SemaChecking.cpp revision ed6d04519bf61948802ab0aa504fa9a7c3d0435a
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*/ << Fn->getSourceRange() 484 << SourceRange(TheCall->getArg(2)->getLocStart(), 485 (*(TheCall->arg_end()-1))->getLocEnd()); 486 return true; 487 } 488 489 if (TheCall->getNumArgs() < 2) { 490 return Diag(TheCall->getLocEnd(), 491 diag::err_typecheck_call_too_few_args_at_least) 492 << 0 /*function call*/ << 2 << TheCall->getNumArgs(); 493 } 494 495 // Determine whether the current function is variadic or not. 496 BlockScopeInfo *CurBlock = getCurBlock(); 497 bool isVariadic; 498 if (CurBlock) 499 isVariadic = CurBlock->isVariadic; 500 else if (getCurFunctionDecl()) { 501 if (FunctionProtoType* FTP = 502 dyn_cast<FunctionProtoType>(getCurFunctionDecl()->getType())) 503 isVariadic = FTP->isVariadic(); 504 else 505 isVariadic = false; 506 } else { 507 isVariadic = getCurMethodDecl()->isVariadic(); 508 } 509 510 if (!isVariadic) { 511 Diag(Fn->getLocStart(), diag::err_va_start_used_in_non_variadic_function); 512 return true; 513 } 514 515 // Verify that the second argument to the builtin is the last argument of the 516 // current function or method. 517 bool SecondArgIsLastNamedArgument = false; 518 const Expr *Arg = TheCall->getArg(1)->IgnoreParenCasts(); 519 520 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Arg)) { 521 if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(DR->getDecl())) { 522 // FIXME: This isn't correct for methods (results in bogus warning). 523 // Get the last formal in the current function. 524 const ParmVarDecl *LastArg; 525 if (CurBlock) 526 LastArg = *(CurBlock->TheDecl->param_end()-1); 527 else if (FunctionDecl *FD = getCurFunctionDecl()) 528 LastArg = *(FD->param_end()-1); 529 else 530 LastArg = *(getCurMethodDecl()->param_end()-1); 531 SecondArgIsLastNamedArgument = PV == LastArg; 532 } 533 } 534 535 if (!SecondArgIsLastNamedArgument) 536 Diag(TheCall->getArg(1)->getLocStart(), 537 diag::warn_second_parameter_of_va_start_not_last_named_argument); 538 return false; 539} 540 541/// SemaBuiltinUnorderedCompare - Handle functions like __builtin_isgreater and 542/// friends. This is declared to take (...), so we have to check everything. 543bool Sema::SemaBuiltinUnorderedCompare(CallExpr *TheCall) { 544 if (TheCall->getNumArgs() < 2) 545 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args) 546 << 0 << 2 << TheCall->getNumArgs()/*function call*/; 547 if (TheCall->getNumArgs() > 2) 548 return Diag(TheCall->getArg(2)->getLocStart(), 549 diag::err_typecheck_call_too_many_args) 550 << 0 /*function call*/ 551 << SourceRange(TheCall->getArg(2)->getLocStart(), 552 (*(TheCall->arg_end()-1))->getLocEnd()); 553 554 Expr *OrigArg0 = TheCall->getArg(0); 555 Expr *OrigArg1 = TheCall->getArg(1); 556 557 // Do standard promotions between the two arguments, returning their common 558 // type. 559 QualType Res = UsualArithmeticConversions(OrigArg0, OrigArg1, false); 560 561 // Make sure any conversions are pushed back into the call; this is 562 // type safe since unordered compare builtins are declared as "_Bool 563 // foo(...)". 564 TheCall->setArg(0, OrigArg0); 565 TheCall->setArg(1, OrigArg1); 566 567 if (OrigArg0->isTypeDependent() || OrigArg1->isTypeDependent()) 568 return false; 569 570 // If the common type isn't a real floating type, then the arguments were 571 // invalid for this operation. 572 if (!Res->isRealFloatingType()) 573 return Diag(OrigArg0->getLocStart(), 574 diag::err_typecheck_call_invalid_ordered_compare) 575 << OrigArg0->getType() << OrigArg1->getType() 576 << SourceRange(OrigArg0->getLocStart(), OrigArg1->getLocEnd()); 577 578 return false; 579} 580 581/// SemaBuiltinSemaBuiltinFPClassification - Handle functions like 582/// __builtin_isnan and friends. This is declared to take (...), so we have 583/// to check everything. We expect the last argument to be a floating point 584/// value. 585bool Sema::SemaBuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs) { 586 if (TheCall->getNumArgs() < NumArgs) 587 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args) 588 << 0 << NumArgs << TheCall->getNumArgs()/*function call*/; 589 if (TheCall->getNumArgs() > NumArgs) 590 return Diag(TheCall->getArg(NumArgs)->getLocStart(), 591 diag::err_typecheck_call_too_many_args) 592 << 0 /*function call*/ 593 << SourceRange(TheCall->getArg(NumArgs)->getLocStart(), 594 (*(TheCall->arg_end()-1))->getLocEnd()); 595 596 Expr *OrigArg = TheCall->getArg(NumArgs-1); 597 598 if (OrigArg->isTypeDependent()) 599 return false; 600 601 // This operation requires a floating-point number 602 if (!OrigArg->getType()->isRealFloatingType()) 603 return Diag(OrigArg->getLocStart(), 604 diag::err_typecheck_call_invalid_unary_fp) 605 << OrigArg->getType() << OrigArg->getSourceRange(); 606 607 return false; 608} 609 610bool Sema::SemaBuiltinStackAddress(CallExpr *TheCall) { 611 // The signature for these builtins is exact; the only thing we need 612 // to check is that the argument is a constant. 613 SourceLocation Loc; 614 if (!TheCall->getArg(0)->isTypeDependent() && 615 !TheCall->getArg(0)->isValueDependent() && 616 !TheCall->getArg(0)->isIntegerConstantExpr(Context, &Loc)) 617 return Diag(Loc, diag::err_stack_const_level) << TheCall->getSourceRange(); 618 619 return false; 620} 621 622/// SemaBuiltinShuffleVector - Handle __builtin_shufflevector. 623// This is declared to take (...), so we have to check everything. 624Action::OwningExprResult Sema::SemaBuiltinShuffleVector(CallExpr *TheCall) { 625 if (TheCall->getNumArgs() < 3) 626 return ExprError(Diag(TheCall->getLocEnd(), 627 diag::err_typecheck_call_too_few_args_at_least) 628 << 0 /*function call*/ << 3 << TheCall->getNumArgs() 629 << TheCall->getSourceRange()); 630 631 unsigned numElements = std::numeric_limits<unsigned>::max(); 632 if (!TheCall->getArg(0)->isTypeDependent() && 633 !TheCall->getArg(1)->isTypeDependent()) { 634 QualType FAType = TheCall->getArg(0)->getType(); 635 QualType SAType = TheCall->getArg(1)->getType(); 636 637 if (!FAType->isVectorType() || !SAType->isVectorType()) { 638 Diag(TheCall->getLocStart(), diag::err_shufflevector_non_vector) 639 << SourceRange(TheCall->getArg(0)->getLocStart(), 640 TheCall->getArg(1)->getLocEnd()); 641 return ExprError(); 642 } 643 644 if (!Context.hasSameUnqualifiedType(FAType, SAType)) { 645 Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector) 646 << SourceRange(TheCall->getArg(0)->getLocStart(), 647 TheCall->getArg(1)->getLocEnd()); 648 return ExprError(); 649 } 650 651 numElements = FAType->getAs<VectorType>()->getNumElements(); 652 if (TheCall->getNumArgs() != numElements+2) { 653 if (TheCall->getNumArgs() < numElements+2) 654 return ExprError(Diag(TheCall->getLocEnd(), 655 diag::err_typecheck_call_too_few_args) 656 << 0 /*function call*/ 657 << numElements+2 << TheCall->getNumArgs() 658 << TheCall->getSourceRange()); 659 return ExprError(Diag(TheCall->getLocEnd(), 660 diag::err_typecheck_call_too_many_args) 661 << 0 /*function call*/ << TheCall->getSourceRange()); 662 } 663 } 664 665 for (unsigned i = 2; i < TheCall->getNumArgs(); i++) { 666 if (TheCall->getArg(i)->isTypeDependent() || 667 TheCall->getArg(i)->isValueDependent()) 668 continue; 669 670 llvm::APSInt Result(32); 671 if (!TheCall->getArg(i)->isIntegerConstantExpr(Result, Context)) 672 return ExprError(Diag(TheCall->getLocStart(), 673 diag::err_shufflevector_nonconstant_argument) 674 << TheCall->getArg(i)->getSourceRange()); 675 676 if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2) 677 return ExprError(Diag(TheCall->getLocStart(), 678 diag::err_shufflevector_argument_too_large) 679 << TheCall->getArg(i)->getSourceRange()); 680 } 681 682 llvm::SmallVector<Expr*, 32> exprs; 683 684 for (unsigned i = 0, e = TheCall->getNumArgs(); i != e; i++) { 685 exprs.push_back(TheCall->getArg(i)); 686 TheCall->setArg(i, 0); 687 } 688 689 return Owned(new (Context) ShuffleVectorExpr(Context, exprs.begin(), 690 exprs.size(), exprs[0]->getType(), 691 TheCall->getCallee()->getLocStart(), 692 TheCall->getRParenLoc())); 693} 694 695/// SemaBuiltinPrefetch - Handle __builtin_prefetch. 