clang  9.0.0svn
AnalysisBasedWarnings.cpp
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1 //=- AnalysisBasedWarnings.cpp - Sema warnings based on libAnalysis -*- 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 defines analysis_warnings::[Policy,Executor].
10 // Together they are used by Sema to issue warnings based on inexpensive
11 // static analysis algorithms in libAnalysis.
12 //
13 //===----------------------------------------------------------------------===//
14 
16 #include "clang/AST/DeclCXX.h"
17 #include "clang/AST/DeclObjC.h"
19 #include "clang/AST/ExprCXX.h"
20 #include "clang/AST/ExprObjC.h"
21 #include "clang/AST/ParentMap.h"
23 #include "clang/AST/StmtCXX.h"
24 #include "clang/AST/StmtObjC.h"
25 #include "clang/AST/StmtVisitor.h"
32 #include "clang/Analysis/CFG.h"
36 #include "clang/Lex/Preprocessor.h"
37 #include "clang/Sema/ScopeInfo.h"
39 #include "llvm/ADT/BitVector.h"
40 #include "llvm/ADT/MapVector.h"
41 #include "llvm/ADT/SmallString.h"
42 #include "llvm/ADT/SmallVector.h"
43 #include "llvm/ADT/StringRef.h"
44 #include "llvm/Support/Casting.h"
45 #include <algorithm>
46 #include <deque>
47 #include <iterator>
48 
49 using namespace clang;
50 
51 //===----------------------------------------------------------------------===//
52 // Unreachable code analysis.
53 //===----------------------------------------------------------------------===//
54 
55 namespace {
56  class UnreachableCodeHandler : public reachable_code::Callback {
57  Sema &S;
58  SourceRange PreviousSilenceableCondVal;
59 
60  public:
61  UnreachableCodeHandler(Sema &s) : S(s) {}
62 
63  void HandleUnreachable(reachable_code::UnreachableKind UK,
65  SourceRange SilenceableCondVal,
66  SourceRange R1,
67  SourceRange R2) override {
68  // Avoid reporting multiple unreachable code diagnostics that are
69  // triggered by the same conditional value.
70  if (PreviousSilenceableCondVal.isValid() &&
71  SilenceableCondVal.isValid() &&
72  PreviousSilenceableCondVal == SilenceableCondVal)
73  return;
74  PreviousSilenceableCondVal = SilenceableCondVal;
75 
76  unsigned diag = diag::warn_unreachable;
77  switch (UK) {
79  diag = diag::warn_unreachable_break;
80  break;
82  diag = diag::warn_unreachable_return;
83  break;
85  diag = diag::warn_unreachable_loop_increment;
86  break;
88  break;
89  }
90 
91  S.Diag(L, diag) << R1 << R2;
92 
93  SourceLocation Open = SilenceableCondVal.getBegin();
94  if (Open.isValid()) {
95  SourceLocation Close = SilenceableCondVal.getEnd();
96  Close = S.getLocForEndOfToken(Close);
97  if (Close.isValid()) {
98  S.Diag(Open, diag::note_unreachable_silence)
99  << FixItHint::CreateInsertion(Open, "/* DISABLES CODE */ (")
100  << FixItHint::CreateInsertion(Close, ")");
101  }
102  }
103  }
104  };
105 } // anonymous namespace
106 
107 /// CheckUnreachable - Check for unreachable code.
109  // As a heuristic prune all diagnostics not in the main file. Currently
110  // the majority of warnings in headers are false positives. These
111  // are largely caused by configuration state, e.g. preprocessor
112  // defined code, etc.
113  //
114  // Note that this is also a performance optimization. Analyzing
115  // headers many times can be expensive.
117  return;
118 
119  UnreachableCodeHandler UC(S);
121 }
122 
123 namespace {
124 /// Warn on logical operator errors in CFGBuilder
125 class LogicalErrorHandler : public CFGCallback {
126  Sema &S;
127 
128 public:
129  LogicalErrorHandler(Sema &S) : CFGCallback(), S(S) {}
130 
131  static bool HasMacroID(const Expr *E) {
132  if (E->getExprLoc().isMacroID())
133  return true;
134 
135  // Recurse to children.
136  for (const Stmt *SubStmt : E->children())
137  if (const Expr *SubExpr = dyn_cast_or_null<Expr>(SubStmt))
138  if (HasMacroID(SubExpr))
139  return true;
140 
141  return false;
142  }
143 
144  void compareAlwaysTrue(const BinaryOperator *B, bool isAlwaysTrue) override {
145  if (HasMacroID(B))
146  return;
147 
148  SourceRange DiagRange = B->getSourceRange();
149  S.Diag(B->getExprLoc(), diag::warn_tautological_overlap_comparison)
150  << DiagRange << isAlwaysTrue;
151  }
152 
153  void compareBitwiseEquality(const BinaryOperator *B,
154  bool isAlwaysTrue) override {
155  if (HasMacroID(B))
156  return;
157 
158  SourceRange DiagRange = B->getSourceRange();
159  S.Diag(B->getExprLoc(), diag::warn_comparison_bitwise_always)
160  << DiagRange << isAlwaysTrue;
161  }
162 };
163 } // anonymous namespace
164 
165 //===----------------------------------------------------------------------===//
166 // Check for infinite self-recursion in functions
167 //===----------------------------------------------------------------------===//
168 
169 // Returns true if the function is called anywhere within the CFGBlock.
