clang 19.0.0git
SemaExceptionSpec.cpp
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1//===--- SemaExceptionSpec.cpp - C++ Exception Specifications ---*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file provides Sema routines for C++ exception specification testing.
10//
11//===----------------------------------------------------------------------===//
12
16#include "clang/AST/Expr.h"
17#include "clang/AST/ExprCXX.h"
18#include "clang/AST/StmtObjC.h"
19#include "clang/AST/TypeLoc.h"
22#include "llvm/ADT/SmallPtrSet.h"
23#include "llvm/ADT/SmallString.h"
24#include <optional>
25
26namespace clang {
27
29{
30 if (const PointerType *PtrTy = T->getAs<PointerType>())
31 T = PtrTy->getPointeeType();
32 else if (const ReferenceType *RefTy = T->getAs<ReferenceType>())
33 T = RefTy->getPointeeType();
34 else if (const MemberPointerType *MPTy = T->getAs<MemberPointerType>())
35 T = MPTy->getPointeeType();
36 return T->getAs<FunctionProtoType>();
37}
38
39/// HACK: 2014-11-14 libstdc++ had a bug where it shadows std::swap with a
40/// member swap function then tries to call std::swap unqualified from the
41/// exception specification of that function. This function detects whether
42/// we're in such a case and turns off delay-parsing of exception
43/// specifications. Libstdc++ 6.1 (released 2016-04-27) appears to have
44/// resolved it as side-effect of commit ddb63209a8d (2015-06-05).
46 auto *RD = dyn_cast<CXXRecordDecl>(CurContext);
47
48 // All the problem cases are member functions named "swap" within class
49 // templates declared directly within namespace std or std::__debug or
50 // std::__profile.
51 if (!RD || !RD->getIdentifier() || !RD->getDescribedClassTemplate() ||
52 !D.getIdentifier() || !D.getIdentifier()->isStr("swap"))
53 return false;
54
55 auto *ND = dyn_cast<NamespaceDecl>(RD->getDeclContext());
56 if (!ND)
57 return false;
58
59 bool IsInStd = ND->isStdNamespace();
60 if (!IsInStd) {
61 // This isn't a direct member of namespace std, but it might still be
62 // libstdc++'s std::__debug::array or std::__profile::array.
63 IdentifierInfo *II = ND->getIdentifier();
64 if (!II || !(II->isStr("__debug") || II->isStr("__profile")) ||
65 !ND->isInStdNamespace())
66 return false;
67 }
68
69 // Only apply this hack within a system header.
71 return false;
72
73 return llvm::StringSwitch<bool>(RD->getIdentifier()->getName())
74 .Case("array", true)
75 .Case("pair", IsInStd)
76 .Case("priority_queue", IsInStd)
77 .Case("stack", IsInStd)
78 .Case("queue", IsInStd)
79 .Default(false);
80}
81
84
85 if (NoexceptExpr->isTypeDependent() ||
86 NoexceptExpr->containsUnexpandedParameterPack()) {
88 return NoexceptExpr;
89 }
90
91 llvm::APSInt Result;
93 NoexceptExpr, Context.BoolTy, Result, CCEK_Noexcept);
94
95 if (Converted.isInvalid()) {
97 // Fill in an expression of 'false' as a fixup.
98 auto *BoolExpr = new (Context)
99 CXXBoolLiteralExpr(false, Context.BoolTy, NoexceptExpr->getBeginLoc());
100 llvm::APSInt Value{1};
101 Value = 0;
102 return ConstantExpr::Create(Context, BoolExpr, APValue{Value});
103 }
104
105 if (Converted.get()->isValueDependent()) {
107 return Converted;
108 }
109
110 if (!Converted.isInvalid())
112 return Converted;
113}
114
115/// CheckSpecifiedExceptionType - Check if the given type is valid in an
116/// exception specification. Incomplete types, or pointers to incomplete types
117/// other than void are not allowed.
118///
119/// \param[in,out] T The exception type. This will be decayed to a pointer type
120/// when the input is an array or a function type.
122 // C++11 [except.spec]p2:
123 // A type cv T, "array of T", or "function returning T" denoted
124 // in an exception-specification is adjusted to type T, "pointer to T", or
125 // "pointer to function returning T", respectively.
126 //
127 // We also apply this rule in C++98.
128 if (T->isArrayType())
130 else if (T->isFunctionType())
131 T = Context.getPointerType(T);
132
133 int Kind = 0;
134 QualType PointeeT = T;
135 if (const PointerType *PT = T->getAs<PointerType>()) {
136 PointeeT = PT->getPointeeType();
137 Kind = 1;
138
139 // cv void* is explicitly permitted, despite being a pointer to an
140 // incomplete type.
141 if (PointeeT->isVoidType())
142 return false;
143 } else if (const ReferenceType *RT = T->getAs<ReferenceType>()) {
144 PointeeT = RT->getPointeeType();
145 Kind = 2;
146
147 if (RT->isRValueReferenceType()) {
148 // C++11 [except.spec]p2:
149 // A type denoted in an exception-specification shall not denote [...]
150 // an rvalue reference type.
151 Diag(Range.getBegin(), diag::err_rref_in_exception_spec)
152 << T << Range;
153 return true;
154 }
155 }
156
157 // C++11 [except.spec]p2:
158 // A type denoted in an exception-specification shall not denote an
159 // incomplete type other than a class currently being defined [...].
160 // A type denoted in an exception-specification shall not denote a
161 // pointer or reference to an incomplete type, other than (cv) void* or a
162 // pointer or reference to a class currently being defined.
163 // In Microsoft mode, downgrade this to a warning.
164 unsigned DiagID = diag::err_incomplete_in_exception_spec;
165 bool ReturnValueOnError = true;
166 if (getLangOpts().MSVCCompat) {
167 DiagID = diag::ext_incomplete_in_exception_spec;
168 ReturnValueOnError = false;
169 }
170 if (!(PointeeT->isRecordType() &&
171 PointeeT->castAs<RecordType>()->isBeingDefined()) &&
172 RequireCompleteType(Range.getBegin(), PointeeT, DiagID, Kind, Range))
173 return ReturnValueOnError;
174
175 // WebAssembly reference types can't be used in exception specifications.
176 if (PointeeT.isWebAssemblyReferenceType()) {
177 Diag(Range.getBegin(), diag::err_wasm_reftype_exception_spec);
178 return true;
179 }
180
181 // The MSVC compatibility mode doesn't extend to sizeless types,
182 // so diagnose them separately.
183 if (PointeeT->isSizelessType() && Kind != 1) {
184 Diag(Range.getBegin(), diag::err_sizeless_in_exception_spec)
185 << (Kind == 2 ? 1 : 0) << PointeeT << Range;
186 return true;
187 }
188
189 return false;
190}
191
192/// CheckDistantExceptionSpec - Check if the given type is a pointer or pointer
193/// to member to a function with an exception specification. This means that
194/// it is invalid to add another level of indirection.
196 // C++17 removes this rule in favor of putting exception specifications into
197 // the type system.
199 return false;
200
201 if (const PointerType *PT = T->getAs<PointerType>())
202 T = PT->getPointeeType();
203 else if (const MemberPointerType *PT = T->getAs<MemberPointerType>())
204 T = PT->getPointeeType();
205 else
206 return false;
207
208 const FunctionProtoType *FnT = T->getAs<FunctionProtoType>();
209 if (!FnT)
210 return false;
211
212 return FnT->hasExceptionSpec();
213}
214
215const FunctionProtoType *
217 if (FPT->getExceptionSpecType() == EST_Unparsed) {
218 Diag(Loc, diag::err_exception_spec_not_parsed);
219 return nullptr;
220 }
221
223 return FPT;
224
225 FunctionDecl *SourceDecl = FPT->getExceptionSpecDecl();
226 const FunctionProtoType *SourceFPT =
227 SourceDecl->getType()->castAs<FunctionProtoType>();
228
229 // If the exception specification has already been resolved, just return it.
231 return SourceFPT;
232
233 // Compute or instantiate the exception specification now.
234 if (SourceFPT->getExceptionSpecType() == EST_Unevaluated)
235 EvaluateImplicitExceptionSpec(Loc, SourceDecl);
236 else
237 InstantiateExceptionSpec(Loc, SourceDecl);
238
239 const FunctionProtoType *Proto =
240 SourceDecl->getType()->castAs<FunctionProtoType>();
242 Diag(Loc, diag::err_exception_spec_not_parsed);
243 Proto = nullptr;
244 }
245 return Proto;
246}
247
248void
251 // If we've fully resolved the exception specification, notify listeners.
253 if (auto *Listener = getASTMutationListener())
254 Listener->ResolvedExceptionSpec(FD);
255
256 for (FunctionDecl *Redecl : FD->redecls())
257 Context.adjustExceptionSpec(Redecl, ESI);
258}
259
261 auto *MD = dyn_cast<CXXMethodDecl>(FD);
262 if (!MD)
263 return false;
264
265 auto EST = MD->getType()->castAs<FunctionProtoType>()->getExceptionSpecType();
266 return EST == EST_Unparsed ||
267 (EST == EST_Unevaluated && MD->getParent()->isBeingDefined());
268}
269
271 Sema &S, const PartialDiagnostic &DiagID, const PartialDiagnostic &NoteID,
272 const FunctionProtoType *Old, SourceLocation OldLoc,
273 const FunctionProtoType *New, SourceLocation NewLoc,
274 bool *MissingExceptionSpecification = nullptr,
275 bool *MissingEmptyExceptionSpecification = nullptr,
276 bool AllowNoexceptAllMatchWithNoSpec = false, bool IsOperatorNew = false);
277
278/// Determine whether a function has an implicitly-generated exception
279/// specification.
281 if (!isa<CXXDestructorDecl>(Decl) &&
282 Decl->getDeclName().getCXXOverloadedOperator() != OO_Delete &&
283 Decl->getDeclName().getCXXOverloadedOperator() != OO_Array_Delete)
284 return false;
285
286 // For a function that the user didn't declare:
287 // - if this is a destructor, its exception specification is implicit.
288 // - if this is 'operator delete' or 'operator delete[]', the exception
289 // specification is as-if an explicit exception specification was given
290 // (per [basic.stc.dynamic]p2).
291 if (!Decl->getTypeSourceInfo())
292 return isa<CXXDestructorDecl>(Decl);
293
294 auto *Ty = Decl->getTypeSourceInfo()->getType()->castAs<FunctionProtoType>();
295 return !Ty->hasExceptionSpec();
296}
297
299 // Just completely ignore this under -fno-exceptions prior to C++17.
300 // In C++17 onwards, the exception specification is part of the type and
301 // we will diagnose mismatches anyway, so it's better to check for them here.
302 if (!getLangOpts().CXXExceptions && !getLangOpts().CPlusPlus17)
303 return false;
304
306 bool IsOperatorNew = OO == OO_New || OO == OO_Array_New;
307 bool MissingExceptionSpecification = false;
308 bool MissingEmptyExceptionSpecification = false;
309
310 unsigned DiagID = diag::err_mismatched_exception_spec;
311 bool ReturnValueOnError = true;
312 if (getLangOpts().MSVCCompat) {
313 DiagID = diag::ext_mismatched_exception_spec;
314 ReturnValueOnError = false;
315 }
316
317 // If we're befriending a member function of a class that's currently being
318 // defined, we might not be able to work out its exception specification yet.
