7417      << ">= 0" << "true" << HasEnumType(E->getLHS())
7418      << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
7419  } else if (op == BO_GT && IsZero(S, E->getLHS())) {
7420    S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison)
7421      << "0 >" << "false" << HasEnumType(E->getRHS())
7422      << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
7423  } else if (op == BO_LE && IsZero(S, E->getLHS())) {
7424    S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison)
7425      << "0 <=" << "true" << HasEnumType(E->getRHS())
7426      << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
7427  }
7428}
7429
7430void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E, Expr *Constant,
7431                                  Expr *Other, const llvm::APSInt &Value,
7432                                  bool RhsConstant) {
7433  // Disable warning in template instantiations.
7434  if (!S.ActiveTemplateInstantiations.empty())
7435    return;
7436
7437  // TODO: Investigate using GetExprRange() to get tighter bounds
7438  // on the bit ranges.
7439  QualType OtherT = Other->getType();
7440  if (const auto *AT = OtherT->getAs<AtomicType>())
7441    OtherT = AT->getValueType();
7442  IntRange OtherRange = IntRange::forValueOfType(S.Context, OtherT);
7443  unsigned OtherWidth = OtherRange.Width;
7444
7445  bool OtherIsBooleanType = Other->isKnownToHaveBooleanValue();
7446
7447  // 0 values are handled later by CheckTrivialUnsignedComparison().
7448  if ((Value == 0) && (!OtherIsBooleanType))
7449    return;
7450
7451  BinaryOperatorKind op = E->getOpcode();
7452  bool IsTrue = true;
7453
7454  // Used for diagnostic printout.
7455  enum {
7456    LiteralConstant = 0,
7457    CXXBoolLiteralTrue,
7458    CXXBoolLiteralFalse
7459  } LiteralOrBoolConstant = LiteralConstant;
7460
7461  if (!OtherIsBooleanType) {
7462    QualType ConstantT = Constant->getType();
7463    QualType CommonT = E->getLHS()->getType();
7464
7465    if (S.Context.hasSameUnqualifiedType(OtherT, ConstantT))
7466      return;
7467    assert((OtherT->isIntegerType() && ConstantT->isIntegerType()) &&
7468           "comparison with non-integer type");
7469
7470    bool ConstantSigned = ConstantT->isSignedIntegerType();
7471    bool CommonSigned = CommonT->isSignedIntegerType();
7472
7473    bool EqualityOnly = false;
7474
7475    if (CommonSigned) {
7476      // The common type is signed, therefore no signed to unsigned conversion.
7477      if (!OtherRange.NonNegative) {
7478        // Check that the constant is representable in type OtherT.
7479        if (ConstantSigned) {
7480          if (OtherWidth >= Value.getMinSignedBits())
7481            return;
7482        } else { // !ConstantSigned
7483          if (OtherWidth >= Value.getActiveBits() + 1)
7484            return;
7485        }
7486      } else { // !OtherSigned
7487               // Check that the constant is representable in type OtherT.
7488        // Negative values are out of range.
7489        if (ConstantSigned) {
7490          if (Value.isNonNegative() && OtherWidth >= Value.getActiveBits())
7491            return;
7492        } else { // !ConstantSigned
7493          if (OtherWidth >= Value.getActiveBits())
7494            return;
7495        }
7496      }
7497    } else { // !CommonSigned
7498      if (OtherRange.NonNegative) {
7499        if (OtherWidth >= Value.getActiveBits())
7500          return;
7501      } else { // OtherSigned
7502        assert(!ConstantSigned &&
7503               "Two signed types converted to unsigned types.");
7504        // Check to see if the constant is representable in OtherT.
7505        if (OtherWidth > Value.getActiveBits())
7506          return;
7507        // Check to see if the constant is equivalent to a negative value
7508        // cast to CommonT.
7509        if (S.Context.getIntWidth(ConstantT) ==
7510                S.Context.getIntWidth(CommonT) &&
7511            Value.isNegative() && Value.getMinSignedBits() <= OtherWidth)
7512          return;
7513        // The constant value rests between values that OtherT can represent
7514        // after conversion.  Relational comparison still works, but equality
7515        // comparisons will be tautological.
7516        EqualityOnly = true;
7517      }
7518    }
7519
7520    bool PositiveConstant = !ConstantSigned || Value.isNonNegative();
7521
7522    if (op == BO_EQ || op == BO_NE) {
7523      IsTrue = op == BO_NE;
7524    } else if (EqualityOnly) {
7525      return;
7526    } else if (RhsConstant) {
7527      if (op == BO_GT || op == BO_GE)
7528        IsTrue = !PositiveConstant;
7529      else // op == BO_LT || op == BO_LE
7530        IsTrue = PositiveConstant;
7531    } else {
7532      if (op == BO_LT || op == BO_LE)
7533        IsTrue = !PositiveConstant;
7534      else // op == BO_GT || op == BO_GE
7535        IsTrue = PositiveConstant;
7536    }
7537  } else {
7538    // Other isKnownToHaveBooleanValue
7539    enum CompareBoolWithConstantResult { AFals, ATrue, Unkwn };
7540    enum ConstantValue { LT_Zero, Zero, One, GT_One, SizeOfConstVal };
7541    enum ConstantSide { Lhs, Rhs, SizeOfConstSides };
7542
7543    static const struct LinkedConditions {
7544      CompareBoolWithConstantResult BO_LT_OP[SizeOfConstSides][SizeOfConstVal];
7545      CompareBoolWithConstantResult BO_GT_OP[SizeOfConstSides][SizeOfConstVal];
7546      CompareBoolWithConstantResult BO_LE_OP[SizeOfConstSides][SizeOfConstVal];
7547      CompareBoolWithConstantResult BO_GE_OP[SizeOfConstSides][SizeOfConstVal];
7548      CompareBoolWithConstantResult BO_EQ_OP[SizeOfConstSides][SizeOfConstVal];
7549      CompareBoolWithConstantResult BO_NE_OP[SizeOfConstSides][SizeOfConstVal];
7550
7551    } TruthTable = {
7552        // Constant on LHS.              | Constant on RHS.              |
7553        // LT_Zero| Zero  | One   |GT_One| LT_Zero| Zero  | One   |GT_One|
7554        { { ATrue, Unkwn, AFals, AFals }, { AFals, AFals, Unkwn, ATrue } },
7555        { { AFals, AFals, Unkwn, ATrue }, { ATrue, Unkwn, AFals, AFals } },
7556        { { ATrue, ATrue, Unkwn, AFals }, { AFals, Unkwn, ATrue, ATrue } },
7557        { { AFals, Unkwn, ATrue, ATrue }, { ATrue, ATrue, Unkwn, AFals } },
7558        { { AFals, Unkwn, Unkwn, AFals }, { AFals, Unkwn, Unkwn, AFals } },
7559        { { ATrue, Unkwn, Unkwn, ATrue }, { ATrue, Unkwn, Unkwn, ATrue } }
7560      };
7561
7562    bool ConstantIsBoolLiteral = isa<CXXBoolLiteralExpr>(Constant);
7563
7564    enum ConstantValue ConstVal = Zero;
7565    if (Value.isUnsigned() || Value.isNonNegative()) {
7566      if (Value == 0) {
7567        LiteralOrBoolConstant =
7568            ConstantIsBoolLiteral ? CXXBoolLiteralFalse : LiteralConstant;
7569        ConstVal = Zero;
7570      } else if (Value == 1) {
7571        LiteralOrBoolConstant =
7572            ConstantIsBoolLiteral ? CXXBoolLiteralTrue : LiteralConstant;
7573        ConstVal = One;
7574      } else {
7575        LiteralOrBoolConstant = LiteralConstant;
7576        ConstVal = GT_One;
7577      }
7578    } else {
7579      ConstVal = LT_Zero;
7580    }
7581
7582    CompareBoolWithConstantResult CmpRes;
7583
7584    switch (op) {
7585    case BO_LT:
7586      CmpRes = TruthTable.BO_LT_OP[RhsConstant][ConstVal];
7587      break;
7588    case BO_GT:
7589      CmpRes = TruthTable.BO_GT_OP[RhsConstant][ConstVal];
7590      break;
7591    case BO_LE:
7592      CmpRes = TruthTable.BO_LE_OP[RhsConstant][ConstVal];
7593      break;
7594    case BO_GE:
7595      CmpRes = TruthTable.BO_GE_OP[RhsConstant][ConstVal];
7596      break;
7597    case BO_EQ:
7598      CmpRes = TruthTable.BO_EQ_OP[RhsConstant][ConstVal];
7599      break;
7600    case BO_NE:
7601      CmpRes = TruthTable.BO_NE_OP[RhsConstant][ConstVal];
7602      break;
7603    default:
7604      CmpRes = Unkwn;
7605      break;
7606    }
7607
7608    if (CmpRes == AFals) {
7609      IsTrue = false;
7610    } else if (CmpRes == ATrue) {
7611      IsTrue = true;
7612    } else {
7613      return;
7614    }
7615  }
7616
7617  // If this is a comparison to an enum constant, include that
7618  // constant in the diagnostic.
7619  const EnumConstantDecl *ED = nullptr;
7620  if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Constant))
7621    ED = dyn_cast<EnumConstantDecl>(DR->getDecl());
7622
7623  SmallString<64> PrettySourceValue;
7624  llvm::raw_svector_ostream OS(PrettySourceValue);
7625  if (ED)
7626    OS << '\'' << *ED << "' (" << Value << ")";
7627  else
7628    OS << Value;
7629
7630  S.DiagRuntimeBehavior(
7631    E->getOperatorLoc(), E,
7632    S.PDiag(diag::warn_out_of_range_compare)
7633        << OS.str() << LiteralOrBoolConstant
7634        << OtherT << (OtherIsBooleanType && !OtherT->isBooleanType()) << IsTrue
7635        << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange());
7636}
7637
7638/// Analyze the operands of the given comparison.  Implements the
7639/// fallback case from AnalyzeComparison.
7640void AnalyzeImpConvsInComparison(Sema &S, BinaryOperator *E) {
7641  AnalyzeImplicitConversions(S, E->getLHS(), E->getOperatorLoc());
7642  AnalyzeImplicitConversions(S, E->getRHS(), E->getOperatorLoc());
7643}
7644
7645/// \brief Implements -Wsign-compare.
7646///
7647/// \param E the binary operator to check for warnings
7648void AnalyzeComparison(Sema &S, BinaryOperator *E) {
7649  // The type the comparison is being performed in.
7650  QualType T = E->getLHS()->getType();
7651
7652  // Only analyze comparison operators where both sides have been converted to
7653  // the same type.
7654  if (!S.Context.hasSameUnqualifiedType(T, E->getRHS()->getType()))
7655    return AnalyzeImpConvsInComparison(S, E);
7656
7657  // Don't analyze value-dependent comparisons directly.
7658  if (E->isValueDependent())
7659    return AnalyzeImpConvsInComparison(S, E);
7660
7661  Expr *LHS = E->getLHS()->IgnoreParenImpCasts();
7662  Expr *RHS = E->getRHS()->IgnoreParenImpCasts();
7663
7664  bool IsComparisonConstant = false;
7665
7666  // Check whether an integer constant comparison results in a value
7667  // of 'true' or 'false'.
7668  if (T->isIntegralType(S.Context)) {
7669    llvm::APSInt RHSValue;
7670    bool IsRHSIntegralLiteral =
7671      RHS->isIntegerConstantExpr(RHSValue, S.Context);
7672    llvm::APSInt LHSValue;
7673    bool IsLHSIntegralLiteral =
7674      LHS->isIntegerConstantExpr(LHSValue, S.Context);
7675    if (IsRHSIntegralLiteral && !IsLHSIntegralLiteral)
7676        DiagnoseOutOfRangeComparison(S, E, RHS, LHS, RHSValue, true);
7677    else if (!IsRHSIntegralLiteral && IsLHSIntegralLiteral)
7678      DiagnoseOutOfRangeComparison(S, E, LHS, RHS, LHSValue, false);
7679    else
7680      IsComparisonConstant =
7681        (IsRHSIntegralLiteral && IsLHSIntegralLiteral);
7682  } else if (!T->hasUnsignedIntegerRepresentation())
7683      IsComparisonConstant = E->isIntegerConstantExpr(S.Context);
7684
7685  // We don't do anything special if this isn't an unsigned integral
7686  // comparison:  we're only interested in integral comparisons, and
7687  // signed comparisons only happen in cases we don't care to warn about.
7688  //
7689  // We also don't care about value-dependent expressions or expressions
7690  // whose result is a constant.
7691  if (!T->hasUnsignedIntegerRepresentation() || IsComparisonConstant)
7692    return AnalyzeImpConvsInComparison(S, E);
7693
7694  // Check to see if one of the (unmodified) operands is of different
7695  // signedness.
7696  Expr *signedOperand, *unsignedOperand;
7697  if (LHS->getType()->hasSignedIntegerRepresentation()) {
7698    assert(!RHS->getType()->hasSignedIntegerRepresentation() &&
7699           "unsigned comparison between two signed integer expressions?");
7700    signedOperand = LHS;
7701    unsignedOperand = RHS;
7702  } else if (RHS->getType()->hasSignedIntegerRepresentation()) {
7703    signedOperand = RHS;
7704    unsignedOperand = LHS;
7705  } else {
7706    CheckTrivialUnsignedComparison(S, E);
7707    return AnalyzeImpConvsInComparison(S, E);
7708  }
7709
7710  // Otherwise, calculate the effective range of the signed operand.
7711  IntRange signedRange = GetExprRange(S.Context, signedOperand);
7712
7713  // Go ahead and analyze implicit conversions in the operands.  Note
7714  // that we skip the implicit conversions on both sides.
7715  AnalyzeImplicitConversions(S, LHS, E->getOperatorLoc());
7716  AnalyzeImplicitConversions(S, RHS, E->getOperatorLoc());
7717
7718  // If the signed range is non-negative, -Wsign-compare won't fire,
7719  // but we should still check for comparisons which are always true
7720  // or false.
7721  if (signedRange.NonNegative)
7722    return CheckTrivialUnsignedComparison(S, E);
7723
7724  // For (in)equality comparisons, if the unsigned operand is a
7725  // constant which cannot collide with a overflowed signed operand,
7726  // then reinterpreting the signed operand as unsigned will not
7727  // change the result of the comparison.
7728  if (E->isEqualityOp()) {
7729    unsigned comparisonWidth = S.Context.getIntWidth(T);
7730    IntRange unsignedRange = GetExprRange(S.Context, unsignedOperand);
7731
7732    // We should never be unable to prove that the unsigned operand is
7733    // non-negative.
7734    assert(unsignedRange.NonNegative && "unsigned range includes negative?");
7735
7736    if (unsignedRange.Width < comparisonWidth)
7737      return;
7738  }
7739
7740  S.DiagRuntimeBehavior(E->getOperatorLoc(), E,
7741    S.PDiag(diag::warn_mixed_sign_comparison)
7742      << LHS->getType() << RHS->getType()
7743      << LHS->getSourceRange() << RHS->getSourceRange());
7744}
7745
7746/// Analyzes an attempt to assign the given value to a bitfield.
7747///
7748/// Returns true if there was something fishy about the attempt.
7749bool AnalyzeBitFieldAssignment(Sema &S, FieldDecl *Bitfield, Expr *Init,
7750                               SourceLocation InitLoc) {
7751  assert(Bitfield->isBitField());
7752  if (Bitfield->isInvalidDecl())
7753    return false;
7754
7755  // White-list bool bitfields.
7756  if (Bitfield->getType()->isBooleanType())
7757    return false;
7758
7759  // Ignore value- or type-dependent expressions.
7760  if (Bitfield->getBitWidth()->isValueDependent() ||
7761      Bitfield->getBitWidth()->isTypeDependent() ||
7762      Init->isValueDependent() ||
7763      Init->isTypeDependent())
7764    return false;
7765
7766  Expr *OriginalInit = Init->IgnoreParenImpCasts();
7767
7768  llvm::APSInt Value;
7769  if (!OriginalInit->EvaluateAsInt(Value, S.Context, Expr::SE_AllowSideEffects))
7770    return false;
7771
7772  unsigned OriginalWidth = Value.getBitWidth();
7773  unsigned FieldWidth = Bitfield->getBitWidthValue(S.Context);
7774
7775  if (OriginalWidth <= FieldWidth)
7776    return false;
7777
7778  // Compute the value which the bitfield will contain.
7779  llvm::APSInt TruncatedValue = Value.trunc(FieldWidth);
7780  TruncatedValue.setIsSigned(Bitfield->getType()->isSignedIntegerType());
7781
7782  // Check whether the stored value is equal to the original value.
7783  TruncatedValue = TruncatedValue.extend(OriginalWidth);
7784  if (llvm::APSInt::isSameValue(Value, TruncatedValue))
7785    return false;
7786
7787  // Special-case bitfields of width 1: booleans are naturally 0/1, and
7788  // therefore don't strictly fit into a signed bitfield of width 1.
7789  if (FieldWidth == 1 && Value == 1)
7790    return false;
7791
7792  std::string PrettyValue = Value.toString(10);
7793  std::string PrettyTrunc = TruncatedValue.toString(10);
7794
7795  S.Diag(InitLoc, diag::warn_impcast_bitfield_precision_constant)
7796    << PrettyValue << PrettyTrunc << OriginalInit->getType()
7797    << Init->getSourceRange();
7798
7799  return true;
7800}
7801
7802/// Analyze the given simple or compound assignment for warning-worthy
7803/// operations.
7804void AnalyzeAssignment(Sema &S, BinaryOperator *E) {
7805  // Just recurse on the LHS.
7806  AnalyzeImplicitConversions(S, E->getLHS(), E->getOperatorLoc());
7807
7808  // We want to recurse on the RHS as normal unless we're assigning to
7809  // a bitfield.
7810  if (FieldDecl *Bitfield = E->getLHS()->getSourceBitField()) {
7811    if (AnalyzeBitFieldAssignment(S, Bitfield, E->getRHS(),
7812                                  E->getOperatorLoc())) {
7813      // Recurse, ignoring any implicit conversions on the RHS.
7814      return AnalyzeImplicitConversions(S, E->getRHS()->IgnoreParenImpCasts(),
7815                                        E->getOperatorLoc());
7816    }
7817  }
7818
7819  AnalyzeImplicitConversions(S, E->getRHS(), E->getOperatorLoc());
7820}
7821
7822/// Diagnose an implicit cast;  purely a helper for CheckImplicitConversion.
7823void DiagnoseImpCast(Sema &S, Expr *E, QualType SourceType, QualType T,
7824                     SourceLocation CContext, unsigned diag,
7825                     bool pruneControlFlow = false) {
7826  if (pruneControlFlow) {
7827    S.DiagRuntimeBehavior(E->getExprLoc(), E,
7828                          S.PDiag(diag)
7829                            << SourceType << T << E->getSourceRange()
7830                            << SourceRange(CContext));
7831    return;
7832  }
7833  S.Diag(E->getExprLoc(), diag)
7834    << SourceType << T << E->getSourceRange() << SourceRange(CContext);
7835}
7836
7837/// Diagnose an implicit cast;  purely a helper for CheckImplicitConversion.