696// This is declared to take (const void*, ...) and can take two 697// optional constant int args. 698bool Sema::SemaBuiltinPrefetch(CallExpr *TheCall) { 699 unsigned NumArgs = TheCall->getNumArgs(); 700 701 if (NumArgs > 3) 702 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_many_args) 703 << 0 /*function call*/ << TheCall->getSourceRange(); 704 705 // Argument 0 is checked for us and the remaining arguments must be 706 // constant integers. 707 for (unsigned i = 1; i != NumArgs; ++i) { 708 Expr *Arg = TheCall->getArg(i); 709 if (Arg->isTypeDependent()) 710 continue; 711 712 if (!Arg->getType()->isIntegralType()) 713 return Diag(TheCall->getLocStart(), diag::err_prefetch_invalid_arg_type) 714 << Arg->getSourceRange(); 715 716 ImpCastExprToType(Arg, Context.IntTy, CastExpr::CK_IntegralCast); 717 TheCall->setArg(i, Arg); 718 719 if (Arg->isValueDependent()) 720 continue; 721 722 llvm::APSInt Result; 723 if (!Arg->isIntegerConstantExpr(Result, Context)) 724 return Diag(TheCall->getLocStart(), diag::err_prefetch_invalid_arg_ice) 725 << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 726 727 // FIXME: gcc issues a warning and rewrites these to 0. These 728 // seems especially odd for the third argument since the default 729 // is 3. 730 if (i == 1) { 731 if (Result.getLimitedValue() > 1) 732 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 733 << "0" << "1" << Arg->getSourceRange(); 734 } else { 735 if (Result.getLimitedValue() > 3) 736 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 737 << "0" << "3" << Arg->getSourceRange(); 738 } 739 } 740 741 return false; 742} 743 744/// SemaBuiltinEHReturnDataRegNo - Handle __builtin_eh_return_data_regno, the 745/// operand must be an integer constant. 746bool Sema::SemaBuiltinEHReturnDataRegNo(CallExpr *TheCall) { 747 llvm::APSInt Result; 748 if (!TheCall->getArg(0)->isIntegerConstantExpr(Result, Context)) 749 return Diag(TheCall->getLocStart(), diag::err_expr_not_ice) 750 << TheCall->getArg(0)->getSourceRange(); 751 752 return false; 753} 754 755 756/// SemaBuiltinObjectSize - Handle __builtin_object_size(void *ptr, 757/// int type). This simply type checks that type is one of the defined 758/// constants (0-3). 759// For compatability check 0-3, llvm only handles 0 and 2. 760bool Sema::SemaBuiltinObjectSize(CallExpr *TheCall) { 761 Expr *Arg = TheCall->getArg(1); 762 if (Arg->isTypeDependent()) 763 return false; 764 765 QualType ArgType = Arg->getType(); 766 const BuiltinType *BT = ArgType->getAs<BuiltinType>(); 767 llvm::APSInt Result(32); 768 if (!BT || BT->getKind() != BuiltinType::Int) 769 return Diag(TheCall->getLocStart(), diag::err_object_size_invalid_argument) 770 << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 771 772 if (Arg->isValueDependent()) 773 return false; 774 775 if (!Arg->isIntegerConstantExpr(Result, Context)) { 776 return Diag(TheCall->getLocStart(), diag::err_object_size_invalid_argument) 777 << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 778 } 779 780 if (Result.getSExtValue() < 0 || Result.getSExtValue() > 3) { 781 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 782 << "0" << "3" << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 783 } 784 785 return false; 786} 787 788/// SemaBuiltinLongjmp - Handle __builtin_longjmp(void *env[5], int val). 789/// This checks that val is a constant 1. 790bool Sema::SemaBuiltinLongjmp(CallExpr *TheCall) { 791 Expr *Arg = TheCall->getArg(1); 792 if (Arg->isTypeDependent() || Arg->isValueDependent()) 793 return false; 794 795 llvm::APSInt Result(32); 796 if (!Arg->isIntegerConstantExpr(Result, Context) || Result != 1) 797 return Diag(TheCall->getLocStart(), diag::err_builtin_longjmp_invalid_val) 798 << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 799 800 return false; 801} 802 803// Handle i > 1 ? "x" : "y", recursivelly 804bool Sema::SemaCheckStringLiteral(const Expr *E, const CallExpr *TheCall, 805 bool HasVAListArg, 806 unsigned format_idx, unsigned firstDataArg) { 807 if (E->isTypeDependent() || E->isValueDependent()) 808 return false; 809 810 switch (E->getStmtClass()) { 811 case Stmt::ConditionalOperatorClass: { 812 const ConditionalOperator *C = cast<ConditionalOperator>(E); 813 return SemaCheckStringLiteral(C->getTrueExpr(), TheCall, 814 HasVAListArg, format_idx, firstDataArg) 815 && SemaCheckStringLiteral(C->getRHS(), TheCall, 816 HasVAListArg, format_idx, firstDataArg); 817 } 818 819 case Stmt::ImplicitCastExprClass: { 820 const ImplicitCastExpr *Expr = cast<ImplicitCastExpr>(E); 821 return SemaCheckStringLiteral(Expr->getSubExpr(), TheCall, HasVAListArg, 822 format_idx, firstDataArg); 823 } 824 825 case Stmt::ParenExprClass: { 826 const ParenExpr *Expr = cast<ParenExpr>(E); 827 return SemaCheckStringLiteral(Expr->getSubExpr(), TheCall, HasVAListArg, 828 format_idx, firstDataArg); 829 } 830 831 case Stmt::DeclRefExprClass: { 832 const DeclRefExpr *DR = cast<DeclRefExpr>(E); 833 834 // As an exception, do not flag errors for variables binding to 835 // const string literals. 836 if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) { 837 bool isConstant = false; 838 QualType T = DR->getType(); 839 840 if (const ArrayType *AT = Context.getAsArrayType(T)) { 841 isConstant = AT->getElementType().isConstant(Context); 842 } else if (const PointerType *PT = T->getAs<PointerType>()) { 843 isConstant = T.isConstant(Context) && 844 PT->getPointeeType().isConstant(Context); 845 } 846 847 if (isConstant) { 848 if (const Expr *Init = VD->getAnyInitializer()) 849 return SemaCheckStringLiteral(Init, TheCall, 850 HasVAListArg, format_idx, firstDataArg); 851 } 852 853 // For vprintf* functions (i.e., HasVAListArg==true), we add a 854 // special check to see if the format string is a function parameter 855 // of the function calling the printf function. If the function 856 // has an attribute indicating it is a printf-like function, then we 857 // should suppress warnings concerning non-literals being used in a call 858 // to a vprintf function. For example: 859 // 860 // void 861 // logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...){ 862 // va_list ap; 863 // va_start(ap, fmt); 864 // vprintf(fmt, ap); // Do NOT emit a warning about "fmt". 865 // ... 866 // 867 // 868 // FIXME: We don't have full attribute support yet, so just check to see 869 // if the argument is a DeclRefExpr that references a parameter. We'll 870 // add proper support for checking the attribute later. 871 if (HasVAListArg) 872 if (isa<ParmVarDecl>(VD)) 873 return true; 874 } 875 876 return false; 877 } 878 879 case Stmt::CallExprClass: { 880 const CallExpr *CE = cast<CallExpr>(E); 881 if (const ImplicitCastExpr *ICE 882 = dyn_cast<ImplicitCastExpr>(CE->getCallee())) { 883 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) { 884 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DRE->getDecl())) { 885 if (const FormatArgAttr *FA = FD->getAttr<FormatArgAttr>()) { 886 unsigned ArgIndex = FA->getFormatIdx(); 887 const Expr *Arg = CE->getArg(ArgIndex - 1); 888 889 return SemaCheckStringLiteral(Arg, TheCall, HasVAListArg, 890 format_idx, firstDataArg); 891 } 892 } 893 } 894 } 895 896 return false; 897 } 898 case Stmt::ObjCStringLiteralClass: 899 case Stmt::StringLiteralClass: { 900 const StringLiteral *StrE = NULL; 901 902 if (const ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(E)) 903 StrE = ObjCFExpr->getString(); 904 else 905 StrE = cast<StringLiteral>(E); 906 907 if (StrE) { 908 CheckPrintfString(StrE, E, TheCall, HasVAListArg, format_idx, 909 firstDataArg); 910 return true; 911 } 912 913 return false; 914 } 915 916 default: 917 return false; 918 } 919} 920 921void 922Sema::CheckNonNullArguments(const NonNullAttr *NonNull, 923 const CallExpr *TheCall) { 924 for (NonNullAttr::iterator i = NonNull->begin(), e = NonNull->end(); 925 i != e; ++i) { 926 const Expr *ArgExpr = TheCall->getArg(*i); 927 if (ArgExpr->isNullPointerConstant(Context, 928 Expr::NPC_ValueDependentIsNotNull)) 929 Diag(TheCall->getCallee()->getLocStart(), diag::warn_null_arg) 930 << ArgExpr->getSourceRange(); 931 } 932} 933 934/// CheckPrintfArguments - Check calls to printf (and similar functions) for 935/// correct use of format strings. 936/// 937/// HasVAListArg - A predicate indicating whether the printf-like 938/// function is passed an explicit va_arg argument (e.g., vprintf) 939/// 940/// format_idx - The index into Args for the format string. 