Expr.cpp revision 01eb9b9683535d8a65c704ad2c545903409e2d36 
1//===--- Expr.cpp - Expression AST Node Implementation --------------------===//
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 the Expr class and subclasses.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/AST/Expr.h"
15#include "clang/AST/ExprCXX.h"
16#include "clang/AST/APValue.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/DeclObjC.h"
19#include "clang/AST/DeclCXX.h"
20#include "clang/AST/DeclTemplate.h"
21#include "clang/AST/RecordLayout.h"
22#include "clang/AST/StmtVisitor.h"
23#include "clang/Basic/Builtins.h"
24#include "clang/Basic/TargetInfo.h"
25#include "llvm/Support/raw_ostream.h"
26#include <algorithm>
27using namespace clang;
28
29//===----------------------------------------------------------------------===//
30// Primary Expressions.
31//===----------------------------------------------------------------------===//
32
33// FIXME: Maybe this should use DeclPrinter with a special "print predefined
34// expr" policy instead.
35std::string PredefinedExpr::ComputeName(ASTContext &Context, IdentType IT,
36                                        const Decl *CurrentDecl) {
37  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurrentDecl)) {
38    if (IT != PrettyFunction)
39      return FD->getNameAsString();
40
41    llvm::SmallString<256> Name;
42    llvm::raw_svector_ostream Out(Name);
43
44    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
45      if (MD->isVirtual())
46        Out << "virtual ";
47    }
48
49    PrintingPolicy Policy(Context.getLangOptions());
50    Policy.SuppressTagKind = true;
51
52    std::string Proto = FD->getQualifiedNameAsString(Policy);
53
54    const FunctionType *AFT = FD->getType()->getAs<FunctionType>();
55    const FunctionProtoType *FT = 0;
56    if (FD->hasWrittenPrototype())
57      FT = dyn_cast<FunctionProtoType>(AFT);
58
59    Proto += "(";
60    if (FT) {
61      llvm::raw_string_ostream POut(Proto);
62      for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
63        if (i) POut << ", ";
64        std::string Param;
65        FD->getParamDecl(i)->getType().getAsStringInternal(Param, Policy);
66        POut << Param;
67      }
68
69      if (FT->isVariadic()) {
70        if (FD->getNumParams()) POut << ", ";
71        POut << "...";
72      }
73    }
74    Proto += ")";
75
76    AFT->getResultType().getAsStringInternal(Proto, Policy);
77
78    Out << Proto;
79
80    Out.flush();
81    return Name.str().str();
82  }
83  if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CurrentDecl)) {
84    llvm::SmallString<256> Name;
85    llvm::raw_svector_ostream Out(Name);
86    Out << (MD->isInstanceMethod() ? '-' : '+');
87    Out << '[';
88    Out << MD->getClassInterface()->getNameAsString();
89    if (const ObjCCategoryImplDecl *CID =
90        dyn_cast<ObjCCategoryImplDecl>(MD->getDeclContext())) {
91      Out << '(';
92      Out <<  CID->getNameAsString();
93      Out <<  ')';
94    }
95    Out <<  ' ';
96    Out << MD->getSelector().getAsString();
97    Out <<  ']';
98
99    Out.flush();
100    return Name.str().str();
101  }
102  if (isa<TranslationUnitDecl>(CurrentDecl) && IT == PrettyFunction) {
103    // __PRETTY_FUNCTION__ -> "top level", the others produce an empty string.
104    return "top level";
105  }
106  return "";
107}
108
109/// getValueAsApproximateDouble - This returns the value as an inaccurate
110/// double.  Note that this may cause loss of precision, but is useful for
111/// debugging dumps, etc.
112double FloatingLiteral::getValueAsApproximateDouble() const {
113  llvm::APFloat V = getValue();
114  bool ignored;
115  V.convert(llvm::APFloat::IEEEdouble, llvm::APFloat::rmNearestTiesToEven,
116            &ignored);
117  return V.convertToDouble();
118}
119
120StringLiteral *StringLiteral::Create(ASTContext &C, const char *StrData,
121                                     unsigned ByteLength, bool Wide,
122                                     QualType Ty,
123                                     const SourceLocation *Loc,
124                                     unsigned NumStrs) {
125  // Allocate enough space for the StringLiteral plus an array of locations for
126  // any concatenated string tokens.
127  void *Mem = C.Allocate(sizeof(StringLiteral)+
128                         sizeof(SourceLocation)*(NumStrs-1),
129                         llvm::alignof<StringLiteral>());
130  StringLiteral *SL = new (Mem) StringLiteral(Ty);
131
132  // OPTIMIZE: could allocate this appended to the StringLiteral.
133  char *AStrData = new (C, 1) char[ByteLength];
134  memcpy(AStrData, StrData, ByteLength);
135  SL->StrData = AStrData;
136  SL->ByteLength = ByteLength;
137  SL->IsWide = Wide;
138  SL->TokLocs[0] = Loc[0];
139  SL->NumConcatenated = NumStrs;
140
141  if (NumStrs != 1)
142    memcpy(&SL->TokLocs[1], Loc+1, sizeof(SourceLocation)*(NumStrs-1));
143  return SL;
144}
145
146StringLiteral *StringLiteral::CreateEmpty(ASTContext &C, unsigned NumStrs) {
147  void *Mem = C.Allocate(sizeof(StringLiteral)+
148                         sizeof(SourceLocation)*(NumStrs-1),
149                         llvm::alignof<StringLiteral>());
150  StringLiteral *SL = new (Mem) StringLiteral(QualType());
151  SL->StrData = 0;
152  SL->ByteLength = 0;
153  SL->NumConcatenated = NumStrs;
154  return SL;
155}
156
157void StringLiteral::DoDestroy(ASTContext &C) {
158  C.Deallocate(const_cast<char*>(StrData));
159  Expr::DoDestroy(C);
160}
161
162void StringLiteral::setString(ASTContext &C, llvm::StringRef Str) {
163  if (StrData)
164    C.Deallocate(const_cast<char*>(StrData));
165
166  char *AStrData = new (C, 1) char[Str.size()];
167  memcpy(AStrData, Str.data(), Str.size());
168  StrData = AStrData;
169  ByteLength = Str.size();
170}
171
172/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
173/// corresponds to, e.g. "sizeof" or "[pre]++".
174const char *UnaryOperator::getOpcodeStr(Opcode Op) {
175  switch (Op) {
176  default: assert(0 && "Unknown unary operator");
177  case PostInc: return "++";
178  case PostDec: return "--";
179  case PreInc:  return "++";
180  case PreDec:  return "--";
181  case AddrOf:  return "&";
182  case Deref:   return "*";
183  case Plus:    return "+";
184  case Minus:   return "-";
185  case Not:     return "~";
186  case LNot:    return "!";
187  case Real:    return "__real";
188  case Imag:    return "__imag";
189  case Extension: return "__extension__";
190  case OffsetOf: return "__builtin_offsetof";
191  }
192}
193
194UnaryOperator::Opcode
195UnaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO, bool Postfix) {
196  switch (OO) {
197  default: assert(false && "No unary operator for overloaded function");
198  case OO_PlusPlus:   return Postfix ? PostInc : PreInc;
199  case OO_MinusMinus: return Postfix ? PostDec : PreDec;
200  case OO_Amp:        return AddrOf;
201  case OO_Star:       return Deref;
202  case OO_Plus:       return Plus;
203  case OO_Minus:      return Minus;
204  case OO_Tilde:      return Not;
205  case OO_Exclaim:    return LNot;
206  }
207}
208
209OverloadedOperatorKind UnaryOperator::getOverloadedOperator(Opcode Opc) {
210  switch (Opc) {
211  case PostInc: case PreInc: return OO_PlusPlus;
212  case PostDec: case PreDec: return OO_MinusMinus;
213  case AddrOf: return OO_Amp;
214  case Deref: return OO_Star;
215  case Plus: return OO_Plus;
216  case Minus: return OO_Minus;
217  case Not: return OO_Tilde;
218  case LNot: return OO_Exclaim;
219  default: return OO_None;
220  }
221}
222
223
224//===----------------------------------------------------------------------===//
225// Postfix Operators.
226//===----------------------------------------------------------------------===//
227
228CallExpr::CallExpr(ASTContext& C, StmtClass SC, Expr *fn, Expr **args,
229                   unsigned numargs, QualType t, SourceLocation rparenloc)
230  : Expr(SC, t,
231         fn->isTypeDependent() || hasAnyTypeDependentArguments(args, numargs),
232         fn->isValueDependent() || hasAnyValueDependentArguments(args,numargs)),
233    NumArgs(numargs) {
234
235  SubExprs = new (C) Stmt*[numargs+1];
236  SubExprs[FN] = fn;
237  for (unsigned i = 0; i != numargs; ++i)
238    SubExprs[i+ARGS_START] = args[i];
239
240  RParenLoc = rparenloc;
241}
242
243CallExpr::CallExpr(ASTContext& C, Expr *fn, Expr **args, unsigned numargs,
244                   QualType t, SourceLocation rparenloc)
245  : Expr(CallExprClass, t,
246         fn->isTypeDependent() || hasAnyTypeDependentArguments(args, numargs),
247         fn->isValueDependent() || hasAnyValueDependentArguments(args,numargs)),
248    NumArgs(numargs) {
249
250  SubExprs = new (C) Stmt*[numargs+1];
251  SubExprs[FN] = fn;
252  for (unsigned i = 0; i != numargs; ++i)
253    SubExprs[i+ARGS_START] = args[i];
254
255  RParenLoc = rparenloc;
256}
257
258CallExpr::CallExpr(ASTContext &C, StmtClass SC, EmptyShell Empty)
259  : Expr(SC, Empty), SubExprs(0), NumArgs(0) {
260  SubExprs = new (C) Stmt*[1];
261}
262
263void CallExpr::DoDestroy(ASTContext& C) {
264  DestroyChildren(C);
265  if (SubExprs) C.Deallocate(SubExprs);
266  this->~CallExpr();
267  C.Deallocate(this);
268}
269
270FunctionDecl *CallExpr::getDirectCallee() {
271  Expr *CEE = getCallee()->IgnoreParenCasts();
272  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE))
273    return dyn_cast<FunctionDecl>(DRE->getDecl());
274
275  return 0;
276}
277
278/// setNumArgs - This changes the number of arguments present in this call.
279/// Any orphaned expressions are deleted by this, and any new operands are set
280/// to null.
281void CallExpr::setNumArgs(ASTContext& C, unsigned NumArgs) {
282  // No change, just return.
283  if (NumArgs == getNumArgs()) return;
284
285  // If shrinking # arguments, just delete the extras and forgot them.
286  if (NumArgs < getNumArgs()) {
287    for (unsigned i = NumArgs, e = getNumArgs(); i != e; ++i)
288      getArg(i)->Destroy(C);
289    this->NumArgs = NumArgs;
290    return;
291  }
292
293  // Otherwise, we are growing the # arguments.  New an bigger argument array.
294  Stmt **NewSubExprs = new (C) Stmt*[NumArgs+1];
295  // Copy over args.
296  for (unsigned i = 0; i != getNumArgs()+ARGS_START; ++i)
297    NewSubExprs[i] = SubExprs[i];
298  // Null out new args.
299  for (unsigned i = getNumArgs()+ARGS_START; i != NumArgs+ARGS_START; ++i)
300    NewSubExprs[i] = 0;
301
302  if (SubExprs) C.Deallocate(SubExprs);
303  SubExprs = NewSubExprs;
304  this->NumArgs = NumArgs;
305}
306
307/// isBuiltinCall - If this is a call to a builtin, return the builtin ID.  If
308/// not, return 0.
309unsigned CallExpr::isBuiltinCall(ASTContext &Context) const {
310  // All simple function calls (e.g. func()) are implicitly cast to pointer to
311  // function. As a result, we try and obtain the DeclRefExpr from the
312  // ImplicitCastExpr.
313  const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(getCallee());
314  if (!ICE) // FIXME: deal with more complex calls (e.g. (func)(), (*func)()).
315    return 0;
316
317  const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr());
318  if (!DRE)
319    return 0;
320
321  const FunctionDecl *FDecl = dyn_cast<FunctionDecl>(DRE->getDecl());
322  if (!FDecl)
323    return 0;
324
325  if (!FDecl->getIdentifier())
326    return 0;
327
328  return FDecl->getBuiltinID();
329}
330
331QualType CallExpr::getCallReturnType() const {
332  QualType CalleeType = getCallee()->getType();
333  if (const PointerType *FnTypePtr = CalleeType->getAs<PointerType>())
334    CalleeType = FnTypePtr->getPointeeType();
335  else if (const BlockPointerType *BPT = CalleeType->getAs<BlockPointerType>())
336    CalleeType = BPT->getPointeeType();
337
338  const FunctionType *FnType = CalleeType->getAs<FunctionType>();
339  return FnType->getResultType();
340}
341
342MemberExpr::MemberExpr(Expr *base, bool isarrow, NestedNameSpecifier *qual,
343                       SourceRange qualrange, NamedDecl *memberdecl,
344                       SourceLocation l, bool has_explicit,
345                       SourceLocation langle,
346                       const TemplateArgument *targs, unsigned numtargs,
347                       SourceLocation rangle, QualType ty)
348  : Expr(MemberExprClass, ty,
349         base->isTypeDependent() || (qual && qual->isDependent()),
350         base->isValueDependent() || (qual && qual->isDependent())),
351    Base(base), MemberDecl(memberdecl), MemberLoc(l), IsArrow(isarrow),
352    HasQualifier(qual != 0), HasExplicitTemplateArgumentList(has_explicit) {
353  // Initialize the qualifier, if any.