170 // For member functions, the additional condition of being call from the
171 // this pointer is required.
172 static bool hasRecursiveCallInPath(const FunctionDecl *FD, CFGBlock &Block) {
173  // Process all the Stmt's in this block to find any calls to FD.
174  for (const auto &B : Block) {
175  if (B.getKind() != CFGElement::Statement)
176  continue;
177 
178  const CallExpr *CE = dyn_cast<CallExpr>(B.getAs<CFGStmt>()->getStmt());
179  if (!CE || !CE->getCalleeDecl() ||
180  CE->getCalleeDecl()->getCanonicalDecl() != FD)
181  continue;
182 
183  // Skip function calls which are qualified with a templated class.
184  if (const DeclRefExpr *DRE =
185  dyn_cast<DeclRefExpr>(CE->getCallee()->IgnoreParenImpCasts())) {
186  if (NestedNameSpecifier *NNS = DRE->getQualifier()) {
187  if (NNS->getKind() == NestedNameSpecifier::TypeSpec &&
188  isa<TemplateSpecializationType>(NNS->getAsType())) {
189  continue;
190  }
191  }
192  }
193 
194  const CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(CE);
195  if (!MCE || isa<CXXThisExpr>(MCE->getImplicitObjectArgument()) ||
196  !MCE->getMethodDecl()->isVirtual())
197  return true;
198  }
199  return false;
200 }
201 
202 // Returns true if every path from the entry block passes through a call to FD.
203 static bool checkForRecursiveFunctionCall(const FunctionDecl *FD, CFG *cfg) {
204  llvm::SmallPtrSet<CFGBlock *, 16> Visited;
206  // Keep track of whether we found at least one recursive path.
207  bool foundRecursion = false;
208 
209  const unsigned ExitID = cfg->getExit().getBlockID();
210 
211  // Seed the work list with the entry block.
212  WorkList.push_back(&cfg->getEntry());
213 
214  while (!WorkList.empty()) {
215  CFGBlock *Block = WorkList.pop_back_val();
216 
217  for (auto I = Block->succ_begin(), E = Block->succ_end(); I != E; ++I) {
218  if (CFGBlock *SuccBlock = *I) {
219  if (!Visited.insert(SuccBlock).second)
220  continue;
221 
222  // Found a path to the exit node without a recursive call.
223  if (ExitID == SuccBlock->getBlockID())
224  return false;
225 
226  // If the successor block contains a recursive call, end analysis there.
227  if (hasRecursiveCallInPath(FD, *SuccBlock)) {
228  foundRecursion = true;
229  continue;
230  }
231 
232  WorkList.push_back(SuccBlock);
233  }
234  }
235  }
236  return foundRecursion;
237 }
238 
239 static void checkRecursiveFunction(Sema &S, const FunctionDecl *FD,
240  const Stmt *Body, AnalysisDeclContext &AC) {
241  FD = FD->getCanonicalDecl();
242 
243  // Only run on non-templated functions and non-templated members of
244  // templated classes.
247  return;
248 
249  CFG *cfg = AC.getCFG();
250  if (!cfg) return;
251 
252  // If the exit block is unreachable, skip processing the function.
253  if (cfg->getExit().pred_empty())
254  return;
255 
256  // Emit diagnostic if a recursive function call is detected for all paths.
257  if (checkForRecursiveFunctionCall(FD, cfg))
258  S.Diag(Body->getBeginLoc(), diag::warn_infinite_recursive_function);
259 }
260 
261 //===----------------------------------------------------------------------===//
262 // Check for throw in a non-throwing function.
263 //===----------------------------------------------------------------------===//
264 
265 /// Determine whether an exception thrown by E, unwinding from ThrowBlock,
266 /// can reach ExitBlock.
267 static bool throwEscapes(Sema &S, const CXXThrowExpr *E, CFGBlock &ThrowBlock,
268  CFG *Body) {
270  llvm::BitVector Queued(Body->getNumBlockIDs());
271 
272  Stack.push_back(&ThrowBlock);
273  Queued[ThrowBlock.getBlockID()] = true;
274 
275  while (!Stack.empty()) {
276  CFGBlock &UnwindBlock = *Stack.back();
277  Stack.pop_back();
278 
279  for (auto &Succ : UnwindBlock.succs()) {
280  if (!Succ.isReachable() || Queued[Succ->getBlockID()])
281  continue;
282 
283  if (Succ->getBlockID() == Body->getExit().getBlockID())
284  return true;
285 
286  if (auto *Catch =
287  dyn_cast_or_null<CXXCatchStmt>(Succ->getLabel())) {
288  QualType Caught = Catch->getCaughtType();
289  if (Caught.isNull() || // catch (...) catches everything
290  !E->getSubExpr() || // throw; is considered cuaght by any handler
291  S.handlerCanCatch(Caught, E->getSubExpr()->getType()))
292  // Exception doesn't escape via this path.