7838void DiagnoseImpCast(Sema &S, Expr *E, QualType T, SourceLocation CContext,
7839                     unsigned diag, bool pruneControlFlow = false) {
7840  DiagnoseImpCast(S, E, E->getType(), T, CContext, diag, pruneControlFlow);
7841}
7842
7843
7844/// Diagnose an implicit cast from a floating point value to an integer value.
7845void DiagnoseFloatingImpCast(Sema &S, Expr *E, QualType T,
7846
7847                             SourceLocation CContext) {
7848  const bool IsBool = T->isSpecificBuiltinType(BuiltinType::Bool);
7849  const bool PruneWarnings = !S.ActiveTemplateInstantiations.empty();
7850
7851  Expr *InnerE = E->IgnoreParenImpCasts();
7852  // We also want to warn on, e.g., "int i = -1.234"
7853  if (UnaryOperator *UOp = dyn_cast<UnaryOperator>(InnerE))
7854    if (UOp->getOpcode() == UO_Minus || UOp->getOpcode() == UO_Plus)
7855      InnerE = UOp->getSubExpr()->IgnoreParenImpCasts();
7856
7857  const bool IsLiteral =
7858      isa<FloatingLiteral>(E) || isa<FloatingLiteral>(InnerE);
7859
7860  llvm::APFloat Value(0.0);
7861  bool IsConstant =
7862    E->EvaluateAsFloat(Value, S.Context, Expr::SE_AllowSideEffects);
7863  if (!IsConstant) {
7864    return DiagnoseImpCast(S, E, T, CContext,
7865                           diag::warn_impcast_float_integer, PruneWarnings);
7866  }
7867
7868  bool isExact = false;
7869
7870  llvm::APSInt IntegerValue(S.Context.getIntWidth(T),
7871                            T->hasUnsignedIntegerRepresentation());
7872  if (Value.convertToInteger(IntegerValue, llvm::APFloat::rmTowardZero,
7873                             &isExact) == llvm::APFloat::opOK &&
7874      isExact) {
7875    if (IsLiteral) return;
7876    return DiagnoseImpCast(S, E, T, CContext, diag::warn_impcast_float_integer,
7877                           PruneWarnings);
7878  }
7879
7880  unsigned DiagID = 0;
7881  if (IsLiteral) {
7882    // Warn on floating point literal to integer.
7883    DiagID = diag::warn_impcast_literal_float_to_integer;
7884  } else if (IntegerValue == 0) {
7885    if (Value.isZero()) {  // Skip -0.0 to 0 conversion.
7886      return DiagnoseImpCast(S, E, T, CContext,
7887                             diag::warn_impcast_float_integer, PruneWarnings);
7888    }
7889    // Warn on non-zero to zero conversion.
7890    DiagID = diag::warn_impcast_float_to_integer_zero;
7891  } else {
7892    if (IntegerValue.isUnsigned()) {
7893      if (!IntegerValue.isMaxValue()) {
7894        return DiagnoseImpCast(S, E, T, CContext,
7895                               diag::warn_impcast_float_integer, PruneWarnings);
7896      }
7897    } else {  // IntegerValue.isSigned()
7898      if (!IntegerValue.isMaxSignedValue() &&
7899          !IntegerValue.isMinSignedValue()) {
7900        return DiagnoseImpCast(S, E, T, CContext,
7901                               diag::warn_impcast_float_integer, PruneWarnings);
7902      }
7903    }
7904    // Warn on evaluatable floating point expression to integer conversion.
7905    DiagID = diag::warn_impcast_float_to_integer;
7906  }
7907
7908  // FIXME: Force the precision of the source value down so we don't print
7909  // digits which are usually useless (we don't really care here if we
7910  // truncate a digit by accident in edge cases).  Ideally, APFloat::toString
7911  // would automatically print the shortest representation, but it's a bit
7912  // tricky to implement.
7913  SmallString<16> PrettySourceValue;
7914  unsigned precision = llvm::APFloat::semanticsPrecision(Value.getSemantics());
7915  precision = (precision * 59 + 195) / 196;
7916  Value.toString(PrettySourceValue, precision);
7917
7918  SmallString<16> PrettyTargetValue;
7919  if (IsBool)
7920    PrettyTargetValue = Value.isZero() ? "false" : "true";
7921  else
7922    IntegerValue.toString(PrettyTargetValue);
7923
7924  if (PruneWarnings) {
7925    S.DiagRuntimeBehavior(E->getExprLoc(), E,
7926                          S.PDiag(DiagID)
7927                              << E->getType() << T.getUnqualifiedType()
7928                              << PrettySourceValue << PrettyTargetValue
7929                              << E->getSourceRange() << SourceRange(CContext));
7930  } else {
7931    S.Diag(E->getExprLoc(), DiagID)
7932        << E->getType() << T.getUnqualifiedType() << PrettySourceValue
7933        << PrettyTargetValue << E->getSourceRange() << SourceRange(CContext);
7934  }
7935}
7936
7937std::string PrettyPrintInRange(const llvm::APSInt &Value, IntRange Range) {
7938  if (!Range.Width) return "0";
7939
7940  llvm::APSInt ValueInRange = Value;
7941  ValueInRange.setIsSigned(!Range.NonNegative);
7942  ValueInRange = ValueInRange.trunc(Range.Width);
7943  return ValueInRange.toString(10);
7944}
7945
7946bool IsImplicitBoolFloatConversion(Sema &S, Expr *Ex, bool ToBool) {
7947  if (!isa<ImplicitCastExpr>(Ex))
7948    return false;
7949
7950  Expr *InnerE = Ex->IgnoreParenImpCasts();
7951  const Type *Target = S.Context.getCanonicalType(Ex->getType()).getTypePtr();
7952  const Type *Source =
7953    S.Context.getCanonicalType(InnerE->getType()).getTypePtr();
7954  if (Target->isDependentType())
7955    return false;
7956
7957  const BuiltinType *FloatCandidateBT =
7958    dyn_cast<BuiltinType>(ToBool ? Source : Target);
7959  const Type *BoolCandidateType = ToBool ? Target : Source;
7960
7961  return (BoolCandidateType->isSpecificBuiltinType(BuiltinType::Bool) &&
7962          FloatCandidateBT && (FloatCandidateBT->isFloatingPoint()));
7963}
7964
7965void CheckImplicitArgumentConversions(Sema &S, CallExpr *TheCall,
7966                                      SourceLocation CC) {
7967  unsigned NumArgs = TheCall->getNumArgs();
7968  for (unsigned i = 0; i < NumArgs; ++i) {
7969    Expr *CurrA = TheCall->getArg(i);
7970    if (!IsImplicitBoolFloatConversion(S, CurrA, true))
7971      continue;
7972
7973    bool IsSwapped = ((i > 0) &&
7974        IsImplicitBoolFloatConversion(S, TheCall->getArg(i - 1), false));
7975    IsSwapped |= ((i < (NumArgs - 1)) &&
7976        IsImplicitBoolFloatConversion(S, TheCall->getArg(i + 1), false));
7977    if (IsSwapped) {
7978      // Warn on this floating-point to bool conversion.
7979      DiagnoseImpCast(S, CurrA->IgnoreParenImpCasts(),
7980                      CurrA->getType(), CC,
7981                      diag::warn_impcast_floating_point_to_bool);
7982    }
7983  }
7984}
7985
7986void DiagnoseNullConversion(Sema &S, Expr *E, QualType T, SourceLocation CC) {
7987  if (S.Diags.isIgnored(diag::warn_impcast_null_pointer_to_integer,
7988                        E->getExprLoc()))
7989    return;
7990
7991  // Don't warn on functions which have return type nullptr_t.
7992  if (isa<CallExpr>(E))
7993    return;
7994
7995  // Check for NULL (GNUNull) or nullptr (CXX11_nullptr).
7996  const Expr::NullPointerConstantKind NullKind =
7997      E->isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull);
7998  if (NullKind != Expr::NPCK_GNUNull && NullKind != Expr::NPCK_CXX11_nullptr)
7999    return;
8000
8001  // Return if target type is a safe conversion.
8002  if (T->isAnyPointerType() || T->isBlockPointerType() ||
8003      T->isMemberPointerType() || !T->isScalarType() || T->isNullPtrType())
8004    return;
8005
8006  SourceLocation Loc = E->getSourceRange().getBegin();
8007
8008  // Venture through the macro stacks to get to the source of macro arguments.
8009  // The new location is a better location than the complete location that was
8010  // passed in.
8011  while (S.SourceMgr.isMacroArgExpansion(Loc))
8012    Loc = S.SourceMgr.getImmediateMacroCallerLoc(Loc);
8013
8014  while (S.SourceMgr.isMacroArgExpansion(CC))
8015    CC = S.SourceMgr.getImmediateMacroCallerLoc(CC);
8016
8017  // __null is usually wrapped in a macro.  Go up a macro if that is the case.
8018  if (NullKind == Expr::NPCK_GNUNull && Loc.isMacroID()) {
8019    StringRef MacroName = Lexer::getImmediateMacroNameForDiagnostics(
8020        Loc, S.SourceMgr, S.getLangOpts());
8021    if (MacroName == "NULL")
8022      Loc = S.SourceMgr.getImmediateExpansionRange(Loc).first;
8023  }
8024
8025  // Only warn if the null and context location are in the same macro expansion.
8026  if (S.SourceMgr.getFileID(Loc) != S.SourceMgr.getFileID(CC))
8027    return;
8028
8029  S.Diag(Loc, diag::warn_impcast_null_pointer_to_integer)
8030      << (NullKind == Expr::NPCK_CXX11_nullptr) << T << clang::SourceRange(CC)
8031      << FixItHint::CreateReplacement(Loc,
8032                                      S.getFixItZeroLiteralForType(T, Loc));
8033}
8034
8035void checkObjCArrayLiteral(Sema &S, QualType TargetType,
8036                           ObjCArrayLiteral *ArrayLiteral);
8037void checkObjCDictionaryLiteral(Sema &S, QualType TargetType,
8038                                ObjCDictionaryLiteral *DictionaryLiteral);
8039
8040/// Check a single element within a collection literal against the
8041/// target element type.
8042void checkObjCCollectionLiteralElement(Sema &S, QualType TargetElementType,
8043                                       Expr *Element, unsigned ElementKind) {
8044  // Skip a bitcast to 'id' or qualified 'id'.
8045  if (auto ICE = dyn_cast<ImplicitCastExpr>(Element)) {
8046    if (ICE->getCastKind() == CK_BitCast &&
8047        ICE->getSubExpr()->getType()->getAs<ObjCObjectPointerType>())
8048      Element = ICE->getSubExpr();
8049  }
8050
8051  QualType ElementType = Element->getType();
8052  ExprResult ElementResult(Element);
8053  if (ElementType->getAs<ObjCObjectPointerType>() &&
8054      S.CheckSingleAssignmentConstraints(TargetElementType,
8055                                         ElementResult,
8056                                         false, false)
8057        != Sema::Compatible) {
8058    S.Diag(Element->getLocStart(),
8059           diag::warn_objc_collection_literal_element)
8060      << ElementType << ElementKind << TargetElementType
8061      << Element->getSourceRange();
8062  }
8063
8064  if (auto ArrayLiteral = dyn_cast<ObjCArrayLiteral>(Element))
8065    checkObjCArrayLiteral(S, TargetElementType, ArrayLiteral);
8066  else if (auto DictionaryLiteral = dyn_cast<ObjCDictionaryLiteral>(Element))
8067    checkObjCDictionaryLiteral(S, TargetElementType, DictionaryLiteral);
8068}
8069
8070/// Check an Objective-C array literal being converted to the given
8071/// target type.
8072void checkObjCArrayLiteral(Sema &S, QualType TargetType,
8073                           ObjCArrayLiteral *ArrayLiteral) {
8074  if (!S.NSArrayDecl)
8075    return;
8076
8077  const auto *TargetObjCPtr = TargetType->getAs<ObjCObjectPointerType>();
8078  if (!TargetObjCPtr)
8079    return;
8080
8081  if (TargetObjCPtr->isUnspecialized() ||
8082      TargetObjCPtr->getInterfaceDecl()->getCanonicalDecl()
8083        != S.NSArrayDecl->getCanonicalDecl())
8084    return;
8085
8086  auto TypeArgs = TargetObjCPtr->getTypeArgs();
8087  if (TypeArgs.size() != 1)
8088    return;
8089
8090  QualType TargetElementType = TypeArgs[0];
8091  for (unsigned I = 0, N = ArrayLiteral->getNumElements(); I != N; ++I) {
8092    checkObjCCollectionLiteralElement(S, TargetElementType,
8093                                      ArrayLiteral->getElement(I),
8094                                      0);
8095  }
8096}
8097
8098/// Check an Objective-C dictionary literal being converted to the given
8099/// target type.
8100void checkObjCDictionaryLiteral(Sema &S, QualType TargetType,
8101                                ObjCDictionaryLiteral *DictionaryLiteral) {
8102  if (!S.NSDictionaryDecl)
8103    return;
8104
8105  const auto *TargetObjCPtr = TargetType->getAs<ObjCObjectPointerType>();
8106  if (!TargetObjCPtr)
8107    return;
8108
8109  if (TargetObjCPtr->isUnspecialized() ||
8110      TargetObjCPtr->getInterfaceDecl()->getCanonicalDecl()
8111        != S.NSDictionaryDecl->getCanonicalDecl())
8112    return;
8113
8114  auto TypeArgs = TargetObjCPtr->getTypeArgs();
8115  if (TypeArgs.size() != 2)
8116    return;
8117
8118  QualType TargetKeyType = TypeArgs[0];
8119  QualType TargetObjectType = TypeArgs[1];
8120  for (unsigned I = 0, N = DictionaryLiteral->getNumElements(); I != N; ++I) {
8121    auto Element = DictionaryLiteral->getKeyValueElement(I);
8122    checkObjCCollectionLiteralElement(S, TargetKeyType, Element.Key, 1);
8123    checkObjCCollectionLiteralElement(S, TargetObjectType, Element.Value, 2);
8124  }
8125}
8126
8127// Helper function to filter out cases for constant width constant conversion.
8128// Don't warn on char array initialization or for non-decimal values.
8129bool isSameWidthConstantConversion(Sema &S, Expr *E, QualType T,
8130                                   SourceLocation CC) {
8131  // If initializing from a constant, and the constant starts with '0',
8132  // then it is a binary, octal, or hexadecimal.  Allow these constants
8133  // to fill all the bits, even if there is a sign change.
8134  if (auto *IntLit = dyn_cast<IntegerLiteral>(E->IgnoreParenImpCasts())) {
8135    const char FirstLiteralCharacter =
8136        S.getSourceManager().getCharacterData(IntLit->getLocStart())[0];
8137    if (FirstLiteralCharacter == '0')
8138      return false;
8139  }
8140
8141  // If the CC location points to a '{', and the type is char, then assume
8142  // assume it is an array initialization.
8143  if (CC.isValid() && T->isCharType()) {
8144    const char FirstContextCharacter =
8145        S.getSourceManager().getCharacterData(CC)[0];
8146    if (FirstContextCharacter == '{')
8147      return false;
8148  }
8149
8150  return true;
8151}
8152
8153void CheckImplicitConversion(Sema &S, Expr *E, QualType T,
8154                             SourceLocation CC, bool *ICContext = nullptr) {
8155  if (E->isTypeDependent() || E->isValueDependent()) return;
8156
8157  const Type *Source = S.Context.getCanonicalType(E->getType()).getTypePtr();
8158  const Type *Target = S.Context.getCanonicalType(T).getTypePtr();
8159  if (Source == Target) return;
8160  if (Target->isDependentType()) return;
8161
8162  // If the conversion context location is invalid don't complain. We also
8163  // don't want to emit a warning if the issue occurs from the expansion of
8164  // a system macro. The problem is that 'getSpellingLoc()' is slow, so we
8165  // delay this check as long as possible. Once we detect we are in that
8166  // scenario, we just return.
8167  if (CC.isInvalid())
8168    return;
8169
8170  // Diagnose implicit casts to bool.
8171  if (Target->isSpecificBuiltinType(BuiltinType::Bool)) {
8172    if (isa<StringLiteral>(E))
8173      // Warn on string literal to bool.  Checks for string literals in logical
8174      // and expressions, for instance, assert(0 && "error here"), are
8175      // prevented by a check in AnalyzeImplicitConversions().
8176      return DiagnoseImpCast(S, E, T, CC,
8177                             diag::warn_impcast_string_literal_to_bool);
8178    if (isa<ObjCStringLiteral>(E) || isa<ObjCArrayLiteral>(E) ||
8179        isa<ObjCDictionaryLiteral>(E) || isa<ObjCBoxedExpr>(E)) {
8180      // This covers the literal expressions that evaluate to Objective-C
8181      // objects.
8182      return DiagnoseImpCast(S, E, T, CC,
8183                             diag::warn_impcast_objective_c_literal_to_bool);
8184    }
8185    if (Source->isPointerType() || Source->canDecayToPointerType()) {
8186      // Warn on pointer to bool conversion that is always true.
8187      S.DiagnoseAlwaysNonNullPointer(E, Expr::NPCK_NotNull, /*IsEqual*/ false,
8188                                     SourceRange(CC));
8189    }
8190  }
8191
8192  // Check implicit casts from Objective-C collection literals to specialized
8193  // collection types, e.g., NSArray<NSString *> *.
8194  if (auto *ArrayLiteral = dyn_cast<ObjCArrayLiteral>(E))
8195    checkObjCArrayLiteral(S, QualType(Target, 0), ArrayLiteral);
8196  else if (auto *DictionaryLiteral = dyn_cast<ObjCDictionaryLiteral>(E))
8197    checkObjCDictionaryLiteral(S, QualType(Target, 0), DictionaryLiteral);
8198
8199  // Strip vector types.
8200  if (isa<VectorType>(Source)) {
8201    if (!isa<VectorType>(Target)) {
8202      if (S.SourceMgr.isInSystemMacro(CC))
8203        return;
8204      return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_vector_scalar);
8205    }
8206
8207    // If the vector cast is cast between two vectors of the same size, it is
8208    // a bitcast, not a conversion.
8209    if (S.Context.getTypeSize(Source) == S.Context.getTypeSize(Target))
8210      return;
8211
8212    Source = cast<VectorType>(Source)->getElementType().getTypePtr();
8213    Target = cast<VectorType>(Target)->getElementType().getTypePtr();
8214  }
8215  if (auto VecTy = dyn_cast<VectorType>(Target))
8216    Target = VecTy->getElementType().getTypePtr();
8217
8218  // Strip complex types.
8219  if (isa<ComplexType>(Source)) {
8220    if (!isa<ComplexType>(Target)) {
8221      if (S.SourceMgr.isInSystemMacro(CC))
8222        return;
8223
8224      return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_complex_scalar);
8225    }
8226
8227    Source = cast<ComplexType>(Source)->getElementType().getTypePtr();
8228    Target = cast<ComplexType>(Target)->getElementType().getTypePtr();
8229  }
8230
8231  const BuiltinType *SourceBT = dyn_cast<BuiltinType>(Source);
8232  const BuiltinType *TargetBT = dyn_cast<BuiltinType>(Target);
8233
8234  // If the source is floating point...
