1 //===--- SemaChecking.cpp - Extra Semantic Checking -----------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements extra semantic analysis beyond what is enforced
11 // by the C type system.
13 //===----------------------------------------------------------------------===//
15 #include "clang/Sema/SemaInternal.h"
16 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/CharUnits.h"
18 #include "clang/AST/DeclCXX.h"
19 #include "clang/AST/DeclObjC.h"
20 #include "clang/AST/EvaluatedExprVisitor.h"
21 #include "clang/AST/Expr.h"
22 #include "clang/AST/ExprCXX.h"
23 #include "clang/AST/ExprObjC.h"
24 #include "clang/AST/StmtCXX.h"
25 #include "clang/AST/StmtObjC.h"
26 #include "clang/Analysis/Analyses/FormatString.h"
27 #include "clang/Basic/CharInfo.h"
28 #include "clang/Basic/TargetBuiltins.h"
29 #include "clang/Basic/TargetInfo.h"
30 #include "clang/Lex/Lexer.h" // TODO: Extract static functions to fix layering.
31 #include "clang/Sema/Initialization.h"
32 #include "clang/Sema/Lookup.h"
33 #include "clang/Sema/ScopeInfo.h"
34 #include "clang/Sema/Sema.h"
35 #include "llvm/ADT/STLExtras.h"
36 #include "llvm/ADT/SmallBitVector.h"
37 #include "llvm/ADT/SmallString.h"
38 #include "llvm/Support/ConvertUTF.h"
39 #include "llvm/Support/raw_ostream.h"
41 using namespace clang;
44 SourceLocation Sema::getLocationOfStringLiteralByte(const StringLiteral *SL,
45 unsigned ByteNo) const {
46 return SL->getLocationOfByte(ByteNo, getSourceManager(), LangOpts,
47 Context.getTargetInfo());
50 /// Checks that a call expression's argument count is the desired number.
51 /// This is useful when doing custom type-checking. Returns true on error.
52 static bool checkArgCount(Sema &S, CallExpr *call, unsigned desiredArgCount) {
53 unsigned argCount = call->getNumArgs();
54 if (argCount == desiredArgCount) return false;
56 if (argCount < desiredArgCount)
57 return S.Diag(call->getLocEnd(), diag::err_typecheck_call_too_few_args)
58 << 0 /*function call*/ << desiredArgCount << argCount
59 << call->getSourceRange();
61 // Highlight all the excess arguments.
62 SourceRange range(call->getArg(desiredArgCount)->getLocStart(),
63 call->getArg(argCount - 1)->getLocEnd());
65 return S.Diag(range.getBegin(), diag::err_typecheck_call_too_many_args)
66 << 0 /*function call*/ << desiredArgCount << argCount
67 << call->getArg(1)->getSourceRange();
70 /// Check that the first argument to __builtin_annotation is an integer
71 /// and the second argument is a non-wide string literal.
72 static bool SemaBuiltinAnnotation(Sema &S, CallExpr *TheCall) {
73 if (checkArgCount(S, TheCall, 2))
76 // First argument should be an integer.
77 Expr *ValArg = TheCall->getArg(0);
78 QualType Ty = ValArg->getType();
79 if (!Ty->isIntegerType()) {
80 S.Diag(ValArg->getLocStart(), diag::err_builtin_annotation_first_arg)
81 << ValArg->getSourceRange();
85 // Second argument should be a constant string.
86 Expr *StrArg = TheCall->getArg(1)->IgnoreParenCasts();
87 StringLiteral *Literal = dyn_cast<StringLiteral>(StrArg);
88 if (!Literal || !Literal->isAscii()) {
89 S.Diag(StrArg->getLocStart(), diag::err_builtin_annotation_second_arg)
90 << StrArg->getSourceRange();
98 /// Check that the argument to __builtin_addressof is a glvalue, and set the
99 /// result type to the corresponding pointer type.
100 static bool SemaBuiltinAddressof(Sema &S, CallExpr *TheCall) {
101 if (checkArgCount(S, TheCall, 1))
104 ExprResult Arg(TheCall->getArg(0));
105 QualType ResultType = S.CheckAddressOfOperand(Arg, TheCall->getLocStart());
106 if (ResultType.isNull())
109 TheCall->setArg(0, Arg.get());
110 TheCall->setType(ResultType);
115 Sema::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
116 ExprResult TheCallResult(TheCall);
118 // Find out if any arguments are required to be integer constant expressions.
119 unsigned ICEArguments = 0;
120 ASTContext::GetBuiltinTypeError Error;
121 Context.GetBuiltinType(BuiltinID, Error, &ICEArguments);
122 if (Error != ASTContext::GE_None)
123 ICEArguments = 0; // Don't diagnose previously diagnosed errors.
125 // If any arguments are required to be ICE's, check and diagnose.
126 for (unsigned ArgNo = 0; ICEArguments != 0; ++ArgNo) {
127 // Skip arguments not required to be ICE's.
128 if ((ICEArguments & (1 << ArgNo)) == 0) continue;
131 if (SemaBuiltinConstantArg(TheCall, ArgNo, Result))
133 ICEArguments &= ~(1 << ArgNo);
137 case Builtin::BI__builtin___CFStringMakeConstantString:
138 assert(TheCall->getNumArgs() == 1 &&
139 "Wrong # arguments to builtin CFStringMakeConstantString");
140 if (CheckObjCString(TheCall->getArg(0)))
143 case Builtin::BI__builtin_stdarg_start:
144 case Builtin::BI__builtin_va_start:
145 if (SemaBuiltinVAStart(TheCall))
148 case Builtin::BI__va_start: {
149 switch (Context.getTargetInfo().getTriple().getArch()) {
150 case llvm::Triple::arm:
151 case llvm::Triple::thumb:
152 if (SemaBuiltinVAStartARM(TheCall))
156 if (SemaBuiltinVAStart(TheCall))
162 case Builtin::BI__builtin_isgreater:
163 case Builtin::BI__builtin_isgreaterequal:
164 case Builtin::BI__builtin_isless:
165 case Builtin::BI__builtin_islessequal:
166 case Builtin::BI__builtin_islessgreater:
167 case Builtin::BI__builtin_isunordered:
168 if (SemaBuiltinUnorderedCompare(TheCall))
171 case Builtin::BI__builtin_fpclassify:
172 if (SemaBuiltinFPClassification(TheCall, 6))
175 case Builtin::BI__builtin_isfinite:
176 case Builtin::BI__builtin_isinf:
177 case Builtin::BI__builtin_isinf_sign:
178 case Builtin::BI__builtin_isnan:
179 case Builtin::BI__builtin_isnormal:
180 if (SemaBuiltinFPClassification(TheCall, 1))
183 case Builtin::BI__builtin_shufflevector:
184 return SemaBuiltinShuffleVector(TheCall);
185 // TheCall will be freed by the smart pointer here, but that's fine, since
186 // SemaBuiltinShuffleVector guts it, but then doesn't release it.
187 case Builtin::BI__builtin_prefetch:
188 if (SemaBuiltinPrefetch(TheCall))
191 case Builtin::BI__assume:
192 if (SemaBuiltinAssume(TheCall))
195 case Builtin::BI__builtin_object_size:
196 if (SemaBuiltinConstantArgRange(TheCall, 1, 0, 3))
199 case Builtin::BI__builtin_longjmp:
200 if (SemaBuiltinLongjmp(TheCall))
204 case Builtin::BI__builtin_classify_type:
205 if (checkArgCount(*this, TheCall, 1)) return true;
206 TheCall->setType(Context.IntTy);
208 case Builtin::BI__builtin_constant_p:
209 if (checkArgCount(*this, TheCall, 1)) return true;
210 TheCall->setType(Context.IntTy);
212 case Builtin::BI__sync_fetch_and_add:
213 case Builtin::BI__sync_fetch_and_add_1:
214 case Builtin::BI__sync_fetch_and_add_2:
215 case Builtin::BI__sync_fetch_and_add_4:
216 case Builtin::BI__sync_fetch_and_add_8:
217 case Builtin::BI__sync_fetch_and_add_16:
218 case Builtin::BI__sync_fetch_and_sub:
219 case Builtin::BI__sync_fetch_and_sub_1:
220 case Builtin::BI__sync_fetch_and_sub_2:
221 case Builtin::BI__sync_fetch_and_sub_4:
222 case Builtin::BI__sync_fetch_and_sub_8:
223 case Builtin::BI__sync_fetch_and_sub_16:
224 case Builtin::BI__sync_fetch_and_or:
225 case Builtin::BI__sync_fetch_and_or_1:
226 case Builtin::BI__sync_fetch_and_or_2:
227 case Builtin::BI__sync_fetch_and_or_4:
228 case Builtin::BI__sync_fetch_and_or_8:
229 case Builtin::BI__sync_fetch_and_or_16:
230 case Builtin::BI__sync_fetch_and_and:
231 case Builtin::BI__sync_fetch_and_and_1:
232 case Builtin::BI__sync_fetch_and_and_2:
233 case Builtin::BI__sync_fetch_and_and_4:
234 case Builtin::BI__sync_fetch_and_and_8:
235 case Builtin::BI__sync_fetch_and_and_16:
236 case Builtin::BI__sync_fetch_and_xor:
237 case Builtin::BI__sync_fetch_and_xor_1:
238 case Builtin::BI__sync_fetch_and_xor_2:
239 case Builtin::BI__sync_fetch_and_xor_4:
240 case Builtin::BI__sync_fetch_and_xor_8:
241 case Builtin::BI__sync_fetch_and_xor_16:
242 case Builtin::BI__sync_add_and_fetch:
243 case Builtin::BI__sync_add_and_fetch_1:
244 case Builtin::BI__sync_add_and_fetch_2:
245 case Builtin::BI__sync_add_and_fetch_4:
246 case Builtin::BI__sync_add_and_fetch_8:
247 case Builtin::BI__sync_add_and_fetch_16:
248 case Builtin::BI__sync_sub_and_fetch:
249 case Builtin::BI__sync_sub_and_fetch_1:
250 case Builtin::BI__sync_sub_and_fetch_2:
251 case Builtin::BI__sync_sub_and_fetch_4:
252 case Builtin::BI__sync_sub_and_fetch_8:
253 case Builtin::BI__sync_sub_and_fetch_16:
254 case Builtin::BI__sync_and_and_fetch:
255 case Builtin::BI__sync_and_and_fetch_1:
256 case Builtin::BI__sync_and_and_fetch_2:
257 case Builtin::BI__sync_and_and_fetch_4:
258 case Builtin::BI__sync_and_and_fetch_8:
259 case Builtin::BI__sync_and_and_fetch_16:
260 case Builtin::BI__sync_or_and_fetch:
261 case Builtin::BI__sync_or_and_fetch_1:
262 case Builtin::BI__sync_or_and_fetch_2:
263 case Builtin::BI__sync_or_and_fetch_4:
264 case Builtin::BI__sync_or_and_fetch_8:
265 case Builtin::BI__sync_or_and_fetch_16:
266 case Builtin::BI__sync_xor_and_fetch:
267 case Builtin::BI__sync_xor_and_fetch_1:
268 case Builtin::BI__sync_xor_and_fetch_2:
269 case Builtin::BI__sync_xor_and_fetch_4:
270 case Builtin::BI__sync_xor_and_fetch_8:
271 case Builtin::BI__sync_xor_and_fetch_16:
272 case Builtin::BI__sync_val_compare_and_swap:
273 case Builtin::BI__sync_val_compare_and_swap_1:
274 case Builtin::BI__sync_val_compare_and_swap_2:
275 case Builtin::BI__sync_val_compare_and_swap_4:
276 case Builtin::BI__sync_val_compare_and_swap_8:
277 case Builtin::BI__sync_val_compare_and_swap_16:
278 case Builtin::BI__sync_bool_compare_and_swap:
279 case Builtin::BI__sync_bool_compare_and_swap_1:
280 case Builtin::BI__sync_bool_compare_and_swap_2:
281 case Builtin::BI__sync_bool_compare_and_swap_4:
282 case Builtin::BI__sync_bool_compare_and_swap_8:
283 case Builtin::BI__sync_bool_compare_and_swap_16:
284 case Builtin::BI__sync_lock_test_and_set:
285 case Builtin::BI__sync_lock_test_and_set_1:
286 case Builtin::BI__sync_lock_test_and_set_2:
287 case Builtin::BI__sync_lock_test_and_set_4:
288 case Builtin::BI__sync_lock_test_and_set_8:
289 case Builtin::BI__sync_lock_test_and_set_16:
290 case Builtin::BI__sync_lock_release:
291 case Builtin::BI__sync_lock_release_1:
292 case Builtin::BI__sync_lock_release_2:
293 case Builtin::BI__sync_lock_release_4:
294 case Builtin::BI__sync_lock_release_8:
295 case Builtin::BI__sync_lock_release_16:
296 case Builtin::BI__sync_swap:
297 case Builtin::BI__sync_swap_1:
298 case Builtin::BI__sync_swap_2:
299 case Builtin::BI__sync_swap_4:
300 case Builtin::BI__sync_swap_8:
301 case Builtin::BI__sync_swap_16:
302 return SemaBuiltinAtomicOverloaded(TheCallResult);
303 #define BUILTIN(ID, TYPE, ATTRS)
304 #define ATOMIC_BUILTIN(ID, TYPE, ATTRS) \
305 case Builtin::BI##ID: \
306 return SemaAtomicOpsOverloaded(TheCallResult, AtomicExpr::AO##ID);
307 #include "clang/Basic/Builtins.def"
308 case Builtin::BI__builtin_annotation:
309 if (SemaBuiltinAnnotation(*this, TheCall))
312 case Builtin::BI__builtin_addressof:
313 if (SemaBuiltinAddressof(*this, TheCall))
316 case Builtin::BI__builtin_operator_new:
317 case Builtin::BI__builtin_operator_delete:
318 if (!getLangOpts().CPlusPlus) {
319 Diag(TheCall->getExprLoc(), diag::err_builtin_requires_language)
320 << (BuiltinID == Builtin::BI__builtin_operator_new
321 ? "__builtin_operator_new"
322 : "__builtin_operator_delete")
326 // CodeGen assumes it can find the global new and delete to call,
327 // so ensure that they are declared.
328 DeclareGlobalNewDelete();
332 // Since the target specific builtins for each arch overlap, only check those
333 // of the arch we are compiling for.
334 if (BuiltinID >= Builtin::FirstTSBuiltin) {
335 switch (Context.getTargetInfo().getTriple().getArch()) {
336 case llvm::Triple::arm:
337 case llvm::Triple::armeb:
338 case llvm::Triple::thumb:
339 case llvm::Triple::thumbeb:
340 if (CheckARMBuiltinFunctionCall(BuiltinID, TheCall))
343 case llvm::Triple::aarch64:
344 case llvm::Triple::aarch64_be:
345 case llvm::Triple::arm64:
346 case llvm::Triple::arm64_be:
347 if (CheckAArch64BuiltinFunctionCall(BuiltinID, TheCall))
350 case llvm::Triple::mips:
351 case llvm::Triple::mipsel:
352 case llvm::Triple::mips64:
353 case llvm::Triple::mips64el:
354 if (CheckMipsBuiltinFunctionCall(BuiltinID, TheCall))
357 case llvm::Triple::x86:
358 case llvm::Triple::x86_64:
359 if (CheckX86BuiltinFunctionCall(BuiltinID, TheCall))
367 return TheCallResult;
370 // Get the valid immediate range for the specified NEON type code.
371 static unsigned RFT(unsigned t, bool shift = false, bool ForceQuad = false) {
372 NeonTypeFlags Type(t);
373 int IsQuad = ForceQuad ? true : Type.isQuad();
374 switch (Type.getEltType()) {
375 case NeonTypeFlags::Int8:
376 case NeonTypeFlags::Poly8:
377 return shift ? 7 : (8 << IsQuad) - 1;
378 case NeonTypeFlags::Int16:
379 case NeonTypeFlags::Poly16:
380 return shift ? 15 : (4 << IsQuad) - 1;
381 case NeonTypeFlags::Int32:
382 return shift ? 31 : (2 << IsQuad) - 1;
383 case NeonTypeFlags::Int64:
384 case NeonTypeFlags::Poly64:
385 return shift ? 63 : (1 << IsQuad) - 1;
386 case NeonTypeFlags::Poly128:
387 return shift ? 127 : (1 << IsQuad) - 1;
388 case NeonTypeFlags::Float16:
389 assert(!shift && "cannot shift float types!");
390 return (4 << IsQuad) - 1;
391 case NeonTypeFlags::Float32:
392 assert(!shift && "cannot shift float types!");
393 return (2 << IsQuad) - 1;
394 case NeonTypeFlags::Float64:
395 assert(!shift && "cannot shift float types!");
396 return (1 << IsQuad) - 1;
398 llvm_unreachable("Invalid NeonTypeFlag!");
401 /// getNeonEltType - Return the QualType corresponding to the elements of
402 /// the vector type specified by the NeonTypeFlags. This is used to check
403 /// the pointer arguments for Neon load/store intrinsics.
404 static QualType getNeonEltType(NeonTypeFlags Flags, ASTContext &Context,
405 bool IsPolyUnsigned, bool IsInt64Long) {
406 switch (Flags.getEltType()) {
407 case NeonTypeFlags::Int8:
408 return Flags.isUnsigned() ? Context.UnsignedCharTy : Context.SignedCharTy;
409 case NeonTypeFlags::Int16:
410 return Flags.isUnsigned() ? Context.UnsignedShortTy : Context.ShortTy;
411 case NeonTypeFlags::Int32:
412 return Flags.isUnsigned() ? Context.UnsignedIntTy : Context.IntTy;
413 case NeonTypeFlags::Int64:
415 return Flags.isUnsigned() ? Context.UnsignedLongTy : Context.LongTy;
417 return Flags.isUnsigned() ? Context.UnsignedLongLongTy
418 : Context.LongLongTy;
419 case NeonTypeFlags::Poly8:
420 return IsPolyUnsigned ? Context.UnsignedCharTy : Context.SignedCharTy;
421 case NeonTypeFlags::Poly16:
422 return IsPolyUnsigned ? Context.UnsignedShortTy : Context.ShortTy;
423 case NeonTypeFlags::Poly64:
424 return Context.UnsignedLongTy;
425 case NeonTypeFlags::Poly128:
427 case NeonTypeFlags::Float16:
428 return Context.HalfTy;
429 case NeonTypeFlags::Float32:
430 return Context.FloatTy;
431 case NeonTypeFlags::Float64:
432 return Context.DoubleTy;
434 llvm_unreachable("Invalid NeonTypeFlag!");
437 bool Sema::CheckNeonBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
442 bool HasConstPtr = false;
444 #define GET_NEON_OVERLOAD_CHECK
445 #include "clang/Basic/arm_neon.inc"
446 #undef GET_NEON_OVERLOAD_CHECK
449 // For NEON intrinsics which are overloaded on vector element type, validate
450 // the immediate which specifies which variant to emit.
451 unsigned ImmArg = TheCall->getNumArgs()-1;
453 if (SemaBuiltinConstantArg(TheCall, ImmArg, Result))
456 TV = Result.getLimitedValue(64);
457 if ((TV > 63) || (mask & (1ULL << TV)) == 0)
458 return Diag(TheCall->getLocStart(), diag::err_invalid_neon_type_code)
459 << TheCall->getArg(ImmArg)->getSourceRange();
462 if (PtrArgNum >= 0) {
463 // Check that pointer arguments have the specified type.
464 Expr *Arg = TheCall->getArg(PtrArgNum);
465 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg))
466 Arg = ICE->getSubExpr();
467 ExprResult RHS = DefaultFunctionArrayLvalueConversion(Arg);
468 QualType RHSTy = RHS.get()->getType();
470 llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch();
471 bool IsPolyUnsigned =
472 Arch == llvm::Triple::aarch64 || Arch == llvm::Triple::arm64;
474 Context.getTargetInfo().getInt64Type() == TargetInfo::SignedLong;
476 getNeonEltType(NeonTypeFlags(TV), Context, IsPolyUnsigned, IsInt64Long);
478 EltTy = EltTy.withConst();
479 QualType LHSTy = Context.getPointerType(EltTy);
480 AssignConvertType ConvTy;
481 ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS);
484 if (DiagnoseAssignmentResult(ConvTy, Arg->getLocStart(), LHSTy, RHSTy,
485 RHS.get(), AA_Assigning))
489 // For NEON intrinsics which take an immediate value as part of the
490 // instruction, range check them here.
491 unsigned i = 0, l = 0, u = 0;
495 #define GET_NEON_IMMEDIATE_CHECK
496 #include "clang/Basic/arm_neon.inc"
497 #undef GET_NEON_IMMEDIATE_CHECK
500 return SemaBuiltinConstantArgRange(TheCall, i, l, u + l);
503 bool Sema::CheckARMBuiltinExclusiveCall(unsigned BuiltinID, CallExpr *TheCall,
505 assert((BuiltinID == ARM::BI__builtin_arm_ldrex ||
506 BuiltinID == ARM::BI__builtin_arm_ldaex ||
507 BuiltinID == ARM::BI__builtin_arm_strex ||
508 BuiltinID == ARM::BI__builtin_arm_stlex ||
509 BuiltinID == AArch64::BI__builtin_arm_ldrex ||
510 BuiltinID == AArch64::BI__builtin_arm_ldaex ||
511 BuiltinID == AArch64::BI__builtin_arm_strex ||
512 BuiltinID == AArch64::BI__builtin_arm_stlex) &&
513 "unexpected ARM builtin");
514 bool IsLdrex = BuiltinID == ARM::BI__builtin_arm_ldrex ||
515 BuiltinID == ARM::BI__builtin_arm_ldaex ||
516 BuiltinID == AArch64::BI__builtin_arm_ldrex ||
517 BuiltinID == AArch64::BI__builtin_arm_ldaex;
519 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
521 // Ensure that we have the proper number of arguments.
522 if (checkArgCount(*this, TheCall, IsLdrex ? 1 : 2))
525 // Inspect the pointer argument of the atomic builtin. This should always be
526 // a pointer type, whose element is an integral scalar or pointer type.
527 // Because it is a pointer type, we don't have to worry about any implicit
529 Expr *PointerArg = TheCall->getArg(IsLdrex ? 0 : 1);
530 ExprResult PointerArgRes = DefaultFunctionArrayLvalueConversion(PointerArg);
531 if (PointerArgRes.isInvalid())
533 PointerArg = PointerArgRes.get();
535 const PointerType *pointerType = PointerArg->getType()->getAs<PointerType>();
537 Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer)
538 << PointerArg->getType() << PointerArg->getSourceRange();
542 // ldrex takes a "const volatile T*" and strex takes a "volatile T*". Our next
543 // task is to insert the appropriate casts into the AST. First work out just
544 // what the appropriate type is.
545 QualType ValType = pointerType->getPointeeType();
546 QualType AddrType = ValType.getUnqualifiedType().withVolatile();
550 // Issue a warning if the cast is dodgy.
551 CastKind CastNeeded = CK_NoOp;
552 if (!AddrType.isAtLeastAsQualifiedAs(ValType)) {
553 CastNeeded = CK_BitCast;
554 Diag(DRE->getLocStart(), diag::ext_typecheck_convert_discards_qualifiers)
555 << PointerArg->getType()
556 << Context.getPointerType(AddrType)
557 << AA_Passing << PointerArg->getSourceRange();
560 // Finally, do the cast and replace the argument with the corrected version.
561 AddrType = Context.getPointerType(AddrType);
562 PointerArgRes = ImpCastExprToType(PointerArg, AddrType, CastNeeded);
563 if (PointerArgRes.isInvalid())
565 PointerArg = PointerArgRes.get();
567 TheCall->setArg(IsLdrex ? 0 : 1, PointerArg);
569 // In general, we allow ints, floats and pointers to be loaded and stored.
570 if (!ValType->isIntegerType() && !ValType->isAnyPointerType() &&
571 !ValType->isBlockPointerType() && !ValType->isFloatingType()) {
572 Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer_intfltptr)
573 << PointerArg->getType() << PointerArg->getSourceRange();
577 // But ARM doesn't have instructions to deal with 128-bit versions.
578 if (Context.getTypeSize(ValType) > MaxWidth) {
579 assert(MaxWidth == 64 && "Diagnostic unexpectedly inaccurate");
580 Diag(DRE->getLocStart(), diag::err_atomic_exclusive_builtin_pointer_size)
581 << PointerArg->getType() << PointerArg->getSourceRange();
585 switch (ValType.getObjCLifetime()) {
586 case Qualifiers::OCL_None:
587 case Qualifiers::OCL_ExplicitNone:
591 case Qualifiers::OCL_Weak:
592 case Qualifiers::OCL_Strong:
593 case Qualifiers::OCL_Autoreleasing:
594 Diag(DRE->getLocStart(), diag::err_arc_atomic_ownership)
595 << ValType << PointerArg->getSourceRange();
601 TheCall->setType(ValType);
605 // Initialize the argument to be stored.
606 ExprResult ValArg = TheCall->getArg(0);
607 InitializedEntity Entity = InitializedEntity::InitializeParameter(
608 Context, ValType, /*consume*/ false);
609 ValArg = PerformCopyInitialization(Entity, SourceLocation(), ValArg);
610 if (ValArg.isInvalid())
612 TheCall->setArg(0, ValArg.get());
614 // __builtin_arm_strex always returns an int. It's marked as such in the .def,
615 // but the custom checker bypasses all default analysis.
616 TheCall->setType(Context.IntTy);
620 bool Sema::CheckARMBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
623 if (BuiltinID == ARM::BI__builtin_arm_ldrex ||
624 BuiltinID == ARM::BI__builtin_arm_ldaex ||
625 BuiltinID == ARM::BI__builtin_arm_strex ||
626 BuiltinID == ARM::BI__builtin_arm_stlex) {
627 return CheckARMBuiltinExclusiveCall(BuiltinID, TheCall, 64);
630 if (CheckNeonBuiltinFunctionCall(BuiltinID, TheCall))
633 // For intrinsics which take an immediate value as part of the instruction,
634 // range check them here.
635 unsigned i = 0, l = 0, u = 0;
637 default: return false;
638 case ARM::BI__builtin_arm_ssat: i = 1; l = 1; u = 31; break;
639 case ARM::BI__builtin_arm_usat: i = 1; u = 31; break;
640 case ARM::BI__builtin_arm_vcvtr_f:
641 case ARM::BI__builtin_arm_vcvtr_d: i = 1; u = 1; break;
642 case ARM::BI__builtin_arm_dmb:
643 case ARM::BI__builtin_arm_dsb:
644 case ARM::BI__builtin_arm_isb: l = 0; u = 15; break;
647 // FIXME: VFP Intrinsics should error if VFP not present.
648 return SemaBuiltinConstantArgRange(TheCall, i, l, u + l);
651 bool Sema::CheckAArch64BuiltinFunctionCall(unsigned BuiltinID,
655 if (BuiltinID == AArch64::BI__builtin_arm_ldrex ||
656 BuiltinID == AArch64::BI__builtin_arm_ldaex ||
657 BuiltinID == AArch64::BI__builtin_arm_strex ||
658 BuiltinID == AArch64::BI__builtin_arm_stlex) {
659 return CheckARMBuiltinExclusiveCall(BuiltinID, TheCall, 128);
662 if (CheckNeonBuiltinFunctionCall(BuiltinID, TheCall))
665 // For intrinsics which take an immediate value as part of the instruction,
666 // range check them here.
667 unsigned i = 0, l = 0, u = 0;
669 default: return false;
670 case AArch64::BI__builtin_arm_dmb:
671 case AArch64::BI__builtin_arm_dsb:
672 case AArch64::BI__builtin_arm_isb: l = 0; u = 15; break;
675 // FIXME: VFP Intrinsics should error if VFP not present.
676 return SemaBuiltinConstantArgRange(TheCall, i, l, u + l);
679 bool Sema::CheckMipsBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
680 unsigned i = 0, l = 0, u = 0;
682 default: return false;
683 case Mips::BI__builtin_mips_wrdsp: i = 1; l = 0; u = 63; break;
684 case Mips::BI__builtin_mips_rddsp: i = 0; l = 0; u = 63; break;
685 case Mips::BI__builtin_mips_append: i = 2; l = 0; u = 31; break;
686 case Mips::BI__builtin_mips_balign: i = 2; l = 0; u = 3; break;
687 case Mips::BI__builtin_mips_precr_sra_ph_w: i = 2; l = 0; u = 31; break;
688 case Mips::BI__builtin_mips_precr_sra_r_ph_w: i = 2; l = 0; u = 31; break;
689 case Mips::BI__builtin_mips_prepend: i = 2; l = 0; u = 31; break;
692 return SemaBuiltinConstantArgRange(TheCall, i, l, u);
695 bool Sema::CheckX86BuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
697 case X86::BI_mm_prefetch:
698 // This is declared to take (const char*, int)
699 return SemaBuiltinConstantArgRange(TheCall, 1, 0, 3);
704 /// Given a FunctionDecl's FormatAttr, attempts to populate the FomatStringInfo
705 /// parameter with the FormatAttr's correct format_idx and firstDataArg.
706 /// Returns true when the format fits the function and the FormatStringInfo has
708 bool Sema::getFormatStringInfo(const FormatAttr *Format, bool IsCXXMember,
709 FormatStringInfo *FSI) {
710 FSI->HasVAListArg = Format->getFirstArg() == 0;
711 FSI->FormatIdx = Format->getFormatIdx() - 1;
712 FSI->FirstDataArg = FSI->HasVAListArg ? 0 : Format->getFirstArg() - 1;
714 // The way the format attribute works in GCC, the implicit this argument
715 // of member functions is counted. However, it doesn't appear in our own
716 // lists, so decrement format_idx in that case.
718 if(FSI->FormatIdx == 0)
721 if (FSI->FirstDataArg != 0)
727 /// Checks if a the given expression evaluates to null.
729 /// \brief Returns true if the value evaluates to null.
730 static bool CheckNonNullExpr(Sema &S,
732 // As a special case, transparent unions initialized with zero are
733 // considered null for the purposes of the nonnull attribute.
734 if (const RecordType *UT = Expr->getType()->getAsUnionType()) {
735 if (UT->getDecl()->hasAttr<TransparentUnionAttr>())
736 if (const CompoundLiteralExpr *CLE =
737 dyn_cast<CompoundLiteralExpr>(Expr))
738 if (const InitListExpr *ILE =
739 dyn_cast<InitListExpr>(CLE->getInitializer()))
740 Expr = ILE->getInit(0);
744 return (!Expr->isValueDependent() &&
745 Expr->EvaluateAsBooleanCondition(Result, S.Context) &&
749 static void CheckNonNullArgument(Sema &S,
751 SourceLocation CallSiteLoc) {
752 if (CheckNonNullExpr(S, ArgExpr))
753 S.Diag(CallSiteLoc, diag::warn_null_arg) << ArgExpr->getSourceRange();
756 static void CheckNonNullArguments(Sema &S,
757 const NamedDecl *FDecl,
758 const Expr * const *ExprArgs,
759 SourceLocation CallSiteLoc) {
760 // Check the attributes attached to the method/function itself.
761 for (const auto *NonNull : FDecl->specific_attrs<NonNullAttr>()) {
762 for (const auto &Val : NonNull->args())
763 CheckNonNullArgument(S, ExprArgs[Val], CallSiteLoc);
766 // Check the attributes on the parameters.
767 ArrayRef<ParmVarDecl*> parms;
768 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(FDecl))
769 parms = FD->parameters();
770 else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(FDecl))
771 parms = MD->parameters();
773 unsigned argIndex = 0;
774 for (ArrayRef<ParmVarDecl*>::iterator I = parms.begin(), E = parms.end();
775 I != E; ++I, ++argIndex) {
776 const ParmVarDecl *PVD = *I;
777 if (PVD->hasAttr<NonNullAttr>())
778 CheckNonNullArgument(S, ExprArgs[argIndex], CallSiteLoc);
782 /// Handles the checks for format strings, non-POD arguments to vararg
783 /// functions, and NULL arguments passed to non-NULL parameters.
784 void Sema::checkCall(NamedDecl *FDecl, ArrayRef<const Expr *> Args,
785 unsigned NumParams, bool IsMemberFunction,
786 SourceLocation Loc, SourceRange Range,
787 VariadicCallType CallType) {
788 // FIXME: We should check as much as we can in the template definition.
789 if (CurContext->isDependentContext())
792 // Printf and scanf checking.
793 llvm::SmallBitVector CheckedVarArgs;
795 for (const auto *I : FDecl->specific_attrs<FormatAttr>()) {
796 // Only create vector if there are format attributes.
797 CheckedVarArgs.resize(Args.size());
799 CheckFormatArguments(I, Args, IsMemberFunction, CallType, Loc, Range,
804 // Refuse POD arguments that weren't caught by the format string
806 if (CallType != VariadicDoesNotApply) {
807 for (unsigned ArgIdx = NumParams; ArgIdx < Args.size(); ++ArgIdx) {
808 // Args[ArgIdx] can be null in malformed code.
809 if (const Expr *Arg = Args[ArgIdx]) {
810 if (CheckedVarArgs.empty() || !CheckedVarArgs[ArgIdx])
811 checkVariadicArgument(Arg, CallType);
817 CheckNonNullArguments(*this, FDecl, Args.data(), Loc);
819 // Type safety checking.
820 for (const auto *I : FDecl->specific_attrs<ArgumentWithTypeTagAttr>())
821 CheckArgumentWithTypeTag(I, Args.data());
825 /// CheckConstructorCall - Check a constructor call for correctness and safety
826 /// properties not enforced by the C type system.
827 void Sema::CheckConstructorCall(FunctionDecl *FDecl,
828 ArrayRef<const Expr *> Args,
829 const FunctionProtoType *Proto,
830 SourceLocation Loc) {
831 VariadicCallType CallType =
832 Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply;
833 checkCall(FDecl, Args, Proto->getNumParams(),
834 /*IsMemberFunction=*/true, Loc, SourceRange(), CallType);
837 /// CheckFunctionCall - Check a direct function call for various correctness
838 /// and safety properties not strictly enforced by the C type system.
839 bool Sema::CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall,
840 const FunctionProtoType *Proto) {
841 bool IsMemberOperatorCall = isa<CXXOperatorCallExpr>(TheCall) &&
842 isa<CXXMethodDecl>(FDecl);
843 bool IsMemberFunction = isa<CXXMemberCallExpr>(TheCall) ||
844 IsMemberOperatorCall;
845 VariadicCallType CallType = getVariadicCallType(FDecl, Proto,
846 TheCall->getCallee());
847 unsigned NumParams = Proto ? Proto->getNumParams() : 0;
848 Expr** Args = TheCall->getArgs();
849 unsigned NumArgs = TheCall->getNumArgs();
850 if (IsMemberOperatorCall) {
851 // If this is a call to a member operator, hide the first argument
853 // FIXME: Our choice of AST representation here is less than ideal.
857 checkCall(FDecl, llvm::makeArrayRef<const Expr *>(Args, NumArgs), NumParams,
858 IsMemberFunction, TheCall->getRParenLoc(),
859 TheCall->getCallee()->getSourceRange(), CallType);
861 IdentifierInfo *FnInfo = FDecl->getIdentifier();
862 // None of the checks below are needed for functions that don't have
863 // simple names (e.g., C++ conversion functions).
867 CheckAbsoluteValueFunction(TheCall, FDecl, FnInfo);
869 unsigned CMId = FDecl->getMemoryFunctionKind();
873 // Handle memory setting and copying functions.
874 if (CMId == Builtin::BIstrlcpy || CMId == Builtin::BIstrlcat)
875 CheckStrlcpycatArguments(TheCall, FnInfo);
876 else if (CMId == Builtin::BIstrncat)
877 CheckStrncatArguments(TheCall, FnInfo);
879 CheckMemaccessArguments(TheCall, CMId, FnInfo);
884 bool Sema::CheckObjCMethodCall(ObjCMethodDecl *Method, SourceLocation lbrac,
885 ArrayRef<const Expr *> Args) {
886 VariadicCallType CallType =
887 Method->isVariadic() ? VariadicMethod : VariadicDoesNotApply;
889 checkCall(Method, Args, Method->param_size(),
890 /*IsMemberFunction=*/false,
891 lbrac, Method->getSourceRange(), CallType);
896 bool Sema::CheckPointerCall(NamedDecl *NDecl, CallExpr *TheCall,
897 const FunctionProtoType *Proto) {
898 const VarDecl *V = dyn_cast<VarDecl>(NDecl);
902 QualType Ty = V->getType();
903 if (!Ty->isBlockPointerType() && !Ty->isFunctionPointerType())
906 VariadicCallType CallType;
907 if (!Proto || !Proto->isVariadic()) {
908 CallType = VariadicDoesNotApply;
909 } else if (Ty->isBlockPointerType()) {
910 CallType = VariadicBlock;
911 } else { // Ty->isFunctionPointerType()
912 CallType = VariadicFunction;
914 unsigned NumParams = Proto ? Proto->getNumParams() : 0;
916 checkCall(NDecl, llvm::makeArrayRef<const Expr *>(TheCall->getArgs(),
917 TheCall->getNumArgs()),
918 NumParams, /*IsMemberFunction=*/false, TheCall->getRParenLoc(),
919 TheCall->getCallee()->getSourceRange(), CallType);
924 /// Checks function calls when a FunctionDecl or a NamedDecl is not available,
925 /// such as function pointers returned from functions.
926 bool Sema::CheckOtherCall(CallExpr *TheCall, const FunctionProtoType *Proto) {
927 VariadicCallType CallType = getVariadicCallType(/*FDecl=*/nullptr, Proto,
928 TheCall->getCallee());
929 unsigned NumParams = Proto ? Proto->getNumParams() : 0;
931 checkCall(/*FDecl=*/nullptr,
932 llvm::makeArrayRef<const Expr *>(TheCall->getArgs(),
933 TheCall->getNumArgs()),
934 NumParams, /*IsMemberFunction=*/false, TheCall->getRParenLoc(),
935 TheCall->getCallee()->getSourceRange(), CallType);
940 static bool isValidOrderingForOp(int64_t Ordering, AtomicExpr::AtomicOp Op) {
941 if (Ordering < AtomicExpr::AO_ABI_memory_order_relaxed ||
942 Ordering > AtomicExpr::AO_ABI_memory_order_seq_cst)
946 case AtomicExpr::AO__c11_atomic_init:
947 llvm_unreachable("There is no ordering argument for an init");
949 case AtomicExpr::AO__c11_atomic_load:
950 case AtomicExpr::AO__atomic_load_n:
951 case AtomicExpr::AO__atomic_load:
952 return Ordering != AtomicExpr::AO_ABI_memory_order_release &&
953 Ordering != AtomicExpr::AO_ABI_memory_order_acq_rel;
955 case AtomicExpr::AO__c11_atomic_store:
956 case AtomicExpr::AO__atomic_store:
957 case AtomicExpr::AO__atomic_store_n:
958 return Ordering != AtomicExpr::AO_ABI_memory_order_consume &&
959 Ordering != AtomicExpr::AO_ABI_memory_order_acquire &&
960 Ordering != AtomicExpr::AO_ABI_memory_order_acq_rel;
967 ExprResult Sema::SemaAtomicOpsOverloaded(ExprResult TheCallResult,
968 AtomicExpr::AtomicOp Op) {
969 CallExpr *TheCall = cast<CallExpr>(TheCallResult.get());
970 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
972 // All these operations take one of the following forms:
974 // C __c11_atomic_init(A *, C)
976 // C __c11_atomic_load(A *, int)
978 // void __atomic_load(A *, CP, int)
980 // C __c11_atomic_add(A *, M, int)
982 // C __atomic_exchange_n(A *, CP, int)
984 // void __atomic_exchange(A *, C *, CP, int)
986 // bool __c11_atomic_compare_exchange_strong(A *, C *, CP, int, int)
988 // bool __atomic_compare_exchange(A *, C *, CP, bool, int, int)
991 const unsigned NumArgs[] = { 2, 2, 3, 3, 3, 4, 5, 6 };
992 const unsigned NumVals[] = { 1, 0, 1, 1, 1, 2, 2, 3 };
994 // C is an appropriate type,
995 // A is volatile _Atomic(C) for __c11 builtins and is C for GNU builtins,
996 // CP is C for __c11 builtins and GNU _n builtins and is C * otherwise,
997 // M is C if C is an integer, and ptrdiff_t if C is a pointer, and
998 // the int parameters are for orderings.
