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/Initialization.h"
16 #include "clang/Sema/Sema.h"
17 #include "clang/Sema/SemaInternal.h"
18 #include "clang/Sema/Initialization.h"
19 #include "clang/Sema/Lookup.h"
20 #include "clang/Sema/ScopeInfo.h"
21 #include "clang/Analysis/Analyses/FormatString.h"
22 #include "clang/AST/ASTContext.h"
23 #include "clang/AST/CharUnits.h"
24 #include "clang/AST/DeclCXX.h"
25 #include "clang/AST/DeclObjC.h"
26 #include "clang/AST/Expr.h"
27 #include "clang/AST/ExprCXX.h"
28 #include "clang/AST/ExprObjC.h"
29 #include "clang/AST/EvaluatedExprVisitor.h"
30 #include "clang/AST/DeclObjC.h"
31 #include "clang/AST/StmtCXX.h"
32 #include "clang/AST/StmtObjC.h"
33 #include "clang/Lex/Preprocessor.h"
34 #include "llvm/ADT/BitVector.h"
35 #include "llvm/ADT/SmallString.h"
36 #include "llvm/ADT/STLExtras.h"
37 #include "llvm/Support/raw_ostream.h"
38 #include "clang/Basic/TargetBuiltins.h"
39 #include "clang/Basic/TargetInfo.h"
40 #include "clang/Basic/ConvertUTF.h"
42 using namespace clang;
45 SourceLocation Sema::getLocationOfStringLiteralByte(const StringLiteral *SL,
46 unsigned ByteNo) const {
47 return SL->getLocationOfByte(ByteNo, PP.getSourceManager(),
48 PP.getLangOpts(), PP.getTargetInfo());
51 /// Checks that a call expression's argument count is the desired number.
52 /// This is useful when doing custom type-checking. Returns true on error.
53 static bool checkArgCount(Sema &S, CallExpr *call, unsigned desiredArgCount) {
54 unsigned argCount = call->getNumArgs();
55 if (argCount == desiredArgCount) return false;
57 if (argCount < desiredArgCount)
58 return S.Diag(call->getLocEnd(), diag::err_typecheck_call_too_few_args)
59 << 0 /*function call*/ << desiredArgCount << argCount
60 << call->getSourceRange();
62 // Highlight all the excess arguments.
63 SourceRange range(call->getArg(desiredArgCount)->getLocStart(),
64 call->getArg(argCount - 1)->getLocEnd());
66 return S.Diag(range.getBegin(), diag::err_typecheck_call_too_many_args)
67 << 0 /*function call*/ << desiredArgCount << argCount
68 << call->getArg(1)->getSourceRange();
71 /// Check that the first argument to __builtin_annotation is an integer
72 /// and the second argument is a non-wide string literal.
73 static bool SemaBuiltinAnnotation(Sema &S, CallExpr *TheCall) {
74 if (checkArgCount(S, TheCall, 2))
77 // First argument should be an integer.
78 Expr *ValArg = TheCall->getArg(0);
79 QualType Ty = ValArg->getType();
80 if (!Ty->isIntegerType()) {
81 S.Diag(ValArg->getLocStart(), diag::err_builtin_annotation_first_arg)
82 << ValArg->getSourceRange();
86 // Second argument should be a constant string.
87 Expr *StrArg = TheCall->getArg(1)->IgnoreParenCasts();
88 StringLiteral *Literal = dyn_cast<StringLiteral>(StrArg);
89 if (!Literal || !Literal->isAscii()) {
90 S.Diag(StrArg->getLocStart(), diag::err_builtin_annotation_second_arg)
91 << StrArg->getSourceRange();
100 Sema::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
101 ExprResult TheCallResult(Owned(TheCall));
103 // Find out if any arguments are required to be integer constant expressions.
104 unsigned ICEArguments = 0;
105 ASTContext::GetBuiltinTypeError Error;
106 Context.GetBuiltinType(BuiltinID, Error, &ICEArguments);
107 if (Error != ASTContext::GE_None)
108 ICEArguments = 0; // Don't diagnose previously diagnosed errors.
110 // If any arguments are required to be ICE's, check and diagnose.
111 for (unsigned ArgNo = 0; ICEArguments != 0; ++ArgNo) {
112 // Skip arguments not required to be ICE's.
113 if ((ICEArguments & (1 << ArgNo)) == 0) continue;
116 if (SemaBuiltinConstantArg(TheCall, ArgNo, Result))
118 ICEArguments &= ~(1 << ArgNo);
122 case Builtin::BI__builtin___CFStringMakeConstantString:
123 assert(TheCall->getNumArgs() == 1 &&
124 "Wrong # arguments to builtin CFStringMakeConstantString");
125 if (CheckObjCString(TheCall->getArg(0)))
128 case Builtin::BI__builtin_stdarg_start:
129 case Builtin::BI__builtin_va_start:
130 if (SemaBuiltinVAStart(TheCall))
133 case Builtin::BI__builtin_isgreater:
134 case Builtin::BI__builtin_isgreaterequal:
135 case Builtin::BI__builtin_isless:
136 case Builtin::BI__builtin_islessequal:
137 case Builtin::BI__builtin_islessgreater:
138 case Builtin::BI__builtin_isunordered:
139 if (SemaBuiltinUnorderedCompare(TheCall))
142 case Builtin::BI__builtin_fpclassify:
143 if (SemaBuiltinFPClassification(TheCall, 6))
146 case Builtin::BI__builtin_isfinite:
147 case Builtin::BI__builtin_isinf:
148 case Builtin::BI__builtin_isinf_sign:
149 case Builtin::BI__builtin_isnan:
150 case Builtin::BI__builtin_isnormal:
151 if (SemaBuiltinFPClassification(TheCall, 1))
154 case Builtin::BI__builtin_shufflevector:
155 return SemaBuiltinShuffleVector(TheCall);
156 // TheCall will be freed by the smart pointer here, but that's fine, since
157 // SemaBuiltinShuffleVector guts it, but then doesn't release it.
158 case Builtin::BI__builtin_prefetch:
159 if (SemaBuiltinPrefetch(TheCall))
162 case Builtin::BI__builtin_object_size:
163 if (SemaBuiltinObjectSize(TheCall))
166 case Builtin::BI__builtin_longjmp:
167 if (SemaBuiltinLongjmp(TheCall))
171 case Builtin::BI__builtin_classify_type:
172 if (checkArgCount(*this, TheCall, 1)) return true;
173 TheCall->setType(Context.IntTy);
175 case Builtin::BI__builtin_constant_p:
176 if (checkArgCount(*this, TheCall, 1)) return true;
177 TheCall->setType(Context.IntTy);
179 case Builtin::BI__sync_fetch_and_add:
180 case Builtin::BI__sync_fetch_and_add_1:
181 case Builtin::BI__sync_fetch_and_add_2:
182 case Builtin::BI__sync_fetch_and_add_4:
183 case Builtin::BI__sync_fetch_and_add_8:
184 case Builtin::BI__sync_fetch_and_add_16:
185 case Builtin::BI__sync_fetch_and_sub:
186 case Builtin::BI__sync_fetch_and_sub_1:
187 case Builtin::BI__sync_fetch_and_sub_2:
188 case Builtin::BI__sync_fetch_and_sub_4:
189 case Builtin::BI__sync_fetch_and_sub_8:
190 case Builtin::BI__sync_fetch_and_sub_16:
191 case Builtin::BI__sync_fetch_and_or:
192 case Builtin::BI__sync_fetch_and_or_1:
193 case Builtin::BI__sync_fetch_and_or_2:
194 case Builtin::BI__sync_fetch_and_or_4:
195 case Builtin::BI__sync_fetch_and_or_8:
196 case Builtin::BI__sync_fetch_and_or_16:
197 case Builtin::BI__sync_fetch_and_and:
198 case Builtin::BI__sync_fetch_and_and_1:
199 case Builtin::BI__sync_fetch_and_and_2:
200 case Builtin::BI__sync_fetch_and_and_4:
201 case Builtin::BI__sync_fetch_and_and_8:
202 case Builtin::BI__sync_fetch_and_and_16:
203 case Builtin::BI__sync_fetch_and_xor:
204 case Builtin::BI__sync_fetch_and_xor_1:
205 case Builtin::BI__sync_fetch_and_xor_2:
206 case Builtin::BI__sync_fetch_and_xor_4:
207 case Builtin::BI__sync_fetch_and_xor_8:
208 case Builtin::BI__sync_fetch_and_xor_16:
209 case Builtin::BI__sync_add_and_fetch:
210 case Builtin::BI__sync_add_and_fetch_1:
211 case Builtin::BI__sync_add_and_fetch_2:
212 case Builtin::BI__sync_add_and_fetch_4:
213 case Builtin::BI__sync_add_and_fetch_8:
214 case Builtin::BI__sync_add_and_fetch_16:
215 case Builtin::BI__sync_sub_and_fetch:
216 case Builtin::BI__sync_sub_and_fetch_1:
217 case Builtin::BI__sync_sub_and_fetch_2:
218 case Builtin::BI__sync_sub_and_fetch_4:
219 case Builtin::BI__sync_sub_and_fetch_8:
220 case Builtin::BI__sync_sub_and_fetch_16:
221 case Builtin::BI__sync_and_and_fetch:
222 case Builtin::BI__sync_and_and_fetch_1:
223 case Builtin::BI__sync_and_and_fetch_2:
224 case Builtin::BI__sync_and_and_fetch_4:
225 case Builtin::BI__sync_and_and_fetch_8:
226 case Builtin::BI__sync_and_and_fetch_16:
227 case Builtin::BI__sync_or_and_fetch:
228 case Builtin::BI__sync_or_and_fetch_1:
229 case Builtin::BI__sync_or_and_fetch_2:
230 case Builtin::BI__sync_or_and_fetch_4:
231 case Builtin::BI__sync_or_and_fetch_8:
232 case Builtin::BI__sync_or_and_fetch_16:
233 case Builtin::BI__sync_xor_and_fetch:
234 case Builtin::BI__sync_xor_and_fetch_1:
235 case Builtin::BI__sync_xor_and_fetch_2:
236 case Builtin::BI__sync_xor_and_fetch_4:
237 case Builtin::BI__sync_xor_and_fetch_8:
238 case Builtin::BI__sync_xor_and_fetch_16:
239 case Builtin::BI__sync_val_compare_and_swap:
240 case Builtin::BI__sync_val_compare_and_swap_1:
241 case Builtin::BI__sync_val_compare_and_swap_2:
242 case Builtin::BI__sync_val_compare_and_swap_4:
243 case Builtin::BI__sync_val_compare_and_swap_8:
244 case Builtin::BI__sync_val_compare_and_swap_16:
245 case Builtin::BI__sync_bool_compare_and_swap:
246 case Builtin::BI__sync_bool_compare_and_swap_1:
247 case Builtin::BI__sync_bool_compare_and_swap_2:
248 case Builtin::BI__sync_bool_compare_and_swap_4:
249 case Builtin::BI__sync_bool_compare_and_swap_8:
250 case Builtin::BI__sync_bool_compare_and_swap_16:
251 case Builtin::BI__sync_lock_test_and_set:
252 case Builtin::BI__sync_lock_test_and_set_1:
253 case Builtin::BI__sync_lock_test_and_set_2:
254 case Builtin::BI__sync_lock_test_and_set_4:
255 case Builtin::BI__sync_lock_test_and_set_8:
256 case Builtin::BI__sync_lock_test_and_set_16:
257 case Builtin::BI__sync_lock_release:
258 case Builtin::BI__sync_lock_release_1:
259 case Builtin::BI__sync_lock_release_2:
260 case Builtin::BI__sync_lock_release_4:
261 case Builtin::BI__sync_lock_release_8:
262 case Builtin::BI__sync_lock_release_16:
263 case Builtin::BI__sync_swap:
264 case Builtin::BI__sync_swap_1:
265 case Builtin::BI__sync_swap_2:
266 case Builtin::BI__sync_swap_4:
267 case Builtin::BI__sync_swap_8:
268 case Builtin::BI__sync_swap_16:
269 return SemaBuiltinAtomicOverloaded(TheCallResult);
270 #define BUILTIN(ID, TYPE, ATTRS)
271 #define ATOMIC_BUILTIN(ID, TYPE, ATTRS) \
272 case Builtin::BI##ID: \
273 return SemaAtomicOpsOverloaded(TheCallResult, AtomicExpr::AO##ID);
274 #include "clang/Basic/Builtins.def"
275 case Builtin::BI__builtin_annotation:
276 if (SemaBuiltinAnnotation(*this, TheCall))
281 // Since the target specific builtins for each arch overlap, only check those
282 // of the arch we are compiling for.
283 if (BuiltinID >= Builtin::FirstTSBuiltin) {
284 switch (Context.getTargetInfo().getTriple().getArch()) {
285 case llvm::Triple::arm:
286 case llvm::Triple::thumb:
287 if (CheckARMBuiltinFunctionCall(BuiltinID, TheCall))
290 case llvm::Triple::mips:
291 case llvm::Triple::mipsel:
292 case llvm::Triple::mips64:
293 case llvm::Triple::mips64el:
294 if (CheckMipsBuiltinFunctionCall(BuiltinID, TheCall))
302 return TheCallResult;
305 // Get the valid immediate range for the specified NEON type code.
306 static unsigned RFT(unsigned t, bool shift = false) {
307 NeonTypeFlags Type(t);
308 int IsQuad = Type.isQuad();
309 switch (Type.getEltType()) {
310 case NeonTypeFlags::Int8:
311 case NeonTypeFlags::Poly8:
312 return shift ? 7 : (8 << IsQuad) - 1;
313 case NeonTypeFlags::Int16:
314 case NeonTypeFlags::Poly16:
315 return shift ? 15 : (4 << IsQuad) - 1;
316 case NeonTypeFlags::Int32:
317 return shift ? 31 : (2 << IsQuad) - 1;
318 case NeonTypeFlags::Int64:
319 return shift ? 63 : (1 << IsQuad) - 1;
320 case NeonTypeFlags::Float16:
321 assert(!shift && "cannot shift float types!");
322 return (4 << IsQuad) - 1;
323 case NeonTypeFlags::Float32:
324 assert(!shift && "cannot shift float types!");
325 return (2 << IsQuad) - 1;
327 llvm_unreachable("Invalid NeonTypeFlag!");
330 /// getNeonEltType - Return the QualType corresponding to the elements of
331 /// the vector type specified by the NeonTypeFlags. This is used to check
332 /// the pointer arguments for Neon load/store intrinsics.
333 static QualType getNeonEltType(NeonTypeFlags Flags, ASTContext &Context) {
334 switch (Flags.getEltType()) {
335 case NeonTypeFlags::Int8:
336 return Flags.isUnsigned() ? Context.UnsignedCharTy : Context.SignedCharTy;
337 case NeonTypeFlags::Int16:
338 return Flags.isUnsigned() ? Context.UnsignedShortTy : Context.ShortTy;
339 case NeonTypeFlags::Int32:
340 return Flags.isUnsigned() ? Context.UnsignedIntTy : Context.IntTy;
341 case NeonTypeFlags::Int64:
342 return Flags.isUnsigned() ? Context.UnsignedLongLongTy : Context.LongLongTy;
343 case NeonTypeFlags::Poly8:
344 return Context.SignedCharTy;
345 case NeonTypeFlags::Poly16:
346 return Context.ShortTy;
347 case NeonTypeFlags::Float16:
348 return Context.UnsignedShortTy;
349 case NeonTypeFlags::Float32:
350 return Context.FloatTy;
352 llvm_unreachable("Invalid NeonTypeFlag!");
355 bool Sema::CheckARMBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
361 bool HasConstPtr = false;
363 #define GET_NEON_OVERLOAD_CHECK
364 #include "clang/Basic/arm_neon.inc"
365 #undef GET_NEON_OVERLOAD_CHECK
368 // For NEON intrinsics which are overloaded on vector element type, validate
369 // the immediate which specifies which variant to emit.
370 unsigned ImmArg = TheCall->getNumArgs()-1;
372 if (SemaBuiltinConstantArg(TheCall, ImmArg, Result))
375 TV = Result.getLimitedValue(64);
376 if ((TV > 63) || (mask & (1ULL << TV)) == 0)
377 return Diag(TheCall->getLocStart(), diag::err_invalid_neon_type_code)
378 << TheCall->getArg(ImmArg)->getSourceRange();
381 if (PtrArgNum >= 0) {
382 // Check that pointer arguments have the specified type.
383 Expr *Arg = TheCall->getArg(PtrArgNum);
384 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg))
385 Arg = ICE->getSubExpr();
386 ExprResult RHS = DefaultFunctionArrayLvalueConversion(Arg);
387 QualType RHSTy = RHS.get()->getType();
388 QualType EltTy = getNeonEltType(NeonTypeFlags(TV), Context);
390 EltTy = EltTy.withConst();
391 QualType LHSTy = Context.getPointerType(EltTy);
392 AssignConvertType ConvTy;
393 ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS);
396 if (DiagnoseAssignmentResult(ConvTy, Arg->getLocStart(), LHSTy, RHSTy,
397 RHS.get(), AA_Assigning))
401 // For NEON intrinsics which take an immediate value as part of the
402 // instruction, range check them here.
403 unsigned i = 0, l = 0, u = 0;
405 default: return false;
406 case ARM::BI__builtin_arm_ssat: i = 1; l = 1; u = 31; break;
407 case ARM::BI__builtin_arm_usat: i = 1; u = 31; break;
408 case ARM::BI__builtin_arm_vcvtr_f:
409 case ARM::BI__builtin_arm_vcvtr_d: i = 1; u = 1; break;
410 #define GET_NEON_IMMEDIATE_CHECK
411 #include "clang/Basic/arm_neon.inc"
412 #undef GET_NEON_IMMEDIATE_CHECK
415 // We can't check the value of a dependent argument.
416 if (TheCall->getArg(i)->isTypeDependent() ||
417 TheCall->getArg(i)->isValueDependent())
420 // Check that the immediate argument is actually a constant.
421 if (SemaBuiltinConstantArg(TheCall, i, Result))
424 // Range check against the upper/lower values for this isntruction.
425 unsigned Val = Result.getZExtValue();
426 if (Val < l || Val > (u + l))
427 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
428 << l << u+l << TheCall->getArg(i)->getSourceRange();
430 // FIXME: VFP Intrinsics should error if VFP not present.
434 bool Sema::CheckMipsBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
435 unsigned i = 0, l = 0, u = 0;
437 default: return false;
438 case Mips::BI__builtin_mips_wrdsp: i = 1; l = 0; u = 63; break;
439 case Mips::BI__builtin_mips_rddsp: i = 0; l = 0; u = 63; break;
440 case Mips::BI__builtin_mips_append: i = 2; l = 0; u = 31; break;
441 case Mips::BI__builtin_mips_balign: i = 2; l = 0; u = 3; break;
442 case Mips::BI__builtin_mips_precr_sra_ph_w: i = 2; l = 0; u = 31; break;
443 case Mips::BI__builtin_mips_precr_sra_r_ph_w: i = 2; l = 0; u = 31; break;
444 case Mips::BI__builtin_mips_prepend: i = 2; l = 0; u = 31; break;
447 // We can't check the value of a dependent argument.
448 if (TheCall->getArg(i)->isTypeDependent() ||
449 TheCall->getArg(i)->isValueDependent())
452 // Check that the immediate argument is actually a constant.
454 if (SemaBuiltinConstantArg(TheCall, i, Result))
457 // Range check against the upper/lower values for this instruction.
458 unsigned Val = Result.getZExtValue();
459 if (Val < l || Val > u)
460 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
461 << l << u << TheCall->getArg(i)->getSourceRange();
466 /// Given a FunctionDecl's FormatAttr, attempts to populate the FomatStringInfo
467 /// parameter with the FormatAttr's correct format_idx and firstDataArg.
468 /// Returns true when the format fits the function and the FormatStringInfo has
470 bool Sema::getFormatStringInfo(const FormatAttr *Format, bool IsCXXMember,
471 FormatStringInfo *FSI) {
472 FSI->HasVAListArg = Format->getFirstArg() == 0;
473 FSI->FormatIdx = Format->getFormatIdx() - 1;
474 FSI->FirstDataArg = FSI->HasVAListArg ? 0 : Format->getFirstArg() - 1;
476 // The way the format attribute works in GCC, the implicit this argument
477 // of member functions is counted. However, it doesn't appear in our own
478 // lists, so decrement format_idx in that case.
480 if(FSI->FormatIdx == 0)
483 if (FSI->FirstDataArg != 0)
489 /// Handles the checks for format strings, non-POD arguments to vararg
490 /// functions, and NULL arguments passed to non-NULL parameters.
491 void Sema::checkCall(NamedDecl *FDecl, Expr **Args,
493 unsigned NumProtoArgs,
494 bool IsMemberFunction,
497 VariadicCallType CallType) {
498 if (CurContext->isDependentContext())
501 // Printf and scanf checking.
502 bool HandledFormatString = false;
503 for (specific_attr_iterator<FormatAttr>
504 I = FDecl->specific_attr_begin<FormatAttr>(),
505 E = FDecl->specific_attr_end<FormatAttr>(); I != E ; ++I)
506 if (CheckFormatArguments(*I, Args, NumArgs, IsMemberFunction, CallType,
508 HandledFormatString = true;
510 // Refuse POD arguments that weren't caught by the format string
512 if (!HandledFormatString && CallType != VariadicDoesNotApply)
513 for (unsigned ArgIdx = NumProtoArgs; ArgIdx < NumArgs; ++ArgIdx) {
514 // Args[ArgIdx] can be null in malformed code.
515 if (Expr *Arg = Args[ArgIdx])
516 variadicArgumentPODCheck(Arg, CallType);
519 for (specific_attr_iterator<NonNullAttr>
520 I = FDecl->specific_attr_begin<NonNullAttr>(),
521 E = FDecl->specific_attr_end<NonNullAttr>(); I != E; ++I)
522 CheckNonNullArguments(*I, Args, Loc);
524 // Type safety checking.
525 for (specific_attr_iterator<ArgumentWithTypeTagAttr>
526 i = FDecl->specific_attr_begin<ArgumentWithTypeTagAttr>(),
527 e = FDecl->specific_attr_end<ArgumentWithTypeTagAttr>(); i != e; ++i) {
528 CheckArgumentWithTypeTag(*i, Args);
532 /// CheckConstructorCall - Check a constructor call for correctness and safety
533 /// properties not enforced by the C type system.
534 void Sema::CheckConstructorCall(FunctionDecl *FDecl, Expr **Args,
536 const FunctionProtoType *Proto,
537 SourceLocation Loc) {
538 VariadicCallType CallType =
539 Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply;
540 checkCall(FDecl, Args, NumArgs, Proto->getNumArgs(),
541 /*IsMemberFunction=*/true, Loc, SourceRange(), CallType);
544 /// CheckFunctionCall - Check a direct function call for various correctness
545 /// and safety properties not strictly enforced by the C type system.
546 bool Sema::CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall,
547 const FunctionProtoType *Proto) {
548 bool IsMemberOperatorCall = isa<CXXOperatorCallExpr>(TheCall) &&
549 isa<CXXMethodDecl>(FDecl);
550 bool IsMemberFunction = isa<CXXMemberCallExpr>(TheCall) ||
551 IsMemberOperatorCall;
552 VariadicCallType CallType = getVariadicCallType(FDecl, Proto,
553 TheCall->getCallee());
554 unsigned NumProtoArgs = Proto ? Proto->getNumArgs() : 0;
555 Expr** Args = TheCall->getArgs();
556 unsigned NumArgs = TheCall->getNumArgs();
557 if (IsMemberOperatorCall) {
558 // If this is a call to a member operator, hide the first argument
560 // FIXME: Our choice of AST representation here is less than ideal.
564 checkCall(FDecl, Args, NumArgs, NumProtoArgs,
565 IsMemberFunction, TheCall->getRParenLoc(),
566 TheCall->getCallee()->getSourceRange(), CallType);
568 IdentifierInfo *FnInfo = FDecl->getIdentifier();
569 // None of the checks below are needed for functions that don't have
570 // simple names (e.g., C++ conversion functions).
574 unsigned CMId = FDecl->getMemoryFunctionKind();
578 // Handle memory setting and copying functions.
579 if (CMId == Builtin::BIstrlcpy || CMId == Builtin::BIstrlcat)
580 CheckStrlcpycatArguments(TheCall, FnInfo);
581 else if (CMId == Builtin::BIstrncat)
582 CheckStrncatArguments(TheCall, FnInfo);
584 CheckMemaccessArguments(TheCall, CMId, FnInfo);
589 bool Sema::CheckObjCMethodCall(ObjCMethodDecl *Method, SourceLocation lbrac,
590 Expr **Args, unsigned NumArgs) {
591 VariadicCallType CallType =
592 Method->isVariadic() ? VariadicMethod : VariadicDoesNotApply;
594 checkCall(Method, Args, NumArgs, Method->param_size(),
595 /*IsMemberFunction=*/false,
596 lbrac, Method->getSourceRange(), CallType);
601 bool Sema::CheckBlockCall(NamedDecl *NDecl, CallExpr *TheCall,
602 const FunctionProtoType *Proto) {
603 const VarDecl *V = dyn_cast<VarDecl>(NDecl);
607 QualType Ty = V->getType();
608 if (!Ty->isBlockPointerType())
611 VariadicCallType CallType =
612 Proto && Proto->isVariadic() ? VariadicBlock : VariadicDoesNotApply ;
613 unsigned NumProtoArgs = Proto ? Proto->getNumArgs() : 0;
615 checkCall(NDecl, TheCall->getArgs(), TheCall->getNumArgs(),
616 NumProtoArgs, /*IsMemberFunction=*/false,
617 TheCall->getRParenLoc(),
618 TheCall->getCallee()->getSourceRange(), CallType);
623 ExprResult Sema::SemaAtomicOpsOverloaded(ExprResult TheCallResult,
624 AtomicExpr::AtomicOp Op) {
625 CallExpr *TheCall = cast<CallExpr>(TheCallResult.get());
626 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
628 // All these operations take one of the following forms:
630 // C __c11_atomic_init(A *, C)
632 // C __c11_atomic_load(A *, int)
634 // void __atomic_load(A *, CP, int)
636 // C __c11_atomic_add(A *, M, int)
638 // C __atomic_exchange_n(A *, CP, int)
640 // void __atomic_exchange(A *, C *, CP, int)
642 // bool __c11_atomic_compare_exchange_strong(A *, C *, CP, int, int)
644 // bool __atomic_compare_exchange(A *, C *, CP, bool, int, int)
647 const unsigned NumArgs[] = { 2, 2, 3, 3, 3, 4, 5, 6 };
648 const unsigned NumVals[] = { 1, 0, 1, 1, 1, 2, 2, 3 };
650 // C is an appropriate type,
651 // A is volatile _Atomic(C) for __c11 builtins and is C for GNU builtins,
652 // CP is C for __c11 builtins and GNU _n builtins and is C * otherwise,
653 // M is C if C is an integer, and ptrdiff_t if C is a pointer, and
654 // the int parameters are for orderings.
656 assert(AtomicExpr::AO__c11_atomic_init == 0 &&
657 AtomicExpr::AO__c11_atomic_fetch_xor + 1 == AtomicExpr::AO__atomic_load
658 && "need to update code for modified C11 atomics");
659 bool IsC11 = Op >= AtomicExpr::AO__c11_atomic_init &&
660 Op <= AtomicExpr::AO__c11_atomic_fetch_xor;
661 bool IsN = Op == AtomicExpr::AO__atomic_load_n ||
662 Op == AtomicExpr::AO__atomic_store_n ||
663 Op == AtomicExpr::AO__atomic_exchange_n ||
664 Op == AtomicExpr::AO__atomic_compare_exchange_n;
665 bool IsAddSub = false;
668 case AtomicExpr::AO__c11_atomic_init:
672 case AtomicExpr::AO__c11_atomic_load:
673 case AtomicExpr::AO__atomic_load_n:
677 case AtomicExpr::AO__c11_atomic_store:
678 case AtomicExpr::AO__atomic_load:
679 case AtomicExpr::AO__atomic_store:
680 case AtomicExpr::AO__atomic_store_n:
684 case AtomicExpr::AO__c11_atomic_fetch_add:
685 case AtomicExpr::AO__c11_atomic_fetch_sub:
686 case AtomicExpr::AO__atomic_fetch_add:
687 case AtomicExpr::AO__atomic_fetch_sub:
688 case AtomicExpr::AO__atomic_add_fetch:
689 case AtomicExpr::AO__atomic_sub_fetch:
692 case AtomicExpr::AO__c11_atomic_fetch_and:
693 case AtomicExpr::AO__c11_atomic_fetch_or:
694 case AtomicExpr::AO__c11_atomic_fetch_xor:
695 case AtomicExpr::AO__atomic_fetch_and:
696 case AtomicExpr::AO__atomic_fetch_or:
697 case AtomicExpr::AO__atomic_fetch_xor:
698 case AtomicExpr::AO__atomic_fetch_nand:
699 case AtomicExpr::AO__atomic_and_fetch:
700 case AtomicExpr::AO__atomic_or_fetch:
701 case AtomicExpr::AO__atomic_xor_fetch:
702 case AtomicExpr::AO__atomic_nand_fetch:
706 case AtomicExpr::AO__c11_atomic_exchange:
707 case AtomicExpr::AO__atomic_exchange_n:
711 case AtomicExpr::AO__atomic_exchange:
715 case AtomicExpr::AO__c11_atomic_compare_exchange_strong:
716 case AtomicExpr::AO__c11_atomic_compare_exchange_weak:
720 case AtomicExpr::AO__atomic_compare_exchange:
721 case AtomicExpr::AO__atomic_compare_exchange_n:
726 // Check we have the right number of arguments.
727 if (TheCall->getNumArgs() < NumArgs[Form]) {
728 Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
729 << 0 << NumArgs[Form] << TheCall->getNumArgs()
730 << TheCall->getCallee()->getSourceRange();
732 } else if (TheCall->getNumArgs() > NumArgs[Form]) {
733 Diag(TheCall->getArg(NumArgs[Form])->getLocStart(),
734 diag::err_typecheck_call_too_many_args)
735 << 0 << NumArgs[Form] << TheCall->getNumArgs()
736 << TheCall->getCallee()->getSourceRange();
740 // Inspect the first argument of the atomic operation.