354  if (HasQualifier) {
355    NameQualifier *NQ = getMemberQualifier();
356    NQ->NNS = qual;
357    NQ->Range = qualrange;
358  }
359
360  // Initialize the explicit template argument list, if any.
361  if (HasExplicitTemplateArgumentList) {
362    ExplicitTemplateArgumentList *ETemplateArgs
363      = getExplicitTemplateArgumentList();
364    ETemplateArgs->LAngleLoc = langle;
365    ETemplateArgs->RAngleLoc = rangle;
366    ETemplateArgs->NumTemplateArgs = numtargs;
367
368    TemplateArgument *TemplateArgs = ETemplateArgs->getTemplateArgs();
369    for (unsigned I = 0; I < numtargs; ++I)
370      new (TemplateArgs + I) TemplateArgument(targs[I]);
371  }
372}
373
374MemberExpr *MemberExpr::Create(ASTContext &C, Expr *base, bool isarrow,
375                               NestedNameSpecifier *qual,
376                               SourceRange qualrange,
377                               NamedDecl *memberdecl,
378                               SourceLocation l,
379                               bool has_explicit,
380                               SourceLocation langle,
381                               const TemplateArgument *targs,
382                               unsigned numtargs,
383                               SourceLocation rangle,
384                               QualType ty) {
385  std::size_t Size = sizeof(MemberExpr);
386  if (qual != 0)
387    Size += sizeof(NameQualifier);
388
389  if (has_explicit)
390    Size += sizeof(ExplicitTemplateArgumentList) +
391    sizeof(TemplateArgument) * numtargs;
392
393  void *Mem = C.Allocate(Size, llvm::alignof<MemberExpr>());
394  return new (Mem) MemberExpr(base, isarrow, qual, qualrange, memberdecl, l,
395                              has_explicit, langle, targs, numtargs, rangle,
396                              ty);
397}
398
399const char *CastExpr::getCastKindName() const {
400  switch (getCastKind()) {
401  case CastExpr::CK_Unknown:
402    return "Unknown";
403  case CastExpr::CK_BitCast:
404    return "BitCast";
405  case CastExpr::CK_NoOp:
406    return "NoOp";
407  case CastExpr::CK_DerivedToBase:
408    return "DerivedToBase";
409  case CastExpr::CK_Dynamic:
410    return "Dynamic";
411  case CastExpr::CK_ToUnion:
412    return "ToUnion";
413  case CastExpr::CK_ArrayToPointerDecay:
414    return "ArrayToPointerDecay";
415  case CastExpr::CK_FunctionToPointerDecay:
416    return "FunctionToPointerDecay";
417  case CastExpr::CK_NullToMemberPointer:
418    return "NullToMemberPointer";
419  case CastExpr::CK_BaseToDerivedMemberPointer:
420    return "BaseToDerivedMemberPointer";
421  case CastExpr::CK_UserDefinedConversion:
422    return "UserDefinedConversion";
423  case CastExpr::CK_ConstructorConversion:
424    return "ConstructorConversion";
425  case CastExpr::CK_IntegralToPointer:
426    return "IntegralToPointer";
427  case CastExpr::CK_PointerToIntegral:
428    return "PointerToIntegral";
429  case CastExpr::CK_ToVoid:
430    return "ToVoid";
431  case CastExpr::CK_VectorSplat:
432    return "VectorSplat";
433  case CastExpr::CK_IntegralCast:
434    return "IntegralCast";
435  case CastExpr::CK_IntegralToFloating:
436    return "IntegralToFloating";
437  case CastExpr::CK_FloatingToIntegral:
438    return "FloatingToIntegral";
439  case CastExpr::CK_FloatingCast:
440    return "FloatingCast";
441  }
442
443  assert(0 && "Unhandled cast kind!");
444  return 0;
445}
446
447/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
448/// corresponds to, e.g. "<<=".
449const char *BinaryOperator::getOpcodeStr(Opcode Op) {
450  switch (Op) {
451  case PtrMemD:   return ".*";
452  case PtrMemI:   return "->*";
453  case Mul:       return "*";
454  case Div:       return "/";
455  case Rem:       return "%";
456  case Add:       return "+";
457  case Sub:       return "-";
458  case Shl:       return "<<";
459  case Shr:       return ">>";
460  case LT:        return "<";
461  case GT:        return ">";
462  case LE:        return "<=";
463  case GE:        return ">=";
464  case EQ:        return "==";
465  case NE:        return "!=";
466  case And:       return "&";
467  case Xor:       return "^";
468  case Or:        return "|";
469  case LAnd:      return "&&";
470  case LOr:       return "||";
471  case Assign:    return "=";
472  case MulAssign: return "*=";
473  case DivAssign: return "/=";
474  case RemAssign: return "%=";
475  case AddAssign: return "+=";
476  case SubAssign: return "-=";
477  case ShlAssign: return "<<=";
478  case ShrAssign: return ">>=";
479  case AndAssign: return "&=";
480  case XorAssign: return "^=";
481  case OrAssign:  return "|=";
482  case Comma:     return ",";
483  }
484
485  return "";
486}
487
488BinaryOperator::Opcode
489BinaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO) {
490  switch (OO) {
491  default: assert(false && "Not an overloadable binary operator");
492  case OO_Plus: return Add;
493  case OO_Minus: return Sub;
494  case OO_Star: return Mul;
495  case OO_Slash: return Div;
496  case OO_Percent: return Rem;
497  case OO_Caret: return Xor;
498  case OO_Amp: return And;
499  case OO_Pipe: return Or;
500  case OO_Equal: return Assign;
501  case OO_Less: return LT;
502  case OO_Greater: return GT;
503  case OO_PlusEqual: return AddAssign;
504  case OO_MinusEqual: return SubAssign;
505  case OO_StarEqual: return MulAssign;
506  case OO_SlashEqual: return DivAssign;
507  case OO_PercentEqual: return RemAssign;
508  case OO_CaretEqual: return XorAssign;
509  case OO_AmpEqual: return AndAssign;
510  case OO_PipeEqual: return OrAssign;
511  case OO_LessLess: return Shl;
512  case OO_GreaterGreater: return Shr;
513  case OO_LessLessEqual: return ShlAssign;
514  case OO_GreaterGreaterEqual: return ShrAssign;
515  case OO_EqualEqual: return EQ;
516  case OO_ExclaimEqual: return NE;
517  case OO_LessEqual: return LE;
518  case OO_GreaterEqual: return GE;
519  case OO_AmpAmp: return LAnd;
520  case OO_PipePipe: return LOr;
521  case OO_Comma: return Comma;
522  case OO_ArrowStar: return PtrMemI;
523  }
524}
525
526OverloadedOperatorKind BinaryOperator::getOverloadedOperator(Opcode Opc) {
527  static const OverloadedOperatorKind OverOps[] = {
528    /* .* Cannot be overloaded */OO_None, OO_ArrowStar,
529    OO_Star, OO_Slash, OO_Percent,
530    OO_Plus, OO_Minus,
531    OO_LessLess, OO_GreaterGreater,
532    OO_Less, OO_Greater, OO_LessEqual, OO_GreaterEqual,
533    OO_EqualEqual, OO_ExclaimEqual,
534    OO_Amp,
535    OO_Caret,
536    OO_Pipe,
537    OO_AmpAmp,
538    OO_PipePipe,
539    OO_Equal, OO_StarEqual,
540    OO_SlashEqual, OO_PercentEqual,
541    OO_PlusEqual, OO_MinusEqual,
542    OO_LessLessEqual, OO_GreaterGreaterEqual,
543    OO_AmpEqual, OO_CaretEqual,
544    OO_PipeEqual,
545    OO_Comma
546  };
547  return OverOps[Opc];
548}
549
550InitListExpr::InitListExpr(SourceLocation lbraceloc,
551                           Expr **initExprs, unsigned numInits,
552                           SourceLocation rbraceloc)
553  : Expr(InitListExprClass, QualType(),
554         hasAnyTypeDependentArguments(initExprs, numInits),
555         hasAnyValueDependentArguments(initExprs, numInits)),
556    LBraceLoc(lbraceloc), RBraceLoc(rbraceloc), SyntacticForm(0),
557    UnionFieldInit(0), HadArrayRangeDesignator(false) {
558
559  InitExprs.insert(InitExprs.end(), initExprs, initExprs+numInits);
560}
561
562void InitListExpr::reserveInits(unsigned NumInits) {
563  if (NumInits > InitExprs.size())
564    InitExprs.reserve(NumInits);
565}
566
567void InitListExpr::resizeInits(ASTContext &Context, unsigned NumInits) {
568  for (unsigned Idx = NumInits, LastIdx = InitExprs.size();
569       Idx < LastIdx; ++Idx)
570    InitExprs[Idx]->Destroy(Context);
571  InitExprs.resize(NumInits, 0);
572}
573
574Expr *InitListExpr::updateInit(unsigned Init, Expr *expr) {
575  if (Init >= InitExprs.size()) {
576    InitExprs.insert(InitExprs.end(), Init - InitExprs.size() + 1, 0);
577    InitExprs.back() = expr;
578    return 0;
579  }
580
581  Expr *Result = cast_or_null<Expr>(InitExprs[Init]);
582  InitExprs[Init] = expr;
583  return Result;
584}
585
586/// getFunctionType - Return the underlying function type for this block.
587///
588const FunctionType *BlockExpr::getFunctionType() const {
589  return getType()->getAs<BlockPointerType>()->
590                    getPointeeType()->getAs<FunctionType>();
591}
592
593SourceLocation BlockExpr::getCaretLocation() const {
594  return TheBlock->getCaretLocation();
595}
596const Stmt *BlockExpr::getBody() const {
597  return TheBlock->getBody();
598}
599Stmt *BlockExpr::getBody() {
600  return TheBlock->getBody();
601}
602
603
604//===----------------------------------------------------------------------===//
605// Generic Expression Routines
606//===----------------------------------------------------------------------===//
607
608/// isUnusedResultAWarning - Return true if this immediate expression should
609/// be warned about if the result is unused.  If so, fill in Loc and Ranges
610/// with location to warn on and the source range[s] to report with the
611/// warning.
612bool Expr::isUnusedResultAWarning(SourceLocation &Loc, SourceRange &R1,
613                                  SourceRange &R2) const {
614  // Don't warn if the expr is type dependent. The type could end up
615  // instantiating to void.
616  if (isTypeDependent())
617    return false;
618
619  switch (getStmtClass()) {
620  default:
621    Loc = getExprLoc();
622    R1 = getSourceRange();
623    return true;
624  case ParenExprClass:
625    return cast<ParenExpr>(this)->getSubExpr()->
626      isUnusedResultAWarning(Loc, R1, R2);
627  case UnaryOperatorClass: {
628    const UnaryOperator *UO = cast<UnaryOperator>(this);
629
630    switch (UO->getOpcode()) {
631    default: break;
632    case UnaryOperator::PostInc:
633    case UnaryOperator::PostDec:
634    case UnaryOperator::PreInc:
635    case UnaryOperator::PreDec:                 // ++/--
636      return false;  // Not a warning.
637    case UnaryOperator::Deref:
638      // Dereferencing a volatile pointer is a side-effect.
639      if (getType().isVolatileQualified())
640        return false;
641      break;
642    case UnaryOperator::Real:
643    case UnaryOperator::Imag:
644      // accessing a piece of a volatile complex is a side-effect.
645      if (UO->getSubExpr()->getType().isVolatileQualified())
646        return false;
647      break;
648    case UnaryOperator::Extension:
649      return UO->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2);
650    }
651    Loc = UO->getOperatorLoc();
652    R1 = UO->getSubExpr()->getSourceRange();
653    return true;
654  }
655  case BinaryOperatorClass: {
656    const BinaryOperator *BO = cast<BinaryOperator>(this);
657    // Consider comma to have side effects if the LHS or RHS does.
