SemaChecking.cpp revision ccfa9639f8d09733bcf1c2572c5bd3daba5bd632
1//===--- SemaChecking.cpp - Extra Semantic Checking -----------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements extra semantic analysis beyond what is enforced 11// by the C type system. 12// 13//===----------------------------------------------------------------------===// 14 15#include "Sema.h" 16#include "clang/Analysis/Analyses/PrintfFormatString.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/CharUnits.h" 19#include "clang/AST/DeclObjC.h" 20#include "clang/AST/ExprCXX.h" 21#include "clang/AST/ExprObjC.h" 22#include "clang/AST/DeclObjC.h" 23#include "clang/AST/StmtCXX.h" 24#include "clang/AST/StmtObjC.h" 25#include "clang/Lex/LiteralSupport.h" 26#include "clang/Lex/Preprocessor.h" 27#include "llvm/ADT/BitVector.h" 28#include "llvm/ADT/STLExtras.h" 29#include <limits> 30using namespace clang; 31 32/// getLocationOfStringLiteralByte - Return a source location that points to the 33/// specified byte of the specified string literal. 34/// 35/// Strings are amazingly complex. They can be formed from multiple tokens and 36/// can have escape sequences in them in addition to the usual trigraph and 37/// escaped newline business. This routine handles this complexity. 38/// 39SourceLocation Sema::getLocationOfStringLiteralByte(const StringLiteral *SL, 40 unsigned ByteNo) const { 41 assert(!SL->isWide() && "This doesn't work for wide strings yet"); 42 43 // Loop over all of the tokens in this string until we find the one that 44 // contains the byte we're looking for. 45 unsigned TokNo = 0; 46 while (1) { 47 assert(TokNo < SL->getNumConcatenated() && "Invalid byte number!"); 48 SourceLocation StrTokLoc = SL->getStrTokenLoc(TokNo); 49 50 // Get the spelling of the string so that we can get the data that makes up 51 // the string literal, not the identifier for the macro it is potentially 52 // expanded through. 53 SourceLocation StrTokSpellingLoc = SourceMgr.getSpellingLoc(StrTokLoc); 54 55 // Re-lex the token to get its length and original spelling. 56 std::pair<FileID, unsigned> LocInfo = 57 SourceMgr.getDecomposedLoc(StrTokSpellingLoc); 58 bool Invalid = false; 59 llvm::StringRef Buffer = SourceMgr.getBufferData(LocInfo.first, &Invalid); 60 if (Invalid) 61 return StrTokSpellingLoc; 62 63 const char *StrData = Buffer.data()+LocInfo.second; 64 65 // Create a langops struct and enable trigraphs. This is sufficient for 66 // relexing tokens. 67 LangOptions LangOpts; 68 LangOpts.Trigraphs = true; 69 70 // Create a lexer starting at the beginning of this token. 71 Lexer TheLexer(StrTokSpellingLoc, LangOpts, Buffer.begin(), StrData, 72 Buffer.end()); 73 Token TheTok; 74 TheLexer.LexFromRawLexer(TheTok); 75 76 // Use the StringLiteralParser to compute the length of the string in bytes. 77 StringLiteralParser SLP(&TheTok, 1, PP); 78 unsigned TokNumBytes = SLP.GetStringLength(); 79 80 // If the byte is in this token, return the location of the byte. 81 if (ByteNo < TokNumBytes || 82 (ByteNo == TokNumBytes && TokNo == SL->getNumConcatenated())) { 83 unsigned Offset = 84 StringLiteralParser::getOffsetOfStringByte(TheTok, ByteNo, PP); 85 86 // Now that we know the offset of the token in the spelling, use the 87 // preprocessor to get the offset in the original source. 88 return PP.AdvanceToTokenCharacter(StrTokLoc, Offset); 89 } 90 91 // Move to the next string token. 92 ++TokNo; 93 ByteNo -= TokNumBytes; 94 } 95} 96 97/// CheckablePrintfAttr - does a function call have a "printf" attribute 98/// and arguments that merit checking? 99bool Sema::CheckablePrintfAttr(const FormatAttr *Format, CallExpr *TheCall) { 100 if (Format->getType() == "printf") return true; 101 if (Format->getType() == "printf0") { 102 // printf0 allows null "format" string; if so don't check format/args 103 unsigned format_idx = Format->getFormatIdx() - 1; 104 // Does the index refer to the implicit object argument? 105 if (isa<CXXMemberCallExpr>(TheCall)) { 106 if (format_idx == 0) 107 return false; 108 --format_idx; 109 } 110 if (format_idx < TheCall->getNumArgs()) { 111 Expr *Format = TheCall->getArg(format_idx)->IgnoreParenCasts(); 112 if (!Format->isNullPointerConstant(Context, 113 Expr::NPC_ValueDependentIsNull)) 114 return true; 115 } 116 } 117 return false; 118} 119 120Action::OwningExprResult 121Sema::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) { 122 OwningExprResult TheCallResult(Owned(TheCall)); 123 124 switch (BuiltinID) { 125 case Builtin::BI__builtin___CFStringMakeConstantString: 126 assert(TheCall->getNumArgs() == 1 && 127 "Wrong # arguments to builtin CFStringMakeConstantString"); 128 if (CheckObjCString(TheCall->getArg(0))) 129 return ExprError(); 130 break; 131 case Builtin::BI__builtin_stdarg_start: 132 case Builtin::BI__builtin_va_start: 133 if (SemaBuiltinVAStart(TheCall)) 134 return ExprError(); 135 break; 136 case Builtin::BI__builtin_isgreater: 137 case Builtin::BI__builtin_isgreaterequal: 138 case Builtin::BI__builtin_isless: 139 case Builtin::BI__builtin_islessequal: 140 case Builtin::BI__builtin_islessgreater: 141 case Builtin::BI__builtin_isunordered: 142 if (SemaBuiltinUnorderedCompare(TheCall)) 143 return ExprError(); 144 break; 145 case Builtin::BI__builtin_fpclassify: 146 if (SemaBuiltinFPClassification(TheCall, 6)) 147 return ExprError(); 148 break; 149 case Builtin::BI__builtin_isfinite: 150 case Builtin::BI__builtin_isinf: 151 case Builtin::BI__builtin_isinf_sign: 152 case Builtin::BI__builtin_isnan: 153 case Builtin::BI__builtin_isnormal: 154 if (SemaBuiltinFPClassification(TheCall, 1)) 155 return ExprError(); 156 break; 157 case Builtin::BI__builtin_return_address: 158 case Builtin::BI__builtin_frame_address: 159 if (SemaBuiltinStackAddress(TheCall)) 160 return ExprError(); 161 break; 162 case Builtin::BI__builtin_eh_return_data_regno: 163 if (SemaBuiltinEHReturnDataRegNo(TheCall)) 164 return ExprError(); 165 break; 166 case Builtin::BI__builtin_shufflevector: 167 return SemaBuiltinShuffleVector(TheCall); 168 // TheCall will be freed by the smart pointer here, but that's fine, since 169 // SemaBuiltinShuffleVector guts it, but then doesn't release it. 170 case Builtin::BI__builtin_prefetch: 171 if (SemaBuiltinPrefetch(TheCall)) 172 return ExprError(); 173 break; 174 case Builtin::BI__builtin_object_size: 175 if (SemaBuiltinObjectSize(TheCall)) 176 return ExprError(); 177 break; 178 case Builtin::BI__builtin_longjmp: 179 if (SemaBuiltinLongjmp(TheCall)) 180 return ExprError(); 181 break; 182 case Builtin::BI__sync_fetch_and_add: 183 case Builtin::BI__sync_fetch_and_sub: 184 case Builtin::BI__sync_fetch_and_or: 185 case Builtin::BI__sync_fetch_and_and: 186 case Builtin::BI__sync_fetch_and_xor: 187 case Builtin::BI__sync_add_and_fetch: 188 case Builtin::BI__sync_sub_and_fetch: 189 case Builtin::BI__sync_and_and_fetch: 190 case Builtin::BI__sync_or_and_fetch: 191 case Builtin::BI__sync_xor_and_fetch: 192 case Builtin::BI__sync_val_compare_and_swap: 193 case Builtin::BI__sync_bool_compare_and_swap: 194 case Builtin::BI__sync_lock_test_and_set: 195 case Builtin::BI__sync_lock_release: 196 if (SemaBuiltinAtomicOverloaded(TheCall)) 197 return ExprError(); 198 break; 199 } 200 201 return move(TheCallResult); 202} 203 204/// CheckFunctionCall - Check a direct function call for various correctness 205/// and safety properties not strictly enforced by the C type system. 206bool Sema::CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall) { 207 // Get the IdentifierInfo* for the called function. 208 IdentifierInfo *FnInfo = FDecl->getIdentifier(); 209 210 // None of the checks below are needed for functions that don't have 211 // simple names (e.g., C++ conversion functions). 212 if (!FnInfo) 213 return false; 214 215 // FIXME: This mechanism should be abstracted to be less fragile and 216 // more efficient. For example, just map function ids to custom 217 // handlers. 218 219 // Printf checking. 220 if (const FormatAttr *Format = FDecl->getAttr<FormatAttr>()) { 221 if (CheckablePrintfAttr(Format, TheCall)) { 222 bool HasVAListArg = Format->getFirstArg() == 0; 223 CheckPrintfArguments(TheCall, HasVAListArg, Format->getFormatIdx() - 1, 224 HasVAListArg ? 0 : Format->getFirstArg() - 1); 225 } 226 } 227 228 for (const NonNullAttr *NonNull = FDecl->getAttr<NonNullAttr>(); NonNull; 229 NonNull = NonNull->getNext<NonNullAttr>()) 230 CheckNonNullArguments(NonNull, TheCall); 231 232 return false; 233} 234 235bool Sema::CheckBlockCall(NamedDecl *NDecl, CallExpr *TheCall) { 236 // Printf checking. 237 const FormatAttr *Format = NDecl->getAttr<FormatAttr>(); 238 if (!Format) 239 return false; 240 241 const VarDecl *V = dyn_cast<VarDecl>(NDecl); 242 if (!V) 243 return false; 244 245 QualType Ty = V->getType(); 246 if (!Ty->isBlockPointerType()) 247 return false; 248 249 if (!CheckablePrintfAttr(Format, TheCall)) 250 return false; 251 252 bool HasVAListArg = Format->getFirstArg() == 0; 253 CheckPrintfArguments(TheCall, HasVAListArg, Format->getFormatIdx() - 1, 254 HasVAListArg ? 0 : Format->getFirstArg() - 1); 255 256 return false; 257} 258 259/// SemaBuiltinAtomicOverloaded - We have a call to a function like 260/// __sync_fetch_and_add, which is an overloaded function based on the pointer 261/// type of its first argument. The main ActOnCallExpr routines have already 262/// promoted the types of arguments because all of these calls are prototyped as 263/// void(...). 264/// 265/// This function goes through and does final semantic checking for these 266/// builtins, 267bool Sema::SemaBuiltinAtomicOverloaded(CallExpr *TheCall) { 268 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts()); 269 FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl()); 270 271 // Ensure that we have at least one argument to do type inference from. 272 if (TheCall->getNumArgs() < 1) 273 return Diag(TheCall->getLocEnd(), 274 diag::err_typecheck_call_too_few_args_at_least) 275 << 0 << 1 << TheCall->getNumArgs() 276 << TheCall->getCallee()->getSourceRange(); 277 278 // Inspect the first argument of the atomic builtin. This should always be 279 // a pointer type, whose element is an integral scalar or pointer type. 280 // Because it is a pointer type, we don't have to worry about any implicit 281 // casts here. 282 Expr *FirstArg = TheCall->getArg(0); 283 if (!FirstArg->getType()->isPointerType()) 284 return Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer) 285 << FirstArg->getType() << FirstArg->getSourceRange(); 286 287 QualType ValType = FirstArg->getType()->getAs<PointerType>()->getPointeeType(); 288 if (!ValType->isIntegerType() && !ValType->isPointerType() && 289 !ValType->isBlockPointerType()) 290 return Diag(DRE->getLocStart(), 291 diag::err_atomic_builtin_must_be_pointer_intptr) 292 << FirstArg->getType() << FirstArg->getSourceRange(); 293 294 // We need to figure out which concrete builtin this maps onto. For example, 295 // __sync_fetch_and_add with a 2 byte object turns into 296 // __sync_fetch_and_add_2. 