941/// 942/// Improper format strings to functions in the printf family can be 943/// the source of bizarre bugs and very serious security holes. A 944/// good source of information is available in the following paper 945/// (which includes additional references): 946/// 947/// FormatGuard: Automatic Protection From printf Format String 948/// Vulnerabilities, Proceedings of the 10th USENIX Security Symposium, 2001. 949/// 950/// TODO: 951/// Functionality implemented: 952/// 953/// We can statically check the following properties for string 954/// literal format strings for non v.*printf functions (where the 955/// arguments are passed directly): 956// 957/// (1) Are the number of format conversions equal to the number of 958/// data arguments? 959/// 960/// (2) Does each format conversion correctly match the type of the 961/// corresponding data argument? 962/// 963/// Moreover, for all printf functions we can: 964/// 965/// (3) Check for a missing format string (when not caught by type checking). 966/// 967/// (4) Check for no-operation flags; e.g. using "#" with format 968/// conversion 'c' (TODO) 969/// 970/// (5) Check the use of '%n', a major source of security holes. 971/// 972/// (6) Check for malformed format conversions that don't specify anything. 973/// 974/// (7) Check for empty format strings. e.g: printf(""); 975/// 976/// (8) Check that the format string is a wide literal. 977/// 978/// All of these checks can be done by parsing the format string. 979/// 980void 981Sema::CheckPrintfArguments(const CallExpr *TheCall, bool HasVAListArg, 982 unsigned format_idx, unsigned firstDataArg) { 983 const Expr *Fn = TheCall->getCallee(); 984 985 // The way the format attribute works in GCC, the implicit this argument 986 // of member functions is counted. However, it doesn't appear in our own 987 // lists, so decrement format_idx in that case. 988 if (isa<CXXMemberCallExpr>(TheCall)) { 989 // Catch a format attribute mistakenly referring to the object argument. 990 if (format_idx == 0) 991 return; 992 --format_idx; 993 if(firstDataArg != 0) 994 --firstDataArg; 995 } 996 997 // CHECK: printf-like function is called with no format string. 998 if (format_idx >= TheCall->getNumArgs()) { 999 Diag(TheCall->getRParenLoc(), diag::warn_printf_missing_format_string) 1000 << Fn->getSourceRange(); 1001 return; 1002 } 1003 1004 const Expr *OrigFormatExpr = TheCall->getArg(format_idx)->IgnoreParenCasts(); 1005 1006 // CHECK: format string is not a string literal. 1007 // 1008 // Dynamically generated format strings are difficult to 1009 // automatically vet at compile time. Requiring that format strings 1010 // are string literals: (1) permits the checking of format strings by 1011 // the compiler and thereby (2) can practically remove the source of 1012 // many format string exploits. 1013 1014 // Format string can be either ObjC string (e.g. @"%d") or 1015 // C string (e.g. "%d") 1016 // ObjC string uses the same format specifiers as C string, so we can use 1017 // the same format string checking logic for both ObjC and C strings. 1018 if (SemaCheckStringLiteral(OrigFormatExpr, TheCall, HasVAListArg, format_idx, 1019 firstDataArg)) 1020 return; // Literal format string found, check done! 1021 1022 // If there are no arguments specified, warn with -Wformat-security, otherwise 1023 // warn only with -Wformat-nonliteral. 1024 if (TheCall->getNumArgs() == format_idx+1) 1025 Diag(TheCall->getArg(format_idx)->getLocStart(), 1026 diag::warn_printf_nonliteral_noargs) 1027 << OrigFormatExpr->getSourceRange(); 1028 else 1029 Diag(TheCall->getArg(format_idx)->getLocStart(), 1030 diag::warn_printf_nonliteral) 1031 << OrigFormatExpr->getSourceRange(); 1032} 1033 1034namespace { 1035class CheckPrintfHandler : public analyze_printf::FormatStringHandler { 1036 Sema &S; 1037 const StringLiteral *FExpr; 1038 const Expr *OrigFormatExpr; 1039 const unsigned FirstDataArg; 1040 const unsigned NumDataArgs; 1041 const bool IsObjCLiteral; 1042 const char *Beg; // Start of format string. 1043 const bool HasVAListArg; 1044 const CallExpr *TheCall; 1045 unsigned FormatIdx; 1046 llvm::BitVector CoveredArgs; 1047 bool usesPositionalArgs; 1048 bool atFirstArg; 1049public: 1050 CheckPrintfHandler(Sema &s, const StringLiteral *fexpr, 1051 const Expr *origFormatExpr, unsigned firstDataArg, 1052 unsigned numDataArgs, bool isObjCLiteral, 1053 const char *beg, bool hasVAListArg, 1054 const CallExpr *theCall, unsigned formatIdx) 1055 : S(s), FExpr(fexpr), OrigFormatExpr(origFormatExpr), 1056 FirstDataArg(firstDataArg), 1057 NumDataArgs(numDataArgs), 1058 IsObjCLiteral(isObjCLiteral), Beg(beg), 1059 HasVAListArg(hasVAListArg), 1060 TheCall(theCall), FormatIdx(formatIdx), 1061 usesPositionalArgs(false), atFirstArg(true) { 1062 CoveredArgs.resize(numDataArgs); 1063 CoveredArgs.reset(); 1064 } 1065 1066 void DoneProcessing(); 1067 1068 void HandleIncompleteFormatSpecifier(const char *startSpecifier, 1069 unsigned specifierLen); 1070 1071 bool 1072 HandleInvalidConversionSpecifier(const analyze_printf::FormatSpecifier &FS, 1073 const char *startSpecifier, 1074 unsigned specifierLen); 1075 1076 virtual void HandleInvalidPosition(const char *startSpecifier, 1077 unsigned specifierLen, 1078 analyze_printf::PositionContext p); 1079 1080 virtual void HandleZeroPosition(const char *startPos, unsigned posLen); 1081 1082 void HandleNullChar(const char *nullCharacter); 1083 1084 bool HandleFormatSpecifier(const analyze_printf::FormatSpecifier &FS, 1085 const char *startSpecifier, 1086 unsigned specifierLen); 1087private: 1088 SourceRange getFormatStringRange(); 1089 SourceRange getFormatSpecifierRange(const char *startSpecifier, 1090 unsigned specifierLen); 1091 SourceLocation getLocationOfByte(const char *x); 1092 1093 bool HandleAmount(const analyze_printf::OptionalAmount &Amt, unsigned k, 1094 const char *startSpecifier, unsigned specifierLen); 1095 void HandleFlags(const analyze_printf::FormatSpecifier &FS, 1096 llvm::StringRef flag, llvm::StringRef cspec, 1097 const char *startSpecifier, unsigned specifierLen); 1098 1099 const Expr *getDataArg(unsigned i) const; 1100}; 1101} 1102 1103SourceRange CheckPrintfHandler::getFormatStringRange() { 1104 return OrigFormatExpr->getSourceRange(); 1105} 1106 1107SourceRange CheckPrintfHandler:: 1108getFormatSpecifierRange(const char *startSpecifier, unsigned specifierLen) { 1109 return SourceRange(getLocationOfByte(startSpecifier), 1110 getLocationOfByte(startSpecifier+specifierLen-1)); 1111} 1112 1113SourceLocation CheckPrintfHandler::getLocationOfByte(const char *x) { 1114 return S.getLocationOfStringLiteralByte(FExpr, x - Beg); 1115} 1116 1117void CheckPrintfHandler:: 1118HandleIncompleteFormatSpecifier(const char *startSpecifier, 1119 unsigned specifierLen) { 1120 SourceLocation Loc = getLocationOfByte(startSpecifier); 1121 S.Diag(Loc, diag::warn_printf_incomplete_specifier) 1122 << getFormatSpecifierRange(startSpecifier, specifierLen); 1123} 1124 1125void 1126CheckPrintfHandler::HandleInvalidPosition(const char *startPos, unsigned posLen, 1127 analyze_printf::PositionContext p) { 1128 SourceLocation Loc = getLocationOfByte(startPos); 1129 S.Diag(Loc, diag::warn_printf_invalid_positional_specifier) 1130 << (unsigned) p << getFormatSpecifierRange(startPos, posLen); 1131} 1132 1133void CheckPrintfHandler::HandleZeroPosition(const char *startPos, 1134 unsigned posLen) { 1135 SourceLocation Loc = getLocationOfByte(startPos); 1136 S.Diag(Loc, diag::warn_printf_zero_positional_specifier) 1137 << getFormatSpecifierRange(startPos, posLen); 1138} 1139 1140bool CheckPrintfHandler:: 1141HandleInvalidConversionSpecifier(const analyze_printf::FormatSpecifier &FS, 1142 const char *startSpecifier, 1143 unsigned specifierLen) { 1144 1145 unsigned argIndex = FS.getArgIndex(); 1146 bool keepGoing = true; 1147 if (argIndex < NumDataArgs) { 1148 // Consider the argument coverered, even though the specifier doesn't 1149 // make sense. 1150 CoveredArgs.set(argIndex); 1151 } 1152 else { 1153 // If argIndex exceeds the number of data arguments we 1154 // don't issue a warning because that is just a cascade of warnings (and 1155 // they may have intended '%%' anyway). We don't want to continue processing 1156 // the format string after this point, however, as we will like just get 1157 // gibberish when trying to match arguments. 