clang 17.0.0git
JumpDiagnostics.cpp
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1//===--- JumpDiagnostics.cpp - Protected scope jump analysis ------*- 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 implements the JumpScopeChecker class, which is used to diagnose
10// jumps that enter a protected scope in an invalid way.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/AST/DeclCXX.h"
15#include "clang/AST/Expr.h"
16#include "clang/AST/ExprCXX.h"
17#include "clang/AST/StmtCXX.h"
18#include "clang/AST/StmtObjC.h"
22#include "llvm/ADT/BitVector.h"
23using namespace clang;
24
25namespace {
26
27/// JumpScopeChecker - This object is used by Sema to diagnose invalid jumps
28/// into VLA and other protected scopes. For example, this rejects:
29/// goto L;
30/// int a[n];
31/// L:
32///
33/// We also detect jumps out of protected scopes when it's not possible to do
34/// cleanups properly. Indirect jumps and ASM jumps can't do cleanups because
35/// the target is unknown. Return statements with \c [[clang::musttail]] cannot
36/// handle any cleanups due to the nature of a tail call.
37class JumpScopeChecker {
38 Sema &S;
39
40 /// Permissive - True when recovering from errors, in which case precautions
41 /// are taken to handle incomplete scope information.
42 const bool Permissive;
43
44 /// GotoScope - This is a record that we use to keep track of all of the
45 /// scopes that are introduced by VLAs and other things that scope jumps like
46 /// gotos. This scope tree has nothing to do with the source scope tree,
47 /// because you can have multiple VLA scopes per compound statement, and most
48 /// compound statements don't introduce any scopes.
49 struct GotoScope {
50 /// ParentScope - The index in ScopeMap of the parent scope. This is 0 for
51 /// the parent scope is the function body.
52 unsigned ParentScope;
53
54 /// InDiag - The note to emit if there is a jump into this scope.
55 unsigned InDiag;
56
57 /// OutDiag - The note to emit if there is an indirect jump out
58 /// of this scope. Direct jumps always clean up their current scope
59 /// in an orderly way.
60 unsigned OutDiag;
61
62 /// Loc - Location to emit the diagnostic.
64
65 GotoScope(unsigned parentScope, unsigned InDiag, unsigned OutDiag,
67 : ParentScope(parentScope), InDiag(InDiag), OutDiag(OutDiag), Loc(L) {}
68 };
69
71 llvm::DenseMap<Stmt*, unsigned> LabelAndGotoScopes;
73
74 SmallVector<Stmt*, 4> IndirectJumps;
75 SmallVector<Stmt*, 4> AsmJumps;
77 SmallVector<LabelDecl*, 4> IndirectJumpTargets;
78 SmallVector<LabelDecl*, 4> AsmJumpTargets;
79public:
80 JumpScopeChecker(Stmt *Body, Sema &S);
81private:
82 void BuildScopeInformation(Decl *D, unsigned &ParentScope);
83 void BuildScopeInformation(VarDecl *D, const BlockDecl *BDecl,
84 unsigned &ParentScope);
85 void BuildScopeInformation(CompoundLiteralExpr *CLE, unsigned &ParentScope);
86 void BuildScopeInformation(Stmt *S, unsigned &origParentScope);
87
88 void VerifyJumps();
89 void VerifyIndirectOrAsmJumps(bool IsAsmGoto);
90 void VerifyMustTailStmts();
91 void NoteJumpIntoScopes(ArrayRef<unsigned> ToScopes);
92 void DiagnoseIndirectOrAsmJump(Stmt *IG, unsigned IGScope, LabelDecl *Target,
93 unsigned TargetScope);
94 void CheckJump(Stmt *From, Stmt *To, SourceLocation DiagLoc,
95 unsigned JumpDiag, unsigned JumpDiagWarning,
96 unsigned JumpDiagCXX98Compat);
97 void CheckGotoStmt(GotoStmt *GS);
98 const Attr *GetMustTailAttr(AttributedStmt *AS);
99
100 unsigned GetDeepestCommonScope(unsigned A, unsigned B);
101};
102} // end anonymous namespace
103
104#define CHECK_PERMISSIVE(x) (assert(Permissive || !(x)), (Permissive && (x)))
105
106JumpScopeChecker::JumpScopeChecker(Stmt *Body, Sema &s)
107 : S(s), Permissive(s.hasAnyUnrecoverableErrorsInThisFunction()) {
108 // Add a scope entry for function scope.
109 Scopes.push_back(GotoScope(~0U, ~0U, ~0U, SourceLocation()));
110
111 // Build information for the top level compound statement, so that we have a
112 // defined scope record for every "goto" and label.
113 unsigned BodyParentScope = 0;
114 BuildScopeInformation(Body, BodyParentScope);
115
116 // Check that all jumps we saw are kosher.
117 VerifyJumps();
118 VerifyIndirectOrAsmJumps(false);
119 VerifyIndirectOrAsmJumps(true);
120 VerifyMustTailStmts();
121}
122
123/// GetDeepestCommonScope - Finds the innermost scope enclosing the
124/// two scopes.
125unsigned JumpScopeChecker::GetDeepestCommonScope(unsigned A, unsigned B) {
126 while (A != B) {
127 // Inner scopes are created after outer scopes and therefore have
128 // higher indices.
129 if (A < B) {
130 assert(Scopes[B].ParentScope < B);
131 B = Scopes[B].ParentScope;
132 } else {
133 assert(Scopes[A].ParentScope < A);
134 A = Scopes[A].ParentScope;
135 }
136 }
137 return A;
138}
139
140typedef std::pair<unsigned,unsigned> ScopePair;
141
142/// GetDiagForGotoScopeDecl - If this decl induces a new goto scope, return a
143/// diagnostic that should be emitted if control goes over it. If not, return 0.
145 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
146 unsigned InDiag = 0;
147 unsigned OutDiag = 0;
148
149 if (VD->getType()->isVariablyModifiedType())
150 InDiag = diag::note_protected_by_vla;
151
152 if (VD->hasAttr<BlocksAttr>())
153 return ScopePair(diag::note_protected_by___block,
154 diag::note_exits___block);
155
156 if (VD->hasAttr<CleanupAttr>())
157 return ScopePair(diag::note_protected_by_cleanup,
158 diag::note_exits_cleanup);
159
160 if (VD->hasLocalStorage()) {
161 switch (VD->getType().isDestructedType()) {
163 return ScopePair(diag::note_protected_by_objc_strong_init,
164 diag::note_exits_objc_strong);
165
167 return ScopePair(diag::note_protected_by_objc_weak_init,
168 diag::note_exits_objc_weak);
169
171 return ScopePair(diag::note_protected_by_non_trivial_c_struct_init,
172 diag::note_exits_dtor);
173
175 OutDiag = diag::note_exits_dtor;
176 break;
177
179 break;
180 }
181 }
182
183 const Expr *Init = VD->getInit();
184 if (S.Context.getLangOpts().CPlusPlus && VD->hasLocalStorage() && Init) {
185 // C++11 [stmt.dcl]p3:
186 // A program that jumps from a point where a variable with automatic
187 // storage duration is not in scope to a point where it is in scope
188 // is ill-formed unless the variable has scalar type, class type with
189 // a trivial default constructor and a trivial destructor, a
190 // cv-qualified version of one of these types, or an array of one of
191 // the preceding types and is declared without an initializer.