741 Expr *Ptr = TheCall->getArg(0);
742 Ptr = DefaultFunctionArrayLvalueConversion(Ptr).get();
743 const PointerType *pointerType = Ptr->getType()->getAs<PointerType>();
745 Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer)
746 << Ptr->getType() << Ptr->getSourceRange();
750 // For a __c11 builtin, this should be a pointer to an _Atomic type.
751 QualType AtomTy = pointerType->getPointeeType(); // 'A'
752 QualType ValType = AtomTy; // 'C'
754 if (!AtomTy->isAtomicType()) {
755 Diag(DRE->getLocStart(), diag::err_atomic_op_needs_atomic)
756 << Ptr->getType() << Ptr->getSourceRange();
759 if (AtomTy.isConstQualified()) {
760 Diag(DRE->getLocStart(), diag::err_atomic_op_needs_non_const_atomic)
761 << Ptr->getType() << Ptr->getSourceRange();
764 ValType = AtomTy->getAs<AtomicType>()->getValueType();
767 // For an arithmetic operation, the implied arithmetic must be well-formed.
768 if (Form == Arithmetic) {
769 // gcc does not enforce these rules for GNU atomics, but we do so for sanity.
770 if (IsAddSub && !ValType->isIntegerType() && !ValType->isPointerType()) {
771 Diag(DRE->getLocStart(), diag::err_atomic_op_needs_atomic_int_or_ptr)
772 << IsC11 << Ptr->getType() << Ptr->getSourceRange();
775 if (!IsAddSub && !ValType->isIntegerType()) {
776 Diag(DRE->getLocStart(), diag::err_atomic_op_bitwise_needs_atomic_int)
777 << IsC11 << Ptr->getType() << Ptr->getSourceRange();
780 } else if (IsN && !ValType->isIntegerType() && !ValType->isPointerType()) {
781 // For __atomic_*_n operations, the value type must be a scalar integral or
782 // pointer type which is 1, 2, 4, 8 or 16 bytes in length.
783 Diag(DRE->getLocStart(), diag::err_atomic_op_needs_atomic_int_or_ptr)
784 << IsC11 << Ptr->getType() << Ptr->getSourceRange();
788 if (!IsC11 && !AtomTy.isTriviallyCopyableType(Context)) {
789 // For GNU atomics, require a trivially-copyable type. This is not part of
790 // the GNU atomics specification, but we enforce it for sanity.
791 Diag(DRE->getLocStart(), diag::err_atomic_op_needs_trivial_copy)
792 << Ptr->getType() << Ptr->getSourceRange();
796 // FIXME: For any builtin other than a load, the ValType must not be
799 switch (ValType.getObjCLifetime()) {
800 case Qualifiers::OCL_None:
801 case Qualifiers::OCL_ExplicitNone:
805 case Qualifiers::OCL_Weak:
806 case Qualifiers::OCL_Strong:
807 case Qualifiers::OCL_Autoreleasing:
808 // FIXME: Can this happen? By this point, ValType should be known
809 // to be trivially copyable.
810 Diag(DRE->getLocStart(), diag::err_arc_atomic_ownership)
811 << ValType << Ptr->getSourceRange();
815 QualType ResultType = ValType;
816 if (Form == Copy || Form == GNUXchg || Form == Init)
817 ResultType = Context.VoidTy;
818 else if (Form == C11CmpXchg || Form == GNUCmpXchg)
819 ResultType = Context.BoolTy;
821 // The type of a parameter passed 'by value'. In the GNU atomics, such
822 // arguments are actually passed as pointers.
823 QualType ByValType = ValType; // 'CP'
825 ByValType = Ptr->getType();
827 // The first argument --- the pointer --- has a fixed type; we
828 // deduce the types of the rest of the arguments accordingly. Walk
829 // the remaining arguments, converting them to the deduced value type.
830 for (unsigned i = 1; i != NumArgs[Form]; ++i) {
832 if (i < NumVals[Form] + 1) {
835 // The second argument is the non-atomic operand. For arithmetic, this
836 // is always passed by value, and for a compare_exchange it is always
837 // passed by address. For the rest, GNU uses by-address and C11 uses
839 assert(Form != Load);
840 if (Form == Init || (Form == Arithmetic && ValType->isIntegerType()))
842 else if (Form == Copy || Form == Xchg)
844 else if (Form == Arithmetic)
845 Ty = Context.getPointerDiffType();
847 Ty = Context.getPointerType(ValType.getUnqualifiedType());
850 // The third argument to compare_exchange / GNU exchange is a
851 // (pointer to a) desired value.
855 // The fourth argument to GNU compare_exchange is a 'weak' flag.
860 // The order(s) are always converted to int.
864 InitializedEntity Entity =
865 InitializedEntity::InitializeParameter(Context, Ty, false);
866 ExprResult Arg = TheCall->getArg(i);
867 Arg = PerformCopyInitialization(Entity, SourceLocation(), Arg);
870 TheCall->setArg(i, Arg.get());
873 // Permute the arguments into a 'consistent' order.
874 SmallVector<Expr*, 5> SubExprs;
875 SubExprs.push_back(Ptr);
878 // Note, AtomicExpr::getVal1() has a special case for this atomic.
879 SubExprs.push_back(TheCall->getArg(1)); // Val1
882 SubExprs.push_back(TheCall->getArg(1)); // Order
887 SubExprs.push_back(TheCall->getArg(2)); // Order
888 SubExprs.push_back(TheCall->getArg(1)); // Val1
891 // Note, AtomicExpr::getVal2() has a special case for this atomic.
892 SubExprs.push_back(TheCall->getArg(3)); // Order
893 SubExprs.push_back(TheCall->getArg(1)); // Val1
894 SubExprs.push_back(TheCall->getArg(2)); // Val2
897 SubExprs.push_back(TheCall->getArg(3)); // Order
898 SubExprs.push_back(TheCall->getArg(1)); // Val1
899 SubExprs.push_back(TheCall->getArg(4)); // OrderFail
900 SubExprs.push_back(TheCall->getArg(2)); // Val2
903 SubExprs.push_back(TheCall->getArg(4)); // Order
904 SubExprs.push_back(TheCall->getArg(1)); // Val1
905 SubExprs.push_back(TheCall->getArg(5)); // OrderFail
906 SubExprs.push_back(TheCall->getArg(2)); // Val2
907 SubExprs.push_back(TheCall->getArg(3)); // Weak
911 return Owned(new (Context) AtomicExpr(TheCall->getCallee()->getLocStart(),
912 SubExprs, ResultType, Op,
913 TheCall->getRParenLoc()));
917 /// checkBuiltinArgument - Given a call to a builtin function, perform
918 /// normal type-checking on the given argument, updating the call in
919 /// place. This is useful when a builtin function requires custom
920 /// type-checking for some of its arguments but not necessarily all of
923 /// Returns true on error.
924 static bool checkBuiltinArgument(Sema &S, CallExpr *E, unsigned ArgIndex) {
925 FunctionDecl *Fn = E->getDirectCallee();
926 assert(Fn && "builtin call without direct callee!");
928 ParmVarDecl *Param = Fn->getParamDecl(ArgIndex);
929 InitializedEntity Entity =
930 InitializedEntity::InitializeParameter(S.Context, Param);
932 ExprResult Arg = E->getArg(0);
933 Arg = S.PerformCopyInitialization(Entity, SourceLocation(), Arg);
937 E->setArg(ArgIndex, Arg.take());
941 /// SemaBuiltinAtomicOverloaded - We have a call to a function like
942 /// __sync_fetch_and_add, which is an overloaded function based on the pointer
943 /// type of its first argument. The main ActOnCallExpr routines have already
944 /// promoted the types of arguments because all of these calls are prototyped as
947 /// This function goes through and does final semantic checking for these
950 Sema::SemaBuiltinAtomicOverloaded(ExprResult TheCallResult) {
951 CallExpr *TheCall = (CallExpr *)TheCallResult.get();
952 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
953 FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
955 // Ensure that we have at least one argument to do type inference from.
956 if (TheCall->getNumArgs() < 1) {
957 Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least)
958 << 0 << 1 << TheCall->getNumArgs()
959 << TheCall->getCallee()->getSourceRange();
963 // Inspect the first argument of the atomic builtin. This should always be
964 // a pointer type, whose element is an integral scalar or pointer type.
965 // Because it is a pointer type, we don't have to worry about any implicit
967 // FIXME: We don't allow floating point scalars as input.
968 Expr *FirstArg = TheCall->getArg(0);
969 ExprResult FirstArgResult = DefaultFunctionArrayLvalueConversion(FirstArg);
970 if (FirstArgResult.isInvalid())
972 FirstArg = FirstArgResult.take();
973 TheCall->setArg(0, FirstArg);
975 const PointerType *pointerType = FirstArg->getType()->getAs<PointerType>();
977 Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer)
978 << FirstArg->getType() << FirstArg->getSourceRange();
982 QualType ValType = pointerType->getPointeeType();
983 if (!ValType->isIntegerType() && !ValType->isAnyPointerType() &&
984 !ValType->isBlockPointerType()) {
985 Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer_intptr)
986 << FirstArg->getType() << FirstArg->getSourceRange();
990 switch (ValType.getObjCLifetime()) {
991 case Qualifiers::OCL_None:
992 case Qualifiers::OCL_ExplicitNone:
996 case Qualifiers::OCL_Weak:
997 case Qualifiers::OCL_Strong:
998 case Qualifiers::OCL_Autoreleasing:
999 Diag(DRE->getLocStart(), diag::err_arc_atomic_ownership)
1000 << ValType << FirstArg->getSourceRange();
1004 // Strip any qualifiers off ValType.
1005 ValType = ValType.getUnqualifiedType();
1007 // The majority of builtins return a value, but a few have special return
1008 // types, so allow them to override appropriately below.
1009 QualType ResultType = ValType;
1011 // We need to figure out which concrete builtin this maps onto. For example,
1012 // __sync_fetch_and_add with a 2 byte object turns into
1013 // __sync_fetch_and_add_2.
1014 #define BUILTIN_ROW(x) \
1015 { Builtin::BI##x##_1, Builtin::BI##x##_2, Builtin::BI##x##_4, \
1016 Builtin::BI##x##_8, Builtin::BI##x##_16 }
1018 static const unsigned BuiltinIndices[][5] = {
1019 BUILTIN_ROW(__sync_fetch_and_add),
1020 BUILTIN_ROW(__sync_fetch_and_sub),
1021 BUILTIN_ROW(__sync_fetch_and_or),
1022 BUILTIN_ROW(__sync_fetch_and_and),
1023 BUILTIN_ROW(__sync_fetch_and_xor),
1025 BUILTIN_ROW(__sync_add_and_fetch),
1026 BUILTIN_ROW(__sync_sub_and_fetch),
1027 BUILTIN_ROW(__sync_and_and_fetch),
1028 BUILTIN_ROW(__sync_or_and_fetch),
1029 BUILTIN_ROW(__sync_xor_and_fetch),
1031 BUILTIN_ROW(__sync_val_compare_and_swap),
1032 BUILTIN_ROW(__sync_bool_compare_and_swap),
1033 BUILTIN_ROW(__sync_lock_test_and_set),
1034 BUILTIN_ROW(__sync_lock_release),
1035 BUILTIN_ROW(__sync_swap)
1039 // Determine the index of the size.
1041 switch (Context.getTypeSizeInChars(ValType).getQuantity()) {
1042 case 1: SizeIndex = 0; break;
1043 case 2: SizeIndex = 1; break;
1044 case 4: SizeIndex = 2; break;
1045 case 8: SizeIndex = 3; break;
1046 case 16: SizeIndex = 4; break;
1048 Diag(DRE->getLocStart(), diag::err_atomic_builtin_pointer_size)
1049 << FirstArg->getType() << FirstArg->getSourceRange();
1053 // Each of these builtins has one pointer argument, followed by some number of
1054 // values (0, 1 or 2) followed by a potentially empty varags list of stuff
1055 // that we ignore. Find out which row of BuiltinIndices to read from as well
1056 // as the number of fixed args.
1057 unsigned BuiltinID = FDecl->getBuiltinID();
1058 unsigned BuiltinIndex, NumFixed = 1;
1059 switch (BuiltinID) {
1060 default: llvm_unreachable("Unknown overloaded atomic builtin!");
1061 case Builtin::BI__sync_fetch_and_add:
1062 case Builtin::BI__sync_fetch_and_add_1:
1063 case Builtin::BI__sync_fetch_and_add_2:
1064 case Builtin::BI__sync_fetch_and_add_4:
1065 case Builtin::BI__sync_fetch_and_add_8:
1066 case Builtin::BI__sync_fetch_and_add_16:
1070 case Builtin::BI__sync_fetch_and_sub:
1071 case Builtin::BI__sync_fetch_and_sub_1:
1072 case Builtin::BI__sync_fetch_and_sub_2:
1073 case Builtin::BI__sync_fetch_and_sub_4:
1074 case Builtin::BI__sync_fetch_and_sub_8:
1075 case Builtin::BI__sync_fetch_and_sub_16:
1079 case Builtin::BI__sync_fetch_and_or:
1080 case Builtin::BI__sync_fetch_and_or_1:
1081 case Builtin::BI__sync_fetch_and_or_2:
1082 case Builtin::BI__sync_fetch_and_or_4:
1083 case Builtin::BI__sync_fetch_and_or_8:
1084 case Builtin::BI__sync_fetch_and_or_16:
1088 case Builtin::BI__sync_fetch_and_and:
1089 case Builtin::BI__sync_fetch_and_and_1:
1090 case Builtin::BI__sync_fetch_and_and_2:
1091 case Builtin::BI__sync_fetch_and_and_4:
1092 case Builtin::BI__sync_fetch_and_and_8:
1093 case Builtin::BI__sync_fetch_and_and_16:
1097 case Builtin::BI__sync_fetch_and_xor:
1098 case Builtin::BI__sync_fetch_and_xor_1:
1099 case Builtin::BI__sync_fetch_and_xor_2:
1100 case Builtin::BI__sync_fetch_and_xor_4:
1101 case Builtin::BI__sync_fetch_and_xor_8:
1102 case Builtin::BI__sync_fetch_and_xor_16:
1106 case Builtin::BI__sync_add_and_fetch:
1107 case Builtin::BI__sync_add_and_fetch_1:
1108 case Builtin::BI__sync_add_and_fetch_2:
1109 case Builtin::BI__sync_add_and_fetch_4:
1110 case Builtin::BI__sync_add_and_fetch_8:
1111 case Builtin::BI__sync_add_and_fetch_16:
1115 case Builtin::BI__sync_sub_and_fetch:
1116 case Builtin::BI__sync_sub_and_fetch_1:
1117 case Builtin::BI__sync_sub_and_fetch_2:
1118 case Builtin::BI__sync_sub_and_fetch_4:
1119 case Builtin::BI__sync_sub_and_fetch_8:
1120 case Builtin::BI__sync_sub_and_fetch_16:
1124 case Builtin::BI__sync_and_and_fetch:
1125 case Builtin::BI__sync_and_and_fetch_1:
1126 case Builtin::BI__sync_and_and_fetch_2:
1127 case Builtin::BI__sync_and_and_fetch_4:
1128 case Builtin::BI__sync_and_and_fetch_8:
1129 case Builtin::BI__sync_and_and_fetch_16:
1133 case Builtin::BI__sync_or_and_fetch:
1134 case Builtin::BI__sync_or_and_fetch_1:
1135 case Builtin::BI__sync_or_and_fetch_2:
1136 case Builtin::BI__sync_or_and_fetch_4:
1137 case Builtin::BI__sync_or_and_fetch_8:
1138 case Builtin::BI__sync_or_and_fetch_16:
1142 case Builtin::BI__sync_xor_and_fetch:
1143 case Builtin::BI__sync_xor_and_fetch_1:
1144 case Builtin::BI__sync_xor_and_fetch_2:
1145 case Builtin::BI__sync_xor_and_fetch_4:
1146 case Builtin::BI__sync_xor_and_fetch_8:
1147 case Builtin::BI__sync_xor_and_fetch_16:
1151 case Builtin::BI__sync_val_compare_and_swap:
1152 case Builtin::BI__sync_val_compare_and_swap_1:
1153 case Builtin::BI__sync_val_compare_and_swap_2:
1154 case Builtin::BI__sync_val_compare_and_swap_4:
1155 case Builtin::BI__sync_val_compare_and_swap_8:
1156 case Builtin::BI__sync_val_compare_and_swap_16:
1161 case Builtin::BI__sync_bool_compare_and_swap:
1162 case Builtin::BI__sync_bool_compare_and_swap_1:
1163 case Builtin::BI__sync_bool_compare_and_swap_2:
1164 case Builtin::BI__sync_bool_compare_and_swap_4:
1165 case Builtin::BI__sync_bool_compare_and_swap_8:
1166 case Builtin::BI__sync_bool_compare_and_swap_16:
1169 ResultType = Context.BoolTy;
1172 case Builtin::BI__sync_lock_test_and_set:
1173 case Builtin::BI__sync_lock_test_and_set_1:
1174 case Builtin::BI__sync_lock_test_and_set_2:
1175 case Builtin::BI__sync_lock_test_and_set_4:
1176 case Builtin::BI__sync_lock_test_and_set_8:
1177 case Builtin::BI__sync_lock_test_and_set_16:
1181 case Builtin::BI__sync_lock_release:
1182 case Builtin::BI__sync_lock_release_1:
1183 case Builtin::BI__sync_lock_release_2:
1184 case Builtin::BI__sync_lock_release_4:
1185 case Builtin::BI__sync_lock_release_8:
1186 case Builtin::BI__sync_lock_release_16:
1189 ResultType = Context.VoidTy;
1192 case Builtin::BI__sync_swap:
1193 case Builtin::BI__sync_swap_1:
1194 case Builtin::BI__sync_swap_2:
1195 case Builtin::BI__sync_swap_4:
1196 case Builtin::BI__sync_swap_8:
1197 case Builtin::BI__sync_swap_16:
1202 // Now that we know how many fixed arguments we expect, first check that we
1203 // have at least that many.
1204 if (TheCall->getNumArgs() < 1+NumFixed) {
1205 Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least)
1206 << 0 << 1+NumFixed << TheCall->getNumArgs()
1207 << TheCall->getCallee()->getSourceRange();
1211 // Get the decl for the concrete builtin from this, we can tell what the
1212 // concrete integer type we should convert to is.
1213 unsigned NewBuiltinID = BuiltinIndices[BuiltinIndex][SizeIndex];
1214 const char *NewBuiltinName = Context.BuiltinInfo.GetName(NewBuiltinID);
1215 FunctionDecl *NewBuiltinDecl;
1216 if (NewBuiltinID == BuiltinID)
1217 NewBuiltinDecl = FDecl;
1219 // Perform builtin lookup to avoid redeclaring it.
1220 DeclarationName DN(&Context.Idents.get(NewBuiltinName));
1221 LookupResult Res(*this, DN, DRE->getLocStart(), LookupOrdinaryName);
1222 LookupName(Res, TUScope, /*AllowBuiltinCreation=*/true);
1223 assert(Res.getFoundDecl());
1224 NewBuiltinDecl = dyn_cast<FunctionDecl>(Res.getFoundDecl());
1225 if (NewBuiltinDecl == 0)
1229 // The first argument --- the pointer --- has a fixed type; we
1230 // deduce the types of the rest of the arguments accordingly. Walk
1231 // the remaining arguments, converting them to the deduced value type.
1232 for (unsigned i = 0; i != NumFixed; ++i) {
1233 ExprResult Arg = TheCall->getArg(i+1);
1235 // GCC does an implicit conversion to the pointer or integer ValType. This
1236 // can fail in some cases (1i -> int**), check for this error case now.
1237 // Initialize the argument.
1238 InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
1239 ValType, /*consume*/ false);
1240 Arg = PerformCopyInitialization(Entity, SourceLocation(), Arg);
1241 if (Arg.isInvalid())
1244 // Okay, we have something that *can* be converted to the right type. Check
1245 // to see if there is a potentially weird extension going on here. This can
1246 // happen when you do an atomic operation on something like an char* and
1247 // pass in 42. The 42 gets converted to char. This is even more strange
1248 // for things like 45.123 -> char, etc.
1249 // FIXME: Do this check.
1250 TheCall->setArg(i+1, Arg.take());
1253 ASTContext& Context = this->getASTContext();
1255 // Create a new DeclRefExpr to refer to the new decl.
1256 DeclRefExpr* NewDRE = DeclRefExpr::Create(
1258 DRE->getQualifierLoc(),
1261 /*enclosing*/ false,
1263 Context.BuiltinFnTy,
1264 DRE->getValueKind());
1266 // Set the callee in the CallExpr.
1267 // FIXME: This loses syntactic information.
1268 QualType CalleePtrTy = Context.getPointerType(NewBuiltinDecl->getType());
1269 ExprResult PromotedCall = ImpCastExprToType(NewDRE, CalleePtrTy,
1270 CK_BuiltinFnToFnPtr);
1271 TheCall->setCallee(PromotedCall.take());
1273 // Change the result type of the call to match the original value type. This
1274 // is arbitrary, but the codegen for these builtins ins design to handle it
1276 TheCall->setType(ResultType);
1278 return TheCallResult;
1281 /// CheckObjCString - Checks that the argument to the builtin
1282 /// CFString constructor is correct
1283 /// Note: It might also make sense to do the UTF-16 conversion here (would
1284 /// simplify the backend).
1285 bool Sema::CheckObjCString(Expr *Arg) {
1286 Arg = Arg->IgnoreParenCasts();
1287 StringLiteral *Literal = dyn_cast<StringLiteral>(Arg);
1289 if (!Literal || !Literal->isAscii()) {
1290 Diag(Arg->getLocStart(), diag::err_cfstring_literal_not_string_constant)
1291 << Arg->getSourceRange();
1295 if (Literal->containsNonAsciiOrNull()) {
1296 StringRef String = Literal->getString();
1297 unsigned NumBytes = String.size();
1298 SmallVector<UTF16, 128> ToBuf(NumBytes);
1299 const UTF8 *FromPtr = (const UTF8 *)String.data();
1300 UTF16 *ToPtr = &ToBuf[0];
1302 ConversionResult Result = ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes,
1303 &ToPtr, ToPtr + NumBytes,
1305 // Check for conversion failure.
1306 if (Result != conversionOK)
1307 Diag(Arg->getLocStart(),
1308 diag::warn_cfstring_truncated) << Arg->getSourceRange();
1313 /// SemaBuiltinVAStart - Check the arguments to __builtin_va_start for validity.
1314 /// Emit an error and return true on failure, return false on success.
1315 bool Sema::SemaBuiltinVAStart(CallExpr *TheCall) {
1316 Expr *Fn = TheCall->getCallee();
1317 if (TheCall->getNumArgs() > 2) {
1318 Diag(TheCall->getArg(2)->getLocStart(),
1319 diag::err_typecheck_call_too_many_args)
1320 << 0 /*function call*/ << 2 << TheCall->getNumArgs()
1321 << Fn->getSourceRange()
1322 << SourceRange(TheCall->getArg(2)->getLocStart(),
1323 (*(TheCall->arg_end()-1))->getLocEnd());
1327 if (TheCall->getNumArgs() < 2) {
1328 return Diag(TheCall->getLocEnd(),
1329 diag::err_typecheck_call_too_few_args_at_least)
1330 << 0 /*function call*/ << 2 << TheCall->getNumArgs();
1333 // Type-check the first argument normally.
1334 if (checkBuiltinArgument(*this, TheCall, 0))
1337 // Determine whether the current function is variadic or not.
1338 BlockScopeInfo *CurBlock = getCurBlock();
1341 isVariadic = CurBlock->TheDecl->isVariadic();
1342 else if (FunctionDecl *FD = getCurFunctionDecl())
1343 isVariadic = FD->isVariadic();
1345 isVariadic = getCurMethodDecl()->isVariadic();
1348 Diag(Fn->getLocStart(), diag::err_va_start_used_in_non_variadic_function);
1352 // Verify that the second argument to the builtin is the last argument of the
1353 // current function or method.
1354 bool SecondArgIsLastNamedArgument = false;
1355 const Expr *Arg = TheCall->getArg(1)->IgnoreParenCasts();
1357 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Arg)) {
1358 if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(DR->getDecl())) {
1359 // FIXME: This isn't correct for methods (results in bogus warning).
1360 // Get the last formal in the current function.
1361 const ParmVarDecl *LastArg;
1363 LastArg = *(CurBlock->TheDecl->param_end()-1);
1364 else if (FunctionDecl *FD = getCurFunctionDecl())
1365 LastArg = *(FD->param_end()-1);
1367 LastArg = *(getCurMethodDecl()->param_end()-1);
1368 SecondArgIsLastNamedArgument = PV == LastArg;
1372 if (!SecondArgIsLastNamedArgument)
1373 Diag(TheCall->getArg(1)->getLocStart(),
1374 diag::warn_second_parameter_of_va_start_not_last_named_argument);
1378 /// SemaBuiltinUnorderedCompare - Handle functions like __builtin_isgreater and
1379 /// friends. This is declared to take (...), so we have to check everything.
1380 bool Sema::SemaBuiltinUnorderedCompare(CallExpr *TheCall) {
1381 if (TheCall->getNumArgs() < 2)
1382 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
1383 << 0 << 2 << TheCall->getNumArgs()/*function call*/;
1384 if (TheCall->getNumArgs() > 2)
1385 return Diag(TheCall->getArg(2)->getLocStart(),
1386 diag::err_typecheck_call_too_many_args)
1387 << 0 /*function call*/ << 2 << TheCall->getNumArgs()
1388 << SourceRange(TheCall->getArg(2)->getLocStart(),
1389 (*(TheCall->arg_end()-1))->getLocEnd());
1391 ExprResult OrigArg0 = TheCall->getArg(0);
1392 ExprResult OrigArg1 = TheCall->getArg(1);
1394 // Do standard promotions between the two arguments, returning their common
1396 QualType Res = UsualArithmeticConversions(OrigArg0, OrigArg1, false);
1397 if (OrigArg0.isInvalid() || OrigArg1.isInvalid())
1400 // Make sure any conversions are pushed back into the call; this is
1401 // type safe since unordered compare builtins are declared as "_Bool
1403 TheCall->setArg(0, OrigArg0.get());
1404 TheCall->setArg(1, OrigArg1.get());
1406 if (OrigArg0.get()->isTypeDependent() || OrigArg1.get()->isTypeDependent())
1409 // If the common type isn't a real floating type, then the arguments were
1410 // invalid for this operation.
1411 if (Res.isNull() || !Res->isRealFloatingType())
1412 return Diag(OrigArg0.get()->getLocStart(),
1413 diag::err_typecheck_call_invalid_ordered_compare)
1414 << OrigArg0.get()->getType() << OrigArg1.get()->getType()
1415 << SourceRange(OrigArg0.get()->getLocStart(), OrigArg1.get()->getLocEnd());
1420 /// SemaBuiltinSemaBuiltinFPClassification - Handle functions like
1421 /// __builtin_isnan and friends. This is declared to take (...), so we have
1422 /// to check everything. We expect the last argument to be a floating point
1424 bool Sema::SemaBuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs) {
1425 if (TheCall->getNumArgs() < NumArgs)
1426 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
1427 << 0 << NumArgs << TheCall->getNumArgs()/*function call*/;
1428 if (TheCall->getNumArgs() > NumArgs)
1429 return Diag(TheCall->getArg(NumArgs)->getLocStart(),
1430 diag::err_typecheck_call_too_many_args)
1431 << 0 /*function call*/ << NumArgs << TheCall->getNumArgs()
1432 << SourceRange(TheCall->getArg(NumArgs)->getLocStart(),
1433 (*(TheCall->arg_end()-1))->getLocEnd());
1435 Expr *OrigArg = TheCall->getArg(NumArgs-1);
1437 if (OrigArg->isTypeDependent())
1440 // This operation requires a non-_Complex floating-point number.
1441 if (!OrigArg->getType()->isRealFloatingType())
1442 return Diag(OrigArg->getLocStart(),
1443 diag::err_typecheck_call_invalid_unary_fp)
1444 << OrigArg->getType() << OrigArg->getSourceRange();
1446 // If this is an implicit conversion from float -> double, remove it.
1447 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(OrigArg)) {
1448 Expr *CastArg = Cast->getSubExpr();
1449 if (CastArg->getType()->isSpecificBuiltinType(BuiltinType::Float)) {
1450 assert(Cast->getType()->isSpecificBuiltinType(BuiltinType::Double) &&
1451 "promotion from float to double is the only expected cast here");
1452 Cast->setSubExpr(0);
1453 TheCall->setArg(NumArgs-1, CastArg);
1460 /// SemaBuiltinShuffleVector - Handle __builtin_shufflevector.
1461 // This is declared to take (...), so we have to check everything.
1462 ExprResult Sema::SemaBuiltinShuffleVector(CallExpr *TheCall) {
1463 if (TheCall->getNumArgs() < 2)
1464 return ExprError(Diag(TheCall->getLocEnd(),
1465 diag::err_typecheck_call_too_few_args_at_least)
1466 << 0 /*function call*/ << 2 << TheCall->getNumArgs()
1467 << TheCall->getSourceRange());
1469 // Determine which of the following types of shufflevector we're checking:
1470 // 1) unary, vector mask: (lhs, mask)
1471 // 2) binary, vector mask: (lhs, rhs, mask)
1472 // 3) binary, scalar mask: (lhs, rhs, index, ..., index)
1473 QualType resType = TheCall->getArg(0)->getType();
1474 unsigned numElements = 0;
1476 if (!TheCall->getArg(0)->isTypeDependent() &&
1477 !TheCall->getArg(1)->isTypeDependent()) {
1478 QualType LHSType = TheCall->getArg(0)->getType();
1479 QualType RHSType = TheCall->getArg(1)->getType();
1481 if (!LHSType->isVectorType() || !RHSType->isVectorType()) {
1482 Diag(TheCall->getLocStart(), diag::err_shufflevector_non_vector)
1483 << SourceRange(TheCall->getArg(0)->getLocStart(),
1484 TheCall->getArg(1)->getLocEnd());
1488 numElements = LHSType->getAs<VectorType>()->getNumElements();
1489 unsigned numResElements = TheCall->getNumArgs() - 2;
1491 // Check to see if we have a call with 2 vector arguments, the unary shuffle
1492 // with mask. If so, verify that RHS is an integer vector type with the
1493 // same number of elts as lhs.