1000 assert(AtomicExpr::AO__c11_atomic_init == 0 &&
1001 AtomicExpr::AO__c11_atomic_fetch_xor + 1 == AtomicExpr::AO__atomic_load
1002 && "need to update code for modified C11 atomics");
1003 bool IsC11 = Op >= AtomicExpr::AO__c11_atomic_init &&
1004 Op <= AtomicExpr::AO__c11_atomic_fetch_xor;
1005 bool IsN = Op == AtomicExpr::AO__atomic_load_n ||
1006 Op == AtomicExpr::AO__atomic_store_n ||
1007 Op == AtomicExpr::AO__atomic_exchange_n ||
1008 Op == AtomicExpr::AO__atomic_compare_exchange_n;
1009 bool IsAddSub = false;
1012 case AtomicExpr::AO__c11_atomic_init:
1016 case AtomicExpr::AO__c11_atomic_load:
1017 case AtomicExpr::AO__atomic_load_n:
1021 case AtomicExpr::AO__c11_atomic_store:
1022 case AtomicExpr::AO__atomic_load:
1023 case AtomicExpr::AO__atomic_store:
1024 case AtomicExpr::AO__atomic_store_n:
1028 case AtomicExpr::AO__c11_atomic_fetch_add:
1029 case AtomicExpr::AO__c11_atomic_fetch_sub:
1030 case AtomicExpr::AO__atomic_fetch_add:
1031 case AtomicExpr::AO__atomic_fetch_sub:
1032 case AtomicExpr::AO__atomic_add_fetch:
1033 case AtomicExpr::AO__atomic_sub_fetch:
1036 case AtomicExpr::AO__c11_atomic_fetch_and:
1037 case AtomicExpr::AO__c11_atomic_fetch_or:
1038 case AtomicExpr::AO__c11_atomic_fetch_xor:
1039 case AtomicExpr::AO__atomic_fetch_and:
1040 case AtomicExpr::AO__atomic_fetch_or:
1041 case AtomicExpr::AO__atomic_fetch_xor:
1042 case AtomicExpr::AO__atomic_fetch_nand:
1043 case AtomicExpr::AO__atomic_and_fetch:
1044 case AtomicExpr::AO__atomic_or_fetch:
1045 case AtomicExpr::AO__atomic_xor_fetch:
1046 case AtomicExpr::AO__atomic_nand_fetch:
1050 case AtomicExpr::AO__c11_atomic_exchange:
1051 case AtomicExpr::AO__atomic_exchange_n:
1055 case AtomicExpr::AO__atomic_exchange:
1059 case AtomicExpr::AO__c11_atomic_compare_exchange_strong:
1060 case AtomicExpr::AO__c11_atomic_compare_exchange_weak:
1064 case AtomicExpr::AO__atomic_compare_exchange:
1065 case AtomicExpr::AO__atomic_compare_exchange_n:
1070 // Check we have the right number of arguments.
1071 if (TheCall->getNumArgs() < NumArgs[Form]) {
1072 Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
1073 << 0 << NumArgs[Form] << TheCall->getNumArgs()
1074 << TheCall->getCallee()->getSourceRange();
1076 } else if (TheCall->getNumArgs() > NumArgs[Form]) {
1077 Diag(TheCall->getArg(NumArgs[Form])->getLocStart(),
1078 diag::err_typecheck_call_too_many_args)
1079 << 0 << NumArgs[Form] << TheCall->getNumArgs()
1080 << TheCall->getCallee()->getSourceRange();
1084 // Inspect the first argument of the atomic operation.
1085 Expr *Ptr = TheCall->getArg(0);
1086 Ptr = DefaultFunctionArrayLvalueConversion(Ptr).get();
1087 const PointerType *pointerType = Ptr->getType()->getAs<PointerType>();
1089 Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer)
1090 << Ptr->getType() << Ptr->getSourceRange();
1094 // For a __c11 builtin, this should be a pointer to an _Atomic type.
1095 QualType AtomTy = pointerType->getPointeeType(); // 'A'
1096 QualType ValType = AtomTy; // 'C'
1098 if (!AtomTy->isAtomicType()) {
1099 Diag(DRE->getLocStart(), diag::err_atomic_op_needs_atomic)
1100 << Ptr->getType() << Ptr->getSourceRange();
1103 if (AtomTy.isConstQualified()) {
1104 Diag(DRE->getLocStart(), diag::err_atomic_op_needs_non_const_atomic)
1105 << Ptr->getType() << Ptr->getSourceRange();
1108 ValType = AtomTy->getAs<AtomicType>()->getValueType();
1111 // For an arithmetic operation, the implied arithmetic must be well-formed.
1112 if (Form == Arithmetic) {
1113 // gcc does not enforce these rules for GNU atomics, but we do so for sanity.
1114 if (IsAddSub && !ValType->isIntegerType() && !ValType->isPointerType()) {
1115 Diag(DRE->getLocStart(), diag::err_atomic_op_needs_atomic_int_or_ptr)
1116 << IsC11 << Ptr->getType() << Ptr->getSourceRange();
1119 if (!IsAddSub && !ValType->isIntegerType()) {
1120 Diag(DRE->getLocStart(), diag::err_atomic_op_bitwise_needs_atomic_int)
1121 << IsC11 << Ptr->getType() << Ptr->getSourceRange();
1124 } else if (IsN && !ValType->isIntegerType() && !ValType->isPointerType()) {
1125 // For __atomic_*_n operations, the value type must be a scalar integral or
1126 // pointer type which is 1, 2, 4, 8 or 16 bytes in length.
1127 Diag(DRE->getLocStart(), diag::err_atomic_op_needs_atomic_int_or_ptr)
1128 << IsC11 << Ptr->getType() << Ptr->getSourceRange();
1132 if (!IsC11 && !AtomTy.isTriviallyCopyableType(Context) &&
1133 !AtomTy->isScalarType()) {
1134 // For GNU atomics, require a trivially-copyable type. This is not part of
1135 // the GNU atomics specification, but we enforce it for sanity.
1136 Diag(DRE->getLocStart(), diag::err_atomic_op_needs_trivial_copy)
1137 << Ptr->getType() << Ptr->getSourceRange();
1141 // FIXME: For any builtin other than a load, the ValType must not be
1144 switch (ValType.getObjCLifetime()) {
1145 case Qualifiers::OCL_None:
1146 case Qualifiers::OCL_ExplicitNone:
1150 case Qualifiers::OCL_Weak:
1151 case Qualifiers::OCL_Strong:
1152 case Qualifiers::OCL_Autoreleasing:
1153 // FIXME: Can this happen? By this point, ValType should be known
1154 // to be trivially copyable.
1155 Diag(DRE->getLocStart(), diag::err_arc_atomic_ownership)
1156 << ValType << Ptr->getSourceRange();
1160 QualType ResultType = ValType;
1161 if (Form == Copy || Form == GNUXchg || Form == Init)
1162 ResultType = Context.VoidTy;
1163 else if (Form == C11CmpXchg || Form == GNUCmpXchg)
1164 ResultType = Context.BoolTy;
1166 // The type of a parameter passed 'by value'. In the GNU atomics, such
1167 // arguments are actually passed as pointers.
1168 QualType ByValType = ValType; // 'CP'
1170 ByValType = Ptr->getType();
1172 // The first argument --- the pointer --- has a fixed type; we
1173 // deduce the types of the rest of the arguments accordingly. Walk
1174 // the remaining arguments, converting them to the deduced value type.
1175 for (unsigned i = 1; i != NumArgs[Form]; ++i) {
1177 if (i < NumVals[Form] + 1) {
1180 // The second argument is the non-atomic operand. For arithmetic, this
1181 // is always passed by value, and for a compare_exchange it is always
1182 // passed by address. For the rest, GNU uses by-address and C11 uses
1184 assert(Form != Load);
1185 if (Form == Init || (Form == Arithmetic && ValType->isIntegerType()))
1187 else if (Form == Copy || Form == Xchg)
1189 else if (Form == Arithmetic)
1190 Ty = Context.getPointerDiffType();
1192 Ty = Context.getPointerType(ValType.getUnqualifiedType());
1195 // The third argument to compare_exchange / GNU exchange is a
1196 // (pointer to a) desired value.
1200 // The fourth argument to GNU compare_exchange is a 'weak' flag.
1201 Ty = Context.BoolTy;
1205 // The order(s) are always converted to int.
1209 InitializedEntity Entity =
1210 InitializedEntity::InitializeParameter(Context, Ty, false);
1211 ExprResult Arg = TheCall->getArg(i);
1212 Arg = PerformCopyInitialization(Entity, SourceLocation(), Arg);
1213 if (Arg.isInvalid())
1215 TheCall->setArg(i, Arg.get());
1218 // Permute the arguments into a 'consistent' order.
1219 SmallVector<Expr*, 5> SubExprs;
1220 SubExprs.push_back(Ptr);
1223 // Note, AtomicExpr::getVal1() has a special case for this atomic.
1224 SubExprs.push_back(TheCall->getArg(1)); // Val1
1227 SubExprs.push_back(TheCall->getArg(1)); // Order
1232 SubExprs.push_back(TheCall->getArg(2)); // Order
1233 SubExprs.push_back(TheCall->getArg(1)); // Val1
1236 // Note, AtomicExpr::getVal2() has a special case for this atomic.
1237 SubExprs.push_back(TheCall->getArg(3)); // Order
1238 SubExprs.push_back(TheCall->getArg(1)); // Val1
1239 SubExprs.push_back(TheCall->getArg(2)); // Val2
1242 SubExprs.push_back(TheCall->getArg(3)); // Order
1243 SubExprs.push_back(TheCall->getArg(1)); // Val1
1244 SubExprs.push_back(TheCall->getArg(4)); // OrderFail
1245 SubExprs.push_back(TheCall->getArg(2)); // Val2
1248 SubExprs.push_back(TheCall->getArg(4)); // Order
1249 SubExprs.push_back(TheCall->getArg(1)); // Val1
1250 SubExprs.push_back(TheCall->getArg(5)); // OrderFail
1251 SubExprs.push_back(TheCall->getArg(2)); // Val2
1252 SubExprs.push_back(TheCall->getArg(3)); // Weak
1256 if (SubExprs.size() >= 2 && Form != Init) {
1257 llvm::APSInt Result(32);
1258 if (SubExprs[1]->isIntegerConstantExpr(Result, Context) &&
1259 !isValidOrderingForOp(Result.getSExtValue(), Op))
1260 Diag(SubExprs[1]->getLocStart(),
1261 diag::warn_atomic_op_has_invalid_memory_order)
1262 << SubExprs[1]->getSourceRange();
1265 AtomicExpr *AE = new (Context) AtomicExpr(TheCall->getCallee()->getLocStart(),
1266 SubExprs, ResultType, Op,
1267 TheCall->getRParenLoc());
1269 if ((Op == AtomicExpr::AO__c11_atomic_load ||
1270 (Op == AtomicExpr::AO__c11_atomic_store)) &&
1271 Context.AtomicUsesUnsupportedLibcall(AE))
1272 Diag(AE->getLocStart(), diag::err_atomic_load_store_uses_lib) <<
1273 ((Op == AtomicExpr::AO__c11_atomic_load) ? 0 : 1);
1279 /// checkBuiltinArgument - Given a call to a builtin function, perform
1280 /// normal type-checking on the given argument, updating the call in
1281 /// place. This is useful when a builtin function requires custom
1282 /// type-checking for some of its arguments but not necessarily all of
1285 /// Returns true on error.
1286 static bool checkBuiltinArgument(Sema &S, CallExpr *E, unsigned ArgIndex) {
1287 FunctionDecl *Fn = E->getDirectCallee();
1288 assert(Fn && "builtin call without direct callee!");
1290 ParmVarDecl *Param = Fn->getParamDecl(ArgIndex);
1291 InitializedEntity Entity =
1292 InitializedEntity::InitializeParameter(S.Context, Param);
1294 ExprResult Arg = E->getArg(0);
1295 Arg = S.PerformCopyInitialization(Entity, SourceLocation(), Arg);
1296 if (Arg.isInvalid())
1299 E->setArg(ArgIndex, Arg.get());
1303 /// SemaBuiltinAtomicOverloaded - We have a call to a function like
1304 /// __sync_fetch_and_add, which is an overloaded function based on the pointer
1305 /// type of its first argument. The main ActOnCallExpr routines have already
1306 /// promoted the types of arguments because all of these calls are prototyped as
1309 /// This function goes through and does final semantic checking for these
1312 Sema::SemaBuiltinAtomicOverloaded(ExprResult TheCallResult) {
1313 CallExpr *TheCall = (CallExpr *)TheCallResult.get();
1314 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
1315 FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
1317 // Ensure that we have at least one argument to do type inference from.
1318 if (TheCall->getNumArgs() < 1) {
1319 Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least)
1320 << 0 << 1 << TheCall->getNumArgs()
1321 << TheCall->getCallee()->getSourceRange();
1325 // Inspect the first argument of the atomic builtin. This should always be
1326 // a pointer type, whose element is an integral scalar or pointer type.
1327 // Because it is a pointer type, we don't have to worry about any implicit
1329 // FIXME: We don't allow floating point scalars as input.
1330 Expr *FirstArg = TheCall->getArg(0);
1331 ExprResult FirstArgResult = DefaultFunctionArrayLvalueConversion(FirstArg);
1332 if (FirstArgResult.isInvalid())
1334 FirstArg = FirstArgResult.get();
1335 TheCall->setArg(0, FirstArg);
1337 const PointerType *pointerType = FirstArg->getType()->getAs<PointerType>();
1339 Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer)
1340 << FirstArg->getType() << FirstArg->getSourceRange();
1344 QualType ValType = pointerType->getPointeeType();
1345 if (!ValType->isIntegerType() && !ValType->isAnyPointerType() &&
1346 !ValType->isBlockPointerType()) {
1347 Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer_intptr)
1348 << FirstArg->getType() << FirstArg->getSourceRange();
1352 switch (ValType.getObjCLifetime()) {
1353 case Qualifiers::OCL_None:
1354 case Qualifiers::OCL_ExplicitNone:
1358 case Qualifiers::OCL_Weak:
1359 case Qualifiers::OCL_Strong:
1360 case Qualifiers::OCL_Autoreleasing:
1361 Diag(DRE->getLocStart(), diag::err_arc_atomic_ownership)
1362 << ValType << FirstArg->getSourceRange();
1366 // Strip any qualifiers off ValType.
1367 ValType = ValType.getUnqualifiedType();
1369 // The majority of builtins return a value, but a few have special return
1370 // types, so allow them to override appropriately below.
1371 QualType ResultType = ValType;
1373 // We need to figure out which concrete builtin this maps onto. For example,
1374 // __sync_fetch_and_add with a 2 byte object turns into
1375 // __sync_fetch_and_add_2.
1376 #define BUILTIN_ROW(x) \
1377 { Builtin::BI##x##_1, Builtin::BI##x##_2, Builtin::BI##x##_4, \
1378 Builtin::BI##x##_8, Builtin::BI##x##_16 }
1380 static const unsigned BuiltinIndices[][5] = {
1381 BUILTIN_ROW(__sync_fetch_and_add),
1382 BUILTIN_ROW(__sync_fetch_and_sub),
1383 BUILTIN_ROW(__sync_fetch_and_or),
1384 BUILTIN_ROW(__sync_fetch_and_and),
1385 BUILTIN_ROW(__sync_fetch_and_xor),
1387 BUILTIN_ROW(__sync_add_and_fetch),
1388 BUILTIN_ROW(__sync_sub_and_fetch),
1389 BUILTIN_ROW(__sync_and_and_fetch),
1390 BUILTIN_ROW(__sync_or_and_fetch),
1391 BUILTIN_ROW(__sync_xor_and_fetch),
1393 BUILTIN_ROW(__sync_val_compare_and_swap),
1394 BUILTIN_ROW(__sync_bool_compare_and_swap),
1395 BUILTIN_ROW(__sync_lock_test_and_set),
1396 BUILTIN_ROW(__sync_lock_release),
1397 BUILTIN_ROW(__sync_swap)
1401 // Determine the index of the size.
1403 switch (Context.getTypeSizeInChars(ValType).getQuantity()) {
1404 case 1: SizeIndex = 0; break;
1405 case 2: SizeIndex = 1; break;
1406 case 4: SizeIndex = 2; break;
1407 case 8: SizeIndex = 3; break;
1408 case 16: SizeIndex = 4; break;
1410 Diag(DRE->getLocStart(), diag::err_atomic_builtin_pointer_size)
1411 << FirstArg->getType() << FirstArg->getSourceRange();
1415 // Each of these builtins has one pointer argument, followed by some number of
1416 // values (0, 1 or 2) followed by a potentially empty varags list of stuff
1417 // that we ignore. Find out which row of BuiltinIndices to read from as well
1418 // as the number of fixed args.
1419 unsigned BuiltinID = FDecl->getBuiltinID();
1420 unsigned BuiltinIndex, NumFixed = 1;
1421 switch (BuiltinID) {
1422 default: llvm_unreachable("Unknown overloaded atomic builtin!");
1423 case Builtin::BI__sync_fetch_and_add:
1424 case Builtin::BI__sync_fetch_and_add_1:
1425 case Builtin::BI__sync_fetch_and_add_2:
1426 case Builtin::BI__sync_fetch_and_add_4:
1427 case Builtin::BI__sync_fetch_and_add_8:
1428 case Builtin::BI__sync_fetch_and_add_16:
1432 case Builtin::BI__sync_fetch_and_sub:
1433 case Builtin::BI__sync_fetch_and_sub_1:
1434 case Builtin::BI__sync_fetch_and_sub_2:
1435 case Builtin::BI__sync_fetch_and_sub_4:
1436 case Builtin::BI__sync_fetch_and_sub_8:
1437 case Builtin::BI__sync_fetch_and_sub_16:
1441 case Builtin::BI__sync_fetch_and_or:
1442 case Builtin::BI__sync_fetch_and_or_1:
1443 case Builtin::BI__sync_fetch_and_or_2:
1444 case Builtin::BI__sync_fetch_and_or_4:
1445 case Builtin::BI__sync_fetch_and_or_8:
1446 case Builtin::BI__sync_fetch_and_or_16:
1450 case Builtin::BI__sync_fetch_and_and:
1451 case Builtin::BI__sync_fetch_and_and_1:
1452 case Builtin::BI__sync_fetch_and_and_2:
1453 case Builtin::BI__sync_fetch_and_and_4:
1454 case Builtin::BI__sync_fetch_and_and_8:
1455 case Builtin::BI__sync_fetch_and_and_16:
1459 case Builtin::BI__sync_fetch_and_xor:
1460 case Builtin::BI__sync_fetch_and_xor_1:
1461 case Builtin::BI__sync_fetch_and_xor_2:
1462 case Builtin::BI__sync_fetch_and_xor_4:
1463 case Builtin::BI__sync_fetch_and_xor_8:
1464 case Builtin::BI__sync_fetch_and_xor_16:
1468 case Builtin::BI__sync_add_and_fetch:
1469 case Builtin::BI__sync_add_and_fetch_1:
1470 case Builtin::BI__sync_add_and_fetch_2:
1471 case Builtin::BI__sync_add_and_fetch_4:
1472 case Builtin::BI__sync_add_and_fetch_8:
1473 case Builtin::BI__sync_add_and_fetch_16:
1477 case Builtin::BI__sync_sub_and_fetch:
1478 case Builtin::BI__sync_sub_and_fetch_1:
1479 case Builtin::BI__sync_sub_and_fetch_2:
1480 case Builtin::BI__sync_sub_and_fetch_4:
1481 case Builtin::BI__sync_sub_and_fetch_8:
1482 case Builtin::BI__sync_sub_and_fetch_16:
1486 case Builtin::BI__sync_and_and_fetch:
1487 case Builtin::BI__sync_and_and_fetch_1:
1488 case Builtin::BI__sync_and_and_fetch_2:
1489 case Builtin::BI__sync_and_and_fetch_4:
1490 case Builtin::BI__sync_and_and_fetch_8:
1491 case Builtin::BI__sync_and_and_fetch_16:
1495 case Builtin::BI__sync_or_and_fetch:
1496 case Builtin::BI__sync_or_and_fetch_1:
1497 case Builtin::BI__sync_or_and_fetch_2:
1498 case Builtin::BI__sync_or_and_fetch_4:
1499 case Builtin::BI__sync_or_and_fetch_8:
1500 case Builtin::BI__sync_or_and_fetch_16:
1504 case Builtin::BI__sync_xor_and_fetch:
1505 case Builtin::BI__sync_xor_and_fetch_1:
1506 case Builtin::BI__sync_xor_and_fetch_2:
1507 case Builtin::BI__sync_xor_and_fetch_4:
1508 case Builtin::BI__sync_xor_and_fetch_8:
1509 case Builtin::BI__sync_xor_and_fetch_16:
1513 case Builtin::BI__sync_val_compare_and_swap:
1514 case Builtin::BI__sync_val_compare_and_swap_1:
1515 case Builtin::BI__sync_val_compare_and_swap_2:
1516 case Builtin::BI__sync_val_compare_and_swap_4:
1517 case Builtin::BI__sync_val_compare_and_swap_8:
1518 case Builtin::BI__sync_val_compare_and_swap_16:
1523 case Builtin::BI__sync_bool_compare_and_swap:
1524 case Builtin::BI__sync_bool_compare_and_swap_1:
1525 case Builtin::BI__sync_bool_compare_and_swap_2:
1526 case Builtin::BI__sync_bool_compare_and_swap_4:
1527 case Builtin::BI__sync_bool_compare_and_swap_8:
1528 case Builtin::BI__sync_bool_compare_and_swap_16:
1531 ResultType = Context.BoolTy;
1534 case Builtin::BI__sync_lock_test_and_set:
1535 case Builtin::BI__sync_lock_test_and_set_1:
1536 case Builtin::BI__sync_lock_test_and_set_2:
1537 case Builtin::BI__sync_lock_test_and_set_4:
1538 case Builtin::BI__sync_lock_test_and_set_8:
1539 case Builtin::BI__sync_lock_test_and_set_16:
1543 case Builtin::BI__sync_lock_release:
1544 case Builtin::BI__sync_lock_release_1:
1545 case Builtin::BI__sync_lock_release_2:
1546 case Builtin::BI__sync_lock_release_4:
1547 case Builtin::BI__sync_lock_release_8:
1548 case Builtin::BI__sync_lock_release_16:
1551 ResultType = Context.VoidTy;
1554 case Builtin::BI__sync_swap:
1555 case Builtin::BI__sync_swap_1:
1556 case Builtin::BI__sync_swap_2:
1557 case Builtin::BI__sync_swap_4:
1558 case Builtin::BI__sync_swap_8:
1559 case Builtin::BI__sync_swap_16:
1564 // Now that we know how many fixed arguments we expect, first check that we
1565 // have at least that many.
1566 if (TheCall->getNumArgs() < 1+NumFixed) {
1567 Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least)
1568 << 0 << 1+NumFixed << TheCall->getNumArgs()
1569 << TheCall->getCallee()->getSourceRange();
1573 // Get the decl for the concrete builtin from this, we can tell what the
1574 // concrete integer type we should convert to is.
1575 unsigned NewBuiltinID = BuiltinIndices[BuiltinIndex][SizeIndex];
1576 const char *NewBuiltinName = Context.BuiltinInfo.GetName(NewBuiltinID);
1577 FunctionDecl *NewBuiltinDecl;
1578 if (NewBuiltinID == BuiltinID)
1579 NewBuiltinDecl = FDecl;
1581 // Perform builtin lookup to avoid redeclaring it.
1582 DeclarationName DN(&Context.Idents.get(NewBuiltinName));
1583 LookupResult Res(*this, DN, DRE->getLocStart(), LookupOrdinaryName);
1584 LookupName(Res, TUScope, /*AllowBuiltinCreation=*/true);
1585 assert(Res.getFoundDecl());
1586 NewBuiltinDecl = dyn_cast<FunctionDecl>(Res.getFoundDecl());
1587 if (!NewBuiltinDecl)
1591 // The first argument --- the pointer --- has a fixed type; we
1592 // deduce the types of the rest of the arguments accordingly. Walk
1593 // the remaining arguments, converting them to the deduced value type.
1594 for (unsigned i = 0; i != NumFixed; ++i) {
1595 ExprResult Arg = TheCall->getArg(i+1);
1597 // GCC does an implicit conversion to the pointer or integer ValType. This
1598 // can fail in some cases (1i -> int**), check for this error case now.
1599 // Initialize the argument.
1600 InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
1601 ValType, /*consume*/ false);
1602 Arg = PerformCopyInitialization(Entity, SourceLocation(), Arg);
1603 if (Arg.isInvalid())
1606 // Okay, we have something that *can* be converted to the right type. Check
1607 // to see if there is a potentially weird extension going on here. This can
1608 // happen when you do an atomic operation on something like an char* and
1609 // pass in 42. The 42 gets converted to char. This is even more strange
1610 // for things like 45.123 -> char, etc.
1611 // FIXME: Do this check.
1612 TheCall->setArg(i+1, Arg.get());
1615 ASTContext& Context = this->getASTContext();
1617 // Create a new DeclRefExpr to refer to the new decl.
1618 DeclRefExpr* NewDRE = DeclRefExpr::Create(
1620 DRE->getQualifierLoc(),
1623 /*enclosing*/ false,
1625 Context.BuiltinFnTy,
1626 DRE->getValueKind());
1628 // Set the callee in the CallExpr.
1629 // FIXME: This loses syntactic information.
1630 QualType CalleePtrTy = Context.getPointerType(NewBuiltinDecl->getType());
1631 ExprResult PromotedCall = ImpCastExprToType(NewDRE, CalleePtrTy,
1632 CK_BuiltinFnToFnPtr);
1633 TheCall->setCallee(PromotedCall.get());
1635 // Change the result type of the call to match the original value type. This
1636 // is arbitrary, but the codegen for these builtins ins design to handle it
1638 TheCall->setType(ResultType);
1640 return TheCallResult;
1643 /// CheckObjCString - Checks that the argument to the builtin
1644 /// CFString constructor is correct
1645 /// Note: It might also make sense to do the UTF-16 conversion here (would
1646 /// simplify the backend).
1647 bool Sema::CheckObjCString(Expr *Arg) {
1648 Arg = Arg->IgnoreParenCasts();
1649 StringLiteral *Literal = dyn_cast<StringLiteral>(Arg);
1651 if (!Literal || !Literal->isAscii()) {
1652 Diag(Arg->getLocStart(), diag::err_cfstring_literal_not_string_constant)
1653 << Arg->getSourceRange();
1657 if (Literal->containsNonAsciiOrNull()) {
1658 StringRef String = Literal->getString();
1659 unsigned NumBytes = String.size();
1660 SmallVector<UTF16, 128> ToBuf(NumBytes);
1661 const UTF8 *FromPtr = (const UTF8 *)String.data();
1662 UTF16 *ToPtr = &ToBuf[0];
1664 ConversionResult Result = ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes,
1665 &ToPtr, ToPtr + NumBytes,
1667 // Check for conversion failure.
1668 if (Result != conversionOK)
1669 Diag(Arg->getLocStart(),
1670 diag::warn_cfstring_truncated) << Arg->getSourceRange();
1675 /// SemaBuiltinVAStart - Check the arguments to __builtin_va_start for validity.
1676 /// Emit an error and return true on failure, return false on success.
1677 bool Sema::SemaBuiltinVAStart(CallExpr *TheCall) {
1678 Expr *Fn = TheCall->getCallee();
1679 if (TheCall->getNumArgs() > 2) {
1680 Diag(TheCall->getArg(2)->getLocStart(),
1681 diag::err_typecheck_call_too_many_args)
1682 << 0 /*function call*/ << 2 << TheCall->getNumArgs()
1683 << Fn->getSourceRange()
1684 << SourceRange(TheCall->getArg(2)->getLocStart(),
1685 (*(TheCall->arg_end()-1))->getLocEnd());
1689 if (TheCall->getNumArgs() < 2) {
1690 return Diag(TheCall->getLocEnd(),
1691 diag::err_typecheck_call_too_few_args_at_least)
1692 << 0 /*function call*/ << 2 << TheCall->getNumArgs();
1695 // Type-check the first argument normally.
1696 if (checkBuiltinArgument(*this, TheCall, 0))
1699 // Determine whether the current function is variadic or not.
1700 BlockScopeInfo *CurBlock = getCurBlock();
1703 isVariadic = CurBlock->TheDecl->isVariadic();
1704 else if (FunctionDecl *FD = getCurFunctionDecl())
1705 isVariadic = FD->isVariadic();
1707 isVariadic = getCurMethodDecl()->isVariadic();
1710 Diag(Fn->getLocStart(), diag::err_va_start_used_in_non_variadic_function);
1714 // Verify that the second argument to the builtin is the last argument of the
1715 // current function or method.
1716 bool SecondArgIsLastNamedArgument = false;
1717 const Expr *Arg = TheCall->getArg(1)->IgnoreParenCasts();
1719 // These are valid if SecondArgIsLastNamedArgument is false after the next
1722 SourceLocation ParamLoc;
1724 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Arg)) {
1725 if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(DR->getDecl())) {
1726 // FIXME: This isn't correct for methods (results in bogus warning).
1727 // Get the last formal in the current function.
1728 const ParmVarDecl *LastArg;
1730 LastArg = *(CurBlock->TheDecl->param_end()-1);
1731 else if (FunctionDecl *FD = getCurFunctionDecl())
1732 LastArg = *(FD->param_end()-1);
1734 LastArg = *(getCurMethodDecl()->param_end()-1);
1735 SecondArgIsLastNamedArgument = PV == LastArg;
1737 Type = PV->getType();
1738 ParamLoc = PV->getLocation();
1742 if (!SecondArgIsLastNamedArgument)
1743 Diag(TheCall->getArg(1)->getLocStart(),
1744 diag::warn_second_parameter_of_va_start_not_last_named_argument);
1745 else if (Type->isReferenceType()) {
1746 Diag(Arg->getLocStart(),
1747 diag::warn_va_start_of_reference_type_is_undefined);
1748 Diag(ParamLoc, diag::note_parameter_type) << Type;
1751 TheCall->setType(Context.VoidTy);
1755 bool Sema::SemaBuiltinVAStartARM(CallExpr *Call) {
1756 // void __va_start(va_list *ap, const char *named_addr, size_t slot_size,
1757 // const char *named_addr);
1759 Expr *Func = Call->getCallee();
1761 if (Call->getNumArgs() < 3)
1762 return Diag(Call->getLocEnd(),
1763 diag::err_typecheck_call_too_few_args_at_least)
1764 << 0 /*function call*/ << 3 << Call->getNumArgs();
1766 // Determine whether the current function is variadic or not.
1768 if (BlockScopeInfo *CurBlock = getCurBlock())
1769 IsVariadic = CurBlock->TheDecl->isVariadic();
1770 else if (FunctionDecl *FD = getCurFunctionDecl())
1771 IsVariadic = FD->isVariadic();
1772 else if (ObjCMethodDecl *MD = getCurMethodDecl())
1773 IsVariadic = MD->isVariadic();
1775 llvm_unreachable("unexpected statement type");
1778 Diag(Func->getLocStart(), diag::err_va_start_used_in_non_variadic_function);
1782 // Type-check the first argument normally.
1783 if (checkBuiltinArgument(*this, Call, 0))
1786 static const struct {
1789 } ArgumentTypes[] = {
1790 { 1, Context.getPointerType(Context.CharTy.withConst()) },
1791 { 2, Context.getSizeType() },
1794 for (const auto &AT : ArgumentTypes) {
1795 const Expr *Arg = Call->getArg(AT.ArgNo)->IgnoreParens();
1796 if (Arg->getType().getCanonicalType() == AT.Type.getCanonicalType())
1798 Diag(Arg->getLocStart(), diag::err_typecheck_convert_incompatible)
1799 << Arg->getType() << AT.Type << 1 /* different class */
1800 << 0 /* qualifier difference */ << 3 /* parameter mismatch */
1801 << AT.ArgNo + 1 << Arg->getType() << AT.Type;
1807 /// SemaBuiltinUnorderedCompare - Handle functions like __builtin_isgreater and
1808 /// friends. This is declared to take (...), so we have to check everything.
1809 bool Sema::SemaBuiltinUnorderedCompare(CallExpr *TheCall) {
1810 if (TheCall->getNumArgs() < 2)
1811 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
1812 << 0 << 2 << TheCall->getNumArgs()/*function call*/;
1813 if (TheCall->getNumArgs() > 2)
1814 return Diag(TheCall->getArg(2)->getLocStart(),
1815 diag::err_typecheck_call_too_many_args)
1816 << 0 /*function call*/ << 2 << TheCall->getNumArgs()
1817 << SourceRange(TheCall->getArg(2)->getLocStart(),
1818 (*(TheCall->arg_end()-1))->getLocEnd());
1820 ExprResult OrigArg0 = TheCall->getArg(0);
1821 ExprResult OrigArg1 = TheCall->getArg(1);
1823 // Do standard promotions between the two arguments, returning their common
1825 QualType Res = UsualArithmeticConversions(OrigArg0, OrigArg1, false);
1826 if (OrigArg0.isInvalid() || OrigArg1.isInvalid())
1829 // Make sure any conversions are pushed back into the call; this is
1830 // type safe since unordered compare builtins are declared as "_Bool
1832 TheCall->setArg(0, OrigArg0.get());
1833 TheCall->setArg(1, OrigArg1.get());
1835 if (OrigArg0.get()->isTypeDependent() || OrigArg1.get()->isTypeDependent())
1838 // If the common type isn't a real floating type, then the arguments were
1839 // invalid for this operation.
1840 if (Res.isNull() || !Res->isRealFloatingType())
1841 return Diag(OrigArg0.get()->getLocStart(),
1842 diag::err_typecheck_call_invalid_ordered_compare)
1843 << OrigArg0.get()->getType() << OrigArg1.get()->getType()
1844 << SourceRange(OrigArg0.get()->getLocStart(), OrigArg1.get()->getLocEnd());
1849 /// SemaBuiltinSemaBuiltinFPClassification - Handle functions like
1850 /// __builtin_isnan and friends. This is declared to take (...), so we have
1851 /// to check everything. We expect the last argument to be a floating point
1853 bool Sema::SemaBuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs) {
1854 if (TheCall->getNumArgs() < NumArgs)
1855 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
1856 << 0 << NumArgs << TheCall->getNumArgs()/*function call*/;
1857 if (TheCall->getNumArgs() > NumArgs)
1858 return Diag(TheCall->getArg(NumArgs)->getLocStart(),
1859 diag::err_typecheck_call_too_many_args)
1860 << 0 /*function call*/ << NumArgs << TheCall->getNumArgs()
1861 << SourceRange(TheCall->getArg(NumArgs)->getLocStart(),
1862 (*(TheCall->arg_end()-1))->getLocEnd());
1864 Expr *OrigArg = TheCall->getArg(NumArgs-1);
1866 if (OrigArg->isTypeDependent())
1869 // This operation requires a non-_Complex floating-point number.
1870 if (!OrigArg->getType()->isRealFloatingType())
1871 return Diag(OrigArg->getLocStart(),
1872 diag::err_typecheck_call_invalid_unary_fp)
1873 << OrigArg->getType() << OrigArg->getSourceRange();
1875 // If this is an implicit conversion from float -> double, remove it.
1876 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(OrigArg)) {
1877 Expr *CastArg = Cast->getSubExpr();
1878 if (CastArg->getType()->isSpecificBuiltinType(BuiltinType::Float)) {
1879 assert(Cast->getType()->isSpecificBuiltinType(BuiltinType::Double) &&
1880 "promotion from float to double is the only expected cast here");
1881 Cast->setSubExpr(nullptr);
1882 TheCall->setArg(NumArgs-1, CastArg);
1889 /// SemaBuiltinShuffleVector - Handle __builtin_shufflevector.
1890 // This is declared to take (...), so we have to check everything.
1891 ExprResult Sema::SemaBuiltinShuffleVector(CallExpr *TheCall) {
1892 if (TheCall->getNumArgs() < 2)
1893 return ExprError(Diag(TheCall->getLocEnd(),
1894 diag::err_typecheck_call_too_few_args_at_least)
1895 << 0 /*function call*/ << 2 << TheCall->getNumArgs()
1896 << TheCall->getSourceRange());
1898 // Determine which of the following types of shufflevector we're checking:
1899 // 1) unary, vector mask: (lhs, mask)
1900 // 2) binary, vector mask: (lhs, rhs, mask)
1901 // 3) binary, scalar mask: (lhs, rhs, index, ..., index)
1902 QualType resType = TheCall->getArg(0)->getType();
1903 unsigned numElements = 0;
1905 if (!TheCall->getArg(0)->isTypeDependent() &&
1906 !TheCall->getArg(1)->isTypeDependent()) {
1907 QualType LHSType = TheCall->getArg(0)->getType();
1908 QualType RHSType = TheCall->getArg(1)->getType();
1910 if (!LHSType->isVectorType() || !RHSType->isVectorType())
1911 return ExprError(Diag(TheCall->getLocStart(),
1912 diag::err_shufflevector_non_vector)
1913 << SourceRange(TheCall->getArg(0)->getLocStart(),
1914 TheCall->getArg(1)->getLocEnd()));
1916 numElements = LHSType->getAs<VectorType>()->getNumElements();
1917 unsigned numResElements = TheCall->getNumArgs() - 2;
1919 // Check to see if we have a call with 2 vector arguments, the unary shuffle
1920 // with mask. If so, verify that RHS is an integer vector type with the
1921 // same number of elts as lhs.