192
193 // C++03 [stmt.dcl.p3:
194 // A program that jumps from a point where a local variable
195 // with automatic storage duration is not in scope to a point
196 // where it is in scope is ill-formed unless the variable has
197 // POD type and is declared without an initializer.
198
199 InDiag = diag::note_protected_by_variable_init;
200
201 // For a variable of (array of) class type declared without an
202 // initializer, we will have call-style initialization and the initializer
203 // will be the CXXConstructExpr with no intervening nodes.
204 if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) {
205 const CXXConstructorDecl *Ctor = CCE->getConstructor();
206 if (Ctor->isTrivial() && Ctor->isDefaultConstructor() &&
207 VD->getInitStyle() == VarDecl::CallInit) {
208 if (OutDiag)
209 InDiag = diag::note_protected_by_variable_nontriv_destructor;
210 else if (!Ctor->getParent()->isPOD())
211 InDiag = diag::note_protected_by_variable_non_pod;
212 else
213 InDiag = 0;
214 }
215 }
216 }
217
218 return ScopePair(InDiag, OutDiag);
219 }
220
221 if (const TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(D)) {
222 if (TD->getUnderlyingType()->isVariablyModifiedType())
223 return ScopePair(isa<TypedefDecl>(TD)
224 ? diag::note_protected_by_vla_typedef
225 : diag::note_protected_by_vla_type_alias,
226 0);
227 }
228
229 return ScopePair(0U, 0U);
230}
231
232/// Build scope information for a declaration that is part of a DeclStmt.
233void JumpScopeChecker::BuildScopeInformation(Decl *D, unsigned &ParentScope) {
234 // If this decl causes a new scope, push and switch to it.
235 std::pair<unsigned,unsigned> Diags = GetDiagForGotoScopeDecl(S, D);
236 if (Diags.first || Diags.second) {
237 Scopes.push_back(GotoScope(ParentScope, Diags.first, Diags.second,
238 D->getLocation()));
239 ParentScope = Scopes.size()-1;
240 }
241
242 // If the decl has an initializer, walk it with the potentially new
243 // scope we just installed.
244 if (VarDecl *VD = dyn_cast<VarDecl>(D))
245 if (Expr *Init = VD->getInit())
246 BuildScopeInformation(Init, ParentScope);
247}
248
249/// Build scope information for a captured block literal variables.
250void JumpScopeChecker::BuildScopeInformation(VarDecl *D,
251 const BlockDecl *BDecl,
252 unsigned &ParentScope) {
253 // exclude captured __block variables; there's no destructor
254 // associated with the block literal for them.
255 if (D->hasAttr<BlocksAttr>())
256 return;
257 QualType T = D->getType();
259 if (destructKind != QualType::DK_none) {
260 std::pair<unsigned,unsigned> Diags;
261 switch (destructKind) {
263 Diags = ScopePair(diag::note_enters_block_captures_cxx_obj,
264 diag::note_exits_block_captures_cxx_obj);
265 break;
267 Diags = ScopePair(diag::note_enters_block_captures_strong,
268 diag::note_exits_block_captures_strong);
269 break;
271 Diags = ScopePair(diag::note_enters_block_captures_weak,
272 diag::note_exits_block_captures_weak);
273 break;
275 Diags = ScopePair(diag::note_enters_block_captures_non_trivial_c_struct,
276 diag::note_exits_block_captures_non_trivial_c_struct);
277 break;
279 llvm_unreachable("non-lifetime captured variable");
280 }
281 SourceLocation Loc = D->getLocation();
282 if (Loc.isInvalid())
283 Loc = BDecl->getLocation();
284 Scopes.push_back(GotoScope(ParentScope,
285 Diags.first, Diags.second, Loc));
286 ParentScope = Scopes.size()-1;
287 }
288}
289
290/// Build scope information for compound literals of C struct types that are
291/// non-trivial to destruct.
292void JumpScopeChecker::BuildScopeInformation(CompoundLiteralExpr *CLE,
293 unsigned &ParentScope) {
294 unsigned InDiag = diag::note_enters_compound_literal_scope;
295 unsigned OutDiag = diag::note_exits_compound_literal_scope;
296 Scopes.push_back(GotoScope(ParentScope, InDiag, OutDiag, CLE->getExprLoc()));
297 ParentScope = Scopes.size() - 1;
298}
299
300/// BuildScopeInformation - The statements from CI to CE are known to form a
301/// coherent VLA scope with a specified parent node. Walk through the
302/// statements, adding any labels or gotos to LabelAndGotoScopes and recursively
303/// walking the AST as needed.
304void JumpScopeChecker::BuildScopeInformation(Stmt *S,
305 unsigned &origParentScope) {
306 // If this is a statement, rather than an expression, scopes within it don't
307 // propagate out into the enclosing scope. Otherwise we have to worry
308 // about block literals, which have the lifetime of their enclosing statement.
309 unsigned independentParentScope = origParentScope;
310 unsigned &ParentScope = ((isa<Expr>(S) && !isa<StmtExpr>(S))
311 ? origParentScope : independentParentScope);
312
313 unsigned StmtsToSkip = 0u;
314
315 // If we found a label, remember that it is in ParentScope scope.
316 switch (S->getStmtClass()) {
317 case Stmt::AddrLabelExprClass:
318 IndirectJumpTargets.push_back(cast<AddrLabelExpr>(S)->getLabel());
319 break;
320
321 case Stmt::ObjCForCollectionStmtClass: {
322 auto *CS = cast<ObjCForCollectionStmt>(S);
323 unsigned Diag = diag::note_protected_by_objc_fast_enumeration;
324 unsigned NewParentScope = Scopes.size();
325 Scopes.push_back(GotoScope(ParentScope, Diag, 0, S->getBeginLoc()));
326 BuildScopeInformation(CS->getBody(), NewParentScope);
327 return;
328 }
329
330 case Stmt::IndirectGotoStmtClass:
331 // "goto *&&lbl;" is a special case which we treat as equivalent
332 // to a normal goto. In addition, we don't calculate scope in the
333 // operand (to avoid recording the address-of-label use), which
334 // works only because of the restricted set of expressions which
335 // we detect as constant targets.
