clang  12.0.0git
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 
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(CompoundLiteralExpr *CLE, unsigned &ParentScope);
79  void BuildScopeInformation(Stmt *S, unsigned &origParentScope);
80 
81  void VerifyJumps();
82  void VerifyIndirectOrAsmJumps(bool IsAsmGoto);
83  void NoteJumpIntoScopes(ArrayRef<unsigned> ToScopes);
84  void DiagnoseIndirectOrAsmJump(Stmt *IG, unsigned IGScope, LabelDecl *Target,
85  unsigned TargetScope);
86  void CheckJump(Stmt *From, Stmt *To, SourceLocation DiagLoc,
87  unsigned JumpDiag, unsigned JumpDiagWarning,
88  unsigned JumpDiagCXX98Compat);
89  void CheckGotoStmt(GotoStmt *GS);
90 
91  unsigned GetDeepestCommonScope(unsigned A, unsigned B);
92 };
93 } // end anonymous namespace
94 
95 #define CHECK_PERMISSIVE(x) (assert(Permissive || !(x)), (Permissive && (x)))
96 
97 JumpScopeChecker::JumpScopeChecker(Stmt *Body, Sema &s)
98  : S(s), Permissive(s.hasAnyUnrecoverableErrorsInThisFunction()) {
99  // Add a scope entry for function scope.
100  Scopes.push_back(GotoScope(~0U, ~0U, ~0U, SourceLocation()));
101 
102  // Build information for the top level compound statement, so that we have a
103  // defined scope record for every "goto" and label.
104  unsigned BodyParentScope = 0;
105  BuildScopeInformation(Body, BodyParentScope);
106 
107  // Check that all jumps we saw are kosher.
108  VerifyJumps();
109  VerifyIndirectOrAsmJumps(false);
110  VerifyIndirectOrAsmJumps(true);
111 }
112 
113 /// GetDeepestCommonScope - Finds the innermost scope enclosing the
114 /// two scopes.
115 unsigned JumpScopeChecker::GetDeepestCommonScope(unsigned A, unsigned B) {
116  while (A != B) {
117  // Inner scopes are created after outer scopes and therefore have
118  // higher indices.
119  if (A < B) {
120  assert(Scopes[B].ParentScope < B);
121  B = Scopes[B].ParentScope;
122  } else {
123  assert(Scopes[A].ParentScope < A);
124  A = Scopes[A].ParentScope;
125  }
126  }
127  return A;
128 }
129 
130 typedef std::pair<unsigned,unsigned> ScopePair;
131 
132 /// GetDiagForGotoScopeDecl - If this decl induces a new goto scope, return a
133 /// diagnostic that should be emitted if control goes over it. If not, return 0.
135  if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
136  unsigned InDiag = 0;
137  unsigned OutDiag = 0;
138 
139  if (VD->getType()->isVariablyModifiedType())
140  InDiag = diag::note_protected_by_vla;
141 
142  if (VD->hasAttr<BlocksAttr>())
143  return ScopePair(diag::note_protected_by___block,
144  diag::note_exits___block);
145 
146  if (VD->hasAttr<CleanupAttr>())
147  return ScopePair(diag::note_protected_by_cleanup,
148  diag::note_exits_cleanup);
149 
150  if (VD->hasLocalStorage()) {
151  switch (VD->getType().isDestructedType()) {
152  case QualType::DK_objc_strong_lifetime:
153  return ScopePair(diag::note_protected_by_objc_strong_init,
154  diag::note_exits_objc_strong);
155 
156  case QualType::DK_objc_weak_lifetime:
157  return ScopePair(diag::note_protected_by_objc_weak_init,
158  diag::note_exits_objc_weak);
159 
160  case QualType::DK_nontrivial_c_struct:
161  return ScopePair(diag::note_protected_by_non_trivial_c_struct_init,
162  diag::note_exits_dtor);
163 
164  case QualType::DK_cxx_destructor:
165  OutDiag = diag::note_exits_dtor;
166  break;
167 
168  case QualType::DK_none:
169  break;
170  }
171  }
172 
173  const Expr *Init = VD->getInit();
174  if (S.Context.getLangOpts().CPlusPlus && VD->hasLocalStorage() && Init) {
175  // C++11 [stmt.dcl]p3:
176  // A program that jumps from a point where a variable with automatic
177  // storage duration is not in scope to a point where it is in scope
178  // is ill-formed unless the variable has scalar type, class type with
179  // a trivial default constructor and a trivial destructor, a
180  // cv-qualified version of one of these types, or an array of one of
181  // the preceding types and is declared without an initializer.
182 
183  // C++03 [stmt.dcl.p3:
184  // A program that jumps from a point where a local variable
185  // with automatic storage duration is not in scope to a point
186  // where it is in scope is ill-formed unless the variable has
187  // POD type and is declared without an initializer.
188 
189  InDiag = diag::note_protected_by_variable_init;
190 
191  // For a variable of (array of) class type declared without an
192  // initializer, we will have call-style initialization and the initializer
193  // will be the CXXConstructExpr with no intervening nodes.
194  if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) {
195  const CXXConstructorDecl *Ctor = CCE->getConstructor();
196  if (Ctor->isTrivial() && Ctor->isDefaultConstructor() &&
197  VD->getInitStyle() == VarDecl::CallInit) {
198  if (OutDiag)
199  InDiag = diag::note_protected_by_variable_nontriv_destructor;
200  else if (!Ctor->getParent()->isPOD())
201  InDiag = diag::note_protected_by_variable_non_pod;
202  else
203  InDiag = 0;
204  }
205  }
206  }
207 
208  return ScopePair(InDiag, OutDiag);
209  }
210 
211  if (const TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(D)) {
212  if (TD->getUnderlyingType()->isVariablyModifiedType())
213  return ScopePair(isa<TypedefDecl>(TD)
214  ? diag::note_protected_by_vla_typedef
215  : diag::note_protected_by_vla_type_alias,
216  0);
217  }
218 
219  return ScopePair(0U, 0U);
220 }
221 
222 /// Build scope information for a declaration that is part of a DeclStmt.