1158 keepGoing = false; 1159 } 1160 1161 const analyze_printf::ConversionSpecifier &CS = 1162 FS.getConversionSpecifier(); 1163 SourceLocation Loc = getLocationOfByte(CS.getStart()); 1164 S.Diag(Loc, diag::warn_printf_invalid_conversion) 1165 << llvm::StringRef(CS.getStart(), CS.getLength()) 1166 << getFormatSpecifierRange(startSpecifier, specifierLen); 1167 1168 return keepGoing; 1169} 1170 1171void CheckPrintfHandler::HandleNullChar(const char *nullCharacter) { 1172 // The presence of a null character is likely an error. 1173 S.Diag(getLocationOfByte(nullCharacter), 1174 diag::warn_printf_format_string_contains_null_char) 1175 << getFormatStringRange(); 1176} 1177 1178const Expr *CheckPrintfHandler::getDataArg(unsigned i) const { 1179 return TheCall->getArg(FirstDataArg + i); 1180} 1181 1182void CheckPrintfHandler::HandleFlags(const analyze_printf::FormatSpecifier &FS, 1183 llvm::StringRef flag, 1184 llvm::StringRef cspec, 1185 const char *startSpecifier, 1186 unsigned specifierLen) { 1187 const analyze_printf::ConversionSpecifier &CS = FS.getConversionSpecifier(); 1188 S.Diag(getLocationOfByte(CS.getStart()), diag::warn_printf_nonsensical_flag) 1189 << flag << cspec << getFormatSpecifierRange(startSpecifier, specifierLen); 1190} 1191 1192bool 1193CheckPrintfHandler::HandleAmount(const analyze_printf::OptionalAmount &Amt, 1194 unsigned k, const char *startSpecifier, 1195 unsigned specifierLen) { 1196 1197 if (Amt.hasDataArgument()) { 1198 if (!HasVAListArg) { 1199 unsigned argIndex = Amt.getArgIndex(); 1200 if (argIndex >= NumDataArgs) { 1201 S.Diag(getLocationOfByte(Amt.getStart()), 1202 diag::warn_printf_asterisk_missing_arg) 1203 << k << getFormatSpecifierRange(startSpecifier, specifierLen); 1204 // Don't do any more checking. We will just emit 1205 // spurious errors. 1206 return false; 1207 } 1208 1209 // Type check the data argument. It should be an 'int'. 1210 // Although not in conformance with C99, we also allow the argument to be 1211 // an 'unsigned int' as that is a reasonably safe case. GCC also 1212 // doesn't emit a warning for that case. 1213 CoveredArgs.set(argIndex); 1214 const Expr *Arg = getDataArg(argIndex); 1215 QualType T = Arg->getType(); 1216 1217 const analyze_printf::ArgTypeResult &ATR = Amt.getArgType(S.Context); 1218 assert(ATR.isValid()); 1219 1220 if (!ATR.matchesType(S.Context, T)) { 1221 S.Diag(getLocationOfByte(Amt.getStart()), 1222 diag::warn_printf_asterisk_wrong_type) 1223 << k 1224 << ATR.getRepresentativeType(S.Context) << T 1225 << getFormatSpecifierRange(startSpecifier, specifierLen) 1226 << Arg->getSourceRange(); 1227 // Don't do any more checking. We will just emit 1228 // spurious errors. 1229 return false; 1230 } 1231 } 1232 } 1233 return true; 1234} 1235 1236bool 1237CheckPrintfHandler::HandleFormatSpecifier(const analyze_printf::FormatSpecifier 1238 &FS, 1239 const char *startSpecifier, 1240 unsigned specifierLen) { 1241 1242 using namespace analyze_printf; 1243 const ConversionSpecifier &CS = FS.getConversionSpecifier(); 1244 1245 if (atFirstArg) { 1246 atFirstArg = false; 1247 usesPositionalArgs = FS.usesPositionalArg(); 1248 } 1249 else if (usesPositionalArgs != FS.usesPositionalArg()) { 1250 // Cannot mix-and-match positional and non-positional arguments. 1251 S.Diag(getLocationOfByte(CS.getStart()), 1252 diag::warn_printf_mix_positional_nonpositional_args) 1253 << getFormatSpecifierRange(startSpecifier, specifierLen); 1254 return false; 1255 } 1256 1257 // First check if the field width, precision, and conversion specifier 1258 // have matching data arguments. 1259 if (!HandleAmount(FS.getFieldWidth(), /* field width */ 0, 1260 startSpecifier, specifierLen)) { 1261 return false; 1262 } 1263 1264 if (!HandleAmount(FS.getPrecision(), /* precision */ 1, 1265 startSpecifier, specifierLen)) { 1266 return false; 1267 } 1268 1269 if (!CS.consumesDataArgument()) { 1270 // FIXME: Technically specifying a precision or field width here 1271 // makes no sense. Worth issuing a warning at some point. 1272 return true; 1273 } 1274 1275 // Consume the argument. 1276 unsigned argIndex = FS.getArgIndex(); 1277 if (argIndex < NumDataArgs) { 1278 // The check to see if the argIndex is valid will come later. 1279 // We set the bit here because we may exit early from this 1280 // function if we encounter some other error. 1281 CoveredArgs.set(argIndex); 1282 } 1283 1284 // Check for using an Objective-C specific conversion specifier 1285 // in a non-ObjC literal. 1286 if (!IsObjCLiteral && CS.isObjCArg()) { 1287 return HandleInvalidConversionSpecifier(FS, startSpecifier, specifierLen); 1288 } 1289 1290 // Are we using '%n'? Issue a warning about this being 1291 // a possible security issue. 1292 if (CS.getKind() == ConversionSpecifier::OutIntPtrArg) { 1293 S.Diag(getLocationOfByte(CS.getStart()), diag::warn_printf_write_back) 1294 << getFormatSpecifierRange(startSpecifier, specifierLen); 1295 // Continue checking the other format specifiers. 1296 return true; 1297 } 1298 1299 if (CS.getKind() == ConversionSpecifier::VoidPtrArg) { 1300 if (FS.getPrecision().getHowSpecified() != OptionalAmount::NotSpecified) 1301 S.Diag(getLocationOfByte(CS.getStart()), 1302 diag::warn_printf_nonsensical_precision) 1303 << CS.getCharacters() 1304 << getFormatSpecifierRange(startSpecifier, specifierLen); 1305 } 1306 if (CS.getKind() == ConversionSpecifier::VoidPtrArg || 1307 CS.getKind() == ConversionSpecifier::CStrArg) { 1308 // FIXME: Instead of using "0", "+", etc., eventually get them from 1309 // the FormatSpecifier. 1310 if (FS.hasLeadingZeros()) 1311 HandleFlags(FS, "0", CS.getCharacters(), startSpecifier, specifierLen); 1312 if (FS.hasPlusPrefix()) 1313 HandleFlags(FS, "+", CS.getCharacters(), startSpecifier, specifierLen); 1314 if (FS.hasSpacePrefix()) 1315 HandleFlags(FS, " ", CS.getCharacters(), startSpecifier, specifierLen); 1316 } 1317 1318 // The remaining checks depend on the data arguments. 1319 if (HasVAListArg) 1320 return true; 1321 1322 if (argIndex >= NumDataArgs) { 1323 if (FS.usesPositionalArg()) { 1324 S.Diag(getLocationOfByte(CS.getStart()), 1325 diag::warn_printf_positional_arg_exceeds_data_args) 1326 << (argIndex+1) << NumDataArgs 1327 << getFormatSpecifierRange(startSpecifier, specifierLen); 1328 } 1329 else { 1330 S.Diag(getLocationOfByte(CS.getStart()), 1331 diag::warn_printf_insufficient_data_args) 1332 << getFormatSpecifierRange(startSpecifier, specifierLen); 1333 } 1334 1335 // Don't do any more checking. 1336 return false; 1337 } 1338 1339 // Now type check the data expression that matches the 1340 // format specifier. 1341 const Expr *Ex = getDataArg(argIndex); 1342 const analyze_printf::ArgTypeResult &ATR = FS.getArgType(S.Context); 1343 if (ATR.isValid() && !ATR.matchesType(S.Context, Ex->getType())) { 1344 // Check if we didn't match because of an implicit cast from a 'char' 1345 // or 'short' to an 'int'. This is done because printf is a varargs 1346 // function. 1347 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Ex)) 1348 if (ICE->getType() == S.Context.IntTy) 1349 if (ATR.matchesType(S.Context, ICE->getSubExpr()->getType())) 1350 return true; 1351 1352 S.Diag(getLocationOfByte(CS.getStart()), 1353 diag::warn_printf_conversion_argument_type_mismatch) 1354 << ATR.getRepresentativeType(S.Context) << Ex->getType() 1355 << getFormatSpecifierRange(startSpecifier, specifierLen) 1356 << Ex->getSourceRange(); 1357 } 1358 1359 return true; 1360} 1361 1362void CheckPrintfHandler::DoneProcessing() { 1363 // Does the number of data arguments exceed the number of 1364 // format conversions in the format string? 1365 if (!HasVAListArg) { 1366 // Find any arguments that weren't covered. 1367 CoveredArgs.flip(); 1368 signed notCoveredArg = CoveredArgs.find_first(); 1369 if (notCoveredArg >= 0) { 1370 assert((unsigned)notCoveredArg < NumDataArgs); 1371 S.Diag(getDataArg((unsigned) notCoveredArg)->getLocStart(), 1372 diag::warn_printf_data_arg_not_used) 1373 << getFormatStringRange(); 1374 } 1375 } 1376} 1377 1378void Sema::CheckPrintfString(const StringLiteral *FExpr, 1379 const Expr *OrigFormatExpr, 1380 const CallExpr *TheCall, bool HasVAListArg, 1381 unsigned format_idx, unsigned firstDataArg) { 1382 1383 // CHECK: is the format string a wide literal? 1384 if (FExpr->isWide()) { 1385 Diag(FExpr->getLocStart(), 1386 diag::warn_printf_format_string_is_wide_literal) 1387 << OrigFormatExpr->getSourceRange(); 1388 return; 1389 } 1390 1391 // Str - The format string. NOTE: this is NOT null-terminated! 