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/Preprocessor.h"
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/BitVector.h"
36 #include "llvm/ADT/STLExtras.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, PP.getSourceManager(),
47 PP.getLangOpts(), PP.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();
99 Sema::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
100 ExprResult TheCallResult(Owned(TheCall));
102 // Find out if any arguments are required to be integer constant expressions.
103 unsigned ICEArguments = 0;
104 ASTContext::GetBuiltinTypeError Error;
105 Context.GetBuiltinType(BuiltinID, Error, &ICEArguments);
106 if (Error != ASTContext::GE_None)
107 ICEArguments = 0; // Don't diagnose previously diagnosed errors.
109 // If any arguments are required to be ICE's, check and diagnose.
110 for (unsigned ArgNo = 0; ICEArguments != 0; ++ArgNo) {
111 // Skip arguments not required to be ICE's.
112 if ((ICEArguments & (1 << ArgNo)) == 0) continue;
115 if (SemaBuiltinConstantArg(TheCall, ArgNo, Result))
117 ICEArguments &= ~(1 << ArgNo);
121 case Builtin::BI__builtin___CFStringMakeConstantString:
122 assert(TheCall->getNumArgs() == 1 &&
123 "Wrong # arguments to builtin CFStringMakeConstantString");
124 if (CheckObjCString(TheCall->getArg(0)))
127 case Builtin::BI__builtin_stdarg_start:
128 case Builtin::BI__builtin_va_start:
129 if (SemaBuiltinVAStart(TheCall))
132 case Builtin::BI__builtin_isgreater:
133 case Builtin::BI__builtin_isgreaterequal:
134 case Builtin::BI__builtin_isless:
135 case Builtin::BI__builtin_islessequal:
136 case Builtin::BI__builtin_islessgreater:
137 case Builtin::BI__builtin_isunordered:
138 if (SemaBuiltinUnorderedCompare(TheCall))
141 case Builtin::BI__builtin_fpclassify:
142 if (SemaBuiltinFPClassification(TheCall, 6))
145 case Builtin::BI__builtin_isfinite:
146 case Builtin::BI__builtin_isinf:
147 case Builtin::BI__builtin_isinf_sign:
148 case Builtin::BI__builtin_isnan:
149 case Builtin::BI__builtin_isnormal:
150 if (SemaBuiltinFPClassification(TheCall, 1))
153 case Builtin::BI__builtin_shufflevector:
154 return SemaBuiltinShuffleVector(TheCall);
155 // TheCall will be freed by the smart pointer here, but that's fine, since
156 // SemaBuiltinShuffleVector guts it, but then doesn't release it.
157 case Builtin::BI__builtin_prefetch:
158 if (SemaBuiltinPrefetch(TheCall))
161 case Builtin::BI__builtin_object_size:
162 if (SemaBuiltinObjectSize(TheCall))
165 case Builtin::BI__builtin_longjmp:
166 if (SemaBuiltinLongjmp(TheCall))
170 case Builtin::BI__builtin_classify_type:
171 if (checkArgCount(*this, TheCall, 1)) return true;
172 TheCall->setType(Context.IntTy);
174 case Builtin::BI__builtin_constant_p:
175 if (checkArgCount(*this, TheCall, 1)) return true;
176 TheCall->setType(Context.IntTy);
178 case Builtin::BI__sync_fetch_and_add:
179 case Builtin::BI__sync_fetch_and_add_1:
180 case Builtin::BI__sync_fetch_and_add_2:
181 case Builtin::BI__sync_fetch_and_add_4:
182 case Builtin::BI__sync_fetch_and_add_8:
183 case Builtin::BI__sync_fetch_and_add_16:
184 case Builtin::BI__sync_fetch_and_sub:
185 case Builtin::BI__sync_fetch_and_sub_1:
186 case Builtin::BI__sync_fetch_and_sub_2:
187 case Builtin::BI__sync_fetch_and_sub_4:
188 case Builtin::BI__sync_fetch_and_sub_8:
189 case Builtin::BI__sync_fetch_and_sub_16:
190 case Builtin::BI__sync_fetch_and_or:
191 case Builtin::BI__sync_fetch_and_or_1:
192 case Builtin::BI__sync_fetch_and_or_2:
193 case Builtin::BI__sync_fetch_and_or_4:
194 case Builtin::BI__sync_fetch_and_or_8:
195 case Builtin::BI__sync_fetch_and_or_16:
196 case Builtin::BI__sync_fetch_and_and:
197 case Builtin::BI__sync_fetch_and_and_1:
198 case Builtin::BI__sync_fetch_and_and_2:
199 case Builtin::BI__sync_fetch_and_and_4:
200 case Builtin::BI__sync_fetch_and_and_8:
201 case Builtin::BI__sync_fetch_and_and_16:
202 case Builtin::BI__sync_fetch_and_xor:
203 case Builtin::BI__sync_fetch_and_xor_1:
204 case Builtin::BI__sync_fetch_and_xor_2:
205 case Builtin::BI__sync_fetch_and_xor_4:
206 case Builtin::BI__sync_fetch_and_xor_8:
207 case Builtin::BI__sync_fetch_and_xor_16:
208 case Builtin::BI__sync_add_and_fetch:
209 case Builtin::BI__sync_add_and_fetch_1:
210 case Builtin::BI__sync_add_and_fetch_2:
211 case Builtin::BI__sync_add_and_fetch_4:
212 case Builtin::BI__sync_add_and_fetch_8:
213 case Builtin::BI__sync_add_and_fetch_16:
214 case Builtin::BI__sync_sub_and_fetch:
215 case Builtin::BI__sync_sub_and_fetch_1:
216 case Builtin::BI__sync_sub_and_fetch_2:
217 case Builtin::BI__sync_sub_and_fetch_4:
218 case Builtin::BI__sync_sub_and_fetch_8:
219 case Builtin::BI__sync_sub_and_fetch_16:
220 case Builtin::BI__sync_and_and_fetch:
221 case Builtin::BI__sync_and_and_fetch_1:
222 case Builtin::BI__sync_and_and_fetch_2:
223 case Builtin::BI__sync_and_and_fetch_4:
224 case Builtin::BI__sync_and_and_fetch_8:
225 case Builtin::BI__sync_and_and_fetch_16:
226 case Builtin::BI__sync_or_and_fetch:
227 case Builtin::BI__sync_or_and_fetch_1:
228 case Builtin::BI__sync_or_and_fetch_2:
229 case Builtin::BI__sync_or_and_fetch_4:
230 case Builtin::BI__sync_or_and_fetch_8:
231 case Builtin::BI__sync_or_and_fetch_16:
232 case Builtin::BI__sync_xor_and_fetch:
233 case Builtin::BI__sync_xor_and_fetch_1:
234 case Builtin::BI__sync_xor_and_fetch_2:
235 case Builtin::BI__sync_xor_and_fetch_4:
236 case Builtin::BI__sync_xor_and_fetch_8:
237 case Builtin::BI__sync_xor_and_fetch_16:
238 case Builtin::BI__sync_val_compare_and_swap:
239 case Builtin::BI__sync_val_compare_and_swap_1:
240 case Builtin::BI__sync_val_compare_and_swap_2:
241 case Builtin::BI__sync_val_compare_and_swap_4:
242 case Builtin::BI__sync_val_compare_and_swap_8:
243 case Builtin::BI__sync_val_compare_and_swap_16:
244 case Builtin::BI__sync_bool_compare_and_swap:
245 case Builtin::BI__sync_bool_compare_and_swap_1:
246 case Builtin::BI__sync_bool_compare_and_swap_2:
247 case Builtin::BI__sync_bool_compare_and_swap_4:
248 case Builtin::BI__sync_bool_compare_and_swap_8:
249 case Builtin::BI__sync_bool_compare_and_swap_16:
250 case Builtin::BI__sync_lock_test_and_set:
251 case Builtin::BI__sync_lock_test_and_set_1:
252 case Builtin::BI__sync_lock_test_and_set_2:
253 case Builtin::BI__sync_lock_test_and_set_4:
254 case Builtin::BI__sync_lock_test_and_set_8:
255 case Builtin::BI__sync_lock_test_and_set_16:
256 case Builtin::BI__sync_lock_release:
257 case Builtin::BI__sync_lock_release_1:
258 case Builtin::BI__sync_lock_release_2:
259 case Builtin::BI__sync_lock_release_4:
260 case Builtin::BI__sync_lock_release_8:
261 case Builtin::BI__sync_lock_release_16:
262 case Builtin::BI__sync_swap:
263 case Builtin::BI__sync_swap_1:
264 case Builtin::BI__sync_swap_2:
265 case Builtin::BI__sync_swap_4:
266 case Builtin::BI__sync_swap_8:
267 case Builtin::BI__sync_swap_16:
268 return SemaBuiltinAtomicOverloaded(TheCallResult);
269 #define BUILTIN(ID, TYPE, ATTRS)
270 #define ATOMIC_BUILTIN(ID, TYPE, ATTRS) \
271 case Builtin::BI##ID: \
272 return SemaAtomicOpsOverloaded(TheCallResult, AtomicExpr::AO##ID);
273 #include "clang/Basic/Builtins.def"
274 case Builtin::BI__builtin_annotation:
275 if (SemaBuiltinAnnotation(*this, TheCall))
280 // Since the target specific builtins for each arch overlap, only check those
281 // of the arch we are compiling for.
282 if (BuiltinID >= Builtin::FirstTSBuiltin) {
283 switch (Context.getTargetInfo().getTriple().getArch()) {
284 case llvm::Triple::arm:
285 case llvm::Triple::thumb:
286 if (CheckARMBuiltinFunctionCall(BuiltinID, TheCall))
289 case llvm::Triple::mips:
290 case llvm::Triple::mipsel:
291 case llvm::Triple::mips64:
292 case llvm::Triple::mips64el:
293 if (CheckMipsBuiltinFunctionCall(BuiltinID, TheCall))
301 return TheCallResult;
304 // Get the valid immediate range for the specified NEON type code.
305 static unsigned RFT(unsigned t, bool shift = false) {
306 NeonTypeFlags Type(t);
307 int IsQuad = Type.isQuad();
308 switch (Type.getEltType()) {
309 case NeonTypeFlags::Int8:
310 case NeonTypeFlags::Poly8:
311 return shift ? 7 : (8 << IsQuad) - 1;
312 case NeonTypeFlags::Int16:
313 case NeonTypeFlags::Poly16:
314 return shift ? 15 : (4 << IsQuad) - 1;
315 case NeonTypeFlags::Int32:
316 return shift ? 31 : (2 << IsQuad) - 1;
317 case NeonTypeFlags::Int64:
318 return shift ? 63 : (1 << IsQuad) - 1;
319 case NeonTypeFlags::Float16:
320 assert(!shift && "cannot shift float types!");
321 return (4 << IsQuad) - 1;
322 case NeonTypeFlags::Float32:
323 assert(!shift && "cannot shift float types!");
324 return (2 << IsQuad) - 1;
326 llvm_unreachable("Invalid NeonTypeFlag!");
329 /// getNeonEltType - Return the QualType corresponding to the elements of
330 /// the vector type specified by the NeonTypeFlags. This is used to check
331 /// the pointer arguments for Neon load/store intrinsics.
332 static QualType getNeonEltType(NeonTypeFlags Flags, ASTContext &Context) {
333 switch (Flags.getEltType()) {
334 case NeonTypeFlags::Int8:
335 return Flags.isUnsigned() ? Context.UnsignedCharTy : Context.SignedCharTy;
336 case NeonTypeFlags::Int16:
337 return Flags.isUnsigned() ? Context.UnsignedShortTy : Context.ShortTy;
338 case NeonTypeFlags::Int32:
339 return Flags.isUnsigned() ? Context.UnsignedIntTy : Context.IntTy;
340 case NeonTypeFlags::Int64:
341 return Flags.isUnsigned() ? Context.UnsignedLongLongTy : Context.LongLongTy;
342 case NeonTypeFlags::Poly8:
343 return Context.SignedCharTy;
344 case NeonTypeFlags::Poly16:
345 return Context.ShortTy;
346 case NeonTypeFlags::Float16:
347 return Context.UnsignedShortTy;
348 case NeonTypeFlags::Float32:
349 return Context.FloatTy;
351 llvm_unreachable("Invalid NeonTypeFlag!");
354 bool Sema::CheckARMBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
360 bool HasConstPtr = false;
362 #define GET_NEON_OVERLOAD_CHECK
363 #include "clang/Basic/arm_neon.inc"
364 #undef GET_NEON_OVERLOAD_CHECK
367 // For NEON intrinsics which are overloaded on vector element type, validate
368 // the immediate which specifies which variant to emit.
369 unsigned ImmArg = TheCall->getNumArgs()-1;
371 if (SemaBuiltinConstantArg(TheCall, ImmArg, Result))
374 TV = Result.getLimitedValue(64);
375 if ((TV > 63) || (mask & (1ULL << TV)) == 0)
376 return Diag(TheCall->getLocStart(), diag::err_invalid_neon_type_code)
377 << TheCall->getArg(ImmArg)->getSourceRange();
380 if (PtrArgNum >= 0) {
381 // Check that pointer arguments have the specified type.
382 Expr *Arg = TheCall->getArg(PtrArgNum);
383 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg))
384 Arg = ICE->getSubExpr();
385 ExprResult RHS = DefaultFunctionArrayLvalueConversion(Arg);
386 QualType RHSTy = RHS.get()->getType();
387 QualType EltTy = getNeonEltType(NeonTypeFlags(TV), Context);
389 EltTy = EltTy.withConst();
390 QualType LHSTy = Context.getPointerType(EltTy);
391 AssignConvertType ConvTy;
392 ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS);
395 if (DiagnoseAssignmentResult(ConvTy, Arg->getLocStart(), LHSTy, RHSTy,
396 RHS.get(), AA_Assigning))
400 // For NEON intrinsics which take an immediate value as part of the
401 // instruction, range check them here.
402 unsigned i = 0, l = 0, u = 0;
404 default: return false;
405 case ARM::BI__builtin_arm_ssat: i = 1; l = 1; u = 31; break;
406 case ARM::BI__builtin_arm_usat: i = 1; u = 31; break;
407 case ARM::BI__builtin_arm_vcvtr_f:
408 case ARM::BI__builtin_arm_vcvtr_d: i = 1; u = 1; break;
409 #define GET_NEON_IMMEDIATE_CHECK
410 #include "clang/Basic/arm_neon.inc"
411 #undef GET_NEON_IMMEDIATE_CHECK
414 // We can't check the value of a dependent argument.
415 if (TheCall->getArg(i)->isTypeDependent() ||
416 TheCall->getArg(i)->isValueDependent())
419 // Check that the immediate argument is actually a constant.
420 if (SemaBuiltinConstantArg(TheCall, i, Result))
423 // Range check against the upper/lower values for this isntruction.
424 unsigned Val = Result.getZExtValue();
425 if (Val < l || Val > (u + l))
426 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
427 << l << u+l << TheCall->getArg(i)->getSourceRange();
429 // FIXME: VFP Intrinsics should error if VFP not present.
433 bool Sema::CheckMipsBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
434 unsigned i = 0, l = 0, u = 0;
436 default: return false;
437 case Mips::BI__builtin_mips_wrdsp: i = 1; l = 0; u = 63; break;
438 case Mips::BI__builtin_mips_rddsp: i = 0; l = 0; u = 63; break;
439 case Mips::BI__builtin_mips_append: i = 2; l = 0; u = 31; break;
440 case Mips::BI__builtin_mips_balign: i = 2; l = 0; u = 3; break;
441 case Mips::BI__builtin_mips_precr_sra_ph_w: i = 2; l = 0; u = 31; break;
442 case Mips::BI__builtin_mips_precr_sra_r_ph_w: i = 2; l = 0; u = 31; break;
443 case Mips::BI__builtin_mips_prepend: i = 2; l = 0; u = 31; break;
446 // We can't check the value of a dependent argument.
447 if (TheCall->getArg(i)->isTypeDependent() ||
448 TheCall->getArg(i)->isValueDependent())
451 // Check that the immediate argument is actually a constant.
453 if (SemaBuiltinConstantArg(TheCall, i, Result))
456 // Range check against the upper/lower values for this instruction.
457 unsigned Val = Result.getZExtValue();
458 if (Val < l || Val > u)
459 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
460 << l << u << TheCall->getArg(i)->getSourceRange();
465 /// Given a FunctionDecl's FormatAttr, attempts to populate the FomatStringInfo
466 /// parameter with the FormatAttr's correct format_idx and firstDataArg.
467 /// Returns true when the format fits the function and the FormatStringInfo has
469 bool Sema::getFormatStringInfo(const FormatAttr *Format, bool IsCXXMember,
470 FormatStringInfo *FSI) {
471 FSI->HasVAListArg = Format->getFirstArg() == 0;
472 FSI->FormatIdx = Format->getFormatIdx() - 1;
473 FSI->FirstDataArg = FSI->HasVAListArg ? 0 : Format->getFirstArg() - 1;
475 // The way the format attribute works in GCC, the implicit this argument
476 // of member functions is counted. However, it doesn't appear in our own
477 // lists, so decrement format_idx in that case.
479 if(FSI->FormatIdx == 0)
482 if (FSI->FirstDataArg != 0)
488 /// Handles the checks for format strings, non-POD arguments to vararg
489 /// functions, and NULL arguments passed to non-NULL parameters.
490 void Sema::checkCall(NamedDecl *FDecl,
491 ArrayRef<const Expr *> Args,
492 unsigned NumProtoArgs,
493 bool IsMemberFunction,
496 VariadicCallType CallType) {
497 if (CurContext->isDependentContext())
500 // Printf and scanf checking.
501 bool HandledFormatString = false;
502 for (specific_attr_iterator<FormatAttr>
503 I = FDecl->specific_attr_begin<FormatAttr>(),
504 E = FDecl->specific_attr_end<FormatAttr>(); I != E ; ++I)
505 if (CheckFormatArguments(*I, Args, IsMemberFunction, CallType, Loc, Range))
506 HandledFormatString = true;
508 // Refuse POD arguments that weren't caught by the format string
510 if (!HandledFormatString && CallType != VariadicDoesNotApply)
511 for (unsigned ArgIdx = NumProtoArgs; ArgIdx < Args.size(); ++ArgIdx) {
512 // Args[ArgIdx] can be null in malformed code.
513 if (const Expr *Arg = Args[ArgIdx])
514 variadicArgumentPODCheck(Arg, CallType);
517 for (specific_attr_iterator<NonNullAttr>
518 I = FDecl->specific_attr_begin<NonNullAttr>(),
519 E = FDecl->specific_attr_end<NonNullAttr>(); I != E; ++I)
520 CheckNonNullArguments(*I, Args.data(), Loc);
522 // Type safety checking.
523 for (specific_attr_iterator<ArgumentWithTypeTagAttr>
524 i = FDecl->specific_attr_begin<ArgumentWithTypeTagAttr>(),
525 e = FDecl->specific_attr_end<ArgumentWithTypeTagAttr>(); i != e; ++i) {
526 CheckArgumentWithTypeTag(*i, Args.data());
530 /// CheckConstructorCall - Check a constructor call for correctness and safety
531 /// properties not enforced by the C type system.
532 void Sema::CheckConstructorCall(FunctionDecl *FDecl,
533 ArrayRef<const Expr *> Args,
534 const FunctionProtoType *Proto,
535 SourceLocation Loc) {
536 VariadicCallType CallType =
537 Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply;
538 checkCall(FDecl, Args, Proto->getNumArgs(),
539 /*IsMemberFunction=*/true, Loc, SourceRange(), CallType);
542 /// CheckFunctionCall - Check a direct function call for various correctness
543 /// and safety properties not strictly enforced by the C type system.
544 bool Sema::CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall,
545 const FunctionProtoType *Proto) {
546 bool IsMemberOperatorCall = isa<CXXOperatorCallExpr>(TheCall) &&
547 isa<CXXMethodDecl>(FDecl);
548 bool IsMemberFunction = isa<CXXMemberCallExpr>(TheCall) ||
549 IsMemberOperatorCall;
550 VariadicCallType CallType = getVariadicCallType(FDecl, Proto,
551 TheCall->getCallee());
552 unsigned NumProtoArgs = Proto ? Proto->getNumArgs() : 0;
553 Expr** Args = TheCall->getArgs();
554 unsigned NumArgs = TheCall->getNumArgs();
555 if (IsMemberOperatorCall) {
556 // If this is a call to a member operator, hide the first argument
558 // FIXME: Our choice of AST representation here is less than ideal.
562 checkCall(FDecl, llvm::makeArrayRef<const Expr *>(Args, NumArgs),
564 IsMemberFunction, TheCall->getRParenLoc(),
565 TheCall->getCallee()->getSourceRange(), CallType);
567 IdentifierInfo *FnInfo = FDecl->getIdentifier();
568 // None of the checks below are needed for functions that don't have
569 // simple names (e.g., C++ conversion functions).
573 unsigned CMId = FDecl->getMemoryFunctionKind();
577 // Handle memory setting and copying functions.
578 if (CMId == Builtin::BIstrlcpy || CMId == Builtin::BIstrlcat)
579 CheckStrlcpycatArguments(TheCall, FnInfo);
580 else if (CMId == Builtin::BIstrncat)
581 CheckStrncatArguments(TheCall, FnInfo);
583 CheckMemaccessArguments(TheCall, CMId, FnInfo);
588 bool Sema::CheckObjCMethodCall(ObjCMethodDecl *Method, SourceLocation lbrac,
589 ArrayRef<const Expr *> Args) {
590 VariadicCallType CallType =
591 Method->isVariadic() ? VariadicMethod : VariadicDoesNotApply;
593 checkCall(Method, Args, Method->param_size(),
594 /*IsMemberFunction=*/false,
595 lbrac, Method->getSourceRange(), CallType);
600 bool Sema::CheckBlockCall(NamedDecl *NDecl, CallExpr *TheCall,
601 const FunctionProtoType *Proto) {
602 const VarDecl *V = dyn_cast<VarDecl>(NDecl);
606 QualType Ty = V->getType();
607 if (!Ty->isBlockPointerType())
610 VariadicCallType CallType =
611 Proto && Proto->isVariadic() ? VariadicBlock : VariadicDoesNotApply ;
612 unsigned NumProtoArgs = Proto ? Proto->getNumArgs() : 0;
615 llvm::makeArrayRef<const Expr *>(TheCall->getArgs(),
616 TheCall->getNumArgs()),
617 NumProtoArgs, /*IsMemberFunction=*/false,
618 TheCall->getRParenLoc(),
619 TheCall->getCallee()->getSourceRange(), CallType);
624 ExprResult Sema::SemaAtomicOpsOverloaded(ExprResult TheCallResult,
625 AtomicExpr::AtomicOp Op) {
626 CallExpr *TheCall = cast<CallExpr>(TheCallResult.get());
627 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
629 // All these operations take one of the following forms:
631 // C __c11_atomic_init(A *, C)
633 // C __c11_atomic_load(A *, int)
635 // void __atomic_load(A *, CP, int)
637 // C __c11_atomic_add(A *, M, int)
639 // C __atomic_exchange_n(A *, CP, int)
641 // void __atomic_exchange(A *, C *, CP, int)
643 // bool __c11_atomic_compare_exchange_strong(A *, C *, CP, int, int)
645 // bool __atomic_compare_exchange(A *, C *, CP, bool, int, int)
648 const unsigned NumArgs[] = { 2, 2, 3, 3, 3, 4, 5, 6 };
649 const unsigned NumVals[] = { 1, 0, 1, 1, 1, 2, 2, 3 };
651 // C is an appropriate type,
652 // A is volatile _Atomic(C) for __c11 builtins and is C for GNU builtins,
653 // CP is C for __c11 builtins and GNU _n builtins and is C * otherwise,
654 // M is C if C is an integer, and ptrdiff_t if C is a pointer, and
655 // the int parameters are for orderings.
657 assert(AtomicExpr::AO__c11_atomic_init == 0 &&
658 AtomicExpr::AO__c11_atomic_fetch_xor + 1 == AtomicExpr::AO__atomic_load
659 && "need to update code for modified C11 atomics");
660 bool IsC11 = Op >= AtomicExpr::AO__c11_atomic_init &&
661 Op <= AtomicExpr::AO__c11_atomic_fetch_xor;
662 bool IsN = Op == AtomicExpr::AO__atomic_load_n ||
663 Op == AtomicExpr::AO__atomic_store_n ||
664 Op == AtomicExpr::AO__atomic_exchange_n ||
665 Op == AtomicExpr::AO__atomic_compare_exchange_n;
666 bool IsAddSub = false;
669 case AtomicExpr::AO__c11_atomic_init:
673 case AtomicExpr::AO__c11_atomic_load:
674 case AtomicExpr::AO__atomic_load_n:
678 case AtomicExpr::AO__c11_atomic_store:
679 case AtomicExpr::AO__atomic_load:
680 case AtomicExpr::AO__atomic_store:
681 case AtomicExpr::AO__atomic_store_n:
685 case AtomicExpr::AO__c11_atomic_fetch_add:
686 case AtomicExpr::AO__c11_atomic_fetch_sub:
687 case AtomicExpr::AO__atomic_fetch_add:
688 case AtomicExpr::AO__atomic_fetch_sub:
689 case AtomicExpr::AO__atomic_add_fetch:
690 case AtomicExpr::AO__atomic_sub_fetch:
693 case AtomicExpr::AO__c11_atomic_fetch_and:
694 case AtomicExpr::AO__c11_atomic_fetch_or:
695 case AtomicExpr::AO__c11_atomic_fetch_xor:
696 case AtomicExpr::AO__atomic_fetch_and:
697 case AtomicExpr::AO__atomic_fetch_or:
698 case AtomicExpr::AO__atomic_fetch_xor:
699 case AtomicExpr::AO__atomic_fetch_nand:
700 case AtomicExpr::AO__atomic_and_fetch:
701 case AtomicExpr::AO__atomic_or_fetch:
702 case AtomicExpr::AO__atomic_xor_fetch:
703 case AtomicExpr::AO__atomic_nand_fetch:
707 case AtomicExpr::AO__c11_atomic_exchange:
708 case AtomicExpr::AO__atomic_exchange_n:
712 case AtomicExpr::AO__atomic_exchange:
716 case AtomicExpr::AO__c11_atomic_compare_exchange_strong:
717 case AtomicExpr::AO__c11_atomic_compare_exchange_weak:
721 case AtomicExpr::AO__atomic_compare_exchange:
722 case AtomicExpr::AO__atomic_compare_exchange_n:
727 // Check we have the right number of arguments.
728 if (TheCall->getNumArgs() < NumArgs[Form]) {
729 Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
730 << 0 << NumArgs[Form] << TheCall->getNumArgs()
731 << TheCall->getCallee()->getSourceRange();
733 } else if (TheCall->getNumArgs() > NumArgs[Form]) {
734 Diag(TheCall->getArg(NumArgs[Form])->getLocStart(),
735 diag::err_typecheck_call_too_many_args)
736 << 0 << NumArgs[Form] << TheCall->getNumArgs()
737 << TheCall->getCallee()->getSourceRange();
741 // Inspect the first argument of the atomic operation.
742 Expr *Ptr = TheCall->getArg(0);
743 Ptr = DefaultFunctionArrayLvalueConversion(Ptr).get();
744 const PointerType *pointerType = Ptr->getType()->getAs<PointerType>();
746 Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer)
747 << Ptr->getType() << Ptr->getSourceRange();
751 // For a __c11 builtin, this should be a pointer to an _Atomic type.
752 QualType AtomTy = pointerType->getPointeeType(); // 'A'
753 QualType ValType = AtomTy; // 'C'
755 if (!AtomTy->isAtomicType()) {
756 Diag(DRE->getLocStart(), diag::err_atomic_op_needs_atomic)
757 << Ptr->getType() << Ptr->getSourceRange();
760 if (AtomTy.isConstQualified()) {
761 Diag(DRE->getLocStart(), diag::err_atomic_op_needs_non_const_atomic)
762 << Ptr->getType() << Ptr->getSourceRange();
765 ValType = AtomTy->getAs<AtomicType>()->getValueType();
768 // For an arithmetic operation, the implied arithmetic must be well-formed.
769 if (Form == Arithmetic) {
770 // gcc does not enforce these rules for GNU atomics, but we do so for sanity.
771 if (IsAddSub && !ValType->isIntegerType() && !ValType->isPointerType()) {
772 Diag(DRE->getLocStart(), diag::err_atomic_op_needs_atomic_int_or_ptr)
773 << IsC11 << Ptr->getType() << Ptr->getSourceRange();
776 if (!IsAddSub && !ValType->isIntegerType()) {
777 Diag(DRE->getLocStart(), diag::err_atomic_op_bitwise_needs_atomic_int)
778 << IsC11 << Ptr->getType() << Ptr->getSourceRange();
781 } else if (IsN && !ValType->isIntegerType() && !ValType->isPointerType()) {
782 // For __atomic_*_n operations, the value type must be a scalar integral or
783 // pointer type which is 1, 2, 4, 8 or 16 bytes in length.
784 Diag(DRE->getLocStart(), diag::err_atomic_op_needs_atomic_int_or_ptr)
785 << IsC11 << Ptr->getType() << Ptr->getSourceRange();
789 if (!IsC11 && !AtomTy.isTriviallyCopyableType(Context)) {
790 // For GNU atomics, require a trivially-copyable type. This is not part of
791 // the GNU atomics specification, but we enforce it for sanity.
792 Diag(DRE->getLocStart(), diag::err_atomic_op_needs_trivial_copy)
793 << Ptr->getType() << Ptr->getSourceRange();
797 // FIXME: For any builtin other than a load, the ValType must not be
800 switch (ValType.getObjCLifetime()) {
801 case Qualifiers::OCL_None:
802 case Qualifiers::OCL_ExplicitNone:
806 case Qualifiers::OCL_Weak:
807 case Qualifiers::OCL_Strong:
808 case Qualifiers::OCL_Autoreleasing:
809 // FIXME: Can this happen? By this point, ValType should be known
810 // to be trivially copyable.
811 Diag(DRE->getLocStart(), diag::err_arc_atomic_ownership)
812 << ValType << Ptr->getSourceRange();
816 QualType ResultType = ValType;
817 if (Form == Copy || Form == GNUXchg || Form == Init)
818 ResultType = Context.VoidTy;
819 else if (Form == C11CmpXchg || Form == GNUCmpXchg)
820 ResultType = Context.BoolTy;
822 // The type of a parameter passed 'by value'. In the GNU atomics, such
823 // arguments are actually passed as pointers.
824 QualType ByValType = ValType; // 'CP'
826 ByValType = Ptr->getType();
828 // The first argument --- the pointer --- has a fixed type; we
829 // deduce the types of the rest of the arguments accordingly. Walk
830 // the remaining arguments, converting them to the deduced value type.
831 for (unsigned i = 1; i != NumArgs[Form]; ++i) {
833 if (i < NumVals[Form] + 1) {
836 // The second argument is the non-atomic operand. For arithmetic, this
837 // is always passed by value, and for a compare_exchange it is always
838 // passed by address. For the rest, GNU uses by-address and C11 uses
840 assert(Form != Load);
841 if (Form == Init || (Form == Arithmetic && ValType->isIntegerType()))
843 else if (Form == Copy || Form == Xchg)
845 else if (Form == Arithmetic)
846 Ty = Context.getPointerDiffType();
848 Ty = Context.getPointerType(ValType.getUnqualifiedType());
851 // The third argument to compare_exchange / GNU exchange is a
852 // (pointer to a) desired value.
856 // The fourth argument to GNU compare_exchange is a 'weak' flag.
861 // The order(s) are always converted to int.
865 InitializedEntity Entity =
866 InitializedEntity::InitializeParameter(Context, Ty, false);
867 ExprResult Arg = TheCall->getArg(i);
868 Arg = PerformCopyInitialization(Entity, SourceLocation(), Arg);
871 TheCall->setArg(i, Arg.get());
874 // Permute the arguments into a 'consistent' order.
875 SmallVector<Expr*, 5> SubExprs;
876 SubExprs.push_back(Ptr);
879 // Note, AtomicExpr::getVal1() has a special case for this atomic.
880 SubExprs.push_back(TheCall->getArg(1)); // Val1
883 SubExprs.push_back(TheCall->getArg(1)); // Order
888 SubExprs.push_back(TheCall->getArg(2)); // Order
889 SubExprs.push_back(TheCall->getArg(1)); // Val1
892 // Note, AtomicExpr::getVal2() has a special case for this atomic.