223 void JumpScopeChecker::BuildScopeInformation(Decl *D, unsigned &ParentScope) {
224  // If this decl causes a new scope, push and switch to it.
225  std::pair<unsigned,unsigned> Diags = GetDiagForGotoScopeDecl(S, D);
226  if (Diags.first || Diags.second) {
227  Scopes.push_back(GotoScope(ParentScope, Diags.first, Diags.second,
228  D->getLocation()));
229  ParentScope = Scopes.size()-1;
230  }
231 
232  // If the decl has an initializer, walk it with the potentially new
233  // scope we just installed.
234  if (VarDecl *VD = dyn_cast<VarDecl>(D))
235  if (Expr *Init = VD->getInit())
236  BuildScopeInformation(Init, ParentScope);
237 }
238 
239 /// Build scope information for a captured block literal variables.
240 void JumpScopeChecker::BuildScopeInformation(VarDecl *D,
241  const BlockDecl *BDecl,
242  unsigned &ParentScope) {
243  // exclude captured __block variables; there's no destructor
244  // associated with the block literal for them.
245  if (D->hasAttr<BlocksAttr>())
246  return;
247  QualType T = D->getType();
248  QualType::DestructionKind destructKind = T.isDestructedType();
249  if (destructKind != QualType::DK_none) {
250  std::pair<unsigned,unsigned> Diags;
251  switch (destructKind) {
252  case QualType::DK_cxx_destructor:
253  Diags = ScopePair(diag::note_enters_block_captures_cxx_obj,
254  diag::note_exits_block_captures_cxx_obj);
255  break;
256  case QualType::DK_objc_strong_lifetime:
257  Diags = ScopePair(diag::note_enters_block_captures_strong,
258  diag::note_exits_block_captures_strong);
259  break;
260  case QualType::DK_objc_weak_lifetime:
261  Diags = ScopePair(diag::note_enters_block_captures_weak,
262  diag::note_exits_block_captures_weak);
263  break;
264  case QualType::DK_nontrivial_c_struct:
265  Diags = ScopePair(diag::note_enters_block_captures_non_trivial_c_struct,
266  diag::note_exits_block_captures_non_trivial_c_struct);
267  break;
268  case QualType::DK_none:
269  llvm_unreachable("non-lifetime captured variable");
270  }
271  SourceLocation Loc = D->getLocation();
272  if (Loc.isInvalid())
273  Loc = BDecl->getLocation();
274  Scopes.push_back(GotoScope(ParentScope,
275  Diags.first, Diags.second, Loc));
276  ParentScope = Scopes.size()-1;
277  }
278 }
279 
280 /// Build scope information for compound literals of C struct types that are
281 /// non-trivial to destruct.
282 void JumpScopeChecker::BuildScopeInformation(CompoundLiteralExpr *CLE,
283  unsigned &ParentScope) {
284  unsigned InDiag = diag::note_enters_compound_literal_scope;
285  unsigned OutDiag = diag::note_exits_compound_literal_scope;
286  Scopes.push_back(GotoScope(ParentScope, InDiag, OutDiag, CLE->getExprLoc()));
287  ParentScope = Scopes.size() - 1;
288 }
289 
290 /// BuildScopeInformation - The statements from CI to CE are known to form a
291 /// coherent VLA scope with a specified parent node. Walk through the
292 /// statements, adding any labels or gotos to LabelAndGotoScopes and recursively
293 /// walking the AST as needed.
294 void JumpScopeChecker::BuildScopeInformation(Stmt *S,
295  unsigned &origParentScope) {
296  // If this is a statement, rather than an expression, scopes within it don't
297  // propagate out into the enclosing scope. Otherwise we have to worry
298  // about block literals, which have the lifetime of their enclosing statement.
299  unsigned independentParentScope = origParentScope;
300  unsigned &ParentScope = ((isa<Expr>(S) && !isa<StmtExpr>(S))
301  ? origParentScope : independentParentScope);
302 
303  unsigned StmtsToSkip = 0u;
304 
305  // If we found a label, remember that it is in ParentScope scope.
306  switch (S->getStmtClass()) {
307  case Stmt::AddrLabelExprClass:
308  IndirectJumpTargets.push_back(cast<AddrLabelExpr>(S)->getLabel());
309  break;
310 
311  case Stmt::ObjCForCollectionStmtClass: {
312  auto *CS = cast<ObjCForCollectionStmt>(S);
313  unsigned Diag = diag::note_protected_by_objc_fast_enumeration;
314  unsigned NewParentScope = Scopes.size();
315  Scopes.push_back(GotoScope(ParentScope, Diag, 0, S->getBeginLoc()));
316  BuildScopeInformation(CS->getBody(), NewParentScope);
317  return;
318  }
319 
320  case Stmt::IndirectGotoStmtClass:
321  // "goto *&&lbl;" is a special case which we treat as equivalent
322  // to a normal goto. In addition, we don't calculate scope in the
323  // operand (to avoid recording the address-of-label use), which
324  // works only because of the restricted set of expressions which
325  // we detect as constant targets.
