clang  10.0.0svn
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 
15 #include "clang/AST/DeclCXX.h"
16 #include "clang/AST/Expr.h"
17 #include "clang/AST/ExprCXX.h"
18 #include "clang/AST/StmtCXX.h"
19 #include "clang/AST/StmtObjC.h"
20 #include "llvm/ADT/BitVector.h"
21 using namespace clang;
22 
23 namespace {
24 
25 /// JumpScopeChecker - This object is used by Sema to diagnose invalid jumps
26 /// into VLA and other protected scopes. For example, this rejects:
27 /// goto L;
28 /// int a[n];
29 /// L:
30 ///
31 class JumpScopeChecker {
32  Sema &S;
33 
34  /// Permissive - True when recovering from errors, in which case precautions
35  /// are taken to handle incomplete scope information.
36  const bool Permissive;
37 
38  /// GotoScope - This is a record that we use to keep track of all of the
39  /// scopes that are introduced by VLAs and other things that scope jumps like
40  /// gotos. This scope tree has nothing to do with the source scope tree,
41  /// because you can have multiple VLA scopes per compound statement, and most
42  /// compound statements don't introduce any scopes.
43  struct GotoScope {
44  /// ParentScope - The index in ScopeMap of the parent scope. This is 0 for
45  /// the parent scope is the function body.
46  unsigned ParentScope;
47 
48  /// InDiag - The note to emit if there is a jump into this scope.
49  unsigned InDiag;
50 
51  /// OutDiag - The note to emit if there is an indirect jump out
52  /// of this scope. Direct jumps always clean up their current scope
53  /// in an orderly way.
54  unsigned OutDiag;
55 
56  /// Loc - Location to emit the diagnostic.
57  SourceLocation Loc;
58 
59  GotoScope(unsigned parentScope, unsigned InDiag, unsigned OutDiag,
61  : ParentScope(parentScope), InDiag(InDiag), OutDiag(OutDiag), Loc(L) {}
62  };
63 
65  llvm::DenseMap<Stmt*, unsigned> LabelAndGotoScopes;
67 
68  SmallVector<Stmt*, 4> IndirectJumps;
69  SmallVector<Stmt*, 4> AsmJumps;
70  SmallVector<LabelDecl*, 4> IndirectJumpTargets;
71  SmallVector<LabelDecl*, 4> AsmJumpTargets;
72 public:
73  JumpScopeChecker(Stmt *Body, Sema &S);
74 private:
75  void BuildScopeInformation(Decl *D, unsigned &ParentScope);
76  void BuildScopeInformation(VarDecl *D, const BlockDecl *BDecl,
77  unsigned &ParentScope);
78  void BuildScopeInformation(Stmt *S, unsigned &origParentScope);
79 
80  void VerifyJumps();
81  void VerifyIndirectOrAsmJumps(bool IsAsmGoto);
82  void NoteJumpIntoScopes(ArrayRef<unsigned> ToScopes);
83  void DiagnoseIndirectOrAsmJump(Stmt *IG, unsigned IGScope, LabelDecl *Target,
84  unsigned TargetScope);
85  void CheckJump(Stmt *From, Stmt *To, SourceLocation DiagLoc,
86  unsigned JumpDiag, unsigned JumpDiagWarning,
87  unsigned JumpDiagCXX98Compat);
88  void CheckGotoStmt(GotoStmt *GS);
89 
90  unsigned GetDeepestCommonScope(unsigned A, unsigned B);
91 };
92 } // end anonymous namespace
93 
94 #define CHECK_PERMISSIVE(x) (assert(Permissive || !(x)), (Permissive && (x)))
95 
96 JumpScopeChecker::JumpScopeChecker(Stmt *Body, Sema &s)
97  : S(s), Permissive(s.hasAnyUnrecoverableErrorsInThisFunction()) {
98  // Add a scope entry for function scope.
99  Scopes.push_back(GotoScope(~0U, ~0U, ~0U, SourceLocation()));
100 
101  // Build information for the top level compound statement, so that we have a
102  // defined scope record for every "goto" and label.
103  unsigned BodyParentScope = 0;
104  BuildScopeInformation(Body, BodyParentScope);
105 
106  // Check that all jumps we saw are kosher.
107  VerifyJumps();
108  VerifyIndirectOrAsmJumps(false);
109  VerifyIndirectOrAsmJumps(true);
110 }
111 
112 /// GetDeepestCommonScope - Finds the innermost scope enclosing the
113 /// two scopes.
114 unsigned JumpScopeChecker::GetDeepestCommonScope(unsigned A, unsigned B) {
115  while (A != B) {
116  // Inner scopes are created after outer scopes and therefore have
117  // higher indices.
118  if (A < B) {
119  assert(Scopes[B].ParentScope < B);
120  B = Scopes[B].ParentScope;
121  } else {
122  assert(Scopes[A].ParentScope < A);
123  A = Scopes[A].ParentScope;
124  }
125  }
126  return A;
127 }
128 
129 typedef std::pair<unsigned,unsigned> ScopePair;
130 
131 /// GetDiagForGotoScopeDecl - If this decl induces a new goto scope, return a
132 /// diagnostic that should be emitted if control goes over it. If not, return 0.
134  if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
135  unsigned InDiag = 0;
136  unsigned OutDiag = 0;
137 
138  if (VD->getType()->isVariablyModifiedType())
139  InDiag = diag::note_protected_by_vla;
140 
141  if (VD->hasAttr<BlocksAttr>())
142  return ScopePair(diag::note_protected_by___block,
143  diag::note_exits___block);
144 
145  if (VD->hasAttr<CleanupAttr>())
146  return ScopePair(diag::note_protected_by_cleanup,
147  diag::note_exits_cleanup);
148 
149  if (VD->hasLocalStorage()) {
150  switch (VD->getType().isDestructedType()) {
151  case QualType::DK_objc_strong_lifetime:
152  return ScopePair(diag::note_protected_by_objc_strong_init,
153  diag::note_exits_objc_strong);
154 
155  case QualType::DK_objc_weak_lifetime:
156  return ScopePair(diag::note_protected_by_objc_weak_init,
157  diag::note_exits_objc_weak);
158 
159  case QualType::DK_nontrivial_c_struct:
160  return ScopePair(diag::note_protected_by_non_trivial_c_struct_init,
161  diag::note_exits_dtor);
162 
163  case QualType::DK_cxx_destructor:
164  OutDiag = diag::note_exits_dtor;
165  break;
166 
167  case QualType::DK_none:
168  break;
169  }
170  }
171 
172  const Expr *Init = VD->getInit();
173  if (S.Context.getLangOpts().CPlusPlus && VD->hasLocalStorage() && Init) {
174  // C++11 [stmt.dcl]p3:
175  // A program that jumps from a point where a variable with automatic
176  // storage duration is not in scope to a point where it is in scope
177  // is ill-formed unless the variable has scalar type, class type with
178  // a trivial default constructor and a trivial destructor, a
179  // cv-qualified version of one of these types, or an array of one of
180  // the preceding types and is declared without an initializer.