1392 const char *Str = FExpr->getStrData(); 1393 1394 // CHECK: empty format string? 1395 unsigned StrLen = FExpr->getByteLength(); 1396 1397 if (StrLen == 0) { 1398 Diag(FExpr->getLocStart(), diag::warn_printf_empty_format_string) 1399 << OrigFormatExpr->getSourceRange(); 1400 return; 1401 } 1402 1403 CheckPrintfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg, 1404 TheCall->getNumArgs() - firstDataArg, 1405 isa<ObjCStringLiteral>(OrigFormatExpr), Str, 1406 HasVAListArg, TheCall, format_idx); 1407 1408 if (!analyze_printf::ParseFormatString(H, Str, Str + StrLen)) 1409 H.DoneProcessing(); 1410} 1411 1412//===--- CHECK: Return Address of Stack Variable --------------------------===// 1413 1414static DeclRefExpr* EvalVal(Expr *E); 1415static DeclRefExpr* EvalAddr(Expr* E); 1416 1417/// CheckReturnStackAddr - Check if a return statement returns the address 1418/// of a stack variable. 1419void 1420Sema::CheckReturnStackAddr(Expr *RetValExp, QualType lhsType, 1421 SourceLocation ReturnLoc) { 1422 1423 // Perform checking for returned stack addresses. 1424 if (lhsType->isPointerType() || lhsType->isBlockPointerType()) { 1425 if (DeclRefExpr *DR = EvalAddr(RetValExp)) 1426 Diag(DR->getLocStart(), diag::warn_ret_stack_addr) 1427 << DR->getDecl()->getDeclName() << RetValExp->getSourceRange(); 1428 1429 // Skip over implicit cast expressions when checking for block expressions. 1430 RetValExp = RetValExp->IgnoreParenCasts(); 1431 1432 if (BlockExpr *C = dyn_cast<BlockExpr>(RetValExp)) 1433 if (C->hasBlockDeclRefExprs()) 1434 Diag(C->getLocStart(), diag::err_ret_local_block) 1435 << C->getSourceRange(); 1436 1437 if (AddrLabelExpr *ALE = dyn_cast<AddrLabelExpr>(RetValExp)) 1438 Diag(ALE->getLocStart(), diag::warn_ret_addr_label) 1439 << ALE->getSourceRange(); 1440 1441 } else if (lhsType->isReferenceType()) { 1442 // Perform checking for stack values returned by reference. 1443 // Check for a reference to the stack 1444 if (DeclRefExpr *DR = EvalVal(RetValExp)) 1445 Diag(DR->getLocStart(), diag::warn_ret_stack_ref) 1446 << DR->getDecl()->getDeclName() << RetValExp->getSourceRange(); 1447 } 1448} 1449 1450/// EvalAddr - EvalAddr and EvalVal are mutually recursive functions that 1451/// check if the expression in a return statement evaluates to an address 1452/// to a location on the stack. The recursion is used to traverse the 1453/// AST of the return expression, with recursion backtracking when we 1454/// encounter a subexpression that (1) clearly does not lead to the address 1455/// of a stack variable or (2) is something we cannot determine leads to 1456/// the address of a stack variable based on such local checking. 1457/// 1458/// EvalAddr processes expressions that are pointers that are used as 1459/// references (and not L-values). EvalVal handles all other values. 1460/// At the base case of the recursion is a check for a DeclRefExpr* in 1461/// the refers to a stack variable. 1462/// 1463/// This implementation handles: 1464/// 1465/// * pointer-to-pointer casts 1466/// * implicit conversions from array references to pointers 1467/// * taking the address of fields 1468/// * arbitrary interplay between "&" and "*" operators 1469/// * pointer arithmetic from an address of a stack variable 1470/// * taking the address of an array element where the array is on the stack 1471static DeclRefExpr* EvalAddr(Expr *E) { 1472 // We should only be called for evaluating pointer expressions. 1473 assert((E->getType()->isAnyPointerType() || 1474 E->getType()->isBlockPointerType() || 1475 E->getType()->isObjCQualifiedIdType()) && 1476 "EvalAddr only works on pointers"); 1477 1478 // Our "symbolic interpreter" is just a dispatch off the currently 1479 // viewed AST node. We then recursively traverse the AST by calling 1480 // EvalAddr and EvalVal appropriately. 1481 switch (E->getStmtClass()) { 1482 case Stmt::ParenExprClass: 1483 // Ignore parentheses. 1484 return EvalAddr(cast<ParenExpr>(E)->getSubExpr()); 1485 1486 case Stmt::UnaryOperatorClass: { 1487 // The only unary operator that make sense to handle here 1488 // is AddrOf. All others don't make sense as pointers. 1489 UnaryOperator *U = cast<UnaryOperator>(E); 1490 1491 if (U->getOpcode() == UnaryOperator::AddrOf) 1492 return EvalVal(U->getSubExpr()); 1493 else 1494 return NULL; 1495 } 1496 1497 case Stmt::BinaryOperatorClass: { 1498 // Handle pointer arithmetic. All other binary operators are not valid 1499 // in this context. 1500 BinaryOperator *B = cast<BinaryOperator>(E); 1501 BinaryOperator::Opcode op = B->getOpcode(); 1502 1503 if (op != BinaryOperator::Add && op != BinaryOperator::Sub) 1504 return NULL; 1505 1506 Expr *Base = B->getLHS(); 1507 1508 // Determine which argument is the real pointer base. It could be 1509 // the RHS argument instead of the LHS. 1510 if (!Base->getType()->isPointerType()) Base = B->getRHS(); 1511 1512 assert (Base->getType()->isPointerType()); 1513 return EvalAddr(Base); 1514 } 1515 1516 // For conditional operators we need to see if either the LHS or RHS are 1517 // valid DeclRefExpr*s. If one of them is valid, we return it. 1518 case Stmt::ConditionalOperatorClass: { 1519 ConditionalOperator *C = cast<ConditionalOperator>(E); 1520 1521 // Handle the GNU extension for missing LHS. 1522 if (Expr *lhsExpr = C->getLHS()) 1523 if (DeclRefExpr* LHS = EvalAddr(lhsExpr)) 1524 return LHS; 1525 1526 return EvalAddr(C->getRHS()); 1527 } 1528 1529 // For casts, we need to handle conversions from arrays to 1530 // pointer values, and pointer-to-pointer conversions. 1531 case Stmt::ImplicitCastExprClass: 1532 case Stmt::CStyleCastExprClass: 1533 case Stmt::CXXFunctionalCastExprClass: { 1534 Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1535 QualType T = SubExpr->getType(); 1536 1537 if (SubExpr->getType()->isPointerType() || 1538 SubExpr->getType()->isBlockPointerType() || 1539 SubExpr->getType()->isObjCQualifiedIdType()) 1540 return EvalAddr(SubExpr); 1541 else if (T->isArrayType()) 1542 return EvalVal(SubExpr); 1543 else 1544 return 0; 1545 } 1546 1547 // C++ casts. For dynamic casts, static casts, and const casts, we 1548 // are always converting from a pointer-to-pointer, so we just blow 1549 // through the cast. In the case the dynamic cast doesn't fail (and 1550 // return NULL), we take the conservative route and report cases 1551 // where we return the address of a stack variable. For Reinterpre 1552 // FIXME: The comment about is wrong; we're not always converting 1553 // from pointer to pointer. I'm guessing that this code should also 1554 // handle references to objects. 1555 case Stmt::CXXStaticCastExprClass: 1556 case Stmt::CXXDynamicCastExprClass: 1557 case Stmt::CXXConstCastExprClass: 1558 case Stmt::CXXReinterpretCastExprClass: { 1559 Expr *S = cast<CXXNamedCastExpr>(E)->getSubExpr(); 1560 if (S->getType()->isPointerType() || S->getType()->isBlockPointerType()) 1561 return EvalAddr(S); 1562 else 1563 return NULL; 1564 } 1565 1566 // Everything else: we simply don't reason about them. 1567 default: 1568 return NULL; 1569 } 1570} 1571 1572 1573/// EvalVal - This function is complements EvalAddr in the mutual recursion. 1574/// See the comments for EvalAddr for more details. 1575static DeclRefExpr* EvalVal(Expr *E) { 1576 1577 // We should only be called for evaluating non-pointer expressions, or 1578 // expressions with a pointer type that are not used as references but instead 1579 // are l-values (e.g., DeclRefExpr with a pointer type). 1580 1581 // Our "symbolic interpreter" is just a dispatch off the currently 1582 // viewed AST node. We then recursively traverse the AST by calling 1583 // EvalAddr and EvalVal appropriately. 1584 switch (E->getStmtClass()) { 1585 case Stmt::DeclRefExprClass: { 1586 // DeclRefExpr: the base case. When we hit a DeclRefExpr we are looking 1587 // at code that refers to a variable's name. We check if it has local 1588 // storage within the function, and if so, return the expression. 1589 DeclRefExpr *DR = cast<DeclRefExpr>(E); 1590 1591 if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl())) 1592 if (V->hasLocalStorage() && !V->getType()->isReferenceType()) return DR; 1593 1594 return NULL; 1595 } 1596 1597 case Stmt::ParenExprClass: 1598 // Ignore parentheses. 