293  break;
294  } else {
295  Stack.push_back(Succ);
296  Queued[Succ->getBlockID()] = true;
297  }
298  }
299  }
300 
301  return false;
302 }
303 
305  CFG *BodyCFG,
306  llvm::function_ref<void(const CXXThrowExpr *, CFGBlock &)> Visit) {
307  llvm::BitVector Reachable(BodyCFG->getNumBlockIDs());
309  for (CFGBlock *B : *BodyCFG) {
310  if (!Reachable[B->getBlockID()])
311  continue;
312  for (CFGElement &E : *B) {
313  Optional<CFGStmt> S = E.getAs<CFGStmt>();
314  if (!S)
315  continue;
316  if (auto *Throw = dyn_cast<CXXThrowExpr>(S->getStmt()))
317  Visit(Throw, *B);
318  }
319  }
320 }
321 
323  const FunctionDecl *FD) {
324  if (!S.getSourceManager().isInSystemHeader(OpLoc) &&
325  FD->getTypeSourceInfo()) {
326  S.Diag(OpLoc, diag::warn_throw_in_noexcept_func) << FD;
327  if (S.getLangOpts().CPlusPlus11 &&
328  (isa<CXXDestructorDecl>(FD) ||
329  FD->getDeclName().getCXXOverloadedOperator() == OO_Delete ||
330  FD->getDeclName().getCXXOverloadedOperator() == OO_Array_Delete)) {
331  if (const auto *Ty = FD->getTypeSourceInfo()->getType()->
332  getAs<FunctionProtoType>())
333  S.Diag(FD->getLocation(), diag::note_throw_in_dtor)
334  << !isa<CXXDestructorDecl>(FD) << !Ty->hasExceptionSpec()
336  } else
337  S.Diag(FD->getLocation(), diag::note_throw_in_function)
339  }
340 }
341 
343  AnalysisDeclContext &AC) {
344  CFG *BodyCFG = AC.getCFG();
345  if (!BodyCFG)
346  return;
347  if (BodyCFG->getExit().pred_empty())
348  return;
349  visitReachableThrows(BodyCFG, [&](const CXXThrowExpr *Throw, CFGBlock &Block) {
350  if (throwEscapes(S, Throw, Block, BodyCFG))
352  });
353 }
354 
355 static bool isNoexcept(const FunctionDecl *FD) {
356  const auto *FPT = FD->getType()->castAs<FunctionProtoType>();
357  if (FPT->isNothrow() || FD->hasAttr<NoThrowAttr>())
358  return true;
359  return false;
360 }
361 
362 //===----------------------------------------------------------------------===//
363 // Check for missing return value.
364 //===----------------------------------------------------------------------===//
365 
372 };
373 
374 /// CheckFallThrough - Check that we don't fall off the end of a
375 /// Statement that should return a value.
376 ///
377 /// \returns AlwaysFallThrough iff we always fall off the end of the statement,
378 /// MaybeFallThrough iff we might or might not fall off the end,
379 /// NeverFallThroughOrReturn iff we never fall off the end of the statement or
380 /// return. We assume NeverFallThrough iff we never fall off the end of the
381 /// statement but we may return. We assume that functions not marked noreturn
382 /// will return.
384  CFG *cfg = AC.getCFG();
385  if (!cfg) return UnknownFallThrough;
386 
387  // The CFG leaves in dead things, and we don't want the dead code paths to
388  // confuse us, so we mark all live things first.
389  llvm::BitVector live(cfg->getNumBlockIDs());
390  unsigned count = reachable_code::ScanReachableFromBlock(&cfg->getEntry(),
391  live);
392 
393  bool AddEHEdges = AC.getAddEHEdges();
394  if (!AddEHEdges && count != cfg->getNumBlockIDs())
395  // When there are things remaining dead, and we didn't add EH edges
396  // from CallExprs to the catch clauses, we have to go back and
397  // mark them as live.
398  for (const auto *B : *cfg) {
399  if (!live[B->getBlockID()]) {
400  if (B->pred_begin() == B->pred_end()) {
401  if (B->getTerminator() && isa<CXXTryStmt>(B->getTerminator()))
402  // When not adding EH edges from calls, catch clauses
403  // can otherwise seem dead. Avoid noting them as dead.
404  count += reachable_code::ScanReachableFromBlock(B, live);
405  continue;
406  }
407  }
408  }
409 
410  // Now we know what is live, we check the live precessors of the exit block
411  // and look for fall through paths, being careful to ignore normal returns,
412  // and exceptional paths.
413  bool HasLiveReturn = false;
414  bool HasFakeEdge = false;
415  bool HasPlainEdge = false;
416  bool HasAbnormalEdge = false;
417 
418  // Ignore default cases that aren't likely to be reachable because all
419  // enums in a switch(X) have explicit case statements.
422 
424  cfg->getExit().filtered_pred_start_end(FO);
425  I.hasMore(); ++I) {
426  const CFGBlock &B = **I;
427  if (!live[B.getBlockID()])
428  continue;
429 
430  // Skip blocks which contain an element marked as no-return. They don't
431  // represent actually viable edges into the exit block, so mark them as
432  // abnormal.
433  if (B.hasNoReturnElement()) {
434  HasAbnormalEdge = true;
435  continue;
436  }
437 
438  // Destructors can appear after the 'return' in the CFG. This is
439  // normal. We need to look pass the destructors for the return
440  // statement (if it exists).