336 if (cast<IndirectGotoStmt>(S)->getConstantTarget()) {
337 LabelAndGotoScopes[S] = ParentScope;
338 Jumps.push_back(S);
339 return;
340 }
341
342 LabelAndGotoScopes[S] = ParentScope;
343 IndirectJumps.push_back(S);
344 break;
345
346 case Stmt::SwitchStmtClass:
347 // Evaluate the C++17 init stmt and condition variable
348 // before entering the scope of the switch statement.
349 if (Stmt *Init = cast<SwitchStmt>(S)->getInit()) {
350 BuildScopeInformation(Init, ParentScope);
351 ++StmtsToSkip;
352 }
353 if (VarDecl *Var = cast<SwitchStmt>(S)->getConditionVariable()) {
354 BuildScopeInformation(Var, ParentScope);
355 ++StmtsToSkip;
356 }
357 [[fallthrough]];
358
359 case Stmt::GotoStmtClass:
360 // Remember both what scope a goto is in as well as the fact that we have
361 // it. This makes the second scan not have to walk the AST again.
362 LabelAndGotoScopes[S] = ParentScope;
363 Jumps.push_back(S);
364 break;
365
366 case Stmt::GCCAsmStmtClass:
367 if (auto *GS = dyn_cast<GCCAsmStmt>(S))
368 if (GS->isAsmGoto()) {
369 // Remember both what scope a goto is in as well as the fact that we
370 // have it. This makes the second scan not have to walk the AST again.
371 LabelAndGotoScopes[S] = ParentScope;
372 AsmJumps.push_back(GS);
373 for (auto *E : GS->labels())
374 AsmJumpTargets.push_back(E->getLabel());
375 }
376 break;
377
378 case Stmt::IfStmtClass: {
379 IfStmt *IS = cast<IfStmt>(S);
380 if (!(IS->isConstexpr() || IS->isConsteval() ||
382 break;
383
384 unsigned Diag = diag::note_protected_by_if_available;
385 if (IS->isConstexpr())
386 Diag = diag::note_protected_by_constexpr_if;
387 else if (IS->isConsteval())
388 Diag = diag::note_protected_by_consteval_if;
389
390 if (VarDecl *Var = IS->getConditionVariable())
391 BuildScopeInformation(Var, ParentScope);
392
393 // Cannot jump into the middle of the condition.
394 unsigned NewParentScope = Scopes.size();
395 Scopes.push_back(GotoScope(ParentScope, Diag, 0, IS->getBeginLoc()));
396
397 if (!IS->isConsteval())
398 BuildScopeInformation(IS->getCond(), NewParentScope);
399
400 // Jumps into either arm of an 'if constexpr' are not allowed.
401 NewParentScope = Scopes.size();
402 Scopes.push_back(GotoScope(ParentScope, Diag, 0, IS->getBeginLoc()));
403 BuildScopeInformation(IS->getThen(), NewParentScope);
404 if (Stmt *Else = IS->getElse()) {
405 NewParentScope = Scopes.size();
406 Scopes.push_back(GotoScope(ParentScope, Diag, 0, IS->getBeginLoc()));
407 BuildScopeInformation(Else, NewParentScope);
408 }
409 return;
410 }
411
412 case Stmt::CXXTryStmtClass: {
413 CXXTryStmt *TS = cast<CXXTryStmt>(S);
414 {
415 unsigned NewParentScope = Scopes.size();
416 Scopes.push_back(GotoScope(ParentScope,
417 diag::note_protected_by_cxx_try,
418 diag::note_exits_cxx_try,
419 TS->getSourceRange().getBegin()));
420 if (Stmt *TryBlock = TS->getTryBlock())
421 BuildScopeInformation(TryBlock, NewParentScope);
422 }
423
424 // Jump from the catch into the try is not allowed either.
425 for (unsigned I = 0, E = TS->getNumHandlers(); I != E; ++I) {
426 CXXCatchStmt *CS = TS->getHandler(I);
427 unsigned NewParentScope = Scopes.size();
428 Scopes.push_back(GotoScope(ParentScope,
429 diag::note_protected_by_cxx_catch,
430 diag::note_exits_cxx_catch,
431 CS->getSourceRange().getBegin()));
432 BuildScopeInformation(CS->getHandlerBlock(), NewParentScope);
433 }
434 return;
435 }
436
437 case Stmt::SEHTryStmtClass: {
438 SEHTryStmt *TS = cast<SEHTryStmt>(S);
439 {
440 unsigned NewParentScope = Scopes.size();
441 Scopes.push_back(GotoScope(ParentScope,
442 diag::note_protected_by_seh_try,
443 diag::note_exits_seh_try,
444 TS->getSourceRange().getBegin()));
445 if (Stmt *TryBlock = TS->getTryBlock())
446 BuildScopeInformation(TryBlock, NewParentScope);
447 }
448
449 // Jump from __except or __finally into the __try are not allowed either.
450 if (SEHExceptStmt *Except = TS->getExceptHandler()) {
451 unsigned NewParentScope = Scopes.size();
452 Scopes.push_back(GotoScope(ParentScope,
453 diag::note_protected_by_seh_except,
454 diag::note_exits_seh_except,
455 Except->getSourceRange().getBegin()));
456 BuildScopeInformation(Except->getBlock(), NewParentScope);
457 } else if (SEHFinallyStmt *Finally = TS->getFinallyHandler()) {
458 unsigned NewParentScope = Scopes.size();
459 Scopes.push_back(GotoScope(ParentScope,
460 diag::note_protected_by_seh_finally,
461 diag::note_exits_seh_finally,
462 Finally->getSourceRange().getBegin()));
463 BuildScopeInformation(Finally->getBlock(), NewParentScope);
464 }
465
466 return;
467 }
468
469 case Stmt::DeclStmtClass: {
470 // If this is a declstmt with a VLA definition, it defines a scope from here
471 // to the end of the containing context.
472 DeclStmt *DS = cast<DeclStmt>(S);
473 // The decl statement creates a scope if any of the decls in it are VLAs
474 // or have the cleanup attribute.
475 for (auto *I : DS->decls())
476 BuildScopeInformation(I, origParentScope);
477 return;
478 }
479
480 case Stmt::ObjCAtTryStmtClass: {
481 // Disallow jumps into any part of an @try statement by pushing a scope and
482 // walking all sub-stmts in that scope.
483 ObjCAtTryStmt *AT = cast<ObjCAtTryStmt>(S);
484 // Recursively walk the AST for the @try part.