181 
182  // C++03 [stmt.dcl.p3:
183  // A program that jumps from a point where a local variable
184  // with automatic storage duration is not in scope to a point
185  // where it is in scope is ill-formed unless the variable has
186  // POD type and is declared without an initializer.
187 
188  InDiag = diag::note_protected_by_variable_init;
189 
190  // For a variable of (array of) class type declared without an
191  // initializer, we will have call-style initialization and the initializer
192  // will be the CXXConstructExpr with no intervening nodes.
193  if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) {
194  const CXXConstructorDecl *Ctor = CCE->getConstructor();
195  if (Ctor->isTrivial() && Ctor->isDefaultConstructor() &&
196  VD->getInitStyle() == VarDecl::CallInit) {
197  if (OutDiag)
198  InDiag = diag::note_protected_by_variable_nontriv_destructor;
199  else if (!Ctor->getParent()->isPOD())
200  InDiag = diag::note_protected_by_variable_non_pod;
201  else
202  InDiag = 0;
203  }
204  }
205  }
206 
207  return ScopePair(InDiag, OutDiag);
208  }
209 
210  if (const TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(D)) {
211  if (TD->getUnderlyingType()->isVariablyModifiedType())
212  return ScopePair(isa<TypedefDecl>(TD)
213  ? diag::note_protected_by_vla_typedef
214  : diag::note_protected_by_vla_type_alias,
215  0);
216  }
217 
218  return ScopePair(0U, 0U);
219 }
220 
221 /// Build scope information for a declaration that is part of a DeclStmt.
222 void JumpScopeChecker::BuildScopeInformation(Decl *D, unsigned &ParentScope) {
223  // If this decl causes a new scope, push and switch to it.
224  std::pair<unsigned,unsigned> Diags = GetDiagForGotoScopeDecl(S, D);
225  if (Diags.first || Diags.second) {
226  Scopes.push_back(GotoScope(ParentScope, Diags.first, Diags.second,
227  D->getLocation()));
228  ParentScope = Scopes.size()-1;
229  }
230 
231  // If the decl has an initializer, walk it with the potentially new
232  // scope we just installed.
233  if (VarDecl *VD = dyn_cast<VarDecl>(D))
234  if (Expr *Init = VD->getInit())
235  BuildScopeInformation(Init, ParentScope);
236 }
237 
238 /// Build scope information for a captured block literal variables.
239 void JumpScopeChecker::BuildScopeInformation(VarDecl *D,
240  const BlockDecl *BDecl,
241  unsigned &ParentScope) {
242  // exclude captured __block variables; there's no destructor
243  // associated with the block literal for them.
244  if (D->hasAttr<BlocksAttr>())
245  return;
246  QualType T = D->getType();
247  QualType::DestructionKind destructKind = T.isDestructedType();
248  if (destructKind != QualType::DK_none) {
249  std::pair<unsigned,unsigned> Diags;
250  switch (destructKind) {
251  case QualType::DK_cxx_destructor:
252  Diags = ScopePair(diag::note_enters_block_captures_cxx_obj,
253  diag::note_exits_block_captures_cxx_obj);
254  break;
255  case QualType::DK_objc_strong_lifetime:
256  Diags = ScopePair(diag::note_enters_block_captures_strong,
257  diag::note_exits_block_captures_strong);
258  break;
259  case QualType::DK_objc_weak_lifetime:
260  Diags = ScopePair(diag::note_enters_block_captures_weak,
261  diag::note_exits_block_captures_weak);
262  break;
263  case QualType::DK_nontrivial_c_struct:
264  Diags = ScopePair(diag::note_enters_block_captures_non_trivial_c_struct,
265  diag::note_exits_block_captures_non_trivial_c_struct);
266  break;
267  case QualType::DK_none:
268  llvm_unreachable("non-lifetime captured variable");
269  }
270  SourceLocation Loc = D->getLocation();
271  if (Loc.isInvalid())
272  Loc = BDecl->getLocation();
273  Scopes.push_back(GotoScope(ParentScope,
274  Diags.first, Diags.second, Loc));
275  ParentScope = Scopes.size()-1;
276  }
277 }
278 
279 /// BuildScopeInformation - The statements from CI to CE are known to form a
280 /// coherent VLA scope with a specified parent node. Walk through the
281 /// statements, adding any labels or gotos to LabelAndGotoScopes and recursively
282 /// walking the AST as needed.
283 void JumpScopeChecker::BuildScopeInformation(Stmt *S,
284  unsigned &origParentScope) {
285  // If this is a statement, rather than an expression, scopes within it don't
286  // propagate out into the enclosing scope. Otherwise we have to worry
287  // about block literals, which have the lifetime of their enclosing statement.
288  unsigned independentParentScope = origParentScope;
289  unsigned &ParentScope = ((isa<Expr>(S) && !isa<StmtExpr>(S))
290  ? origParentScope : independentParentScope);
291 
292  unsigned StmtsToSkip = 0u;
293 
294  // If we found a label, remember that it is in ParentScope scope.