1494 if (TheCall->getNumArgs() == 2) {
1495 if (!RHSType->hasIntegerRepresentation() ||
1496 RHSType->getAs<VectorType>()->getNumElements() != numElements)
1497 Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector)
1498 << SourceRange(TheCall->getArg(1)->getLocStart(),
1499 TheCall->getArg(1)->getLocEnd());
1500 numResElements = numElements;
1502 else if (!Context.hasSameUnqualifiedType(LHSType, RHSType)) {
1503 Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector)
1504 << SourceRange(TheCall->getArg(0)->getLocStart(),
1505 TheCall->getArg(1)->getLocEnd());
1507 } else if (numElements != numResElements) {
1508 QualType eltType = LHSType->getAs<VectorType>()->getElementType();
1509 resType = Context.getVectorType(eltType, numResElements,
1510 VectorType::GenericVector);
1514 for (unsigned i = 2; i < TheCall->getNumArgs(); i++) {
1515 if (TheCall->getArg(i)->isTypeDependent() ||
1516 TheCall->getArg(i)->isValueDependent())
1519 llvm::APSInt Result(32);
1520 if (!TheCall->getArg(i)->isIntegerConstantExpr(Result, Context))
1521 return ExprError(Diag(TheCall->getLocStart(),
1522 diag::err_shufflevector_nonconstant_argument)
1523 << TheCall->getArg(i)->getSourceRange());
1525 if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2)
1526 return ExprError(Diag(TheCall->getLocStart(),
1527 diag::err_shufflevector_argument_too_large)
1528 << TheCall->getArg(i)->getSourceRange());
1531 SmallVector<Expr*, 32> exprs;
1533 for (unsigned i = 0, e = TheCall->getNumArgs(); i != e; i++) {
1534 exprs.push_back(TheCall->getArg(i));
1535 TheCall->setArg(i, 0);
1538 return Owned(new (Context) ShuffleVectorExpr(Context, exprs, resType,
1539 TheCall->getCallee()->getLocStart(),
1540 TheCall->getRParenLoc()));
1543 /// SemaBuiltinPrefetch - Handle __builtin_prefetch.
1544 // This is declared to take (const void*, ...) and can take two
1545 // optional constant int args.
1546 bool Sema::SemaBuiltinPrefetch(CallExpr *TheCall) {
1547 unsigned NumArgs = TheCall->getNumArgs();
1550 return Diag(TheCall->getLocEnd(),
1551 diag::err_typecheck_call_too_many_args_at_most)
1552 << 0 /*function call*/ << 3 << NumArgs
1553 << TheCall->getSourceRange();
1555 // Argument 0 is checked for us and the remaining arguments must be
1556 // constant integers.
1557 for (unsigned i = 1; i != NumArgs; ++i) {
1558 Expr *Arg = TheCall->getArg(i);
1560 // We can't check the value of a dependent argument.
1561 if (Arg->isTypeDependent() || Arg->isValueDependent())
1564 llvm::APSInt Result;
1565 if (SemaBuiltinConstantArg(TheCall, i, Result))
1568 // FIXME: gcc issues a warning and rewrites these to 0. These
1569 // seems especially odd for the third argument since the default
1572 if (Result.getLimitedValue() > 1)
1573 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
1574 << "0" << "1" << Arg->getSourceRange();
1576 if (Result.getLimitedValue() > 3)
1577 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
1578 << "0" << "3" << Arg->getSourceRange();
1585 /// SemaBuiltinConstantArg - Handle a check if argument ArgNum of CallExpr
1586 /// TheCall is a constant expression.
1587 bool Sema::SemaBuiltinConstantArg(CallExpr *TheCall, int ArgNum,
1588 llvm::APSInt &Result) {
1589 Expr *Arg = TheCall->getArg(ArgNum);
1590 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
1591 FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
1593 if (Arg->isTypeDependent() || Arg->isValueDependent()) return false;
1595 if (!Arg->isIntegerConstantExpr(Result, Context))
1596 return Diag(TheCall->getLocStart(), diag::err_constant_integer_arg_type)
1597 << FDecl->getDeclName() << Arg->getSourceRange();
1602 /// SemaBuiltinObjectSize - Handle __builtin_object_size(void *ptr,
1603 /// int type). This simply type checks that type is one of the defined
1604 /// constants (0-3).
1605 // For compatibility check 0-3, llvm only handles 0 and 2.
1606 bool Sema::SemaBuiltinObjectSize(CallExpr *TheCall) {
1607 llvm::APSInt Result;
1609 // We can't check the value of a dependent argument.
1610 if (TheCall->getArg(1)->isTypeDependent() ||
1611 TheCall->getArg(1)->isValueDependent())
1614 // Check constant-ness first.
1615 if (SemaBuiltinConstantArg(TheCall, 1, Result))
1618 Expr *Arg = TheCall->getArg(1);
1619 if (Result.getSExtValue() < 0 || Result.getSExtValue() > 3) {
1620 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
1621 << "0" << "3" << SourceRange(Arg->getLocStart(), Arg->getLocEnd());
1627 /// SemaBuiltinLongjmp - Handle __builtin_longjmp(void *env[5], int val).
1628 /// This checks that val is a constant 1.
1629 bool Sema::SemaBuiltinLongjmp(CallExpr *TheCall) {
1630 Expr *Arg = TheCall->getArg(1);
1631 llvm::APSInt Result;
1633 // TODO: This is less than ideal. Overload this to take a value.
1634 if (SemaBuiltinConstantArg(TheCall, 1, Result))
1638 return Diag(TheCall->getLocStart(), diag::err_builtin_longjmp_invalid_val)
1639 << SourceRange(Arg->getLocStart(), Arg->getLocEnd());
1644 // Determine if an expression is a string literal or constant string.
1645 // If this function returns false on the arguments to a function expecting a
1646 // format string, we will usually need to emit a warning.
1647 // True string literals are then checked by CheckFormatString.
1648 Sema::StringLiteralCheckType
1649 Sema::checkFormatStringExpr(const Expr *E, Expr **Args,
1650 unsigned NumArgs, bool HasVAListArg,
1651 unsigned format_idx, unsigned firstDataArg,
1652 FormatStringType Type, VariadicCallType CallType,
1653 bool inFunctionCall) {
1655 if (E->isTypeDependent() || E->isValueDependent())
1656 return SLCT_NotALiteral;
1658 E = E->IgnoreParenCasts();
1660 if (E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull))
1661 // Technically -Wformat-nonliteral does not warn about this case.
1662 // The behavior of printf and friends in this case is implementation
1663 // dependent. Ideally if the format string cannot be null then
1664 // it should have a 'nonnull' attribute in the function prototype.
1665 return SLCT_CheckedLiteral;
1667 switch (E->getStmtClass()) {
1668 case Stmt::BinaryConditionalOperatorClass:
1669 case Stmt::ConditionalOperatorClass: {
1670 // The expression is a literal if both sub-expressions were, and it was
1671 // completely checked only if both sub-expressions were checked.
1672 const AbstractConditionalOperator *C =
1673 cast<AbstractConditionalOperator>(E);
1674 StringLiteralCheckType Left =
1675 checkFormatStringExpr(C->getTrueExpr(), Args, NumArgs,
1676 HasVAListArg, format_idx, firstDataArg,
1677 Type, CallType, inFunctionCall);
1678 if (Left == SLCT_NotALiteral)
1679 return SLCT_NotALiteral;
1680 StringLiteralCheckType Right =
1681 checkFormatStringExpr(C->getFalseExpr(), Args, NumArgs,
1682 HasVAListArg, format_idx, firstDataArg,
1683 Type, CallType, inFunctionCall);
1684 return Left < Right ? Left : Right;
1687 case Stmt::ImplicitCastExprClass: {
1688 E = cast<ImplicitCastExpr>(E)->getSubExpr();
1692 case Stmt::OpaqueValueExprClass:
1693 if (const Expr *src = cast<OpaqueValueExpr>(E)->getSourceExpr()) {
1697 return SLCT_NotALiteral;
1699 case Stmt::PredefinedExprClass:
1700 // While __func__, etc., are technically not string literals, they
1701 // cannot contain format specifiers and thus are not a security
1703 return SLCT_UncheckedLiteral;
1705 case Stmt::DeclRefExprClass: {
1706 const DeclRefExpr *DR = cast<DeclRefExpr>(E);
1708 // As an exception, do not flag errors for variables binding to
1709 // const string literals.
1710 if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
1711 bool isConstant = false;
1712 QualType T = DR->getType();
1714 if (const ArrayType *AT = Context.getAsArrayType(T)) {
1715 isConstant = AT->getElementType().isConstant(Context);
1716 } else if (const PointerType *PT = T->getAs<PointerType>()) {
1717 isConstant = T.isConstant(Context) &&
1718 PT->getPointeeType().isConstant(Context);
1719 } else if (T->isObjCObjectPointerType()) {
1720 // In ObjC, there is usually no "const ObjectPointer" type,
1721 // so don't check if the pointee type is constant.
1722 isConstant = T.isConstant(Context);
1726 if (const Expr *Init = VD->getAnyInitializer()) {
1727 // Look through initializers like const char c[] = { "foo" }
1728 if (const InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
1729 if (InitList->isStringLiteralInit())
1730 Init = InitList->getInit(0)->IgnoreParenImpCasts();
1732 return checkFormatStringExpr(Init, Args, NumArgs,
1733 HasVAListArg, format_idx,
1734 firstDataArg, Type, CallType,
1735 /*inFunctionCall*/false);
1739 // For vprintf* functions (i.e., HasVAListArg==true), we add a
1740 // special check to see if the format string is a function parameter
1741 // of the function calling the printf function. If the function
1742 // has an attribute indicating it is a printf-like function, then we
1743 // should suppress warnings concerning non-literals being used in a call
1744 // to a vprintf function. For example:
1747 // logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...){
1749 // va_start(ap, fmt);
1750 // vprintf(fmt, ap); // Do NOT emit a warning about "fmt".
1754 if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(VD)) {
1755 if (const NamedDecl *ND = dyn_cast<NamedDecl>(PV->getDeclContext())) {
1756 int PVIndex = PV->getFunctionScopeIndex() + 1;
1757 for (specific_attr_iterator<FormatAttr>
1758 i = ND->specific_attr_begin<FormatAttr>(),
1759 e = ND->specific_attr_end<FormatAttr>(); i != e ; ++i) {
1760 FormatAttr *PVFormat = *i;
1761 // adjust for implicit parameter
1762 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
1763 if (MD->isInstance())
1765 // We also check if the formats are compatible.
1766 // We can't pass a 'scanf' string to a 'printf' function.
1767 if (PVIndex == PVFormat->getFormatIdx() &&
1768 Type == GetFormatStringType(PVFormat))
1769 return SLCT_UncheckedLiteral;
1776 return SLCT_NotALiteral;
1779 case Stmt::CallExprClass:
1780 case Stmt::CXXMemberCallExprClass: {
1781 const CallExpr *CE = cast<CallExpr>(E);
1782 if (const NamedDecl *ND = dyn_cast_or_null<NamedDecl>(CE->getCalleeDecl())) {
1783 if (const FormatArgAttr *FA = ND->getAttr<FormatArgAttr>()) {
1784 unsigned ArgIndex = FA->getFormatIdx();
1785 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
1786 if (MD->isInstance())
1788 const Expr *Arg = CE->getArg(ArgIndex - 1);
1790 return checkFormatStringExpr(Arg, Args, NumArgs,
1791 HasVAListArg, format_idx, firstDataArg,
1792 Type, CallType, inFunctionCall);
1793 } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
1794 unsigned BuiltinID = FD->getBuiltinID();
1795 if (BuiltinID == Builtin::BI__builtin___CFStringMakeConstantString ||
1796 BuiltinID == Builtin::BI__builtin___NSStringMakeConstantString) {
1797 const Expr *Arg = CE->getArg(0);
1798 return checkFormatStringExpr(Arg, Args, NumArgs,
1799 HasVAListArg, format_idx,
1800 firstDataArg, Type, CallType,
1806 return SLCT_NotALiteral;
1808 case Stmt::ObjCStringLiteralClass:
1809 case Stmt::StringLiteralClass: {
1810 const StringLiteral *StrE = NULL;
1812 if (const ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(E))
1813 StrE = ObjCFExpr->getString();
1815 StrE = cast<StringLiteral>(E);
1818 CheckFormatString(StrE, E, Args, NumArgs, HasVAListArg, format_idx,
1819 firstDataArg, Type, inFunctionCall, CallType);
1820 return SLCT_CheckedLiteral;
1823 return SLCT_NotALiteral;
1827 return SLCT_NotALiteral;
1832 Sema::CheckNonNullArguments(const NonNullAttr *NonNull,
1833 const Expr * const *ExprArgs,
1834 SourceLocation CallSiteLoc) {
1835 for (NonNullAttr::args_iterator i = NonNull->args_begin(),
1836 e = NonNull->args_end();
1838 const Expr *ArgExpr = ExprArgs[*i];
1839 if (ArgExpr->isNullPointerConstant(Context,
1840 Expr::NPC_ValueDependentIsNotNull))
1841 Diag(CallSiteLoc, diag::warn_null_arg) << ArgExpr->getSourceRange();
1845 Sema::FormatStringType Sema::GetFormatStringType(const FormatAttr *Format) {
1846 return llvm::StringSwitch<FormatStringType>(Format->getType())
1847 .Case("scanf", FST_Scanf)
1848 .Cases("printf", "printf0", FST_Printf)
1849 .Cases("NSString", "CFString", FST_NSString)
1850 .Case("strftime", FST_Strftime)
1851 .Case("strfmon", FST_Strfmon)
1852 .Cases("kprintf", "cmn_err", "vcmn_err", "zcmn_err", FST_Kprintf)
1853 .Default(FST_Unknown);
1856 /// CheckFormatArguments - Check calls to printf and scanf (and similar
1857 /// functions) for correct use of format strings.
1858 /// Returns true if a format string has been fully checked.
1859 bool Sema::CheckFormatArguments(const FormatAttr *Format, Expr **Args,
1860 unsigned NumArgs, bool IsCXXMember,
1861 VariadicCallType CallType,
1862 SourceLocation Loc, SourceRange Range) {
1863 FormatStringInfo FSI;
1864 if (getFormatStringInfo(Format, IsCXXMember, &FSI))
1865 return CheckFormatArguments(Args, NumArgs, FSI.HasVAListArg, FSI.FormatIdx,
1866 FSI.FirstDataArg, GetFormatStringType(Format),
1867 CallType, Loc, Range);
1871 bool Sema::CheckFormatArguments(Expr **Args, unsigned NumArgs,
1872 bool HasVAListArg, unsigned format_idx,
1873 unsigned firstDataArg, FormatStringType Type,
1874 VariadicCallType CallType,
1875 SourceLocation Loc, SourceRange Range) {
1876 // CHECK: printf/scanf-like function is called with no format string.
1877 if (format_idx >= NumArgs) {
1878 Diag(Loc, diag::warn_missing_format_string) << Range;
1882 const Expr *OrigFormatExpr = Args[format_idx]->IgnoreParenCasts();
1884 // CHECK: format string is not a string literal.
1886 // Dynamically generated format strings are difficult to
1887 // automatically vet at compile time. Requiring that format strings
1888 // are string literals: (1) permits the checking of format strings by
1889 // the compiler and thereby (2) can practically remove the source of
1890 // many format string exploits.
1892 // Format string can be either ObjC string (e.g. @"%d") or
1893 // C string (e.g. "%d")
1894 // ObjC string uses the same format specifiers as C string, so we can use
1895 // the same format string checking logic for both ObjC and C strings.
1896 StringLiteralCheckType CT =
1897 checkFormatStringExpr(OrigFormatExpr, Args, NumArgs, HasVAListArg,
1898 format_idx, firstDataArg, Type, CallType);
1899 if (CT != SLCT_NotALiteral)
1900 // Literal format string found, check done!
1901 return CT == SLCT_CheckedLiteral;
1903 // Strftime is particular as it always uses a single 'time' argument,
1904 // so it is safe to pass a non-literal string.
1905 if (Type == FST_Strftime)
1908 // Do not emit diag when the string param is a macro expansion and the
1909 // format is either NSString or CFString. This is a hack to prevent
1910 // diag when using the NSLocalizedString and CFCopyLocalizedString macros
1911 // which are usually used in place of NS and CF string literals.
1912 if (Type == FST_NSString &&
1913 SourceMgr.isInSystemMacro(Args[format_idx]->getLocStart()))
1916 // If there are no arguments specified, warn with -Wformat-security, otherwise
1917 // warn only with -Wformat-nonliteral.
1918 if (NumArgs == format_idx+1)
1919 Diag(Args[format_idx]->getLocStart(),
1920 diag::warn_format_nonliteral_noargs)
1921 << OrigFormatExpr->getSourceRange();
1923 Diag(Args[format_idx]->getLocStart(),
1924 diag::warn_format_nonliteral)
1925 << OrigFormatExpr->getSourceRange();
1930 class CheckFormatHandler : public analyze_format_string::FormatStringHandler {
1933 const StringLiteral *FExpr;
1934 const Expr *OrigFormatExpr;
1935 const unsigned FirstDataArg;
1936 const unsigned NumDataArgs;
1937 const char *Beg; // Start of format string.
1938 const bool HasVAListArg;
1939 const Expr * const *Args;
1940 const unsigned NumArgs;
1942 llvm::BitVector CoveredArgs;
1943 bool usesPositionalArgs;
1945 bool inFunctionCall;
1946 Sema::VariadicCallType CallType;
1948 CheckFormatHandler(Sema &s, const StringLiteral *fexpr,
1949 const Expr *origFormatExpr, unsigned firstDataArg,
1950 unsigned numDataArgs, const char *beg, bool hasVAListArg,
1951 Expr **args, unsigned numArgs,
1952 unsigned formatIdx, bool inFunctionCall,
1953 Sema::VariadicCallType callType)
1954 : S(s), FExpr(fexpr), OrigFormatExpr(origFormatExpr),
1955 FirstDataArg(firstDataArg), NumDataArgs(numDataArgs),
1956 Beg(beg), HasVAListArg(hasVAListArg),
1957 Args(args), NumArgs(numArgs), FormatIdx(formatIdx),
1958 usesPositionalArgs(false), atFirstArg(true),
1959 inFunctionCall(inFunctionCall), CallType(callType) {
1960 CoveredArgs.resize(numDataArgs);
1961 CoveredArgs.reset();
1964 void DoneProcessing();
1966 void HandleIncompleteSpecifier(const char *startSpecifier,
1967 unsigned specifierLen);
1969 void HandleInvalidLengthModifier(
1970 const analyze_format_string::FormatSpecifier &FS,
1971 const analyze_format_string::ConversionSpecifier &CS,
1972 const char *startSpecifier, unsigned specifierLen, unsigned DiagID);
1974 void HandleNonStandardLengthModifier(
1975 const analyze_format_string::FormatSpecifier &FS,
1976 const char *startSpecifier, unsigned specifierLen);
1978 void HandleNonStandardConversionSpecifier(
1979 const analyze_format_string::ConversionSpecifier &CS,
1980 const char *startSpecifier, unsigned specifierLen);
1982 virtual void HandlePosition(const char *startPos, unsigned posLen);
1984 virtual void HandleInvalidPosition(const char *startSpecifier,
1985 unsigned specifierLen,
1986 analyze_format_string::PositionContext p);
1988 virtual void HandleZeroPosition(const char *startPos, unsigned posLen);
1990 void HandleNullChar(const char *nullCharacter);
1992 template <typename Range>
1993 static void EmitFormatDiagnostic(Sema &S, bool inFunctionCall,
1994 const Expr *ArgumentExpr,
1995 PartialDiagnostic PDiag,
1996 SourceLocation StringLoc,
1997 bool IsStringLocation, Range StringRange,
1998 ArrayRef<FixItHint> Fixit = ArrayRef<FixItHint>());
2001 bool HandleInvalidConversionSpecifier(unsigned argIndex, SourceLocation Loc,
2002 const char *startSpec,
2003 unsigned specifierLen,
2004 const char *csStart, unsigned csLen);
2006 void HandlePositionalNonpositionalArgs(SourceLocation Loc,
2007 const char *startSpec,
2008 unsigned specifierLen);
2010 SourceRange getFormatStringRange();
2011 CharSourceRange getSpecifierRange(const char *startSpecifier,
2012 unsigned specifierLen);
2013 SourceLocation getLocationOfByte(const char *x);
2015 const Expr *getDataArg(unsigned i) const;
2017 bool CheckNumArgs(const analyze_format_string::FormatSpecifier &FS,
2018 const analyze_format_string::ConversionSpecifier &CS,
2019 const char *startSpecifier, unsigned specifierLen,
2022 template <typename Range>
2023 void EmitFormatDiagnostic(PartialDiagnostic PDiag, SourceLocation StringLoc,
2024 bool IsStringLocation, Range StringRange,
2025 ArrayRef<FixItHint> Fixit = ArrayRef<FixItHint>());
2027 void CheckPositionalAndNonpositionalArgs(
2028 const analyze_format_string::FormatSpecifier *FS);
2032 SourceRange CheckFormatHandler::getFormatStringRange() {
2033 return OrigFormatExpr->getSourceRange();
2036 CharSourceRange CheckFormatHandler::
2037 getSpecifierRange(const char *startSpecifier, unsigned specifierLen) {
2038 SourceLocation Start = getLocationOfByte(startSpecifier);
2039 SourceLocation End = getLocationOfByte(startSpecifier + specifierLen - 1);
2041 // Advance the end SourceLocation by one due to half-open ranges.
2042 End = End.getLocWithOffset(1);
2044 return CharSourceRange::getCharRange(Start, End);
2047 SourceLocation CheckFormatHandler::getLocationOfByte(const char *x) {
2048 return S.getLocationOfStringLiteralByte(FExpr, x - Beg);
2051 void CheckFormatHandler::HandleIncompleteSpecifier(const char *startSpecifier,
2052 unsigned specifierLen){
2053 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_incomplete_specifier),
2054 getLocationOfByte(startSpecifier),
2055 /*IsStringLocation*/true,
2056 getSpecifierRange(startSpecifier, specifierLen));
2059 void CheckFormatHandler::HandleInvalidLengthModifier(
2060 const analyze_format_string::FormatSpecifier &FS,
2061 const analyze_format_string::ConversionSpecifier &CS,
2062 const char *startSpecifier, unsigned specifierLen, unsigned DiagID) {
2063 using namespace analyze_format_string;
2065 const LengthModifier &LM = FS.getLengthModifier();
2066 CharSourceRange LMRange = getSpecifierRange(LM.getStart(), LM.getLength());
2068 // See if we know how to fix this length modifier.
2069 llvm::Optional<LengthModifier> FixedLM = FS.getCorrectedLengthModifier();
2071 EmitFormatDiagnostic(S.PDiag(DiagID) << LM.toString() << CS.toString(),
2072 getLocationOfByte(LM.getStart()),
2073 /*IsStringLocation*/true,
2074 getSpecifierRange(startSpecifier, specifierLen));
2076 S.Diag(getLocationOfByte(LM.getStart()), diag::note_format_fix_specifier)
2077 << FixedLM->toString()
2078 << FixItHint::CreateReplacement(LMRange, FixedLM->toString());
2082 if (DiagID == diag::warn_format_nonsensical_length)
2083 Hint = FixItHint::CreateRemoval(LMRange);
2085 EmitFormatDiagnostic(S.PDiag(DiagID) << LM.toString() << CS.toString(),
2086 getLocationOfByte(LM.getStart()),
2087 /*IsStringLocation*/true,
2088 getSpecifierRange(startSpecifier, specifierLen),
2093 void CheckFormatHandler::HandleNonStandardLengthModifier(
2094 const analyze_format_string::FormatSpecifier &FS,
2095 const char *startSpecifier, unsigned specifierLen) {
2096 using namespace analyze_format_string;
2098 const LengthModifier &LM = FS.getLengthModifier();
2099 CharSourceRange LMRange = getSpecifierRange(LM.getStart(), LM.getLength());
2101 // See if we know how to fix this length modifier.
2102 llvm::Optional<LengthModifier> FixedLM = FS.getCorrectedLengthModifier();
2104 EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
2105 << LM.toString() << 0,
2106 getLocationOfByte(LM.getStart()),
2107 /*IsStringLocation*/true,
2108 getSpecifierRange(startSpecifier, specifierLen));
2110 S.Diag(getLocationOfByte(LM.getStart()), diag::note_format_fix_specifier)
2111 << FixedLM->toString()
2112 << FixItHint::CreateReplacement(LMRange, FixedLM->toString());
2115 EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
2116 << LM.toString() << 0,
2117 getLocationOfByte(LM.getStart()),
2118 /*IsStringLocation*/true,
2119 getSpecifierRange(startSpecifier, specifierLen));
2123 void CheckFormatHandler::HandleNonStandardConversionSpecifier(
2124 const analyze_format_string::ConversionSpecifier &CS,
2125 const char *startSpecifier, unsigned specifierLen) {
2126 using namespace analyze_format_string;
2128 // See if we know how to fix this conversion specifier.
2129 llvm::Optional<ConversionSpecifier> FixedCS = CS.getStandardSpecifier();
2131 EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
2132 << CS.toString() << /*conversion specifier*/1,
2133 getLocationOfByte(CS.getStart()),
2134 /*IsStringLocation*/true,
2135 getSpecifierRange(startSpecifier, specifierLen));
2137 CharSourceRange CSRange = getSpecifierRange(CS.getStart(), CS.getLength());
2138 S.Diag(getLocationOfByte(CS.getStart()), diag::note_format_fix_specifier)
2139 << FixedCS->toString()
2140 << FixItHint::CreateReplacement(CSRange, FixedCS->toString());
2142 EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard)
2143 << CS.toString() << /*conversion specifier*/1,
2144 getLocationOfByte(CS.getStart()),
2145 /*IsStringLocation*/true,
2146 getSpecifierRange(startSpecifier, specifierLen));
2150 void CheckFormatHandler::HandlePosition(const char *startPos,
2152 EmitFormatDiagnostic(S.PDiag(diag::warn_format_non_standard_positional_arg),
2153 getLocationOfByte(startPos),
2154 /*IsStringLocation*/true,
2155 getSpecifierRange(startPos, posLen));
2159 CheckFormatHandler::HandleInvalidPosition(const char *startPos, unsigned posLen,
2160 analyze_format_string::PositionContext p) {
2161 EmitFormatDiagnostic(S.PDiag(diag::warn_format_invalid_positional_specifier)
2163 getLocationOfByte(startPos), /*IsStringLocation*/true,
2164 getSpecifierRange(startPos, posLen));
2167 void CheckFormatHandler::HandleZeroPosition(const char *startPos,
2169 EmitFormatDiagnostic(S.PDiag(diag::warn_format_zero_positional_specifier),
2170 getLocationOfByte(startPos),
2171 /*IsStringLocation*/true,
2172 getSpecifierRange(startPos, posLen));
2175 void CheckFormatHandler::HandleNullChar(const char *nullCharacter) {
2176 if (!isa<ObjCStringLiteral>(OrigFormatExpr)) {
2177 // The presence of a null character is likely an error.
2178 EmitFormatDiagnostic(
2179 S.PDiag(diag::warn_printf_format_string_contains_null_char),
2180 getLocationOfByte(nullCharacter), /*IsStringLocation*/true,
2181 getFormatStringRange());
2185 // Note that this may return NULL if there was an error parsing or building
2186 // one of the argument expressions.
2187 const Expr *CheckFormatHandler::getDataArg(unsigned i) const {
2188 return Args[FirstDataArg + i];
2191 void CheckFormatHandler::DoneProcessing() {
2192 // Does the number of data arguments exceed the number of
2193 // format conversions in the format string?
2194 if (!HasVAListArg) {
2195 // Find any arguments that weren't covered.
2197 signed notCoveredArg = CoveredArgs.find_first();
2198 if (notCoveredArg >= 0) {
2199 assert((unsigned)notCoveredArg < NumDataArgs);
2200 if (const Expr *E = getDataArg((unsigned) notCoveredArg)) {
2201 SourceLocation Loc = E->getLocStart();
2202 if (!S.getSourceManager().isInSystemMacro(Loc)) {
2203 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_data_arg_not_used),
2204 Loc, /*IsStringLocation*/false,
2205 getFormatStringRange());
2213 CheckFormatHandler::HandleInvalidConversionSpecifier(unsigned argIndex,
2215 const char *startSpec,
2216 unsigned specifierLen,
2217 const char *csStart,
2220 bool keepGoing = true;
2221 if (argIndex < NumDataArgs) {
2222 // Consider the argument coverered, even though the specifier doesn't
2224 CoveredArgs.set(argIndex);
2227 // If argIndex exceeds the number of data arguments we
2228 // don't issue a warning because that is just a cascade of warnings (and
2229 // they may have intended '%%' anyway). We don't want to continue processing
2230 // the format string after this point, however, as we will like just get
2231 // gibberish when trying to match arguments.