1922 if (TheCall->getNumArgs() == 2) {
1923 if (!RHSType->hasIntegerRepresentation() ||
1924 RHSType->getAs<VectorType>()->getNumElements() != numElements)
1925 return ExprError(Diag(TheCall->getLocStart(),
1926 diag::err_shufflevector_incompatible_vector)
1927 << SourceRange(TheCall->getArg(1)->getLocStart(),
1928 TheCall->getArg(1)->getLocEnd()));
1929 } else if (!Context.hasSameUnqualifiedType(LHSType, RHSType)) {
1930 return ExprError(Diag(TheCall->getLocStart(),
1931 diag::err_shufflevector_incompatible_vector)
1932 << SourceRange(TheCall->getArg(0)->getLocStart(),
1933 TheCall->getArg(1)->getLocEnd()));
1934 } else if (numElements != numResElements) {
1935 QualType eltType = LHSType->getAs<VectorType>()->getElementType();
1936 resType = Context.getVectorType(eltType, numResElements,
1937 VectorType::GenericVector);
1941 for (unsigned i = 2; i < TheCall->getNumArgs(); i++) {
1942 if (TheCall->getArg(i)->isTypeDependent() ||
1943 TheCall->getArg(i)->isValueDependent())
1946 llvm::APSInt Result(32);
1947 if (!TheCall->getArg(i)->isIntegerConstantExpr(Result, Context))
1948 return ExprError(Diag(TheCall->getLocStart(),
1949 diag::err_shufflevector_nonconstant_argument)
1950 << TheCall->getArg(i)->getSourceRange());
1952 // Allow -1 which will be translated to undef in the IR.
1953 if (Result.isSigned() && Result.isAllOnesValue())
1956 if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2)
1957 return ExprError(Diag(TheCall->getLocStart(),
1958 diag::err_shufflevector_argument_too_large)
1959 << TheCall->getArg(i)->getSourceRange());
1962 SmallVector<Expr*, 32> exprs;
1964 for (unsigned i = 0, e = TheCall->getNumArgs(); i != e; i++) {
1965 exprs.push_back(TheCall->getArg(i));
1966 TheCall->setArg(i, nullptr);
1969 return new (Context) ShuffleVectorExpr(Context, exprs, resType,
1970 TheCall->getCallee()->getLocStart(),
1971 TheCall->getRParenLoc());
1974 /// SemaConvertVectorExpr - Handle __builtin_convertvector
1975 ExprResult Sema::SemaConvertVectorExpr(Expr *E, TypeSourceInfo *TInfo,
1976 SourceLocation BuiltinLoc,
1977 SourceLocation RParenLoc) {
1978 ExprValueKind VK = VK_RValue;
1979 ExprObjectKind OK = OK_Ordinary;
1980 QualType DstTy = TInfo->getType();
1981 QualType SrcTy = E->getType();
1983 if (!SrcTy->isVectorType() && !SrcTy->isDependentType())
1984 return ExprError(Diag(BuiltinLoc,
1985 diag::err_convertvector_non_vector)
1986 << E->getSourceRange());
1987 if (!DstTy->isVectorType() && !DstTy->isDependentType())
1988 return ExprError(Diag(BuiltinLoc,
1989 diag::err_convertvector_non_vector_type));
1991 if (!SrcTy->isDependentType() && !DstTy->isDependentType()) {
1992 unsigned SrcElts = SrcTy->getAs<VectorType>()->getNumElements();
1993 unsigned DstElts = DstTy->getAs<VectorType>()->getNumElements();
1994 if (SrcElts != DstElts)
1995 return ExprError(Diag(BuiltinLoc,
1996 diag::err_convertvector_incompatible_vector)
1997 << E->getSourceRange());
2000 return new (Context)
2001 ConvertVectorExpr(E, TInfo, DstTy, VK, OK, BuiltinLoc, RParenLoc);
2004 /// SemaBuiltinPrefetch - Handle __builtin_prefetch.
2005 // This is declared to take (const void*, ...) and can take two
2006 // optional constant int args.
2007 bool Sema::SemaBuiltinPrefetch(CallExpr *TheCall) {
2008 unsigned NumArgs = TheCall->getNumArgs();
2011 return Diag(TheCall->getLocEnd(),
2012 diag::err_typecheck_call_too_many_args_at_most)
2013 << 0 /*function call*/ << 3 << NumArgs
2014 << TheCall->getSourceRange();
2016 // Argument 0 is checked for us and the remaining arguments must be
2017 // constant integers.
2018 for (unsigned i = 1; i != NumArgs; ++i)
2019 if (SemaBuiltinConstantArgRange(TheCall, i, 0, i == 1 ? 1 : 3))
2025 /// SemaBuiltinAssume - Handle __assume (MS Extension).
2026 // __assume does not evaluate its arguments, and should warn if its argument
2027 // has side effects.
2028 bool Sema::SemaBuiltinAssume(CallExpr *TheCall) {
2029 Expr *Arg = TheCall->getArg(0);
2030 if (Arg->isInstantiationDependent()) return false;
2032 if (Arg->HasSideEffects(Context))
2033 return Diag(Arg->getLocStart(), diag::warn_assume_side_effects)
2034 << Arg->getSourceRange();
2039 /// SemaBuiltinConstantArg - Handle a check if argument ArgNum of CallExpr
2040 /// TheCall is a constant expression.
2041 bool Sema::SemaBuiltinConstantArg(CallExpr *TheCall, int ArgNum,
2042 llvm::APSInt &Result) {
2043 Expr *Arg = TheCall->getArg(ArgNum);
2044 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
2045 FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
2047 if (Arg->isTypeDependent() || Arg->isValueDependent()) return false;
2049 if (!Arg->isIntegerConstantExpr(Result, Context))
2050 return Diag(TheCall->getLocStart(), diag::err_constant_integer_arg_type)
2051 << FDecl->getDeclName() << Arg->getSourceRange();
2056 /// SemaBuiltinConstantArgRange - Handle a check if argument ArgNum of CallExpr
2057 /// TheCall is a constant expression in the range [Low, High].
2058 bool Sema::SemaBuiltinConstantArgRange(CallExpr *TheCall, int ArgNum,
2059 int Low, int High) {
2060 llvm::APSInt Result;
2062 // We can't check the value of a dependent argument.
2063 Expr *Arg = TheCall->getArg(ArgNum);
2064 if (Arg->isTypeDependent() || Arg->isValueDependent())
2067 // Check constant-ness first.
2068 if (SemaBuiltinConstantArg(TheCall, ArgNum, Result))
2071 if (Result.getSExtValue() < Low || Result.getSExtValue() > High)
2072 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
2073 << Low << High << Arg->getSourceRange();
2078 /// SemaBuiltinLongjmp - Handle __builtin_longjmp(void *env[5], int val).
2079 /// This checks that val is a constant 1.
2080 bool Sema::SemaBuiltinLongjmp(CallExpr *TheCall) {
2081 Expr *Arg = TheCall->getArg(1);
2082 llvm::APSInt Result;
2084 // TODO: This is less than ideal. Overload this to take a value.
2085 if (SemaBuiltinConstantArg(TheCall, 1, Result))
2089 return Diag(TheCall->getLocStart(), diag::err_builtin_longjmp_invalid_val)
2090 << SourceRange(Arg->getLocStart(), Arg->getLocEnd());
2096 enum StringLiteralCheckType {
2098 SLCT_UncheckedLiteral,
2103 // Determine if an expression is a string literal or constant string.
2104 // If this function returns false on the arguments to a function expecting a
2105 // format string, we will usually need to emit a warning.
2106 // True string literals are then checked by CheckFormatString.
2107 static StringLiteralCheckType
2108 checkFormatStringExpr(Sema &S, const Expr *E, ArrayRef<const Expr *> Args,
2109 bool HasVAListArg, unsigned format_idx,
2110 unsigned firstDataArg, Sema::FormatStringType Type,
2111 Sema::VariadicCallType CallType, bool InFunctionCall,
2112 llvm::SmallBitVector &CheckedVarArgs) {
2114 if (E->isTypeDependent() || E->isValueDependent())
2115 return SLCT_NotALiteral;
2117 E = E->IgnoreParenCasts();
2119 if (E->isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull))
2120 // Technically -Wformat-nonliteral does not warn about this case.
2121 // The behavior of printf and friends in this case is implementation
2122 // dependent. Ideally if the format string cannot be null then
2123 // it should have a 'nonnull' attribute in the function prototype.
2124 return SLCT_UncheckedLiteral;
2126 switch (E->getStmtClass()) {
2127 case Stmt::BinaryConditionalOperatorClass:
2128 case Stmt::ConditionalOperatorClass: {
2129 // The expression is a literal if both sub-expressions were, and it was
2130 // completely checked only if both sub-expressions were checked.
2131 const AbstractConditionalOperator *C =
2132 cast<AbstractConditionalOperator>(E);
2133 StringLiteralCheckType Left =
2134 checkFormatStringExpr(S, C->getTrueExpr(), Args,
2135 HasVAListArg, format_idx, firstDataArg,
2136 Type, CallType, InFunctionCall, CheckedVarArgs);
2137 if (Left == SLCT_NotALiteral)
2138 return SLCT_NotALiteral;
2139 StringLiteralCheckType Right =
2140 checkFormatStringExpr(S, C->getFalseExpr(), Args,
2141 HasVAListArg, format_idx, firstDataArg,
2142 Type, CallType, InFunctionCall, CheckedVarArgs);
2143 return Left < Right ? Left : Right;
2146 case Stmt::ImplicitCastExprClass: {
2147 E = cast<ImplicitCastExpr>(E)->getSubExpr();
2151 case Stmt::OpaqueValueExprClass:
2152 if (const Expr *src = cast<OpaqueValueExpr>(E)->getSourceExpr()) {
2156 return SLCT_NotALiteral;
2158 case Stmt::PredefinedExprClass:
2159 // While __func__, etc., are technically not string literals, they
2160 // cannot contain format specifiers and thus are not a security
2162 return SLCT_UncheckedLiteral;
2164 case Stmt::DeclRefExprClass: {
2165 const DeclRefExpr *DR = cast<DeclRefExpr>(E);
2167 // As an exception, do not flag errors for variables binding to
2168 // const string literals.
2169 if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
2170 bool isConstant = false;
2171 QualType T = DR->getType();
2173 if (const ArrayType *AT = S.Context.getAsArrayType(T)) {
2174 isConstant = AT->getElementType().isConstant(S.Context);
2175 } else if (const PointerType *PT = T->getAs<PointerType>()) {
2176 isConstant = T.isConstant(S.Context) &&
2177 PT->getPointeeType().isConstant(S.Context);
2178 } else if (T->isObjCObjectPointerType()) {
2179 // In ObjC, there is usually no "const ObjectPointer" type,
2180 // so don't check if the pointee type is constant.
2181 isConstant = T.isConstant(S.Context);
2185 if (const Expr *Init = VD->getAnyInitializer()) {
2186 // Look through initializers like const char c[] = { "foo" }
2187 if (const InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
2188 if (InitList->isStringLiteralInit())
2189 Init = InitList->getInit(0)->IgnoreParenImpCasts();
2191 return checkFormatStringExpr(S, Init, Args,
2192 HasVAListArg, format_idx,
2193 firstDataArg, Type, CallType,
2194 /*InFunctionCall*/false, CheckedVarArgs);
2198 // For vprintf* functions (i.e., HasVAListArg==true), we add a
2199 // special check to see if the format string is a function parameter
2200 // of the function calling the printf function. If the function
2201 // has an attribute indicating it is a printf-like function, then we
2202 // should suppress warnings concerning non-literals being used in a call
2203 // to a vprintf function. For example:
2206 // logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...){
2208 // va_start(ap, fmt);
2209 // vprintf(fmt, ap); // Do NOT emit a warning about "fmt".
2213 if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(VD)) {
2214 if (const NamedDecl *ND = dyn_cast<NamedDecl>(PV->getDeclContext())) {
2215 int PVIndex = PV->getFunctionScopeIndex() + 1;
2216 for (const auto *PVFormat : ND->specific_attrs<FormatAttr>()) {
2217 // adjust for implicit parameter
2218 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
2219 if (MD->isInstance())
2221 // We also check if the formats are compatible.
2222 // We can't pass a 'scanf' string to a 'printf' function.
2223 if (PVIndex == PVFormat->getFormatIdx() &&
2224 Type == S.GetFormatStringType(PVFormat))
2225 return SLCT_UncheckedLiteral;
2232 return SLCT_NotALiteral;
2235 case Stmt::CallExprClass:
2236 case Stmt::CXXMemberCallExprClass: {
2237 const CallExpr *CE = cast<CallExpr>(E);
2238 if (const NamedDecl *ND = dyn_cast_or_null<NamedDecl>(CE->getCalleeDecl())) {
2239 if (const FormatArgAttr *FA = ND->getAttr<FormatArgAttr>()) {
2240 unsigned ArgIndex = FA->getFormatIdx();
2241 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
2242 if (MD->isInstance())
2244 const Expr *Arg = CE->getArg(ArgIndex - 1);
2246 return checkFormatStringExpr(S, Arg, Args,
2247 HasVAListArg, format_idx, firstDataArg,
2248 Type, CallType, InFunctionCall,
2250 } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
2251 unsigned BuiltinID = FD->getBuiltinID();
2252 if (BuiltinID == Builtin::BI__builtin___CFStringMakeConstantString ||
2253 BuiltinID == Builtin::BI__builtin___NSStringMakeConstantString) {
2254 const Expr *Arg = CE->getArg(0);
2255 return checkFormatStringExpr(S, Arg, Args,
2256 HasVAListArg, format_idx,
2257 firstDataArg, Type, CallType,
2258 InFunctionCall, CheckedVarArgs);
2263 return SLCT_NotALiteral;
2265 case Stmt::ObjCStringLiteralClass:
2266 case Stmt::StringLiteralClass: {
2267 const StringLiteral *StrE = nullptr;
2269 if (const ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(E))
2270 StrE = ObjCFExpr->getString();
2272 StrE = cast<StringLiteral>(E);
2275 S.CheckFormatString(StrE, E, Args, HasVAListArg, format_idx, firstDataArg,
2276 Type, InFunctionCall, CallType, CheckedVarArgs);
2277 return SLCT_CheckedLiteral;
2280 return SLCT_NotALiteral;
2284 return SLCT_NotALiteral;
2288 Sema::FormatStringType Sema::GetFormatStringType(const FormatAttr *Format) {
2289 return llvm::StringSwitch<FormatStringType>(Format->getType()->getName())
2290 .Case("scanf", FST_Scanf)
2291 .Cases("printf", "printf0", FST_Printf)
2292 .Cases("NSString", "CFString", FST_NSString)
2293 .Case("strftime", FST_Strftime)
2294 .Case("strfmon", FST_Strfmon)
2295 .Cases("kprintf", "cmn_err", "vcmn_err", "zcmn_err", FST_Kprintf)
2296 .Default(FST_Unknown);
2299 /// CheckFormatArguments - Check calls to printf and scanf (and similar
2300 /// functions) for correct use of format strings.
2301 /// Returns true if a format string has been fully checked.
2302 bool Sema::CheckFormatArguments(const FormatAttr *Format,
2303 ArrayRef<const Expr *> Args,
2305 VariadicCallType CallType,
2306 SourceLocation Loc, SourceRange Range,
2307 llvm::SmallBitVector &CheckedVarArgs) {
2308 FormatStringInfo FSI;
2309 if (getFormatStringInfo(Format, IsCXXMember, &FSI))
2310 return CheckFormatArguments(Args, FSI.HasVAListArg, FSI.FormatIdx,
2311 FSI.FirstDataArg, GetFormatStringType(Format),
2312 CallType, Loc, Range, CheckedVarArgs);
2316 bool Sema::CheckFormatArguments(ArrayRef<const Expr *> Args,
2317 bool HasVAListArg, unsigned format_idx,
2318 unsigned firstDataArg, FormatStringType Type,
2319 VariadicCallType CallType,
2320 SourceLocation Loc, SourceRange Range,
2321 llvm::SmallBitVector &CheckedVarArgs) {
2322 // CHECK: printf/scanf-like function is called with no format string.
2323 if (format_idx >= Args.size()) {
2324 Diag(Loc, diag::warn_missing_format_string) << Range;
2328 const Expr *OrigFormatExpr = Args[format_idx]->IgnoreParenCasts();
2330 // CHECK: format string is not a string literal.
2332 // Dynamically generated format strings are difficult to
2333 // automatically vet at compile time. Requiring that format strings
2334 // are string literals: (1) permits the checking of format strings by
2335 // the compiler and thereby (2) can practically remove the source of
2336 // many format string exploits.
2338 // Format string can be either ObjC string (e.g. @"%d") or
2339 // C string (e.g. "%d")
2340 // ObjC string uses the same format specifiers as C string, so we can use
2341 // the same format string checking logic for both ObjC and C strings.
2342 StringLiteralCheckType CT =
2343 checkFormatStringExpr(*this, OrigFormatExpr, Args, HasVAListArg,
2344 format_idx, firstDataArg, Type, CallType,
2345 /*IsFunctionCall*/true, CheckedVarArgs);
2346 if (CT != SLCT_NotALiteral)
2347 // Literal format string found, check done!
2348 return CT == SLCT_CheckedLiteral;
2350 // Strftime is particular as it always uses a single 'time' argument,
2351 // so it is safe to pass a non-literal string.
2352 if (Type == FST_Strftime)
2355 // Do not emit diag when the string param is a macro expansion and the
2356 // format is either NSString or CFString. This is a hack to prevent
2357 // diag when using the NSLocalizedString and CFCopyLocalizedString macros
2358 // which are usually used in place of NS and CF string literals.
2359 if (Type == FST_NSString &&
2360 SourceMgr.isInSystemMacro(Args[format_idx]->getLocStart()))
2363 // If there are no arguments specified, warn with -Wformat-security, otherwise
2364 // warn only with -Wformat-nonliteral.
2365 if (Args.size() == firstDataArg)
2366 Diag(Args[format_idx]->getLocStart(),
2367 diag::warn_format_nonliteral_noargs)
2368 << OrigFormatExpr->getSourceRange();
2370 Diag(Args[format_idx]->getLocStart(),
2371 diag::warn_format_nonliteral)
2372 << OrigFormatExpr->getSourceRange();
2377 class CheckFormatHandler : public analyze_format_string::FormatStringHandler {
2380 const StringLiteral *FExpr;
2381 const Expr *OrigFormatExpr;
2382 const unsigned FirstDataArg;
2383 const unsigned NumDataArgs;
2384 const char *Beg; // Start of format string.
2385 const bool HasVAListArg;
2386 ArrayRef<const Expr *> Args;
2388 llvm::SmallBitVector CoveredArgs;
2389 bool usesPositionalArgs;
2391 bool inFunctionCall;
2392 Sema::VariadicCallType CallType;
2393 llvm::SmallBitVector &CheckedVarArgs;
2395 CheckFormatHandler(Sema &s, const StringLiteral *fexpr,
2396 const Expr *origFormatExpr, unsigned firstDataArg,
2397 unsigned numDataArgs, const char *beg, bool hasVAListArg,
2398 ArrayRef<const Expr *> Args,
2399 unsigned formatIdx, bool inFunctionCall,
2400 Sema::VariadicCallType callType,
2401 llvm::SmallBitVector &CheckedVarArgs)
2402 : S(s), FExpr(fexpr), OrigFormatExpr(origFormatExpr),
2403 FirstDataArg(firstDataArg), NumDataArgs(numDataArgs),
2404 Beg(beg), HasVAListArg(hasVAListArg),
2405 Args(Args), FormatIdx(formatIdx),
2406 usesPositionalArgs(false), atFirstArg(true),
2407 inFunctionCall(inFunctionCall), CallType(callType),
2408 CheckedVarArgs(CheckedVarArgs) {
2409 CoveredArgs.resize(numDataArgs);
2410 CoveredArgs.reset();
2413 void DoneProcessing();
2415 void HandleIncompleteSpecifier(const char *startSpecifier,
2416 unsigned specifierLen) override;
2418 void HandleInvalidLengthModifier(
2419 const analyze_format_string::FormatSpecifier &FS,
2420 const analyze_format_string::ConversionSpecifier &CS,
2421 const char *startSpecifier, unsigned specifierLen,
2424 void HandleNonStandardLengthModifier(
2425 const analyze_format_string::FormatSpecifier &FS,
2426 const char *startSpecifier, unsigned specifierLen);
2428 void HandleNonStandardConversionSpecifier(
2429 const analyze_format_string::ConversionSpecifier &CS,
2430 const char *startSpecifier, unsigned specifierLen);
2432 void HandlePosition(const char *startPos, unsigned posLen) override;
2434 void HandleInvalidPosition(const char *startSpecifier,
2435 unsigned specifierLen,
2436 analyze_format_string::PositionContext p) override;
2438 void HandleZeroPosition(const char *startPos, unsigned posLen) override;
2440 void HandleNullChar(const char *nullCharacter) override;
2442 template <typename Range>
2443 static void EmitFormatDiagnostic(Sema &S, bool inFunctionCall,
2444 const Expr *ArgumentExpr,
2445 PartialDiagnostic PDiag,
2446 SourceLocation StringLoc,
2447 bool IsStringLocation, Range StringRange,
2448 ArrayRef<FixItHint> Fixit = None);
2451 bool HandleInvalidConversionSpecifier(unsigned argIndex, SourceLocation Loc,
2452 const char *startSpec,
2453 unsigned specifierLen,
2454 const char *csStart, unsigned csLen);
2456 void HandlePositionalNonpositionalArgs(SourceLocation Loc,
2457 const char *startSpec,
2458 unsigned specifierLen);
2460 SourceRange getFormatStringRange();
2461 CharSourceRange getSpecifierRange(const char *startSpecifier,
2462 unsigned specifierLen);
2463 SourceLocation getLocationOfByte(const char *x);
2465 const Expr *getDataArg(unsigned i) const;
2467 bool CheckNumArgs(const analyze_format_string::FormatSpecifier &FS,
2468 const analyze_format_string::ConversionSpecifier &CS,
2469 const char *startSpecifier, unsigned specifierLen,
2472 template <typename Range>
2473 void EmitFormatDiagnostic(PartialDiagnostic PDiag, SourceLocation StringLoc,
2474 bool IsStringLocation, Range StringRange,
2475 ArrayRef<FixItHint> Fixit = None);
2479 SourceRange CheckFormatHandler::getFormatStringRange() {
2480 return OrigFormatExpr->getSourceRange();
2483 CharSourceRange CheckFormatHandler::
2484 getSpecifierRange(const char *startSpecifier, unsigned specifierLen) {
2485 SourceLocation Start = getLocationOfByte(startSpecifier);
2486 SourceLocation End = getLocationOfByte(startSpecifier + specifierLen - 1);
2488 // Advance the end SourceLocation by one due to half-open ranges.
2489 End = End.getLocWithOffset(1);
2491 return CharSourceRange::getCharRange(Start, End);
2494 SourceLocation CheckFormatHandler::getLocationOfByte(const char *x) {
2495 return S.getLocationOfStringLiteralByte(FExpr, x - Beg);
2498 void CheckFormatHandler::HandleIncompleteSpecifier(const char *startSpecifier,
2499 unsigned specifierLen){
2500 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_incomplete_specifier),
2501 getLocationOfByte(startSpecifier),
2502 /*IsStringLocation*/true,
2503 getSpecifierRange(startSpecifier, specifierLen));
2506 void CheckFormatHandler::HandleInvalidLengthModifier(
2507 const analyze_format_string::FormatSpecifier &FS,
2508 const analyze_format_string::ConversionSpecifier &CS,
2509 const char *startSpecifier, unsigned specifierLen, unsigned DiagID) {
2510 using namespace analyze_format_string;
2512 const LengthModifier &LM = FS.getLengthModifier();
2513 CharSourceRange LMRange = getSpecifierRange(LM.getStart(), LM.getLength());
2515 // See if we know how to fix this length modifier.
2516 Optional<LengthModifier> FixedLM = FS.getCorrectedLengthModifier();
2518 EmitFormatDiagnostic(S.PDiag(DiagID) << LM.toString() << CS.toString(),
2519 getLocationOfByte(LM.getStart()),
2520 /*IsStringLocation*/true,
2521 getSpecifierRange(startSpecifier, specifierLen));
2523 S.Diag(getLocationOfByte(LM.getStart()), diag::note_format_fix_specifier)
2524 << FixedLM->toString()
2525 << FixItHint::CreateReplacement(LMRange, FixedLM->toString());
2529 if (DiagID == diag::warn_format_nonsensical_length)
2530 Hint = FixItHint::CreateRemoval(LMRange);
2532 EmitFormatDiagnostic(S.PDiag(DiagID) << LM.toString() << CS.toString(),
2533 getLocationOfByte(LM.getStart()),
2534 /*IsStringLocation*/true,
2535 getSpecifierRange(startSpecifier, specifierLen),
2540 void CheckFormatHandler::HandleNonStandardLengthModifier(
2541 const analyze_format_string::FormatSpecifier &FS,
2542 const char *startSpecifier, unsigned specifierLen) {
2543 using namespace analyze_format_string;
2545 const LengthModifier &LM = FS.getLengthModifier();
2546 CharSourceRange LMRange = getSpecifierRange(LM.getStart(), LM.getLength());
2548 // See if we know how to fix this length modifier.
2549 Optional<LengthModifier> FixedLM = FS.getCorrectedLengthModifier();
2551 EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
2552 << LM.toString() << 0,
2553 getLocationOfByte(LM.getStart()),
2554 /*IsStringLocation*/true,
2555 getSpecifierRange(startSpecifier, specifierLen));
2557 S.Diag(getLocationOfByte(LM.getStart()), diag::note_format_fix_specifier)
2558 << FixedLM->toString()
2559 << FixItHint::CreateReplacement(LMRange, FixedLM->toString());
2562 EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
2563 << LM.toString() << 0,
2564 getLocationOfByte(LM.getStart()),
2565 /*IsStringLocation*/true,
2566 getSpecifierRange(startSpecifier, specifierLen));
2570 void CheckFormatHandler::HandleNonStandardConversionSpecifier(
2571 const analyze_format_string::ConversionSpecifier &CS,
2572 const char *startSpecifier, unsigned specifierLen) {
2573 using namespace analyze_format_string;
2575 // See if we know how to fix this conversion specifier.
2576 Optional<ConversionSpecifier> FixedCS = CS.getStandardSpecifier();
2578 EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
2579 << CS.toString() << /*conversion specifier*/1,
2580 getLocationOfByte(CS.getStart()),
2581 /*IsStringLocation*/true,
2582 getSpecifierRange(startSpecifier, specifierLen));
2584 CharSourceRange CSRange = getSpecifierRange(CS.getStart(), CS.getLength());
2585 S.Diag(getLocationOfByte(CS.getStart()), diag::note_format_fix_specifier)
2586 << FixedCS->toString()
2587 << FixItHint::CreateReplacement(CSRange, FixedCS->toString());
2589 EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
2590 << CS.toString() << /*conversion specifier*/1,
2591 getLocationOfByte(CS.getStart()),
2592 /*IsStringLocation*/true,
2593 getSpecifierRange(startSpecifier, specifierLen));
2597 void CheckFormatHandler::HandlePosition(const char *startPos,
2599 EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard_positional_arg),
2600 getLocationOfByte(startPos),
2601 /*IsStringLocation*/true,
2602 getSpecifierRange(startPos, posLen));
2606 CheckFormatHandler::HandleInvalidPosition(const char *startPos, unsigned posLen,
2607 analyze_format_string::PositionContext p) {
2608 EmitFormatDiagnostic(S.PDiag(diag::warn_format_invalid_positional_specifier)
2610 getLocationOfByte(startPos), /*IsStringLocation*/true,
2611 getSpecifierRange(startPos, posLen));
2614 void CheckFormatHandler::HandleZeroPosition(const char *startPos,
2616 EmitFormatDiagnostic(S.PDiag(diag::warn_format_zero_positional_specifier),
2617 getLocationOfByte(startPos),
2618 /*IsStringLocation*/true,
2619 getSpecifierRange(startPos, posLen));
2622 void CheckFormatHandler::HandleNullChar(const char *nullCharacter) {
2623 if (!isa<ObjCStringLiteral>(OrigFormatExpr)) {
2624 // The presence of a null character is likely an error.
2625 EmitFormatDiagnostic(
2626 S.PDiag(diag::warn_printf_format_string_contains_null_char),
2627 getLocationOfByte(nullCharacter), /*IsStringLocation*/true,
2628 getFormatStringRange());
2632 // Note that this may return NULL if there was an error parsing or building
2633 // one of the argument expressions.
2634 const Expr *CheckFormatHandler::getDataArg(unsigned i) const {
2635 return Args[FirstDataArg + i];
2638 void CheckFormatHandler::DoneProcessing() {
2639 // Does the number of data arguments exceed the number of
2640 // format conversions in the format string?
2641 if (!HasVAListArg) {
2642 // Find any arguments that weren't covered.
2644 signed notCoveredArg = CoveredArgs.find_first();
2645 if (notCoveredArg >= 0) {
2646 assert((unsigned)notCoveredArg < NumDataArgs);
2647 if (const Expr *E = getDataArg((unsigned) notCoveredArg)) {
2648 SourceLocation Loc = E->getLocStart();
2649 if (!S.getSourceManager().isInSystemMacro(Loc)) {
2650 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_data_arg_not_used),
2651 Loc, /*IsStringLocation*/false,
2652 getFormatStringRange());
2660 CheckFormatHandler::HandleInvalidConversionSpecifier(unsigned argIndex,
2662 const char *startSpec,
2663 unsigned specifierLen,
2664 const char *csStart,
2667 bool keepGoing = true;
2668 if (argIndex < NumDataArgs) {
2669 // Consider the argument coverered, even though the specifier doesn't
2671 CoveredArgs.set(argIndex);
2674 // If argIndex exceeds the number of data arguments we
2675 // don't issue a warning because that is just a cascade of warnings (and
2676 // they may have intended '%%' anyway). We don't want to continue processing
2677 // the format string after this point, however, as we will like just get
2678 // gibberish when trying to match arguments.
2682 EmitFormatDiagnostic(S.PDiag(diag::warn_format_invalid_conversion)
2683 << StringRef(csStart, csLen),
2684 Loc, /*IsStringLocation*/true,
2685 getSpecifierRange(startSpec, specifierLen));
2691 CheckFormatHandler::HandlePositionalNonpositionalArgs(SourceLocation Loc,
2692 const char *startSpec,
2693 unsigned specifierLen) {
2694 EmitFormatDiagnostic(
2695 S.PDiag(diag::warn_format_mix_positional_nonpositional_args),
2696 Loc, /*isStringLoc*/true, getSpecifierRange(startSpec, specifierLen));
2700 CheckFormatHandler::CheckNumArgs(
2701 const analyze_format_string::FormatSpecifier &FS,
2702 const analyze_format_string::ConversionSpecifier &CS,
2703 const char *startSpecifier, unsigned specifierLen, unsigned argIndex) {
2705 if (argIndex >= NumDataArgs) {
2706 PartialDiagnostic PDiag = FS.usesPositionalArg()
2707 ? (S.PDiag(diag::warn_printf_positional_arg_exceeds_data_args)
2708 << (argIndex+1) << NumDataArgs)
2709 : S.PDiag(diag::warn_printf_insufficient_data_args);
2710 EmitFormatDiagnostic(
2711 PDiag, getLocationOfByte(CS.getStart()), /*IsStringLocation*/true,
2712 getSpecifierRange(startSpecifier, specifierLen));
2718 template<typename Range>
2719 void CheckFormatHandler::EmitFormatDiagnostic(PartialDiagnostic PDiag,
2721 bool IsStringLocation,
2723 ArrayRef<FixItHint> FixIt) {
2724 EmitFormatDiagnostic(S, inFunctionCall, Args[FormatIdx], PDiag,
2725 Loc, IsStringLocation, StringRange, FixIt);
2728 /// \brief If the format string is not within the funcion call, emit a note
2729 /// so that the function call and string are in diagnostic messages.
2731 /// \param InFunctionCall if true, the format string is within the function
2732 /// call and only one diagnostic message will be produced. Otherwise, an
2733 /// extra note will be emitted pointing to location of the format string.
2735 /// \param ArgumentExpr the expression that is passed as the format string
2736 /// argument in the function call. Used for getting locations when two
2737 /// diagnostics are emitted.
2739 /// \param PDiag the callee should already have provided any strings for the
2740 /// diagnostic message. This function only adds locations and fixits
2743 /// \param Loc primary location for diagnostic. If two diagnostics are
2744 /// required, one will be at Loc and a new SourceLocation will be created for
2747 /// \param IsStringLocation if true, Loc points to the format string should be
2748 /// used for the note. Otherwise, Loc points to the argument list and will
2749 /// be used with PDiag.
2751 /// \param StringRange some or all of the string to highlight. This is
2752 /// templated so it can accept either a CharSourceRange or a SourceRange.
2754 /// \param FixIt optional fix it hint for the format string.
2755 template<typename Range>
2756 void CheckFormatHandler::EmitFormatDiagnostic(Sema &S, bool InFunctionCall,
2757 const Expr *ArgumentExpr,
2758 PartialDiagnostic PDiag,
2760 bool IsStringLocation,
2762 ArrayRef<FixItHint> FixIt) {
2763 if (InFunctionCall) {
2764 const Sema::SemaDiagnosticBuilder &D = S.Diag(Loc, PDiag);
2766 for (ArrayRef<FixItHint>::iterator I = FixIt.begin(), E = FixIt.end();
2771 S.Diag(IsStringLocation ? ArgumentExpr->getExprLoc() : Loc, PDiag)
2772 << ArgumentExpr->getSourceRange();
2774 const Sema::SemaDiagnosticBuilder &Note =
2775 S.Diag(IsStringLocation ? Loc : StringRange.getBegin(),
2776 diag::note_format_string_defined);
2778 Note << StringRange;
2779 for (ArrayRef<FixItHint>::iterator I = FixIt.begin(), E = FixIt.end();
2786 //===--- CHECK: Printf format string checking ------------------------------===//
2789 class CheckPrintfHandler : public CheckFormatHandler {
2792 CheckPrintfHandler(Sema &s, const StringLiteral *fexpr,
2793 const Expr *origFormatExpr, unsigned firstDataArg,
2794 unsigned numDataArgs, bool isObjC,
2795 const char *beg, bool hasVAListArg,
2796 ArrayRef<const Expr *> Args,
2797 unsigned formatIdx, bool inFunctionCall,
2798 Sema::VariadicCallType CallType,
2799 llvm::SmallBitVector &CheckedVarArgs)
2800 : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg,
2801 numDataArgs, beg, hasVAListArg, Args,
2802 formatIdx, inFunctionCall, CallType, CheckedVarArgs),
2807 bool HandleInvalidPrintfConversionSpecifier(
2808 const analyze_printf::PrintfSpecifier &FS,
2809 const char *startSpecifier,
2810 unsigned specifierLen) override;
2812 bool HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier &FS,
2813 const char *startSpecifier,
2814 unsigned specifierLen) override;
2815 bool checkFormatExpr(const analyze_printf::PrintfSpecifier &FS,
2816 const char *StartSpecifier,
2817 unsigned SpecifierLen,
2820 bool HandleAmount(const analyze_format_string::OptionalAmount &Amt, unsigned k,
2821 const char *startSpecifier, unsigned specifierLen);
2822 void HandleInvalidAmount(const analyze_printf::PrintfSpecifier &FS,
2823 const analyze_printf::OptionalAmount &Amt,
2825 const char *startSpecifier, unsigned specifierLen);
2826 void HandleFlag(const analyze_printf::PrintfSpecifier &FS,
2827 const analyze_printf::OptionalFlag &flag,
2828 const char *startSpecifier, unsigned specifierLen);
2829 void HandleIgnoredFlag(const analyze_printf::PrintfSpecifier &FS,
2830 const analyze_printf::OptionalFlag &ignoredFlag,
2831 const analyze_printf::OptionalFlag &flag,
2832 const char *startSpecifier, unsigned specifierLen);
2833 bool checkForCStrMembers(const analyze_printf::ArgType &AT,
2839 bool CheckPrintfHandler::HandleInvalidPrintfConversionSpecifier(
2840 const analyze_printf::PrintfSpecifier &FS,
2841 const char *startSpecifier,
2842 unsigned specifierLen) {
2843 const analyze_printf::PrintfConversionSpecifier &CS =
2844 FS.getConversionSpecifier();
2846 return HandleInvalidConversionSpecifier(FS.getArgIndex(),
2847 getLocationOfByte(CS.getStart()),
2848 startSpecifier, specifierLen,
2849 CS.getStart(), CS.getLength());
2852 bool CheckPrintfHandler::HandleAmount(
2853 const analyze_format_string::OptionalAmount &Amt,
2854 unsigned k, const char *startSpecifier,
2855 unsigned specifierLen) {
2857 if (Amt.hasDataArgument()) {
2858 if (!HasVAListArg) {
2859 unsigned argIndex = Amt.getArgIndex();
2860 if (argIndex >= NumDataArgs) {
2861 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_asterisk_missing_arg)
2863 getLocationOfByte(Amt.getStart()),
2864 /*IsStringLocation*/true,
2865 getSpecifierRange(startSpecifier, specifierLen));
2866 // Don't do any more checking. We will just emit
2871 // Type check the data argument. It should be an 'int'.
2872 // Although not in conformance with C99, we also allow the argument to be
2873 // an 'unsigned int' as that is a reasonably safe case. GCC also
2874 // doesn't emit a warning for that case.
2875 CoveredArgs.set(argIndex);
2876 const Expr *Arg = getDataArg(argIndex);
2880 QualType T = Arg->getType();
2882 const analyze_printf::ArgType &AT = Amt.getArgType(S.Context);
2883 assert(AT.isValid());
2885 if (!AT.matchesType(S.Context, T)) {
2886 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_asterisk_wrong_type)
2887 << k << AT.getRepresentativeTypeName(S.Context)
2888 << T << Arg->getSourceRange(),
2889 getLocationOfByte(Amt.getStart()),
2890 /*IsStringLocation*/true,
2891 getSpecifierRange(startSpecifier, specifierLen));
2892 // Don't do any more checking. We will just emit
2901 void CheckPrintfHandler::HandleInvalidAmount(
2902 const analyze_printf::PrintfSpecifier &FS,
2903 const analyze_printf::OptionalAmount &Amt,
2905 const char *startSpecifier,
2906 unsigned specifierLen) {
2907 const analyze_printf::PrintfConversionSpecifier &CS =
2908 FS.getConversionSpecifier();
2911 Amt.getHowSpecified() == analyze_printf::OptionalAmount::Constant
2912 ? FixItHint::CreateRemoval(getSpecifierRange(Amt.getStart(),
2913 Amt.getConstantLength()))
2916 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_nonsensical_optional_amount)
2917 << type << CS.toString(),
2918 getLocationOfByte(Amt.getStart()),
2919 /*IsStringLocation*/true,
2920 getSpecifierRange(startSpecifier, specifierLen),
2924 void CheckPrintfHandler::HandleFlag(const analyze_printf::PrintfSpecifier &FS,
2925 const analyze_printf::OptionalFlag &flag,
2926 const char *startSpecifier,
2927 unsigned specifierLen) {
2928 // Warn about pointless flag with a fixit removal.
2929 const analyze_printf::PrintfConversionSpecifier &CS =
2930 FS.getConversionSpecifier();
2931 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_nonsensical_flag)
2932 << flag.toString() << CS.toString(),
2933 getLocationOfByte(flag.getPosition()),
2934 /*IsStringLocation*/true,
2935 getSpecifierRange(startSpecifier, specifierLen),
2936 FixItHint::CreateRemoval(
2937 getSpecifierRange(flag.getPosition(), 1)));
2940 void CheckPrintfHandler::HandleIgnoredFlag(
2941 const analyze_printf::PrintfSpecifier &FS,
2942 const analyze_printf::OptionalFlag &ignoredFlag,
2943 const analyze_printf::OptionalFlag &flag,
2944 const char *startSpecifier,
2945 unsigned specifierLen) {
2946 // Warn about ignored flag with a fixit removal.