893 SubExprs.push_back(TheCall->getArg(3)); // Order
894 SubExprs.push_back(TheCall->getArg(1)); // Val1
895 SubExprs.push_back(TheCall->getArg(2)); // Val2
898 SubExprs.push_back(TheCall->getArg(3)); // Order
899 SubExprs.push_back(TheCall->getArg(1)); // Val1
900 SubExprs.push_back(TheCall->getArg(4)); // OrderFail
901 SubExprs.push_back(TheCall->getArg(2)); // Val2
904 SubExprs.push_back(TheCall->getArg(4)); // Order
905 SubExprs.push_back(TheCall->getArg(1)); // Val1
906 SubExprs.push_back(TheCall->getArg(5)); // OrderFail
907 SubExprs.push_back(TheCall->getArg(2)); // Val2
908 SubExprs.push_back(TheCall->getArg(3)); // Weak
912 return Owned(new (Context) AtomicExpr(TheCall->getCallee()->getLocStart(),
913 SubExprs, ResultType, Op,
914 TheCall->getRParenLoc()));
918 /// checkBuiltinArgument - Given a call to a builtin function, perform
919 /// normal type-checking on the given argument, updating the call in
920 /// place. This is useful when a builtin function requires custom
921 /// type-checking for some of its arguments but not necessarily all of
924 /// Returns true on error.
925 static bool checkBuiltinArgument(Sema &S, CallExpr *E, unsigned ArgIndex) {
926 FunctionDecl *Fn = E->getDirectCallee();
927 assert(Fn && "builtin call without direct callee!");
929 ParmVarDecl *Param = Fn->getParamDecl(ArgIndex);
930 InitializedEntity Entity =
931 InitializedEntity::InitializeParameter(S.Context, Param);
933 ExprResult Arg = E->getArg(0);
934 Arg = S.PerformCopyInitialization(Entity, SourceLocation(), Arg);
938 E->setArg(ArgIndex, Arg.take());
942 /// SemaBuiltinAtomicOverloaded - We have a call to a function like
943 /// __sync_fetch_and_add, which is an overloaded function based on the pointer
944 /// type of its first argument. The main ActOnCallExpr routines have already
945 /// promoted the types of arguments because all of these calls are prototyped as
948 /// This function goes through and does final semantic checking for these
951 Sema::SemaBuiltinAtomicOverloaded(ExprResult TheCallResult) {
952 CallExpr *TheCall = (CallExpr *)TheCallResult.get();
953 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
954 FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
956 // Ensure that we have at least one argument to do type inference from.
957 if (TheCall->getNumArgs() < 1) {
958 Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least)
959 << 0 << 1 << TheCall->getNumArgs()
960 << TheCall->getCallee()->getSourceRange();
964 // Inspect the first argument of the atomic builtin. This should always be
965 // a pointer type, whose element is an integral scalar or pointer type.
966 // Because it is a pointer type, we don't have to worry about any implicit
968 // FIXME: We don't allow floating point scalars as input.
969 Expr *FirstArg = TheCall->getArg(0);
970 ExprResult FirstArgResult = DefaultFunctionArrayLvalueConversion(FirstArg);
971 if (FirstArgResult.isInvalid())
973 FirstArg = FirstArgResult.take();
974 TheCall->setArg(0, FirstArg);
976 const PointerType *pointerType = FirstArg->getType()->getAs<PointerType>();
978 Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer)
979 << FirstArg->getType() << FirstArg->getSourceRange();
983 QualType ValType = pointerType->getPointeeType();
984 if (!ValType->isIntegerType() && !ValType->isAnyPointerType() &&
985 !ValType->isBlockPointerType()) {
986 Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer_intptr)
987 << FirstArg->getType() << FirstArg->getSourceRange();
991 switch (ValType.getObjCLifetime()) {
992 case Qualifiers::OCL_None:
993 case Qualifiers::OCL_ExplicitNone:
997 case Qualifiers::OCL_Weak:
998 case Qualifiers::OCL_Strong:
999 case Qualifiers::OCL_Autoreleasing:
1000 Diag(DRE->getLocStart(), diag::err_arc_atomic_ownership)
1001 << ValType << FirstArg->getSourceRange();
1005 // Strip any qualifiers off ValType.
1006 ValType = ValType.getUnqualifiedType();
1008 // The majority of builtins return a value, but a few have special return
1009 // types, so allow them to override appropriately below.
1010 QualType ResultType = ValType;
1012 // We need to figure out which concrete builtin this maps onto. For example,
1013 // __sync_fetch_and_add with a 2 byte object turns into
1014 // __sync_fetch_and_add_2.
1015 #define BUILTIN_ROW(x) \
1016 { Builtin::BI##x##_1, Builtin::BI##x##_2, Builtin::BI##x##_4, \
1017 Builtin::BI##x##_8, Builtin::BI##x##_16 }
1019 static const unsigned BuiltinIndices[][5] = {
1020 BUILTIN_ROW(__sync_fetch_and_add),
1021 BUILTIN_ROW(__sync_fetch_and_sub),
1022 BUILTIN_ROW(__sync_fetch_and_or),
1023 BUILTIN_ROW(__sync_fetch_and_and),
1024 BUILTIN_ROW(__sync_fetch_and_xor),
1026 BUILTIN_ROW(__sync_add_and_fetch),
1027 BUILTIN_ROW(__sync_sub_and_fetch),
1028 BUILTIN_ROW(__sync_and_and_fetch),
1029 BUILTIN_ROW(__sync_or_and_fetch),
1030 BUILTIN_ROW(__sync_xor_and_fetch),
1032 BUILTIN_ROW(__sync_val_compare_and_swap),
1033 BUILTIN_ROW(__sync_bool_compare_and_swap),
1034 BUILTIN_ROW(__sync_lock_test_and_set),
1035 BUILTIN_ROW(__sync_lock_release),
1036 BUILTIN_ROW(__sync_swap)
1040 // Determine the index of the size.
1042 switch (Context.getTypeSizeInChars(ValType).getQuantity()) {
1043 case 1: SizeIndex = 0; break;
1044 case 2: SizeIndex = 1; break;
1045 case 4: SizeIndex = 2; break;
1046 case 8: SizeIndex = 3; break;
1047 case 16: SizeIndex = 4; break;
1049 Diag(DRE->getLocStart(), diag::err_atomic_builtin_pointer_size)
1050 << FirstArg->getType() << FirstArg->getSourceRange();
1054 // Each of these builtins has one pointer argument, followed by some number of
1055 // values (0, 1 or 2) followed by a potentially empty varags list of stuff
1056 // that we ignore. Find out which row of BuiltinIndices to read from as well
1057 // as the number of fixed args.
1058 unsigned BuiltinID = FDecl->getBuiltinID();
1059 unsigned BuiltinIndex, NumFixed = 1;
1060 switch (BuiltinID) {
1061 default: llvm_unreachable("Unknown overloaded atomic builtin!");
1062 case Builtin::BI__sync_fetch_and_add:
1063 case Builtin::BI__sync_fetch_and_add_1:
1064 case Builtin::BI__sync_fetch_and_add_2:
1065 case Builtin::BI__sync_fetch_and_add_4:
1066 case Builtin::BI__sync_fetch_and_add_8:
1067 case Builtin::BI__sync_fetch_and_add_16:
1071 case Builtin::BI__sync_fetch_and_sub:
1072 case Builtin::BI__sync_fetch_and_sub_1:
1073 case Builtin::BI__sync_fetch_and_sub_2:
1074 case Builtin::BI__sync_fetch_and_sub_4:
1075 case Builtin::BI__sync_fetch_and_sub_8:
1076 case Builtin::BI__sync_fetch_and_sub_16:
1080 case Builtin::BI__sync_fetch_and_or:
1081 case Builtin::BI__sync_fetch_and_or_1:
1082 case Builtin::BI__sync_fetch_and_or_2:
1083 case Builtin::BI__sync_fetch_and_or_4:
1084 case Builtin::BI__sync_fetch_and_or_8:
1085 case Builtin::BI__sync_fetch_and_or_16:
1089 case Builtin::BI__sync_fetch_and_and:
1090 case Builtin::BI__sync_fetch_and_and_1:
1091 case Builtin::BI__sync_fetch_and_and_2:
1092 case Builtin::BI__sync_fetch_and_and_4:
1093 case Builtin::BI__sync_fetch_and_and_8:
1094 case Builtin::BI__sync_fetch_and_and_16:
1098 case Builtin::BI__sync_fetch_and_xor:
1099 case Builtin::BI__sync_fetch_and_xor_1:
1100 case Builtin::BI__sync_fetch_and_xor_2:
1101 case Builtin::BI__sync_fetch_and_xor_4:
1102 case Builtin::BI__sync_fetch_and_xor_8:
1103 case Builtin::BI__sync_fetch_and_xor_16:
1107 case Builtin::BI__sync_add_and_fetch:
1108 case Builtin::BI__sync_add_and_fetch_1:
1109 case Builtin::BI__sync_add_and_fetch_2:
1110 case Builtin::BI__sync_add_and_fetch_4:
1111 case Builtin::BI__sync_add_and_fetch_8:
1112 case Builtin::BI__sync_add_and_fetch_16:
1116 case Builtin::BI__sync_sub_and_fetch:
1117 case Builtin::BI__sync_sub_and_fetch_1:
1118 case Builtin::BI__sync_sub_and_fetch_2:
1119 case Builtin::BI__sync_sub_and_fetch_4:
1120 case Builtin::BI__sync_sub_and_fetch_8:
1121 case Builtin::BI__sync_sub_and_fetch_16:
1125 case Builtin::BI__sync_and_and_fetch:
1126 case Builtin::BI__sync_and_and_fetch_1:
1127 case Builtin::BI__sync_and_and_fetch_2:
1128 case Builtin::BI__sync_and_and_fetch_4:
1129 case Builtin::BI__sync_and_and_fetch_8:
1130 case Builtin::BI__sync_and_and_fetch_16:
1134 case Builtin::BI__sync_or_and_fetch:
1135 case Builtin::BI__sync_or_and_fetch_1:
1136 case Builtin::BI__sync_or_and_fetch_2:
1137 case Builtin::BI__sync_or_and_fetch_4:
1138 case Builtin::BI__sync_or_and_fetch_8:
1139 case Builtin::BI__sync_or_and_fetch_16:
1143 case Builtin::BI__sync_xor_and_fetch:
1144 case Builtin::BI__sync_xor_and_fetch_1:
1145 case Builtin::BI__sync_xor_and_fetch_2:
1146 case Builtin::BI__sync_xor_and_fetch_4:
1147 case Builtin::BI__sync_xor_and_fetch_8:
1148 case Builtin::BI__sync_xor_and_fetch_16:
1152 case Builtin::BI__sync_val_compare_and_swap:
1153 case Builtin::BI__sync_val_compare_and_swap_1:
1154 case Builtin::BI__sync_val_compare_and_swap_2:
1155 case Builtin::BI__sync_val_compare_and_swap_4:
1156 case Builtin::BI__sync_val_compare_and_swap_8:
1157 case Builtin::BI__sync_val_compare_and_swap_16:
1162 case Builtin::BI__sync_bool_compare_and_swap:
1163 case Builtin::BI__sync_bool_compare_and_swap_1:
1164 case Builtin::BI__sync_bool_compare_and_swap_2:
1165 case Builtin::BI__sync_bool_compare_and_swap_4:
1166 case Builtin::BI__sync_bool_compare_and_swap_8:
1167 case Builtin::BI__sync_bool_compare_and_swap_16:
1170 ResultType = Context.BoolTy;
1173 case Builtin::BI__sync_lock_test_and_set:
1174 case Builtin::BI__sync_lock_test_and_set_1:
1175 case Builtin::BI__sync_lock_test_and_set_2:
1176 case Builtin::BI__sync_lock_test_and_set_4:
1177 case Builtin::BI__sync_lock_test_and_set_8:
1178 case Builtin::BI__sync_lock_test_and_set_16:
1182 case Builtin::BI__sync_lock_release:
1183 case Builtin::BI__sync_lock_release_1:
1184 case Builtin::BI__sync_lock_release_2:
1185 case Builtin::BI__sync_lock_release_4:
1186 case Builtin::BI__sync_lock_release_8:
1187 case Builtin::BI__sync_lock_release_16:
1190 ResultType = Context.VoidTy;
1193 case Builtin::BI__sync_swap:
1194 case Builtin::BI__sync_swap_1:
1195 case Builtin::BI__sync_swap_2:
1196 case Builtin::BI__sync_swap_4:
1197 case Builtin::BI__sync_swap_8:
1198 case Builtin::BI__sync_swap_16:
1203 // Now that we know how many fixed arguments we expect, first check that we
1204 // have at least that many.
1205 if (TheCall->getNumArgs() < 1+NumFixed) {
1206 Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least)
1207 << 0 << 1+NumFixed << TheCall->getNumArgs()
1208 << TheCall->getCallee()->getSourceRange();
1212 // Get the decl for the concrete builtin from this, we can tell what the
1213 // concrete integer type we should convert to is.
1214 unsigned NewBuiltinID = BuiltinIndices[BuiltinIndex][SizeIndex];
1215 const char *NewBuiltinName = Context.BuiltinInfo.GetName(NewBuiltinID);
1216 FunctionDecl *NewBuiltinDecl;
1217 if (NewBuiltinID == BuiltinID)
1218 NewBuiltinDecl = FDecl;
1220 // Perform builtin lookup to avoid redeclaring it.
1221 DeclarationName DN(&Context.Idents.get(NewBuiltinName));
1222 LookupResult Res(*this, DN, DRE->getLocStart(), LookupOrdinaryName);
1223 LookupName(Res, TUScope, /*AllowBuiltinCreation=*/true);
1224 assert(Res.getFoundDecl());
1225 NewBuiltinDecl = dyn_cast<FunctionDecl>(Res.getFoundDecl());
1226 if (NewBuiltinDecl == 0)
1230 // The first argument --- the pointer --- has a fixed type; we
1231 // deduce the types of the rest of the arguments accordingly. Walk
1232 // the remaining arguments, converting them to the deduced value type.
1233 for (unsigned i = 0; i != NumFixed; ++i) {
1234 ExprResult Arg = TheCall->getArg(i+1);
1236 // GCC does an implicit conversion to the pointer or integer ValType. This
1237 // can fail in some cases (1i -> int**), check for this error case now.
1238 // Initialize the argument.
1239 InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
1240 ValType, /*consume*/ false);
1241 Arg = PerformCopyInitialization(Entity, SourceLocation(), Arg);
1242 if (Arg.isInvalid())
1245 // Okay, we have something that *can* be converted to the right type. Check
1246 // to see if there is a potentially weird extension going on here. This can
1247 // happen when you do an atomic operation on something like an char* and
1248 // pass in 42. The 42 gets converted to char. This is even more strange
1249 // for things like 45.123 -> char, etc.
1250 // FIXME: Do this check.
1251 TheCall->setArg(i+1, Arg.take());
1254 ASTContext& Context = this->getASTContext();
1256 // Create a new DeclRefExpr to refer to the new decl.
1257 DeclRefExpr* NewDRE = DeclRefExpr::Create(
1259 DRE->getQualifierLoc(),
1262 /*enclosing*/ false,
1264 Context.BuiltinFnTy,
1265 DRE->getValueKind());
1267 // Set the callee in the CallExpr.
1268 // FIXME: This loses syntactic information.
1269 QualType CalleePtrTy = Context.getPointerType(NewBuiltinDecl->getType());
1270 ExprResult PromotedCall = ImpCastExprToType(NewDRE, CalleePtrTy,
1271 CK_BuiltinFnToFnPtr);
1272 TheCall->setCallee(PromotedCall.take());
1274 // Change the result type of the call to match the original value type. This
1275 // is arbitrary, but the codegen for these builtins ins design to handle it
1277 TheCall->setType(ResultType);
1279 return TheCallResult;
1282 /// CheckObjCString - Checks that the argument to the builtin
1283 /// CFString constructor is correct
1284 /// Note: It might also make sense to do the UTF-16 conversion here (would
1285 /// simplify the backend).
1286 bool Sema::CheckObjCString(Expr *Arg) {
1287 Arg = Arg->IgnoreParenCasts();
1288 StringLiteral *Literal = dyn_cast<StringLiteral>(Arg);
1290 if (!Literal || !Literal->isAscii()) {
1291 Diag(Arg->getLocStart(), diag::err_cfstring_literal_not_string_constant)
1292 << Arg->getSourceRange();
1296 if (Literal->containsNonAsciiOrNull()) {
1297 StringRef String = Literal->getString();
1298 unsigned NumBytes = String.size();
1299 SmallVector<UTF16, 128> ToBuf(NumBytes);
1300 const UTF8 *FromPtr = (const UTF8 *)String.data();
1301 UTF16 *ToPtr = &ToBuf[0];
1303 ConversionResult Result = ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes,
1304 &ToPtr, ToPtr + NumBytes,
1306 // Check for conversion failure.
1307 if (Result != conversionOK)
1308 Diag(Arg->getLocStart(),
1309 diag::warn_cfstring_truncated) << Arg->getSourceRange();
1314 /// SemaBuiltinVAStart - Check the arguments to __builtin_va_start for validity.
1315 /// Emit an error and return true on failure, return false on success.
1316 bool Sema::SemaBuiltinVAStart(CallExpr *TheCall) {
1317 Expr *Fn = TheCall->getCallee();
1318 if (TheCall->getNumArgs() > 2) {
1319 Diag(TheCall->getArg(2)->getLocStart(),
1320 diag::err_typecheck_call_too_many_args)
1321 << 0 /*function call*/ << 2 << TheCall->getNumArgs()
1322 << Fn->getSourceRange()
1323 << SourceRange(TheCall->getArg(2)->getLocStart(),
1324 (*(TheCall->arg_end()-1))->getLocEnd());
1328 if (TheCall->getNumArgs() < 2) {
1329 return Diag(TheCall->getLocEnd(),
1330 diag::err_typecheck_call_too_few_args_at_least)
1331 << 0 /*function call*/ << 2 << TheCall->getNumArgs();
1334 // Type-check the first argument normally.
1335 if (checkBuiltinArgument(*this, TheCall, 0))
1338 // Determine whether the current function is variadic or not.
1339 BlockScopeInfo *CurBlock = getCurBlock();
1342 isVariadic = CurBlock->TheDecl->isVariadic();
1343 else if (FunctionDecl *FD = getCurFunctionDecl())
1344 isVariadic = FD->isVariadic();
1346 isVariadic = getCurMethodDecl()->isVariadic();
1349 Diag(Fn->getLocStart(), diag::err_va_start_used_in_non_variadic_function);
1353 // Verify that the second argument to the builtin is the last argument of the
1354 // current function or method.
1355 bool SecondArgIsLastNamedArgument = false;
1356 const Expr *Arg = TheCall->getArg(1)->IgnoreParenCasts();
1358 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Arg)) {
1359 if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(DR->getDecl())) {
1360 // FIXME: This isn't correct for methods (results in bogus warning).
1361 // Get the last formal in the current function.
1362 const ParmVarDecl *LastArg;
1364 LastArg = *(CurBlock->TheDecl->param_end()-1);
1365 else if (FunctionDecl *FD = getCurFunctionDecl())
1366 LastArg = *(FD->param_end()-1);
1368 LastArg = *(getCurMethodDecl()->param_end()-1);
1369 SecondArgIsLastNamedArgument = PV == LastArg;
1373 if (!SecondArgIsLastNamedArgument)
1374 Diag(TheCall->getArg(1)->getLocStart(),
1375 diag::warn_second_parameter_of_va_start_not_last_named_argument);
1379 /// SemaBuiltinUnorderedCompare - Handle functions like __builtin_isgreater and
1380 /// friends. This is declared to take (...), so we have to check everything.
1381 bool Sema::SemaBuiltinUnorderedCompare(CallExpr *TheCall) {
1382 if (TheCall->getNumArgs() < 2)
1383 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
1384 << 0 << 2 << TheCall->getNumArgs()/*function call*/;
1385 if (TheCall->getNumArgs() > 2)
1386 return Diag(TheCall->getArg(2)->getLocStart(),
1387 diag::err_typecheck_call_too_many_args)
1388 << 0 /*function call*/ << 2 << TheCall->getNumArgs()
1389 << SourceRange(TheCall->getArg(2)->getLocStart(),
1390 (*(TheCall->arg_end()-1))->getLocEnd());
1392 ExprResult OrigArg0 = TheCall->getArg(0);
1393 ExprResult OrigArg1 = TheCall->getArg(1);
1395 // Do standard promotions between the two arguments, returning their common
1397 QualType Res = UsualArithmeticConversions(OrigArg0, OrigArg1, false);
1398 if (OrigArg0.isInvalid() || OrigArg1.isInvalid())
1401 // Make sure any conversions are pushed back into the call; this is
1402 // type safe since unordered compare builtins are declared as "_Bool
1404 TheCall->setArg(0, OrigArg0.get());
1405 TheCall->setArg(1, OrigArg1.get());
1407 if (OrigArg0.get()->isTypeDependent() || OrigArg1.get()->isTypeDependent())
1410 // If the common type isn't a real floating type, then the arguments were
1411 // invalid for this operation.
1412 if (Res.isNull() || !Res->isRealFloatingType())
1413 return Diag(OrigArg0.get()->getLocStart(),
1414 diag::err_typecheck_call_invalid_ordered_compare)
1415 << OrigArg0.get()->getType() << OrigArg1.get()->getType()
1416 << SourceRange(OrigArg0.get()->getLocStart(), OrigArg1.get()->getLocEnd());
1421 /// SemaBuiltinSemaBuiltinFPClassification - Handle functions like
1422 /// __builtin_isnan and friends. This is declared to take (...), so we have
1423 /// to check everything. We expect the last argument to be a floating point
1425 bool Sema::SemaBuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs) {
1426 if (TheCall->getNumArgs() < NumArgs)
1427 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
1428 << 0 << NumArgs << TheCall->getNumArgs()/*function call*/;
1429 if (TheCall->getNumArgs() > NumArgs)
1430 return Diag(TheCall->getArg(NumArgs)->getLocStart(),
1431 diag::err_typecheck_call_too_many_args)
1432 << 0 /*function call*/ << NumArgs << TheCall->getNumArgs()
1433 << SourceRange(TheCall->getArg(NumArgs)->getLocStart(),
1434 (*(TheCall->arg_end()-1))->getLocEnd());
1436 Expr *OrigArg = TheCall->getArg(NumArgs-1);
1438 if (OrigArg->isTypeDependent())
1441 // This operation requires a non-_Complex floating-point number.
1442 if (!OrigArg->getType()->isRealFloatingType())
1443 return Diag(OrigArg->getLocStart(),
1444 diag::err_typecheck_call_invalid_unary_fp)
1445 << OrigArg->getType() << OrigArg->getSourceRange();
1447 // If this is an implicit conversion from float -> double, remove it.
1448 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(OrigArg)) {
1449 Expr *CastArg = Cast->getSubExpr();
1450 if (CastArg->getType()->isSpecificBuiltinType(BuiltinType::Float)) {
1451 assert(Cast->getType()->isSpecificBuiltinType(BuiltinType::Double) &&
1452 "promotion from float to double is the only expected cast here");
1453 Cast->setSubExpr(0);
1454 TheCall->setArg(NumArgs-1, CastArg);
1461 /// SemaBuiltinShuffleVector - Handle __builtin_shufflevector.
1462 // This is declared to take (...), so we have to check everything.
1463 ExprResult Sema::SemaBuiltinShuffleVector(CallExpr *TheCall) {
1464 if (TheCall->getNumArgs() < 2)
1465 return ExprError(Diag(TheCall->getLocEnd(),
1466 diag::err_typecheck_call_too_few_args_at_least)
1467 << 0 /*function call*/ << 2 << TheCall->getNumArgs()
1468 << TheCall->getSourceRange());
1470 // Determine which of the following types of shufflevector we're checking:
1471 // 1) unary, vector mask: (lhs, mask)
1472 // 2) binary, vector mask: (lhs, rhs, mask)
1473 // 3) binary, scalar mask: (lhs, rhs, index, ..., index)
1474 QualType resType = TheCall->getArg(0)->getType();
1475 unsigned numElements = 0;
1477 if (!TheCall->getArg(0)->isTypeDependent() &&
1478 !TheCall->getArg(1)->isTypeDependent()) {
1479 QualType LHSType = TheCall->getArg(0)->getType();
1480 QualType RHSType = TheCall->getArg(1)->getType();
1482 if (!LHSType->isVectorType() || !RHSType->isVectorType()) {
1483 Diag(TheCall->getLocStart(), diag::err_shufflevector_non_vector)
1484 << SourceRange(TheCall->getArg(0)->getLocStart(),
1485 TheCall->getArg(1)->getLocEnd());
1489 numElements = LHSType->getAs<VectorType>()->getNumElements();
1490 unsigned numResElements = TheCall->getNumArgs() - 2;
1492 // Check to see if we have a call with 2 vector arguments, the unary shuffle
1493 // with mask. If so, verify that RHS is an integer vector type with the
1494 // same number of elts as lhs.
1495 if (TheCall->getNumArgs() == 2) {
1496 if (!RHSType->hasIntegerRepresentation() ||
1497 RHSType->getAs<VectorType>()->getNumElements() != numElements)
1498 Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector)
1499 << SourceRange(TheCall->getArg(1)->getLocStart(),
1500 TheCall->getArg(1)->getLocEnd());
1501 numResElements = numElements;
1503 else if (!Context.hasSameUnqualifiedType(LHSType, RHSType)) {
1504 Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector)
1505 << SourceRange(TheCall->getArg(0)->getLocStart(),
1506 TheCall->getArg(1)->getLocEnd());
1508 } else if (numElements != numResElements) {
1509 QualType eltType = LHSType->getAs<VectorType>()->getElementType();
1510 resType = Context.getVectorType(eltType, numResElements,
1511 VectorType::GenericVector);
1515 for (unsigned i = 2; i < TheCall->getNumArgs(); i++) {
1516 if (TheCall->getArg(i)->isTypeDependent() ||
1517 TheCall->getArg(i)->isValueDependent())
1520 llvm::APSInt Result(32);
1521 if (!TheCall->getArg(i)->isIntegerConstantExpr(Result, Context))
1522 return ExprError(Diag(TheCall->getLocStart(),
1523 diag::err_shufflevector_nonconstant_argument)
1524 << TheCall->getArg(i)->getSourceRange());
1526 if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2)
1527 return ExprError(Diag(TheCall->getLocStart(),
1528 diag::err_shufflevector_argument_too_large)
1529 << TheCall->getArg(i)->getSourceRange());
1532 SmallVector<Expr*, 32> exprs;
1534 for (unsigned i = 0, e = TheCall->getNumArgs(); i != e; i++) {
1535 exprs.push_back(TheCall->getArg(i));
1536 TheCall->setArg(i, 0);
1539 return Owned(new (Context) ShuffleVectorExpr(Context, exprs, resType,
1540 TheCall->getCallee()->getLocStart(),
1541 TheCall->getRParenLoc()));
1544 /// SemaBuiltinPrefetch - Handle __builtin_prefetch.
1545 // This is declared to take (const void*, ...) and can take two
1546 // optional constant int args.
1547 bool Sema::SemaBuiltinPrefetch(CallExpr *TheCall) {
1548 unsigned NumArgs = TheCall->getNumArgs();
1551 return Diag(TheCall->getLocEnd(),
1552 diag::err_typecheck_call_too_many_args_at_most)
1553 << 0 /*function call*/ << 3 << NumArgs
1554 << TheCall->getSourceRange();
1556 // Argument 0 is checked for us and the remaining arguments must be
1557 // constant integers.
1558 for (unsigned i = 1; i != NumArgs; ++i) {
1559 Expr *Arg = TheCall->getArg(i);
1561 // We can't check the value of a dependent argument.
1562 if (Arg->isTypeDependent() || Arg->isValueDependent())
1565 llvm::APSInt Result;
1566 if (SemaBuiltinConstantArg(TheCall, i, Result))
1569 // FIXME: gcc issues a warning and rewrites these to 0. These
1570 // seems especially odd for the third argument since the default
1573 if (Result.getLimitedValue() > 1)
1574 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
1575 << "0" << "1" << Arg->getSourceRange();
1577 if (Result.getLimitedValue() > 3)
1578 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
1579 << "0" << "3" << Arg->getSourceRange();
1586 /// SemaBuiltinConstantArg - Handle a check if argument ArgNum of CallExpr
1587 /// TheCall is a constant expression.
1588 bool Sema::SemaBuiltinConstantArg(CallExpr *TheCall, int ArgNum,
1589 llvm::APSInt &Result) {
1590 Expr *Arg = TheCall->getArg(ArgNum);
1591 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
1592 FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
1594 if (Arg->isTypeDependent() || Arg->isValueDependent()) return false;
1596 if (!Arg->isIntegerConstantExpr(Result, Context))
1597 return Diag(TheCall->getLocStart(), diag::err_constant_integer_arg_type)
1598 << FDecl->getDeclName() << Arg->getSourceRange();
1603 /// SemaBuiltinObjectSize - Handle __builtin_object_size(void *ptr,
1604 /// int type). This simply type checks that type is one of the defined
1605 /// constants (0-3).
1606 // For compatibility check 0-3, llvm only handles 0 and 2.
1607 bool Sema::SemaBuiltinObjectSize(CallExpr *TheCall) {
1608 llvm::APSInt Result;
1610 // We can't check the value of a dependent argument.
1611 if (TheCall->getArg(1)->isTypeDependent() ||
1612 TheCall->getArg(1)->isValueDependent())
1615 // Check constant-ness first.
1616 if (SemaBuiltinConstantArg(TheCall, 1, Result))
1619 Expr *Arg = TheCall->getArg(1);
1620 if (Result.getSExtValue() < 0 || Result.getSExtValue() > 3) {
1621 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
1622 << "0" << "3" << SourceRange(Arg->getLocStart(), Arg->getLocEnd());
1628 /// SemaBuiltinLongjmp - Handle __builtin_longjmp(void *env[5], int val).
1629 /// This checks that val is a constant 1.
1630 bool Sema::SemaBuiltinLongjmp(CallExpr *TheCall) {
1631 Expr *Arg = TheCall->getArg(1);
1632 llvm::APSInt Result;
1634 // TODO: This is less than ideal. Overload this to take a value.
1635 if (SemaBuiltinConstantArg(TheCall, 1, Result))
1639 return Diag(TheCall->getLocStart(), diag::err_builtin_longjmp_invalid_val)
1640 << SourceRange(Arg->getLocStart(), Arg->getLocEnd());
1645 // Determine if an expression is a string literal or constant string.
1646 // If this function returns false on the arguments to a function expecting a
1647 // format string, we will usually need to emit a warning.
1648 // True string literals are then checked by CheckFormatString.
1649 Sema::StringLiteralCheckType
1650 Sema::checkFormatStringExpr(const Expr *E, ArrayRef<const Expr *> Args,
1652 unsigned format_idx, unsigned firstDataArg,
1653 FormatStringType Type, VariadicCallType CallType,
1654 bool inFunctionCall) {
1656 if (E->isTypeDependent() || E->isValueDependent())
1657 return SLCT_NotALiteral;
1659 E = E->IgnoreParenCasts();
1661 if (E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull))
1662 // Technically -Wformat-nonliteral does not warn about this case.
1663 // The behavior of printf and friends in this case is implementation
1664 // dependent. Ideally if the format string cannot be null then
1665 // it should have a 'nonnull' attribute in the function prototype.
1666 return SLCT_CheckedLiteral;
1668 switch (E->getStmtClass()) {
1669 case Stmt::BinaryConditionalOperatorClass:
1670 case Stmt::ConditionalOperatorClass: {
1671 // The expression is a literal if both sub-expressions were, and it was
1672 // completely checked only if both sub-expressions were checked.
1673 const AbstractConditionalOperator *C =
1674 cast<AbstractConditionalOperator>(E);
1675 StringLiteralCheckType Left =
1676 checkFormatStringExpr(C->getTrueExpr(), Args,
1677 HasVAListArg, format_idx, firstDataArg,
1678 Type, CallType, inFunctionCall);
1679 if (Left == SLCT_NotALiteral)
1680 return SLCT_NotALiteral;
1681 StringLiteralCheckType Right =
1682 checkFormatStringExpr(C->getFalseExpr(), Args,
1683 HasVAListArg, format_idx, firstDataArg,
1684 Type, CallType, inFunctionCall);
1685 return Left < Right ? Left : Right;
1688 case Stmt::ImplicitCastExprClass: {
1689 E = cast<ImplicitCastExpr>(E)->getSubExpr();
1693 case Stmt::OpaqueValueExprClass:
1694 if (const Expr *src = cast<OpaqueValueExpr>(E)->getSourceExpr()) {
1698 return SLCT_NotALiteral;
1700 case Stmt::PredefinedExprClass:
1701 // While __func__, etc., are technically not string literals, they
1702 // cannot contain format specifiers and thus are not a security
1704 return SLCT_UncheckedLiteral;
1706 case Stmt::DeclRefExprClass: {
1707 const DeclRefExpr *DR = cast<DeclRefExpr>(E);
1709 // As an exception, do not flag errors for variables binding to
1710 // const string literals.