441  CFGBlock::const_reverse_iterator ri = B.rbegin(), re = B.rend();
442 
443  for ( ; ri != re ; ++ri)
444  if (ri->getAs<CFGStmt>())
445  break;
446 
447  // No more CFGElements in the block?
448  if (ri == re) {
449  if (B.getTerminator() && isa<CXXTryStmt>(B.getTerminator())) {
450  HasAbnormalEdge = true;
451  continue;
452  }
453  // A labeled empty statement, or the entry block...
454  HasPlainEdge = true;
455  continue;
456  }
457 
458  CFGStmt CS = ri->castAs<CFGStmt>();
459  const Stmt *S = CS.getStmt();
460  if (isa<ReturnStmt>(S) || isa<CoreturnStmt>(S)) {
461  HasLiveReturn = true;
462  continue;
463  }
464  if (isa<ObjCAtThrowStmt>(S)) {
465  HasFakeEdge = true;
466  continue;
467  }
468  if (isa<CXXThrowExpr>(S)) {
469  HasFakeEdge = true;
470  continue;
471  }
472  if (isa<MSAsmStmt>(S)) {
473  // TODO: Verify this is correct.
474  HasFakeEdge = true;
475  HasLiveReturn = true;
476  continue;
477  }
478  if (isa<CXXTryStmt>(S)) {
479  HasAbnormalEdge = true;
480  continue;
481  }
482  if (std::find(B.succ_begin(), B.succ_end(), &cfg->getExit())
483  == B.succ_end()) {
484  HasAbnormalEdge = true;
485  continue;
486  }
487 
488  HasPlainEdge = true;
489  }
490  if (!HasPlainEdge) {
491  if (HasLiveReturn)
492  return NeverFallThrough;
494  }
495  if (HasAbnormalEdge || HasFakeEdge || HasLiveReturn)
496  return MaybeFallThrough;
497  // This says AlwaysFallThrough for calls to functions that are not marked
498  // noreturn, that don't return. If people would like this warning to be more
499  // accurate, such functions should be marked as noreturn.
500  return AlwaysFallThrough;
501 }
502 
503 namespace {
504 
505 struct CheckFallThroughDiagnostics {
506  unsigned diag_MaybeFallThrough_HasNoReturn;
507  unsigned diag_MaybeFallThrough_ReturnsNonVoid;
508  unsigned diag_AlwaysFallThrough_HasNoReturn;
509  unsigned diag_AlwaysFallThrough_ReturnsNonVoid;
510  unsigned diag_NeverFallThroughOrReturn;
511  enum { Function, Block, Lambda, Coroutine } funMode;
512  SourceLocation FuncLoc;
513 
514  static CheckFallThroughDiagnostics MakeForFunction(const Decl *Func) {
515  CheckFallThroughDiagnostics D;
516  D.FuncLoc = Func->getLocation();
517  D.diag_MaybeFallThrough_HasNoReturn =
518  diag::warn_falloff_noreturn_function;
519  D.diag_MaybeFallThrough_ReturnsNonVoid =
520  diag::warn_maybe_falloff_nonvoid_function;
521  D.diag_AlwaysFallThrough_HasNoReturn =
522  diag::warn_falloff_noreturn_function;
523  D.diag_AlwaysFallThrough_ReturnsNonVoid =
524  diag::warn_falloff_nonvoid_function;
525 
526  // Don't suggest that virtual functions be marked "noreturn", since they
527  // might be overridden by non-noreturn functions.
528  bool isVirtualMethod = false;
529  if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Func))
530  isVirtualMethod = Method->isVirtual();
531 
532  // Don't suggest that template instantiations be marked "noreturn"
533  bool isTemplateInstantiation = false;
534  if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(Func))
535  isTemplateInstantiation = Function->isTemplateInstantiation();
536 
537  if (!isVirtualMethod && !isTemplateInstantiation)
538  D.diag_NeverFallThroughOrReturn =
539  diag::warn_suggest_noreturn_function;
540  else
541  D.diag_NeverFallThroughOrReturn = 0;
542 
543  D.funMode = Function;
544  return D;
545  }
546 
547  static CheckFallThroughDiagnostics MakeForCoroutine(const Decl *Func) {
548  CheckFallThroughDiagnostics D;
549  D.FuncLoc = Func->getLocation();
550  D.diag_MaybeFallThrough_HasNoReturn = 0;
551  D.diag_MaybeFallThrough_ReturnsNonVoid =
552  diag::warn_maybe_falloff_nonvoid_coroutine;
553  D.diag_AlwaysFallThrough_HasNoReturn = 0;
554  D.diag_AlwaysFallThrough_ReturnsNonVoid =
555  diag::warn_falloff_nonvoid_coroutine;
556  D.funMode = Coroutine;
557  return D;
558  }
559 