319 // If not, defer the check until later.
321 DelayedEquivalentExceptionSpecChecks.push_back({New, Old});
322 return false;
323 }
324
325 // Check the types as written: they must match before any exception
326 // specification adjustment is applied.
328 *this, PDiag(DiagID), PDiag(diag::note_previous_declaration),
329 Old->getType()->getAs<FunctionProtoType>(), Old->getLocation(),
330 New->getType()->getAs<FunctionProtoType>(), New->getLocation(),
331 &MissingExceptionSpecification, &MissingEmptyExceptionSpecification,
332 /*AllowNoexceptAllMatchWithNoSpec=*/true, IsOperatorNew)) {
333 // C++11 [except.spec]p4 [DR1492]:
334 // If a declaration of a function has an implicit
335 // exception-specification, other declarations of the function shall
336 // not specify an exception-specification.
337 if (getLangOpts().CPlusPlus11 && getLangOpts().CXXExceptions &&
339 Diag(New->getLocation(), diag::ext_implicit_exception_spec_mismatch)
341 if (Old->getLocation().isValid())
342 Diag(Old->getLocation(), diag::note_previous_declaration);
343 }
344 return false;
345 }
346
347 // The failure was something other than an missing exception
348 // specification; return an error, except in MS mode where this is a warning.
349 if (!MissingExceptionSpecification)
350 return ReturnValueOnError;
351
352 const auto *NewProto = New->getType()->castAs<FunctionProtoType>();
353
354 // The new function declaration is only missing an empty exception
355 // specification "throw()". If the throw() specification came from a
356 // function in a system header that has C linkage, just add an empty
357 // exception specification to the "new" declaration. Note that C library
358 // implementations are permitted to add these nothrow exception
359 // specifications.
360 //
361 // Likewise if the old function is a builtin.
362 if (MissingEmptyExceptionSpecification &&
363 (Old->getLocation().isInvalid() ||
365 Old->getBuiltinID()) &&
366 Old->isExternC()) {
368 NewProto->getReturnType(), NewProto->getParamTypes(),
369 NewProto->getExtProtoInfo().withExceptionSpec(EST_DynamicNone)));
370 return false;
371 }
372
373 const auto *OldProto = Old->getType()->castAs<FunctionProtoType>();
374
375 FunctionProtoType::ExceptionSpecInfo ESI = OldProto->getExceptionSpecType();
376 if (ESI.Type == EST_Dynamic) {
377 // FIXME: What if the exceptions are described in terms of the old
378 // prototype's parameters?
379 ESI.Exceptions = OldProto->exceptions();
380 }
381
382 if (ESI.Type == EST_NoexceptFalse)
383 ESI.Type = EST_None;
384 if (ESI.Type == EST_NoexceptTrue)
385 ESI.Type = EST_BasicNoexcept;
386
387 // For dependent noexcept, we can't just take the expression from the old
388 // prototype. It likely contains references to the old prototype's parameters.
389 if (ESI.Type == EST_DependentNoexcept) {
390 New->setInvalidDecl();
391 } else {
392 // Update the type of the function with the appropriate exception
393 // specification.
395 NewProto->getReturnType(), NewProto->getParamTypes(),
396 NewProto->getExtProtoInfo().withExceptionSpec(ESI)));
397 }
398
399 if (getLangOpts().MSVCCompat && isDynamicExceptionSpec(ESI.Type)) {
400 DiagID = diag::ext_missing_exception_specification;
401 ReturnValueOnError = false;
402 } else if (New->isReplaceableGlobalAllocationFunction() &&
403 ESI.Type != EST_DependentNoexcept) {
404 // Allow missing exception specifications in redeclarations as an extension,
405 // when declaring a replaceable global allocation function.
406 DiagID = diag::ext_missing_exception_specification;
407 ReturnValueOnError = false;
408 } else if (ESI.Type == EST_NoThrow) {
409 // Don't emit any warning for missing 'nothrow' in MSVC.
410 if (getLangOpts().MSVCCompat) {
411 return false;
412 }
413 // Allow missing attribute 'nothrow' in redeclarations, since this is a very
414 // common omission.
415 DiagID = diag::ext_missing_exception_specification;
416 ReturnValueOnError = false;
417 } else {
418 DiagID = diag::err_missing_exception_specification;
419 ReturnValueOnError = true;
420 }
421
422 // Warn about the lack of exception specification.
423 SmallString<128> ExceptionSpecString;
424 llvm::raw_svector_ostream OS(ExceptionSpecString);
425 switch (OldProto->getExceptionSpecType()) {
426 case EST_DynamicNone:
427 OS << "throw()";
428 break;
429
430 case EST_Dynamic: {
431 OS << "throw(";
432 bool OnFirstException = true;
433 for (const auto &E : OldProto->exceptions()) {
434 if (OnFirstException)
435 OnFirstException = false;
436 else
437 OS << ", ";
438
439 OS << E.getAsString(getPrintingPolicy());
440 }
441 OS << ")";
442 break;
443 }
444
446 OS << "noexcept";
447 break;
448
451 case EST_NoexceptTrue:
452 OS << "noexcept(";
453 assert(OldProto->getNoexceptExpr() != nullptr && "Expected non-null Expr");
454 OldProto->getNoexceptExpr()->printPretty(OS, nullptr, getPrintingPolicy());
455 OS << ")";
456 break;
457 case EST_NoThrow:
458 OS <<"__attribute__((nothrow))";
459 break;
460 case EST_None:
461 case EST_MSAny:
462 case EST_Unevaluated:
464 case EST_Unparsed:
465 llvm_unreachable("This spec type is compatible with none.");
466 }
467
468 SourceLocation FixItLoc;
469 if (TypeSourceInfo *TSInfo = New->getTypeSourceInfo()) {
470 TypeLoc TL = TSInfo->getTypeLoc().IgnoreParens();
471 // FIXME: Preserve enough information so that we can produce a correct fixit
472 // location when there is a trailing return type.
473 if (auto FTLoc = TL.getAs<FunctionProtoTypeLoc>())
474 if (!FTLoc.getTypePtr()->hasTrailingReturn())
475 FixItLoc = getLocForEndOfToken(FTLoc.getLocalRangeEnd());
476 }
477
478 if (FixItLoc.isInvalid())
479 Diag(New->getLocation(), DiagID)
480 << New << OS.str();
481 else {
482 Diag(New->getLocation(), DiagID)
483 << New << OS.str()
484 << FixItHint::CreateInsertion(FixItLoc, " " + OS.str().str());
485 }
486
487 if (Old->getLocation().isValid())
488 Diag(Old->getLocation(), diag::note_previous_declaration);
489
490 return ReturnValueOnError;
491}
492
493/// CheckEquivalentExceptionSpec - Check if the two types have equivalent
494/// exception specifications. Exception specifications are equivalent if
495/// they allow exactly the same set of exception types. It does not matter how
496/// that is achieved. See C++ [except.spec]p2.
498 const FunctionProtoType *Old, SourceLocation OldLoc,
499 const FunctionProtoType *New, SourceLocation NewLoc) {
500 if (!getLangOpts().CXXExceptions)
501 return false;
502
503 unsigned DiagID = diag::err_mismatched_exception_spec;
504 if (getLangOpts().MSVCCompat)
505 DiagID = diag::ext_mismatched_exception_spec;
507 *this, PDiag(DiagID), PDiag(diag::note_previous_declaration),
508 Old, OldLoc, New, NewLoc);
509
510 // In Microsoft mode, mismatching exception specifications just cause a warning.
511 if (getLangOpts().MSVCCompat)
512 return false;
513 return Result;
514}
515
516/// CheckEquivalentExceptionSpec - Check if the two types have compatible
517/// exception specifications. See C++ [except.spec]p3.
518///
519/// \return \c false if the exception specifications match, \c true if there is
520/// a problem. If \c true is returned, either a diagnostic has already been
521/// produced or \c *MissingExceptionSpecification is set to \c true.
523 Sema &S, const PartialDiagnostic &DiagID, const PartialDiagnostic &NoteID,
524 const FunctionProtoType *Old, SourceLocation OldLoc,
525 const FunctionProtoType *New, SourceLocation NewLoc,
526 bool *MissingExceptionSpecification,
527 bool *MissingEmptyExceptionSpecification,
528 bool AllowNoexceptAllMatchWithNoSpec, bool IsOperatorNew) {
529 if (MissingExceptionSpecification)
530 *MissingExceptionSpecification = false;
531
532 if (MissingEmptyExceptionSpecification)
533 *MissingEmptyExceptionSpecification = false;
534
535 Old = S.ResolveExceptionSpec(NewLoc, Old);
536 if (!Old)
537 return false;
538 New = S.ResolveExceptionSpec(NewLoc, New);
539 if (!New)
540 return false;
541
542 // C++0x [except.spec]p3: Two exception-specifications are compatible if:
543 // - both are non-throwing, regardless of their form,
544 // - both have the form noexcept(constant-expression) and the constant-
545 // expressions are equivalent,
546 // - both are dynamic-exception-specifications that have the same set of
547 // adjusted types.
548 //
549 // C++0x [except.spec]p12: An exception-specification is non-throwing if it is
550 // of the form throw(), noexcept, or noexcept(constant-expression) where the
551 // constant-expression yields true.
552 //
553 // C++0x [except.spec]p4: If any declaration of a function has an exception-
554 // specifier that is not a noexcept-specification allowing all exceptions,
555 // all declarations [...] of that function shall have a compatible
556 // exception-specification.
557 //
558 // That last point basically means that noexcept(false) matches no spec.
559 // It's considered when AllowNoexceptAllMatchWithNoSpec is true.
560
563
564 assert(!isUnresolvedExceptionSpec(OldEST) &&
565 !isUnresolvedExceptionSpec(NewEST) &&
566 "Shouldn't see unknown exception specifications here");
567
568 CanThrowResult OldCanThrow = Old->canThrow();
569 CanThrowResult NewCanThrow = New->canThrow();
570
571 // Any non-throwing specifications are compatible.
572 if (OldCanThrow == CT_Cannot && NewCanThrow == CT_Cannot)
573 return false;
574
575 // Any throws-anything specifications are usually compatible.
576 if (OldCanThrow == CT_Can && OldEST != EST_Dynamic &&
577 NewCanThrow == CT_Can && NewEST != EST_Dynamic) {
578 // The exception is that the absence of an exception specification only
579 // matches noexcept(false) for functions, as described above.
580 if (!AllowNoexceptAllMatchWithNoSpec &&
581 ((OldEST == EST_None && NewEST == EST_NoexceptFalse) ||
582 (OldEST == EST_NoexceptFalse && NewEST == EST_None))) {
583 // This is the disallowed case.
584 } else {
585 return false;
586 }
587 }
588
589 // C++14 [except.spec]p3:
590 // Two exception-specifications are compatible if [...] both have the form
591 // noexcept(constant-expression) and the constant-expressions are equivalent
592 if (OldEST == EST_DependentNoexcept && NewEST == EST_DependentNoexcept) {
593 llvm::FoldingSetNodeID OldFSN, NewFSN;
594 Old->getNoexceptExpr()->Profile(OldFSN, S.Context, true);
595 New->getNoexceptExpr()->Profile(NewFSN, S.Context, true);
596 if (OldFSN == NewFSN)
597 return false;
598 }
599
600 // Dynamic exception specifications with the same set of adjusted types
601 // are compatible.