8235  if (SourceBT && SourceBT->isFloatingPoint()) {
8236    // ...and the target is floating point...
8237    if (TargetBT && TargetBT->isFloatingPoint()) {
8238      // ...then warn if we're dropping FP rank.
8239
8240      // Builtin FP kinds are ordered by increasing FP rank.
8241      if (SourceBT->getKind() > TargetBT->getKind()) {
8242        // Don't warn about float constants that are precisely
8243        // representable in the target type.
8244        Expr::EvalResult result;
8245        if (E->EvaluateAsRValue(result, S.Context)) {
8246          // Value might be a float, a float vector, or a float complex.
8247          if (IsSameFloatAfterCast(result.Val,
8248                   S.Context.getFloatTypeSemantics(QualType(TargetBT, 0)),
8249                   S.Context.getFloatTypeSemantics(QualType(SourceBT, 0))))
8250            return;
8251        }
8252
8253        if (S.SourceMgr.isInSystemMacro(CC))
8254          return;
8255
8256        DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_float_precision);
8257      }
8258      // ... or possibly if we're increasing rank, too
8259      else if (TargetBT->getKind() > SourceBT->getKind()) {
8260        if (S.SourceMgr.isInSystemMacro(CC))
8261          return;
8262
8263        DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_double_promotion);
8264      }
8265      return;
8266    }
8267
8268    // If the target is integral, always warn.
8269    if (TargetBT && TargetBT->isInteger()) {
8270      if (S.SourceMgr.isInSystemMacro(CC))
8271        return;
8272
8273      DiagnoseFloatingImpCast(S, E, T, CC);
8274    }
8275
8276    // Detect the case where a call result is converted from floating-point to
8277    // to bool, and the final argument to the call is converted from bool, to
8278    // discover this typo:
8279    //
8280    //    bool b = fabs(x < 1.0);  // should be "bool b = fabs(x) < 1.0;"
8281    //
8282    // FIXME: This is an incredibly special case; is there some more general
8283    // way to detect this class of misplaced-parentheses bug?
8284    if (Target->isBooleanType() && isa<CallExpr>(E)) {
8285      // Check last argument of function call to see if it is an
8286      // implicit cast from a type matching the type the result
8287      // is being cast to.
8288      CallExpr *CEx = cast<CallExpr>(E);
8289      if (unsigned NumArgs = CEx->getNumArgs()) {
8290        Expr *LastA = CEx->getArg(NumArgs - 1);
8291        Expr *InnerE = LastA->IgnoreParenImpCasts();
8292        if (isa<ImplicitCastExpr>(LastA) &&
8293            InnerE->getType()->isBooleanType()) {
8294          // Warn on this floating-point to bool conversion
8295          DiagnoseImpCast(S, E, T, CC,
8296                          diag::warn_impcast_floating_point_to_bool);
8297        }
8298      }
8299    }
8300    return;
8301  }
8302
8303  DiagnoseNullConversion(S, E, T, CC);
8304
8305  if (!Source->isIntegerType() || !Target->isIntegerType())
8306    return;
8307
8308  // TODO: remove this early return once the false positives for constant->bool
8309  // in templates, macros, etc, are reduced or removed.
8310  if (Target->isSpecificBuiltinType(BuiltinType::Bool))
8311    return;
8312
8313  IntRange SourceRange = GetExprRange(S.Context, E);
8314  IntRange TargetRange = IntRange::forTargetOfCanonicalType(S.Context, Target);
8315
8316  if (SourceRange.Width > TargetRange.Width) {
8317    // If the source is a constant, use a default-on diagnostic.
8318    // TODO: this should happen for bitfield stores, too.
8319    llvm::APSInt Value(32);
8320    if (E->EvaluateAsInt(Value, S.Context, Expr::SE_AllowSideEffects)) {
8321      if (S.SourceMgr.isInSystemMacro(CC))
8322        return;
8323
8324      std::string PrettySourceValue = Value.toString(10);
8325      std::string PrettyTargetValue = PrettyPrintInRange(Value, TargetRange);
8326
8327      S.DiagRuntimeBehavior(E->getExprLoc(), E,
8328        S.PDiag(diag::warn_impcast_integer_precision_constant)
8329            << PrettySourceValue << PrettyTargetValue
8330            << E->getType() << T << E->getSourceRange()
8331            << clang::SourceRange(CC));
8332      return;
8333    }
8334
8335    // People want to build with -Wshorten-64-to-32 and not -Wconversion.
8336    if (S.SourceMgr.isInSystemMacro(CC))
8337      return;
8338
8339    if (TargetRange.Width == 32 && S.Context.getIntWidth(E->getType()) == 64)
8340      return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_integer_64_32,
8341                             /* pruneControlFlow */ true);
8342    return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_integer_precision);
8343  }
8344
8345  if (TargetRange.Width == SourceRange.Width && !TargetRange.NonNegative &&
8346      SourceRange.NonNegative && Source->isSignedIntegerType()) {
8347    // Warn when doing a signed to signed conversion, warn if the positive
8348    // source value is exactly the width of the target type, which will
8349    // cause a negative value to be stored.
8350
8351    llvm::APSInt Value;
8352    if (E->EvaluateAsInt(Value, S.Context, Expr::SE_AllowSideEffects) &&
8353        !S.SourceMgr.isInSystemMacro(CC)) {
8354      if (isSameWidthConstantConversion(S, E, T, CC)) {
8355        std::string PrettySourceValue = Value.toString(10);
8356        std::string PrettyTargetValue = PrettyPrintInRange(Value, TargetRange);
8357
8358        S.DiagRuntimeBehavior(
8359            E->getExprLoc(), E,
8360            S.PDiag(diag::warn_impcast_integer_precision_constant)
8361                << PrettySourceValue << PrettyTargetValue << E->getType() << T
8362                << E->getSourceRange() << clang::SourceRange(CC));
8363        return;
8364      }
8365    }
8366
8367    // Fall through for non-constants to give a sign conversion warning.
8368  }
8369
8370  if ((TargetRange.NonNegative && !SourceRange.NonNegative) ||
8371      (!TargetRange.NonNegative && SourceRange.NonNegative &&
8372       SourceRange.Width == TargetRange.Width)) {
8373    if (S.SourceMgr.isInSystemMacro(CC))
8374      return;
8375
8376    unsigned DiagID = diag::warn_impcast_integer_sign;
8377
8378    // Traditionally, gcc has warned about this under -Wsign-compare.
8379    // We also want to warn about it in -Wconversion.
8380    // So if -Wconversion is off, use a completely identical diagnostic
8381    // in the sign-compare group.
8382    // The conditional-checking code will
8383    if (ICContext) {
8384      DiagID = diag::warn_impcast_integer_sign_conditional;
8385      *ICContext = true;
8386    }
8387
8388    return DiagnoseImpCast(S, E, T, CC, DiagID);
8389  }
8390
8391  // Diagnose conversions between different enumeration types.
8392  // In C, we pretend that the type of an EnumConstantDecl is its enumeration
8393  // type, to give us better diagnostics.
8394  QualType SourceType = E->getType();
8395  if (!S.getLangOpts().CPlusPlus) {
8396    if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
8397      if (EnumConstantDecl *ECD = dyn_cast<EnumConstantDecl>(DRE->getDecl())) {
8398        EnumDecl *Enum = cast<EnumDecl>(ECD->getDeclContext());
8399        SourceType = S.Context.getTypeDeclType(Enum);
8400        Source = S.Context.getCanonicalType(SourceType).getTypePtr();
8401      }
8402  }
8403
8404  if (const EnumType *SourceEnum = Source->getAs<EnumType>())
8405    if (const EnumType *TargetEnum = Target->getAs<EnumType>())
8406      if (SourceEnum->getDecl()->hasNameForLinkage() &&
8407          TargetEnum->getDecl()->hasNameForLinkage() &&
8408          SourceEnum != TargetEnum) {
8409        if (S.SourceMgr.isInSystemMacro(CC))
8410          return;
8411
8412        return DiagnoseImpCast(S, E, SourceType, T, CC,
8413                               diag::warn_impcast_different_enum_types);
8414      }
8415}
8416
8417void CheckConditionalOperator(Sema &S, ConditionalOperator *E,
8418                              SourceLocation CC, QualType T);
8419
8420void CheckConditionalOperand(Sema &S, Expr *E, QualType T,
8421                             SourceLocation CC, bool &ICContext) {
8422  E = E->IgnoreParenImpCasts();
8423
8424  if (isa<ConditionalOperator>(E))
8425    return CheckConditionalOperator(S, cast<ConditionalOperator>(E), CC, T);
8426
8427  AnalyzeImplicitConversions(S, E, CC);
8428  if (E->getType() != T)
8429    return CheckImplicitConversion(S, E, T, CC, &ICContext);
8430}
8431
8432void CheckConditionalOperator(Sema &S, ConditionalOperator *E,
8433                              SourceLocation CC, QualType T) {
8434  AnalyzeImplicitConversions(S, E->getCond(), E->getQuestionLoc());
8435
8436  bool Suspicious = false;
8437  CheckConditionalOperand(S, E->getTrueExpr(), T, CC, Suspicious);
8438  CheckConditionalOperand(S, E->getFalseExpr(), T, CC, Suspicious);
8439
8440  // If -Wconversion would have warned about either of the candidates
8441  // for a signedness conversion to the context type...
8442  if (!Suspicious) return;
8443
8444  // ...but it's currently ignored...
8445  if (!S.Diags.isIgnored(diag::warn_impcast_integer_sign_conditional, CC))
8446    return;
8447
8448  // ...then check whether it would have warned about either of the
8449  // candidates for a signedness conversion to the condition type.
8450  if (E->getType() == T) return;
8451
8452  Suspicious = false;
8453  CheckImplicitConversion(S, E->getTrueExpr()->IgnoreParenImpCasts(),
8454                          E->getType(), CC, &Suspicious);
8455  if (!Suspicious)
8456    CheckImplicitConversion(S, E->getFalseExpr()->IgnoreParenImpCasts(),
8457                            E->getType(), CC, &Suspicious);
8458}
8459
8460/// CheckBoolLikeConversion - Check conversion of given expression to boolean.
8461/// Input argument E is a logical expression.
8462void CheckBoolLikeConversion(Sema &S, Expr *E, SourceLocation CC) {
8463  if (S.getLangOpts().Bool)
8464    return;
8465  CheckImplicitConversion(S, E->IgnoreParenImpCasts(), S.Context.BoolTy, CC);
8466}
8467
8468/// AnalyzeImplicitConversions - Find and report any interesting
8469/// implicit conversions in the given expression.  There are a couple
8470/// of competing diagnostics here, -Wconversion and -Wsign-compare.
8471void AnalyzeImplicitConversions(Sema &S, Expr *OrigE, SourceLocation CC) {
8472  QualType T = OrigE->getType();
8473  Expr *E = OrigE->IgnoreParenImpCasts();
8474
8475  if (E->isTypeDependent() || E->isValueDependent())
8476    return;
8477
8478  // For conditional operators, we analyze the arguments as if they
8479  // were being fed directly into the output.
8480  if (isa<ConditionalOperator>(E)) {
8481    ConditionalOperator *CO = cast<ConditionalOperator>(E);
8482    CheckConditionalOperator(S, CO, CC, T);
8483    return;
8484  }
8485
8486  // Check implicit argument conversions for function calls.
8487  if (CallExpr *Call = dyn_cast<CallExpr>(E))
8488    CheckImplicitArgumentConversions(S, Call, CC);
8489
8490  // Go ahead and check any implicit conversions we might have skipped.
8491  // The non-canonical typecheck is just an optimization;
8492  // CheckImplicitConversion will filter out dead implicit conversions.
8493  if (E->getType() != T)
8494    CheckImplicitConversion(S, E, T, CC);
8495
8496  // Now continue drilling into this expression.
8497
8498  if (PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) {
8499    // The bound subexpressions in a PseudoObjectExpr are not reachable
8500    // as transitive children.
8501    // FIXME: Use a more uniform representation for this.
8502    for (auto *SE : POE->semantics())
8503      if (auto *OVE = dyn_cast<OpaqueValueExpr>(SE))
8504        AnalyzeImplicitConversions(S, OVE->getSourceExpr(), CC);
8505  }
8506
8507  // Skip past explicit casts.
8508  if (isa<ExplicitCastExpr>(E)) {
8509    E = cast<ExplicitCastExpr>(E)->getSubExpr()->IgnoreParenImpCasts();
8510    return AnalyzeImplicitConversions(S, E, CC);
8511  }
8512
8513  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
8514    // Do a somewhat different check with comparison operators.
8515    if (BO->isComparisonOp())
8516      return AnalyzeComparison(S, BO);
8517
8518    // And with simple assignments.
8519    if (BO->getOpcode() == BO_Assign)
8520      return AnalyzeAssignment(S, BO);
8521  }
8522
8523  // These break the otherwise-useful invariant below.  Fortunately,
8524  // we don't really need to recurse into them, because any internal
8525  // expressions should have been analyzed already when they were
8526  // built into statements.
8527  if (isa<StmtExpr>(E)) return;
8528
8529  // Don't descend into unevaluated contexts.
8530  if (isa<UnaryExprOrTypeTraitExpr>(E)) return;
8531
8532  // Now just recurse over the expression's children.
8533  CC = E->getExprLoc();
8534  BinaryOperator *BO = dyn_cast<BinaryOperator>(E);
8535  bool IsLogicalAndOperator = BO && BO->getOpcode() == BO_LAnd;
8536  for (Stmt *SubStmt : E->children()) {
8537    Expr *ChildExpr = dyn_cast_or_null<Expr>(SubStmt);
8538    if (!ChildExpr)
8539      continue;
8540
8541    if (IsLogicalAndOperator &&
8542        isa<StringLiteral>(ChildExpr->IgnoreParenImpCasts()))
8543      // Ignore checking string literals that are in logical and operators.
8544      // This is a common pattern for asserts.
8545      continue;
8546    AnalyzeImplicitConversions(S, ChildExpr, CC);
8547  }
8548
8549  if (BO && BO->isLogicalOp()) {
8550    Expr *SubExpr = BO->getLHS()->IgnoreParenImpCasts();
8551    if (!IsLogicalAndOperator || !isa<StringLiteral>(SubExpr))
8552      ::CheckBoolLikeConversion(S, SubExpr, BO->getExprLoc());
8553
8554    SubExpr = BO->getRHS()->IgnoreParenImpCasts();
8555    if (!IsLogicalAndOperator || !isa<StringLiteral>(SubExpr))
8556      ::CheckBoolLikeConversion(S, SubExpr, BO->getExprLoc());
8557  }
8558
8559  if (const UnaryOperator *U = dyn_cast<UnaryOperator>(E))
8560    if (U->getOpcode() == UO_LNot)
8561      ::CheckBoolLikeConversion(S, U->getSubExpr(), CC);
8562}
8563
8564} // end anonymous namespace
8565
8566static bool checkOpenCLEnqueueLocalSizeArgs(Sema &S, CallExpr *TheCall,
8567                                            unsigned Start, unsigned End) {
8568  bool IllegalParams = false;
8569  for (unsigned I = Start; I <= End; ++I) {
8570    QualType Ty = TheCall->getArg(I)->getType();
8571    // Taking into account implicit conversions,
8572    // allow any integer within 32 bits range
8573    if (!Ty->isIntegerType() ||
8574        S.Context.getTypeSizeInChars(Ty).getQuantity() > 4) {
8575      S.Diag(TheCall->getArg(I)->getLocStart(),
8576             diag::err_opencl_enqueue_kernel_invalid_local_size_type);
8577      IllegalParams = true;
8578    }
8579    // Potentially emit standard warnings for implicit conversions if enabled
8580    // using -Wconversion.
8581    CheckImplicitConversion(S, TheCall->getArg(I), S.Context.UnsignedIntTy,
8582                            TheCall->getArg(I)->getLocStart());
8583  }
8584  return IllegalParams;
8585}
8586
8587// Helper function for Sema::DiagnoseAlwaysNonNullPointer.
8588// Returns true when emitting a warning about taking the address of a reference.
8589static bool CheckForReference(Sema &SemaRef, const Expr *E,
8590                              const PartialDiagnostic &PD) {
8591  E = E->IgnoreParenImpCasts();
8592
8593  const FunctionDecl *FD = nullptr;
8594
8595  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
8596    if (!DRE->getDecl()->getType()->isReferenceType())
8597      return false;
8598  } else if (const MemberExpr *M = dyn_cast<MemberExpr>(E)) {
8599    if (!M->getMemberDecl()->getType()->isReferenceType())
8600      return false;
8601  } else if (const CallExpr *Call = dyn_cast<CallExpr>(E)) {
8602    if (!Call->getCallReturnType(SemaRef.Context)->isReferenceType())
8603      return false;
8604    FD = Call->getDirectCallee();
8605  } else {
8606    return false;
8607  }
8608
8609  SemaRef.Diag(E->getExprLoc(), PD);
8610
8611  // If possible, point to location of function.
8612  if (FD) {
8613    SemaRef.Diag(FD->getLocation(), diag::note_reference_is_return_value) << FD;
8614  }
8615
8616  return true;
8617}
8618
8619// Returns true if the SourceLocation is expanded from any macro body.
8620// Returns false if the SourceLocation is invalid, is from not in a macro
8621// expansion, or is from expanded from a top-level macro argument.
8622static bool IsInAnyMacroBody(const SourceManager &SM, SourceLocation Loc) {
8623  if (Loc.isInvalid())
8624    return false;
8625
8626  while (Loc.isMacroID()) {
8627    if (SM.isMacroBodyExpansion(Loc))
8628      return true;
8629    Loc = SM.getImmediateMacroCallerLoc(Loc);
8630  }
8631
8632  return false;
8633}
8634
8635/// \brief Diagnose pointers that are always non-null.
8636/// \param E the expression containing the pointer
8637/// \param NullKind NPCK_NotNull if E is a cast to bool, otherwise, E is
8638/// compared to a null pointer
8639/// \param IsEqual True when the comparison is equal to a null pointer
8640/// \param Range Extra SourceRange to highlight in the diagnostic
8641void Sema::DiagnoseAlwaysNonNullPointer(Expr *E,
8642                                        Expr::NullPointerConstantKind NullKind,
8643                                        bool IsEqual, SourceRange Range) {
8644  if (!E)
8645    return;
8646
8647  // Don't warn inside macros.