2947 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_ignored_flag)
2948 << ignoredFlag.toString() << flag.toString(),
2949 getLocationOfByte(ignoredFlag.getPosition()),
2950 /*IsStringLocation*/true,
2951 getSpecifierRange(startSpecifier, specifierLen),
2952 FixItHint::CreateRemoval(
2953 getSpecifierRange(ignoredFlag.getPosition(), 1)));
2956 // Determines if the specified is a C++ class or struct containing
2957 // a member with the specified name and kind (e.g. a CXXMethodDecl named
2959 template<typename MemberKind>
2960 static llvm::SmallPtrSet<MemberKind*, 1>
2961 CXXRecordMembersNamed(StringRef Name, Sema &S, QualType Ty) {
2962 const RecordType *RT = Ty->getAs<RecordType>();
2963 llvm::SmallPtrSet<MemberKind*, 1> Results;
2967 const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl());
2968 if (!RD || !RD->getDefinition())
2971 LookupResult R(S, &S.Context.Idents.get(Name), SourceLocation(),
2972 Sema::LookupMemberName);
2973 R.suppressDiagnostics();
2975 // We just need to include all members of the right kind turned up by the
2976 // filter, at this point.
2977 if (S.LookupQualifiedName(R, RT->getDecl()))
2978 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
2979 NamedDecl *decl = (*I)->getUnderlyingDecl();
2980 if (MemberKind *FK = dyn_cast<MemberKind>(decl))
2986 /// Check if we could call '.c_str()' on an object.
2988 /// FIXME: This returns the wrong results in some cases (if cv-qualifiers don't
2989 /// allow the call, or if it would be ambiguous).
2990 bool Sema::hasCStrMethod(const Expr *E) {
2991 typedef llvm::SmallPtrSet<CXXMethodDecl*, 1> MethodSet;
2993 CXXRecordMembersNamed<CXXMethodDecl>("c_str", *this, E->getType());
2994 for (MethodSet::iterator MI = Results.begin(), ME = Results.end();
2996 if ((*MI)->getMinRequiredArguments() == 0)
3001 // Check if a (w)string was passed when a (w)char* was needed, and offer a
3002 // better diagnostic if so. AT is assumed to be valid.
3003 // Returns true when a c_str() conversion method is found.
3004 bool CheckPrintfHandler::checkForCStrMembers(
3005 const analyze_printf::ArgType &AT, const Expr *E) {
3006 typedef llvm::SmallPtrSet<CXXMethodDecl*, 1> MethodSet;
3009 CXXRecordMembersNamed<CXXMethodDecl>("c_str", S, E->getType());
3011 for (MethodSet::iterator MI = Results.begin(), ME = Results.end();
3013 const CXXMethodDecl *Method = *MI;
3014 if (Method->getMinRequiredArguments() == 0 &&
3015 AT.matchesType(S.Context, Method->getReturnType())) {
3016 // FIXME: Suggest parens if the expression needs them.
3017 SourceLocation EndLoc = S.getLocForEndOfToken(E->getLocEnd());
3018 S.Diag(E->getLocStart(), diag::note_printf_c_str)
3020 << FixItHint::CreateInsertion(EndLoc, ".c_str()");
3029 CheckPrintfHandler::HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier
3031 const char *startSpecifier,
3032 unsigned specifierLen) {
3034 using namespace analyze_format_string;
3035 using namespace analyze_printf;
3036 const PrintfConversionSpecifier &CS = FS.getConversionSpecifier();
3038 if (FS.consumesDataArgument()) {
3041 usesPositionalArgs = FS.usesPositionalArg();
3043 else if (usesPositionalArgs != FS.usesPositionalArg()) {
3044 HandlePositionalNonpositionalArgs(getLocationOfByte(CS.getStart()),
3045 startSpecifier, specifierLen);
3050 // First check if the field width, precision, and conversion specifier
3051 // have matching data arguments.
3052 if (!HandleAmount(FS.getFieldWidth(), /* field width */ 0,
3053 startSpecifier, specifierLen)) {
3057 if (!HandleAmount(FS.getPrecision(), /* precision */ 1,
3058 startSpecifier, specifierLen)) {
3062 if (!CS.consumesDataArgument()) {
3063 // FIXME: Technically specifying a precision or field width here
3064 // makes no sense. Worth issuing a warning at some point.
3068 // Consume the argument.
3069 unsigned argIndex = FS.getArgIndex();
3070 if (argIndex < NumDataArgs) {
3071 // The check to see if the argIndex is valid will come later.
3072 // We set the bit here because we may exit early from this
3073 // function if we encounter some other error.
3074 CoveredArgs.set(argIndex);
3077 // Check for using an Objective-C specific conversion specifier
3078 // in a non-ObjC literal.
3079 if (!ObjCContext && CS.isObjCArg()) {
3080 return HandleInvalidPrintfConversionSpecifier(FS, startSpecifier,
3084 // Check for invalid use of field width
3085 if (!FS.hasValidFieldWidth()) {
3086 HandleInvalidAmount(FS, FS.getFieldWidth(), /* field width */ 0,
3087 startSpecifier, specifierLen);
3090 // Check for invalid use of precision
3091 if (!FS.hasValidPrecision()) {
3092 HandleInvalidAmount(FS, FS.getPrecision(), /* precision */ 1,
3093 startSpecifier, specifierLen);
3096 // Check each flag does not conflict with any other component.
3097 if (!FS.hasValidThousandsGroupingPrefix())
3098 HandleFlag(FS, FS.hasThousandsGrouping(), startSpecifier, specifierLen);
3099 if (!FS.hasValidLeadingZeros())
3100 HandleFlag(FS, FS.hasLeadingZeros(), startSpecifier, specifierLen);
3101 if (!FS.hasValidPlusPrefix())
3102 HandleFlag(FS, FS.hasPlusPrefix(), startSpecifier, specifierLen);
3103 if (!FS.hasValidSpacePrefix())
3104 HandleFlag(FS, FS.hasSpacePrefix(), startSpecifier, specifierLen);
3105 if (!FS.hasValidAlternativeForm())
3106 HandleFlag(FS, FS.hasAlternativeForm(), startSpecifier, specifierLen);
3107 if (!FS.hasValidLeftJustified())
3108 HandleFlag(FS, FS.isLeftJustified(), startSpecifier, specifierLen);
3110 // Check that flags are not ignored by another flag
3111 if (FS.hasSpacePrefix() && FS.hasPlusPrefix()) // ' ' ignored by '+'
3112 HandleIgnoredFlag(FS, FS.hasSpacePrefix(), FS.hasPlusPrefix(),
3113 startSpecifier, specifierLen);
3114 if (FS.hasLeadingZeros() && FS.isLeftJustified()) // '0' ignored by '-'
3115 HandleIgnoredFlag(FS, FS.hasLeadingZeros(), FS.isLeftJustified(),
3116 startSpecifier, specifierLen);
3118 // Check the length modifier is valid with the given conversion specifier.
3119 if (!FS.hasValidLengthModifier(S.getASTContext().getTargetInfo()))
3120 HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
3121 diag::warn_format_nonsensical_length);
3122 else if (!FS.hasStandardLengthModifier())
3123 HandleNonStandardLengthModifier(FS, startSpecifier, specifierLen);
3124 else if (!FS.hasStandardLengthConversionCombination())
3125 HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
3126 diag::warn_format_non_standard_conversion_spec);
3128 if (!FS.hasStandardConversionSpecifier(S.getLangOpts()))
3129 HandleNonStandardConversionSpecifier(CS, startSpecifier, specifierLen);
3131 // The remaining checks depend on the data arguments.
3135 if (!CheckNumArgs(FS, CS, startSpecifier, specifierLen, argIndex))
3138 const Expr *Arg = getDataArg(argIndex);
3142 return checkFormatExpr(FS, startSpecifier, specifierLen, Arg);
3145 static bool requiresParensToAddCast(const Expr *E) {
3146 // FIXME: We should have a general way to reason about operator
3147 // precedence and whether parens are actually needed here.
3148 // Take care of a few common cases where they aren't.
3149 const Expr *Inside = E->IgnoreImpCasts();
3150 if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(Inside))
3151 Inside = POE->getSyntacticForm()->IgnoreImpCasts();
3153 switch (Inside->getStmtClass()) {
3154 case Stmt::ArraySubscriptExprClass:
3155 case Stmt::CallExprClass:
3156 case Stmt::CharacterLiteralClass:
3157 case Stmt::CXXBoolLiteralExprClass:
3158 case Stmt::DeclRefExprClass:
3159 case Stmt::FloatingLiteralClass:
3160 case Stmt::IntegerLiteralClass:
3161 case Stmt::MemberExprClass:
3162 case Stmt::ObjCArrayLiteralClass:
3163 case Stmt::ObjCBoolLiteralExprClass:
3164 case Stmt::ObjCBoxedExprClass:
3165 case Stmt::ObjCDictionaryLiteralClass:
3166 case Stmt::ObjCEncodeExprClass:
3167 case Stmt::ObjCIvarRefExprClass:
3168 case Stmt::ObjCMessageExprClass:
3169 case Stmt::ObjCPropertyRefExprClass:
3170 case Stmt::ObjCStringLiteralClass:
3171 case Stmt::ObjCSubscriptRefExprClass:
3172 case Stmt::ParenExprClass:
3173 case Stmt::StringLiteralClass:
3174 case Stmt::UnaryOperatorClass:
3182 CheckPrintfHandler::checkFormatExpr(const analyze_printf::PrintfSpecifier &FS,
3183 const char *StartSpecifier,
3184 unsigned SpecifierLen,
3186 using namespace analyze_format_string;
3187 using namespace analyze_printf;
3188 // Now type check the data expression that matches the
3189 // format specifier.
3190 const analyze_printf::ArgType &AT = FS.getArgType(S.Context,
3195 QualType ExprTy = E->getType();
3196 while (const TypeOfExprType *TET = dyn_cast<TypeOfExprType>(ExprTy)) {
3197 ExprTy = TET->getUnderlyingExpr()->getType();
3200 if (AT.matchesType(S.Context, ExprTy))
3203 // Look through argument promotions for our error message's reported type.
3204 // This includes the integral and floating promotions, but excludes array
3205 // and function pointer decay; seeing that an argument intended to be a
3206 // string has type 'char [6]' is probably more confusing than 'char *'.
3207 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
3208 if (ICE->getCastKind() == CK_IntegralCast ||
3209 ICE->getCastKind() == CK_FloatingCast) {
3210 E = ICE->getSubExpr();
3211 ExprTy = E->getType();
3213 // Check if we didn't match because of an implicit cast from a 'char'
3214 // or 'short' to an 'int'. This is done because printf is a varargs
3216 if (ICE->getType() == S.Context.IntTy ||
3217 ICE->getType() == S.Context.UnsignedIntTy) {
3218 // All further checking is done on the subexpression.
3219 if (AT.matchesType(S.Context, ExprTy))
3223 } else if (const CharacterLiteral *CL = dyn_cast<CharacterLiteral>(E)) {
3224 // Special case for 'a', which has type 'int' in C.
3225 // Note, however, that we do /not/ want to treat multibyte constants like
3226 // 'MooV' as characters! This form is deprecated but still exists.
3227 if (ExprTy == S.Context.IntTy)
3228 if (llvm::isUIntN(S.Context.getCharWidth(), CL->getValue()))
3229 ExprTy = S.Context.CharTy;
3232 // Look through enums to their underlying type.
3233 bool IsEnum = false;
3234 if (auto EnumTy = ExprTy->getAs<EnumType>()) {
3235 ExprTy = EnumTy->getDecl()->getIntegerType();
3239 // %C in an Objective-C context prints a unichar, not a wchar_t.
3240 // If the argument is an integer of some kind, believe the %C and suggest
3241 // a cast instead of changing the conversion specifier.
3242 QualType IntendedTy = ExprTy;
3244 FS.getConversionSpecifier().getKind() == ConversionSpecifier::CArg) {
3245 if (ExprTy->isIntegralOrUnscopedEnumerationType() &&
3246 !ExprTy->isCharType()) {
3247 // 'unichar' is defined as a typedef of unsigned short, but we should
3248 // prefer using the typedef if it is visible.
3249 IntendedTy = S.Context.UnsignedShortTy;
3251 // While we are here, check if the value is an IntegerLiteral that happens
3252 // to be within the valid range.
3253 if (const IntegerLiteral *IL = dyn_cast<IntegerLiteral>(E)) {
3254 const llvm::APInt &V = IL->getValue();
3255 if (V.getActiveBits() <= S.Context.getTypeSize(IntendedTy))
3259 LookupResult Result(S, &S.Context.Idents.get("unichar"), E->getLocStart(),
3260 Sema::LookupOrdinaryName);
3261 if (S.LookupName(Result, S.getCurScope())) {
3262 NamedDecl *ND = Result.getFoundDecl();
3263 if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(ND))
3264 if (TD->getUnderlyingType() == IntendedTy)
3265 IntendedTy = S.Context.getTypedefType(TD);
3270 // Special-case some of Darwin's platform-independence types by suggesting
3271 // casts to primitive types that are known to be large enough.
3272 bool ShouldNotPrintDirectly = false;
3273 if (S.Context.getTargetInfo().getTriple().isOSDarwin()) {
3274 // Use a 'while' to peel off layers of typedefs.
3275 QualType TyTy = IntendedTy;
3276 while (const TypedefType *UserTy = TyTy->getAs<TypedefType>()) {
3277 StringRef Name = UserTy->getDecl()->getName();
3278 QualType CastTy = llvm::StringSwitch<QualType>(Name)
3279 .Case("NSInteger", S.Context.LongTy)
3280 .Case("NSUInteger", S.Context.UnsignedLongTy)
3281 .Case("SInt32", S.Context.IntTy)
3282 .Case("UInt32", S.Context.UnsignedIntTy)
3283 .Default(QualType());
3285 if (!CastTy.isNull()) {
3286 ShouldNotPrintDirectly = true;
3287 IntendedTy = CastTy;
3290 TyTy = UserTy->desugar();
3294 // We may be able to offer a FixItHint if it is a supported type.
3295 PrintfSpecifier fixedFS = FS;
3296 bool success = fixedFS.fixType(IntendedTy, S.getLangOpts(),
3297 S.Context, ObjCContext);
3300 // Get the fix string from the fixed format specifier
3301 SmallString<16> buf;
3302 llvm::raw_svector_ostream os(buf);
3303 fixedFS.toString(os);
3305 CharSourceRange SpecRange = getSpecifierRange(StartSpecifier, SpecifierLen);
3307 if (IntendedTy == ExprTy) {
3308 // In this case, the specifier is wrong and should be changed to match
3310 EmitFormatDiagnostic(
3311 S.PDiag(diag::warn_format_conversion_argument_type_mismatch)
3312 << AT.getRepresentativeTypeName(S.Context) << IntendedTy << IsEnum
3313 << E->getSourceRange(),
3315 /*IsStringLocation*/false,
3317 FixItHint::CreateReplacement(SpecRange, os.str()));
3320 // The canonical type for formatting this value is different from the
3321 // actual type of the expression. (This occurs, for example, with Darwin's
3322 // NSInteger on 32-bit platforms, where it is typedef'd as 'int', but
3323 // should be printed as 'long' for 64-bit compatibility.)
3324 // Rather than emitting a normal format/argument mismatch, we want to
3325 // add a cast to the recommended type (and correct the format string
3327 SmallString<16> CastBuf;
3328 llvm::raw_svector_ostream CastFix(CastBuf);
3330 IntendedTy.print(CastFix, S.Context.getPrintingPolicy());
3333 SmallVector<FixItHint,4> Hints;
3334 if (!AT.matchesType(S.Context, IntendedTy))
3335 Hints.push_back(FixItHint::CreateReplacement(SpecRange, os.str()));
3337 if (const CStyleCastExpr *CCast = dyn_cast<CStyleCastExpr>(E)) {
3338 // If there's already a cast present, just replace it.
3339 SourceRange CastRange(CCast->getLParenLoc(), CCast->getRParenLoc());
3340 Hints.push_back(FixItHint::CreateReplacement(CastRange, CastFix.str()));
3342 } else if (!requiresParensToAddCast(E)) {
3343 // If the expression has high enough precedence,
3344 // just write the C-style cast.
3345 Hints.push_back(FixItHint::CreateInsertion(E->getLocStart(),
3348 // Otherwise, add parens around the expression as well as the cast.
3350 Hints.push_back(FixItHint::CreateInsertion(E->getLocStart(),
3353 SourceLocation After = S.getLocForEndOfToken(E->getLocEnd());
3354 Hints.push_back(FixItHint::CreateInsertion(After, ")"));
3357 if (ShouldNotPrintDirectly) {
3358 // The expression has a type that should not be printed directly.
3359 // We extract the name from the typedef because we don't want to show
3360 // the underlying type in the diagnostic.
3361 StringRef Name = cast<TypedefType>(ExprTy)->getDecl()->getName();
3363 EmitFormatDiagnostic(S.PDiag(diag::warn_format_argument_needs_cast)
3364 << Name << IntendedTy << IsEnum
3365 << E->getSourceRange(),
3366 E->getLocStart(), /*IsStringLocation=*/false,
3369 // In this case, the expression could be printed using a different
3370 // specifier, but we've decided that the specifier is probably correct
3371 // and we should cast instead. Just use the normal warning message.
3372 EmitFormatDiagnostic(
3373 S.PDiag(diag::warn_format_conversion_argument_type_mismatch)
3374 << AT.getRepresentativeTypeName(S.Context) << ExprTy << IsEnum
3375 << E->getSourceRange(),
3376 E->getLocStart(), /*IsStringLocation*/false,
3381 const CharSourceRange &CSR = getSpecifierRange(StartSpecifier,
3383 // Since the warning for passing non-POD types to variadic functions
3384 // was deferred until now, we emit a warning for non-POD
3386 switch (S.isValidVarArgType(ExprTy)) {
3387 case Sema::VAK_Valid:
3388 case Sema::VAK_ValidInCXX11:
3389 EmitFormatDiagnostic(
3390 S.PDiag(diag::warn_format_conversion_argument_type_mismatch)
3391 << AT.getRepresentativeTypeName(S.Context) << ExprTy << IsEnum
3393 << E->getSourceRange(),
3394 E->getLocStart(), /*IsStringLocation*/false, CSR);
3397 case Sema::VAK_Undefined:
3398 EmitFormatDiagnostic(
3399 S.PDiag(diag::warn_non_pod_vararg_with_format_string)
3400 << S.getLangOpts().CPlusPlus11
3403 << AT.getRepresentativeTypeName(S.Context)
3405 << E->getSourceRange(),
3406 E->getLocStart(), /*IsStringLocation*/false, CSR);
3407 checkForCStrMembers(AT, E);
3410 case Sema::VAK_Invalid:
3411 if (ExprTy->isObjCObjectType())
3412 EmitFormatDiagnostic(
3413 S.PDiag(diag::err_cannot_pass_objc_interface_to_vararg_format)
3414 << S.getLangOpts().CPlusPlus11
3417 << AT.getRepresentativeTypeName(S.Context)
3419 << E->getSourceRange(),
3420 E->getLocStart(), /*IsStringLocation*/false, CSR);
3422 // FIXME: If this is an initializer list, suggest removing the braces
3423 // or inserting a cast to the target type.
3424 S.Diag(E->getLocStart(), diag::err_cannot_pass_to_vararg_format)
3425 << isa<InitListExpr>(E) << ExprTy << CallType
3426 << AT.getRepresentativeTypeName(S.Context)
3427 << E->getSourceRange();
3431 assert(FirstDataArg + FS.getArgIndex() < CheckedVarArgs.size() &&
3432 "format string specifier index out of range");
3433 CheckedVarArgs[FirstDataArg + FS.getArgIndex()] = true;
3439 //===--- CHECK: Scanf format string checking ------------------------------===//
3442 class CheckScanfHandler : public CheckFormatHandler {
3444 CheckScanfHandler(Sema &s, const StringLiteral *fexpr,
3445 const Expr *origFormatExpr, unsigned firstDataArg,
3446 unsigned numDataArgs, const char *beg, bool hasVAListArg,
3447 ArrayRef<const Expr *> Args,
3448 unsigned formatIdx, bool inFunctionCall,
3449 Sema::VariadicCallType CallType,
3450 llvm::SmallBitVector &CheckedVarArgs)
3451 : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg,
3452 numDataArgs, beg, hasVAListArg,
3453 Args, formatIdx, inFunctionCall, CallType,
3457 bool HandleScanfSpecifier(const analyze_scanf::ScanfSpecifier &FS,
3458 const char *startSpecifier,
3459 unsigned specifierLen) override;
3461 bool HandleInvalidScanfConversionSpecifier(
3462 const analyze_scanf::ScanfSpecifier &FS,
3463 const char *startSpecifier,
3464 unsigned specifierLen) override;
3466 void HandleIncompleteScanList(const char *start, const char *end) override;
3470 void CheckScanfHandler::HandleIncompleteScanList(const char *start,
3472 EmitFormatDiagnostic(S.PDiag(diag::warn_scanf_scanlist_incomplete),
3473 getLocationOfByte(end), /*IsStringLocation*/true,
3474 getSpecifierRange(start, end - start));
3477 bool CheckScanfHandler::HandleInvalidScanfConversionSpecifier(
3478 const analyze_scanf::ScanfSpecifier &FS,
3479 const char *startSpecifier,
3480 unsigned specifierLen) {
3482 const analyze_scanf::ScanfConversionSpecifier &CS =
3483 FS.getConversionSpecifier();
3485 return HandleInvalidConversionSpecifier(FS.getArgIndex(),
3486 getLocationOfByte(CS.getStart()),
3487 startSpecifier, specifierLen,
3488 CS.getStart(), CS.getLength());
3491 bool CheckScanfHandler::HandleScanfSpecifier(
3492 const analyze_scanf::ScanfSpecifier &FS,
3493 const char *startSpecifier,
3494 unsigned specifierLen) {
3496 using namespace analyze_scanf;
3497 using namespace analyze_format_string;
3499 const ScanfConversionSpecifier &CS = FS.getConversionSpecifier();
3501 // Handle case where '%' and '*' don't consume an argument. These shouldn't
3502 // be used to decide if we are using positional arguments consistently.
3503 if (FS.consumesDataArgument()) {
3506 usesPositionalArgs = FS.usesPositionalArg();
3508 else if (usesPositionalArgs != FS.usesPositionalArg()) {
3509 HandlePositionalNonpositionalArgs(getLocationOfByte(CS.getStart()),
3510 startSpecifier, specifierLen);
3515 // Check if the field with is non-zero.
3516 const OptionalAmount &Amt = FS.getFieldWidth();
3517 if (Amt.getHowSpecified() == OptionalAmount::Constant) {
3518 if (Amt.getConstantAmount() == 0) {
3519 const CharSourceRange &R = getSpecifierRange(Amt.getStart(),
3520 Amt.getConstantLength());
3521 EmitFormatDiagnostic(S.PDiag(diag::warn_scanf_nonzero_width),
3522 getLocationOfByte(Amt.getStart()),
3523 /*IsStringLocation*/true, R,
3524 FixItHint::CreateRemoval(R));
3528 if (!FS.consumesDataArgument()) {
3529 // FIXME: Technically specifying a precision or field width here
3530 // makes no sense. Worth issuing a warning at some point.
3534 // Consume the argument.
3535 unsigned argIndex = FS.getArgIndex();
3536 if (argIndex < NumDataArgs) {
3537 // The check to see if the argIndex is valid will come later.
3538 // We set the bit here because we may exit early from this
3539 // function if we encounter some other error.
3540 CoveredArgs.set(argIndex);
3543 // Check the length modifier is valid with the given conversion specifier.
3544 if (!FS.hasValidLengthModifier(S.getASTContext().getTargetInfo()))
3545 HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
3546 diag::warn_format_nonsensical_length);
3547 else if (!FS.hasStandardLengthModifier())
3548 HandleNonStandardLengthModifier(FS, startSpecifier, specifierLen);
3549 else if (!FS.hasStandardLengthConversionCombination())
3550 HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
3551 diag::warn_format_non_standard_conversion_spec);
3553 if (!FS.hasStandardConversionSpecifier(S.getLangOpts()))
3554 HandleNonStandardConversionSpecifier(CS, startSpecifier, specifierLen);
3556 // The remaining checks depend on the data arguments.
3560 if (!CheckNumArgs(FS, CS, startSpecifier, specifierLen, argIndex))
3563 // Check that the argument type matches the format specifier.
3564 const Expr *Ex = getDataArg(argIndex);
3568 const analyze_format_string::ArgType &AT = FS.getArgType(S.Context);
3569 if (AT.isValid() && !AT.matchesType(S.Context, Ex->getType())) {
3570 ScanfSpecifier fixedFS = FS;
3571 bool success = fixedFS.fixType(Ex->getType(),
3572 Ex->IgnoreImpCasts()->getType(),
3573 S.getLangOpts(), S.Context);
3576 // Get the fix string from the fixed format specifier.
3577 SmallString<128> buf;
3578 llvm::raw_svector_ostream os(buf);
3579 fixedFS.toString(os);
3581 EmitFormatDiagnostic(
3582 S.PDiag(diag::warn_format_conversion_argument_type_mismatch)
3583 << AT.getRepresentativeTypeName(S.Context) << Ex->getType() << false
3584 << Ex->getSourceRange(),
3586 /*IsStringLocation*/false,
3587 getSpecifierRange(startSpecifier, specifierLen),
3588 FixItHint::CreateReplacement(
3589 getSpecifierRange(startSpecifier, specifierLen),
3592 EmitFormatDiagnostic(
3593 S.PDiag(diag::warn_format_conversion_argument_type_mismatch)
3594 << AT.getRepresentativeTypeName(S.Context) << Ex->getType() << false
3595 << Ex->getSourceRange(),
3597 /*IsStringLocation*/false,
3598 getSpecifierRange(startSpecifier, specifierLen));
3605 void Sema::CheckFormatString(const StringLiteral *FExpr,
3606 const Expr *OrigFormatExpr,
3607 ArrayRef<const Expr *> Args,
3608 bool HasVAListArg, unsigned format_idx,
3609 unsigned firstDataArg, FormatStringType Type,
3610 bool inFunctionCall, VariadicCallType CallType,
3611 llvm::SmallBitVector &CheckedVarArgs) {
3613 // CHECK: is the format string a wide literal?
3614 if (!FExpr->isAscii() && !FExpr->isUTF8()) {
3615 CheckFormatHandler::EmitFormatDiagnostic(
3616 *this, inFunctionCall, Args[format_idx],
3617 PDiag(diag::warn_format_string_is_wide_literal), FExpr->getLocStart(),
3618 /*IsStringLocation*/true, OrigFormatExpr->getSourceRange());
3622 // Str - The format string. NOTE: this is NOT null-terminated!
3623 StringRef StrRef = FExpr->getString();
3624 const char *Str = StrRef.data();
3625 // Account for cases where the string literal is truncated in a declaration.
3626 const ConstantArrayType *T = Context.getAsConstantArrayType(FExpr->getType());
3627 assert(T && "String literal not of constant array type!");
3628 size_t TypeSize = T->getSize().getZExtValue();
3629 size_t StrLen = std::min(std::max(TypeSize, size_t(1)) - 1, StrRef.size());
3630 const unsigned numDataArgs = Args.size() - firstDataArg;
3632 // Emit a warning if the string literal is truncated and does not contain an
3633 // embedded null character.
3634 if (TypeSize <= StrRef.size() &&
3635 StrRef.substr(0, TypeSize).find('\0') == StringRef::npos) {
3636 CheckFormatHandler::EmitFormatDiagnostic(
3637 *this, inFunctionCall, Args[format_idx],
3638 PDiag(diag::warn_printf_format_string_not_null_terminated),
3639 FExpr->getLocStart(),
3640 /*IsStringLocation=*/true, OrigFormatExpr->getSourceRange());
3644 // CHECK: empty format string?
3645 if (StrLen == 0 && numDataArgs > 0) {
3646 CheckFormatHandler::EmitFormatDiagnostic(
3647 *this, inFunctionCall, Args[format_idx],
3648 PDiag(diag::warn_empty_format_string), FExpr->getLocStart(),
3649 /*IsStringLocation*/true, OrigFormatExpr->getSourceRange());
3653 if (Type == FST_Printf || Type == FST_NSString) {
3654 CheckPrintfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg,
3655 numDataArgs, (Type == FST_NSString),
3656 Str, HasVAListArg, Args, format_idx,
3657 inFunctionCall, CallType, CheckedVarArgs);
3659 if (!analyze_format_string::ParsePrintfString(H, Str, Str + StrLen,
3661 Context.getTargetInfo()))
3663 } else if (Type == FST_Scanf) {
3664 CheckScanfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg, numDataArgs,
3665 Str, HasVAListArg, Args, format_idx,
3666 inFunctionCall, CallType, CheckedVarArgs);
3668 if (!analyze_format_string::ParseScanfString(H, Str, Str + StrLen,
3670 Context.getTargetInfo()))
3672 } // TODO: handle other formats
3675 //===--- CHECK: Warn on use of wrong absolute value function. -------------===//
3677 // Returns the related absolute value function that is larger, of 0 if one
3679 static unsigned getLargerAbsoluteValueFunction(unsigned AbsFunction) {
3680 switch (AbsFunction) {
3684 case Builtin::BI__builtin_abs:
3685 return Builtin::BI__builtin_labs;
3686 case Builtin::BI__builtin_labs:
3687 return Builtin::BI__builtin_llabs;
3688 case Builtin::BI__builtin_llabs:
3691 case Builtin::BI__builtin_fabsf:
3692 return Builtin::BI__builtin_fabs;
3693 case Builtin::BI__builtin_fabs:
3694 return Builtin::BI__builtin_fabsl;
3695 case Builtin::BI__builtin_fabsl:
3698 case Builtin::BI__builtin_cabsf:
3699 return Builtin::BI__builtin_cabs;
3700 case Builtin::BI__builtin_cabs:
3701 return Builtin::BI__builtin_cabsl;
3702 case Builtin::BI__builtin_cabsl:
3705 case Builtin::BIabs:
3706 return Builtin::BIlabs;
3707 case Builtin::BIlabs:
3708 return Builtin::BIllabs;
3709 case Builtin::BIllabs:
3712 case Builtin::BIfabsf:
3713 return Builtin::BIfabs;
3714 case Builtin::BIfabs:
3715 return Builtin::BIfabsl;
3716 case Builtin::BIfabsl:
3719 case Builtin::BIcabsf:
3720 return Builtin::BIcabs;
3721 case Builtin::BIcabs:
3722 return Builtin::BIcabsl;
3723 case Builtin::BIcabsl:
3728 // Returns the argument type of the absolute value function.
3729 static QualType getAbsoluteValueArgumentType(ASTContext &Context,
3734 ASTContext::GetBuiltinTypeError Error = ASTContext::GE_None;
3735 QualType BuiltinType = Context.GetBuiltinType(AbsType, Error);
3736 if (Error != ASTContext::GE_None)
3739 const FunctionProtoType *FT = BuiltinType->getAs<FunctionProtoType>();
3743 if (FT->getNumParams() != 1)
3746 return FT->getParamType(0);
3749 // Returns the best absolute value function, or zero, based on type and
3750 // current absolute value function.
3751 static unsigned getBestAbsFunction(ASTContext &Context, QualType ArgType,
3752 unsigned AbsFunctionKind) {
3753 unsigned BestKind = 0;
3754 uint64_t ArgSize = Context.getTypeSize(ArgType);
3755 for (unsigned Kind = AbsFunctionKind; Kind != 0;
3756 Kind = getLargerAbsoluteValueFunction(Kind)) {
3757 QualType ParamType = getAbsoluteValueArgumentType(Context, Kind);
3758 if (Context.getTypeSize(ParamType) >= ArgSize) {
3761 else if (Context.hasSameType(ParamType, ArgType)) {
3770 enum AbsoluteValueKind {
3776 static AbsoluteValueKind getAbsoluteValueKind(QualType T) {
3777 if (T->isIntegralOrEnumerationType())
3779 if (T->isRealFloatingType())
3780 return AVK_Floating;
3781 if (T->isAnyComplexType())
3784 llvm_unreachable("Type not integer, floating, or complex");
3787 // Changes the absolute value function to a different type. Preserves whether
3788 // the function is a builtin.
3789 static unsigned changeAbsFunction(unsigned AbsKind,
3790 AbsoluteValueKind ValueKind) {
3791 switch (ValueKind) {
3796 case Builtin::BI__builtin_fabsf:
3797 case Builtin::BI__builtin_fabs:
3798 case Builtin::BI__builtin_fabsl:
3799 case Builtin::BI__builtin_cabsf:
3800 case Builtin::BI__builtin_cabs:
3801 case Builtin::BI__builtin_cabsl:
3802 return Builtin::BI__builtin_abs;
3803 case Builtin::BIfabsf:
3804 case Builtin::BIfabs:
3805 case Builtin::BIfabsl:
3806 case Builtin::BIcabsf:
3807 case Builtin::BIcabs:
3808 case Builtin::BIcabsl:
3809 return Builtin::BIabs;
3815 case Builtin::BI__builtin_abs:
3816 case Builtin::BI__builtin_labs:
3817 case Builtin::BI__builtin_llabs:
3818 case Builtin::BI__builtin_cabsf:
3819 case Builtin::BI__builtin_cabs:
3820 case Builtin::BI__builtin_cabsl:
3821 return Builtin::BI__builtin_fabsf;
3822 case Builtin::BIabs:
3823 case Builtin::BIlabs:
3824 case Builtin::BIllabs:
3825 case Builtin::BIcabsf:
3826 case Builtin::BIcabs:
3827 case Builtin::BIcabsl:
3828 return Builtin::BIfabsf;
3834 case Builtin::BI__builtin_abs:
3835 case Builtin::BI__builtin_labs:
3836 case Builtin::BI__builtin_llabs:
3837 case Builtin::BI__builtin_fabsf:
3838 case Builtin::BI__builtin_fabs:
3839 case Builtin::BI__builtin_fabsl:
3840 return Builtin::BI__builtin_cabsf;
3841 case Builtin::BIabs:
3842 case Builtin::BIlabs:
3843 case Builtin::BIllabs:
3844 case Builtin::BIfabsf:
3845 case Builtin::BIfabs:
3846 case Builtin::BIfabsl:
3847 return Builtin::BIcabsf;
3850 llvm_unreachable("Unable to convert function");
3853 static unsigned getAbsoluteValueFunctionKind(const FunctionDecl *FDecl) {
3854 const IdentifierInfo *FnInfo = FDecl->getIdentifier();
3858 switch (FDecl->getBuiltinID()) {
3861 case Builtin::BI__builtin_abs:
3862 case Builtin::BI__builtin_fabs:
3863 case Builtin::BI__builtin_fabsf:
3864 case Builtin::BI__builtin_fabsl:
3865 case Builtin::BI__builtin_labs:
3866 case Builtin::BI__builtin_llabs:
3867 case Builtin::BI__builtin_cabs:
3868 case Builtin::BI__builtin_cabsf:
3869 case Builtin::BI__builtin_cabsl:
3870 case Builtin::BIabs:
3871 case Builtin::BIlabs:
3872 case Builtin::BIllabs:
3873 case Builtin::BIfabs:
3874 case Builtin::BIfabsf:
3875 case Builtin::BIfabsl:
3876 case Builtin::BIcabs:
3877 case Builtin::BIcabsf:
3878 case Builtin::BIcabsl:
3879 return FDecl->getBuiltinID();
3881 llvm_unreachable("Unknown Builtin type");
3884 // If the replacement is valid, emit a note with replacement function.
3885 // Additionally, suggest including the proper header if not already included.
3886 static void emitReplacement(Sema &S, SourceLocation Loc, SourceRange Range,
3887 unsigned AbsKind, QualType ArgType) {
3888 bool EmitHeaderHint = true;
3889 const char *HeaderName = nullptr;
3890 const char *FunctionName = nullptr;
3891 if (S.getLangOpts().CPlusPlus && !ArgType->isAnyComplexType()) {
3892 FunctionName = "std::abs";
3893 if (ArgType->isIntegralOrEnumerationType()) {
3894 HeaderName = "cstdlib";
3895 } else if (ArgType->isRealFloatingType()) {
3896 HeaderName = "cmath";
3898 llvm_unreachable("Invalid Type");
3901 // Lookup all std::abs
3902 if (NamespaceDecl *Std = S.getStdNamespace()) {
3903 LookupResult R(S, &S.Context.Idents.get("abs"), Loc, Sema::LookupAnyName);
3904 R.suppressDiagnostics();
3905 S.LookupQualifiedName(R, Std);
3907 for (const auto *I : R) {
3908 const FunctionDecl *FDecl = nullptr;
3909 if (const UsingShadowDecl *UsingD = dyn_cast<UsingShadowDecl>(I)) {
3910 FDecl = dyn_cast<FunctionDecl>(UsingD->getTargetDecl());
3912 FDecl = dyn_cast<FunctionDecl>(I);
3917 // Found std::abs(), check that they are the right ones.
3918 if (FDecl->getNumParams() != 1)
3921 // Check that the parameter type can handle the argument.
3922 QualType ParamType = FDecl->getParamDecl(0)->getType();
3923 if (getAbsoluteValueKind(ArgType) == getAbsoluteValueKind(ParamType) &&
3924 S.Context.getTypeSize(ArgType) <=
3925 S.Context.getTypeSize(ParamType)) {
3926 // Found a function, don't need the header hint.
3927 EmitHeaderHint = false;
3933 FunctionName = S.Context.BuiltinInfo.GetName(AbsKind);
3934 HeaderName = S.Context.BuiltinInfo.getHeaderName(AbsKind);
3937 DeclarationName DN(&S.Context.Idents.get(FunctionName));
3938 LookupResult R(S, DN, Loc, Sema::LookupAnyName);
3939 R.suppressDiagnostics();
3940 S.LookupName(R, S.getCurScope());
3942 if (R.isSingleResult()) {
3943 FunctionDecl *FD = dyn_cast<FunctionDecl>(R.getFoundDecl());
3944 if (FD && FD->getBuiltinID() == AbsKind) {
3945 EmitHeaderHint = false;
3949 } else if (!R.empty()) {
3955 S.Diag(Loc, diag::note_replace_abs_function)
3956 << FunctionName << FixItHint::CreateReplacement(Range, FunctionName);
3961 if (!EmitHeaderHint)
3964 S.Diag(Loc, diag::note_include_header_or_declare) << HeaderName
3968 static bool IsFunctionStdAbs(const FunctionDecl *FDecl) {
3972 if (!FDecl->getIdentifier() || !FDecl->getIdentifier()->isStr("abs"))
3975 const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(FDecl->getDeclContext());
3977 while (ND && ND->isInlineNamespace()) {
3978 ND = dyn_cast<NamespaceDecl>(ND->getDeclContext());
3981 if (!ND || !ND->getIdentifier() || !ND->getIdentifier()->isStr("std"))
3984 if (!isa<TranslationUnitDecl>(ND->getDeclContext()))
3990 // Warn when using the wrong abs() function.