602 if (OldEST == EST_Dynamic && NewEST == EST_Dynamic) {
603 bool Success = true;
604 // Both have a dynamic exception spec. Collect the first set, then compare
605 // to the second.
606 llvm::SmallPtrSet<CanQualType, 8> OldTypes, NewTypes;
607 for (const auto &I : Old->exceptions())
608 OldTypes.insert(S.Context.getCanonicalType(I).getUnqualifiedType());
609
610 for (const auto &I : New->exceptions()) {
612 if (OldTypes.count(TypePtr))
613 NewTypes.insert(TypePtr);
614 else {
615 Success = false;
616 break;
617 }
618 }
619
620 if (Success && OldTypes.size() == NewTypes.size())
621 return false;
622 }
623
624 // As a special compatibility feature, under C++0x we accept no spec and
625 // throw(std::bad_alloc) as equivalent for operator new and operator new[].
626 // This is because the implicit declaration changed, but old code would break.
627 if (S.getLangOpts().CPlusPlus11 && IsOperatorNew) {
628 const FunctionProtoType *WithExceptions = nullptr;
629 if (OldEST == EST_None && NewEST == EST_Dynamic)
630 WithExceptions = New;
631 else if (OldEST == EST_Dynamic && NewEST == EST_None)
632 WithExceptions = Old;
633 if (WithExceptions && WithExceptions->getNumExceptions() == 1) {
634 // One has no spec, the other throw(something). If that something is
635 // std::bad_alloc, all conditions are met.
636 QualType Exception = *WithExceptions->exception_begin();
637 if (CXXRecordDecl *ExRecord = Exception->getAsCXXRecordDecl()) {
638 IdentifierInfo* Name = ExRecord->getIdentifier();
639 if (Name && Name->getName() == "bad_alloc") {
640 // It's called bad_alloc, but is it in std?
641 if (ExRecord->isInStdNamespace()) {
642 return false;
643 }
644 }
645 }
646 }
647 }
648
649 // If the caller wants to handle the case that the new function is
650 // incompatible due to a missing exception specification, let it.
651 if (MissingExceptionSpecification && OldEST != EST_None &&
652 NewEST == EST_None) {
653 // The old type has an exception specification of some sort, but
654 // the new type does not.
655 *MissingExceptionSpecification = true;
656
657 if (MissingEmptyExceptionSpecification && OldCanThrow == CT_Cannot) {
658 // The old type has a throw() or noexcept(true) exception specification
659 // and the new type has no exception specification, and the caller asked
660 // to handle this itself.
661 *MissingEmptyExceptionSpecification = true;
662 }
663
664 return true;
665 }
666
667 S.Diag(NewLoc, DiagID);
668 if (NoteID.getDiagID() != 0 && OldLoc.isValid())
669 S.Diag(OldLoc, NoteID);
670 return true;
671}
672
674 const PartialDiagnostic &NoteID,
675 const FunctionProtoType *Old,
676 SourceLocation OldLoc,
677 const FunctionProtoType *New,
678 SourceLocation NewLoc) {
679 if (!getLangOpts().CXXExceptions)
680 return false;
681 return CheckEquivalentExceptionSpecImpl(*this, DiagID, NoteID, Old, OldLoc,
682 New, NewLoc);
683}
684
685bool Sema::handlerCanCatch(QualType HandlerType, QualType ExceptionType) {
686 // [except.handle]p3:
687 // A handler is a match for an exception object of type E if:
688
689 // HandlerType must be ExceptionType or derived from it, or pointer or
690 // reference to such types.
691 const ReferenceType *RefTy = HandlerType->getAs<ReferenceType>();
692 if (RefTy)
693 HandlerType = RefTy->getPointeeType();
694
695 // -- the handler is of type cv T or cv T& and E and T are the same type
696 if (Context.hasSameUnqualifiedType(ExceptionType, HandlerType))
697 return true;
698
699 // FIXME: ObjC pointer types?
700 if (HandlerType->isPointerType() || HandlerType->isMemberPointerType()) {
701 if (RefTy && (!HandlerType.isConstQualified() ||
702 HandlerType.isVolatileQualified()))
703 return false;
704
705 // -- the handler is of type cv T or const T& where T is a pointer or
706 // pointer to member type and E is std::nullptr_t
707 if (ExceptionType->isNullPtrType())
708 return true;
709
710 // -- the handler is of type cv T or const T& where T is a pointer or
711 // pointer to member type and E is a pointer or pointer to member type
712 // that can be converted to T by one or more of
713 // -- a qualification conversion
714 // -- a function pointer conversion
715 bool LifetimeConv;
717 // FIXME: Should we treat the exception as catchable if a lifetime
718 // conversion is required?
719 if (IsQualificationConversion(ExceptionType, HandlerType, false,
720 LifetimeConv) ||
721 IsFunctionConversion(ExceptionType, HandlerType, Result))
722 return true;
723
724 // -- a standard pointer conversion [...]
725 if (!ExceptionType->isPointerType() || !HandlerType->isPointerType())
726 return false;
727
728 // Handle the "qualification conversion" portion.
729 Qualifiers EQuals, HQuals;
730 ExceptionType = Context.getUnqualifiedArrayType(
731 ExceptionType->getPointeeType(), EQuals);
732 HandlerType = Context.getUnqualifiedArrayType(
733 HandlerType->getPointeeType(), HQuals);
734 if (!HQuals.compatiblyIncludes(EQuals))
735 return false;
736
737 if (HandlerType->isVoidType() && ExceptionType->isObjectType())
738 return true;
739
740 // The only remaining case is a derived-to-base conversion.
741 }
742
743 // -- the handler is of type cg T or cv T& and T is an unambiguous public
744 // base class of E
745 if (!ExceptionType->isRecordType() || !HandlerType->isRecordType())
746 return false;
747 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
748 /*DetectVirtual=*/false);
749 if (!IsDerivedFrom(SourceLocation(), ExceptionType, HandlerType, Paths) ||
750 Paths.isAmbiguous(Context.getCanonicalType(HandlerType)))
751 return false;
752
753 // Do this check from a context without privileges.
754 switch (CheckBaseClassAccess(SourceLocation(), HandlerType, ExceptionType,
755 Paths.front(),
756 /*Diagnostic*/ 0,
757 /*ForceCheck*/ true,
758 /*ForceUnprivileged*/ true)) {
759 case AR_accessible: return true;
760 case AR_inaccessible: return false;
761 case AR_dependent:
762 llvm_unreachable("access check dependent for unprivileged context");
763 case AR_delayed:
764 llvm_unreachable("access check delayed in non-declaration");
765 }
766 llvm_unreachable("unexpected access check result");
767}
768
769/// CheckExceptionSpecSubset - Check whether the second function type's
770/// exception specification is a subset (or equivalent) of the first function
771/// type. This is used by override and pointer assignment checks.
773 const PartialDiagnostic &DiagID, const PartialDiagnostic &NestedDiagID,
774 const PartialDiagnostic &NoteID, const PartialDiagnostic &NoThrowDiagID,
775 const FunctionProtoType *Superset, bool SkipSupersetFirstParameter,
776 SourceLocation SuperLoc, const FunctionProtoType *Subset,
777 bool SkipSubsetFirstParameter, SourceLocation SubLoc) {
778
779 // Just auto-succeed under -fno-exceptions.
780 if (!getLangOpts().CXXExceptions)
781 return false;
782
783 // FIXME: As usual, we could be more specific in our error messages, but
784 // that better waits until we've got types with source locations.
785
786 if (!SubLoc.isValid())
787 SubLoc = SuperLoc;
788
789 // Resolve the exception specifications, if needed.
790 Superset = ResolveExceptionSpec(SuperLoc, Superset);
791 if (!Superset)
792 return false;
793 Subset = ResolveExceptionSpec(SubLoc, Subset);
794 if (!Subset)
795 return false;
796
799 assert(!isUnresolvedExceptionSpec(SuperEST) &&
800 !isUnresolvedExceptionSpec(SubEST) &&
801 "Shouldn't see unknown exception specifications here");
802
803 // If there are dependent noexcept specs, assume everything is fine. Unlike
804 // with the equivalency check, this is safe in this case, because we don't
805 // want to merge declarations. Checks after instantiation will catch any
806 // omissions we make here.
807 if (SuperEST == EST_DependentNoexcept || SubEST == EST_DependentNoexcept)
808 return false;
809
810 CanThrowResult SuperCanThrow = Superset->canThrow();
811 CanThrowResult SubCanThrow = Subset->canThrow();
812
813 // If the superset contains everything or the subset contains nothing, we're
814 // done.
815 if ((SuperCanThrow == CT_Can && SuperEST != EST_Dynamic) ||
816 SubCanThrow == CT_Cannot)
817 return CheckParamExceptionSpec(NestedDiagID, NoteID, Superset,
818 SkipSupersetFirstParameter, SuperLoc, Subset,
819 SkipSubsetFirstParameter, SubLoc);
820
821 // Allow __declspec(nothrow) to be missing on redeclaration as an extension in
822 // some cases.
823 if (NoThrowDiagID.getDiagID() != 0 && SubCanThrow == CT_Can &&
824 SuperCanThrow == CT_Cannot && SuperEST == EST_NoThrow) {
825 Diag(SubLoc, NoThrowDiagID);
826 if (NoteID.getDiagID() != 0)
827 Diag(SuperLoc, NoteID);
828 return true;
829 }
830
831 // If the subset contains everything or the superset contains nothing, we've
832 // failed.
833 if ((SubCanThrow == CT_Can && SubEST != EST_Dynamic) ||
834 SuperCanThrow == CT_Cannot) {
835 Diag(SubLoc, DiagID);
836 if (NoteID.getDiagID() != 0)
837 Diag(SuperLoc, NoteID);
838 return true;
839 }
840
841 assert(SuperEST == EST_Dynamic && SubEST == EST_Dynamic &&
842 "Exception spec subset: non-dynamic case slipped through.");
843
844 // Neither contains everything or nothing. Do a proper comparison.
845 for (QualType SubI : Subset->exceptions()) {
846 if (const ReferenceType *RefTy = SubI->getAs<ReferenceType>())
847 SubI = RefTy->getPointeeType();
848
849 // Make sure it's in the superset.
850 bool Contained = false;
851 for (QualType SuperI : Superset->exceptions()) {
852 // [except.spec]p5:
853 // the target entity shall allow at least the exceptions allowed by the
854 // source
855 //
856 // We interpret this as meaning that a handler for some target type would
857 // catch an exception of each source type.
858 if (handlerCanCatch(SuperI, SubI)) {
859 Contained = true;
860 break;
861 }
862 }
863 if (!Contained) {
864 Diag(SubLoc, DiagID);
865 if (NoteID.getDiagID() != 0)
866 Diag(SuperLoc, NoteID);
867 return true;
868 }
869 }
870 // We've run half the gauntlet.