658    if (BO->getOpcode() == BinaryOperator::Comma)
659      return BO->getRHS()->isUnusedResultAWarning(Loc, R1, R2) ||
660             BO->getLHS()->isUnusedResultAWarning(Loc, R1, R2);
661
662    if (BO->isAssignmentOp())
663      return false;
664    Loc = BO->getOperatorLoc();
665    R1 = BO->getLHS()->getSourceRange();
666    R2 = BO->getRHS()->getSourceRange();
667    return true;
668  }
669  case CompoundAssignOperatorClass:
670    return false;
671
672  case ConditionalOperatorClass: {
673    // The condition must be evaluated, but if either the LHS or RHS is a
674    // warning, warn about them.
675    const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
676    if (Exp->getLHS() &&
677        Exp->getLHS()->isUnusedResultAWarning(Loc, R1, R2))
678      return true;
679    return Exp->getRHS()->isUnusedResultAWarning(Loc, R1, R2);
680  }
681
682  case MemberExprClass:
683    // If the base pointer or element is to a volatile pointer/field, accessing
684    // it is a side effect.
685    if (getType().isVolatileQualified())
686      return false;
687    Loc = cast<MemberExpr>(this)->getMemberLoc();
688    R1 = SourceRange(Loc, Loc);
689    R2 = cast<MemberExpr>(this)->getBase()->getSourceRange();
690    return true;
691
692  case ArraySubscriptExprClass:
693    // If the base pointer or element is to a volatile pointer/field, accessing
694    // it is a side effect.
695    if (getType().isVolatileQualified())
696      return false;
697    Loc = cast<ArraySubscriptExpr>(this)->getRBracketLoc();
698    R1 = cast<ArraySubscriptExpr>(this)->getLHS()->getSourceRange();
699    R2 = cast<ArraySubscriptExpr>(this)->getRHS()->getSourceRange();
700    return true;
701
702  case CallExprClass:
703  case CXXOperatorCallExprClass:
704  case CXXMemberCallExprClass: {
705    // If this is a direct call, get the callee.
706    const CallExpr *CE = cast<CallExpr>(this);
707    if (const FunctionDecl *FD = CE->getDirectCallee()) {
708      // If the callee has attribute pure, const, or warn_unused_result, warn
709      // about it. void foo() { strlen("bar"); } should warn.
710      //
711      // Note: If new cases are added here, DiagnoseUnusedExprResult should be
712      // updated to match for QoI.
713      if (FD->getAttr<WarnUnusedResultAttr>() ||
714          FD->getAttr<PureAttr>() || FD->getAttr<ConstAttr>()) {
715        Loc = CE->getCallee()->getLocStart();
716        R1 = CE->getCallee()->getSourceRange();
717
718        if (unsigned NumArgs = CE->getNumArgs())
719          R2 = SourceRange(CE->getArg(0)->getLocStart(),
720                           CE->getArg(NumArgs-1)->getLocEnd());
721        return true;
722      }
723    }
724    return false;
725  }
726  case ObjCMessageExprClass:
727    return false;
728
729  case ObjCImplicitSetterGetterRefExprClass: {   // Dot syntax for message send.
730#if 0
731    const ObjCImplicitSetterGetterRefExpr *Ref =
732      cast<ObjCImplicitSetterGetterRefExpr>(this);
733    // FIXME: We really want the location of the '.' here.
734    Loc = Ref->getLocation();
735    R1 = SourceRange(Ref->getLocation(), Ref->getLocation());
736    if (Ref->getBase())
737      R2 = Ref->getBase()->getSourceRange();
738#else
739    Loc = getExprLoc();
740    R1 = getSourceRange();
741#endif
742    return true;
743  }
744  case StmtExprClass: {
745    // Statement exprs don't logically have side effects themselves, but are
746    // sometimes used in macros in ways that give them a type that is unused.
747    // For example ({ blah; foo(); }) will end up with a type if foo has a type.
748    // however, if the result of the stmt expr is dead, we don't want to emit a
749    // warning.
750    const CompoundStmt *CS = cast<StmtExpr>(this)->getSubStmt();
751    if (!CS->body_empty())
752      if (const Expr *E = dyn_cast<Expr>(CS->body_back()))
753        return E->isUnusedResultAWarning(Loc, R1, R2);
754
755    Loc = cast<StmtExpr>(this)->getLParenLoc();
756    R1 = getSourceRange();
757    return true;
758  }
759  case CStyleCastExprClass:
760    // If this is an explicit cast to void, allow it.  People do this when they
761    // think they know what they're doing :).
762    if (getType()->isVoidType())
763      return false;
764    Loc = cast<CStyleCastExpr>(this)->getLParenLoc();
765    R1 = cast<CStyleCastExpr>(this)->getSubExpr()->getSourceRange();
766    return true;
767  case CXXFunctionalCastExprClass:
768    // If this is a cast to void, check the operand.  Otherwise, the result of
769    // the cast is unused.
770    if (getType()->isVoidType())
771      return cast<CastExpr>(this)->getSubExpr()
772               ->isUnusedResultAWarning(Loc, R1, R2);
773    Loc = cast<CXXFunctionalCastExpr>(this)->getTypeBeginLoc();
774    R1 = cast<CXXFunctionalCastExpr>(this)->getSubExpr()->getSourceRange();
775    return true;
776
777  case ImplicitCastExprClass:
778    // Check the operand, since implicit casts are inserted by Sema
779    return cast<ImplicitCastExpr>(this)
780      ->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2);
781
782  case CXXDefaultArgExprClass:
783    return cast<CXXDefaultArgExpr>(this)
784      ->getExpr()->isUnusedResultAWarning(Loc, R1, R2);
785
786  case CXXNewExprClass:
787    // FIXME: In theory, there might be new expressions that don't have side
788    // effects (e.g. a placement new with an uninitialized POD).
789  case CXXDeleteExprClass:
790    return false;
791  case CXXBindTemporaryExprClass:
792    return cast<CXXBindTemporaryExpr>(this)
793      ->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2);
794  case CXXExprWithTemporariesClass:
795    return cast<CXXExprWithTemporaries>(this)
796      ->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2);
797  }
798}
799
800/// DeclCanBeLvalue - Determine whether the given declaration can be
801/// an lvalue. This is a helper routine for isLvalue.
802static bool DeclCanBeLvalue(const NamedDecl *Decl, ASTContext &Ctx) {
803  // C++ [temp.param]p6:
804  //   A non-type non-reference template-parameter is not an lvalue.
805  if (const NonTypeTemplateParmDecl *NTTParm
806        = dyn_cast<NonTypeTemplateParmDecl>(Decl))
807    return NTTParm->getType()->isReferenceType();
808
809  return isa<VarDecl>(Decl) || isa<FieldDecl>(Decl) ||
810    // C++ 3.10p2: An lvalue refers to an object or function.
811    (Ctx.getLangOptions().CPlusPlus &&
812     (isa<FunctionDecl>(Decl) || isa<OverloadedFunctionDecl>(Decl) ||
813      isa<FunctionTemplateDecl>(Decl)));
814}
815
816/// isLvalue - C99 6.3.2.1: an lvalue is an expression with an object type or an
817/// incomplete type other than void. Nonarray expressions that can be lvalues:
818///  - name, where name must be a variable
819///  - e[i]
820///  - (e), where e must be an lvalue
821///  - e.name, where e must be an lvalue
822///  - e->name
823///  - *e, the type of e cannot be a function type
824///  - string-constant
825///  - (__real__ e) and (__imag__ e) where e is an lvalue  [GNU extension]
826///  - reference type [C++ [expr]]
827///
828Expr::isLvalueResult Expr::isLvalue(ASTContext &Ctx) const {
829  assert(!TR->isReferenceType() && "Expressions can't have reference type.");
830
831  isLvalueResult Res = isLvalueInternal(Ctx);
832  if (Res != LV_Valid || Ctx.getLangOptions().CPlusPlus)
833    return Res;
834
835  // first, check the type (C99 6.3.2.1). Expressions with function
836  // type in C are not lvalues, but they can be lvalues in C++.
837  if (TR->isFunctionType() || TR == Ctx.OverloadTy)
838    return LV_NotObjectType;
839
840  // Allow qualified void which is an incomplete type other than void (yuck).
841  if (TR->isVoidType() && !Ctx.getCanonicalType(TR).hasQualifiers())
842    return LV_IncompleteVoidType;
843
844  return LV_Valid;
845}
846
847// Check whether the expression can be sanely treated like an l-value
848Expr::isLvalueResult Expr::isLvalueInternal(ASTContext &Ctx) const {
849  switch (getStmtClass()) {
850  case StringLiteralClass:  // C99 6.5.1p4
851  case ObjCEncodeExprClass: // @encode behaves like its string in every way.
852    return LV_Valid;
853  case ArraySubscriptExprClass: // C99 6.5.3p4 (e1[e2] == (*((e1)+(e2))))
854    // For vectors, make sure base is an lvalue (i.e. not a function call).
855    if (cast<ArraySubscriptExpr>(this)->getBase()->getType()->isVectorType())
856      return cast<ArraySubscriptExpr>(this)->getBase()->isLvalue(Ctx);
857    return LV_Valid;
858  case DeclRefExprClass:
859  case QualifiedDeclRefExprClass: { // C99 6.5.1p2
860    const NamedDecl *RefdDecl = cast<DeclRefExpr>(this)->getDecl();
861    if (DeclCanBeLvalue(RefdDecl, Ctx))
862      return LV_Valid;
863    break;
864  }
865  case BlockDeclRefExprClass: {
866    const BlockDeclRefExpr *BDR = cast<BlockDeclRefExpr>(this);
867    if (isa<VarDecl>(BDR->getDecl()))
868      return LV_Valid;
869    break;
870  }
871  case MemberExprClass: {
872    const MemberExpr *m = cast<MemberExpr>(this);
873    if (Ctx.getLangOptions().CPlusPlus) { // C++ [expr.ref]p4:
874      NamedDecl *Member = m->getMemberDecl();
875      // C++ [expr.ref]p4:
876      //   If E2 is declared to have type "reference to T", then E1.E2
877      //   is an lvalue.
878      if (ValueDecl *Value = dyn_cast<ValueDecl>(Member))
879        if (Value->getType()->isReferenceType())
880          return LV_Valid;
881
882      //   -- If E2 is a static data member [...] then E1.E2 is an lvalue.
883      if (isa<VarDecl>(Member) && Member->getDeclContext()->isRecord())
884        return LV_Valid;
885
886      //   -- If E2 is a non-static data member [...]. If E1 is an
887      //      lvalue, then E1.E2 is an lvalue.
888      if (isa<FieldDecl>(Member))
889        return m->isArrow() ? LV_Valid : m->getBase()->isLvalue(Ctx);
890
891      //   -- If it refers to a static member function [...], then
892      //      E1.E2 is an lvalue.
893      //   -- Otherwise, if E1.E2 refers to a non-static member
894      //      function [...], then E1.E2 is not an lvalue.
895      if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Member))
896        return Method->isStatic()? LV_Valid : LV_MemberFunction;
897
898      //   -- If E2 is a member enumerator [...], the expression E1.E2
899      //      is not an lvalue.
900      if (isa<EnumConstantDecl>(Member))
901        return LV_InvalidExpression;
902
903        // Not an lvalue.
904      return LV_InvalidExpression;
905    }
906
907    // C99 6.5.2.3p4
908    return m->isArrow() ? LV_Valid : m->getBase()->isLvalue(Ctx);
909  }
910  case UnaryOperatorClass:
911    if (cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Deref)
912      return LV_Valid; // C99 6.5.3p4
913
914    if (cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Real ||
915        cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Imag ||
916        cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Extension)
917      return cast<UnaryOperator>(this)->getSubExpr()->isLvalue(Ctx);  // GNU.
918
919    if (Ctx.getLangOptions().CPlusPlus && // C++ [expr.pre.incr]p1
920        (cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::PreInc ||
921         cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::PreDec))
922      return LV_Valid;
923    break;
924  case ImplicitCastExprClass:
925    return cast<ImplicitCastExpr>(this)->isLvalueCast()? LV_Valid
926                                                       : LV_InvalidExpression;
927  case ParenExprClass: // C99 6.5.1p5
928    return cast<ParenExpr>(this)->getSubExpr()->isLvalue(Ctx);
929  case BinaryOperatorClass:
930  case CompoundAssignOperatorClass: {
931    const BinaryOperator *BinOp = cast<BinaryOperator>(this);
932
933    if (Ctx.getLangOptions().CPlusPlus && // C++ [expr.comma]p1
934        BinOp->getOpcode() == BinaryOperator::Comma)
935      return BinOp->getRHS()->isLvalue(Ctx);
936
937    // C++ [expr.mptr.oper]p6
938    // The result of a .* expression is an lvalue only if its first operand is
939    // an lvalue and its second operand is a pointer to data member.
940    if (BinOp->getOpcode() == BinaryOperator::PtrMemD &&
941        !BinOp->getType()->isFunctionType())
942      return BinOp->getLHS()->isLvalue(Ctx);
943
944    // The result of an ->* expression is an lvalue only if its second operand
945    // is a pointer to data member.