297#define BUILTIN_ROW(x) \ 298 { Builtin::BI##x##_1, Builtin::BI##x##_2, Builtin::BI##x##_4, \ 299 Builtin::BI##x##_8, Builtin::BI##x##_16 } 300 301 static const unsigned BuiltinIndices[][5] = { 302 BUILTIN_ROW(__sync_fetch_and_add), 303 BUILTIN_ROW(__sync_fetch_and_sub), 304 BUILTIN_ROW(__sync_fetch_and_or), 305 BUILTIN_ROW(__sync_fetch_and_and), 306 BUILTIN_ROW(__sync_fetch_and_xor), 307 308 BUILTIN_ROW(__sync_add_and_fetch), 309 BUILTIN_ROW(__sync_sub_and_fetch), 310 BUILTIN_ROW(__sync_and_and_fetch), 311 BUILTIN_ROW(__sync_or_and_fetch), 312 BUILTIN_ROW(__sync_xor_and_fetch), 313 314 BUILTIN_ROW(__sync_val_compare_and_swap), 315 BUILTIN_ROW(__sync_bool_compare_and_swap), 316 BUILTIN_ROW(__sync_lock_test_and_set), 317 BUILTIN_ROW(__sync_lock_release) 318 }; 319#undef BUILTIN_ROW 320 321 // Determine the index of the size. 322 unsigned SizeIndex; 323 switch (Context.getTypeSizeInChars(ValType).getQuantity()) { 324 case 1: SizeIndex = 0; break; 325 case 2: SizeIndex = 1; break; 326 case 4: SizeIndex = 2; break; 327 case 8: SizeIndex = 3; break; 328 case 16: SizeIndex = 4; break; 329 default: 330 return Diag(DRE->getLocStart(), diag::err_atomic_builtin_pointer_size) 331 << FirstArg->getType() << FirstArg->getSourceRange(); 332 } 333 334 // Each of these builtins has one pointer argument, followed by some number of 335 // values (0, 1 or 2) followed by a potentially empty varags list of stuff 336 // that we ignore. Find out which row of BuiltinIndices to read from as well 337 // as the number of fixed args. 338 unsigned BuiltinID = FDecl->getBuiltinID(); 339 unsigned BuiltinIndex, NumFixed = 1; 340 switch (BuiltinID) { 341 default: assert(0 && "Unknown overloaded atomic builtin!"); 342 case Builtin::BI__sync_fetch_and_add: BuiltinIndex = 0; break; 343 case Builtin::BI__sync_fetch_and_sub: BuiltinIndex = 1; break; 344 case Builtin::BI__sync_fetch_and_or: BuiltinIndex = 2; break; 345 case Builtin::BI__sync_fetch_and_and: BuiltinIndex = 3; break; 346 case Builtin::BI__sync_fetch_and_xor: BuiltinIndex = 4; break; 347 348 case Builtin::BI__sync_add_and_fetch: BuiltinIndex = 5; break; 349 case Builtin::BI__sync_sub_and_fetch: BuiltinIndex = 6; break; 350 case Builtin::BI__sync_and_and_fetch: BuiltinIndex = 7; break; 351 case Builtin::BI__sync_or_and_fetch: BuiltinIndex = 8; break; 352 case Builtin::BI__sync_xor_and_fetch: BuiltinIndex = 9; break; 353 354 case Builtin::BI__sync_val_compare_and_swap: 355 BuiltinIndex = 10; 356 NumFixed = 2; 357 break; 358 case Builtin::BI__sync_bool_compare_and_swap: 359 BuiltinIndex = 11; 360 NumFixed = 2; 361 break; 362 case Builtin::BI__sync_lock_test_and_set: BuiltinIndex = 12; break; 363 case Builtin::BI__sync_lock_release: 364 BuiltinIndex = 13; 365 NumFixed = 0; 366 break; 367 } 368 369 // Now that we know how many fixed arguments we expect, first check that we 370 // have at least that many. 371 if (TheCall->getNumArgs() < 1+NumFixed) 372 return Diag(TheCall->getLocEnd(), 373 diag::err_typecheck_call_too_few_args_at_least) 374 << 0 << 1+NumFixed << TheCall->getNumArgs() 375 << TheCall->getCallee()->getSourceRange(); 376 377 378 // Get the decl for the concrete builtin from this, we can tell what the 379 // concrete integer type we should convert to is. 380 unsigned NewBuiltinID = BuiltinIndices[BuiltinIndex][SizeIndex]; 381 const char *NewBuiltinName = Context.BuiltinInfo.GetName(NewBuiltinID); 382 IdentifierInfo *NewBuiltinII = PP.getIdentifierInfo(NewBuiltinName); 383 FunctionDecl *NewBuiltinDecl = 384 cast<FunctionDecl>(LazilyCreateBuiltin(NewBuiltinII, NewBuiltinID, 385 TUScope, false, DRE->getLocStart())); 386 const FunctionProtoType *BuiltinFT = 387 NewBuiltinDecl->getType()->getAs<FunctionProtoType>(); 388 ValType = BuiltinFT->getArgType(0)->getAs<PointerType>()->getPointeeType(); 389 390 // If the first type needs to be converted (e.g. void** -> int*), do it now. 391 if (BuiltinFT->getArgType(0) != FirstArg->getType()) { 392 ImpCastExprToType(FirstArg, BuiltinFT->getArgType(0), CastExpr::CK_BitCast); 393 TheCall->setArg(0, FirstArg); 394 } 395 396 // Next, walk the valid ones promoting to the right type. 397 for (unsigned i = 0; i != NumFixed; ++i) { 398 Expr *Arg = TheCall->getArg(i+1); 399 400 // If the argument is an implicit cast, then there was a promotion due to 401 // "...", just remove it now. 402 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg)) { 403 Arg = ICE->getSubExpr(); 404 ICE->setSubExpr(0); 405 ICE->Destroy(Context); 406 TheCall->setArg(i+1, Arg); 407 } 408 409 // GCC does an implicit conversion to the pointer or integer ValType. This 410 // can fail in some cases (1i -> int**), check for this error case now. 411 CastExpr::CastKind Kind = CastExpr::CK_Unknown; 412 CXXMethodDecl *ConversionDecl = 0; 413 if (CheckCastTypes(Arg->getSourceRange(), ValType, Arg, Kind, 414 ConversionDecl)) 415 return true; 416 417 // Okay, we have something that *can* be converted to the right type. Check 418 // to see if there is a potentially weird extension going on here. This can 419 // happen when you do an atomic operation on something like an char* and 420 // pass in 42. The 42 gets converted to char. This is even more strange 421 // for things like 45.123 -> char, etc. 422 // FIXME: Do this check. 423 ImpCastExprToType(Arg, ValType, Kind, /*isLvalue=*/false); 424 TheCall->setArg(i+1, Arg); 425 } 426 427 // Switch the DeclRefExpr to refer to the new decl. 428 DRE->setDecl(NewBuiltinDecl); 429 DRE->setType(NewBuiltinDecl->getType()); 430 431 // Set the callee in the CallExpr. 432 // FIXME: This leaks the original parens and implicit casts. 433 Expr *PromotedCall = DRE; 434 UsualUnaryConversions(PromotedCall); 435 TheCall->setCallee(PromotedCall); 436 437 438 // Change the result type of the call to match the result type of the decl. 439 TheCall->setType(NewBuiltinDecl->getResultType()); 440 return false; 441} 442 443 444/// CheckObjCString - Checks that the argument to the builtin 445/// CFString constructor is correct 446/// FIXME: GCC currently emits the following warning: 447/// "warning: input conversion stopped due to an input byte that does not 448/// belong to the input codeset UTF-8" 449/// Note: It might also make sense to do the UTF-16 conversion here (would 450/// simplify the backend). 451bool Sema::CheckObjCString(Expr *Arg) { 452 Arg = Arg->IgnoreParenCasts(); 453 StringLiteral *Literal = dyn_cast<StringLiteral>(Arg); 454 455 if (!Literal || Literal->isWide()) { 456 Diag(Arg->getLocStart(), diag::err_cfstring_literal_not_string_constant) 457 << Arg->getSourceRange(); 458 return true; 459 } 460 461 const char *Data = Literal->getStrData(); 462 unsigned Length = Literal->getByteLength(); 463 464 for (unsigned i = 0; i < Length; ++i) { 465 if (!Data[i]) { 466 Diag(getLocationOfStringLiteralByte(Literal, i), 467 diag::warn_cfstring_literal_contains_nul_character) 468 << Arg->getSourceRange(); 469 break; 470 } 471 } 472 473 return false; 474} 475 476/// SemaBuiltinVAStart - Check the arguments to __builtin_va_start for validity. 477/// Emit an error and return true on failure, return false on success. 478bool Sema::SemaBuiltinVAStart(CallExpr *TheCall) { 479 Expr *Fn = TheCall->getCallee(); 480 if (TheCall->getNumArgs() > 2) { 481 Diag(TheCall->getArg(2)->getLocStart(), 482 diag::err_typecheck_call_too_many_args) 483 << 0 /*function call*/ << 2 << TheCall->getNumArgs() 484 << Fn->getSourceRange() 485 << SourceRange(TheCall->getArg(2)->getLocStart(), 486 (*(TheCall->arg_end()-1))->getLocEnd()); 487 return true; 488 } 489 490 if (TheCall->getNumArgs() < 2) { 491 return Diag(TheCall->getLocEnd(), 492 diag::err_typecheck_call_too_few_args_at_least) 493 << 0 /*function call*/ << 2 << TheCall->getNumArgs(); 494 } 495 496 // Determine whether the current function is variadic or not. 497 BlockScopeInfo *CurBlock = getCurBlock(); 498 bool isVariadic; 499 if (CurBlock) 500 isVariadic = CurBlock->isVariadic; 501 else if (getCurFunctionDecl()) { 502 if (FunctionProtoType* FTP = 503 dyn_cast<FunctionProtoType>(getCurFunctionDecl()->getType())) 504 isVariadic = FTP->isVariadic(); 505 else 506 isVariadic = false; 507 } else { 508 isVariadic = getCurMethodDecl()->isVariadic(); 509 } 510 511 if (!isVariadic) { 512 Diag(Fn->getLocStart(), diag::err_va_start_used_in_non_variadic_function); 513 return true; 514 } 515 516 // Verify that the second argument to the builtin is the last argument of the 517 // current function or method. 518 bool SecondArgIsLastNamedArgument = false; 519 const Expr *Arg = TheCall->getArg(1)->IgnoreParenCasts(); 520 521 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Arg)) { 522 if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(DR->getDecl())) { 523 // FIXME: This isn't correct for methods (results in bogus warning). 524 // Get the last formal in the current function. 525 const ParmVarDecl *LastArg; 526 if (CurBlock) 527 LastArg = *(CurBlock->TheDecl->param_end()-1); 528 else if (FunctionDecl *FD = getCurFunctionDecl()) 529 LastArg = *(FD->param_end()-1); 530 else 531 LastArg = *(getCurMethodDecl()->param_end()-1); 532 SecondArgIsLastNamedArgument = PV == LastArg; 533 } 534 } 535 536 if (!SecondArgIsLastNamedArgument) 537 Diag(TheCall->getArg(1)->getLocStart(), 538 diag::warn_second_parameter_of_va_start_not_last_named_argument); 539 return false; 540} 541 542/// SemaBuiltinUnorderedCompare - Handle functions like __builtin_isgreater and 543/// friends. This is declared to take (...), so we have to check everything. 544bool Sema::SemaBuiltinUnorderedCompare(CallExpr *TheCall) { 545 if (TheCall->getNumArgs() < 2) 546 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args) 547 << 0 << 2 << TheCall->getNumArgs()/*function call*/; 548 if (TheCall->getNumArgs() > 2) 549 return Diag(TheCall->getArg(2)->getLocStart(), 550 diag::err_typecheck_call_too_many_args) 551 << 0 /*function call*/ << 2 << TheCall->getNumArgs() 552 << SourceRange(TheCall->getArg(2)->getLocStart(), 553 (*(TheCall->arg_end()-1))->getLocEnd()); 554 555 Expr *OrigArg0 = TheCall->getArg(0); 556 Expr *OrigArg1 = TheCall->getArg(1); 557 558 // Do standard promotions between the two arguments, returning their common 559 // type. 560 QualType Res = UsualArithmeticConversions(OrigArg0, OrigArg1, false); 561 562 // Make sure any conversions are pushed back into the call; this is 563 // type safe since unordered compare builtins are declared as "_Bool 564 // foo(...)". 