326  if (cast<IndirectGotoStmt>(S)->getConstantTarget()) {
327  LabelAndGotoScopes[S] = ParentScope;
328  Jumps.push_back(S);
329  return;
330  }
331 
332  LabelAndGotoScopes[S] = ParentScope;
333  IndirectJumps.push_back(S);
334  break;
335 
336  case Stmt::SwitchStmtClass:
337  // Evaluate the C++17 init stmt and condition variable
338  // before entering the scope of the switch statement.
339  if (Stmt *Init = cast<SwitchStmt>(S)->getInit()) {
340  BuildScopeInformation(Init, ParentScope);
341  ++StmtsToSkip;
342  }
343  if (VarDecl *Var = cast<SwitchStmt>(S)->getConditionVariable()) {
344  BuildScopeInformation(Var, ParentScope);
345  ++StmtsToSkip;
346  }
347  LLVM_FALLTHROUGH;
348 
349  case Stmt::GotoStmtClass:
350  // Remember both what scope a goto is in as well as the fact that we have
351  // it. This makes the second scan not have to walk the AST again.
352  LabelAndGotoScopes[S] = ParentScope;
353  Jumps.push_back(S);
354  break;
355 
356  case Stmt::GCCAsmStmtClass:
357  if (auto *GS = dyn_cast<GCCAsmStmt>(S))
358  if (GS->isAsmGoto()) {
359  // Remember both what scope a goto is in as well as the fact that we
360  // have it. This makes the second scan not have to walk the AST again.
361  LabelAndGotoScopes[S] = ParentScope;
362  AsmJumps.push_back(GS);
363  for (auto *E : GS->labels())
364  AsmJumpTargets.push_back(E->getLabel());
365  }
366  break;
367 
368  case Stmt::IfStmtClass: {
369  IfStmt *IS = cast<IfStmt>(S);
370  if (!(IS->isConstexpr() || IS->isObjCAvailabilityCheck()))
371  break;
372 
373  unsigned Diag = IS->isConstexpr() ? diag::note_protected_by_constexpr_if
374  : diag::note_protected_by_if_available;
375 
376  if (VarDecl *Var = IS->getConditionVariable())
377  BuildScopeInformation(Var, ParentScope);
378 
379  // Cannot jump into the middle of the condition.
380  unsigned NewParentScope = Scopes.size();
381  Scopes.push_back(GotoScope(ParentScope, Diag, 0, IS->getBeginLoc()));
382  BuildScopeInformation(IS->getCond(), NewParentScope);
383 
384  // Jumps into either arm of an 'if constexpr' are not allowed.
385  NewParentScope = Scopes.size();
386  Scopes.push_back(GotoScope(ParentScope, Diag, 0, IS->getBeginLoc()));
387  BuildScopeInformation(IS->getThen(), NewParentScope);
388  if (Stmt *Else = IS->getElse()) {
389  NewParentScope = Scopes.size();
390  Scopes.push_back(GotoScope(ParentScope, Diag, 0, IS->getBeginLoc()));
391  BuildScopeInformation(Else, NewParentScope);
392  }
393  return;
394  }
395 
396  case Stmt::CXXTryStmtClass: {
397  CXXTryStmt *TS = cast<CXXTryStmt>(S);
398  {
399  unsigned NewParentScope = Scopes.size();
400  Scopes.push_back(GotoScope(ParentScope,
401  diag::note_protected_by_cxx_try,
402  diag::note_exits_cxx_try,
403  TS->getSourceRange().getBegin()));
404  if (Stmt *TryBlock = TS->getTryBlock())
405  BuildScopeInformation(TryBlock, NewParentScope);
406  }
407 
408  // Jump from the catch into the try is not allowed either.
409  for (unsigned I = 0, E = TS->getNumHandlers(); I != E; ++I) {
410  CXXCatchStmt *CS = TS->getHandler(I);
411  unsigned NewParentScope = Scopes.size();
412  Scopes.push_back(GotoScope(ParentScope,
413  diag::note_protected_by_cxx_catch,
414  diag::note_exits_cxx_catch,
415  CS->getSourceRange().getBegin()));
416  BuildScopeInformation(CS->getHandlerBlock(), NewParentScope);
417  }
418  return;
419  }
420 
421  case Stmt::SEHTryStmtClass: {
422  SEHTryStmt *TS = cast<SEHTryStmt>(S);
423  {
424  unsigned NewParentScope = Scopes.size();
425  Scopes.push_back(GotoScope(ParentScope,
426  diag::note_protected_by_seh_try,
427  diag::note_exits_seh_try,
428  TS->getSourceRange().getBegin()));
429  if (Stmt *TryBlock = TS->getTryBlock())
430  BuildScopeInformation(TryBlock, NewParentScope);
431  }
432 
433  // Jump from __except or __finally into the __try are not allowed either.
434  if (SEHExceptStmt *Except = TS->getExceptHandler()) {
435  unsigned NewParentScope = Scopes.size();
436  Scopes.push_back(GotoScope(ParentScope,
437  diag::note_protected_by_seh_except,
438  diag::note_exits_seh_except,
439  Except->getSourceRange().getBegin()));
440  BuildScopeInformation(Except->getBlock(), NewParentScope);
441  } else if (SEHFinallyStmt *Finally = TS->getFinallyHandler()) {
442  unsigned NewParentScope = Scopes.size();
443  Scopes.push_back(GotoScope(ParentScope,
444  diag::note_protected_by_seh_finally,
445  diag::note_exits_seh_finally,
446  Finally->getSourceRange().getBegin()));
447  BuildScopeInformation(Finally->getBlock(), NewParentScope);
448  }
449 
450  return;
451  }
452 
453  case Stmt::DeclStmtClass: {
454  // If this is a declstmt with a VLA definition, it defines a scope from here
455  // to the end of the containing context.