8648  if (E->getExprLoc().isMacroID()) {
8649    const SourceManager &SM = getSourceManager();
8650    if (IsInAnyMacroBody(SM, E->getExprLoc()) ||
8651        IsInAnyMacroBody(SM, Range.getBegin()))
8652      return;
8653  }
8654  E = E->IgnoreImpCasts();
8655
8656  const bool IsCompare = NullKind != Expr::NPCK_NotNull;
8657
8658  if (isa<CXXThisExpr>(E)) {
8659    unsigned DiagID = IsCompare ? diag::warn_this_null_compare
8660                                : diag::warn_this_bool_conversion;
8661    Diag(E->getExprLoc(), DiagID) << E->getSourceRange() << Range << IsEqual;
8662    return;
8663  }
8664
8665  bool IsAddressOf = false;
8666
8667  if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
8668    if (UO->getOpcode() != UO_AddrOf)
8669      return;
8670    IsAddressOf = true;
8671    E = UO->getSubExpr();
8672  }
8673
8674  if (IsAddressOf) {
8675    unsigned DiagID = IsCompare
8676                          ? diag::warn_address_of_reference_null_compare
8677                          : diag::warn_address_of_reference_bool_conversion;
8678    PartialDiagnostic PD = PDiag(DiagID) << E->getSourceRange() << Range
8679                                         << IsEqual;
8680    if (CheckForReference(*this, E, PD)) {
8681      return;
8682    }
8683  }
8684
8685  auto ComplainAboutNonnullParamOrCall = [&](const Attr *NonnullAttr) {
8686    bool IsParam = isa<NonNullAttr>(NonnullAttr);
8687    std::string Str;
8688    llvm::raw_string_ostream S(Str);
8689    E->printPretty(S, nullptr, getPrintingPolicy());
8690    unsigned DiagID = IsCompare ? diag::warn_nonnull_expr_compare
8691                                : diag::warn_cast_nonnull_to_bool;
8692    Diag(E->getExprLoc(), DiagID) << IsParam << S.str()
8693      << E->getSourceRange() << Range << IsEqual;
8694    Diag(NonnullAttr->getLocation(), diag::note_declared_nonnull) << IsParam;
8695  };
8696
8697  // If we have a CallExpr that is tagged with returns_nonnull, we can complain.
8698  if (auto *Call = dyn_cast<CallExpr>(E->IgnoreParenImpCasts())) {
8699    if (auto *Callee = Call->getDirectCallee()) {
8700      if (const Attr *A = Callee->getAttr<ReturnsNonNullAttr>()) {
8701        ComplainAboutNonnullParamOrCall(A);
8702        return;
8703      }
8704    }
8705  }
8706
8707  // Expect to find a single Decl.  Skip anything more complicated.
8708  ValueDecl *D = nullptr;
8709  if (DeclRefExpr *R = dyn_cast<DeclRefExpr>(E)) {
8710    D = R->getDecl();
8711  } else if (MemberExpr *M = dyn_cast<MemberExpr>(E)) {
8712    D = M->getMemberDecl();
8713  }
8714
8715  // Weak Decls can be null.
8716  if (!D || D->isWeak())
8717    return;
8718
8719  // Check for parameter decl with nonnull attribute
8720  if (const auto* PV = dyn_cast<ParmVarDecl>(D)) {
8721    if (getCurFunction() &&
8722        !getCurFunction()->ModifiedNonNullParams.count(PV)) {
8723      if (const Attr *A = PV->getAttr<NonNullAttr>()) {
8724        ComplainAboutNonnullParamOrCall(A);
8725        return;
8726      }
8727
8728      if (const auto *FD = dyn_cast<FunctionDecl>(PV->getDeclContext())) {
8729        auto ParamIter = llvm::find(FD->parameters(), PV);
8730        assert(ParamIter != FD->param_end());
8731        unsigned ParamNo = std::distance(FD->param_begin(), ParamIter);
8732
8733        for (const auto *NonNull : FD->specific_attrs<NonNullAttr>()) {
8734          if (!NonNull->args_size()) {
8735              ComplainAboutNonnullParamOrCall(NonNull);
8736              return;
8737          }
8738
8739          for (unsigned ArgNo : NonNull->args()) {
8740            if (ArgNo == ParamNo) {
8741              ComplainAboutNonnullParamOrCall(NonNull);
8742              return;
8743            }
8744          }
8745        }
8746      }
8747    }
8748  }
8749
8750  QualType T = D->getType();
8751  const bool IsArray = T->isArrayType();
8752  const bool IsFunction = T->isFunctionType();
8753
8754  // Address of function is used to silence the function warning.
8755  if (IsAddressOf && IsFunction) {
8756    return;
8757  }
8758
8759  // Found nothing.
8760  if (!IsAddressOf && !IsFunction && !IsArray)
8761    return;
8762
8763  // Pretty print the expression for the diagnostic.
8764  std::string Str;
8765  llvm::raw_string_ostream S(Str);
8766  E->printPretty(S, nullptr, getPrintingPolicy());
8767
8768  unsigned DiagID = IsCompare ? diag::warn_null_pointer_compare
8769                              : diag::warn_impcast_pointer_to_bool;
8770  enum {
8771    AddressOf,
8772    FunctionPointer,
8773    ArrayPointer
8774  } DiagType;
8775  if (IsAddressOf)
8776    DiagType = AddressOf;
8777  else if (IsFunction)
8778    DiagType = FunctionPointer;
8779  else if (IsArray)
8780    DiagType = ArrayPointer;
8781  else
8782    llvm_unreachable("Could not determine diagnostic.");
8783  Diag(E->getExprLoc(), DiagID) << DiagType << S.str() << E->getSourceRange()
8784                                << Range << IsEqual;
8785
8786  if (!IsFunction)
8787    return;
8788
8789  // Suggest '&' to silence the function warning.
8790  Diag(E->getExprLoc(), diag::note_function_warning_silence)
8791      << FixItHint::CreateInsertion(E->getLocStart(), "&");
8792
8793  // Check to see if '()' fixit should be emitted.
8794  QualType ReturnType;
8795  UnresolvedSet<4> NonTemplateOverloads;
8796  tryExprAsCall(*E, ReturnType, NonTemplateOverloads);
8797  if (ReturnType.isNull())
8798    return;
8799
8800  if (IsCompare) {
8801    // There are two cases here.  If there is null constant, the only suggest
8802    // for a pointer return type.  If the null is 0, then suggest if the return
8803    // type is a pointer or an integer type.
8804    if (!ReturnType->isPointerType()) {
8805      if (NullKind == Expr::NPCK_ZeroExpression ||
8806          NullKind == Expr::NPCK_ZeroLiteral) {
8807        if (!ReturnType->isIntegerType())
8808          return;
8809      } else {
8810        return;
8811      }
8812    }
8813  } else { // !IsCompare
8814    // For function to bool, only suggest if the function pointer has bool
8815    // return type.
8816    if (!ReturnType->isSpecificBuiltinType(BuiltinType::Bool))
8817      return;
8818  }
8819  Diag(E->getExprLoc(), diag::note_function_to_function_call)
8820      << FixItHint::CreateInsertion(getLocForEndOfToken(E->getLocEnd()), "()");
8821}
8822
8823/// Diagnoses "dangerous" implicit conversions within the given
8824/// expression (which is a full expression).  Implements -Wconversion
8825/// and -Wsign-compare.
8826///
8827/// \param CC the "context" location of the implicit conversion, i.e.
8828///   the most location of the syntactic entity requiring the implicit
8829///   conversion
8830void Sema::CheckImplicitConversions(Expr *E, SourceLocation CC) {
8831  // Don't diagnose in unevaluated contexts.
8832  if (isUnevaluatedContext())
8833    return;
8834
8835  // Don't diagnose for value- or type-dependent expressions.
8836  if (E->isTypeDependent() || E->isValueDependent())
8837    return;
8838
8839  // Check for array bounds violations in cases where the check isn't triggered
8840  // elsewhere for other Expr types (like BinaryOperators), e.g. when an
8841  // ArraySubscriptExpr is on the RHS of a variable initialization.
8842  CheckArrayAccess(E);
8843
8844  // This is not the right CC for (e.g.) a variable initialization.
8845  AnalyzeImplicitConversions(*this, E, CC);
8846}
8847
8848/// CheckBoolLikeConversion - Check conversion of given expression to boolean.
8849/// Input argument E is a logical expression.
8850void Sema::CheckBoolLikeConversion(Expr *E, SourceLocation CC) {
8851  ::CheckBoolLikeConversion(*this, E, CC);
8852}
8853
8854/// Diagnose when expression is an integer constant expression and its evaluation
8855/// results in integer overflow
8856void Sema::CheckForIntOverflow (Expr *E) {
8857  // Use a work list to deal with nested struct initializers.
8858  SmallVector<Expr *, 2> Exprs(1, E);
8859
8860  do {
8861    Expr *E = Exprs.pop_back_val();
8862
8863    if (isa<BinaryOperator>(E->IgnoreParenCasts())) {
8864      E->IgnoreParenCasts()->EvaluateForOverflow(Context);
8865      continue;
8866    }
8867
8868    if (auto InitList = dyn_cast<InitListExpr>(E))
8869      Exprs.append(InitList->inits().begin(), InitList->inits().end());
8870  } while (!Exprs.empty());
8871}
8872
8873namespace {
8874/// \brief Visitor for expressions which looks for unsequenced operations on the
8875/// same object.
8876class SequenceChecker : public EvaluatedExprVisitor<SequenceChecker> {
8877  typedef EvaluatedExprVisitor<SequenceChecker> Base;
8878
8879  /// \brief A tree of sequenced regions within an expression. Two regions are
8880  /// unsequenced if one is an ancestor or a descendent of the other. When we
8881  /// finish processing an expression with sequencing, such as a comma
8882  /// expression, we fold its tree nodes into its parent, since they are
8883  /// unsequenced with respect to nodes we will visit later.
8884  class SequenceTree {
8885    struct Value {
8886      explicit Value(unsigned Parent) : Parent(Parent), Merged(false) {}
8887      unsigned Parent : 31;
8888      unsigned Merged : 1;
8889    };
8890    SmallVector<Value, 8> Values;
8891
8892  public:
8893    /// \brief A region within an expression which may be sequenced with respect
8894    /// to some other region.
8895    class Seq {
8896      explicit Seq(unsigned N) : Index(N) {}
8897      unsigned Index;
8898      friend class SequenceTree;
8899    public:
8900      Seq() : Index(0) {}
8901    };
8902
8903    SequenceTree() { Values.push_back(Value(0)); }
8904    Seq root() const { return Seq(0); }
8905
8906    /// \brief Create a new sequence of operations, which is an unsequenced
8907    /// subset of \p Parent. This sequence of operations is sequenced with
8908    /// respect to other children of \p Parent.
8909    Seq allocate(Seq Parent) {
8910      Values.push_back(Value(Parent.Index));
8911      return Seq(Values.size() - 1);
8912    }
8913
8914    /// \brief Merge a sequence of operations into its parent.
8915    void merge(Seq S) {
8916      Values[S.Index].Merged = true;
8917    }
8918
8919    /// \brief Determine whether two operations are unsequenced. This operation
8920    /// is asymmetric: \p Cur should be the more recent sequence, and \p Old
8921    /// should have been merged into its parent as appropriate.
8922    bool isUnsequenced(Seq Cur, Seq Old) {
8923      unsigned C = representative(Cur.Index);
8924      unsigned Target = representative(Old.Index);
8925      while (C >= Target) {
8926        if (C == Target)
8927          return true;
8928        C = Values[C].Parent;
8929      }
8930      return false;
8931    }
8932
8933  private:
8934    /// \brief Pick a representative for a sequence.
8935    unsigned representative(unsigned K) {
8936      if (Values[K].Merged)
8937        // Perform path compression as we go.
8938        return Values[K].Parent = representative(Values[K].Parent);
8939      return K;
8940    }
8941  };
8942
8943  /// An object for which we can track unsequenced uses.
8944  typedef NamedDecl *Object;
8945
8946  /// Different flavors of object usage which we track. We only track the
8947  /// least-sequenced usage of each kind.
8948  enum UsageKind {
8949    /// A read of an object. Multiple unsequenced reads are OK.
8950    UK_Use,
8951    /// A modification of an object which is sequenced before the value
8952    /// computation of the expression, such as ++n in C++.
8953    UK_ModAsValue,
8954    /// A modification of an object which is not sequenced before the value
8955    /// computation of the expression, such as n++.
8956    UK_ModAsSideEffect,
8957
8958    UK_Count = UK_ModAsSideEffect + 1
8959  };
8960
8961  struct Usage {
8962    Usage() : Use(nullptr), Seq() {}
8963    Expr *Use;
8964    SequenceTree::Seq Seq;
8965  };
8966
8967  struct UsageInfo {
8968    UsageInfo() : Diagnosed(false) {}
8969    Usage Uses[UK_Count];
8970    /// Have we issued a diagnostic for this variable already?
8971    bool Diagnosed;
8972  };
8973  typedef llvm::SmallDenseMap<Object, UsageInfo, 16> UsageInfoMap;
8974
8975  Sema &SemaRef;
8976  /// Sequenced regions within the expression.
8977  SequenceTree Tree;
8978  /// Declaration modifications and references which we have seen.
8979  UsageInfoMap UsageMap;
8980  /// The region we are currently within.
8981  SequenceTree::Seq Region;
8982  /// Filled in with declarations which were modified as a side-effect
8983  /// (that is, post-increment operations).
8984  SmallVectorImpl<std::pair<Object, Usage> > *ModAsSideEffect;
8985  /// Expressions to check later. We defer checking these to reduce
8986  /// stack usage.
8987  SmallVectorImpl<Expr *> &WorkList;
8988
8989  /// RAII object wrapping the visitation of a sequenced subexpression of an
8990  /// expression. At the end of this process, the side-effects of the evaluation
8991  /// become sequenced with respect to the value computation of the result, so
8992  /// we downgrade any UK_ModAsSideEffect within the evaluation to
8993  /// UK_ModAsValue.
8994  struct SequencedSubexpression {
8995    SequencedSubexpression(SequenceChecker &Self)
8996      : Self(Self), OldModAsSideEffect(Self.ModAsSideEffect) {
8997      Self.ModAsSideEffect = &ModAsSideEffect;
8998    }
8999    ~SequencedSubexpression() {
9000      for (auto &M : llvm::reverse(ModAsSideEffect)) {
9001        UsageInfo &U = Self.UsageMap[M.first];
9002        auto &SideEffectUsage = U.Uses[UK_ModAsSideEffect];
9003        Self.addUsage(U, M.first, SideEffectUsage.Use, UK_ModAsValue);
9004        SideEffectUsage = M.second;
9005      }
9006      Self.ModAsSideEffect = OldModAsSideEffect;
9007    }
9008
9009    SequenceChecker &Self;
9010    SmallVector<std::pair<Object, Usage>, 4> ModAsSideEffect;
9011    SmallVectorImpl<std::pair<Object, Usage> > *OldModAsSideEffect;
9012  };
9013
9014  /// RAII object wrapping the visitation of a subexpression which we might
9015  /// choose to evaluate as a constant. If any subexpression is evaluated and
9016  /// found to be non-constant, this allows us to suppress the evaluation of
9017  /// the outer expression.
9018  class EvaluationTracker {
9019  public:
9020    EvaluationTracker(SequenceChecker &Self)
9021        : Self(Self), Prev(Self.EvalTracker), EvalOK(true) {
9022      Self.EvalTracker = this;
9023    }
9024    ~EvaluationTracker() {
9025      Self.EvalTracker = Prev;
9026      if (Prev)
9027        Prev->EvalOK &= EvalOK;
9028    }
9029
9030    bool evaluate(const Expr *E, bool &Result) {
9031      if (!EvalOK || E->isValueDependent())
9032        return false;
9033      EvalOK = E->EvaluateAsBooleanCondition(Result, Self.SemaRef.Context);
9034      return EvalOK;
9035    }
9036
9037  private:
9038    SequenceChecker &Self;
9039    EvaluationTracker *Prev;
9040    bool EvalOK;
9041  } *EvalTracker;
9042
9043  /// \brief Find the object which is produced by the specified expression,
9044  /// if any.
9045  Object getObject(Expr *E, bool Mod) const {
9046    E = E->IgnoreParenCasts();
9047    if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
9048      if (Mod && (UO->getOpcode() == UO_PreInc || UO->getOpcode() == UO_PreDec))
9049        return getObject(UO->getSubExpr(), Mod);
9050    } else if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
9051      if (BO->getOpcode() == BO_Comma)
9052        return getObject(BO->getRHS(), Mod);
9053      if (Mod && BO->isAssignmentOp())
9054        return getObject(BO->getLHS(), Mod);
9055    } else if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
9056      // FIXME: Check for more interesting cases, like "x.n = ++x.n".
9057      if (isa<CXXThisExpr>(ME->getBase()->IgnoreParenCasts()))
9058        return ME->getMemberDecl();
9059    } else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
9060      // FIXME: If this is a reference, map through to its value.
9061      return DRE->getDecl();
9062    return nullptr;
9063  }
9064
9065  /// \brief Note that an object was modified or used by an expression.
9066  void addUsage(UsageInfo &UI, Object O, Expr *Ref, UsageKind UK) {
9067    Usage &U = UI.Uses[UK];
9068    if (!U.Use || !Tree.isUnsequenced(Region, U.Seq)) {
9069      if (UK == UK_ModAsSideEffect && ModAsSideEffect)
9070        ModAsSideEffect->push_back(std::make_pair(O, U));
9071      U.Use = Ref;
9072      U.Seq = Region;
9073    }
9074  }
9075  /// \brief Check whether a modification or use conflicts with a prior usage.
9076  void checkUsage(Object O, UsageInfo &UI, Expr *Ref, UsageKind OtherKind,
9077                  bool IsModMod) {
9078    if (UI.Diagnosed)
9079      return;
9080
9081    const Usage &U = UI.Uses[OtherKind];
9082    if (!U.Use || !Tree.isUnsequenced(Region, U.Seq))
9083      return;
9084
9085    Expr *Mod = U.Use;
9086    Expr *ModOrUse = Ref;
9087    if (OtherKind == UK_Use)
9088      std::swap(Mod, ModOrUse);
9089
9090    SemaRef.Diag(Mod->getExprLoc(),
9091                 IsModMod ? diag::warn_unsequenced_mod_mod
9092                          : diag::warn_unsequenced_mod_use)
9093      << O << SourceRange(ModOrUse->getExprLoc());
9094    UI.Diagnosed = true;
9095  }
9096
9097  void notePreUse(Object O, Expr *Use) {
9098    UsageInfo &U = UsageMap[O];
9099    // Uses conflict with other modifications.
9100    checkUsage(O, U, Use, UK_ModAsValue, false);
9101  }
9102  void notePostUse(Object O, Expr *Use) {
9103    UsageInfo &U = UsageMap[O];
9104    checkUsage(O, U, Use, UK_ModAsSideEffect, false);
9105    addUsage(U, O, Use, UK_Use);
9106  }
9107
9108  void notePreMod(Object O, Expr *Mod) {
9109    UsageInfo &U = UsageMap[O];
9110    // Modifications conflict with other modifications and with uses.