565 TheCall->setArg(0, OrigArg0); 566 TheCall->setArg(1, OrigArg1); 567 568 if (OrigArg0->isTypeDependent() || OrigArg1->isTypeDependent()) 569 return false; 570 571 // If the common type isn't a real floating type, then the arguments were 572 // invalid for this operation. 573 if (!Res->isRealFloatingType()) 574 return Diag(OrigArg0->getLocStart(), 575 diag::err_typecheck_call_invalid_ordered_compare) 576 << OrigArg0->getType() << OrigArg1->getType() 577 << SourceRange(OrigArg0->getLocStart(), OrigArg1->getLocEnd()); 578 579 return false; 580} 581 582/// SemaBuiltinSemaBuiltinFPClassification - Handle functions like 583/// __builtin_isnan and friends. This is declared to take (...), so we have 584/// to check everything. We expect the last argument to be a floating point 585/// value. 586bool Sema::SemaBuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs) { 587 if (TheCall->getNumArgs() < NumArgs) 588 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args) 589 << 0 << NumArgs << TheCall->getNumArgs()/*function call*/; 590 if (TheCall->getNumArgs() > NumArgs) 591 return Diag(TheCall->getArg(NumArgs)->getLocStart(), 592 diag::err_typecheck_call_too_many_args) 593 << 0 /*function call*/ << NumArgs << TheCall->getNumArgs() 594 << SourceRange(TheCall->getArg(NumArgs)->getLocStart(), 595 (*(TheCall->arg_end()-1))->getLocEnd()); 596 597 Expr *OrigArg = TheCall->getArg(NumArgs-1); 598 599 if (OrigArg->isTypeDependent()) 600 return false; 601 602 // This operation requires a floating-point number 603 if (!OrigArg->getType()->isRealFloatingType()) 604 return Diag(OrigArg->getLocStart(), 605 diag::err_typecheck_call_invalid_unary_fp) 606 << OrigArg->getType() << OrigArg->getSourceRange(); 607 608 return false; 609} 610 611bool Sema::SemaBuiltinStackAddress(CallExpr *TheCall) { 612 // The signature for these builtins is exact; the only thing we need 613 // to check is that the argument is a constant. 614 SourceLocation Loc; 615 if (!TheCall->getArg(0)->isTypeDependent() && 616 !TheCall->getArg(0)->isValueDependent() && 617 !TheCall->getArg(0)->isIntegerConstantExpr(Context, &Loc)) 618 return Diag(Loc, diag::err_stack_const_level) << TheCall->getSourceRange(); 619 620 return false; 621} 622 623/// SemaBuiltinShuffleVector - Handle __builtin_shufflevector. 624// This is declared to take (...), so we have to check everything. 625Action::OwningExprResult Sema::SemaBuiltinShuffleVector(CallExpr *TheCall) { 626 if (TheCall->getNumArgs() < 3) 627 return ExprError(Diag(TheCall->getLocEnd(), 628 diag::err_typecheck_call_too_few_args_at_least) 629 << 0 /*function call*/ << 3 << TheCall->getNumArgs() 630 << TheCall->getSourceRange()); 631 632 unsigned numElements = std::numeric_limits<unsigned>::max(); 633 if (!TheCall->getArg(0)->isTypeDependent() && 634 !TheCall->getArg(1)->isTypeDependent()) { 635 QualType FAType = TheCall->getArg(0)->getType(); 636 QualType SAType = TheCall->getArg(1)->getType(); 637 638 if (!FAType->isVectorType() || !SAType->isVectorType()) { 639 Diag(TheCall->getLocStart(), diag::err_shufflevector_non_vector) 640 << SourceRange(TheCall->getArg(0)->getLocStart(), 641 TheCall->getArg(1)->getLocEnd()); 642 return ExprError(); 643 } 644 645 if (!Context.hasSameUnqualifiedType(FAType, SAType)) { 646 Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector) 647 << SourceRange(TheCall->getArg(0)->getLocStart(), 648 TheCall->getArg(1)->getLocEnd()); 649 return ExprError(); 650 } 651 652 numElements = FAType->getAs<VectorType>()->getNumElements(); 653 if (TheCall->getNumArgs() != numElements+2) { 654 if (TheCall->getNumArgs() < numElements+2) 655 return ExprError(Diag(TheCall->getLocEnd(), 656 diag::err_typecheck_call_too_few_args) 657 << 0 /*function call*/ 658 << numElements+2 << TheCall->getNumArgs() 659 << TheCall->getSourceRange()); 660 return ExprError(Diag(TheCall->getLocEnd(), 661 diag::err_typecheck_call_too_many_args) 662 << 0 /*function call*/ 663 << numElements+2 << TheCall->getNumArgs() 664 << TheCall->getSourceRange()); 665 } 666 } 667 668 for (unsigned i = 2; i < TheCall->getNumArgs(); i++) { 669 if (TheCall->getArg(i)->isTypeDependent() || 670 TheCall->getArg(i)->isValueDependent()) 671 continue; 672 673 llvm::APSInt Result(32); 674 if (!TheCall->getArg(i)->isIntegerConstantExpr(Result, Context)) 675 return ExprError(Diag(TheCall->getLocStart(), 676 diag::err_shufflevector_nonconstant_argument) 677 << TheCall->getArg(i)->getSourceRange()); 678 679 if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2) 680 return ExprError(Diag(TheCall->getLocStart(), 681 diag::err_shufflevector_argument_too_large) 682 << TheCall->getArg(i)->getSourceRange()); 683 } 684 685 llvm::SmallVector<Expr*, 32> exprs; 686 687 for (unsigned i = 0, e = TheCall->getNumArgs(); i != e; i++) { 688 exprs.push_back(TheCall->getArg(i)); 689 TheCall->setArg(i, 0); 690 } 691 692 return Owned(new (Context) ShuffleVectorExpr(Context, exprs.begin(), 693 exprs.size(), exprs[0]->getType(), 694 TheCall->getCallee()->getLocStart(), 695 TheCall->getRParenLoc())); 696} 697 698/// SemaBuiltinPrefetch - Handle __builtin_prefetch. 699// This is declared to take (const void*, ...) and can take two 700// optional constant int args. 701bool Sema::SemaBuiltinPrefetch(CallExpr *TheCall) { 702 unsigned NumArgs = TheCall->getNumArgs(); 703 704 if (NumArgs > 3) 705 return Diag(TheCall->getLocEnd(), 706 diag::err_typecheck_call_too_many_args_at_most) 707 << 0 /*function call*/ << 3 << NumArgs 708 << TheCall->getSourceRange(); 709 710 // Argument 0 is checked for us and the remaining arguments must be 711 // constant integers. 712 for (unsigned i = 1; i != NumArgs; ++i) { 713 Expr *Arg = TheCall->getArg(i); 714 if (Arg->isTypeDependent()) 715 continue; 716 717 if (!Arg->getType()->isIntegralType()) 718 return Diag(TheCall->getLocStart(), diag::err_prefetch_invalid_arg_type) 719 << Arg->getSourceRange(); 720 721 ImpCastExprToType(Arg, Context.IntTy, CastExpr::CK_IntegralCast); 722 TheCall->setArg(i, Arg); 723 724 if (Arg->isValueDependent()) 725 continue; 726 727 llvm::APSInt Result; 728 if (!Arg->isIntegerConstantExpr(Result, Context)) 729 return Diag(TheCall->getLocStart(), diag::err_prefetch_invalid_arg_ice) 730 << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 731 732 // FIXME: gcc issues a warning and rewrites these to 0. These 733 // seems especially odd for the third argument since the default 734 // is 3. 735 if (i == 1) { 736 if (Result.getLimitedValue() > 1) 737 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 738 << "0" << "1" << Arg->getSourceRange(); 739 } else { 740 if (Result.getLimitedValue() > 3) 741 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 742 << "0" << "3" << Arg->getSourceRange(); 743 } 744 } 745 746 return false; 747} 748 749/// SemaBuiltinEHReturnDataRegNo - Handle __builtin_eh_return_data_regno, the 750/// operand must be an integer constant. 751bool Sema::SemaBuiltinEHReturnDataRegNo(CallExpr *TheCall) { 752 llvm::APSInt Result; 753 if (!TheCall->getArg(0)->isIntegerConstantExpr(Result, Context)) 754 return Diag(TheCall->getLocStart(), diag::err_expr_not_ice) 755 << TheCall->getArg(0)->getSourceRange(); 756 757 return false; 758} 759 760 761/// SemaBuiltinObjectSize - Handle __builtin_object_size(void *ptr, 762/// int type). This simply type checks that type is one of the defined 763/// constants (0-3). 764// For compatability check 0-3, llvm only handles 0 and 2. 765bool Sema::SemaBuiltinObjectSize(CallExpr *TheCall) { 766 Expr *Arg = TheCall->getArg(1); 767 if (Arg->isTypeDependent()) 768 return false; 769 770 QualType ArgType = Arg->getType(); 771 const BuiltinType *BT = ArgType->getAs<BuiltinType>(); 772 llvm::APSInt Result(32); 773 if (!BT || BT->getKind() != BuiltinType::Int) 774 return Diag(TheCall->getLocStart(), diag::err_object_size_invalid_argument) 775 << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 776 777 if (Arg->isValueDependent()) 778 return false; 779 780 if (!Arg->isIntegerConstantExpr(Result, Context)) { 781 return Diag(TheCall->getLocStart(), diag::err_object_size_invalid_argument) 782 << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 783 } 784 785 if (Result.getSExtValue() < 0 || Result.getSExtValue() > 3) { 786 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 787 << "0" << "3" << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 788 } 789 790 return false; 791} 792 793/// SemaBuiltinLongjmp - Handle __builtin_longjmp(void *env[5], int val). 794/// This checks that val is a constant 1. 795bool Sema::SemaBuiltinLongjmp(CallExpr *TheCall) { 796 Expr *Arg = TheCall->getArg(1); 797 if (Arg->isTypeDependent() || Arg->isValueDependent()) 798 return false; 799 800 llvm::APSInt Result(32); 801 if (!Arg->isIntegerConstantExpr(Result, Context) || Result != 1) 802 return Diag(TheCall->getLocStart(), diag::err_builtin_longjmp_invalid_val) 803 << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 804 805 return false; 806} 807 808// Handle i > 1 ? "x" : "y", recursivelly 809bool Sema::SemaCheckStringLiteral(const Expr *E, const CallExpr *TheCall, 810 bool HasVAListArg, 811 unsigned format_idx, unsigned firstDataArg) { 812 if (E->isTypeDependent() || E->isValueDependent()) 813 return false; 814 815 switch (E->getStmtClass()) { 816 case Stmt::ConditionalOperatorClass: { 817 const ConditionalOperator *C = cast<ConditionalOperator>(E); 818 return SemaCheckStringLiteral(C->getTrueExpr(), TheCall, 819 HasVAListArg, format_idx, firstDataArg) 820 && SemaCheckStringLiteral(C->getRHS(), TheCall, 821 HasVAListArg, format_idx, firstDataArg); 822 } 823 824 case Stmt::ImplicitCastExprClass: { 825 const ImplicitCastExpr *Expr = cast<ImplicitCastExpr>(E); 826 return SemaCheckStringLiteral(Expr->getSubExpr(), TheCall, HasVAListArg, 827 format_idx, firstDataArg); 828 } 829 830 case Stmt::ParenExprClass: { 831 const ParenExpr *Expr = cast<ParenExpr>(E); 832 return SemaCheckStringLiteral(Expr->getSubExpr(), TheCall, HasVAListArg, 833 format_idx, firstDataArg); 834 } 835 836 case Stmt::DeclRefExprClass: { 837 const DeclRefExpr *DR = cast<DeclRefExpr>(E); 838 839 // As an exception, do not flag errors for variables binding to 840 // const string literals. 