1711 if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
1712 bool isConstant = false;
1713 QualType T = DR->getType();
1715 if (const ArrayType *AT = Context.getAsArrayType(T)) {
1716 isConstant = AT->getElementType().isConstant(Context);
1717 } else if (const PointerType *PT = T->getAs<PointerType>()) {
1718 isConstant = T.isConstant(Context) &&
1719 PT->getPointeeType().isConstant(Context);
1720 } else if (T->isObjCObjectPointerType()) {
1721 // In ObjC, there is usually no "const ObjectPointer" type,
1722 // so don't check if the pointee type is constant.
1723 isConstant = T.isConstant(Context);
1727 if (const Expr *Init = VD->getAnyInitializer()) {
1728 // Look through initializers like const char c[] = { "foo" }
1729 if (const InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
1730 if (InitList->isStringLiteralInit())
1731 Init = InitList->getInit(0)->IgnoreParenImpCasts();
1733 return checkFormatStringExpr(Init, Args,
1734 HasVAListArg, format_idx,
1735 firstDataArg, Type, CallType,
1736 /*inFunctionCall*/false);
1740 // For vprintf* functions (i.e., HasVAListArg==true), we add a
1741 // special check to see if the format string is a function parameter
1742 // of the function calling the printf function. If the function
1743 // has an attribute indicating it is a printf-like function, then we
1744 // should suppress warnings concerning non-literals being used in a call
1745 // to a vprintf function. For example:
1748 // logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...){
1750 // va_start(ap, fmt);
1751 // vprintf(fmt, ap); // Do NOT emit a warning about "fmt".
1755 if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(VD)) {
1756 if (const NamedDecl *ND = dyn_cast<NamedDecl>(PV->getDeclContext())) {
1757 int PVIndex = PV->getFunctionScopeIndex() + 1;
1758 for (specific_attr_iterator<FormatAttr>
1759 i = ND->specific_attr_begin<FormatAttr>(),
1760 e = ND->specific_attr_end<FormatAttr>(); i != e ; ++i) {
1761 FormatAttr *PVFormat = *i;
1762 // adjust for implicit parameter
1763 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
1764 if (MD->isInstance())
1766 // We also check if the formats are compatible.
1767 // We can't pass a 'scanf' string to a 'printf' function.
1768 if (PVIndex == PVFormat->getFormatIdx() &&
1769 Type == GetFormatStringType(PVFormat))
1770 return SLCT_UncheckedLiteral;
1777 return SLCT_NotALiteral;
1780 case Stmt::CallExprClass:
1781 case Stmt::CXXMemberCallExprClass: {
1782 const CallExpr *CE = cast<CallExpr>(E);
1783 if (const NamedDecl *ND = dyn_cast_or_null<NamedDecl>(CE->getCalleeDecl())) {
1784 if (const FormatArgAttr *FA = ND->getAttr<FormatArgAttr>()) {
1785 unsigned ArgIndex = FA->getFormatIdx();
1786 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
1787 if (MD->isInstance())
1789 const Expr *Arg = CE->getArg(ArgIndex - 1);
1791 return checkFormatStringExpr(Arg, Args,
1792 HasVAListArg, format_idx, firstDataArg,
1793 Type, CallType, inFunctionCall);
1794 } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
1795 unsigned BuiltinID = FD->getBuiltinID();
1796 if (BuiltinID == Builtin::BI__builtin___CFStringMakeConstantString ||
1797 BuiltinID == Builtin::BI__builtin___NSStringMakeConstantString) {
1798 const Expr *Arg = CE->getArg(0);
1799 return checkFormatStringExpr(Arg, Args,
1800 HasVAListArg, format_idx,
1801 firstDataArg, Type, CallType,
1807 return SLCT_NotALiteral;
1809 case Stmt::ObjCStringLiteralClass:
1810 case Stmt::StringLiteralClass: {
1811 const StringLiteral *StrE = NULL;
1813 if (const ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(E))
1814 StrE = ObjCFExpr->getString();
1816 StrE = cast<StringLiteral>(E);
1819 CheckFormatString(StrE, E, Args, HasVAListArg, format_idx,
1820 firstDataArg, Type, inFunctionCall, CallType);
1821 return SLCT_CheckedLiteral;
1824 return SLCT_NotALiteral;
1828 return SLCT_NotALiteral;
1833 Sema::CheckNonNullArguments(const NonNullAttr *NonNull,
1834 const Expr * const *ExprArgs,
1835 SourceLocation CallSiteLoc) {
1836 for (NonNullAttr::args_iterator i = NonNull->args_begin(),
1837 e = NonNull->args_end();
1839 const Expr *ArgExpr = ExprArgs[*i];
1841 // As a special case, transparent unions initialized with zero are
1842 // considered null for the purposes of the nonnull attribute.
1843 if (const RecordType *UT = ArgExpr->getType()->getAsUnionType()) {
1844 if (UT->getDecl()->hasAttr<TransparentUnionAttr>())
1845 if (const CompoundLiteralExpr *CLE =
1846 dyn_cast<CompoundLiteralExpr>(ArgExpr))
1847 if (const InitListExpr *ILE =
1848 dyn_cast<InitListExpr>(CLE->getInitializer()))
1849 ArgExpr = ILE->getInit(0);
1853 if (ArgExpr->EvaluateAsBooleanCondition(Result, Context) && !Result)
1854 Diag(CallSiteLoc, diag::warn_null_arg) << ArgExpr->getSourceRange();
1858 Sema::FormatStringType Sema::GetFormatStringType(const FormatAttr *Format) {
1859 return llvm::StringSwitch<FormatStringType>(Format->getType())
1860 .Case("scanf", FST_Scanf)
1861 .Cases("printf", "printf0", FST_Printf)
1862 .Cases("NSString", "CFString", FST_NSString)
1863 .Case("strftime", FST_Strftime)
1864 .Case("strfmon", FST_Strfmon)
1865 .Cases("kprintf", "cmn_err", "vcmn_err", "zcmn_err", FST_Kprintf)
1866 .Default(FST_Unknown);
1869 /// CheckFormatArguments - Check calls to printf and scanf (and similar
1870 /// functions) for correct use of format strings.
1871 /// Returns true if a format string has been fully checked.
1872 bool Sema::CheckFormatArguments(const FormatAttr *Format,
1873 ArrayRef<const Expr *> Args,
1875 VariadicCallType CallType,
1876 SourceLocation Loc, SourceRange Range) {
1877 FormatStringInfo FSI;
1878 if (getFormatStringInfo(Format, IsCXXMember, &FSI))
1879 return CheckFormatArguments(Args, FSI.HasVAListArg, FSI.FormatIdx,
1880 FSI.FirstDataArg, GetFormatStringType(Format),
1881 CallType, Loc, Range);
1885 bool Sema::CheckFormatArguments(ArrayRef<const Expr *> Args,
1886 bool HasVAListArg, unsigned format_idx,
1887 unsigned firstDataArg, FormatStringType Type,
1888 VariadicCallType CallType,
1889 SourceLocation Loc, SourceRange Range) {
1890 // CHECK: printf/scanf-like function is called with no format string.
1891 if (format_idx >= Args.size()) {
1892 Diag(Loc, diag::warn_missing_format_string) << Range;
1896 const Expr *OrigFormatExpr = Args[format_idx]->IgnoreParenCasts();
1898 // CHECK: format string is not a string literal.
1900 // Dynamically generated format strings are difficult to
1901 // automatically vet at compile time. Requiring that format strings
1902 // are string literals: (1) permits the checking of format strings by
1903 // the compiler and thereby (2) can practically remove the source of
1904 // many format string exploits.
1906 // Format string can be either ObjC string (e.g. @"%d") or
1907 // C string (e.g. "%d")
1908 // ObjC string uses the same format specifiers as C string, so we can use
1909 // the same format string checking logic for both ObjC and C strings.
1910 StringLiteralCheckType CT =
1911 checkFormatStringExpr(OrigFormatExpr, Args, HasVAListArg,
1912 format_idx, firstDataArg, Type, CallType);
1913 if (CT != SLCT_NotALiteral)
1914 // Literal format string found, check done!
1915 return CT == SLCT_CheckedLiteral;
1917 // Strftime is particular as it always uses a single 'time' argument,
1918 // so it is safe to pass a non-literal string.
1919 if (Type == FST_Strftime)
1922 // Do not emit diag when the string param is a macro expansion and the
1923 // format is either NSString or CFString. This is a hack to prevent
1924 // diag when using the NSLocalizedString and CFCopyLocalizedString macros
1925 // which are usually used in place of NS and CF string literals.
1926 if (Type == FST_NSString &&
1927 SourceMgr.isInSystemMacro(Args[format_idx]->getLocStart()))
1930 // If there are no arguments specified, warn with -Wformat-security, otherwise
1931 // warn only with -Wformat-nonliteral.
1932 if (Args.size() == format_idx+1)
1933 Diag(Args[format_idx]->getLocStart(),
1934 diag::warn_format_nonliteral_noargs)
1935 << OrigFormatExpr->getSourceRange();
1937 Diag(Args[format_idx]->getLocStart(),
1938 diag::warn_format_nonliteral)
1939 << OrigFormatExpr->getSourceRange();
1944 class CheckFormatHandler : public analyze_format_string::FormatStringHandler {
1947 const StringLiteral *FExpr;
1948 const Expr *OrigFormatExpr;
1949 const unsigned FirstDataArg;
1950 const unsigned NumDataArgs;
1951 const char *Beg; // Start of format string.
1952 const bool HasVAListArg;
1953 ArrayRef<const Expr *> Args;
1955 llvm::BitVector CoveredArgs;
1956 bool usesPositionalArgs;
1958 bool inFunctionCall;
1959 Sema::VariadicCallType CallType;
1961 CheckFormatHandler(Sema &s, const StringLiteral *fexpr,
1962 const Expr *origFormatExpr, unsigned firstDataArg,
1963 unsigned numDataArgs, const char *beg, bool hasVAListArg,
1964 ArrayRef<const Expr *> Args,
1965 unsigned formatIdx, bool inFunctionCall,
1966 Sema::VariadicCallType callType)
1967 : S(s), FExpr(fexpr), OrigFormatExpr(origFormatExpr),
1968 FirstDataArg(firstDataArg), NumDataArgs(numDataArgs),
1969 Beg(beg), HasVAListArg(hasVAListArg),
1970 Args(Args), FormatIdx(formatIdx),
1971 usesPositionalArgs(false), atFirstArg(true),
1972 inFunctionCall(inFunctionCall), CallType(callType) {
1973 CoveredArgs.resize(numDataArgs);
1974 CoveredArgs.reset();
1977 void DoneProcessing();
1979 void HandleIncompleteSpecifier(const char *startSpecifier,
1980 unsigned specifierLen);
1982 void HandleInvalidLengthModifier(
1983 const analyze_format_string::FormatSpecifier &FS,
1984 const analyze_format_string::ConversionSpecifier &CS,
1985 const char *startSpecifier, unsigned specifierLen, unsigned DiagID);
1987 void HandleNonStandardLengthModifier(
1988 const analyze_format_string::FormatSpecifier &FS,
1989 const char *startSpecifier, unsigned specifierLen);
1991 void HandleNonStandardConversionSpecifier(
1992 const analyze_format_string::ConversionSpecifier &CS,
1993 const char *startSpecifier, unsigned specifierLen);
1995 virtual void HandlePosition(const char *startPos, unsigned posLen);
1997 virtual void HandleInvalidPosition(const char *startSpecifier,
1998 unsigned specifierLen,
1999 analyze_format_string::PositionContext p);
2001 virtual void HandleZeroPosition(const char *startPos, unsigned posLen);
2003 void HandleNullChar(const char *nullCharacter);
2005 template <typename Range>
2006 static void EmitFormatDiagnostic(Sema &S, bool inFunctionCall,
2007 const Expr *ArgumentExpr,
2008 PartialDiagnostic PDiag,
2009 SourceLocation StringLoc,
2010 bool IsStringLocation, Range StringRange,
2011 ArrayRef<FixItHint> Fixit = None);
2014 bool HandleInvalidConversionSpecifier(unsigned argIndex, SourceLocation Loc,
2015 const char *startSpec,
2016 unsigned specifierLen,
2017 const char *csStart, unsigned csLen);
2019 void HandlePositionalNonpositionalArgs(SourceLocation Loc,
2020 const char *startSpec,
2021 unsigned specifierLen);
2023 SourceRange getFormatStringRange();
2024 CharSourceRange getSpecifierRange(const char *startSpecifier,
2025 unsigned specifierLen);
2026 SourceLocation getLocationOfByte(const char *x);
2028 const Expr *getDataArg(unsigned i) const;
2030 bool CheckNumArgs(const analyze_format_string::FormatSpecifier &FS,
2031 const analyze_format_string::ConversionSpecifier &CS,
2032 const char *startSpecifier, unsigned specifierLen,
2035 template <typename Range>
2036 void EmitFormatDiagnostic(PartialDiagnostic PDiag, SourceLocation StringLoc,
2037 bool IsStringLocation, Range StringRange,
2038 ArrayRef<FixItHint> Fixit = None);
2040 void CheckPositionalAndNonpositionalArgs(
2041 const analyze_format_string::FormatSpecifier *FS);
2045 SourceRange CheckFormatHandler::getFormatStringRange() {
2046 return OrigFormatExpr->getSourceRange();
2049 CharSourceRange CheckFormatHandler::
2050 getSpecifierRange(const char *startSpecifier, unsigned specifierLen) {
2051 SourceLocation Start = getLocationOfByte(startSpecifier);
2052 SourceLocation End = getLocationOfByte(startSpecifier + specifierLen - 1);
2054 // Advance the end SourceLocation by one due to half-open ranges.
2055 End = End.getLocWithOffset(1);
2057 return CharSourceRange::getCharRange(Start, End);
2060 SourceLocation CheckFormatHandler::getLocationOfByte(const char *x) {
2061 return S.getLocationOfStringLiteralByte(FExpr, x - Beg);
2064 void CheckFormatHandler::HandleIncompleteSpecifier(const char *startSpecifier,
2065 unsigned specifierLen){
2066 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_incomplete_specifier),
2067 getLocationOfByte(startSpecifier),
2068 /*IsStringLocation*/true,
2069 getSpecifierRange(startSpecifier, specifierLen));
2072 void CheckFormatHandler::HandleInvalidLengthModifier(
2073 const analyze_format_string::FormatSpecifier &FS,
2074 const analyze_format_string::ConversionSpecifier &CS,
2075 const char *startSpecifier, unsigned specifierLen, unsigned DiagID) {
2076 using namespace analyze_format_string;
2078 const LengthModifier &LM = FS.getLengthModifier();
2079 CharSourceRange LMRange = getSpecifierRange(LM.getStart(), LM.getLength());
2081 // See if we know how to fix this length modifier.
2082 Optional<LengthModifier> FixedLM = FS.getCorrectedLengthModifier();
2084 EmitFormatDiagnostic(S.PDiag(DiagID) << LM.toString() << CS.toString(),
2085 getLocationOfByte(LM.getStart()),
2086 /*IsStringLocation*/true,
2087 getSpecifierRange(startSpecifier, specifierLen));
2089 S.Diag(getLocationOfByte(LM.getStart()), diag::note_format_fix_specifier)
2090 << FixedLM->toString()
2091 << FixItHint::CreateReplacement(LMRange, FixedLM->toString());
2095 if (DiagID == diag::warn_format_nonsensical_length)
2096 Hint = FixItHint::CreateRemoval(LMRange);
2098 EmitFormatDiagnostic(S.PDiag(DiagID) << LM.toString() << CS.toString(),
2099 getLocationOfByte(LM.getStart()),
2100 /*IsStringLocation*/true,
2101 getSpecifierRange(startSpecifier, specifierLen),
2106 void CheckFormatHandler::HandleNonStandardLengthModifier(
2107 const analyze_format_string::FormatSpecifier &FS,
2108 const char *startSpecifier, unsigned specifierLen) {
2109 using namespace analyze_format_string;
2111 const LengthModifier &LM = FS.getLengthModifier();
2112 CharSourceRange LMRange = getSpecifierRange(LM.getStart(), LM.getLength());
2114 // See if we know how to fix this length modifier.
2115 Optional<LengthModifier> FixedLM = FS.getCorrectedLengthModifier();
2117 EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
2118 << LM.toString() << 0,
2119 getLocationOfByte(LM.getStart()),
2120 /*IsStringLocation*/true,
2121 getSpecifierRange(startSpecifier, specifierLen));
2123 S.Diag(getLocationOfByte(LM.getStart()), diag::note_format_fix_specifier)
2124 << FixedLM->toString()
2125 << FixItHint::CreateReplacement(LMRange, FixedLM->toString());
2128 EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
2129 << LM.toString() << 0,
2130 getLocationOfByte(LM.getStart()),
2131 /*IsStringLocation*/true,
2132 getSpecifierRange(startSpecifier, specifierLen));
2136 void CheckFormatHandler::HandleNonStandardConversionSpecifier(
2137 const analyze_format_string::ConversionSpecifier &CS,
2138 const char *startSpecifier, unsigned specifierLen) {
2139 using namespace analyze_format_string;
2141 // See if we know how to fix this conversion specifier.
2142 Optional<ConversionSpecifier> FixedCS = CS.getStandardSpecifier();
2144 EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
2145 << CS.toString() << /*conversion specifier*/1,
2146 getLocationOfByte(CS.getStart()),
2147 /*IsStringLocation*/true,
2148 getSpecifierRange(startSpecifier, specifierLen));
2150 CharSourceRange CSRange = getSpecifierRange(CS.getStart(), CS.getLength());
2151 S.Diag(getLocationOfByte(CS.getStart()), diag::note_format_fix_specifier)
2152 << FixedCS->toString()
2153 << FixItHint::CreateReplacement(CSRange, FixedCS->toString());
2155 EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
2156 << CS.toString() << /*conversion specifier*/1,
2157 getLocationOfByte(CS.getStart()),
2158 /*IsStringLocation*/true,
2159 getSpecifierRange(startSpecifier, specifierLen));
2163 void CheckFormatHandler::HandlePosition(const char *startPos,
2165 EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard_positional_arg),
2166 getLocationOfByte(startPos),
2167 /*IsStringLocation*/true,
2168 getSpecifierRange(startPos, posLen));
2172 CheckFormatHandler::HandleInvalidPosition(const char *startPos, unsigned posLen,
2173 analyze_format_string::PositionContext p) {
2174 EmitFormatDiagnostic(S.PDiag(diag::warn_format_invalid_positional_specifier)
2176 getLocationOfByte(startPos), /*IsStringLocation*/true,
2177 getSpecifierRange(startPos, posLen));
2180 void CheckFormatHandler::HandleZeroPosition(const char *startPos,
2182 EmitFormatDiagnostic(S.PDiag(diag::warn_format_zero_positional_specifier),
2183 getLocationOfByte(startPos),
2184 /*IsStringLocation*/true,
2185 getSpecifierRange(startPos, posLen));
2188 void CheckFormatHandler::HandleNullChar(const char *nullCharacter) {
2189 if (!isa<ObjCStringLiteral>(OrigFormatExpr)) {
2190 // The presence of a null character is likely an error.
2191 EmitFormatDiagnostic(
2192 S.PDiag(diag::warn_printf_format_string_contains_null_char),
2193 getLocationOfByte(nullCharacter), /*IsStringLocation*/true,
2194 getFormatStringRange());
2198 // Note that this may return NULL if there was an error parsing or building
2199 // one of the argument expressions.
2200 const Expr *CheckFormatHandler::getDataArg(unsigned i) const {
2201 return Args[FirstDataArg + i];
2204 void CheckFormatHandler::DoneProcessing() {
2205 // Does the number of data arguments exceed the number of
2206 // format conversions in the format string?
2207 if (!HasVAListArg) {
2208 // Find any arguments that weren't covered.
2210 signed notCoveredArg = CoveredArgs.find_first();
2211 if (notCoveredArg >= 0) {
2212 assert((unsigned)notCoveredArg < NumDataArgs);
2213 if (const Expr *E = getDataArg((unsigned) notCoveredArg)) {
2214 SourceLocation Loc = E->getLocStart();
2215 if (!S.getSourceManager().isInSystemMacro(Loc)) {
2216 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_data_arg_not_used),
2217 Loc, /*IsStringLocation*/false,
2218 getFormatStringRange());
2226 CheckFormatHandler::HandleInvalidConversionSpecifier(unsigned argIndex,
2228 const char *startSpec,
2229 unsigned specifierLen,
2230 const char *csStart,
2233 bool keepGoing = true;
2234 if (argIndex < NumDataArgs) {
2235 // Consider the argument coverered, even though the specifier doesn't
2237 CoveredArgs.set(argIndex);
2240 // If argIndex exceeds the number of data arguments we
2241 // don't issue a warning because that is just a cascade of warnings (and
2242 // they may have intended '%%' anyway). We don't want to continue processing
2243 // the format string after this point, however, as we will like just get
2244 // gibberish when trying to match arguments.
2248 EmitFormatDiagnostic(S.PDiag(diag::warn_format_invalid_conversion)
2249 << StringRef(csStart, csLen),
2250 Loc, /*IsStringLocation*/true,
2251 getSpecifierRange(startSpec, specifierLen));
2257 CheckFormatHandler::HandlePositionalNonpositionalArgs(SourceLocation Loc,
2258 const char *startSpec,
2259 unsigned specifierLen) {
2260 EmitFormatDiagnostic(
2261 S.PDiag(diag::warn_format_mix_positional_nonpositional_args),
2262 Loc, /*isStringLoc*/true, getSpecifierRange(startSpec, specifierLen));
2266 CheckFormatHandler::CheckNumArgs(
2267 const analyze_format_string::FormatSpecifier &FS,
2268 const analyze_format_string::ConversionSpecifier &CS,
2269 const char *startSpecifier, unsigned specifierLen, unsigned argIndex) {
2271 if (argIndex >= NumDataArgs) {
2272 PartialDiagnostic PDiag = FS.usesPositionalArg()
2273 ? (S.PDiag(diag::warn_printf_positional_arg_exceeds_data_args)
2274 << (argIndex+1) << NumDataArgs)
2275 : S.PDiag(diag::warn_printf_insufficient_data_args);
2276 EmitFormatDiagnostic(
2277 PDiag, getLocationOfByte(CS.getStart()), /*IsStringLocation*/true,
2278 getSpecifierRange(startSpecifier, specifierLen));
2284 template<typename Range>
2285 void CheckFormatHandler::EmitFormatDiagnostic(PartialDiagnostic PDiag,
2287 bool IsStringLocation,
2289 ArrayRef<FixItHint> FixIt) {
2290 EmitFormatDiagnostic(S, inFunctionCall, Args[FormatIdx], PDiag,
2291 Loc, IsStringLocation, StringRange, FixIt);
2294 /// \brief If the format string is not within the funcion call, emit a note
2295 /// so that the function call and string are in diagnostic messages.
2297 /// \param InFunctionCall if true, the format string is within the function
2298 /// call and only one diagnostic message will be produced. Otherwise, an
2299 /// extra note will be emitted pointing to location of the format string.
2301 /// \param ArgumentExpr the expression that is passed as the format string
2302 /// argument in the function call. Used for getting locations when two
2303 /// diagnostics are emitted.
2305 /// \param PDiag the callee should already have provided any strings for the
2306 /// diagnostic message. This function only adds locations and fixits
2309 /// \param Loc primary location for diagnostic. If two diagnostics are
2310 /// required, one will be at Loc and a new SourceLocation will be created for
2313 /// \param IsStringLocation if true, Loc points to the format string should be
2314 /// used for the note. Otherwise, Loc points to the argument list and will
2315 /// be used with PDiag.
2317 /// \param StringRange some or all of the string to highlight. This is
2318 /// templated so it can accept either a CharSourceRange or a SourceRange.
2320 /// \param FixIt optional fix it hint for the format string.
2321 template<typename Range>
2322 void CheckFormatHandler::EmitFormatDiagnostic(Sema &S, bool InFunctionCall,
2323 const Expr *ArgumentExpr,
2324 PartialDiagnostic PDiag,
2326 bool IsStringLocation,
2328 ArrayRef<FixItHint> FixIt) {
2329 if (InFunctionCall) {
2330 const Sema::SemaDiagnosticBuilder &D = S.Diag(Loc, PDiag);
2332 for (ArrayRef<FixItHint>::iterator I = FixIt.begin(), E = FixIt.end();
2337 S.Diag(IsStringLocation ? ArgumentExpr->getExprLoc() : Loc, PDiag)
2338 << ArgumentExpr->getSourceRange();
2340 const Sema::SemaDiagnosticBuilder &Note =
2341 S.Diag(IsStringLocation ? Loc : StringRange.getBegin(),
2342 diag::note_format_string_defined);
2344 Note << StringRange;
2345 for (ArrayRef<FixItHint>::iterator I = FixIt.begin(), E = FixIt.end();
2352 //===--- CHECK: Printf format string checking ------------------------------===//
2355 class CheckPrintfHandler : public CheckFormatHandler {
2358 CheckPrintfHandler(Sema &s, const StringLiteral *fexpr,
2359 const Expr *origFormatExpr, unsigned firstDataArg,
2360 unsigned numDataArgs, bool isObjC,
2361 const char *beg, bool hasVAListArg,
2362 ArrayRef<const Expr *> Args,
2363 unsigned formatIdx, bool inFunctionCall,
2364 Sema::VariadicCallType CallType)
2365 : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg,
2366 numDataArgs, beg, hasVAListArg, Args,
2367 formatIdx, inFunctionCall, CallType), ObjCContext(isObjC)
2371 bool HandleInvalidPrintfConversionSpecifier(
2372 const analyze_printf::PrintfSpecifier &FS,
2373 const char *startSpecifier,
2374 unsigned specifierLen);
2376 bool HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier &FS,
2377 const char *startSpecifier,
2378 unsigned specifierLen);
2379 bool checkFormatExpr(const analyze_printf::PrintfSpecifier &FS,
2380 const char *StartSpecifier,
2381 unsigned SpecifierLen,
2384 bool HandleAmount(const analyze_format_string::OptionalAmount &Amt, unsigned k,
2385 const char *startSpecifier, unsigned specifierLen);
2386 void HandleInvalidAmount(const analyze_printf::PrintfSpecifier &FS,
2387 const analyze_printf::OptionalAmount &Amt,
2389 const char *startSpecifier, unsigned specifierLen);
2390 void HandleFlag(const analyze_printf::PrintfSpecifier &FS,
2391 const analyze_printf::OptionalFlag &flag,
2392 const char *startSpecifier, unsigned specifierLen);
2393 void HandleIgnoredFlag(const analyze_printf::PrintfSpecifier &FS,
2394 const analyze_printf::OptionalFlag &ignoredFlag,
2395 const analyze_printf::OptionalFlag &flag,
2396 const char *startSpecifier, unsigned specifierLen);
2397 bool checkForCStrMembers(const analyze_printf::ArgType &AT,
2398 const Expr *E, const CharSourceRange &CSR);
2403 bool CheckPrintfHandler::HandleInvalidPrintfConversionSpecifier(
2404 const analyze_printf::PrintfSpecifier &FS,
2405 const char *startSpecifier,
2406 unsigned specifierLen) {
2407 const analyze_printf::PrintfConversionSpecifier &CS =
2408 FS.getConversionSpecifier();
2410 return HandleInvalidConversionSpecifier(FS.getArgIndex(),
2411 getLocationOfByte(CS.getStart()),
2412 startSpecifier, specifierLen,
2413 CS.getStart(), CS.getLength());
2416 bool CheckPrintfHandler::HandleAmount(
2417 const analyze_format_string::OptionalAmount &Amt,
2418 unsigned k, const char *startSpecifier,
2419 unsigned specifierLen) {
2421 if (Amt.hasDataArgument()) {
2422 if (!HasVAListArg) {
2423 unsigned argIndex = Amt.getArgIndex();
2424 if (argIndex >= NumDataArgs) {
2425 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_asterisk_missing_arg)
2427 getLocationOfByte(Amt.getStart()),
2428 /*IsStringLocation*/true,
2429 getSpecifierRange(startSpecifier, specifierLen));
2430 // Don't do any more checking. We will just emit
2435 // Type check the data argument. It should be an 'int'.
2436 // Although not in conformance with C99, we also allow the argument to be
2437 // an 'unsigned int' as that is a reasonably safe case. GCC also
2438 // doesn't emit a warning for that case.
2439 CoveredArgs.set(argIndex);
2440 const Expr *Arg = getDataArg(argIndex);
2444 QualType T = Arg->getType();
2446 const analyze_printf::ArgType &AT = Amt.getArgType(S.Context);
2447 assert(AT.isValid());
2449 if (!AT.matchesType(S.Context, T)) {
2450 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_asterisk_wrong_type)
2451 << k << AT.getRepresentativeTypeName(S.Context)
2452 << T << Arg->getSourceRange(),
2453 getLocationOfByte(Amt.getStart()),
2454 /*IsStringLocation*/true,
2455 getSpecifierRange(startSpecifier, specifierLen));
2456 // Don't do any more checking. We will just emit
2465 void CheckPrintfHandler::HandleInvalidAmount(
2466 const analyze_printf::PrintfSpecifier &FS,
2467 const analyze_printf::OptionalAmount &Amt,
2469 const char *startSpecifier,
2470 unsigned specifierLen) {
2471 const analyze_printf::PrintfConversionSpecifier &CS =
2472 FS.getConversionSpecifier();
2475 Amt.getHowSpecified() == analyze_printf::OptionalAmount::Constant
2476 ? FixItHint::CreateRemoval(getSpecifierRange(Amt.getStart(),
2477 Amt.getConstantLength()))
2480 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_nonsensical_optional_amount)
2481 << type << CS.toString(),
2482 getLocationOfByte(Amt.getStart()),
2483 /*IsStringLocation*/true,
2484 getSpecifierRange(startSpecifier, specifierLen),
2488 void CheckPrintfHandler::HandleFlag(const analyze_printf::PrintfSpecifier &FS,
2489 const analyze_printf::OptionalFlag &flag,
2490 const char *startSpecifier,
2491 unsigned specifierLen) {
2492 // Warn about pointless flag with a fixit removal.
2493 const analyze_printf::PrintfConversionSpecifier &CS =
2494 FS.getConversionSpecifier();
2495 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_nonsensical_flag)
2496 << flag.toString() << CS.toString(),
2497 getLocationOfByte(flag.getPosition()),
2498 /*IsStringLocation*/true,
2499 getSpecifierRange(startSpecifier, specifierLen),
2500 FixItHint::CreateRemoval(
2501 getSpecifierRange(flag.getPosition(), 1)));
2504 void CheckPrintfHandler::HandleIgnoredFlag(
2505 const analyze_printf::PrintfSpecifier &FS,
2506 const analyze_printf::OptionalFlag &ignoredFlag,
2507 const analyze_printf::OptionalFlag &flag,
2508 const char *startSpecifier,
2509 unsigned specifierLen) {
2510 // Warn about ignored flag with a fixit removal.
2511 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_ignored_flag)
2512 << ignoredFlag.toString() << flag.toString(),
2513 getLocationOfByte(ignoredFlag.getPosition()),
2514 /*IsStringLocation*/true,
2515 getSpecifierRange(startSpecifier, specifierLen),
2516 FixItHint::CreateRemoval(
2517 getSpecifierRange(ignoredFlag.getPosition(), 1)));
2520 // Determines if the specified is a C++ class or struct containing
2521 // a member with the specified name and kind (e.g. a CXXMethodDecl named
2523 template<typename MemberKind>
2524 static llvm::SmallPtrSet<MemberKind*, 1>
2525 CXXRecordMembersNamed(StringRef Name, Sema &S, QualType Ty) {
2526 const RecordType *RT = Ty->getAs<RecordType>();
2527 llvm::SmallPtrSet<MemberKind*, 1> Results;
2531 const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl());
2535 LookupResult R(S, &S.PP.getIdentifierTable().get(Name), SourceLocation(),
2536 Sema::LookupMemberName);
2538 // We just need to include all members of the right kind turned up by the
2539 // filter, at this point.