560  static CheckFallThroughDiagnostics MakeForBlock() {
561  CheckFallThroughDiagnostics D;
562  D.diag_MaybeFallThrough_HasNoReturn =
563  diag::err_noreturn_block_has_return_expr;
564  D.diag_MaybeFallThrough_ReturnsNonVoid =
565  diag::err_maybe_falloff_nonvoid_block;
566  D.diag_AlwaysFallThrough_HasNoReturn =
567  diag::err_noreturn_block_has_return_expr;
568  D.diag_AlwaysFallThrough_ReturnsNonVoid =
569  diag::err_falloff_nonvoid_block;
570  D.diag_NeverFallThroughOrReturn = 0;
571  D.funMode = Block;
572  return D;
573  }
574 
575  static CheckFallThroughDiagnostics MakeForLambda() {
576  CheckFallThroughDiagnostics D;
577  D.diag_MaybeFallThrough_HasNoReturn =
578  diag::err_noreturn_lambda_has_return_expr;
579  D.diag_MaybeFallThrough_ReturnsNonVoid =
580  diag::warn_maybe_falloff_nonvoid_lambda;
581  D.diag_AlwaysFallThrough_HasNoReturn =
582  diag::err_noreturn_lambda_has_return_expr;
583  D.diag_AlwaysFallThrough_ReturnsNonVoid =
584  diag::warn_falloff_nonvoid_lambda;
585  D.diag_NeverFallThroughOrReturn = 0;
586  D.funMode = Lambda;
587  return D;
588  }
589 
590  bool checkDiagnostics(DiagnosticsEngine &D, bool ReturnsVoid,
591  bool HasNoReturn) const {
592  if (funMode == Function) {
593  return (ReturnsVoid ||
594  D.isIgnored(diag::warn_maybe_falloff_nonvoid_function,
595  FuncLoc)) &&
596  (!HasNoReturn ||
597  D.isIgnored(diag::warn_noreturn_function_has_return_expr,
598  FuncLoc)) &&
599  (!ReturnsVoid ||
600  D.isIgnored(diag::warn_suggest_noreturn_block, FuncLoc));
601  }
602  if (funMode == Coroutine) {
603  return (ReturnsVoid ||
604  D.isIgnored(diag::warn_maybe_falloff_nonvoid_function, FuncLoc) ||
605  D.isIgnored(diag::warn_maybe_falloff_nonvoid_coroutine,
606  FuncLoc)) &&
607  (!HasNoReturn);
608  }
609  // For blocks / lambdas.
610  return ReturnsVoid && !HasNoReturn;
611  }
612 };
613 
614 } // anonymous namespace
615 
616 /// CheckFallThroughForBody - Check that we don't fall off the end of a
617 /// function that should return a value. Check that we don't fall off the end
618 /// of a noreturn function. We assume that functions and blocks not marked
619 /// noreturn will return.
620 static void CheckFallThroughForBody(Sema &S, const Decl *D, const Stmt *Body,
621  const BlockExpr *blkExpr,
622  const CheckFallThroughDiagnostics &CD,
625 
626  bool ReturnsVoid = false;
627  bool HasNoReturn = false;
628  bool IsCoroutine = FSI->isCoroutine();
629 
630  if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
631  if (const auto *CBody = dyn_cast<CoroutineBodyStmt>(Body))
632  ReturnsVoid = CBody->getFallthroughHandler() != nullptr;
633  else
634  ReturnsVoid = FD->getReturnType()->isVoidType();
635  HasNoReturn = FD->isNoReturn();
636  }
637  else if (const auto *MD = dyn_cast<ObjCMethodDecl>(D)) {
638  ReturnsVoid = MD->getReturnType()->isVoidType();
639  HasNoReturn = MD->hasAttr<NoReturnAttr>();
640  }
641  else if (isa<BlockDecl>(D)) {
642  QualType BlockTy = blkExpr->getType();
643  if (const FunctionType *FT =
644  BlockTy->getPointeeType()->getAs<FunctionType>()) {
645  if (FT->getReturnType()->isVoidType())
646  ReturnsVoid = true;
647  if (FT->getNoReturnAttr())
648  HasNoReturn = true;
649  }
650  }
651 
652  DiagnosticsEngine &Diags = S.getDiagnostics();
653 
654  // Short circuit for compilation speed.
655  if (CD.checkDiagnostics(Diags, ReturnsVoid, HasNoReturn))
656  return;
657  SourceLocation LBrace = Body->getBeginLoc(), RBrace = Body->getEndLoc();
658  auto EmitDiag = [&](SourceLocation Loc, unsigned DiagID) {
659  if (IsCoroutine)
660  S.Diag(Loc, DiagID) << FSI->CoroutinePromise->getType();
661  else
662  S.Diag(Loc, DiagID);
663  };
664 
665  // cpu_dispatch functions permit empty function bodies for ICC compatibility.
667  return;
668 
669  // Either in a function body compound statement, or a function-try-block.