841 if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) { 842 bool isConstant = false; 843 QualType T = DR->getType(); 844 845 if (const ArrayType *AT = Context.getAsArrayType(T)) { 846 isConstant = AT->getElementType().isConstant(Context); 847 } else if (const PointerType *PT = T->getAs<PointerType>()) { 848 isConstant = T.isConstant(Context) && 849 PT->getPointeeType().isConstant(Context); 850 } 851 852 if (isConstant) { 853 if (const Expr *Init = VD->getAnyInitializer()) 854 return SemaCheckStringLiteral(Init, TheCall, 855 HasVAListArg, format_idx, firstDataArg); 856 } 857 858 // For vprintf* functions (i.e., HasVAListArg==true), we add a 859 // special check to see if the format string is a function parameter 860 // of the function calling the printf function. If the function 861 // has an attribute indicating it is a printf-like function, then we 862 // should suppress warnings concerning non-literals being used in a call 863 // to a vprintf function. For example: 864 // 865 // void 866 // logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...){ 867 // va_list ap; 868 // va_start(ap, fmt); 869 // vprintf(fmt, ap); // Do NOT emit a warning about "fmt". 870 // ... 871 // 872 // 873 // FIXME: We don't have full attribute support yet, so just check to see 874 // if the argument is a DeclRefExpr that references a parameter. We'll 875 // add proper support for checking the attribute later. 876 if (HasVAListArg) 877 if (isa<ParmVarDecl>(VD)) 878 return true; 879 } 880 881 return false; 882 } 883 884 case Stmt::CallExprClass: { 885 const CallExpr *CE = cast<CallExpr>(E); 886 if (const ImplicitCastExpr *ICE 887 = dyn_cast<ImplicitCastExpr>(CE->getCallee())) { 888 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) { 889 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DRE->getDecl())) { 890 if (const FormatArgAttr *FA = FD->getAttr<FormatArgAttr>()) { 891 unsigned ArgIndex = FA->getFormatIdx(); 892 const Expr *Arg = CE->getArg(ArgIndex - 1); 893 894 return SemaCheckStringLiteral(Arg, TheCall, HasVAListArg, 895 format_idx, firstDataArg); 896 } 897 } 898 } 899 } 900 901 return false; 902 } 903 case Stmt::ObjCStringLiteralClass: 904 case Stmt::StringLiteralClass: { 905 const StringLiteral *StrE = NULL; 906 907 if (const ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(E)) 908 StrE = ObjCFExpr->getString(); 909 else 910 StrE = cast<StringLiteral>(E); 911 912 if (StrE) { 913 CheckPrintfString(StrE, E, TheCall, HasVAListArg, format_idx, 914 firstDataArg); 915 return true; 916 } 917 918 return false; 919 } 920 921 default: 922 return false; 923 } 924} 925 926void 927Sema::CheckNonNullArguments(const NonNullAttr *NonNull, 928 const CallExpr *TheCall) { 929 for (NonNullAttr::iterator i = NonNull->begin(), e = NonNull->end(); 930 i != e; ++i) { 931 const Expr *ArgExpr = TheCall->getArg(*i); 932 if (ArgExpr->isNullPointerConstant(Context, 933 Expr::NPC_ValueDependentIsNotNull)) 934 Diag(TheCall->getCallee()->getLocStart(), diag::warn_null_arg) 935 << ArgExpr->getSourceRange(); 936 } 937} 938 939/// CheckPrintfArguments - Check calls to printf (and similar functions) for 940/// correct use of format strings. 941/// 942/// HasVAListArg - A predicate indicating whether the printf-like 943/// function is passed an explicit va_arg argument (e.g., vprintf) 944/// 945/// format_idx - The index into Args for the format string. 946/// 947/// Improper format strings to functions in the printf family can be 948/// the source of bizarre bugs and very serious security holes. A 949/// good source of information is available in the following paper 950/// (which includes additional references): 951/// 952/// FormatGuard: Automatic Protection From printf Format String 953/// Vulnerabilities, Proceedings of the 10th USENIX Security Symposium, 2001. 954/// 955/// TODO: 956/// Functionality implemented: 957/// 958/// We can statically check the following properties for string 959/// literal format strings for non v.*printf functions (where the 960/// arguments are passed directly): 961// 962/// (1) Are the number of format conversions equal to the number of 963/// data arguments? 964/// 965/// (2) Does each format conversion correctly match the type of the 966/// corresponding data argument? 967/// 968/// Moreover, for all printf functions we can: 969/// 970/// (3) Check for a missing format string (when not caught by type checking). 971/// 972/// (4) Check for no-operation flags; e.g. using "#" with format 973/// conversion 'c' (TODO) 974/// 975/// (5) Check the use of '%n', a major source of security holes. 976/// 977/// (6) Check for malformed format conversions that don't specify anything. 978/// 979/// (7) Check for empty format strings. e.g: printf(""); 980/// 981/// (8) Check that the format string is a wide literal. 982/// 983/// All of these checks can be done by parsing the format string. 984/// 985void 986Sema::CheckPrintfArguments(const CallExpr *TheCall, bool HasVAListArg, 987 unsigned format_idx, unsigned firstDataArg) { 988 const Expr *Fn = TheCall->getCallee(); 989 990 // The way the format attribute works in GCC, the implicit this argument 991 // of member functions is counted. However, it doesn't appear in our own 992 // lists, so decrement format_idx in that case. 993 if (isa<CXXMemberCallExpr>(TheCall)) { 994 // Catch a format attribute mistakenly referring to the object argument. 995 if (format_idx == 0) 996 return; 997 --format_idx; 998 if(firstDataArg != 0) 999 --firstDataArg; 1000 } 1001 1002 // CHECK: printf-like function is called with no format string. 1003 if (format_idx >= TheCall->getNumArgs()) { 1004 Diag(TheCall->getRParenLoc(), diag::warn_printf_missing_format_string) 1005 << Fn->getSourceRange(); 1006 return; 1007 } 1008 1009 const Expr *OrigFormatExpr = TheCall->getArg(format_idx)->IgnoreParenCasts(); 1010 1011 // CHECK: format string is not a string literal. 1012 // 1013 // Dynamically generated format strings are difficult to 1014 // automatically vet at compile time. Requiring that format strings 1015 // are string literals: (1) permits the checking of format strings by 1016 // the compiler and thereby (2) can practically remove the source of 1017 // many format string exploits. 1018 1019 // Format string can be either ObjC string (e.g. @"%d") or 1020 // C string (e.g. "%d") 1021 // ObjC string uses the same format specifiers as C string, so we can use 1022 // the same format string checking logic for both ObjC and C strings. 1023 if (SemaCheckStringLiteral(OrigFormatExpr, TheCall, HasVAListArg, format_idx, 1024 firstDataArg)) 1025 return; // Literal format string found, check done! 1026 1027 // If there are no arguments specified, warn with -Wformat-security, otherwise 1028 // warn only with -Wformat-nonliteral. 1029 if (TheCall->getNumArgs() == format_idx+1) 1030 Diag(TheCall->getArg(format_idx)->getLocStart(), 1031 diag::warn_printf_nonliteral_noargs) 1032 << OrigFormatExpr->getSourceRange(); 1033 else 1034 Diag(TheCall->getArg(format_idx)->getLocStart(), 1035 diag::warn_printf_nonliteral) 1036 << OrigFormatExpr->getSourceRange(); 1037} 1038 1039namespace { 1040class CheckPrintfHandler : public analyze_printf::FormatStringHandler { 1041 Sema &S; 1042 const StringLiteral *FExpr; 1043 const Expr *OrigFormatExpr; 1044 const unsigned FirstDataArg; 1045 const unsigned NumDataArgs; 1046 const bool IsObjCLiteral; 1047 const char *Beg; // Start of format string. 1048 const bool HasVAListArg; 1049 const CallExpr *TheCall; 1050 unsigned FormatIdx; 1051 llvm::BitVector CoveredArgs; 1052 bool usesPositionalArgs; 1053 bool atFirstArg; 1054public: 1055 CheckPrintfHandler(Sema &s, const StringLiteral *fexpr, 1056 const Expr *origFormatExpr, unsigned firstDataArg, 1057 unsigned numDataArgs, bool isObjCLiteral, 1058 const char *beg, bool hasVAListArg, 1059 const CallExpr *theCall, unsigned formatIdx) 1060 : S(s), FExpr(fexpr), OrigFormatExpr(origFormatExpr), 1061 FirstDataArg(firstDataArg), 1062 NumDataArgs(numDataArgs), 1063 IsObjCLiteral(isObjCLiteral), Beg(beg), 1064 HasVAListArg(hasVAListArg), 1065 TheCall(theCall), FormatIdx(formatIdx), 1066 usesPositionalArgs(false), atFirstArg(true) { 1067 CoveredArgs.resize(numDataArgs); 1068 CoveredArgs.reset(); 1069 } 1070 1071 void DoneProcessing(); 1072 1073 void HandleIncompleteFormatSpecifier(const char *startSpecifier, 1074 unsigned specifierLen); 1075 1076 bool 1077 HandleInvalidConversionSpecifier(const analyze_printf::FormatSpecifier &FS, 1078 const char *startSpecifier, 1079 unsigned specifierLen); 1080 1081 virtual void HandleInvalidPosition(const char *startSpecifier, 1082 unsigned specifierLen, 1083 analyze_printf::PositionContext p); 1084 1085 virtual void HandleZeroPosition(const char *startPos, unsigned posLen); 1086 1087 void HandleNullChar(const char *nullCharacter); 1088 1089 bool HandleFormatSpecifier(const analyze_printf::FormatSpecifier &FS, 1090 const char *startSpecifier, 1091 unsigned specifierLen); 1092private: 1093 SourceRange getFormatStringRange(); 1094 SourceRange getFormatSpecifierRange(const char *startSpecifier, 1095 unsigned specifierLen); 1096 SourceLocation getLocationOfByte(const char *x); 1097 1098 bool HandleAmount(const analyze_printf::OptionalAmount &Amt, unsigned k, 1099 const char *startSpecifier, unsigned specifierLen); 1100 void HandleFlags(const analyze_printf::FormatSpecifier &FS, 1101 llvm::StringRef flag, llvm::StringRef cspec, 1102 const char *startSpecifier, unsigned specifierLen); 1103 1104 const Expr *getDataArg(unsigned i) const; 1105}; 1106} 1107 1108SourceRange CheckPrintfHandler::getFormatStringRange() { 1109 return OrigFormatExpr->getSourceRange(); 1110} 1111 1112SourceRange CheckPrintfHandler:: 1113getFormatSpecifierRange(const char *startSpecifier, unsigned specifierLen) { 1114 return SourceRange(getLocationOfByte(startSpecifier), 1115 getLocationOfByte(startSpecifier+specifierLen-1)); 1116} 1117 1118SourceLocation CheckPrintfHandler::getLocationOfByte(const char *x) { 1119 return S.getLocationOfStringLiteralByte(FExpr, x - Beg); 1120} 1121 1122void CheckPrintfHandler:: 1123HandleIncompleteFormatSpecifier(const char *startSpecifier, 1124 unsigned specifierLen) { 1125 SourceLocation Loc = getLocationOfByte(startSpecifier); 1126 S.Diag(Loc, diag::warn_printf_incomplete_specifier) 1127 << getFormatSpecifierRange(startSpecifier, specifierLen); 1128} 1129 1130void 1131CheckPrintfHandler::HandleInvalidPosition(const char *startPos, unsigned posLen, 1132 analyze_printf::PositionContext p) { 1133 SourceLocation Loc = getLocationOfByte(startPos); 1134 S.Diag(Loc, diag::warn_printf_invalid_positional_specifier) 1135 << (unsigned) p << getFormatSpecifierRange(startPos, posLen); 1136} 1137 1138void CheckPrintfHandler::HandleZeroPosition(const char *startPos, 1139 unsigned posLen) { 1140 SourceLocation Loc = getLocationOfByte(startPos); 1141 S.Diag(Loc, diag::warn_printf_zero_positional_specifier) 1142 << getFormatSpecifierRange(startPos, posLen); 1143} 1144 1145bool CheckPrintfHandler:: 1146HandleInvalidConversionSpecifier(const analyze_printf::FormatSpecifier &FS, 1147 const char *startSpecifier, 1148 unsigned specifierLen) { 1149 1150 unsigned argIndex = FS.getArgIndex(); 1151 bool keepGoing = true; 1152 if (argIndex < NumDataArgs) { 1153 // Consider the argument coverered, even though the specifier doesn't 1154 // make sense. 