295  switch (S->getStmtClass()) {
296  case Stmt::AddrLabelExprClass:
297  IndirectJumpTargets.push_back(cast<AddrLabelExpr>(S)->getLabel());
298  break;
299 
300  case Stmt::ObjCForCollectionStmtClass: {
301  auto *CS = cast<ObjCForCollectionStmt>(S);
302  unsigned Diag = diag::note_protected_by_objc_fast_enumeration;
303  unsigned NewParentScope = Scopes.size();
304  Scopes.push_back(GotoScope(ParentScope, Diag, 0, S->getBeginLoc()));
305  BuildScopeInformation(CS->getBody(), NewParentScope);
306  return;
307  }
308 
309  case Stmt::IndirectGotoStmtClass:
310  // "goto *&&lbl;" is a special case which we treat as equivalent
311  // to a normal goto. In addition, we don't calculate scope in the
312  // operand (to avoid recording the address-of-label use), which
313  // works only because of the restricted set of expressions which
314  // we detect as constant targets.
315  if (cast<IndirectGotoStmt>(S)->getConstantTarget()) {
316  LabelAndGotoScopes[S] = ParentScope;
317  Jumps.push_back(S);
318  return;
319  }
320 
321  LabelAndGotoScopes[S] = ParentScope;
322  IndirectJumps.push_back(S);
323  break;
324 
325  case Stmt::SwitchStmtClass:
326  // Evaluate the C++17 init stmt and condition variable
327  // before entering the scope of the switch statement.
328  if (Stmt *Init = cast<SwitchStmt>(S)->getInit()) {
329  BuildScopeInformation(Init, ParentScope);
330  ++StmtsToSkip;
331  }
332  if (VarDecl *Var = cast<SwitchStmt>(S)->getConditionVariable()) {
333  BuildScopeInformation(Var, ParentScope);
334  ++StmtsToSkip;
335  }
336  LLVM_FALLTHROUGH;
337 
338  case Stmt::GotoStmtClass:
339  // Remember both what scope a goto is in as well as the fact that we have
340  // it. This makes the second scan not have to walk the AST again.
341  LabelAndGotoScopes[S] = ParentScope;
342  Jumps.push_back(S);
343  break;
344 
345  case Stmt::GCCAsmStmtClass:
346  if (auto *GS = dyn_cast<GCCAsmStmt>(S))
347  if (GS->isAsmGoto()) {
348  // Remember both what scope a goto is in as well as the fact that we
349  // have it. This makes the second scan not have to walk the AST again.
350  LabelAndGotoScopes[S] = ParentScope;
351  AsmJumps.push_back(GS);
352  for (auto *E : GS->labels())
353  AsmJumpTargets.push_back(E->getLabel());
354  }
355  break;
356 
357  case Stmt::IfStmtClass: {
358  IfStmt *IS = cast<IfStmt>(S);
359  if (!(IS->isConstexpr() || IS->isObjCAvailabilityCheck()))
360  break;
361 
362  unsigned Diag = IS->isConstexpr() ? diag::note_protected_by_constexpr_if
363  : diag::note_protected_by_if_available;
364 
365  if (VarDecl *Var = IS->getConditionVariable())
366  BuildScopeInformation(Var, ParentScope);
367 
368  // Cannot jump into the middle of the condition.
369  unsigned NewParentScope = Scopes.size();
370  Scopes.push_back(GotoScope(ParentScope, Diag, 0, IS->getBeginLoc()));
371  BuildScopeInformation(IS->getCond(), NewParentScope);
372 
373  // Jumps into either arm of an 'if constexpr' are not allowed.
374  NewParentScope = Scopes.size();
375  Scopes.push_back(GotoScope(ParentScope, Diag, 0, IS->getBeginLoc()));
376  BuildScopeInformation(IS->getThen(), NewParentScope);
377  if (Stmt *Else = IS->getElse()) {
378  NewParentScope = Scopes.size();
379  Scopes.push_back(GotoScope(ParentScope, Diag, 0, IS->getBeginLoc()));
380  BuildScopeInformation(Else, NewParentScope);
381  }
382  return;
383  }
384 
385  case Stmt::CXXTryStmtClass: {
386  CXXTryStmt *TS = cast<CXXTryStmt>(S);
387  {
388  unsigned NewParentScope = Scopes.size();
389  Scopes.push_back(GotoScope(ParentScope,
390  diag::note_protected_by_cxx_try,
391  diag::note_exits_cxx_try,
392  TS->getSourceRange().getBegin()));
393  if (Stmt *TryBlock = TS->getTryBlock())
394  BuildScopeInformation(TryBlock, NewParentScope);
395  }
396 
397  // Jump from the catch into the try is not allowed either.
398  for (unsigned I = 0, E = TS->getNumHandlers(); I != E; ++I) {
399  CXXCatchStmt *CS = TS->getHandler(I);
400  unsigned NewParentScope = Scopes.size();
401  Scopes.push_back(GotoScope(ParentScope,
402  diag::note_protected_by_cxx_catch,
403  diag::note_exits_cxx_catch,
404  CS->getSourceRange().getBegin()));
405  BuildScopeInformation(CS->getHandlerBlock(), NewParentScope);
406  }
407  return;
408  }
409 
410  case Stmt::SEHTryStmtClass: {
411  SEHTryStmt *TS = cast<SEHTryStmt>(S);
412  {
413  unsigned NewParentScope = Scopes.size();
414  Scopes.push_back(GotoScope(ParentScope,
415  diag::note_protected_by_seh_try,
416  diag::note_exits_seh_try,
417  TS->getSourceRange().getBegin()));
418  if (Stmt *TryBlock = TS->getTryBlock())
419  BuildScopeInformation(TryBlock, NewParentScope);
420  }
421 
422  // Jump from __except or __finally into the __try are not allowed either.
423  if (SEHExceptStmt *Except = TS->getExceptHandler()) {
424  unsigned NewParentScope = Scopes.size();
425  Scopes.push_back(GotoScope(ParentScope,
426  diag::note_protected_by_seh_except,
427  diag::note_exits_seh_except,
428  Except->getSourceRange().getBegin()));
429  BuildScopeInformation(Except->getBlock(), NewParentScope);
430  } else if (SEHFinallyStmt *Finally = TS->getFinallyHandler()) {
431  unsigned NewParentScope = Scopes.size();
432  Scopes.push_back(GotoScope(ParentScope,
433  diag::note_protected_by_seh_finally,
434  diag::note_exits_seh_finally,
435  Finally->getSourceRange().getBegin()));
436  BuildScopeInformation(Finally->getBlock(), NewParentScope);
437  }
438 
439  return;
440  }
441 
442  case Stmt::DeclStmtClass: {
443  // If this is a declstmt with a VLA definition, it defines a scope from here
444  // to the end of the containing context.