456  DeclStmt *DS = cast<DeclStmt>(S);
457  // The decl statement creates a scope if any of the decls in it are VLAs
458  // or have the cleanup attribute.
459  for (auto *I : DS->decls())
460  BuildScopeInformation(I, origParentScope);
461  return;
462  }
463 
464  case Stmt::ObjCAtTryStmtClass: {
465  // Disallow jumps into any part of an @try statement by pushing a scope and
466  // walking all sub-stmts in that scope.
467  ObjCAtTryStmt *AT = cast<ObjCAtTryStmt>(S);
468  // Recursively walk the AST for the @try part.
469  {
470  unsigned NewParentScope = Scopes.size();
471  Scopes.push_back(GotoScope(ParentScope,
472  diag::note_protected_by_objc_try,
473  diag::note_exits_objc_try,
474  AT->getAtTryLoc()));
475  if (Stmt *TryPart = AT->getTryBody())
476  BuildScopeInformation(TryPart, NewParentScope);
477  }
478 
479  // Jump from the catch to the finally or try is not valid.
480  for (unsigned I = 0, N = AT->getNumCatchStmts(); I != N; ++I) {
481  ObjCAtCatchStmt *AC = AT->getCatchStmt(I);
482  unsigned NewParentScope = Scopes.size();
483  Scopes.push_back(GotoScope(ParentScope,
484  diag::note_protected_by_objc_catch,
485  diag::note_exits_objc_catch,
486  AC->getAtCatchLoc()));
487  // @catches are nested and it isn't
488  BuildScopeInformation(AC->getCatchBody(), NewParentScope);
489  }
490 
491  // Jump from the finally to the try or catch is not valid.
492  if (ObjCAtFinallyStmt *AF = AT->getFinallyStmt()) {
493  unsigned NewParentScope = Scopes.size();
494  Scopes.push_back(GotoScope(ParentScope,
495  diag::note_protected_by_objc_finally,
496  diag::note_exits_objc_finally,
497  AF->getAtFinallyLoc()));
498  BuildScopeInformation(AF, NewParentScope);
499  }
500 
501  return;
502  }
503 
504  case Stmt::ObjCAtSynchronizedStmtClass: {
505  // Disallow jumps into the protected statement of an @synchronized, but
506  // allow jumps into the object expression it protects.
507  ObjCAtSynchronizedStmt *AS = cast<ObjCAtSynchronizedStmt>(S);
508  // Recursively walk the AST for the @synchronized object expr, it is
509  // evaluated in the normal scope.
510  BuildScopeInformation(AS->getSynchExpr(), ParentScope);
511 
512  // Recursively walk the AST for the @synchronized part, protected by a new
513  // scope.
514  unsigned NewParentScope = Scopes.size();
515  Scopes.push_back(GotoScope(ParentScope,
516  diag::note_protected_by_objc_synchronized,
517  diag::note_exits_objc_synchronized,
518  AS->getAtSynchronizedLoc()));
519  BuildScopeInformation(AS->getSynchBody(), NewParentScope);
520  return;
521  }
522 
523  case Stmt::ObjCAutoreleasePoolStmtClass: {
524  // Disallow jumps into the protected statement of an @autoreleasepool.
525  ObjCAutoreleasePoolStmt *AS = cast<ObjCAutoreleasePoolStmt>(S);
526  // Recursively walk the AST for the @autoreleasepool part, protected by a
527  // new scope.
528  unsigned NewParentScope = Scopes.size();
529  Scopes.push_back(GotoScope(ParentScope,
530  diag::note_protected_by_objc_autoreleasepool,
531  diag::note_exits_objc_autoreleasepool,
532  AS->getAtLoc()));
533  BuildScopeInformation(AS->getSubStmt(), NewParentScope);
534  return;
535  }
536 
537  case Stmt::ExprWithCleanupsClass: {
538  // Disallow jumps past full-expressions that use blocks with
539  // non-trivial cleanups of their captures. This is theoretically
540  // implementable but a lot of work which we haven't felt up to doing.
541  ExprWithCleanups *EWC = cast<ExprWithCleanups>(S);
542  for (unsigned i = 0, e = EWC->getNumObjects(); i != e; ++i) {
543  if (auto *BDecl = EWC->getObject(i).dyn_cast<BlockDecl *>())
544  for (const auto &CI : BDecl->captures()) {
545  VarDecl *variable = CI.getVariable();
546  BuildScopeInformation(variable, BDecl, origParentScope);
547  }
548  else if (auto *CLE = EWC->getObject(i).dyn_cast<CompoundLiteralExpr *>())
549  BuildScopeInformation(CLE, origParentScope);
550  else
551  llvm_unreachable("unexpected cleanup object type");
552  }
553  break;
554  }
555 
556  case Stmt::MaterializeTemporaryExprClass: {
557  // Disallow jumps out of scopes containing temporaries lifetime-extended to
558  // automatic storage duration.
559  MaterializeTemporaryExpr *MTE = cast<MaterializeTemporaryExpr>(S);
560  if (MTE->getStorageDuration() == SD_Automatic) {
563  const Expr *ExtendedObject =
565  Adjustments);
566  if (ExtendedObject->getType().isDestructedType()) {
567  Scopes.push_back(GotoScope(ParentScope, 0,
568  diag::note_exits_temporary_dtor,
569  ExtendedObject->getExprLoc()));
570  origParentScope = Scopes.size()-1;
571  }
572  }
573  break;
574  }
575 
576  case Stmt::CaseStmtClass:
577  case Stmt::DefaultStmtClass:
578  case Stmt::LabelStmtClass:
579  LabelAndGotoScopes[S] = ParentScope;
580  break;
581 
582  default:
583  break;
584  }
585 
586  for (Stmt *SubStmt : S->children()) {
587  if (!SubStmt)
588  continue;
589  if (StmtsToSkip) {
590  --StmtsToSkip;
591  continue;
592  }
593 
594  // Cases, labels, and defaults aren't "scope parents". It's also
595  // important to handle these iteratively instead of recursively in
596  // order to avoid blowing out the stack.