2540 if (S.LookupQualifiedName(R, RT->getDecl()))
2541 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
2542 NamedDecl *decl = (*I)->getUnderlyingDecl();
2543 if (MemberKind *FK = dyn_cast<MemberKind>(decl))
2549 // Check if a (w)string was passed when a (w)char* was needed, and offer a
2550 // better diagnostic if so. AT is assumed to be valid.
2551 // Returns true when a c_str() conversion method is found.
2552 bool CheckPrintfHandler::checkForCStrMembers(
2553 const analyze_printf::ArgType &AT, const Expr *E,
2554 const CharSourceRange &CSR) {
2555 typedef llvm::SmallPtrSet<CXXMethodDecl*, 1> MethodSet;
2558 CXXRecordMembersNamed<CXXMethodDecl>("c_str", S, E->getType());
2560 for (MethodSet::iterator MI = Results.begin(), ME = Results.end();
2562 const CXXMethodDecl *Method = *MI;
2563 if (Method->getNumParams() == 0 &&
2564 AT.matchesType(S.Context, Method->getResultType())) {
2565 // FIXME: Suggest parens if the expression needs them.
2566 SourceLocation EndLoc =
2567 S.getPreprocessor().getLocForEndOfToken(E->getLocEnd());
2568 S.Diag(E->getLocStart(), diag::note_printf_c_str)
2570 << FixItHint::CreateInsertion(EndLoc, ".c_str()");
2579 CheckPrintfHandler::HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier
2581 const char *startSpecifier,
2582 unsigned specifierLen) {
2584 using namespace analyze_format_string;
2585 using namespace analyze_printf;
2586 const PrintfConversionSpecifier &CS = FS.getConversionSpecifier();
2588 if (FS.consumesDataArgument()) {
2591 usesPositionalArgs = FS.usesPositionalArg();
2593 else if (usesPositionalArgs != FS.usesPositionalArg()) {
2594 HandlePositionalNonpositionalArgs(getLocationOfByte(CS.getStart()),
2595 startSpecifier, specifierLen);
2600 // First check if the field width, precision, and conversion specifier
2601 // have matching data arguments.
2602 if (!HandleAmount(FS.getFieldWidth(), /* field width */ 0,
2603 startSpecifier, specifierLen)) {
2607 if (!HandleAmount(FS.getPrecision(), /* precision */ 1,
2608 startSpecifier, specifierLen)) {
2612 if (!CS.consumesDataArgument()) {
2613 // FIXME: Technically specifying a precision or field width here
2614 // makes no sense. Worth issuing a warning at some point.
2618 // Consume the argument.
2619 unsigned argIndex = FS.getArgIndex();
2620 if (argIndex < NumDataArgs) {
2621 // The check to see if the argIndex is valid will come later.
2622 // We set the bit here because we may exit early from this
2623 // function if we encounter some other error.
2624 CoveredArgs.set(argIndex);
2627 // FreeBSD extensions
2628 if (CS.getKind() == ConversionSpecifier::FreeBSDbArg ||
2629 CS.getKind() == ConversionSpecifier::FreeBSDDArg) {
2630 // claim the second argument
2631 CoveredArgs.set(argIndex + 1);
2633 // Now type check the data expression that matches the
2634 // format specifier.
2635 const Expr *Ex = getDataArg(argIndex);
2636 const analyze_printf::ArgType &AT =
2637 (CS.getKind() == ConversionSpecifier::FreeBSDbArg) ?
2638 ArgType(S.Context.IntTy) : ArgType::CStrTy;
2639 if (AT.isValid() && !AT.matchesType(S.Context, Ex->getType()))
2640 S.Diag(getLocationOfByte(CS.getStart()),
2641 diag::warn_printf_conversion_argument_type_mismatch)
2642 << AT.getRepresentativeType(S.Context) << Ex->getType()
2643 << getSpecifierRange(startSpecifier, specifierLen)
2644 << Ex->getSourceRange();
2646 // Now type check the data expression that matches the
2647 // format specifier.
2648 Ex = getDataArg(argIndex + 1);
2649 const analyze_printf::ArgType &AT2 = ArgType::CStrTy;
2650 if (AT2.isValid() && !AT2.matchesType(S.Context, Ex->getType()))
2651 S.Diag(getLocationOfByte(CS.getStart()),
2652 diag::warn_printf_conversion_argument_type_mismatch)
2653 << AT2.getRepresentativeType(S.Context) << Ex->getType()
2654 << getSpecifierRange(startSpecifier, specifierLen)
2655 << Ex->getSourceRange();
2659 // END OF FREEBSD EXTENSIONS
2661 // Check for using an Objective-C specific conversion specifier
2662 // in a non-ObjC literal.
2663 if (!ObjCContext && CS.isObjCArg()) {
2664 return HandleInvalidPrintfConversionSpecifier(FS, startSpecifier,
2668 // Check for invalid use of field width
2669 if (!FS.hasValidFieldWidth()) {
2670 HandleInvalidAmount(FS, FS.getFieldWidth(), /* field width */ 0,
2671 startSpecifier, specifierLen);
2674 // Check for invalid use of precision
2675 if (!FS.hasValidPrecision()) {
2676 HandleInvalidAmount(FS, FS.getPrecision(), /* precision */ 1,
2677 startSpecifier, specifierLen);
2680 // Check each flag does not conflict with any other component.
2681 if (!FS.hasValidThousandsGroupingPrefix())
2682 HandleFlag(FS, FS.hasThousandsGrouping(), startSpecifier, specifierLen);
2683 if (!FS.hasValidLeadingZeros())
2684 HandleFlag(FS, FS.hasLeadingZeros(), startSpecifier, specifierLen);
2685 if (!FS.hasValidPlusPrefix())
2686 HandleFlag(FS, FS.hasPlusPrefix(), startSpecifier, specifierLen);
2687 if (!FS.hasValidSpacePrefix())
2688 HandleFlag(FS, FS.hasSpacePrefix(), startSpecifier, specifierLen);
2689 if (!FS.hasValidAlternativeForm())
2690 HandleFlag(FS, FS.hasAlternativeForm(), startSpecifier, specifierLen);
2691 if (!FS.hasValidLeftJustified())
2692 HandleFlag(FS, FS.isLeftJustified(), startSpecifier, specifierLen);
2694 // Check that flags are not ignored by another flag
2695 if (FS.hasSpacePrefix() && FS.hasPlusPrefix()) // ' ' ignored by '+'
2696 HandleIgnoredFlag(FS, FS.hasSpacePrefix(), FS.hasPlusPrefix(),
2697 startSpecifier, specifierLen);
2698 if (FS.hasLeadingZeros() && FS.isLeftJustified()) // '0' ignored by '-'
2699 HandleIgnoredFlag(FS, FS.hasLeadingZeros(), FS.isLeftJustified(),
2700 startSpecifier, specifierLen);
2702 // Check the length modifier is valid with the given conversion specifier.
2703 if (!FS.hasValidLengthModifier(S.getASTContext().getTargetInfo()))
2704 HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
2705 diag::warn_format_nonsensical_length);
2706 else if (!FS.hasStandardLengthModifier())
2707 HandleNonStandardLengthModifier(FS, startSpecifier, specifierLen);
2708 else if (!FS.hasStandardLengthConversionCombination())
2709 HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
2710 diag::warn_format_non_standard_conversion_spec);
2712 if (!FS.hasStandardConversionSpecifier(S.getLangOpts()))
2713 HandleNonStandardConversionSpecifier(CS, startSpecifier, specifierLen);
2715 // The remaining checks depend on the data arguments.
2719 if (!CheckNumArgs(FS, CS, startSpecifier, specifierLen, argIndex))
2722 const Expr *Arg = getDataArg(argIndex);
2726 return checkFormatExpr(FS, startSpecifier, specifierLen, Arg);
2729 static bool requiresParensToAddCast(const Expr *E) {
2730 // FIXME: We should have a general way to reason about operator
2731 // precedence and whether parens are actually needed here.
2732 // Take care of a few common cases where they aren't.
2733 const Expr *Inside = E->IgnoreImpCasts();
2734 if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(Inside))
2735 Inside = POE->getSyntacticForm()->IgnoreImpCasts();
2737 switch (Inside->getStmtClass()) {
2738 case Stmt::ArraySubscriptExprClass:
2739 case Stmt::CallExprClass:
2740 case Stmt::CharacterLiteralClass:
2741 case Stmt::CXXBoolLiteralExprClass:
2742 case Stmt::DeclRefExprClass:
2743 case Stmt::FloatingLiteralClass:
2744 case Stmt::IntegerLiteralClass:
2745 case Stmt::MemberExprClass:
2746 case Stmt::ObjCArrayLiteralClass:
2747 case Stmt::ObjCBoolLiteralExprClass:
2748 case Stmt::ObjCBoxedExprClass:
2749 case Stmt::ObjCDictionaryLiteralClass:
2750 case Stmt::ObjCEncodeExprClass:
2751 case Stmt::ObjCIvarRefExprClass:
2752 case Stmt::ObjCMessageExprClass:
2753 case Stmt::ObjCPropertyRefExprClass:
2754 case Stmt::ObjCStringLiteralClass:
2755 case Stmt::ObjCSubscriptRefExprClass:
2756 case Stmt::ParenExprClass:
2757 case Stmt::StringLiteralClass:
2758 case Stmt::UnaryOperatorClass:
2766 CheckPrintfHandler::checkFormatExpr(const analyze_printf::PrintfSpecifier &FS,
2767 const char *StartSpecifier,
2768 unsigned SpecifierLen,
2770 using namespace analyze_format_string;
2771 using namespace analyze_printf;
2772 // Now type check the data expression that matches the
2773 // format specifier.
2774 const analyze_printf::ArgType &AT = FS.getArgType(S.Context,
2779 QualType ExprTy = E->getType();
2780 while (const TypeOfExprType *TET = dyn_cast<TypeOfExprType>(ExprTy)) {
2781 ExprTy = TET->getUnderlyingExpr()->getType();
2784 if (AT.matchesType(S.Context, ExprTy))
2787 // Look through argument promotions for our error message's reported type.
2788 // This includes the integral and floating promotions, but excludes array
2789 // and function pointer decay; seeing that an argument intended to be a
2790 // string has type 'char [6]' is probably more confusing than 'char *'.
2791 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2792 if (ICE->getCastKind() == CK_IntegralCast ||
2793 ICE->getCastKind() == CK_FloatingCast) {
2794 E = ICE->getSubExpr();
2795 ExprTy = E->getType();
2797 // Check if we didn't match because of an implicit cast from a 'char'
2798 // or 'short' to an 'int'. This is done because printf is a varargs
2800 if (ICE->getType() == S.Context.IntTy ||
2801 ICE->getType() == S.Context.UnsignedIntTy) {
2802 // All further checking is done on the subexpression.
2803 if (AT.matchesType(S.Context, ExprTy))
2807 } else if (const CharacterLiteral *CL = dyn_cast<CharacterLiteral>(E)) {
2808 // Special case for 'a', which has type 'int' in C.
2809 // Note, however, that we do /not/ want to treat multibyte constants like
2810 // 'MooV' as characters! This form is deprecated but still exists.
2811 if (ExprTy == S.Context.IntTy)
2812 if (llvm::isUIntN(S.Context.getCharWidth(), CL->getValue()))
2813 ExprTy = S.Context.CharTy;
2816 // %C in an Objective-C context prints a unichar, not a wchar_t.
2817 // If the argument is an integer of some kind, believe the %C and suggest
2818 // a cast instead of changing the conversion specifier.
2819 QualType IntendedTy = ExprTy;
2821 FS.getConversionSpecifier().getKind() == ConversionSpecifier::CArg) {
2822 if (ExprTy->isIntegralOrUnscopedEnumerationType() &&
2823 !ExprTy->isCharType()) {
2824 // 'unichar' is defined as a typedef of unsigned short, but we should
2825 // prefer using the typedef if it is visible.
2826 IntendedTy = S.Context.UnsignedShortTy;
2828 LookupResult Result(S, &S.Context.Idents.get("unichar"), E->getLocStart(),
2829 Sema::LookupOrdinaryName);
2830 if (S.LookupName(Result, S.getCurScope())) {
2831 NamedDecl *ND = Result.getFoundDecl();
2832 if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(ND))
2833 if (TD->getUnderlyingType() == IntendedTy)
2834 IntendedTy = S.Context.getTypedefType(TD);
2839 // Special-case some of Darwin's platform-independence types by suggesting
2840 // casts to primitive types that are known to be large enough.
2841 bool ShouldNotPrintDirectly = false;
2842 if (S.Context.getTargetInfo().getTriple().isOSDarwin()) {
2843 // Use a 'while' to peel off layers of typedefs.
2844 QualType TyTy = IntendedTy;
2845 while (const TypedefType *UserTy = TyTy->getAs<TypedefType>()) {
2846 StringRef Name = UserTy->getDecl()->getName();
2847 QualType CastTy = llvm::StringSwitch<QualType>(Name)
2848 .Case("NSInteger", S.Context.LongTy)
2849 .Case("NSUInteger", S.Context.UnsignedLongTy)
2850 .Case("SInt32", S.Context.IntTy)
2851 .Case("UInt32", S.Context.UnsignedIntTy)
2852 .Default(QualType());
2854 if (!CastTy.isNull()) {
2855 ShouldNotPrintDirectly = true;
2856 IntendedTy = CastTy;
2859 TyTy = UserTy->desugar();
2863 // We may be able to offer a FixItHint if it is a supported type.
2864 PrintfSpecifier fixedFS = FS;
2865 bool success = fixedFS.fixType(IntendedTy, S.getLangOpts(),
2866 S.Context, ObjCContext);
2869 // Get the fix string from the fixed format specifier
2870 SmallString<16> buf;
2871 llvm::raw_svector_ostream os(buf);
2872 fixedFS.toString(os);
2874 CharSourceRange SpecRange = getSpecifierRange(StartSpecifier, SpecifierLen);
2876 if (IntendedTy == ExprTy) {
2877 // In this case, the specifier is wrong and should be changed to match
2879 EmitFormatDiagnostic(
2880 S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
2881 << AT.getRepresentativeTypeName(S.Context) << IntendedTy
2882 << E->getSourceRange(),
2884 /*IsStringLocation*/false,
2886 FixItHint::CreateReplacement(SpecRange, os.str()));
2889 // The canonical type for formatting this value is different from the
2890 // actual type of the expression. (This occurs, for example, with Darwin's
2891 // NSInteger on 32-bit platforms, where it is typedef'd as 'int', but
2892 // should be printed as 'long' for 64-bit compatibility.)
2893 // Rather than emitting a normal format/argument mismatch, we want to
2894 // add a cast to the recommended type (and correct the format string
2896 SmallString<16> CastBuf;
2897 llvm::raw_svector_ostream CastFix(CastBuf);
2899 IntendedTy.print(CastFix, S.Context.getPrintingPolicy());
2902 SmallVector<FixItHint,4> Hints;
2903 if (!AT.matchesType(S.Context, IntendedTy))
2904 Hints.push_back(FixItHint::CreateReplacement(SpecRange, os.str()));
2906 if (const CStyleCastExpr *CCast = dyn_cast<CStyleCastExpr>(E)) {
2907 // If there's already a cast present, just replace it.
2908 SourceRange CastRange(CCast->getLParenLoc(), CCast->getRParenLoc());
2909 Hints.push_back(FixItHint::CreateReplacement(CastRange, CastFix.str()));
2911 } else if (!requiresParensToAddCast(E)) {
2912 // If the expression has high enough precedence,
2913 // just write the C-style cast.
2914 Hints.push_back(FixItHint::CreateInsertion(E->getLocStart(),
2917 // Otherwise, add parens around the expression as well as the cast.
2919 Hints.push_back(FixItHint::CreateInsertion(E->getLocStart(),
2922 SourceLocation After = S.PP.getLocForEndOfToken(E->getLocEnd());
2923 Hints.push_back(FixItHint::CreateInsertion(After, ")"));
2926 if (ShouldNotPrintDirectly) {
2927 // The expression has a type that should not be printed directly.
2928 // We extract the name from the typedef because we don't want to show
2929 // the underlying type in the diagnostic.
2930 StringRef Name = cast<TypedefType>(ExprTy)->getDecl()->getName();
2932 EmitFormatDiagnostic(S.PDiag(diag::warn_format_argument_needs_cast)
2933 << Name << IntendedTy
2934 << E->getSourceRange(),
2935 E->getLocStart(), /*IsStringLocation=*/false,
2938 // In this case, the expression could be printed using a different
2939 // specifier, but we've decided that the specifier is probably correct
2940 // and we should cast instead. Just use the normal warning message.
2941 EmitFormatDiagnostic(
2942 S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
2943 << AT.getRepresentativeTypeName(S.Context) << ExprTy
2944 << E->getSourceRange(),
2945 E->getLocStart(), /*IsStringLocation*/false,
2950 const CharSourceRange &CSR = getSpecifierRange(StartSpecifier,
2952 // Since the warning for passing non-POD types to variadic functions
2953 // was deferred until now, we emit a warning for non-POD
2955 if (S.isValidVarArgType(ExprTy) == Sema::VAK_Invalid) {
2957 if (ExprTy->isObjCObjectType())
2958 DiagKind = diag::err_cannot_pass_objc_interface_to_vararg_format;
2960 DiagKind = diag::warn_non_pod_vararg_with_format_string;
2962 EmitFormatDiagnostic(
2964 << S.getLangOpts().CPlusPlus11
2967 << AT.getRepresentativeTypeName(S.Context)
2969 << E->getSourceRange(),
2970 E->getLocStart(), /*IsStringLocation*/false, CSR);
2972 checkForCStrMembers(AT, E, CSR);
2974 EmitFormatDiagnostic(
2975 S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
2976 << AT.getRepresentativeTypeName(S.Context) << ExprTy
2978 << E->getSourceRange(),
2979 E->getLocStart(), /*IsStringLocation*/false, CSR);
2985 //===--- CHECK: Scanf format string checking ------------------------------===//
2988 class CheckScanfHandler : public CheckFormatHandler {
2990 CheckScanfHandler(Sema &s, const StringLiteral *fexpr,
2991 const Expr *origFormatExpr, unsigned firstDataArg,
2992 unsigned numDataArgs, const char *beg, bool hasVAListArg,
2993 ArrayRef<const Expr *> Args,
2994 unsigned formatIdx, bool inFunctionCall,
2995 Sema::VariadicCallType CallType)
2996 : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg,
2997 numDataArgs, beg, hasVAListArg,
2998 Args, formatIdx, inFunctionCall, CallType)
3001 bool HandleScanfSpecifier(const analyze_scanf::ScanfSpecifier &FS,
3002 const char *startSpecifier,
3003 unsigned specifierLen);
3005 bool HandleInvalidScanfConversionSpecifier(
3006 const analyze_scanf::ScanfSpecifier &FS,
3007 const char *startSpecifier,
3008 unsigned specifierLen);
3010 void HandleIncompleteScanList(const char *start, const char *end);
3014 void CheckScanfHandler::HandleIncompleteScanList(const char *start,
3016 EmitFormatDiagnostic(S.PDiag(diag::warn_scanf_scanlist_incomplete),
3017 getLocationOfByte(end), /*IsStringLocation*/true,
3018 getSpecifierRange(start, end - start));
3021 bool CheckScanfHandler::HandleInvalidScanfConversionSpecifier(
3022 const analyze_scanf::ScanfSpecifier &FS,
3023 const char *startSpecifier,
3024 unsigned specifierLen) {
3026 const analyze_scanf::ScanfConversionSpecifier &CS =
3027 FS.getConversionSpecifier();
3029 return HandleInvalidConversionSpecifier(FS.getArgIndex(),
3030 getLocationOfByte(CS.getStart()),
3031 startSpecifier, specifierLen,
3032 CS.getStart(), CS.getLength());
3035 bool CheckScanfHandler::HandleScanfSpecifier(
3036 const analyze_scanf::ScanfSpecifier &FS,
3037 const char *startSpecifier,
3038 unsigned specifierLen) {
3040 using namespace analyze_scanf;
3041 using namespace analyze_format_string;
3043 const ScanfConversionSpecifier &CS = FS.getConversionSpecifier();
3045 // Handle case where '%' and '*' don't consume an argument. These shouldn't
3046 // be used to decide if we are using positional arguments consistently.
3047 if (FS.consumesDataArgument()) {
3050 usesPositionalArgs = FS.usesPositionalArg();
3052 else if (usesPositionalArgs != FS.usesPositionalArg()) {
3053 HandlePositionalNonpositionalArgs(getLocationOfByte(CS.getStart()),
3054 startSpecifier, specifierLen);
3059 // Check if the field with is non-zero.
3060 const OptionalAmount &Amt = FS.getFieldWidth();
3061 if (Amt.getHowSpecified() == OptionalAmount::Constant) {
3062 if (Amt.getConstantAmount() == 0) {
3063 const CharSourceRange &R = getSpecifierRange(Amt.getStart(),
3064 Amt.getConstantLength());
3065 EmitFormatDiagnostic(S.PDiag(diag::warn_scanf_nonzero_width),
3066 getLocationOfByte(Amt.getStart()),
3067 /*IsStringLocation*/true, R,
3068 FixItHint::CreateRemoval(R));
3072 if (!FS.consumesDataArgument()) {
3073 // FIXME: Technically specifying a precision or field width here
3074 // makes no sense. Worth issuing a warning at some point.
3078 // Consume the argument.
3079 unsigned argIndex = FS.getArgIndex();
3080 if (argIndex < NumDataArgs) {
3081 // The check to see if the argIndex is valid will come later.
3082 // We set the bit here because we may exit early from this
3083 // function if we encounter some other error.
3084 CoveredArgs.set(argIndex);
3087 // Check the length modifier is valid with the given conversion specifier.
3088 if (!FS.hasValidLengthModifier(S.getASTContext().getTargetInfo()))
3089 HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
3090 diag::warn_format_nonsensical_length);
3091 else if (!FS.hasStandardLengthModifier())
3092 HandleNonStandardLengthModifier(FS, startSpecifier, specifierLen);
3093 else if (!FS.hasStandardLengthConversionCombination())
3094 HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
3095 diag::warn_format_non_standard_conversion_spec);
3097 if (!FS.hasStandardConversionSpecifier(S.getLangOpts()))
3098 HandleNonStandardConversionSpecifier(CS, startSpecifier, specifierLen);
3100 // The remaining checks depend on the data arguments.
3104 if (!CheckNumArgs(FS, CS, startSpecifier, specifierLen, argIndex))
3107 // Check that the argument type matches the format specifier.
3108 const Expr *Ex = getDataArg(argIndex);
3112 const analyze_format_string::ArgType &AT = FS.getArgType(S.Context);
3113 if (AT.isValid() && !AT.matchesType(S.Context, Ex->getType())) {
3114 ScanfSpecifier fixedFS = FS;
3115 bool success = fixedFS.fixType(Ex->getType(), S.getLangOpts(),
3119 // Get the fix string from the fixed format specifier.
3120 SmallString<128> buf;
3121 llvm::raw_svector_ostream os(buf);
3122 fixedFS.toString(os);
3124 EmitFormatDiagnostic(
3125 S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
3126 << AT.getRepresentativeTypeName(S.Context) << Ex->getType()
3127 << Ex->getSourceRange(),
3129 /*IsStringLocation*/false,
3130 getSpecifierRange(startSpecifier, specifierLen),
3131 FixItHint::CreateReplacement(
3132 getSpecifierRange(startSpecifier, specifierLen),
3135 EmitFormatDiagnostic(
3136 S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
3137 << AT.getRepresentativeTypeName(S.Context) << Ex->getType()
3138 << Ex->getSourceRange(),
3140 /*IsStringLocation*/false,
3141 getSpecifierRange(startSpecifier, specifierLen));
3148 void Sema::CheckFormatString(const StringLiteral *FExpr,
3149 const Expr *OrigFormatExpr,
3150 ArrayRef<const Expr *> Args,
3151 bool HasVAListArg, unsigned format_idx,
3152 unsigned firstDataArg, FormatStringType Type,
3153 bool inFunctionCall, VariadicCallType CallType) {
3155 // CHECK: is the format string a wide literal?
3156 if (!FExpr->isAscii() && !FExpr->isUTF8()) {
3157 CheckFormatHandler::EmitFormatDiagnostic(
3158 *this, inFunctionCall, Args[format_idx],
3159 PDiag(diag::warn_format_string_is_wide_literal), FExpr->getLocStart(),
3160 /*IsStringLocation*/true, OrigFormatExpr->getSourceRange());
3164 // Str - The format string. NOTE: this is NOT null-terminated!
3165 StringRef StrRef = FExpr->getString();
3166 const char *Str = StrRef.data();
3167 unsigned StrLen = StrRef.size();
3168 const unsigned numDataArgs = Args.size() - firstDataArg;
3170 // CHECK: empty format string?
3171 if (StrLen == 0 && numDataArgs > 0) {
3172 CheckFormatHandler::EmitFormatDiagnostic(
3173 *this, inFunctionCall, Args[format_idx],
3174 PDiag(diag::warn_empty_format_string), FExpr->getLocStart(),
3175 /*IsStringLocation*/true, OrigFormatExpr->getSourceRange());
3179 if (Type == FST_Printf || Type == FST_NSString) {
3180 CheckPrintfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg,
3181 numDataArgs, (Type == FST_NSString),
3182 Str, HasVAListArg, Args, format_idx,
3183 inFunctionCall, CallType);
3185 if (!analyze_format_string::ParsePrintfString(H, Str, Str + StrLen,
3187 Context.getTargetInfo()))
3189 } else if (Type == FST_Scanf) {
3190 CheckScanfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg, numDataArgs,
3191 Str, HasVAListArg, Args, format_idx,
3192 inFunctionCall, CallType);
3194 if (!analyze_format_string::ParseScanfString(H, Str, Str + StrLen,
3196 Context.getTargetInfo()))
3198 } // TODO: handle other formats
3201 //===--- CHECK: Standard memory functions ---------------------------------===//
3203 /// \brief Determine whether the given type is a dynamic class type (e.g.,
3204 /// whether it has a vtable).
3205 static bool isDynamicClassType(QualType T) {
3206 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
3207 if (CXXRecordDecl *Definition = Record->getDefinition())
3208 if (Definition->isDynamicClass())
3214 /// \brief If E is a sizeof expression, returns its argument expression,
3215 /// otherwise returns NULL.
3216 static const Expr *getSizeOfExprArg(const Expr* E) {
3217 if (const UnaryExprOrTypeTraitExpr *SizeOf =
3218 dyn_cast<UnaryExprOrTypeTraitExpr>(E))
3219 if (SizeOf->getKind() == clang::UETT_SizeOf && !SizeOf->isArgumentType())
3220 return SizeOf->getArgumentExpr()->IgnoreParenImpCasts();
3225 /// \brief If E is a sizeof expression, returns its argument type.
3226 static QualType getSizeOfArgType(const Expr* E) {
3227 if (const UnaryExprOrTypeTraitExpr *SizeOf =
3228 dyn_cast<UnaryExprOrTypeTraitExpr>(E))
3229 if (SizeOf->getKind() == clang::UETT_SizeOf)
3230 return SizeOf->getTypeOfArgument();
3235 /// \brief Check for dangerous or invalid arguments to memset().
3237 /// This issues warnings on known problematic, dangerous or unspecified
3238 /// arguments to the standard 'memset', 'memcpy', 'memmove', and 'memcmp'
3241 /// \param Call The call expression to diagnose.
3242 void Sema::CheckMemaccessArguments(const CallExpr *Call,
3244 IdentifierInfo *FnName) {
3247 // It is possible to have a non-standard definition of memset. Validate
3248 // we have enough arguments, and if not, abort further checking.
3249 unsigned ExpectedNumArgs = (BId == Builtin::BIstrndup ? 2 : 3);
3250 if (Call->getNumArgs() < ExpectedNumArgs)
3253 unsigned LastArg = (BId == Builtin::BImemset ||
3254 BId == Builtin::BIstrndup ? 1 : 2);
3255 unsigned LenArg = (BId == Builtin::BIstrndup ? 1 : 2);
3256 const Expr *LenExpr = Call->getArg(LenArg)->IgnoreParenImpCasts();
3258 // We have special checking when the length is a sizeof expression.
3259 QualType SizeOfArgTy = getSizeOfArgType(LenExpr);
3260 const Expr *SizeOfArg = getSizeOfExprArg(LenExpr);
3261 llvm::FoldingSetNodeID SizeOfArgID;
3263 for (unsigned ArgIdx = 0; ArgIdx != LastArg; ++ArgIdx) {
3264 const Expr *Dest = Call->getArg(ArgIdx)->IgnoreParenImpCasts();
3265 SourceRange ArgRange = Call->getArg(ArgIdx)->getSourceRange();
3267 QualType DestTy = Dest->getType();
3268 if (const PointerType *DestPtrTy = DestTy->getAs<PointerType>()) {
3269 QualType PointeeTy = DestPtrTy->getPointeeType();
3271 // Never warn about void type pointers. This can be used to suppress
3273 if (PointeeTy->isVoidType())
3276 // Catch "memset(p, 0, sizeof(p))" -- needs to be sizeof(*p). Do this by
3277 // actually comparing the expressions for equality. Because computing the
3278 // expression IDs can be expensive, we only do this if the diagnostic is
3281 Diags.getDiagnosticLevel(diag::warn_sizeof_pointer_expr_memaccess,
3282 SizeOfArg->getExprLoc())) {
3283 // We only compute IDs for expressions if the warning is enabled, and
3284 // cache the sizeof arg's ID.
3285 if (SizeOfArgID == llvm::FoldingSetNodeID())
3286 SizeOfArg->Profile(SizeOfArgID, Context, true);
3287 llvm::FoldingSetNodeID DestID;
3288 Dest->Profile(DestID, Context, true);
3289 if (DestID == SizeOfArgID) {
3290 // TODO: For strncpy() and friends, this could suggest sizeof(dst)
3291 // over sizeof(src) as well.
3292 unsigned ActionIdx = 0; // Default is to suggest dereferencing.
3293 StringRef ReadableName = FnName->getName();
3295 if (const UnaryOperator *UnaryOp = dyn_cast<UnaryOperator>(Dest))
3296 if (UnaryOp->getOpcode() == UO_AddrOf)
3297 ActionIdx = 1; // If its an address-of operator, just remove it.
3298 if (!PointeeTy->isIncompleteType() &&
3299 (Context.getTypeSize(PointeeTy) == Context.getCharWidth()))
3300 ActionIdx = 2; // If the pointee's size is sizeof(char),
3301 // suggest an explicit length.
3303 // If the function is defined as a builtin macro, do not show macro
3305 SourceLocation SL = SizeOfArg->getExprLoc();
3306 SourceRange DSR = Dest->getSourceRange();
3307 SourceRange SSR = SizeOfArg->getSourceRange();
3308 SourceManager &SM = PP.getSourceManager();
3310 if (SM.isMacroArgExpansion(SL)) {
3311 ReadableName = Lexer::getImmediateMacroName(SL, SM, LangOpts);
3312 SL = SM.getSpellingLoc(SL);
3313 DSR = SourceRange(SM.getSpellingLoc(DSR.getBegin()),
3314 SM.getSpellingLoc(DSR.getEnd()));
3315 SSR = SourceRange(SM.getSpellingLoc(SSR.getBegin()),
3316 SM.getSpellingLoc(SSR.getEnd()));
3319 DiagRuntimeBehavior(SL, SizeOfArg,
3320 PDiag(diag::warn_sizeof_pointer_expr_memaccess)
3326 DiagRuntimeBehavior(SL, SizeOfArg,
3327 PDiag(diag::warn_sizeof_pointer_expr_memaccess_note)
3335 // Also check for cases where the sizeof argument is the exact same
3336 // type as the memory argument, and where it points to a user-defined
3338 if (SizeOfArgTy != QualType()) {
3339 if (PointeeTy->isRecordType() &&
3340 Context.typesAreCompatible(SizeOfArgTy, DestTy)) {
3341 DiagRuntimeBehavior(LenExpr->getExprLoc(), Dest,
3342 PDiag(diag::warn_sizeof_pointer_type_memaccess)
3343 << FnName << SizeOfArgTy << ArgIdx
3344 << PointeeTy << Dest->getSourceRange()
3345 << LenExpr->getSourceRange());
3350 // Always complain about dynamic classes.
3351 if (isDynamicClassType(PointeeTy)) {
3353 unsigned OperationType = 0;
3354 // "overwritten" if we're warning about the destination for any call
3355 // but memcmp; otherwise a verb appropriate to the call.