445  DeclStmt *DS = cast<DeclStmt>(S);
446  // The decl statement creates a scope if any of the decls in it are VLAs
447  // or have the cleanup attribute.
448  for (auto *I : DS->decls())
449  BuildScopeInformation(I, origParentScope);
450  return;
451  }
452 
453  case Stmt::ObjCAtTryStmtClass: {
454  // Disallow jumps into any part of an @try statement by pushing a scope and
455  // walking all sub-stmts in that scope.
456  ObjCAtTryStmt *AT = cast<ObjCAtTryStmt>(S);
457  // Recursively walk the AST for the @try part.
458  {
459  unsigned NewParentScope = Scopes.size();
460  Scopes.push_back(GotoScope(ParentScope,
461  diag::note_protected_by_objc_try,
462  diag::note_exits_objc_try,
463  AT->getAtTryLoc()));
464  if (Stmt *TryPart = AT->getTryBody())
465  BuildScopeInformation(TryPart, NewParentScope);
466  }
467 
468  // Jump from the catch to the finally or try is not valid.
469  for (unsigned I = 0, N = AT->getNumCatchStmts(); I != N; ++I) {
470  ObjCAtCatchStmt *AC = AT->getCatchStmt(I);
471  unsigned NewParentScope = Scopes.size();
472  Scopes.push_back(GotoScope(ParentScope,
473  diag::note_protected_by_objc_catch,
474  diag::note_exits_objc_catch,
475  AC->getAtCatchLoc()));
476  // @catches are nested and it isn't
477  BuildScopeInformation(AC->getCatchBody(), NewParentScope);
478  }
479 
480  // Jump from the finally to the try or catch is not valid.
481  if (ObjCAtFinallyStmt *AF = AT->getFinallyStmt()) {
482  unsigned NewParentScope = Scopes.size();
483  Scopes.push_back(GotoScope(ParentScope,
484  diag::note_protected_by_objc_finally,
485  diag::note_exits_objc_finally,
486  AF->getAtFinallyLoc()));
487  BuildScopeInformation(AF, NewParentScope);
488  }
489 
490  return;
491  }
492 
493  case Stmt::ObjCAtSynchronizedStmtClass: {
494  // Disallow jumps into the protected statement of an @synchronized, but
495  // allow jumps into the object expression it protects.
496  ObjCAtSynchronizedStmt *AS = cast<ObjCAtSynchronizedStmt>(S);
497  // Recursively walk the AST for the @synchronized object expr, it is
498  // evaluated in the normal scope.
499  BuildScopeInformation(AS->getSynchExpr(), ParentScope);
500 
501  // Recursively walk the AST for the @synchronized part, protected by a new
502  // scope.
503  unsigned NewParentScope = Scopes.size();
504  Scopes.push_back(GotoScope(ParentScope,
505  diag::note_protected_by_objc_synchronized,
506  diag::note_exits_objc_synchronized,
507  AS->getAtSynchronizedLoc()));
508  BuildScopeInformation(AS->getSynchBody(), NewParentScope);
509  return;
510  }
511 
512  case Stmt::ObjCAutoreleasePoolStmtClass: {
513  // Disallow jumps into the protected statement of an @autoreleasepool.
514  ObjCAutoreleasePoolStmt *AS = cast<ObjCAutoreleasePoolStmt>(S);
515  // Recursively walk the AST for the @autoreleasepool part, protected by a
516  // new scope.
517  unsigned NewParentScope = Scopes.size();
518  Scopes.push_back(GotoScope(ParentScope,
519  diag::note_protected_by_objc_autoreleasepool,
520  diag::note_exits_objc_autoreleasepool,
521  AS->getAtLoc()));
522  BuildScopeInformation(AS->getSubStmt(), NewParentScope);
523  return;
524  }
525 
526  case Stmt::ExprWithCleanupsClass: {
527  // Disallow jumps past full-expressions that use blocks with
528  // non-trivial cleanups of their captures. This is theoretically
529  // implementable but a lot of work which we haven't felt up to doing.
530  ExprWithCleanups *EWC = cast<ExprWithCleanups>(S);
531  for (unsigned i = 0, e = EWC->getNumObjects(); i != e; ++i) {
532  const BlockDecl *BDecl = EWC->getObject(i);
533  for (const auto &CI : BDecl->captures()) {
534  VarDecl *variable = CI.getVariable();
535  BuildScopeInformation(variable, BDecl, origParentScope);
536  }
537  }
538  break;
539  }
540 
541  case Stmt::MaterializeTemporaryExprClass: {
542  // Disallow jumps out of scopes containing temporaries lifetime-extended to
543  // automatic storage duration.
544  MaterializeTemporaryExpr *MTE = cast<MaterializeTemporaryExpr>(S);
545  if (MTE->getStorageDuration() == SD_Automatic) {
548  const Expr *ExtendedObject =
550  CommaLHS, Adjustments);
551  if (ExtendedObject->getType().isDestructedType()) {
552  Scopes.push_back(GotoScope(ParentScope, 0,
553  diag::note_exits_temporary_dtor,
554  ExtendedObject->getExprLoc()));
555  origParentScope = Scopes.size()-1;
556  }
557  }
558  break;
559  }
560 
561  case Stmt::CaseStmtClass:
562  case Stmt::DefaultStmtClass:
563  case Stmt::LabelStmtClass:
564  LabelAndGotoScopes[S] = ParentScope;
565  break;
566 
567  default:
568  break;
569  }
570 
571  for (Stmt *SubStmt : S->children()) {
572  if (!SubStmt)
573  continue;
574  if (StmtsToSkip) {
575  --StmtsToSkip;
576  continue;
577  }
578 
579  // Cases, labels, and defaults aren't "scope parents". It's also
580  // important to handle these iteratively instead of recursively in
581  // order to avoid blowing out the stack.
582  while (true) {
583  Stmt *Next;
584  if (SwitchCase *SC = dyn_cast<SwitchCase>(SubStmt))
585  Next = SC->getSubStmt();
586  else if (LabelStmt *LS = dyn_cast<LabelStmt>(SubStmt))
587  Next = LS->getSubStmt();
588  else
589  break;
590 
591  LabelAndGotoScopes[SubStmt] = ParentScope;
592  SubStmt = Next;
593  }
594 
595  // Recursively walk the AST.