1155 CoveredArgs.set(argIndex); 1156 } 1157 else { 1158 // If argIndex exceeds the number of data arguments we 1159 // don't issue a warning because that is just a cascade of warnings (and 1160 // they may have intended '%%' anyway). We don't want to continue processing 1161 // the format string after this point, however, as we will like just get 1162 // gibberish when trying to match arguments. 1163 keepGoing = false; 1164 } 1165 1166 const analyze_printf::ConversionSpecifier &CS = 1167 FS.getConversionSpecifier(); 1168 SourceLocation Loc = getLocationOfByte(CS.getStart()); 1169 S.Diag(Loc, diag::warn_printf_invalid_conversion) 1170 << llvm::StringRef(CS.getStart(), CS.getLength()) 1171 << getFormatSpecifierRange(startSpecifier, specifierLen); 1172 1173 return keepGoing; 1174} 1175 1176void CheckPrintfHandler::HandleNullChar(const char *nullCharacter) { 1177 // The presence of a null character is likely an error. 1178 S.Diag(getLocationOfByte(nullCharacter), 1179 diag::warn_printf_format_string_contains_null_char) 1180 << getFormatStringRange(); 1181} 1182 1183const Expr *CheckPrintfHandler::getDataArg(unsigned i) const { 1184 return TheCall->getArg(FirstDataArg + i); 1185} 1186 1187void CheckPrintfHandler::HandleFlags(const analyze_printf::FormatSpecifier &FS, 1188 llvm::StringRef flag, 1189 llvm::StringRef cspec, 1190 const char *startSpecifier, 1191 unsigned specifierLen) { 1192 const analyze_printf::ConversionSpecifier &CS = FS.getConversionSpecifier(); 1193 S.Diag(getLocationOfByte(CS.getStart()), diag::warn_printf_nonsensical_flag) 1194 << flag << cspec << getFormatSpecifierRange(startSpecifier, specifierLen); 1195} 1196 1197bool 1198CheckPrintfHandler::HandleAmount(const analyze_printf::OptionalAmount &Amt, 1199 unsigned k, const char *startSpecifier, 1200 unsigned specifierLen) { 1201 1202 if (Amt.hasDataArgument()) { 1203 if (!HasVAListArg) { 1204 unsigned argIndex = Amt.getArgIndex(); 1205 if (argIndex >= NumDataArgs) { 1206 S.Diag(getLocationOfByte(Amt.getStart()), 1207 diag::warn_printf_asterisk_missing_arg) 1208 << k << getFormatSpecifierRange(startSpecifier, specifierLen); 1209 // Don't do any more checking. We will just emit 1210 // spurious errors. 1211 return false; 1212 } 1213 1214 // Type check the data argument. It should be an 'int'. 1215 // Although not in conformance with C99, we also allow the argument to be 1216 // an 'unsigned int' as that is a reasonably safe case. GCC also 1217 // doesn't emit a warning for that case. 1218 CoveredArgs.set(argIndex); 1219 const Expr *Arg = getDataArg(argIndex); 1220 QualType T = Arg->getType(); 1221 1222 const analyze_printf::ArgTypeResult &ATR = Amt.getArgType(S.Context); 1223 assert(ATR.isValid()); 1224 1225 if (!ATR.matchesType(S.Context, T)) { 1226 S.Diag(getLocationOfByte(Amt.getStart()), 1227 diag::warn_printf_asterisk_wrong_type) 1228 << k 1229 << ATR.getRepresentativeType(S.Context) << T 1230 << getFormatSpecifierRange(startSpecifier, specifierLen) 1231 << Arg->getSourceRange(); 1232 // Don't do any more checking. We will just emit 1233 // spurious errors. 1234 return false; 1235 } 1236 } 1237 } 1238 return true; 1239} 1240 1241bool 1242CheckPrintfHandler::HandleFormatSpecifier(const analyze_printf::FormatSpecifier 1243 &FS, 1244 const char *startSpecifier, 1245 unsigned specifierLen) { 1246 1247 using namespace analyze_printf; 1248 const ConversionSpecifier &CS = FS.getConversionSpecifier(); 1249 1250 if (atFirstArg) { 1251 atFirstArg = false; 1252 usesPositionalArgs = FS.usesPositionalArg(); 1253 } 1254 else if (usesPositionalArgs != FS.usesPositionalArg()) { 1255 // Cannot mix-and-match positional and non-positional arguments. 1256 S.Diag(getLocationOfByte(CS.getStart()), 1257 diag::warn_printf_mix_positional_nonpositional_args) 1258 << getFormatSpecifierRange(startSpecifier, specifierLen); 1259 return false; 1260 } 1261 1262 // First check if the field width, precision, and conversion specifier 1263 // have matching data arguments. 1264 if (!HandleAmount(FS.getFieldWidth(), /* field width */ 0, 1265 startSpecifier, specifierLen)) { 1266 return false; 1267 } 1268 1269 if (!HandleAmount(FS.getPrecision(), /* precision */ 1, 1270 startSpecifier, specifierLen)) { 1271 return false; 1272 } 1273 1274 if (!CS.consumesDataArgument()) { 1275 // FIXME: Technically specifying a precision or field width here 1276 // makes no sense. Worth issuing a warning at some point. 1277 return true; 1278 } 1279 1280 // Consume the argument. 1281 unsigned argIndex = FS.getArgIndex(); 1282 if (argIndex < NumDataArgs) { 1283 // The check to see if the argIndex is valid will come later. 1284 // We set the bit here because we may exit early from this 1285 // function if we encounter some other error. 1286 CoveredArgs.set(argIndex); 1287 } 1288 1289 // Check for using an Objective-C specific conversion specifier 1290 // in a non-ObjC literal. 1291 if (!IsObjCLiteral && CS.isObjCArg()) { 1292 return HandleInvalidConversionSpecifier(FS, startSpecifier, specifierLen); 1293 } 1294 1295 // Are we using '%n'? Issue a warning about this being 1296 // a possible security issue. 1297 if (CS.getKind() == ConversionSpecifier::OutIntPtrArg) { 1298 S.Diag(getLocationOfByte(CS.getStart()), diag::warn_printf_write_back) 1299 << getFormatSpecifierRange(startSpecifier, specifierLen); 1300 // Continue checking the other format specifiers. 1301 return true; 1302 } 1303 1304 if (CS.getKind() == ConversionSpecifier::VoidPtrArg) { 1305 if (FS.getPrecision().getHowSpecified() != OptionalAmount::NotSpecified) 1306 S.Diag(getLocationOfByte(CS.getStart()), 1307 diag::warn_printf_nonsensical_precision) 1308 << CS.getCharacters() 1309 << getFormatSpecifierRange(startSpecifier, specifierLen); 1310 } 1311 if (CS.getKind() == ConversionSpecifier::VoidPtrArg || 1312 CS.getKind() == ConversionSpecifier::CStrArg) { 1313 // FIXME: Instead of using "0", "+", etc., eventually get them from 1314 // the FormatSpecifier. 1315 if (FS.hasLeadingZeros()) 1316 HandleFlags(FS, "0", CS.getCharacters(), startSpecifier, specifierLen); 1317 if (FS.hasPlusPrefix()) 1318 HandleFlags(FS, "+", CS.getCharacters(), startSpecifier, specifierLen); 1319 if (FS.hasSpacePrefix()) 1320 HandleFlags(FS, " ", CS.getCharacters(), startSpecifier, specifierLen); 1321 } 1322 1323 // The remaining checks depend on the data arguments. 1324 if (HasVAListArg) 1325 return true; 1326 1327 if (argIndex >= NumDataArgs) { 1328 if (FS.usesPositionalArg()) { 1329 S.Diag(getLocationOfByte(CS.getStart()), 1330 diag::warn_printf_positional_arg_exceeds_data_args) 1331 << (argIndex+1) << NumDataArgs 1332 << getFormatSpecifierRange(startSpecifier, specifierLen); 1333 } 1334 else { 1335 S.Diag(getLocationOfByte(CS.getStart()), 1336 diag::warn_printf_insufficient_data_args) 1337 << getFormatSpecifierRange(startSpecifier, specifierLen); 1338 } 1339 1340 // Don't do any more checking. 1341 return false; 1342 } 1343 1344 // Now type check the data expression that matches the 1345 // format specifier. 1346 const Expr *Ex = getDataArg(argIndex); 1347 const analyze_printf::ArgTypeResult &ATR = FS.getArgType(S.Context); 1348 if (ATR.isValid() && !ATR.matchesType(S.Context, Ex->getType())) { 1349 // Check if we didn't match because of an implicit cast from a 'char' 1350 // or 'short' to an 'int'. This is done because printf is a varargs 1351 // function. 1352 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Ex)) 1353 if (ICE->getType() == S.Context.IntTy) 1354 if (ATR.matchesType(S.Context, ICE->getSubExpr()->getType())) 1355 return true; 1356 1357 S.Diag(getLocationOfByte(CS.getStart()), 1358 diag::warn_printf_conversion_argument_type_mismatch) 1359 << ATR.getRepresentativeType(S.Context) << Ex->getType() 1360 << getFormatSpecifierRange(startSpecifier, specifierLen) 1361 << Ex->getSourceRange(); 1362 } 1363 1364 return true; 1365} 1366 1367void CheckPrintfHandler::DoneProcessing() { 1368 // Does the number of data arguments exceed the number of 1369 // format conversions in the format string? 1370 if (!HasVAListArg) { 1371 // Find any arguments that weren't covered. 1372 CoveredArgs.flip(); 1373 signed notCoveredArg = CoveredArgs.find_first(); 1374 if (notCoveredArg >= 0) { 1375 assert((unsigned)notCoveredArg < NumDataArgs); 1376 S.Diag(getDataArg((unsigned) notCoveredArg)->getLocStart(), 1377 diag::warn_printf_data_arg_not_used) 1378 << getFormatStringRange(); 1379 } 1380 } 1381} 1382 1383void Sema::CheckPrintfString(const StringLiteral *FExpr, 1384 const Expr *OrigFormatExpr, 1385 const CallExpr *TheCall, bool HasVAListArg, 1386 unsigned format_idx, unsigned firstDataArg) { 1387 1388 // CHECK: is the format string a wide literal? 1389 if (FExpr->isWide()) { 1390 Diag(FExpr->getLocStart(), 1391 diag::warn_printf_format_string_is_wide_literal) 1392 << OrigFormatExpr->getSourceRange(); 1393 return; 1394 } 1395 1396 // Str - The format string. NOTE: this is NOT null-terminated! 1397 const char *Str = FExpr->getStrData(); 1398 1399 // CHECK: empty format string? 1400 unsigned StrLen = FExpr->getByteLength(); 1401 1402 if (StrLen == 0) { 1403 Diag(FExpr->getLocStart(), diag::warn_printf_empty_format_string) 1404 << OrigFormatExpr->getSourceRange(); 1405 return; 1406 } 1407 1408 CheckPrintfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg, 1409 TheCall->getNumArgs() - firstDataArg, 1410 isa<ObjCStringLiteral>(OrigFormatExpr), Str, 1411 HasVAListArg, TheCall, format_idx); 1412 1413 if (!analyze_printf::ParseFormatString(H, Str, Str + StrLen)) 1414 H.DoneProcessing(); 1415} 1416 1417//===--- CHECK: Return Address of Stack Variable --------------------------===// 1418 1419static DeclRefExpr* EvalVal(Expr *E); 1420static DeclRefExpr* EvalAddr(Expr* E); 1421 1422/// CheckReturnStackAddr - Check if a return statement returns the address 1423/// of a stack variable. 1424void 1425Sema::CheckReturnStackAddr(Expr *RetValExp, QualType lhsType, 1426 SourceLocation ReturnLoc) { 1427 1428 // Perform checking for returned stack addresses. 1429 if (lhsType->isPointerType() || lhsType->isBlockPointerType()) { 1430 if (DeclRefExpr *DR = EvalAddr(RetValExp)) 1431 Diag(DR->getLocStart(), diag::warn_ret_stack_addr) 1432 << DR->getDecl()->getDeclName() << RetValExp->getSourceRange(); 1433 1434 // Skip over implicit cast expressions when checking for block expressions. 