2235 EmitFormatDiagnostic(S.PDiag(diag::warn_format_invalid_conversion)
2236 << StringRef(csStart, csLen),
2237 Loc, /*IsStringLocation*/true,
2238 getSpecifierRange(startSpec, specifierLen));
2244 CheckFormatHandler::HandlePositionalNonpositionalArgs(SourceLocation Loc,
2245 const char *startSpec,
2246 unsigned specifierLen) {
2247 EmitFormatDiagnostic(
2248 S.PDiag(diag::warn_format_mix_positional_nonpositional_args),
2249 Loc, /*isStringLoc*/true, getSpecifierRange(startSpec, specifierLen));
2253 CheckFormatHandler::CheckNumArgs(
2254 const analyze_format_string::FormatSpecifier &FS,
2255 const analyze_format_string::ConversionSpecifier &CS,
2256 const char *startSpecifier, unsigned specifierLen, unsigned argIndex) {
2258 if (argIndex >= NumDataArgs) {
2259 PartialDiagnostic PDiag = FS.usesPositionalArg()
2260 ? (S.PDiag(diag::warn_printf_positional_arg_exceeds_data_args)
2261 << (argIndex+1) << NumDataArgs)
2262 : S.PDiag(diag::warn_printf_insufficient_data_args);
2263 EmitFormatDiagnostic(
2264 PDiag, getLocationOfByte(CS.getStart()), /*IsStringLocation*/true,
2265 getSpecifierRange(startSpecifier, specifierLen));
2271 template<typename Range>
2272 void CheckFormatHandler::EmitFormatDiagnostic(PartialDiagnostic PDiag,
2274 bool IsStringLocation,
2276 ArrayRef<FixItHint> FixIt) {
2277 EmitFormatDiagnostic(S, inFunctionCall, Args[FormatIdx], PDiag,
2278 Loc, IsStringLocation, StringRange, FixIt);
2281 /// \brief If the format string is not within the funcion call, emit a note
2282 /// so that the function call and string are in diagnostic messages.
2284 /// \param InFunctionCall if true, the format string is within the function
2285 /// call and only one diagnostic message will be produced. Otherwise, an
2286 /// extra note will be emitted pointing to location of the format string.
2288 /// \param ArgumentExpr the expression that is passed as the format string
2289 /// argument in the function call. Used for getting locations when two
2290 /// diagnostics are emitted.
2292 /// \param PDiag the callee should already have provided any strings for the
2293 /// diagnostic message. This function only adds locations and fixits
2296 /// \param Loc primary location for diagnostic. If two diagnostics are
2297 /// required, one will be at Loc and a new SourceLocation will be created for
2300 /// \param IsStringLocation if true, Loc points to the format string should be
2301 /// used for the note. Otherwise, Loc points to the argument list and will
2302 /// be used with PDiag.
2304 /// \param StringRange some or all of the string to highlight. This is
2305 /// templated so it can accept either a CharSourceRange or a SourceRange.
2307 /// \param FixIt optional fix it hint for the format string.
2308 template<typename Range>
2309 void CheckFormatHandler::EmitFormatDiagnostic(Sema &S, bool InFunctionCall,
2310 const Expr *ArgumentExpr,
2311 PartialDiagnostic PDiag,
2313 bool IsStringLocation,
2315 ArrayRef<FixItHint> FixIt) {
2316 if (InFunctionCall) {
2317 const Sema::SemaDiagnosticBuilder &D = S.Diag(Loc, PDiag);
2319 for (ArrayRef<FixItHint>::iterator I = FixIt.begin(), E = FixIt.end();
2324 S.Diag(IsStringLocation ? ArgumentExpr->getExprLoc() : Loc, PDiag)
2325 << ArgumentExpr->getSourceRange();
2327 const Sema::SemaDiagnosticBuilder &Note =
2328 S.Diag(IsStringLocation ? Loc : StringRange.getBegin(),
2329 diag::note_format_string_defined);
2331 Note << StringRange;
2332 for (ArrayRef<FixItHint>::iterator I = FixIt.begin(), E = FixIt.end();
2339 //===--- CHECK: Printf format string checking ------------------------------===//
2342 class CheckPrintfHandler : public CheckFormatHandler {
2345 CheckPrintfHandler(Sema &s, const StringLiteral *fexpr,
2346 const Expr *origFormatExpr, unsigned firstDataArg,
2347 unsigned numDataArgs, bool isObjC,
2348 const char *beg, bool hasVAListArg,
2349 Expr **Args, unsigned NumArgs,
2350 unsigned formatIdx, bool inFunctionCall,
2351 Sema::VariadicCallType CallType)
2352 : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg,
2353 numDataArgs, beg, hasVAListArg, Args, NumArgs,
2354 formatIdx, inFunctionCall, CallType), ObjCContext(isObjC)
2358 bool HandleInvalidPrintfConversionSpecifier(
2359 const analyze_printf::PrintfSpecifier &FS,
2360 const char *startSpecifier,
2361 unsigned specifierLen);
2363 bool HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier &FS,
2364 const char *startSpecifier,
2365 unsigned specifierLen);
2366 bool checkFormatExpr(const analyze_printf::PrintfSpecifier &FS,
2367 const char *StartSpecifier,
2368 unsigned SpecifierLen,
2371 bool HandleAmount(const analyze_format_string::OptionalAmount &Amt, unsigned k,
2372 const char *startSpecifier, unsigned specifierLen);
2373 void HandleInvalidAmount(const analyze_printf::PrintfSpecifier &FS,
2374 const analyze_printf::OptionalAmount &Amt,
2376 const char *startSpecifier, unsigned specifierLen);
2377 void HandleFlag(const analyze_printf::PrintfSpecifier &FS,
2378 const analyze_printf::OptionalFlag &flag,
2379 const char *startSpecifier, unsigned specifierLen);
2380 void HandleIgnoredFlag(const analyze_printf::PrintfSpecifier &FS,
2381 const analyze_printf::OptionalFlag &ignoredFlag,
2382 const analyze_printf::OptionalFlag &flag,
2383 const char *startSpecifier, unsigned specifierLen);
2384 bool checkForCStrMembers(const analyze_printf::ArgType &AT,
2385 const Expr *E, const CharSourceRange &CSR);
2390 bool CheckPrintfHandler::HandleInvalidPrintfConversionSpecifier(
2391 const analyze_printf::PrintfSpecifier &FS,
2392 const char *startSpecifier,
2393 unsigned specifierLen) {
2394 const analyze_printf::PrintfConversionSpecifier &CS =
2395 FS.getConversionSpecifier();
2397 return HandleInvalidConversionSpecifier(FS.getArgIndex(),
2398 getLocationOfByte(CS.getStart()),
2399 startSpecifier, specifierLen,
2400 CS.getStart(), CS.getLength());
2403 bool CheckPrintfHandler::HandleAmount(
2404 const analyze_format_string::OptionalAmount &Amt,
2405 unsigned k, const char *startSpecifier,
2406 unsigned specifierLen) {
2408 if (Amt.hasDataArgument()) {
2409 if (!HasVAListArg) {
2410 unsigned argIndex = Amt.getArgIndex();
2411 if (argIndex >= NumDataArgs) {
2412 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_asterisk_missing_arg)
2414 getLocationOfByte(Amt.getStart()),
2415 /*IsStringLocation*/true,
2416 getSpecifierRange(startSpecifier, specifierLen));
2417 // Don't do any more checking. We will just emit
2422 // Type check the data argument. It should be an 'int'.
2423 // Although not in conformance with C99, we also allow the argument to be
2424 // an 'unsigned int' as that is a reasonably safe case. GCC also
2425 // doesn't emit a warning for that case.
2426 CoveredArgs.set(argIndex);
2427 const Expr *Arg = getDataArg(argIndex);
2431 QualType T = Arg->getType();
2433 const analyze_printf::ArgType &AT = Amt.getArgType(S.Context);
2434 assert(AT.isValid());
2436 if (!AT.matchesType(S.Context, T)) {
2437 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_asterisk_wrong_type)
2438 << k << AT.getRepresentativeTypeName(S.Context)
2439 << T << Arg->getSourceRange(),
2440 getLocationOfByte(Amt.getStart()),
2441 /*IsStringLocation*/true,
2442 getSpecifierRange(startSpecifier, specifierLen));
2443 // Don't do any more checking. We will just emit
2452 void CheckPrintfHandler::HandleInvalidAmount(
2453 const analyze_printf::PrintfSpecifier &FS,
2454 const analyze_printf::OptionalAmount &Amt,
2456 const char *startSpecifier,
2457 unsigned specifierLen) {
2458 const analyze_printf::PrintfConversionSpecifier &CS =
2459 FS.getConversionSpecifier();
2462 Amt.getHowSpecified() == analyze_printf::OptionalAmount::Constant
2463 ? FixItHint::CreateRemoval(getSpecifierRange(Amt.getStart(),
2464 Amt.getConstantLength()))
2467 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_nonsensical_optional_amount)
2468 << type << CS.toString(),
2469 getLocationOfByte(Amt.getStart()),
2470 /*IsStringLocation*/true,
2471 getSpecifierRange(startSpecifier, specifierLen),
2475 void CheckPrintfHandler::HandleFlag(const analyze_printf::PrintfSpecifier &FS,
2476 const analyze_printf::OptionalFlag &flag,
2477 const char *startSpecifier,
2478 unsigned specifierLen) {
2479 // Warn about pointless flag with a fixit removal.
2480 const analyze_printf::PrintfConversionSpecifier &CS =
2481 FS.getConversionSpecifier();
2482 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_nonsensical_flag)
2483 << flag.toString() << CS.toString(),
2484 getLocationOfByte(flag.getPosition()),
2485 /*IsStringLocation*/true,
2486 getSpecifierRange(startSpecifier, specifierLen),
2487 FixItHint::CreateRemoval(
2488 getSpecifierRange(flag.getPosition(), 1)));
2491 void CheckPrintfHandler::HandleIgnoredFlag(
2492 const analyze_printf::PrintfSpecifier &FS,
2493 const analyze_printf::OptionalFlag &ignoredFlag,
2494 const analyze_printf::OptionalFlag &flag,
2495 const char *startSpecifier,
2496 unsigned specifierLen) {
2497 // Warn about ignored flag with a fixit removal.
2498 EmitFormatDiagnostic(S.PDiag(diag::warn_printf_ignored_flag)
2499 << ignoredFlag.toString() << flag.toString(),
2500 getLocationOfByte(ignoredFlag.getPosition()),
2501 /*IsStringLocation*/true,
2502 getSpecifierRange(startSpecifier, specifierLen),
2503 FixItHint::CreateRemoval(
2504 getSpecifierRange(ignoredFlag.getPosition(), 1)));
2507 // Determines if the specified is a C++ class or struct containing
2508 // a member with the specified name and kind (e.g. a CXXMethodDecl named
2510 template<typename MemberKind>
2511 static llvm::SmallPtrSet<MemberKind*, 1>
2512 CXXRecordMembersNamed(StringRef Name, Sema &S, QualType Ty) {
2513 const RecordType *RT = Ty->getAs<RecordType>();
2514 llvm::SmallPtrSet<MemberKind*, 1> Results;
2518 const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl());
2522 LookupResult R(S, &S.PP.getIdentifierTable().get(Name), SourceLocation(),
2523 Sema::LookupMemberName);
2525 // We just need to include all members of the right kind turned up by the
2526 // filter, at this point.
2527 if (S.LookupQualifiedName(R, RT->getDecl()))
2528 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
2529 NamedDecl *decl = (*I)->getUnderlyingDecl();
2530 if (MemberKind *FK = dyn_cast<MemberKind>(decl))
2536 // Check if a (w)string was passed when a (w)char* was needed, and offer a
2537 // better diagnostic if so. AT is assumed to be valid.
2538 // Returns true when a c_str() conversion method is found.
2539 bool CheckPrintfHandler::checkForCStrMembers(
2540 const analyze_printf::ArgType &AT, const Expr *E,
2541 const CharSourceRange &CSR) {
2542 typedef llvm::SmallPtrSet<CXXMethodDecl*, 1> MethodSet;
2545 CXXRecordMembersNamed<CXXMethodDecl>("c_str", S, E->getType());
2547 for (MethodSet::iterator MI = Results.begin(), ME = Results.end();
2549 const CXXMethodDecl *Method = *MI;
2550 if (Method->getNumParams() == 0 &&
2551 AT.matchesType(S.Context, Method->getResultType())) {
2552 // FIXME: Suggest parens if the expression needs them.
2553 SourceLocation EndLoc =
2554 S.getPreprocessor().getLocForEndOfToken(E->getLocEnd());
2555 S.Diag(E->getLocStart(), diag::note_printf_c_str)
2557 << FixItHint::CreateInsertion(EndLoc, ".c_str()");
2566 CheckPrintfHandler::HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier
2568 const char *startSpecifier,
2569 unsigned specifierLen) {
2571 using namespace analyze_format_string;
2572 using namespace analyze_printf;
2573 const PrintfConversionSpecifier &CS = FS.getConversionSpecifier();
2575 if (FS.consumesDataArgument()) {
2578 usesPositionalArgs = FS.usesPositionalArg();
2580 else if (usesPositionalArgs != FS.usesPositionalArg()) {
2581 HandlePositionalNonpositionalArgs(getLocationOfByte(CS.getStart()),
2582 startSpecifier, specifierLen);
2587 // First check if the field width, precision, and conversion specifier
2588 // have matching data arguments.
2589 if (!HandleAmount(FS.getFieldWidth(), /* field width */ 0,
2590 startSpecifier, specifierLen)) {
2594 if (!HandleAmount(FS.getPrecision(), /* precision */ 1,
2595 startSpecifier, specifierLen)) {
2599 if (!CS.consumesDataArgument()) {
2600 // FIXME: Technically specifying a precision or field width here
2601 // makes no sense. Worth issuing a warning at some point.
2605 // Consume the argument.
2606 unsigned argIndex = FS.getArgIndex();
2607 if (argIndex < NumDataArgs) {
2608 // The check to see if the argIndex is valid will come later.
2609 // We set the bit here because we may exit early from this
2610 // function if we encounter some other error.
2611 CoveredArgs.set(argIndex);
2614 // Check for using an Objective-C specific conversion specifier
2615 // in a non-ObjC literal.
2616 if (!ObjCContext && CS.isObjCArg()) {
2617 return HandleInvalidPrintfConversionSpecifier(FS, startSpecifier,
2621 // Check for invalid use of field width
2622 if (!FS.hasValidFieldWidth()) {
2623 HandleInvalidAmount(FS, FS.getFieldWidth(), /* field width */ 0,
2624 startSpecifier, specifierLen);
2627 // Check for invalid use of precision
2628 if (!FS.hasValidPrecision()) {
2629 HandleInvalidAmount(FS, FS.getPrecision(), /* precision */ 1,
2630 startSpecifier, specifierLen);
2633 // Check each flag does not conflict with any other component.
2634 if (!FS.hasValidThousandsGroupingPrefix())
2635 HandleFlag(FS, FS.hasThousandsGrouping(), startSpecifier, specifierLen);
2636 if (!FS.hasValidLeadingZeros())
2637 HandleFlag(FS, FS.hasLeadingZeros(), startSpecifier, specifierLen);
2638 if (!FS.hasValidPlusPrefix())
2639 HandleFlag(FS, FS.hasPlusPrefix(), startSpecifier, specifierLen);
2640 if (!FS.hasValidSpacePrefix())
2641 HandleFlag(FS, FS.hasSpacePrefix(), startSpecifier, specifierLen);
2642 if (!FS.hasValidAlternativeForm())
2643 HandleFlag(FS, FS.hasAlternativeForm(), startSpecifier, specifierLen);
2644 if (!FS.hasValidLeftJustified())
2645 HandleFlag(FS, FS.isLeftJustified(), startSpecifier, specifierLen);
2647 // Check that flags are not ignored by another flag
2648 if (FS.hasSpacePrefix() && FS.hasPlusPrefix()) // ' ' ignored by '+'
2649 HandleIgnoredFlag(FS, FS.hasSpacePrefix(), FS.hasPlusPrefix(),
2650 startSpecifier, specifierLen);
2651 if (FS.hasLeadingZeros() && FS.isLeftJustified()) // '0' ignored by '-'
2652 HandleIgnoredFlag(FS, FS.hasLeadingZeros(), FS.isLeftJustified(),
2653 startSpecifier, specifierLen);
2655 // Check the length modifier is valid with the given conversion specifier.
2656 if (!FS.hasValidLengthModifier(S.getASTContext().getTargetInfo()))
2657 HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
2658 diag::warn_format_nonsensical_length);
2659 else if (!FS.hasStandardLengthModifier())
2660 HandleNonStandardLengthModifier(FS, startSpecifier, specifierLen);
2661 else if (!FS.hasStandardLengthConversionCombination())
2662 HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
2663 diag::warn_format_non_standard_conversion_spec);
2665 if (!FS.hasStandardConversionSpecifier(S.getLangOpts()))
2666 HandleNonStandardConversionSpecifier(CS, startSpecifier, specifierLen);
2668 // The remaining checks depend on the data arguments.
2672 if (!CheckNumArgs(FS, CS, startSpecifier, specifierLen, argIndex))
2675 const Expr *Arg = getDataArg(argIndex);
2679 return checkFormatExpr(FS, startSpecifier, specifierLen, Arg);
2682 static bool requiresParensToAddCast(const Expr *E) {
2683 // FIXME: We should have a general way to reason about operator
2684 // precedence and whether parens are actually needed here.
2685 // Take care of a few common cases where they aren't.
2686 const Expr *Inside = E->IgnoreImpCasts();
2687 if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(Inside))
2688 Inside = POE->getSyntacticForm()->IgnoreImpCasts();
2690 switch (Inside->getStmtClass()) {
2691 case Stmt::ArraySubscriptExprClass:
2692 case Stmt::CallExprClass:
2693 case Stmt::DeclRefExprClass:
2694 case Stmt::MemberExprClass:
2695 case Stmt::ObjCIvarRefExprClass:
2696 case Stmt::ObjCMessageExprClass:
2697 case Stmt::ObjCPropertyRefExprClass:
2698 case Stmt::ParenExprClass:
2699 case Stmt::UnaryOperatorClass:
2707 CheckPrintfHandler::checkFormatExpr(const analyze_printf::PrintfSpecifier &FS,
2708 const char *StartSpecifier,
2709 unsigned SpecifierLen,
2711 using namespace analyze_format_string;
2712 using namespace analyze_printf;
2713 // Now type check the data expression that matches the
2714 // format specifier.
2715 const analyze_printf::ArgType &AT = FS.getArgType(S.Context,
2720 QualType IntendedTy = E->getType();
2721 if (AT.matchesType(S.Context, IntendedTy))
2724 // Look through argument promotions for our error message's reported type.
2725 // This includes the integral and floating promotions, but excludes array
2726 // and function pointer decay; seeing that an argument intended to be a
2727 // string has type 'char [6]' is probably more confusing than 'char *'.
2728 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2729 if (ICE->getCastKind() == CK_IntegralCast ||
2730 ICE->getCastKind() == CK_FloatingCast) {
2731 E = ICE->getSubExpr();
2732 IntendedTy = E->getType();
2734 // Check if we didn't match because of an implicit cast from a 'char'
2735 // or 'short' to an 'int'. This is done because printf is a varargs
2737 if (ICE->getType() == S.Context.IntTy ||
2738 ICE->getType() == S.Context.UnsignedIntTy) {
2739 // All further checking is done on the subexpression.
2740 if (AT.matchesType(S.Context, IntendedTy))
2746 if (S.Context.getTargetInfo().getTriple().isOSDarwin()) {
2747 // Special-case some of Darwin's platform-independence types.
2748 if (const TypedefType *UserTy = IntendedTy->getAs<TypedefType>()) {
2749 StringRef Name = UserTy->getDecl()->getName();
2750 IntendedTy = llvm::StringSwitch<QualType>(Name)
2751 .Case("NSInteger", S.Context.LongTy)
2752 .Case("NSUInteger", S.Context.UnsignedLongTy)
2753 .Case("SInt32", S.Context.IntTy)
2754 .Case("UInt32", S.Context.UnsignedIntTy)
2755 .Default(IntendedTy);
2759 // We may be able to offer a FixItHint if it is a supported type.
2760 PrintfSpecifier fixedFS = FS;
2761 bool success = fixedFS.fixType(IntendedTy, S.getLangOpts(),
2762 S.Context, ObjCContext);
2765 // Get the fix string from the fixed format specifier
2766 SmallString<16> buf;
2767 llvm::raw_svector_ostream os(buf);
2768 fixedFS.toString(os);
2770 CharSourceRange SpecRange = getSpecifierRange(StartSpecifier, SpecifierLen);
2772 if (IntendedTy != E->getType()) {
2773 // The canonical type for formatting this value is different from the
2774 // actual type of the expression. (This occurs, for example, with Darwin's
2775 // NSInteger on 32-bit platforms, where it is typedef'd as 'int', but
2776 // should be printed as 'long' for 64-bit compatibility.)
2777 // Rather than emitting a normal format/argument mismatch, we want to
2778 // add a cast to the recommended type (and correct the format string
2780 SmallString<16> CastBuf;
2781 llvm::raw_svector_ostream CastFix(CastBuf);
2783 IntendedTy.print(CastFix, S.Context.getPrintingPolicy());
2786 SmallVector<FixItHint,4> Hints;
2787 if (!AT.matchesType(S.Context, IntendedTy))
2788 Hints.push_back(FixItHint::CreateReplacement(SpecRange, os.str()));
2790 if (const CStyleCastExpr *CCast = dyn_cast<CStyleCastExpr>(E)) {
2791 // If there's already a cast present, just replace it.
2792 SourceRange CastRange(CCast->getLParenLoc(), CCast->getRParenLoc());
2793 Hints.push_back(FixItHint::CreateReplacement(CastRange, CastFix.str()));
2795 } else if (!requiresParensToAddCast(E)) {
2796 // If the expression has high enough precedence,
2797 // just write the C-style cast.
2798 Hints.push_back(FixItHint::CreateInsertion(E->getLocStart(),
2801 // Otherwise, add parens around the expression as well as the cast.
2803 Hints.push_back(FixItHint::CreateInsertion(E->getLocStart(),
2806 SourceLocation After = S.PP.getLocForEndOfToken(E->getLocEnd());
2807 Hints.push_back(FixItHint::CreateInsertion(After, ")"));
2810 // We extract the name from the typedef because we don't want to show
2811 // the underlying type in the diagnostic.
2812 const TypedefType *UserTy = cast<TypedefType>(E->getType());
2813 StringRef Name = UserTy->getDecl()->getName();
2815 // Finally, emit the diagnostic.
2816 EmitFormatDiagnostic(S.PDiag(diag::warn_format_argument_needs_cast)
2817 << Name << IntendedTy
2818 << E->getSourceRange(),
2819 E->getLocStart(), /*IsStringLocation=*/false,
2822 EmitFormatDiagnostic(
2823 S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
2824 << AT.getRepresentativeTypeName(S.Context) << IntendedTy
2825 << E->getSourceRange(),
2827 /*IsStringLocation*/false,
2829 FixItHint::CreateReplacement(SpecRange, os.str()));
2832 const CharSourceRange &CSR = getSpecifierRange(StartSpecifier,
2834 // Since the warning for passing non-POD types to variadic functions
2835 // was deferred until now, we emit a warning for non-POD
2837 if (S.isValidVarArgType(E->getType()) == Sema::VAK_Invalid) {
2839 if (E->getType()->isObjCObjectType())
2840 DiagKind = diag::err_cannot_pass_objc_interface_to_vararg_format;
2842 DiagKind = diag::warn_non_pod_vararg_with_format_string;
2844 EmitFormatDiagnostic(
2846 << S.getLangOpts().CPlusPlus0x
2849 << AT.getRepresentativeTypeName(S.Context)
2851 << E->getSourceRange(),
2852 E->getLocStart(), /*IsStringLocation*/false, CSR);
2854 checkForCStrMembers(AT, E, CSR);
2856 EmitFormatDiagnostic(
2857 S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
2858 << AT.getRepresentativeTypeName(S.Context) << E->getType()
2860 << E->getSourceRange(),
2861 E->getLocStart(), /*IsStringLocation*/false, CSR);
2867 //===--- CHECK: Scanf format string checking ------------------------------===//
2870 class CheckScanfHandler : public CheckFormatHandler {
2872 CheckScanfHandler(Sema &s, const StringLiteral *fexpr,
2873 const Expr *origFormatExpr, unsigned firstDataArg,
2874 unsigned numDataArgs, const char *beg, bool hasVAListArg,
2875 Expr **Args, unsigned NumArgs,
2876 unsigned formatIdx, bool inFunctionCall,
2877 Sema::VariadicCallType CallType)
2878 : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg,
2879 numDataArgs, beg, hasVAListArg,
2880 Args, NumArgs, formatIdx, inFunctionCall, CallType)
2883 bool HandleScanfSpecifier(const analyze_scanf::ScanfSpecifier &FS,
2884 const char *startSpecifier,
2885 unsigned specifierLen);
2887 bool HandleInvalidScanfConversionSpecifier(
2888 const analyze_scanf::ScanfSpecifier &FS,
2889 const char *startSpecifier,
2890 unsigned specifierLen);
2892 void HandleIncompleteScanList(const char *start, const char *end);
2896 void CheckScanfHandler::HandleIncompleteScanList(const char *start,
2898 EmitFormatDiagnostic(S.PDiag(diag::warn_scanf_scanlist_incomplete),
2899 getLocationOfByte(end), /*IsStringLocation*/true,
2900 getSpecifierRange(start, end - start));
2903 bool CheckScanfHandler::HandleInvalidScanfConversionSpecifier(
2904 const analyze_scanf::ScanfSpecifier &FS,
2905 const char *startSpecifier,
2906 unsigned specifierLen) {
2908 const analyze_scanf::ScanfConversionSpecifier &CS =
2909 FS.getConversionSpecifier();
2911 return HandleInvalidConversionSpecifier(FS.getArgIndex(),
2912 getLocationOfByte(CS.getStart()),
2913 startSpecifier, specifierLen,
2914 CS.getStart(), CS.getLength());
2917 bool CheckScanfHandler::HandleScanfSpecifier(
2918 const analyze_scanf::ScanfSpecifier &FS,
2919 const char *startSpecifier,
2920 unsigned specifierLen) {
2922 using namespace analyze_scanf;
2923 using namespace analyze_format_string;
2925 const ScanfConversionSpecifier &CS = FS.getConversionSpecifier();
2927 // Handle case where '%' and '*' don't consume an argument. These shouldn't
2928 // be used to decide if we are using positional arguments consistently.
2929 if (FS.consumesDataArgument()) {
2932 usesPositionalArgs = FS.usesPositionalArg();
2934 else if (usesPositionalArgs != FS.usesPositionalArg()) {
2935 HandlePositionalNonpositionalArgs(getLocationOfByte(CS.getStart()),
2936 startSpecifier, specifierLen);
2941 // Check if the field with is non-zero.
2942 const OptionalAmount &Amt = FS.getFieldWidth();
2943 if (Amt.getHowSpecified() == OptionalAmount::Constant) {
2944 if (Amt.getConstantAmount() == 0) {
2945 const CharSourceRange &R = getSpecifierRange(Amt.getStart(),
2946 Amt.getConstantLength());
2947 EmitFormatDiagnostic(S.PDiag(diag::warn_scanf_nonzero_width),
2948 getLocationOfByte(Amt.getStart()),
2949 /*IsStringLocation*/true, R,
2950 FixItHint::CreateRemoval(R));
2954 if (!FS.consumesDataArgument()) {
2955 // FIXME: Technically specifying a precision or field width here
2956 // makes no sense. Worth issuing a warning at some point.
2960 // Consume the argument.
2961 unsigned argIndex = FS.getArgIndex();
2962 if (argIndex < NumDataArgs) {
2963 // The check to see if the argIndex is valid will come later.
2964 // We set the bit here because we may exit early from this
2965 // function if we encounter some other error.
2966 CoveredArgs.set(argIndex);
2969 // Check the length modifier is valid with the given conversion specifier.
2970 if (!FS.hasValidLengthModifier(S.getASTContext().getTargetInfo()))
2971 HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
2972 diag::warn_format_nonsensical_length);
2973 else if (!FS.hasStandardLengthModifier())
2974 HandleNonStandardLengthModifier(FS, startSpecifier, specifierLen);
2975 else if (!FS.hasStandardLengthConversionCombination())
2976 HandleInvalidLengthModifier(FS, CS, startSpecifier, specifierLen,
2977 diag::warn_format_non_standard_conversion_spec);
2979 if (!FS.hasStandardConversionSpecifier(S.getLangOpts()))
2980 HandleNonStandardConversionSpecifier(CS, startSpecifier, specifierLen);
2982 // The remaining checks depend on the data arguments.
2986 if (!CheckNumArgs(FS, CS, startSpecifier, specifierLen, argIndex))
2989 // Check that the argument type matches the format specifier.
2990 const Expr *Ex = getDataArg(argIndex);
2994 const analyze_format_string::ArgType &AT = FS.getArgType(S.Context);
2995 if (AT.isValid() && !AT.matchesType(S.Context, Ex->getType())) {
2996 ScanfSpecifier fixedFS = FS;
2997 bool success = fixedFS.fixType(Ex->getType(), S.getLangOpts(),
3001 // Get the fix string from the fixed format specifier.
3002 SmallString<128> buf;
3003 llvm::raw_svector_ostream os(buf);
3004 fixedFS.toString(os);
3006 EmitFormatDiagnostic(
3007 S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
3008 << AT.getRepresentativeTypeName(S.Context) << Ex->getType()
3009 << Ex->getSourceRange(),
3011 /*IsStringLocation*/false,
3012 getSpecifierRange(startSpecifier, specifierLen),
3013 FixItHint::CreateReplacement(
3014 getSpecifierRange(startSpecifier, specifierLen),
3017 EmitFormatDiagnostic(
3018 S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
3019 << AT.getRepresentativeTypeName(S.Context) << Ex->getType()
3020 << Ex->getSourceRange(),
3022 /*IsStringLocation*/false,
3023 getSpecifierRange(startSpecifier, specifierLen));
3030 void Sema::CheckFormatString(const StringLiteral *FExpr,
3031 const Expr *OrigFormatExpr,
3032 Expr **Args, unsigned NumArgs,
3033 bool HasVAListArg, unsigned format_idx,
3034 unsigned firstDataArg, FormatStringType Type,
3035 bool inFunctionCall, VariadicCallType CallType) {
3037 // CHECK: is the format string a wide literal?