946    if (BinOp->getOpcode() == BinaryOperator::PtrMemI &&
947        !BinOp->getType()->isFunctionType()) {
948      QualType Ty = BinOp->getRHS()->getType();
949      if (Ty->isMemberPointerType() && !Ty->isMemberFunctionPointerType())
950        return LV_Valid;
951    }
952
953    if (!BinOp->isAssignmentOp())
954      return LV_InvalidExpression;
955
956    if (Ctx.getLangOptions().CPlusPlus)
957      // C++ [expr.ass]p1:
958      //   The result of an assignment operation [...] is an lvalue.
959      return LV_Valid;
960
961
962    // C99 6.5.16:
963    //   An assignment expression [...] is not an lvalue.
964    return LV_InvalidExpression;
965  }
966  case CallExprClass:
967  case CXXOperatorCallExprClass:
968  case CXXMemberCallExprClass: {
969    // C++0x [expr.call]p10
970    //   A function call is an lvalue if and only if the result type
971    //   is an lvalue reference.
972    QualType ReturnType = cast<CallExpr>(this)->getCallReturnType();
973    if (ReturnType->isLValueReferenceType())
974      return LV_Valid;
975
976    break;
977  }
978  case CompoundLiteralExprClass: // C99 6.5.2.5p5
979    return LV_Valid;
980  case ChooseExprClass:
981    // __builtin_choose_expr is an lvalue if the selected operand is.
982    return cast<ChooseExpr>(this)->getChosenSubExpr(Ctx)->isLvalue(Ctx);
983  case ExtVectorElementExprClass:
984    if (cast<ExtVectorElementExpr>(this)->containsDuplicateElements())
985      return LV_DuplicateVectorComponents;
986    return LV_Valid;
987  case ObjCIvarRefExprClass: // ObjC instance variables are lvalues.
988    return LV_Valid;
989  case ObjCPropertyRefExprClass: // FIXME: check if read-only property.
990    return LV_Valid;
991  case ObjCImplicitSetterGetterRefExprClass: // FIXME: check if read-only property.
992    return LV_Valid;
993  case PredefinedExprClass:
994    return LV_Valid;
995  case CXXDefaultArgExprClass:
996    return cast<CXXDefaultArgExpr>(this)->getExpr()->isLvalue(Ctx);
997  case CXXConditionDeclExprClass:
998    return LV_Valid;
999  case CStyleCastExprClass:
1000  case CXXFunctionalCastExprClass:
1001  case CXXStaticCastExprClass:
1002  case CXXDynamicCastExprClass:
1003  case CXXReinterpretCastExprClass:
1004  case CXXConstCastExprClass:
1005    // The result of an explicit cast is an lvalue if the type we are
1006    // casting to is an lvalue reference type. See C++ [expr.cast]p1,
1007    // C++ [expr.static.cast]p2, C++ [expr.dynamic.cast]p2,
1008    // C++ [expr.reinterpret.cast]p1, C++ [expr.const.cast]p1.
1009    if (cast<ExplicitCastExpr>(this)->getTypeAsWritten()->
1010          isLValueReferenceType())
1011      return LV_Valid;
1012    break;
1013  case CXXTypeidExprClass:
1014    // C++ 5.2.8p1: The result of a typeid expression is an lvalue of ...
1015    return LV_Valid;
1016  case CXXBindTemporaryExprClass:
1017    return cast<CXXBindTemporaryExpr>(this)->getSubExpr()->
1018      isLvalueInternal(Ctx);
1019  case ConditionalOperatorClass: {
1020    // Complicated handling is only for C++.
1021    if (!Ctx.getLangOptions().CPlusPlus)
1022      return LV_InvalidExpression;
1023
1024    // Sema should have taken care to ensure that a CXXTemporaryObjectExpr is
1025    // everywhere there's an object converted to an rvalue. Also, any other
1026    // casts should be wrapped by ImplicitCastExprs. There's just the special
1027    // case involving throws to work out.
1028    const ConditionalOperator *Cond = cast<ConditionalOperator>(this);
1029    Expr *True = Cond->getTrueExpr();
1030    Expr *False = Cond->getFalseExpr();
1031    // C++0x 5.16p2
1032    //   If either the second or the third operand has type (cv) void, [...]
1033    //   the result [...] is an rvalue.
1034    if (True->getType()->isVoidType() || False->getType()->isVoidType())
1035      return LV_InvalidExpression;
1036
1037    // Both sides must be lvalues for the result to be an lvalue.
1038    if (True->isLvalue(Ctx) != LV_Valid || False->isLvalue(Ctx) != LV_Valid)
1039      return LV_InvalidExpression;
1040
1041    // That's it.
1042    return LV_Valid;
1043  }
1044
1045  default:
1046    break;
1047  }
1048  return LV_InvalidExpression;
1049}
1050
1051/// isModifiableLvalue - C99 6.3.2.1: an lvalue that does not have array type,
1052/// does not have an incomplete type, does not have a const-qualified type, and
1053/// if it is a structure or union, does not have any member (including,
1054/// recursively, any member or element of all contained aggregates or unions)
1055/// with a const-qualified type.
1056Expr::isModifiableLvalueResult
1057Expr::isModifiableLvalue(ASTContext &Ctx, SourceLocation *Loc) const {
1058  isLvalueResult lvalResult = isLvalue(Ctx);
1059
1060  switch (lvalResult) {
1061  case LV_Valid:
1062    // C++ 3.10p11: Functions cannot be modified, but pointers to
1063    // functions can be modifiable.
1064    if (Ctx.getLangOptions().CPlusPlus && TR->isFunctionType())
1065      return MLV_NotObjectType;
1066    break;
1067
1068  case LV_NotObjectType: return MLV_NotObjectType;
1069  case LV_IncompleteVoidType: return MLV_IncompleteVoidType;
1070  case LV_DuplicateVectorComponents: return MLV_DuplicateVectorComponents;
1071  case LV_InvalidExpression:
1072    // If the top level is a C-style cast, and the subexpression is a valid
1073    // lvalue, then this is probably a use of the old-school "cast as lvalue"
1074    // GCC extension.  We don't support it, but we want to produce good
1075    // diagnostics when it happens so that the user knows why.
1076    if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(IgnoreParens())) {
1077      if (CE->getSubExpr()->isLvalue(Ctx) == LV_Valid) {
1078        if (Loc)
1079          *Loc = CE->getLParenLoc();
1080        return MLV_LValueCast;
1081      }
1082    }
1083    return MLV_InvalidExpression;
1084  case LV_MemberFunction: return MLV_MemberFunction;
1085  }
1086
1087  // The following is illegal:
1088  //   void takeclosure(void (^C)(void));
1089  //   void func() { int x = 1; takeclosure(^{ x = 7; }); }
1090  //
1091  if (const BlockDeclRefExpr *BDR = dyn_cast<BlockDeclRefExpr>(this)) {
1092    if (!BDR->isByRef() && isa<VarDecl>(BDR->getDecl()))
1093      return MLV_NotBlockQualified;
1094  }
1095
1096  // Assigning to an 'implicit' property?
1097  if (const ObjCImplicitSetterGetterRefExpr* Expr =
1098        dyn_cast<ObjCImplicitSetterGetterRefExpr>(this)) {
1099    if (Expr->getSetterMethod() == 0)
1100      return MLV_NoSetterProperty;
1101  }
1102
1103  QualType CT = Ctx.getCanonicalType(getType());
1104
1105  if (CT.isConstQualified())
1106    return MLV_ConstQualified;
1107  if (CT->isArrayType())
1108    return MLV_ArrayType;
1109  if (CT->isIncompleteType())
1110    return MLV_IncompleteType;
1111
1112  if (const RecordType *r = CT->getAs<RecordType>()) {
1113    if (r->hasConstFields())
1114      return MLV_ConstQualified;
1115  }
1116
1117  return MLV_Valid;
1118}
1119
1120/// isOBJCGCCandidate - Check if an expression is objc gc'able.
1121/// returns true, if it is; false otherwise.
1122bool Expr::isOBJCGCCandidate(ASTContext &Ctx) const {
1123  switch (getStmtClass()) {
1124  default:
1125    return false;
1126  case ObjCIvarRefExprClass:
1127    return true;
1128  case Expr::UnaryOperatorClass:
1129    return cast<UnaryOperator>(this)->getSubExpr()->isOBJCGCCandidate(Ctx);
1130  case ParenExprClass:
1131    return cast<ParenExpr>(this)->getSubExpr()->isOBJCGCCandidate(Ctx);
1132  case ImplicitCastExprClass:
1133    return cast<ImplicitCastExpr>(this)->getSubExpr()->isOBJCGCCandidate(Ctx);
1134  case CStyleCastExprClass:
1135    return cast<CStyleCastExpr>(this)->getSubExpr()->isOBJCGCCandidate(Ctx);
1136  case DeclRefExprClass:
1137  case QualifiedDeclRefExprClass: {
1138    const Decl *D = cast<DeclRefExpr>(this)->getDecl();
1139    if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
1140      if (VD->hasGlobalStorage())
1141        return true;
1142      QualType T = VD->getType();
1143      // dereferencing to a  pointer is always a gc'able candidate,
1144      // unless it is __weak.
1145      return T->isPointerType() &&
1146             (Ctx.getObjCGCAttrKind(T) != Qualifiers::Weak);
1147    }
1148    return false;
1149  }
1150  case MemberExprClass: {
1151    const MemberExpr *M = cast<MemberExpr>(this);
1152    return M->getBase()->isOBJCGCCandidate(Ctx);
1153  }
1154  case ArraySubscriptExprClass:
1155    return cast<ArraySubscriptExpr>(this)->getBase()->isOBJCGCCandidate(Ctx);
1156  }
1157}
1158Expr* Expr::IgnoreParens() {
1159  Expr* E = this;
1160  while (ParenExpr* P = dyn_cast<ParenExpr>(E))
1161    E = P->getSubExpr();
1162
1163  return E;
1164}
1165
1166/// IgnoreParenCasts - Ignore parentheses and casts.  Strip off any ParenExpr
1167/// or CastExprs or ImplicitCastExprs, returning their operand.
1168Expr *Expr::IgnoreParenCasts() {
1169  Expr *E = this;
1170  while (true) {
1171    if (ParenExpr *P = dyn_cast<ParenExpr>(E))
1172      E = P->getSubExpr();
1173    else if (CastExpr *P = dyn_cast<CastExpr>(E))
1174      E = P->getSubExpr();
1175    else
1176      return E;
1177  }
1178}
1179
1180/// IgnoreParenNoopCasts - Ignore parentheses and casts that do not change the
1181/// value (including ptr->int casts of the same size).  Strip off any
1182/// ParenExpr or CastExprs, returning their operand.
1183Expr *Expr::IgnoreParenNoopCasts(ASTContext &Ctx) {
1184  Expr *E = this;
1185  while (true) {
1186    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
1187      E = P->getSubExpr();
1188      continue;
1189    }
1190
1191    if (CastExpr *P = dyn_cast<CastExpr>(E)) {
1192      // We ignore integer <-> casts that are of the same width, ptr<->ptr and
1193      // ptr<->int casts of the same width.  We also ignore all identify casts.
1194      Expr *SE = P->getSubExpr();
1195
1196      if (Ctx.hasSameUnqualifiedType(E->getType(), SE->getType())) {
1197        E = SE;
1198        continue;
1199      }
1200
1201      if ((E->getType()->isPointerType() || E->getType()->isIntegralType()) &&
1202          (SE->getType()->isPointerType() || SE->getType()->isIntegralType()) &&
1203          Ctx.getTypeSize(E->getType()) == Ctx.getTypeSize(SE->getType())) {
1204        E = SE;
1205        continue;
1206      }
1207    }
1208
1209    return E;
1210  }
1211}
1212
1213
1214/// hasAnyTypeDependentArguments - Determines if any of the expressions
1215/// in Exprs is type-dependent.
1216bool Expr::hasAnyTypeDependentArguments(Expr** Exprs, unsigned NumExprs) {
1217  for (unsigned I = 0; I < NumExprs; ++I)
1218    if (Exprs[I]->isTypeDependent())
1219      return true;
1220
1221  return false;
1222}
1223
1224/// hasAnyValueDependentArguments - Determines if any of the expressions
1225/// in Exprs is value-dependent.
1226bool Expr::hasAnyValueDependentArguments(Expr** Exprs, unsigned NumExprs) {
1227  for (unsigned I = 0; I < NumExprs; ++I)
1228    if (Exprs[I]->isValueDependent())
1229      return true;
1230
1231  return false;
1232}
1233
1234bool Expr::isConstantInitializer(ASTContext &Ctx) const {
1235  // This function is attempting whether an expression is an initializer
1236  // which can be evaluated at compile-time.  isEvaluatable handles most
1237  // of the cases, but it can't deal with some initializer-specific
1238  // expressions, and it can't deal with aggregates; we deal with those here,
1239  // and fall back to isEvaluatable for the other cases.