597  while (true) {
598  Stmt *Next;
599  if (SwitchCase *SC = dyn_cast<SwitchCase>(SubStmt))
600  Next = SC->getSubStmt();
601  else if (LabelStmt *LS = dyn_cast<LabelStmt>(SubStmt))
602  Next = LS->getSubStmt();
603  else
604  break;
605 
606  LabelAndGotoScopes[SubStmt] = ParentScope;
607  SubStmt = Next;
608  }
609 
610  // Recursively walk the AST.
611  BuildScopeInformation(SubStmt, ParentScope);
612  }
613 }
614 
615 /// VerifyJumps - Verify each element of the Jumps array to see if they are
616 /// valid, emitting diagnostics if not.
617 void JumpScopeChecker::VerifyJumps() {
618  while (!Jumps.empty()) {
619  Stmt *Jump = Jumps.pop_back_val();
620 
621  // With a goto,
622  if (GotoStmt *GS = dyn_cast<GotoStmt>(Jump)) {
623  // The label may not have a statement if it's coming from inline MS ASM.
624  if (GS->getLabel()->getStmt()) {
625  CheckJump(GS, GS->getLabel()->getStmt(), GS->getGotoLoc(),
626  diag::err_goto_into_protected_scope,
627  diag::ext_goto_into_protected_scope,
628  diag::warn_cxx98_compat_goto_into_protected_scope);
629  }
630  CheckGotoStmt(GS);
631  continue;
632  }
633 
634  // We only get indirect gotos here when they have a constant target.
635  if (IndirectGotoStmt *IGS = dyn_cast<IndirectGotoStmt>(Jump)) {
636  LabelDecl *Target = IGS->getConstantTarget();
637  CheckJump(IGS, Target->getStmt(), IGS->getGotoLoc(),
638  diag::err_goto_into_protected_scope,
639  diag::ext_goto_into_protected_scope,
640  diag::warn_cxx98_compat_goto_into_protected_scope);
641  continue;
642  }
643 
644  SwitchStmt *SS = cast<SwitchStmt>(Jump);
645  for (SwitchCase *SC = SS->getSwitchCaseList(); SC;
646  SC = SC->getNextSwitchCase()) {
647  if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(SC)))
648  continue;
649  SourceLocation Loc;
650  if (CaseStmt *CS = dyn_cast<CaseStmt>(SC))
651  Loc = CS->getBeginLoc();
652  else if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC))
653  Loc = DS->getBeginLoc();
654  else
655  Loc = SC->getBeginLoc();
656  CheckJump(SS, SC, Loc, diag::err_switch_into_protected_scope, 0,
657  diag::warn_cxx98_compat_switch_into_protected_scope);
658  }
659  }
660 }
661 
662 /// VerifyIndirectOrAsmJumps - Verify whether any possible indirect goto or
663 /// asm goto jump might cross a protection boundary. Unlike direct jumps,
664 /// indirect or asm goto jumps count cleanups as protection boundaries:
665 /// since there's no way to know where the jump is going, we can't implicitly
666 /// run the right cleanups the way we can with direct jumps.
667 /// Thus, an indirect/asm jump is "trivial" if it bypasses no
668 /// initializations and no teardowns. More formally, an indirect/asm jump
669 /// from A to B is trivial if the path out from A to DCA(A,B) is
670 /// trivial and the path in from DCA(A,B) to B is trivial, where
671 /// DCA(A,B) is the deepest common ancestor of A and B.
672 /// Jump-triviality is transitive but asymmetric.
673 ///
674 /// A path in is trivial if none of the entered scopes have an InDiag.
675 /// A path out is trivial is none of the exited scopes have an OutDiag.
676 ///
677 /// Under these definitions, this function checks that the indirect
678 /// jump between A and B is trivial for every indirect goto statement A
679 /// and every label B whose address was taken in the function.
680 void JumpScopeChecker::VerifyIndirectOrAsmJumps(bool IsAsmGoto) {
681  SmallVector<Stmt*, 4> GotoJumps = IsAsmGoto ? AsmJumps : IndirectJumps;
682  if (GotoJumps.empty())
683  return;
684  SmallVector<LabelDecl *, 4> JumpTargets =
685  IsAsmGoto ? AsmJumpTargets : IndirectJumpTargets;
686  // If there aren't any address-of-label expressions in this function,
687  // complain about the first indirect goto.
688  if (JumpTargets.empty()) {
689  assert(!IsAsmGoto &&"only indirect goto can get here");
690  S.Diag(GotoJumps[0]->getBeginLoc(),
691  diag::err_indirect_goto_without_addrlabel);
692  return;
693  }
694  // Collect a single representative of every scope containing an
695  // indirect or asm goto. For most code bases, this substantially cuts
696  // down on the number of jump sites we'll have to consider later.