9111    checkUsage(O, U, Mod, UK_ModAsValue, true);
9112    checkUsage(O, U, Mod, UK_Use, false);
9113  }
9114  void notePostMod(Object O, Expr *Use, UsageKind UK) {
9115    UsageInfo &U = UsageMap[O];
9116    checkUsage(O, U, Use, UK_ModAsSideEffect, true);
9117    addUsage(U, O, Use, UK);
9118  }
9119
9120public:
9121  SequenceChecker(Sema &S, Expr *E, SmallVectorImpl<Expr *> &WorkList)
9122      : Base(S.Context), SemaRef(S), Region(Tree.root()),
9123        ModAsSideEffect(nullptr), WorkList(WorkList), EvalTracker(nullptr) {
9124    Visit(E);
9125  }
9126
9127  void VisitStmt(Stmt *S) {
9128    // Skip all statements which aren't expressions for now.
9129  }
9130
9131  void VisitExpr(Expr *E) {
9132    // By default, just recurse to evaluated subexpressions.
9133    Base::VisitStmt(E);
9134  }
9135
9136  void VisitCastExpr(CastExpr *E) {
9137    Object O = Object();
9138    if (E->getCastKind() == CK_LValueToRValue)
9139      O = getObject(E->getSubExpr(), false);
9140
9141    if (O)
9142      notePreUse(O, E);
9143    VisitExpr(E);
9144    if (O)
9145      notePostUse(O, E);
9146  }
9147
9148  void VisitBinComma(BinaryOperator *BO) {
9149    // C++11 [expr.comma]p1:
9150    //   Every value computation and side effect associated with the left
9151    //   expression is sequenced before every value computation and side
9152    //   effect associated with the right expression.
9153    SequenceTree::Seq LHS = Tree.allocate(Region);
9154    SequenceTree::Seq RHS = Tree.allocate(Region);
9155    SequenceTree::Seq OldRegion = Region;
9156
9157    {
9158      SequencedSubexpression SeqLHS(*this);
9159      Region = LHS;
9160      Visit(BO->getLHS());
9161    }
9162
9163    Region = RHS;
9164    Visit(BO->getRHS());
9165
9166    Region = OldRegion;
9167
9168    // Forget that LHS and RHS are sequenced. They are both unsequenced
9169    // with respect to other stuff.
9170    Tree.merge(LHS);
9171    Tree.merge(RHS);
9172  }
9173
9174  void VisitBinAssign(BinaryOperator *BO) {
9175    // The modification is sequenced after the value computation of the LHS
9176    // and RHS, so check it before inspecting the operands and update the
9177    // map afterwards.
9178    Object O = getObject(BO->getLHS(), true);
9179    if (!O)
9180      return VisitExpr(BO);
9181
9182    notePreMod(O, BO);
9183
9184    // C++11 [expr.ass]p7:
9185    //   E1 op= E2 is equivalent to E1 = E1 op E2, except that E1 is evaluated
9186    //   only once.
9187    //
9188    // Therefore, for a compound assignment operator, O is considered used
9189    // everywhere except within the evaluation of E1 itself.
9190    if (isa<CompoundAssignOperator>(BO))
9191      notePreUse(O, BO);
9192
9193    Visit(BO->getLHS());
9194
9195    if (isa<CompoundAssignOperator>(BO))
9196      notePostUse(O, BO);
9197
9198    Visit(BO->getRHS());
9199
9200    // C++11 [expr.ass]p1:
9201    //   the assignment is sequenced [...] before the value computation of the
9202    //   assignment expression.
9203    // C11 6.5.16/3 has no such rule.
9204    notePostMod(O, BO, SemaRef.getLangOpts().CPlusPlus ? UK_ModAsValue
9205                                                       : UK_ModAsSideEffect);
9206  }
9207
9208  void VisitCompoundAssignOperator(CompoundAssignOperator *CAO) {
9209    VisitBinAssign(CAO);
9210  }
9211
9212  void VisitUnaryPreInc(UnaryOperator *UO) { VisitUnaryPreIncDec(UO); }
9213  void VisitUnaryPreDec(UnaryOperator *UO) { VisitUnaryPreIncDec(UO); }
9214  void VisitUnaryPreIncDec(UnaryOperator *UO) {
9215    Object O = getObject(UO->getSubExpr(), true);
9216    if (!O)
9217      return VisitExpr(UO);
9218
9219    notePreMod(O, UO);
9220    Visit(UO->getSubExpr());
9221    // C++11 [expr.pre.incr]p1:
9222    //   the expression ++x is equivalent to x+=1
9223    notePostMod(O, UO, SemaRef.getLangOpts().CPlusPlus ? UK_ModAsValue
9224                                                       : UK_ModAsSideEffect);
9225  }
9226
9227  void VisitUnaryPostInc(UnaryOperator *UO) { VisitUnaryPostIncDec(UO); }
9228  void VisitUnaryPostDec(UnaryOperator *UO) { VisitUnaryPostIncDec(UO); }
9229  void VisitUnaryPostIncDec(UnaryOperator *UO) {
9230    Object O = getObject(UO->getSubExpr(), true);
9231    if (!O)
9232      return VisitExpr(UO);
9233
9234    notePreMod(O, UO);
9235    Visit(UO->getSubExpr());
9236    notePostMod(O, UO, UK_ModAsSideEffect);
9237  }
9238
9239  /// Don't visit the RHS of '&&' or '||' if it might not be evaluated.
9240  void VisitBinLOr(BinaryOperator *BO) {
9241    // The side-effects of the LHS of an '&&' are sequenced before the
9242    // value computation of the RHS, and hence before the value computation
9243    // of the '&&' itself, unless the LHS evaluates to zero. We treat them
9244    // as if they were unconditionally sequenced.
9245    EvaluationTracker Eval(*this);
9246    {
9247      SequencedSubexpression Sequenced(*this);
9248      Visit(BO->getLHS());
9249    }
9250
9251    bool Result;
9252    if (Eval.evaluate(BO->getLHS(), Result)) {
9253      if (!Result)
9254        Visit(BO->getRHS());
9255    } else {
9256      // Check for unsequenced operations in the RHS, treating it as an
9257      // entirely separate evaluation.
9258      //
9259      // FIXME: If there are operations in the RHS which are unsequenced
9260      // with respect to operations outside the RHS, and those operations
9261      // are unconditionally evaluated, diagnose them.
9262      WorkList.push_back(BO->getRHS());
9263    }
9264  }
9265  void VisitBinLAnd(BinaryOperator *BO) {
9266    EvaluationTracker Eval(*this);
9267    {
9268      SequencedSubexpression Sequenced(*this);
9269      Visit(BO->getLHS());
9270    }
9271
9272    bool Result;
9273    if (Eval.evaluate(BO->getLHS(), Result)) {
9274      if (Result)
9275        Visit(BO->getRHS());
9276    } else {
9277      WorkList.push_back(BO->getRHS());
9278    }
9279  }
9280
9281  // Only visit the condition, unless we can be sure which subexpression will
9282  // be chosen.
9283  void VisitAbstractConditionalOperator(AbstractConditionalOperator *CO) {
9284    EvaluationTracker Eval(*this);
9285    {
9286      SequencedSubexpression Sequenced(*this);
9287      Visit(CO->getCond());
9288    }
9289
9290    bool Result;
9291    if (Eval.evaluate(CO->getCond(), Result))
9292      Visit(Result ? CO->getTrueExpr() : CO->getFalseExpr());
9293    else {
9294      WorkList.push_back(CO->getTrueExpr());
9295      WorkList.push_back(CO->getFalseExpr());
9296    }
9297  }
9298
9299  void VisitCallExpr(CallExpr *CE) {
9300    // C++11 [intro.execution]p15:
9301    //   When calling a function [...], every value computation and side effect
9302    //   associated with any argument expression, or with the postfix expression
9303    //   designating the called function, is sequenced before execution of every
9304    //   expression or statement in the body of the function [and thus before
9305    //   the value computation of its result].
9306    SequencedSubexpression Sequenced(*this);
9307    Base::VisitCallExpr(CE);
9308
9309    // FIXME: CXXNewExpr and CXXDeleteExpr implicitly call functions.
9310  }
9311
9312  void VisitCXXConstructExpr(CXXConstructExpr *CCE) {
9313    // This is a call, so all subexpressions are sequenced before the result.
9314    SequencedSubexpression Sequenced(*this);
9315
9316    if (!CCE->isListInitialization())
9317      return VisitExpr(CCE);
9318
9319    // In C++11, list initializations are sequenced.
9320    SmallVector<SequenceTree::Seq, 32> Elts;
9321    SequenceTree::Seq Parent = Region;
9322    for (CXXConstructExpr::arg_iterator I = CCE->arg_begin(),
9323                                        E = CCE->arg_end();
9324         I != E; ++I) {
9325      Region = Tree.allocate(Parent);
9326      Elts.push_back(Region);
9327      Visit(*I);
9328    }
9329
9330    // Forget that the initializers are sequenced.
9331    Region = Parent;
9332    for (unsigned I = 0; I < Elts.size(); ++I)
9333      Tree.merge(Elts[I]);
9334  }
9335
9336  void VisitInitListExpr(InitListExpr *ILE) {
9337    if (!SemaRef.getLangOpts().CPlusPlus11)
9338      return VisitExpr(ILE);
9339
9340    // In C++11, list initializations are sequenced.
9341    SmallVector<SequenceTree::Seq, 32> Elts;
9342    SequenceTree::Seq Parent = Region;
9343    for (unsigned I = 0; I < ILE->getNumInits(); ++I) {
9344      Expr *E = ILE->getInit(I);
9345      if (!E) continue;
9346      Region = Tree.allocate(Parent);
9347      Elts.push_back(Region);
9348      Visit(E);
9349    }
9350
9351    // Forget that the initializers are sequenced.
9352    Region = Parent;
9353    for (unsigned I = 0; I < Elts.size(); ++I)
9354      Tree.merge(Elts[I]);
9355  }
9356};
9357} // end anonymous namespace
9358
9359void Sema::CheckUnsequencedOperations(Expr *E) {
9360  SmallVector<Expr *, 8> WorkList;
9361  WorkList.push_back(E);
9362  while (!WorkList.empty()) {
9363    Expr *Item = WorkList.pop_back_val();
9364    SequenceChecker(*this, Item, WorkList);
9365  }
9366}
9367
9368void Sema::CheckCompletedExpr(Expr *E, SourceLocation CheckLoc,
9369                              bool IsConstexpr) {
9370  CheckImplicitConversions(E, CheckLoc);
9371  CheckUnsequencedOperations(E);
9372  if (!IsConstexpr && !E->isValueDependent())
9373    CheckForIntOverflow(E);
9374}
9375
9376void Sema::CheckBitFieldInitialization(SourceLocation InitLoc,
9377                                       FieldDecl *BitField,
9378                                       Expr *Init) {
9379  (void) AnalyzeBitFieldAssignment(*this, BitField, Init, InitLoc);
9380}
9381
9382static void diagnoseArrayStarInParamType(Sema &S, QualType PType,
9383                                         SourceLocation Loc) {
9384  if (!PType->isVariablyModifiedType())
9385    return;
9386  if (const auto *PointerTy = dyn_cast<PointerType>(PType)) {
9387    diagnoseArrayStarInParamType(S, PointerTy->getPointeeType(), Loc);
9388    return;
9389  }
9390  if (const auto *ReferenceTy = dyn_cast<ReferenceType>(PType)) {
9391    diagnoseArrayStarInParamType(S, ReferenceTy->getPointeeType(), Loc);
9392    return;
9393  }
9394  if (const auto *ParenTy = dyn_cast<ParenType>(PType)) {
9395    diagnoseArrayStarInParamType(S, ParenTy->getInnerType(), Loc);
9396    return;
9397  }
9398
9399  const ArrayType *AT = S.Context.getAsArrayType(PType);
9400  if (!AT)
9401    return;
9402
9403  if (AT->getSizeModifier() != ArrayType::Star) {
9404    diagnoseArrayStarInParamType(S, AT->getElementType(), Loc);
9405    return;
9406  }
9407
9408  S.Diag(Loc, diag::err_array_star_in_function_definition);
9409}
9410
9411/// CheckParmsForFunctionDef - Check that the parameters of the given
9412/// function are appropriate for the definition of a function. This
9413/// takes care of any checks that cannot be performed on the
9414/// declaration itself, e.g., that the types of each of the function
9415/// parameters are complete.
9416bool Sema::CheckParmsForFunctionDef(ArrayRef<ParmVarDecl *> Parameters,
9417                                    bool CheckParameterNames) {
9418  bool HasInvalidParm = false;
9419  for (ParmVarDecl *Param : Parameters) {
9420    // C99 6.7.5.3p4: the parameters in a parameter type list in a
9421    // function declarator that is part of a function definition of
9422    // that function shall not have incomplete type.
9423    //
9424    // This is also C++ [dcl.fct]p6.
9425    if (!Param->isInvalidDecl() &&
9426        RequireCompleteType(Param->getLocation(), Param->getType(),
9427                            diag::err_typecheck_decl_incomplete_type)) {
9428      Param->setInvalidDecl();
9429      HasInvalidParm = true;
9430    }
9431
9432    // C99 6.9.1p5: If the declarator includes a parameter type list, the
9433    // declaration of each parameter shall include an identifier.
9434    if (CheckParameterNames &&
9435        Param->getIdentifier() == nullptr &&
9436        !Param->isImplicit() &&
9437        !getLangOpts().CPlusPlus)
9438      Diag(Param->getLocation(), diag::err_parameter_name_omitted);
9439
9440    // C99 6.7.5.3p12:
9441    //   If the function declarator is not part of a definition of that
9442    //   function, parameters may have incomplete type and may use the [*]
9443    //   notation in their sequences of declarator specifiers to specify
9444    //   variable length array types.
9445    QualType PType = Param->getOriginalType();
9446    // FIXME: This diagnostic should point the '[*]' if source-location
9447    // information is added for it.
9448    diagnoseArrayStarInParamType(*this, PType, Param->getLocation());
9449
9450    // MSVC destroys objects passed by value in the callee.  Therefore a
9451    // function definition which takes such a parameter must be able to call the
9452    // object's destructor.  However, we don't perform any direct access check
9453    // on the dtor.
9454    if (getLangOpts().CPlusPlus && Context.getTargetInfo()
9455                                       .getCXXABI()
9456                                       .areArgsDestroyedLeftToRightInCallee()) {
9457      if (!Param->isInvalidDecl()) {
9458        if (const RecordType *RT = Param->getType()->getAs<RecordType>()) {
9459          CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
9460          if (!ClassDecl->isInvalidDecl() &&
9461              !ClassDecl->hasIrrelevantDestructor() &&
9462              !ClassDecl->isDependentContext()) {
9463            CXXDestructorDecl *Destructor = LookupDestructor(ClassDecl);
9464            MarkFunctionReferenced(Param->getLocation(), Destructor);
9465            DiagnoseUseOfDecl(Destructor, Param->getLocation());
9466          }
9467        }
9468      }
9469    }
9470
9471    // Parameters with the pass_object_size attribute only need to be marked
9472    // constant at function definitions. Because we lack information about
9473    // whether we're on a declaration or definition when we're instantiating the
9474    // attribute, we need to check for constness here.
9475    if (const auto *Attr = Param->getAttr<PassObjectSizeAttr>())
9476      if (!Param->getType().isConstQualified())
9477        Diag(Param->getLocation(), diag::err_attribute_pointers_only)
9478            << Attr->getSpelling() << 1;
9479  }
9480
9481  return HasInvalidParm;
9482}
9483
9484/// CheckCastAlign - Implements -Wcast-align, which warns when a
9485/// pointer cast increases the alignment requirements.
9486void Sema::CheckCastAlign(Expr *Op, QualType T, SourceRange TRange) {
9487  // This is actually a lot of work to potentially be doing on every
9488  // cast; don't do it if we're ignoring -Wcast_align (as is the default).
9489  if (getDiagnostics().isIgnored(diag::warn_cast_align, TRange.getBegin()))
9490    return;
9491
9492  // Ignore dependent types.
9493  if (T->isDependentType() || Op->getType()->isDependentType())
9494    return;
9495
9496  // Require that the destination be a pointer type.
9497  const PointerType *DestPtr = T->getAs<PointerType>();
9498  if (!DestPtr) return;
9499
9500  // If the destination has alignment 1, we're done.
9501  QualType DestPointee = DestPtr->getPointeeType();
9502  if (DestPointee->isIncompleteType()) return;
9503  CharUnits DestAlign = Context.getTypeAlignInChars(DestPointee);
9504  if (DestAlign.isOne()) return;
9505
9506  // Require that the source be a pointer type.
9507  const PointerType *SrcPtr = Op->getType()->getAs<PointerType>();
9508  if (!SrcPtr) return;
9509  QualType SrcPointee = SrcPtr->getPointeeType();
9510
9511  // Whitelist casts from cv void*.  We already implicitly
9512  // whitelisted casts to cv void*, since they have alignment 1.
9513  // Also whitelist casts involving incomplete types, which implicitly
9514  // includes 'void'.
9515  if (SrcPointee->isIncompleteType()) return;
9516
9517  CharUnits SrcAlign = Context.getTypeAlignInChars(SrcPointee);
9518  if (SrcAlign >= DestAlign) return;
9519
9520  Diag(TRange.getBegin(), diag::warn_cast_align)
9521    << Op->getType() << T
9522    << static_cast<unsigned>(SrcAlign.getQuantity())
9523    << static_cast<unsigned>(DestAlign.getQuantity())
9524    << TRange << Op->getSourceRange();
9525}
9526
9527/// \brief Check whether this array fits the idiom of a size-one tail padded
9528/// array member of a struct.
9529///
9530/// We avoid emitting out-of-bounds access warnings for such arrays as they are
9531/// commonly used to emulate flexible arrays in C89 code.
9532static bool IsTailPaddedMemberArray(Sema &S, const llvm::APInt &Size,
9533                                    const NamedDecl *ND) {
9534  if (Size != 1 || !ND) return false;
9535
9536  const FieldDecl *FD = dyn_cast<FieldDecl>(ND);
9537  if (!FD) return false;
9538
9539  // Don't consider sizes resulting from macro expansions or template argument
9540  // substitution to form C89 tail-padded arrays.
9541
9542  TypeSourceInfo *TInfo = FD->getTypeSourceInfo();
9543  while (TInfo) {
9544    TypeLoc TL = TInfo->getTypeLoc();
9545    // Look through typedefs.
9546    if (TypedefTypeLoc TTL = TL.getAs<TypedefTypeLoc>()) {
9547      const TypedefNameDecl *TDL = TTL.getTypedefNameDecl();
9548      TInfo = TDL->getTypeSourceInfo();
9549      continue;
9550    }
9551    if (ConstantArrayTypeLoc CTL = TL.getAs<ConstantArrayTypeLoc>()) {
9552      const Expr *SizeExpr = dyn_cast<IntegerLiteral>(CTL.getSizeExpr());
9553      if (!SizeExpr || SizeExpr->getExprLoc().isMacroID())
9554        return false;
9555    }
9556    break;
9557  }
9558
9559  const RecordDecl *RD = dyn_cast<RecordDecl>(FD->getDeclContext());
9560  if (!RD) return false;
9561  if (RD->isUnion()) return false;
9562  if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) {
9563    if (!CRD->isStandardLayout()) return false;
9564  }
9565
9566  // See if this is the last field decl in the record.