1240
1241  // FIXME: This function assumes the variable being assigned to
1242  // isn't a reference type!
1243
1244  switch (getStmtClass()) {
1245  default: break;
1246  case StringLiteralClass:
1247  case ObjCStringLiteralClass:
1248  case ObjCEncodeExprClass:
1249    return true;
1250  case CompoundLiteralExprClass: {
1251    // This handles gcc's extension that allows global initializers like
1252    // "struct x {int x;} x = (struct x) {};".
1253    // FIXME: This accepts other cases it shouldn't!
1254    const Expr *Exp = cast<CompoundLiteralExpr>(this)->getInitializer();
1255    return Exp->isConstantInitializer(Ctx);
1256  }
1257  case InitListExprClass: {
1258    // FIXME: This doesn't deal with fields with reference types correctly.
1259    // FIXME: This incorrectly allows pointers cast to integers to be assigned
1260    // to bitfields.
1261    const InitListExpr *Exp = cast<InitListExpr>(this);
1262    unsigned numInits = Exp->getNumInits();
1263    for (unsigned i = 0; i < numInits; i++) {
1264      if (!Exp->getInit(i)->isConstantInitializer(Ctx))
1265        return false;
1266    }
1267    return true;
1268  }
1269  case ImplicitValueInitExprClass:
1270    return true;
1271  case ParenExprClass:
1272    return cast<ParenExpr>(this)->getSubExpr()->isConstantInitializer(Ctx);
1273  case UnaryOperatorClass: {
1274    const UnaryOperator* Exp = cast<UnaryOperator>(this);
1275    if (Exp->getOpcode() == UnaryOperator::Extension)
1276      return Exp->getSubExpr()->isConstantInitializer(Ctx);
1277    break;
1278  }
1279  case BinaryOperatorClass: {
1280    // Special case &&foo - &&bar.  It would be nice to generalize this somehow
1281    // but this handles the common case.
1282    const BinaryOperator *Exp = cast<BinaryOperator>(this);
1283    if (Exp->getOpcode() == BinaryOperator::Sub &&
1284        isa<AddrLabelExpr>(Exp->getLHS()->IgnoreParenNoopCasts(Ctx)) &&
1285        isa<AddrLabelExpr>(Exp->getRHS()->IgnoreParenNoopCasts(Ctx)))
1286      return true;
1287    break;
1288  }
1289  case ImplicitCastExprClass:
1290  case CStyleCastExprClass:
1291    // Handle casts with a destination that's a struct or union; this
1292    // deals with both the gcc no-op struct cast extension and the
1293    // cast-to-union extension.
1294    if (getType()->isRecordType())
1295      return cast<CastExpr>(this)->getSubExpr()->isConstantInitializer(Ctx);
1296
1297    // Integer->integer casts can be handled here, which is important for
1298    // things like (int)(&&x-&&y).  Scary but true.
1299    if (getType()->isIntegerType() &&
1300        cast<CastExpr>(this)->getSubExpr()->getType()->isIntegerType())
1301      return cast<CastExpr>(this)->getSubExpr()->isConstantInitializer(Ctx);
1302
1303    break;
1304  }
1305  return isEvaluatable(Ctx);
1306}
1307
1308/// isIntegerConstantExpr - this recursive routine will test if an expression is
1309/// an integer constant expression.
1310
1311/// FIXME: Pass up a reason why! Invalid operation in i-c-e, division by zero,
1312/// comma, etc
1313///
1314/// FIXME: Handle offsetof.  Two things to do:  Handle GCC's __builtin_offsetof
1315/// to support gcc 4.0+  and handle the idiom GCC recognizes with a null pointer
1316/// cast+dereference.
1317
1318// CheckICE - This function does the fundamental ICE checking: the returned
1319// ICEDiag contains a Val of 0, 1, or 2, and a possibly null SourceLocation.
1320// Note that to reduce code duplication, this helper does no evaluation
1321// itself; the caller checks whether the expression is evaluatable, and
1322// in the rare cases where CheckICE actually cares about the evaluated
1323// value, it calls into Evalute.
1324//
1325// Meanings of Val:
1326// 0: This expression is an ICE if it can be evaluated by Evaluate.
1327// 1: This expression is not an ICE, but if it isn't evaluated, it's
1328//    a legal subexpression for an ICE. This return value is used to handle
1329//    the comma operator in C99 mode.
1330// 2: This expression is not an ICE, and is not a legal subexpression for one.
1331
1332struct ICEDiag {
1333  unsigned Val;
1334  SourceLocation Loc;
1335
1336  public:
1337  ICEDiag(unsigned v, SourceLocation l) : Val(v), Loc(l) {}
1338  ICEDiag() : Val(0) {}
1339};
1340
1341ICEDiag NoDiag() { return ICEDiag(); }
1342
1343static ICEDiag CheckEvalInICE(const Expr* E, ASTContext &Ctx) {
1344  Expr::EvalResult EVResult;
1345  if (!E->Evaluate(EVResult, Ctx) || EVResult.HasSideEffects ||
1346      !EVResult.Val.isInt()) {
1347    return ICEDiag(2, E->getLocStart());
1348  }
1349  return NoDiag();
1350}
1351
1352static ICEDiag CheckICE(const Expr* E, ASTContext &Ctx) {
1353  assert(!E->isValueDependent() && "Should not see value dependent exprs!");
1354  if (!E->getType()->isIntegralType()) {
1355    return ICEDiag(2, E->getLocStart());
1356  }
1357
1358  switch (E->getStmtClass()) {
1359#define STMT(Node, Base) case Expr::Node##Class:
1360#define EXPR(Node, Base)
1361#include "clang/AST/StmtNodes.def"
1362  case Expr::PredefinedExprClass:
1363  case Expr::FloatingLiteralClass:
1364  case Expr::ImaginaryLiteralClass:
1365  case Expr::StringLiteralClass:
1366  case Expr::ArraySubscriptExprClass:
1367  case Expr::MemberExprClass:
1368  case Expr::CompoundAssignOperatorClass:
1369  case Expr::CompoundLiteralExprClass:
1370  case Expr::ExtVectorElementExprClass:
1371  case Expr::InitListExprClass:
1372  case Expr::DesignatedInitExprClass:
1373  case Expr::ImplicitValueInitExprClass:
1374  case Expr::ParenListExprClass:
1375  case Expr::VAArgExprClass:
1376  case Expr::AddrLabelExprClass:
1377  case Expr::StmtExprClass:
1378  case Expr::CXXMemberCallExprClass:
1379  case Expr::CXXDynamicCastExprClass:
1380  case Expr::CXXTypeidExprClass:
1381  case Expr::CXXNullPtrLiteralExprClass:
1382  case Expr::CXXThisExprClass:
1383  case Expr::CXXThrowExprClass:
1384  case Expr::CXXConditionDeclExprClass: // FIXME: is this correct?
1385  case Expr::CXXNewExprClass:
1386  case Expr::CXXDeleteExprClass:
1387  case Expr::CXXPseudoDestructorExprClass:
1388  case Expr::UnresolvedFunctionNameExprClass:
1389  case Expr::UnresolvedDeclRefExprClass:
1390  case Expr::TemplateIdRefExprClass:
1391  case Expr::CXXConstructExprClass:
1392  case Expr::CXXBindTemporaryExprClass:
1393  case Expr::CXXExprWithTemporariesClass:
1394  case Expr::CXXTemporaryObjectExprClass:
1395  case Expr::CXXUnresolvedConstructExprClass:
1396  case Expr::CXXUnresolvedMemberExprClass:
1397  case Expr::ObjCStringLiteralClass:
1398  case Expr::ObjCEncodeExprClass:
1399  case Expr::ObjCMessageExprClass:
1400  case Expr::ObjCSelectorExprClass:
1401  case Expr::ObjCProtocolExprClass:
1402  case Expr::ObjCIvarRefExprClass:
1403  case Expr::ObjCPropertyRefExprClass:
1404  case Expr::ObjCImplicitSetterGetterRefExprClass:
1405  case Expr::ObjCSuperExprClass:
1406  case Expr::ObjCIsaExprClass:
1407  case Expr::ShuffleVectorExprClass:
1408  case Expr::BlockExprClass:
1409  case Expr::BlockDeclRefExprClass:
1410  case Expr::NoStmtClass:
1411  case Expr::ExprClass:
1412    return ICEDiag(2, E->getLocStart());
1413
1414  case Expr::GNUNullExprClass:
1415    // GCC considers the GNU __null value to be an integral constant expression.
1416    return NoDiag();
1417
1418  case Expr::ParenExprClass:
1419    return CheckICE(cast<ParenExpr>(E)->getSubExpr(), Ctx);
1420  case Expr::IntegerLiteralClass:
1421  case Expr::CharacterLiteralClass:
1422  case Expr::CXXBoolLiteralExprClass:
1423  case Expr::CXXZeroInitValueExprClass:
1424  case Expr::TypesCompatibleExprClass:
1425  case Expr::UnaryTypeTraitExprClass:
1426    return NoDiag();
1427  case Expr::CallExprClass:
1428  case Expr::CXXOperatorCallExprClass: {
1429    const CallExpr *CE = cast<CallExpr>(E);
1430    if (CE->isBuiltinCall(Ctx))
1431      return CheckEvalInICE(E, Ctx);
1432    return ICEDiag(2, E->getLocStart());
1433  }
1434  case Expr::DeclRefExprClass:
1435  case Expr::QualifiedDeclRefExprClass:
1436    if (isa<EnumConstantDecl>(cast<DeclRefExpr>(E)->getDecl()))
1437      return NoDiag();
1438    if (Ctx.getLangOptions().CPlusPlus &&
1439        E->getType().getCVRQualifiers() == Qualifiers::Const) {
1440      // C++ 7.1.5.1p2
1441      //   A variable of non-volatile const-qualified integral or enumeration
1442      //   type initialized by an ICE can be used in ICEs.
1443      if (const VarDecl *Dcl =
1444              dyn_cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl())) {
1445        if (Dcl->isInitKnownICE()) {
1446          // We have already checked whether this subexpression is an
1447          // integral constant expression.
1448          if (Dcl->isInitICE())
1449            return NoDiag();
1450          else
1451            return ICEDiag(2, E->getLocStart());
1452        }
1453
1454        if (const Expr *Init = Dcl->getInit()) {
1455          ICEDiag Result = CheckICE(Init, Ctx);
1456          // Cache the result of the ICE test.
1457          Dcl->setInitKnownICE(Ctx, Result.Val == 0);
1458          return Result;
1459        }
1460      }
1461    }
1462    return ICEDiag(2, E->getLocStart());
1463  case Expr::UnaryOperatorClass: {
1464    const UnaryOperator *Exp = cast<UnaryOperator>(E);
1465    switch (Exp->getOpcode()) {
1466    case UnaryOperator::PostInc:
1467    case UnaryOperator::PostDec:
1468    case UnaryOperator::PreInc:
1469    case UnaryOperator::PreDec:
1470    case UnaryOperator::AddrOf:
1471    case UnaryOperator::Deref:
1472      return ICEDiag(2, E->getLocStart());
1473
1474    case UnaryOperator::Extension:
1475    case UnaryOperator::LNot:
1476    case UnaryOperator::Plus:
1477    case UnaryOperator::Minus:
1478    case UnaryOperator::Not:
1479    case UnaryOperator::Real:
1480    case UnaryOperator::Imag:
1481      return CheckICE(Exp->getSubExpr(), Ctx);
1482    case UnaryOperator::OffsetOf:
1483      // Note that per C99, offsetof must be an ICE. And AFAIK, using
1484      // Evaluate matches the proposed gcc behavior for cases like
1485      // "offsetof(struct s{int x[4];}, x[!.0])".  This doesn't affect
1486      // compliance: we should warn earlier for offsetof expressions with
1487      // array subscripts that aren't ICEs, and if the array subscripts
1488      // are ICEs, the value of the offsetof must be an integer constant.