697  typedef std::pair<unsigned, Stmt*> JumpScope;
698  SmallVector<JumpScope, 32> JumpScopes;
699  {
700  llvm::DenseMap<unsigned, Stmt*> JumpScopesMap;
701  for (SmallVectorImpl<Stmt *>::iterator I = GotoJumps.begin(),
702  E = GotoJumps.end();
703  I != E; ++I) {
704  Stmt *IG = *I;
705  if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(IG)))
706  continue;
707  unsigned IGScope = LabelAndGotoScopes[IG];
708  Stmt *&Entry = JumpScopesMap[IGScope];
709  if (!Entry) Entry = IG;
710  }
711  JumpScopes.reserve(JumpScopesMap.size());
712  for (llvm::DenseMap<unsigned, Stmt *>::iterator I = JumpScopesMap.begin(),
713  E = JumpScopesMap.end();
714  I != E; ++I)
715  JumpScopes.push_back(*I);
716  }
717 
718  // Collect a single representative of every scope containing a
719  // label whose address was taken somewhere in the function.
720  // For most code bases, there will be only one such scope.
721  llvm::DenseMap<unsigned, LabelDecl*> TargetScopes;
722  for (SmallVectorImpl<LabelDecl *>::iterator I = JumpTargets.begin(),
723  E = JumpTargets.end();
724  I != E; ++I) {
725  LabelDecl *TheLabel = *I;
726  if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(TheLabel->getStmt())))
727  continue;
728  unsigned LabelScope = LabelAndGotoScopes[TheLabel->getStmt()];
729  LabelDecl *&Target = TargetScopes[LabelScope];
730  if (!Target) Target = TheLabel;
731  }
732 
733  // For each target scope, make sure it's trivially reachable from
734  // every scope containing a jump site.
735  //
736  // A path between scopes always consists of exitting zero or more
737  // scopes, then entering zero or more scopes. We build a set of
738  // of scopes S from which the target scope can be trivially
739  // entered, then verify that every jump scope can be trivially
740  // exitted to reach a scope in S.
741  llvm::BitVector Reachable(Scopes.size(), false);
742  for (llvm::DenseMap<unsigned,LabelDecl*>::iterator
743  TI = TargetScopes.begin(), TE = TargetScopes.end(); TI != TE; ++TI) {
744  unsigned TargetScope = TI->first;
745  LabelDecl *TargetLabel = TI->second;
746 
747  Reachable.reset();
748 
749  // Mark all the enclosing scopes from which you can safely jump
750  // into the target scope. 'Min' will end up being the index of
751  // the shallowest such scope.
752  unsigned Min = TargetScope;
753  while (true) {
754  Reachable.set(Min);
755 
756  // Don't go beyond the outermost scope.
757  if (Min == 0) break;
758 
759  // Stop if we can't trivially enter the current scope.
760  if (Scopes[Min].InDiag) break;
761 
762  Min = Scopes[Min].ParentScope;
763  }
764 
765  // Walk through all the jump sites, checking that they can trivially
766  // reach this label scope.
768  I = JumpScopes.begin(), E = JumpScopes.end(); I != E; ++I) {
769  unsigned Scope = I->first;
770 
771  // Walk out the "scope chain" for this scope, looking for a scope
772  // we've marked reachable. For well-formed code this amortizes
773  // to O(JumpScopes.size() / Scopes.size()): we only iterate
774  // when we see something unmarked, and in well-formed code we
775  // mark everything we iterate past.
776  bool IsReachable = false;
777  while (true) {
778  if (Reachable.test(Scope)) {
779  // If we find something reachable, mark all the scopes we just
780  // walked through as reachable.
781  for (unsigned S = I->first; S != Scope; S = Scopes[S].ParentScope)
782  Reachable.set(S);
783  IsReachable = true;
784  break;
785  }
786 
787  // Don't walk out if we've reached the top-level scope or we've
788  // gotten shallower than the shallowest reachable scope.
789  if (Scope == 0 || Scope < Min) break;
790 
791  // Don't walk out through an out-diagnostic.
792  if (Scopes[Scope].OutDiag) break;
793 
794  Scope = Scopes[Scope].ParentScope;
795  }
796 
797  // Only diagnose if we didn't find something.
798  if (IsReachable) continue;
799 
800  DiagnoseIndirectOrAsmJump(I->second, I->first, TargetLabel, TargetScope);
801  }
802  }
803 }
804 
805 /// Return true if a particular error+note combination must be downgraded to a
806 /// warning in Microsoft mode.
807 static bool IsMicrosoftJumpWarning(unsigned JumpDiag, unsigned InDiagNote) {
808  return (JumpDiag == diag::err_goto_into_protected_scope &&
809  (InDiagNote == diag::note_protected_by_variable_init ||
810  InDiagNote == diag::note_protected_by_variable_nontriv_destructor));
811 }
812 
813 /// Return true if a particular note should be downgraded to a compatibility
814 /// warning in C++11 mode.
815 static bool IsCXX98CompatWarning(Sema &S, unsigned InDiagNote) {
816  return S.getLangOpts().CPlusPlus11 &&
817  InDiagNote == diag::note_protected_by_variable_non_pod;
818 }
819 
820 /// Produce primary diagnostic for an indirect jump statement.
822  LabelDecl *Target, bool &Diagnosed) {
823  if (Diagnosed)
824  return;
825  bool IsAsmGoto = isa<GCCAsmStmt>(Jump);
826  S.Diag(Jump->getBeginLoc(), diag::err_indirect_goto_in_protected_scope)
827  << IsAsmGoto;
828  S.Diag(Target->getStmt()->getIdentLoc(), diag::note_indirect_goto_target)
829  << IsAsmGoto;
830  Diagnosed = true;
831 }
832 
833 /// Produce note diagnostics for a jump into a protected scope.