871 return CheckParamExceptionSpec(NestedDiagID, NoteID, Superset,
872 SkipSupersetFirstParameter, SuperLoc, Subset,
873 SkipSupersetFirstParameter, SubLoc);
874}
875
876static bool
878 const PartialDiagnostic &NoteID, QualType Target,
879 SourceLocation TargetLoc, QualType Source,
880 SourceLocation SourceLoc) {
882 if (!TFunc)
883 return false;
884 const FunctionProtoType *SFunc = GetUnderlyingFunction(Source);
885 if (!SFunc)
886 return false;
887
888 return S.CheckEquivalentExceptionSpec(DiagID, NoteID, TFunc, TargetLoc,
889 SFunc, SourceLoc);
890}
891
892/// CheckParamExceptionSpec - Check if the parameter and return types of the
893/// two functions have equivalent exception specs. This is part of the
894/// assignment and override compatibility check. We do not check the parameters
895/// of parameter function pointers recursively, as no sane programmer would
896/// even be able to write such a function type.
898 const PartialDiagnostic &DiagID, const PartialDiagnostic &NoteID,
899 const FunctionProtoType *Target, bool SkipTargetFirstParameter,
900 SourceLocation TargetLoc, const FunctionProtoType *Source,
901 bool SkipSourceFirstParameter, SourceLocation SourceLoc) {
902 auto RetDiag = DiagID;
903 RetDiag << 0;
905 *this, RetDiag, PDiag(),
906 Target->getReturnType(), TargetLoc, Source->getReturnType(),
907 SourceLoc))
908 return true;
909
910 // We shouldn't even be testing this unless the arguments are otherwise
911 // compatible.
912 assert((Target->getNumParams() - (unsigned)SkipTargetFirstParameter) ==
913 (Source->getNumParams() - (unsigned)SkipSourceFirstParameter) &&
914 "Functions have different argument counts.");
915 for (unsigned i = 0, E = Target->getNumParams(); i != E; ++i) {
916 auto ParamDiag = DiagID;
917 ParamDiag << 1;
919 *this, ParamDiag, PDiag(),
920 Target->getParamType(i + (SkipTargetFirstParameter ? 1 : 0)),
921 TargetLoc, Source->getParamType(SkipSourceFirstParameter ? 1 : 0),
922 SourceLoc))
923 return true;
924 }
925 return false;
926}
927
929 // First we check for applicability.
930 // Target type must be a function, function pointer or function reference.
931 const FunctionProtoType *ToFunc = GetUnderlyingFunction(ToType);
932 if (!ToFunc || ToFunc->hasDependentExceptionSpec())
933 return false;
934
935 // SourceType must be a function or function pointer.
936 const FunctionProtoType *FromFunc = GetUnderlyingFunction(From->getType());
937 if (!FromFunc || FromFunc->hasDependentExceptionSpec())
938 return false;
939
940 unsigned DiagID = diag::err_incompatible_exception_specs;
941 unsigned NestedDiagID = diag::err_deep_exception_specs_differ;
942 // This is not an error in C++17 onwards, unless the noexceptness doesn't
943 // match, but in that case we have a full-on type mismatch, not just a
944 // type sugar mismatch.
945 if (getLangOpts().CPlusPlus17) {
946 DiagID = diag::warn_incompatible_exception_specs;
947 NestedDiagID = diag::warn_deep_exception_specs_differ;
948 }
949
950 // Now we've got the correct types on both sides, check their compatibility.
951 // This means that the source of the conversion can only throw a subset of
952 // the exceptions of the target, and any exception specs on arguments or
953 // return types must be equivalent.
954 //
955 // FIXME: If there is a nested dependent exception specification, we should
956 // not be checking it here. This is fine:
957 // template<typename T> void f() {
958 // void (*p)(void (*) throw(T));
959 // void (*q)(void (*) throw(int)) = p;
960 // }
961 // ... because it might be instantiated with T=int.
962 return CheckExceptionSpecSubset(PDiag(DiagID), PDiag(NestedDiagID), PDiag(),
963 PDiag(), ToFunc, 0,
964 From->getSourceRange().getBegin(), FromFunc,
965 0, SourceLocation()) &&
966 !getLangOpts().CPlusPlus17;
967}
968
970 const CXXMethodDecl *Old) {
971 // If the new exception specification hasn't been parsed yet, skip the check.
972 // We'll get called again once it's been parsed.
975 return false;
976
977 // Don't check uninstantiated template destructors at all. We can only
978 // synthesize correct specs after the template is instantiated.
979 if (isa<CXXDestructorDecl>(New) && New->getParent()->isDependentType())
980 return false;
981
982 // If the old exception specification hasn't been parsed yet, or the new
983 // exception specification can't be computed yet, remember that we need to
984 // perform this check when we get to the end of the outermost
985 // lexically-surrounding class.
987 DelayedOverridingExceptionSpecChecks.push_back({New, Old});
988 return false;
989 }
990
991 unsigned DiagID = diag::err_override_exception_spec;
992 if (getLangOpts().MSVCCompat)
993 DiagID = diag::ext_override_exception_spec;
995 PDiag(DiagID), PDiag(diag::err_deep_exception_specs_differ),
996 PDiag(diag::note_overridden_virtual_function),
997 PDiag(diag::ext_override_exception_spec),
1000 New->getType()->castAs<FunctionProtoType>(),
1002}
1003
1006 for (const Stmt *SubStmt : S->children()) {
1007 if (!SubStmt)
1008 continue;
1009 R = mergeCanThrow(R, Self.canThrow(SubStmt));
1010 if (R == CT_Can)
1011 break;
1012 }
1013 return R;
1014}
1015
1017 SourceLocation Loc) {
1018 // As an extension, we assume that __attribute__((nothrow)) functions don't
1019 // throw.
1020 if (D && isa<FunctionDecl>(D) && D->hasAttr<NoThrowAttr>())
1021 return CT_Cannot;
1022
1023 QualType T;
1024
1025 // In C++1z, just look at the function type of the callee.
1026 if (S.getLangOpts().CPlusPlus17 && E && isa<CallExpr>(E)) {
1027 E = cast<CallExpr>(E)->getCallee();
1028 T = E->getType();
1029 if (T->isSpecificPlaceholderType(BuiltinType::BoundMember)) {
1030 // Sadly we don't preserve the actual type as part of the "bound member"
1031 // placeholder, so we need to reconstruct it.
1032 E = E->IgnoreParenImpCasts();
1033
1034 // Could be a call to a pointer-to-member or a plain member access.
1035 if (auto *Op = dyn_cast<BinaryOperator>(E)) {
1036 assert(Op->getOpcode() == BO_PtrMemD || Op->getOpcode() == BO_PtrMemI);
1037 T = Op->getRHS()->getType()
1038 ->castAs<MemberPointerType>()->getPointeeType();
1039 } else {
1040 T = cast<MemberExpr>(E)->getMemberDecl()->getType();
1041 }
1042 }
1043 } else if (const ValueDecl *VD = dyn_cast_or_null<ValueDecl>(D))
1044 T = VD->getType();
1045 else
1046 // If we have no clue what we're calling, assume the worst.
1047 return CT_Can;
1048
1049 const FunctionProtoType *FT;
1050 if ((FT = T->getAs<FunctionProtoType>())) {
1051 } else if (const PointerType *PT = T->getAs<PointerType>())
1052 FT = PT->getPointeeType()->getAs<FunctionProtoType>();
1053 else if (const ReferenceType *RT = T->getAs<ReferenceType>())
1054 FT = RT->getPointeeType()->getAs<FunctionProtoType>();
1055 else if (const MemberPointerType *MT = T->getAs<MemberPointerType>())
1056 FT = MT->getPointeeType()->getAs<FunctionProtoType>();
1057 else if (const BlockPointerType *BT = T->getAs<BlockPointerType>())
1058 FT = BT->getPointeeType()->getAs<FunctionProtoType>();
1059
1060 if (!FT)
1061 return CT_Can;
1062
1063 if (Loc.isValid() || (Loc.isInvalid() && E))
1064 FT = S.ResolveExceptionSpec(Loc.isInvalid() ? E->getBeginLoc() : Loc, FT);
1065 if (!FT)
1066 return CT_Can;
1067
1068 return FT->canThrow();
1069}
1070
1073
1074 // Initialization might throw.
1075 if (!VD->isUsableInConstantExpressions(Self.Context))
1076 if (const Expr *Init = VD->getInit())
1077 CT = mergeCanThrow(CT, Self.canThrow(Init));
1078
1079 // Destructor might throw.
1081 if (auto *RD =
1083 if (auto *Dtor = RD->getDestructor()) {
1084 CT = mergeCanThrow(
1085 CT, Sema::canCalleeThrow(Self, nullptr, Dtor, VD->getLocation()));
1086 }
1087 }
1088 }
1089
1090 // If this is a decomposition declaration, bindings might throw.
1091 if (auto *DD = dyn_cast<DecompositionDecl>(VD))
1092 for (auto *B : DD->bindings())
1093 if (auto *HD = B->getHoldingVar())
1094 CT = mergeCanThrow(CT, canVarDeclThrow(Self, HD));
1095
1096 return CT;
1097}
1098
1100 if (DC->isTypeDependent())
1101 return CT_Dependent;
1102
1103 if (!DC->getTypeAsWritten()->isReferenceType())
1104 return CT_Cannot;
1105
1106 if (DC->getSubExpr()->isTypeDependent())
1107 return CT_Dependent;
1108
1109 return DC->getCastKind() == clang::CK_Dynamic? CT_Can : CT_Cannot;
1110}
1111
1113 if (DC->isTypeOperand())
1114 return CT_Cannot;
1115
1116 Expr *Op = DC->getExprOperand();
1117 if (Op->isTypeDependent())
1118 return CT_Dependent;
1119
1120 const RecordType *RT = Op->getType()->getAs<RecordType>();
1121 if (!RT)
1122 return CT_Cannot;
1123
1124 if (!cast<CXXRecordDecl>(RT->getDecl())->isPolymorphic())
1125 return CT_Cannot;
1126
1127 if (Op->Classify(S.Context).isPRValue())
1128 return CT_Cannot;
1129
1130 return CT_Can;
1131}
1132
1134 // C++ [expr.unary.noexcept]p3:
1135 // [Can throw] if in a potentially-evaluated context the expression would
1136 // contain:
1137 switch (S->getStmtClass()) {
1138 case Expr::ConstantExprClass:
1139 return canThrow(cast<ConstantExpr>(S)->getSubExpr());
1140
1141 case Expr::CXXThrowExprClass:
1142 // - a potentially evaluated throw-expression
1143 return CT_Can;
1144
1145 case Expr::CXXDynamicCastExprClass: {
1146 // - a potentially evaluated dynamic_cast expression dynamic_cast<T>(v),
1147 // where T is a reference type, that requires a run-time check
1148 auto *CE = cast<CXXDynamicCastExpr>(S);
1149 // FIXME: Properly determine whether a variably-modified type can throw.