596  BuildScopeInformation(SubStmt, ParentScope);
597  }
598 }
599 
600 /// VerifyJumps - Verify each element of the Jumps array to see if they are
601 /// valid, emitting diagnostics if not.
602 void JumpScopeChecker::VerifyJumps() {
603  while (!Jumps.empty()) {
604  Stmt *Jump = Jumps.pop_back_val();
605 
606  // With a goto,
607  if (GotoStmt *GS = dyn_cast<GotoStmt>(Jump)) {
608  // The label may not have a statement if it's coming from inline MS ASM.
609  if (GS->getLabel()->getStmt()) {
610  CheckJump(GS, GS->getLabel()->getStmt(), GS->getGotoLoc(),
611  diag::err_goto_into_protected_scope,
612  diag::ext_goto_into_protected_scope,
613  diag::warn_cxx98_compat_goto_into_protected_scope);
614  }
615  CheckGotoStmt(GS);
616  continue;
617  }
618 
619  // We only get indirect gotos here when they have a constant target.
620  if (IndirectGotoStmt *IGS = dyn_cast<IndirectGotoStmt>(Jump)) {
621  LabelDecl *Target = IGS->getConstantTarget();
622  CheckJump(IGS, Target->getStmt(), IGS->getGotoLoc(),
623  diag::err_goto_into_protected_scope,
624  diag::ext_goto_into_protected_scope,
625  diag::warn_cxx98_compat_goto_into_protected_scope);
626  continue;
627  }
628 
629  SwitchStmt *SS = cast<SwitchStmt>(Jump);
630  for (SwitchCase *SC = SS->getSwitchCaseList(); SC;
631  SC = SC->getNextSwitchCase()) {
632  if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(SC)))
633  continue;
634  SourceLocation Loc;
635  if (CaseStmt *CS = dyn_cast<CaseStmt>(SC))
636  Loc = CS->getBeginLoc();
637  else if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC))
638  Loc = DS->getBeginLoc();
639  else
640  Loc = SC->getBeginLoc();
641  CheckJump(SS, SC, Loc, diag::err_switch_into_protected_scope, 0,
642  diag::warn_cxx98_compat_switch_into_protected_scope);
643  }
644  }
645 }
646 
647 /// VerifyIndirectOrAsmJumps - Verify whether any possible indirect goto or
648 /// asm goto jump might cross a protection boundary. Unlike direct jumps,
649 /// indirect or asm goto jumps count cleanups as protection boundaries:
650 /// since there's no way to know where the jump is going, we can't implicitly
651 /// run the right cleanups the way we can with direct jumps.
652 /// Thus, an indirect/asm jump is "trivial" if it bypasses no
653 /// initializations and no teardowns. More formally, an indirect/asm jump
654 /// from A to B is trivial if the path out from A to DCA(A,B) is
655 /// trivial and the path in from DCA(A,B) to B is trivial, where
656 /// DCA(A,B) is the deepest common ancestor of A and B.
657 /// Jump-triviality is transitive but asymmetric.
658 ///
659 /// A path in is trivial if none of the entered scopes have an InDiag.
660 /// A path out is trivial is none of the exited scopes have an OutDiag.
661 ///
662 /// Under these definitions, this function checks that the indirect
663 /// jump between A and B is trivial for every indirect goto statement A
664 /// and every label B whose address was taken in the function.
665 void JumpScopeChecker::VerifyIndirectOrAsmJumps(bool IsAsmGoto) {
666  SmallVector<Stmt*, 4> GotoJumps = IsAsmGoto ? AsmJumps : IndirectJumps;
667  if (GotoJumps.empty())
668  return;
669  SmallVector<LabelDecl *, 4> JumpTargets =
670  IsAsmGoto ? AsmJumpTargets : IndirectJumpTargets;
671  // If there aren't any address-of-label expressions in this function,
672  // complain about the first indirect goto.
673  if (JumpTargets.empty()) {
674  assert(!IsAsmGoto &&"only indirect goto can get here");
675  S.Diag(GotoJumps[0]->getBeginLoc(),
676  diag::err_indirect_goto_without_addrlabel);
677  return;
678  }
679  // Collect a single representative of every scope containing an
680  // indirect or asm goto. For most code bases, this substantially cuts
681  // down on the number of jump sites we'll have to consider later.
682  typedef std::pair<unsigned, Stmt*> JumpScope;
683  SmallVector<JumpScope, 32> JumpScopes;
684  {
685  llvm::DenseMap<unsigned, Stmt*> JumpScopesMap;
686  for (SmallVectorImpl<Stmt *>::iterator I = GotoJumps.begin(),
687  E = GotoJumps.end();
688  I != E; ++I) {
689  Stmt *IG = *I;
690  if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(IG)))
691  continue;
692  unsigned IGScope = LabelAndGotoScopes[IG];
693  Stmt *&Entry = JumpScopesMap[IGScope];
694  if (!Entry) Entry = IG;
695  }
696  JumpScopes.reserve(JumpScopesMap.size());
697  for (llvm::DenseMap<unsigned, Stmt *>::iterator I = JumpScopesMap.begin(),
698  E = JumpScopesMap.end();
699  I != E; ++I)
700  JumpScopes.push_back(*I);
701  }
702 
703  // Collect a single representative of every scope containing a
704  // label whose address was taken somewhere in the function.
705  // For most code bases, there will be only one such scope.
706  llvm::DenseMap<unsigned, LabelDecl*> TargetScopes;
707  for (SmallVectorImpl<LabelDecl *>::iterator I = JumpTargets.begin(),
708  E = JumpTargets.end();
709  I != E; ++I) {
710  LabelDecl *TheLabel = *I;
711  if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(TheLabel->getStmt())))
712  continue;
713  unsigned LabelScope = LabelAndGotoScopes[TheLabel->getStmt()];
714  LabelDecl *&Target = TargetScopes[LabelScope];
715  if (!Target) Target = TheLabel;
716  }
717 
718  // For each target scope, make sure it's trivially reachable from
719  // every scope containing a jump site.
720  //
721  // A path between scopes always consists of exitting zero or more
722  // scopes, then entering zero or more scopes. We build a set of
723  // of scopes S from which the target scope can be trivially
724  // entered, then verify that every jump scope can be trivially
725  // exitted to reach a scope in S.