9567  const Decl *D = FD;
9568  while ((D = D->getNextDeclInContext()))
9569    if (isa<FieldDecl>(D))
9570      return false;
9571  return true;
9572}
9573
9574void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
9575                            const ArraySubscriptExpr *ASE,
9576                            bool AllowOnePastEnd, bool IndexNegated) {
9577  IndexExpr = IndexExpr->IgnoreParenImpCasts();
9578  if (IndexExpr->isValueDependent())
9579    return;
9580
9581  const Type *EffectiveType =
9582      BaseExpr->getType()->getPointeeOrArrayElementType();
9583  BaseExpr = BaseExpr->IgnoreParenCasts();
9584  const ConstantArrayType *ArrayTy =
9585    Context.getAsConstantArrayType(BaseExpr->getType());
9586  if (!ArrayTy)
9587    return;
9588
9589  llvm::APSInt index;
9590  if (!IndexExpr->EvaluateAsInt(index, Context, Expr::SE_AllowSideEffects))
9591    return;
9592  if (IndexNegated)
9593    index = -index;
9594
9595  const NamedDecl *ND = nullptr;
9596  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(BaseExpr))
9597    ND = dyn_cast<NamedDecl>(DRE->getDecl());
9598  if (const MemberExpr *ME = dyn_cast<MemberExpr>(BaseExpr))
9599    ND = dyn_cast<NamedDecl>(ME->getMemberDecl());
9600
9601  if (index.isUnsigned() || !index.isNegative()) {
9602    llvm::APInt size = ArrayTy->getSize();
9603    if (!size.isStrictlyPositive())
9604      return;
9605
9606    const Type *BaseType = BaseExpr->getType()->getPointeeOrArrayElementType();
9607    if (BaseType != EffectiveType) {
9608      // Make sure we're comparing apples to apples when comparing index to size
9609      uint64_t ptrarith_typesize = Context.getTypeSize(EffectiveType);
9610      uint64_t array_typesize = Context.getTypeSize(BaseType);
9611      // Handle ptrarith_typesize being zero, such as when casting to void*
9612      if (!ptrarith_typesize) ptrarith_typesize = 1;
9613      if (ptrarith_typesize != array_typesize) {
9614        // There's a cast to a different size type involved
9615        uint64_t ratio = array_typesize / ptrarith_typesize;
9616        // TODO: Be smarter about handling cases where array_typesize is not a
9617        // multiple of ptrarith_typesize
9618        if (ptrarith_typesize * ratio == array_typesize)
9619          size *= llvm::APInt(size.getBitWidth(), ratio);
9620      }
9621    }
9622
9623    if (size.getBitWidth() > index.getBitWidth())
9624      index = index.zext(size.getBitWidth());
9625    else if (size.getBitWidth() < index.getBitWidth())
9626      size = size.zext(index.getBitWidth());
9627
9628    // For array subscripting the index must be less than size, but for pointer
9629    // arithmetic also allow the index (offset) to be equal to size since
9630    // computing the next address after the end of the array is legal and
9631    // commonly done e.g. in C++ iterators and range-based for loops.
9632    if (AllowOnePastEnd ? index.ule(size) : index.ult(size))
9633      return;
9634
9635    // Also don't warn for arrays of size 1 which are members of some
9636    // structure. These are often used to approximate flexible arrays in C89
9637    // code.
9638    if (IsTailPaddedMemberArray(*this, size, ND))
9639      return;
9640
9641    // Suppress the warning if the subscript expression (as identified by the
9642    // ']' location) and the index expression are both from macro expansions
9643    // within a system header.
9644    if (ASE) {
9645      SourceLocation RBracketLoc = SourceMgr.getSpellingLoc(
9646          ASE->getRBracketLoc());
9647      if (SourceMgr.isInSystemHeader(RBracketLoc)) {
9648        SourceLocation IndexLoc = SourceMgr.getSpellingLoc(
9649            IndexExpr->getLocStart());
9650        if (SourceMgr.isWrittenInSameFile(RBracketLoc, IndexLoc))
9651          return;
9652      }
9653    }
9654
9655    unsigned DiagID = diag::warn_ptr_arith_exceeds_bounds;
9656    if (ASE)
9657      DiagID = diag::warn_array_index_exceeds_bounds;
9658
9659    DiagRuntimeBehavior(BaseExpr->getLocStart(), BaseExpr,
9660                        PDiag(DiagID) << index.toString(10, true)
9661                          << size.toString(10, true)
9662                          << (unsigned)size.getLimitedValue(~0U)
9663                          << IndexExpr->getSourceRange());
9664  } else {
9665    unsigned DiagID = diag::warn_array_index_precedes_bounds;
9666    if (!ASE) {
9667      DiagID = diag::warn_ptr_arith_precedes_bounds;
9668      if (index.isNegative()) index = -index;
9669    }
9670
9671    DiagRuntimeBehavior(BaseExpr->getLocStart(), BaseExpr,
9672                        PDiag(DiagID) << index.toString(10, true)
9673                          << IndexExpr->getSourceRange());
9674  }
9675
9676  if (!ND) {
9677    // Try harder to find a NamedDecl to point at in the note.
9678    while (const ArraySubscriptExpr *ASE =
9679           dyn_cast<ArraySubscriptExpr>(BaseExpr))
9680      BaseExpr = ASE->getBase()->IgnoreParenCasts();
9681    if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(BaseExpr))
9682      ND = dyn_cast<NamedDecl>(DRE->getDecl());
9683    if (const MemberExpr *ME = dyn_cast<MemberExpr>(BaseExpr))
9684      ND = dyn_cast<NamedDecl>(ME->getMemberDecl());
9685  }
9686
9687  if (ND)
9688    DiagRuntimeBehavior(ND->getLocStart(), BaseExpr,
9689                        PDiag(diag::note_array_index_out_of_bounds)
9690                          << ND->getDeclName());
9691}
9692
9693void Sema::CheckArrayAccess(const Expr *expr) {
9694  int AllowOnePastEnd = 0;
9695  while (expr) {
9696    expr = expr->IgnoreParenImpCasts();
9697    switch (expr->getStmtClass()) {
9698      case Stmt::ArraySubscriptExprClass: {
9699        const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(expr);
9700        CheckArrayAccess(ASE->getBase(), ASE->getIdx(), ASE,
9701                         AllowOnePastEnd > 0);
9702        return;
9703      }
9704      case Stmt::OMPArraySectionExprClass: {
9705        const OMPArraySectionExpr *ASE = cast<OMPArraySectionExpr>(expr);
9706        if (ASE->getLowerBound())
9707          CheckArrayAccess(ASE->getBase(), ASE->getLowerBound(),
9708                           /*ASE=*/nullptr, AllowOnePastEnd > 0);
9709        return;
9710      }
9711      case Stmt::UnaryOperatorClass: {
9712        // Only unwrap the * and & unary operators
9713        const UnaryOperator *UO = cast<UnaryOperator>(expr);
9714        expr = UO->getSubExpr();
9715        switch (UO->getOpcode()) {
9716          case UO_AddrOf:
9717            AllowOnePastEnd++;
9718            break;
9719          case UO_Deref:
9720            AllowOnePastEnd--;
9721            break;
9722          default:
9723            return;
9724        }
9725        break;
9726      }
9727      case Stmt::ConditionalOperatorClass: {
9728        const ConditionalOperator *cond = cast<ConditionalOperator>(expr);
9729        if (const Expr *lhs = cond->getLHS())
9730          CheckArrayAccess(lhs);
9731        if (const Expr *rhs = cond->getRHS())
9732          CheckArrayAccess(rhs);
9733        return;
9734      }
9735      default:
9736        return;
9737    }
9738  }
9739}
9740
9741//===--- CHECK: Objective-C retain cycles ----------------------------------//
9742
9743namespace {
9744  struct RetainCycleOwner {
9745    RetainCycleOwner() : Variable(nullptr), Indirect(false) {}
9746    VarDecl *Variable;
9747    SourceRange Range;
9748    SourceLocation Loc;
9749    bool Indirect;
9750
9751    void setLocsFrom(Expr *e) {
9752      Loc = e->getExprLoc();
9753      Range = e->getSourceRange();
9754    }
9755  };
9756} // end anonymous namespace
9757
9758/// Consider whether capturing the given variable can possibly lead to
9759/// a retain cycle.
9760static bool considerVariable(VarDecl *var, Expr *ref, RetainCycleOwner &owner) {
9761  // In ARC, it's captured strongly iff the variable has __strong
9762  // lifetime.  In MRR, it's captured strongly if the variable is
9763  // __block and has an appropriate type.
9764  if (var->getType().getObjCLifetime() != Qualifiers::OCL_Strong)
9765    return false;
9766
9767  owner.Variable = var;
9768  if (ref)
9769    owner.setLocsFrom(ref);
9770  return true;
9771}
9772
9773static bool findRetainCycleOwner(Sema &S, Expr *e, RetainCycleOwner &owner) {
9774  while (true) {
9775    e = e->IgnoreParens();
9776    if (CastExpr *cast = dyn_cast<CastExpr>(e)) {
9777      switch (cast->getCastKind()) {
9778      case CK_BitCast:
9779      case CK_LValueBitCast:
9780      case CK_LValueToRValue:
9781      case CK_ARCReclaimReturnedObject:
9782        e = cast->getSubExpr();
9783        continue;
9784
9785      default:
9786        return false;
9787      }
9788    }
9789
9790    if (ObjCIvarRefExpr *ref = dyn_cast<ObjCIvarRefExpr>(e)) {
9791      ObjCIvarDecl *ivar = ref->getDecl();
9792      if (ivar->getType().getObjCLifetime() != Qualifiers::OCL_Strong)
9793        return false;
9794
9795      // Try to find a retain cycle in the base.
9796      if (!findRetainCycleOwner(S, ref->getBase(), owner))
9797        return false;
9798
9799      if (ref->isFreeIvar()) owner.setLocsFrom(ref);
9800      owner.Indirect = true;
9801      return true;
9802    }
9803
9804    if (DeclRefExpr *ref = dyn_cast<DeclRefExpr>(e)) {
9805      VarDecl *var = dyn_cast<VarDecl>(ref->getDecl());
9806      if (!var) return false;
9807      return considerVariable(var, ref, owner);
9808    }
9809
9810    if (MemberExpr *member = dyn_cast<MemberExpr>(e)) {
9811      if (member->isArrow()) return false;
9812
9813      // Don't count this as an indirect ownership.
9814      e = member->getBase();
9815      continue;
9816    }
9817
9818    if (PseudoObjectExpr *pseudo = dyn_cast<PseudoObjectExpr>(e)) {
9819      // Only pay attention to pseudo-objects on property references.
9820      ObjCPropertyRefExpr *pre
9821        = dyn_cast<ObjCPropertyRefExpr>(pseudo->getSyntacticForm()
9822                                              ->IgnoreParens());
9823      if (!pre) return false;
9824      if (pre->isImplicitProperty()) return false;
9825      ObjCPropertyDecl *property = pre->getExplicitProperty();
9826      if (!property->isRetaining() &&
9827          !(property->getPropertyIvarDecl() &&
9828            property->getPropertyIvarDecl()->getType()
9829              .getObjCLifetime() == Qualifiers::OCL_Strong))
9830          return false;
9831
9832      owner.Indirect = true;
9833      if (pre->isSuperReceiver()) {
9834        owner.Variable = S.getCurMethodDecl()->getSelfDecl();
9835        if (!owner.Variable)
9836          return false;
9837        owner.Loc = pre->getLocation();
9838        owner.Range = pre->getSourceRange();
9839        return true;
9840      }
9841      e = const_cast<Expr*>(cast<OpaqueValueExpr>(pre->getBase())
9842                              ->getSourceExpr());
9843      continue;
9844    }
9845
9846    // Array ivars?
9847
9848    return false;
9849  }
9850}
9851
9852namespace {
9853  struct FindCaptureVisitor : EvaluatedExprVisitor<FindCaptureVisitor> {
9854    FindCaptureVisitor(ASTContext &Context, VarDecl *variable)
9855      : EvaluatedExprVisitor<FindCaptureVisitor>(Context),
9856        Context(Context), Variable(variable), Capturer(nullptr),
9857        VarWillBeReased(false) {}
9858    ASTContext &Context;
9859    VarDecl *Variable;
9860    Expr *Capturer;
9861    bool VarWillBeReased;
9862
9863    void VisitDeclRefExpr(DeclRefExpr *ref) {
9864      if (ref->getDecl() == Variable && !Capturer)
9865        Capturer = ref;
9866    }
9867
9868    void VisitObjCIvarRefExpr(ObjCIvarRefExpr *ref) {
9869      if (Capturer) return;
9870      Visit(ref->getBase());
9871      if (Capturer && ref->isFreeIvar())
9872        Capturer = ref;
9873    }
9874
9875    void VisitBlockExpr(BlockExpr *block) {
9876      // Look inside nested blocks
9877      if (block->getBlockDecl()->capturesVariable(Variable))
9878        Visit(block->getBlockDecl()->getBody());
9879    }
9880
9881    void VisitOpaqueValueExpr(OpaqueValueExpr *OVE) {
9882      if (Capturer) return;
9883      if (OVE->getSourceExpr())
9884        Visit(OVE->getSourceExpr());
9885    }
9886    void VisitBinaryOperator(BinaryOperator *BinOp) {
9887      if (!Variable || VarWillBeReased || BinOp->getOpcode() != BO_Assign)
9888        return;
9889      Expr *LHS = BinOp->getLHS();
9890      if (const DeclRefExpr *DRE = dyn_cast_or_null<DeclRefExpr>(LHS)) {
9891        if (DRE->getDecl() != Variable)
9892          return;
9893        if (Expr *RHS = BinOp->getRHS()) {
9894          RHS = RHS->IgnoreParenCasts();
9895          llvm::APSInt Value;
9896          VarWillBeReased =
9897            (RHS && RHS->isIntegerConstantExpr(Value, Context) && Value == 0);
9898        }
9899      }
9900    }
9901  };
9902} // end anonymous namespace
9903
9904/// Check whether the given argument is a block which captures a
9905/// variable.
9906static Expr *findCapturingExpr(Sema &S, Expr *e, RetainCycleOwner &owner) {
9907  assert(owner.Variable && owner.Loc.isValid());
9908
9909  e = e->IgnoreParenCasts();
9910
9911  // Look through [^{...} copy] and Block_copy(^{...}).
9912  if (ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(e)) {
9913    Selector Cmd = ME->getSelector();
9914    if (Cmd.isUnarySelector() && Cmd.getNameForSlot(0) == "copy") {
9915      e = ME->getInstanceReceiver();
9916      if (!e)
9917        return nullptr;
9918      e = e->IgnoreParenCasts();
9919    }
9920  } else if (CallExpr *CE = dyn_cast<CallExpr>(e)) {
9921    if (CE->getNumArgs() == 1) {
9922      FunctionDecl *Fn = dyn_cast_or_null<FunctionDecl>(CE->getCalleeDecl());
9923      if (Fn) {
9924        const IdentifierInfo *FnI = Fn->getIdentifier();
9925        if (FnI && FnI->isStr("_Block_copy")) {
9926          e = CE->getArg(0)->IgnoreParenCasts();
9927        }
9928      }
9929    }
9930  }
9931
9932  BlockExpr *block = dyn_cast<BlockExpr>(e);
9933  if (!block || !block->getBlockDecl()->capturesVariable(owner.Variable))
9934    return nullptr;
9935
9936  FindCaptureVisitor visitor(S.Context, owner.Variable);
9937  visitor.Visit(block->getBlockDecl()->getBody());
9938  return visitor.VarWillBeReased ? nullptr : visitor.Capturer;
9939}
9940
9941static void diagnoseRetainCycle(Sema &S, Expr *capturer,
9942                                RetainCycleOwner &owner) {
9943  assert(capturer);
9944  assert(owner.Variable && owner.Loc.isValid());
9945
9946  S.Diag(capturer->getExprLoc(), diag::warn_arc_retain_cycle)
9947    << owner.Variable << capturer->getSourceRange();
9948  S.Diag(owner.Loc, diag::note_arc_retain_cycle_owner)
9949    << owner.Indirect << owner.Range;
9950}
9951
9952/// Check for a keyword selector that starts with the word 'add' or
9953/// 'set'.
9954static bool isSetterLikeSelector(Selector sel) {
9955  if (sel.isUnarySelector()) return false;
9956
9957  StringRef str = sel.getNameForSlot(0);
9958  while (!str.empty() && str.front() == '_') str = str.substr(1);
9959  if (str.startswith("set"))
9960    str = str.substr(3);
9961  else if (str.startswith("add")) {
9962    // Specially whitelist 'addOperationWithBlock:'.