834 void JumpScopeChecker::NoteJumpIntoScopes(ArrayRef<unsigned> ToScopes) {
835  if (CHECK_PERMISSIVE(ToScopes.empty()))
836  return;
837  for (unsigned I = 0, E = ToScopes.size(); I != E; ++I)
838  if (Scopes[ToScopes[I]].InDiag)
839  S.Diag(Scopes[ToScopes[I]].Loc, Scopes[ToScopes[I]].InDiag);
840 }
841 
842 /// Diagnose an indirect jump which is known to cross scopes.
843 void JumpScopeChecker::DiagnoseIndirectOrAsmJump(Stmt *Jump, unsigned JumpScope,
844  LabelDecl *Target,
845  unsigned TargetScope) {
846  if (CHECK_PERMISSIVE(JumpScope == TargetScope))
847  return;
848 
849  unsigned Common = GetDeepestCommonScope(JumpScope, TargetScope);
850  bool Diagnosed = false;
851 
852  // Walk out the scope chain until we reach the common ancestor.
853  for (unsigned I = JumpScope; I != Common; I = Scopes[I].ParentScope)
854  if (Scopes[I].OutDiag) {
855  DiagnoseIndirectOrAsmJumpStmt(S, Jump, Target, Diagnosed);
856  S.Diag(Scopes[I].Loc, Scopes[I].OutDiag);
857  }
858 
859  SmallVector<unsigned, 10> ToScopesCXX98Compat;
860 
861  // Now walk into the scopes containing the label whose address was taken.
862  for (unsigned I = TargetScope; I != Common; I = Scopes[I].ParentScope)
863  if (IsCXX98CompatWarning(S, Scopes[I].InDiag))
864  ToScopesCXX98Compat.push_back(I);
865  else if (Scopes[I].InDiag) {
866  DiagnoseIndirectOrAsmJumpStmt(S, Jump, Target, Diagnosed);
867  S.Diag(Scopes[I].Loc, Scopes[I].InDiag);
868  }
869 
870  // Diagnose this jump if it would be ill-formed in C++98.
871  if (!Diagnosed && !ToScopesCXX98Compat.empty()) {
872  bool IsAsmGoto = isa<GCCAsmStmt>(Jump);
873  S.Diag(Jump->getBeginLoc(),
874  diag::warn_cxx98_compat_indirect_goto_in_protected_scope)
875  << IsAsmGoto;
876  S.Diag(Target->getStmt()->getIdentLoc(), diag::note_indirect_goto_target)
877  << IsAsmGoto;
878  NoteJumpIntoScopes(ToScopesCXX98Compat);
879  }
880 }
881 
882 /// CheckJump - Validate that the specified jump statement is valid: that it is
883 /// jumping within or out of its current scope, not into a deeper one.
884 void JumpScopeChecker::CheckJump(Stmt *From, Stmt *To, SourceLocation DiagLoc,
885  unsigned JumpDiagError, unsigned JumpDiagWarning,
886  unsigned JumpDiagCXX98Compat) {
887  if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(From)))
888  return;
889  if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(To)))
890  return;
891 
892  unsigned FromScope = LabelAndGotoScopes[From];
893  unsigned ToScope = LabelAndGotoScopes[To];
894 
895  // Common case: exactly the same scope, which is fine.
896  if (FromScope == ToScope) return;
897 
898  // Warn on gotos out of __finally blocks.
899  if (isa<GotoStmt>(From) || isa<IndirectGotoStmt>(From)) {
900  // If FromScope > ToScope, FromScope is more nested and the jump goes to a
901  // less nested scope. Check if it crosses a __finally along the way.
902  for (unsigned I = FromScope; I > ToScope; I = Scopes[I].ParentScope) {
903  if (Scopes[I].InDiag == diag::note_protected_by_seh_finally) {
904  S.Diag(From->getBeginLoc(), diag::warn_jump_out_of_seh_finally);
905  break;
906  }
907  }
908  }
909 
910  unsigned CommonScope = GetDeepestCommonScope(FromScope, ToScope);
911 
912  // It's okay to jump out from a nested scope.
913  if (CommonScope == ToScope) return;
914 
915  // Pull out (and reverse) any scopes we might need to diagnose skipping.
916  SmallVector<unsigned, 10> ToScopesCXX98Compat;
917  SmallVector<unsigned, 10> ToScopesError;
918  SmallVector<unsigned, 10> ToScopesWarning;
919  for (unsigned I = ToScope; I != CommonScope; I = Scopes[I].ParentScope) {
920  if (S.getLangOpts().MSVCCompat && JumpDiagWarning != 0 &&
921  IsMicrosoftJumpWarning(JumpDiagError, Scopes[I].InDiag))
922  ToScopesWarning.push_back(I);
923  else if (IsCXX98CompatWarning(S, Scopes[I].InDiag))
924  ToScopesCXX98Compat.push_back(I);
925  else if (Scopes[I].InDiag)
926  ToScopesError.push_back(I);
927  }
928 
929  // Handle warnings.
930  if (!ToScopesWarning.empty()) {
931  S.Diag(DiagLoc, JumpDiagWarning);
932  NoteJumpIntoScopes(ToScopesWarning);
933  }
934 
935  // Handle errors.
936  if (!ToScopesError.empty()) {
937  S.Diag(DiagLoc, JumpDiagError);
938  NoteJumpIntoScopes(ToScopesError);
939  }
940 
941  // Handle -Wc++98-compat warnings if the jump is well-formed.