3356 if (ArgIdx != 0 || BId == Builtin::BImemcmp) {
3357 if (BId == Builtin::BImemcpy)
3359 else if(BId == Builtin::BImemmove)
3361 else if (BId == Builtin::BImemcmp)
3365 DiagRuntimeBehavior(
3366 Dest->getExprLoc(), Dest,
3367 PDiag(diag::warn_dyn_class_memaccess)
3368 << (BId == Builtin::BImemcmp ? ArgIdx + 2 : ArgIdx)
3369 << FnName << PointeeTy
3371 << Call->getCallee()->getSourceRange());
3372 } else if (PointeeTy.hasNonTrivialObjCLifetime() &&
3373 BId != Builtin::BImemset)
3374 DiagRuntimeBehavior(
3375 Dest->getExprLoc(), Dest,
3376 PDiag(diag::warn_arc_object_memaccess)
3377 << ArgIdx << FnName << PointeeTy
3378 << Call->getCallee()->getSourceRange());
3382 DiagRuntimeBehavior(
3383 Dest->getExprLoc(), Dest,
3384 PDiag(diag::note_bad_memaccess_silence)
3385 << FixItHint::CreateInsertion(ArgRange.getBegin(), "(void*)"));
3391 // A little helper routine: ignore addition and subtraction of integer literals.
3392 // This intentionally does not ignore all integer constant expressions because
3393 // we don't want to remove sizeof().
3394 static const Expr *ignoreLiteralAdditions(const Expr *Ex, ASTContext &Ctx) {
3395 Ex = Ex->IgnoreParenCasts();
3398 const BinaryOperator * BO = dyn_cast<BinaryOperator>(Ex);
3399 if (!BO || !BO->isAdditiveOp())
3402 const Expr *RHS = BO->getRHS()->IgnoreParenCasts();
3403 const Expr *LHS = BO->getLHS()->IgnoreParenCasts();
3405 if (isa<IntegerLiteral>(RHS))
3407 else if (isa<IntegerLiteral>(LHS))
3416 static bool isConstantSizeArrayWithMoreThanOneElement(QualType Ty,
3417 ASTContext &Context) {
3418 // Only handle constant-sized or VLAs, but not flexible members.
3419 if (const ConstantArrayType *CAT = Context.getAsConstantArrayType(Ty)) {
3420 // Only issue the FIXIT for arrays of size > 1.
3421 if (CAT->getSize().getSExtValue() <= 1)
3423 } else if (!Ty->isVariableArrayType()) {
3429 // Warn if the user has made the 'size' argument to strlcpy or strlcat
3430 // be the size of the source, instead of the destination.
3431 void Sema::CheckStrlcpycatArguments(const CallExpr *Call,
3432 IdentifierInfo *FnName) {
3434 // Don't crash if the user has the wrong number of arguments
3435 if (Call->getNumArgs() != 3)
3438 const Expr *SrcArg = ignoreLiteralAdditions(Call->getArg(1), Context);
3439 const Expr *SizeArg = ignoreLiteralAdditions(Call->getArg(2), Context);
3440 const Expr *CompareWithSrc = NULL;
3442 // Look for 'strlcpy(dst, x, sizeof(x))'
3443 if (const Expr *Ex = getSizeOfExprArg(SizeArg))
3444 CompareWithSrc = Ex;
3446 // Look for 'strlcpy(dst, x, strlen(x))'
3447 if (const CallExpr *SizeCall = dyn_cast<CallExpr>(SizeArg)) {
3448 if (SizeCall->isBuiltinCall() == Builtin::BIstrlen
3449 && SizeCall->getNumArgs() == 1)
3450 CompareWithSrc = ignoreLiteralAdditions(SizeCall->getArg(0), Context);
3454 if (!CompareWithSrc)
3457 // Determine if the argument to sizeof/strlen is equal to the source
3458 // argument. In principle there's all kinds of things you could do
3459 // here, for instance creating an == expression and evaluating it with
3460 // EvaluateAsBooleanCondition, but this uses a more direct technique:
3461 const DeclRefExpr *SrcArgDRE = dyn_cast<DeclRefExpr>(SrcArg);
3465 const DeclRefExpr *CompareWithSrcDRE = dyn_cast<DeclRefExpr>(CompareWithSrc);
3466 if (!CompareWithSrcDRE ||
3467 SrcArgDRE->getDecl() != CompareWithSrcDRE->getDecl())
3470 const Expr *OriginalSizeArg = Call->getArg(2);
3471 Diag(CompareWithSrcDRE->getLocStart(), diag::warn_strlcpycat_wrong_size)
3472 << OriginalSizeArg->getSourceRange() << FnName;
3474 // Output a FIXIT hint if the destination is an array (rather than a
3475 // pointer to an array). This could be enhanced to handle some
3476 // pointers if we know the actual size, like if DstArg is 'array+2'
3477 // we could say 'sizeof(array)-2'.
3478 const Expr *DstArg = Call->getArg(0)->IgnoreParenImpCasts();
3479 if (!isConstantSizeArrayWithMoreThanOneElement(DstArg->getType(), Context))
3482 SmallString<128> sizeString;
3483 llvm::raw_svector_ostream OS(sizeString);
3485 DstArg->printPretty(OS, 0, getPrintingPolicy());
3488 Diag(OriginalSizeArg->getLocStart(), diag::note_strlcpycat_wrong_size)
3489 << FixItHint::CreateReplacement(OriginalSizeArg->getSourceRange(),
3493 /// Check if two expressions refer to the same declaration.
3494 static bool referToTheSameDecl(const Expr *E1, const Expr *E2) {
3495 if (const DeclRefExpr *D1 = dyn_cast_or_null<DeclRefExpr>(E1))
3496 if (const DeclRefExpr *D2 = dyn_cast_or_null<DeclRefExpr>(E2))
3497 return D1->getDecl() == D2->getDecl();
3501 static const Expr *getStrlenExprArg(const Expr *E) {
3502 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
3503 const FunctionDecl *FD = CE->getDirectCallee();
3504 if (!FD || FD->getMemoryFunctionKind() != Builtin::BIstrlen)
3506 return CE->getArg(0)->IgnoreParenCasts();
3511 // Warn on anti-patterns as the 'size' argument to strncat.
3512 // The correct size argument should look like following:
3513 // strncat(dst, src, sizeof(dst) - strlen(dest) - 1);
3514 void Sema::CheckStrncatArguments(const CallExpr *CE,
3515 IdentifierInfo *FnName) {
3516 // Don't crash if the user has the wrong number of arguments.
3517 if (CE->getNumArgs() < 3)
3519 const Expr *DstArg = CE->getArg(0)->IgnoreParenCasts();
3520 const Expr *SrcArg = CE->getArg(1)->IgnoreParenCasts();
3521 const Expr *LenArg = CE->getArg(2)->IgnoreParenCasts();
3523 // Identify common expressions, which are wrongly used as the size argument
3524 // to strncat and may lead to buffer overflows.
3525 unsigned PatternType = 0;
3526 if (const Expr *SizeOfArg = getSizeOfExprArg(LenArg)) {
3528 if (referToTheSameDecl(SizeOfArg, DstArg))
3531 else if (referToTheSameDecl(SizeOfArg, SrcArg))
3533 } else if (const BinaryOperator *BE = dyn_cast<BinaryOperator>(LenArg)) {
3534 if (BE->getOpcode() == BO_Sub) {
3535 const Expr *L = BE->getLHS()->IgnoreParenCasts();
3536 const Expr *R = BE->getRHS()->IgnoreParenCasts();
3537 // - sizeof(dst) - strlen(dst)
3538 if (referToTheSameDecl(DstArg, getSizeOfExprArg(L)) &&
3539 referToTheSameDecl(DstArg, getStrlenExprArg(R)))
3541 // - sizeof(src) - (anything)
3542 else if (referToTheSameDecl(SrcArg, getSizeOfExprArg(L)))
3547 if (PatternType == 0)
3550 // Generate the diagnostic.
3551 SourceLocation SL = LenArg->getLocStart();
3552 SourceRange SR = LenArg->getSourceRange();
3553 SourceManager &SM = PP.getSourceManager();
3555 // If the function is defined as a builtin macro, do not show macro expansion.
3556 if (SM.isMacroArgExpansion(SL)) {
3557 SL = SM.getSpellingLoc(SL);
3558 SR = SourceRange(SM.getSpellingLoc(SR.getBegin()),
3559 SM.getSpellingLoc(SR.getEnd()));
3562 // Check if the destination is an array (rather than a pointer to an array).
3563 QualType DstTy = DstArg->getType();
3564 bool isKnownSizeArray = isConstantSizeArrayWithMoreThanOneElement(DstTy,
3566 if (!isKnownSizeArray) {
3567 if (PatternType == 1)
3568 Diag(SL, diag::warn_strncat_wrong_size) << SR;
3570 Diag(SL, diag::warn_strncat_src_size) << SR;
3574 if (PatternType == 1)
3575 Diag(SL, diag::warn_strncat_large_size) << SR;
3577 Diag(SL, diag::warn_strncat_src_size) << SR;
3579 SmallString<128> sizeString;
3580 llvm::raw_svector_ostream OS(sizeString);
3582 DstArg->printPretty(OS, 0, getPrintingPolicy());
3585 DstArg->printPretty(OS, 0, getPrintingPolicy());
3588 Diag(SL, diag::note_strncat_wrong_size)
3589 << FixItHint::CreateReplacement(SR, OS.str());
3592 //===--- CHECK: Return Address of Stack Variable --------------------------===//
3594 static Expr *EvalVal(Expr *E, SmallVectorImpl<DeclRefExpr *> &refVars,
3596 static Expr *EvalAddr(Expr* E, SmallVectorImpl<DeclRefExpr *> &refVars,
3599 /// CheckReturnStackAddr - Check if a return statement returns the address
3600 /// of a stack variable.
3602 Sema::CheckReturnStackAddr(Expr *RetValExp, QualType lhsType,
3603 SourceLocation ReturnLoc) {
3606 SmallVector<DeclRefExpr *, 8> refVars;
3608 // Perform checking for returned stack addresses, local blocks,
3609 // label addresses or references to temporaries.
3610 if (lhsType->isPointerType() ||
3611 (!getLangOpts().ObjCAutoRefCount && lhsType->isBlockPointerType())) {
3612 stackE = EvalAddr(RetValExp, refVars, /*ParentDecl=*/0);
3613 } else if (lhsType->isReferenceType()) {
3614 stackE = EvalVal(RetValExp, refVars, /*ParentDecl=*/0);
3618 return; // Nothing suspicious was found.
3620 SourceLocation diagLoc;
3621 SourceRange diagRange;
3622 if (refVars.empty()) {
3623 diagLoc = stackE->getLocStart();
3624 diagRange = stackE->getSourceRange();
3626 // We followed through a reference variable. 'stackE' contains the
3627 // problematic expression but we will warn at the return statement pointing
3628 // at the reference variable. We will later display the "trail" of
3629 // reference variables using notes.
3630 diagLoc = refVars[0]->getLocStart();
3631 diagRange = refVars[0]->getSourceRange();
3634 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(stackE)) { //address of local var.
3635 Diag(diagLoc, lhsType->isReferenceType() ? diag::warn_ret_stack_ref
3636 : diag::warn_ret_stack_addr)
3637 << DR->getDecl()->getDeclName() << diagRange;
3638 } else if (isa<BlockExpr>(stackE)) { // local block.
3639 Diag(diagLoc, diag::err_ret_local_block) << diagRange;
3640 } else if (isa<AddrLabelExpr>(stackE)) { // address of label.
3641 Diag(diagLoc, diag::warn_ret_addr_label) << diagRange;
3642 } else { // local temporary.
3643 Diag(diagLoc, lhsType->isReferenceType() ? diag::warn_ret_local_temp_ref
3644 : diag::warn_ret_local_temp_addr)
3648 // Display the "trail" of reference variables that we followed until we
3649 // found the problematic expression using notes.
3650 for (unsigned i = 0, e = refVars.size(); i != e; ++i) {
3651 VarDecl *VD = cast<VarDecl>(refVars[i]->getDecl());
3652 // If this var binds to another reference var, show the range of the next
3653 // var, otherwise the var binds to the problematic expression, in which case
3654 // show the range of the expression.
3655 SourceRange range = (i < e-1) ? refVars[i+1]->getSourceRange()
3656 : stackE->getSourceRange();
3657 Diag(VD->getLocation(), diag::note_ref_var_local_bind)
3658 << VD->getDeclName() << range;
3662 /// EvalAddr - EvalAddr and EvalVal are mutually recursive functions that
3663 /// check if the expression in a return statement evaluates to an address
3664 /// to a location on the stack, a local block, an address of a label, or a
3665 /// reference to local temporary. The recursion is used to traverse the
3666 /// AST of the return expression, with recursion backtracking when we
3667 /// encounter a subexpression that (1) clearly does not lead to one of the
3668 /// above problematic expressions (2) is something we cannot determine leads to
3669 /// a problematic expression based on such local checking.
3671 /// Both EvalAddr and EvalVal follow through reference variables to evaluate
3672 /// the expression that they point to. Such variables are added to the
3673 /// 'refVars' vector so that we know what the reference variable "trail" was.
3675 /// EvalAddr processes expressions that are pointers that are used as
3676 /// references (and not L-values). EvalVal handles all other values.
3677 /// At the base case of the recursion is a check for the above problematic
3680 /// This implementation handles:
3682 /// * pointer-to-pointer casts
3683 /// * implicit conversions from array references to pointers
3684 /// * taking the address of fields
3685 /// * arbitrary interplay between "&" and "*" operators
3686 /// * pointer arithmetic from an address of a stack variable
3687 /// * taking the address of an array element where the array is on the stack
3688 static Expr *EvalAddr(Expr *E, SmallVectorImpl<DeclRefExpr *> &refVars,
3690 if (E->isTypeDependent())
3693 // We should only be called for evaluating pointer expressions.
3694 assert((E->getType()->isAnyPointerType() ||
3695 E->getType()->isBlockPointerType() ||
3696 E->getType()->isObjCQualifiedIdType()) &&
3697 "EvalAddr only works on pointers");
3699 E = E->IgnoreParens();
3701 // Our "symbolic interpreter" is just a dispatch off the currently
3702 // viewed AST node. We then recursively traverse the AST by calling
3703 // EvalAddr and EvalVal appropriately.
3704 switch (E->getStmtClass()) {
3705 case Stmt::DeclRefExprClass: {
3706 DeclRefExpr *DR = cast<DeclRefExpr>(E);
3708 if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl()))
3709 // If this is a reference variable, follow through to the expression that
3711 if (V->hasLocalStorage() &&
3712 V->getType()->isReferenceType() && V->hasInit()) {
3713 // Add the reference variable to the "trail".
3714 refVars.push_back(DR);
3715 return EvalAddr(V->getInit(), refVars, ParentDecl);
3721 case Stmt::UnaryOperatorClass: {
3722 // The only unary operator that make sense to handle here
3723 // is AddrOf. All others don't make sense as pointers.
3724 UnaryOperator *U = cast<UnaryOperator>(E);
3726 if (U->getOpcode() == UO_AddrOf)
3727 return EvalVal(U->getSubExpr(), refVars, ParentDecl);
3732 case Stmt::BinaryOperatorClass: {
3733 // Handle pointer arithmetic. All other binary operators are not valid
3735 BinaryOperator *B = cast<BinaryOperator>(E);
3736 BinaryOperatorKind op = B->getOpcode();
3738 if (op != BO_Add && op != BO_Sub)
3741 Expr *Base = B->getLHS();
3743 // Determine which argument is the real pointer base. It could be
3744 // the RHS argument instead of the LHS.
3745 if (!Base->getType()->isPointerType()) Base = B->getRHS();
3747 assert (Base->getType()->isPointerType());
3748 return EvalAddr(Base, refVars, ParentDecl);
3751 // For conditional operators we need to see if either the LHS or RHS are
3752 // valid DeclRefExpr*s. If one of them is valid, we return it.
3753 case Stmt::ConditionalOperatorClass: {
3754 ConditionalOperator *C = cast<ConditionalOperator>(E);
3756 // Handle the GNU extension for missing LHS.
3757 if (Expr *lhsExpr = C->getLHS()) {
3758 // In C++, we can have a throw-expression, which has 'void' type.
3759 if (!lhsExpr->getType()->isVoidType())
3760 if (Expr* LHS = EvalAddr(lhsExpr, refVars, ParentDecl))
3764 // In C++, we can have a throw-expression, which has 'void' type.
3765 if (C->getRHS()->getType()->isVoidType())
3768 return EvalAddr(C->getRHS(), refVars, ParentDecl);
3771 case Stmt::BlockExprClass:
3772 if (cast<BlockExpr>(E)->getBlockDecl()->hasCaptures())
3773 return E; // local block.
3776 case Stmt::AddrLabelExprClass:
3777 return E; // address of label.
3779 case Stmt::ExprWithCleanupsClass:
3780 return EvalAddr(cast<ExprWithCleanups>(E)->getSubExpr(), refVars,
3783 // For casts, we need to handle conversions from arrays to
3784 // pointer values, and pointer-to-pointer conversions.
3785 case Stmt::ImplicitCastExprClass:
3786 case Stmt::CStyleCastExprClass:
3787 case Stmt::CXXFunctionalCastExprClass:
3788 case Stmt::ObjCBridgedCastExprClass:
3789 case Stmt::CXXStaticCastExprClass:
3790 case Stmt::CXXDynamicCastExprClass:
3791 case Stmt::CXXConstCastExprClass:
3792 case Stmt::CXXReinterpretCastExprClass: {
3793 Expr* SubExpr = cast<CastExpr>(E)->getSubExpr();
3794 switch (cast<CastExpr>(E)->getCastKind()) {
3796 case CK_LValueToRValue:
3798 case CK_BaseToDerived:
3799 case CK_DerivedToBase:
3800 case CK_UncheckedDerivedToBase:
3802 case CK_CPointerToObjCPointerCast:
3803 case CK_BlockPointerToObjCPointerCast:
3804 case CK_AnyPointerToBlockPointerCast:
3805 return EvalAddr(SubExpr, refVars, ParentDecl);
3807 case CK_ArrayToPointerDecay:
3808 return EvalVal(SubExpr, refVars, ParentDecl);
3815 case Stmt::MaterializeTemporaryExprClass:
3816 if (Expr *Result = EvalAddr(
3817 cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr(),
3818 refVars, ParentDecl))
3823 // Everything else: we simply don't reason about them.
3830 /// EvalVal - This function is complements EvalAddr in the mutual recursion.
3831 /// See the comments for EvalAddr for more details.
3832 static Expr *EvalVal(Expr *E, SmallVectorImpl<DeclRefExpr *> &refVars,
3835 // We should only be called for evaluating non-pointer expressions, or
3836 // expressions with a pointer type that are not used as references but instead
3837 // are l-values (e.g., DeclRefExpr with a pointer type).
3839 // Our "symbolic interpreter" is just a dispatch off the currently
3840 // viewed AST node. We then recursively traverse the AST by calling
3841 // EvalAddr and EvalVal appropriately.
3843 E = E->IgnoreParens();
3844 switch (E->getStmtClass()) {
3845 case Stmt::ImplicitCastExprClass: {
3846 ImplicitCastExpr *IE = cast<ImplicitCastExpr>(E);
3847 if (IE->getValueKind() == VK_LValue) {
3848 E = IE->getSubExpr();
3854 case Stmt::ExprWithCleanupsClass:
3855 return EvalVal(cast<ExprWithCleanups>(E)->getSubExpr(), refVars,ParentDecl);
3857 case Stmt::DeclRefExprClass: {
3858 // When we hit a DeclRefExpr we are looking at code that refers to a
3859 // variable's name. If it's not a reference variable we check if it has
3860 // local storage within the function, and if so, return the expression.
3861 DeclRefExpr *DR = cast<DeclRefExpr>(E);
3863 if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl())) {
3864 // Check if it refers to itself, e.g. "int& i = i;".
3865 if (V == ParentDecl)
3868 if (V->hasLocalStorage()) {
3869 if (!V->getType()->isReferenceType())
3872 // Reference variable, follow through to the expression that
3875 // Add the reference variable to the "trail".
3876 refVars.push_back(DR);
3877 return EvalVal(V->getInit(), refVars, V);
3885 case Stmt::UnaryOperatorClass: {
3886 // The only unary operator that make sense to handle here
3887 // is Deref. All others don't resolve to a "name." This includes
3888 // handling all sorts of rvalues passed to a unary operator.
3889 UnaryOperator *U = cast<UnaryOperator>(E);
3891 if (U->getOpcode() == UO_Deref)
3892 return EvalAddr(U->getSubExpr(), refVars, ParentDecl);
3897 case Stmt::ArraySubscriptExprClass: {
3898 // Array subscripts are potential references to data on the stack. We
3899 // retrieve the DeclRefExpr* for the array variable if it indeed
3900 // has local storage.
3901 return EvalAddr(cast<ArraySubscriptExpr>(E)->getBase(), refVars,ParentDecl);
3904 case Stmt::ConditionalOperatorClass: {
3905 // For conditional operators we need to see if either the LHS or RHS are
3906 // non-NULL Expr's. If one is non-NULL, we return it.
3907 ConditionalOperator *C = cast<ConditionalOperator>(E);
3909 // Handle the GNU extension for missing LHS.
3910 if (Expr *lhsExpr = C->getLHS())
3911 if (Expr *LHS = EvalVal(lhsExpr, refVars, ParentDecl))
3914 return EvalVal(C->getRHS(), refVars, ParentDecl);
3917 // Accesses to members are potential references to data on the stack.
3918 case Stmt::MemberExprClass: {
3919 MemberExpr *M = cast<MemberExpr>(E);
3921 // Check for indirect access. We only want direct field accesses.
3925 // Check whether the member type is itself a reference, in which case
3926 // we're not going to refer to the member, but to what the member refers to.
3927 if (M->getMemberDecl()->getType()->isReferenceType())
3930 return EvalVal(M->getBase(), refVars, ParentDecl);
3933 case Stmt::MaterializeTemporaryExprClass:
3934 if (Expr *Result = EvalVal(
3935 cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr(),
3936 refVars, ParentDecl))
3942 // Check that we don't return or take the address of a reference to a
3943 // temporary. This is only useful in C++.
3944 if (!E->isTypeDependent() && E->isRValue())
3947 // Everything else: we simply don't reason about them.
3953 //===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===//
3955 /// Check for comparisons of floating point operands using != and ==.
3956 /// Issue a warning if these are no self-comparisons, as they are not likely
3957 /// to do what the programmer intended.
3958 void Sema::CheckFloatComparison(SourceLocation Loc, Expr* LHS, Expr *RHS) {
3959 Expr* LeftExprSansParen = LHS->IgnoreParenImpCasts();
3960 Expr* RightExprSansParen = RHS->IgnoreParenImpCasts();
3962 // Special case: check for x == x (which is OK).
3963 // Do not emit warnings for such cases.
3964 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LeftExprSansParen))
3965 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RightExprSansParen))
3966 if (DRL->getDecl() == DRR->getDecl())
3970 // Special case: check for comparisons against literals that can be exactly
3971 // represented by APFloat. In such cases, do not emit a warning. This
3972 // is a heuristic: often comparison against such literals are used to
3973 // detect if a value in a variable has not changed. This clearly can
3974 // lead to false negatives.
3975 if (FloatingLiteral* FLL = dyn_cast<FloatingLiteral>(LeftExprSansParen)) {
3979 if (FloatingLiteral* FLR = dyn_cast<FloatingLiteral>(RightExprSansParen))
3983 // Check for comparisons with builtin types.
3984 if (CallExpr* CL = dyn_cast<CallExpr>(LeftExprSansParen))
3985 if (CL->isBuiltinCall())
3988 if (CallExpr* CR = dyn_cast<CallExpr>(RightExprSansParen))
3989 if (CR->isBuiltinCall())
3992 // Emit the diagnostic.
3993 Diag(Loc, diag::warn_floatingpoint_eq)
3994 << LHS->getSourceRange() << RHS->getSourceRange();
3997 //===--- CHECK: Integer mixed-sign comparisons (-Wsign-compare) --------===//
3998 //===--- CHECK: Lossy implicit conversions (-Wconversion) --------------===//
4002 /// Structure recording the 'active' range of an integer-valued
4005 /// The number of bits active in the int.
4008 /// True if the int is known not to have negative values.
4011 IntRange(unsigned Width, bool NonNegative)
4012 : Width(Width), NonNegative(NonNegative)
4015 /// Returns the range of the bool type.
4016 static IntRange forBoolType() {
4017 return IntRange(1, true);
4020 /// Returns the range of an opaque value of the given integral type.
4021 static IntRange forValueOfType(ASTContext &C, QualType T) {
4022 return forValueOfCanonicalType(C,
4023 T->getCanonicalTypeInternal().getTypePtr());
4026 /// Returns the range of an opaque value of a canonical integral type.
4027 static IntRange forValueOfCanonicalType(ASTContext &C, const Type *T) {
4028 assert(T->isCanonicalUnqualified());
4030 if (const VectorType *VT = dyn_cast<VectorType>(T))
4031 T = VT->getElementType().getTypePtr();
4032 if (const ComplexType *CT = dyn_cast<ComplexType>(T))
4033 T = CT->getElementType().getTypePtr();
4035 // For enum types, use the known bit width of the enumerators.
4036 if (const EnumType *ET = dyn_cast<EnumType>(T)) {
4037 EnumDecl *Enum = ET->getDecl();
4038 if (!Enum->isCompleteDefinition())
4039 return IntRange(C.getIntWidth(QualType(T, 0)), false);
4041 unsigned NumPositive = Enum->getNumPositiveBits();
4042 unsigned NumNegative = Enum->getNumNegativeBits();
4044 if (NumNegative == 0)
4045 return IntRange(NumPositive, true/*NonNegative*/);
4047 return IntRange(std::max(NumPositive + 1, NumNegative),
4048 false/*NonNegative*/);
4051 const BuiltinType *BT = cast<BuiltinType>(T);
4052 assert(BT->isInteger());
4054 return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger());
4057 /// Returns the "target" range of a canonical integral type, i.e.
4058 /// the range of values expressible in the type.
4060 /// This matches forValueOfCanonicalType except that enums have the
4061 /// full range of their type, not the range of their enumerators.
4062 static IntRange forTargetOfCanonicalType(ASTContext &C, const Type *T) {
4063 assert(T->isCanonicalUnqualified());
4065 if (const VectorType *VT = dyn_cast<VectorType>(T))
4066 T = VT->getElementType().getTypePtr();
4067 if (const ComplexType *CT = dyn_cast<ComplexType>(T))
4068 T = CT->getElementType().getTypePtr();
4069 if (const EnumType *ET = dyn_cast<EnumType>(T))
4070 T = C.getCanonicalType(ET->getDecl()->getIntegerType()).getTypePtr();
4072 const BuiltinType *BT = cast<BuiltinType>(T);
4073 assert(BT->isInteger());
4075 return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger());
4078 /// Returns the supremum of two ranges: i.e. their conservative merge.
4079 static IntRange join(IntRange L, IntRange R) {
4080 return IntRange(std::max(L.Width, R.Width),
4081 L.NonNegative && R.NonNegative);
4084 /// Returns the infinum of two ranges: i.e. their aggressive merge.
4085 static IntRange meet(IntRange L, IntRange R) {
4086 return IntRange(std::min(L.Width, R.Width),
4087 L.NonNegative || R.NonNegative);
4091 static IntRange GetValueRange(ASTContext &C, llvm::APSInt &value,
4092 unsigned MaxWidth) {
4093 if (value.isSigned() && value.isNegative())
4094 return IntRange(value.getMinSignedBits(), false);
4096 if (value.getBitWidth() > MaxWidth)
4097 value = value.trunc(MaxWidth);
4099 // isNonNegative() just checks the sign bit without considering
4101 return IntRange(value.getActiveBits(), true);
4104 static IntRange GetValueRange(ASTContext &C, APValue &result, QualType Ty,
4105 unsigned MaxWidth) {
4107 return GetValueRange(C, result.getInt(), MaxWidth);
4109 if (result.isVector()) {
4110 IntRange R = GetValueRange(C, result.getVectorElt(0), Ty, MaxWidth);
4111 for (unsigned i = 1, e = result.getVectorLength(); i != e; ++i) {
4112 IntRange El = GetValueRange(C, result.getVectorElt(i), Ty, MaxWidth);
4113 R = IntRange::join(R, El);
4118 if (result.isComplexInt()) {
4119 IntRange R = GetValueRange(C, result.getComplexIntReal(), MaxWidth);
4120 IntRange I = GetValueRange(C, result.getComplexIntImag(), MaxWidth);
4121 return IntRange::join(R, I);
4124 // This can happen with lossless casts to intptr_t of "based" lvalues.
4125 // Assume it might use arbitrary bits.
4126 // FIXME: The only reason we need to pass the type in here is to get
4127 // the sign right on this one case. It would be nice if APValue
4129 assert(result.isLValue() || result.isAddrLabelDiff());
4130 return IntRange(MaxWidth, Ty->isUnsignedIntegerOrEnumerationType());
4133 /// Pseudo-evaluate the given integer expression, estimating the
4134 /// range of values it might take.
4136 /// \param MaxWidth - the width to which the value will be truncated
4137 static IntRange GetExprRange(ASTContext &C, Expr *E, unsigned MaxWidth) {
4138 E = E->IgnoreParens();
4140 // Try a full evaluation first.
4141 Expr::EvalResult result;
4142 if (E->EvaluateAsRValue(result, C))
4143 return GetValueRange(C, result.Val, E->getType(), MaxWidth);
4145 // I think we only want to look through implicit casts here; if the
4146 // user has an explicit widening cast, we should treat the value as
4147 // being of the new, wider type.
4148 if (ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E)) {
4149 if (CE->getCastKind() == CK_NoOp || CE->getCastKind() == CK_LValueToRValue)
4150 return GetExprRange(C, CE->getSubExpr(), MaxWidth);
4152 IntRange OutputTypeRange = IntRange::forValueOfType(C, CE->getType());
4154 bool isIntegerCast = (CE->getCastKind() == CK_IntegralCast);
4156 // Assume that non-integer casts can span the full range of the type.
4158 return OutputTypeRange;
4161 = GetExprRange(C, CE->getSubExpr(),
4162 std::min(MaxWidth, OutputTypeRange.Width));
4164 // Bail out if the subexpr's range is as wide as the cast type.
4165 if (SubRange.Width >= OutputTypeRange.Width)
4166 return OutputTypeRange;
4168 // Otherwise, we take the smaller width, and we're non-negative if
4169 // either the output type or the subexpr is.
4170 return IntRange(SubRange.Width,
4171 SubRange.NonNegative || OutputTypeRange.NonNegative);
4174 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
4175 // If we can fold the condition, just take that operand.
4177 if (CO->getCond()->EvaluateAsBooleanCondition(CondResult, C))
4178 return GetExprRange(C, CondResult ? CO->getTrueExpr()
4179 : CO->getFalseExpr(),
4182 // Otherwise, conservatively merge.
4183 IntRange L = GetExprRange(C, CO->getTrueExpr(), MaxWidth);
4184 IntRange R = GetExprRange(C, CO->getFalseExpr(), MaxWidth);
4185 return IntRange::join(L, R);
4188 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
4189 switch (BO->getOpcode()) {
4191 // Boolean-valued operations are single-bit and positive.
4200 return IntRange::forBoolType();
4202 // The type of the assignments is the type of the LHS, so the RHS
4203 // is not necessarily the same type.
4212 return IntRange::forValueOfType(C, E->getType());
4214 // Simple assignments just pass through the RHS, which will have
4215 // been coerced to the LHS type.
4218 return GetExprRange(C, BO->getRHS(), MaxWidth);
4220 // Operations with opaque sources are black-listed.
4223 return IntRange::forValueOfType(C, E->getType());
4225 // Bitwise-and uses the *infinum* of the two source ranges.
4228 return IntRange::meet(GetExprRange(C, BO->getLHS(), MaxWidth),
4229 GetExprRange(C, BO->getRHS(), MaxWidth));
4231 // Left shift gets black-listed based on a judgement call.
4233 // ...except that we want to treat '1 << (blah)' as logically
4234 // positive. It's an important idiom.
4235 if (IntegerLiteral *I
4236 = dyn_cast<IntegerLiteral>(BO->getLHS()->IgnoreParenCasts())) {
4237 if (I->getValue() == 1) {
4238 IntRange R = IntRange::forValueOfType(C, E->getType());
4239 return IntRange(R.Width, /*NonNegative*/ true);
4245 return IntRange::forValueOfType(C, E->getType());
4247 // Right shift by a constant can narrow its left argument.