726  llvm::BitVector Reachable(Scopes.size(), false);
727  for (llvm::DenseMap<unsigned,LabelDecl*>::iterator
728  TI = TargetScopes.begin(), TE = TargetScopes.end(); TI != TE; ++TI) {
729  unsigned TargetScope = TI->first;
730  LabelDecl *TargetLabel = TI->second;
731 
732  Reachable.reset();
733 
734  // Mark all the enclosing scopes from which you can safely jump
735  // into the target scope. 'Min' will end up being the index of
736  // the shallowest such scope.
737  unsigned Min = TargetScope;
738  while (true) {
739  Reachable.set(Min);
740 
741  // Don't go beyond the outermost scope.
742  if (Min == 0) break;
743 
744  // Stop if we can't trivially enter the current scope.
745  if (Scopes[Min].InDiag) break;
746 
747  Min = Scopes[Min].ParentScope;
748  }
749 
750  // Walk through all the jump sites, checking that they can trivially
751  // reach this label scope.
753  I = JumpScopes.begin(), E = JumpScopes.end(); I != E; ++I) {
754  unsigned Scope = I->first;
755 
756  // Walk out the "scope chain" for this scope, looking for a scope
757  // we've marked reachable. For well-formed code this amortizes
758  // to O(JumpScopes.size() / Scopes.size()): we only iterate
759  // when we see something unmarked, and in well-formed code we
760  // mark everything we iterate past.
761  bool IsReachable = false;
762  while (true) {
763  if (Reachable.test(Scope)) {
764  // If we find something reachable, mark all the scopes we just
765  // walked through as reachable.
766  for (unsigned S = I->first; S != Scope; S = Scopes[S].ParentScope)
767  Reachable.set(S);
768  IsReachable = true;
769  break;
770  }
771 
772  // Don't walk out if we've reached the top-level scope or we've
773  // gotten shallower than the shallowest reachable scope.
774  if (Scope == 0 || Scope < Min) break;
775 
776  // Don't walk out through an out-diagnostic.
777  if (Scopes[Scope].OutDiag) break;
778 
779  Scope = Scopes[Scope].ParentScope;
780  }
781 
782  // Only diagnose if we didn't find something.
783  if (IsReachable) continue;
784 
785  DiagnoseIndirectOrAsmJump(I->second, I->first, TargetLabel, TargetScope);
786  }
787  }
788 }
789 
790 /// Return true if a particular error+note combination must be downgraded to a
791 /// warning in Microsoft mode.
792 static bool IsMicrosoftJumpWarning(unsigned JumpDiag, unsigned InDiagNote) {
793  return (JumpDiag == diag::err_goto_into_protected_scope &&
794  (InDiagNote == diag::note_protected_by_variable_init ||
795  InDiagNote == diag::note_protected_by_variable_nontriv_destructor));
796 }
797 
798 /// Return true if a particular note should be downgraded to a compatibility
799 /// warning in C++11 mode.
800 static bool IsCXX98CompatWarning(Sema &S, unsigned InDiagNote) {
801  return S.getLangOpts().CPlusPlus11 &&
802  InDiagNote == diag::note_protected_by_variable_non_pod;
803 }
804 
805 /// Produce primary diagnostic for an indirect jump statement.
807  LabelDecl *Target, bool &Diagnosed) {
808  if (Diagnosed)
809  return;
810  bool IsAsmGoto = isa<GCCAsmStmt>(Jump);
811  S.Diag(Jump->getBeginLoc(), diag::err_indirect_goto_in_protected_scope)
812  << IsAsmGoto;
813  S.Diag(Target->getStmt()->getIdentLoc(), diag::note_indirect_goto_target)
814  << IsAsmGoto;
815  Diagnosed = true;
816 }
817 
818 /// Produce note diagnostics for a jump into a protected scope.
819 void JumpScopeChecker::NoteJumpIntoScopes(ArrayRef<unsigned> ToScopes) {
820  if (CHECK_PERMISSIVE(ToScopes.empty()))
821  return;
822  for (unsigned I = 0, E = ToScopes.size(); I != E; ++I)
823  if (Scopes[ToScopes[I]].InDiag)
824  S.Diag(Scopes[ToScopes[I]].Loc, Scopes[ToScopes[I]].InDiag);
825 }
826 
827 /// Diagnose an indirect jump which is known to cross scopes.
828 void JumpScopeChecker::DiagnoseIndirectOrAsmJump(Stmt *Jump, unsigned JumpScope,
829  LabelDecl *Target,
830  unsigned TargetScope) {
831  if (CHECK_PERMISSIVE(JumpScope == TargetScope))
832  return;
833 
834  unsigned Common = GetDeepestCommonScope(JumpScope, TargetScope);
835  bool Diagnosed = false;
836 
837  // Walk out the scope chain until we reach the common ancestor.
838  for (unsigned I = JumpScope; I != Common; I = Scopes[I].ParentScope)
839  if (Scopes[I].OutDiag) {
840  DiagnoseIndirectOrAsmJumpStmt(S, Jump, Target, Diagnosed);
841  S.Diag(Scopes[I].Loc, Scopes[I].OutDiag);
842  }
843 
844  SmallVector<unsigned, 10> ToScopesCXX98Compat;
845 
846  // Now walk into the scopes containing the label whose address was taken.
847  for (unsigned I = TargetScope; I != Common; I = Scopes[I].ParentScope)
848  if (IsCXX98CompatWarning(S, Scopes[I].InDiag))
849  ToScopesCXX98Compat.push_back(I);
850  else if (Scopes[I].InDiag) {
851  DiagnoseIndirectOrAsmJumpStmt(S, Jump, Target, Diagnosed);
852  S.Diag(Scopes[I].Loc, Scopes[I].InDiag);
853  }
854 
855  // Diagnose this jump if it would be ill-formed in C++98.
856  if (!Diagnosed && !ToScopesCXX98Compat.empty()) {
857  bool IsAsmGoto = isa<GCCAsmStmt>(Jump);
858  S.Diag(Jump->getBeginLoc(),
859  diag::warn_cxx98_compat_indirect_goto_in_protected_scope)
860  << IsAsmGoto;
861  S.Diag(Target->getStmt()->getIdentLoc(), diag::note_indirect_goto_target)
862  << IsAsmGoto;
863  NoteJumpIntoScopes(ToScopesCXX98Compat);
864  }
865 }
866 
867 /// CheckJump - Validate that the specified jump statement is valid: that it is
868 /// jumping within or out of its current scope, not into a deeper one.