485 {
486 unsigned NewParentScope = Scopes.size();
487 Scopes.push_back(GotoScope(ParentScope,
488 diag::note_protected_by_objc_try,
489 diag::note_exits_objc_try,
490 AT->getAtTryLoc()));
491 if (Stmt *TryPart = AT->getTryBody())
492 BuildScopeInformation(TryPart, NewParentScope);
493 }
494
495 // Jump from the catch to the finally or try is not valid.
496 for (ObjCAtCatchStmt *AC : AT->catch_stmts()) {
497 unsigned NewParentScope = Scopes.size();
498 Scopes.push_back(GotoScope(ParentScope,
499 diag::note_protected_by_objc_catch,
500 diag::note_exits_objc_catch,
501 AC->getAtCatchLoc()));
502 // @catches are nested and it isn't
503 BuildScopeInformation(AC->getCatchBody(), NewParentScope);
504 }
505
506 // Jump from the finally to the try or catch is not valid.
507 if (ObjCAtFinallyStmt *AF = AT->getFinallyStmt()) {
508 unsigned NewParentScope = Scopes.size();
509 Scopes.push_back(GotoScope(ParentScope,
510 diag::note_protected_by_objc_finally,
511 diag::note_exits_objc_finally,
512 AF->getAtFinallyLoc()));
513 BuildScopeInformation(AF, NewParentScope);
514 }
515
516 return;
517 }
518
519 case Stmt::ObjCAtSynchronizedStmtClass: {
520 // Disallow jumps into the protected statement of an @synchronized, but
521 // allow jumps into the object expression it protects.
522 ObjCAtSynchronizedStmt *AS = cast<ObjCAtSynchronizedStmt>(S);
523 // Recursively walk the AST for the @synchronized object expr, it is
524 // evaluated in the normal scope.
525 BuildScopeInformation(AS->getSynchExpr(), ParentScope);
526
527 // Recursively walk the AST for the @synchronized part, protected by a new
528 // scope.
529 unsigned NewParentScope = Scopes.size();
530 Scopes.push_back(GotoScope(ParentScope,
531 diag::note_protected_by_objc_synchronized,
532 diag::note_exits_objc_synchronized,
533 AS->getAtSynchronizedLoc()));
534 BuildScopeInformation(AS->getSynchBody(), NewParentScope);
535 return;
536 }
537
538 case Stmt::ObjCAutoreleasePoolStmtClass: {
539 // Disallow jumps into the protected statement of an @autoreleasepool.
540 ObjCAutoreleasePoolStmt *AS = cast<ObjCAutoreleasePoolStmt>(S);
541 // Recursively walk the AST for the @autoreleasepool part, protected by a
542 // new scope.
543 unsigned NewParentScope = Scopes.size();
544 Scopes.push_back(GotoScope(ParentScope,
545 diag::note_protected_by_objc_autoreleasepool,
546 diag::note_exits_objc_autoreleasepool,
547 AS->getAtLoc()));
548 BuildScopeInformation(AS->getSubStmt(), NewParentScope);
549 return;
550 }
551
552 case Stmt::ExprWithCleanupsClass: {
553 // Disallow jumps past full-expressions that use blocks with
554 // non-trivial cleanups of their captures. This is theoretically
555 // implementable but a lot of work which we haven't felt up to doing.
556 ExprWithCleanups *EWC = cast<ExprWithCleanups>(S);
557 for (unsigned i = 0, e = EWC->getNumObjects(); i != e; ++i) {
558 if (auto *BDecl = EWC->getObject(i).dyn_cast<BlockDecl *>())
559 for (const auto &CI : BDecl->captures()) {
560 VarDecl *variable = CI.getVariable();
561 BuildScopeInformation(variable, BDecl, origParentScope);
562 }
563 else if (auto *CLE = EWC->getObject(i).dyn_cast<CompoundLiteralExpr *>())
564 BuildScopeInformation(CLE, origParentScope);
565 else
566 llvm_unreachable("unexpected cleanup object type");
567 }
568 break;
569 }
570
571 case Stmt::MaterializeTemporaryExprClass: {
572 // Disallow jumps out of scopes containing temporaries lifetime-extended to
573 // automatic storage duration.
574 MaterializeTemporaryExpr *MTE = cast<MaterializeTemporaryExpr>(S);
575 if (MTE->getStorageDuration() == SD_Automatic) {
578 const Expr *ExtendedObject =
580 Adjustments);
581 if (ExtendedObject->getType().isDestructedType()) {
582 Scopes.push_back(GotoScope(ParentScope, 0,
583 diag::note_exits_temporary_dtor,
584 ExtendedObject->getExprLoc()));
585 origParentScope = Scopes.size()-1;
586 }
587 }
588 break;
589 }
590
591 case Stmt::CaseStmtClass:
592 case Stmt::DefaultStmtClass:
593 case Stmt::LabelStmtClass:
594 LabelAndGotoScopes[S] = ParentScope;
595 break;
596
597 case Stmt::AttributedStmtClass: {
598 AttributedStmt *AS = cast<AttributedStmt>(S);
599 if (GetMustTailAttr(AS)) {
600 LabelAndGotoScopes[AS] = ParentScope;
601 MustTailStmts.push_back(AS);
602 }
603 break;
604 }
605
606 default:
607 if (auto *ED = dyn_cast<OMPExecutableDirective>(S)) {
608 if (!ED->isStandaloneDirective()) {
609 unsigned NewParentScope = Scopes.size();
610 Scopes.emplace_back(ParentScope,
611 diag::note_omp_protected_structured_block,
612 diag::note_omp_exits_structured_block,
613 ED->getStructuredBlock()->getBeginLoc());
614 BuildScopeInformation(ED->getStructuredBlock(), NewParentScope);
615 return;
616 }
617 }
618 break;
619 }
620
621 for (Stmt *SubStmt : S->children()) {
622 if (!SubStmt)
623 continue;
624 if (StmtsToSkip) {
625 --StmtsToSkip;
626 continue;
627 }
628
629 // Cases, labels, and defaults aren't "scope parents". It's also
630 // important to handle these iteratively instead of recursively in
631 // order to avoid blowing out the stack.
632 while (true) {
633 Stmt *Next;
634 if (SwitchCase *SC = dyn_cast<SwitchCase>(SubStmt))
635 Next = SC->getSubStmt();
636 else if (LabelStmt *LS = dyn_cast<LabelStmt>(SubStmt))
637 Next = LS->getSubStmt();
638 else
639 break;
640
641 LabelAndGotoScopes[SubStmt] = ParentScope;
642 SubStmt = Next;
643 }
644
645 // Recursively walk the AST.
646 BuildScopeInformation(SubStmt, ParentScope);
647 }
648}
649
650/// VerifyJumps - Verify each element of the Jumps array to see if they are
651/// valid, emitting diagnostics if not.