4249 case BO_ShrAssign: {
4250 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth);
4252 // If the shift amount is a positive constant, drop the width by
4255 if (BO->getRHS()->isIntegerConstantExpr(shift, C) &&
4256 shift.isNonNegative()) {
4257 unsigned zext = shift.getZExtValue();
4258 if (zext >= L.Width)
4259 L.Width = (L.NonNegative ? 0 : 1);
4267 // Comma acts as its right operand.
4269 return GetExprRange(C, BO->getRHS(), MaxWidth);
4271 // Black-list pointer subtractions.
4273 if (BO->getLHS()->getType()->isPointerType())
4274 return IntRange::forValueOfType(C, E->getType());
4277 // The width of a division result is mostly determined by the size
4280 // Don't 'pre-truncate' the operands.
4281 unsigned opWidth = C.getIntWidth(E->getType());
4282 IntRange L = GetExprRange(C, BO->getLHS(), opWidth);
4284 // If the divisor is constant, use that.
4285 llvm::APSInt divisor;
4286 if (BO->getRHS()->isIntegerConstantExpr(divisor, C)) {
4287 unsigned log2 = divisor.logBase2(); // floor(log_2(divisor))
4288 if (log2 >= L.Width)
4289 L.Width = (L.NonNegative ? 0 : 1);
4291 L.Width = std::min(L.Width - log2, MaxWidth);
4295 // Otherwise, just use the LHS's width.
4296 IntRange R = GetExprRange(C, BO->getRHS(), opWidth);
4297 return IntRange(L.Width, L.NonNegative && R.NonNegative);
4300 // The result of a remainder can't be larger than the result of
4303 // Don't 'pre-truncate' the operands.
4304 unsigned opWidth = C.getIntWidth(E->getType());
4305 IntRange L = GetExprRange(C, BO->getLHS(), opWidth);
4306 IntRange R = GetExprRange(C, BO->getRHS(), opWidth);
4308 IntRange meet = IntRange::meet(L, R);
4309 meet.Width = std::min(meet.Width, MaxWidth);
4313 // The default behavior is okay for these.
4321 // The default case is to treat the operation as if it were closed
4322 // on the narrowest type that encompasses both operands.
4323 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth);
4324 IntRange R = GetExprRange(C, BO->getRHS(), MaxWidth);
4325 return IntRange::join(L, R);
4328 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
4329 switch (UO->getOpcode()) {
4330 // Boolean-valued operations are white-listed.
4332 return IntRange::forBoolType();
4334 // Operations with opaque sources are black-listed.
4336 case UO_AddrOf: // should be impossible
4337 return IntRange::forValueOfType(C, E->getType());
4340 return GetExprRange(C, UO->getSubExpr(), MaxWidth);
4344 if (dyn_cast<OffsetOfExpr>(E)) {
4345 IntRange::forValueOfType(C, E->getType());
4348 if (FieldDecl *BitField = E->getSourceBitField())
4349 return IntRange(BitField->getBitWidthValue(C),
4350 BitField->getType()->isUnsignedIntegerOrEnumerationType());
4352 return IntRange::forValueOfType(C, E->getType());
4355 static IntRange GetExprRange(ASTContext &C, Expr *E) {
4356 return GetExprRange(C, E, C.getIntWidth(E->getType()));
4359 /// Checks whether the given value, which currently has the given
4360 /// source semantics, has the same value when coerced through the
4361 /// target semantics.
4362 static bool IsSameFloatAfterCast(const llvm::APFloat &value,
4363 const llvm::fltSemantics &Src,
4364 const llvm::fltSemantics &Tgt) {
4365 llvm::APFloat truncated = value;
4368 truncated.convert(Src, llvm::APFloat::rmNearestTiesToEven, &ignored);
4369 truncated.convert(Tgt, llvm::APFloat::rmNearestTiesToEven, &ignored);
4371 return truncated.bitwiseIsEqual(value);
4374 /// Checks whether the given value, which currently has the given
4375 /// source semantics, has the same value when coerced through the
4376 /// target semantics.
4378 /// The value might be a vector of floats (or a complex number).
4379 static bool IsSameFloatAfterCast(const APValue &value,
4380 const llvm::fltSemantics &Src,
4381 const llvm::fltSemantics &Tgt) {
4382 if (value.isFloat())
4383 return IsSameFloatAfterCast(value.getFloat(), Src, Tgt);
4385 if (value.isVector()) {
4386 for (unsigned i = 0, e = value.getVectorLength(); i != e; ++i)
4387 if (!IsSameFloatAfterCast(value.getVectorElt(i), Src, Tgt))
4392 assert(value.isComplexFloat());
4393 return (IsSameFloatAfterCast(value.getComplexFloatReal(), Src, Tgt) &&
4394 IsSameFloatAfterCast(value.getComplexFloatImag(), Src, Tgt));
4397 static void AnalyzeImplicitConversions(Sema &S, Expr *E, SourceLocation CC);
4399 static bool IsZero(Sema &S, Expr *E) {
4400 // Suppress cases where we are comparing against an enum constant.
4401 if (const DeclRefExpr *DR =
4402 dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()))
4403 if (isa<EnumConstantDecl>(DR->getDecl()))
4406 // Suppress cases where the '0' value is expanded from a macro.
4407 if (E->getLocStart().isMacroID())
4411 return E->isIntegerConstantExpr(Value, S.Context) && Value == 0;
4414 static bool HasEnumType(Expr *E) {
4415 // Strip off implicit integral promotions.
4416 while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
4417 if (ICE->getCastKind() != CK_IntegralCast &&
4418 ICE->getCastKind() != CK_NoOp)
4420 E = ICE->getSubExpr();
4423 return E->getType()->isEnumeralType();
4426 static void CheckTrivialUnsignedComparison(Sema &S, BinaryOperator *E) {
4427 BinaryOperatorKind op = E->getOpcode();
4428 if (E->isValueDependent())
4431 if (op == BO_LT && IsZero(S, E->getRHS())) {
4432 S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison)
4433 << "< 0" << "false" << HasEnumType(E->getLHS())
4434 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
4435 } else if (op == BO_GE && IsZero(S, E->getRHS())) {
4436 S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison)
4437 << ">= 0" << "true" << HasEnumType(E->getLHS())
4438 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
4439 } else if (op == BO_GT && IsZero(S, E->getLHS())) {
4440 S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison)
4441 << "0 >" << "false" << HasEnumType(E->getRHS())
4442 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
4443 } else if (op == BO_LE && IsZero(S, E->getLHS())) {
4444 S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison)
4445 << "0 <=" << "true" << HasEnumType(E->getRHS())
4446 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
4450 static void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E,
4451 Expr *Constant, Expr *Other,
4454 // 0 values are handled later by CheckTrivialUnsignedComparison().
4458 BinaryOperatorKind op = E->getOpcode();
4459 QualType OtherT = Other->getType();
4460 QualType ConstantT = Constant->getType();
4461 QualType CommonT = E->getLHS()->getType();
4462 if (S.Context.hasSameUnqualifiedType(OtherT, ConstantT))
4464 assert((OtherT->isIntegerType() && ConstantT->isIntegerType())
4465 && "comparison with non-integer type");
4467 bool ConstantSigned = ConstantT->isSignedIntegerType();
4468 bool CommonSigned = CommonT->isSignedIntegerType();
4470 bool EqualityOnly = false;
4472 // TODO: Investigate using GetExprRange() to get tighter bounds on
4473 // on the bit ranges.
4474 IntRange OtherRange = IntRange::forValueOfType(S.Context, OtherT);
4475 unsigned OtherWidth = OtherRange.Width;
4478 // The common type is signed, therefore no signed to unsigned conversion.
4479 if (!OtherRange.NonNegative) {
4480 // Check that the constant is representable in type OtherT.
4481 if (ConstantSigned) {
4482 if (OtherWidth >= Value.getMinSignedBits())
4484 } else { // !ConstantSigned
4485 if (OtherWidth >= Value.getActiveBits() + 1)
4488 } else { // !OtherSigned
4489 // Check that the constant is representable in type OtherT.
4490 // Negative values are out of range.
4491 if (ConstantSigned) {
4492 if (Value.isNonNegative() && OtherWidth >= Value.getActiveBits())
4494 } else { // !ConstantSigned
4495 if (OtherWidth >= Value.getActiveBits())
4499 } else { // !CommonSigned
4500 if (OtherRange.NonNegative) {
4501 if (OtherWidth >= Value.getActiveBits())
4503 } else if (!OtherRange.NonNegative && !ConstantSigned) {
4504 // Check to see if the constant is representable in OtherT.
4505 if (OtherWidth > Value.getActiveBits())
4507 // Check to see if the constant is equivalent to a negative value
4509 if (S.Context.getIntWidth(ConstantT) == S.Context.getIntWidth(CommonT) &&
4510 Value.isNegative() && Value.getMinSignedBits() <= OtherWidth)
4512 // The constant value rests between values that OtherT can represent after
4513 // conversion. Relational comparison still works, but equality
4514 // comparisons will be tautological.
4515 EqualityOnly = true;
4516 } else { // OtherSigned && ConstantSigned
4517 assert(0 && "Two signed types converted to unsigned types.");
4521 bool PositiveConstant = !ConstantSigned || Value.isNonNegative();
4524 if (op == BO_EQ || op == BO_NE) {
4525 IsTrue = op == BO_NE;
4526 } else if (EqualityOnly) {
4528 } else if (RhsConstant) {
4529 if (op == BO_GT || op == BO_GE)
4530 IsTrue = !PositiveConstant;
4531 else // op == BO_LT || op == BO_LE
4532 IsTrue = PositiveConstant;
4534 if (op == BO_LT || op == BO_LE)
4535 IsTrue = !PositiveConstant;
4536 else // op == BO_GT || op == BO_GE
4537 IsTrue = PositiveConstant;
4540 // If this is a comparison to an enum constant, include that
4541 // constant in the diagnostic.
4542 const EnumConstantDecl *ED = 0;
4543 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Constant))
4544 ED = dyn_cast<EnumConstantDecl>(DR->getDecl());
4546 SmallString<64> PrettySourceValue;
4547 llvm::raw_svector_ostream OS(PrettySourceValue);
4549 OS << '\'' << *ED << "' (" << Value << ")";
4553 S.Diag(E->getOperatorLoc(), diag::warn_out_of_range_compare)
4554 << OS.str() << OtherT << IsTrue
4555 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
4558 /// Analyze the operands of the given comparison. Implements the
4559 /// fallback case from AnalyzeComparison.
4560 static void AnalyzeImpConvsInComparison(Sema &S, BinaryOperator *E) {
4561 AnalyzeImplicitConversions(S, E->getLHS(), E->getOperatorLoc());
4562 AnalyzeImplicitConversions(S, E->getRHS(), E->getOperatorLoc());
4565 /// \brief Implements -Wsign-compare.
4567 /// \param E the binary operator to check for warnings
4568 static void AnalyzeComparison(Sema &S, BinaryOperator *E) {
4569 // The type the comparison is being performed in.
4570 QualType T = E->getLHS()->getType();
4571 assert(S.Context.hasSameUnqualifiedType(T, E->getRHS()->getType())
4572 && "comparison with mismatched types");
4573 if (E->isValueDependent())
4574 return AnalyzeImpConvsInComparison(S, E);
4576 Expr *LHS = E->getLHS()->IgnoreParenImpCasts();
4577 Expr *RHS = E->getRHS()->IgnoreParenImpCasts();
4579 bool IsComparisonConstant = false;
4581 // Check whether an integer constant comparison results in a value
4582 // of 'true' or 'false'.
4583 if (T->isIntegralType(S.Context)) {
4584 llvm::APSInt RHSValue;
4585 bool IsRHSIntegralLiteral =
4586 RHS->isIntegerConstantExpr(RHSValue, S.Context);
4587 llvm::APSInt LHSValue;
4588 bool IsLHSIntegralLiteral =
4589 LHS->isIntegerConstantExpr(LHSValue, S.Context);
4590 if (IsRHSIntegralLiteral && !IsLHSIntegralLiteral)
4591 DiagnoseOutOfRangeComparison(S, E, RHS, LHS, RHSValue, true);
4592 else if (!IsRHSIntegralLiteral && IsLHSIntegralLiteral)
4593 DiagnoseOutOfRangeComparison(S, E, LHS, RHS, LHSValue, false);
4595 IsComparisonConstant =
4596 (IsRHSIntegralLiteral && IsLHSIntegralLiteral);
4597 } else if (!T->hasUnsignedIntegerRepresentation())
4598 IsComparisonConstant = E->isIntegerConstantExpr(S.Context);
4600 // We don't do anything special if this isn't an unsigned integral
4601 // comparison: we're only interested in integral comparisons, and
4602 // signed comparisons only happen in cases we don't care to warn about.
4604 // We also don't care about value-dependent expressions or expressions
4605 // whose result is a constant.
4606 if (!T->hasUnsignedIntegerRepresentation() || IsComparisonConstant)
4607 return AnalyzeImpConvsInComparison(S, E);
4609 // Check to see if one of the (unmodified) operands is of different
4611 Expr *signedOperand, *unsignedOperand;
4612 if (LHS->getType()->hasSignedIntegerRepresentation()) {
4613 assert(!RHS->getType()->hasSignedIntegerRepresentation() &&
4614 "unsigned comparison between two signed integer expressions?");
4615 signedOperand = LHS;
4616 unsignedOperand = RHS;
4617 } else if (RHS->getType()->hasSignedIntegerRepresentation()) {
4618 signedOperand = RHS;
4619 unsignedOperand = LHS;
4621 CheckTrivialUnsignedComparison(S, E);
4622 return AnalyzeImpConvsInComparison(S, E);
4625 // Otherwise, calculate the effective range of the signed operand.
4626 IntRange signedRange = GetExprRange(S.Context, signedOperand);
4628 // Go ahead and analyze implicit conversions in the operands. Note
4629 // that we skip the implicit conversions on both sides.
4630 AnalyzeImplicitConversions(S, LHS, E->getOperatorLoc());
4631 AnalyzeImplicitConversions(S, RHS, E->getOperatorLoc());
4633 // If the signed range is non-negative, -Wsign-compare won't fire,
4634 // but we should still check for comparisons which are always true
4636 if (signedRange.NonNegative)
4637 return CheckTrivialUnsignedComparison(S, E);
4639 // For (in)equality comparisons, if the unsigned operand is a
4640 // constant which cannot collide with a overflowed signed operand,
4641 // then reinterpreting the signed operand as unsigned will not
4642 // change the result of the comparison.
4643 if (E->isEqualityOp()) {
4644 unsigned comparisonWidth = S.Context.getIntWidth(T);
4645 IntRange unsignedRange = GetExprRange(S.Context, unsignedOperand);
4647 // We should never be unable to prove that the unsigned operand is
4649 assert(unsignedRange.NonNegative && "unsigned range includes negative?");
4651 if (unsignedRange.Width < comparisonWidth)
4655 S.DiagRuntimeBehavior(E->getOperatorLoc(), E,
4656 S.PDiag(diag::warn_mixed_sign_comparison)
4657 << LHS->getType() << RHS->getType()
4658 << LHS->getSourceRange() << RHS->getSourceRange());
4661 /// Analyzes an attempt to assign the given value to a bitfield.
4663 /// Returns true if there was something fishy about the attempt.
4664 static bool AnalyzeBitFieldAssignment(Sema &S, FieldDecl *Bitfield, Expr *Init,
4665 SourceLocation InitLoc) {
4666 assert(Bitfield->isBitField());
4667 if (Bitfield->isInvalidDecl())
4670 // White-list bool bitfields.
4671 if (Bitfield->getType()->isBooleanType())
4674 // Ignore value- or type-dependent expressions.
4675 if (Bitfield->getBitWidth()->isValueDependent() ||
4676 Bitfield->getBitWidth()->isTypeDependent() ||
4677 Init->isValueDependent() ||
4678 Init->isTypeDependent())
4681 Expr *OriginalInit = Init->IgnoreParenImpCasts();
4684 if (!OriginalInit->EvaluateAsInt(Value, S.Context, Expr::SE_AllowSideEffects))
4687 unsigned OriginalWidth = Value.getBitWidth();
4688 unsigned FieldWidth = Bitfield->getBitWidthValue(S.Context);
4690 if (OriginalWidth <= FieldWidth)
4693 // Compute the value which the bitfield will contain.
4694 llvm::APSInt TruncatedValue = Value.trunc(FieldWidth);
4695 TruncatedValue.setIsSigned(Bitfield->getType()->isSignedIntegerType());
4697 // Check whether the stored value is equal to the original value.
4698 TruncatedValue = TruncatedValue.extend(OriginalWidth);
4699 if (llvm::APSInt::isSameValue(Value, TruncatedValue))
4702 // Special-case bitfields of width 1: booleans are naturally 0/1, and
4703 // therefore don't strictly fit into a signed bitfield of width 1.
4704 if (FieldWidth == 1 && Value == 1)
4707 std::string PrettyValue = Value.toString(10);
4708 std::string PrettyTrunc = TruncatedValue.toString(10);
4710 S.Diag(InitLoc, diag::warn_impcast_bitfield_precision_constant)
4711 << PrettyValue << PrettyTrunc << OriginalInit->getType()
4712 << Init->getSourceRange();
4717 /// Analyze the given simple or compound assignment for warning-worthy
4719 static void AnalyzeAssignment(Sema &S, BinaryOperator *E) {
4720 // Just recurse on the LHS.
4721 AnalyzeImplicitConversions(S, E->getLHS(), E->getOperatorLoc());
4723 // We want to recurse on the RHS as normal unless we're assigning to
4725 if (FieldDecl *Bitfield = E->getLHS()->getSourceBitField()) {
4726 if (AnalyzeBitFieldAssignment(S, Bitfield, E->getRHS(),
4727 E->getOperatorLoc())) {
4728 // Recurse, ignoring any implicit conversions on the RHS.
4729 return AnalyzeImplicitConversions(S, E->getRHS()->IgnoreParenImpCasts(),
4730 E->getOperatorLoc());
4734 AnalyzeImplicitConversions(S, E->getRHS(), E->getOperatorLoc());
4737 /// Diagnose an implicit cast; purely a helper for CheckImplicitConversion.
4738 static void DiagnoseImpCast(Sema &S, Expr *E, QualType SourceType, QualType T,
4739 SourceLocation CContext, unsigned diag,
4740 bool pruneControlFlow = false) {
4741 if (pruneControlFlow) {
4742 S.DiagRuntimeBehavior(E->getExprLoc(), E,
4744 << SourceType << T << E->getSourceRange()
4745 << SourceRange(CContext));
4748 S.Diag(E->getExprLoc(), diag)
4749 << SourceType << T << E->getSourceRange() << SourceRange(CContext);
4752 /// Diagnose an implicit cast; purely a helper for CheckImplicitConversion.
4753 static void DiagnoseImpCast(Sema &S, Expr *E, QualType T,
4754 SourceLocation CContext, unsigned diag,
4755 bool pruneControlFlow = false) {
4756 DiagnoseImpCast(S, E, E->getType(), T, CContext, diag, pruneControlFlow);
4759 /// Diagnose an implicit cast from a literal expression. Does not warn when the
4760 /// cast wouldn't lose information.
4761 void DiagnoseFloatingLiteralImpCast(Sema &S, FloatingLiteral *FL, QualType T,
4762 SourceLocation CContext) {
4763 // Try to convert the literal exactly to an integer. If we can, don't warn.
4764 bool isExact = false;
4765 const llvm::APFloat &Value = FL->getValue();
4766 llvm::APSInt IntegerValue(S.Context.getIntWidth(T),
4767 T->hasUnsignedIntegerRepresentation());
4768 if (Value.convertToInteger(IntegerValue,
4769 llvm::APFloat::rmTowardZero, &isExact)
4770 == llvm::APFloat::opOK && isExact)
4773 SmallString<16> PrettySourceValue;
4774 Value.toString(PrettySourceValue);
4775 SmallString<16> PrettyTargetValue;
4776 if (T->isSpecificBuiltinType(BuiltinType::Bool))
4777 PrettyTargetValue = IntegerValue == 0 ? "false" : "true";
4779 IntegerValue.toString(PrettyTargetValue);
4781 S.Diag(FL->getExprLoc(), diag::warn_impcast_literal_float_to_integer)
4782 << FL->getType() << T.getUnqualifiedType() << PrettySourceValue
4783 << PrettyTargetValue << FL->getSourceRange() << SourceRange(CContext);
4786 std::string PrettyPrintInRange(const llvm::APSInt &Value, IntRange Range) {
4787 if (!Range.Width) return "0";
4789 llvm::APSInt ValueInRange = Value;
4790 ValueInRange.setIsSigned(!Range.NonNegative);
4791 ValueInRange = ValueInRange.trunc(Range.Width);
4792 return ValueInRange.toString(10);
4795 static bool IsImplicitBoolFloatConversion(Sema &S, Expr *Ex, bool ToBool) {
4796 if (!isa<ImplicitCastExpr>(Ex))
4799 Expr *InnerE = Ex->IgnoreParenImpCasts();
4800 const Type *Target = S.Context.getCanonicalType(Ex->getType()).getTypePtr();
4801 const Type *Source =
4802 S.Context.getCanonicalType(InnerE->getType()).getTypePtr();
4803 if (Target->isDependentType())
4806 const BuiltinType *FloatCandidateBT =
4807 dyn_cast<BuiltinType>(ToBool ? Source : Target);
4808 const Type *BoolCandidateType = ToBool ? Target : Source;
4810 return (BoolCandidateType->isSpecificBuiltinType(BuiltinType::Bool) &&
4811 FloatCandidateBT && (FloatCandidateBT->isFloatingPoint()));
4814 void CheckImplicitArgumentConversions(Sema &S, CallExpr *TheCall,
4815 SourceLocation CC) {
4816 unsigned NumArgs = TheCall->getNumArgs();
4817 for (unsigned i = 0; i < NumArgs; ++i) {
4818 Expr *CurrA = TheCall->getArg(i);
4819 if (!IsImplicitBoolFloatConversion(S, CurrA, true))
4822 bool IsSwapped = ((i > 0) &&
4823 IsImplicitBoolFloatConversion(S, TheCall->getArg(i - 1), false));
4824 IsSwapped |= ((i < (NumArgs - 1)) &&
4825 IsImplicitBoolFloatConversion(S, TheCall->getArg(i + 1), false));
4827 // Warn on this floating-point to bool conversion.
4828 DiagnoseImpCast(S, CurrA->IgnoreParenImpCasts(),
4829 CurrA->getType(), CC,
4830 diag::warn_impcast_floating_point_to_bool);
4835 void CheckImplicitConversion(Sema &S, Expr *E, QualType T,
4836 SourceLocation CC, bool *ICContext = 0) {
4837 if (E->isTypeDependent() || E->isValueDependent()) return;
4839 const Type *Source = S.Context.getCanonicalType(E->getType()).getTypePtr();
4840 const Type *Target = S.Context.getCanonicalType(T).getTypePtr();
4841 if (Source == Target) return;
4842 if (Target->isDependentType()) return;
4844 // If the conversion context location is invalid don't complain. We also
4845 // don't want to emit a warning if the issue occurs from the expansion of
4846 // a system macro. The problem is that 'getSpellingLoc()' is slow, so we
4847 // delay this check as long as possible. Once we detect we are in that
4848 // scenario, we just return.
4852 // Diagnose implicit casts to bool.
4853 if (Target->isSpecificBuiltinType(BuiltinType::Bool)) {
4854 if (isa<StringLiteral>(E))
4855 // Warn on string literal to bool. Checks for string literals in logical
4856 // expressions, for instances, assert(0 && "error here"), is prevented
4857 // by a check in AnalyzeImplicitConversions().
4858 return DiagnoseImpCast(S, E, T, CC,
4859 diag::warn_impcast_string_literal_to_bool);
4860 if (Source->isFunctionType()) {
4861 // Warn on function to bool. Checks free functions and static member
4862 // functions. Weakly imported functions are excluded from the check,
4863 // since it's common to test their value to check whether the linker
4864 // found a definition for them.
4866 if (DeclRefExpr* R = dyn_cast<DeclRefExpr>(E)) {
4868 } else if (MemberExpr *M = dyn_cast<MemberExpr>(E)) {
4869 D = M->getMemberDecl();
4872 if (D && !D->isWeak()) {
4873 if (FunctionDecl* F = dyn_cast<FunctionDecl>(D)) {
4874 S.Diag(E->getExprLoc(), diag::warn_impcast_function_to_bool)
4875 << F << E->getSourceRange() << SourceRange(CC);
4876 S.Diag(E->getExprLoc(), diag::note_function_to_bool_silence)
4877 << FixItHint::CreateInsertion(E->getExprLoc(), "&");
4878 QualType ReturnType;
4879 UnresolvedSet<4> NonTemplateOverloads;
4880 S.isExprCallable(*E, ReturnType, NonTemplateOverloads);
4881 if (!ReturnType.isNull()
4882 && ReturnType->isSpecificBuiltinType(BuiltinType::Bool))
4883 S.Diag(E->getExprLoc(), diag::note_function_to_bool_call)
4884 << FixItHint::CreateInsertion(
4885 S.getPreprocessor().getLocForEndOfToken(E->getLocEnd()), "()");
4892 // Strip vector types.
4893 if (isa<VectorType>(Source)) {
4894 if (!isa<VectorType>(Target)) {
4895 if (S.SourceMgr.isInSystemMacro(CC))
4897 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_vector_scalar);
4900 // If the vector cast is cast between two vectors of the same size, it is
4901 // a bitcast, not a conversion.
4902 if (S.Context.getTypeSize(Source) == S.Context.getTypeSize(Target))
4905 Source = cast<VectorType>(Source)->getElementType().getTypePtr();
4906 Target = cast<VectorType>(Target)->getElementType().getTypePtr();
4909 // Strip complex types.
4910 if (isa<ComplexType>(Source)) {
4911 if (!isa<ComplexType>(Target)) {
4912 if (S.SourceMgr.isInSystemMacro(CC))
4915 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_complex_scalar);
4918 Source = cast<ComplexType>(Source)->getElementType().getTypePtr();
4919 Target = cast<ComplexType>(Target)->getElementType().getTypePtr();
4922 const BuiltinType *SourceBT = dyn_cast<BuiltinType>(Source);
4923 const BuiltinType *TargetBT = dyn_cast<BuiltinType>(Target);
4925 // If the source is floating point...
4926 if (SourceBT && SourceBT->isFloatingPoint()) {
4927 // ...and the target is floating point...
4928 if (TargetBT && TargetBT->isFloatingPoint()) {
4929 // ...then warn if we're dropping FP rank.
4931 // Builtin FP kinds are ordered by increasing FP rank.
4932 if (SourceBT->getKind() > TargetBT->getKind()) {
4933 // Don't warn about float constants that are precisely
4934 // representable in the target type.
4935 Expr::EvalResult result;
4936 if (E->EvaluateAsRValue(result, S.Context)) {
4937 // Value might be a float, a float vector, or a float complex.
4938 if (IsSameFloatAfterCast(result.Val,
4939 S.Context.getFloatTypeSemantics(QualType(TargetBT, 0)),
4940 S.Context.getFloatTypeSemantics(QualType(SourceBT, 0))))
4944 if (S.SourceMgr.isInSystemMacro(CC))
4947 DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_float_precision);
4952 // If the target is integral, always warn.
4953 if (TargetBT && TargetBT->isInteger()) {
4954 if (S.SourceMgr.isInSystemMacro(CC))
4957 Expr *InnerE = E->IgnoreParenImpCasts();
4958 // We also want to warn on, e.g., "int i = -1.234"
4959 if (UnaryOperator *UOp = dyn_cast<UnaryOperator>(InnerE))
4960 if (UOp->getOpcode() == UO_Minus || UOp->getOpcode() == UO_Plus)
4961 InnerE = UOp->getSubExpr()->IgnoreParenImpCasts();
4963 if (FloatingLiteral *FL = dyn_cast<FloatingLiteral>(InnerE)) {
4964 DiagnoseFloatingLiteralImpCast(S, FL, T, CC);
4966 DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_float_integer);
4970 // If the target is bool, warn if expr is a function or method call.
4971 if (Target->isSpecificBuiltinType(BuiltinType::Bool) &&
4973 // Check last argument of function call to see if it is an
4974 // implicit cast from a type matching the type the result
4975 // is being cast to.
4976 CallExpr *CEx = cast<CallExpr>(E);
4977 unsigned NumArgs = CEx->getNumArgs();
4979 Expr *LastA = CEx->getArg(NumArgs - 1);
4980 Expr *InnerE = LastA->IgnoreParenImpCasts();
4981 const Type *InnerType =
4982 S.Context.getCanonicalType(InnerE->getType()).getTypePtr();
4983 if (isa<ImplicitCastExpr>(LastA) && (InnerType == Target)) {
4984 // Warn on this floating-point to bool conversion
4985 DiagnoseImpCast(S, E, T, CC,
4986 diag::warn_impcast_floating_point_to_bool);
4993 if ((E->isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull)
4994 == Expr::NPCK_GNUNull) && !Target->isAnyPointerType()
4995 && !Target->isBlockPointerType() && !Target->isMemberPointerType()
4996 && Target->isScalarType() && !Target->isNullPtrType()) {
4997 SourceLocation Loc = E->getSourceRange().getBegin();
4998 if (Loc.isMacroID())
4999 Loc = S.SourceMgr.getImmediateExpansionRange(Loc).first;
5000 if (!Loc.isMacroID() || CC.isMacroID())
5001 S.Diag(Loc, diag::warn_impcast_null_pointer_to_integer)
5002 << T << clang::SourceRange(CC)
5003 << FixItHint::CreateReplacement(Loc, S.getFixItZeroLiteralForType(T));
5006 if (!Source->isIntegerType() || !Target->isIntegerType())
5009 // TODO: remove this early return once the false positives for constant->bool
5010 // in templates, macros, etc, are reduced or removed.
5011 if (Target->isSpecificBuiltinType(BuiltinType::Bool))
5014 IntRange SourceRange = GetExprRange(S.Context, E);
5015 IntRange TargetRange = IntRange::forTargetOfCanonicalType(S.Context, Target);
5017 if (SourceRange.Width > TargetRange.Width) {
5018 // If the source is a constant, use a default-on diagnostic.
5019 // TODO: this should happen for bitfield stores, too.
5020 llvm::APSInt Value(32);
5021 if (E->isIntegerConstantExpr(Value, S.Context)) {
5022 if (S.SourceMgr.isInSystemMacro(CC))
5025 std::string PrettySourceValue = Value.toString(10);
5026 std::string PrettyTargetValue = PrettyPrintInRange(Value, TargetRange);
5028 S.DiagRuntimeBehavior(E->getExprLoc(), E,
5029 S.PDiag(diag::warn_impcast_integer_precision_constant)
5030 << PrettySourceValue << PrettyTargetValue
5031 << E->getType() << T << E->getSourceRange()
5032 << clang::SourceRange(CC));
5036 // People want to build with -Wshorten-64-to-32 and not -Wconversion.
5037 if (S.SourceMgr.isInSystemMacro(CC))
5040 if (TargetRange.Width == 32 && S.Context.getIntWidth(E->getType()) == 64)
5041 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_integer_64_32,
5042 /* pruneControlFlow */ true);
5043 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_integer_precision);
5046 if ((TargetRange.NonNegative && !SourceRange.NonNegative) ||
5047 (!TargetRange.NonNegative && SourceRange.NonNegative &&
5048 SourceRange.Width == TargetRange.Width)) {
5050 if (S.SourceMgr.isInSystemMacro(CC))
5053 unsigned DiagID = diag::warn_impcast_integer_sign;
5055 // Traditionally, gcc has warned about this under -Wsign-compare.
5056 // We also want to warn about it in -Wconversion.
5057 // So if -Wconversion is off, use a completely identical diagnostic
5058 // in the sign-compare group.
5059 // The conditional-checking code will
5061 DiagID = diag::warn_impcast_integer_sign_conditional;
5065 return DiagnoseImpCast(S, E, T, CC, DiagID);
5068 // Diagnose conversions between different enumeration types.
5069 // In C, we pretend that the type of an EnumConstantDecl is its enumeration
5070 // type, to give us better diagnostics.