3038 if (!FExpr->isAscii() && !FExpr->isUTF8()) {
3039 CheckFormatHandler::EmitFormatDiagnostic(
3040 *this, inFunctionCall, Args[format_idx],
3041 PDiag(diag::warn_format_string_is_wide_literal), FExpr->getLocStart(),
3042 /*IsStringLocation*/true, OrigFormatExpr->getSourceRange());
3046 // Str - The format string. NOTE: this is NOT null-terminated!
3047 StringRef StrRef = FExpr->getString();
3048 const char *Str = StrRef.data();
3049 unsigned StrLen = StrRef.size();
3050 const unsigned numDataArgs = NumArgs - firstDataArg;
3052 // CHECK: empty format string?
3053 if (StrLen == 0 && numDataArgs > 0) {
3054 CheckFormatHandler::EmitFormatDiagnostic(
3055 *this, inFunctionCall, Args[format_idx],
3056 PDiag(diag::warn_empty_format_string), FExpr->getLocStart(),
3057 /*IsStringLocation*/true, OrigFormatExpr->getSourceRange());
3061 if (Type == FST_Printf || Type == FST_NSString) {
3062 CheckPrintfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg,
3063 numDataArgs, (Type == FST_NSString),
3064 Str, HasVAListArg, Args, NumArgs, format_idx,
3065 inFunctionCall, CallType);
3067 if (!analyze_format_string::ParsePrintfString(H, Str, Str + StrLen,
3069 Context.getTargetInfo()))
3071 } else if (Type == FST_Scanf) {
3072 CheckScanfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg, numDataArgs,
3073 Str, HasVAListArg, Args, NumArgs, format_idx,
3074 inFunctionCall, CallType);
3076 if (!analyze_format_string::ParseScanfString(H, Str, Str + StrLen,
3078 Context.getTargetInfo()))
3080 } // TODO: handle other formats
3083 //===--- CHECK: Standard memory functions ---------------------------------===//
3085 /// \brief Determine whether the given type is a dynamic class type (e.g.,
3086 /// whether it has a vtable).
3087 static bool isDynamicClassType(QualType T) {
3088 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
3089 if (CXXRecordDecl *Definition = Record->getDefinition())
3090 if (Definition->isDynamicClass())
3096 /// \brief If E is a sizeof expression, returns its argument expression,
3097 /// otherwise returns NULL.
3098 static const Expr *getSizeOfExprArg(const Expr* E) {
3099 if (const UnaryExprOrTypeTraitExpr *SizeOf =
3100 dyn_cast<UnaryExprOrTypeTraitExpr>(E))
3101 if (SizeOf->getKind() == clang::UETT_SizeOf && !SizeOf->isArgumentType())
3102 return SizeOf->getArgumentExpr()->IgnoreParenImpCasts();
3107 /// \brief If E is a sizeof expression, returns its argument type.
3108 static QualType getSizeOfArgType(const Expr* E) {
3109 if (const UnaryExprOrTypeTraitExpr *SizeOf =
3110 dyn_cast<UnaryExprOrTypeTraitExpr>(E))
3111 if (SizeOf->getKind() == clang::UETT_SizeOf)
3112 return SizeOf->getTypeOfArgument();
3117 /// \brief Check for dangerous or invalid arguments to memset().
3119 /// This issues warnings on known problematic, dangerous or unspecified
3120 /// arguments to the standard 'memset', 'memcpy', 'memmove', and 'memcmp'
3123 /// \param Call The call expression to diagnose.
3124 void Sema::CheckMemaccessArguments(const CallExpr *Call,
3126 IdentifierInfo *FnName) {
3129 // It is possible to have a non-standard definition of memset. Validate
3130 // we have enough arguments, and if not, abort further checking.
3131 unsigned ExpectedNumArgs = (BId == Builtin::BIstrndup ? 2 : 3);
3132 if (Call->getNumArgs() < ExpectedNumArgs)
3135 unsigned LastArg = (BId == Builtin::BImemset ||
3136 BId == Builtin::BIstrndup ? 1 : 2);
3137 unsigned LenArg = (BId == Builtin::BIstrndup ? 1 : 2);
3138 const Expr *LenExpr = Call->getArg(LenArg)->IgnoreParenImpCasts();
3140 // We have special checking when the length is a sizeof expression.
3141 QualType SizeOfArgTy = getSizeOfArgType(LenExpr);
3142 const Expr *SizeOfArg = getSizeOfExprArg(LenExpr);
3143 llvm::FoldingSetNodeID SizeOfArgID;
3145 for (unsigned ArgIdx = 0; ArgIdx != LastArg; ++ArgIdx) {
3146 const Expr *Dest = Call->getArg(ArgIdx)->IgnoreParenImpCasts();
3147 SourceRange ArgRange = Call->getArg(ArgIdx)->getSourceRange();
3149 QualType DestTy = Dest->getType();
3150 if (const PointerType *DestPtrTy = DestTy->getAs<PointerType>()) {
3151 QualType PointeeTy = DestPtrTy->getPointeeType();
3153 // Never warn about void type pointers. This can be used to suppress
3155 if (PointeeTy->isVoidType())
3158 // Catch "memset(p, 0, sizeof(p))" -- needs to be sizeof(*p). Do this by
3159 // actually comparing the expressions for equality. Because computing the
3160 // expression IDs can be expensive, we only do this if the diagnostic is
3163 Diags.getDiagnosticLevel(diag::warn_sizeof_pointer_expr_memaccess,
3164 SizeOfArg->getExprLoc())) {
3165 // We only compute IDs for expressions if the warning is enabled, and
3166 // cache the sizeof arg's ID.
3167 if (SizeOfArgID == llvm::FoldingSetNodeID())
3168 SizeOfArg->Profile(SizeOfArgID, Context, true);
3169 llvm::FoldingSetNodeID DestID;
3170 Dest->Profile(DestID, Context, true);
3171 if (DestID == SizeOfArgID) {
3172 // TODO: For strncpy() and friends, this could suggest sizeof(dst)
3173 // over sizeof(src) as well.
3174 unsigned ActionIdx = 0; // Default is to suggest dereferencing.
3175 StringRef ReadableName = FnName->getName();
3177 if (const UnaryOperator *UnaryOp = dyn_cast<UnaryOperator>(Dest))
3178 if (UnaryOp->getOpcode() == UO_AddrOf)
3179 ActionIdx = 1; // If its an address-of operator, just remove it.
3180 if (Context.getTypeSize(PointeeTy) == Context.getCharWidth())
3181 ActionIdx = 2; // If the pointee's size is sizeof(char),
3182 // suggest an explicit length.
3184 // If the function is defined as a builtin macro, do not show macro
3186 SourceLocation SL = SizeOfArg->getExprLoc();
3187 SourceRange DSR = Dest->getSourceRange();
3188 SourceRange SSR = SizeOfArg->getSourceRange();
3189 SourceManager &SM = PP.getSourceManager();
3191 if (SM.isMacroArgExpansion(SL)) {
3192 ReadableName = Lexer::getImmediateMacroName(SL, SM, LangOpts);
3193 SL = SM.getSpellingLoc(SL);
3194 DSR = SourceRange(SM.getSpellingLoc(DSR.getBegin()),
3195 SM.getSpellingLoc(DSR.getEnd()));
3196 SSR = SourceRange(SM.getSpellingLoc(SSR.getBegin()),
3197 SM.getSpellingLoc(SSR.getEnd()));
3200 DiagRuntimeBehavior(SL, SizeOfArg,
3201 PDiag(diag::warn_sizeof_pointer_expr_memaccess)
3207 DiagRuntimeBehavior(SL, SizeOfArg,
3208 PDiag(diag::warn_sizeof_pointer_expr_memaccess_note)
3216 // Also check for cases where the sizeof argument is the exact same
3217 // type as the memory argument, and where it points to a user-defined
3219 if (SizeOfArgTy != QualType()) {
3220 if (PointeeTy->isRecordType() &&
3221 Context.typesAreCompatible(SizeOfArgTy, DestTy)) {
3222 DiagRuntimeBehavior(LenExpr->getExprLoc(), Dest,
3223 PDiag(diag::warn_sizeof_pointer_type_memaccess)
3224 << FnName << SizeOfArgTy << ArgIdx
3225 << PointeeTy << Dest->getSourceRange()
3226 << LenExpr->getSourceRange());
3231 // Always complain about dynamic classes.
3232 if (isDynamicClassType(PointeeTy)) {
3234 unsigned OperationType = 0;
3235 // "overwritten" if we're warning about the destination for any call
3236 // but memcmp; otherwise a verb appropriate to the call.
3237 if (ArgIdx != 0 || BId == Builtin::BImemcmp) {
3238 if (BId == Builtin::BImemcpy)
3240 else if(BId == Builtin::BImemmove)
3242 else if (BId == Builtin::BImemcmp)
3246 DiagRuntimeBehavior(
3247 Dest->getExprLoc(), Dest,
3248 PDiag(diag::warn_dyn_class_memaccess)
3249 << (BId == Builtin::BImemcmp ? ArgIdx + 2 : ArgIdx)
3250 << FnName << PointeeTy
3252 << Call->getCallee()->getSourceRange());
3253 } else if (PointeeTy.hasNonTrivialObjCLifetime() &&
3254 BId != Builtin::BImemset)
3255 DiagRuntimeBehavior(
3256 Dest->getExprLoc(), Dest,
3257 PDiag(diag::warn_arc_object_memaccess)
3258 << ArgIdx << FnName << PointeeTy
3259 << Call->getCallee()->getSourceRange());
3263 DiagRuntimeBehavior(
3264 Dest->getExprLoc(), Dest,
3265 PDiag(diag::note_bad_memaccess_silence)
3266 << FixItHint::CreateInsertion(ArgRange.getBegin(), "(void*)"));
3272 // A little helper routine: ignore addition and subtraction of integer literals.
3273 // This intentionally does not ignore all integer constant expressions because
3274 // we don't want to remove sizeof().
3275 static const Expr *ignoreLiteralAdditions(const Expr *Ex, ASTContext &Ctx) {
3276 Ex = Ex->IgnoreParenCasts();
3279 const BinaryOperator * BO = dyn_cast<BinaryOperator>(Ex);
3280 if (!BO || !BO->isAdditiveOp())
3283 const Expr *RHS = BO->getRHS()->IgnoreParenCasts();
3284 const Expr *LHS = BO->getLHS()->IgnoreParenCasts();
3286 if (isa<IntegerLiteral>(RHS))
3288 else if (isa<IntegerLiteral>(LHS))
3297 static bool isConstantSizeArrayWithMoreThanOneElement(QualType Ty,
3298 ASTContext &Context) {
3299 // Only handle constant-sized or VLAs, but not flexible members.
3300 if (const ConstantArrayType *CAT = Context.getAsConstantArrayType(Ty)) {
3301 // Only issue the FIXIT for arrays of size > 1.
3302 if (CAT->getSize().getSExtValue() <= 1)
3304 } else if (!Ty->isVariableArrayType()) {
3310 // Warn if the user has made the 'size' argument to strlcpy or strlcat
3311 // be the size of the source, instead of the destination.
3312 void Sema::CheckStrlcpycatArguments(const CallExpr *Call,
3313 IdentifierInfo *FnName) {
3315 // Don't crash if the user has the wrong number of arguments
3316 if (Call->getNumArgs() != 3)
3319 const Expr *SrcArg = ignoreLiteralAdditions(Call->getArg(1), Context);
3320 const Expr *SizeArg = ignoreLiteralAdditions(Call->getArg(2), Context);
3321 const Expr *CompareWithSrc = NULL;
3323 // Look for 'strlcpy(dst, x, sizeof(x))'
3324 if (const Expr *Ex = getSizeOfExprArg(SizeArg))
3325 CompareWithSrc = Ex;
3327 // Look for 'strlcpy(dst, x, strlen(x))'
3328 if (const CallExpr *SizeCall = dyn_cast<CallExpr>(SizeArg)) {
3329 if (SizeCall->isBuiltinCall() == Builtin::BIstrlen
3330 && SizeCall->getNumArgs() == 1)
3331 CompareWithSrc = ignoreLiteralAdditions(SizeCall->getArg(0), Context);
3335 if (!CompareWithSrc)
3338 // Determine if the argument to sizeof/strlen is equal to the source
3339 // argument. In principle there's all kinds of things you could do
3340 // here, for instance creating an == expression and evaluating it with
3341 // EvaluateAsBooleanCondition, but this uses a more direct technique:
3342 const DeclRefExpr *SrcArgDRE = dyn_cast<DeclRefExpr>(SrcArg);
3346 const DeclRefExpr *CompareWithSrcDRE = dyn_cast<DeclRefExpr>(CompareWithSrc);
3347 if (!CompareWithSrcDRE ||
3348 SrcArgDRE->getDecl() != CompareWithSrcDRE->getDecl())
3351 const Expr *OriginalSizeArg = Call->getArg(2);
3352 Diag(CompareWithSrcDRE->getLocStart(), diag::warn_strlcpycat_wrong_size)
3353 << OriginalSizeArg->getSourceRange() << FnName;
3355 // Output a FIXIT hint if the destination is an array (rather than a
3356 // pointer to an array). This could be enhanced to handle some
3357 // pointers if we know the actual size, like if DstArg is 'array+2'
3358 // we could say 'sizeof(array)-2'.
3359 const Expr *DstArg = Call->getArg(0)->IgnoreParenImpCasts();
3360 if (!isConstantSizeArrayWithMoreThanOneElement(DstArg->getType(), Context))
3363 SmallString<128> sizeString;
3364 llvm::raw_svector_ostream OS(sizeString);
3366 DstArg->printPretty(OS, 0, getPrintingPolicy());
3369 Diag(OriginalSizeArg->getLocStart(), diag::note_strlcpycat_wrong_size)
3370 << FixItHint::CreateReplacement(OriginalSizeArg->getSourceRange(),
3374 /// Check if two expressions refer to the same declaration.
3375 static bool referToTheSameDecl(const Expr *E1, const Expr *E2) {
3376 if (const DeclRefExpr *D1 = dyn_cast_or_null<DeclRefExpr>(E1))
3377 if (const DeclRefExpr *D2 = dyn_cast_or_null<DeclRefExpr>(E2))
3378 return D1->getDecl() == D2->getDecl();
3382 static const Expr *getStrlenExprArg(const Expr *E) {
3383 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
3384 const FunctionDecl *FD = CE->getDirectCallee();
3385 if (!FD || FD->getMemoryFunctionKind() != Builtin::BIstrlen)
3387 return CE->getArg(0)->IgnoreParenCasts();
3392 // Warn on anti-patterns as the 'size' argument to strncat.
3393 // The correct size argument should look like following:
3394 // strncat(dst, src, sizeof(dst) - strlen(dest) - 1);
3395 void Sema::CheckStrncatArguments(const CallExpr *CE,
3396 IdentifierInfo *FnName) {
3397 // Don't crash if the user has the wrong number of arguments.
3398 if (CE->getNumArgs() < 3)
3400 const Expr *DstArg = CE->getArg(0)->IgnoreParenCasts();
3401 const Expr *SrcArg = CE->getArg(1)->IgnoreParenCasts();
3402 const Expr *LenArg = CE->getArg(2)->IgnoreParenCasts();
3404 // Identify common expressions, which are wrongly used as the size argument
3405 // to strncat and may lead to buffer overflows.
3406 unsigned PatternType = 0;
3407 if (const Expr *SizeOfArg = getSizeOfExprArg(LenArg)) {
3409 if (referToTheSameDecl(SizeOfArg, DstArg))
3412 else if (referToTheSameDecl(SizeOfArg, SrcArg))
3414 } else if (const BinaryOperator *BE = dyn_cast<BinaryOperator>(LenArg)) {
3415 if (BE->getOpcode() == BO_Sub) {
3416 const Expr *L = BE->getLHS()->IgnoreParenCasts();
3417 const Expr *R = BE->getRHS()->IgnoreParenCasts();
3418 // - sizeof(dst) - strlen(dst)
3419 if (referToTheSameDecl(DstArg, getSizeOfExprArg(L)) &&
3420 referToTheSameDecl(DstArg, getStrlenExprArg(R)))
3422 // - sizeof(src) - (anything)
3423 else if (referToTheSameDecl(SrcArg, getSizeOfExprArg(L)))
3428 if (PatternType == 0)
3431 // Generate the diagnostic.
3432 SourceLocation SL = LenArg->getLocStart();
3433 SourceRange SR = LenArg->getSourceRange();
3434 SourceManager &SM = PP.getSourceManager();
3436 // If the function is defined as a builtin macro, do not show macro expansion.
3437 if (SM.isMacroArgExpansion(SL)) {
3438 SL = SM.getSpellingLoc(SL);
3439 SR = SourceRange(SM.getSpellingLoc(SR.getBegin()),
3440 SM.getSpellingLoc(SR.getEnd()));
3443 // Check if the destination is an array (rather than a pointer to an array).
3444 QualType DstTy = DstArg->getType();
3445 bool isKnownSizeArray = isConstantSizeArrayWithMoreThanOneElement(DstTy,
3447 if (!isKnownSizeArray) {
3448 if (PatternType == 1)
3449 Diag(SL, diag::warn_strncat_wrong_size) << SR;
3451 Diag(SL, diag::warn_strncat_src_size) << SR;
3455 if (PatternType == 1)
3456 Diag(SL, diag::warn_strncat_large_size) << SR;
3458 Diag(SL, diag::warn_strncat_src_size) << SR;
3460 SmallString<128> sizeString;
3461 llvm::raw_svector_ostream OS(sizeString);
3463 DstArg->printPretty(OS, 0, getPrintingPolicy());
3466 DstArg->printPretty(OS, 0, getPrintingPolicy());
3469 Diag(SL, diag::note_strncat_wrong_size)
3470 << FixItHint::CreateReplacement(SR, OS.str());
3473 //===--- CHECK: Return Address of Stack Variable --------------------------===//
3475 static Expr *EvalVal(Expr *E, SmallVectorImpl<DeclRefExpr *> &refVars,
3477 static Expr *EvalAddr(Expr* E, SmallVectorImpl<DeclRefExpr *> &refVars,
3480 /// CheckReturnStackAddr - Check if a return statement returns the address
3481 /// of a stack variable.
3483 Sema::CheckReturnStackAddr(Expr *RetValExp, QualType lhsType,
3484 SourceLocation ReturnLoc) {
3487 SmallVector<DeclRefExpr *, 8> refVars;
3489 // Perform checking for returned stack addresses, local blocks,
3490 // label addresses or references to temporaries.
3491 if (lhsType->isPointerType() ||
3492 (!getLangOpts().ObjCAutoRefCount && lhsType->isBlockPointerType())) {
3493 stackE = EvalAddr(RetValExp, refVars, /*ParentDecl=*/0);
3494 } else if (lhsType->isReferenceType()) {
3495 stackE = EvalVal(RetValExp, refVars, /*ParentDecl=*/0);
3499 return; // Nothing suspicious was found.
3501 SourceLocation diagLoc;
3502 SourceRange diagRange;
3503 if (refVars.empty()) {
3504 diagLoc = stackE->getLocStart();
3505 diagRange = stackE->getSourceRange();
3507 // We followed through a reference variable. 'stackE' contains the
3508 // problematic expression but we will warn at the return statement pointing
3509 // at the reference variable. We will later display the "trail" of
3510 // reference variables using notes.
3511 diagLoc = refVars[0]->getLocStart();
3512 diagRange = refVars[0]->getSourceRange();
3515 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(stackE)) { //address of local var.
3516 Diag(diagLoc, lhsType->isReferenceType() ? diag::warn_ret_stack_ref
3517 : diag::warn_ret_stack_addr)
3518 << DR->getDecl()->getDeclName() << diagRange;
3519 } else if (isa<BlockExpr>(stackE)) { // local block.
3520 Diag(diagLoc, diag::err_ret_local_block) << diagRange;
3521 } else if (isa<AddrLabelExpr>(stackE)) { // address of label.
3522 Diag(diagLoc, diag::warn_ret_addr_label) << diagRange;
3523 } else { // local temporary.
3524 Diag(diagLoc, lhsType->isReferenceType() ? diag::warn_ret_local_temp_ref
3525 : diag::warn_ret_local_temp_addr)
3529 // Display the "trail" of reference variables that we followed until we
3530 // found the problematic expression using notes.
3531 for (unsigned i = 0, e = refVars.size(); i != e; ++i) {
3532 VarDecl *VD = cast<VarDecl>(refVars[i]->getDecl());
3533 // If this var binds to another reference var, show the range of the next
3534 // var, otherwise the var binds to the problematic expression, in which case
3535 // show the range of the expression.
3536 SourceRange range = (i < e-1) ? refVars[i+1]->getSourceRange()
3537 : stackE->getSourceRange();
3538 Diag(VD->getLocation(), diag::note_ref_var_local_bind)
3539 << VD->getDeclName() << range;
3543 /// EvalAddr - EvalAddr and EvalVal are mutually recursive functions that
3544 /// check if the expression in a return statement evaluates to an address
3545 /// to a location on the stack, a local block, an address of a label, or a
3546 /// reference to local temporary. The recursion is used to traverse the
3547 /// AST of the return expression, with recursion backtracking when we
3548 /// encounter a subexpression that (1) clearly does not lead to one of the
3549 /// above problematic expressions (2) is something we cannot determine leads to
3550 /// a problematic expression based on such local checking.
3552 /// Both EvalAddr and EvalVal follow through reference variables to evaluate
3553 /// the expression that they point to. Such variables are added to the
3554 /// 'refVars' vector so that we know what the reference variable "trail" was.
3556 /// EvalAddr processes expressions that are pointers that are used as
3557 /// references (and not L-values). EvalVal handles all other values.
3558 /// At the base case of the recursion is a check for the above problematic
3561 /// This implementation handles:
3563 /// * pointer-to-pointer casts
3564 /// * implicit conversions from array references to pointers
3565 /// * taking the address of fields
3566 /// * arbitrary interplay between "&" and "*" operators
3567 /// * pointer arithmetic from an address of a stack variable
3568 /// * taking the address of an array element where the array is on the stack
3569 static Expr *EvalAddr(Expr *E, SmallVectorImpl<DeclRefExpr *> &refVars,
3571 if (E->isTypeDependent())
3574 // We should only be called for evaluating pointer expressions.
3575 assert((E->getType()->isAnyPointerType() ||
3576 E->getType()->isBlockPointerType() ||
3577 E->getType()->isObjCQualifiedIdType()) &&
3578 "EvalAddr only works on pointers");
3580 E = E->IgnoreParens();
3582 // Our "symbolic interpreter" is just a dispatch off the currently
3583 // viewed AST node. We then recursively traverse the AST by calling
3584 // EvalAddr and EvalVal appropriately.
3585 switch (E->getStmtClass()) {
3586 case Stmt::DeclRefExprClass: {
3587 DeclRefExpr *DR = cast<DeclRefExpr>(E);
3589 if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl()))
3590 // If this is a reference variable, follow through to the expression that
3592 if (V->hasLocalStorage() &&
3593 V->getType()->isReferenceType() && V->hasInit()) {
3594 // Add the reference variable to the "trail".
3595 refVars.push_back(DR);
3596 return EvalAddr(V->getInit(), refVars, ParentDecl);
3602 case Stmt::UnaryOperatorClass: {
3603 // The only unary operator that make sense to handle here
3604 // is AddrOf. All others don't make sense as pointers.
3605 UnaryOperator *U = cast<UnaryOperator>(E);
3607 if (U->getOpcode() == UO_AddrOf)
3608 return EvalVal(U->getSubExpr(), refVars, ParentDecl);
3613 case Stmt::BinaryOperatorClass: {
3614 // Handle pointer arithmetic. All other binary operators are not valid
3616 BinaryOperator *B = cast<BinaryOperator>(E);
3617 BinaryOperatorKind op = B->getOpcode();
3619 if (op != BO_Add && op != BO_Sub)
3622 Expr *Base = B->getLHS();
3624 // Determine which argument is the real pointer base. It could be
3625 // the RHS argument instead of the LHS.
3626 if (!Base->getType()->isPointerType()) Base = B->getRHS();
3628 assert (Base->getType()->isPointerType());
3629 return EvalAddr(Base, refVars, ParentDecl);
3632 // For conditional operators we need to see if either the LHS or RHS are
3633 // valid DeclRefExpr*s. If one of them is valid, we return it.
3634 case Stmt::ConditionalOperatorClass: {
3635 ConditionalOperator *C = cast<ConditionalOperator>(E);
3637 // Handle the GNU extension for missing LHS.
3638 if (Expr *lhsExpr = C->getLHS()) {
3639 // In C++, we can have a throw-expression, which has 'void' type.
3640 if (!lhsExpr->getType()->isVoidType())
3641 if (Expr* LHS = EvalAddr(lhsExpr, refVars, ParentDecl))
3645 // In C++, we can have a throw-expression, which has 'void' type.
3646 if (C->getRHS()->getType()->isVoidType())
3649 return EvalAddr(C->getRHS(), refVars, ParentDecl);
3652 case Stmt::BlockExprClass:
3653 if (cast<BlockExpr>(E)->getBlockDecl()->hasCaptures())
3654 return E; // local block.
3657 case Stmt::AddrLabelExprClass:
3658 return E; // address of label.
3660 case Stmt::ExprWithCleanupsClass:
3661 return EvalAddr(cast<ExprWithCleanups>(E)->getSubExpr(), refVars,
3664 // For casts, we need to handle conversions from arrays to
3665 // pointer values, and pointer-to-pointer conversions.
3666 case Stmt::ImplicitCastExprClass:
3667 case Stmt::CStyleCastExprClass:
3668 case Stmt::CXXFunctionalCastExprClass:
3669 case Stmt::ObjCBridgedCastExprClass:
3670 case Stmt::CXXStaticCastExprClass:
3671 case Stmt::CXXDynamicCastExprClass:
3672 case Stmt::CXXConstCastExprClass:
3673 case Stmt::CXXReinterpretCastExprClass: {
3674 Expr* SubExpr = cast<CastExpr>(E)->getSubExpr();
3675 switch (cast<CastExpr>(E)->getCastKind()) {
3677 case CK_LValueToRValue:
3679 case CK_BaseToDerived:
3680 case CK_DerivedToBase:
3681 case CK_UncheckedDerivedToBase:
3683 case CK_CPointerToObjCPointerCast:
3684 case CK_BlockPointerToObjCPointerCast:
3685 case CK_AnyPointerToBlockPointerCast:
3686 return EvalAddr(SubExpr, refVars, ParentDecl);
3688 case CK_ArrayToPointerDecay:
3689 return EvalVal(SubExpr, refVars, ParentDecl);
3696 case Stmt::MaterializeTemporaryExprClass:
3697 if (Expr *Result = EvalAddr(
3698 cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr(),
3699 refVars, ParentDecl))
3704 // Everything else: we simply don't reason about them.
3711 /// EvalVal - This function is complements EvalAddr in the mutual recursion.
3712 /// See the comments for EvalAddr for more details.
3713 static Expr *EvalVal(Expr *E, SmallVectorImpl<DeclRefExpr *> &refVars,
3716 // We should only be called for evaluating non-pointer expressions, or
3717 // expressions with a pointer type that are not used as references but instead
3718 // are l-values (e.g., DeclRefExpr with a pointer type).
3720 // Our "symbolic interpreter" is just a dispatch off the currently
3721 // viewed AST node. We then recursively traverse the AST by calling
3722 // EvalAddr and EvalVal appropriately.
3724 E = E->IgnoreParens();
3725 switch (E->getStmtClass()) {
3726 case Stmt::ImplicitCastExprClass: {
3727 ImplicitCastExpr *IE = cast<ImplicitCastExpr>(E);
3728 if (IE->getValueKind() == VK_LValue) {
3729 E = IE->getSubExpr();
3735 case Stmt::ExprWithCleanupsClass:
3736 return EvalVal(cast<ExprWithCleanups>(E)->getSubExpr(), refVars,ParentDecl);
3738 case Stmt::DeclRefExprClass: {
3739 // When we hit a DeclRefExpr we are looking at code that refers to a
3740 // variable's name. If it's not a reference variable we check if it has
3741 // local storage within the function, and if so, return the expression.
3742 DeclRefExpr *DR = cast<DeclRefExpr>(E);
3744 if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl())) {
3745 // Check if it refers to itself, e.g. "int& i = i;".
3746 if (V == ParentDecl)
3749 if (V->hasLocalStorage()) {
3750 if (!V->getType()->isReferenceType())
3753 // Reference variable, follow through to the expression that
3756 // Add the reference variable to the "trail".
3757 refVars.push_back(DR);
3758 return EvalVal(V->getInit(), refVars, V);
3766 case Stmt::UnaryOperatorClass: {
3767 // The only unary operator that make sense to handle here
3768 // is Deref. All others don't resolve to a "name." This includes
3769 // handling all sorts of rvalues passed to a unary operator.
3770 UnaryOperator *U = cast<UnaryOperator>(E);
3772 if (U->getOpcode() == UO_Deref)
3773 return EvalAddr(U->getSubExpr(), refVars, ParentDecl);
3778 case Stmt::ArraySubscriptExprClass: {
3779 // Array subscripts are potential references to data on the stack. We
3780 // retrieve the DeclRefExpr* for the array variable if it indeed
3781 // has local storage.
3782 return EvalAddr(cast<ArraySubscriptExpr>(E)->getBase(), refVars,ParentDecl);
3785 case Stmt::ConditionalOperatorClass: {
3786 // For conditional operators we need to see if either the LHS or RHS are
3787 // non-NULL Expr's. If one is non-NULL, we return it.
3788 ConditionalOperator *C = cast<ConditionalOperator>(E);
3790 // Handle the GNU extension for missing LHS.
3791 if (Expr *lhsExpr = C->getLHS())
3792 if (Expr *LHS = EvalVal(lhsExpr, refVars, ParentDecl))
3795 return EvalVal(C->getRHS(), refVars, ParentDecl);
3798 // Accesses to members are potential references to data on the stack.