1435 RetValExp = RetValExp->IgnoreParenCasts(); 1436 1437 if (BlockExpr *C = dyn_cast<BlockExpr>(RetValExp)) 1438 if (C->hasBlockDeclRefExprs()) 1439 Diag(C->getLocStart(), diag::err_ret_local_block) 1440 << C->getSourceRange(); 1441 1442 if (AddrLabelExpr *ALE = dyn_cast<AddrLabelExpr>(RetValExp)) 1443 Diag(ALE->getLocStart(), diag::warn_ret_addr_label) 1444 << ALE->getSourceRange(); 1445 1446 } else if (lhsType->isReferenceType()) { 1447 // Perform checking for stack values returned by reference. 1448 // Check for a reference to the stack 1449 if (DeclRefExpr *DR = EvalVal(RetValExp)) 1450 Diag(DR->getLocStart(), diag::warn_ret_stack_ref) 1451 << DR->getDecl()->getDeclName() << RetValExp->getSourceRange(); 1452 } 1453} 1454 1455/// EvalAddr - EvalAddr and EvalVal are mutually recursive functions that 1456/// check if the expression in a return statement evaluates to an address 1457/// to a location on the stack. The recursion is used to traverse the 1458/// AST of the return expression, with recursion backtracking when we 1459/// encounter a subexpression that (1) clearly does not lead to the address 1460/// of a stack variable or (2) is something we cannot determine leads to 1461/// the address of a stack variable based on such local checking. 1462/// 1463/// EvalAddr processes expressions that are pointers that are used as 1464/// references (and not L-values). EvalVal handles all other values. 1465/// At the base case of the recursion is a check for a DeclRefExpr* in 1466/// the refers to a stack variable. 1467/// 1468/// This implementation handles: 1469/// 1470/// * pointer-to-pointer casts 1471/// * implicit conversions from array references to pointers 1472/// * taking the address of fields 1473/// * arbitrary interplay between "&" and "*" operators 1474/// * pointer arithmetic from an address of a stack variable 1475/// * taking the address of an array element where the array is on the stack 1476static DeclRefExpr* EvalAddr(Expr *E) { 1477 // We should only be called for evaluating pointer expressions. 1478 assert((E->getType()->isAnyPointerType() || 1479 E->getType()->isBlockPointerType() || 1480 E->getType()->isObjCQualifiedIdType()) && 1481 "EvalAddr only works on pointers"); 1482 1483 // Our "symbolic interpreter" is just a dispatch off the currently 1484 // viewed AST node. We then recursively traverse the AST by calling 1485 // EvalAddr and EvalVal appropriately. 1486 switch (E->getStmtClass()) { 1487 case Stmt::ParenExprClass: 1488 // Ignore parentheses. 1489 return EvalAddr(cast<ParenExpr>(E)->getSubExpr()); 1490 1491 case Stmt::UnaryOperatorClass: { 1492 // The only unary operator that make sense to handle here 1493 // is AddrOf. All others don't make sense as pointers. 1494 UnaryOperator *U = cast<UnaryOperator>(E); 1495 1496 if (U->getOpcode() == UnaryOperator::AddrOf) 1497 return EvalVal(U->getSubExpr()); 1498 else 1499 return NULL; 1500 } 1501 1502 case Stmt::BinaryOperatorClass: { 1503 // Handle pointer arithmetic. All other binary operators are not valid 1504 // in this context. 1505 BinaryOperator *B = cast<BinaryOperator>(E); 1506 BinaryOperator::Opcode op = B->getOpcode(); 1507 1508 if (op != BinaryOperator::Add && op != BinaryOperator::Sub) 1509 return NULL; 1510 1511 Expr *Base = B->getLHS(); 1512 1513 // Determine which argument is the real pointer base. It could be 1514 // the RHS argument instead of the LHS. 1515 if (!Base->getType()->isPointerType()) Base = B->getRHS(); 1516 1517 assert (Base->getType()->isPointerType()); 1518 return EvalAddr(Base); 1519 } 1520 1521 // For conditional operators we need to see if either the LHS or RHS are 1522 // valid DeclRefExpr*s. If one of them is valid, we return it. 1523 case Stmt::ConditionalOperatorClass: { 1524 ConditionalOperator *C = cast<ConditionalOperator>(E); 1525 1526 // Handle the GNU extension for missing LHS. 1527 if (Expr *lhsExpr = C->getLHS()) 1528 if (DeclRefExpr* LHS = EvalAddr(lhsExpr)) 1529 return LHS; 1530 1531 return EvalAddr(C->getRHS()); 1532 } 1533 1534 // For casts, we need to handle conversions from arrays to 1535 // pointer values, and pointer-to-pointer conversions. 1536 case Stmt::ImplicitCastExprClass: 1537 case Stmt::CStyleCastExprClass: 1538 case Stmt::CXXFunctionalCastExprClass: { 1539 Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1540 QualType T = SubExpr->getType(); 1541 1542 if (SubExpr->getType()->isPointerType() || 1543 SubExpr->getType()->isBlockPointerType() || 1544 SubExpr->getType()->isObjCQualifiedIdType()) 1545 return EvalAddr(SubExpr); 1546 else if (T->isArrayType()) 1547 return EvalVal(SubExpr); 1548 else 1549 return 0; 1550 } 1551 1552 // C++ casts. For dynamic casts, static casts, and const casts, we 1553 // are always converting from a pointer-to-pointer, so we just blow 1554 // through the cast. In the case the dynamic cast doesn't fail (and 1555 // return NULL), we take the conservative route and report cases 1556 // where we return the address of a stack variable. For Reinterpre 1557 // FIXME: The comment about is wrong; we're not always converting 1558 // from pointer to pointer. I'm guessing that this code should also 1559 // handle references to objects. 1560 case Stmt::CXXStaticCastExprClass: 1561 case Stmt::CXXDynamicCastExprClass: 1562 case Stmt::CXXConstCastExprClass: 1563 case Stmt::CXXReinterpretCastExprClass: { 1564 Expr *S = cast<CXXNamedCastExpr>(E)->getSubExpr(); 1565 if (S->getType()->isPointerType() || S->getType()->isBlockPointerType()) 1566 return EvalAddr(S); 1567 else 1568 return NULL; 1569 } 1570 1571 // Everything else: we simply don't reason about them. 1572 default: 1573 return NULL; 1574 } 1575} 1576 1577 1578/// EvalVal - This function is complements EvalAddr in the mutual recursion. 1579/// See the comments for EvalAddr for more details. 1580static DeclRefExpr* EvalVal(Expr *E) { 1581 1582 // We should only be called for evaluating non-pointer expressions, or 1583 // expressions with a pointer type that are not used as references but instead 1584 // are l-values (e.g., DeclRefExpr with a pointer type). 1585 1586 // Our "symbolic interpreter" is just a dispatch off the currently 1587 // viewed AST node. We then recursively traverse the AST by calling 1588 // EvalAddr and EvalVal appropriately. 1589 switch (E->getStmtClass()) { 1590 case Stmt::DeclRefExprClass: { 1591 // DeclRefExpr: the base case. When we hit a DeclRefExpr we are looking 1592 // at code that refers to a variable's name. We check if it has local 1593 // storage within the function, and if so, return the expression. 1594 DeclRefExpr *DR = cast<DeclRefExpr>(E); 1595 1596 if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl())) 1597 if (V->hasLocalStorage() && !V->getType()->isReferenceType()) return DR; 1598 1599 return NULL; 1600 } 1601 1602 case Stmt::ParenExprClass: 1603 // Ignore parentheses. 1604 return EvalVal(cast<ParenExpr>(E)->getSubExpr()); 1605 1606 case Stmt::UnaryOperatorClass: { 1607 // The only unary operator that make sense to handle here 1608 // is Deref. All others don't resolve to a "name." This includes 1609 // handling all sorts of rvalues passed to a unary operator. 1610 UnaryOperator *U = cast<UnaryOperator>(E); 1611 1612 if (U->getOpcode() == UnaryOperator::Deref) 1613 return EvalAddr(U->getSubExpr()); 1614 1615 return NULL; 1616 } 1617 1618 case Stmt::ArraySubscriptExprClass: { 1619 // Array subscripts are potential references to data on the stack. We 1620 // retrieve the DeclRefExpr* for the array variable if it indeed 1621 // has local storage. 1622 return EvalAddr(cast<ArraySubscriptExpr>(E)->getBase()); 1623 } 1624 1625 case Stmt::ConditionalOperatorClass: { 1626 // For conditional operators we need to see if either the LHS or RHS are 1627 // non-NULL DeclRefExpr's. If one is non-NULL, we return it. 1628 ConditionalOperator *C = cast<ConditionalOperator>(E); 1629 1630 // Handle the GNU extension for missing LHS. 1631 if (Expr *lhsExpr = C->getLHS()) 1632 if (DeclRefExpr *LHS = EvalVal(lhsExpr)) 1633 return LHS; 1634 1635 return EvalVal(C->getRHS()); 1636 } 1637 1638 // Accesses to members are potential references to data on the stack. 1639 case Stmt::MemberExprClass: { 1640 MemberExpr *M = cast<MemberExpr>(E); 1641 1642 // Check for indirect access. We only want direct field accesses. 1643 if (!M->isArrow()) 1644 return EvalVal(M->getBase()); 1645 else 1646 return NULL; 1647 } 1648 1649 // Everything else: we simply don't reason about them. 1650 default: 1651 return NULL; 1652 } 1653} 1654 1655//===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===// 1656 1657/// Check for comparisons of floating point operands using != and ==. 1658/// Issue a warning if these are no self-comparisons, as they are not likely 1659/// to do what the programmer intended. 1660void Sema::CheckFloatComparison(SourceLocation loc, Expr* lex, Expr *rex) { 1661 bool EmitWarning = true; 1662 1663 Expr* LeftExprSansParen = lex->IgnoreParens(); 1664 Expr* RightExprSansParen = rex->IgnoreParens(); 1665 1666 // Special case: check for x == x (which is OK). 1667 // Do not emit warnings for such cases. 1668 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LeftExprSansParen)) 1669 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RightExprSansParen)) 1670 if (DRL->getDecl() == DRR->getDecl()) 1671 EmitWarning = false; 1672 1673 1674 // Special case: check for comparisons against literals that can be exactly 1675 // represented by APFloat. In such cases, do not emit a warning. This 1676 // is a heuristic: often comparison against such literals are used to 1677 // detect if a value in a variable has not changed. This clearly can 1678 // lead to false negatives. 1679 if (EmitWarning) { 1680 if (FloatingLiteral* FLL = dyn_cast<FloatingLiteral>(LeftExprSansParen)) { 1681 if (FLL->isExact()) 1682 EmitWarning = false; 1683 } else 1684 if (FloatingLiteral* FLR = dyn_cast<FloatingLiteral>(RightExprSansParen)){ 1685 if (FLR->isExact()) 1686 EmitWarning = false; 1687 } 1688 } 1689 1690 // Check for comparisons with builtin types. 1691 if (EmitWarning) 1692 if (CallExpr* CL = dyn_cast<CallExpr>(LeftExprSansParen)) 1693 if (CL->isBuiltinCall(Context)) 1694 EmitWarning = false; 1695 1696 if (EmitWarning) 1697 if (CallExpr* CR = dyn_cast<CallExpr>(RightExprSansParen)) 1698 if (CR->isBuiltinCall(Context)) 1699 EmitWarning = false; 1700 1701 // Emit the diagnostic. 1702 if (EmitWarning) 1703 Diag(loc, diag::warn_floatingpoint_eq) 1704 << lex->getSourceRange() << rex->getSourceRange(); 1705} 1706 1707//===--- CHECK: Integer mixed-sign comparisons (-Wsign-compare) --------===// 1708//===--- CHECK: Lossy implicit conversions (-Wconversion) --------------===// 1709 1710namespace { 1711 1712/// Structure recording the 'active' range of an integer-valued 1713/// expression. 