1150 if (CE->getType()->isVariablyModifiedType())
1151 return CT_Can;
1153 if (CT == CT_Can)
1154 return CT;
1155 return mergeCanThrow(CT, canSubStmtsThrow(*this, CE));
1156 }
1157
1158 case Expr::CXXTypeidExprClass:
1159 // - a potentially evaluated typeid expression applied to a glvalue
1160 // expression whose type is a polymorphic class type
1161 return canTypeidThrow(*this, cast<CXXTypeidExpr>(S));
1162
1163 // - a potentially evaluated call to a function, member function, function
1164 // pointer, or member function pointer that does not have a non-throwing
1165 // exception-specification
1166 case Expr::CallExprClass:
1167 case Expr::CXXMemberCallExprClass:
1168 case Expr::CXXOperatorCallExprClass:
1169 case Expr::UserDefinedLiteralClass: {
1170 const CallExpr *CE = cast<CallExpr>(S);
1171 CanThrowResult CT;
1172 if (CE->isTypeDependent())
1173 CT = CT_Dependent;
1174 else if (isa<CXXPseudoDestructorExpr>(CE->getCallee()->IgnoreParens()))
1175 CT = CT_Cannot;
1176 else
1177 CT = canCalleeThrow(*this, CE, CE->getCalleeDecl());
1178 if (CT == CT_Can)
1179 return CT;
1180 return mergeCanThrow(CT, canSubStmtsThrow(*this, CE));
1181 }
1182
1183 case Expr::CXXConstructExprClass:
1184 case Expr::CXXTemporaryObjectExprClass: {
1185 auto *CE = cast<CXXConstructExpr>(S);
1186 // FIXME: Properly determine whether a variably-modified type can throw.
1187 if (CE->getType()->isVariablyModifiedType())
1188 return CT_Can;
1189 CanThrowResult CT = canCalleeThrow(*this, CE, CE->getConstructor());
1190 if (CT == CT_Can)
1191 return CT;
1192 return mergeCanThrow(CT, canSubStmtsThrow(*this, CE));
1193 }
1194
1195 case Expr::CXXInheritedCtorInitExprClass: {
1196 auto *ICIE = cast<CXXInheritedCtorInitExpr>(S);
1197 return canCalleeThrow(*this, ICIE, ICIE->getConstructor());
1198 }
1199
1200 case Expr::LambdaExprClass: {
1201 const LambdaExpr *Lambda = cast<LambdaExpr>(S);
1204 Cap = Lambda->capture_init_begin(),
1205 CapEnd = Lambda->capture_init_end();
1206 Cap != CapEnd; ++Cap)
1207 CT = mergeCanThrow(CT, canThrow(*Cap));
1208 return CT;
1209 }
1210
1211 case Expr::CXXNewExprClass: {
1212 auto *NE = cast<CXXNewExpr>(S);
1213 CanThrowResult CT;
1214 if (NE->isTypeDependent())
1215 CT = CT_Dependent;
1216 else
1217 CT = canCalleeThrow(*this, NE, NE->getOperatorNew());
1218 if (CT == CT_Can)
1219 return CT;
1220 return mergeCanThrow(CT, canSubStmtsThrow(*this, NE));
1221 }
1222
1223 case Expr::CXXDeleteExprClass: {
1224 auto *DE = cast<CXXDeleteExpr>(S);
1225 CanThrowResult CT;
1226 QualType DTy = DE->getDestroyedType();
1227 if (DTy.isNull() || DTy->isDependentType()) {
1228 CT = CT_Dependent;
1229 } else {
1230 CT = canCalleeThrow(*this, DE, DE->getOperatorDelete());
1231 if (const RecordType *RT = DTy->getAs<RecordType>()) {
1232 const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1233 const CXXDestructorDecl *DD = RD->getDestructor();
1234 if (DD)
1235 CT = mergeCanThrow(CT, canCalleeThrow(*this, DE, DD));
1236 }
1237 if (CT == CT_Can)
1238 return CT;
1239 }
1240 return mergeCanThrow(CT, canSubStmtsThrow(*this, DE));
1241 }
1242
1243 case Expr::CXXBindTemporaryExprClass: {
1244 auto *BTE = cast<CXXBindTemporaryExpr>(S);
1245 // The bound temporary has to be destroyed again, which might throw.
1246 CanThrowResult CT =
1247 canCalleeThrow(*this, BTE, BTE->getTemporary()->getDestructor());
1248 if (CT == CT_Can)
1249 return CT;
1250 return mergeCanThrow(CT, canSubStmtsThrow(*this, BTE));
1251 }
1252
1253 case Expr::PseudoObjectExprClass: {
1254 auto *POE = cast<PseudoObjectExpr>(S);
1256 for (const Expr *E : POE->semantics()) {
1257 CT = mergeCanThrow(CT, canThrow(E));
1258 if (CT == CT_Can)
1259 break;
1260 }
1261 return CT;
1262 }
1263
1264 // ObjC message sends are like function calls, but never have exception
1265 // specs.
1266 case Expr::ObjCMessageExprClass:
1267 case Expr::ObjCPropertyRefExprClass:
1268 case Expr::ObjCSubscriptRefExprClass:
1269 return CT_Can;
1270
1271 // All the ObjC literals that are implemented as calls are
1272 // potentially throwing unless we decide to close off that
1273 // possibility.
1274 case Expr::ObjCArrayLiteralClass:
1275 case Expr::ObjCDictionaryLiteralClass:
1276 case Expr::ObjCBoxedExprClass:
1277 return CT_Can;
1278
1279 // Many other things have subexpressions, so we have to test those.
1280 // Some are simple:
1281 case Expr::CoawaitExprClass:
1282 case Expr::ConditionalOperatorClass:
1283 case Expr::CoyieldExprClass:
1284 case Expr::CXXRewrittenBinaryOperatorClass:
1285 case Expr::CXXStdInitializerListExprClass:
1286 case Expr::DesignatedInitExprClass:
1287 case Expr::DesignatedInitUpdateExprClass:
1288 case Expr::ExprWithCleanupsClass:
1289 case Expr::ExtVectorElementExprClass:
1290 case Expr::InitListExprClass:
1291 case Expr::ArrayInitLoopExprClass:
1292 case Expr::MemberExprClass:
1293 case Expr::ObjCIsaExprClass:
1294 case Expr::ObjCIvarRefExprClass:
1295 case Expr::ParenExprClass:
1296 case Expr::ParenListExprClass:
1297 case Expr::ShuffleVectorExprClass:
1298 case Expr::StmtExprClass:
1299 case Expr::ConvertVectorExprClass:
1300 case Expr::VAArgExprClass:
1301 case Expr::CXXParenListInitExprClass:
1302 return canSubStmtsThrow(*this, S);
1303
1304 case Expr::CompoundLiteralExprClass:
1305 case Expr::CXXConstCastExprClass:
1306 case Expr::CXXAddrspaceCastExprClass:
1307 case Expr::CXXReinterpretCastExprClass:
1308 case Expr::BuiltinBitCastExprClass:
1309 // FIXME: Properly determine whether a variably-modified type can throw.
1310 if (cast<Expr>(S)->getType()->isVariablyModifiedType())
1311 return CT_Can;
1312 return canSubStmtsThrow(*this, S);
1313
1314 // Some might be dependent for other reasons.
1315 case Expr::ArraySubscriptExprClass:
1316 case Expr::MatrixSubscriptExprClass:
1317 case Expr::OMPArraySectionExprClass:
1318 case Expr::OMPArrayShapingExprClass:
1319 case Expr::OMPIteratorExprClass:
1320 case Expr::BinaryOperatorClass:
1321 case Expr::DependentCoawaitExprClass:
1322 case Expr::CompoundAssignOperatorClass:
1323 case Expr::CStyleCastExprClass:
1324 case Expr::CXXStaticCastExprClass:
1325 case Expr::CXXFunctionalCastExprClass:
1326 case Expr::ImplicitCastExprClass:
1327 case Expr::MaterializeTemporaryExprClass:
1328 case Expr::UnaryOperatorClass: {
1329 // FIXME: Properly determine whether a variably-modified type can throw.
1330 if (auto *CE = dyn_cast<CastExpr>(S))
1331 if (CE->getType()->isVariablyModifiedType())
1332 return CT_Can;
1333 CanThrowResult CT =
1334 cast<Expr>(S)->isTypeDependent() ? CT_Dependent : CT_Cannot;
1335 return mergeCanThrow(CT, canSubStmtsThrow(*this, S));
1336 }
1337
1338 case Expr::CXXDefaultArgExprClass:
1339 return canThrow(cast<CXXDefaultArgExpr>(S)->getExpr());
1340
1341 case Expr::CXXDefaultInitExprClass:
1342 return canThrow(cast<CXXDefaultInitExpr>(S)->getExpr());
1343
1344 case Expr::ChooseExprClass: {
1345 auto *CE = cast<ChooseExpr>(S);
1346 if (CE->isTypeDependent() || CE->isValueDependent())
1347 return CT_Dependent;
1348 return canThrow(CE->getChosenSubExpr());
1349 }
1350
1351 case Expr::GenericSelectionExprClass:
1352 if (cast<GenericSelectionExpr>(S)->isResultDependent())
1353 return CT_Dependent;
1354 return canThrow(cast<GenericSelectionExpr>(S)->getResultExpr());
1355
1356 // Some expressions are always dependent.
1357 case Expr::CXXDependentScopeMemberExprClass:
1358 case Expr::CXXUnresolvedConstructExprClass:
1359 case Expr::DependentScopeDeclRefExprClass:
1360 case Expr::CXXFoldExprClass:
1361 case Expr::RecoveryExprClass:
1362 return CT_Dependent;
1363
1364 case Expr::AsTypeExprClass:
1365 case Expr::BinaryConditionalOperatorClass:
1366 case Expr::BlockExprClass:
1367 case Expr::CUDAKernelCallExprClass:
1368 case Expr::DeclRefExprClass:
1369 case Expr::ObjCBridgedCastExprClass:
1370 case Expr::ObjCIndirectCopyRestoreExprClass:
1371 case Expr::ObjCProtocolExprClass:
1372 case Expr::ObjCSelectorExprClass:
1373 case Expr::ObjCAvailabilityCheckExprClass:
1374 case Expr::OffsetOfExprClass:
1375 case Expr::PackExpansionExprClass:
1376 case Expr::SubstNonTypeTemplateParmExprClass:
1377 case Expr::SubstNonTypeTemplateParmPackExprClass:
1378 case Expr::FunctionParmPackExprClass:
1379 case Expr::UnaryExprOrTypeTraitExprClass:
1380 case Expr::UnresolvedLookupExprClass:
1381 case Expr::UnresolvedMemberExprClass:
1382 case Expr::TypoExprClass:
1383 // FIXME: Many of the above can throw.