1599 return EvalVal(cast<ParenExpr>(E)->getSubExpr()); 1600 1601 case Stmt::UnaryOperatorClass: { 1602 // The only unary operator that make sense to handle here 1603 // is Deref. All others don't resolve to a "name." This includes 1604 // handling all sorts of rvalues passed to a unary operator. 1605 UnaryOperator *U = cast<UnaryOperator>(E); 1606 1607 if (U->getOpcode() == UnaryOperator::Deref) 1608 return EvalAddr(U->getSubExpr()); 1609 1610 return NULL; 1611 } 1612 1613 case Stmt::ArraySubscriptExprClass: { 1614 // Array subscripts are potential references to data on the stack. We 1615 // retrieve the DeclRefExpr* for the array variable if it indeed 1616 // has local storage. 1617 return EvalAddr(cast<ArraySubscriptExpr>(E)->getBase()); 1618 } 1619 1620 case Stmt::ConditionalOperatorClass: { 1621 // For conditional operators we need to see if either the LHS or RHS are 1622 // non-NULL DeclRefExpr's. If one is non-NULL, we return it. 1623 ConditionalOperator *C = cast<ConditionalOperator>(E); 1624 1625 // Handle the GNU extension for missing LHS. 1626 if (Expr *lhsExpr = C->getLHS()) 1627 if (DeclRefExpr *LHS = EvalVal(lhsExpr)) 1628 return LHS; 1629 1630 return EvalVal(C->getRHS()); 1631 } 1632 1633 // Accesses to members are potential references to data on the stack. 1634 case Stmt::MemberExprClass: { 1635 MemberExpr *M = cast<MemberExpr>(E); 1636 1637 // Check for indirect access. We only want direct field accesses. 1638 if (!M->isArrow()) 1639 return EvalVal(M->getBase()); 1640 else 1641 return NULL; 1642 } 1643 1644 // Everything else: we simply don't reason about them. 1645 default: 1646 return NULL; 1647 } 1648} 1649 1650//===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===// 1651 1652/// Check for comparisons of floating point operands using != and ==. 1653/// Issue a warning if these are no self-comparisons, as they are not likely 1654/// to do what the programmer intended. 1655void Sema::CheckFloatComparison(SourceLocation loc, Expr* lex, Expr *rex) { 1656 bool EmitWarning = true; 1657 1658 Expr* LeftExprSansParen = lex->IgnoreParens(); 1659 Expr* RightExprSansParen = rex->IgnoreParens(); 1660 1661 // Special case: check for x == x (which is OK). 1662 // Do not emit warnings for such cases. 1663 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LeftExprSansParen)) 1664 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RightExprSansParen)) 1665 if (DRL->getDecl() == DRR->getDecl()) 1666 EmitWarning = false; 1667 1668 1669 // Special case: check for comparisons against literals that can be exactly 1670 // represented by APFloat. In such cases, do not emit a warning. This 1671 // is a heuristic: often comparison against such literals are used to 1672 // detect if a value in a variable has not changed. This clearly can 1673 // lead to false negatives. 1674 if (EmitWarning) { 1675 if (FloatingLiteral* FLL = dyn_cast<FloatingLiteral>(LeftExprSansParen)) { 1676 if (FLL->isExact()) 1677 EmitWarning = false; 1678 } else 1679 if (FloatingLiteral* FLR = dyn_cast<FloatingLiteral>(RightExprSansParen)){ 1680 if (FLR->isExact()) 1681 EmitWarning = false; 1682 } 1683 } 1684 1685 // Check for comparisons with builtin types. 1686 if (EmitWarning) 1687 if (CallExpr* CL = dyn_cast<CallExpr>(LeftExprSansParen)) 1688 if (CL->isBuiltinCall(Context)) 1689 EmitWarning = false; 1690 1691 if (EmitWarning) 1692 if (CallExpr* CR = dyn_cast<CallExpr>(RightExprSansParen)) 1693 if (CR->isBuiltinCall(Context)) 1694 EmitWarning = false; 1695 1696 // Emit the diagnostic. 1697 if (EmitWarning) 1698 Diag(loc, diag::warn_floatingpoint_eq) 1699 << lex->getSourceRange() << rex->getSourceRange(); 1700} 1701 1702//===--- CHECK: Integer mixed-sign comparisons (-Wsign-compare) --------===// 1703//===--- CHECK: Lossy implicit conversions (-Wconversion) --------------===// 1704 1705namespace { 1706 1707/// Structure recording the 'active' range of an integer-valued 1708/// expression. 1709struct IntRange { 1710 /// The number of bits active in the int. 1711 unsigned Width; 1712 1713 /// True if the int is known not to have negative values. 1714 bool NonNegative; 1715 1716 IntRange() {} 1717 IntRange(unsigned Width, bool NonNegative) 1718 : Width(Width), NonNegative(NonNegative) 1719 {} 1720 1721 // Returns the range of the bool type. 1722 static IntRange forBoolType() { 1723 return IntRange(1, true); 1724 } 1725 1726 // Returns the range of an integral type. 1727 static IntRange forType(ASTContext &C, QualType T) { 1728 return forCanonicalType(C, T->getCanonicalTypeInternal().getTypePtr()); 1729 } 1730 1731 // Returns the range of an integeral type based on its canonical 1732 // representation. 1733 static IntRange forCanonicalType(ASTContext &C, const Type *T) { 1734 assert(T->isCanonicalUnqualified()); 1735 1736 if (const VectorType *VT = dyn_cast<VectorType>(T)) 1737 T = VT->getElementType().getTypePtr(); 1738 if (const ComplexType *CT = dyn_cast<ComplexType>(T)) 1739 T = CT->getElementType().getTypePtr(); 1740 if (const EnumType *ET = dyn_cast<EnumType>(T)) 1741 T = ET->getDecl()->getIntegerType().getTypePtr(); 1742 1743 const BuiltinType *BT = cast<BuiltinType>(T); 1744 assert(BT->isInteger()); 1745 1746 return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger()); 1747 } 1748 1749 // Returns the supremum of two ranges: i.e. their conservative merge. 1750 static IntRange join(IntRange L, IntRange R) { 1751 return IntRange(std::max(L.Width, R.Width), 1752 L.NonNegative && R.NonNegative); 1753 } 1754 1755 // Returns the infinum of two ranges: i.e. their aggressive merge. 1756 static IntRange meet(IntRange L, IntRange R) { 1757 return IntRange(std::min(L.Width, R.Width), 1758 L.NonNegative || R.NonNegative); 1759 } 1760}; 1761 1762IntRange GetValueRange(ASTContext &C, llvm::APSInt &value, unsigned MaxWidth) { 1763 if (value.isSigned() && value.isNegative()) 1764 return IntRange(value.getMinSignedBits(), false); 1765 1766 if (value.getBitWidth() > MaxWidth) 1767 value.trunc(MaxWidth); 1768 1769 // isNonNegative() just checks the sign bit without considering 1770 // signedness. 1771 return IntRange(value.getActiveBits(), true); 1772} 1773 1774IntRange GetValueRange(ASTContext &C, APValue &result, QualType Ty, 1775 unsigned MaxWidth) { 1776 if (result.isInt()) 1777 return GetValueRange(C, result.getInt(), MaxWidth); 1778 1779 if (result.isVector()) { 1780 IntRange R = GetValueRange(C, result.getVectorElt(0), Ty, MaxWidth); 1781 for (unsigned i = 1, e = result.getVectorLength(); i != e; ++i) { 1782 IntRange El = GetValueRange(C, result.getVectorElt(i), Ty, MaxWidth); 1783 R = IntRange::join(R, El); 1784 } 1785 return R; 1786 } 1787 1788 if (result.isComplexInt()) { 1789 IntRange R = GetValueRange(C, result.getComplexIntReal(), MaxWidth); 1790 IntRange I = GetValueRange(C, result.getComplexIntImag(), MaxWidth); 1791 return IntRange::join(R, I); 1792 } 1793 1794 // This can happen with lossless casts to intptr_t of "based" lvalues. 1795 // Assume it might use arbitrary bits. 1796 // FIXME: The only reason we need to pass the type in here is to get 1797 // the sign right on this one case. It would be nice if APValue 1798 // preserved this. 1799 assert(result.isLValue()); 1800 return IntRange(MaxWidth, Ty->isUnsignedIntegerType()); 1801} 1802 1803/// Pseudo-evaluate the given integer expression, estimating the 1804/// range of values it might take. 1805/// 1806/// \param MaxWidth - the width to which the value will be truncated 1807IntRange GetExprRange(ASTContext &C, Expr *E, unsigned MaxWidth) { 1808 E = E->IgnoreParens(); 1809 1810 // Try a full evaluation first. 1811 Expr::EvalResult result; 1812 if (E->Evaluate(result, C)) 1813 return GetValueRange(C, result.Val, E->getType(), MaxWidth); 1814 1815 // I think we only want to look through implicit casts here; if the 1816 // user has an explicit widening cast, we should treat the value as 1817 // being of the new, wider type. 1818 if (ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E)) { 1819 if (CE->getCastKind() == CastExpr::CK_NoOp) 1820 return GetExprRange(C, CE->getSubExpr(), MaxWidth); 1821 1822 IntRange OutputTypeRange = IntRange::forType(C, CE->getType()); 1823 1824 bool isIntegerCast = (CE->getCastKind() == CastExpr::CK_IntegralCast); 1825 if (!isIntegerCast && CE->getCastKind() == CastExpr::CK_Unknown) 1826 isIntegerCast = CE->getSubExpr()->getType()->isIntegerType(); 1827 1828 // Assume that non-integer casts can span the full range of the type. 1829 if (!isIntegerCast) 1830 return OutputTypeRange; 1831 1832 IntRange SubRange 1833 = GetExprRange(C, CE->getSubExpr(), 1834 std::min(MaxWidth, OutputTypeRange.Width)); 1835 1836 // Bail out if the subexpr's range is as wide as the cast type. 1837 if (SubRange.Width >= OutputTypeRange.Width) 1838 return OutputTypeRange; 1839 1840 // Otherwise, we take the smaller width, and we're non-negative if 1841 // either the output type or the subexpr is. 1842 return IntRange(SubRange.Width, 1843 SubRange.NonNegative || OutputTypeRange.NonNegative); 1844 } 1845 1846 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) { 1847 // If we can fold the condition, just take that operand. 