652void JumpScopeChecker::VerifyJumps() {
653 while (!Jumps.empty()) {
654 Stmt *Jump = Jumps.pop_back_val();
655
656 // With a goto,
657 if (GotoStmt *GS = dyn_cast<GotoStmt>(Jump)) {
658 // The label may not have a statement if it's coming from inline MS ASM.
659 if (GS->getLabel()->getStmt()) {
660 CheckJump(GS, GS->getLabel()->getStmt(), GS->getGotoLoc(),
661 diag::err_goto_into_protected_scope,
662 diag::ext_goto_into_protected_scope,
663 diag::warn_cxx98_compat_goto_into_protected_scope);
664 }
665 CheckGotoStmt(GS);
666 continue;
667 }
668
669 // We only get indirect gotos here when they have a constant target.
670 if (IndirectGotoStmt *IGS = dyn_cast<IndirectGotoStmt>(Jump)) {
671 LabelDecl *Target = IGS->getConstantTarget();
672 CheckJump(IGS, Target->getStmt(), IGS->getGotoLoc(),
673 diag::err_goto_into_protected_scope,
674 diag::ext_goto_into_protected_scope,
675 diag::warn_cxx98_compat_goto_into_protected_scope);
676 continue;
677 }
678
679 SwitchStmt *SS = cast<SwitchStmt>(Jump);
680 for (SwitchCase *SC = SS->getSwitchCaseList(); SC;
681 SC = SC->getNextSwitchCase()) {
682 if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(SC)))
683 continue;
684 SourceLocation Loc;
685 if (CaseStmt *CS = dyn_cast<CaseStmt>(SC))
686 Loc = CS->getBeginLoc();
687 else if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC))
688 Loc = DS->getBeginLoc();
689 else
690 Loc = SC->getBeginLoc();
691 CheckJump(SS, SC, Loc, diag::err_switch_into_protected_scope, 0,
692 diag::warn_cxx98_compat_switch_into_protected_scope);
693 }
694 }
695}
696
697/// VerifyIndirectOrAsmJumps - Verify whether any possible indirect goto or
698/// asm goto jump might cross a protection boundary. Unlike direct jumps,
699/// indirect or asm goto jumps count cleanups as protection boundaries:
700/// since there's no way to know where the jump is going, we can't implicitly
701/// run the right cleanups the way we can with direct jumps.
702/// Thus, an indirect/asm jump is "trivial" if it bypasses no
703/// initializations and no teardowns. More formally, an indirect/asm jump
704/// from A to B is trivial if the path out from A to DCA(A,B) is
705/// trivial and the path in from DCA(A,B) to B is trivial, where
706/// DCA(A,B) is the deepest common ancestor of A and B.
707/// Jump-triviality is transitive but asymmetric.
708///
709/// A path in is trivial if none of the entered scopes have an InDiag.
710/// A path out is trivial is none of the exited scopes have an OutDiag.
711///
712/// Under these definitions, this function checks that the indirect
713/// jump between A and B is trivial for every indirect goto statement A
714/// and every label B whose address was taken in the function.
715void JumpScopeChecker::VerifyIndirectOrAsmJumps(bool IsAsmGoto) {
716 SmallVector<Stmt*, 4> GotoJumps = IsAsmGoto ? AsmJumps : IndirectJumps;
717 if (GotoJumps.empty())
718 return;
719 SmallVector<LabelDecl *, 4> JumpTargets =
720 IsAsmGoto ? AsmJumpTargets : IndirectJumpTargets;
721 // If there aren't any address-of-label expressions in this function,
722 // complain about the first indirect goto.
723 if (JumpTargets.empty()) {
724 assert(!IsAsmGoto &&"only indirect goto can get here");
725 S.Diag(GotoJumps[0]->getBeginLoc(),
726 diag::err_indirect_goto_without_addrlabel);
727 return;
728 }
729 // Collect a single representative of every scope containing an
730 // indirect or asm goto. For most code bases, this substantially cuts
731 // down on the number of jump sites we'll have to consider later.
732 typedef std::pair<unsigned, Stmt*> JumpScope;
734 {
735 llvm::DenseMap<unsigned, Stmt*> JumpScopesMap;
736 for (SmallVectorImpl<Stmt *>::iterator I = GotoJumps.begin(),
737 E = GotoJumps.end();
738 I != E; ++I) {
739 Stmt *IG = *I;
740 if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(IG)))
741 continue;
742 unsigned IGScope = LabelAndGotoScopes[IG];
743 Stmt *&Entry = JumpScopesMap[IGScope];
744 if (!Entry) Entry = IG;
745 }
746 JumpScopes.reserve(JumpScopesMap.size());
747 for (llvm::DenseMap<unsigned, Stmt *>::iterator I = JumpScopesMap.begin(),
748 E = JumpScopesMap.end();
749 I != E; ++I)
750 JumpScopes.push_back(*I);
751 }
752
753 // Collect a single representative of every scope containing a
754 // label whose address was taken somewhere in the function.
755 // For most code bases, there will be only one such scope.
756 llvm::DenseMap<unsigned, LabelDecl*> TargetScopes;
757 for (SmallVectorImpl<LabelDecl *>::iterator I = JumpTargets.begin(),
758 E = JumpTargets.end();
759 I != E; ++I) {
760 LabelDecl *TheLabel = *I;
761 if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(TheLabel->getStmt())))
762 continue;
763 unsigned LabelScope = LabelAndGotoScopes[TheLabel->getStmt()];
764 LabelDecl *&Target = TargetScopes[LabelScope];
765 if (!Target) Target = TheLabel;
766 }
767
768 // For each target scope, make sure it's trivially reachable from
769 // every scope containing a jump site.
770 //
771 // A path between scopes always consists of exitting zero or more
772 // scopes, then entering zero or more scopes. We build a set of
773 // of scopes S from which the target scope can be trivially
774 // entered, then verify that every jump scope can be trivially
775 // exitted to reach a scope in S.
776 llvm::BitVector Reachable(Scopes.size(), false);
777 for (llvm::DenseMap<unsigned,LabelDecl*>::iterator
778 TI = TargetScopes.begin(), TE = TargetScopes.end(); TI != TE; ++TI) {
779 unsigned TargetScope = TI->first;
780 LabelDecl *TargetLabel = TI->second;
781
782 Reachable.reset();
783
784 // Mark all the enclosing scopes from which you can safely jump
785 // into the target scope. 'Min' will end up being the index of
786 // the shallowest such scope.
787 unsigned Min = TargetScope;
788 while (true) {
789 Reachable.set(Min);
790
791 // Don't go beyond the outermost scope.
792 if (Min == 0) break;
793
794 // Stop if we can't trivially enter the current scope.