1384 return CT_Cannot;
1385
1386 case Expr::AddrLabelExprClass:
1387 case Expr::ArrayTypeTraitExprClass:
1388 case Expr::AtomicExprClass:
1389 case Expr::TypeTraitExprClass:
1390 case Expr::CXXBoolLiteralExprClass:
1391 case Expr::CXXNoexceptExprClass:
1392 case Expr::CXXNullPtrLiteralExprClass:
1393 case Expr::CXXPseudoDestructorExprClass:
1394 case Expr::CXXScalarValueInitExprClass:
1395 case Expr::CXXThisExprClass:
1396 case Expr::CXXUuidofExprClass:
1397 case Expr::CharacterLiteralClass:
1398 case Expr::ExpressionTraitExprClass:
1399 case Expr::FloatingLiteralClass:
1400 case Expr::GNUNullExprClass:
1401 case Expr::ImaginaryLiteralClass:
1402 case Expr::ImplicitValueInitExprClass:
1403 case Expr::IntegerLiteralClass:
1404 case Expr::FixedPointLiteralClass:
1405 case Expr::ArrayInitIndexExprClass:
1406 case Expr::NoInitExprClass:
1407 case Expr::ObjCEncodeExprClass:
1408 case Expr::ObjCStringLiteralClass:
1409 case Expr::ObjCBoolLiteralExprClass:
1410 case Expr::OpaqueValueExprClass:
1411 case Expr::PredefinedExprClass:
1412 case Expr::SizeOfPackExprClass:
1413 case Expr::PackIndexingExprClass:
1414 case Expr::StringLiteralClass:
1415 case Expr::SourceLocExprClass:
1416 case Expr::ConceptSpecializationExprClass:
1417 case Expr::RequiresExprClass:
1418 // These expressions can never throw.
1419 return CT_Cannot;
1420
1421 case Expr::MSPropertyRefExprClass:
1422 case Expr::MSPropertySubscriptExprClass:
1423 llvm_unreachable("Invalid class for expression");
1424
1425 // Most statements can throw if any substatement can throw.
1426 case Stmt::OpenACCComputeConstructClass:
1427 case Stmt::AttributedStmtClass:
1428 case Stmt::BreakStmtClass:
1429 case Stmt::CapturedStmtClass:
1430 case Stmt::CaseStmtClass:
1431 case Stmt::CompoundStmtClass:
1432 case Stmt::ContinueStmtClass:
1433 case Stmt::CoreturnStmtClass:
1434 case Stmt::CoroutineBodyStmtClass:
1435 case Stmt::CXXCatchStmtClass:
1436 case Stmt::CXXForRangeStmtClass:
1437 case Stmt::DefaultStmtClass:
1438 case Stmt::DoStmtClass:
1439 case Stmt::ForStmtClass:
1440 case Stmt::GCCAsmStmtClass:
1441 case Stmt::GotoStmtClass:
1442 case Stmt::IndirectGotoStmtClass:
1443 case Stmt::LabelStmtClass:
1444 case Stmt::MSAsmStmtClass:
1445 case Stmt::MSDependentExistsStmtClass:
1446 case Stmt::NullStmtClass:
1447 case Stmt::ObjCAtCatchStmtClass:
1448 case Stmt::ObjCAtFinallyStmtClass:
1449 case Stmt::ObjCAtSynchronizedStmtClass:
1450 case Stmt::ObjCAutoreleasePoolStmtClass:
1451 case Stmt::ObjCForCollectionStmtClass:
1452 case Stmt::OMPAtomicDirectiveClass:
1453 case Stmt::OMPBarrierDirectiveClass:
1454 case Stmt::OMPCancelDirectiveClass:
1455 case Stmt::OMPCancellationPointDirectiveClass:
1456 case Stmt::OMPCriticalDirectiveClass:
1457 case Stmt::OMPDistributeDirectiveClass:
1458 case Stmt::OMPDistributeParallelForDirectiveClass:
1459 case Stmt::OMPDistributeParallelForSimdDirectiveClass:
1460 case Stmt::OMPDistributeSimdDirectiveClass:
1461 case Stmt::OMPFlushDirectiveClass:
1462 case Stmt::OMPDepobjDirectiveClass:
1463 case Stmt::OMPScanDirectiveClass:
1464 case Stmt::OMPForDirectiveClass:
1465 case Stmt::OMPForSimdDirectiveClass:
1466 case Stmt::OMPMasterDirectiveClass:
1467 case Stmt::OMPMasterTaskLoopDirectiveClass:
1468 case Stmt::OMPMaskedTaskLoopDirectiveClass:
1469 case Stmt::OMPMasterTaskLoopSimdDirectiveClass:
1470 case Stmt::OMPMaskedTaskLoopSimdDirectiveClass:
1471 case Stmt::OMPOrderedDirectiveClass:
1472 case Stmt::OMPCanonicalLoopClass:
1473 case Stmt::OMPParallelDirectiveClass:
1474 case Stmt::OMPParallelForDirectiveClass:
1475 case Stmt::OMPParallelForSimdDirectiveClass:
1476 case Stmt::OMPParallelMasterDirectiveClass:
1477 case Stmt::OMPParallelMaskedDirectiveClass:
1478 case Stmt::OMPParallelMasterTaskLoopDirectiveClass:
1479 case Stmt::OMPParallelMaskedTaskLoopDirectiveClass:
1480 case Stmt::OMPParallelMasterTaskLoopSimdDirectiveClass:
1481 case Stmt::OMPParallelMaskedTaskLoopSimdDirectiveClass:
1482 case Stmt::OMPParallelSectionsDirectiveClass:
1483 case Stmt::OMPSectionDirectiveClass:
1484 case Stmt::OMPSectionsDirectiveClass:
1485 case Stmt::OMPSimdDirectiveClass:
1486 case Stmt::OMPTileDirectiveClass:
1487 case Stmt::OMPUnrollDirectiveClass:
1488 case Stmt::OMPSingleDirectiveClass:
1489 case Stmt::OMPTargetDataDirectiveClass:
1490 case Stmt::OMPTargetDirectiveClass:
1491 case Stmt::OMPTargetEnterDataDirectiveClass:
1492 case Stmt::OMPTargetExitDataDirectiveClass:
1493 case Stmt::OMPTargetParallelDirectiveClass:
1494 case Stmt::OMPTargetParallelForDirectiveClass:
1495 case Stmt::OMPTargetParallelForSimdDirectiveClass:
1496 case Stmt::OMPTargetSimdDirectiveClass:
1497 case Stmt::OMPTargetTeamsDirectiveClass:
1498 case Stmt::OMPTargetTeamsDistributeDirectiveClass:
1499 case Stmt::OMPTargetTeamsDistributeParallelForDirectiveClass:
1500 case Stmt::OMPTargetTeamsDistributeParallelForSimdDirectiveClass:
1501 case Stmt::OMPTargetTeamsDistributeSimdDirectiveClass:
1502 case Stmt::OMPTargetUpdateDirectiveClass:
1503 case Stmt::OMPScopeDirectiveClass:
1504 case Stmt::OMPTaskDirectiveClass:
1505 case Stmt::OMPTaskgroupDirectiveClass:
1506 case Stmt::OMPTaskLoopDirectiveClass:
1507 case Stmt::OMPTaskLoopSimdDirectiveClass:
1508 case Stmt::OMPTaskwaitDirectiveClass:
1509 case Stmt::OMPTaskyieldDirectiveClass:
1510 case Stmt::OMPErrorDirectiveClass:
1511 case Stmt::OMPTeamsDirectiveClass:
1512 case Stmt::OMPTeamsDistributeDirectiveClass:
1513 case Stmt::OMPTeamsDistributeParallelForDirectiveClass:
1514 case Stmt::OMPTeamsDistributeParallelForSimdDirectiveClass:
1515 case Stmt::OMPTeamsDistributeSimdDirectiveClass:
1516 case Stmt::OMPInteropDirectiveClass:
1517 case Stmt::OMPDispatchDirectiveClass:
1518 case Stmt::OMPMaskedDirectiveClass:
1519 case Stmt::OMPMetaDirectiveClass:
1520 case Stmt::OMPGenericLoopDirectiveClass:
1521 case Stmt::OMPTeamsGenericLoopDirectiveClass:
1522 case Stmt::OMPTargetTeamsGenericLoopDirectiveClass:
1523 case Stmt::OMPParallelGenericLoopDirectiveClass:
1524 case Stmt::OMPTargetParallelGenericLoopDirectiveClass:
1525 case Stmt::ReturnStmtClass:
1526 case Stmt::SEHExceptStmtClass:
1527 case Stmt::SEHFinallyStmtClass:
1528 case Stmt::SEHLeaveStmtClass:
1529 case Stmt::SEHTryStmtClass:
1530 case Stmt::SwitchStmtClass:
1531 case Stmt::WhileStmtClass:
1532 return canSubStmtsThrow(*this, S);
1533
1534 case Stmt::DeclStmtClass: {
1536 for (const Decl *D : cast<DeclStmt>(S)->decls()) {
1537 if (auto *VD = dyn_cast<VarDecl>(D))
1538 CT = mergeCanThrow(CT, canVarDeclThrow(*this, VD));
1539
1540 // FIXME: Properly determine whether a variably-modified type can throw.
1541 if (auto *TND = dyn_cast<TypedefNameDecl>(D))
1542 if (TND->getUnderlyingType()->isVariablyModifiedType())
1543 return CT_Can;
1544 if (auto *VD = dyn_cast<ValueDecl>(D))
1545 if (VD->getType()->isVariablyModifiedType())
1546 return CT_Can;
1547 }
1548 return CT;
1549 }
1550
1551 case Stmt::IfStmtClass: {
1552 auto *IS = cast<IfStmt>(S);
1554 if (const Stmt *Init = IS->getInit())
1555 CT = mergeCanThrow(CT, canThrow(Init));
1556 if (const Stmt *CondDS = IS->getConditionVariableDeclStmt())
1557 CT = mergeCanThrow(CT, canThrow(CondDS));
1558 CT = mergeCanThrow(CT, canThrow(IS->getCond()));
1559
1560 // For 'if constexpr', consider only the non-discarded case.
1561 // FIXME: We should add a DiscardedStmt marker to the AST.
1562 if (std::optional<const Stmt *> Case = IS->getNondiscardedCase(Context))
1563 return *Case ? mergeCanThrow(CT, canThrow(*Case)) : CT;
1564
1565 CanThrowResult Then = canThrow(IS->getThen());
1566 CanThrowResult Else = IS->getElse() ? canThrow(IS->getElse()) : CT_Cannot;
1567 if (Then == Else)
1568 return mergeCanThrow(CT, Then);
1569
1570 // For a dependent 'if constexpr', the result is dependent if it depends on
1571 // the value of the condition.
1572 return mergeCanThrow(CT, IS->isConstexpr() ? CT_Dependent
1573 : mergeCanThrow(Then, Else));
1574 }
1575
1576 case Stmt::CXXTryStmtClass: {
1577 auto *TS = cast<CXXTryStmt>(S);
1578 // try /*...*/ catch (...) { H } can throw only if H can throw.
1579 // Any other try-catch can throw if any substatement can throw.
1580 const CXXCatchStmt *FinalHandler = TS->getHandler(TS->getNumHandlers() - 1);
1581 if (!FinalHandler->getExceptionDecl())
1582 return canThrow(FinalHandler->getHandlerBlock());
1583 return canSubStmtsThrow(*this, S);
1584 }
1585
1586 case Stmt::ObjCAtThrowStmtClass:
1587 return CT_Can;
1588
1589 case Stmt::ObjCAtTryStmtClass: {
1590 auto *TS = cast<ObjCAtTryStmt>(S);
1591
1592 // @catch(...) need not be last in Objective-C. Walk backwards until we
1593 // see one or hit the @try.