1489      return CheckEvalInICE(E, Ctx);
1490    }
1491  }
1492  case Expr::SizeOfAlignOfExprClass: {
1493    const SizeOfAlignOfExpr *Exp = cast<SizeOfAlignOfExpr>(E);
1494    if (Exp->isSizeOf() && Exp->getTypeOfArgument()->isVariableArrayType())
1495      return ICEDiag(2, E->getLocStart());
1496    return NoDiag();
1497  }
1498  case Expr::BinaryOperatorClass: {
1499    const BinaryOperator *Exp = cast<BinaryOperator>(E);
1500    switch (Exp->getOpcode()) {
1501    case BinaryOperator::PtrMemD:
1502    case BinaryOperator::PtrMemI:
1503    case BinaryOperator::Assign:
1504    case BinaryOperator::MulAssign:
1505    case BinaryOperator::DivAssign:
1506    case BinaryOperator::RemAssign:
1507    case BinaryOperator::AddAssign:
1508    case BinaryOperator::SubAssign:
1509    case BinaryOperator::ShlAssign:
1510    case BinaryOperator::ShrAssign:
1511    case BinaryOperator::AndAssign:
1512    case BinaryOperator::XorAssign:
1513    case BinaryOperator::OrAssign:
1514      return ICEDiag(2, E->getLocStart());
1515
1516    case BinaryOperator::Mul:
1517    case BinaryOperator::Div:
1518    case BinaryOperator::Rem:
1519    case BinaryOperator::Add:
1520    case BinaryOperator::Sub:
1521    case BinaryOperator::Shl:
1522    case BinaryOperator::Shr:
1523    case BinaryOperator::LT:
1524    case BinaryOperator::GT:
1525    case BinaryOperator::LE:
1526    case BinaryOperator::GE:
1527    case BinaryOperator::EQ:
1528    case BinaryOperator::NE:
1529    case BinaryOperator::And:
1530    case BinaryOperator::Xor:
1531    case BinaryOperator::Or:
1532    case BinaryOperator::Comma: {
1533      ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
1534      ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
1535      if (Exp->getOpcode() == BinaryOperator::Div ||
1536          Exp->getOpcode() == BinaryOperator::Rem) {
1537        // Evaluate gives an error for undefined Div/Rem, so make sure
1538        // we don't evaluate one.
1539        if (LHSResult.Val != 2 && RHSResult.Val != 2) {
1540          llvm::APSInt REval = Exp->getRHS()->EvaluateAsInt(Ctx);
1541          if (REval == 0)
1542            return ICEDiag(1, E->getLocStart());
1543          if (REval.isSigned() && REval.isAllOnesValue()) {
1544            llvm::APSInt LEval = Exp->getLHS()->EvaluateAsInt(Ctx);
1545            if (LEval.isMinSignedValue())
1546              return ICEDiag(1, E->getLocStart());
1547          }
1548        }
1549      }
1550      if (Exp->getOpcode() == BinaryOperator::Comma) {
1551        if (Ctx.getLangOptions().C99) {
1552          // C99 6.6p3 introduces a strange edge case: comma can be in an ICE
1553          // if it isn't evaluated.
1554          if (LHSResult.Val == 0 && RHSResult.Val == 0)
1555            return ICEDiag(1, E->getLocStart());
1556        } else {
1557          // In both C89 and C++, commas in ICEs are illegal.
1558          return ICEDiag(2, E->getLocStart());
1559        }
1560      }
1561      if (LHSResult.Val >= RHSResult.Val)
1562        return LHSResult;
1563      return RHSResult;
1564    }
1565    case BinaryOperator::LAnd:
1566    case BinaryOperator::LOr: {
1567      ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
1568      ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
1569      if (LHSResult.Val == 0 && RHSResult.Val == 1) {
1570        // Rare case where the RHS has a comma "side-effect"; we need
1571        // to actually check the condition to see whether the side
1572        // with the comma is evaluated.
1573        if ((Exp->getOpcode() == BinaryOperator::LAnd) !=
1574            (Exp->getLHS()->EvaluateAsInt(Ctx) == 0))
1575          return RHSResult;
1576        return NoDiag();
1577      }
1578
1579      if (LHSResult.Val >= RHSResult.Val)
1580        return LHSResult;
1581      return RHSResult;
1582    }
1583    }
1584  }
1585  case Expr::CastExprClass:
1586  case Expr::ImplicitCastExprClass:
1587  case Expr::ExplicitCastExprClass:
1588  case Expr::CStyleCastExprClass:
1589  case Expr::CXXFunctionalCastExprClass:
1590  case Expr::CXXNamedCastExprClass:
1591  case Expr::CXXStaticCastExprClass:
1592  case Expr::CXXReinterpretCastExprClass:
1593  case Expr::CXXConstCastExprClass: {
1594    const Expr *SubExpr = cast<CastExpr>(E)->getSubExpr();
1595    if (SubExpr->getType()->isIntegralType())
1596      return CheckICE(SubExpr, Ctx);
1597    if (isa<FloatingLiteral>(SubExpr->IgnoreParens()))
1598      return NoDiag();
1599    return ICEDiag(2, E->getLocStart());
1600  }
1601  case Expr::ConditionalOperatorClass: {
1602    const ConditionalOperator *Exp = cast<ConditionalOperator>(E);
1603    // If the condition (ignoring parens) is a __builtin_constant_p call,
1604    // then only the true side is actually considered in an integer constant
1605    // expression, and it is fully evaluated.  This is an important GNU
1606    // extension.  See GCC PR38377 for discussion.
1607    if (const CallExpr *CallCE = dyn_cast<CallExpr>(Exp->getCond()->IgnoreParenCasts()))
1608      if (CallCE->isBuiltinCall(Ctx) == Builtin::BI__builtin_constant_p) {
1609        Expr::EvalResult EVResult;
1610        if (!E->Evaluate(EVResult, Ctx) || EVResult.HasSideEffects ||
1611            !EVResult.Val.isInt()) {
1612          return ICEDiag(2, E->getLocStart());
1613        }
1614        return NoDiag();
1615      }
1616    ICEDiag CondResult = CheckICE(Exp->getCond(), Ctx);
1617    ICEDiag TrueResult = CheckICE(Exp->getTrueExpr(), Ctx);
1618    ICEDiag FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
1619    if (CondResult.Val == 2)
1620      return CondResult;
1621    if (TrueResult.Val == 2)
1622      return TrueResult;
1623    if (FalseResult.Val == 2)
1624      return FalseResult;
1625    if (CondResult.Val == 1)
1626      return CondResult;
1627    if (TrueResult.Val == 0 && FalseResult.Val == 0)
1628      return NoDiag();
1629    // Rare case where the diagnostics depend on which side is evaluated
1630    // Note that if we get here, CondResult is 0, and at least one of
1631    // TrueResult and FalseResult is non-zero.
1632    if (Exp->getCond()->EvaluateAsInt(Ctx) == 0) {
1633      return FalseResult;
1634    }
1635    return TrueResult;
1636  }
1637  case Expr::CXXDefaultArgExprClass:
1638    return CheckICE(cast<CXXDefaultArgExpr>(E)->getExpr(), Ctx);
1639  case Expr::ChooseExprClass: {
1640    return CheckICE(cast<ChooseExpr>(E)->getChosenSubExpr(Ctx), Ctx);
1641  }
1642  }
1643
1644  // Silence a GCC warning
1645  return ICEDiag(2, E->getLocStart());
1646}
1647
1648bool Expr::isIntegerConstantExpr(llvm::APSInt &Result, ASTContext &Ctx,
1649                                 SourceLocation *Loc, bool isEvaluated) const {
1650  ICEDiag d = CheckICE(this, Ctx);
1651  if (d.Val != 0) {
1652    if (Loc) *Loc = d.Loc;
1653    return false;
1654  }
1655  EvalResult EvalResult;
1656  if (!Evaluate(EvalResult, Ctx))
1657    assert(0 && "ICE cannot be evaluated!");
1658  assert(!EvalResult.HasSideEffects && "ICE with side effects!");
1659  assert(EvalResult.Val.isInt() && "ICE that isn't integer!");
1660  Result = EvalResult.Val.getInt();
1661  return true;
1662}
1663
1664/// isNullPointerConstant - C99 6.3.2.3p3 -  Return true if this is either an
1665/// integer constant expression with the value zero, or if this is one that is
1666/// cast to void*.
1667bool Expr::isNullPointerConstant(ASTContext &Ctx,
1668                                 NullPointerConstantValueDependence NPC) const {
1669  if (isValueDependent()) {
1670    switch (NPC) {
1671    case NPC_NeverValueDependent:
1672      assert(false && "Unexpected value dependent expression!");
1673      // If the unthinkable happens, fall through to the safest alternative.
1674
1675    case NPC_ValueDependentIsNull:
1676      return isTypeDependent() || getType()->isIntegralType();
1677
1678    case NPC_ValueDependentIsNotNull:
1679      return false;
1680    }
1681  }
1682
1683  // Strip off a cast to void*, if it exists. Except in C++.
1684  if (const ExplicitCastExpr *CE = dyn_cast<ExplicitCastExpr>(this)) {
1685    if (!Ctx.getLangOptions().CPlusPlus) {
1686      // Check that it is a cast to void*.
1687      if (const PointerType *PT = CE->getType()->getAs<PointerType>()) {
1688        QualType Pointee = PT->getPointeeType();
1689        if (!Pointee.hasQualifiers() &&
1690            Pointee->isVoidType() &&                              // to void*
1691            CE->getSubExpr()->getType()->isIntegerType())         // from int.
1692          return CE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
1693      }
1694    }
1695  } else if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(this)) {
1696    // Ignore the ImplicitCastExpr type entirely.
1697    return ICE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
1698  } else if (const ParenExpr *PE = dyn_cast<ParenExpr>(this)) {
1699    // Accept ((void*)0) as a null pointer constant, as many other
1700    // implementations do.
1701    return PE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
1702  } else if (const CXXDefaultArgExpr *DefaultArg
1703               = dyn_cast<CXXDefaultArgExpr>(this)) {
1704    // See through default argument expressions
1705    return DefaultArg->getExpr()->isNullPointerConstant(Ctx, NPC);
1706  } else if (isa<GNUNullExpr>(this)) {
1707    // The GNU __null extension is always a null pointer constant.
1708    return true;
1709  }
1710
1711  // C++0x nullptr_t is always a null pointer constant.
1712  if (getType()->isNullPtrType())
1713    return true;
1714
1715  // This expression must be an integer type.
1716  if (!getType()->isIntegerType() ||
1717      (Ctx.getLangOptions().CPlusPlus && getType()->isEnumeralType()))
1718    return false;
1719
1720  // If we have an integer constant expression, we need to *evaluate* it and
1721  // test for the value 0.
1722  llvm::APSInt Result;
1723  return isIntegerConstantExpr(Result, Ctx) && Result == 0;
1724}
1725
1726FieldDecl *Expr::getBitField() {
1727  Expr *E = this->IgnoreParens();
1728
1729  if (MemberExpr *MemRef = dyn_cast<MemberExpr>(E))
1730    if (FieldDecl *Field = dyn_cast<FieldDecl>(MemRef->getMemberDecl()))
1731      if (Field->isBitField())
1732        return Field;
1733
1734  if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(E))
1735    if (BinOp->isAssignmentOp() && BinOp->getLHS())
1736      return BinOp->getLHS()->getBitField();
1737
1738  return 0;
1739}
1740
1741/// isArrow - Return true if the base expression is a pointer to vector,
1742/// return false if the base expression is a vector.
1743bool ExtVectorElementExpr::isArrow() const {
1744  return getBase()->getType()->isPointerType();
1745}
1746
1747unsigned ExtVectorElementExpr::getNumElements() const {
1748  if (const VectorType *VT = getType()->getAs<VectorType>())
1749    return VT->getNumElements();
1750  return 1;
1751}
1752
1753/// containsDuplicateElements - Return true if any element access is repeated.
1754bool ExtVectorElementExpr::containsDuplicateElements() const {
1755  // FIXME: Refactor this code to an accessor on the AST node which returns the
1756  // "type" of component access, and share with code below and in Sema.
1757  llvm::StringRef Comp = Accessor->getName();
1758
1759  // Halving swizzles do not contain duplicate elements.
1760  if (Comp == "hi" || Comp == "lo" || Comp == "even" || Comp == "odd")
1761    return false;
1762
1763  // Advance past s-char prefix on hex swizzles.
1764  if (Comp[0] == 's' || Comp[0] == 'S')
1765    Comp = Comp.substr(1);
1766
1767  for (unsigned i = 0, e = Comp.size(); i != e; ++i)
1768    if (Comp.substr(i + 1).find(Comp[i]) != llvm::StringRef::npos)
1769        return true;
1770
1771  return false;
1772}
1773
1774/// getEncodedElementAccess - We encode the fields as a llvm ConstantArray.
1775void ExtVectorElementExpr::getEncodedElementAccess(
1776                                  llvm::SmallVectorImpl<unsigned> &Elts) const {
1777  llvm::StringRef Comp = Accessor->getName();
1778  if (Comp[0] == 's' || Comp[0] == 'S')
1779    Comp = Comp.substr(1);
1780
1781  bool isHi =   Comp == "hi";
1782  bool isLo =   Comp == "lo";
1783  bool isEven = Comp == "even";
1784  bool isOdd  = Comp == "odd";
1785
1786  for (unsigned i = 0, e = getNumElements(); i != e; ++i) {
1787    uint64_t Index;
1788
1789    if (isHi)
1790      Index = e + i;
1791    else if (isLo)
1792      Index = i;
1793    else if (isEven)
1794      Index = 2 * i;
1795    else if (isOdd)
1796      Index = 2 * i + 1;
1797    else
1798      Index = ExtVectorType::getAccessorIdx(Comp[i]);
1799
1800    Elts.push_back(Index);
1801  }
1802}
1803
1804// constructor for instance messages.