795 if (Scopes[Min].InDiag) break;
796
797 Min = Scopes[Min].ParentScope;
798 }
799
800 // Walk through all the jump sites, checking that they can trivially
801 // reach this label scope.
803 I = JumpScopes.begin(), E = JumpScopes.end(); I != E; ++I) {
804 unsigned Scope = I->first;
805
806 // Walk out the "scope chain" for this scope, looking for a scope
807 // we've marked reachable. For well-formed code this amortizes
808 // to O(JumpScopes.size() / Scopes.size()): we only iterate
809 // when we see something unmarked, and in well-formed code we
810 // mark everything we iterate past.
811 bool IsReachable = false;
812 while (true) {
813 if (Reachable.test(Scope)) {
814 // If we find something reachable, mark all the scopes we just
815 // walked through as reachable.
816 for (unsigned S = I->first; S != Scope; S = Scopes[S].ParentScope)
817 Reachable.set(S);
818 IsReachable = true;
819 break;
820 }
821
822 // Don't walk out if we've reached the top-level scope or we've
823 // gotten shallower than the shallowest reachable scope.
824 if (Scope == 0 || Scope < Min) break;
825
826 // Don't walk out through an out-diagnostic.
827 if (Scopes[Scope].OutDiag) break;
828
829 Scope = Scopes[Scope].ParentScope;
830 }
831
832 // Only diagnose if we didn't find something.
833 if (IsReachable) continue;
834
835 DiagnoseIndirectOrAsmJump(I->second, I->first, TargetLabel, TargetScope);
836 }
837 }
838}
839
840/// Return true if a particular error+note combination must be downgraded to a
841/// warning in Microsoft mode.
842static bool IsMicrosoftJumpWarning(unsigned JumpDiag, unsigned InDiagNote) {
843 return (JumpDiag == diag::err_goto_into_protected_scope &&
844 (InDiagNote == diag::note_protected_by_variable_init ||
845 InDiagNote == diag::note_protected_by_variable_nontriv_destructor));
846}
847
848/// Return true if a particular note should be downgraded to a compatibility
849/// warning in C++11 mode.
850static bool IsCXX98CompatWarning(Sema &S, unsigned InDiagNote) {
851 return S.getLangOpts().CPlusPlus11 &&
852 InDiagNote == diag::note_protected_by_variable_non_pod;
853}
854
855/// Produce primary diagnostic for an indirect jump statement.
857 LabelDecl *Target, bool &Diagnosed) {
858 if (Diagnosed)
859 return;
860 bool IsAsmGoto = isa<GCCAsmStmt>(Jump);
861 S.Diag(Jump->getBeginLoc(), diag::err_indirect_goto_in_protected_scope)
862 << IsAsmGoto;
863 S.Diag(Target->getStmt()->getIdentLoc(), diag::note_indirect_goto_target)
864 << IsAsmGoto;
865 Diagnosed = true;
866}
867
868/// Produce note diagnostics for a jump into a protected scope.
869void JumpScopeChecker::NoteJumpIntoScopes(ArrayRef<unsigned> ToScopes) {
870 if (CHECK_PERMISSIVE(ToScopes.empty()))
871 return;
872 for (unsigned I = 0, E = ToScopes.size(); I != E; ++I)
873 if (Scopes[ToScopes[I]].InDiag)
874 S.Diag(Scopes[ToScopes[I]].Loc, Scopes[ToScopes[I]].InDiag);
875}
876
877/// Diagnose an indirect jump which is known to cross scopes.
878void JumpScopeChecker::DiagnoseIndirectOrAsmJump(Stmt *Jump, unsigned JumpScope,
879 LabelDecl *Target,
880 unsigned TargetScope) {
881 if (CHECK_PERMISSIVE(JumpScope == TargetScope))
882 return;
883
884 unsigned Common = GetDeepestCommonScope(JumpScope, TargetScope);
885 bool Diagnosed = false;
886
887 // Walk out the scope chain until we reach the common ancestor.
888 for (unsigned I = JumpScope; I != Common; I = Scopes[I].ParentScope)
889 if (Scopes[I].OutDiag) {
890 DiagnoseIndirectOrAsmJumpStmt(S, Jump, Target, Diagnosed);
891 S.Diag(Scopes[I].Loc, Scopes[I].OutDiag);
892 }
893
894 SmallVector<unsigned, 10> ToScopesCXX98Compat;
895
896 // Now walk into the scopes containing the label whose address was taken.
897 for (unsigned I = TargetScope; I != Common; I = Scopes[I].ParentScope)
898 if (IsCXX98CompatWarning(S, Scopes[I].InDiag))
899 ToScopesCXX98Compat.push_back(I);
900 else if (Scopes[I].InDiag) {
901 DiagnoseIndirectOrAsmJumpStmt(S, Jump, Target, Diagnosed);
902 S.Diag(Scopes[I].Loc, Scopes[I].InDiag);
903 }
904
905 // Diagnose this jump if it would be ill-formed in C++98.
906 if (!Diagnosed && !ToScopesCXX98Compat.empty()) {
907 bool IsAsmGoto = isa<GCCAsmStmt>(Jump);
908 S.Diag(Jump->getBeginLoc(),
909 diag::warn_cxx98_compat_indirect_goto_in_protected_scope)
910 << IsAsmGoto;
911 S.Diag(Target->getStmt()->getIdentLoc(), diag::note_indirect_goto_target)
912 << IsAsmGoto;
913 NoteJumpIntoScopes(ToScopesCXX98Compat);
914 }
915}
916
917/// CheckJump - Validate that the specified jump statement is valid: that it is
918/// jumping within or out of its current scope, not into a deeper one.
919void JumpScopeChecker::CheckJump(Stmt *From, Stmt *To, SourceLocation DiagLoc,
920 unsigned JumpDiagError, unsigned JumpDiagWarning,
921 unsigned JumpDiagCXX98Compat) {
922 if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(From)))
923 return;
924 if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(To)))
925 return;
926
927 unsigned FromScope = LabelAndGotoScopes[From];
928 unsigned ToScope = LabelAndGotoScopes[To];
929
930 // Common case: exactly the same scope, which is fine.
931 if (FromScope == ToScope) return;
932
933 // Warn on gotos out of __finally blocks.
934 if (isa<GotoStmt>(From) || isa<IndirectGotoStmt>(From)) {
935 // If FromScope > ToScope, FromScope is more nested and the jump goes to a
936 // less nested scope. Check if it crosses a __finally along the way.