9963    if (sel.getNumArgs() == 1 && str.startswith("addOperationWithBlock"))
9964      return false;
9965    str = str.substr(3);
9966  }
9967  else
9968    return false;
9969
9970  if (str.empty()) return true;
9971  return !isLowercase(str.front());
9972}
9973
9974static Optional<int> GetNSMutableArrayArgumentIndex(Sema &S,
9975                                                    ObjCMessageExpr *Message) {
9976  bool IsMutableArray = S.NSAPIObj->isSubclassOfNSClass(
9977                                                Message->getReceiverInterface(),
9978                                                NSAPI::ClassId_NSMutableArray);
9979  if (!IsMutableArray) {
9980    return None;
9981  }
9982
9983  Selector Sel = Message->getSelector();
9984
9985  Optional<NSAPI::NSArrayMethodKind> MKOpt =
9986    S.NSAPIObj->getNSArrayMethodKind(Sel);
9987  if (!MKOpt) {
9988    return None;
9989  }
9990
9991  NSAPI::NSArrayMethodKind MK = *MKOpt;
9992
9993  switch (MK) {
9994    case NSAPI::NSMutableArr_addObject:
9995    case NSAPI::NSMutableArr_insertObjectAtIndex:
9996    case NSAPI::NSMutableArr_setObjectAtIndexedSubscript:
9997      return 0;
9998    case NSAPI::NSMutableArr_replaceObjectAtIndex:
9999      return 1;
10000
10001    default:
10002      return None;
10003  }
10004
10005  return None;
10006}
10007
10008static
10009Optional<int> GetNSMutableDictionaryArgumentIndex(Sema &S,
10010                                                  ObjCMessageExpr *Message) {
10011  bool IsMutableDictionary = S.NSAPIObj->isSubclassOfNSClass(
10012                                            Message->getReceiverInterface(),
10013                                            NSAPI::ClassId_NSMutableDictionary);
10014  if (!IsMutableDictionary) {
10015    return None;
10016  }
10017
10018  Selector Sel = Message->getSelector();
10019
10020  Optional<NSAPI::NSDictionaryMethodKind> MKOpt =
10021    S.NSAPIObj->getNSDictionaryMethodKind(Sel);
10022  if (!MKOpt) {
10023    return None;
10024  }
10025
10026  NSAPI::NSDictionaryMethodKind MK = *MKOpt;
10027
10028  switch (MK) {
10029    case NSAPI::NSMutableDict_setObjectForKey:
10030    case NSAPI::NSMutableDict_setValueForKey:
10031    case NSAPI::NSMutableDict_setObjectForKeyedSubscript:
10032      return 0;
10033
10034    default:
10035      return None;
10036  }
10037
10038  return None;
10039}
10040
10041static Optional<int> GetNSSetArgumentIndex(Sema &S, ObjCMessageExpr *Message) {
10042  bool IsMutableSet = S.NSAPIObj->isSubclassOfNSClass(
10043                                                Message->getReceiverInterface(),
10044                                                NSAPI::ClassId_NSMutableSet);
10045
10046  bool IsMutableOrderedSet = S.NSAPIObj->isSubclassOfNSClass(
10047                                            Message->getReceiverInterface(),
10048                                            NSAPI::ClassId_NSMutableOrderedSet);
10049  if (!IsMutableSet && !IsMutableOrderedSet) {
10050    return None;
10051  }
10052
10053  Selector Sel = Message->getSelector();
10054
10055  Optional<NSAPI::NSSetMethodKind> MKOpt = S.NSAPIObj->getNSSetMethodKind(Sel);
10056  if (!MKOpt) {
10057    return None;
10058  }
10059
10060  NSAPI::NSSetMethodKind MK = *MKOpt;
10061
10062  switch (MK) {
10063    case NSAPI::NSMutableSet_addObject:
10064    case NSAPI::NSOrderedSet_setObjectAtIndex:
10065    case NSAPI::NSOrderedSet_setObjectAtIndexedSubscript:
10066    case NSAPI::NSOrderedSet_insertObjectAtIndex:
10067      return 0;
10068    case NSAPI::NSOrderedSet_replaceObjectAtIndexWithObject:
10069      return 1;
10070  }
10071
10072  return None;
10073}
10074
10075void Sema::CheckObjCCircularContainer(ObjCMessageExpr *Message) {
10076  if (!Message->isInstanceMessage()) {
10077    return;
10078  }
10079
10080  Optional<int> ArgOpt;
10081
10082  if (!(ArgOpt = GetNSMutableArrayArgumentIndex(*this, Message)) &&
10083      !(ArgOpt = GetNSMutableDictionaryArgumentIndex(*this, Message)) &&
10084      !(ArgOpt = GetNSSetArgumentIndex(*this, Message))) {
10085    return;
10086  }
10087
10088  int ArgIndex = *ArgOpt;
10089
10090  Expr *Arg = Message->getArg(ArgIndex)->IgnoreImpCasts();
10091  if (OpaqueValueExpr *OE = dyn_cast<OpaqueValueExpr>(Arg)) {
10092    Arg = OE->getSourceExpr()->IgnoreImpCasts();
10093  }
10094
10095  if (Message->getReceiverKind() == ObjCMessageExpr::SuperInstance) {
10096    if (DeclRefExpr *ArgRE = dyn_cast<DeclRefExpr>(Arg)) {
10097      if (ArgRE->isObjCSelfExpr()) {
10098        Diag(Message->getSourceRange().getBegin(),
10099             diag::warn_objc_circular_container)
10100          << ArgRE->getDecl()->getName() << StringRef("super");
10101      }
10102    }
10103  } else {
10104    Expr *Receiver = Message->getInstanceReceiver()->IgnoreImpCasts();
10105
10106    if (OpaqueValueExpr *OE = dyn_cast<OpaqueValueExpr>(Receiver)) {
10107      Receiver = OE->getSourceExpr()->IgnoreImpCasts();
10108    }
10109
10110    if (DeclRefExpr *ReceiverRE = dyn_cast<DeclRefExpr>(Receiver)) {
10111      if (DeclRefExpr *ArgRE = dyn_cast<DeclRefExpr>(Arg)) {
10112        if (ReceiverRE->getDecl() == ArgRE->getDecl()) {
10113          ValueDecl *Decl = ReceiverRE->getDecl();
10114          Diag(Message->getSourceRange().getBegin(),
10115               diag::warn_objc_circular_container)
10116            << Decl->getName() << Decl->getName();
10117          if (!ArgRE->isObjCSelfExpr()) {
10118            Diag(Decl->getLocation(),
10119                 diag::note_objc_circular_container_declared_here)
10120              << Decl->getName();
10121          }
10122        }
10123      }
10124    } else if (ObjCIvarRefExpr *IvarRE = dyn_cast<ObjCIvarRefExpr>(Receiver)) {
10125      if (ObjCIvarRefExpr *IvarArgRE = dyn_cast<ObjCIvarRefExpr>(Arg)) {
10126        if (IvarRE->getDecl() == IvarArgRE->getDecl()) {
10127          ObjCIvarDecl *Decl = IvarRE->getDecl();
10128          Diag(Message->getSourceRange().getBegin(),
10129               diag::warn_objc_circular_container)
10130            << Decl->getName() << Decl->getName();
10131          Diag(Decl->getLocation(),
10132               diag::note_objc_circular_container_declared_here)
10133            << Decl->getName();
10134        }
10135      }
10136    }
10137  }
10138}
10139
10140/// Check a message send to see if it's likely to cause a retain cycle.
10141void Sema::checkRetainCycles(ObjCMessageExpr *msg) {
10142  // Only check instance methods whose selector looks like a setter.
10143  if (!msg->isInstanceMessage() || !isSetterLikeSelector(msg->getSelector()))
10144    return;
10145
10146  // Try to find a variable that the receiver is strongly owned by.
10147  RetainCycleOwner owner;
10148  if (msg->getReceiverKind() == ObjCMessageExpr::Instance) {
10149    if (!findRetainCycleOwner(*this, msg->getInstanceReceiver(), owner))
10150      return;
10151  } else {
10152    assert(msg->getReceiverKind() == ObjCMessageExpr::SuperInstance);
10153    owner.Variable = getCurMethodDecl()->getSelfDecl();
10154    owner.Loc = msg->getSuperLoc();
10155    owner.Range = msg->getSuperLoc();
10156  }
10157
10158  // Check whether the receiver is captured by any of the arguments.
10159  for (unsigned i = 0, e = msg->getNumArgs(); i != e; ++i)
10160    if (Expr *capturer = findCapturingExpr(*this, msg->getArg(i), owner))
10161      return diagnoseRetainCycle(*this, capturer, owner);
10162}
10163
10164/// Check a property assign to see if it's likely to cause a retain cycle.
10165void Sema::checkRetainCycles(Expr *receiver, Expr *argument) {
10166  RetainCycleOwner owner;
10167  if (!findRetainCycleOwner(*this, receiver, owner))
10168    return;
10169
10170  if (Expr *capturer = findCapturingExpr(*this, argument, owner))
10171    diagnoseRetainCycle(*this, capturer, owner);
10172}
10173
10174void Sema::checkRetainCycles(VarDecl *Var, Expr *Init) {
10175  RetainCycleOwner Owner;
10176  if (!considerVariable(Var, /*DeclRefExpr=*/nullptr, Owner))
10177    return;
10178
10179  // Because we don't have an expression for the variable, we have to set the
10180  // location explicitly here.
10181  Owner.Loc = Var->getLocation();
10182  Owner.Range = Var->getSourceRange();
10183
10184  if (Expr *Capturer = findCapturingExpr(*this, Init, Owner))
10185    diagnoseRetainCycle(*this, Capturer, Owner);
10186}
10187
10188static bool checkUnsafeAssignLiteral(Sema &S, SourceLocation Loc,
10189                                     Expr *RHS, bool isProperty) {
10190  // Check if RHS is an Objective-C object literal, which also can get
10191  // immediately zapped in a weak reference.  Note that we explicitly
10192  // allow ObjCStringLiterals, since those are designed to never really die.
10193  RHS = RHS->IgnoreParenImpCasts();
10194
10195  // This enum needs to match with the 'select' in
10196  // warn_objc_arc_literal_assign (off-by-1).
10197  Sema::ObjCLiteralKind Kind = S.CheckLiteralKind(RHS);
10198  if (Kind == Sema::LK_String || Kind == Sema::LK_None)
10199    return false;
10200
10201  S.Diag(Loc, diag::warn_arc_literal_assign)
10202    << (unsigned) Kind
10203    << (isProperty ? 0 : 1)
10204    << RHS->getSourceRange();
10205
10206  return true;
10207}
10208
10209static bool checkUnsafeAssignObject(Sema &S, SourceLocation Loc,
10210                                    Qualifiers::ObjCLifetime LT,
10211                                    Expr *RHS, bool isProperty) {
10212  // Strip off any implicit cast added to get to the one ARC-specific.
10213  while (ImplicitCastExpr *cast = dyn_cast<ImplicitCastExpr>(RHS)) {
10214    if (cast->getCastKind() == CK_ARCConsumeObject) {
10215      S.Diag(Loc, diag::warn_arc_retained_assign)
10216        << (LT == Qualifiers::OCL_ExplicitNone)
10217        << (isProperty ? 0 : 1)
10218        << RHS->getSourceRange();
10219      return true;
10220    }
10221    RHS = cast->getSubExpr();
10222  }
10223
10224  if (LT == Qualifiers::OCL_Weak &&
10225      checkUnsafeAssignLiteral(S, Loc, RHS, isProperty))
10226    return true;
10227
10228  return false;
10229}
10230
10231bool Sema::checkUnsafeAssigns(SourceLocation Loc,
10232                              QualType LHS, Expr *RHS) {
10233  Qualifiers::ObjCLifetime LT = LHS.getObjCLifetime();
10234
10235  if (LT != Qualifiers::OCL_Weak && LT != Qualifiers::OCL_ExplicitNone)
10236    return false;
10237
10238  if (checkUnsafeAssignObject(*this, Loc, LT, RHS, false))
10239    return true;
10240
10241  return false;
10242}
10243
10244void Sema::checkUnsafeExprAssigns(SourceLocation Loc,
10245                              Expr *LHS, Expr *RHS) {
10246  QualType LHSType;
10247  // PropertyRef on LHS type need be directly obtained from
10248  // its declaration as it has a PseudoType.
10249  ObjCPropertyRefExpr *PRE
10250    = dyn_cast<ObjCPropertyRefExpr>(LHS->IgnoreParens());
10251  if (PRE && !PRE->isImplicitProperty()) {
10252    const ObjCPropertyDecl *PD = PRE->getExplicitProperty();
10253    if (PD)
10254      LHSType = PD->getType();
10255  }
10256
10257  if (LHSType.isNull())
10258    LHSType = LHS->getType();
10259
10260  Qualifiers::ObjCLifetime LT = LHSType.getObjCLifetime();
10261
10262  if (LT == Qualifiers::OCL_Weak) {
10263    if (!Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, Loc))
10264      getCurFunction()->markSafeWeakUse(LHS);
10265  }
10266
10267  if (checkUnsafeAssigns(Loc, LHSType, RHS))
10268    return;
10269
10270  // FIXME. Check for other life times.
10271  if (LT != Qualifiers::OCL_None)
10272    return;
10273
10274  if (PRE) {
10275    if (PRE->isImplicitProperty())
10276      return;
10277    const ObjCPropertyDecl *PD = PRE->getExplicitProperty();
10278    if (!PD)
10279      return;
10280
10281    unsigned Attributes = PD->getPropertyAttributes();
10282    if (Attributes & ObjCPropertyDecl::OBJC_PR_assign) {
10283      // when 'assign' attribute was not explicitly specified
10284      // by user, ignore it and rely on property type itself
10285      // for lifetime info.
10286      unsigned AsWrittenAttr = PD->getPropertyAttributesAsWritten();
10287      if (!(AsWrittenAttr & ObjCPropertyDecl::OBJC_PR_assign) &&
10288          LHSType->isObjCRetainableType())
10289        return;
10290
10291      while (ImplicitCastExpr *cast = dyn_cast<ImplicitCastExpr>(RHS)) {
10292        if (cast->getCastKind() == CK_ARCConsumeObject) {
10293          Diag(Loc, diag::warn_arc_retained_property_assign)
10294          << RHS->getSourceRange();
10295          return;
10296        }
10297        RHS = cast->getSubExpr();
10298      }
10299    }
10300    else if (Attributes & ObjCPropertyDecl::OBJC_PR_weak) {
10301      if (checkUnsafeAssignObject(*this, Loc, Qualifiers::OCL_Weak, RHS, true))
10302        return;
10303    }
10304  }
10305}
10306
10307//===--- CHECK: Empty statement body (-Wempty-body) ---------------------===//
10308
10309namespace {
10310bool ShouldDiagnoseEmptyStmtBody(const SourceManager &SourceMgr,
10311                                 SourceLocation StmtLoc,
10312                                 const NullStmt *Body) {
10313  // Do not warn if the body is a macro that expands to nothing, e.g:
10314  //
10315  // #define CALL(x)
10316  // if (condition)
10317  //   CALL(0);
10318  //
10319  if (Body->hasLeadingEmptyMacro())
10320    return false;
10321
10322  // Get line numbers of statement and body.
10323  bool StmtLineInvalid;
10324  unsigned StmtLine = SourceMgr.getPresumedLineNumber(StmtLoc,
10325                                                      &StmtLineInvalid);
10326  if (StmtLineInvalid)
10327    return false;
10328
10329  bool BodyLineInvalid;
10330  unsigned BodyLine = SourceMgr.getSpellingLineNumber(Body->getSemiLoc(),
10331                                                      &BodyLineInvalid);
10332  if (BodyLineInvalid)
10333    return false;
10334
10335  // Warn if null statement and body are on the same line.
10336  if (StmtLine != BodyLine)
10337    return false;
10338
10339  return true;
10340}
10341} // end anonymous namespace
10342
10343void Sema::DiagnoseEmptyStmtBody(SourceLocation StmtLoc,
10344                                 const Stmt *Body,
10345                                 unsigned DiagID) {
10346  // Since this is a syntactic check, don't emit diagnostic for template
10347  // instantiations, this just adds noise.
10348  if (CurrentInstantiationScope)
10349    return;
10350
10351  // The body should be a null statement.
10352  const NullStmt *NBody = dyn_cast<NullStmt>(Body);
10353  if (!NBody)
10354    return;
10355
10356  // Do the usual checks.
10357  if (!ShouldDiagnoseEmptyStmtBody(SourceMgr, StmtLoc, NBody))
10358    return;
10359
10360  Diag(NBody->getSemiLoc(), DiagID);
10361  Diag(NBody->getSemiLoc(), diag::note_empty_body_on_separate_line);
10362}
10363
10364void Sema::DiagnoseEmptyLoopBody(const Stmt *S,
10365                                 const Stmt *PossibleBody) {
10366  assert(!CurrentInstantiationScope); // Ensured by caller
10367
10368  SourceLocation StmtLoc;
10369  const Stmt *Body;
10370  unsigned DiagID;
10371  if (const ForStmt *FS = dyn_cast<ForStmt>(S)) {
10372    StmtLoc = FS->getRParenLoc();
10373    Body = FS->getBody();
10374    DiagID = diag::warn_empty_for_body;
10375  } else if (const WhileStmt *WS = dyn_cast<WhileStmt>(S)) {
10376    StmtLoc = WS->getCond()->getSourceRange().getEnd();
10377    Body = WS->getBody();
10378    DiagID = diag::warn_empty_while_body;
10379  } else
10380    return; // Neither `for' nor `while'.
10381
10382  // The body should be a null statement.
10383  const NullStmt *NBody = dyn_cast<NullStmt>(Body);
10384  if (!NBody)
10385    return;
10386
10387  // Skip expensive checks if diagnostic is disabled.
10388  if (Diags.isIgnored(DiagID, NBody->getSemiLoc()))
10389    return;
10390
10391  // Do the usual checks.
10392  if (!ShouldDiagnoseEmptyStmtBody(SourceMgr, StmtLoc, NBody))
10393    return;
10394
10395  // `for(...);' and `while(...);' are popular idioms, so in order to keep
10396  // noise level low, emit diagnostics only if for/while is followed by a
10397  // CompoundStmt, e.g.:
10398  //    for (int i = 0; i < n; i++);
10399  //    {
10400  //      a(i);
10401  //    }
10402  // or if for/while is followed by a statement with more indentation
10403  // than for/while itself:
10404  //    for (int i = 0; i < n; i++);
10405  //      a(i);
10406  bool ProbableTypo = isa<CompoundStmt>(PossibleBody);
10407  if (!ProbableTypo) {
10408    bool BodyColInvalid;
10409    unsigned BodyCol = SourceMgr.getPresumedColumnNumber(
10410                             PossibleBody->getLocStart(),
10411                             &BodyColInvalid);
10412    if (BodyColInvalid)
10413      return;
10414
10415    bool StmtColInvalid;
10416    unsigned StmtCol = SourceMgr.getPresumedColumnNumber(
10417                             S->getLocStart(),
10418                             &StmtColInvalid);
10419    if (StmtColInvalid)
10420      return;
10421
10422    if (BodyCol > StmtCol)
10423      ProbableTypo = true;
10424  }
10425
10426  if (ProbableTypo) {
10427    Diag(NBody->getSemiLoc(), DiagID);
10428    Diag(NBody->getSemiLoc(), diag::note_empty_body_on_separate_line);
10429  }
10430}
10431
10432//===--- CHECK: Warn on self move with std::move. -------------------------===//
10433
10434/// DiagnoseSelfMove - Emits a warning if a value is moved to itself.
10435void Sema::DiagnoseSelfMove(const Expr *LHSExpr, const Expr *RHSExpr,
10436                             SourceLocation OpLoc) {
10437  if (Diags.isIgnored(diag::warn_sizeof_pointer_expr_memaccess, OpLoc))
10438    return;
10439
10440  if (!ActiveTemplateInstantiations.empty())
10441    return;
10442
10443  // Strip parens and casts away.
10444  LHSExpr = LHSExpr->IgnoreParenImpCasts();
10445  RHSExpr = RHSExpr->IgnoreParenImpCasts();
10446
10447  // Check for a call expression
10448  const CallExpr *CE = dyn_cast<CallExpr>(RHSExpr);
10449  if (!CE || CE->getNumArgs() != 1)
10450    return;
10451
10452  // Check for a call to std::move
10453  const FunctionDecl *FD = CE->getDirectCallee();
10454  if (!FD || !FD->isInStdNamespace() || !FD->getIdentifier() ||
10455      !FD->getIdentifier()->isStr("move"))
10456    return;
10457
10458  // Get argument from std::move
10459  RHSExpr = CE->getArg(0);
10460
10461  const DeclRefExpr *LHSDeclRef = dyn_cast<DeclRefExpr>(LHSExpr);
10462  const DeclRefExpr *RHSDeclRef = dyn_cast<DeclRefExpr>(RHSExpr);
10463
10464  // Two DeclRefExpr's, check that the decls are the same.