942  if (ToScopesError.empty() && !ToScopesCXX98Compat.empty()) {
943  S.Diag(DiagLoc, JumpDiagCXX98Compat);
944  NoteJumpIntoScopes(ToScopesCXX98Compat);
945  }
946 }
947 
948 void JumpScopeChecker::CheckGotoStmt(GotoStmt *GS) {
949  if (GS->getLabel()->isMSAsmLabel()) {
950  S.Diag(GS->getGotoLoc(), diag::err_goto_ms_asm_label)
951  << GS->getLabel()->getIdentifier();
952  S.Diag(GS->getLabel()->getLocation(), diag::note_goto_ms_asm_label)
953  << GS->getLabel()->getIdentifier();
954  }
955 }
956 
957 void Sema::DiagnoseInvalidJumps(Stmt *Body) {
958  (void)JumpScopeChecker(Body, *this);
959 }
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:655
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:78
Stmt - This represents one statement.
Definition: Stmt.h:68
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:1866
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:1517
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:89
Stmt * getHandlerBlock() const
Definition: StmtCXX.h:51
bool isPOD() const
Whether this class is a POD-type (C++ [class]p4)
Definition: DeclCXX.h:1115
SourceLocation getIdentLoc() const
Definition: Stmt.h:1778
Represents a call to a C++ constructor.
Definition: ExprCXX.h:1426
Represents a C++ constructor within a class.
Definition: DeclCXX.h:2413
Represents a prvalue temporary that is written into memory so that a reference can bind to it...
Definition: ExprCXX.h:4406
bool isDefaultConstructor() const
Whether this constructor is a default constructor (C++ [class.ctor]p5), which can be used to default-...
Definition: DeclCXX.cpp:2588
Represents a variable declaration or definition.
Definition: Decl.h:820
CompoundLiteralExpr - [C99 6.5.2.5].
Definition: Expr.h:3303
#define CHECK_PERMISSIVE(x)
Stmt * getThen()
Definition: Stmt.h:1953
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:3296
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:244
LabelStmt - Represents a label, which has a substatement.
Definition: Stmt.h:1764
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:275
Represents Objective-C&#39;s @catch statement.
Definition: StmtObjC.h:77
IndirectGotoStmt - This represents an indirect goto.
Definition: Stmt.h:2561
child_range children()
Definition: Stmt.cpp:224
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:1532
const LangOptions & getLangOpts() const
Definition: Sema.h:1430
__device__ __2f16 float bool s
const ObjCAtCatchStmt * getCatchStmt(unsigned I) const
Retrieve a @catch statement.
Definition: StmtObjC.h:217
bool hasAttr() const
Definition: DeclBase.h:547
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:340
bool isConstexpr() const
Definition: Stmt.h:2039
Represents a block literal declaration, which is like an unnamed FunctionDecl.
Definition: Decl.h:4064
This represents one expression.
Definition: Expr.h:110
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:2048
QualType getType() const
Definition: Expr.h:142
LabelDecl * getLabel() const
Definition: Stmt.h:2535
StorageDuration getStorageDuration() const
Retrieve the storage duration for the materialized temporary.
Definition: ExprCXX.h:4431
const Stmt * getTryBody() const
Retrieve the @try body.
Definition: StmtObjC.h:208
std::pair< unsigned, unsigned > ScopePair
SwitchCase * getSwitchCaseList()
Definition: Stmt.h:2204
SourceLocation getAtLoc() const
Definition: StmtObjC.h:388
Expr * getCond()
Definition: Stmt.h:1941
bool isTrivial() const
Whether this function is "trivial" in some specialized C++ senses.
Definition: Decl.h:2122
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:1962
DeclStmt - Adaptor class for mixing declarations with statements and expressions. ...
Definition: Stmt.h:1257
Represents the declaration of a label.
Definition: Decl.h:451
SourceLocation getGotoLoc() const
Definition: Stmt.h:2538
bool isMSAsmLabel() const
Definition: Decl.h:485
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1196
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:226
Base class for declarations which introduce a typedef-name.
Definition: Decl.h:3091
LabelStmt * getStmt() const
Definition: Decl.h:475
Dataflow Directional Tag Classes.
ArrayRef< Capture > captures() const
Definition: Decl.h:4191
StmtClass getStmtClass() const
Definition: Stmt.h:1148
const CXXRecordDecl * getParent() const
Return the parent of this method declaration, which is the class in which this method is defined...
Definition: DeclCXX.h:2076
SEHExceptStmt * getExceptHandler() const
Returns 0 if not defined.
Definition: Stmt.cpp:1146
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:2075
unsigned getNumObjects() const
Definition: ExprCXX.h:3329
decl_range decls()
Definition: Stmt.h:1305
Represents Objective-C&#39;s @finally statement.
Definition: StmtObjC.h:127
SEHFinallyStmt * getFinallyHandler() const
Definition: Stmt.cpp:1150
GotoStmt - This represents a direct goto.
Definition: Stmt.h:2522
const SwitchCase * getNextSwitchCase() const
Definition: Stmt.h:1507
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:3331
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:263
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:630
ASTContext & Context
Definition: Sema.h:399
Automatic storage duration (most local variables).
Definition: Specifiers.h:313
SourceLocation getBegin() const
Expr * getSubExpr() const
Retrieve the temporary-generating subexpression whose value will be materialized into a glvalue...
Definition: ExprCXX.h:4423
const LangOptions & getLangOpts() const
Definition: ASTContext.h:664
Represents Objective-C&#39;s @autoreleasepool Statement.
Definition: StmtObjC.h:368
CompoundStmt * getTryBlock() const
Definition: Stmt.h:3354
SourceLocation getLocation() const
Definition: DeclBase.h:430
static bool IsCXX98CompatWarning(Sema &S, unsigned InDiagNote)
Return true if a particular note should be downgraded to a compatibility warning in C++11 mode...