1848 bool CondResult; 1849 if (CO->getCond()->EvaluateAsBooleanCondition(CondResult, C)) 1850 return GetExprRange(C, CondResult ? CO->getTrueExpr() 1851 : CO->getFalseExpr(), 1852 MaxWidth); 1853 1854 // Otherwise, conservatively merge. 1855 IntRange L = GetExprRange(C, CO->getTrueExpr(), MaxWidth); 1856 IntRange R = GetExprRange(C, CO->getFalseExpr(), MaxWidth); 1857 return IntRange::join(L, R); 1858 } 1859 1860 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { 1861 switch (BO->getOpcode()) { 1862 1863 // Boolean-valued operations are single-bit and positive. 1864 case BinaryOperator::LAnd: 1865 case BinaryOperator::LOr: 1866 case BinaryOperator::LT: 1867 case BinaryOperator::GT: 1868 case BinaryOperator::LE: 1869 case BinaryOperator::GE: 1870 case BinaryOperator::EQ: 1871 case BinaryOperator::NE: 1872 return IntRange::forBoolType(); 1873 1874 // The type of these compound assignments is the type of the LHS, 1875 // so the RHS is not necessarily an integer. 1876 case BinaryOperator::MulAssign: 1877 case BinaryOperator::DivAssign: 1878 case BinaryOperator::RemAssign: 1879 case BinaryOperator::AddAssign: 1880 case BinaryOperator::SubAssign: 1881 return IntRange::forType(C, E->getType()); 1882 1883 // Operations with opaque sources are black-listed. 1884 case BinaryOperator::PtrMemD: 1885 case BinaryOperator::PtrMemI: 1886 return IntRange::forType(C, E->getType()); 1887 1888 // Bitwise-and uses the *infinum* of the two source ranges. 1889 case BinaryOperator::And: 1890 case BinaryOperator::AndAssign: 1891 return IntRange::meet(GetExprRange(C, BO->getLHS(), MaxWidth), 1892 GetExprRange(C, BO->getRHS(), MaxWidth)); 1893 1894 // Left shift gets black-listed based on a judgement call. 1895 case BinaryOperator::Shl: 1896 // ...except that we want to treat '1 << (blah)' as logically 1897 // positive. It's an important idiom. 1898 if (IntegerLiteral *I 1899 = dyn_cast<IntegerLiteral>(BO->getLHS()->IgnoreParenCasts())) { 1900 if (I->getValue() == 1) { 1901 IntRange R = IntRange::forType(C, E->getType()); 1902 return IntRange(R.Width, /*NonNegative*/ true); 1903 } 1904 } 1905 // fallthrough 1906 1907 case BinaryOperator::ShlAssign: 1908 return IntRange::forType(C, E->getType()); 1909 1910 // Right shift by a constant can narrow its left argument. 1911 case BinaryOperator::Shr: 1912 case BinaryOperator::ShrAssign: { 1913 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth); 1914 1915 // If the shift amount is a positive constant, drop the width by 1916 // that much. 1917 llvm::APSInt shift; 1918 if (BO->getRHS()->isIntegerConstantExpr(shift, C) && 1919 shift.isNonNegative()) { 1920 unsigned zext = shift.getZExtValue(); 1921 if (zext >= L.Width) 1922 L.Width = (L.NonNegative ? 0 : 1); 1923 else 1924 L.Width -= zext; 1925 } 1926 1927 return L; 1928 } 1929 1930 // Comma acts as its right operand. 1931 case BinaryOperator::Comma: 1932 return GetExprRange(C, BO->getRHS(), MaxWidth); 1933 1934 // Black-list pointer subtractions. 1935 case BinaryOperator::Sub: 1936 if (BO->getLHS()->getType()->isPointerType()) 1937 return IntRange::forType(C, E->getType()); 1938 // fallthrough 1939 1940 default: 1941 break; 1942 } 1943 1944 // Treat every other operator as if it were closed on the 1945 // narrowest type that encompasses both operands. 1946 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth); 1947 IntRange R = GetExprRange(C, BO->getRHS(), MaxWidth); 1948 return IntRange::join(L, R); 1949 } 1950 1951 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) { 1952 switch (UO->getOpcode()) { 1953 // Boolean-valued operations are white-listed. 1954 case UnaryOperator::LNot: 1955 return IntRange::forBoolType(); 1956 1957 // Operations with opaque sources are black-listed. 1958 case UnaryOperator::Deref: 1959 case UnaryOperator::AddrOf: // should be impossible 1960 case UnaryOperator::OffsetOf: 1961 return IntRange::forType(C, E->getType()); 1962 1963 default: 1964 return GetExprRange(C, UO->getSubExpr(), MaxWidth); 1965 } 1966 } 1967 1968 FieldDecl *BitField = E->getBitField(); 1969 if (BitField) { 1970 llvm::APSInt BitWidthAP = BitField->getBitWidth()->EvaluateAsInt(C); 1971 unsigned BitWidth = BitWidthAP.getZExtValue(); 1972 1973 return IntRange(BitWidth, BitField->getType()->isUnsignedIntegerType()); 1974 } 1975 1976 return IntRange::forType(C, E->getType()); 1977} 1978 1979/// Checks whether the given value, which currently has the given 1980/// source semantics, has the same value when coerced through the 1981/// target semantics. 1982bool IsSameFloatAfterCast(const llvm::APFloat &value, 1983 const llvm::fltSemantics &Src, 1984 const llvm::fltSemantics &Tgt) { 1985 llvm::APFloat truncated = value; 1986 1987 bool ignored; 1988 truncated.convert(Src, llvm::APFloat::rmNearestTiesToEven, &ignored); 1989 truncated.convert(Tgt, llvm::APFloat::rmNearestTiesToEven, &ignored); 1990 1991 return truncated.bitwiseIsEqual(value); 1992} 1993 1994/// Checks whether the given value, which currently has the given 1995/// source semantics, has the same value when coerced through the 1996/// target semantics. 1997/// 1998/// The value might be a vector of floats (or a complex number). 1999bool IsSameFloatAfterCast(const APValue &value, 2000 const llvm::fltSemantics &Src, 2001 const llvm::fltSemantics &Tgt) { 2002 if (value.isFloat()) 2003 return IsSameFloatAfterCast(value.getFloat(), Src, Tgt); 2004 2005 if (value.isVector()) { 2006 for (unsigned i = 0, e = value.getVectorLength(); i != e; ++i) 2007 if (!IsSameFloatAfterCast(value.getVectorElt(i), Src, Tgt)) 2008 return false; 2009 return true; 2010 } 2011 2012 assert(value.isComplexFloat()); 2013 return (IsSameFloatAfterCast(value.getComplexFloatReal(), Src, Tgt) && 2014 IsSameFloatAfterCast(value.getComplexFloatImag(), Src, Tgt)); 2015} 2016 2017} // end anonymous namespace 2018 2019/// \brief Implements -Wsign-compare. 2020/// 2021/// \param lex the left-hand expression 2022/// \param rex the right-hand expression 2023/// \param OpLoc the location of the joining operator 2024/// \param BinOpc binary opcode or 0 2025void Sema::CheckSignCompare(Expr *lex, Expr *rex, SourceLocation OpLoc, 2026 const BinaryOperator::Opcode* BinOpc) { 2027 // Don't warn if we're in an unevaluated context. 2028 if (ExprEvalContexts.back().Context == Unevaluated) 2029 return; 2030 2031 // If either expression is value-dependent, don't warn. We'll get another 2032 // chance at instantiation time. 2033 if (lex->isValueDependent() || rex->isValueDependent()) 2034 return; 2035 2036 QualType lt = lex->getType(), rt = rex->getType(); 2037 2038 // Only warn if both operands are integral. 2039 if (!lt->isIntegerType() || !rt->isIntegerType()) 2040 return; 2041 2042 // In C, the width of a bitfield determines its type, and the 2043 // declared type only contributes the signedness. This duplicates 2044 // the work that will later be done by UsualUnaryConversions. 2045 // Eventually, this check will be reorganized in a way that avoids 2046 // this duplication. 2047 if (!getLangOptions().CPlusPlus) { 2048 QualType tmp; 2049 tmp = Context.isPromotableBitField(lex); 2050 if (!tmp.isNull()) lt = tmp; 2051 tmp = Context.isPromotableBitField(rex); 2052 if (!tmp.isNull()) rt = tmp; 2053 } 2054 2055 if (const EnumType *E = lt->getAs<EnumType>()) 2056 lt = E->getDecl()->getPromotionType(); 2057 if (const EnumType *E = rt->getAs<EnumType>()) 2058 rt = E->getDecl()->getPromotionType(); 2059 2060 // The rule is that the signed operand becomes unsigned, so isolate the 2061 // signed operand. 