10465  if (LHSDeclRef && RHSDeclRef) {
10466    if (!LHSDeclRef->getDecl() || !RHSDeclRef->getDecl())
10467      return;
10468    if (LHSDeclRef->getDecl()->getCanonicalDecl() !=
10469        RHSDeclRef->getDecl()->getCanonicalDecl())
10470      return;
10471
10472    Diag(OpLoc, diag::warn_self_move) << LHSExpr->getType()
10473                                        << LHSExpr->getSourceRange()
10474                                        << RHSExpr->getSourceRange();
10475    return;
10476  }
10477
10478  // Member variables require a different approach to check for self moves.
10479  // MemberExpr's are the same if every nested MemberExpr refers to the same
10480  // Decl and that the base Expr's are DeclRefExpr's with the same Decl or
10481  // the base Expr's are CXXThisExpr's.
10482  const Expr *LHSBase = LHSExpr;
10483  const Expr *RHSBase = RHSExpr;
10484  const MemberExpr *LHSME = dyn_cast<MemberExpr>(LHSExpr);
10485  const MemberExpr *RHSME = dyn_cast<MemberExpr>(RHSExpr);
10486  if (!LHSME || !RHSME)
10487    return;
10488
10489  while (LHSME && RHSME) {
10490    if (LHSME->getMemberDecl()->getCanonicalDecl() !=
10491        RHSME->getMemberDecl()->getCanonicalDecl())
10492      return;
10493
10494    LHSBase = LHSME->getBase();
10495    RHSBase = RHSME->getBase();
10496    LHSME = dyn_cast<MemberExpr>(LHSBase);
10497    RHSME = dyn_cast<MemberExpr>(RHSBase);
10498  }
10499
10500  LHSDeclRef = dyn_cast<DeclRefExpr>(LHSBase);
10501  RHSDeclRef = dyn_cast<DeclRefExpr>(RHSBase);
10502  if (LHSDeclRef && RHSDeclRef) {
10503    if (!LHSDeclRef->getDecl() || !RHSDeclRef->getDecl())
10504      return;
10505    if (LHSDeclRef->getDecl()->getCanonicalDecl() !=
10506        RHSDeclRef->getDecl()->getCanonicalDecl())
10507      return;
10508
10509    Diag(OpLoc, diag::warn_self_move) << LHSExpr->getType()
10510                                        << LHSExpr->getSourceRange()
10511                                        << RHSExpr->getSourceRange();
10512    return;
10513  }
10514
10515  if (isa<CXXThisExpr>(LHSBase) && isa<CXXThisExpr>(RHSBase))
10516    Diag(OpLoc, diag::warn_self_move) << LHSExpr->getType()
10517                                        << LHSExpr->getSourceRange()
10518                                        << RHSExpr->getSourceRange();
10519}
10520
10521//===--- Layout compatibility ----------------------------------------------//
10522
10523namespace {
10524
10525bool isLayoutCompatible(ASTContext &C, QualType T1, QualType T2);
10526
10527/// \brief Check if two enumeration types are layout-compatible.
10528bool isLayoutCompatible(ASTContext &C, EnumDecl *ED1, EnumDecl *ED2) {
10529  // C++11 [dcl.enum] p8:
10530  // Two enumeration types are layout-compatible if they have the same
10531  // underlying type.
10532  return ED1->isComplete() && ED2->isComplete() &&
10533         C.hasSameType(ED1->getIntegerType(), ED2->getIntegerType());
10534}
10535
10536/// \brief Check if two fields are layout-compatible.
10537bool isLayoutCompatible(ASTContext &C, FieldDecl *Field1, FieldDecl *Field2) {
10538  if (!isLayoutCompatible(C, Field1->getType(), Field2->getType()))
10539    return false;
10540
10541  if (Field1->isBitField() != Field2->isBitField())
10542    return false;
10543
10544  if (Field1->isBitField()) {
10545    // Make sure that the bit-fields are the same length.
10546    unsigned Bits1 = Field1->getBitWidthValue(C);
10547    unsigned Bits2 = Field2->getBitWidthValue(C);
10548
10549    if (Bits1 != Bits2)
10550      return false;
10551  }
10552
10553  return true;
10554}
10555
10556/// \brief Check if two standard-layout structs are layout-compatible.
10557/// (C++11 [class.mem] p17)
10558bool isLayoutCompatibleStruct(ASTContext &C,
10559                              RecordDecl *RD1,
10560                              RecordDecl *RD2) {
10561  // If both records are C++ classes, check that base classes match.
10562  if (const CXXRecordDecl *D1CXX = dyn_cast<CXXRecordDecl>(RD1)) {
10563    // If one of records is a CXXRecordDecl we are in C++ mode,
10564    // thus the other one is a CXXRecordDecl, too.
10565    const CXXRecordDecl *D2CXX = cast<CXXRecordDecl>(RD2);
10566    // Check number of base classes.
10567    if (D1CXX->getNumBases() != D2CXX->getNumBases())
10568      return false;
10569
10570    // Check the base classes.
10571    for (CXXRecordDecl::base_class_const_iterator
10572               Base1 = D1CXX->bases_begin(),
10573           BaseEnd1 = D1CXX->bases_end(),
10574              Base2 = D2CXX->bases_begin();
10575         Base1 != BaseEnd1;
10576         ++Base1, ++Base2) {
10577      if (!isLayoutCompatible(C, Base1->getType(), Base2->getType()))
10578        return false;
10579    }
10580  } else if (const CXXRecordDecl *D2CXX = dyn_cast<CXXRecordDecl>(RD2)) {
10581    // If only RD2 is a C++ class, it should have zero base classes.
10582    if (D2CXX->getNumBases() > 0)
10583      return false;
10584  }
10585
10586  // Check the fields.
10587  RecordDecl::field_iterator Field2 = RD2->field_begin(),
10588                             Field2End = RD2->field_end(),
10589                             Field1 = RD1->field_begin(),
10590                             Field1End = RD1->field_end();
10591  for ( ; Field1 != Field1End && Field2 != Field2End; ++Field1, ++Field2) {
10592    if (!isLayoutCompatible(C, *Field1, *Field2))
10593      return false;
10594  }
10595  if (Field1 != Field1End || Field2 != Field2End)
10596    return false;
10597
10598  return true;
10599}
10600
10601/// \brief Check if two standard-layout unions are layout-compatible.
10602/// (C++11 [class.mem] p18)
10603bool isLayoutCompatibleUnion(ASTContext &C,
10604                             RecordDecl *RD1,
10605                             RecordDecl *RD2) {
10606  llvm::SmallPtrSet<FieldDecl *, 8> UnmatchedFields;
10607  for (auto *Field2 : RD2->fields())
10608    UnmatchedFields.insert(Field2);
10609
10610  for (auto *Field1 : RD1->fields()) {
10611    llvm::SmallPtrSet<FieldDecl *, 8>::iterator
10612        I = UnmatchedFields.begin(),
10613        E = UnmatchedFields.end();
10614
10615    for ( ; I != E; ++I) {
10616      if (isLayoutCompatible(C, Field1, *I)) {
10617        bool Result = UnmatchedFields.erase(*I);
10618        (void) Result;
10619        assert(Result);
10620        break;
10621      }
10622    }
10623    if (I == E)
10624      return false;
10625  }
10626
10627  return UnmatchedFields.empty();
10628}
10629
10630bool isLayoutCompatible(ASTContext &C, RecordDecl *RD1, RecordDecl *RD2) {
10631  if (RD1->isUnion() != RD2->isUnion())
10632    return false;
10633
10634  if (RD1->isUnion())
10635    return isLayoutCompatibleUnion(C, RD1, RD2);
10636  else
10637    return isLayoutCompatibleStruct(C, RD1, RD2);
10638}
10639
10640/// \brief Check if two types are layout-compatible in C++11 sense.
10641bool isLayoutCompatible(ASTContext &C, QualType T1, QualType T2) {
10642  if (T1.isNull() || T2.isNull())
10643    return false;
10644
10645  // C++11 [basic.types] p11:
10646  // If two types T1 and T2 are the same type, then T1 and T2 are
10647  // layout-compatible types.
10648  if (C.hasSameType(T1, T2))
10649    return true;
10650
10651  T1 = T1.getCanonicalType().getUnqualifiedType();
10652  T2 = T2.getCanonicalType().getUnqualifiedType();
10653
10654  const Type::TypeClass TC1 = T1->getTypeClass();
10655  const Type::TypeClass TC2 = T2->getTypeClass();
10656
10657  if (TC1 != TC2)
10658    return false;
10659
10660  if (TC1 == Type::Enum) {
10661    return isLayoutCompatible(C,
10662                              cast<EnumType>(T1)->getDecl(),
10663                              cast<EnumType>(T2)->getDecl());
10664  } else if (TC1 == Type::Record) {
10665    if (!T1->isStandardLayoutType() || !T2->isStandardLayoutType())
10666      return false;
10667
10668    return isLayoutCompatible(C,
10669                              cast<RecordType>(T1)->getDecl(),
10670                              cast<RecordType>(T2)->getDecl());
10671  }
10672
10673  return false;
10674}
10675} // end anonymous namespace
10676
10677//===--- CHECK: pointer_with_type_tag attribute: datatypes should match ----//
10678
10679namespace {
10680/// \brief Given a type tag expression find the type tag itself.
10681///
10682/// \param TypeExpr Type tag expression, as it appears in user's code.
10683///
10684/// \param VD Declaration of an identifier that appears in a type tag.
10685///
10686/// \param MagicValue Type tag magic value.
10687bool FindTypeTagExpr(const Expr *TypeExpr, const ASTContext &Ctx,
10688                     const ValueDecl **VD, uint64_t *MagicValue) {
10689  while(true) {
10690    if (!TypeExpr)
10691      return false;
10692
10693    TypeExpr = TypeExpr->IgnoreParenImpCasts()->IgnoreParenCasts();
10694
10695    switch (TypeExpr->getStmtClass()) {
10696    case Stmt::UnaryOperatorClass: {
10697      const UnaryOperator *UO = cast<UnaryOperator>(TypeExpr);
10698      if (UO->getOpcode() == UO_AddrOf || UO->getOpcode() == UO_Deref) {
10699        TypeExpr = UO->getSubExpr();
10700        continue;
10701      }
10702      return false;
10703    }
10704
10705    case Stmt::DeclRefExprClass: {
10706      const DeclRefExpr *DRE = cast<DeclRefExpr>(TypeExpr);
10707      *VD = DRE->getDecl();
10708      return true;
10709    }
10710
10711    case Stmt::IntegerLiteralClass: {
10712      const IntegerLiteral *IL = cast<IntegerLiteral>(TypeExpr);
10713      llvm::APInt MagicValueAPInt = IL->getValue();
10714      if (MagicValueAPInt.getActiveBits() <= 64) {
10715        *MagicValue = MagicValueAPInt.getZExtValue();
10716        return true;
10717      } else
10718        return false;
10719    }
10720
10721    case Stmt::BinaryConditionalOperatorClass:
10722    case Stmt::ConditionalOperatorClass: {
10723      const AbstractConditionalOperator *ACO =
10724          cast<AbstractConditionalOperator>(TypeExpr);
10725      bool Result;
10726      if (ACO->getCond()->EvaluateAsBooleanCondition(Result, Ctx)) {
10727        if (Result)
10728          TypeExpr = ACO->getTrueExpr();
10729        else
10730          TypeExpr = ACO->getFalseExpr();
10731        continue;
10732      }
10733      return false;
10734    }
10735
10736    case Stmt::BinaryOperatorClass: {
10737      const BinaryOperator *BO = cast<BinaryOperator>(TypeExpr);
10738      if (BO->getOpcode() == BO_Comma) {
10739        TypeExpr = BO->getRHS();
10740        continue;
10741      }
10742      return false;
10743    }
10744
10745    default:
10746      return false;
10747    }
10748  }
10749}
10750
10751/// \brief Retrieve the C type corresponding to type tag TypeExpr.
10752///
10753/// \param TypeExpr Expression that specifies a type tag.
10754///
10755/// \param MagicValues Registered magic values.
10756///
10757/// \param FoundWrongKind Set to true if a type tag was found, but of a wrong
10758///        kind.
10759///
10760/// \param TypeInfo Information about the corresponding C type.
10761///
10762/// \returns true if the corresponding C type was found.
10763bool GetMatchingCType(
10764        const IdentifierInfo *ArgumentKind,
10765        const Expr *TypeExpr, const ASTContext &Ctx,
10766        const llvm::DenseMap<Sema::TypeTagMagicValue,
10767                             Sema::TypeTagData> *MagicValues,
10768        bool &FoundWrongKind,
10769        Sema::TypeTagData &TypeInfo) {
10770  FoundWrongKind = false;
10771
10772  // Variable declaration that has type_tag_for_datatype attribute.
10773  const ValueDecl *VD = nullptr;
10774
10775  uint64_t MagicValue;
10776
10777  if (!FindTypeTagExpr(TypeExpr, Ctx, &VD, &MagicValue))
10778    return false;
10779
10780  if (VD) {
10781    if (TypeTagForDatatypeAttr *I = VD->getAttr<TypeTagForDatatypeAttr>()) {
10782      if (I->getArgumentKind() != ArgumentKind) {
10783        FoundWrongKind = true;
10784        return false;
10785      }
10786      TypeInfo.Type = I->getMatchingCType();
10787      TypeInfo.LayoutCompatible = I->getLayoutCompatible();
10788      TypeInfo.MustBeNull = I->getMustBeNull();
10789      return true;
10790    }
10791    return false;
10792  }
10793
10794  if (!MagicValues)
10795    return false;
10796
10797  llvm::DenseMap<Sema::TypeTagMagicValue,
10798                 Sema::TypeTagData>::const_iterator I =
10799      MagicValues->find(std::make_pair(ArgumentKind, MagicValue));
10800  if (I == MagicValues->end())
10801    return false;
10802
10803  TypeInfo = I->second;
10804  return true;
10805}
10806} // end anonymous namespace
10807
10808void Sema::RegisterTypeTagForDatatype(const IdentifierInfo *ArgumentKind,
10809                                      uint64_t MagicValue, QualType Type,
10810                                      bool LayoutCompatible,
10811                                      bool MustBeNull) {
10812  if (!TypeTagForDatatypeMagicValues)
10813    TypeTagForDatatypeMagicValues.reset(
10814        new llvm::DenseMap<TypeTagMagicValue, TypeTagData>);
10815
10816  TypeTagMagicValue Magic(ArgumentKind, MagicValue);
10817  (*TypeTagForDatatypeMagicValues)[Magic] =
10818      TypeTagData(Type, LayoutCompatible, MustBeNull);
10819}
10820
10821namespace {
10822bool IsSameCharType(QualType T1, QualType T2) {
10823  const BuiltinType *BT1 = T1->getAs<BuiltinType>();
10824  if (!BT1)
10825    return false;
10826
10827  const BuiltinType *BT2 = T2->getAs<BuiltinType>();
10828  if (!BT2)
10829    return false;
10830
10831  BuiltinType::Kind T1Kind = BT1->getKind();
10832  BuiltinType::Kind T2Kind = BT2->getKind();
10833
10834  return (T1Kind == BuiltinType::SChar  && T2Kind == BuiltinType::Char_S) ||
10835         (T1Kind == BuiltinType::UChar  && T2Kind == BuiltinType::Char_U) ||
10836         (T1Kind == BuiltinType::Char_U && T2Kind == BuiltinType::UChar) ||
10837         (T1Kind == BuiltinType::Char_S && T2Kind == BuiltinType::SChar);
10838}
10839} // end anonymous namespace
10840
10841void Sema::CheckArgumentWithTypeTag(const ArgumentWithTypeTagAttr *Attr,
10842                                    const Expr * const *ExprArgs) {
10843  const IdentifierInfo *ArgumentKind = Attr->getArgumentKind();
10844  bool IsPointerAttr = Attr->getIsPointer();
10845
10846  const Expr *TypeTagExpr = ExprArgs[Attr->getTypeTagIdx()];
10847  bool FoundWrongKind;
10848  TypeTagData TypeInfo;
10849  if (!GetMatchingCType(ArgumentKind, TypeTagExpr, Context,
10850                        TypeTagForDatatypeMagicValues.get(),
10851                        FoundWrongKind, TypeInfo)) {
10852    if (FoundWrongKind)
10853      Diag(TypeTagExpr->getExprLoc(),
10854           diag::warn_type_tag_for_datatype_wrong_kind)
10855        << TypeTagExpr->getSourceRange();
10856    return;
10857  }
10858
10859  const Expr *ArgumentExpr = ExprArgs[Attr->getArgumentIdx()];
10860  if (IsPointerAttr) {
10861    // Skip implicit cast of pointer to `void *' (as a function argument).
10862    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgumentExpr))
10863      if (ICE->getType()->isVoidPointerType() &&
10864          ICE->getCastKind() == CK_BitCast)
10865        ArgumentExpr = ICE->getSubExpr();
10866  }
10867  QualType ArgumentType = ArgumentExpr->getType();
10868
10869  // Passing a `void*' pointer shouldn't trigger a warning.
10870  if (IsPointerAttr && ArgumentType->isVoidPointerType())
10871    return;
10872
10873  if (TypeInfo.MustBeNull) {
10874    // Type tag with matching void type requires a null pointer.
10875    if (!ArgumentExpr->isNullPointerConstant(Context,
10876                                             Expr::NPC_ValueDependentIsNotNull)) {
10877      Diag(ArgumentExpr->getExprLoc(),
10878           diag::warn_type_safety_null_pointer_required)
10879          << ArgumentKind->getName()
10880          << ArgumentExpr->getSourceRange()
10881          << TypeTagExpr->getSourceRange();
10882    }
10883    return;
10884  }
10885
10886  QualType RequiredType = TypeInfo.Type;
10887  if (IsPointerAttr)
10888    RequiredType = Context.getPointerType(RequiredType);
10889
10890  bool mismatch = false;
10891  if (!TypeInfo.LayoutCompatible) {
10892    mismatch = !Context.hasSameType(ArgumentType, RequiredType);
10893
10894    // C++11 [basic.fundamental] p1:
10895    // Plain char, signed char, and unsigned char are three distinct types.
10896    //
10897    // But we treat plain `char' as equivalent to `signed char' or `unsigned
10898    // char' depending on the current char signedness mode.
10899    if (mismatch)
10900      if ((IsPointerAttr && IsSameCharType(ArgumentType->getPointeeType(),
10901                                           RequiredType->getPointeeType())) ||
10902          (!IsPointerAttr && IsSameCharType(ArgumentType, RequiredType)))
10903        mismatch = false;
10904  } else
10905    if (IsPointerAttr)
10906      mismatch = !isLayoutCompatible(Context,
10907                                     ArgumentType->getPointeeType(),
10908                                     RequiredType->getPointeeType());
10909    else
10910      mismatch = !isLayoutCompatible(Context, ArgumentType, RequiredType);
10911
10912  if (mismatch)
10913    Diag(ArgumentExpr->getExprLoc(), diag::warn_type_safety_type_mismatch)
10914        << ArgumentType << ArgumentKind
10915        << TypeInfo.LayoutCompatible << RequiredType
10916        << ArgumentExpr->getSourceRange()
10917        << TypeTagExpr->getSourceRange();
10918}
10919