937 for (unsigned I = FromScope; I > ToScope; I = Scopes[I].ParentScope) {
938 if (Scopes[I].InDiag == diag::note_protected_by_seh_finally) {
939 S.Diag(From->getBeginLoc(), diag::warn_jump_out_of_seh_finally);
940 break;
941 }
942 if (Scopes[I].InDiag == diag::note_omp_protected_structured_block) {
943 S.Diag(From->getBeginLoc(), diag::err_goto_into_protected_scope);
944 S.Diag(To->getBeginLoc(), diag::note_omp_exits_structured_block);
945 break;
946 }
947 }
948 }
949
950 unsigned CommonScope = GetDeepestCommonScope(FromScope, ToScope);
951
952 // It's okay to jump out from a nested scope.
953 if (CommonScope == ToScope) return;
954
955 // Pull out (and reverse) any scopes we might need to diagnose skipping.
956 SmallVector<unsigned, 10> ToScopesCXX98Compat;
957 SmallVector<unsigned, 10> ToScopesError;
958 SmallVector<unsigned, 10> ToScopesWarning;
959 for (unsigned I = ToScope; I != CommonScope; I = Scopes[I].ParentScope) {
960 if (S.getLangOpts().MSVCCompat && JumpDiagWarning != 0 &&
961 IsMicrosoftJumpWarning(JumpDiagError, Scopes[I].InDiag))
962 ToScopesWarning.push_back(I);
963 else if (IsCXX98CompatWarning(S, Scopes[I].InDiag))
964 ToScopesCXX98Compat.push_back(I);
965 else if (Scopes[I].InDiag)
966 ToScopesError.push_back(I);
967 }
968
969 // Handle warnings.
970 if (!ToScopesWarning.empty()) {
971 S.Diag(DiagLoc, JumpDiagWarning);
972 NoteJumpIntoScopes(ToScopesWarning);
973 assert(isa<LabelStmt>(To));
974 LabelStmt *Label = cast<LabelStmt>(To);
975 Label->setSideEntry(true);
976 }
977
978 // Handle errors.
979 if (!ToScopesError.empty()) {
980 S.Diag(DiagLoc, JumpDiagError);
981 NoteJumpIntoScopes(ToScopesError);
982 }
983
984 // Handle -Wc++98-compat warnings if the jump is well-formed.
985 if (ToScopesError.empty() && !ToScopesCXX98Compat.empty()) {
986 S.Diag(DiagLoc, JumpDiagCXX98Compat);
987 NoteJumpIntoScopes(ToScopesCXX98Compat);
988 }
989}
990
991void JumpScopeChecker::CheckGotoStmt(GotoStmt *GS) {
992 if (GS->getLabel()->isMSAsmLabel()) {
993 S.Diag(GS->getGotoLoc(), diag::err_goto_ms_asm_label)
994 << GS->getLabel()->getIdentifier();
995 S.Diag(GS->getLabel()->getLocation(), diag::note_goto_ms_asm_label)
996 << GS->getLabel()->getIdentifier();
997 }
998}
999
1000void JumpScopeChecker::VerifyMustTailStmts() {
1001 for (AttributedStmt *AS : MustTailStmts) {
1002 for (unsigned I = LabelAndGotoScopes[AS]; I; I = Scopes[I].ParentScope) {
1003 if (Scopes[I].OutDiag) {
1004 S.Diag(AS->getBeginLoc(), diag::err_musttail_scope);
1005 S.Diag(Scopes[I].Loc, Scopes[I].OutDiag);
1006 }
1007 }
1008 }
1009}
1010
1011const Attr *JumpScopeChecker::GetMustTailAttr(AttributedStmt *AS) {
1012 ArrayRef<const Attr *> Attrs = AS->getAttrs();
1013 const auto *Iter =
1014 llvm::find_if(Attrs, [](const Attr *A) { return isa<MustTailAttr>(A); });
1015 return Iter != Attrs.end() ? *Iter : nullptr;
1016}
1017
1019 (void)JumpScopeChecker(Body, *this);
1020}
Defines the C++ Decl subclasses, other than those for templates (found in DeclTemplate....
Defines the clang::Expr interface and subclasses for C++ expressions.
std::pair< unsigned, unsigned > ScopePair
static ScopePair GetDiagForGotoScopeDecl(Sema &S, const Decl *D)
GetDiagForGotoScopeDecl - If this decl induces a new goto scope, return a diagnostic that should be e...
static bool IsCXX98CompatWarning(Sema &S, unsigned InDiagNote)
Return true if a particular note should be downgraded to a compatibility warning in C++11 mode.
static bool IsMicrosoftJumpWarning(unsigned JumpDiag, unsigned InDiagNote)
Return true if a particular error+note combination must be downgraded to a warning in Microsoft mode.
#define CHECK_PERMISSIVE(x)
static void DiagnoseIndirectOrAsmJumpStmt(Sema &S, Stmt *Jump, LabelDecl *Target, bool &Diagnosed)
Produce primary diagnostic for an indirect jump statement.
static DiagnosticBuilder Diag(DiagnosticsEngine *Diags, const LangOptions &Features, FullSourceLoc TokLoc, const char *TokBegin, const char *TokRangeBegin, const char *TokRangeEnd, unsigned DiagID)
Produce a diagnostic highlighting some portion of a literal.
Defines the clang::SourceLocation class and associated facilities.
Defines the Objective-C statement AST node classes.
This file defines OpenMP AST classes for executable directives and clauses.
std::string Label
__device__ __2f16 float bool s
const LangOptions & getLangOpts() const
Definition: ASTContext.h:762
Attr - This represents one attribute.
Definition: Attr.h:40
Represents an attribute applied to a statement.
Definition: Stmt.h:1892
ArrayRef< const Attr * > getAttrs() const
Definition: Stmt.h:1926
SourceLocation getBeginLoc() const
Definition: Stmt.h:1933
Represents a block literal declaration, which is like an unnamed FunctionDecl.
Definition: Decl.h:4334
ArrayRef< Capture > captures() const
Definition: Decl.h:4461
CXXCatchStmt - This represents a C++ catch block.
Definition: StmtCXX.h:28
Stmt * getHandlerBlock() const
Definition: StmtCXX.h:51
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: StmtCXX.h:43
Represents a call to a C++ constructor.
Definition: ExprCXX.h:1518
Represents a C++ constructor within a class.
Definition: DeclCXX.h:2474
bool isDefaultConstructor() const
Whether this constructor is a default constructor (C++ [class.ctor]p5), which can be used to default-...
Definition: DeclCXX.cpp:2684
const CXXRecordDecl * getParent() const
Return the parent of this method declaration, which is the class in which this method is defined.
Definition: DeclCXX.h:2133
bool isPOD() const
Whether this class is a POD-type (C++ [class]p4)
Definition: DeclCXX.h:1152
CXXTryStmt - A C++ try block, including all handlers.