1595 if (const Stmt *Finally = TS->getFinallyStmt())
1596 CT = mergeCanThrow(CT, canThrow(Finally));
1597 for (unsigned I = TS->getNumCatchStmts(); I != 0; --I) {
1598 const ObjCAtCatchStmt *Catch = TS->getCatchStmt(I - 1);
1599 CT = mergeCanThrow(CT, canThrow(Catch));
1600 // If we reach a @catch(...), no earlier exceptions can escape.
1601 if (Catch->hasEllipsis())
1602 return CT;
1603 }
1604
1605 // Didn't find an @catch(...). Exceptions from the @try body can escape.
1606 return mergeCanThrow(CT, canThrow(TS->getTryBody()));
1607 }
1608
1609 case Stmt::SYCLUniqueStableNameExprClass:
1610 return CT_Cannot;
1611 case Stmt::NoStmtClass:
1612 llvm_unreachable("Invalid class for statement");
1613 }
1614 llvm_unreachable("Bogus StmtClass");
1615}
1616
1617} // end namespace clang
Defines the Diagnostic-related interfaces.
Defines the clang::Expr interface and subclasses for C++ expressions.
Defines the SourceManager interface.
Defines the Objective-C statement AST node classes.
Defines the clang::TypeLoc interface and its subclasses.
APValue - This class implements a discriminated union of [uninitialized] [APSInt] [APFloat],...
Definition: APValue.h:122
SourceManager & getSourceManager()
Definition: ASTContext.h:700
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:2549
QualType getPointerType(QualType T) const
Return the uniqued reference to the type for a pointer to the specified type.
CanQualType BoolTy
Definition: ASTContext.h:1087
QualType getUnqualifiedArrayType(QualType T, Qualifiers &Quals)
Return this type as a completely-unqualified array type, capturing the qualifiers in Quals.
void adjustExceptionSpec(FunctionDecl *FD, const FunctionProtoType::ExceptionSpecInfo &ESI, bool AsWritten=false)
Change the exception specification on a function once it is delay-parsed, instantiated,...
bool hasSameUnqualifiedType(QualType T1, QualType T2) const
Determine whether the given types are equivalent after cvr-qualifiers have been removed.
Definition: ASTContext.h:2592
QualType getArrayDecayedType(QualType T) const
Return the properly qualified result of decaying the specified array type to a pointer.
QualType getFunctionType(QualType ResultTy, ArrayRef< QualType > Args, const FunctionProtoType::ExtProtoInfo &EPI) const
Return a normal function type with a typed argument list.
Definition: ASTContext.h:1553
PtrTy get() const
Definition: Ownership.h:170
bool isInvalid() const
Definition: Ownership.h:166
Pointer to a block type.
Definition: Type.h:2977
BasePaths - Represents the set of paths from a derived class to one of its (direct or indirect) bases...
A boolean literal, per ([C++ lex.bool] Boolean literals).
Definition: ExprCXX.h:720
CXXCatchStmt - This represents a C++ catch block.
Definition: StmtCXX.h:28
Stmt * getHandlerBlock() const
Definition: StmtCXX.h:51
VarDecl * getExceptionDecl() const
Definition: StmtCXX.h:49
Represents a C++ destructor within a class.
Definition: DeclCXX.h:2792
A C++ dynamic_cast expression (C++ [expr.dynamic.cast]).
Definition: ExprCXX.h:478
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:2053
const CXXRecordDecl * getParent() const
Return the parent of this method declaration, which is the class in which this method is defined.
Definition: DeclCXX.h:2179
Represents a C++ struct/union/class.
Definition: DeclCXX.h:258
CXXDestructorDecl * getDestructor() const
Returns the destructor decl for this class.
Definition: DeclCXX.cpp:1972
A C++ typeid expression (C++ [expr.typeid]), which gets the type_info that corresponds to the supplie...
Definition: ExprCXX.h:845
bool isTypeOperand() const
Definition: ExprCXX.h:881
Expr * getExprOperand() const
Definition: ExprCXX.h:892
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2795
Expr * getCallee()
Definition: Expr.h:2945
Decl * getCalleeDecl()
Definition: Expr.h:2959
CanQual< T > getUnqualifiedType() const
Retrieve the unqualified form of this type.
CastKind getCastKind() const
Definition: Expr.h:3509
Expr * getSubExpr()
Definition: Expr.h:3515
static ConstantExpr * Create(const ASTContext &Context, Expr *E, const APValue &Result)
Definition: Expr.cpp:339
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:85
void setInvalidDecl(bool Invalid=true)
setInvalidDecl - Indicates the Decl had a semantic error.
Definition: DeclBase.cpp:132
SourceLocation getLocation() const
Definition: DeclBase.h:444
bool hasAttr() const
Definition: DeclBase.h:582
OverloadedOperatorKind getCXXOverloadedOperator() const
If this name is the name of an overloadable operator in C++ (e.g., operator+), retrieve the kind of o...
TypeSourceInfo * getTypeSourceInfo() const
Definition: Decl.h:799
Information about one declarator, including the parsed type information and the identifier.
Definition: DeclSpec.h:1899
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: DeclSpec.h:2082
IdentifierInfo * getIdentifier() const
Definition: DeclSpec.h:2329
QualType getTypeAsWritten() const
getTypeAsWritten - Returns the type that this expression is casting to, as written in the source code...
Definition: Expr.h:3727
bool isPRValue() const
Definition: Expr.h:377
This represents one expression.
Definition: Expr.h:110
bool isValueDependent() const
Determines whether the value of this expression depends on.
Definition: Expr.h:169
bool isTypeDependent() const
Determines whether the type of this expression depends on.
Definition: Expr.h:186
bool containsUnexpandedParameterPack() const
Whether this expression contains an unexpanded parameter pack (for C++11 variadic templates).
Definition: Expr.h:233
Expr * IgnoreParenImpCasts() LLVM_READONLY
Skip past any parentheses and implicit casts which might surround this expression until reaching a fi...
Definition: Expr.cpp:3034
Expr * IgnoreParens() LLVM_READONLY
Skip past any parentheses which might surround this expression until reaching a fixed point.
Definition: Expr.cpp:3030
Classification Classify(ASTContext &Ctx) const
Classify - Classify this expression according to the C++11 expression taxonomy.
Definition: Expr.h:399
QualType getType() const
Definition: Expr.h:142
static FixItHint CreateInsertion(SourceLocation InsertionLoc, StringRef Code, bool BeforePreviousInsertions=false)
Create a code modification hint that inserts the given code string at a specific location.
Definition: Diagnostic.h:97
Represents a function declaration or definition.
Definition: Decl.h:1959
unsigned getBuiltinID(bool ConsiderWrapperFunctions=false) const
Returns a value indicating whether this function corresponds to a builtin function.
Definition: Decl.cpp:3587
bool hasCXXExplicitFunctionObjectParameter() const
Definition: Decl.cpp:3686
bool isExternC() const
Determines whether this function is a function with external, C linkage.
Definition: Decl.cpp:3447
bool isReplaceableGlobalAllocationFunction(std::optional< unsigned > *AlignmentParam=nullptr, bool *IsNothrow=nullptr) const
Determines whether this function is one of the replaceable global allocation functions: void *operato...
Definition: Decl.cpp:3321
Represents a prototype with parameter type info, e.g.
Definition: Type.h:4198
bool hasDependentExceptionSpec() const
Return whether this function has a dependent exception spec.
Definition: Type.cpp:3586
ExceptionSpecificationType getExceptionSpecType() const
Get the kind of exception specification on this function.
Definition: Type.h:4457
unsigned getNumParams() const
Definition: Type.h:4431
QualType getParamType(unsigned i) const
Definition: Type.h:4433
unsigned getNumExceptions() const
Return the number of types in the exception specification.
Definition: Type.h:4500
bool hasExceptionSpec() const
Return whether this function has any kind of exception spec.
Definition: Type.h:4463
CanThrowResult canThrow() const
Determine whether this function type has a non-throwing exception specification.
Definition: Type.cpp:3607
Expr * getNoexceptExpr() const
Return the expression inside noexcept(expression), or a null pointer if there is none (because the ex...
Definition: Type.h:4515
ArrayRef< QualType > exceptions() const
Definition: Type.h:4600
exception_iterator exception_begin() const
Definition: Type.h:4604
FunctionDecl * getExceptionSpecDecl() const
If this function type has an exception specification which hasn't been determined yet (either because...
Definition: Type.h:4525
QualType getReturnType() const
Definition: Type.h:4115
One of these records is kept for each identifier that is lexed.
bool isStr(const char(&Str)[StrLen]) const
Return true if this is the identifier for the specified string.
A C++ lambda expression, which produces a function object (of unspecified type) that can be invoked l...
Definition: ExprCXX.h:1938
capture_init_iterator capture_init_end()
Retrieve the iterator pointing one past the last initialization argument for this lambda expression.
Definition: ExprCXX.h:2076
Expr *const * const_capture_init_iterator
Const iterator that walks over the capture initialization arguments.
Definition: ExprCXX.h:2050
capture_init_iterator capture_init_begin()
Retrieve the first initialization argument for this lambda expression (which initializes the first ca...
Definition: ExprCXX.h:2064
A pointer to member type per C++ 8.3.3 - Pointers to members.
Definition: Type.h:3088
DeclarationName getDeclName() const
Get the actual, stored name of the declaration, which may be a special name.
Definition: Decl.h:315
Represents Objective-C's @catch statement.
Definition: StmtObjC.h:77
bool hasEllipsis() const
Definition: StmtObjC.h:113
PointerType - C99 6.7.5.1 - Pointer Declarators.
Definition: Type.h:2897
A (possibly-)qualified type.
Definition: Type.h:737
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:6984
@ DK_cxx_destructor
Definition: Type.h:1313
bool isNull() const
Return true if this QualType doesn't point to a type yet.
Definition: Type.h:804
bool isWebAssemblyReferenceType() const
Returns true if it is a WebAssembly Reference Type.
Definition: Type.cpp:2775
bool isConstQualified() const
Determine whether this type is const-qualified.
Definition: Type.h:6973
The collection of all-type qualifiers we support.
Definition: Type.h:147
bool compatiblyIncludes(Qualifiers other) const
Determines if these qualifiers compatibly include another set.
Definition: Type.h:532
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:5091
RecordDecl * getDecl() const
Definition: Type.h:5101
redecl_range redecls() const
Returns an iterator range for all the redeclarations of the same decl.
Definition: Redeclarable.h:296
Base for LValueReferenceType and RValueReferenceType.
Definition: Type.h:3008
QualType getPointeeType() const
Definition: Type.h:3026
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:425
bool CheckSpecifiedExceptionType(QualType &T, SourceRange Range)
CheckSpecifiedExceptionType - Check if the given type is valid in an exception specification.
void EvaluateImplicitExceptionSpec(SourceLocation Loc, FunctionDecl *FD)
Evaluate the implicit exception specification for a defaulted special member function.
SmallVector< std::pair< const CXXMethodDecl *, const CXXMethodDecl * >, 2 > DelayedOverridingExceptionSpecChecks
All the overriding functions seen during a class definition that had their exception spec checks dela...
Definition: Sema.h:996
SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID, bool DeferHint=false)
Emit a diagnostic.