3991 void Sema::CheckAbsoluteValueFunction(const CallExpr *Call,
3992 const FunctionDecl *FDecl,
3993 IdentifierInfo *FnInfo) {
3994 if (Call->getNumArgs() != 1)
3997 unsigned AbsKind = getAbsoluteValueFunctionKind(FDecl);
3998 bool IsStdAbs = IsFunctionStdAbs(FDecl);
3999 if (AbsKind == 0 && !IsStdAbs)
4002 QualType ArgType = Call->getArg(0)->IgnoreParenImpCasts()->getType();
4003 QualType ParamType = Call->getArg(0)->getType();
4005 // Unsigned types cannot be negative. Suggest removing the absolute value
4007 if (ArgType->isUnsignedIntegerType()) {
4008 const char *FunctionName =
4009 IsStdAbs ? "std::abs" : Context.BuiltinInfo.GetName(AbsKind);
4010 Diag(Call->getExprLoc(), diag::warn_unsigned_abs) << ArgType << ParamType;
4011 Diag(Call->getExprLoc(), diag::note_remove_abs)
4013 << FixItHint::CreateRemoval(Call->getCallee()->getSourceRange());
4017 // std::abs has overloads which prevent most of the absolute value problems
4022 AbsoluteValueKind ArgValueKind = getAbsoluteValueKind(ArgType);
4023 AbsoluteValueKind ParamValueKind = getAbsoluteValueKind(ParamType);
4025 // The argument and parameter are the same kind. Check if they are the right
4027 if (ArgValueKind == ParamValueKind) {
4028 if (Context.getTypeSize(ArgType) <= Context.getTypeSize(ParamType))
4031 unsigned NewAbsKind = getBestAbsFunction(Context, ArgType, AbsKind);
4032 Diag(Call->getExprLoc(), diag::warn_abs_too_small)
4033 << FDecl << ArgType << ParamType;
4035 if (NewAbsKind == 0)
4038 emitReplacement(*this, Call->getExprLoc(),
4039 Call->getCallee()->getSourceRange(), NewAbsKind, ArgType);
4043 // ArgValueKind != ParamValueKind
4044 // The wrong type of absolute value function was used. Attempt to find the
4046 unsigned NewAbsKind = changeAbsFunction(AbsKind, ArgValueKind);
4047 NewAbsKind = getBestAbsFunction(Context, ArgType, NewAbsKind);
4048 if (NewAbsKind == 0)
4051 Diag(Call->getExprLoc(), diag::warn_wrong_absolute_value_type)
4052 << FDecl << ParamValueKind << ArgValueKind;
4054 emitReplacement(*this, Call->getExprLoc(),
4055 Call->getCallee()->getSourceRange(), NewAbsKind, ArgType);
4059 //===--- CHECK: Standard memory functions ---------------------------------===//
4061 /// \brief Takes the expression passed to the size_t parameter of functions
4062 /// such as memcmp, strncat, etc and warns if it's a comparison.
4064 /// This is to catch typos like `if (memcmp(&a, &b, sizeof(a) > 0))`.
4065 static bool CheckMemorySizeofForComparison(Sema &S, const Expr *E,
4066 IdentifierInfo *FnName,
4067 SourceLocation FnLoc,
4068 SourceLocation RParenLoc) {
4069 const BinaryOperator *Size = dyn_cast<BinaryOperator>(E);
4073 // if E is binop and op is >, <, >=, <=, ==, &&, ||:
4074 if (!Size->isComparisonOp() && !Size->isEqualityOp() && !Size->isLogicalOp())
4077 SourceRange SizeRange = Size->getSourceRange();
4078 S.Diag(Size->getOperatorLoc(), diag::warn_memsize_comparison)
4079 << SizeRange << FnName;
4080 S.Diag(FnLoc, diag::note_memsize_comparison_paren)
4081 << FnName << FixItHint::CreateInsertion(
4082 S.getLocForEndOfToken(Size->getLHS()->getLocEnd()), ")")
4083 << FixItHint::CreateRemoval(RParenLoc);
4084 S.Diag(SizeRange.getBegin(), diag::note_memsize_comparison_cast_silence)
4085 << FixItHint::CreateInsertion(SizeRange.getBegin(), "(size_t)(")
4086 << FixItHint::CreateInsertion(S.getLocForEndOfToken(SizeRange.getEnd()),
4092 /// \brief Determine whether the given type is or contains a dynamic class type
4093 /// (e.g., whether it has a vtable).
4094 static const CXXRecordDecl *getContainedDynamicClass(QualType T,
4095 bool &IsContained) {
4096 // Look through array types while ignoring qualifiers.
4097 const Type *Ty = T->getBaseElementTypeUnsafe();
4098 IsContained = false;
4100 const CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
4101 RD = RD ? RD->getDefinition() : nullptr;
4105 if (RD->isDynamicClass())
4108 // Check all the fields. If any bases were dynamic, the class is dynamic.
4109 // It's impossible for a class to transitively contain itself by value, so
4110 // infinite recursion is impossible.
4111 for (auto *FD : RD->fields()) {
4113 if (const CXXRecordDecl *ContainedRD =
4114 getContainedDynamicClass(FD->getType(), SubContained)) {
4123 /// \brief If E is a sizeof expression, returns its argument expression,
4124 /// otherwise returns NULL.
4125 static const Expr *getSizeOfExprArg(const Expr* E) {
4126 if (const UnaryExprOrTypeTraitExpr *SizeOf =
4127 dyn_cast<UnaryExprOrTypeTraitExpr>(E))
4128 if (SizeOf->getKind() == clang::UETT_SizeOf && !SizeOf->isArgumentType())
4129 return SizeOf->getArgumentExpr()->IgnoreParenImpCasts();
4134 /// \brief If E is a sizeof expression, returns its argument type.
4135 static QualType getSizeOfArgType(const Expr* E) {
4136 if (const UnaryExprOrTypeTraitExpr *SizeOf =
4137 dyn_cast<UnaryExprOrTypeTraitExpr>(E))
4138 if (SizeOf->getKind() == clang::UETT_SizeOf)
4139 return SizeOf->getTypeOfArgument();
4144 /// \brief Check for dangerous or invalid arguments to memset().
4146 /// This issues warnings on known problematic, dangerous or unspecified
4147 /// arguments to the standard 'memset', 'memcpy', 'memmove', and 'memcmp'
4150 /// \param Call The call expression to diagnose.
4151 void Sema::CheckMemaccessArguments(const CallExpr *Call,
4153 IdentifierInfo *FnName) {
4156 // It is possible to have a non-standard definition of memset. Validate
4157 // we have enough arguments, and if not, abort further checking.
4158 unsigned ExpectedNumArgs = (BId == Builtin::BIstrndup ? 2 : 3);
4159 if (Call->getNumArgs() < ExpectedNumArgs)
4162 unsigned LastArg = (BId == Builtin::BImemset ||
4163 BId == Builtin::BIstrndup ? 1 : 2);
4164 unsigned LenArg = (BId == Builtin::BIstrndup ? 1 : 2);
4165 const Expr *LenExpr = Call->getArg(LenArg)->IgnoreParenImpCasts();
4167 if (CheckMemorySizeofForComparison(*this, LenExpr, FnName,
4168 Call->getLocStart(), Call->getRParenLoc()))
4171 // We have special checking when the length is a sizeof expression.
4172 QualType SizeOfArgTy = getSizeOfArgType(LenExpr);
4173 const Expr *SizeOfArg = getSizeOfExprArg(LenExpr);
4174 llvm::FoldingSetNodeID SizeOfArgID;
4176 for (unsigned ArgIdx = 0; ArgIdx != LastArg; ++ArgIdx) {
4177 const Expr *Dest = Call->getArg(ArgIdx)->IgnoreParenImpCasts();
4178 SourceRange ArgRange = Call->getArg(ArgIdx)->getSourceRange();
4180 QualType DestTy = Dest->getType();
4181 if (const PointerType *DestPtrTy = DestTy->getAs<PointerType>()) {
4182 QualType PointeeTy = DestPtrTy->getPointeeType();
4184 // Never warn about void type pointers. This can be used to suppress
4186 if (PointeeTy->isVoidType())
4189 // Catch "memset(p, 0, sizeof(p))" -- needs to be sizeof(*p). Do this by
4190 // actually comparing the expressions for equality. Because computing the
4191 // expression IDs can be expensive, we only do this if the diagnostic is
4194 !Diags.isIgnored(diag::warn_sizeof_pointer_expr_memaccess,
4195 SizeOfArg->getExprLoc())) {
4196 // We only compute IDs for expressions if the warning is enabled, and
4197 // cache the sizeof arg's ID.
4198 if (SizeOfArgID == llvm::FoldingSetNodeID())
4199 SizeOfArg->Profile(SizeOfArgID, Context, true);
4200 llvm::FoldingSetNodeID DestID;
4201 Dest->Profile(DestID, Context, true);
4202 if (DestID == SizeOfArgID) {
4203 // TODO: For strncpy() and friends, this could suggest sizeof(dst)
4204 // over sizeof(src) as well.
4205 unsigned ActionIdx = 0; // Default is to suggest dereferencing.
4206 StringRef ReadableName = FnName->getName();
4208 if (const UnaryOperator *UnaryOp = dyn_cast<UnaryOperator>(Dest))
4209 if (UnaryOp->getOpcode() == UO_AddrOf)
4210 ActionIdx = 1; // If its an address-of operator, just remove it.
4211 if (!PointeeTy->isIncompleteType() &&
4212 (Context.getTypeSize(PointeeTy) == Context.getCharWidth()))
4213 ActionIdx = 2; // If the pointee's size is sizeof(char),
4214 // suggest an explicit length.
4216 // If the function is defined as a builtin macro, do not show macro
4218 SourceLocation SL = SizeOfArg->getExprLoc();
4219 SourceRange DSR = Dest->getSourceRange();
4220 SourceRange SSR = SizeOfArg->getSourceRange();
4221 SourceManager &SM = getSourceManager();
4223 if (SM.isMacroArgExpansion(SL)) {
4224 ReadableName = Lexer::getImmediateMacroName(SL, SM, LangOpts);
4225 SL = SM.getSpellingLoc(SL);
4226 DSR = SourceRange(SM.getSpellingLoc(DSR.getBegin()),
4227 SM.getSpellingLoc(DSR.getEnd()));
4228 SSR = SourceRange(SM.getSpellingLoc(SSR.getBegin()),
4229 SM.getSpellingLoc(SSR.getEnd()));
4232 DiagRuntimeBehavior(SL, SizeOfArg,
4233 PDiag(diag::warn_sizeof_pointer_expr_memaccess)
4239 DiagRuntimeBehavior(SL, SizeOfArg,
4240 PDiag(diag::warn_sizeof_pointer_expr_memaccess_note)
4248 // Also check for cases where the sizeof argument is the exact same
4249 // type as the memory argument, and where it points to a user-defined
4251 if (SizeOfArgTy != QualType()) {
4252 if (PointeeTy->isRecordType() &&
4253 Context.typesAreCompatible(SizeOfArgTy, DestTy)) {
4254 DiagRuntimeBehavior(LenExpr->getExprLoc(), Dest,
4255 PDiag(diag::warn_sizeof_pointer_type_memaccess)
4256 << FnName << SizeOfArgTy << ArgIdx
4257 << PointeeTy << Dest->getSourceRange()
4258 << LenExpr->getSourceRange());
4263 // Always complain about dynamic classes.
4265 if (const CXXRecordDecl *ContainedRD =
4266 getContainedDynamicClass(PointeeTy, IsContained)) {
4268 unsigned OperationType = 0;
4269 // "overwritten" if we're warning about the destination for any call
4270 // but memcmp; otherwise a verb appropriate to the call.
4271 if (ArgIdx != 0 || BId == Builtin::BImemcmp) {
4272 if (BId == Builtin::BImemcpy)
4274 else if(BId == Builtin::BImemmove)
4276 else if (BId == Builtin::BImemcmp)
4280 DiagRuntimeBehavior(
4281 Dest->getExprLoc(), Dest,
4282 PDiag(diag::warn_dyn_class_memaccess)
4283 << (BId == Builtin::BImemcmp ? ArgIdx + 2 : ArgIdx)
4284 << FnName << IsContained << ContainedRD << OperationType
4285 << Call->getCallee()->getSourceRange());
4286 } else if (PointeeTy.hasNonTrivialObjCLifetime() &&
4287 BId != Builtin::BImemset)
4288 DiagRuntimeBehavior(
4289 Dest->getExprLoc(), Dest,
4290 PDiag(diag::warn_arc_object_memaccess)
4291 << ArgIdx << FnName << PointeeTy
4292 << Call->getCallee()->getSourceRange());
4296 DiagRuntimeBehavior(
4297 Dest->getExprLoc(), Dest,
4298 PDiag(diag::note_bad_memaccess_silence)
4299 << FixItHint::CreateInsertion(ArgRange.getBegin(), "(void*)"));
4305 // A little helper routine: ignore addition and subtraction of integer literals.
4306 // This intentionally does not ignore all integer constant expressions because
4307 // we don't want to remove sizeof().
4308 static const Expr *ignoreLiteralAdditions(const Expr *Ex, ASTContext &Ctx) {
4309 Ex = Ex->IgnoreParenCasts();
4312 const BinaryOperator * BO = dyn_cast<BinaryOperator>(Ex);
4313 if (!BO || !BO->isAdditiveOp())
4316 const Expr *RHS = BO->getRHS()->IgnoreParenCasts();
4317 const Expr *LHS = BO->getLHS()->IgnoreParenCasts();
4319 if (isa<IntegerLiteral>(RHS))
4321 else if (isa<IntegerLiteral>(LHS))
4330 static bool isConstantSizeArrayWithMoreThanOneElement(QualType Ty,
4331 ASTContext &Context) {
4332 // Only handle constant-sized or VLAs, but not flexible members.
4333 if (const ConstantArrayType *CAT = Context.getAsConstantArrayType(Ty)) {
4334 // Only issue the FIXIT for arrays of size > 1.
4335 if (CAT->getSize().getSExtValue() <= 1)
4337 } else if (!Ty->isVariableArrayType()) {
4343 // Warn if the user has made the 'size' argument to strlcpy or strlcat
4344 // be the size of the source, instead of the destination.
4345 void Sema::CheckStrlcpycatArguments(const CallExpr *Call,
4346 IdentifierInfo *FnName) {
4348 // Don't crash if the user has the wrong number of arguments
4349 if (Call->getNumArgs() != 3)
4352 const Expr *SrcArg = ignoreLiteralAdditions(Call->getArg(1), Context);
4353 const Expr *SizeArg = ignoreLiteralAdditions(Call->getArg(2), Context);
4354 const Expr *CompareWithSrc = nullptr;
4356 if (CheckMemorySizeofForComparison(*this, SizeArg, FnName,
4357 Call->getLocStart(), Call->getRParenLoc()))
4360 // Look for 'strlcpy(dst, x, sizeof(x))'
4361 if (const Expr *Ex = getSizeOfExprArg(SizeArg))
4362 CompareWithSrc = Ex;
4364 // Look for 'strlcpy(dst, x, strlen(x))'
4365 if (const CallExpr *SizeCall = dyn_cast<CallExpr>(SizeArg)) {
4366 if (SizeCall->getBuiltinCallee() == Builtin::BIstrlen &&
4367 SizeCall->getNumArgs() == 1)
4368 CompareWithSrc = ignoreLiteralAdditions(SizeCall->getArg(0), Context);
4372 if (!CompareWithSrc)
4375 // Determine if the argument to sizeof/strlen is equal to the source
4376 // argument. In principle there's all kinds of things you could do
4377 // here, for instance creating an == expression and evaluating it with
4378 // EvaluateAsBooleanCondition, but this uses a more direct technique:
4379 const DeclRefExpr *SrcArgDRE = dyn_cast<DeclRefExpr>(SrcArg);
4383 const DeclRefExpr *CompareWithSrcDRE = dyn_cast<DeclRefExpr>(CompareWithSrc);
4384 if (!CompareWithSrcDRE ||
4385 SrcArgDRE->getDecl() != CompareWithSrcDRE->getDecl())
4388 const Expr *OriginalSizeArg = Call->getArg(2);
4389 Diag(CompareWithSrcDRE->getLocStart(), diag::warn_strlcpycat_wrong_size)
4390 << OriginalSizeArg->getSourceRange() << FnName;
4392 // Output a FIXIT hint if the destination is an array (rather than a
4393 // pointer to an array). This could be enhanced to handle some
4394 // pointers if we know the actual size, like if DstArg is 'array+2'
4395 // we could say 'sizeof(array)-2'.
4396 const Expr *DstArg = Call->getArg(0)->IgnoreParenImpCasts();
4397 if (!isConstantSizeArrayWithMoreThanOneElement(DstArg->getType(), Context))
4400 SmallString<128> sizeString;
4401 llvm::raw_svector_ostream OS(sizeString);
4403 DstArg->printPretty(OS, nullptr, getPrintingPolicy());
4406 Diag(OriginalSizeArg->getLocStart(), diag::note_strlcpycat_wrong_size)
4407 << FixItHint::CreateReplacement(OriginalSizeArg->getSourceRange(),
4411 /// Check if two expressions refer to the same declaration.
4412 static bool referToTheSameDecl(const Expr *E1, const Expr *E2) {
4413 if (const DeclRefExpr *D1 = dyn_cast_or_null<DeclRefExpr>(E1))
4414 if (const DeclRefExpr *D2 = dyn_cast_or_null<DeclRefExpr>(E2))
4415 return D1->getDecl() == D2->getDecl();
4419 static const Expr *getStrlenExprArg(const Expr *E) {
4420 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
4421 const FunctionDecl *FD = CE->getDirectCallee();
4422 if (!FD || FD->getMemoryFunctionKind() != Builtin::BIstrlen)
4424 return CE->getArg(0)->IgnoreParenCasts();
4429 // Warn on anti-patterns as the 'size' argument to strncat.
4430 // The correct size argument should look like following:
4431 // strncat(dst, src, sizeof(dst) - strlen(dest) - 1);
4432 void Sema::CheckStrncatArguments(const CallExpr *CE,
4433 IdentifierInfo *FnName) {
4434 // Don't crash if the user has the wrong number of arguments.
4435 if (CE->getNumArgs() < 3)
4437 const Expr *DstArg = CE->getArg(0)->IgnoreParenCasts();
4438 const Expr *SrcArg = CE->getArg(1)->IgnoreParenCasts();
4439 const Expr *LenArg = CE->getArg(2)->IgnoreParenCasts();
4441 if (CheckMemorySizeofForComparison(*this, LenArg, FnName, CE->getLocStart(),
4442 CE->getRParenLoc()))
4445 // Identify common expressions, which are wrongly used as the size argument
4446 // to strncat and may lead to buffer overflows.
4447 unsigned PatternType = 0;
4448 if (const Expr *SizeOfArg = getSizeOfExprArg(LenArg)) {
4450 if (referToTheSameDecl(SizeOfArg, DstArg))
4453 else if (referToTheSameDecl(SizeOfArg, SrcArg))
4455 } else if (const BinaryOperator *BE = dyn_cast<BinaryOperator>(LenArg)) {
4456 if (BE->getOpcode() == BO_Sub) {
4457 const Expr *L = BE->getLHS()->IgnoreParenCasts();
4458 const Expr *R = BE->getRHS()->IgnoreParenCasts();
4459 // - sizeof(dst) - strlen(dst)
4460 if (referToTheSameDecl(DstArg, getSizeOfExprArg(L)) &&
4461 referToTheSameDecl(DstArg, getStrlenExprArg(R)))
4463 // - sizeof(src) - (anything)
4464 else if (referToTheSameDecl(SrcArg, getSizeOfExprArg(L)))
4469 if (PatternType == 0)
4472 // Generate the diagnostic.
4473 SourceLocation SL = LenArg->getLocStart();
4474 SourceRange SR = LenArg->getSourceRange();
4475 SourceManager &SM = getSourceManager();
4477 // If the function is defined as a builtin macro, do not show macro expansion.
4478 if (SM.isMacroArgExpansion(SL)) {
4479 SL = SM.getSpellingLoc(SL);
4480 SR = SourceRange(SM.getSpellingLoc(SR.getBegin()),
4481 SM.getSpellingLoc(SR.getEnd()));
4484 // Check if the destination is an array (rather than a pointer to an array).
4485 QualType DstTy = DstArg->getType();
4486 bool isKnownSizeArray = isConstantSizeArrayWithMoreThanOneElement(DstTy,
4488 if (!isKnownSizeArray) {
4489 if (PatternType == 1)
4490 Diag(SL, diag::warn_strncat_wrong_size) << SR;
4492 Diag(SL, diag::warn_strncat_src_size) << SR;
4496 if (PatternType == 1)
4497 Diag(SL, diag::warn_strncat_large_size) << SR;
4499 Diag(SL, diag::warn_strncat_src_size) << SR;
4501 SmallString<128> sizeString;
4502 llvm::raw_svector_ostream OS(sizeString);
4504 DstArg->printPretty(OS, nullptr, getPrintingPolicy());
4507 DstArg->printPretty(OS, nullptr, getPrintingPolicy());
4510 Diag(SL, diag::note_strncat_wrong_size)
4511 << FixItHint::CreateReplacement(SR, OS.str());
4514 //===--- CHECK: Return Address of Stack Variable --------------------------===//
4516 static Expr *EvalVal(Expr *E, SmallVectorImpl<DeclRefExpr *> &refVars,
4518 static Expr *EvalAddr(Expr* E, SmallVectorImpl<DeclRefExpr *> &refVars,
4521 /// CheckReturnStackAddr - Check if a return statement returns the address
4522 /// of a stack variable.
4524 CheckReturnStackAddr(Sema &S, Expr *RetValExp, QualType lhsType,
4525 SourceLocation ReturnLoc) {
4527 Expr *stackE = nullptr;
4528 SmallVector<DeclRefExpr *, 8> refVars;
4530 // Perform checking for returned stack addresses, local blocks,
4531 // label addresses or references to temporaries.
4532 if (lhsType->isPointerType() ||
4533 (!S.getLangOpts().ObjCAutoRefCount && lhsType->isBlockPointerType())) {
4534 stackE = EvalAddr(RetValExp, refVars, /*ParentDecl=*/nullptr);
4535 } else if (lhsType->isReferenceType()) {
4536 stackE = EvalVal(RetValExp, refVars, /*ParentDecl=*/nullptr);
4540 return; // Nothing suspicious was found.
4542 SourceLocation diagLoc;
4543 SourceRange diagRange;
4544 if (refVars.empty()) {
4545 diagLoc = stackE->getLocStart();
4546 diagRange = stackE->getSourceRange();
4548 // We followed through a reference variable. 'stackE' contains the
4549 // problematic expression but we will warn at the return statement pointing
4550 // at the reference variable. We will later display the "trail" of
4551 // reference variables using notes.
4552 diagLoc = refVars[0]->getLocStart();
4553 diagRange = refVars[0]->getSourceRange();
4556 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(stackE)) { //address of local var.
4557 S.Diag(diagLoc, lhsType->isReferenceType() ? diag::warn_ret_stack_ref
4558 : diag::warn_ret_stack_addr)
4559 << DR->getDecl()->getDeclName() << diagRange;
4560 } else if (isa<BlockExpr>(stackE)) { // local block.
4561 S.Diag(diagLoc, diag::err_ret_local_block) << diagRange;
4562 } else if (isa<AddrLabelExpr>(stackE)) { // address of label.
4563 S.Diag(diagLoc, diag::warn_ret_addr_label) << diagRange;
4564 } else { // local temporary.
4565 S.Diag(diagLoc, lhsType->isReferenceType() ? diag::warn_ret_local_temp_ref
4566 : diag::warn_ret_local_temp_addr)
4570 // Display the "trail" of reference variables that we followed until we
4571 // found the problematic expression using notes.
4572 for (unsigned i = 0, e = refVars.size(); i != e; ++i) {
4573 VarDecl *VD = cast<VarDecl>(refVars[i]->getDecl());
4574 // If this var binds to another reference var, show the range of the next
4575 // var, otherwise the var binds to the problematic expression, in which case
4576 // show the range of the expression.
4577 SourceRange range = (i < e-1) ? refVars[i+1]->getSourceRange()
4578 : stackE->getSourceRange();
4579 S.Diag(VD->getLocation(), diag::note_ref_var_local_bind)
4580 << VD->getDeclName() << range;
4584 /// EvalAddr - EvalAddr and EvalVal are mutually recursive functions that
4585 /// check if the expression in a return statement evaluates to an address
4586 /// to a location on the stack, a local block, an address of a label, or a
4587 /// reference to local temporary. The recursion is used to traverse the
4588 /// AST of the return expression, with recursion backtracking when we
4589 /// encounter a subexpression that (1) clearly does not lead to one of the
4590 /// above problematic expressions (2) is something we cannot determine leads to
4591 /// a problematic expression based on such local checking.
4593 /// Both EvalAddr and EvalVal follow through reference variables to evaluate
4594 /// the expression that they point to. Such variables are added to the
4595 /// 'refVars' vector so that we know what the reference variable "trail" was.
4597 /// EvalAddr processes expressions that are pointers that are used as
4598 /// references (and not L-values). EvalVal handles all other values.
4599 /// At the base case of the recursion is a check for the above problematic
4602 /// This implementation handles:
4604 /// * pointer-to-pointer casts
4605 /// * implicit conversions from array references to pointers
4606 /// * taking the address of fields
4607 /// * arbitrary interplay between "&" and "*" operators
4608 /// * pointer arithmetic from an address of a stack variable
4609 /// * taking the address of an array element where the array is on the stack
4610 static Expr *EvalAddr(Expr *E, SmallVectorImpl<DeclRefExpr *> &refVars,
4612 if (E->isTypeDependent())
4615 // We should only be called for evaluating pointer expressions.
4616 assert((E->getType()->isAnyPointerType() ||
4617 E->getType()->isBlockPointerType() ||
4618 E->getType()->isObjCQualifiedIdType()) &&
4619 "EvalAddr only works on pointers");
4621 E = E->IgnoreParens();
4623 // Our "symbolic interpreter" is just a dispatch off the currently
4624 // viewed AST node. We then recursively traverse the AST by calling
4625 // EvalAddr and EvalVal appropriately.
4626 switch (E->getStmtClass()) {
4627 case Stmt::DeclRefExprClass: {
4628 DeclRefExpr *DR = cast<DeclRefExpr>(E);
4630 // If we leave the immediate function, the lifetime isn't about to end.
4631 if (DR->refersToEnclosingLocal())
4634 if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl()))
4635 // If this is a reference variable, follow through to the expression that
4637 if (V->hasLocalStorage() &&
4638 V->getType()->isReferenceType() && V->hasInit()) {
4639 // Add the reference variable to the "trail".
4640 refVars.push_back(DR);
4641 return EvalAddr(V->getInit(), refVars, ParentDecl);
4647 case Stmt::UnaryOperatorClass: {
4648 // The only unary operator that make sense to handle here
4649 // is AddrOf. All others don't make sense as pointers.
4650 UnaryOperator *U = cast<UnaryOperator>(E);
4652 if (U->getOpcode() == UO_AddrOf)
4653 return EvalVal(U->getSubExpr(), refVars, ParentDecl);
4658 case Stmt::BinaryOperatorClass: {
4659 // Handle pointer arithmetic. All other binary operators are not valid
4661 BinaryOperator *B = cast<BinaryOperator>(E);
4662 BinaryOperatorKind op = B->getOpcode();
4664 if (op != BO_Add && op != BO_Sub)
4667 Expr *Base = B->getLHS();
4669 // Determine which argument is the real pointer base. It could be
4670 // the RHS argument instead of the LHS.
4671 if (!Base->getType()->isPointerType()) Base = B->getRHS();
4673 assert (Base->getType()->isPointerType());
4674 return EvalAddr(Base, refVars, ParentDecl);
4677 // For conditional operators we need to see if either the LHS or RHS are
4678 // valid DeclRefExpr*s. If one of them is valid, we return it.
4679 case Stmt::ConditionalOperatorClass: {
4680 ConditionalOperator *C = cast<ConditionalOperator>(E);
4682 // Handle the GNU extension for missing LHS.
4683 // FIXME: That isn't a ConditionalOperator, so doesn't get here.
4684 if (Expr *LHSExpr = C->getLHS()) {
4685 // In C++, we can have a throw-expression, which has 'void' type.
4686 if (!LHSExpr->getType()->isVoidType())
4687 if (Expr *LHS = EvalAddr(LHSExpr, refVars, ParentDecl))
4691 // In C++, we can have a throw-expression, which has 'void' type.
4692 if (C->getRHS()->getType()->isVoidType())
4695 return EvalAddr(C->getRHS(), refVars, ParentDecl);
4698 case Stmt::BlockExprClass:
4699 if (cast<BlockExpr>(E)->getBlockDecl()->hasCaptures())
4700 return E; // local block.
4703 case Stmt::AddrLabelExprClass:
4704 return E; // address of label.
4706 case Stmt::ExprWithCleanupsClass:
4707 return EvalAddr(cast<ExprWithCleanups>(E)->getSubExpr(), refVars,
4710 // For casts, we need to handle conversions from arrays to
4711 // pointer values, and pointer-to-pointer conversions.
4712 case Stmt::ImplicitCastExprClass:
4713 case Stmt::CStyleCastExprClass:
4714 case Stmt::CXXFunctionalCastExprClass:
4715 case Stmt::ObjCBridgedCastExprClass:
4716 case Stmt::CXXStaticCastExprClass:
4717 case Stmt::CXXDynamicCastExprClass:
4718 case Stmt::CXXConstCastExprClass:
4719 case Stmt::CXXReinterpretCastExprClass: {
4720 Expr* SubExpr = cast<CastExpr>(E)->getSubExpr();
4721 switch (cast<CastExpr>(E)->getCastKind()) {
4722 case CK_LValueToRValue:
4724 case CK_BaseToDerived:
4725 case CK_DerivedToBase:
4726 case CK_UncheckedDerivedToBase:
4728 case CK_CPointerToObjCPointerCast:
4729 case CK_BlockPointerToObjCPointerCast:
4730 case CK_AnyPointerToBlockPointerCast:
4731 return EvalAddr(SubExpr, refVars, ParentDecl);
4733 case CK_ArrayToPointerDecay:
4734 return EvalVal(SubExpr, refVars, ParentDecl);
4737 if (SubExpr->getType()->isAnyPointerType() ||
4738 SubExpr->getType()->isBlockPointerType() ||
4739 SubExpr->getType()->isObjCQualifiedIdType())
4740 return EvalAddr(SubExpr, refVars, ParentDecl);
4749 case Stmt::MaterializeTemporaryExprClass:
4750 if (Expr *Result = EvalAddr(
4751 cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr(),
4752 refVars, ParentDecl))
4757 // Everything else: we simply don't reason about them.
4764 /// EvalVal - This function is complements EvalAddr in the mutual recursion.
4765 /// See the comments for EvalAddr for more details.
4766 static Expr *EvalVal(Expr *E, SmallVectorImpl<DeclRefExpr *> &refVars,
4769 // We should only be called for evaluating non-pointer expressions, or
4770 // expressions with a pointer type that are not used as references but instead
4771 // are l-values (e.g., DeclRefExpr with a pointer type).
4773 // Our "symbolic interpreter" is just a dispatch off the currently
4774 // viewed AST node. We then recursively traverse the AST by calling
4775 // EvalAddr and EvalVal appropriately.
4777 E = E->IgnoreParens();
4778 switch (E->getStmtClass()) {
4779 case Stmt::ImplicitCastExprClass: {
4780 ImplicitCastExpr *IE = cast<ImplicitCastExpr>(E);
4781 if (IE->getValueKind() == VK_LValue) {
4782 E = IE->getSubExpr();
4788 case Stmt::ExprWithCleanupsClass:
4789 return EvalVal(cast<ExprWithCleanups>(E)->getSubExpr(), refVars,ParentDecl);
4791 case Stmt::DeclRefExprClass: {
4792 // When we hit a DeclRefExpr we are looking at code that refers to a
4793 // variable's name. If it's not a reference variable we check if it has
4794 // local storage within the function, and if so, return the expression.
4795 DeclRefExpr *DR = cast<DeclRefExpr>(E);
4797 // If we leave the immediate function, the lifetime isn't about to end.
4798 if (DR->refersToEnclosingLocal())
4801 if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl())) {
4802 // Check if it refers to itself, e.g. "int& i = i;".
4803 if (V == ParentDecl)
4806 if (V->hasLocalStorage()) {
4807 if (!V->getType()->isReferenceType())
4810 // Reference variable, follow through to the expression that
4813 // Add the reference variable to the "trail".
4814 refVars.push_back(DR);
4815 return EvalVal(V->getInit(), refVars, V);
4823 case Stmt::UnaryOperatorClass: {
4824 // The only unary operator that make sense to handle here
4825 // is Deref. All others don't resolve to a "name." This includes
4826 // handling all sorts of rvalues passed to a unary operator.
4827 UnaryOperator *U = cast<UnaryOperator>(E);
4829 if (U->getOpcode() == UO_Deref)
4830 return EvalAddr(U->getSubExpr(), refVars, ParentDecl);
4835 case Stmt::ArraySubscriptExprClass: {
4836 // Array subscripts are potential references to data on the stack. We
4837 // retrieve the DeclRefExpr* for the array variable if it indeed
4838 // has local storage.
4839 return EvalAddr(cast<ArraySubscriptExpr>(E)->getBase(), refVars,ParentDecl);
4842 case Stmt::ConditionalOperatorClass: {
4843 // For conditional operators we need to see if either the LHS or RHS are
4844 // non-NULL Expr's. If one is non-NULL, we return it.
4845 ConditionalOperator *C = cast<ConditionalOperator>(E);
4847 // Handle the GNU extension for missing LHS.
4848 if (Expr *LHSExpr = C->getLHS()) {
4849 // In C++, we can have a throw-expression, which has 'void' type.
4850 if (!LHSExpr->getType()->isVoidType())
4851 if (Expr *LHS = EvalVal(LHSExpr, refVars, ParentDecl))
4855 // In C++, we can have a throw-expression, which has 'void' type.
4856 if (C->getRHS()->getType()->isVoidType())
4859 return EvalVal(C->getRHS(), refVars, ParentDecl);
4862 // Accesses to members are potential references to data on the stack.
4863 case Stmt::MemberExprClass: {
4864 MemberExpr *M = cast<MemberExpr>(E);
4866 // Check for indirect access. We only want direct field accesses.
4870 // Check whether the member type is itself a reference, in which case
4871 // we're not going to refer to the member, but to what the member refers to.
4872 if (M->getMemberDecl()->getType()->isReferenceType())
4875 return EvalVal(M->getBase(), refVars, ParentDecl);
4878 case Stmt::MaterializeTemporaryExprClass:
4879 if (Expr *Result = EvalVal(
4880 cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr(),
4881 refVars, ParentDecl))
4887 // Check that we don't return or take the address of a reference to a
4888 // temporary. This is only useful in C++.
4889 if (!E->isTypeDependent() && E->isRValue())
4892 // Everything else: we simply don't reason about them.
4899 Sema::CheckReturnValExpr(Expr *RetValExp, QualType lhsType,
4900 SourceLocation ReturnLoc,
4902 const AttrVec *Attrs,
4903 const FunctionDecl *FD) {
4904 CheckReturnStackAddr(*this, RetValExp, lhsType, ReturnLoc);
4906 // Check if the return value is null but should not be.
4907 if (Attrs && hasSpecificAttr<ReturnsNonNullAttr>(*Attrs) &&
4908 CheckNonNullExpr(*this, RetValExp))
4909 Diag(ReturnLoc, diag::warn_null_ret)
4910 << (isObjCMethod ? 1 : 0) << RetValExp->getSourceRange();
4912 // C++11 [basic.stc.dynamic.allocation]p4:
4913 // If an allocation function declared with a non-throwing
4914 // exception-specification fails to allocate storage, it shall return
4915 // a null pointer. Any other allocation function that fails to allocate
4916 // storage shall indicate failure only by throwing an exception [...]
4918 OverloadedOperatorKind Op = FD->getOverloadedOperator();
4919 if (Op == OO_New || Op == OO_Array_New) {
4920 const FunctionProtoType *Proto
4921 = FD->getType()->castAs<FunctionProtoType>();
4922 if (!Proto->isNothrow(Context, /*ResultIfDependent*/true) &&
4923 CheckNonNullExpr(*this, RetValExp))
4924 Diag(ReturnLoc, diag::warn_operator_new_returns_null)
4925 << FD << getLangOpts().CPlusPlus11;
4930 //===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===//
4932 /// Check for comparisons of floating point operands using != and ==.
4933 /// Issue a warning if these are no self-comparisons, as they are not likely
4934 /// to do what the programmer intended.
4935 void Sema::CheckFloatComparison(SourceLocation Loc, Expr* LHS, Expr *RHS) {
4936 Expr* LeftExprSansParen = LHS->IgnoreParenImpCasts();
4937 Expr* RightExprSansParen = RHS->IgnoreParenImpCasts();
4939 // Special case: check for x == x (which is OK).
4940 // Do not emit warnings for such cases.
4941 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LeftExprSansParen))
4942 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RightExprSansParen))
4943 if (DRL->getDecl() == DRR->getDecl())
4947 // Special case: check for comparisons against literals that can be exactly
4948 // represented by APFloat. In such cases, do not emit a warning. This
4949 // is a heuristic: often comparison against such literals are used to
4950 // detect if a value in a variable has not changed. This clearly can
4951 // lead to false negatives.
4952 if (FloatingLiteral* FLL = dyn_cast<FloatingLiteral>(LeftExprSansParen)) {
4956 if (FloatingLiteral* FLR = dyn_cast<FloatingLiteral>(RightExprSansParen))
4960 // Check for comparisons with builtin types.
4961 if (CallExpr* CL = dyn_cast<CallExpr>(LeftExprSansParen))
4962 if (CL->getBuiltinCallee())
4965 if (CallExpr* CR = dyn_cast<CallExpr>(RightExprSansParen))
4966 if (CR->getBuiltinCallee())
4969 // Emit the diagnostic.
4970 Diag(Loc, diag::warn_floatingpoint_eq)
4971 << LHS->getSourceRange() << RHS->getSourceRange();
4974 //===--- CHECK: Integer mixed-sign comparisons (-Wsign-compare) --------===//
4975 //===--- CHECK: Lossy implicit conversions (-Wconversion) --------------===//
4979 /// Structure recording the 'active' range of an integer-valued
4982 /// The number of bits active in the int.
4985 /// True if the int is known not to have negative values.
4988 IntRange(unsigned Width, bool NonNegative)
4989 : Width(Width), NonNegative(NonNegative)
4992 /// Returns the range of the bool type.
4993 static IntRange forBoolType() {
4994 return IntRange(1, true);
4997 /// Returns the range of an opaque value of the given integral type.
4998 static IntRange forValueOfType(ASTContext &C, QualType T) {
4999 return forValueOfCanonicalType(C,
5000 T->getCanonicalTypeInternal().getTypePtr());
5003 /// Returns the range of an opaque value of a canonical integral type.
5004 static IntRange forValueOfCanonicalType(ASTContext &C, const Type *T) {
5005 assert(T->isCanonicalUnqualified());
5007 if (const VectorType *VT = dyn_cast<VectorType>(T))
5008 T = VT->getElementType().getTypePtr();
5009 if (const ComplexType *CT = dyn_cast<ComplexType>(T))
5010 T = CT->getElementType().getTypePtr();
5011 if (const AtomicType *AT = dyn_cast<AtomicType>(T))
5012 T = AT->getValueType().getTypePtr();
5014 // For enum types, use the known bit width of the enumerators.