3799 case Stmt::MemberExprClass: {
3800 MemberExpr *M = cast<MemberExpr>(E);
3802 // Check for indirect access. We only want direct field accesses.
3806 // Check whether the member type is itself a reference, in which case
3807 // we're not going to refer to the member, but to what the member refers to.
3808 if (M->getMemberDecl()->getType()->isReferenceType())
3811 return EvalVal(M->getBase(), refVars, ParentDecl);
3814 case Stmt::MaterializeTemporaryExprClass:
3815 if (Expr *Result = EvalVal(
3816 cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr(),
3817 refVars, ParentDecl))
3823 // Check that we don't return or take the address of a reference to a
3824 // temporary. This is only useful in C++.
3825 if (!E->isTypeDependent() && E->isRValue())
3828 // Everything else: we simply don't reason about them.
3834 //===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===//
3836 /// Check for comparisons of floating point operands using != and ==.
3837 /// Issue a warning if these are no self-comparisons, as they are not likely
3838 /// to do what the programmer intended.
3839 void Sema::CheckFloatComparison(SourceLocation Loc, Expr* LHS, Expr *RHS) {
3840 Expr* LeftExprSansParen = LHS->IgnoreParenImpCasts();
3841 Expr* RightExprSansParen = RHS->IgnoreParenImpCasts();
3843 // Special case: check for x == x (which is OK).
3844 // Do not emit warnings for such cases.
3845 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LeftExprSansParen))
3846 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RightExprSansParen))
3847 if (DRL->getDecl() == DRR->getDecl())
3851 // Special case: check for comparisons against literals that can be exactly
3852 // represented by APFloat. In such cases, do not emit a warning. This
3853 // is a heuristic: often comparison against such literals are used to
3854 // detect if a value in a variable has not changed. This clearly can
3855 // lead to false negatives.
3856 if (FloatingLiteral* FLL = dyn_cast<FloatingLiteral>(LeftExprSansParen)) {
3860 if (FloatingLiteral* FLR = dyn_cast<FloatingLiteral>(RightExprSansParen))
3864 // Check for comparisons with builtin types.
3865 if (CallExpr* CL = dyn_cast<CallExpr>(LeftExprSansParen))
3866 if (CL->isBuiltinCall())
3869 if (CallExpr* CR = dyn_cast<CallExpr>(RightExprSansParen))
3870 if (CR->isBuiltinCall())
3873 // Emit the diagnostic.
3874 Diag(Loc, diag::warn_floatingpoint_eq)
3875 << LHS->getSourceRange() << RHS->getSourceRange();
3878 //===--- CHECK: Integer mixed-sign comparisons (-Wsign-compare) --------===//
3879 //===--- CHECK: Lossy implicit conversions (-Wconversion) --------------===//
3883 /// Structure recording the 'active' range of an integer-valued
3886 /// The number of bits active in the int.
3889 /// True if the int is known not to have negative values.
3892 IntRange(unsigned Width, bool NonNegative)
3893 : Width(Width), NonNegative(NonNegative)
3896 /// Returns the range of the bool type.
3897 static IntRange forBoolType() {
3898 return IntRange(1, true);
3901 /// Returns the range of an opaque value of the given integral type.
3902 static IntRange forValueOfType(ASTContext &C, QualType T) {
3903 return forValueOfCanonicalType(C,
3904 T->getCanonicalTypeInternal().getTypePtr());
3907 /// Returns the range of an opaque value of a canonical integral type.
3908 static IntRange forValueOfCanonicalType(ASTContext &C, const Type *T) {
3909 assert(T->isCanonicalUnqualified());
3911 if (const VectorType *VT = dyn_cast<VectorType>(T))
3912 T = VT->getElementType().getTypePtr();
3913 if (const ComplexType *CT = dyn_cast<ComplexType>(T))
3914 T = CT->getElementType().getTypePtr();
3916 // For enum types, use the known bit width of the enumerators.
3917 if (const EnumType *ET = dyn_cast<EnumType>(T)) {
3918 EnumDecl *Enum = ET->getDecl();
3919 if (!Enum->isCompleteDefinition())
3920 return IntRange(C.getIntWidth(QualType(T, 0)), false);
3922 unsigned NumPositive = Enum->getNumPositiveBits();
3923 unsigned NumNegative = Enum->getNumNegativeBits();
3925 return IntRange(std::max(NumPositive, NumNegative), NumNegative == 0);
3928 const BuiltinType *BT = cast<BuiltinType>(T);
3929 assert(BT->isInteger());
3931 return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger());
3934 /// Returns the "target" range of a canonical integral type, i.e.
3935 /// the range of values expressible in the type.
3937 /// This matches forValueOfCanonicalType except that enums have the
3938 /// full range of their type, not the range of their enumerators.
3939 static IntRange forTargetOfCanonicalType(ASTContext &C, const Type *T) {
3940 assert(T->isCanonicalUnqualified());
3942 if (const VectorType *VT = dyn_cast<VectorType>(T))
3943 T = VT->getElementType().getTypePtr();
3944 if (const ComplexType *CT = dyn_cast<ComplexType>(T))
3945 T = CT->getElementType().getTypePtr();
3946 if (const EnumType *ET = dyn_cast<EnumType>(T))
3947 T = C.getCanonicalType(ET->getDecl()->getIntegerType()).getTypePtr();
3949 const BuiltinType *BT = cast<BuiltinType>(T);
3950 assert(BT->isInteger());
3952 return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger());
3955 /// Returns the supremum of two ranges: i.e. their conservative merge.
3956 static IntRange join(IntRange L, IntRange R) {
3957 return IntRange(std::max(L.Width, R.Width),
3958 L.NonNegative && R.NonNegative);
3961 /// Returns the infinum of two ranges: i.e. their aggressive merge.
3962 static IntRange meet(IntRange L, IntRange R) {
3963 return IntRange(std::min(L.Width, R.Width),
3964 L.NonNegative || R.NonNegative);
3968 static IntRange GetValueRange(ASTContext &C, llvm::APSInt &value,
3969 unsigned MaxWidth) {
3970 if (value.isSigned() && value.isNegative())
3971 return IntRange(value.getMinSignedBits(), false);
3973 if (value.getBitWidth() > MaxWidth)
3974 value = value.trunc(MaxWidth);
3976 // isNonNegative() just checks the sign bit without considering
3978 return IntRange(value.getActiveBits(), true);
3981 static IntRange GetValueRange(ASTContext &C, APValue &result, QualType Ty,
3982 unsigned MaxWidth) {
3984 return GetValueRange(C, result.getInt(), MaxWidth);
3986 if (result.isVector()) {
3987 IntRange R = GetValueRange(C, result.getVectorElt(0), Ty, MaxWidth);
3988 for (unsigned i = 1, e = result.getVectorLength(); i != e; ++i) {
3989 IntRange El = GetValueRange(C, result.getVectorElt(i), Ty, MaxWidth);
3990 R = IntRange::join(R, El);
3995 if (result.isComplexInt()) {
3996 IntRange R = GetValueRange(C, result.getComplexIntReal(), MaxWidth);
3997 IntRange I = GetValueRange(C, result.getComplexIntImag(), MaxWidth);
3998 return IntRange::join(R, I);
4001 // This can happen with lossless casts to intptr_t of "based" lvalues.
4002 // Assume it might use arbitrary bits.
4003 // FIXME: The only reason we need to pass the type in here is to get
4004 // the sign right on this one case. It would be nice if APValue
4006 assert(result.isLValue() || result.isAddrLabelDiff());
4007 return IntRange(MaxWidth, Ty->isUnsignedIntegerOrEnumerationType());
4010 /// Pseudo-evaluate the given integer expression, estimating the
4011 /// range of values it might take.
4013 /// \param MaxWidth - the width to which the value will be truncated
4014 static IntRange GetExprRange(ASTContext &C, Expr *E, unsigned MaxWidth) {
4015 E = E->IgnoreParens();
4017 // Try a full evaluation first.
4018 Expr::EvalResult result;
4019 if (E->EvaluateAsRValue(result, C))
4020 return GetValueRange(C, result.Val, E->getType(), MaxWidth);
4022 // I think we only want to look through implicit casts here; if the
4023 // user has an explicit widening cast, we should treat the value as
4024 // being of the new, wider type.
4025 if (ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E)) {
4026 if (CE->getCastKind() == CK_NoOp || CE->getCastKind() == CK_LValueToRValue)
4027 return GetExprRange(C, CE->getSubExpr(), MaxWidth);
4029 IntRange OutputTypeRange = IntRange::forValueOfType(C, CE->getType());
4031 bool isIntegerCast = (CE->getCastKind() == CK_IntegralCast);
4033 // Assume that non-integer casts can span the full range of the type.
4035 return OutputTypeRange;
4038 = GetExprRange(C, CE->getSubExpr(),
4039 std::min(MaxWidth, OutputTypeRange.Width));
4041 // Bail out if the subexpr's range is as wide as the cast type.
4042 if (SubRange.Width >= OutputTypeRange.Width)
4043 return OutputTypeRange;
4045 // Otherwise, we take the smaller width, and we're non-negative if
4046 // either the output type or the subexpr is.
4047 return IntRange(SubRange.Width,
4048 SubRange.NonNegative || OutputTypeRange.NonNegative);
4051 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
4052 // If we can fold the condition, just take that operand.
4054 if (CO->getCond()->EvaluateAsBooleanCondition(CondResult, C))
4055 return GetExprRange(C, CondResult ? CO->getTrueExpr()
4056 : CO->getFalseExpr(),
4059 // Otherwise, conservatively merge.
4060 IntRange L = GetExprRange(C, CO->getTrueExpr(), MaxWidth);
4061 IntRange R = GetExprRange(C, CO->getFalseExpr(), MaxWidth);
4062 return IntRange::join(L, R);
4065 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
4066 switch (BO->getOpcode()) {
4068 // Boolean-valued operations are single-bit and positive.
4077 return IntRange::forBoolType();
4079 // The type of the assignments is the type of the LHS, so the RHS
4080 // is not necessarily the same type.
4089 return IntRange::forValueOfType(C, E->getType());
4091 // Simple assignments just pass through the RHS, which will have
4092 // been coerced to the LHS type.
4095 return GetExprRange(C, BO->getRHS(), MaxWidth);
4097 // Operations with opaque sources are black-listed.
4100 return IntRange::forValueOfType(C, E->getType());
4102 // Bitwise-and uses the *infinum* of the two source ranges.
4105 return IntRange::meet(GetExprRange(C, BO->getLHS(), MaxWidth),
4106 GetExprRange(C, BO->getRHS(), MaxWidth));
4108 // Left shift gets black-listed based on a judgement call.
4110 // ...except that we want to treat '1 << (blah)' as logically
4111 // positive. It's an important idiom.
4112 if (IntegerLiteral *I
4113 = dyn_cast<IntegerLiteral>(BO->getLHS()->IgnoreParenCasts())) {
4114 if (I->getValue() == 1) {
4115 IntRange R = IntRange::forValueOfType(C, E->getType());
4116 return IntRange(R.Width, /*NonNegative*/ true);
4122 return IntRange::forValueOfType(C, E->getType());
4124 // Right shift by a constant can narrow its left argument.
4126 case BO_ShrAssign: {
4127 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth);
4129 // If the shift amount is a positive constant, drop the width by
4132 if (BO->getRHS()->isIntegerConstantExpr(shift, C) &&
4133 shift.isNonNegative()) {
4134 unsigned zext = shift.getZExtValue();
4135 if (zext >= L.Width)
4136 L.Width = (L.NonNegative ? 0 : 1);
4144 // Comma acts as its right operand.
4146 return GetExprRange(C, BO->getRHS(), MaxWidth);
4148 // Black-list pointer subtractions.
4150 if (BO->getLHS()->getType()->isPointerType())
4151 return IntRange::forValueOfType(C, E->getType());
4154 // The width of a division result is mostly determined by the size
4157 // Don't 'pre-truncate' the operands.
4158 unsigned opWidth = C.getIntWidth(E->getType());
4159 IntRange L = GetExprRange(C, BO->getLHS(), opWidth);
4161 // If the divisor is constant, use that.
4162 llvm::APSInt divisor;
4163 if (BO->getRHS()->isIntegerConstantExpr(divisor, C)) {
4164 unsigned log2 = divisor.logBase2(); // floor(log_2(divisor))
4165 if (log2 >= L.Width)
4166 L.Width = (L.NonNegative ? 0 : 1);
4168 L.Width = std::min(L.Width - log2, MaxWidth);
4172 // Otherwise, just use the LHS's width.
4173 IntRange R = GetExprRange(C, BO->getRHS(), opWidth);
4174 return IntRange(L.Width, L.NonNegative && R.NonNegative);
4177 // The result of a remainder can't be larger than the result of
4180 // Don't 'pre-truncate' the operands.
4181 unsigned opWidth = C.getIntWidth(E->getType());
4182 IntRange L = GetExprRange(C, BO->getLHS(), opWidth);
4183 IntRange R = GetExprRange(C, BO->getRHS(), opWidth);
4185 IntRange meet = IntRange::meet(L, R);
4186 meet.Width = std::min(meet.Width, MaxWidth);
4190 // The default behavior is okay for these.
4198 // The default case is to treat the operation as if it were closed
4199 // on the narrowest type that encompasses both operands.
4200 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth);
4201 IntRange R = GetExprRange(C, BO->getRHS(), MaxWidth);
4202 return IntRange::join(L, R);
4205 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
4206 switch (UO->getOpcode()) {
4207 // Boolean-valued operations are white-listed.
4209 return IntRange::forBoolType();
4211 // Operations with opaque sources are black-listed.
4213 case UO_AddrOf: // should be impossible
4214 return IntRange::forValueOfType(C, E->getType());
4217 return GetExprRange(C, UO->getSubExpr(), MaxWidth);
4221 if (dyn_cast<OffsetOfExpr>(E)) {
4222 IntRange::forValueOfType(C, E->getType());
4225 if (FieldDecl *BitField = E->getBitField())
4226 return IntRange(BitField->getBitWidthValue(C),
4227 BitField->getType()->isUnsignedIntegerOrEnumerationType());
4229 return IntRange::forValueOfType(C, E->getType());
4232 static IntRange GetExprRange(ASTContext &C, Expr *E) {
4233 return GetExprRange(C, E, C.getIntWidth(E->getType()));
4236 /// Checks whether the given value, which currently has the given
4237 /// source semantics, has the same value when coerced through the
4238 /// target semantics.
4239 static bool IsSameFloatAfterCast(const llvm::APFloat &value,
4240 const llvm::fltSemantics &Src,
4241 const llvm::fltSemantics &Tgt) {
4242 llvm::APFloat truncated = value;
4245 truncated.convert(Src, llvm::APFloat::rmNearestTiesToEven, &ignored);
4246 truncated.convert(Tgt, llvm::APFloat::rmNearestTiesToEven, &ignored);
4248 return truncated.bitwiseIsEqual(value);
4251 /// Checks whether the given value, which currently has the given
4252 /// source semantics, has the same value when coerced through the
4253 /// target semantics.
4255 /// The value might be a vector of floats (or a complex number).
4256 static bool IsSameFloatAfterCast(const APValue &value,
4257 const llvm::fltSemantics &Src,
4258 const llvm::fltSemantics &Tgt) {
4259 if (value.isFloat())
4260 return IsSameFloatAfterCast(value.getFloat(), Src, Tgt);
4262 if (value.isVector()) {
4263 for (unsigned i = 0, e = value.getVectorLength(); i != e; ++i)
4264 if (!IsSameFloatAfterCast(value.getVectorElt(i), Src, Tgt))
4269 assert(value.isComplexFloat());
4270 return (IsSameFloatAfterCast(value.getComplexFloatReal(), Src, Tgt) &&
4271 IsSameFloatAfterCast(value.getComplexFloatImag(), Src, Tgt));
4274 static void AnalyzeImplicitConversions(Sema &S, Expr *E, SourceLocation CC);
4276 static bool IsZero(Sema &S, Expr *E) {
4277 // Suppress cases where we are comparing against an enum constant.
4278 if (const DeclRefExpr *DR =
4279 dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()))
4280 if (isa<EnumConstantDecl>(DR->getDecl()))
4283 // Suppress cases where the '0' value is expanded from a macro.
4284 if (E->getLocStart().isMacroID())
4288 return E->isIntegerConstantExpr(Value, S.Context) && Value == 0;
4291 static bool HasEnumType(Expr *E) {
4292 // Strip off implicit integral promotions.
4293 while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
4294 if (ICE->getCastKind() != CK_IntegralCast &&
4295 ICE->getCastKind() != CK_NoOp)
4297 E = ICE->getSubExpr();
4300 return E->getType()->isEnumeralType();
4303 static void CheckTrivialUnsignedComparison(Sema &S, BinaryOperator *E) {
4304 BinaryOperatorKind op = E->getOpcode();
4305 if (E->isValueDependent())
4308 if (op == BO_LT && IsZero(S, E->getRHS())) {
4309 S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison)
4310 << "< 0" << "false" << HasEnumType(E->getLHS())
4311 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
4312 } else if (op == BO_GE && IsZero(S, E->getRHS())) {
4313 S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison)
4314 << ">= 0" << "true" << HasEnumType(E->getLHS())
4315 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
4316 } else if (op == BO_GT && IsZero(S, E->getLHS())) {
4317 S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison)
4318 << "0 >" << "false" << HasEnumType(E->getRHS())
4319 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
4320 } else if (op == BO_LE && IsZero(S, E->getLHS())) {
4321 S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison)
4322 << "0 <=" << "true" << HasEnumType(E->getRHS())
4323 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
4327 static void DiagnoseOutOfRangeComparison(Sema &S, BinaryOperator *E,
4328 Expr *Constant, Expr *Other,
4331 BinaryOperatorKind op = E->getOpcode();
4332 QualType OtherT = Other->getType();
4333 QualType ConstantT = Constant->getType();
4334 if (S.Context.hasSameUnqualifiedType(OtherT, ConstantT))
4336 assert((OtherT->isIntegerType() && ConstantT->isIntegerType())
4337 && "comparison with non-integer type");
4338 // FIXME. handle cases for signedness to catch (signed char)N == 200
4339 IntRange OtherRange = IntRange::forValueOfType(S.Context, OtherT);
4340 IntRange LitRange = GetValueRange(S.Context, Value, Value.getBitWidth());
4341 if (OtherRange.Width >= LitRange.Width)
4346 else if (op == BO_NE)
4348 else if (RhsConstant) {
4349 if (op == BO_GT || op == BO_GE)
4350 IsTrue = !LitRange.NonNegative;
4351 else // op == BO_LT || op == BO_LE
4352 IsTrue = LitRange.NonNegative;
4354 if (op == BO_LT || op == BO_LE)
4355 IsTrue = !LitRange.NonNegative;
4356 else // op == BO_GT || op == BO_GE
4357 IsTrue = LitRange.NonNegative;
4359 SmallString<16> PrettySourceValue(Value.toString(10));
4360 S.Diag(E->getOperatorLoc(), diag::warn_out_of_range_compare)
4361 << PrettySourceValue << OtherT << IsTrue
4362 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
4365 /// Analyze the operands of the given comparison. Implements the
4366 /// fallback case from AnalyzeComparison.
4367 static void AnalyzeImpConvsInComparison(Sema &S, BinaryOperator *E) {
4368 AnalyzeImplicitConversions(S, E->getLHS(), E->getOperatorLoc());
4369 AnalyzeImplicitConversions(S, E->getRHS(), E->getOperatorLoc());
4372 /// \brief Implements -Wsign-compare.
4374 /// \param E the binary operator to check for warnings
4375 static void AnalyzeComparison(Sema &S, BinaryOperator *E) {
4376 // The type the comparison is being performed in.
4377 QualType T = E->getLHS()->getType();
4378 assert(S.Context.hasSameUnqualifiedType(T, E->getRHS()->getType())
4379 && "comparison with mismatched types");
4380 if (E->isValueDependent())
4381 return AnalyzeImpConvsInComparison(S, E);
4383 Expr *LHS = E->getLHS()->IgnoreParenImpCasts();
4384 Expr *RHS = E->getRHS()->IgnoreParenImpCasts();
4386 bool IsComparisonConstant = false;
4388 // Check whether an integer constant comparison results in a value
4389 // of 'true' or 'false'.
4390 if (T->isIntegralType(S.Context)) {
4391 llvm::APSInt RHSValue;
4392 bool IsRHSIntegralLiteral =
4393 RHS->isIntegerConstantExpr(RHSValue, S.Context);
4394 llvm::APSInt LHSValue;
4395 bool IsLHSIntegralLiteral =
4396 LHS->isIntegerConstantExpr(LHSValue, S.Context);
4397 if (IsRHSIntegralLiteral && !IsLHSIntegralLiteral)
4398 DiagnoseOutOfRangeComparison(S, E, RHS, LHS, RHSValue, true);
4399 else if (!IsRHSIntegralLiteral && IsLHSIntegralLiteral)
4400 DiagnoseOutOfRangeComparison(S, E, LHS, RHS, LHSValue, false);
4402 IsComparisonConstant =
4403 (IsRHSIntegralLiteral && IsLHSIntegralLiteral);
4404 } else if (!T->hasUnsignedIntegerRepresentation())
4405 IsComparisonConstant = E->isIntegerConstantExpr(S.Context);
4407 // We don't do anything special if this isn't an unsigned integral
4408 // comparison: we're only interested in integral comparisons, and
4409 // signed comparisons only happen in cases we don't care to warn about.
4411 // We also don't care about value-dependent expressions or expressions
4412 // whose result is a constant.
4413 if (!T->hasUnsignedIntegerRepresentation() || IsComparisonConstant)
4414 return AnalyzeImpConvsInComparison(S, E);
4416 // Check to see if one of the (unmodified) operands is of different
4418 Expr *signedOperand, *unsignedOperand;
4419 if (LHS->getType()->hasSignedIntegerRepresentation()) {
4420 assert(!RHS->getType()->hasSignedIntegerRepresentation() &&
4421 "unsigned comparison between two signed integer expressions?");
4422 signedOperand = LHS;
4423 unsignedOperand = RHS;
4424 } else if (RHS->getType()->hasSignedIntegerRepresentation()) {
4425 signedOperand = RHS;
4426 unsignedOperand = LHS;
4428 CheckTrivialUnsignedComparison(S, E);
4429 return AnalyzeImpConvsInComparison(S, E);
4432 // Otherwise, calculate the effective range of the signed operand.
4433 IntRange signedRange = GetExprRange(S.Context, signedOperand);
4435 // Go ahead and analyze implicit conversions in the operands. Note
4436 // that we skip the implicit conversions on both sides.
4437 AnalyzeImplicitConversions(S, LHS, E->getOperatorLoc());
4438 AnalyzeImplicitConversions(S, RHS, E->getOperatorLoc());
4440 // If the signed range is non-negative, -Wsign-compare won't fire,
4441 // but we should still check for comparisons which are always true
4443 if (signedRange.NonNegative)
4444 return CheckTrivialUnsignedComparison(S, E);
4446 // For (in)equality comparisons, if the unsigned operand is a
4447 // constant which cannot collide with a overflowed signed operand,
4448 // then reinterpreting the signed operand as unsigned will not
4449 // change the result of the comparison.
4450 if (E->isEqualityOp()) {
4451 unsigned comparisonWidth = S.Context.getIntWidth(T);
4452 IntRange unsignedRange = GetExprRange(S.Context, unsignedOperand);
4454 // We should never be unable to prove that the unsigned operand is
4456 assert(unsignedRange.NonNegative && "unsigned range includes negative?");
4458 if (unsignedRange.Width < comparisonWidth)
4462 S.DiagRuntimeBehavior(E->getOperatorLoc(), E,
4463 S.PDiag(diag::warn_mixed_sign_comparison)
4464 << LHS->getType() << RHS->getType()
4465 << LHS->getSourceRange() << RHS->getSourceRange());
4468 /// Analyzes an attempt to assign the given value to a bitfield.
4470 /// Returns true if there was something fishy about the attempt.
4471 static bool AnalyzeBitFieldAssignment(Sema &S, FieldDecl *Bitfield, Expr *Init,
4472 SourceLocation InitLoc) {
4473 assert(Bitfield->isBitField());
4474 if (Bitfield->isInvalidDecl())
4477 // White-list bool bitfields.
4478 if (Bitfield->getType()->isBooleanType())
4481 // Ignore value- or type-dependent expressions.
4482 if (Bitfield->getBitWidth()->isValueDependent() ||
4483 Bitfield->getBitWidth()->isTypeDependent() ||
4484 Init->isValueDependent() ||
4485 Init->isTypeDependent())
4488 Expr *OriginalInit = Init->IgnoreParenImpCasts();
4491 if (!OriginalInit->EvaluateAsInt(Value, S.Context, Expr::SE_AllowSideEffects))
4494 unsigned OriginalWidth = Value.getBitWidth();
4495 unsigned FieldWidth = Bitfield->getBitWidthValue(S.Context);
4497 if (OriginalWidth <= FieldWidth)
4500 // Compute the value which the bitfield will contain.
4501 llvm::APSInt TruncatedValue = Value.trunc(FieldWidth);
4502 TruncatedValue.setIsSigned(Bitfield->getType()->isSignedIntegerType());
4504 // Check whether the stored value is equal to the original value.
4505 TruncatedValue = TruncatedValue.extend(OriginalWidth);
4506 if (llvm::APSInt::isSameValue(Value, TruncatedValue))
4509 // Special-case bitfields of width 1: booleans are naturally 0/1, and
4510 // therefore don't strictly fit into a signed bitfield of width 1.
4511 if (FieldWidth == 1 && Value == 1)
4514 std::string PrettyValue = Value.toString(10);
4515 std::string PrettyTrunc = TruncatedValue.toString(10);
4517 S.Diag(InitLoc, diag::warn_impcast_bitfield_precision_constant)
4518 << PrettyValue << PrettyTrunc << OriginalInit->getType()
4519 << Init->getSourceRange();
4524 /// Analyze the given simple or compound assignment for warning-worthy
4526 static void AnalyzeAssignment(Sema &S, BinaryOperator *E) {
4527 // Just recurse on the LHS.
4528 AnalyzeImplicitConversions(S, E->getLHS(), E->getOperatorLoc());
4530 // We want to recurse on the RHS as normal unless we're assigning to
4532 if (FieldDecl *Bitfield = E->getLHS()->getBitField()) {
4533 if (AnalyzeBitFieldAssignment(S, Bitfield, E->getRHS(),
4534 E->getOperatorLoc())) {
4535 // Recurse, ignoring any implicit conversions on the RHS.
4536 return AnalyzeImplicitConversions(S, E->getRHS()->IgnoreParenImpCasts(),
4537 E->getOperatorLoc());
4541 AnalyzeImplicitConversions(S, E->getRHS(), E->getOperatorLoc());
4544 /// Diagnose an implicit cast; purely a helper for CheckImplicitConversion.
4545 static void DiagnoseImpCast(Sema &S, Expr *E, QualType SourceType, QualType T,
4546 SourceLocation CContext, unsigned diag,
4547 bool pruneControlFlow = false) {
4548 if (pruneControlFlow) {
4549 S.DiagRuntimeBehavior(E->getExprLoc(), E,
4551 << SourceType << T << E->getSourceRange()
4552 << SourceRange(CContext));
4555 S.Diag(E->getExprLoc(), diag)
4556 << SourceType << T << E->getSourceRange() << SourceRange(CContext);
4559 /// Diagnose an implicit cast; purely a helper for CheckImplicitConversion.
4560 static void DiagnoseImpCast(Sema &S, Expr *E, QualType T,
4561 SourceLocation CContext, unsigned diag,
4562 bool pruneControlFlow = false) {
4563 DiagnoseImpCast(S, E, E->getType(), T, CContext, diag, pruneControlFlow);
4566 /// Diagnose an implicit cast from a literal expression. Does not warn when the
4567 /// cast wouldn't lose information.
4568 void DiagnoseFloatingLiteralImpCast(Sema &S, FloatingLiteral *FL, QualType T,
4569 SourceLocation CContext) {
4570 // Try to convert the literal exactly to an integer. If we can, don't warn.
4571 bool isExact = false;
4572 const llvm::APFloat &Value = FL->getValue();
4573 llvm::APSInt IntegerValue(S.Context.getIntWidth(T),
4574 T->hasUnsignedIntegerRepresentation());
4575 if (Value.convertToInteger(IntegerValue,
4576 llvm::APFloat::rmTowardZero, &isExact)
4577 == llvm::APFloat::opOK && isExact)
4580 SmallString<16> PrettySourceValue;
4581 Value.toString(PrettySourceValue);
4582 SmallString<16> PrettyTargetValue;
4583 if (T->isSpecificBuiltinType(BuiltinType::Bool))
4584 PrettyTargetValue = IntegerValue == 0 ? "false" : "true";
4586 IntegerValue.toString(PrettyTargetValue);
4588 S.Diag(FL->getExprLoc(), diag::warn_impcast_literal_float_to_integer)
4589 << FL->getType() << T.getUnqualifiedType() << PrettySourceValue
4590 << PrettyTargetValue << FL->getSourceRange() << SourceRange(CContext);
4593 std::string PrettyPrintInRange(const llvm::APSInt &Value, IntRange Range) {
4594 if (!Range.Width) return "0";
4596 llvm::APSInt ValueInRange = Value;
4597 ValueInRange.setIsSigned(!Range.NonNegative);
4598 ValueInRange = ValueInRange.trunc(Range.Width);
4599 return ValueInRange.toString(10);
4602 static bool IsImplicitBoolFloatConversion(Sema &S, Expr *Ex, bool ToBool) {
4603 if (!isa<ImplicitCastExpr>(Ex))
4606 Expr *InnerE = Ex->IgnoreParenImpCasts();
4607 const Type *Target = S.Context.getCanonicalType(Ex->getType()).getTypePtr();
4608 const Type *Source =
4609 S.Context.getCanonicalType(InnerE->getType()).getTypePtr();
4610 if (Target->isDependentType())
4613 const BuiltinType *FloatCandidateBT =
4614 dyn_cast<BuiltinType>(ToBool ? Source : Target);
4615 const Type *BoolCandidateType = ToBool ? Target : Source;
4617 return (BoolCandidateType->isSpecificBuiltinType(BuiltinType::Bool) &&
4618 FloatCandidateBT && (FloatCandidateBT->isFloatingPoint()));
4621 void CheckImplicitArgumentConversions(Sema &S, CallExpr *TheCall,
4622 SourceLocation CC) {
4623 unsigned NumArgs = TheCall->getNumArgs();
4624 for (unsigned i = 0; i < NumArgs; ++i) {
4625 Expr *CurrA = TheCall->getArg(i);
4626 if (!IsImplicitBoolFloatConversion(S, CurrA, true))
4629 bool IsSwapped = ((i > 0) &&
4630 IsImplicitBoolFloatConversion(S, TheCall->getArg(i - 1), false));
4631 IsSwapped |= ((i < (NumArgs - 1)) &&
4632 IsImplicitBoolFloatConversion(S, TheCall->getArg(i + 1), false));
4634 // Warn on this floating-point to bool conversion.