5071 QualType SourceType = E->getType();
5072 if (!S.getLangOpts().CPlusPlus) {
5073 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
5074 if (EnumConstantDecl *ECD = dyn_cast<EnumConstantDecl>(DRE->getDecl())) {
5075 EnumDecl *Enum = cast<EnumDecl>(ECD->getDeclContext());
5076 SourceType = S.Context.getTypeDeclType(Enum);
5077 Source = S.Context.getCanonicalType(SourceType).getTypePtr();
5081 if (const EnumType *SourceEnum = Source->getAs<EnumType>())
5082 if (const EnumType *TargetEnum = Target->getAs<EnumType>())
5083 if (SourceEnum->getDecl()->hasNameForLinkage() &&
5084 TargetEnum->getDecl()->hasNameForLinkage() &&
5085 SourceEnum != TargetEnum) {
5086 if (S.SourceMgr.isInSystemMacro(CC))
5089 return DiagnoseImpCast(S, E, SourceType, T, CC,
5090 diag::warn_impcast_different_enum_types);
5096 void CheckConditionalOperator(Sema &S, ConditionalOperator *E,
5097 SourceLocation CC, QualType T);
5099 void CheckConditionalOperand(Sema &S, Expr *E, QualType T,
5100 SourceLocation CC, bool &ICContext) {
5101 E = E->IgnoreParenImpCasts();
5103 if (isa<ConditionalOperator>(E))
5104 return CheckConditionalOperator(S, cast<ConditionalOperator>(E), CC, T);
5106 AnalyzeImplicitConversions(S, E, CC);
5107 if (E->getType() != T)
5108 return CheckImplicitConversion(S, E, T, CC, &ICContext);
5112 void CheckConditionalOperator(Sema &S, ConditionalOperator *E,
5113 SourceLocation CC, QualType T) {
5114 AnalyzeImplicitConversions(S, E->getCond(), CC);
5116 bool Suspicious = false;
5117 CheckConditionalOperand(S, E->getTrueExpr(), T, CC, Suspicious);
5118 CheckConditionalOperand(S, E->getFalseExpr(), T, CC, Suspicious);
5120 // If -Wconversion would have warned about either of the candidates
5121 // for a signedness conversion to the context type...
5122 if (!Suspicious) return;
5124 // ...but it's currently ignored...
5125 if (S.Diags.getDiagnosticLevel(diag::warn_impcast_integer_sign_conditional,
5129 // ...then check whether it would have warned about either of the
5130 // candidates for a signedness conversion to the condition type.
5131 if (E->getType() == T) return;
5134 CheckImplicitConversion(S, E->getTrueExpr()->IgnoreParenImpCasts(),
5135 E->getType(), CC, &Suspicious);
5137 CheckImplicitConversion(S, E->getFalseExpr()->IgnoreParenImpCasts(),
5138 E->getType(), CC, &Suspicious);
5141 /// AnalyzeImplicitConversions - Find and report any interesting
5142 /// implicit conversions in the given expression. There are a couple
5143 /// of competing diagnostics here, -Wconversion and -Wsign-compare.
5144 void AnalyzeImplicitConversions(Sema &S, Expr *OrigE, SourceLocation CC) {
5145 QualType T = OrigE->getType();
5146 Expr *E = OrigE->IgnoreParenImpCasts();
5148 if (E->isTypeDependent() || E->isValueDependent())
5151 // For conditional operators, we analyze the arguments as if they
5152 // were being fed directly into the output.
5153 if (isa<ConditionalOperator>(E)) {
5154 ConditionalOperator *CO = cast<ConditionalOperator>(E);
5155 CheckConditionalOperator(S, CO, CC, T);
5159 // Check implicit argument conversions for function calls.
5160 if (CallExpr *Call = dyn_cast<CallExpr>(E))
5161 CheckImplicitArgumentConversions(S, Call, CC);
5163 // Go ahead and check any implicit conversions we might have skipped.
5164 // The non-canonical typecheck is just an optimization;
5165 // CheckImplicitConversion will filter out dead implicit conversions.
5166 if (E->getType() != T)
5167 CheckImplicitConversion(S, E, T, CC);
5169 // Now continue drilling into this expression.
5171 // Skip past explicit casts.
5172 if (isa<ExplicitCastExpr>(E)) {
5173 E = cast<ExplicitCastExpr>(E)->getSubExpr()->IgnoreParenImpCasts();
5174 return AnalyzeImplicitConversions(S, E, CC);
5177 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
5178 // Do a somewhat different check with comparison operators.
5179 if (BO->isComparisonOp())
5180 return AnalyzeComparison(S, BO);
5182 // And with simple assignments.
5183 if (BO->getOpcode() == BO_Assign)
5184 return AnalyzeAssignment(S, BO);
5187 // These break the otherwise-useful invariant below. Fortunately,
5188 // we don't really need to recurse into them, because any internal
5189 // expressions should have been analyzed already when they were
5190 // built into statements.
5191 if (isa<StmtExpr>(E)) return;
5193 // Don't descend into unevaluated contexts.
5194 if (isa<UnaryExprOrTypeTraitExpr>(E)) return;
5196 // Now just recurse over the expression's children.
5197 CC = E->getExprLoc();
5198 BinaryOperator *BO = dyn_cast<BinaryOperator>(E);
5199 bool IsLogicalOperator = BO && BO->isLogicalOp();
5200 for (Stmt::child_range I = E->children(); I; ++I) {
5201 Expr *ChildExpr = dyn_cast_or_null<Expr>(*I);
5205 if (IsLogicalOperator &&
5206 isa<StringLiteral>(ChildExpr->IgnoreParenImpCasts()))
5207 // Ignore checking string literals that are in logical operators.
5209 AnalyzeImplicitConversions(S, ChildExpr, CC);
5213 } // end anonymous namespace
5215 /// Diagnoses "dangerous" implicit conversions within the given
5216 /// expression (which is a full expression). Implements -Wconversion
5217 /// and -Wsign-compare.
5219 /// \param CC the "context" location of the implicit conversion, i.e.
5220 /// the most location of the syntactic entity requiring the implicit
5222 void Sema::CheckImplicitConversions(Expr *E, SourceLocation CC) {
5223 // Don't diagnose in unevaluated contexts.
5224 if (isUnevaluatedContext())
5227 // Don't diagnose for value- or type-dependent expressions.
5228 if (E->isTypeDependent() || E->isValueDependent())
5231 // Check for array bounds violations in cases where the check isn't triggered
5232 // elsewhere for other Expr types (like BinaryOperators), e.g. when an
5233 // ArraySubscriptExpr is on the RHS of a variable initialization.
5234 CheckArrayAccess(E);
5236 // This is not the right CC for (e.g.) a variable initialization.
5237 AnalyzeImplicitConversions(*this, E, CC);
5240 /// Diagnose when expression is an integer constant expression and its evaluation
5241 /// results in integer overflow
5242 void Sema::CheckForIntOverflow (Expr *E) {
5243 if (isa<BinaryOperator>(E->IgnoreParens())) {
5244 llvm::SmallVector<PartialDiagnosticAt, 4> Diags;
5245 E->EvaluateForOverflow(Context, &Diags);
5250 /// \brief Visitor for expressions which looks for unsequenced operations on the
5252 class SequenceChecker : public EvaluatedExprVisitor<SequenceChecker> {
5253 /// \brief A tree of sequenced regions within an expression. Two regions are
5254 /// unsequenced if one is an ancestor or a descendent of the other. When we
5255 /// finish processing an expression with sequencing, such as a comma
5256 /// expression, we fold its tree nodes into its parent, since they are
5257 /// unsequenced with respect to nodes we will visit later.
5258 class SequenceTree {
5260 explicit Value(unsigned Parent) : Parent(Parent), Merged(false) {}
5261 unsigned Parent : 31;
5264 llvm::SmallVector<Value, 8> Values;
5267 /// \brief A region within an expression which may be sequenced with respect
5268 /// to some other region.
5270 explicit Seq(unsigned N) : Index(N) {}
5272 friend class SequenceTree;
5277 SequenceTree() { Values.push_back(Value(0)); }
5278 Seq root() const { return Seq(0); }
5280 /// \brief Create a new sequence of operations, which is an unsequenced
5281 /// subset of \p Parent. This sequence of operations is sequenced with
5282 /// respect to other children of \p Parent.
5283 Seq allocate(Seq Parent) {
5284 Values.push_back(Value(Parent.Index));
5285 return Seq(Values.size() - 1);
5288 /// \brief Merge a sequence of operations into its parent.
5290 Values[S.Index].Merged = true;
5293 /// \brief Determine whether two operations are unsequenced. This operation
5294 /// is asymmetric: \p Cur should be the more recent sequence, and \p Old
5295 /// should have been merged into its parent as appropriate.
5296 bool isUnsequenced(Seq Cur, Seq Old) {
5297 unsigned C = representative(Cur.Index);
5298 unsigned Target = representative(Old.Index);
5299 while (C >= Target) {
5302 C = Values[C].Parent;
5308 /// \brief Pick a representative for a sequence.
5309 unsigned representative(unsigned K) {
5310 if (Values[K].Merged)
5311 // Perform path compression as we go.
5312 return Values[K].Parent = representative(Values[K].Parent);
5317 /// An object for which we can track unsequenced uses.
5318 typedef NamedDecl *Object;
5320 /// Different flavors of object usage which we track. We only track the
5321 /// least-sequenced usage of each kind.
5323 /// A read of an object. Multiple unsequenced reads are OK.
5325 /// A modification of an object which is sequenced before the value
5326 /// computation of the expression, such as ++n.
5328 /// A modification of an object which is not sequenced before the value
5329 /// computation of the expression, such as n++.
5332 UK_Count = UK_ModAsSideEffect + 1
5336 Usage() : Use(0), Seq() {}
5338 SequenceTree::Seq Seq;
5342 UsageInfo() : Diagnosed(false) {}
5343 Usage Uses[UK_Count];
5344 /// Have we issued a diagnostic for this variable already?
5347 typedef llvm::SmallDenseMap<Object, UsageInfo, 16> UsageInfoMap;
5350 /// Sequenced regions within the expression.
5352 /// Declaration modifications and references which we have seen.
5353 UsageInfoMap UsageMap;
5354 /// The region we are currently within.
5355 SequenceTree::Seq Region;
5356 /// Filled in with declarations which were modified as a side-effect
5357 /// (that is, post-increment operations).
5358 llvm::SmallVectorImpl<std::pair<Object, Usage> > *ModAsSideEffect;
5359 /// Expressions to check later. We defer checking these to reduce
5361 llvm::SmallVectorImpl<Expr*> &WorkList;
5363 /// RAII object wrapping the visitation of a sequenced subexpression of an
5364 /// expression. At the end of this process, the side-effects of the evaluation
5365 /// become sequenced with respect to the value computation of the result, so
5366 /// we downgrade any UK_ModAsSideEffect within the evaluation to
5368 struct SequencedSubexpression {
5369 SequencedSubexpression(SequenceChecker &Self)
5370 : Self(Self), OldModAsSideEffect(Self.ModAsSideEffect) {
5371 Self.ModAsSideEffect = &ModAsSideEffect;
5373 ~SequencedSubexpression() {
5374 for (unsigned I = 0, E = ModAsSideEffect.size(); I != E; ++I) {
5375 UsageInfo &U = Self.UsageMap[ModAsSideEffect[I].first];
5376 U.Uses[UK_ModAsSideEffect] = ModAsSideEffect[I].second;
5377 Self.addUsage(U, ModAsSideEffect[I].first,
5378 ModAsSideEffect[I].second.Use, UK_ModAsValue);
5380 Self.ModAsSideEffect = OldModAsSideEffect;
5383 SequenceChecker &Self;
5384 llvm::SmallVector<std::pair<Object, Usage>, 4> ModAsSideEffect;
5385 llvm::SmallVectorImpl<std::pair<Object, Usage> > *OldModAsSideEffect;
5388 /// \brief Find the object which is produced by the specified expression,
5390 Object getObject(Expr *E, bool Mod) const {
5391 E = E->IgnoreParenCasts();
5392 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
5393 if (Mod && (UO->getOpcode() == UO_PreInc || UO->getOpcode() == UO_PreDec))
5394 return getObject(UO->getSubExpr(), Mod);
5395 } else if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
5396 if (BO->getOpcode() == BO_Comma)
5397 return getObject(BO->getRHS(), Mod);
5398 if (Mod && BO->isAssignmentOp())
5399 return getObject(BO->getLHS(), Mod);
5400 } else if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
5401 // FIXME: Check for more interesting cases, like "x.n = ++x.n".
5402 if (isa<CXXThisExpr>(ME->getBase()->IgnoreParenCasts()))
5403 return ME->getMemberDecl();
5404 } else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
5405 // FIXME: If this is a reference, map through to its value.
5406 return DRE->getDecl();
5410 /// \brief Note that an object was modified or used by an expression.
5411 void addUsage(UsageInfo &UI, Object O, Expr *Ref, UsageKind UK) {
5412 Usage &U = UI.Uses[UK];
5413 if (!U.Use || !Tree.isUnsequenced(Region, U.Seq)) {
5414 if (UK == UK_ModAsSideEffect && ModAsSideEffect)
5415 ModAsSideEffect->push_back(std::make_pair(O, U));
5420 /// \brief Check whether a modification or use conflicts with a prior usage.
5421 void checkUsage(Object O, UsageInfo &UI, Expr *Ref, UsageKind OtherKind,
5426 const Usage &U = UI.Uses[OtherKind];
5427 if (!U.Use || !Tree.isUnsequenced(Region, U.Seq))
5431 Expr *ModOrUse = Ref;
5432 if (OtherKind == UK_Use)
5433 std::swap(Mod, ModOrUse);
5435 SemaRef.Diag(Mod->getExprLoc(),
5436 IsModMod ? diag::warn_unsequenced_mod_mod
5437 : diag::warn_unsequenced_mod_use)
5438 << O << SourceRange(ModOrUse->getExprLoc());
5439 UI.Diagnosed = true;
5442 void notePreUse(Object O, Expr *Use) {
5443 UsageInfo &U = UsageMap[O];
5444 // Uses conflict with other modifications.
5445 checkUsage(O, U, Use, UK_ModAsValue, false);
5447 void notePostUse(Object O, Expr *Use) {
5448 UsageInfo &U = UsageMap[O];
5449 checkUsage(O, U, Use, UK_ModAsSideEffect, false);
5450 addUsage(U, O, Use, UK_Use);
5453 void notePreMod(Object O, Expr *Mod) {
5454 UsageInfo &U = UsageMap[O];
5455 // Modifications conflict with other modifications and with uses.
5456 checkUsage(O, U, Mod, UK_ModAsValue, true);
5457 checkUsage(O, U, Mod, UK_Use, false);
5459 void notePostMod(Object O, Expr *Use, UsageKind UK) {
5460 UsageInfo &U = UsageMap[O];
5461 checkUsage(O, U, Use, UK_ModAsSideEffect, true);
5462 addUsage(U, O, Use, UK);
5466 SequenceChecker(Sema &S, Expr *E,
5467 llvm::SmallVectorImpl<Expr*> &WorkList)
5468 : EvaluatedExprVisitor<SequenceChecker>(S.Context), SemaRef(S),
5469 Region(Tree.root()), ModAsSideEffect(0), WorkList(WorkList) {
5473 void VisitStmt(Stmt *S) {
5474 // Skip all statements which aren't expressions for now.
5477 void VisitExpr(Expr *E) {
5478 // By default, just recurse to evaluated subexpressions.
5479 EvaluatedExprVisitor<SequenceChecker>::VisitStmt(E);
5482 void VisitCastExpr(CastExpr *E) {
5483 Object O = Object();
5484 if (E->getCastKind() == CK_LValueToRValue)
5485 O = getObject(E->getSubExpr(), false);
5494 void VisitBinComma(BinaryOperator *BO) {
5495 // C++11 [expr.comma]p1:
5496 // Every value computation and side effect associated with the left
5497 // expression is sequenced before every value computation and side
5498 // effect associated with the right expression.
5499 SequenceTree::Seq LHS = Tree.allocate(Region);
5500 SequenceTree::Seq RHS = Tree.allocate(Region);
5501 SequenceTree::Seq OldRegion = Region;
5504 SequencedSubexpression SeqLHS(*this);
5506 Visit(BO->getLHS());
5510 Visit(BO->getRHS());
5514 // Forget that LHS and RHS are sequenced. They are both unsequenced
5515 // with respect to other stuff.
5520 void VisitBinAssign(BinaryOperator *BO) {
5521 // The modification is sequenced after the value computation of the LHS
5522 // and RHS, so check it before inspecting the operands and update the
5524 Object O = getObject(BO->getLHS(), true);
5526 return VisitExpr(BO);
5530 // C++11 [expr.ass]p7:
5531 // E1 op= E2 is equivalent to E1 = E1 op E2, except that E1 is evaluated
5534 // Therefore, for a compound assignment operator, O is considered used
5535 // everywhere except within the evaluation of E1 itself.
5536 if (isa<CompoundAssignOperator>(BO))
5539 Visit(BO->getLHS());
5541 if (isa<CompoundAssignOperator>(BO))
5544 Visit(BO->getRHS());
5546 notePostMod(O, BO, UK_ModAsValue);
5548 void VisitCompoundAssignOperator(CompoundAssignOperator *CAO) {
5549 VisitBinAssign(CAO);
5552 void VisitUnaryPreInc(UnaryOperator *UO) { VisitUnaryPreIncDec(UO); }
5553 void VisitUnaryPreDec(UnaryOperator *UO) { VisitUnaryPreIncDec(UO); }
5554 void VisitUnaryPreIncDec(UnaryOperator *UO) {
5555 Object O = getObject(UO->getSubExpr(), true);
5557 return VisitExpr(UO);
5560 Visit(UO->getSubExpr());
5561 notePostMod(O, UO, UK_ModAsValue);
5564 void VisitUnaryPostInc(UnaryOperator *UO) { VisitUnaryPostIncDec(UO); }
5565 void VisitUnaryPostDec(UnaryOperator *UO) { VisitUnaryPostIncDec(UO); }
5566 void VisitUnaryPostIncDec(UnaryOperator *UO) {
5567 Object O = getObject(UO->getSubExpr(), true);
5569 return VisitExpr(UO);
5572 Visit(UO->getSubExpr());
5573 notePostMod(O, UO, UK_ModAsSideEffect);
5576 /// Don't visit the RHS of '&&' or '||' if it might not be evaluated.
5577 void VisitBinLOr(BinaryOperator *BO) {
5578 // The side-effects of the LHS of an '&&' are sequenced before the
5579 // value computation of the RHS, and hence before the value computation
5580 // of the '&&' itself, unless the LHS evaluates to zero. We treat them
5581 // as if they were unconditionally sequenced.
5583 SequencedSubexpression Sequenced(*this);
5584 Visit(BO->getLHS());
5588 if (!BO->getLHS()->isValueDependent() &&
5589 BO->getLHS()->EvaluateAsBooleanCondition(Result, SemaRef.Context)) {
5591 Visit(BO->getRHS());
5593 // Check for unsequenced operations in the RHS, treating it as an
5594 // entirely separate evaluation.
5596 // FIXME: If there are operations in the RHS which are unsequenced
5597 // with respect to operations outside the RHS, and those operations
5598 // are unconditionally evaluated, diagnose them.
5599 WorkList.push_back(BO->getRHS());
5602 void VisitBinLAnd(BinaryOperator *BO) {
5604 SequencedSubexpression Sequenced(*this);
5605 Visit(BO->getLHS());
5609 if (!BO->getLHS()->isValueDependent() &&
5610 BO->getLHS()->EvaluateAsBooleanCondition(Result, SemaRef.Context)) {
5612 Visit(BO->getRHS());
5614 WorkList.push_back(BO->getRHS());
5618 // Only visit the condition, unless we can be sure which subexpression will
5620 void VisitAbstractConditionalOperator(AbstractConditionalOperator *CO) {
5621 SequencedSubexpression Sequenced(*this);
5622 Visit(CO->getCond());
5625 if (!CO->getCond()->isValueDependent() &&
5626 CO->getCond()->EvaluateAsBooleanCondition(Result, SemaRef.Context))
5627 Visit(Result ? CO->getTrueExpr() : CO->getFalseExpr());
5629 WorkList.push_back(CO->getTrueExpr());
5630 WorkList.push_back(CO->getFalseExpr());
5634 void VisitCXXConstructExpr(CXXConstructExpr *CCE) {
5635 if (!CCE->isListInitialization())
5636 return VisitExpr(CCE);
5638 // In C++11, list initializations are sequenced.
5639 llvm::SmallVector<SequenceTree::Seq, 32> Elts;
5640 SequenceTree::Seq Parent = Region;
5641 for (CXXConstructExpr::arg_iterator I = CCE->arg_begin(),
5644 Region = Tree.allocate(Parent);
5645 Elts.push_back(Region);
5649 // Forget that the initializers are sequenced.
5651 for (unsigned I = 0; I < Elts.size(); ++I)
5652 Tree.merge(Elts[I]);
5655 void VisitInitListExpr(InitListExpr *ILE) {
5656 if (!SemaRef.getLangOpts().CPlusPlus11)
5657 return VisitExpr(ILE);
5659 // In C++11, list initializations are sequenced.
5660 llvm::SmallVector<SequenceTree::Seq, 32> Elts;
5661 SequenceTree::Seq Parent = Region;
5662 for (unsigned I = 0; I < ILE->getNumInits(); ++I) {
5663 Expr *E = ILE->getInit(I);
5665 Region = Tree.allocate(Parent);
5666 Elts.push_back(Region);
5670 // Forget that the initializers are sequenced.
5672 for (unsigned I = 0; I < Elts.size(); ++I)
5673 Tree.merge(Elts[I]);
5678 void Sema::CheckUnsequencedOperations(Expr *E) {
5679 llvm::SmallVector<Expr*, 8> WorkList;
5680 WorkList.push_back(E);
5681 while (!WorkList.empty()) {
5682 Expr *Item = WorkList.back();
5683 WorkList.pop_back();
5684 SequenceChecker(*this, Item, WorkList);
5688 void Sema::CheckCompletedExpr(Expr *E, SourceLocation CheckLoc,
5690 CheckImplicitConversions(E, CheckLoc);
5691 CheckUnsequencedOperations(E);
5692 if (!IsConstexpr && !E->isValueDependent())
5693 CheckForIntOverflow(E);
5696 void Sema::CheckBitFieldInitialization(SourceLocation InitLoc,
5697 FieldDecl *BitField,
5699 (void) AnalyzeBitFieldAssignment(*this, BitField, Init, InitLoc);
5702 /// CheckParmsForFunctionDef - Check that the parameters of the given
5703 /// function are appropriate for the definition of a function. This
5704 /// takes care of any checks that cannot be performed on the
5705 /// declaration itself, e.g., that the types of each of the function
5706 /// parameters are complete.
5707 bool Sema::CheckParmsForFunctionDef(ParmVarDecl **P, ParmVarDecl **PEnd,
5708 bool CheckParameterNames) {
5709 bool HasInvalidParm = false;
5710 for (; P != PEnd; ++P) {
5711 ParmVarDecl *Param = *P;
5713 // C99 6.7.5.3p4: the parameters in a parameter type list in a
5714 // function declarator that is part of a function definition of
5715 // that function shall not have incomplete type.
5717 // This is also C++ [dcl.fct]p6.
5718 if (!Param->isInvalidDecl() &&
5719 RequireCompleteType(Param->getLocation(), Param->getType(),
5720 diag::err_typecheck_decl_incomplete_type)) {
5721 Param->setInvalidDecl();
5722 HasInvalidParm = true;
5725 // C99 6.9.1p5: If the declarator includes a parameter type list, the
5726 // declaration of each parameter shall include an identifier.
5727 if (CheckParameterNames &&
5728 Param->getIdentifier() == 0 &&
5729 !Param->isImplicit() &&
5730 !getLangOpts().CPlusPlus)
5731 Diag(Param->getLocation(), diag::err_parameter_name_omitted);
5734 // If the function declarator is not part of a definition of that
5735 // function, parameters may have incomplete type and may use the [*]
5736 // notation in their sequences of declarator specifiers to specify
5737 // variable length array types.
5738 QualType PType = Param->getOriginalType();
5739 while (const ArrayType *AT = Context.getAsArrayType(PType)) {
5740 if (AT->getSizeModifier() == ArrayType::Star) {
5741 // FIXME: This diagnostic should point the '[*]' if source-location
5742 // information is added for it.
5743 Diag(Param->getLocation(), diag::err_array_star_in_function_definition);
5746 PType= AT->getElementType();
5750 return HasInvalidParm;
5753 /// CheckCastAlign - Implements -Wcast-align, which warns when a
5754 /// pointer cast increases the alignment requirements.
5755 void Sema::CheckCastAlign(Expr *Op, QualType T, SourceRange TRange) {
5756 // This is actually a lot of work to potentially be doing on every
5757 // cast; don't do it if we're ignoring -Wcast_align (as is the default).
5758 if (getDiagnostics().getDiagnosticLevel(diag::warn_cast_align,
5760 == DiagnosticsEngine::Ignored)
5763 // Ignore dependent types.
5764 if (T->isDependentType() || Op->getType()->isDependentType())
5767 // Require that the destination be a pointer type.
5768 const PointerType *DestPtr = T->getAs<PointerType>();
5769 if (!DestPtr) return;
5771 // If the destination has alignment 1, we're done.
5772 QualType DestPointee = DestPtr->getPointeeType();
5773 if (DestPointee->isIncompleteType()) return;
5774 CharUnits DestAlign = Context.getTypeAlignInChars(DestPointee);
5775 if (DestAlign.isOne()) return;
5777 // Require that the source be a pointer type.
5778 const PointerType *SrcPtr = Op->getType()->getAs<PointerType>();
5779 if (!SrcPtr) return;
5780 QualType SrcPointee = SrcPtr->getPointeeType();
5782 // Whitelist casts from cv void*. We already implicitly
5783 // whitelisted casts to cv void*, since they have alignment 1.
5784 // Also whitelist casts involving incomplete types, which implicitly
5786 if (SrcPointee->isIncompleteType()) return;
5788 CharUnits SrcAlign = Context.getTypeAlignInChars(SrcPointee);
5789 if (SrcAlign >= DestAlign) return;
5791 Diag(TRange.getBegin(), diag::warn_cast_align)
5792 << Op->getType() << T
5793 << static_cast<unsigned>(SrcAlign.getQuantity())
5794 << static_cast<unsigned>(DestAlign.getQuantity())
5795 << TRange << Op->getSourceRange();
5798 static const Type* getElementType(const Expr *BaseExpr) {
5799 const Type* EltType = BaseExpr->getType().getTypePtr();
5800 if (EltType->isAnyPointerType())
5801 return EltType->getPointeeType().getTypePtr();
5802 else if (EltType->isArrayType())
5803 return EltType->getBaseElementTypeUnsafe();
5807 /// \brief Check whether this array fits the idiom of a size-one tail padded
5808 /// array member of a struct.
5810 /// We avoid emitting out-of-bounds access warnings for such arrays as they are
5811 /// commonly used to emulate flexible arrays in C89 code.
5812 static bool IsTailPaddedMemberArray(Sema &S, llvm::APInt Size,
5813 const NamedDecl *ND) {
5814 if (Size != 1 || !ND) return false;
5816 const FieldDecl *FD = dyn_cast<FieldDecl>(ND);
5817 if (!FD) return false;
5819 // Don't consider sizes resulting from macro expansions or template argument
5820 // substitution to form C89 tail-padded arrays.
5822 TypeSourceInfo *TInfo = FD->getTypeSourceInfo();
5824 TypeLoc TL = TInfo->getTypeLoc();
5825 // Look through typedefs.
5826 if (TypedefTypeLoc TTL = TL.getAs<TypedefTypeLoc>()) {
5827 const TypedefNameDecl *TDL = TTL.getTypedefNameDecl();
5828 TInfo = TDL->getTypeSourceInfo();
5831 if (ConstantArrayTypeLoc CTL = TL.getAs<ConstantArrayTypeLoc>()) {
5832 const Expr *SizeExpr = dyn_cast<IntegerLiteral>(CTL.getSizeExpr());
5833 if (!SizeExpr || SizeExpr->getExprLoc().isMacroID())
5839 const RecordDecl *RD = dyn_cast<RecordDecl>(FD->getDeclContext());
5840 if (!RD) return false;
5841 if (RD->isUnion()) return false;
5842 if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) {
5843 if (!CRD->isStandardLayout()) return false;
5846 // See if this is the last field decl in the record.
5848 while ((D = D->getNextDeclInContext()))
5849 if (isa<FieldDecl>(D))
5854 void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
5855 const ArraySubscriptExpr *ASE,
5856 bool AllowOnePastEnd, bool IndexNegated) {
5857 IndexExpr = IndexExpr->IgnoreParenImpCasts();
5858 if (IndexExpr->isValueDependent())
5861 const Type *EffectiveType = getElementType(BaseExpr);
5862 BaseExpr = BaseExpr->IgnoreParenCasts();
5863 const ConstantArrayType *ArrayTy =
5864 Context.getAsConstantArrayType(BaseExpr->getType());
5869 if (!IndexExpr->EvaluateAsInt(index, Context))
5874 const NamedDecl *ND = NULL;
5875 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(BaseExpr))
5876 ND = dyn_cast<NamedDecl>(DRE->getDecl());
5877 if (const MemberExpr *ME = dyn_cast<MemberExpr>(BaseExpr))
5878 ND = dyn_cast<NamedDecl>(ME->getMemberDecl());
5880 if (index.isUnsigned() || !index.isNegative()) {
5881 llvm::APInt size = ArrayTy->getSize();
5882 if (!size.isStrictlyPositive())
5885 const Type* BaseType = getElementType(BaseExpr);
5886 if (BaseType != EffectiveType) {
5887 // Make sure we're comparing apples to apples when comparing index to size
5888 uint64_t ptrarith_typesize = Context.getTypeSize(EffectiveType);
5889 uint64_t array_typesize = Context.getTypeSize(BaseType);
5890 // Handle ptrarith_typesize being zero, such as when casting to void*
5891 if (!ptrarith_typesize) ptrarith_typesize = 1;
5892 if (ptrarith_typesize != array_typesize) {
5893 // There's a cast to a different size type involved
5894 uint64_t ratio = array_typesize / ptrarith_typesize;
5895 // TODO: Be smarter about handling cases where array_typesize is not a
5896 // multiple of ptrarith_typesize
5897 if (ptrarith_typesize * ratio == array_typesize)
5898 size *= llvm::APInt(size.getBitWidth(), ratio);
5902 if (size.getBitWidth() > index.getBitWidth())
5903 index = index.zext(size.getBitWidth());
5904 else if (size.getBitWidth() < index.getBitWidth())
5905 size = size.zext(index.getBitWidth());
5907 // For array subscripting the index must be less than size, but for pointer
5908 // arithmetic also allow the index (offset) to be equal to size since
5909 // computing the next address after the end of the array is legal and
5910 // commonly done e.g. in C++ iterators and range-based for loops.
5911 if (AllowOnePastEnd ? index.ule(size) : index.ult(size))
5914 // Also don't warn for arrays of size 1 which are members of some
5915 // structure. These are often used to approximate flexible arrays in C89
5917 if (IsTailPaddedMemberArray(*this, size, ND))
5920 // Suppress the warning if the subscript expression (as identified by the
5921 // ']' location) and the index expression are both from macro expansions
5922 // within a system header.
5924 SourceLocation RBracketLoc = SourceMgr.getSpellingLoc(
5925 ASE->getRBracketLoc());
5926 if (SourceMgr.isInSystemHeader(RBracketLoc)) {
5927 SourceLocation IndexLoc = SourceMgr.getSpellingLoc(
5928 IndexExpr->getLocStart());
5929 if (SourceMgr.isFromSameFile(RBracketLoc, IndexLoc))
5934 unsigned DiagID = diag::warn_ptr_arith_exceeds_bounds;
5936 DiagID = diag::warn_array_index_exceeds_bounds;
5938 DiagRuntimeBehavior(BaseExpr->getLocStart(), BaseExpr,
5939 PDiag(DiagID) << index.toString(10, true)
5940 << size.toString(10, true)
5941 << (unsigned)size.getLimitedValue(~0U)
5942 << IndexExpr->getSourceRange());
5944 unsigned DiagID = diag::warn_array_index_precedes_bounds;
5946 DiagID = diag::warn_ptr_arith_precedes_bounds;
5947 if (index.isNegative()) index = -index;
5950 DiagRuntimeBehavior(BaseExpr->getLocStart(), BaseExpr,
5951 PDiag(DiagID) << index.toString(10, true)
5952 << IndexExpr->getSourceRange());
5956 // Try harder to find a NamedDecl to point at in the note.