1714struct IntRange { 1715 /// The number of bits active in the int. 1716 unsigned Width; 1717 1718 /// True if the int is known not to have negative values. 1719 bool NonNegative; 1720 1721 IntRange() {} 1722 IntRange(unsigned Width, bool NonNegative) 1723 : Width(Width), NonNegative(NonNegative) 1724 {} 1725 1726 // Returns the range of the bool type. 1727 static IntRange forBoolType() { 1728 return IntRange(1, true); 1729 } 1730 1731 // Returns the range of an integral type. 1732 static IntRange forType(ASTContext &C, QualType T) { 1733 return forCanonicalType(C, T->getCanonicalTypeInternal().getTypePtr()); 1734 } 1735 1736 // Returns the range of an integeral type based on its canonical 1737 // representation. 1738 static IntRange forCanonicalType(ASTContext &C, const Type *T) { 1739 assert(T->isCanonicalUnqualified()); 1740 1741 if (const VectorType *VT = dyn_cast<VectorType>(T)) 1742 T = VT->getElementType().getTypePtr(); 1743 if (const ComplexType *CT = dyn_cast<ComplexType>(T)) 1744 T = CT->getElementType().getTypePtr(); 1745 if (const EnumType *ET = dyn_cast<EnumType>(T)) 1746 T = ET->getDecl()->getIntegerType().getTypePtr(); 1747 1748 const BuiltinType *BT = cast<BuiltinType>(T); 1749 assert(BT->isInteger()); 1750 1751 return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger()); 1752 } 1753 1754 // Returns the supremum of two ranges: i.e. their conservative merge. 1755 static IntRange join(IntRange L, IntRange R) { 1756 return IntRange(std::max(L.Width, R.Width), 1757 L.NonNegative && R.NonNegative); 1758 } 1759 1760 // Returns the infinum of two ranges: i.e. their aggressive merge. 1761 static IntRange meet(IntRange L, IntRange R) { 1762 return IntRange(std::min(L.Width, R.Width), 1763 L.NonNegative || R.NonNegative); 1764 } 1765}; 1766 1767IntRange GetValueRange(ASTContext &C, llvm::APSInt &value, unsigned MaxWidth) { 1768 if (value.isSigned() && value.isNegative()) 1769 return IntRange(value.getMinSignedBits(), false); 1770 1771 if (value.getBitWidth() > MaxWidth) 1772 value.trunc(MaxWidth); 1773 1774 // isNonNegative() just checks the sign bit without considering 1775 // signedness. 1776 return IntRange(value.getActiveBits(), true); 1777} 1778 1779IntRange GetValueRange(ASTContext &C, APValue &result, QualType Ty, 1780 unsigned MaxWidth) { 1781 if (result.isInt()) 1782 return GetValueRange(C, result.getInt(), MaxWidth); 1783 1784 if (result.isVector()) { 1785 IntRange R = GetValueRange(C, result.getVectorElt(0), Ty, MaxWidth); 1786 for (unsigned i = 1, e = result.getVectorLength(); i != e; ++i) { 1787 IntRange El = GetValueRange(C, result.getVectorElt(i), Ty, MaxWidth); 1788 R = IntRange::join(R, El); 1789 } 1790 return R; 1791 } 1792 1793 if (result.isComplexInt()) { 1794 IntRange R = GetValueRange(C, result.getComplexIntReal(), MaxWidth); 1795 IntRange I = GetValueRange(C, result.getComplexIntImag(), MaxWidth); 1796 return IntRange::join(R, I); 1797 } 1798 1799 // This can happen with lossless casts to intptr_t of "based" lvalues. 1800 // Assume it might use arbitrary bits. 1801 // FIXME: The only reason we need to pass the type in here is to get 1802 // the sign right on this one case. It would be nice if APValue 1803 // preserved this. 1804 assert(result.isLValue()); 1805 return IntRange(MaxWidth, Ty->isUnsignedIntegerType()); 1806} 1807 1808/// Pseudo-evaluate the given integer expression, estimating the 1809/// range of values it might take. 1810/// 1811/// \param MaxWidth - the width to which the value will be truncated 1812IntRange GetExprRange(ASTContext &C, Expr *E, unsigned MaxWidth) { 1813 E = E->IgnoreParens(); 1814 1815 // Try a full evaluation first. 1816 Expr::EvalResult result; 1817 if (E->Evaluate(result, C)) 1818 return GetValueRange(C, result.Val, E->getType(), MaxWidth); 1819 1820 // I think we only want to look through implicit casts here; if the 1821 // user has an explicit widening cast, we should treat the value as 1822 // being of the new, wider type. 1823 if (ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E)) { 1824 if (CE->getCastKind() == CastExpr::CK_NoOp) 1825 return GetExprRange(C, CE->getSubExpr(), MaxWidth); 1826 1827 IntRange OutputTypeRange = IntRange::forType(C, CE->getType()); 1828 1829 bool isIntegerCast = (CE->getCastKind() == CastExpr::CK_IntegralCast); 1830 if (!isIntegerCast && CE->getCastKind() == CastExpr::CK_Unknown) 1831 isIntegerCast = CE->getSubExpr()->getType()->isIntegerType(); 1832 1833 // Assume that non-integer casts can span the full range of the type. 1834 if (!isIntegerCast) 1835 return OutputTypeRange; 1836 1837 IntRange SubRange 1838 = GetExprRange(C, CE->getSubExpr(), 1839 std::min(MaxWidth, OutputTypeRange.Width)); 1840 1841 // Bail out if the subexpr's range is as wide as the cast type. 1842 if (SubRange.Width >= OutputTypeRange.Width) 1843 return OutputTypeRange; 1844 1845 // Otherwise, we take the smaller width, and we're non-negative if 1846 // either the output type or the subexpr is. 1847 return IntRange(SubRange.Width, 1848 SubRange.NonNegative || OutputTypeRange.NonNegative); 1849 } 1850 1851 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) { 1852 // If we can fold the condition, just take that operand. 1853 bool CondResult; 1854 if (CO->getCond()->EvaluateAsBooleanCondition(CondResult, C)) 1855 return GetExprRange(C, CondResult ? CO->getTrueExpr() 1856 : CO->getFalseExpr(), 1857 MaxWidth); 1858 1859 // Otherwise, conservatively merge. 1860 IntRange L = GetExprRange(C, CO->getTrueExpr(), MaxWidth); 1861 IntRange R = GetExprRange(C, CO->getFalseExpr(), MaxWidth); 1862 return IntRange::join(L, R); 1863 } 1864 1865 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { 1866 switch (BO->getOpcode()) { 1867 1868 // Boolean-valued operations are single-bit and positive. 1869 case BinaryOperator::LAnd: 1870 case BinaryOperator::LOr: 1871 case BinaryOperator::LT: 1872 case BinaryOperator::GT: 1873 case BinaryOperator::LE: 1874 case BinaryOperator::GE: 1875 case BinaryOperator::EQ: 1876 case BinaryOperator::NE: 1877 return IntRange::forBoolType(); 1878 1879 // The type of these compound assignments is the type of the LHS, 1880 // so the RHS is not necessarily an integer. 1881 case BinaryOperator::MulAssign: 1882 case BinaryOperator::DivAssign: 1883 case BinaryOperator::RemAssign: 1884 case BinaryOperator::AddAssign: 1885 case BinaryOperator::SubAssign: 1886 return IntRange::forType(C, E->getType()); 1887 1888 // Operations with opaque sources are black-listed. 1889 case BinaryOperator::PtrMemD: 1890 case BinaryOperator::PtrMemI: 1891 return IntRange::forType(C, E->getType()); 1892 1893 // Bitwise-and uses the *infinum* of the two source ranges. 1894 case BinaryOperator::And: 1895 case BinaryOperator::AndAssign: 1896 return IntRange::meet(GetExprRange(C, BO->getLHS(), MaxWidth), 1897 GetExprRange(C, BO->getRHS(), MaxWidth)); 1898 1899 // Left shift gets black-listed based on a judgement call. 1900 case BinaryOperator::Shl: 1901 // ...except that we want to treat '1 << (blah)' as logically 1902 // positive. It's an important idiom. 1903 if (IntegerLiteral *I 1904 = dyn_cast<IntegerLiteral>(BO->getLHS()->IgnoreParenCasts())) { 1905 if (I->getValue() == 1) { 1906 IntRange R = IntRange::forType(C, E->getType()); 1907 return IntRange(R.Width, /*NonNegative*/ true); 1908 } 1909 } 1910 // fallthrough 1911 1912 case BinaryOperator::ShlAssign: 1913 return IntRange::forType(C, E->getType()); 1914 1915 // Right shift by a constant can narrow its left argument. 1916 case BinaryOperator::Shr: 1917 case BinaryOperator::ShrAssign: { 1918 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth); 1919 1920 // If the shift amount is a positive constant, drop the width by 1921 // that much. 1922 llvm::APSInt shift; 1923 if (BO->getRHS()->isIntegerConstantExpr(shift, C) && 1924 shift.isNonNegative()) { 1925 unsigned zext = shift.getZExtValue(); 1926 if (zext >= L.Width) 1927 L.Width = (L.NonNegative ? 0 : 1); 1928 else 1929 L.Width -= zext; 1930 } 1931 1932 return L; 1933 } 1934 1935 // Comma acts as its right operand. 1936 case BinaryOperator::Comma: 1937 return GetExprRange(C, BO->getRHS(), MaxWidth); 1938 1939 // Black-list pointer subtractions. 1940 case BinaryOperator::Sub: 1941 if (BO->getLHS()->getType()->isPointerType()) 1942 return IntRange::forType(C, E->getType()); 1943 // fallthrough 1944 1945 default: 1946 break; 1947 } 1948 1949 // Treat every other operator as if it were closed on the 1950 // narrowest type that encompasses both operands. 1951 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth); 1952 IntRange R = GetExprRange(C, BO->getRHS(), MaxWidth); 1953 return IntRange::join(L, R); 1954 } 1955 1956 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) { 1957 switch (UO->getOpcode()) { 1958 // Boolean-valued operations are white-listed. 1959 case UnaryOperator::LNot: 1960 return IntRange::forBoolType(); 1961 1962 // Operations with opaque sources are black-listed. 1963 case UnaryOperator::Deref: 1964 case UnaryOperator::AddrOf: // should be impossible 1965 case UnaryOperator::OffsetOf: 1966 return IntRange::forType(C, E->getType()); 1967 1968 default: 1969 return GetExprRange(C, UO->getSubExpr(), MaxWidth); 1970 } 1971 } 1972 1973 FieldDecl *BitField = E->getBitField(); 1974 if (BitField) { 1975 llvm::APSInt BitWidthAP = BitField->getBitWidth()->EvaluateAsInt(C); 1976 unsigned BitWidth = BitWidthAP.getZExtValue(); 1977 1978 return IntRange(BitWidth, BitField->getType()->isUnsignedIntegerType()); 1979 } 1980 1981 return IntRange::forType(C, E->getType()); 1982} 1983 1984/// Checks whether the given value, which currently has the given 1985/// source semantics, has the same value when coerced through the 1986/// target semantics. 1987bool IsSameFloatAfterCast(const llvm::APFloat &value, 1988 const llvm::fltSemantics &Src, 1989 const llvm::fltSemantics &Tgt) { 1990 llvm::APFloat truncated = value; 1991 1992 bool ignored; 1993 truncated.convert(Src, llvm::APFloat::rmNearestTiesToEven, &ignored); 1994 truncated.convert(Tgt, llvm::APFloat::rmNearestTiesToEven, &ignored); 1995 1996 return truncated.bitwiseIsEqual(value); 1997} 1998 1999/// Checks whether the given value, which currently has the given 2000/// source semantics, has the same value when coerced through the 2001/// target semantics. 2002/// 2003/// The value might be a vector of floats (or a complex number). 