5015 if (const EnumType *ET = dyn_cast<EnumType>(T)) {
5016 EnumDecl *Enum = ET->getDecl();
5017 if (!Enum->isCompleteDefinition())
5018 return IntRange(C.getIntWidth(QualType(T, 0)), false);
5020 unsigned NumPositive = Enum->getNumPositiveBits();
5021 unsigned NumNegative = Enum->getNumNegativeBits();
5023 if (NumNegative == 0)
5024 return IntRange(NumPositive, true/*NonNegative*/);
5026 return IntRange(std::max(NumPositive + 1, NumNegative),
5027 false/*NonNegative*/);
5030 const BuiltinType *BT = cast<BuiltinType>(T);
5031 assert(BT->isInteger());
5033 return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger());
5036 /// Returns the "target" range of a canonical integral type, i.e.
5037 /// the range of values expressible in the type.
5039 /// This matches forValueOfCanonicalType except that enums have the
5040 /// full range of their type, not the range of their enumerators.
5041 static IntRange forTargetOfCanonicalType(ASTContext &C, const Type *T) {
5042 assert(T->isCanonicalUnqualified());
5044 if (const VectorType *VT = dyn_cast<VectorType>(T))
5045 T = VT->getElementType().getTypePtr();
5046 if (const ComplexType *CT = dyn_cast<ComplexType>(T))
5047 T = CT->getElementType().getTypePtr();
5048 if (const AtomicType *AT = dyn_cast<AtomicType>(T))
5049 T = AT->getValueType().getTypePtr();
5050 if (const EnumType *ET = dyn_cast<EnumType>(T))
5051 T = C.getCanonicalType(ET->getDecl()->getIntegerType()).getTypePtr();
5053 const BuiltinType *BT = cast<BuiltinType>(T);
5054 assert(BT->isInteger());
5056 return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger());
5059 /// Returns the supremum of two ranges: i.e. their conservative merge.
5060 static IntRange join(IntRange L, IntRange R) {
5061 return IntRange(std::max(L.Width, R.Width),
5062 L.NonNegative && R.NonNegative);
5065 /// Returns the infinum of two ranges: i.e. their aggressive merge.
5066 static IntRange meet(IntRange L, IntRange R) {
5067 return IntRange(std::min(L.Width, R.Width),
5068 L.NonNegative || R.NonNegative);
5072 static IntRange GetValueRange(ASTContext &C, llvm::APSInt &value,
5073 unsigned MaxWidth) {
5074 if (value.isSigned() && value.isNegative())
5075 return IntRange(value.getMinSignedBits(), false);
5077 if (value.getBitWidth() > MaxWidth)
5078 value = value.trunc(MaxWidth);
5080 // isNonNegative() just checks the sign bit without considering
5082 return IntRange(value.getActiveBits(), true);
5085 static IntRange GetValueRange(ASTContext &C, APValue &result, QualType Ty,
5086 unsigned MaxWidth) {
5088 return GetValueRange(C, result.getInt(), MaxWidth);
5090 if (result.isVector()) {
5091 IntRange R = GetValueRange(C, result.getVectorElt(0), Ty, MaxWidth);
5092 for (unsigned i = 1, e = result.getVectorLength(); i != e; ++i) {
5093 IntRange El = GetValueRange(C, result.getVectorElt(i), Ty, MaxWidth);
5094 R = IntRange::join(R, El);
5099 if (result.isComplexInt()) {
5100 IntRange R = GetValueRange(C, result.getComplexIntReal(), MaxWidth);
5101 IntRange I = GetValueRange(C, result.getComplexIntImag(), MaxWidth);
5102 return IntRange::join(R, I);
5105 // This can happen with lossless casts to intptr_t of "based" lvalues.
5106 // Assume it might use arbitrary bits.
5107 // FIXME: The only reason we need to pass the type in here is to get
5108 // the sign right on this one case. It would be nice if APValue
5110 assert(result.isLValue() || result.isAddrLabelDiff());
5111 return IntRange(MaxWidth, Ty->isUnsignedIntegerOrEnumerationType());
5114 static QualType GetExprType(Expr *E) {
5115 QualType Ty = E->getType();
5116 if (const AtomicType *AtomicRHS = Ty->getAs<AtomicType>())
5117 Ty = AtomicRHS->getValueType();
5121 /// Pseudo-evaluate the given integer expression, estimating the
5122 /// range of values it might take.
5124 /// \param MaxWidth - the width to which the value will be truncated
5125 static IntRange GetExprRange(ASTContext &C, Expr *E, unsigned MaxWidth) {
5126 E = E->IgnoreParens();
5128 // Try a full evaluation first.
5129 Expr::EvalResult result;
5130 if (E->EvaluateAsRValue(result, C))
5131 return GetValueRange(C, result.Val, GetExprType(E), MaxWidth);
5133 // I think we only want to look through implicit casts here; if the
5134 // user has an explicit widening cast, we should treat the value as
5135 // being of the new, wider type.
5136 if (ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E)) {
5137 if (CE->getCastKind() == CK_NoOp || CE->getCastKind() == CK_LValueToRValue)
5138 return GetExprRange(C, CE->getSubExpr(), MaxWidth);
5140 IntRange OutputTypeRange = IntRange::forValueOfType(C, GetExprType(CE));
5142 bool isIntegerCast = (CE->getCastKind() == CK_IntegralCast);
5144 // Assume that non-integer casts can span the full range of the type.
5146 return OutputTypeRange;
5149 = GetExprRange(C, CE->getSubExpr(),
5150 std::min(MaxWidth, OutputTypeRange.Width));
5152 // Bail out if the subexpr's range is as wide as the cast type.
5153 if (SubRange.Width >= OutputTypeRange.Width)
5154 return OutputTypeRange;
5156 // Otherwise, we take the smaller width, and we're non-negative if
5157 // either the output type or the subexpr is.
5158 return IntRange(SubRange.Width,
5159 SubRange.NonNegative || OutputTypeRange.NonNegative);
5162 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
5163 // If we can fold the condition, just take that operand.
5165 if (CO->getCond()->EvaluateAsBooleanCondition(CondResult, C))
5166 return GetExprRange(C, CondResult ? CO->getTrueExpr()
5167 : CO->getFalseExpr(),
5170 // Otherwise, conservatively merge.
5171 IntRange L = GetExprRange(C, CO->getTrueExpr(), MaxWidth);
5172 IntRange R = GetExprRange(C, CO->getFalseExpr(), MaxWidth);
5173 return IntRange::join(L, R);
5176 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
5177 switch (BO->getOpcode()) {
5179 // Boolean-valued operations are single-bit and positive.
5188 return IntRange::forBoolType();
5190 // The type of the assignments is the type of the LHS, so the RHS
5191 // is not necessarily the same type.
5200 return IntRange::forValueOfType(C, GetExprType(E));
5202 // Simple assignments just pass through the RHS, which will have
5203 // been coerced to the LHS type.
5206 return GetExprRange(C, BO->getRHS(), MaxWidth);
5208 // Operations with opaque sources are black-listed.
5211 return IntRange::forValueOfType(C, GetExprType(E));
5213 // Bitwise-and uses the *infinum* of the two source ranges.
5216 return IntRange::meet(GetExprRange(C, BO->getLHS(), MaxWidth),
5217 GetExprRange(C, BO->getRHS(), MaxWidth));
5219 // Left shift gets black-listed based on a judgement call.
5221 // ...except that we want to treat '1 << (blah)' as logically
5222 // positive. It's an important idiom.
5223 if (IntegerLiteral *I
5224 = dyn_cast<IntegerLiteral>(BO->getLHS()->IgnoreParenCasts())) {
5225 if (I->getValue() == 1) {
5226 IntRange R = IntRange::forValueOfType(C, GetExprType(E));
5227 return IntRange(R.Width, /*NonNegative*/ true);
5233 return IntRange::forValueOfType(C, GetExprType(E));
5235 // Right shift by a constant can narrow its left argument.
5237 case BO_ShrAssign: {
5238 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth);
5240 // If the shift amount is a positive constant, drop the width by
5243 if (BO->getRHS()->isIntegerConstantExpr(shift, C) &&
5244 shift.isNonNegative()) {
5245 unsigned zext = shift.getZExtValue();
5246 if (zext >= L.Width)
5247 L.Width = (L.NonNegative ? 0 : 1);
5255 // Comma acts as its right operand.
5257 return GetExprRange(C, BO->getRHS(), MaxWidth);
5259 // Black-list pointer subtractions.
5261 if (BO->getLHS()->getType()->isPointerType())
5262 return IntRange::forValueOfType(C, GetExprType(E));
5265 // The width of a division result is mostly determined by the size
5268 // Don't 'pre-truncate' the operands.
5269 unsigned opWidth = C.getIntWidth(GetExprType(E));
5270 IntRange L = GetExprRange(C, BO->getLHS(), opWidth);
5272 // If the divisor is constant, use that.
5273 llvm::APSInt divisor;
5274 if (BO->getRHS()->isIntegerConstantExpr(divisor, C)) {
5275 unsigned log2 = divisor.logBase2(); // floor(log_2(divisor))
5276 if (log2 >= L.Width)
5277 L.Width = (L.NonNegative ? 0 : 1);
5279 L.Width = std::min(L.Width - log2, MaxWidth);
5283 // Otherwise, just use the LHS's width.
5284 IntRange R = GetExprRange(C, BO->getRHS(), opWidth);
5285 return IntRange(L.Width, L.NonNegative && R.NonNegative);
5288 // The result of a remainder can't be larger than the result of
5291 // Don't 'pre-truncate' the operands.
5292 unsigned opWidth = C.getIntWidth(GetExprType(E));
5293 IntRange L = GetExprRange(C, BO->getLHS(), opWidth);
5294 IntRange R = GetExprRange(C, BO->getRHS(), opWidth);
5296 IntRange meet = IntRange::meet(L, R);
5297 meet.Width = std::min(meet.Width, MaxWidth);
5301 // The default behavior is okay for these.
5309 // The default case is to treat the operation as if it were closed
5310 // on the narrowest type that encompasses both operands.
5311 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth);
5312 IntRange R = GetExprRange(C, BO->getRHS(), MaxWidth);
5313 return IntRange::join(L, R);
5316 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
5317 switch (UO->getOpcode()) {
5318 // Boolean-valued operations are white-listed.
5320 return IntRange::forBoolType();
5322 // Operations with opaque sources are black-listed.
5324 case UO_AddrOf: // should be impossible
5325 return IntRange::forValueOfType(C, GetExprType(E));
5328 return GetExprRange(C, UO->getSubExpr(), MaxWidth);
5332 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E))
5333 return GetExprRange(C, OVE->getSourceExpr(), MaxWidth);
5335 if (FieldDecl *BitField = E->getSourceBitField())
5336 return IntRange(BitField->getBitWidthValue(C),
5337 BitField->getType()->isUnsignedIntegerOrEnumerationType());
5339 return IntRange::forValueOfType(C, GetExprType(E));
5342 static IntRange GetExprRange(ASTContext &C, Expr *E) {
5343 return GetExprRange(C, E, C.getIntWidth(GetExprType(E)));
5346 /// Checks whether the given value, which currently has the given
5347 /// source semantics, has the same value when coerced through the
5348 /// target semantics.
5349 static bool IsSameFloatAfterCast(const llvm::APFloat &value,
5350 const llvm::fltSemantics &Src,
5351 const llvm::fltSemantics &Tgt) {
5352 llvm::APFloat truncated = value;
5355 truncated.convert(Src, llvm::APFloat::rmNearestTiesToEven, &ignored);
5356 truncated.convert(Tgt, llvm::APFloat::rmNearestTiesToEven, &ignored);
5358 return truncated.bitwiseIsEqual(value);
5361 /// Checks whether the given value, which currently has the given
5362 /// source semantics, has the same value when coerced through the
5363 /// target semantics.
5365 /// The value might be a vector of floats (or a complex number).
5366 static bool IsSameFloatAfterCast(const APValue &value,
5367 const llvm::fltSemantics &Src,
5368 const llvm::fltSemantics &Tgt) {
5369 if (value.isFloat())
5370 return IsSameFloatAfterCast(value.getFloat(), Src, Tgt);
5372 if (value.isVector()) {
5373 for (unsigned i = 0, e = value.getVectorLength(); i != e; ++i)
5374 if (!IsSameFloatAfterCast(value.getVectorElt(i), Src, Tgt))
5379 assert(value.isComplexFloat());
5380 return (IsSameFloatAfterCast(value.getComplexFloatReal(), Src, Tgt) &&
5381 IsSameFloatAfterCast(value.getComplexFloatImag(), Src, Tgt));
5384 static void AnalyzeImplicitConversions(Sema &S, Expr *E, SourceLocation CC);
5386 static bool IsZero(Sema &S, Expr *E) {
5387 // Suppress cases where we are comparing against an enum constant.
5388 if (const DeclRefExpr *DR =
5389 dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()))
5390 if (isa<EnumConstantDecl>(DR->getDecl()))
5393 // Suppress cases where the '0' value is expanded from a macro.
5394 if (E->getLocStart().isMacroID())
5398 return E->isIntegerConstantExpr(Value, S.Context) && Value == 0;
5401 static bool HasEnumType(Expr *E) {
5402 // Strip off implicit integral promotions.
5403 while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
5404 if (ICE->getCastKind() != CK_IntegralCast &&
5405 ICE->getCastKind() != CK_NoOp)
5407 E = ICE->getSubExpr();
5410 return E->getType()->isEnumeralType();
5413 static void CheckTrivialUnsignedComparison(Sema &S, BinaryOperator *E) {
5414 // Disable warning in template instantiations.
5415 if (!S.ActiveTemplateInstantiations.empty())
5418 BinaryOperatorKind op = E->getOpcode();
5419 if (E->isValueDependent())
5422 if (op == BO_LT && IsZero(S, E->getRHS())) {
5423 S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison)
5424 << "< 0" << "false" << HasEnumType(E->getLHS())
5425 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
5426 } else if (op == BO_GE && IsZero(S, E->getRHS())) {
5427 S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison)
5428 << ">= 0" << "true" << HasEnumType(E->getLHS())
5429 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
5430 } else if (op == BO_GT && IsZero(S, E->getLHS())) {
5431 S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison)
5432 << "0 >" << "false" << HasEnumType(E->getRHS())
5433 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
5434 } else if (op == BO_LE && IsZero(S, E->getLHS())) {
5435 S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison)
5436 << "0 <=" << "true" << HasEnumType(E->getRHS())
5437 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
5441 static void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E,
5442 Expr *Constant, Expr *Other,
5445 // Disable warning in template instantiations.
5446 if (!S.ActiveTemplateInstantiations.empty())
5449 // TODO: Investigate using GetExprRange() to get tighter bounds
5450 // on the bit ranges.
5451 QualType OtherT = Other->getType();
5452 if (const AtomicType *AT = dyn_cast<AtomicType>(OtherT))
5453 OtherT = AT->getValueType();
5454 IntRange OtherRange = IntRange::forValueOfType(S.Context, OtherT);
5455 unsigned OtherWidth = OtherRange.Width;
5457 bool OtherIsBooleanType = Other->isKnownToHaveBooleanValue();
5459 // 0 values are handled later by CheckTrivialUnsignedComparison().
5460 if ((Value == 0) && (!OtherIsBooleanType))
5463 BinaryOperatorKind op = E->getOpcode();
5466 // Used for diagnostic printout.
5468 LiteralConstant = 0,
5471 } LiteralOrBoolConstant = LiteralConstant;
5473 if (!OtherIsBooleanType) {
5474 QualType ConstantT = Constant->getType();
5475 QualType CommonT = E->getLHS()->getType();
5477 if (S.Context.hasSameUnqualifiedType(OtherT, ConstantT))
5479 assert((OtherT->isIntegerType() && ConstantT->isIntegerType()) &&
5480 "comparison with non-integer type");
5482 bool ConstantSigned = ConstantT->isSignedIntegerType();
5483 bool CommonSigned = CommonT->isSignedIntegerType();
5485 bool EqualityOnly = false;
5488 // The common type is signed, therefore no signed to unsigned conversion.
5489 if (!OtherRange.NonNegative) {
5490 // Check that the constant is representable in type OtherT.
5491 if (ConstantSigned) {
5492 if (OtherWidth >= Value.getMinSignedBits())
5494 } else { // !ConstantSigned
5495 if (OtherWidth >= Value.getActiveBits() + 1)
5498 } else { // !OtherSigned
5499 // Check that the constant is representable in type OtherT.
5500 // Negative values are out of range.
5501 if (ConstantSigned) {
5502 if (Value.isNonNegative() && OtherWidth >= Value.getActiveBits())
5504 } else { // !ConstantSigned
5505 if (OtherWidth >= Value.getActiveBits())
5509 } else { // !CommonSigned
5510 if (OtherRange.NonNegative) {
5511 if (OtherWidth >= Value.getActiveBits())
5513 } else { // OtherSigned
5514 assert(!ConstantSigned &&
5515 "Two signed types converted to unsigned types.");
5516 // Check to see if the constant is representable in OtherT.
5517 if (OtherWidth > Value.getActiveBits())
5519 // Check to see if the constant is equivalent to a negative value
5521 if (S.Context.getIntWidth(ConstantT) ==
5522 S.Context.getIntWidth(CommonT) &&
5523 Value.isNegative() && Value.getMinSignedBits() <= OtherWidth)
5525 // The constant value rests between values that OtherT can represent
5526 // after conversion. Relational comparison still works, but equality
5527 // comparisons will be tautological.
5528 EqualityOnly = true;
5532 bool PositiveConstant = !ConstantSigned || Value.isNonNegative();
5534 if (op == BO_EQ || op == BO_NE) {
5535 IsTrue = op == BO_NE;
5536 } else if (EqualityOnly) {
5538 } else if (RhsConstant) {
5539 if (op == BO_GT || op == BO_GE)
5540 IsTrue = !PositiveConstant;
5541 else // op == BO_LT || op == BO_LE
5542 IsTrue = PositiveConstant;
5544 if (op == BO_LT || op == BO_LE)
5545 IsTrue = !PositiveConstant;
5546 else // op == BO_GT || op == BO_GE
5547 IsTrue = PositiveConstant;
5550 // Other isKnownToHaveBooleanValue
5551 enum CompareBoolWithConstantResult { AFals, ATrue, Unkwn };
5552 enum ConstantValue { LT_Zero, Zero, One, GT_One, SizeOfConstVal };
5553 enum ConstantSide { Lhs, Rhs, SizeOfConstSides };
5555 static const struct LinkedConditions {
5556 CompareBoolWithConstantResult BO_LT_OP[SizeOfConstSides][SizeOfConstVal];
5557 CompareBoolWithConstantResult BO_GT_OP[SizeOfConstSides][SizeOfConstVal];
5558 CompareBoolWithConstantResult BO_LE_OP[SizeOfConstSides][SizeOfConstVal];
5559 CompareBoolWithConstantResult BO_GE_OP[SizeOfConstSides][SizeOfConstVal];
5560 CompareBoolWithConstantResult BO_EQ_OP[SizeOfConstSides][SizeOfConstVal];
5561 CompareBoolWithConstantResult BO_NE_OP[SizeOfConstSides][SizeOfConstVal];
5564 // Constant on LHS. | Constant on RHS. |
5565 // LT_Zero| Zero | One |GT_One| LT_Zero| Zero | One |GT_One|
5566 { { ATrue, Unkwn, AFals, AFals }, { AFals, AFals, Unkwn, ATrue } },
5567 { { AFals, AFals, Unkwn, ATrue }, { ATrue, Unkwn, AFals, AFals } },
5568 { { ATrue, ATrue, Unkwn, AFals }, { AFals, Unkwn, ATrue, ATrue } },
5569 { { AFals, Unkwn, ATrue, ATrue }, { ATrue, ATrue, Unkwn, AFals } },
5570 { { AFals, Unkwn, Unkwn, AFals }, { AFals, Unkwn, Unkwn, AFals } },
5571 { { ATrue, Unkwn, Unkwn, ATrue }, { ATrue, Unkwn, Unkwn, ATrue } }
5574 bool ConstantIsBoolLiteral = isa<CXXBoolLiteralExpr>(Constant);
5576 enum ConstantValue ConstVal = Zero;
5577 if (Value.isUnsigned() || Value.isNonNegative()) {
5579 LiteralOrBoolConstant =
5580 ConstantIsBoolLiteral ? CXXBoolLiteralFalse : LiteralConstant;
5582 } else if (Value == 1) {
5583 LiteralOrBoolConstant =
5584 ConstantIsBoolLiteral ? CXXBoolLiteralTrue : LiteralConstant;
5587 LiteralOrBoolConstant = LiteralConstant;
5594 CompareBoolWithConstantResult CmpRes;
5598 CmpRes = TruthTable.BO_LT_OP[RhsConstant][ConstVal];
5601 CmpRes = TruthTable.BO_GT_OP[RhsConstant][ConstVal];
5604 CmpRes = TruthTable.BO_LE_OP[RhsConstant][ConstVal];
5607 CmpRes = TruthTable.BO_GE_OP[RhsConstant][ConstVal];
5610 CmpRes = TruthTable.BO_EQ_OP[RhsConstant][ConstVal];
5613 CmpRes = TruthTable.BO_NE_OP[RhsConstant][ConstVal];
5620 if (CmpRes == AFals) {
5622 } else if (CmpRes == ATrue) {
5629 // If this is a comparison to an enum constant, include that
5630 // constant in the diagnostic.
5631 const EnumConstantDecl *ED = nullptr;
5632 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Constant))
5633 ED = dyn_cast<EnumConstantDecl>(DR->getDecl());
5635 SmallString<64> PrettySourceValue;
5636 llvm::raw_svector_ostream OS(PrettySourceValue);
5638 OS << '\'' << *ED << "' (" << Value << ")";
5642 S.DiagRuntimeBehavior(
5643 E->getOperatorLoc(), E,
5644 S.PDiag(diag::warn_out_of_range_compare)
5645 << OS.str() << LiteralOrBoolConstant
5646 << OtherT << (OtherIsBooleanType && !OtherT->isBooleanType()) << IsTrue
5647 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange());
5650 /// Analyze the operands of the given comparison. Implements the
5651 /// fallback case from AnalyzeComparison.
5652 static void AnalyzeImpConvsInComparison(Sema &S, BinaryOperator *E) {
5653 AnalyzeImplicitConversions(S, E->getLHS(), E->getOperatorLoc());
5654 AnalyzeImplicitConversions(S, E->getRHS(), E->getOperatorLoc());
5657 /// \brief Implements -Wsign-compare.
5659 /// \param E the binary operator to check for warnings
5660 static void AnalyzeComparison(Sema &S, BinaryOperator *E) {
5661 // The type the comparison is being performed in.
5662 QualType T = E->getLHS()->getType();
5663 assert(S.Context.hasSameUnqualifiedType(T, E->getRHS()->getType())
5664 && "comparison with mismatched types");
5665 if (E->isValueDependent())
5666 return AnalyzeImpConvsInComparison(S, E);
5668 Expr *LHS = E->getLHS()->IgnoreParenImpCasts();
5669 Expr *RHS = E->getRHS()->IgnoreParenImpCasts();
5671 bool IsComparisonConstant = false;
5673 // Check whether an integer constant comparison results in a value
5674 // of 'true' or 'false'.
5675 if (T->isIntegralType(S.Context)) {
5676 llvm::APSInt RHSValue;
5677 bool IsRHSIntegralLiteral =
5678 RHS->isIntegerConstantExpr(RHSValue, S.Context);
5679 llvm::APSInt LHSValue;
5680 bool IsLHSIntegralLiteral =
5681 LHS->isIntegerConstantExpr(LHSValue, S.Context);
5682 if (IsRHSIntegralLiteral && !IsLHSIntegralLiteral)
5683 DiagnoseOutOfRangeComparison(S, E, RHS, LHS, RHSValue, true);
5684 else if (!IsRHSIntegralLiteral && IsLHSIntegralLiteral)
5685 DiagnoseOutOfRangeComparison(S, E, LHS, RHS, LHSValue, false);
5687 IsComparisonConstant =
5688 (IsRHSIntegralLiteral && IsLHSIntegralLiteral);
5689 } else if (!T->hasUnsignedIntegerRepresentation())
5690 IsComparisonConstant = E->isIntegerConstantExpr(S.Context);
5692 // We don't do anything special if this isn't an unsigned integral
5693 // comparison: we're only interested in integral comparisons, and
5694 // signed comparisons only happen in cases we don't care to warn about.
5696 // We also don't care about value-dependent expressions or expressions
5697 // whose result is a constant.
5698 if (!T->hasUnsignedIntegerRepresentation() || IsComparisonConstant)
5699 return AnalyzeImpConvsInComparison(S, E);
5701 // Check to see if one of the (unmodified) operands is of different
5703 Expr *signedOperand, *unsignedOperand;
5704 if (LHS->getType()->hasSignedIntegerRepresentation()) {
5705 assert(!RHS->getType()->hasSignedIntegerRepresentation() &&
5706 "unsigned comparison between two signed integer expressions?");
5707 signedOperand = LHS;
5708 unsignedOperand = RHS;
5709 } else if (RHS->getType()->hasSignedIntegerRepresentation()) {
5710 signedOperand = RHS;
5711 unsignedOperand = LHS;
5713 CheckTrivialUnsignedComparison(S, E);
5714 return AnalyzeImpConvsInComparison(S, E);
5717 // Otherwise, calculate the effective range of the signed operand.
5718 IntRange signedRange = GetExprRange(S.Context, signedOperand);
5720 // Go ahead and analyze implicit conversions in the operands. Note
5721 // that we skip the implicit conversions on both sides.
5722 AnalyzeImplicitConversions(S, LHS, E->getOperatorLoc());
5723 AnalyzeImplicitConversions(S, RHS, E->getOperatorLoc());
5725 // If the signed range is non-negative, -Wsign-compare won't fire,
5726 // but we should still check for comparisons which are always true
5728 if (signedRange.NonNegative)
5729 return CheckTrivialUnsignedComparison(S, E);
5731 // For (in)equality comparisons, if the unsigned operand is a
5732 // constant which cannot collide with a overflowed signed operand,
5733 // then reinterpreting the signed operand as unsigned will not
5734 // change the result of the comparison.
5735 if (E->isEqualityOp()) {
5736 unsigned comparisonWidth = S.Context.getIntWidth(T);
5737 IntRange unsignedRange = GetExprRange(S.Context, unsignedOperand);
5739 // We should never be unable to prove that the unsigned operand is
5741 assert(unsignedRange.NonNegative && "unsigned range includes negative?");
5743 if (unsignedRange.Width < comparisonWidth)
5747 S.DiagRuntimeBehavior(E->getOperatorLoc(), E,
5748 S.PDiag(diag::warn_mixed_sign_comparison)
5749 << LHS->getType() << RHS->getType()
5750 << LHS->getSourceRange() << RHS->getSourceRange());
5753 /// Analyzes an attempt to assign the given value to a bitfield.
5755 /// Returns true if there was something fishy about the attempt.
5756 static bool AnalyzeBitFieldAssignment(Sema &S, FieldDecl *Bitfield, Expr *Init,
5757 SourceLocation InitLoc) {
5758 assert(Bitfield->isBitField());
5759 if (Bitfield->isInvalidDecl())
5762 // White-list bool bitfields.
5763 if (Bitfield->getType()->isBooleanType())
5766 // Ignore value- or type-dependent expressions.
5767 if (Bitfield->getBitWidth()->isValueDependent() ||
5768 Bitfield->getBitWidth()->isTypeDependent() ||
5769 Init->isValueDependent() ||
5770 Init->isTypeDependent())
5773 Expr *OriginalInit = Init->IgnoreParenImpCasts();
5776 if (!OriginalInit->EvaluateAsInt(Value, S.Context, Expr::SE_AllowSideEffects))
5779 unsigned OriginalWidth = Value.getBitWidth();
5780 unsigned FieldWidth = Bitfield->getBitWidthValue(S.Context);
5782 if (OriginalWidth <= FieldWidth)
5785 // Compute the value which the bitfield will contain.
5786 llvm::APSInt TruncatedValue = Value.trunc(FieldWidth);
5787 TruncatedValue.setIsSigned(Bitfield->getType()->isSignedIntegerType());
5789 // Check whether the stored value is equal to the original value.
5790 TruncatedValue = TruncatedValue.extend(OriginalWidth);
5791 if (llvm::APSInt::isSameValue(Value, TruncatedValue))
5794 // Special-case bitfields of width 1: booleans are naturally 0/1, and
5795 // therefore don't strictly fit into a signed bitfield of width 1.
5796 if (FieldWidth == 1 && Value == 1)
5799 std::string PrettyValue = Value.toString(10);
5800 std::string PrettyTrunc = TruncatedValue.toString(10);
5802 S.Diag(InitLoc, diag::warn_impcast_bitfield_precision_constant)
5803 << PrettyValue << PrettyTrunc << OriginalInit->getType()
5804 << Init->getSourceRange();
5809 /// Analyze the given simple or compound assignment for warning-worthy
5811 static void AnalyzeAssignment(Sema &S, BinaryOperator *E) {
5812 // Just recurse on the LHS.
5813 AnalyzeImplicitConversions(S, E->getLHS(), E->getOperatorLoc());
5815 // We want to recurse on the RHS as normal unless we're assigning to
5817 if (FieldDecl *Bitfield = E->getLHS()->getSourceBitField()) {
5818 if (AnalyzeBitFieldAssignment(S, Bitfield, E->getRHS(),
5819 E->getOperatorLoc())) {
5820 // Recurse, ignoring any implicit conversions on the RHS.
5821 return AnalyzeImplicitConversions(S, E->getRHS()->IgnoreParenImpCasts(),
5822 E->getOperatorLoc());
5826 AnalyzeImplicitConversions(S, E->getRHS(), E->getOperatorLoc());
5829 /// Diagnose an implicit cast; purely a helper for CheckImplicitConversion.
5830 static void DiagnoseImpCast(Sema &S, Expr *E, QualType SourceType, QualType T,
5831 SourceLocation CContext, unsigned diag,
5832 bool pruneControlFlow = false) {
5833 if (pruneControlFlow) {
5834 S.DiagRuntimeBehavior(E->getExprLoc(), E,
5836 << SourceType << T << E->getSourceRange()
5837 << SourceRange(CContext));
5840 S.Diag(E->getExprLoc(), diag)
5841 << SourceType << T << E->getSourceRange() << SourceRange(CContext);
5844 /// Diagnose an implicit cast; purely a helper for CheckImplicitConversion.
5845 static void DiagnoseImpCast(Sema &S, Expr *E, QualType T,
5846 SourceLocation CContext, unsigned diag,
5847 bool pruneControlFlow = false) {
5848 DiagnoseImpCast(S, E, E->getType(), T, CContext, diag, pruneControlFlow);
5851 /// Diagnose an implicit cast from a literal expression. Does not warn when the
5852 /// cast wouldn't lose information.
5853 void DiagnoseFloatingLiteralImpCast(Sema &S, FloatingLiteral *FL, QualType T,
5854 SourceLocation CContext) {
5855 // Try to convert the literal exactly to an integer. If we can, don't warn.
5856 bool isExact = false;
5857 const llvm::APFloat &Value = FL->getValue();
5858 llvm::APSInt IntegerValue(S.Context.getIntWidth(T),
5859 T->hasUnsignedIntegerRepresentation());
5860 if (Value.convertToInteger(IntegerValue,
5861 llvm::APFloat::rmTowardZero, &isExact)
5862 == llvm::APFloat::opOK && isExact)
5865 // FIXME: Force the precision of the source value down so we don't print
5866 // digits which are usually useless (we don't really care here if we
5867 // truncate a digit by accident in edge cases). Ideally, APFloat::toString
5868 // would automatically print the shortest representation, but it's a bit
5869 // tricky to implement.
5870 SmallString<16> PrettySourceValue;
5871 unsigned precision = llvm::APFloat::semanticsPrecision(Value.getSemantics());
5872 precision = (precision * 59 + 195) / 196;
5873 Value.toString(PrettySourceValue, precision);
5875 SmallString<16> PrettyTargetValue;
5876 if (T->isSpecificBuiltinType(BuiltinType::Bool))
5877 PrettyTargetValue = IntegerValue == 0 ? "false" : "true";
5879 IntegerValue.toString(PrettyTargetValue);
5881 S.Diag(FL->getExprLoc(), diag::warn_impcast_literal_float_to_integer)
5882 << FL->getType() << T.getUnqualifiedType() << PrettySourceValue
5883 << PrettyTargetValue << FL->getSourceRange() << SourceRange(CContext);
5886 std::string PrettyPrintInRange(const llvm::APSInt &Value, IntRange Range) {
5887 if (!Range.Width) return "0";
5889 llvm::APSInt ValueInRange = Value;
5890 ValueInRange.setIsSigned(!Range.NonNegative);
5891 ValueInRange = ValueInRange.trunc(Range.Width);
5892 return ValueInRange.toString(10);
5895 static bool IsImplicitBoolFloatConversion(Sema &S, Expr *Ex, bool ToBool) {
5896 if (!isa<ImplicitCastExpr>(Ex))
5899 Expr *InnerE = Ex->IgnoreParenImpCasts();
5900 const Type *Target = S.Context.getCanonicalType(Ex->getType()).getTypePtr();
5901 const Type *Source =
5902 S.Context.getCanonicalType(InnerE->getType()).getTypePtr();
5903 if (Target->isDependentType())
5906 const BuiltinType *FloatCandidateBT =
5907 dyn_cast<BuiltinType>(ToBool ? Source : Target);
5908 const Type *BoolCandidateType = ToBool ? Target : Source;
5910 return (BoolCandidateType->isSpecificBuiltinType(BuiltinType::Bool) &&
5911 FloatCandidateBT && (FloatCandidateBT->isFloatingPoint()));
5914 void CheckImplicitArgumentConversions(Sema &S, CallExpr *TheCall,
5915 SourceLocation CC) {
5916 unsigned NumArgs = TheCall->getNumArgs();
5917 for (unsigned i = 0; i < NumArgs; ++i) {
5918 Expr *CurrA = TheCall->getArg(i);
5919 if (!IsImplicitBoolFloatConversion(S, CurrA, true))
5922 bool IsSwapped = ((i > 0) &&
5923 IsImplicitBoolFloatConversion(S, TheCall->getArg(i - 1), false));
5924 IsSwapped |= ((i < (NumArgs - 1)) &&
5925 IsImplicitBoolFloatConversion(S, TheCall->getArg(i + 1), false));
5927 // Warn on this floating-point to bool conversion.
5928 DiagnoseImpCast(S, CurrA->IgnoreParenImpCasts(),
5929 CurrA->getType(), CC,
5930 diag::warn_impcast_floating_point_to_bool);
5935 void CheckImplicitConversion(Sema &S, Expr *E, QualType T,
5936 SourceLocation CC, bool *ICContext = nullptr) {
5937 if (E->isTypeDependent() || E->isValueDependent()) return;
5939 const Type *Source = S.Context.getCanonicalType(E->getType()).getTypePtr();
5940 const Type *Target = S.Context.getCanonicalType(T).getTypePtr();
5941 if (Source == Target) return;
5942 if (Target->isDependentType()) return;
5944 // If the conversion context location is invalid don't complain. We also
5945 // don't want to emit a warning if the issue occurs from the expansion of
5946 // a system macro. The problem is that 'getSpellingLoc()' is slow, so we
5947 // delay this check as long as possible. Once we detect we are in that
5948 // scenario, we just return.
5952 // Diagnose implicit casts to bool.
5953 if (Target->isSpecificBuiltinType(BuiltinType::Bool)) {
5954 if (isa<StringLiteral>(E))
5955 // Warn on string literal to bool. Checks for string literals in logical
5956 // and expressions, for instance, assert(0 && "error here"), are
5957 // prevented by a check in AnalyzeImplicitConversions().
5958 return DiagnoseImpCast(S, E, T, CC,
5959 diag::warn_impcast_string_literal_to_bool);
5960 if (isa<ObjCStringLiteral>(E) || isa<ObjCArrayLiteral>(E) ||
5961 isa<ObjCDictionaryLiteral>(E) || isa<ObjCBoxedExpr>(E)) {
5962 // This covers the literal expressions that evaluate to Objective-C
5964 return DiagnoseImpCast(S, E, T, CC,
5965 diag::warn_impcast_objective_c_literal_to_bool);
5967 if (Source->isPointerType() || Source->canDecayToPointerType()) {
5968 // Warn on pointer to bool conversion that is always true.
5969 S.DiagnoseAlwaysNonNullPointer(E, Expr::NPCK_NotNull, /*IsEqual*/ false,
5974 // Strip vector types.
5975 if (isa<VectorType>(Source)) {
5976 if (!isa<VectorType>(Target)) {
5977 if (S.SourceMgr.isInSystemMacro(CC))
5979 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_vector_scalar);
5982 // If the vector cast is cast between two vectors of the same size, it is
5983 // a bitcast, not a conversion.
5984 if (S.Context.getTypeSize(Source) == S.Context.getTypeSize(Target))
5987 Source = cast<VectorType>(Source)->getElementType().getTypePtr();
5988 Target = cast<VectorType>(Target)->getElementType().getTypePtr();
5990 if (auto VecTy = dyn_cast<VectorType>(Target))
5991 Target = VecTy->getElementType().getTypePtr();
5993 // Strip complex types.
5994 if (isa<ComplexType>(Source)) {
5995 if (!isa<ComplexType>(Target)) {
5996 if (S.SourceMgr.isInSystemMacro(CC))
5999 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_complex_scalar);
6002 Source = cast<ComplexType>(Source)->getElementType().getTypePtr();
6003 Target = cast<ComplexType>(Target)->getElementType().getTypePtr();
6006 const BuiltinType *SourceBT = dyn_cast<BuiltinType>(Source);
6007 const BuiltinType *TargetBT = dyn_cast<BuiltinType>(Target);
6009 // If the source is floating point...
6010 if (SourceBT && SourceBT->isFloatingPoint()) {
6011 // ...and the target is floating point...
6012 if (TargetBT && TargetBT->isFloatingPoint()) {
6013 // ...then warn if we're dropping FP rank.
6015 // Builtin FP kinds are ordered by increasing FP rank.
6016 if (SourceBT->getKind() > TargetBT->getKind()) {
6017 // Don't warn about float constants that are precisely
6018 // representable in the target type.
6019 Expr::EvalResult result;
6020 if (E->EvaluateAsRValue(result, S.Context)) {
6021 // Value might be a float, a float vector, or a float complex.
6022 if (IsSameFloatAfterCast(result.Val,
6023 S.Context.getFloatTypeSemantics(QualType(TargetBT, 0)),
6024 S.Context.getFloatTypeSemantics(QualType(SourceBT, 0))))
6028 if (S.SourceMgr.isInSystemMacro(CC))
6031 DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_float_precision);
6036 // If the target is integral, always warn.