670  switch (CheckFallThrough(AC)) {
671  case UnknownFallThrough:
672  break;
673 
674  case MaybeFallThrough:
675  if (HasNoReturn)
676  EmitDiag(RBrace, CD.diag_MaybeFallThrough_HasNoReturn);
677  else if (!ReturnsVoid)
678  EmitDiag(RBrace, CD.diag_MaybeFallThrough_ReturnsNonVoid);
679  break;
680  case AlwaysFallThrough:
681  if (HasNoReturn)
682  EmitDiag(RBrace, CD.diag_AlwaysFallThrough_HasNoReturn);
683  else if (!ReturnsVoid)
684  EmitDiag(RBrace, CD.diag_AlwaysFallThrough_ReturnsNonVoid);
685  break;
687  if (ReturnsVoid && !HasNoReturn && CD.diag_NeverFallThroughOrReturn) {
688  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
689  S.Diag(LBrace, CD.diag_NeverFallThroughOrReturn) << 0 << FD;
690  } else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) {
691  S.Diag(LBrace, CD.diag_NeverFallThroughOrReturn) << 1 << MD;
692  } else {
693  S.Diag(LBrace, CD.diag_NeverFallThroughOrReturn);
694  }
695  }
696  break;
697  case NeverFallThrough:
698  break;
699  }
700 }
701 
702 //===----------------------------------------------------------------------===//
703 // -Wuninitialized
704 //===----------------------------------------------------------------------===//
705 
706 namespace {
707 /// ContainsReference - A visitor class to search for references to
708 /// a particular declaration (the needle) within any evaluated component of an
709 /// expression (recursively).
710 class ContainsReference : public ConstEvaluatedExprVisitor<ContainsReference> {
711  bool FoundReference;
712  const DeclRefExpr *Needle;
713 
714 public:
716 
717  ContainsReference(ASTContext &Context, const DeclRefExpr *Needle)
718  : Inherited(Context), FoundReference(false), Needle(Needle) {}
719 
720  void VisitExpr(const Expr *E) {
721  // Stop evaluating if we already have a reference.
722  if (FoundReference)
723  return;
724 
725  Inherited::VisitExpr(E);
726  }
727 
728  void VisitDeclRefExpr(const DeclRefExpr *E) {
729  if (E == Needle)
730  FoundReference = true;
731  else
732  Inherited::VisitDeclRefExpr(E);
733  }
734 
735  bool doesContainReference() const { return FoundReference; }
736 };
737 } // anonymous namespace
738 
739 static bool SuggestInitializationFixit(Sema &S, const VarDecl *VD) {
740  QualType VariableTy = VD->getType().getCanonicalType();
741  if (VariableTy->isBlockPointerType() &&
742  !VD->hasAttr<BlocksAttr>()) {
743  S.Diag(VD->getLocation(), diag::note_block_var_fixit_add_initialization)
744  << VD->getDeclName()
745  << FixItHint::CreateInsertion(VD->getLocation(), "__block ");
746  return true;
747  }
748 
749  // Don't issue a fixit if there is already an initializer.
750  if (VD->getInit())
751  return false;
752 
753  // Don't suggest a fixit inside macros.
754  if (VD->getEndLoc().isMacroID())
755  return false;
756 
758 
759  // Suggest possible initialization (if any).
760  std::string Init = S.getFixItZeroInitializerForType(VariableTy, Loc);
761  if (Init.empty())
762  return false;
763 
764  S.Diag(Loc, diag::note_var_fixit_add_initialization) << VD->getDeclName()
765  << FixItHint::CreateInsertion(Loc, Init);
766  return true;
767 }
768 
769 /// Create a fixit to remove an if-like statement, on the assumption that its
770 /// condition is CondVal.
771 static void CreateIfFixit(Sema &S, const Stmt *If, const Stmt *Then,
772  const Stmt *Else, bool CondVal,
773  FixItHint &Fixit1, FixItHint &Fixit2) {
774  if (CondVal) {
775  // If condition is always true, remove all but the 'then'.
776  Fixit1 = FixItHint::CreateRemoval(
778  if (Else) {
779  SourceLocation ElseKwLoc = S.getLocForEndOfToken(Then->getEndLoc());
780  Fixit2 =
781  FixItHint::CreateRemoval(SourceRange(ElseKwLoc, Else->getEndLoc()));
782  }
783  } else {
784  // If condition is always false, remove all but the 'else'.
785  if (Else)
787  If->getBeginLoc(), Else->getBeginLoc()));
788  else
790  }
791 }
792 
793 /// DiagUninitUse -- Helper function to produce a diagnostic for an
794 /// uninitialized use of a variable.
795 static void DiagUninitUse(Sema &S, const VarDecl *VD, const UninitUse &Use,
796  bool IsCapturedByBlock) {
797  bool Diagnosed = false;
798 
799  switch (Use.getKind()) {
800  case UninitUse::Always:
801  S.Diag(Use.getUser()->getBeginLoc(), diag::warn_uninit_var)
802  << VD->getDeclName() << IsCapturedByBlock
803  << Use.getUser()->getSourceRange();
804  return;
805 
808  S.Diag(VD->getLocation(), diag::warn_sometimes_uninit_var)
809  << VD->getDeclName() << IsCapturedByBlock
810  << (Use.getKind() == UninitUse::AfterDecl ? 4 : 5)
811  << const_cast<DeclContext*>(VD->getLexicalDeclContext())
812  << VD->getSourceRange();
813  S.Diag(Use.getUser()->getBeginLoc(), diag::note_uninit_var_use)
814  << IsCapturedByBlock << Use.getUser()->getSourceRange();
815  return;
816 
817  case UninitUse::Maybe:
819  // Carry on to report sometimes-uninitialized branches, if possible,
820  // or a 'may be used uninitialized' diagnostic otherwise.
821  break;
822  }
823 
824  // Diagnose each branch which leads to a sometimes-uninitialized use.