Definition: StmtCXX.h:69
CXXCatchStmt * getHandler(unsigned i)
Definition: StmtCXX.h:107
unsigned getNumHandlers() const
Definition: StmtCXX.h:106
CompoundStmt * getTryBlock()
Definition: StmtCXX.h:99
CaseStmt - Represent a case statement.
Definition: Stmt.h:1613
CompoundLiteralExpr - [C99 6.5.2.5].
Definition: Expr.h:3412
DeclStmt - Adaptor class for mixing declarations with statements and expressions.
Definition: Stmt.h:1311
decl_range decls()
Definition: Stmt.h:1359
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.h:1337
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:83
SourceLocation getLocation() const
Definition: DeclBase.h:432
bool hasAttr() const
Definition: DeclBase.h:560
Represents an expression – generally a full-expression – that introduces cleanups to be run at the en...
Definition: ExprCXX.h:3420
CleanupObject getObject(unsigned i) const
Definition: ExprCXX.h:3450
unsigned getNumObjects() const
Definition: ExprCXX.h:3448
This represents one expression.
Definition: Expr.h:110
const Expr * skipRValueSubobjectAdjustments(SmallVectorImpl< const Expr * > &CommaLHS, SmallVectorImpl< SubobjectAdjustment > &Adjustments) const
Walk outwards from an expression we want to bind a reference to and find the expression whose lifetim...
Definition: Expr.cpp:82
SourceLocation getExprLoc() const LLVM_READONLY
getExprLoc - Return the preferred location for the arrow when diagnosing a problem with a generic exp...
Definition: Expr.cpp:330
QualType getType() const
Definition: Expr.h:142
bool isTrivial() const
Whether this function is "trivial" in some specialized C++ senses.
Definition: Decl.h:2272
GotoStmt - This represents a direct goto.
Definition: Stmt.h:2649
SourceLocation getGotoLoc() const
Definition: Stmt.h:2665
LabelDecl * getLabel() const
Definition: Stmt.h:2662
IfStmt - This represents an if/then/else.
Definition: Stmt.h:1950
Stmt * getThen()
Definition: Stmt.h:2039
Expr * getCond()
Definition: Stmt.h:2027
bool isConstexpr() const
Definition: Stmt.h:2138
bool isObjCAvailabilityCheck() const
Definition: Stmt.cpp:1001
Stmt * getElse()
Definition: Stmt.h:2048
SourceLocation getBeginLoc() const
Definition: Stmt.h:2157
bool isConsteval() const
Definition: Stmt.h:2125
VarDecl * getConditionVariable()
Retrieve the variable declared in this "if" statement, if any.
Definition: Stmt.cpp:980
IndirectGotoStmt - This represents an indirect goto.
Definition: Stmt.h:2688
Represents the declaration of a label.
Definition: Decl.h:494
LabelStmt * getStmt() const
Definition: Decl.h:518
bool isMSAsmLabel() const
Definition: Decl.h:528
LabelStmt - Represents a label, which has a substatement.
Definition: Stmt.h:1843
Represents a prvalue temporary that is written into memory so that a reference can bind to it.
Definition: ExprCXX.h:4562
StorageDuration getStorageDuration() const
Retrieve the storage duration for the materialized temporary.
Definition: ExprCXX.h:4587
Expr * getSubExpr() const
Retrieve the temporary-generating subexpression whose value will be materialized into a glvalue.
Definition: ExprCXX.h:4579
IdentifierInfo * getIdentifier() const
Get the identifier that names this declaration, if there is one.
Definition: Decl.h:268
Represents Objective-C's @catch statement.
Definition: StmtObjC.h:77
Represents Objective-C's @finally statement.
Definition: StmtObjC.h:127
Represents Objective-C's @synchronized statement.
Definition: StmtObjC.h:302
const Expr * getSynchExpr() const
Definition: StmtObjC.h:330
const CompoundStmt * getSynchBody() const
Definition: StmtObjC.h:322
SourceLocation getAtSynchronizedLoc() const
Definition: StmtObjC.h:319
Represents Objective-C's @try ... @catch ... @finally statement.
Definition: StmtObjC.h:167
const ObjCAtFinallyStmt * getFinallyStmt() const
Retrieve the @finally statement, if any.
Definition: StmtObjC.h:239
const Stmt * getTryBody() const
Retrieve the @try body.
Definition: StmtObjC.h:212
SourceLocation getAtTryLoc() const
Retrieve the location of the @ in the @try.
Definition: StmtObjC.h:208
catch_range catch_stmts()
Definition: StmtObjC.h:281
Represents Objective-C's @autoreleasepool Statement.
Definition: StmtObjC.h:393
SourceLocation getAtLoc() const
Definition: StmtObjC.h:413
const Stmt * getSubStmt() const
Definition: StmtObjC.h:404
A (possibly-)qualified type.
Definition: Type.h:736
@ DK_cxx_destructor
Definition: Type.h:1278
@ DK_nontrivial_c_struct
Definition: Type.h:1281
@ DK_objc_weak_lifetime
Definition: Type.h:1280
@ DK_objc_strong_lifetime
Definition: Type.h:1279
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after.
Definition: Type.h:1288
CompoundStmt * getTryBlock() const
Definition: Stmt.h:3481
SEHFinallyStmt * getFinallyHandler() const
Definition: Stmt.cpp:1255
SEHExceptStmt * getExceptHandler() const
Returns 0 if not defined.
Definition: Stmt.cpp:1251
Scope - A scope is a transient data structure that is used while parsing the program.
Definition: Scope.h:41
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:356
SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID, bool DeferHint=false)
Emit a diagnostic.
Definition: Sema.cpp:1884
ASTContext & Context
Definition: Sema.h:407
const LangOptions & getLangOpts() const
Definition: Sema.h:1645
void DiagnoseInvalidJumps(Stmt *Body)
Encodes a location in the source.
SourceLocation getBegin() const
Stmt - This represents one statement.
Definition: Stmt.h:72
SourceRange getSourceRange() const LLVM_READONLY
SourceLocation tokens are not useful in isolation - they are low level value objects created/interpre...
Definition: Stmt.cpp:325
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:337
const SwitchCase * getNextSwitchCase() const
Definition: Stmt.h:1586
SwitchStmt - This represents a 'switch' stmt.
Definition: Stmt.h:2195
SwitchCase * getSwitchCaseList()
Definition: Stmt.h:2327
Base class for declarations which introduce a typedef-name.
Definition: Decl.h:3290
QualType getType() const
Definition: Decl.h:712
Represents a variable declaration or definition.
Definition: Decl.h:913
@ CallInit
Call-style initialization (C++98)
Definition: Decl.h:921
@ SD_Automatic
Automatic storage duration (most local variables).
Definition: Specifiers.h:313