6037 if (TargetBT && TargetBT->isInteger()) {
6038 if (S.SourceMgr.isInSystemMacro(CC))
6041 Expr *InnerE = E->IgnoreParenImpCasts();
6042 // We also want to warn on, e.g., "int i = -1.234"
6043 if (UnaryOperator *UOp = dyn_cast<UnaryOperator>(InnerE))
6044 if (UOp->getOpcode() == UO_Minus || UOp->getOpcode() == UO_Plus)
6045 InnerE = UOp->getSubExpr()->IgnoreParenImpCasts();
6047 if (FloatingLiteral *FL = dyn_cast<FloatingLiteral>(InnerE)) {
6048 DiagnoseFloatingLiteralImpCast(S, FL, T, CC);
6050 DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_float_integer);
6054 // If the target is bool, warn if expr is a function or method call.
6055 if (Target->isSpecificBuiltinType(BuiltinType::Bool) &&
6057 // Check last argument of function call to see if it is an
6058 // implicit cast from a type matching the type the result
6059 // is being cast to.
6060 CallExpr *CEx = cast<CallExpr>(E);
6061 unsigned NumArgs = CEx->getNumArgs();
6063 Expr *LastA = CEx->getArg(NumArgs - 1);
6064 Expr *InnerE = LastA->IgnoreParenImpCasts();
6065 const Type *InnerType =
6066 S.Context.getCanonicalType(InnerE->getType()).getTypePtr();
6067 if (isa<ImplicitCastExpr>(LastA) && (InnerType == Target)) {
6068 // Warn on this floating-point to bool conversion
6069 DiagnoseImpCast(S, E, T, CC,
6070 diag::warn_impcast_floating_point_to_bool);
6077 if ((E->isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull)
6078 == Expr::NPCK_GNUNull) && !Target->isAnyPointerType()
6079 && !Target->isBlockPointerType() && !Target->isMemberPointerType()
6080 && Target->isScalarType() && !Target->isNullPtrType()) {
6081 SourceLocation Loc = E->getSourceRange().getBegin();
6082 if (Loc.isMacroID())
6083 Loc = S.SourceMgr.getImmediateExpansionRange(Loc).first;
6084 if (!Loc.isMacroID() || CC.isMacroID())
6085 S.Diag(Loc, diag::warn_impcast_null_pointer_to_integer)
6086 << T << clang::SourceRange(CC)
6087 << FixItHint::CreateReplacement(Loc,
6088 S.getFixItZeroLiteralForType(T, Loc));
6091 if (!Source->isIntegerType() || !Target->isIntegerType())
6094 // TODO: remove this early return once the false positives for constant->bool
6095 // in templates, macros, etc, are reduced or removed.
6096 if (Target->isSpecificBuiltinType(BuiltinType::Bool))
6099 IntRange SourceRange = GetExprRange(S.Context, E);
6100 IntRange TargetRange = IntRange::forTargetOfCanonicalType(S.Context, Target);
6102 if (SourceRange.Width > TargetRange.Width) {
6103 // If the source is a constant, use a default-on diagnostic.
6104 // TODO: this should happen for bitfield stores, too.
6105 llvm::APSInt Value(32);
6106 if (E->isIntegerConstantExpr(Value, S.Context)) {
6107 if (S.SourceMgr.isInSystemMacro(CC))
6110 std::string PrettySourceValue = Value.toString(10);
6111 std::string PrettyTargetValue = PrettyPrintInRange(Value, TargetRange);
6113 S.DiagRuntimeBehavior(E->getExprLoc(), E,
6114 S.PDiag(diag::warn_impcast_integer_precision_constant)
6115 << PrettySourceValue << PrettyTargetValue
6116 << E->getType() << T << E->getSourceRange()
6117 << clang::SourceRange(CC));
6121 // People want to build with -Wshorten-64-to-32 and not -Wconversion.
6122 if (S.SourceMgr.isInSystemMacro(CC))
6125 if (TargetRange.Width == 32 && S.Context.getIntWidth(E->getType()) == 64)
6126 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_integer_64_32,
6127 /* pruneControlFlow */ true);
6128 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_integer_precision);
6131 if ((TargetRange.NonNegative && !SourceRange.NonNegative) ||
6132 (!TargetRange.NonNegative && SourceRange.NonNegative &&
6133 SourceRange.Width == TargetRange.Width)) {
6135 if (S.SourceMgr.isInSystemMacro(CC))
6138 unsigned DiagID = diag::warn_impcast_integer_sign;
6140 // Traditionally, gcc has warned about this under -Wsign-compare.
6141 // We also want to warn about it in -Wconversion.
6142 // So if -Wconversion is off, use a completely identical diagnostic
6143 // in the sign-compare group.
6144 // The conditional-checking code will
6146 DiagID = diag::warn_impcast_integer_sign_conditional;
6150 return DiagnoseImpCast(S, E, T, CC, DiagID);
6153 // Diagnose conversions between different enumeration types.
6154 // In C, we pretend that the type of an EnumConstantDecl is its enumeration
6155 // type, to give us better diagnostics.
6156 QualType SourceType = E->getType();
6157 if (!S.getLangOpts().CPlusPlus) {
6158 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
6159 if (EnumConstantDecl *ECD = dyn_cast<EnumConstantDecl>(DRE->getDecl())) {
6160 EnumDecl *Enum = cast<EnumDecl>(ECD->getDeclContext());
6161 SourceType = S.Context.getTypeDeclType(Enum);
6162 Source = S.Context.getCanonicalType(SourceType).getTypePtr();
6166 if (const EnumType *SourceEnum = Source->getAs<EnumType>())
6167 if (const EnumType *TargetEnum = Target->getAs<EnumType>())
6168 if (SourceEnum->getDecl()->hasNameForLinkage() &&
6169 TargetEnum->getDecl()->hasNameForLinkage() &&
6170 SourceEnum != TargetEnum) {
6171 if (S.SourceMgr.isInSystemMacro(CC))
6174 return DiagnoseImpCast(S, E, SourceType, T, CC,
6175 diag::warn_impcast_different_enum_types);
6181 void CheckConditionalOperator(Sema &S, ConditionalOperator *E,
6182 SourceLocation CC, QualType T);
6184 void CheckConditionalOperand(Sema &S, Expr *E, QualType T,
6185 SourceLocation CC, bool &ICContext) {
6186 E = E->IgnoreParenImpCasts();
6188 if (isa<ConditionalOperator>(E))
6189 return CheckConditionalOperator(S, cast<ConditionalOperator>(E), CC, T);
6191 AnalyzeImplicitConversions(S, E, CC);
6192 if (E->getType() != T)
6193 return CheckImplicitConversion(S, E, T, CC, &ICContext);
6197 void CheckConditionalOperator(Sema &S, ConditionalOperator *E,
6198 SourceLocation CC, QualType T) {
6199 AnalyzeImplicitConversions(S, E->getCond(), CC);
6201 bool Suspicious = false;
6202 CheckConditionalOperand(S, E->getTrueExpr(), T, CC, Suspicious);
6203 CheckConditionalOperand(S, E->getFalseExpr(), T, CC, Suspicious);
6205 // If -Wconversion would have warned about either of the candidates
6206 // for a signedness conversion to the context type...
6207 if (!Suspicious) return;
6209 // ...but it's currently ignored...
6210 if (!S.Diags.isIgnored(diag::warn_impcast_integer_sign_conditional, CC))
6213 // ...then check whether it would have warned about either of the
6214 // candidates for a signedness conversion to the condition type.
6215 if (E->getType() == T) return;
6218 CheckImplicitConversion(S, E->getTrueExpr()->IgnoreParenImpCasts(),
6219 E->getType(), CC, &Suspicious);
6221 CheckImplicitConversion(S, E->getFalseExpr()->IgnoreParenImpCasts(),
6222 E->getType(), CC, &Suspicious);
6225 /// AnalyzeImplicitConversions - Find and report any interesting
6226 /// implicit conversions in the given expression. There are a couple
6227 /// of competing diagnostics here, -Wconversion and -Wsign-compare.
6228 void AnalyzeImplicitConversions(Sema &S, Expr *OrigE, SourceLocation CC) {
6229 QualType T = OrigE->getType();
6230 Expr *E = OrigE->IgnoreParenImpCasts();
6232 if (E->isTypeDependent() || E->isValueDependent())
6235 // For conditional operators, we analyze the arguments as if they
6236 // were being fed directly into the output.
6237 if (isa<ConditionalOperator>(E)) {
6238 ConditionalOperator *CO = cast<ConditionalOperator>(E);
6239 CheckConditionalOperator(S, CO, CC, T);
6243 // Check implicit argument conversions for function calls.
6244 if (CallExpr *Call = dyn_cast<CallExpr>(E))
6245 CheckImplicitArgumentConversions(S, Call, CC);
6247 // Go ahead and check any implicit conversions we might have skipped.
6248 // The non-canonical typecheck is just an optimization;
6249 // CheckImplicitConversion will filter out dead implicit conversions.
6250 if (E->getType() != T)
6251 CheckImplicitConversion(S, E, T, CC);
6253 // Now continue drilling into this expression.
6255 if (PseudoObjectExpr * POE = dyn_cast<PseudoObjectExpr>(E)) {
6256 if (POE->getResultExpr())
6257 E = POE->getResultExpr();
6260 if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E))
6261 return AnalyzeImplicitConversions(S, OVE->getSourceExpr(), CC);
6263 // Skip past explicit casts.
6264 if (isa<ExplicitCastExpr>(E)) {
6265 E = cast<ExplicitCastExpr>(E)->getSubExpr()->IgnoreParenImpCasts();
6266 return AnalyzeImplicitConversions(S, E, CC);
6269 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
6270 // Do a somewhat different check with comparison operators.
6271 if (BO->isComparisonOp())
6272 return AnalyzeComparison(S, BO);
6274 // And with simple assignments.
6275 if (BO->getOpcode() == BO_Assign)
6276 return AnalyzeAssignment(S, BO);
6279 // These break the otherwise-useful invariant below. Fortunately,
6280 // we don't really need to recurse into them, because any internal
6281 // expressions should have been analyzed already when they were
6282 // built into statements.
6283 if (isa<StmtExpr>(E)) return;
6285 // Don't descend into unevaluated contexts.
6286 if (isa<UnaryExprOrTypeTraitExpr>(E)) return;
6288 // Now just recurse over the expression's children.
6289 CC = E->getExprLoc();
6290 BinaryOperator *BO = dyn_cast<BinaryOperator>(E);
6291 bool IsLogicalAndOperator = BO && BO->getOpcode() == BO_LAnd;
6292 for (Stmt::child_range I = E->children(); I; ++I) {
6293 Expr *ChildExpr = dyn_cast_or_null<Expr>(*I);
6297 if (IsLogicalAndOperator &&
6298 isa<StringLiteral>(ChildExpr->IgnoreParenImpCasts()))
6299 // Ignore checking string literals that are in logical and operators.
6300 // This is a common pattern for asserts.
6302 AnalyzeImplicitConversions(S, ChildExpr, CC);
6306 } // end anonymous namespace
6314 // Helper function for Sema::DiagnoseAlwaysNonNullPointer.
6315 // Returns true when emitting a warning about taking the address of a reference.
6316 static bool CheckForReference(Sema &SemaRef, const Expr *E,
6317 PartialDiagnostic PD) {
6318 E = E->IgnoreParenImpCasts();
6320 const FunctionDecl *FD = nullptr;
6322 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
6323 if (!DRE->getDecl()->getType()->isReferenceType())
6325 } else if (const MemberExpr *M = dyn_cast<MemberExpr>(E)) {
6326 if (!M->getMemberDecl()->getType()->isReferenceType())
6328 } else if (const CallExpr *Call = dyn_cast<CallExpr>(E)) {
6329 if (!Call->getCallReturnType()->isReferenceType())
6331 FD = Call->getDirectCallee();
6336 SemaRef.Diag(E->getExprLoc(), PD);
6338 // If possible, point to location of function.
6340 SemaRef.Diag(FD->getLocation(), diag::note_reference_is_return_value) << FD;
6346 /// \brief Diagnose pointers that are always non-null.
6347 /// \param E the expression containing the pointer
6348 /// \param NullKind NPCK_NotNull if E is a cast to bool, otherwise, E is
6349 /// compared to a null pointer
6350 /// \param IsEqual True when the comparison is equal to a null pointer
6351 /// \param Range Extra SourceRange to highlight in the diagnostic
6352 void Sema::DiagnoseAlwaysNonNullPointer(Expr *E,
6353 Expr::NullPointerConstantKind NullKind,
6354 bool IsEqual, SourceRange Range) {
6358 // Don't warn inside macros.
6359 if (E->getExprLoc().isMacroID())
6361 E = E->IgnoreImpCasts();
6363 const bool IsCompare = NullKind != Expr::NPCK_NotNull;
6365 if (isa<CXXThisExpr>(E)) {
6366 unsigned DiagID = IsCompare ? diag::warn_this_null_compare
6367 : diag::warn_this_bool_conversion;
6368 Diag(E->getExprLoc(), DiagID) << E->getSourceRange() << Range << IsEqual;
6372 bool IsAddressOf = false;
6374 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
6375 if (UO->getOpcode() != UO_AddrOf)
6378 E = UO->getSubExpr();
6382 unsigned DiagID = IsCompare
6383 ? diag::warn_address_of_reference_null_compare
6384 : diag::warn_address_of_reference_bool_conversion;
6385 PartialDiagnostic PD = PDiag(DiagID) << E->getSourceRange() << Range
6387 if (CheckForReference(*this, E, PD)) {
6392 // Expect to find a single Decl. Skip anything more complicated.
6393 ValueDecl *D = nullptr;
6394 if (DeclRefExpr *R = dyn_cast<DeclRefExpr>(E)) {
6396 } else if (MemberExpr *M = dyn_cast<MemberExpr>(E)) {
6397 D = M->getMemberDecl();
6400 // Weak Decls can be null.
6401 if (!D || D->isWeak())
6404 QualType T = D->getType();
6405 const bool IsArray = T->isArrayType();
6406 const bool IsFunction = T->isFunctionType();
6408 // Address of function is used to silence the function warning.
6409 if (IsAddressOf && IsFunction) {
6414 if (!IsAddressOf && !IsFunction && !IsArray)
6417 // Pretty print the expression for the diagnostic.
6419 llvm::raw_string_ostream S(Str);
6420 E->printPretty(S, nullptr, getPrintingPolicy());
6422 unsigned DiagID = IsCompare ? diag::warn_null_pointer_compare
6423 : diag::warn_impcast_pointer_to_bool;
6426 DiagType = AddressOf;
6427 else if (IsFunction)
6428 DiagType = FunctionPointer;
6430 DiagType = ArrayPointer;
6432 llvm_unreachable("Could not determine diagnostic.");
6433 Diag(E->getExprLoc(), DiagID) << DiagType << S.str() << E->getSourceRange()
6434 << Range << IsEqual;
6439 // Suggest '&' to silence the function warning.
6440 Diag(E->getExprLoc(), diag::note_function_warning_silence)
6441 << FixItHint::CreateInsertion(E->getLocStart(), "&");
6443 // Check to see if '()' fixit should be emitted.
6444 QualType ReturnType;
6445 UnresolvedSet<4> NonTemplateOverloads;
6446 tryExprAsCall(*E, ReturnType, NonTemplateOverloads);
6447 if (ReturnType.isNull())
6451 // There are two cases here. If there is null constant, the only suggest
6452 // for a pointer return type. If the null is 0, then suggest if the return
6453 // type is a pointer or an integer type.
6454 if (!ReturnType->isPointerType()) {
6455 if (NullKind == Expr::NPCK_ZeroExpression ||
6456 NullKind == Expr::NPCK_ZeroLiteral) {
6457 if (!ReturnType->isIntegerType())
6463 } else { // !IsCompare
6464 // For function to bool, only suggest if the function pointer has bool
6466 if (!ReturnType->isSpecificBuiltinType(BuiltinType::Bool))
6469 Diag(E->getExprLoc(), diag::note_function_to_function_call)
6470 << FixItHint::CreateInsertion(getLocForEndOfToken(E->getLocEnd()), "()");
6474 /// Diagnoses "dangerous" implicit conversions within the given
6475 /// expression (which is a full expression). Implements -Wconversion
6476 /// and -Wsign-compare.
6478 /// \param CC the "context" location of the implicit conversion, i.e.
6479 /// the most location of the syntactic entity requiring the implicit
6481 void Sema::CheckImplicitConversions(Expr *E, SourceLocation CC) {
6482 // Don't diagnose in unevaluated contexts.
6483 if (isUnevaluatedContext())
6486 // Don't diagnose for value- or type-dependent expressions.
6487 if (E->isTypeDependent() || E->isValueDependent())
6490 // Check for array bounds violations in cases where the check isn't triggered
6491 // elsewhere for other Expr types (like BinaryOperators), e.g. when an
6492 // ArraySubscriptExpr is on the RHS of a variable initialization.
6493 CheckArrayAccess(E);
6495 // This is not the right CC for (e.g.) a variable initialization.
6496 AnalyzeImplicitConversions(*this, E, CC);
6499 /// Diagnose when expression is an integer constant expression and its evaluation
6500 /// results in integer overflow
6501 void Sema::CheckForIntOverflow (Expr *E) {
6502 if (isa<BinaryOperator>(E->IgnoreParens()))
6503 E->EvaluateForOverflow(Context);
6507 /// \brief Visitor for expressions which looks for unsequenced operations on the
6509 class SequenceChecker : public EvaluatedExprVisitor<SequenceChecker> {
6510 typedef EvaluatedExprVisitor<SequenceChecker> Base;
6512 /// \brief A tree of sequenced regions within an expression. Two regions are
6513 /// unsequenced if one is an ancestor or a descendent of the other. When we
6514 /// finish processing an expression with sequencing, such as a comma
6515 /// expression, we fold its tree nodes into its parent, since they are
6516 /// unsequenced with respect to nodes we will visit later.
6517 class SequenceTree {
6519 explicit Value(unsigned Parent) : Parent(Parent), Merged(false) {}
6520 unsigned Parent : 31;
6523 SmallVector<Value, 8> Values;
6526 /// \brief A region within an expression which may be sequenced with respect
6527 /// to some other region.
6529 explicit Seq(unsigned N) : Index(N) {}
6531 friend class SequenceTree;
6536 SequenceTree() { Values.push_back(Value(0)); }
6537 Seq root() const { return Seq(0); }
6539 /// \brief Create a new sequence of operations, which is an unsequenced
6540 /// subset of \p Parent. This sequence of operations is sequenced with
6541 /// respect to other children of \p Parent.
6542 Seq allocate(Seq Parent) {
6543 Values.push_back(Value(Parent.Index));
6544 return Seq(Values.size() - 1);
6547 /// \brief Merge a sequence of operations into its parent.
6549 Values[S.Index].Merged = true;
6552 /// \brief Determine whether two operations are unsequenced. This operation
6553 /// is asymmetric: \p Cur should be the more recent sequence, and \p Old
6554 /// should have been merged into its parent as appropriate.
6555 bool isUnsequenced(Seq Cur, Seq Old) {
6556 unsigned C = representative(Cur.Index);
6557 unsigned Target = representative(Old.Index);
6558 while (C >= Target) {
6561 C = Values[C].Parent;
6567 /// \brief Pick a representative for a sequence.
6568 unsigned representative(unsigned K) {
6569 if (Values[K].Merged)
6570 // Perform path compression as we go.
6571 return Values[K].Parent = representative(Values[K].Parent);
6576 /// An object for which we can track unsequenced uses.
6577 typedef NamedDecl *Object;
6579 /// Different flavors of object usage which we track. We only track the
6580 /// least-sequenced usage of each kind.
6582 /// A read of an object. Multiple unsequenced reads are OK.
6584 /// A modification of an object which is sequenced before the value
6585 /// computation of the expression, such as ++n in C++.
6587 /// A modification of an object which is not sequenced before the value
6588 /// computation of the expression, such as n++.
6591 UK_Count = UK_ModAsSideEffect + 1
6595 Usage() : Use(nullptr), Seq() {}
6597 SequenceTree::Seq Seq;
6601 UsageInfo() : Diagnosed(false) {}
6602 Usage Uses[UK_Count];
6603 /// Have we issued a diagnostic for this variable already?
6606 typedef llvm::SmallDenseMap<Object, UsageInfo, 16> UsageInfoMap;
6609 /// Sequenced regions within the expression.
6611 /// Declaration modifications and references which we have seen.
6612 UsageInfoMap UsageMap;
6613 /// The region we are currently within.
6614 SequenceTree::Seq Region;
6615 /// Filled in with declarations which were modified as a side-effect
6616 /// (that is, post-increment operations).
6617 SmallVectorImpl<std::pair<Object, Usage> > *ModAsSideEffect;
6618 /// Expressions to check later. We defer checking these to reduce
6620 SmallVectorImpl<Expr *> &WorkList;
6622 /// RAII object wrapping the visitation of a sequenced subexpression of an
6623 /// expression. At the end of this process, the side-effects of the evaluation
6624 /// become sequenced with respect to the value computation of the result, so
6625 /// we downgrade any UK_ModAsSideEffect within the evaluation to
6627 struct SequencedSubexpression {
6628 SequencedSubexpression(SequenceChecker &Self)
6629 : Self(Self), OldModAsSideEffect(Self.ModAsSideEffect) {
6630 Self.ModAsSideEffect = &ModAsSideEffect;
6632 ~SequencedSubexpression() {
6633 for (unsigned I = 0, E = ModAsSideEffect.size(); I != E; ++I) {
6634 UsageInfo &U = Self.UsageMap[ModAsSideEffect[I].first];
6635 U.Uses[UK_ModAsSideEffect] = ModAsSideEffect[I].second;
6636 Self.addUsage(U, ModAsSideEffect[I].first,
6637 ModAsSideEffect[I].second.Use, UK_ModAsValue);
6639 Self.ModAsSideEffect = OldModAsSideEffect;
6642 SequenceChecker &Self;
6643 SmallVector<std::pair<Object, Usage>, 4> ModAsSideEffect;
6644 SmallVectorImpl<std::pair<Object, Usage> > *OldModAsSideEffect;
6647 /// RAII object wrapping the visitation of a subexpression which we might
6648 /// choose to evaluate as a constant. If any subexpression is evaluated and
6649 /// found to be non-constant, this allows us to suppress the evaluation of
6650 /// the outer expression.
6651 class EvaluationTracker {
6653 EvaluationTracker(SequenceChecker &Self)
6654 : Self(Self), Prev(Self.EvalTracker), EvalOK(true) {
6655 Self.EvalTracker = this;
6657 ~EvaluationTracker() {
6658 Self.EvalTracker = Prev;
6660 Prev->EvalOK &= EvalOK;
6663 bool evaluate(const Expr *E, bool &Result) {
6664 if (!EvalOK || E->isValueDependent())
6666 EvalOK = E->EvaluateAsBooleanCondition(Result, Self.SemaRef.Context);
6671 SequenceChecker &Self;
6672 EvaluationTracker *Prev;
6676 /// \brief Find the object which is produced by the specified expression,
6678 Object getObject(Expr *E, bool Mod) const {
6679 E = E->IgnoreParenCasts();
6680 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
6681 if (Mod && (UO->getOpcode() == UO_PreInc || UO->getOpcode() == UO_PreDec))
6682 return getObject(UO->getSubExpr(), Mod);
6683 } else if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
6684 if (BO->getOpcode() == BO_Comma)
6685 return getObject(BO->getRHS(), Mod);
6686 if (Mod && BO->isAssignmentOp())
6687 return getObject(BO->getLHS(), Mod);
6688 } else if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
6689 // FIXME: Check for more interesting cases, like "x.n = ++x.n".
6690 if (isa<CXXThisExpr>(ME->getBase()->IgnoreParenCasts()))
6691 return ME->getMemberDecl();
6692 } else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
6693 // FIXME: If this is a reference, map through to its value.
6694 return DRE->getDecl();
6698 /// \brief Note that an object was modified or used by an expression.
6699 void addUsage(UsageInfo &UI, Object O, Expr *Ref, UsageKind UK) {
6700 Usage &U = UI.Uses[UK];
6701 if (!U.Use || !Tree.isUnsequenced(Region, U.Seq)) {
6702 if (UK == UK_ModAsSideEffect && ModAsSideEffect)
6703 ModAsSideEffect->push_back(std::make_pair(O, U));
6708 /// \brief Check whether a modification or use conflicts with a prior usage.
6709 void checkUsage(Object O, UsageInfo &UI, Expr *Ref, UsageKind OtherKind,
6714 const Usage &U = UI.Uses[OtherKind];
6715 if (!U.Use || !Tree.isUnsequenced(Region, U.Seq))
6719 Expr *ModOrUse = Ref;
6720 if (OtherKind == UK_Use)
6721 std::swap(Mod, ModOrUse);
6723 SemaRef.Diag(Mod->getExprLoc(),
6724 IsModMod ? diag::warn_unsequenced_mod_mod
6725 : diag::warn_unsequenced_mod_use)
6726 << O << SourceRange(ModOrUse->getExprLoc());
6727 UI.Diagnosed = true;
6730 void notePreUse(Object O, Expr *Use) {
6731 UsageInfo &U = UsageMap[O];
6732 // Uses conflict with other modifications.
6733 checkUsage(O, U, Use, UK_ModAsValue, false);
6735 void notePostUse(Object O, Expr *Use) {
6736 UsageInfo &U = UsageMap[O];
6737 checkUsage(O, U, Use, UK_ModAsSideEffect, false);
6738 addUsage(U, O, Use, UK_Use);
6741 void notePreMod(Object O, Expr *Mod) {
6742 UsageInfo &U = UsageMap[O];
6743 // Modifications conflict with other modifications and with uses.
6744 checkUsage(O, U, Mod, UK_ModAsValue, true);
6745 checkUsage(O, U, Mod, UK_Use, false);
6747 void notePostMod(Object O, Expr *Use, UsageKind UK) {
6748 UsageInfo &U = UsageMap[O];
6749 checkUsage(O, U, Use, UK_ModAsSideEffect, true);
6750 addUsage(U, O, Use, UK);
6754 SequenceChecker(Sema &S, Expr *E, SmallVectorImpl<Expr *> &WorkList)
6755 : Base(S.Context), SemaRef(S), Region(Tree.root()),
6756 ModAsSideEffect(nullptr), WorkList(WorkList), EvalTracker(nullptr) {
6760 void VisitStmt(Stmt *S) {
6761 // Skip all statements which aren't expressions for now.
6764 void VisitExpr(Expr *E) {
6765 // By default, just recurse to evaluated subexpressions.
6769 void VisitCastExpr(CastExpr *E) {
6770 Object O = Object();
6771 if (E->getCastKind() == CK_LValueToRValue)
6772 O = getObject(E->getSubExpr(), false);
6781 void VisitBinComma(BinaryOperator *BO) {
6782 // C++11 [expr.comma]p1:
6783 // Every value computation and side effect associated with the left
6784 // expression is sequenced before every value computation and side
6785 // effect associated with the right expression.
6786 SequenceTree::Seq LHS = Tree.allocate(Region);
6787 SequenceTree::Seq RHS = Tree.allocate(Region);
6788 SequenceTree::Seq OldRegion = Region;
6791 SequencedSubexpression SeqLHS(*this);
6793 Visit(BO->getLHS());
6797 Visit(BO->getRHS());
6801 // Forget that LHS and RHS are sequenced. They are both unsequenced
6802 // with respect to other stuff.
6807 void VisitBinAssign(BinaryOperator *BO) {
6808 // The modification is sequenced after the value computation of the LHS
6809 // and RHS, so check it before inspecting the operands and update the
6811 Object O = getObject(BO->getLHS(), true);
6813 return VisitExpr(BO);
6817 // C++11 [expr.ass]p7:
6818 // E1 op= E2 is equivalent to E1 = E1 op E2, except that E1 is evaluated
6821 // Therefore, for a compound assignment operator, O is considered used
6822 // everywhere except within the evaluation of E1 itself.
6823 if (isa<CompoundAssignOperator>(BO))
6826 Visit(BO->getLHS());
6828 if (isa<CompoundAssignOperator>(BO))
6831 Visit(BO->getRHS());
6833 // C++11 [expr.ass]p1:
6834 // the assignment is sequenced [...] before the value computation of the
6835 // assignment expression.
6836 // C11 6.5.16/3 has no such rule.
6837 notePostMod(O, BO, SemaRef.getLangOpts().CPlusPlus ? UK_ModAsValue
6838 : UK_ModAsSideEffect);
6840 void VisitCompoundAssignOperator(CompoundAssignOperator *CAO) {
6841 VisitBinAssign(CAO);
6844 void VisitUnaryPreInc(UnaryOperator *UO) { VisitUnaryPreIncDec(UO); }
6845 void VisitUnaryPreDec(UnaryOperator *UO) { VisitUnaryPreIncDec(UO); }
6846 void VisitUnaryPreIncDec(UnaryOperator *UO) {
6847 Object O = getObject(UO->getSubExpr(), true);
6849 return VisitExpr(UO);
6852 Visit(UO->getSubExpr());
6853 // C++11 [expr.pre.incr]p1:
6854 // the expression ++x is equivalent to x+=1
6855 notePostMod(O, UO, SemaRef.getLangOpts().CPlusPlus ? UK_ModAsValue
6856 : UK_ModAsSideEffect);
6859 void VisitUnaryPostInc(UnaryOperator *UO) { VisitUnaryPostIncDec(UO); }
6860 void VisitUnaryPostDec(UnaryOperator *UO) { VisitUnaryPostIncDec(UO); }
6861 void VisitUnaryPostIncDec(UnaryOperator *UO) {
6862 Object O = getObject(UO->getSubExpr(), true);
6864 return VisitExpr(UO);
6867 Visit(UO->getSubExpr());
6868 notePostMod(O, UO, UK_ModAsSideEffect);
6871 /// Don't visit the RHS of '&&' or '||' if it might not be evaluated.
6872 void VisitBinLOr(BinaryOperator *BO) {
6873 // The side-effects of the LHS of an '&&' are sequenced before the
6874 // value computation of the RHS, and hence before the value computation
6875 // of the '&&' itself, unless the LHS evaluates to zero. We treat them
6876 // as if they were unconditionally sequenced.
6877 EvaluationTracker Eval(*this);
6879 SequencedSubexpression Sequenced(*this);
6880 Visit(BO->getLHS());
6884 if (Eval.evaluate(BO->getLHS(), Result)) {
6886 Visit(BO->getRHS());
6888 // Check for unsequenced operations in the RHS, treating it as an
6889 // entirely separate evaluation.
6891 // FIXME: If there are operations in the RHS which are unsequenced
6892 // with respect to operations outside the RHS, and those operations
6893 // are unconditionally evaluated, diagnose them.
6894 WorkList.push_back(BO->getRHS());
6897 void VisitBinLAnd(BinaryOperator *BO) {
6898 EvaluationTracker Eval(*this);
6900 SequencedSubexpression Sequenced(*this);
6901 Visit(BO->getLHS());
6905 if (Eval.evaluate(BO->getLHS(), Result)) {
6907 Visit(BO->getRHS());
6909 WorkList.push_back(BO->getRHS());
6913 // Only visit the condition, unless we can be sure which subexpression will
6915 void VisitAbstractConditionalOperator(AbstractConditionalOperator *CO) {
6916 EvaluationTracker Eval(*this);
6918 SequencedSubexpression Sequenced(*this);
6919 Visit(CO->getCond());
6923 if (Eval.evaluate(CO->getCond(), Result))
6924 Visit(Result ? CO->getTrueExpr() : CO->getFalseExpr());
6926 WorkList.push_back(CO->getTrueExpr());
6927 WorkList.push_back(CO->getFalseExpr());
6931 void VisitCallExpr(CallExpr *CE) {
6932 // C++11 [intro.execution]p15:
6933 // When calling a function [...], every value computation and side effect
6934 // associated with any argument expression, or with the postfix expression
6935 // designating the called function, is sequenced before execution of every
6936 // expression or statement in the body of the function [and thus before
6937 // the value computation of its result].
6938 SequencedSubexpression Sequenced(*this);
6939 Base::VisitCallExpr(CE);
6941 // FIXME: CXXNewExpr and CXXDeleteExpr implicitly call functions.
6944 void VisitCXXConstructExpr(CXXConstructExpr *CCE) {
6945 // This is a call, so all subexpressions are sequenced before the result.
6946 SequencedSubexpression Sequenced(*this);
6948 if (!CCE->isListInitialization())
6949 return VisitExpr(CCE);
6951 // In C++11, list initializations are sequenced.
6952 SmallVector<SequenceTree::Seq, 32> Elts;
6953 SequenceTree::Seq Parent = Region;
6954 for (CXXConstructExpr::arg_iterator I = CCE->arg_begin(),
6957 Region = Tree.allocate(Parent);
6958 Elts.push_back(Region);
6962 // Forget that the initializers are sequenced.
6964 for (unsigned I = 0; I < Elts.size(); ++I)
6965 Tree.merge(Elts[I]);
6968 void VisitInitListExpr(InitListExpr *ILE) {
6969 if (!SemaRef.getLangOpts().CPlusPlus11)
6970 return VisitExpr(ILE);
6972 // In C++11, list initializations are sequenced.
6973 SmallVector<SequenceTree::Seq, 32> Elts;
6974 SequenceTree::Seq Parent = Region;
6975 for (unsigned I = 0; I < ILE->getNumInits(); ++I) {
6976 Expr *E = ILE->getInit(I);
6978 Region = Tree.allocate(Parent);
6979 Elts.push_back(Region);
6983 // Forget that the initializers are sequenced.
6985 for (unsigned I = 0; I < Elts.size(); ++I)
6986 Tree.merge(Elts[I]);
6991 void Sema::CheckUnsequencedOperations(Expr *E) {
6992 SmallVector<Expr *, 8> WorkList;
6993 WorkList.push_back(E);
6994 while (!WorkList.empty()) {
6995 Expr *Item = WorkList.pop_back_val();
6996 SequenceChecker(*this, Item, WorkList);
7000 void Sema::CheckCompletedExpr(Expr *E, SourceLocation CheckLoc,
7002 CheckImplicitConversions(E, CheckLoc);
7003 CheckUnsequencedOperations(E);
7004 if (!IsConstexpr && !E->isValueDependent())
7005 CheckForIntOverflow(E);
7008 void Sema::CheckBitFieldInitialization(SourceLocation InitLoc,
7009 FieldDecl *BitField,
7011 (void) AnalyzeBitFieldAssignment(*this, BitField, Init, InitLoc);
7014 /// CheckParmsForFunctionDef - Check that the parameters of the given
7015 /// function are appropriate for the definition of a function. This
7016 /// takes care of any checks that cannot be performed on the
7017 /// declaration itself, e.g., that the types of each of the function
7018 /// parameters are complete.
7019 bool Sema::CheckParmsForFunctionDef(ParmVarDecl *const *P,
7020 ParmVarDecl *const *PEnd,
7021 bool CheckParameterNames) {
7022 bool HasInvalidParm = false;
7023 for (; P != PEnd; ++P) {
7024 ParmVarDecl *Param = *P;
7026 // C99 6.7.5.3p4: the parameters in a parameter type list in a
7027 // function declarator that is part of a function definition of
7028 // that function shall not have incomplete type.
7030 // This is also C++ [dcl.fct]p6.
7031 if (!Param->isInvalidDecl() &&
7032 RequireCompleteType(Param->getLocation(), Param->getType(),
7033 diag::err_typecheck_decl_incomplete_type)) {
7034 Param->setInvalidDecl();
7035 HasInvalidParm = true;
7038 // C99 6.9.1p5: If the declarator includes a parameter type list, the
7039 // declaration of each parameter shall include an identifier.
7040 if (CheckParameterNames &&
7041 Param->getIdentifier() == nullptr &&
7042 !Param->isImplicit() &&
7043 !getLangOpts().CPlusPlus)
7044 Diag(Param->getLocation(), diag::err_parameter_name_omitted);
7047 // If the function declarator is not part of a definition of that
7048 // function, parameters may have incomplete type and may use the [*]
7049 // notation in their sequences of declarator specifiers to specify
7050 // variable length array types.
7051 QualType PType = Param->getOriginalType();
7052 while (const ArrayType *AT = Context.getAsArrayType(PType)) {
7053 if (AT->getSizeModifier() == ArrayType::Star) {
7054 // FIXME: This diagnostic should point the '[*]' if source-location
7055 // information is added for it.
7056 Diag(Param->getLocation(), diag::err_array_star_in_function_definition);
7059 PType= AT->getElementType();
7062 // MSVC destroys objects passed by value in the callee. Therefore a
7063 // function definition which takes such a parameter must be able to call the
7064 // object's destructor. However, we don't perform any direct access check
7066 if (getLangOpts().CPlusPlus && Context.getTargetInfo()
7068 .areArgsDestroyedLeftToRightInCallee()) {
7069 if (!Param->isInvalidDecl()) {
7070 if (const RecordType *RT = Param->getType()->getAs<RecordType>()) {
7071 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
7072 if (!ClassDecl->isInvalidDecl() &&
7073 !ClassDecl->hasIrrelevantDestructor() &&
7074 !ClassDecl->isDependentContext()) {
7075 CXXDestructorDecl *Destructor = LookupDestructor(ClassDecl);
7076 MarkFunctionReferenced(Param->getLocation(), Destructor);
7077 DiagnoseUseOfDecl(Destructor, Param->getLocation());
7084 return HasInvalidParm;
7087 /// CheckCastAlign - Implements -Wcast-align, which warns when a
7088 /// pointer cast increases the alignment requirements.
7089 void Sema::CheckCastAlign(Expr *Op, QualType T, SourceRange TRange) {
7090 // This is actually a lot of work to potentially be doing on every
7091 // cast; don't do it if we're ignoring -Wcast_align (as is the default).
7092 if (getDiagnostics().isIgnored(diag::warn_cast_align, TRange.getBegin()))
7095 // Ignore dependent types.
7096 if (T->isDependentType() || Op->getType()->isDependentType())
7099 // Require that the destination be a pointer type.
7100 const PointerType *DestPtr = T->getAs<PointerType>();
7101 if (!DestPtr) return;
7103 // If the destination has alignment 1, we're done.
7104 QualType DestPointee = DestPtr->getPointeeType();
7105 if (DestPointee->isIncompleteType()) return;
7106 CharUnits DestAlign = Context.getTypeAlignInChars(DestPointee);
7107 if (DestAlign.isOne()) return;
7109 // Require that the source be a pointer type.
7110 const PointerType *SrcPtr = Op->getType()->getAs<PointerType>();
7111 if (!SrcPtr) return;
7112 QualType SrcPointee = SrcPtr->getPointeeType();
7114 // Whitelist casts from cv void*. We already implicitly
7115 // whitelisted casts to cv void*, since they have alignment 1.
7116 // Also whitelist casts involving incomplete types, which implicitly
7118 if (SrcPointee->isIncompleteType()) return;
7120 CharUnits SrcAlign = Context.getTypeAlignInChars(SrcPointee);
7121 if (SrcAlign >= DestAlign) return;
7123 Diag(TRange.getBegin(), diag::warn_cast_align)
7124 << Op->getType() << T
7125 << static_cast<unsigned>(SrcAlign.getQuantity())
7126 << static_cast<unsigned>(DestAlign.getQuantity())
7127 << TRange << Op->getSourceRange();
7130 static const Type* getElementType(const Expr *BaseExpr) {
7131 const Type* EltType = BaseExpr->getType().getTypePtr();
7132 if (EltType->isAnyPointerType())
7133 return EltType->getPointeeType().getTypePtr();
7134 else if (EltType->isArrayType())
7135 return EltType->getBaseElementTypeUnsafe();
7139 /// \brief Check whether this array fits the idiom of a size-one tail padded
7140 /// array member of a struct.