5957 while (const ArraySubscriptExpr *ASE =
5958 dyn_cast<ArraySubscriptExpr>(BaseExpr))
5959 BaseExpr = ASE->getBase()->IgnoreParenCasts();
5960 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(BaseExpr))
5961 ND = dyn_cast<NamedDecl>(DRE->getDecl());
5962 if (const MemberExpr *ME = dyn_cast<MemberExpr>(BaseExpr))
5963 ND = dyn_cast<NamedDecl>(ME->getMemberDecl());
5967 DiagRuntimeBehavior(ND->getLocStart(), BaseExpr,
5968 PDiag(diag::note_array_index_out_of_bounds)
5969 << ND->getDeclName());
5972 void Sema::CheckArrayAccess(const Expr *expr) {
5973 int AllowOnePastEnd = 0;
5975 expr = expr->IgnoreParenImpCasts();
5976 switch (expr->getStmtClass()) {
5977 case Stmt::ArraySubscriptExprClass: {
5978 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(expr);
5979 CheckArrayAccess(ASE->getBase(), ASE->getIdx(), ASE,
5980 AllowOnePastEnd > 0);
5983 case Stmt::UnaryOperatorClass: {
5984 // Only unwrap the * and & unary operators
5985 const UnaryOperator *UO = cast<UnaryOperator>(expr);
5986 expr = UO->getSubExpr();
5987 switch (UO->getOpcode()) {
5999 case Stmt::ConditionalOperatorClass: {
6000 const ConditionalOperator *cond = cast<ConditionalOperator>(expr);
6001 if (const Expr *lhs = cond->getLHS())
6002 CheckArrayAccess(lhs);
6003 if (const Expr *rhs = cond->getRHS())
6004 CheckArrayAccess(rhs);
6013 //===--- CHECK: Objective-C retain cycles ----------------------------------//
6016 struct RetainCycleOwner {
6017 RetainCycleOwner() : Variable(0), Indirect(false) {}
6023 void setLocsFrom(Expr *e) {
6024 Loc = e->getExprLoc();
6025 Range = e->getSourceRange();
6030 /// Consider whether capturing the given variable can possibly lead to
6032 static bool considerVariable(VarDecl *var, Expr *ref, RetainCycleOwner &owner) {
6033 // In ARC, it's captured strongly iff the variable has __strong
6034 // lifetime. In MRR, it's captured strongly if the variable is
6035 // __block and has an appropriate type.
6036 if (var->getType().getObjCLifetime() != Qualifiers::OCL_Strong)
6039 owner.Variable = var;
6041 owner.setLocsFrom(ref);
6045 static bool findRetainCycleOwner(Sema &S, Expr *e, RetainCycleOwner &owner) {
6047 e = e->IgnoreParens();
6048 if (CastExpr *cast = dyn_cast<CastExpr>(e)) {
6049 switch (cast->getCastKind()) {
6051 case CK_LValueBitCast:
6052 case CK_LValueToRValue:
6053 case CK_ARCReclaimReturnedObject:
6054 e = cast->getSubExpr();
6062 if (ObjCIvarRefExpr *ref = dyn_cast<ObjCIvarRefExpr>(e)) {
6063 ObjCIvarDecl *ivar = ref->getDecl();
6064 if (ivar->getType().getObjCLifetime() != Qualifiers::OCL_Strong)
6067 // Try to find a retain cycle in the base.
6068 if (!findRetainCycleOwner(S, ref->getBase(), owner))
6071 if (ref->isFreeIvar()) owner.setLocsFrom(ref);
6072 owner.Indirect = true;
6076 if (DeclRefExpr *ref = dyn_cast<DeclRefExpr>(e)) {
6077 VarDecl *var = dyn_cast<VarDecl>(ref->getDecl());
6078 if (!var) return false;
6079 return considerVariable(var, ref, owner);
6082 if (MemberExpr *member = dyn_cast<MemberExpr>(e)) {
6083 if (member->isArrow()) return false;
6085 // Don't count this as an indirect ownership.
6086 e = member->getBase();
6090 if (PseudoObjectExpr *pseudo = dyn_cast<PseudoObjectExpr>(e)) {
6091 // Only pay attention to pseudo-objects on property references.
6092 ObjCPropertyRefExpr *pre
6093 = dyn_cast<ObjCPropertyRefExpr>(pseudo->getSyntacticForm()
6095 if (!pre) return false;
6096 if (pre->isImplicitProperty()) return false;
6097 ObjCPropertyDecl *property = pre->getExplicitProperty();
6098 if (!property->isRetaining() &&
6099 !(property->getPropertyIvarDecl() &&
6100 property->getPropertyIvarDecl()->getType()
6101 .getObjCLifetime() == Qualifiers::OCL_Strong))
6104 owner.Indirect = true;
6105 if (pre->isSuperReceiver()) {
6106 owner.Variable = S.getCurMethodDecl()->getSelfDecl();
6107 if (!owner.Variable)
6109 owner.Loc = pre->getLocation();
6110 owner.Range = pre->getSourceRange();
6113 e = const_cast<Expr*>(cast<OpaqueValueExpr>(pre->getBase())
6125 struct FindCaptureVisitor : EvaluatedExprVisitor<FindCaptureVisitor> {
6126 FindCaptureVisitor(ASTContext &Context, VarDecl *variable)
6127 : EvaluatedExprVisitor<FindCaptureVisitor>(Context),
6128 Variable(variable), Capturer(0) {}
6133 void VisitDeclRefExpr(DeclRefExpr *ref) {
6134 if (ref->getDecl() == Variable && !Capturer)
6138 void VisitObjCIvarRefExpr(ObjCIvarRefExpr *ref) {
6139 if (Capturer) return;
6140 Visit(ref->getBase());
6141 if (Capturer && ref->isFreeIvar())
6145 void VisitBlockExpr(BlockExpr *block) {
6146 // Look inside nested blocks
6147 if (block->getBlockDecl()->capturesVariable(Variable))
6148 Visit(block->getBlockDecl()->getBody());
6151 void VisitOpaqueValueExpr(OpaqueValueExpr *OVE) {
6152 if (Capturer) return;
6153 if (OVE->getSourceExpr())
6154 Visit(OVE->getSourceExpr());
6159 /// Check whether the given argument is a block which captures a
6161 static Expr *findCapturingExpr(Sema &S, Expr *e, RetainCycleOwner &owner) {
6162 assert(owner.Variable && owner.Loc.isValid());
6164 e = e->IgnoreParenCasts();
6166 // Look through [^{...} copy] and Block_copy(^{...}).
6167 if (ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(e)) {
6168 Selector Cmd = ME->getSelector();
6169 if (Cmd.isUnarySelector() && Cmd.getNameForSlot(0) == "copy") {
6170 e = ME->getInstanceReceiver();
6173 e = e->IgnoreParenCasts();
6175 } else if (CallExpr *CE = dyn_cast<CallExpr>(e)) {
6176 if (CE->getNumArgs() == 1) {
6177 FunctionDecl *Fn = dyn_cast_or_null<FunctionDecl>(CE->getCalleeDecl());
6179 const IdentifierInfo *FnI = Fn->getIdentifier();
6180 if (FnI && FnI->isStr("_Block_copy")) {
6181 e = CE->getArg(0)->IgnoreParenCasts();
6187 BlockExpr *block = dyn_cast<BlockExpr>(e);
6188 if (!block || !block->getBlockDecl()->capturesVariable(owner.Variable))
6191 FindCaptureVisitor visitor(S.Context, owner.Variable);
6192 visitor.Visit(block->getBlockDecl()->getBody());
6193 return visitor.Capturer;
6196 static void diagnoseRetainCycle(Sema &S, Expr *capturer,
6197 RetainCycleOwner &owner) {
6199 assert(owner.Variable && owner.Loc.isValid());
6201 S.Diag(capturer->getExprLoc(), diag::warn_arc_retain_cycle)
6202 << owner.Variable << capturer->getSourceRange();
6203 S.Diag(owner.Loc, diag::note_arc_retain_cycle_owner)
6204 << owner.Indirect << owner.Range;
6207 /// Check for a keyword selector that starts with the word 'add' or
6209 static bool isSetterLikeSelector(Selector sel) {
6210 if (sel.isUnarySelector()) return false;
6212 StringRef str = sel.getNameForSlot(0);
6213 while (!str.empty() && str.front() == '_') str = str.substr(1);
6214 if (str.startswith("set"))
6215 str = str.substr(3);
6216 else if (str.startswith("add")) {
6217 // Specially whitelist 'addOperationWithBlock:'.
6218 if (sel.getNumArgs() == 1 && str.startswith("addOperationWithBlock"))
6220 str = str.substr(3);
6225 if (str.empty()) return true;
6226 return !isLowercase(str.front());
6229 /// Check a message send to see if it's likely to cause a retain cycle.
6230 void Sema::checkRetainCycles(ObjCMessageExpr *msg) {
6231 // Only check instance methods whose selector looks like a setter.
6232 if (!msg->isInstanceMessage() || !isSetterLikeSelector(msg->getSelector()))
6235 // Try to find a variable that the receiver is strongly owned by.
6236 RetainCycleOwner owner;
6237 if (msg->getReceiverKind() == ObjCMessageExpr::Instance) {
6238 if (!findRetainCycleOwner(*this, msg->getInstanceReceiver(), owner))
6241 assert(msg->getReceiverKind() == ObjCMessageExpr::SuperInstance);
6242 owner.Variable = getCurMethodDecl()->getSelfDecl();
6243 owner.Loc = msg->getSuperLoc();
6244 owner.Range = msg->getSuperLoc();
6247 // Check whether the receiver is captured by any of the arguments.
6248 for (unsigned i = 0, e = msg->getNumArgs(); i != e; ++i)
6249 if (Expr *capturer = findCapturingExpr(*this, msg->getArg(i), owner))
6250 return diagnoseRetainCycle(*this, capturer, owner);
6253 /// Check a property assign to see if it's likely to cause a retain cycle.
6254 void Sema::checkRetainCycles(Expr *receiver, Expr *argument) {
6255 RetainCycleOwner owner;
6256 if (!findRetainCycleOwner(*this, receiver, owner))
6259 if (Expr *capturer = findCapturingExpr(*this, argument, owner))
6260 diagnoseRetainCycle(*this, capturer, owner);
6263 void Sema::checkRetainCycles(VarDecl *Var, Expr *Init) {
6264 RetainCycleOwner Owner;
6265 if (!considerVariable(Var, /*DeclRefExpr=*/0, Owner))
6268 // Because we don't have an expression for the variable, we have to set the
6269 // location explicitly here.
6270 Owner.Loc = Var->getLocation();
6271 Owner.Range = Var->getSourceRange();
6273 if (Expr *Capturer = findCapturingExpr(*this, Init, Owner))
6274 diagnoseRetainCycle(*this, Capturer, Owner);
6277 static bool checkUnsafeAssignLiteral(Sema &S, SourceLocation Loc,
6278 Expr *RHS, bool isProperty) {
6279 // Check if RHS is an Objective-C object literal, which also can get
6280 // immediately zapped in a weak reference. Note that we explicitly
6281 // allow ObjCStringLiterals, since those are designed to never really die.
6282 RHS = RHS->IgnoreParenImpCasts();
6284 // This enum needs to match with the 'select' in
6285 // warn_objc_arc_literal_assign (off-by-1).
6286 Sema::ObjCLiteralKind Kind = S.CheckLiteralKind(RHS);
6287 if (Kind == Sema::LK_String || Kind == Sema::LK_None)
6290 S.Diag(Loc, diag::warn_arc_literal_assign)
6292 << (isProperty ? 0 : 1)
6293 << RHS->getSourceRange();
6298 static bool checkUnsafeAssignObject(Sema &S, SourceLocation Loc,
6299 Qualifiers::ObjCLifetime LT,
6300 Expr *RHS, bool isProperty) {
6301 // Strip off any implicit cast added to get to the one ARC-specific.
6302 while (ImplicitCastExpr *cast = dyn_cast<ImplicitCastExpr>(RHS)) {
6303 if (cast->getCastKind() == CK_ARCConsumeObject) {
6304 S.Diag(Loc, diag::warn_arc_retained_assign)
6305 << (LT == Qualifiers::OCL_ExplicitNone)
6306 << (isProperty ? 0 : 1)
6307 << RHS->getSourceRange();
6310 RHS = cast->getSubExpr();
6313 if (LT == Qualifiers::OCL_Weak &&
6314 checkUnsafeAssignLiteral(S, Loc, RHS, isProperty))
6320 bool Sema::checkUnsafeAssigns(SourceLocation Loc,
6321 QualType LHS, Expr *RHS) {
6322 Qualifiers::ObjCLifetime LT = LHS.getObjCLifetime();
6324 if (LT != Qualifiers::OCL_Weak && LT != Qualifiers::OCL_ExplicitNone)
6327 if (checkUnsafeAssignObject(*this, Loc, LT, RHS, false))
6333 void Sema::checkUnsafeExprAssigns(SourceLocation Loc,
6334 Expr *LHS, Expr *RHS) {
6336 // PropertyRef on LHS type need be directly obtained from
6337 // its declaration as it has a PsuedoType.
6338 ObjCPropertyRefExpr *PRE
6339 = dyn_cast<ObjCPropertyRefExpr>(LHS->IgnoreParens());
6340 if (PRE && !PRE->isImplicitProperty()) {
6341 const ObjCPropertyDecl *PD = PRE->getExplicitProperty();
6343 LHSType = PD->getType();
6346 if (LHSType.isNull())
6347 LHSType = LHS->getType();
6349 Qualifiers::ObjCLifetime LT = LHSType.getObjCLifetime();
6351 if (LT == Qualifiers::OCL_Weak) {
6352 DiagnosticsEngine::Level Level =
6353 Diags.getDiagnosticLevel(diag::warn_arc_repeated_use_of_weak, Loc);
6354 if (Level != DiagnosticsEngine::Ignored)
6355 getCurFunction()->markSafeWeakUse(LHS);
6358 if (checkUnsafeAssigns(Loc, LHSType, RHS))
6361 // FIXME. Check for other life times.
6362 if (LT != Qualifiers::OCL_None)
6366 if (PRE->isImplicitProperty())
6368 const ObjCPropertyDecl *PD = PRE->getExplicitProperty();
6372 unsigned Attributes = PD->getPropertyAttributes();
6373 if (Attributes & ObjCPropertyDecl::OBJC_PR_assign) {
6374 // when 'assign' attribute was not explicitly specified
6375 // by user, ignore it and rely on property type itself
6376 // for lifetime info.
6377 unsigned AsWrittenAttr = PD->getPropertyAttributesAsWritten();
6378 if (!(AsWrittenAttr & ObjCPropertyDecl::OBJC_PR_assign) &&
6379 LHSType->isObjCRetainableType())
6382 while (ImplicitCastExpr *cast = dyn_cast<ImplicitCastExpr>(RHS)) {
6383 if (cast->getCastKind() == CK_ARCConsumeObject) {
6384 Diag(Loc, diag::warn_arc_retained_property_assign)
6385 << RHS->getSourceRange();
6388 RHS = cast->getSubExpr();
6391 else if (Attributes & ObjCPropertyDecl::OBJC_PR_weak) {
6392 if (checkUnsafeAssignObject(*this, Loc, Qualifiers::OCL_Weak, RHS, true))
6398 //===--- CHECK: Empty statement body (-Wempty-body) ---------------------===//
6401 bool ShouldDiagnoseEmptyStmtBody(const SourceManager &SourceMgr,
6402 SourceLocation StmtLoc,
6403 const NullStmt *Body) {
6404 // Do not warn if the body is a macro that expands to nothing, e.g:
6410 if (Body->hasLeadingEmptyMacro())
6413 // Get line numbers of statement and body.
6414 bool StmtLineInvalid;
6415 unsigned StmtLine = SourceMgr.getSpellingLineNumber(StmtLoc,
6417 if (StmtLineInvalid)
6420 bool BodyLineInvalid;
6421 unsigned BodyLine = SourceMgr.getSpellingLineNumber(Body->getSemiLoc(),
6423 if (BodyLineInvalid)
6426 // Warn if null statement and body are on the same line.
6427 if (StmtLine != BodyLine)
6432 } // Unnamed namespace
6434 void Sema::DiagnoseEmptyStmtBody(SourceLocation StmtLoc,
6437 // Since this is a syntactic check, don't emit diagnostic for template
6438 // instantiations, this just adds noise.
6439 if (CurrentInstantiationScope)
6442 // The body should be a null statement.
6443 const NullStmt *NBody = dyn_cast<NullStmt>(Body);
6447 // Do the usual checks.
6448 if (!ShouldDiagnoseEmptyStmtBody(SourceMgr, StmtLoc, NBody))
6451 Diag(NBody->getSemiLoc(), DiagID);
6452 Diag(NBody->getSemiLoc(), diag::note_empty_body_on_separate_line);
6455 void Sema::DiagnoseEmptyLoopBody(const Stmt *S,
6456 const Stmt *PossibleBody) {
6457 assert(!CurrentInstantiationScope); // Ensured by caller
6459 SourceLocation StmtLoc;
6462 if (const ForStmt *FS = dyn_cast<ForStmt>(S)) {
6463 StmtLoc = FS->getRParenLoc();
6464 Body = FS->getBody();
6465 DiagID = diag::warn_empty_for_body;
6466 } else if (const WhileStmt *WS = dyn_cast<WhileStmt>(S)) {
6467 StmtLoc = WS->getCond()->getSourceRange().getEnd();
6468 Body = WS->getBody();
6469 DiagID = diag::warn_empty_while_body;
6471 return; // Neither `for' nor `while'.
6473 // The body should be a null statement.
6474 const NullStmt *NBody = dyn_cast<NullStmt>(Body);
6478 // Skip expensive checks if diagnostic is disabled.
6479 if (Diags.getDiagnosticLevel(DiagID, NBody->getSemiLoc()) ==
6480 DiagnosticsEngine::Ignored)
6483 // Do the usual checks.
6484 if (!ShouldDiagnoseEmptyStmtBody(SourceMgr, StmtLoc, NBody))
6487 // `for(...);' and `while(...);' are popular idioms, so in order to keep
6488 // noise level low, emit diagnostics only if for/while is followed by a
6489 // CompoundStmt, e.g.:
6490 // for (int i = 0; i < n; i++);
6494 // or if for/while is followed by a statement with more indentation
6495 // than for/while itself:
6496 // for (int i = 0; i < n; i++);
6498 bool ProbableTypo = isa<CompoundStmt>(PossibleBody);
6499 if (!ProbableTypo) {
6500 bool BodyColInvalid;
6501 unsigned BodyCol = SourceMgr.getPresumedColumnNumber(
6502 PossibleBody->getLocStart(),
6507 bool StmtColInvalid;
6508 unsigned StmtCol = SourceMgr.getPresumedColumnNumber(
6514 if (BodyCol > StmtCol)
6515 ProbableTypo = true;
6519 Diag(NBody->getSemiLoc(), DiagID);
6520 Diag(NBody->getSemiLoc(), diag::note_empty_body_on_separate_line);
6524 //===--- Layout compatibility ----------------------------------------------//
6528 bool isLayoutCompatible(ASTContext &C, QualType T1, QualType T2);
6530 /// \brief Check if two enumeration types are layout-compatible.
6531 bool isLayoutCompatible(ASTContext &C, EnumDecl *ED1, EnumDecl *ED2) {
6532 // C++11 [dcl.enum] p8:
6533 // Two enumeration types are layout-compatible if they have the same
6535 return ED1->isComplete() && ED2->isComplete() &&
6536 C.hasSameType(ED1->getIntegerType(), ED2->getIntegerType());
6539 /// \brief Check if two fields are layout-compatible.
6540 bool isLayoutCompatible(ASTContext &C, FieldDecl *Field1, FieldDecl *Field2) {
6541 if (!isLayoutCompatible(C, Field1->getType(), Field2->getType()))
6544 if (Field1->isBitField() != Field2->isBitField())
6547 if (Field1->isBitField()) {
6548 // Make sure that the bit-fields are the same length.
6549 unsigned Bits1 = Field1->getBitWidthValue(C);
6550 unsigned Bits2 = Field2->getBitWidthValue(C);
6559 /// \brief Check if two standard-layout structs are layout-compatible.
6560 /// (C++11 [class.mem] p17)
6561 bool isLayoutCompatibleStruct(ASTContext &C,
6564 // If both records are C++ classes, check that base classes match.
6565 if (const CXXRecordDecl *D1CXX = dyn_cast<CXXRecordDecl>(RD1)) {
6566 // If one of records is a CXXRecordDecl we are in C++ mode,
6567 // thus the other one is a CXXRecordDecl, too.
6568 const CXXRecordDecl *D2CXX = cast<CXXRecordDecl>(RD2);
6569 // Check number of base classes.
6570 if (D1CXX->getNumBases() != D2CXX->getNumBases())
6573 // Check the base classes.
6574 for (CXXRecordDecl::base_class_const_iterator
6575 Base1 = D1CXX->bases_begin(),
6576 BaseEnd1 = D1CXX->bases_end(),
6577 Base2 = D2CXX->bases_begin();
6580 if (!isLayoutCompatible(C, Base1->getType(), Base2->getType()))
6583 } else if (const CXXRecordDecl *D2CXX = dyn_cast<CXXRecordDecl>(RD2)) {
6584 // If only RD2 is a C++ class, it should have zero base classes.
6585 if (D2CXX->getNumBases() > 0)
6589 // Check the fields.
6590 RecordDecl::field_iterator Field2 = RD2->field_begin(),
6591 Field2End = RD2->field_end(),
6592 Field1 = RD1->field_begin(),
6593 Field1End = RD1->field_end();
6594 for ( ; Field1 != Field1End && Field2 != Field2End; ++Field1, ++Field2) {
6595 if (!isLayoutCompatible(C, *Field1, *Field2))
6598 if (Field1 != Field1End || Field2 != Field2End)
6604 /// \brief Check if two standard-layout unions are layout-compatible.
6605 /// (C++11 [class.mem] p18)
6606 bool isLayoutCompatibleUnion(ASTContext &C,
6609 llvm::SmallPtrSet<FieldDecl *, 8> UnmatchedFields;
6610 for (RecordDecl::field_iterator Field2 = RD2->field_begin(),
6611 Field2End = RD2->field_end();
6612 Field2 != Field2End; ++Field2) {
6613 UnmatchedFields.insert(*Field2);
6616 for (RecordDecl::field_iterator Field1 = RD1->field_begin(),
6617 Field1End = RD1->field_end();
6618 Field1 != Field1End; ++Field1) {
6619 llvm::SmallPtrSet<FieldDecl *, 8>::iterator
6620 I = UnmatchedFields.begin(),
6621 E = UnmatchedFields.end();
6623 for ( ; I != E; ++I) {
6624 if (isLayoutCompatible(C, *Field1, *I)) {
6625 bool Result = UnmatchedFields.erase(*I);
6635 return UnmatchedFields.empty();
6638 bool isLayoutCompatible(ASTContext &C, RecordDecl *RD1, RecordDecl *RD2) {
6639 if (RD1->isUnion() != RD2->isUnion())
6643 return isLayoutCompatibleUnion(C, RD1, RD2);
6645 return isLayoutCompatibleStruct(C, RD1, RD2);
6648 /// \brief Check if two types are layout-compatible in C++11 sense.
6649 bool isLayoutCompatible(ASTContext &C, QualType T1, QualType T2) {
6650 if (T1.isNull() || T2.isNull())
6653 // C++11 [basic.types] p11:
6654 // If two types T1 and T2 are the same type, then T1 and T2 are
6655 // layout-compatible types.
6656 if (C.hasSameType(T1, T2))
6659 T1 = T1.getCanonicalType().getUnqualifiedType();
6660 T2 = T2.getCanonicalType().getUnqualifiedType();
6662 const Type::TypeClass TC1 = T1->getTypeClass();
6663 const Type::TypeClass TC2 = T2->getTypeClass();
6668 if (TC1 == Type::Enum) {
6669 return isLayoutCompatible(C,
6670 cast<EnumType>(T1)->getDecl(),
6671 cast<EnumType>(T2)->getDecl());
6672 } else if (TC1 == Type::Record) {
6673 if (!T1->isStandardLayoutType() || !T2->isStandardLayoutType())
6676 return isLayoutCompatible(C,
6677 cast<RecordType>(T1)->getDecl(),
6678 cast<RecordType>(T2)->getDecl());
6685 //===--- CHECK: pointer_with_type_tag attribute: datatypes should match ----//
6688 /// \brief Given a type tag expression find the type tag itself.
6690 /// \param TypeExpr Type tag expression, as it appears in user's code.
6692 /// \param VD Declaration of an identifier that appears in a type tag.
6694 /// \param MagicValue Type tag magic value.
6695 bool FindTypeTagExpr(const Expr *TypeExpr, const ASTContext &Ctx,
6696 const ValueDecl **VD, uint64_t *MagicValue) {
6701 TypeExpr = TypeExpr->IgnoreParenImpCasts()->IgnoreParenCasts();
6703 switch (TypeExpr->getStmtClass()) {
6704 case Stmt::UnaryOperatorClass: {
6705 const UnaryOperator *UO = cast<UnaryOperator>(TypeExpr);
6706 if (UO->getOpcode() == UO_AddrOf || UO->getOpcode() == UO_Deref) {
6707 TypeExpr = UO->getSubExpr();
6713 case Stmt::DeclRefExprClass: {
6714 const DeclRefExpr *DRE = cast<DeclRefExpr>(TypeExpr);
6715 *VD = DRE->getDecl();
6719 case Stmt::IntegerLiteralClass: {
6720 const IntegerLiteral *IL = cast<IntegerLiteral>(TypeExpr);
6721 llvm::APInt MagicValueAPInt = IL->getValue();
6722 if (MagicValueAPInt.getActiveBits() <= 64) {
6723 *MagicValue = MagicValueAPInt.getZExtValue();
6729 case Stmt::BinaryConditionalOperatorClass:
6730 case Stmt::ConditionalOperatorClass: {
6731 const AbstractConditionalOperator *ACO =
6732 cast<AbstractConditionalOperator>(TypeExpr);
6734 if (ACO->getCond()->EvaluateAsBooleanCondition(Result, Ctx)) {
6736 TypeExpr = ACO->getTrueExpr();
6738 TypeExpr = ACO->getFalseExpr();
6744 case Stmt::BinaryOperatorClass: {
6745 const BinaryOperator *BO = cast<BinaryOperator>(TypeExpr);
6746 if (BO->getOpcode() == BO_Comma) {
6747 TypeExpr = BO->getRHS();
6759 /// \brief Retrieve the C type corresponding to type tag TypeExpr.
6761 /// \param TypeExpr Expression that specifies a type tag.
6763 /// \param MagicValues Registered magic values.
6765 /// \param FoundWrongKind Set to true if a type tag was found, but of a wrong
6768 /// \param TypeInfo Information about the corresponding C type.
6770 /// \returns true if the corresponding C type was found.
6771 bool GetMatchingCType(
6772 const IdentifierInfo *ArgumentKind,
6773 const Expr *TypeExpr, const ASTContext &Ctx,
6774 const llvm::DenseMap<Sema::TypeTagMagicValue,
6775 Sema::TypeTagData> *MagicValues,
6776 bool &FoundWrongKind,
6777 Sema::TypeTagData &TypeInfo) {
6778 FoundWrongKind = false;
6780 // Variable declaration that has type_tag_for_datatype attribute.
6781 const ValueDecl *VD = NULL;
6783 uint64_t MagicValue;
6785 if (!FindTypeTagExpr(TypeExpr, Ctx, &VD, &MagicValue))
6789 for (specific_attr_iterator<TypeTagForDatatypeAttr>
6790 I = VD->specific_attr_begin<TypeTagForDatatypeAttr>(),
6791 E = VD->specific_attr_end<TypeTagForDatatypeAttr>();
6793 if (I->getArgumentKind() != ArgumentKind) {
6794 FoundWrongKind = true;
6797 TypeInfo.Type = I->getMatchingCType();
6798 TypeInfo.LayoutCompatible = I->getLayoutCompatible();
6799 TypeInfo.MustBeNull = I->getMustBeNull();
6808 llvm::DenseMap<Sema::TypeTagMagicValue,
6809 Sema::TypeTagData>::const_iterator I =
6810 MagicValues->find(std::make_pair(ArgumentKind, MagicValue));
6811 if (I == MagicValues->end())
6814 TypeInfo = I->second;
6817 } // unnamed namespace
6819 void Sema::RegisterTypeTagForDatatype(const IdentifierInfo *ArgumentKind,
6820 uint64_t MagicValue, QualType Type,
6821 bool LayoutCompatible,
6823 if (!TypeTagForDatatypeMagicValues)
6824 TypeTagForDatatypeMagicValues.reset(
6825 new llvm::DenseMap<TypeTagMagicValue, TypeTagData>);
6827 TypeTagMagicValue Magic(ArgumentKind, MagicValue);
6828 (*TypeTagForDatatypeMagicValues)[Magic] =
6829 TypeTagData(Type, LayoutCompatible, MustBeNull);
6833 bool IsSameCharType(QualType T1, QualType T2) {
6834 const BuiltinType *BT1 = T1->getAs<BuiltinType>();
6838 const BuiltinType *BT2 = T2->getAs<BuiltinType>();
6842 BuiltinType::Kind T1Kind = BT1->getKind();
6843 BuiltinType::Kind T2Kind = BT2->getKind();
6845 return (T1Kind == BuiltinType::SChar && T2Kind == BuiltinType::Char_S) ||
6846 (T1Kind == BuiltinType::UChar && T2Kind == BuiltinType::Char_U) ||
6847 (T1Kind == BuiltinType::Char_U && T2Kind == BuiltinType::UChar) ||
6848 (T1Kind == BuiltinType::Char_S && T2Kind == BuiltinType::SChar);
6850 } // unnamed namespace
6852 void Sema::CheckArgumentWithTypeTag(const ArgumentWithTypeTagAttr *Attr,
6853 const Expr * const *ExprArgs) {
6854 const IdentifierInfo *ArgumentKind = Attr->getArgumentKind();
6855 bool IsPointerAttr = Attr->getIsPointer();
6857 const Expr *TypeTagExpr = ExprArgs[Attr->getTypeTagIdx()];
6858 bool FoundWrongKind;
6859 TypeTagData TypeInfo;
6860 if (!GetMatchingCType(ArgumentKind, TypeTagExpr, Context,
6861 TypeTagForDatatypeMagicValues.get(),
6862 FoundWrongKind, TypeInfo)) {
6864 Diag(TypeTagExpr->getExprLoc(),
6865 diag::warn_type_tag_for_datatype_wrong_kind)
6866 << TypeTagExpr->getSourceRange();
6870 const Expr *ArgumentExpr = ExprArgs[Attr->getArgumentIdx()];
6871 if (IsPointerAttr) {
6872 // Skip implicit cast of pointer to `void *' (as a function argument).
6873 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgumentExpr))
6874 if (ICE->getType()->isVoidPointerType() &&
6875 ICE->getCastKind() == CK_BitCast)
6876 ArgumentExpr = ICE->getSubExpr();
6878 QualType ArgumentType = ArgumentExpr->getType();
6880 // Passing a `void*' pointer shouldn't trigger a warning.
6881 if (IsPointerAttr && ArgumentType->isVoidPointerType())
6884 if (TypeInfo.MustBeNull) {
6885 // Type tag with matching void type requires a null pointer.
6886 if (!ArgumentExpr->isNullPointerConstant(Context,
6887 Expr::NPC_ValueDependentIsNotNull)) {
6888 Diag(ArgumentExpr->getExprLoc(),
6889 diag::warn_type_safety_null_pointer_required)
6890 << ArgumentKind->getName()
6891 << ArgumentExpr->getSourceRange()
6892 << TypeTagExpr->getSourceRange();
6897 QualType RequiredType = TypeInfo.Type;
6899 RequiredType = Context.getPointerType(RequiredType);
6901 bool mismatch = false;
6902 if (!TypeInfo.LayoutCompatible) {
6903 mismatch = !Context.hasSameType(ArgumentType, RequiredType);
6905 // C++11 [basic.fundamental] p1:
6906 // Plain char, signed char, and unsigned char are three distinct types.
6908 // But we treat plain `char' as equivalent to `signed char' or `unsigned
6909 // char' depending on the current char signedness mode.
6911 if ((IsPointerAttr && IsSameCharType(ArgumentType->getPointeeType(),
6912 RequiredType->getPointeeType())) ||
6913 (!IsPointerAttr && IsSameCharType(ArgumentType, RequiredType)))
6917 mismatch = !isLayoutCompatible(Context,
6918 ArgumentType->getPointeeType(),
6919 RequiredType->getPointeeType());
6921 mismatch = !isLayoutCompatible(Context, ArgumentType, RequiredType);
6924 Diag(ArgumentExpr->getExprLoc(), diag::warn_type_safety_type_mismatch)
6925 << ArgumentType << ArgumentKind->getName()
6926 << TypeInfo.LayoutCompatible << RequiredType
6927 << ArgumentExpr->getSourceRange()
6928 << TypeTagExpr->getSourceRange();