1805ObjCMessageExpr::ObjCMessageExpr(Expr *receiver, Selector selInfo,
1806                QualType retType, ObjCMethodDecl *mproto,
1807                SourceLocation LBrac, SourceLocation RBrac,
1808                Expr **ArgExprs, unsigned nargs)
1809  : Expr(ObjCMessageExprClass, retType), SelName(selInfo),
1810    MethodProto(mproto) {
1811  NumArgs = nargs;
1812  SubExprs = new Stmt*[NumArgs+1];
1813  SubExprs[RECEIVER] = receiver;
1814  if (NumArgs) {
1815    for (unsigned i = 0; i != NumArgs; ++i)
1816      SubExprs[i+ARGS_START] = static_cast<Expr *>(ArgExprs[i]);
1817  }
1818  LBracloc = LBrac;
1819  RBracloc = RBrac;
1820}
1821
1822// constructor for class messages.
1823// FIXME: clsName should be typed to ObjCInterfaceType
1824ObjCMessageExpr::ObjCMessageExpr(IdentifierInfo *clsName, Selector selInfo,
1825                QualType retType, ObjCMethodDecl *mproto,
1826                SourceLocation LBrac, SourceLocation RBrac,
1827                Expr **ArgExprs, unsigned nargs)
1828  : Expr(ObjCMessageExprClass, retType), SelName(selInfo),
1829    MethodProto(mproto) {
1830  NumArgs = nargs;
1831  SubExprs = new Stmt*[NumArgs+1];
1832  SubExprs[RECEIVER] = (Expr*) ((uintptr_t) clsName | IsClsMethDeclUnknown);
1833  if (NumArgs) {
1834    for (unsigned i = 0; i != NumArgs; ++i)
1835      SubExprs[i+ARGS_START] = static_cast<Expr *>(ArgExprs[i]);
1836  }
1837  LBracloc = LBrac;
1838  RBracloc = RBrac;
1839}
1840
1841// constructor for class messages.
1842ObjCMessageExpr::ObjCMessageExpr(ObjCInterfaceDecl *cls, Selector selInfo,
1843                                 QualType retType, ObjCMethodDecl *mproto,
1844                                 SourceLocation LBrac, SourceLocation RBrac,
1845                                 Expr **ArgExprs, unsigned nargs)
1846: Expr(ObjCMessageExprClass, retType), SelName(selInfo),
1847MethodProto(mproto) {
1848  NumArgs = nargs;
1849  SubExprs = new Stmt*[NumArgs+1];
1850  SubExprs[RECEIVER] = (Expr*) ((uintptr_t) cls | IsClsMethDeclKnown);
1851  if (NumArgs) {
1852    for (unsigned i = 0; i != NumArgs; ++i)
1853      SubExprs[i+ARGS_START] = static_cast<Expr *>(ArgExprs[i]);
1854  }
1855  LBracloc = LBrac;
1856  RBracloc = RBrac;
1857}
1858
1859ObjCMessageExpr::ClassInfo ObjCMessageExpr::getClassInfo() const {
1860  uintptr_t x = (uintptr_t) SubExprs[RECEIVER];
1861  switch (x & Flags) {
1862    default:
1863      assert(false && "Invalid ObjCMessageExpr.");
1864    case IsInstMeth:
1865      return ClassInfo(0, 0);
1866    case IsClsMethDeclUnknown:
1867      return ClassInfo(0, (IdentifierInfo*) (x & ~Flags));
1868    case IsClsMethDeclKnown: {
1869      ObjCInterfaceDecl* D = (ObjCInterfaceDecl*) (x & ~Flags);
1870      return ClassInfo(D, D->getIdentifier());
1871    }
1872  }
1873}
1874
1875void ObjCMessageExpr::setClassInfo(const ObjCMessageExpr::ClassInfo &CI) {
1876  if (CI.first == 0 && CI.second == 0)
1877    SubExprs[RECEIVER] = (Expr*)((uintptr_t)0 | IsInstMeth);
1878  else if (CI.first == 0)
1879    SubExprs[RECEIVER] = (Expr*)((uintptr_t)CI.second | IsClsMethDeclUnknown);
1880  else
1881    SubExprs[RECEIVER] = (Expr*)((uintptr_t)CI.first | IsClsMethDeclKnown);
1882}
1883
1884
1885bool ChooseExpr::isConditionTrue(ASTContext &C) const {
1886  return getCond()->EvaluateAsInt(C) != 0;
1887}
1888
1889void ShuffleVectorExpr::setExprs(ASTContext &C, Expr ** Exprs,
1890                                 unsigned NumExprs) {
1891  if (SubExprs) C.Deallocate(SubExprs);
1892
1893  SubExprs = new (C) Stmt* [NumExprs];
1894  this->NumExprs = NumExprs;
1895  memcpy(SubExprs, Exprs, sizeof(Expr *) * NumExprs);
1896}
1897
1898void ShuffleVectorExpr::DoDestroy(ASTContext& C) {
1899  DestroyChildren(C);
1900  if (SubExprs) C.Deallocate(SubExprs);
1901  this->~ShuffleVectorExpr();
1902  C.Deallocate(this);
1903}
1904
1905void SizeOfAlignOfExpr::DoDestroy(ASTContext& C) {
1906  // Override default behavior of traversing children. If this has a type
1907  // operand and the type is a variable-length array, the child iteration
1908  // will iterate over the size expression. However, this expression belongs
1909  // to the type, not to this, so we don't want to delete it.
1910  // We still want to delete this expression.
1911  if (isArgumentType()) {
1912    this->~SizeOfAlignOfExpr();
1913    C.Deallocate(this);
1914  }
1915  else
1916    Expr::DoDestroy(C);
1917}
1918
1919//===----------------------------------------------------------------------===//
1920//  DesignatedInitExpr
1921//===----------------------------------------------------------------------===//
1922
1923IdentifierInfo *DesignatedInitExpr::Designator::getFieldName() {
1924  assert(Kind == FieldDesignator && "Only valid on a field designator");
1925  if (Field.NameOrField & 0x01)
1926    return reinterpret_cast<IdentifierInfo *>(Field.NameOrField&~0x01);
1927  else
1928    return getField()->getIdentifier();
1929}
1930
1931DesignatedInitExpr::DesignatedInitExpr(QualType Ty, unsigned NumDesignators,
1932                                       const Designator *Designators,
1933                                       SourceLocation EqualOrColonLoc,
1934                                       bool GNUSyntax,
1935                                       Expr **IndexExprs,
1936                                       unsigned NumIndexExprs,
1937                                       Expr *Init)
1938  : Expr(DesignatedInitExprClass, Ty,
1939         Init->isTypeDependent(), Init->isValueDependent()),
1940    EqualOrColonLoc(EqualOrColonLoc), GNUSyntax(GNUSyntax),
1941    NumDesignators(NumDesignators), NumSubExprs(NumIndexExprs + 1) {
1942  this->Designators = new Designator[NumDesignators];
1943
1944  // Record the initializer itself.
1945  child_iterator Child = child_begin();
1946  *Child++ = Init;
1947
1948  // Copy the designators and their subexpressions, computing
1949  // value-dependence along the way.
1950  unsigned IndexIdx = 0;
1951  for (unsigned I = 0; I != NumDesignators; ++I) {
1952    this->Designators[I] = Designators[I];
1953
1954    if (this->Designators[I].isArrayDesignator()) {
1955      // Compute type- and value-dependence.
1956      Expr *Index = IndexExprs[IndexIdx];
1957      ValueDependent = ValueDependent ||
1958        Index->isTypeDependent() || Index->isValueDependent();
1959
1960      // Copy the index expressions into permanent storage.
1961      *Child++ = IndexExprs[IndexIdx++];
1962    } else if (this->Designators[I].isArrayRangeDesignator()) {
1963      // Compute type- and value-dependence.
1964      Expr *Start = IndexExprs[IndexIdx];
1965      Expr *End = IndexExprs[IndexIdx + 1];
1966      ValueDependent = ValueDependent ||
1967        Start->isTypeDependent() || Start->isValueDependent() ||
1968        End->isTypeDependent() || End->isValueDependent();
1969
1970      // Copy the start/end expressions into permanent storage.
1971      *Child++ = IndexExprs[IndexIdx++];
1972      *Child++ = IndexExprs[IndexIdx++];
1973    }
1974  }
1975
1976  assert(IndexIdx == NumIndexExprs && "Wrong number of index expressions");
1977}
1978
1979DesignatedInitExpr *
1980DesignatedInitExpr::Create(ASTContext &C, Designator *Designators,
1981                           unsigned NumDesignators,
1982                           Expr **IndexExprs, unsigned NumIndexExprs,
1983                           SourceLocation ColonOrEqualLoc,
1984                           bool UsesColonSyntax, Expr *Init) {
1985  void *Mem = C.Allocate(sizeof(DesignatedInitExpr) +
1986                         sizeof(Stmt *) * (NumIndexExprs + 1), 8);
1987  return new (Mem) DesignatedInitExpr(C.VoidTy, NumDesignators, Designators,
1988                                      ColonOrEqualLoc, UsesColonSyntax,
1989                                      IndexExprs, NumIndexExprs, Init);
1990}
1991
1992DesignatedInitExpr *DesignatedInitExpr::CreateEmpty(ASTContext &C,
1993                                                    unsigned NumIndexExprs) {
1994  void *Mem = C.Allocate(sizeof(DesignatedInitExpr) +
1995                         sizeof(Stmt *) * (NumIndexExprs + 1), 8);
1996  return new (Mem) DesignatedInitExpr(NumIndexExprs + 1);
1997}
1998
1999void DesignatedInitExpr::setDesignators(const Designator *Desigs,
2000                                        unsigned NumDesigs) {
2001  if (Designators)
2002    delete [] Designators;
2003
2004  Designators = new Designator[NumDesigs];
2005  NumDesignators = NumDesigs;
2006  for (unsigned I = 0; I != NumDesigs; ++I)
2007    Designators[I] = Desigs[I];
2008}
2009
2010SourceRange DesignatedInitExpr::getSourceRange() const {
2011  SourceLocation StartLoc;
2012  Designator &First =
2013    *const_cast<DesignatedInitExpr*>(this)->designators_begin();
2014  if (First.isFieldDesignator()) {
2015    if (GNUSyntax)
2016      StartLoc = SourceLocation::getFromRawEncoding(First.Field.FieldLoc);
2017    else
2018      StartLoc = SourceLocation::getFromRawEncoding(First.Field.DotLoc);
2019  } else
2020    StartLoc =
2021      SourceLocation::getFromRawEncoding(First.ArrayOrRange.LBracketLoc);
2022  return SourceRange(StartLoc, getInit()->getSourceRange().getEnd());
2023}
2024
2025Expr *DesignatedInitExpr::getArrayIndex(const Designator& D) {
2026  assert(D.Kind == Designator::ArrayDesignator && "Requires array designator");
2027  char* Ptr = static_cast<char*>(static_cast<void *>(this));
2028  Ptr += sizeof(DesignatedInitExpr);
2029  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
2030  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
2031}
2032
2033Expr *DesignatedInitExpr::getArrayRangeStart(const Designator& D) {
2034  assert(D.Kind == Designator::ArrayRangeDesignator &&
2035         "Requires array range designator");
2036  char* Ptr = static_cast<char*>(static_cast<void *>(this));
2037  Ptr += sizeof(DesignatedInitExpr);
2038  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
2039  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
2040}
2041
2042Expr *DesignatedInitExpr::getArrayRangeEnd(const Designator& D) {
2043  assert(D.Kind == Designator::ArrayRangeDesignator &&
2044         "Requires array range designator");
2045  char* Ptr = static_cast<char*>(static_cast<void *>(this));
2046  Ptr += sizeof(DesignatedInitExpr);
2047  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
2048  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 2));
2049}
2050
2051/// \brief Replaces the designator at index @p Idx with the series
2052/// of designators in [First, Last).