2062 Expr *signedOperand = lex, *unsignedOperand = rex; 2063 QualType signedType = lt, unsignedType = rt; 2064 if (lt->isSignedIntegerType()) { 2065 if (rt->isSignedIntegerType()) return; 2066 } else { 2067 if (!rt->isSignedIntegerType()) return; 2068 std::swap(signedOperand, unsignedOperand); 2069 std::swap(signedType, unsignedType); 2070 } 2071 2072 unsigned unsignedWidth = Context.getIntWidth(unsignedType); 2073 unsigned signedWidth = Context.getIntWidth(signedType); 2074 2075 // If the unsigned type is strictly smaller than the signed type, 2076 // then (1) the result type will be signed and (2) the unsigned 2077 // value will fit fully within the signed type, and thus the result 2078 // of the comparison will be exact. 2079 if (signedWidth > unsignedWidth) 2080 return; 2081 2082 // Otherwise, calculate the effective ranges. 2083 IntRange signedRange = GetExprRange(Context, signedOperand, signedWidth); 2084 IntRange unsignedRange = GetExprRange(Context, unsignedOperand, unsignedWidth); 2085 2086 // We should never be unable to prove that the unsigned operand is 2087 // non-negative. 2088 assert(unsignedRange.NonNegative && "unsigned range includes negative?"); 2089 2090 // If the signed operand is non-negative, then the signed->unsigned 2091 // conversion won't change it. 2092 if (signedRange.NonNegative) { 2093 // Emit warnings for comparisons of unsigned to integer constant 0. 2094 // always false: x < 0 (or 0 > x) 2095 // always true: x >= 0 (or 0 <= x) 2096 llvm::APSInt X; 2097 if (BinOpc && signedOperand->isIntegerConstantExpr(X, Context) && X == 0) { 2098 if (signedOperand != lex) { 2099 if (*BinOpc == BinaryOperator::LT) { 2100 Diag(OpLoc, diag::warn_lunsigned_always_true_comparison) 2101 << "< 0" << "false" 2102 << lex->getSourceRange() << rex->getSourceRange(); 2103 } 2104 else if (*BinOpc == BinaryOperator::GE) { 2105 Diag(OpLoc, diag::warn_lunsigned_always_true_comparison) 2106 << ">= 0" << "true" 2107 << lex->getSourceRange() << rex->getSourceRange(); 2108 } 2109 } 2110 else { 2111 if (*BinOpc == BinaryOperator::GT) { 2112 Diag(OpLoc, diag::warn_runsigned_always_true_comparison) 2113 << "0 >" << "false" 2114 << lex->getSourceRange() << rex->getSourceRange(); 2115 } 2116 else if (*BinOpc == BinaryOperator::LE) { 2117 Diag(OpLoc, diag::warn_runsigned_always_true_comparison) 2118 << "0 <=" << "true" 2119 << lex->getSourceRange() << rex->getSourceRange(); 2120 } 2121 } 2122 } 2123 return; 2124 } 2125 2126 // For (in)equality comparisons, if the unsigned operand is a 2127 // constant which cannot collide with a overflowed signed operand, 2128 // then reinterpreting the signed operand as unsigned will not 2129 // change the result of the comparison. 2130 if (BinOpc && 2131 (*BinOpc == BinaryOperator::EQ || *BinOpc == BinaryOperator::NE) && 2132 unsignedRange.Width < unsignedWidth) 2133 return; 2134 2135 Diag(OpLoc, BinOpc ? diag::warn_mixed_sign_comparison 2136 : diag::warn_mixed_sign_conditional) 2137 << lt << rt << lex->getSourceRange() << rex->getSourceRange(); 2138} 2139 2140/// Diagnose an implicit cast; purely a helper for CheckImplicitConversion. 2141static void DiagnoseImpCast(Sema &S, Expr *E, QualType T, unsigned diag) { 2142 S.Diag(E->getExprLoc(), diag) << E->getType() << T << E->getSourceRange(); 2143} 2144 2145/// Implements -Wconversion. 2146void Sema::CheckImplicitConversion(Expr *E, QualType T) { 2147 // Don't diagnose in unevaluated contexts. 2148 if (ExprEvalContexts.back().Context == Sema::Unevaluated) 2149 return; 2150 2151 // Don't diagnose for value-dependent expressions. 2152 if (E->isValueDependent()) 2153 return; 2154 2155 const Type *Source = Context.getCanonicalType(E->getType()).getTypePtr(); 2156 const Type *Target = Context.getCanonicalType(T).getTypePtr(); 2157 2158 // Never diagnose implicit casts to bool. 2159 if (Target->isSpecificBuiltinType(BuiltinType::Bool)) 2160 return; 2161 2162 // Strip vector types. 2163 if (isa<VectorType>(Source)) { 2164 if (!isa<VectorType>(Target)) 2165 return DiagnoseImpCast(*this, E, T, diag::warn_impcast_vector_scalar); 2166 2167 Source = cast<VectorType>(Source)->getElementType().getTypePtr(); 2168 Target = cast<VectorType>(Target)->getElementType().getTypePtr(); 2169 } 2170 2171 // Strip complex types. 2172 if (isa<ComplexType>(Source)) { 2173 if (!isa<ComplexType>(Target)) 2174 return DiagnoseImpCast(*this, E, T, diag::warn_impcast_complex_scalar); 2175 2176 Source = cast<ComplexType>(Source)->getElementType().getTypePtr(); 2177 Target = cast<ComplexType>(Target)->getElementType().getTypePtr(); 2178 } 2179 2180 const BuiltinType *SourceBT = dyn_cast<BuiltinType>(Source); 2181 const BuiltinType *TargetBT = dyn_cast<BuiltinType>(Target); 2182 2183 // If the source is floating point... 2184 if (SourceBT && SourceBT->isFloatingPoint()) { 2185 // ...and the target is floating point... 2186 if (TargetBT && TargetBT->isFloatingPoint()) { 2187 // ...then warn if we're dropping FP rank. 2188 2189 // Builtin FP kinds are ordered by increasing FP rank. 2190 if (SourceBT->getKind() > TargetBT->getKind()) { 2191 // Don't warn about float constants that are precisely 2192 // representable in the target type. 2193 Expr::EvalResult result; 2194 if (E->Evaluate(result, Context)) { 2195 // Value might be a float, a float vector, or a float complex. 2196 if (IsSameFloatAfterCast(result.Val, 2197 Context.getFloatTypeSemantics(QualType(TargetBT, 0)), 2198 Context.getFloatTypeSemantics(QualType(SourceBT, 0)))) 2199 return; 2200 } 2201 2202 DiagnoseImpCast(*this, E, T, diag::warn_impcast_float_precision); 2203 } 2204 return; 2205 } 2206 2207 // If the target is integral, always warn. 2208 if ((TargetBT && TargetBT->isInteger())) 2209 // TODO: don't warn for integer values? 2210 return DiagnoseImpCast(*this, E, T, diag::warn_impcast_float_integer); 2211 2212 return; 2213 } 2214 2215 if (!Source->isIntegerType() || !Target->isIntegerType()) 2216 return; 2217 2218 IntRange SourceRange = GetExprRange(Context, E, Context.getIntWidth(E->getType())); 2219 IntRange TargetRange = IntRange::forCanonicalType(Context, Target); 2220 2221 // FIXME: also signed<->unsigned? 2222 2223 if (SourceRange.Width > TargetRange.Width) { 2224 // People want to build with -Wshorten-64-to-32 and not -Wconversion 2225 // and by god we'll let them. 2226 if (SourceRange.Width == 64 && TargetRange.Width == 32) 2227 return DiagnoseImpCast(*this, E, T, diag::warn_impcast_integer_64_32); 2228 return DiagnoseImpCast(*this, E, T, diag::warn_impcast_integer_precision); 2229 } 2230 2231 return; 2232} 2233 2234/// CheckParmsForFunctionDef - Check that the parameters of the given 2235/// function are appropriate for the definition of a function. This 2236/// takes care of any checks that cannot be performed on the 2237/// declaration itself, e.g., that the types of each of the function 2238/// parameters are complete. 2239bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 2240 bool HasInvalidParm = false; 2241 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2242 ParmVarDecl *Param = FD->getParamDecl(p); 2243 2244 // C99 6.7.5.3p4: the parameters in a parameter type list in a 2245 // function declarator that is part of a function definition of 2246 // that function shall not have incomplete type. 2247 // 2248 // This is also C++ [dcl.fct]p6. 2249 if (!Param->isInvalidDecl() && 2250 RequireCompleteType(Param->getLocation(), Param->getType(), 2251 diag::err_typecheck_decl_incomplete_type)) { 2252 Param->setInvalidDecl(); 2253 HasInvalidParm = true; 2254 } 2255 2256 // C99 6.9.1p5: If the declarator includes a parameter type list, the 2257 // declaration of each parameter shall include an identifier. 2258 if (Param->getIdentifier() == 0 && 2259 !Param->isImplicit() && 2260 !getLangOptions().CPlusPlus) 2261 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 2262 2263 // C99 6.7.5.3p12: 2264 // If the function declarator is not part of a definition of that 2265 // function, parameters may have incomplete type and may use the [*] 2266 // notation in their sequences of declarator specifiers to specify 2267 // variable length array types. 2268 QualType PType = Param->getOriginalType(); 2269 if (const ArrayType *AT = Context.getAsArrayType(PType)) { 2270 if (AT->getSizeModifier() == ArrayType::Star) { 2271 // FIXME: This diagnosic should point the the '[*]' if source-location 2272 // information is added for it. 2273 Diag(Param->getLocation(), diag::err_array_star_in_function_definition); 2274 } 2275 } 2276 } 2277 2278 return HasInvalidParm; 2279} 2280