7142 /// We avoid emitting out-of-bounds access warnings for such arrays as they are
7143 /// commonly used to emulate flexible arrays in C89 code.
7144 static bool IsTailPaddedMemberArray(Sema &S, llvm::APInt Size,
7145 const NamedDecl *ND) {
7146 if (Size != 1 || !ND) return false;
7148 const FieldDecl *FD = dyn_cast<FieldDecl>(ND);
7149 if (!FD) return false;
7151 // Don't consider sizes resulting from macro expansions or template argument
7152 // substitution to form C89 tail-padded arrays.
7154 TypeSourceInfo *TInfo = FD->getTypeSourceInfo();
7156 TypeLoc TL = TInfo->getTypeLoc();
7157 // Look through typedefs.
7158 if (TypedefTypeLoc TTL = TL.getAs<TypedefTypeLoc>()) {
7159 const TypedefNameDecl *TDL = TTL.getTypedefNameDecl();
7160 TInfo = TDL->getTypeSourceInfo();
7163 if (ConstantArrayTypeLoc CTL = TL.getAs<ConstantArrayTypeLoc>()) {
7164 const Expr *SizeExpr = dyn_cast<IntegerLiteral>(CTL.getSizeExpr());
7165 if (!SizeExpr || SizeExpr->getExprLoc().isMacroID())
7171 const RecordDecl *RD = dyn_cast<RecordDecl>(FD->getDeclContext());
7172 if (!RD) return false;
7173 if (RD->isUnion()) return false;
7174 if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) {
7175 if (!CRD->isStandardLayout()) return false;
7178 // See if this is the last field decl in the record.
7180 while ((D = D->getNextDeclInContext()))
7181 if (isa<FieldDecl>(D))
7186 void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
7187 const ArraySubscriptExpr *ASE,
7188 bool AllowOnePastEnd, bool IndexNegated) {
7189 IndexExpr = IndexExpr->IgnoreParenImpCasts();
7190 if (IndexExpr->isValueDependent())
7193 const Type *EffectiveType = getElementType(BaseExpr);
7194 BaseExpr = BaseExpr->IgnoreParenCasts();
7195 const ConstantArrayType *ArrayTy =
7196 Context.getAsConstantArrayType(BaseExpr->getType());
7201 if (!IndexExpr->EvaluateAsInt(index, Context))
7206 const NamedDecl *ND = nullptr;
7207 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(BaseExpr))
7208 ND = dyn_cast<NamedDecl>(DRE->getDecl());
7209 if (const MemberExpr *ME = dyn_cast<MemberExpr>(BaseExpr))
7210 ND = dyn_cast<NamedDecl>(ME->getMemberDecl());
7212 if (index.isUnsigned() || !index.isNegative()) {
7213 llvm::APInt size = ArrayTy->getSize();
7214 if (!size.isStrictlyPositive())
7217 const Type* BaseType = getElementType(BaseExpr);
7218 if (BaseType != EffectiveType) {
7219 // Make sure we're comparing apples to apples when comparing index to size
7220 uint64_t ptrarith_typesize = Context.getTypeSize(EffectiveType);
7221 uint64_t array_typesize = Context.getTypeSize(BaseType);
7222 // Handle ptrarith_typesize being zero, such as when casting to void*
7223 if (!ptrarith_typesize) ptrarith_typesize = 1;
7224 if (ptrarith_typesize != array_typesize) {
7225 // There's a cast to a different size type involved
7226 uint64_t ratio = array_typesize / ptrarith_typesize;
7227 // TODO: Be smarter about handling cases where array_typesize is not a
7228 // multiple of ptrarith_typesize
7229 if (ptrarith_typesize * ratio == array_typesize)
7230 size *= llvm::APInt(size.getBitWidth(), ratio);
7234 if (size.getBitWidth() > index.getBitWidth())
7235 index = index.zext(size.getBitWidth());
7236 else if (size.getBitWidth() < index.getBitWidth())
7237 size = size.zext(index.getBitWidth());
7239 // For array subscripting the index must be less than size, but for pointer
7240 // arithmetic also allow the index (offset) to be equal to size since
7241 // computing the next address after the end of the array is legal and
7242 // commonly done e.g. in C++ iterators and range-based for loops.
7243 if (AllowOnePastEnd ? index.ule(size) : index.ult(size))
7246 // Also don't warn for arrays of size 1 which are members of some
7247 // structure. These are often used to approximate flexible arrays in C89
7249 if (IsTailPaddedMemberArray(*this, size, ND))
7252 // Suppress the warning if the subscript expression (as identified by the
7253 // ']' location) and the index expression are both from macro expansions
7254 // within a system header.
7256 SourceLocation RBracketLoc = SourceMgr.getSpellingLoc(
7257 ASE->getRBracketLoc());
7258 if (SourceMgr.isInSystemHeader(RBracketLoc)) {
7259 SourceLocation IndexLoc = SourceMgr.getSpellingLoc(
7260 IndexExpr->getLocStart());
7261 if (SourceMgr.isWrittenInSameFile(RBracketLoc, IndexLoc))
7266 unsigned DiagID = diag::warn_ptr_arith_exceeds_bounds;
7268 DiagID = diag::warn_array_index_exceeds_bounds;
7270 DiagRuntimeBehavior(BaseExpr->getLocStart(), BaseExpr,
7271 PDiag(DiagID) << index.toString(10, true)
7272 << size.toString(10, true)
7273 << (unsigned)size.getLimitedValue(~0U)
7274 << IndexExpr->getSourceRange());
7276 unsigned DiagID = diag::warn_array_index_precedes_bounds;
7278 DiagID = diag::warn_ptr_arith_precedes_bounds;
7279 if (index.isNegative()) index = -index;
7282 DiagRuntimeBehavior(BaseExpr->getLocStart(), BaseExpr,
7283 PDiag(DiagID) << index.toString(10, true)
7284 << IndexExpr->getSourceRange());
7288 // Try harder to find a NamedDecl to point at in the note.
7289 while (const ArraySubscriptExpr *ASE =
7290 dyn_cast<ArraySubscriptExpr>(BaseExpr))
7291 BaseExpr = ASE->getBase()->IgnoreParenCasts();
7292 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(BaseExpr))
7293 ND = dyn_cast<NamedDecl>(DRE->getDecl());
7294 if (const MemberExpr *ME = dyn_cast<MemberExpr>(BaseExpr))
7295 ND = dyn_cast<NamedDecl>(ME->getMemberDecl());
7299 DiagRuntimeBehavior(ND->getLocStart(), BaseExpr,
7300 PDiag(diag::note_array_index_out_of_bounds)
7301 << ND->getDeclName());
7304 void Sema::CheckArrayAccess(const Expr *expr) {
7305 int AllowOnePastEnd = 0;
7307 expr = expr->IgnoreParenImpCasts();
7308 switch (expr->getStmtClass()) {
7309 case Stmt::ArraySubscriptExprClass: {
7310 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(expr);
7311 CheckArrayAccess(ASE->getBase(), ASE->getIdx(), ASE,
7312 AllowOnePastEnd > 0);
7315 case Stmt::UnaryOperatorClass: {
7316 // Only unwrap the * and & unary operators
7317 const UnaryOperator *UO = cast<UnaryOperator>(expr);
7318 expr = UO->getSubExpr();
7319 switch (UO->getOpcode()) {
7331 case Stmt::ConditionalOperatorClass: {
7332 const ConditionalOperator *cond = cast<ConditionalOperator>(expr);
7333 if (const Expr *lhs = cond->getLHS())
7334 CheckArrayAccess(lhs);
7335 if (const Expr *rhs = cond->getRHS())
7336 CheckArrayAccess(rhs);
7345 //===--- CHECK: Objective-C retain cycles ----------------------------------//
7348 struct RetainCycleOwner {
7349 RetainCycleOwner() : Variable(nullptr), Indirect(false) {}
7355 void setLocsFrom(Expr *e) {
7356 Loc = e->getExprLoc();
7357 Range = e->getSourceRange();
7362 /// Consider whether capturing the given variable can possibly lead to
7364 static bool considerVariable(VarDecl *var, Expr *ref, RetainCycleOwner &owner) {
7365 // In ARC, it's captured strongly iff the variable has __strong
7366 // lifetime. In MRR, it's captured strongly if the variable is
7367 // __block and has an appropriate type.
7368 if (var->getType().getObjCLifetime() != Qualifiers::OCL_Strong)
7371 owner.Variable = var;
7373 owner.setLocsFrom(ref);
7377 static bool findRetainCycleOwner(Sema &S, Expr *e, RetainCycleOwner &owner) {
7379 e = e->IgnoreParens();
7380 if (CastExpr *cast = dyn_cast<CastExpr>(e)) {
7381 switch (cast->getCastKind()) {
7383 case CK_LValueBitCast:
7384 case CK_LValueToRValue:
7385 case CK_ARCReclaimReturnedObject:
7386 e = cast->getSubExpr();
7394 if (ObjCIvarRefExpr *ref = dyn_cast<ObjCIvarRefExpr>(e)) {
7395 ObjCIvarDecl *ivar = ref->getDecl();
7396 if (ivar->getType().getObjCLifetime() != Qualifiers::OCL_Strong)
7399 // Try to find a retain cycle in the base.
7400 if (!findRetainCycleOwner(S, ref->getBase(), owner))
7403 if (ref->isFreeIvar()) owner.setLocsFrom(ref);
7404 owner.Indirect = true;
7408 if (DeclRefExpr *ref = dyn_cast<DeclRefExpr>(e)) {
7409 VarDecl *var = dyn_cast<VarDecl>(ref->getDecl());
7410 if (!var) return false;
7411 return considerVariable(var, ref, owner);
7414 if (MemberExpr *member = dyn_cast<MemberExpr>(e)) {
7415 if (member->isArrow()) return false;
7417 // Don't count this as an indirect ownership.
7418 e = member->getBase();
7422 if (PseudoObjectExpr *pseudo = dyn_cast<PseudoObjectExpr>(e)) {
7423 // Only pay attention to pseudo-objects on property references.
7424 ObjCPropertyRefExpr *pre
7425 = dyn_cast<ObjCPropertyRefExpr>(pseudo->getSyntacticForm()
7427 if (!pre) return false;
7428 if (pre->isImplicitProperty()) return false;
7429 ObjCPropertyDecl *property = pre->getExplicitProperty();
7430 if (!property->isRetaining() &&
7431 !(property->getPropertyIvarDecl() &&
7432 property->getPropertyIvarDecl()->getType()
7433 .getObjCLifetime() == Qualifiers::OCL_Strong))
7436 owner.Indirect = true;
7437 if (pre->isSuperReceiver()) {
7438 owner.Variable = S.getCurMethodDecl()->getSelfDecl();
7439 if (!owner.Variable)
7441 owner.Loc = pre->getLocation();
7442 owner.Range = pre->getSourceRange();
7445 e = const_cast<Expr*>(cast<OpaqueValueExpr>(pre->getBase())
7457 struct FindCaptureVisitor : EvaluatedExprVisitor<FindCaptureVisitor> {
7458 FindCaptureVisitor(ASTContext &Context, VarDecl *variable)
7459 : EvaluatedExprVisitor<FindCaptureVisitor>(Context),
7460 Context(Context), Variable(variable), Capturer(nullptr),
7461 VarWillBeReased(false) {}
7462 ASTContext &Context;
7465 bool VarWillBeReased;
7467 void VisitDeclRefExpr(DeclRefExpr *ref) {
7468 if (ref->getDecl() == Variable && !Capturer)
7472 void VisitObjCIvarRefExpr(ObjCIvarRefExpr *ref) {
7473 if (Capturer) return;
7474 Visit(ref->getBase());
7475 if (Capturer && ref->isFreeIvar())
7479 void VisitBlockExpr(BlockExpr *block) {
7480 // Look inside nested blocks
7481 if (block->getBlockDecl()->capturesVariable(Variable))
7482 Visit(block->getBlockDecl()->getBody());
7485 void VisitOpaqueValueExpr(OpaqueValueExpr *OVE) {
7486 if (Capturer) return;
7487 if (OVE->getSourceExpr())
7488 Visit(OVE->getSourceExpr());
7490 void VisitBinaryOperator(BinaryOperator *BinOp) {
7491 if (!Variable || VarWillBeReased || BinOp->getOpcode() != BO_Assign)
7493 Expr *LHS = BinOp->getLHS();
7494 if (const DeclRefExpr *DRE = dyn_cast_or_null<DeclRefExpr>(LHS)) {
7495 if (DRE->getDecl() != Variable)
7497 if (Expr *RHS = BinOp->getRHS()) {
7498 RHS = RHS->IgnoreParenCasts();
7501 (RHS && RHS->isIntegerConstantExpr(Value, Context) && Value == 0);
7508 /// Check whether the given argument is a block which captures a
7510 static Expr *findCapturingExpr(Sema &S, Expr *e, RetainCycleOwner &owner) {
7511 assert(owner.Variable && owner.Loc.isValid());
7513 e = e->IgnoreParenCasts();
7515 // Look through [^{...} copy] and Block_copy(^{...}).
7516 if (ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(e)) {
7517 Selector Cmd = ME->getSelector();
7518 if (Cmd.isUnarySelector() && Cmd.getNameForSlot(0) == "copy") {
7519 e = ME->getInstanceReceiver();
7522 e = e->IgnoreParenCasts();
7524 } else if (CallExpr *CE = dyn_cast<CallExpr>(e)) {
7525 if (CE->getNumArgs() == 1) {
7526 FunctionDecl *Fn = dyn_cast_or_null<FunctionDecl>(CE->getCalleeDecl());
7528 const IdentifierInfo *FnI = Fn->getIdentifier();
7529 if (FnI && FnI->isStr("_Block_copy")) {
7530 e = CE->getArg(0)->IgnoreParenCasts();
7536 BlockExpr *block = dyn_cast<BlockExpr>(e);
7537 if (!block || !block->getBlockDecl()->capturesVariable(owner.Variable))
7540 FindCaptureVisitor visitor(S.Context, owner.Variable);
7541 visitor.Visit(block->getBlockDecl()->getBody());
7542 return visitor.VarWillBeReased ? nullptr : visitor.Capturer;
7545 static void diagnoseRetainCycle(Sema &S, Expr *capturer,
7546 RetainCycleOwner &owner) {
7548 assert(owner.Variable && owner.Loc.isValid());
7550 S.Diag(capturer->getExprLoc(), diag::warn_arc_retain_cycle)
7551 << owner.Variable << capturer->getSourceRange();
7552 S.Diag(owner.Loc, diag::note_arc_retain_cycle_owner)
7553 << owner.Indirect << owner.Range;
7556 /// Check for a keyword selector that starts with the word 'add' or
7558 static bool isSetterLikeSelector(Selector sel) {
7559 if (sel.isUnarySelector()) return false;
7561 StringRef str = sel.getNameForSlot(0);
7562 while (!str.empty() && str.front() == '_') str = str.substr(1);
7563 if (str.startswith("set"))
7564 str = str.substr(3);
7565 else if (str.startswith("add")) {
7566 // Specially whitelist 'addOperationWithBlock:'.
7567 if (sel.getNumArgs() == 1 && str.startswith("addOperationWithBlock"))
7569 str = str.substr(3);
7574 if (str.empty()) return true;
7575 return !isLowercase(str.front());
7578 /// Check a message send to see if it's likely to cause a retain cycle.
7579 void Sema::checkRetainCycles(ObjCMessageExpr *msg) {
7580 // Only check instance methods whose selector looks like a setter.
7581 if (!msg->isInstanceMessage() || !isSetterLikeSelector(msg->getSelector()))
7584 // Try to find a variable that the receiver is strongly owned by.
7585 RetainCycleOwner owner;
7586 if (msg->getReceiverKind() == ObjCMessageExpr::Instance) {
7587 if (!findRetainCycleOwner(*this, msg->getInstanceReceiver(), owner))
7590 assert(msg->getReceiverKind() == ObjCMessageExpr::SuperInstance);
7591 owner.Variable = getCurMethodDecl()->getSelfDecl();
7592 owner.Loc = msg->getSuperLoc();
7593 owner.Range = msg->getSuperLoc();
7596 // Check whether the receiver is captured by any of the arguments.
7597 for (unsigned i = 0, e = msg->getNumArgs(); i != e; ++i)
7598 if (Expr *capturer = findCapturingExpr(*this, msg->getArg(i), owner))
7599 return diagnoseRetainCycle(*this, capturer, owner);
7602 /// Check a property assign to see if it's likely to cause a retain cycle.
7603 void Sema::checkRetainCycles(Expr *receiver, Expr *argument) {
7604 RetainCycleOwner owner;
7605 if (!findRetainCycleOwner(*this, receiver, owner))
7608 if (Expr *capturer = findCapturingExpr(*this, argument, owner))
7609 diagnoseRetainCycle(*this, capturer, owner);
7612 void Sema::checkRetainCycles(VarDecl *Var, Expr *Init) {
7613 RetainCycleOwner Owner;
7614 if (!considerVariable(Var, /*DeclRefExpr=*/nullptr, Owner))
7617 // Because we don't have an expression for the variable, we have to set the
7618 // location explicitly here.
7619 Owner.Loc = Var->getLocation();
7620 Owner.Range = Var->getSourceRange();
7622 if (Expr *Capturer = findCapturingExpr(*this, Init, Owner))
7623 diagnoseRetainCycle(*this, Capturer, Owner);
7626 static bool checkUnsafeAssignLiteral(Sema &S, SourceLocation Loc,
7627 Expr *RHS, bool isProperty) {
7628 // Check if RHS is an Objective-C object literal, which also can get
7629 // immediately zapped in a weak reference. Note that we explicitly
7630 // allow ObjCStringLiterals, since those are designed to never really die.
7631 RHS = RHS->IgnoreParenImpCasts();
7633 // This enum needs to match with the 'select' in
7634 // warn_objc_arc_literal_assign (off-by-1).
7635 Sema::ObjCLiteralKind Kind = S.CheckLiteralKind(RHS);
7636 if (Kind == Sema::LK_String || Kind == Sema::LK_None)
7639 S.Diag(Loc, diag::warn_arc_literal_assign)
7641 << (isProperty ? 0 : 1)
7642 << RHS->getSourceRange();
7647 static bool checkUnsafeAssignObject(Sema &S, SourceLocation Loc,
7648 Qualifiers::ObjCLifetime LT,
7649 Expr *RHS, bool isProperty) {
7650 // Strip off any implicit cast added to get to the one ARC-specific.
7651 while (ImplicitCastExpr *cast = dyn_cast<ImplicitCastExpr>(RHS)) {
7652 if (cast->getCastKind() == CK_ARCConsumeObject) {
7653 S.Diag(Loc, diag::warn_arc_retained_assign)
7654 << (LT == Qualifiers::OCL_ExplicitNone)
7655 << (isProperty ? 0 : 1)
7656 << RHS->getSourceRange();
7659 RHS = cast->getSubExpr();
7662 if (LT == Qualifiers::OCL_Weak &&
7663 checkUnsafeAssignLiteral(S, Loc, RHS, isProperty))
7669 bool Sema::checkUnsafeAssigns(SourceLocation Loc,
7670 QualType LHS, Expr *RHS) {
7671 Qualifiers::ObjCLifetime LT = LHS.getObjCLifetime();
7673 if (LT != Qualifiers::OCL_Weak && LT != Qualifiers::OCL_ExplicitNone)
7676 if (checkUnsafeAssignObject(*this, Loc, LT, RHS, false))
7682 void Sema::checkUnsafeExprAssigns(SourceLocation Loc,
7683 Expr *LHS, Expr *RHS) {
7685 // PropertyRef on LHS type need be directly obtained from
7686 // its declaration as it has a PseudoType.
7687 ObjCPropertyRefExpr *PRE
7688 = dyn_cast<ObjCPropertyRefExpr>(LHS->IgnoreParens());
7689 if (PRE && !PRE->isImplicitProperty()) {
7690 const ObjCPropertyDecl *PD = PRE->getExplicitProperty();
7692 LHSType = PD->getType();
7695 if (LHSType.isNull())
7696 LHSType = LHS->getType();
7698 Qualifiers::ObjCLifetime LT = LHSType.getObjCLifetime();
7700 if (LT == Qualifiers::OCL_Weak) {
7701 if (!Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, Loc))
7702 getCurFunction()->markSafeWeakUse(LHS);
7705 if (checkUnsafeAssigns(Loc, LHSType, RHS))
7708 // FIXME. Check for other life times.
7709 if (LT != Qualifiers::OCL_None)
7713 if (PRE->isImplicitProperty())
7715 const ObjCPropertyDecl *PD = PRE->getExplicitProperty();
7719 unsigned Attributes = PD->getPropertyAttributes();
7720 if (Attributes & ObjCPropertyDecl::OBJC_PR_assign) {
7721 // when 'assign' attribute was not explicitly specified
7722 // by user, ignore it and rely on property type itself
7723 // for lifetime info.
7724 unsigned AsWrittenAttr = PD->getPropertyAttributesAsWritten();
7725 if (!(AsWrittenAttr & ObjCPropertyDecl::OBJC_PR_assign) &&
7726 LHSType->isObjCRetainableType())
7729 while (ImplicitCastExpr *cast = dyn_cast<ImplicitCastExpr>(RHS)) {
7730 if (cast->getCastKind() == CK_ARCConsumeObject) {
7731 Diag(Loc, diag::warn_arc_retained_property_assign)
7732 << RHS->getSourceRange();
7735 RHS = cast->getSubExpr();
7738 else if (Attributes & ObjCPropertyDecl::OBJC_PR_weak) {
7739 if (checkUnsafeAssignObject(*this, Loc, Qualifiers::OCL_Weak, RHS, true))
7745 //===--- CHECK: Empty statement body (-Wempty-body) ---------------------===//
7748 bool ShouldDiagnoseEmptyStmtBody(const SourceManager &SourceMgr,
7749 SourceLocation StmtLoc,
7750 const NullStmt *Body) {
7751 // Do not warn if the body is a macro that expands to nothing, e.g:
7757 if (Body->hasLeadingEmptyMacro())
7760 // Get line numbers of statement and body.
7761 bool StmtLineInvalid;
7762 unsigned StmtLine = SourceMgr.getSpellingLineNumber(StmtLoc,
7764 if (StmtLineInvalid)
7767 bool BodyLineInvalid;
7768 unsigned BodyLine = SourceMgr.getSpellingLineNumber(Body->getSemiLoc(),
7770 if (BodyLineInvalid)
7773 // Warn if null statement and body are on the same line.
7774 if (StmtLine != BodyLine)
7779 } // Unnamed namespace
7781 void Sema::DiagnoseEmptyStmtBody(SourceLocation StmtLoc,
7784 // Since this is a syntactic check, don't emit diagnostic for template
7785 // instantiations, this just adds noise.
7786 if (CurrentInstantiationScope)
7789 // The body should be a null statement.
7790 const NullStmt *NBody = dyn_cast<NullStmt>(Body);
7794 // Do the usual checks.
7795 if (!ShouldDiagnoseEmptyStmtBody(SourceMgr, StmtLoc, NBody))
7798 Diag(NBody->getSemiLoc(), DiagID);
7799 Diag(NBody->getSemiLoc(), diag::note_empty_body_on_separate_line);
7802 void Sema::DiagnoseEmptyLoopBody(const Stmt *S,
7803 const Stmt *PossibleBody) {
7804 assert(!CurrentInstantiationScope); // Ensured by caller
7806 SourceLocation StmtLoc;
7809 if (const ForStmt *FS = dyn_cast<ForStmt>(S)) {
7810 StmtLoc = FS->getRParenLoc();
7811 Body = FS->getBody();
7812 DiagID = diag::warn_empty_for_body;
7813 } else if (const WhileStmt *WS = dyn_cast<WhileStmt>(S)) {
7814 StmtLoc = WS->getCond()->getSourceRange().getEnd();
7815 Body = WS->getBody();
7816 DiagID = diag::warn_empty_while_body;
7818 return; // Neither `for' nor `while'.
7820 // The body should be a null statement.
7821 const NullStmt *NBody = dyn_cast<NullStmt>(Body);
7825 // Skip expensive checks if diagnostic is disabled.
7826 if (Diags.isIgnored(DiagID, NBody->getSemiLoc()))
7829 // Do the usual checks.
7830 if (!ShouldDiagnoseEmptyStmtBody(SourceMgr, StmtLoc, NBody))
7833 // `for(...);' and `while(...);' are popular idioms, so in order to keep
7834 // noise level low, emit diagnostics only if for/while is followed by a
7835 // CompoundStmt, e.g.:
7836 // for (int i = 0; i < n; i++);
7840 // or if for/while is followed by a statement with more indentation
7841 // than for/while itself:
7842 // for (int i = 0; i < n; i++);
7844 bool ProbableTypo = isa<CompoundStmt>(PossibleBody);
7845 if (!ProbableTypo) {
7846 bool BodyColInvalid;
7847 unsigned BodyCol = SourceMgr.getPresumedColumnNumber(
7848 PossibleBody->getLocStart(),
7853 bool StmtColInvalid;
7854 unsigned StmtCol = SourceMgr.getPresumedColumnNumber(
7860 if (BodyCol > StmtCol)
7861 ProbableTypo = true;
7865 Diag(NBody->getSemiLoc(), DiagID);
7866 Diag(NBody->getSemiLoc(), diag::note_empty_body_on_separate_line);
7870 //===--- Layout compatibility ----------------------------------------------//
7874 bool isLayoutCompatible(ASTContext &C, QualType T1, QualType T2);
7876 /// \brief Check if two enumeration types are layout-compatible.
7877 bool isLayoutCompatible(ASTContext &C, EnumDecl *ED1, EnumDecl *ED2) {
7878 // C++11 [dcl.enum] p8:
7879 // Two enumeration types are layout-compatible if they have the same
7881 return ED1->isComplete() && ED2->isComplete() &&
7882 C.hasSameType(ED1->getIntegerType(), ED2->getIntegerType());
7885 /// \brief Check if two fields are layout-compatible.
7886 bool isLayoutCompatible(ASTContext &C, FieldDecl *Field1, FieldDecl *Field2) {
7887 if (!isLayoutCompatible(C, Field1->getType(), Field2->getType()))
7890 if (Field1->isBitField() != Field2->isBitField())
7893 if (Field1->isBitField()) {
7894 // Make sure that the bit-fields are the same length.
7895 unsigned Bits1 = Field1->getBitWidthValue(C);
7896 unsigned Bits2 = Field2->getBitWidthValue(C);
7905 /// \brief Check if two standard-layout structs are layout-compatible.
7906 /// (C++11 [class.mem] p17)
7907 bool isLayoutCompatibleStruct(ASTContext &C,
7910 // If both records are C++ classes, check that base classes match.
7911 if (const CXXRecordDecl *D1CXX = dyn_cast<CXXRecordDecl>(RD1)) {
7912 // If one of records is a CXXRecordDecl we are in C++ mode,
7913 // thus the other one is a CXXRecordDecl, too.
7914 const CXXRecordDecl *D2CXX = cast<CXXRecordDecl>(RD2);
7915 // Check number of base classes.
7916 if (D1CXX->getNumBases() != D2CXX->getNumBases())
7919 // Check the base classes.
7920 for (CXXRecordDecl::base_class_const_iterator
7921 Base1 = D1CXX->bases_begin(),
7922 BaseEnd1 = D1CXX->bases_end(),
7923 Base2 = D2CXX->bases_begin();
7926 if (!isLayoutCompatible(C, Base1->getType(), Base2->getType()))
7929 } else if (const CXXRecordDecl *D2CXX = dyn_cast<CXXRecordDecl>(RD2)) {
7930 // If only RD2 is a C++ class, it should have zero base classes.
7931 if (D2CXX->getNumBases() > 0)
7935 // Check the fields.
7936 RecordDecl::field_iterator Field2 = RD2->field_begin(),
7937 Field2End = RD2->field_end(),
7938 Field1 = RD1->field_begin(),
7939 Field1End = RD1->field_end();
7940 for ( ; Field1 != Field1End && Field2 != Field2End; ++Field1, ++Field2) {
7941 if (!isLayoutCompatible(C, *Field1, *Field2))
7944 if (Field1 != Field1End || Field2 != Field2End)
7950 /// \brief Check if two standard-layout unions are layout-compatible.
7951 /// (C++11 [class.mem] p18)
7952 bool isLayoutCompatibleUnion(ASTContext &C,
7955 llvm::SmallPtrSet<FieldDecl *, 8> UnmatchedFields;
7956 for (auto *Field2 : RD2->fields())
7957 UnmatchedFields.insert(Field2);
7959 for (auto *Field1 : RD1->fields()) {
7960 llvm::SmallPtrSet<FieldDecl *, 8>::iterator
7961 I = UnmatchedFields.begin(),
7962 E = UnmatchedFields.end();
7964 for ( ; I != E; ++I) {
7965 if (isLayoutCompatible(C, Field1, *I)) {
7966 bool Result = UnmatchedFields.erase(*I);
7976 return UnmatchedFields.empty();
7979 bool isLayoutCompatible(ASTContext &C, RecordDecl *RD1, RecordDecl *RD2) {
7980 if (RD1->isUnion() != RD2->isUnion())
7984 return isLayoutCompatibleUnion(C, RD1, RD2);
7986 return isLayoutCompatibleStruct(C, RD1, RD2);
7989 /// \brief Check if two types are layout-compatible in C++11 sense.
7990 bool isLayoutCompatible(ASTContext &C, QualType T1, QualType T2) {
7991 if (T1.isNull() || T2.isNull())
7994 // C++11 [basic.types] p11:
7995 // If two types T1 and T2 are the same type, then T1 and T2 are
7996 // layout-compatible types.
7997 if (C.hasSameType(T1, T2))
8000 T1 = T1.getCanonicalType().getUnqualifiedType();
8001 T2 = T2.getCanonicalType().getUnqualifiedType();
8003 const Type::TypeClass TC1 = T1->getTypeClass();
8004 const Type::TypeClass TC2 = T2->getTypeClass();
8009 if (TC1 == Type::Enum) {
8010 return isLayoutCompatible(C,
8011 cast<EnumType>(T1)->getDecl(),
8012 cast<EnumType>(T2)->getDecl());
8013 } else if (TC1 == Type::Record) {
8014 if (!T1->isStandardLayoutType() || !T2->isStandardLayoutType())
8017 return isLayoutCompatible(C,
8018 cast<RecordType>(T1)->getDecl(),
8019 cast<RecordType>(T2)->getDecl());
8026 //===--- CHECK: pointer_with_type_tag attribute: datatypes should match ----//
8029 /// \brief Given a type tag expression find the type tag itself.
8031 /// \param TypeExpr Type tag expression, as it appears in user's code.
8033 /// \param VD Declaration of an identifier that appears in a type tag.
8035 /// \param MagicValue Type tag magic value.
8036 bool FindTypeTagExpr(const Expr *TypeExpr, const ASTContext &Ctx,
8037 const ValueDecl **VD, uint64_t *MagicValue) {
8042 TypeExpr = TypeExpr->IgnoreParenImpCasts()->IgnoreParenCasts();
8044 switch (TypeExpr->getStmtClass()) {
8045 case Stmt::UnaryOperatorClass: {
8046 const UnaryOperator *UO = cast<UnaryOperator>(TypeExpr);
8047 if (UO->getOpcode() == UO_AddrOf || UO->getOpcode() == UO_Deref) {
8048 TypeExpr = UO->getSubExpr();
8054 case Stmt::DeclRefExprClass: {
8055 const DeclRefExpr *DRE = cast<DeclRefExpr>(TypeExpr);
8056 *VD = DRE->getDecl();
8060 case Stmt::IntegerLiteralClass: {
8061 const IntegerLiteral *IL = cast<IntegerLiteral>(TypeExpr);
8062 llvm::APInt MagicValueAPInt = IL->getValue();
8063 if (MagicValueAPInt.getActiveBits() <= 64) {
8064 *MagicValue = MagicValueAPInt.getZExtValue();
8070 case Stmt::BinaryConditionalOperatorClass:
8071 case Stmt::ConditionalOperatorClass: {
8072 const AbstractConditionalOperator *ACO =
8073 cast<AbstractConditionalOperator>(TypeExpr);
8075 if (ACO->getCond()->EvaluateAsBooleanCondition(Result, Ctx)) {
8077 TypeExpr = ACO->getTrueExpr();
8079 TypeExpr = ACO->getFalseExpr();
8085 case Stmt::BinaryOperatorClass: {
8086 const BinaryOperator *BO = cast<BinaryOperator>(TypeExpr);
8087 if (BO->getOpcode() == BO_Comma) {
8088 TypeExpr = BO->getRHS();
8100 /// \brief Retrieve the C type corresponding to type tag TypeExpr.
8102 /// \param TypeExpr Expression that specifies a type tag.
8104 /// \param MagicValues Registered magic values.
8106 /// \param FoundWrongKind Set to true if a type tag was found, but of a wrong
8109 /// \param TypeInfo Information about the corresponding C type.
8111 /// \returns true if the corresponding C type was found.
8112 bool GetMatchingCType(
8113 const IdentifierInfo *ArgumentKind,
8114 const Expr *TypeExpr, const ASTContext &Ctx,
8115 const llvm::DenseMap<Sema::TypeTagMagicValue,
8116 Sema::TypeTagData> *MagicValues,
8117 bool &FoundWrongKind,
8118 Sema::TypeTagData &TypeInfo) {
8119 FoundWrongKind = false;
8121 // Variable declaration that has type_tag_for_datatype attribute.
8122 const ValueDecl *VD = nullptr;
8124 uint64_t MagicValue;
8126 if (!FindTypeTagExpr(TypeExpr, Ctx, &VD, &MagicValue))
8130 if (TypeTagForDatatypeAttr *I = VD->getAttr<TypeTagForDatatypeAttr>()) {
8131 if (I->getArgumentKind() != ArgumentKind) {
8132 FoundWrongKind = true;
8135 TypeInfo.Type = I->getMatchingCType();
8136 TypeInfo.LayoutCompatible = I->getLayoutCompatible();
8137 TypeInfo.MustBeNull = I->getMustBeNull();
8146 llvm::DenseMap<Sema::TypeTagMagicValue,
8147 Sema::TypeTagData>::const_iterator I =
8148 MagicValues->find(std::make_pair(ArgumentKind, MagicValue));
8149 if (I == MagicValues->end())
8152 TypeInfo = I->second;
8155 } // unnamed namespace
8157 void Sema::RegisterTypeTagForDatatype(const IdentifierInfo *ArgumentKind,
8158 uint64_t MagicValue, QualType Type,
8159 bool LayoutCompatible,
8161 if (!TypeTagForDatatypeMagicValues)
8162 TypeTagForDatatypeMagicValues.reset(
8163 new llvm::DenseMap<TypeTagMagicValue, TypeTagData>);
8165 TypeTagMagicValue Magic(ArgumentKind, MagicValue);
8166 (*TypeTagForDatatypeMagicValues)[Magic] =
8167 TypeTagData(Type, LayoutCompatible, MustBeNull);
8171 bool IsSameCharType(QualType T1, QualType T2) {
8172 const BuiltinType *BT1 = T1->getAs<BuiltinType>();
8176 const BuiltinType *BT2 = T2->getAs<BuiltinType>();
8180 BuiltinType::Kind T1Kind = BT1->getKind();
8181 BuiltinType::Kind T2Kind = BT2->getKind();
8183 return (T1Kind == BuiltinType::SChar && T2Kind == BuiltinType::Char_S) ||
8184 (T1Kind == BuiltinType::UChar && T2Kind == BuiltinType::Char_U) ||
8185 (T1Kind == BuiltinType::Char_U && T2Kind == BuiltinType::UChar) ||
8186 (T1Kind == BuiltinType::Char_S && T2Kind == BuiltinType::SChar);
8188 } // unnamed namespace
8190 void Sema::CheckArgumentWithTypeTag(const ArgumentWithTypeTagAttr *Attr,
8191 const Expr * const *ExprArgs) {
8192 const IdentifierInfo *ArgumentKind = Attr->getArgumentKind();
8193 bool IsPointerAttr = Attr->getIsPointer();
8195 const Expr *TypeTagExpr = ExprArgs[Attr->getTypeTagIdx()];
8196 bool FoundWrongKind;
8197 TypeTagData TypeInfo;
8198 if (!GetMatchingCType(ArgumentKind, TypeTagExpr, Context,
8199 TypeTagForDatatypeMagicValues.get(),
8200 FoundWrongKind, TypeInfo)) {
8202 Diag(TypeTagExpr->getExprLoc(),
8203 diag::warn_type_tag_for_datatype_wrong_kind)
8204 << TypeTagExpr->getSourceRange();
8208 const Expr *ArgumentExpr = ExprArgs[Attr->getArgumentIdx()];
8209 if (IsPointerAttr) {
8210 // Skip implicit cast of pointer to `void *' (as a function argument).
8211 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgumentExpr))
8212 if (ICE->getType()->isVoidPointerType() &&
8213 ICE->getCastKind() == CK_BitCast)
8214 ArgumentExpr = ICE->getSubExpr();
8216 QualType ArgumentType = ArgumentExpr->getType();
8218 // Passing a `void*' pointer shouldn't trigger a warning.
8219 if (IsPointerAttr && ArgumentType->isVoidPointerType())
8222 if (TypeInfo.MustBeNull) {
8223 // Type tag with matching void type requires a null pointer.
8224 if (!ArgumentExpr->isNullPointerConstant(Context,
8225 Expr::NPC_ValueDependentIsNotNull)) {
8226 Diag(ArgumentExpr->getExprLoc(),
8227 diag::warn_type_safety_null_pointer_required)
8228 << ArgumentKind->getName()
8229 << ArgumentExpr->getSourceRange()
8230 << TypeTagExpr->getSourceRange();
8235 QualType RequiredType = TypeInfo.Type;
8237 RequiredType = Context.getPointerType(RequiredType);
8239 bool mismatch = false;
8240 if (!TypeInfo.LayoutCompatible) {
8241 mismatch = !Context.hasSameType(ArgumentType, RequiredType);
8243 // C++11 [basic.fundamental] p1:
8244 // Plain char, signed char, and unsigned char are three distinct types.
8246 // But we treat plain `char' as equivalent to `signed char' or `unsigned
8247 // char' depending on the current char signedness mode.
8249 if ((IsPointerAttr && IsSameCharType(ArgumentType->getPointeeType(),
8250 RequiredType->getPointeeType())) ||
8251 (!IsPointerAttr && IsSameCharType(ArgumentType, RequiredType)))
8255 mismatch = !isLayoutCompatible(Context,
8256 ArgumentType->getPointeeType(),
8257 RequiredType->getPointeeType());
8259 mismatch = !isLayoutCompatible(Context, ArgumentType, RequiredType);
8262 Diag(ArgumentExpr->getExprLoc(), diag::warn_type_safety_type_mismatch)
8263 << ArgumentType << ArgumentKind
8264 << TypeInfo.LayoutCompatible << RequiredType
8265 << ArgumentExpr->getSourceRange()
8266 << TypeTagExpr->getSourceRange();