825  for (UninitUse::branch_iterator I = Use.branch_begin(), E = Use.branch_end();
826  I != E; ++I) {
827  assert(Use.getKind() == UninitUse::Sometimes);
828 
829  const Expr *User = Use.getUser();
830  const Stmt *Term = I->Terminator;
831 
832  // Information used when building the diagnostic.
833  unsigned DiagKind;
834  StringRef Str;
835  SourceRange Range;
836 
837  // FixIts to suppress the diagnostic by removing the dead condition.
838  // For all binary terminators, branch 0 is taken if the condition is true,
839  // and branch 1 is taken if the condition is false.
840  int RemoveDiagKind = -1;
841  const char *FixitStr =
842  S.getLangOpts().CPlusPlus ? (I->Output ? "true" : "false")
843  : (I->Output ? "1" : "0");
844  FixItHint Fixit1, Fixit2;
845 
846  switch (Term ? Term->getStmtClass() : Stmt::DeclStmtClass) {
847  default:
848  // Don't know how to report this. Just fall back to 'may be used
849  // uninitialized'. FIXME: Can this happen?
850  continue;
851 
852  // "condition is true / condition is false".
853  case Stmt::IfStmtClass: {
854  const IfStmt *IS = cast<IfStmt>(Term);
855  DiagKind = 0;
856  Str = "if";
857  Range = IS->getCond()->getSourceRange();
858  RemoveDiagKind = 0;
859  CreateIfFixit(S, IS, IS->getThen(), IS->getElse(),
860  I->Output, Fixit1, Fixit2);
861  break;
862  }
863  case Stmt::ConditionalOperatorClass: {
864  const ConditionalOperator *CO = cast<ConditionalOperator>(Term);
865  DiagKind = 0;
866  Str = "?:";
867  Range = CO->getCond()->getSourceRange();
868  RemoveDiagKind = 0;
869  CreateIfFixit(S, CO, CO->getTrueExpr(), CO->getFalseExpr(),
870  I->Output, Fixit1, Fixit2);
871  break;
872  }
873  case Stmt::BinaryOperatorClass: {
874  const BinaryOperator *BO = cast<BinaryOperator>(Term);
875  if (!BO->isLogicalOp())
876  continue;
877  DiagKind = 0;
878  Str = BO->getOpcodeStr();
879  Range = BO->getLHS()->getSourceRange();
880  RemoveDiagKind = 0;
881  if ((BO->getOpcode() == BO_LAnd && I->Output) ||
882  (BO->getOpcode() == BO_LOr && !I->Output))
883  // true && y -> y, false || y -> y.
884  Fixit1 = FixItHint::CreateRemoval(
885  SourceRange(BO->getBeginLoc(), BO->getOperatorLoc()));
886  else
887  // false && y -> false, true || y -> true.
888  Fixit1 = FixItHint::CreateReplacement(BO->getSourceRange(), FixitStr);
889  break;
890  }
891 
892  // "loop is entered / loop is exited".
893  case Stmt::WhileStmtClass:
894  DiagKind = 1;
895  Str = "while";
896  Range = cast<WhileStmt>(Term)->getCond()->getSourceRange();
897  RemoveDiagKind = 1;
898  Fixit1 = FixItHint::CreateReplacement(Range, FixitStr);
899  break;
900  case Stmt::ForStmtClass:
901  DiagKind = 1;
902  Str = "for";
903  Range = cast<ForStmt>(Term)->getCond()->getSourceRange();
904  RemoveDiagKind = 1;
905  if (I->Output)
906  Fixit1 = FixItHint::CreateRemoval(Range);
907  else
908  Fixit1 = FixItHint::CreateReplacement(Range, FixitStr);
909  break;
910  case Stmt::CXXForRangeStmtClass:
911  if (I->Output == 1) {
912  // The use occurs if a range-based for loop's body never executes.
913  // That may be impossible, and there's no syntactic fix for this,
914  // so treat it as a 'may be uninitialized' case.
915  continue;
916  }
917  DiagKind = 1;
918  Str = "for";
919  Range = cast<CXXForRangeStmt>(Term)->getRangeInit()->getSourceRange();
920  break;
921 
922  // "condition is true / loop is exited".
923  case Stmt::DoStmtClass:
924  DiagKind = 2;
925  Str = "do";
926  Range = cast<DoStmt>(Term)->getCond()->getSourceRange();
927  RemoveDiagKind = 1;
928  Fixit1 = FixItHint::CreateReplacement(Range, FixitStr);
929  break;
930 
931  // "switch case is taken".