869 void JumpScopeChecker::CheckJump(Stmt *From, Stmt *To, SourceLocation DiagLoc,
870  unsigned JumpDiagError, unsigned JumpDiagWarning,
871  unsigned JumpDiagCXX98Compat) {
872  if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(From)))
873  return;
874  if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(To)))
875  return;
876 
877  unsigned FromScope = LabelAndGotoScopes[From];
878  unsigned ToScope = LabelAndGotoScopes[To];
879 
880  // Common case: exactly the same scope, which is fine.
881  if (FromScope == ToScope) return;
882 
883  // Warn on gotos out of __finally blocks.
884  if (isa<GotoStmt>(From) || isa<IndirectGotoStmt>(From)) {
885  // If FromScope > ToScope, FromScope is more nested and the jump goes to a
886  // less nested scope. Check if it crosses a __finally along the way.
887  for (unsigned I = FromScope; I > ToScope; I = Scopes[I].ParentScope) {
888  if (Scopes[I].InDiag == diag::note_protected_by_seh_finally) {
889  S.Diag(From->getBeginLoc(), diag::warn_jump_out_of_seh_finally);
890  break;
891  }
892  }
893  }
894 
895  unsigned CommonScope = GetDeepestCommonScope(FromScope, ToScope);
896 
897  // It's okay to jump out from a nested scope.
898  if (CommonScope == ToScope) return;
899 
900  // Pull out (and reverse) any scopes we might need to diagnose skipping.
901  SmallVector<unsigned, 10> ToScopesCXX98Compat;
902  SmallVector<unsigned, 10> ToScopesError;
903  SmallVector<unsigned, 10> ToScopesWarning;
904  for (unsigned I = ToScope; I != CommonScope; I = Scopes[I].ParentScope) {
905  if (S.getLangOpts().MSVCCompat && JumpDiagWarning != 0 &&
906  IsMicrosoftJumpWarning(JumpDiagError, Scopes[I].InDiag))
907  ToScopesWarning.push_back(I);
908  else if (IsCXX98CompatWarning(S, Scopes[I].InDiag))
909  ToScopesCXX98Compat.push_back(I);
910  else if (Scopes[I].InDiag)
911  ToScopesError.push_back(I);
912  }
913 
914  // Handle warnings.
915  if (!ToScopesWarning.empty()) {
916  S.Diag(DiagLoc, JumpDiagWarning);
917  NoteJumpIntoScopes(ToScopesWarning);
918  }
919 
920  // Handle errors.
921  if (!ToScopesError.empty()) {
922  S.Diag(DiagLoc, JumpDiagError);
923  NoteJumpIntoScopes(ToScopesError);
924  }
925 
926  // Handle -Wc++98-compat warnings if the jump is well-formed.
927  if (ToScopesError.empty() && !ToScopesCXX98Compat.empty()) {
928  S.Diag(DiagLoc, JumpDiagCXX98Compat);
929  NoteJumpIntoScopes(ToScopesCXX98Compat);
930  }
931 }
932 
933 void JumpScopeChecker::CheckGotoStmt(GotoStmt *GS) {
934  if (GS->getLabel()->isMSAsmLabel()) {
935  S.Diag(GS->getGotoLoc(), diag::err_goto_ms_asm_label)
936  << GS->getLabel()->getIdentifier();
937  S.Diag(GS->getLabel()->getLocation(), diag::note_goto_ms_asm_label)
938  << GS->getLabel()->getIdentifier();
939  }
940 }
941 
942 void Sema::DiagnoseInvalidJumps(Stmt *Body) {
943  (void)JumpScopeChecker(Body, *this);
944 }
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.
A (possibly-)qualified type.
Definition: Type.h:643
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:76
Stmt - This represents one statement.
Definition: Stmt.h:66
const ObjCAtFinallyStmt * getFinallyStmt() const
Retrieve the @finally statement, if any.
Definition: StmtObjC.h:235
CXXCatchStmt * getHandler(unsigned i)
Definition: StmtCXX.h:107
IfStmt - This represents an if/then/else.
Definition: Stmt.h:1822
static bool IsMicrosoftJumpWarning(unsigned JumpDiag, unsigned InDiagNote)
Return true if a particular error+note combination must be downgraded to a warning in Microsoft mode...
SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID)
Emit a diagnostic.
Definition: Sema.h:1375
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:88
Stmt * getHandlerBlock() const
Definition: StmtCXX.h:51
bool isPOD() const
Whether this class is a POD-type (C++ [class]p4)
Definition: DeclCXX.h:1085
SourceLocation getIdentLoc() const
Definition: Stmt.h:1734
Represents a call to a C++ constructor.
Definition: ExprCXX.h:1422
Represents a C++ constructor within a class.
Definition: DeclCXX.h:2365
Represents a prvalue temporary that is written into memory so that a reference can bind to it...
Definition: ExprCXX.h:4419
bool isDefaultConstructor() const
Whether this constructor is a default constructor (C++ [class.ctor]p5), which can be used to default-...
Definition: DeclCXX.cpp:2498
Represents a variable declaration or definition.
Definition: Decl.h:827
#define CHECK_PERMISSIVE(x)
Stmt * getThen()
Definition: Stmt.h:1909
Defines the Objective-C statement AST node classes.
Represents an expression – generally a full-expression – that introduces cleanups to be run at the ...
Definition: ExprCXX.h:3306
Defines the clang::Expr interface and subclasses for C++ expressions.
const Stmt * getSubStmt() const
Definition: StmtObjC.h:379
IdentifierInfo * getIdentifier() const
Get the identifier that names this declaration, if there is one.
Definition: Decl.h:269
LabelStmt - Represents a label, which has a substatement.
Definition: Stmt.h:1720
Expr * GetTemporaryExpr() const
Retrieve the temporary-generating subexpression whose value will be materialized into a glvalue...
Definition: ExprCXX.h:4457
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:274
Represents Objective-C&#39;s @catch statement.