4635 DiagnoseImpCast(S, CurrA->IgnoreParenImpCasts(),
4636 CurrA->getType(), CC,
4637 diag::warn_impcast_floating_point_to_bool);
4642 void CheckImplicitConversion(Sema &S, Expr *E, QualType T,
4643 SourceLocation CC, bool *ICContext = 0) {
4644 if (E->isTypeDependent() || E->isValueDependent()) return;
4646 const Type *Source = S.Context.getCanonicalType(E->getType()).getTypePtr();
4647 const Type *Target = S.Context.getCanonicalType(T).getTypePtr();
4648 if (Source == Target) return;
4649 if (Target->isDependentType()) return;
4651 // If the conversion context location is invalid don't complain. We also
4652 // don't want to emit a warning if the issue occurs from the expansion of
4653 // a system macro. The problem is that 'getSpellingLoc()' is slow, so we
4654 // delay this check as long as possible. Once we detect we are in that
4655 // scenario, we just return.
4659 // Diagnose implicit casts to bool.
4660 if (Target->isSpecificBuiltinType(BuiltinType::Bool)) {
4661 if (isa<StringLiteral>(E))
4662 // Warn on string literal to bool. Checks for string literals in logical
4663 // expressions, for instances, assert(0 && "error here"), is prevented
4664 // by a check in AnalyzeImplicitConversions().
4665 return DiagnoseImpCast(S, E, T, CC,
4666 diag::warn_impcast_string_literal_to_bool);
4667 if (Source->isFunctionType()) {
4668 // Warn on function to bool. Checks free functions and static member
4669 // functions. Weakly imported functions are excluded from the check,
4670 // since it's common to test their value to check whether the linker
4671 // found a definition for them.
4673 if (DeclRefExpr* R = dyn_cast<DeclRefExpr>(E)) {
4675 } else if (MemberExpr *M = dyn_cast<MemberExpr>(E)) {
4676 D = M->getMemberDecl();
4679 if (D && !D->isWeak()) {
4680 if (FunctionDecl* F = dyn_cast<FunctionDecl>(D)) {
4681 S.Diag(E->getExprLoc(), diag::warn_impcast_function_to_bool)
4682 << F << E->getSourceRange() << SourceRange(CC);
4683 S.Diag(E->getExprLoc(), diag::note_function_to_bool_silence)
4684 << FixItHint::CreateInsertion(E->getExprLoc(), "&");
4685 QualType ReturnType;
4686 UnresolvedSet<4> NonTemplateOverloads;
4687 S.isExprCallable(*E, ReturnType, NonTemplateOverloads);
4688 if (!ReturnType.isNull()
4689 && ReturnType->isSpecificBuiltinType(BuiltinType::Bool))
4690 S.Diag(E->getExprLoc(), diag::note_function_to_bool_call)
4691 << FixItHint::CreateInsertion(
4692 S.getPreprocessor().getLocForEndOfToken(E->getLocEnd()), "()");
4699 // Strip vector types.
4700 if (isa<VectorType>(Source)) {
4701 if (!isa<VectorType>(Target)) {
4702 if (S.SourceMgr.isInSystemMacro(CC))
4704 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_vector_scalar);
4707 // If the vector cast is cast between two vectors of the same size, it is
4708 // a bitcast, not a conversion.
4709 if (S.Context.getTypeSize(Source) == S.Context.getTypeSize(Target))
4712 Source = cast<VectorType>(Source)->getElementType().getTypePtr();
4713 Target = cast<VectorType>(Target)->getElementType().getTypePtr();
4716 // Strip complex types.
4717 if (isa<ComplexType>(Source)) {
4718 if (!isa<ComplexType>(Target)) {
4719 if (S.SourceMgr.isInSystemMacro(CC))
4722 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_complex_scalar);
4725 Source = cast<ComplexType>(Source)->getElementType().getTypePtr();
4726 Target = cast<ComplexType>(Target)->getElementType().getTypePtr();
4729 const BuiltinType *SourceBT = dyn_cast<BuiltinType>(Source);
4730 const BuiltinType *TargetBT = dyn_cast<BuiltinType>(Target);
4732 // If the source is floating point...
4733 if (SourceBT && SourceBT->isFloatingPoint()) {
4734 // ...and the target is floating point...
4735 if (TargetBT && TargetBT->isFloatingPoint()) {
4736 // ...then warn if we're dropping FP rank.
4738 // Builtin FP kinds are ordered by increasing FP rank.
4739 if (SourceBT->getKind() > TargetBT->getKind()) {
4740 // Don't warn about float constants that are precisely
4741 // representable in the target type.
4742 Expr::EvalResult result;
4743 if (E->EvaluateAsRValue(result, S.Context)) {
4744 // Value might be a float, a float vector, or a float complex.
4745 if (IsSameFloatAfterCast(result.Val,
4746 S.Context.getFloatTypeSemantics(QualType(TargetBT, 0)),
4747 S.Context.getFloatTypeSemantics(QualType(SourceBT, 0))))
4751 if (S.SourceMgr.isInSystemMacro(CC))
4754 DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_float_precision);
4759 // If the target is integral, always warn.
4760 if (TargetBT && TargetBT->isInteger()) {
4761 if (S.SourceMgr.isInSystemMacro(CC))
4764 Expr *InnerE = E->IgnoreParenImpCasts();
4765 // We also want to warn on, e.g., "int i = -1.234"
4766 if (UnaryOperator *UOp = dyn_cast<UnaryOperator>(InnerE))
4767 if (UOp->getOpcode() == UO_Minus || UOp->getOpcode() == UO_Plus)
4768 InnerE = UOp->getSubExpr()->IgnoreParenImpCasts();
4770 if (FloatingLiteral *FL = dyn_cast<FloatingLiteral>(InnerE)) {
4771 DiagnoseFloatingLiteralImpCast(S, FL, T, CC);
4773 DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_float_integer);
4777 // If the target is bool, warn if expr is a function or method call.
4778 if (Target->isSpecificBuiltinType(BuiltinType::Bool) &&
4780 // Check last argument of function call to see if it is an
4781 // implicit cast from a type matching the type the result
4782 // is being cast to.
4783 CallExpr *CEx = cast<CallExpr>(E);
4784 unsigned NumArgs = CEx->getNumArgs();
4786 Expr *LastA = CEx->getArg(NumArgs - 1);
4787 Expr *InnerE = LastA->IgnoreParenImpCasts();
4788 const Type *InnerType =
4789 S.Context.getCanonicalType(InnerE->getType()).getTypePtr();
4790 if (isa<ImplicitCastExpr>(LastA) && (InnerType == Target)) {
4791 // Warn on this floating-point to bool conversion
4792 DiagnoseImpCast(S, E, T, CC,
4793 diag::warn_impcast_floating_point_to_bool);
4800 if ((E->isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull)
4801 == Expr::NPCK_GNUNull) && !Target->isAnyPointerType()
4802 && !Target->isBlockPointerType() && !Target->isMemberPointerType()
4803 && Target->isScalarType()) {
4804 SourceLocation Loc = E->getSourceRange().getBegin();
4805 if (Loc.isMacroID())
4806 Loc = S.SourceMgr.getImmediateExpansionRange(Loc).first;
4807 if (!Loc.isMacroID() || CC.isMacroID())
4808 S.Diag(Loc, diag::warn_impcast_null_pointer_to_integer)
4809 << T << clang::SourceRange(CC)
4810 << FixItHint::CreateReplacement(Loc, S.getFixItZeroLiteralForType(T));
4813 if (!Source->isIntegerType() || !Target->isIntegerType())
4816 // TODO: remove this early return once the false positives for constant->bool
4817 // in templates, macros, etc, are reduced or removed.
4818 if (Target->isSpecificBuiltinType(BuiltinType::Bool))
4821 IntRange SourceRange = GetExprRange(S.Context, E);
4822 IntRange TargetRange = IntRange::forTargetOfCanonicalType(S.Context, Target);
4824 if (SourceRange.Width > TargetRange.Width) {
4825 // If the source is a constant, use a default-on diagnostic.
4826 // TODO: this should happen for bitfield stores, too.
4827 llvm::APSInt Value(32);
4828 if (E->isIntegerConstantExpr(Value, S.Context)) {
4829 if (S.SourceMgr.isInSystemMacro(CC))
4832 std::string PrettySourceValue = Value.toString(10);
4833 std::string PrettyTargetValue = PrettyPrintInRange(Value, TargetRange);
4835 S.DiagRuntimeBehavior(E->getExprLoc(), E,
4836 S.PDiag(diag::warn_impcast_integer_precision_constant)
4837 << PrettySourceValue << PrettyTargetValue
4838 << E->getType() << T << E->getSourceRange()
4839 << clang::SourceRange(CC));
4843 // People want to build with -Wshorten-64-to-32 and not -Wconversion.
4844 if (S.SourceMgr.isInSystemMacro(CC))
4847 if (TargetRange.Width == 32 && S.Context.getIntWidth(E->getType()) == 64)
4848 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_integer_64_32,
4849 /* pruneControlFlow */ true);
4850 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_integer_precision);
4853 if ((TargetRange.NonNegative && !SourceRange.NonNegative) ||
4854 (!TargetRange.NonNegative && SourceRange.NonNegative &&
4855 SourceRange.Width == TargetRange.Width)) {
4857 if (S.SourceMgr.isInSystemMacro(CC))
4860 unsigned DiagID = diag::warn_impcast_integer_sign;
4862 // Traditionally, gcc has warned about this under -Wsign-compare.
4863 // We also want to warn about it in -Wconversion.
4864 // So if -Wconversion is off, use a completely identical diagnostic
4865 // in the sign-compare group.
4866 // The conditional-checking code will
4868 DiagID = diag::warn_impcast_integer_sign_conditional;
4872 return DiagnoseImpCast(S, E, T, CC, DiagID);
4875 // Diagnose conversions between different enumeration types.
4876 // In C, we pretend that the type of an EnumConstantDecl is its enumeration
4877 // type, to give us better diagnostics.
4878 QualType SourceType = E->getType();
4879 if (!S.getLangOpts().CPlusPlus) {
4880 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
4881 if (EnumConstantDecl *ECD = dyn_cast<EnumConstantDecl>(DRE->getDecl())) {
4882 EnumDecl *Enum = cast<EnumDecl>(ECD->getDeclContext());
4883 SourceType = S.Context.getTypeDeclType(Enum);
4884 Source = S.Context.getCanonicalType(SourceType).getTypePtr();
4888 if (const EnumType *SourceEnum = Source->getAs<EnumType>())
4889 if (const EnumType *TargetEnum = Target->getAs<EnumType>())
4890 if ((SourceEnum->getDecl()->getIdentifier() ||
4891 SourceEnum->getDecl()->getTypedefNameForAnonDecl()) &&
4892 (TargetEnum->getDecl()->getIdentifier() ||
4893 TargetEnum->getDecl()->getTypedefNameForAnonDecl()) &&
4894 SourceEnum != TargetEnum) {
4895 if (S.SourceMgr.isInSystemMacro(CC))
4898 return DiagnoseImpCast(S, E, SourceType, T, CC,
4899 diag::warn_impcast_different_enum_types);
4905 void CheckConditionalOperator(Sema &S, ConditionalOperator *E,
4906 SourceLocation CC, QualType T);
4908 void CheckConditionalOperand(Sema &S, Expr *E, QualType T,
4909 SourceLocation CC, bool &ICContext) {
4910 E = E->IgnoreParenImpCasts();
4912 if (isa<ConditionalOperator>(E))
4913 return CheckConditionalOperator(S, cast<ConditionalOperator>(E), CC, T);
4915 AnalyzeImplicitConversions(S, E, CC);
4916 if (E->getType() != T)
4917 return CheckImplicitConversion(S, E, T, CC, &ICContext);
4921 void CheckConditionalOperator(Sema &S, ConditionalOperator *E,
4922 SourceLocation CC, QualType T) {
4923 AnalyzeImplicitConversions(S, E->getCond(), CC);
4925 bool Suspicious = false;
4926 CheckConditionalOperand(S, E->getTrueExpr(), T, CC, Suspicious);
4927 CheckConditionalOperand(S, E->getFalseExpr(), T, CC, Suspicious);
4929 // If -Wconversion would have warned about either of the candidates
4930 // for a signedness conversion to the context type...
4931 if (!Suspicious) return;
4933 // ...but it's currently ignored...
4934 if (S.Diags.getDiagnosticLevel(diag::warn_impcast_integer_sign_conditional,
4938 // ...then check whether it would have warned about either of the
4939 // candidates for a signedness conversion to the condition type.
4940 if (E->getType() == T) return;
4943 CheckImplicitConversion(S, E->getTrueExpr()->IgnoreParenImpCasts(),
4944 E->getType(), CC, &Suspicious);
4946 CheckImplicitConversion(S, E->getFalseExpr()->IgnoreParenImpCasts(),
4947 E->getType(), CC, &Suspicious);
4950 /// AnalyzeImplicitConversions - Find and report any interesting
4951 /// implicit conversions in the given expression. There are a couple
4952 /// of competing diagnostics here, -Wconversion and -Wsign-compare.
4953 void AnalyzeImplicitConversions(Sema &S, Expr *OrigE, SourceLocation CC) {
4954 QualType T = OrigE->getType();
4955 Expr *E = OrigE->IgnoreParenImpCasts();
4957 if (E->isTypeDependent() || E->isValueDependent())
4960 // For conditional operators, we analyze the arguments as if they
4961 // were being fed directly into the output.
4962 if (isa<ConditionalOperator>(E)) {
4963 ConditionalOperator *CO = cast<ConditionalOperator>(E);
4964 CheckConditionalOperator(S, CO, CC, T);
4968 // Check implicit argument conversions for function calls.
4969 if (CallExpr *Call = dyn_cast<CallExpr>(E))
4970 CheckImplicitArgumentConversions(S, Call, CC);
4972 // Go ahead and check any implicit conversions we might have skipped.
4973 // The non-canonical typecheck is just an optimization;
4974 // CheckImplicitConversion will filter out dead implicit conversions.
4975 if (E->getType() != T)
4976 CheckImplicitConversion(S, E, T, CC);
4978 // Now continue drilling into this expression.
4980 // Skip past explicit casts.
4981 if (isa<ExplicitCastExpr>(E)) {
4982 E = cast<ExplicitCastExpr>(E)->getSubExpr()->IgnoreParenImpCasts();
4983 return AnalyzeImplicitConversions(S, E, CC);
4986 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
4987 // Do a somewhat different check with comparison operators.
4988 if (BO->isComparisonOp())
4989 return AnalyzeComparison(S, BO);
4991 // And with simple assignments.
4992 if (BO->getOpcode() == BO_Assign)
4993 return AnalyzeAssignment(S, BO);
4996 // These break the otherwise-useful invariant below. Fortunately,
4997 // we don't really need to recurse into them, because any internal
4998 // expressions should have been analyzed already when they were
4999 // built into statements.
5000 if (isa<StmtExpr>(E)) return;
5002 // Don't descend into unevaluated contexts.
5003 if (isa<UnaryExprOrTypeTraitExpr>(E)) return;
5005 // Now just recurse over the expression's children.
5006 CC = E->getExprLoc();
5007 BinaryOperator *BO = dyn_cast<BinaryOperator>(E);
5008 bool IsLogicalOperator = BO && BO->isLogicalOp();
5009 for (Stmt::child_range I = E->children(); I; ++I) {
5010 Expr *ChildExpr = dyn_cast_or_null<Expr>(*I);
5014 if (IsLogicalOperator &&
5015 isa<StringLiteral>(ChildExpr->IgnoreParenImpCasts()))
5016 // Ignore checking string literals that are in logical operators.
5018 AnalyzeImplicitConversions(S, ChildExpr, CC);
5022 } // end anonymous namespace
5024 /// Diagnoses "dangerous" implicit conversions within the given
5025 /// expression (which is a full expression). Implements -Wconversion
5026 /// and -Wsign-compare.
5028 /// \param CC the "context" location of the implicit conversion, i.e.
5029 /// the most location of the syntactic entity requiring the implicit
5031 void Sema::CheckImplicitConversions(Expr *E, SourceLocation CC) {
5032 // Don't diagnose in unevaluated contexts.
5033 if (isUnevaluatedContext())
5036 // Don't diagnose for value- or type-dependent expressions.
5037 if (E->isTypeDependent() || E->isValueDependent())
5040 // Check for array bounds violations in cases where the check isn't triggered
5041 // elsewhere for other Expr types (like BinaryOperators), e.g. when an
5042 // ArraySubscriptExpr is on the RHS of a variable initialization.
5043 CheckArrayAccess(E);
5045 // This is not the right CC for (e.g.) a variable initialization.
5046 AnalyzeImplicitConversions(*this, E, CC);
5049 void Sema::CheckBitFieldInitialization(SourceLocation InitLoc,
5050 FieldDecl *BitField,
5052 (void) AnalyzeBitFieldAssignment(*this, BitField, Init, InitLoc);
5055 /// CheckParmsForFunctionDef - Check that the parameters of the given
5056 /// function are appropriate for the definition of a function. This
5057 /// takes care of any checks that cannot be performed on the
5058 /// declaration itself, e.g., that the types of each of the function
5059 /// parameters are complete.
5060 bool Sema::CheckParmsForFunctionDef(ParmVarDecl **P, ParmVarDecl **PEnd,
5061 bool CheckParameterNames) {
5062 bool HasInvalidParm = false;
5063 for (; P != PEnd; ++P) {
5064 ParmVarDecl *Param = *P;
5066 // C99 6.7.5.3p4: the parameters in a parameter type list in a
5067 // function declarator that is part of a function definition of
5068 // that function shall not have incomplete type.
5070 // This is also C++ [dcl.fct]p6.
5071 if (!Param->isInvalidDecl() &&
5072 RequireCompleteType(Param->getLocation(), Param->getType(),
5073 diag::err_typecheck_decl_incomplete_type)) {
5074 Param->setInvalidDecl();
5075 HasInvalidParm = true;
5078 // C99 6.9.1p5: If the declarator includes a parameter type list, the
5079 // declaration of each parameter shall include an identifier.
5080 if (CheckParameterNames &&
5081 Param->getIdentifier() == 0 &&
5082 !Param->isImplicit() &&
5083 !getLangOpts().CPlusPlus)
5084 Diag(Param->getLocation(), diag::err_parameter_name_omitted);
5087 // If the function declarator is not part of a definition of that
5088 // function, parameters may have incomplete type and may use the [*]
5089 // notation in their sequences of declarator specifiers to specify
5090 // variable length array types.
5091 QualType PType = Param->getOriginalType();
5092 if (const ArrayType *AT = Context.getAsArrayType(PType)) {
5093 if (AT->getSizeModifier() == ArrayType::Star) {
5094 // FIXME: This diagnosic should point the '[*]' if source-location
5095 // information is added for it.
5096 Diag(Param->getLocation(), diag::err_array_star_in_function_definition);
5101 return HasInvalidParm;
5104 /// CheckCastAlign - Implements -Wcast-align, which warns when a
5105 /// pointer cast increases the alignment requirements.
5106 void Sema::CheckCastAlign(Expr *Op, QualType T, SourceRange TRange) {
5107 // This is actually a lot of work to potentially be doing on every
5108 // cast; don't do it if we're ignoring -Wcast_align (as is the default).
5109 if (getDiagnostics().getDiagnosticLevel(diag::warn_cast_align,
5111 == DiagnosticsEngine::Ignored)
5114 // Ignore dependent types.
5115 if (T->isDependentType() || Op->getType()->isDependentType())
5118 // Require that the destination be a pointer type.
5119 const PointerType *DestPtr = T->getAs<PointerType>();
5120 if (!DestPtr) return;
5122 // If the destination has alignment 1, we're done.
5123 QualType DestPointee = DestPtr->getPointeeType();
5124 if (DestPointee->isIncompleteType()) return;
5125 CharUnits DestAlign = Context.getTypeAlignInChars(DestPointee);
5126 if (DestAlign.isOne()) return;
5128 // Require that the source be a pointer type.
5129 const PointerType *SrcPtr = Op->getType()->getAs<PointerType>();
5130 if (!SrcPtr) return;
5131 QualType SrcPointee = SrcPtr->getPointeeType();
5133 // Whitelist casts from cv void*. We already implicitly
5134 // whitelisted casts to cv void*, since they have alignment 1.
5135 // Also whitelist casts involving incomplete types, which implicitly
5137 if (SrcPointee->isIncompleteType()) return;
5139 CharUnits SrcAlign = Context.getTypeAlignInChars(SrcPointee);
5140 if (SrcAlign >= DestAlign) return;
5142 Diag(TRange.getBegin(), diag::warn_cast_align)
5143 << Op->getType() << T
5144 << static_cast<unsigned>(SrcAlign.getQuantity())
5145 << static_cast<unsigned>(DestAlign.getQuantity())
5146 << TRange << Op->getSourceRange();
5149 static const Type* getElementType(const Expr *BaseExpr) {
5150 const Type* EltType = BaseExpr->getType().getTypePtr();
5151 if (EltType->isAnyPointerType())
5152 return EltType->getPointeeType().getTypePtr();
5153 else if (EltType->isArrayType())
5154 return EltType->getBaseElementTypeUnsafe();
5158 /// \brief Check whether this array fits the idiom of a size-one tail padded
5159 /// array member of a struct.
5161 /// We avoid emitting out-of-bounds access warnings for such arrays as they are
5162 /// commonly used to emulate flexible arrays in C89 code.
5163 static bool IsTailPaddedMemberArray(Sema &S, llvm::APInt Size,
5164 const NamedDecl *ND) {
5165 if (Size != 1 || !ND) return false;
5167 const FieldDecl *FD = dyn_cast<FieldDecl>(ND);
5168 if (!FD) return false;
5170 // Don't consider sizes resulting from macro expansions or template argument
5171 // substitution to form C89 tail-padded arrays.
5173 TypeSourceInfo *TInfo = FD->getTypeSourceInfo();
5175 TypeLoc TL = TInfo->getTypeLoc();
5176 // Look through typedefs.
5177 const TypedefTypeLoc *TTL = dyn_cast<TypedefTypeLoc>(&TL);
5179 const TypedefNameDecl *TDL = TTL->getTypedefNameDecl();
5180 TInfo = TDL->getTypeSourceInfo();
5183 ConstantArrayTypeLoc CTL = cast<ConstantArrayTypeLoc>(TL);
5184 const Expr *SizeExpr = dyn_cast<IntegerLiteral>(CTL.getSizeExpr());
5185 if (!SizeExpr || SizeExpr->getExprLoc().isMacroID())
5190 const RecordDecl *RD = dyn_cast<RecordDecl>(FD->getDeclContext());
5191 if (!RD) return false;
5192 if (RD->isUnion()) return false;
5193 if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) {
5194 if (!CRD->isStandardLayout()) return false;
5197 // See if this is the last field decl in the record.
5199 while ((D = D->getNextDeclInContext()))
5200 if (isa<FieldDecl>(D))
5205 void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
5206 const ArraySubscriptExpr *ASE,
5207 bool AllowOnePastEnd, bool IndexNegated) {
5208 IndexExpr = IndexExpr->IgnoreParenImpCasts();
5209 if (IndexExpr->isValueDependent())
5212 const Type *EffectiveType = getElementType(BaseExpr);
5213 BaseExpr = BaseExpr->IgnoreParenCasts();
5214 const ConstantArrayType *ArrayTy =
5215 Context.getAsConstantArrayType(BaseExpr->getType());
5220 if (!IndexExpr->EvaluateAsInt(index, Context))
5225 const NamedDecl *ND = NULL;
5226 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(BaseExpr))
5227 ND = dyn_cast<NamedDecl>(DRE->getDecl());
5228 if (const MemberExpr *ME = dyn_cast<MemberExpr>(BaseExpr))
5229 ND = dyn_cast<NamedDecl>(ME->getMemberDecl());
5231 if (index.isUnsigned() || !index.isNegative()) {
5232 llvm::APInt size = ArrayTy->getSize();
5233 if (!size.isStrictlyPositive())
5236 const Type* BaseType = getElementType(BaseExpr);
5237 if (BaseType != EffectiveType) {
5238 // Make sure we're comparing apples to apples when comparing index to size
5239 uint64_t ptrarith_typesize = Context.getTypeSize(EffectiveType);
5240 uint64_t array_typesize = Context.getTypeSize(BaseType);
5241 // Handle ptrarith_typesize being zero, such as when casting to void*
5242 if (!ptrarith_typesize) ptrarith_typesize = 1;
5243 if (ptrarith_typesize != array_typesize) {
5244 // There's a cast to a different size type involved
5245 uint64_t ratio = array_typesize / ptrarith_typesize;
5246 // TODO: Be smarter about handling cases where array_typesize is not a
5247 // multiple of ptrarith_typesize
5248 if (ptrarith_typesize * ratio == array_typesize)
5249 size *= llvm::APInt(size.getBitWidth(), ratio);
5253 if (size.getBitWidth() > index.getBitWidth())
5254 index = index.zext(size.getBitWidth());
5255 else if (size.getBitWidth() < index.getBitWidth())
5256 size = size.zext(index.getBitWidth());
5258 // For array subscripting the index must be less than size, but for pointer
5259 // arithmetic also allow the index (offset) to be equal to size since
5260 // computing the next address after the end of the array is legal and
5261 // commonly done e.g. in C++ iterators and range-based for loops.
5262 if (AllowOnePastEnd ? index.ule(size) : index.ult(size))
5265 // Also don't warn for arrays of size 1 which are members of some
5266 // structure. These are often used to approximate flexible arrays in C89
5268 if (IsTailPaddedMemberArray(*this, size, ND))
5271 // Suppress the warning if the subscript expression (as identified by the
5272 // ']' location) and the index expression are both from macro expansions
5273 // within a system header.
5275 SourceLocation RBracketLoc = SourceMgr.getSpellingLoc(
5276 ASE->getRBracketLoc());
5277 if (SourceMgr.isInSystemHeader(RBracketLoc)) {
5278 SourceLocation IndexLoc = SourceMgr.getSpellingLoc(
5279 IndexExpr->getLocStart());
5280 if (SourceMgr.isFromSameFile(RBracketLoc, IndexLoc))
5285 unsigned DiagID = diag::warn_ptr_arith_exceeds_bounds;
5287 DiagID = diag::warn_array_index_exceeds_bounds;
5289 DiagRuntimeBehavior(BaseExpr->getLocStart(), BaseExpr,
5290 PDiag(DiagID) << index.toString(10, true)
5291 << size.toString(10, true)
5292 << (unsigned)size.getLimitedValue(~0U)
5293 << IndexExpr->getSourceRange());
5295 unsigned DiagID = diag::warn_array_index_precedes_bounds;
5297 DiagID = diag::warn_ptr_arith_precedes_bounds;
5298 if (index.isNegative()) index = -index;
5301 DiagRuntimeBehavior(BaseExpr->getLocStart(), BaseExpr,
5302 PDiag(DiagID) << index.toString(10, true)
5303 << IndexExpr->getSourceRange());
5307 // Try harder to find a NamedDecl to point at in the note.
5308 while (const ArraySubscriptExpr *ASE =
5309 dyn_cast<ArraySubscriptExpr>(BaseExpr))
5310 BaseExpr = ASE->getBase()->IgnoreParenCasts();
5311 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(BaseExpr))
5312 ND = dyn_cast<NamedDecl>(DRE->getDecl());
5313 if (const MemberExpr *ME = dyn_cast<MemberExpr>(BaseExpr))
5314 ND = dyn_cast<NamedDecl>(ME->getMemberDecl());
5318 DiagRuntimeBehavior(ND->getLocStart(), BaseExpr,
5319 PDiag(diag::note_array_index_out_of_bounds)
5320 << ND->getDeclName());
5323 void Sema::CheckArrayAccess(const Expr *expr) {
5324 int AllowOnePastEnd = 0;
5326 expr = expr->IgnoreParenImpCasts();
5327 switch (expr->getStmtClass()) {
5328 case Stmt::ArraySubscriptExprClass: {
5329 const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(expr);
5330 CheckArrayAccess(ASE->getBase(), ASE->getIdx(), ASE,
5331 AllowOnePastEnd > 0);
5334 case Stmt::UnaryOperatorClass: {
5335 // Only unwrap the * and & unary operators
5336 const UnaryOperator *UO = cast<UnaryOperator>(expr);
5337 expr = UO->getSubExpr();
5338 switch (UO->getOpcode()) {
5350 case Stmt::ConditionalOperatorClass: {
5351 const ConditionalOperator *cond = cast<ConditionalOperator>(expr);
5352 if (const Expr *lhs = cond->getLHS())
5353 CheckArrayAccess(lhs);
5354 if (const Expr *rhs = cond->getRHS())
5355 CheckArrayAccess(rhs);
5364 //===--- CHECK: Objective-C retain cycles ----------------------------------//
5367 struct RetainCycleOwner {
5368 RetainCycleOwner() : Variable(0), Indirect(false) {}
5374 void setLocsFrom(Expr *e) {
5375 Loc = e->getExprLoc();
5376 Range = e->getSourceRange();
5381 /// Consider whether capturing the given variable can possibly lead to
5383 static bool considerVariable(VarDecl *var, Expr *ref, RetainCycleOwner &owner) {
5384 // In ARC, it's captured strongly iff the variable has __strong
5385 // lifetime. In MRR, it's captured strongly if the variable is
5386 // __block and has an appropriate type.