2053void DesignatedInitExpr::ExpandDesignator(unsigned Idx,
2054                                          const Designator *First,
2055                                          const Designator *Last) {
2056  unsigned NumNewDesignators = Last - First;
2057  if (NumNewDesignators == 0) {
2058    std::copy_backward(Designators + Idx + 1,
2059                       Designators + NumDesignators,
2060                       Designators + Idx);
2061    --NumNewDesignators;
2062    return;
2063  } else if (NumNewDesignators == 1) {
2064    Designators[Idx] = *First;
2065    return;
2066  }
2067
2068  Designator *NewDesignators
2069    = new Designator[NumDesignators - 1 + NumNewDesignators];
2070  std::copy(Designators, Designators + Idx, NewDesignators);
2071  std::copy(First, Last, NewDesignators + Idx);
2072  std::copy(Designators + Idx + 1, Designators + NumDesignators,
2073            NewDesignators + Idx + NumNewDesignators);
2074  delete [] Designators;
2075  Designators = NewDesignators;
2076  NumDesignators = NumDesignators - 1 + NumNewDesignators;
2077}
2078
2079void DesignatedInitExpr::DoDestroy(ASTContext &C) {
2080  delete [] Designators;
2081  Expr::DoDestroy(C);
2082}
2083
2084ParenListExpr::ParenListExpr(ASTContext& C, SourceLocation lparenloc,
2085                             Expr **exprs, unsigned nexprs,
2086                             SourceLocation rparenloc)
2087: Expr(ParenListExprClass, QualType(),
2088       hasAnyTypeDependentArguments(exprs, nexprs),
2089       hasAnyValueDependentArguments(exprs, nexprs)),
2090  NumExprs(nexprs), LParenLoc(lparenloc), RParenLoc(rparenloc) {
2091
2092  Exprs = new (C) Stmt*[nexprs];
2093  for (unsigned i = 0; i != nexprs; ++i)
2094    Exprs[i] = exprs[i];
2095}
2096
2097void ParenListExpr::DoDestroy(ASTContext& C) {
2098  DestroyChildren(C);
2099  if (Exprs) C.Deallocate(Exprs);
2100  this->~ParenListExpr();
2101  C.Deallocate(this);
2102}
2103
2104//===----------------------------------------------------------------------===//
2105//  ExprIterator.
2106//===----------------------------------------------------------------------===//
2107
2108Expr* ExprIterator::operator[](size_t idx) { return cast<Expr>(I[idx]); }
2109Expr* ExprIterator::operator*() const { return cast<Expr>(*I); }
2110Expr* ExprIterator::operator->() const { return cast<Expr>(*I); }
2111const Expr* ConstExprIterator::operator[](size_t idx) const {
2112  return cast<Expr>(I[idx]);
2113}
2114const Expr* ConstExprIterator::operator*() const { return cast<Expr>(*I); }
2115const Expr* ConstExprIterator::operator->() const { return cast<Expr>(*I); }
2116
2117//===----------------------------------------------------------------------===//
2118//  Child Iterators for iterating over subexpressions/substatements
2119//===----------------------------------------------------------------------===//
2120
2121// DeclRefExpr
2122Stmt::child_iterator DeclRefExpr::child_begin() { return child_iterator(); }
2123Stmt::child_iterator DeclRefExpr::child_end() { return child_iterator(); }
2124
2125// ObjCIvarRefExpr
2126Stmt::child_iterator ObjCIvarRefExpr::child_begin() { return &Base; }
2127Stmt::child_iterator ObjCIvarRefExpr::child_end() { return &Base+1; }
2128
2129// ObjCPropertyRefExpr
2130Stmt::child_iterator ObjCPropertyRefExpr::child_begin() { return &Base; }
2131Stmt::child_iterator ObjCPropertyRefExpr::child_end() { return &Base+1; }
2132
2133// ObjCImplicitSetterGetterRefExpr
2134Stmt::child_iterator ObjCImplicitSetterGetterRefExpr::child_begin() {
2135  return &Base;
2136}
2137Stmt::child_iterator ObjCImplicitSetterGetterRefExpr::child_end() {
2138  return &Base+1;
2139}
2140
2141// ObjCSuperExpr
2142Stmt::child_iterator ObjCSuperExpr::child_begin() { return child_iterator(); }
2143Stmt::child_iterator ObjCSuperExpr::child_end() { return child_iterator(); }
2144
2145// ObjCIsaExpr
2146Stmt::child_iterator ObjCIsaExpr::child_begin() { return &Base; }
2147Stmt::child_iterator ObjCIsaExpr::child_end() { return &Base+1; }
2148
2149// PredefinedExpr
2150Stmt::child_iterator PredefinedExpr::child_begin() { return child_iterator(); }
2151Stmt::child_iterator PredefinedExpr::child_end() { return child_iterator(); }
2152
2153// IntegerLiteral
2154Stmt::child_iterator IntegerLiteral::child_begin() { return child_iterator(); }
2155Stmt::child_iterator IntegerLiteral::child_end() { return child_iterator(); }
2156
2157// CharacterLiteral
2158Stmt::child_iterator CharacterLiteral::child_begin() { return child_iterator();}
2159Stmt::child_iterator CharacterLiteral::child_end() { return child_iterator(); }
2160
2161// FloatingLiteral
2162Stmt::child_iterator FloatingLiteral::child_begin() { return child_iterator(); }
2163Stmt::child_iterator FloatingLiteral::child_end() { return child_iterator(); }
2164
2165// ImaginaryLiteral
2166Stmt::child_iterator ImaginaryLiteral::child_begin() { return &Val; }
2167Stmt::child_iterator ImaginaryLiteral::child_end() { return &Val+1; }
2168
2169// StringLiteral
2170Stmt::child_iterator StringLiteral::child_begin() { return child_iterator(); }
2171Stmt::child_iterator StringLiteral::child_end() { return child_iterator(); }
2172
2173// ParenExpr
2174Stmt::child_iterator ParenExpr::child_begin() { return &Val; }
2175Stmt::child_iterator ParenExpr::child_end() { return &Val+1; }
2176
2177// UnaryOperator
2178Stmt::child_iterator UnaryOperator::child_begin() { return &Val; }
2179Stmt::child_iterator UnaryOperator::child_end() { return &Val+1; }
2180
2181// SizeOfAlignOfExpr
2182Stmt::child_iterator SizeOfAlignOfExpr::child_begin() {
2183  // If this is of a type and the type is a VLA type (and not a typedef), the
2184  // size expression of the VLA needs to be treated as an executable expression.
2185  // Why isn't this weirdness documented better in StmtIterator?
2186  if (isArgumentType()) {
2187    if (VariableArrayType* T = dyn_cast<VariableArrayType>(
2188                                   getArgumentType().getTypePtr()))
2189      return child_iterator(T);
2190    return child_iterator();
2191  }
2192  return child_iterator(&Argument.Ex);
2193}
2194Stmt::child_iterator SizeOfAlignOfExpr::child_end() {
2195  if (isArgumentType())
2196    return child_iterator();
2197  return child_iterator(&Argument.Ex + 1);
2198}
2199
2200// ArraySubscriptExpr
2201Stmt::child_iterator ArraySubscriptExpr::child_begin() {
2202  return &SubExprs[0];
2203}
2204Stmt::child_iterator ArraySubscriptExpr::child_end() {
2205  return &SubExprs[0]+END_EXPR;
2206}
2207
2208// CallExpr
2209Stmt::child_iterator CallExpr::child_begin() {
2210  return &SubExprs[0];
2211}
2212Stmt::child_iterator CallExpr::child_end() {
2213  return &SubExprs[0]+NumArgs+ARGS_START;
2214}
2215
2216// MemberExpr
2217Stmt::child_iterator MemberExpr::child_begin() { return &Base; }
2218Stmt::child_iterator MemberExpr::child_end() { return &Base+1; }
2219
2220// ExtVectorElementExpr
2221Stmt::child_iterator ExtVectorElementExpr::child_begin() { return &Base; }
2222Stmt::child_iterator ExtVectorElementExpr::child_end() { return &Base+1; }
2223
2224// CompoundLiteralExpr
2225Stmt::child_iterator CompoundLiteralExpr::child_begin() { return &Init; }
2226Stmt::child_iterator CompoundLiteralExpr::child_end() { return &Init+1; }
2227
2228// CastExpr
2229Stmt::child_iterator CastExpr::child_begin() { return &Op; }
2230Stmt::child_iterator CastExpr::child_end() { return &Op+1; }
2231
2232// BinaryOperator
2233Stmt::child_iterator BinaryOperator::child_begin() {
2234  return &SubExprs[0];
2235}
2236Stmt::child_iterator BinaryOperator::child_end() {
2237  return &SubExprs[0]+END_EXPR;
2238}
2239
2240// ConditionalOperator
2241Stmt::child_iterator ConditionalOperator::child_begin() {
2242  return &SubExprs[0];
2243}
2244Stmt::child_iterator ConditionalOperator::child_end() {
2245  return &SubExprs[0]+END_EXPR;
2246}
2247
2248// AddrLabelExpr
2249Stmt::child_iterator AddrLabelExpr::child_begin() { return child_iterator(); }
2250Stmt::child_iterator AddrLabelExpr::child_end() { return child_iterator(); }
2251
2252// StmtExpr
2253Stmt::child_iterator StmtExpr::child_begin() { return &SubStmt; }
2254Stmt::child_iterator StmtExpr::child_end() { return &SubStmt+1; }
2255
2256// TypesCompatibleExpr
2257Stmt::child_iterator TypesCompatibleExpr::child_begin() {
2258  return child_iterator();
2259}
2260
2261Stmt::child_iterator TypesCompatibleExpr::child_end() {
2262  return child_iterator();
2263}
2264
2265// ChooseExpr
2266Stmt::child_iterator ChooseExpr::child_begin() { return &SubExprs[0]; }
2267Stmt::child_iterator ChooseExpr::child_end() { return &SubExprs[0]+END_EXPR; }
2268
2269// GNUNullExpr
2270Stmt::child_iterator GNUNullExpr::child_begin() { return child_iterator(); }
2271Stmt::child_iterator GNUNullExpr::child_end() { return child_iterator(); }
2272
2273// ShuffleVectorExpr
2274Stmt::child_iterator ShuffleVectorExpr::child_begin() {
2275  return &SubExprs[0];
2276}
2277Stmt::child_iterator ShuffleVectorExpr::child_end() {
2278  return &SubExprs[0]+NumExprs;
2279}
2280
2281// VAArgExpr
2282Stmt::child_iterator VAArgExpr::child_begin() { return &Val; }
2283Stmt::child_iterator VAArgExpr::child_end() { return &Val+1; }
2284
2285// InitListExpr
2286Stmt::child_iterator InitListExpr::child_begin() {
2287  return InitExprs.size() ? &InitExprs[0] : 0;
2288}
2289Stmt::child_iterator InitListExpr::child_end() {
2290  return InitExprs.size() ? &InitExprs[0] + InitExprs.size() : 0;
2291}
2292
2293// DesignatedInitExpr
2294Stmt::child_iterator DesignatedInitExpr::child_begin() {
2295  char* Ptr = static_cast<char*>(static_cast<void *>(this));
2296  Ptr += sizeof(DesignatedInitExpr);
2297  return reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
2298}
2299Stmt::child_iterator DesignatedInitExpr::child_end() {
2300  return child_iterator(&*child_begin() + NumSubExprs);
2301}
2302
2303// ImplicitValueInitExpr
2304Stmt::child_iterator ImplicitValueInitExpr::child_begin() {
2305  return child_iterator();
2306}
2307
2308Stmt::child_iterator ImplicitValueInitExpr::child_end() {
2309  return child_iterator();
2310}
2311
2312// ParenListExpr
2313Stmt::child_iterator ParenListExpr::child_begin() {
2314  return &Exprs[0];
2315}
2316Stmt::child_iterator ParenListExpr::child_end() {
2317  return &Exprs[0]+NumExprs;
2318}
2319
2320// ObjCStringLiteral
2321Stmt::child_iterator ObjCStringLiteral::child_begin() {
2322  return &String;
2323}
2324Stmt::child_iterator ObjCStringLiteral::child_end() {
2325  return &String+1;
2326}
2327
2328// ObjCEncodeExpr
2329Stmt::child_iterator ObjCEncodeExpr::child_begin() { return child_iterator(); }
2330Stmt::child_iterator ObjCEncodeExpr::child_end() { return child_iterator(); }
2331
2332// ObjCSelectorExpr
2333Stmt::child_iterator ObjCSelectorExpr::child_begin() {
2334  return child_iterator();
2335}
2336Stmt::child_iterator ObjCSelectorExpr::child_end() {
2337  return child_iterator();
2338}
2339
2340// ObjCProtocolExpr
2341Stmt::child_iterator ObjCProtocolExpr::child_begin() {
2342  return child_iterator();
2343}
2344Stmt::child_iterator ObjCProtocolExpr::child_end() {
2345  return child_iterator();
2346}
2347
2348// ObjCMessageExpr
2349Stmt::child_iterator ObjCMessageExpr::child_begin() {
2350  return getReceiver() ? &SubExprs[0] : &SubExprs[0] + ARGS_START;
2351}
2352Stmt::child_iterator ObjCMessageExpr::child_end() {
2353  return &SubExprs[0]+ARGS_START+getNumArgs();
2354}
2355
2356// Blocks
2357Stmt::child_iterator BlockExpr::child_begin() { return child_iterator(); }
2358Stmt::child_iterator BlockExpr::child_end() { return child_iterator(); }
2359
2360Stmt::child_iterator BlockDeclRefExpr::child_begin() { return child_iterator();}
2361Stmt::child_iterator BlockDeclRefExpr::child_end() { return child_iterator(); }
2362