Definition: StmtObjC.h:77
IndirectGotoStmt - This represents an indirect goto.
Definition: Stmt.h:2504
child_range children()
Definition: Stmt.cpp:223
Scope - A scope is a transient data structure that is used while parsing the program.
Definition: Scope.h:40
CaseStmt - Represent a case statement.
Definition: Stmt.h:1488
const LangOptions & getLangOpts() const
Definition: Sema.h:1288
const ObjCAtCatchStmt * getCatchStmt(unsigned I) const
Retrieve a @catch statement.
Definition: StmtObjC.h:217
bool hasAttr() const
Definition: DeclBase.h:542
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:331
bool isConstexpr() const
Definition: Stmt.h:1995
Represents a block literal declaration, which is like an unnamed FunctionDecl.
Definition: Decl.h:3951
This represents one expression.
Definition: Expr.h:108
const CompoundStmt * getSynchBody() const
Definition: StmtObjC.h:297
Represents Objective-C&#39;s @synchronized statement.
Definition: StmtObjC.h:277
static void DiagnoseIndirectOrAsmJumpStmt(Sema &S, Stmt *Jump, LabelDecl *Target, bool &Diagnosed)
Produce primary diagnostic for an indirect jump statement.
CXXTryStmt - A C++ try block, including all handlers.
Definition: StmtCXX.h:68
SourceLocation getAtTryLoc() const
Retrieve the location of the @ in the @try.
Definition: StmtObjC.h:204
SourceLocation getBeginLoc() const
Definition: Stmt.h:2000
QualType getType() const
Definition: Expr.h:137
LabelDecl * getLabel() const
Definition: Stmt.h:2478
StorageDuration getStorageDuration() const
Retrieve the storage duration for the materialized temporary.
Definition: ExprCXX.h:4460
const Stmt * getTryBody() const
Retrieve the @try body.
Definition: StmtObjC.h:208
std::pair< unsigned, unsigned > ScopePair
SwitchCase * getSwitchCaseList()
Definition: Stmt.h:2156
SourceLocation getAtLoc() const
Definition: StmtObjC.h:388
Expr * getCond()
Definition: Stmt.h:1897
bool isTrivial() const
Whether this function is "trivial" in some specialized C++ senses.
Definition: Decl.h:2076
Encodes a location in the source.
const Stmt * getCatchBody() const
Definition: StmtObjC.h:93
unsigned getNumHandlers() const
Definition: StmtCXX.h:106
Stmt * getElse()
Definition: Stmt.h:1918
DeclStmt - Adaptor class for mixing declarations with statements and expressions. ...
Definition: Stmt.h:1213
Represents the declaration of a label.
Definition: Decl.h:476
SourceLocation getGotoLoc() const
Definition: Stmt.h:2481
bool isMSAsmLabel() const
Definition: Decl.h:510
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1160
SourceLocation getAtCatchLoc() const
Definition: StmtObjC.h:105
SourceLocation getExprLoc() const LLVM_READONLY
getExprLoc - Return the preferred location for the arrow when diagnosing a problem with a generic exp...
Definition: Expr.cpp:221
Base class for declarations which introduce a typedef-name.
Definition: Decl.h:2985
LabelStmt * getStmt() const
Definition: Decl.h:500
Dataflow Directional Tag Classes.
ArrayRef< Capture > captures() const
Definition: Decl.h:4078
StmtClass getStmtClass() const
Definition: Stmt.h:1097
const CXXRecordDecl * getParent() const
Return the parent of this method declaration, which is the class in which this method is defined...
Definition: DeclCXX.h:2028
SEHExceptStmt * getExceptHandler() const
Returns 0 if not defined.
Definition: Stmt.cpp:1135
const Expr * getSynchExpr() const
Definition: StmtObjC.h:305
bool isObjCAvailabilityCheck() const
Definition: Stmt.cpp:907
SwitchStmt - This represents a &#39;switch&#39; stmt.
Definition: Stmt.h:2027
unsigned getNumObjects() const
Definition: ExprCXX.h:3337
decl_range decls()
Definition: Stmt.h:1261
Represents Objective-C&#39;s @finally statement.
Definition: StmtObjC.h:127
SEHFinallyStmt * getFinallyHandler() const
Definition: Stmt.cpp:1139
GotoStmt - This represents a direct goto.
Definition: Stmt.h:2465
const SwitchCase * getNextSwitchCase() const
Definition: Stmt.h:1463
static ScopePair GetDiagForGotoScopeDecl(Sema &S, const Decl *D)
GetDiagForGotoScopeDecl - If this decl induces a new goto scope, return a diagnostic that should be e...
Defines the C++ Decl subclasses, other than those for templates (found in DeclTemplate.h) and friends (in DeclFriend.h).
VarDecl * getConditionVariable()
Retrieve the variable declared in this "if" statement, if any.
Definition: Stmt.cpp:886
CXXCatchStmt - This represents a C++ catch block.
Definition: StmtCXX.h:28
CleanupObject getObject(unsigned i) const
Definition: ExprCXX.h:3339
SourceLocation getAtSynchronizedLoc() const
Definition: StmtObjC.h:294
CompoundStmt * getTryBlock()
Definition: StmtCXX.h:99
Represents Objective-C&#39;s @try ... @catch ... @finally statement.
Definition: StmtObjC.h:165
SourceRange getSourceRange() const LLVM_READONLY
SourceLocation tokens are not useful in isolation - they are low level value objects created/interpre...
Definition: Stmt.cpp:262
unsigned getNumCatchStmts() const
Retrieve the number of @catch statements in this try-catch-finally block.
Definition: StmtObjC.h:214
QualType getType() const
Definition: Decl.h:655
ASTContext & Context
Definition: Sema.h:377
Automatic storage duration (most local variables).
Definition: Specifiers.h:308
SourceLocation getBegin() const
const LangOptions & getLangOpts() const
Definition: ASTContext.h:723
Represents Objective-C&#39;s @autoreleasepool Statement.
Definition: StmtObjC.h:368
CompoundStmt * getTryBlock() const
Definition: Stmt.h:3297
SourceLocation getLocation() const
Definition: DeclBase.h:429
static bool IsCXX98CompatWarning(Sema &S, unsigned InDiagNote)
Return true if a particular note should be downgraded to a compatibility warning in C++11 mode...