5387 if (var->getType().getObjCLifetime() != Qualifiers::OCL_Strong)
5390 owner.Variable = var;
5392 owner.setLocsFrom(ref);
5396 static bool findRetainCycleOwner(Sema &S, Expr *e, RetainCycleOwner &owner) {
5398 e = e->IgnoreParens();
5399 if (CastExpr *cast = dyn_cast<CastExpr>(e)) {
5400 switch (cast->getCastKind()) {
5402 case CK_LValueBitCast:
5403 case CK_LValueToRValue:
5404 case CK_ARCReclaimReturnedObject:
5405 e = cast->getSubExpr();
5413 if (ObjCIvarRefExpr *ref = dyn_cast<ObjCIvarRefExpr>(e)) {
5414 ObjCIvarDecl *ivar = ref->getDecl();
5415 if (ivar->getType().getObjCLifetime() != Qualifiers::OCL_Strong)
5418 // Try to find a retain cycle in the base.
5419 if (!findRetainCycleOwner(S, ref->getBase(), owner))
5422 if (ref->isFreeIvar()) owner.setLocsFrom(ref);
5423 owner.Indirect = true;
5427 if (DeclRefExpr *ref = dyn_cast<DeclRefExpr>(e)) {
5428 VarDecl *var = dyn_cast<VarDecl>(ref->getDecl());
5429 if (!var) return false;
5430 return considerVariable(var, ref, owner);
5433 if (MemberExpr *member = dyn_cast<MemberExpr>(e)) {
5434 if (member->isArrow()) return false;
5436 // Don't count this as an indirect ownership.
5437 e = member->getBase();
5441 if (PseudoObjectExpr *pseudo = dyn_cast<PseudoObjectExpr>(e)) {
5442 // Only pay attention to pseudo-objects on property references.
5443 ObjCPropertyRefExpr *pre
5444 = dyn_cast<ObjCPropertyRefExpr>(pseudo->getSyntacticForm()
5446 if (!pre) return false;
5447 if (pre->isImplicitProperty()) return false;
5448 ObjCPropertyDecl *property = pre->getExplicitProperty();
5449 if (!property->isRetaining() &&
5450 !(property->getPropertyIvarDecl() &&
5451 property->getPropertyIvarDecl()->getType()
5452 .getObjCLifetime() == Qualifiers::OCL_Strong))
5455 owner.Indirect = true;
5456 if (pre->isSuperReceiver()) {
5457 owner.Variable = S.getCurMethodDecl()->getSelfDecl();
5458 if (!owner.Variable)
5460 owner.Loc = pre->getLocation();
5461 owner.Range = pre->getSourceRange();
5464 e = const_cast<Expr*>(cast<OpaqueValueExpr>(pre->getBase())
5476 struct FindCaptureVisitor : EvaluatedExprVisitor<FindCaptureVisitor> {
5477 FindCaptureVisitor(ASTContext &Context, VarDecl *variable)
5478 : EvaluatedExprVisitor<FindCaptureVisitor>(Context),
5479 Variable(variable), Capturer(0) {}
5484 void VisitDeclRefExpr(DeclRefExpr *ref) {
5485 if (ref->getDecl() == Variable && !Capturer)
5489 void VisitObjCIvarRefExpr(ObjCIvarRefExpr *ref) {
5490 if (Capturer) return;
5491 Visit(ref->getBase());
5492 if (Capturer && ref->isFreeIvar())
5496 void VisitBlockExpr(BlockExpr *block) {
5497 // Look inside nested blocks
5498 if (block->getBlockDecl()->capturesVariable(Variable))
5499 Visit(block->getBlockDecl()->getBody());
5502 void VisitOpaqueValueExpr(OpaqueValueExpr *OVE) {
5503 if (Capturer) return;
5504 if (OVE->getSourceExpr())
5505 Visit(OVE->getSourceExpr());
5510 /// Check whether the given argument is a block which captures a
5512 static Expr *findCapturingExpr(Sema &S, Expr *e, RetainCycleOwner &owner) {
5513 assert(owner.Variable && owner.Loc.isValid());
5515 e = e->IgnoreParenCasts();
5517 // Look through [^{...} copy] and Block_copy(^{...}).
5518 if (ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(e)) {
5519 Selector Cmd = ME->getSelector();
5520 if (Cmd.isUnarySelector() && Cmd.getNameForSlot(0) == "copy") {
5521 e = ME->getInstanceReceiver();
5524 e = e->IgnoreParenCasts();
5526 } else if (CallExpr *CE = dyn_cast<CallExpr>(e)) {
5527 if (CE->getNumArgs() == 1) {
5528 FunctionDecl *Fn = dyn_cast_or_null<FunctionDecl>(CE->getCalleeDecl());
5530 const IdentifierInfo *FnI = Fn->getIdentifier();
5531 if (FnI && FnI->isStr("_Block_copy")) {
5532 e = CE->getArg(0)->IgnoreParenCasts();
5538 BlockExpr *block = dyn_cast<BlockExpr>(e);
5539 if (!block || !block->getBlockDecl()->capturesVariable(owner.Variable))
5542 FindCaptureVisitor visitor(S.Context, owner.Variable);
5543 visitor.Visit(block->getBlockDecl()->getBody());
5544 return visitor.Capturer;
5547 static void diagnoseRetainCycle(Sema &S, Expr *capturer,
5548 RetainCycleOwner &owner) {
5550 assert(owner.Variable && owner.Loc.isValid());
5552 S.Diag(capturer->getExprLoc(), diag::warn_arc_retain_cycle)
5553 << owner.Variable << capturer->getSourceRange();
5554 S.Diag(owner.Loc, diag::note_arc_retain_cycle_owner)
5555 << owner.Indirect << owner.Range;
5558 /// Check for a keyword selector that starts with the word 'add' or
5560 static bool isSetterLikeSelector(Selector sel) {
5561 if (sel.isUnarySelector()) return false;
5563 StringRef str = sel.getNameForSlot(0);
5564 while (!str.empty() && str.front() == '_') str = str.substr(1);
5565 if (str.startswith("set"))
5566 str = str.substr(3);
5567 else if (str.startswith("add")) {
5568 // Specially whitelist 'addOperationWithBlock:'.
5569 if (sel.getNumArgs() == 1 && str.startswith("addOperationWithBlock"))
5571 str = str.substr(3);
5576 if (str.empty()) return true;
5577 return !islower(str.front());
5580 /// Check a message send to see if it's likely to cause a retain cycle.
5581 void Sema::checkRetainCycles(ObjCMessageExpr *msg) {
5582 // Only check instance methods whose selector looks like a setter.
5583 if (!msg->isInstanceMessage() || !isSetterLikeSelector(msg->getSelector()))
5586 // Try to find a variable that the receiver is strongly owned by.
5587 RetainCycleOwner owner;
5588 if (msg->getReceiverKind() == ObjCMessageExpr::Instance) {
5589 if (!findRetainCycleOwner(*this, msg->getInstanceReceiver(), owner))
5592 assert(msg->getReceiverKind() == ObjCMessageExpr::SuperInstance);
5593 owner.Variable = getCurMethodDecl()->getSelfDecl();
5594 owner.Loc = msg->getSuperLoc();
5595 owner.Range = msg->getSuperLoc();
5598 // Check whether the receiver is captured by any of the arguments.
5599 for (unsigned i = 0, e = msg->getNumArgs(); i != e; ++i)
5600 if (Expr *capturer = findCapturingExpr(*this, msg->getArg(i), owner))
5601 return diagnoseRetainCycle(*this, capturer, owner);
5604 /// Check a property assign to see if it's likely to cause a retain cycle.
5605 void Sema::checkRetainCycles(Expr *receiver, Expr *argument) {
5606 RetainCycleOwner owner;
5607 if (!findRetainCycleOwner(*this, receiver, owner))
5610 if (Expr *capturer = findCapturingExpr(*this, argument, owner))
5611 diagnoseRetainCycle(*this, capturer, owner);
5614 void Sema::checkRetainCycles(VarDecl *Var, Expr *Init) {
5615 RetainCycleOwner Owner;
5616 if (!considerVariable(Var, /*DeclRefExpr=*/0, Owner))
5619 // Because we don't have an expression for the variable, we have to set the
5620 // location explicitly here.
5621 Owner.Loc = Var->getLocation();
5622 Owner.Range = Var->getSourceRange();
5624 if (Expr *Capturer = findCapturingExpr(*this, Init, Owner))
5625 diagnoseRetainCycle(*this, Capturer, Owner);
5628 bool Sema::checkUnsafeAssigns(SourceLocation Loc,
5629 QualType LHS, Expr *RHS) {
5630 Qualifiers::ObjCLifetime LT = LHS.getObjCLifetime();
5631 if (LT != Qualifiers::OCL_Weak && LT != Qualifiers::OCL_ExplicitNone)
5633 // strip off any implicit cast added to get to the one arc-specific
5634 while (ImplicitCastExpr *cast = dyn_cast<ImplicitCastExpr>(RHS)) {
5635 if (cast->getCastKind() == CK_ARCConsumeObject) {
5636 Diag(Loc, diag::warn_arc_retained_assign)
5637 << (LT == Qualifiers::OCL_ExplicitNone) << 1
5638 << RHS->getSourceRange();
5641 RHS = cast->getSubExpr();
5646 void Sema::checkUnsafeExprAssigns(SourceLocation Loc,
5647 Expr *LHS, Expr *RHS) {
5649 // PropertyRef on LHS type need be directly obtained from
5650 // its declaration as it has a PsuedoType.
5651 ObjCPropertyRefExpr *PRE
5652 = dyn_cast<ObjCPropertyRefExpr>(LHS->IgnoreParens());
5653 if (PRE && !PRE->isImplicitProperty()) {
5654 const ObjCPropertyDecl *PD = PRE->getExplicitProperty();
5656 LHSType = PD->getType();
5659 if (LHSType.isNull())
5660 LHSType = LHS->getType();
5662 Qualifiers::ObjCLifetime LT = LHSType.getObjCLifetime();
5664 if (LT == Qualifiers::OCL_Weak) {
5665 DiagnosticsEngine::Level Level =
5666 Diags.getDiagnosticLevel(diag::warn_arc_repeated_use_of_weak, Loc);
5667 if (Level != DiagnosticsEngine::Ignored)
5668 getCurFunction()->markSafeWeakUse(LHS);
5671 if (checkUnsafeAssigns(Loc, LHSType, RHS))
5674 // FIXME. Check for other life times.
5675 if (LT != Qualifiers::OCL_None)
5679 if (PRE->isImplicitProperty())
5681 const ObjCPropertyDecl *PD = PRE->getExplicitProperty();
5685 unsigned Attributes = PD->getPropertyAttributes();
5686 if (Attributes & ObjCPropertyDecl::OBJC_PR_assign) {
5687 // when 'assign' attribute was not explicitly specified
5688 // by user, ignore it and rely on property type itself
5689 // for lifetime info.
5690 unsigned AsWrittenAttr = PD->getPropertyAttributesAsWritten();
5691 if (!(AsWrittenAttr & ObjCPropertyDecl::OBJC_PR_assign) &&
5692 LHSType->isObjCRetainableType())
5695 while (ImplicitCastExpr *cast = dyn_cast<ImplicitCastExpr>(RHS)) {
5696 if (cast->getCastKind() == CK_ARCConsumeObject) {
5697 Diag(Loc, diag::warn_arc_retained_property_assign)
5698 << RHS->getSourceRange();
5701 RHS = cast->getSubExpr();
5704 else if (Attributes & ObjCPropertyDecl::OBJC_PR_weak) {
5705 while (ImplicitCastExpr *cast = dyn_cast<ImplicitCastExpr>(RHS)) {
5706 if (cast->getCastKind() == CK_ARCConsumeObject) {
5707 Diag(Loc, diag::warn_arc_retained_assign)
5708 << 0 << 0<< RHS->getSourceRange();
5711 RHS = cast->getSubExpr();
5717 //===--- CHECK: Empty statement body (-Wempty-body) ---------------------===//
5720 bool ShouldDiagnoseEmptyStmtBody(const SourceManager &SourceMgr,
5721 SourceLocation StmtLoc,
5722 const NullStmt *Body) {
5723 // Do not warn if the body is a macro that expands to nothing, e.g:
5729 if (Body->hasLeadingEmptyMacro())
5732 // Get line numbers of statement and body.
5733 bool StmtLineInvalid;
5734 unsigned StmtLine = SourceMgr.getSpellingLineNumber(StmtLoc,
5736 if (StmtLineInvalid)
5739 bool BodyLineInvalid;
5740 unsigned BodyLine = SourceMgr.getSpellingLineNumber(Body->getSemiLoc(),
5742 if (BodyLineInvalid)
5745 // Warn if null statement and body are on the same line.
5746 if (StmtLine != BodyLine)
5751 } // Unnamed namespace
5753 void Sema::DiagnoseEmptyStmtBody(SourceLocation StmtLoc,
5756 // Since this is a syntactic check, don't emit diagnostic for template
5757 // instantiations, this just adds noise.
5758 if (CurrentInstantiationScope)
5761 // The body should be a null statement.
5762 const NullStmt *NBody = dyn_cast<NullStmt>(Body);
5766 // Do the usual checks.
5767 if (!ShouldDiagnoseEmptyStmtBody(SourceMgr, StmtLoc, NBody))
5770 Diag(NBody->getSemiLoc(), DiagID);
5771 Diag(NBody->getSemiLoc(), diag::note_empty_body_on_separate_line);
5774 void Sema::DiagnoseEmptyLoopBody(const Stmt *S,
5775 const Stmt *PossibleBody) {
5776 assert(!CurrentInstantiationScope); // Ensured by caller
5778 SourceLocation StmtLoc;
5781 if (const ForStmt *FS = dyn_cast<ForStmt>(S)) {
5782 StmtLoc = FS->getRParenLoc();
5783 Body = FS->getBody();
5784 DiagID = diag::warn_empty_for_body;
5785 } else if (const WhileStmt *WS = dyn_cast<WhileStmt>(S)) {
5786 StmtLoc = WS->getCond()->getSourceRange().getEnd();
5787 Body = WS->getBody();
5788 DiagID = diag::warn_empty_while_body;
5790 return; // Neither `for' nor `while'.
5792 // The body should be a null statement.
5793 const NullStmt *NBody = dyn_cast<NullStmt>(Body);
5797 // Skip expensive checks if diagnostic is disabled.
5798 if (Diags.getDiagnosticLevel(DiagID, NBody->getSemiLoc()) ==
5799 DiagnosticsEngine::Ignored)
5802 // Do the usual checks.
5803 if (!ShouldDiagnoseEmptyStmtBody(SourceMgr, StmtLoc, NBody))
5806 // `for(...);' and `while(...);' are popular idioms, so in order to keep
5807 // noise level low, emit diagnostics only if for/while is followed by a
5808 // CompoundStmt, e.g.:
5809 // for (int i = 0; i < n; i++);
5813 // or if for/while is followed by a statement with more indentation
5814 // than for/while itself:
5815 // for (int i = 0; i < n; i++);
5817 bool ProbableTypo = isa<CompoundStmt>(PossibleBody);
5818 if (!ProbableTypo) {
5819 bool BodyColInvalid;
5820 unsigned BodyCol = SourceMgr.getPresumedColumnNumber(
5821 PossibleBody->getLocStart(),
5826 bool StmtColInvalid;
5827 unsigned StmtCol = SourceMgr.getPresumedColumnNumber(
5833 if (BodyCol > StmtCol)
5834 ProbableTypo = true;
5838 Diag(NBody->getSemiLoc(), DiagID);
5839 Diag(NBody->getSemiLoc(), diag::note_empty_body_on_separate_line);
5843 //===--- Layout compatibility ----------------------------------------------//
5847 bool isLayoutCompatible(ASTContext &C, QualType T1, QualType T2);
5849 /// \brief Check if two enumeration types are layout-compatible.
5850 bool isLayoutCompatible(ASTContext &C, EnumDecl *ED1, EnumDecl *ED2) {
5851 // C++11 [dcl.enum] p8:
5852 // Two enumeration types are layout-compatible if they have the same
5854 return ED1->isComplete() && ED2->isComplete() &&
5855 C.hasSameType(ED1->getIntegerType(), ED2->getIntegerType());
5858 /// \brief Check if two fields are layout-compatible.
5859 bool isLayoutCompatible(ASTContext &C, FieldDecl *Field1, FieldDecl *Field2) {
5860 if (!isLayoutCompatible(C, Field1->getType(), Field2->getType()))
5863 if (Field1->isBitField() != Field2->isBitField())
5866 if (Field1->isBitField()) {
5867 // Make sure that the bit-fields are the same length.
5868 unsigned Bits1 = Field1->getBitWidthValue(C);
5869 unsigned Bits2 = Field2->getBitWidthValue(C);
5878 /// \brief Check if two standard-layout structs are layout-compatible.
5879 /// (C++11 [class.mem] p17)
5880 bool isLayoutCompatibleStruct(ASTContext &C,
5883 // If both records are C++ classes, check that base classes match.
5884 if (const CXXRecordDecl *D1CXX = dyn_cast<CXXRecordDecl>(RD1)) {
5885 // If one of records is a CXXRecordDecl we are in C++ mode,
5886 // thus the other one is a CXXRecordDecl, too.
5887 const CXXRecordDecl *D2CXX = cast<CXXRecordDecl>(RD2);
5888 // Check number of base classes.
5889 if (D1CXX->getNumBases() != D2CXX->getNumBases())
5892 // Check the base classes.
5893 for (CXXRecordDecl::base_class_const_iterator
5894 Base1 = D1CXX->bases_begin(),
5895 BaseEnd1 = D1CXX->bases_end(),
5896 Base2 = D2CXX->bases_begin();
5899 if (!isLayoutCompatible(C, Base1->getType(), Base2->getType()))
5902 } else if (const CXXRecordDecl *D2CXX = dyn_cast<CXXRecordDecl>(RD2)) {
5903 // If only RD2 is a C++ class, it should have zero base classes.
5904 if (D2CXX->getNumBases() > 0)
5908 // Check the fields.
5909 RecordDecl::field_iterator Field2 = RD2->field_begin(),
5910 Field2End = RD2->field_end(),
5911 Field1 = RD1->field_begin(),
5912 Field1End = RD1->field_end();
5913 for ( ; Field1 != Field1End && Field2 != Field2End; ++Field1, ++Field2) {
5914 if (!isLayoutCompatible(C, *Field1, *Field2))
5917 if (Field1 != Field1End || Field2 != Field2End)
5923 /// \brief Check if two standard-layout unions are layout-compatible.
5924 /// (C++11 [class.mem] p18)
5925 bool isLayoutCompatibleUnion(ASTContext &C,
5928 llvm::SmallPtrSet<FieldDecl *, 8> UnmatchedFields;
5929 for (RecordDecl::field_iterator Field2 = RD2->field_begin(),
5930 Field2End = RD2->field_end();
5931 Field2 != Field2End; ++Field2) {
5932 UnmatchedFields.insert(*Field2);
5935 for (RecordDecl::field_iterator Field1 = RD1->field_begin(),
5936 Field1End = RD1->field_end();
5937 Field1 != Field1End; ++Field1) {
5938 llvm::SmallPtrSet<FieldDecl *, 8>::iterator
5939 I = UnmatchedFields.begin(),
5940 E = UnmatchedFields.end();
5942 for ( ; I != E; ++I) {
5943 if (isLayoutCompatible(C, *Field1, *I)) {
5944 bool Result = UnmatchedFields.erase(*I);
5954 return UnmatchedFields.empty();
5957 bool isLayoutCompatible(ASTContext &C, RecordDecl *RD1, RecordDecl *RD2) {
5958 if (RD1->isUnion() != RD2->isUnion())
5962 return isLayoutCompatibleUnion(C, RD1, RD2);
5964 return isLayoutCompatibleStruct(C, RD1, RD2);
5967 /// \brief Check if two types are layout-compatible in C++11 sense.
5968 bool isLayoutCompatible(ASTContext &C, QualType T1, QualType T2) {
5969 if (T1.isNull() || T2.isNull())
5972 // C++11 [basic.types] p11:
5973 // If two types T1 and T2 are the same type, then T1 and T2 are
5974 // layout-compatible types.
5975 if (C.hasSameType(T1, T2))
5978 T1 = T1.getCanonicalType().getUnqualifiedType();
5979 T2 = T2.getCanonicalType().getUnqualifiedType();
5981 const Type::TypeClass TC1 = T1->getTypeClass();
5982 const Type::TypeClass TC2 = T2->getTypeClass();
5987 if (TC1 == Type::Enum) {
5988 return isLayoutCompatible(C,
5989 cast<EnumType>(T1)->getDecl(),
5990 cast<EnumType>(T2)->getDecl());
5991 } else if (TC1 == Type::Record) {
5992 if (!T1->isStandardLayoutType() || !T2->isStandardLayoutType())
5995 return isLayoutCompatible(C,
5996 cast<RecordType>(T1)->getDecl(),
5997 cast<RecordType>(T2)->getDecl());
6004 //===--- CHECK: pointer_with_type_tag attribute: datatypes should match ----//
6007 /// \brief Given a type tag expression find the type tag itself.
6009 /// \param TypeExpr Type tag expression, as it appears in user's code.
6011 /// \param VD Declaration of an identifier that appears in a type tag.
6013 /// \param MagicValue Type tag magic value.
6014 bool FindTypeTagExpr(const Expr *TypeExpr, const ASTContext &Ctx,
6015 const ValueDecl **VD, uint64_t *MagicValue) {
6020 TypeExpr = TypeExpr->IgnoreParenImpCasts()->IgnoreParenCasts();
6022 switch (TypeExpr->getStmtClass()) {
6023 case Stmt::UnaryOperatorClass: {
6024 const UnaryOperator *UO = cast<UnaryOperator>(TypeExpr);
6025 if (UO->getOpcode() == UO_AddrOf || UO->getOpcode() == UO_Deref) {
6026 TypeExpr = UO->getSubExpr();
6032 case Stmt::DeclRefExprClass: {
6033 const DeclRefExpr *DRE = cast<DeclRefExpr>(TypeExpr);
6034 *VD = DRE->getDecl();
6038 case Stmt::IntegerLiteralClass: {
6039 const IntegerLiteral *IL = cast<IntegerLiteral>(TypeExpr);
6040 llvm::APInt MagicValueAPInt = IL->getValue();
6041 if (MagicValueAPInt.getActiveBits() <= 64) {
6042 *MagicValue = MagicValueAPInt.getZExtValue();
6048 case Stmt::BinaryConditionalOperatorClass:
6049 case Stmt::ConditionalOperatorClass: {
6050 const AbstractConditionalOperator *ACO =
6051 cast<AbstractConditionalOperator>(TypeExpr);
6053 if (ACO->getCond()->EvaluateAsBooleanCondition(Result, Ctx)) {
6055 TypeExpr = ACO->getTrueExpr();
6057 TypeExpr = ACO->getFalseExpr();
6063 case Stmt::BinaryOperatorClass: {
6064 const BinaryOperator *BO = cast<BinaryOperator>(TypeExpr);
6065 if (BO->getOpcode() == BO_Comma) {
6066 TypeExpr = BO->getRHS();
6078 /// \brief Retrieve the C type corresponding to type tag TypeExpr.
6080 /// \param TypeExpr Expression that specifies a type tag.
6082 /// \param MagicValues Registered magic values.
6084 /// \param FoundWrongKind Set to true if a type tag was found, but of a wrong
6087 /// \param TypeInfo Information about the corresponding C type.
6089 /// \returns true if the corresponding C type was found.
6090 bool GetMatchingCType(
6091 const IdentifierInfo *ArgumentKind,
6092 const Expr *TypeExpr, const ASTContext &Ctx,
6093 const llvm::DenseMap<Sema::TypeTagMagicValue,
6094 Sema::TypeTagData> *MagicValues,
6095 bool &FoundWrongKind,
6096 Sema::TypeTagData &TypeInfo) {
6097 FoundWrongKind = false;
6099 // Variable declaration that has type_tag_for_datatype attribute.
6100 const ValueDecl *VD = NULL;
6102 uint64_t MagicValue;
6104 if (!FindTypeTagExpr(TypeExpr, Ctx, &VD, &MagicValue))
6108 for (specific_attr_iterator<TypeTagForDatatypeAttr>
6109 I = VD->specific_attr_begin<TypeTagForDatatypeAttr>(),
6110 E = VD->specific_attr_end<TypeTagForDatatypeAttr>();
6112 if (I->getArgumentKind() != ArgumentKind) {
6113 FoundWrongKind = true;
6116 TypeInfo.Type = I->getMatchingCType();
6117 TypeInfo.LayoutCompatible = I->getLayoutCompatible();
6118 TypeInfo.MustBeNull = I->getMustBeNull();
6127 llvm::DenseMap<Sema::TypeTagMagicValue,
6128 Sema::TypeTagData>::const_iterator I =
6129 MagicValues->find(std::make_pair(ArgumentKind, MagicValue));
6130 if (I == MagicValues->end())
6133 TypeInfo = I->second;
6136 } // unnamed namespace
6138 void Sema::RegisterTypeTagForDatatype(const IdentifierInfo *ArgumentKind,
6139 uint64_t MagicValue, QualType Type,
6140 bool LayoutCompatible,
6142 if (!TypeTagForDatatypeMagicValues)
6143 TypeTagForDatatypeMagicValues.reset(
6144 new llvm::DenseMap<TypeTagMagicValue, TypeTagData>);
6146 TypeTagMagicValue Magic(ArgumentKind, MagicValue);
6147 (*TypeTagForDatatypeMagicValues)[Magic] =
6148 TypeTagData(Type, LayoutCompatible, MustBeNull);
6152 bool IsSameCharType(QualType T1, QualType T2) {
6153 const BuiltinType *BT1 = T1->getAs<BuiltinType>();
6157 const BuiltinType *BT2 = T2->getAs<BuiltinType>();
6161 BuiltinType::Kind T1Kind = BT1->getKind();
6162 BuiltinType::Kind T2Kind = BT2->getKind();
6164 return (T1Kind == BuiltinType::SChar && T2Kind == BuiltinType::Char_S) ||
6165 (T1Kind == BuiltinType::UChar && T2Kind == BuiltinType::Char_U) ||
6166 (T1Kind == BuiltinType::Char_U && T2Kind == BuiltinType::UChar) ||
6167 (T1Kind == BuiltinType::Char_S && T2Kind == BuiltinType::SChar);
6169 } // unnamed namespace
6171 void Sema::CheckArgumentWithTypeTag(const ArgumentWithTypeTagAttr *Attr,
6172 const Expr * const *ExprArgs) {
6173 const IdentifierInfo *ArgumentKind = Attr->getArgumentKind();
6174 bool IsPointerAttr = Attr->getIsPointer();
6176 const Expr *TypeTagExpr = ExprArgs[Attr->getTypeTagIdx()];
6177 bool FoundWrongKind;
6178 TypeTagData TypeInfo;
6179 if (!GetMatchingCType(ArgumentKind, TypeTagExpr, Context,
6180 TypeTagForDatatypeMagicValues.get(),
6181 FoundWrongKind, TypeInfo)) {
6183 Diag(TypeTagExpr->getExprLoc(),
6184 diag::warn_type_tag_for_datatype_wrong_kind)
6185 << TypeTagExpr->getSourceRange();
6189 const Expr *ArgumentExpr = ExprArgs[Attr->getArgumentIdx()];
6190 if (IsPointerAttr) {
6191 // Skip implicit cast of pointer to `void *' (as a function argument).
6192 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgumentExpr))
6193 if (ICE->getType()->isVoidPointerType() &&
6194 ICE->getCastKind() == CK_BitCast)
6195 ArgumentExpr = ICE->getSubExpr();
6197 QualType ArgumentType = ArgumentExpr->getType();
6199 // Passing a `void*' pointer shouldn't trigger a warning.
6200 if (IsPointerAttr && ArgumentType->isVoidPointerType())
6203 if (TypeInfo.MustBeNull) {
6204 // Type tag with matching void type requires a null pointer.
6205 if (!ArgumentExpr->isNullPointerConstant(Context,
6206 Expr::NPC_ValueDependentIsNotNull)) {
6207 Diag(ArgumentExpr->getExprLoc(),
6208 diag::warn_type_safety_null_pointer_required)
6209 << ArgumentKind->getName()
6210 << ArgumentExpr->getSourceRange()
6211 << TypeTagExpr->getSourceRange();
6216 QualType RequiredType = TypeInfo.Type;
6218 RequiredType = Context.getPointerType(RequiredType);
6220 bool mismatch = false;
6221 if (!TypeInfo.LayoutCompatible) {
6222 mismatch = !Context.hasSameType(ArgumentType, RequiredType);
6224 // C++11 [basic.fundamental] p1:
6225 // Plain char, signed char, and unsigned char are three distinct types.
6227 // But we treat plain `char' as equivalent to `signed char' or `unsigned
6228 // char' depending on the current char signedness mode.
6230 if ((IsPointerAttr && IsSameCharType(ArgumentType->getPointeeType(),
6231 RequiredType->getPointeeType())) ||
6232 (!IsPointerAttr && IsSameCharType(ArgumentType, RequiredType)))
6236 mismatch = !isLayoutCompatible(Context,
6237 ArgumentType->getPointeeType(),
6238 RequiredType->getPointeeType());
6240 mismatch = !isLayoutCompatible(Context, ArgumentType, RequiredType);
6243 Diag(ArgumentExpr->getExprLoc(), diag::warn_type_safety_type_mismatch)
6244 << ArgumentType << ArgumentKind->getName()
6245 << TypeInfo.LayoutCompatible << RequiredType
6246 << ArgumentExpr->getSourceRange()
6247 << TypeTagExpr->getSourceRange();