Definition: Sema.cpp:1924
void InstantiateExceptionSpec(SourceLocation PointOfInstantiation, FunctionDecl *Function)
@ AR_dependent
Definition: Sema.h:8174
@ AR_accessible
Definition: Sema.h:8172
@ AR_inaccessible
Definition: Sema.h:8173
@ AR_delayed
Definition: Sema.h:8175
ASTContext & Context
Definition: Sema.h:476
bool IsQualificationConversion(QualType FromType, QualType ToType, bool CStyle, bool &ObjCLifetimeConversion)
IsQualificationConversion - Determines whether the conversion from an rvalue of type FromType to ToTy...
PrintingPolicy getPrintingPolicy() const
Retrieve a suitable printing policy for diagnostics.
Definition: Sema.h:3429
ExprResult CheckConvertedConstantExpression(Expr *From, QualType T, llvm::APSInt &Value, CCEKind CCE)
bool CheckParamExceptionSpec(const PartialDiagnostic &NestedDiagID, const PartialDiagnostic &NoteID, const FunctionProtoType *Target, bool SkipTargetFirstParameter, SourceLocation TargetLoc, const FunctionProtoType *Source, bool SkipSourceFirstParameter, SourceLocation SourceLoc)
CheckParamExceptionSpec - Check if the parameter and return types of the two functions have equivalen...
SourceLocation getLocForEndOfToken(SourceLocation Loc, unsigned Offset=0)
Calls Lexer::getLocForEndOfToken()
Definition: Sema.cpp:58
const LangOptions & getLangOpts() const
Definition: Sema.h:1794
const FunctionProtoType * ResolveExceptionSpec(SourceLocation Loc, const FunctionProtoType *FPT)
ExprResult ActOnNoexceptSpec(Expr *NoexceptExpr, ExceptionSpecificationType &EST)
Check the given noexcept-specifier, convert its expression, and compute the appropriate ExceptionSpec...
AccessResult CheckBaseClassAccess(SourceLocation AccessLoc, QualType Base, QualType Derived, const CXXBasePath &Path, unsigned DiagID, bool ForceCheck=false, bool ForceUnprivileged=false)
Checks access for a hierarchy conversion.
SmallVector< std::pair< FunctionDecl *, FunctionDecl * >, 2 > DelayedEquivalentExceptionSpecChecks
All the function redeclarations seen during a class definition that had their exception spec checks d...
Definition: Sema.h:1004
bool isLibstdcxxEagerExceptionSpecHack(const Declarator &D)
Determine if we're in a case where we need to (incorrectly) eagerly parse an exception specification ...
bool CheckExceptionSpecSubset(const PartialDiagnostic &DiagID, const PartialDiagnostic &NestedDiagID, const PartialDiagnostic &NoteID, const PartialDiagnostic &NoThrowDiagID, const FunctionProtoType *Superset, bool SkipSupersetFirstParameter, SourceLocation SuperLoc, const FunctionProtoType *Subset, bool SkipSubsetFirstParameter, SourceLocation SubLoc)
CheckExceptionSpecSubset - Check whether the second function type's exception specification is a subs...
DeclContext * CurContext
CurContext - This is the current declaration context of parsing.
Definition: Sema.h:489
CanThrowResult canThrow(const Stmt *E)
@ CCEK_Noexcept
Condition in a noexcept(bool) specifier.
Definition: Sema.h:4045
bool handlerCanCatch(QualType HandlerType, QualType ExceptionType)
bool CheckDistantExceptionSpec(QualType T)
CheckDistantExceptionSpec - Check if the given type is a pointer or pointer to member to a function w...
bool RequireCompleteType(SourceLocation Loc, QualType T, CompleteTypeKind Kind, TypeDiagnoser &Diagnoser)
Ensure that the type T is a complete type.
Definition: SemaType.cpp:9240
PartialDiagnostic PDiag(unsigned DiagID=0)
Build a partial diagnostic.
Definition: SemaInternal.h:24
bool CheckEquivalentExceptionSpec(FunctionDecl *Old, FunctionDecl *New)
bool CheckOverridingFunctionExceptionSpec(const CXXMethodDecl *New, const CXXMethodDecl *Old)
CheckOverridingFunctionExceptionSpec - Checks whether the exception spec is a subset of base spec.
void UpdateExceptionSpec(FunctionDecl *FD, const FunctionProtoType::ExceptionSpecInfo &ESI)
bool IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base)
Determine whether the type Derived is a C++ class that is derived from the type Base.
bool CheckExceptionSpecCompatibility(Expr *From, QualType ToType)
bool IsFunctionConversion(QualType FromType, QualType ToType, QualType &ResultTy)
Determine whether the conversion from FromType to ToType is a valid conversion that strips "noexcept"...
ASTMutationListener * getASTMutationListener() const
Definition: Sema.cpp:541
static CanThrowResult canCalleeThrow(Sema &S, const Expr *E, const Decl *D, SourceLocation Loc=SourceLocation())
Determine whether the callee of a particular function call can throw.
Encodes a location in the source.
bool isValid() const
Return true if this is a valid SourceLocation object.
bool isInSystemHeader(SourceLocation Loc) const
Returns if a SourceLocation is in a system header.
A trivial tuple used to represent a source range.
SourceLocation getBegin() const
Stmt - This represents one statement.
Definition: Stmt.h:84
@ NoStmtClass
Definition: Stmt.h:87
SourceRange getSourceRange() const LLVM_READONLY
SourceLocation tokens are not useful in isolation - they are low level value objects created/interpre...
Definition: Stmt.cpp:326
void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context, bool Canonical, bool ProfileLambdaExpr=false) const
Produce a unique representation of the given statement.
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:338
bool isDependentType() const
Whether this declaration declares a type that is dependent, i.e., a type that somehow depends on temp...
Definition: Decl.h:3703
bool isBeingDefined() const
Determines whether this type is in the process of being defined.
Definition: Type.cpp:3904
Base wrapper for a particular "section" of type source info.
Definition: TypeLoc.h:59
T getAs() const
Convert to the specified TypeLoc type, returning a null TypeLoc if this TypeLoc is not of the desired...
Definition: TypeLoc.h:89
TypeLoc IgnoreParens() const
Definition: TypeLoc.h:1199
A container of type source information.
Definition: Type.h:6872
bool isSizelessType() const
As an extension, we classify types as one of "sized" or "sizeless"; every type is one or the other.
Definition: Type.cpp:2403
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1819
bool isVoidType() const
Definition: Type.h:7442
bool isArrayType() const
Definition: Type.h:7219
bool isPointerType() const
Definition: Type.h:7153
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:7719
bool isSpecificPlaceholderType(unsigned K) const
Test for a specific placeholder type.
Definition: Type.h:7431
bool isReferenceType() const
Definition: Type.h:7165
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee.
Definition: Type.cpp:651
bool isDependentType() const
Whether this type is a dependent type, meaning that its definition somehow depends on a template para...
Definition: Type.h:2419
const Type * getBaseElementTypeUnsafe() const
Get the base element type of this type, potentially discarding type qualifiers.
Definition: Type.h:7602
bool isMemberPointerType() const
Definition: Type.h:7201
bool isObjectType() const
Determine whether this type is an object type.
Definition: Type.h:2175
bool isFunctionType() const
Definition: Type.h:7149
const T * getAs() const
Member-template getAs<specific type>'.
Definition: Type.h:7652
bool isNullPtrType() const
Definition: Type.h:7467
bool isRecordType() const
Definition: Type.h:7243
Represent the declaration of a variable (in which case it is an lvalue) a function (in which case it ...
Definition: Decl.h:706
void setType(QualType newType)
Definition: Decl.h:718
QualType getType() const
Definition: Decl.h:717
Represents a variable declaration or definition.
Definition: Decl.h:918
QualType::DestructionKind needsDestruction(const ASTContext &Ctx) const
Would the destruction of this variable have any effect, and if so, what kind?
Definition: Decl.cpp:2810
const Expr * getInit() const
Definition: Decl.h:1352
bool isUsableInConstantExpressions(const ASTContext &C) const
Determine whether this variable's value can be used in a constant expression, according to the releva...
Definition: Decl.cpp:2500
The JSON file list parser is used to communicate input to InstallAPI.
@ Self
'self' clause, allowed on Compute and Combined Constructs, plus 'update'.
OverloadedOperatorKind
Enumeration specifying the different kinds of C++ overloaded operators.
Definition: OperatorKinds.h:21
@ CPlusPlus11
Definition: LangStandard.h:55
@ CPlusPlus17
Definition: LangStandard.h:57
CanThrowResult
Possible results from evaluation of a noexcept expression.
static const FunctionProtoType * GetUnderlyingFunction(QualType T)
bool isDynamicExceptionSpec(ExceptionSpecificationType ESpecType)
static bool CheckEquivalentExceptionSpecImpl(Sema &S, const PartialDiagnostic &DiagID, const PartialDiagnostic &NoteID, const FunctionProtoType *Old, SourceLocation OldLoc, const FunctionProtoType *New, SourceLocation NewLoc, bool *MissingExceptionSpecification=nullptr, bool *MissingEmptyExceptionSpecification=nullptr, bool AllowNoexceptAllMatchWithNoSpec=false, bool IsOperatorNew=false)
CheckEquivalentExceptionSpec - Check if the two types have compatible exception specifications.
bool isUnresolvedExceptionSpec(ExceptionSpecificationType ESpecType)
static bool hasImplicitExceptionSpec(FunctionDecl *Decl)
Determine whether a function has an implicitly-generated exception specification.
CanThrowResult mergeCanThrow(CanThrowResult CT1, CanThrowResult CT2)
@ Result
The result type of a method or function.
static CanThrowResult canVarDeclThrow(Sema &Self, const VarDecl *VD)
static CanThrowResult canDynamicCastThrow(const CXXDynamicCastExpr *DC)
static CanThrowResult canSubStmtsThrow(Sema &Self, const Stmt *S)
static CanThrowResult canTypeidThrow(Sema &S, const CXXTypeidExpr *DC)
static bool CheckSpecForTypesEquivalent(Sema &S, const PartialDiagnostic &DiagID, const PartialDiagnostic &NoteID, QualType Target, SourceLocation TargetLoc, QualType Source, SourceLocation SourceLoc)
@ Success
Template argument deduction was successful.
ExceptionSpecificationType
The various types of exception specifications that exist in C++11.
@ EST_DependentNoexcept
noexcept(expression), value-dependent
@ EST_DynamicNone
throw()
@ EST_Uninstantiated
not instantiated yet
@ EST_Unparsed
not parsed yet
@ EST_NoThrow
Microsoft __declspec(nothrow) extension.
@ EST_None
no exception specification
@ EST_MSAny
Microsoft throw(...) extension.
@ EST_BasicNoexcept
noexcept
@ EST_NoexceptFalse
noexcept(expression), evals to 'false'
@ EST_Unevaluated
not evaluated yet, for special member function
@ EST_NoexceptTrue
noexcept(expression), evals to 'true'
@ EST_Dynamic
throw(T1, T2)
static bool exceptionSpecNotKnownYet(const FunctionDecl *FD)
Holds information about the various types of exception specification.
Definition: Type.h:4249
ExceptionSpecificationType Type
The kind of exception specification this is.
Definition: Type.h:4251
ArrayRef< QualType > Exceptions
Explicitly-specified list of exception types.
Definition: Type.h:4254