2004bool IsSameFloatAfterCast(const APValue &value, 2005 const llvm::fltSemantics &Src, 2006 const llvm::fltSemantics &Tgt) { 2007 if (value.isFloat()) 2008 return IsSameFloatAfterCast(value.getFloat(), Src, Tgt); 2009 2010 if (value.isVector()) { 2011 for (unsigned i = 0, e = value.getVectorLength(); i != e; ++i) 2012 if (!IsSameFloatAfterCast(value.getVectorElt(i), Src, Tgt)) 2013 return false; 2014 return true; 2015 } 2016 2017 assert(value.isComplexFloat()); 2018 return (IsSameFloatAfterCast(value.getComplexFloatReal(), Src, Tgt) && 2019 IsSameFloatAfterCast(value.getComplexFloatImag(), Src, Tgt)); 2020} 2021 2022} // end anonymous namespace 2023 2024/// \brief Implements -Wsign-compare. 2025/// 2026/// \param lex the left-hand expression 2027/// \param rex the right-hand expression 2028/// \param OpLoc the location of the joining operator 2029/// \param BinOpc binary opcode or 0 2030void Sema::CheckSignCompare(Expr *lex, Expr *rex, SourceLocation OpLoc, 2031 const BinaryOperator::Opcode* BinOpc) { 2032 // Don't warn if we're in an unevaluated context. 2033 if (ExprEvalContexts.back().Context == Unevaluated) 2034 return; 2035 2036 // If either expression is value-dependent, don't warn. We'll get another 2037 // chance at instantiation time. 2038 if (lex->isValueDependent() || rex->isValueDependent()) 2039 return; 2040 2041 QualType lt = lex->getType(), rt = rex->getType(); 2042 2043 // Only warn if both operands are integral. 2044 if (!lt->isIntegerType() || !rt->isIntegerType()) 2045 return; 2046 2047 // In C, the width of a bitfield determines its type, and the 2048 // declared type only contributes the signedness. This duplicates 2049 // the work that will later be done by UsualUnaryConversions. 2050 // Eventually, this check will be reorganized in a way that avoids 2051 // this duplication. 2052 if (!getLangOptions().CPlusPlus) { 2053 QualType tmp; 2054 tmp = Context.isPromotableBitField(lex); 2055 if (!tmp.isNull()) lt = tmp; 2056 tmp = Context.isPromotableBitField(rex); 2057 if (!tmp.isNull()) rt = tmp; 2058 } 2059 2060 if (const EnumType *E = lt->getAs<EnumType>()) 2061 lt = E->getDecl()->getPromotionType(); 2062 if (const EnumType *E = rt->getAs<EnumType>()) 2063 rt = E->getDecl()->getPromotionType(); 2064 2065 // The rule is that the signed operand becomes unsigned, so isolate the 2066 // signed operand. 2067 Expr *signedOperand = lex, *unsignedOperand = rex; 2068 QualType signedType = lt, unsignedType = rt; 2069 if (lt->isSignedIntegerType()) { 2070 if (rt->isSignedIntegerType()) return; 2071 } else { 2072 if (!rt->isSignedIntegerType()) return; 2073 std::swap(signedOperand, unsignedOperand); 2074 std::swap(signedType, unsignedType); 2075 } 2076 2077 unsigned unsignedWidth = Context.getIntWidth(unsignedType); 2078 unsigned signedWidth = Context.getIntWidth(signedType); 2079 2080 // If the unsigned type is strictly smaller than the signed type, 2081 // then (1) the result type will be signed and (2) the unsigned 2082 // value will fit fully within the signed type, and thus the result 2083 // of the comparison will be exact. 2084 if (signedWidth > unsignedWidth) 2085 return; 2086 2087 // Otherwise, calculate the effective ranges. 2088 IntRange signedRange = GetExprRange(Context, signedOperand, signedWidth); 2089 IntRange unsignedRange = GetExprRange(Context, unsignedOperand, unsignedWidth); 2090 2091 // We should never be unable to prove that the unsigned operand is 2092 // non-negative. 2093 assert(unsignedRange.NonNegative && "unsigned range includes negative?"); 2094 2095 // If the signed operand is non-negative, then the signed->unsigned 2096 // conversion won't change it. 2097 if (signedRange.NonNegative) { 2098 // Emit warnings for comparisons of unsigned to integer constant 0. 2099 // always false: x < 0 (or 0 > x) 2100 // always true: x >= 0 (or 0 <= x) 2101 llvm::APSInt X; 2102 if (BinOpc && signedOperand->isIntegerConstantExpr(X, Context) && X == 0) { 2103 if (signedOperand != lex) { 2104 if (*BinOpc == BinaryOperator::LT) { 2105 Diag(OpLoc, diag::warn_lunsigned_always_true_comparison) 2106 << "< 0" << "false" 2107 << lex->getSourceRange() << rex->getSourceRange(); 2108 } 2109 else if (*BinOpc == BinaryOperator::GE) { 2110 Diag(OpLoc, diag::warn_lunsigned_always_true_comparison) 2111 << ">= 0" << "true" 2112 << lex->getSourceRange() << rex->getSourceRange(); 2113 } 2114 } 2115 else { 2116 if (*BinOpc == BinaryOperator::GT) { 2117 Diag(OpLoc, diag::warn_runsigned_always_true_comparison) 2118 << "0 >" << "false" 2119 << lex->getSourceRange() << rex->getSourceRange(); 2120 } 2121 else if (*BinOpc == BinaryOperator::LE) { 2122 Diag(OpLoc, diag::warn_runsigned_always_true_comparison) 2123 << "0 <=" << "true" 2124 << lex->getSourceRange() << rex->getSourceRange(); 2125 } 2126 } 2127 } 2128 return; 2129 } 2130 2131 // For (in)equality comparisons, if the unsigned operand is a 2132 // constant which cannot collide with a overflowed signed operand, 2133 // then reinterpreting the signed operand as unsigned will not 2134 // change the result of the comparison. 2135 if (BinOpc && 2136 (*BinOpc == BinaryOperator::EQ || *BinOpc == BinaryOperator::NE) && 2137 unsignedRange.Width < unsignedWidth) 2138 return; 2139 2140 Diag(OpLoc, BinOpc ? diag::warn_mixed_sign_comparison 2141 : diag::warn_mixed_sign_conditional) 2142 << lt << rt << lex->getSourceRange() << rex->getSourceRange(); 2143} 2144 2145/// Diagnose an implicit cast; purely a helper for CheckImplicitConversion. 2146static void DiagnoseImpCast(Sema &S, Expr *E, QualType T, unsigned diag) { 2147 S.Diag(E->getExprLoc(), diag) << E->getType() << T << E->getSourceRange(); 2148} 2149 2150/// Implements -Wconversion. 2151void Sema::CheckImplicitConversion(Expr *E, QualType T) { 2152 // Don't diagnose in unevaluated contexts. 2153 if (ExprEvalContexts.back().Context == Sema::Unevaluated) 2154 return; 2155 2156 // Don't diagnose for value-dependent expressions. 2157 if (E->isValueDependent()) 2158 return; 2159 2160 const Type *Source = Context.getCanonicalType(E->getType()).getTypePtr(); 2161 const Type *Target = Context.getCanonicalType(T).getTypePtr(); 2162 2163 // Never diagnose implicit casts to bool. 2164 if (Target->isSpecificBuiltinType(BuiltinType::Bool)) 2165 return; 2166 2167 // Strip vector types. 2168 if (isa<VectorType>(Source)) { 2169 if (!isa<VectorType>(Target)) 2170 return DiagnoseImpCast(*this, E, T, diag::warn_impcast_vector_scalar); 2171 2172 Source = cast<VectorType>(Source)->getElementType().getTypePtr(); 2173 Target = cast<VectorType>(Target)->getElementType().getTypePtr(); 2174 } 2175 2176 // Strip complex types. 2177 if (isa<ComplexType>(Source)) { 2178 if (!isa<ComplexType>(Target)) 2179 return DiagnoseImpCast(*this, E, T, diag::warn_impcast_complex_scalar); 2180 2181 Source = cast<ComplexType>(Source)->getElementType().getTypePtr(); 2182 Target = cast<ComplexType>(Target)->getElementType().getTypePtr(); 2183 } 2184 2185 const BuiltinType *SourceBT = dyn_cast<BuiltinType>(Source); 2186 const BuiltinType *TargetBT = dyn_cast<BuiltinType>(Target); 2187 2188 // If the source is floating point... 2189 if (SourceBT && SourceBT->isFloatingPoint()) { 2190 // ...and the target is floating point... 2191 if (TargetBT && TargetBT->isFloatingPoint()) { 2192 // ...then warn if we're dropping FP rank. 2193 2194 // Builtin FP kinds are ordered by increasing FP rank. 2195 if (SourceBT->getKind() > TargetBT->getKind()) { 2196 // Don't warn about float constants that are precisely 2197 // representable in the target type. 2198 Expr::EvalResult result; 2199 if (E->Evaluate(result, Context)) { 2200 // Value might be a float, a float vector, or a float complex. 2201 if (IsSameFloatAfterCast(result.Val, 2202 Context.getFloatTypeSemantics(QualType(TargetBT, 0)), 2203 Context.getFloatTypeSemantics(QualType(SourceBT, 0)))) 2204 return; 2205 } 2206 2207 DiagnoseImpCast(*this, E, T, diag::warn_impcast_float_precision); 2208 } 2209 return; 2210 } 2211 2212 // If the target is integral, always warn. 2213 if ((TargetBT && TargetBT->isInteger())) 2214 // TODO: don't warn for integer values? 2215 return DiagnoseImpCast(*this, E, T, diag::warn_impcast_float_integer); 2216 2217 return; 2218 } 2219 2220 if (!Source->isIntegerType() || !Target->isIntegerType()) 2221 return; 2222 2223 IntRange SourceRange = GetExprRange(Context, E, Context.getIntWidth(E->getType())); 2224 IntRange TargetRange = IntRange::forCanonicalType(Context, Target); 2225 2226 // FIXME: also signed<->unsigned? 2227 2228 if (SourceRange.Width > TargetRange.Width) { 2229 // People want to build with -Wshorten-64-to-32 and not -Wconversion 2230 // and by god we'll let them. 2231 if (SourceRange.Width == 64 && TargetRange.Width == 32) 2232 return DiagnoseImpCast(*this, E, T, diag::warn_impcast_integer_64_32); 2233 return DiagnoseImpCast(*this, E, T, diag::warn_impcast_integer_precision); 2234 } 2235 2236 return; 2237} 2238 2239/// CheckParmsForFunctionDef - Check that the parameters of the given 2240/// function are appropriate for the definition of a function. This 2241/// takes care of any checks that cannot be performed on the 2242/// declaration itself, e.g., that the types of each of the function 2243/// parameters are complete. 2244bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 2245 bool HasInvalidParm = false; 2246 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2247 ParmVarDecl *Param = FD->getParamDecl(p); 2248 2249 // C99 6.7.5.3p4: the parameters in a parameter type list in a 2250 // function declarator that is part of a function definition of 2251 // that function shall not have incomplete type. 2252 // 2253 // This is also C++ [dcl.fct]p6. 2254 if (!Param->isInvalidDecl() && 2255 RequireCompleteType(Param->getLocation(), Param->getType(), 2256 diag::err_typecheck_decl_incomplete_type)) { 2257 Param->setInvalidDecl(); 2258 HasInvalidParm = true; 2259 } 2260 2261 // C99 6.9.1p5: If the declarator includes a parameter type list, the 2262 // declaration of each parameter shall include an identifier. 2263 if (Param->getIdentifier() == 0 && 2264 !Param->isImplicit() && 2265 !getLangOptions().CPlusPlus) 2266 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 2267 2268 // C99 6.7.5.3p12: 2269 // If the function declarator is not part of a definition of that 2270 // function, parameters may have incomplete type and may use the [*] 2271 // notation in their sequences of declarator specifiers to specify 2272 // variable length array types. 2273 QualType PType = Param->getOriginalType(); 2274 if (const ArrayType *AT = Context.getAsArrayType(PType)) { 2275 if (AT->getSizeModifier() == ArrayType::Star) { 2276 // FIXME: This diagnosic should point the the '[*]' if source-location 2277 // information is added for it. 2278 Diag(Param->getLocation(), diag::err_array_star_in_function_definition); 2279 } 2280 } 2281 } 2282 2283 return HasInvalidParm; 2284} 2285