932  case Stmt::CaseStmtClass:
933  DiagKind = 3;
934  Str = "case";
935  Range = cast<CaseStmt>(Term)->getLHS()->getSourceRange();
936  break;
937  case Stmt::DefaultStmtClass:
938  DiagKind = 3;
939  Str = "default";
940  Range = cast<DefaultStmt>(Term)->getDefaultLoc();
941  break;
942  }
943 
944  S.Diag(Range.getBegin(), diag::warn_sometimes_uninit_var)
945  << VD->getDeclName() << IsCapturedByBlock << DiagKind
946  << Str << I->Output << Range;
947  S.Diag(User->getBeginLoc(), diag::note_uninit_var_use)
948  << IsCapturedByBlock << User->getSourceRange();
949  if (RemoveDiagKind != -1)
950  S.Diag(Fixit1.RemoveRange.getBegin(), diag::note_uninit_fixit_remove_cond)
951  << RemoveDiagKind << Str << I->Output << Fixit1 << Fixit2;
952 
953  Diagnosed = true;
954  }
955 
956  if (!Diagnosed)
957  S.Diag(Use.getUser()->getBeginLoc(), diag::warn_maybe_uninit_var)
958  << VD->getDeclName() << IsCapturedByBlock
959  << Use.getUser()->getSourceRange();
960 }
961 
962 /// DiagnoseUninitializedUse -- Helper function for diagnosing uses of an
963 /// uninitialized variable. This manages the different forms of diagnostic
964 /// emitted for particular types of uses. Returns true if the use was diagnosed
965 /// as a warning. If a particular use is one we omit warnings for, returns
966 /// false.
967 static bool DiagnoseUninitializedUse(Sema &S, const VarDecl *VD,
968  const UninitUse &Use,
969  bool alwaysReportSelfInit = false) {
970  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Use.getUser())) {
971  // Inspect the initializer of the variable declaration which is
972  // being referenced prior to its initialization. We emit
973  // specialized diagnostics for self-initialization, and we
974  // specifically avoid warning about self references which take the
975  // form of:
976  //
977  // int x = x;
978  //
979  // This is used to indicate to GCC that 'x' is intentionally left
980  // uninitialized. Proven code paths which access 'x' in
981  // an uninitialized state after this will still warn.
982  if (const Expr *Initializer = VD->getInit()) {
983  if (!alwaysReportSelfInit && DRE == Initializer->IgnoreParenImpCasts())
984  return false;
985 
986  ContainsReference CR(S.Context, DRE);
987  CR.Visit(Initializer);
988  if (CR.doesContainReference()) {
989  S.Diag(DRE->getBeginLoc(), diag::warn_uninit_self_reference_in_init)
990  << VD->getDeclName() << VD->getLocation() << DRE->getSourceRange();
991  return true;
992  }
993  }
994 
995  DiagUninitUse(S, VD, Use, false);
996  } else {
997  const BlockExpr *BE = cast<BlockExpr>(Use.getUser());
998  if (VD->getType()->isBlockPointerType() && !VD->hasAttr<BlocksAttr>())
999  S.Diag(BE->getBeginLoc(),
1000  diag::warn_uninit_byref_blockvar_captured_by_block)
1001  << VD->getDeclName();
1002  else
1003  DiagUninitUse(S, VD, Use, true);
1004  }
1005 
1006  // Report where the variable was declared when the use wasn't within
1007  // the initializer of that declaration & we didn't already suggest
1008  // an initialization fixit.
1009  if (!SuggestInitializationFixit(S, VD))
1010  S.Diag(VD->getBeginLoc(), diag::note_var_declared_here)
1011  << VD->getDeclName();
1012 
1013  return true;
1014 }
1015 
1016 namespace {
1017  class FallthroughMapper : public RecursiveASTVisitor<FallthroughMapper> {
1018  public:
1019  FallthroughMapper(Sema &S)
1020  : FoundSwitchStatements(false),
1021  S(S) {
1022  }
1023 
1024  bool foundSwitchStatements() const { return FoundSwitchStatements; }
1025 
1026  void markFallthroughVisited(const AttributedStmt *Stmt) {
1027  bool Found = FallthroughStmts.erase(Stmt);
1028  assert(Found);
1029  (void)Found;
1030  }
1031 
1032  typedef llvm::SmallPtrSet<const AttributedStmt*, 8> AttrStmts;
1033 
1034  const AttrStmts &getFallthroughStmts() const {
1035  return FallthroughStmts;
1036  }
1037 
1038  void fillReachableBlocks(CFG *Cfg) {
1039  assert(ReachableBlocks.empty() && "ReachableBlocks already filled");
1040  std::deque<const CFGBlock *> BlockQueue;
1041 
1042  ReachableBlocks.insert(&Cfg->getEntry());
1043  BlockQueue.push_back(&Cfg->getEntry());
1044  // Mark all case blocks reachable to avoid problems with switching on
1045  // constants, covered enums, etc.
1046  // These blocks can contain fall-through annotations, and we don't want to
1047  // issue a warn_fallthrough_attr_unreachable for them.
1048  for (const auto *B : *Cfg) {
1049  const Stmt *L = B->getLabel();
1050  if (L && isa<SwitchCase>(L) && ReachableBlocks.insert(B).second)
1051  BlockQueue.push_back(B);
1052  }
1053 
1054  while (!BlockQueue.empty()) {
1055  const CFGBlock *P = BlockQueue.front();
1056  BlockQueue.pop_front();
1058  E = P->succ_end();
1059  I != E; ++I) {
1060  if (*I && ReachableBlocks.insert(*I).second)
1061  BlockQueue.push_back(*I);
1062  }
1063  }
1064  }
1065 
1066  bool checkFallThroughIntoBlock(const CFGBlock &B, int &AnnotatedCnt,
1067  bool IsTemplateInstantiation) {
1068  assert(!ReachableBlocks.empty() && "ReachableBlocks empty");
1069 
1070  int UnannotatedCnt = 0;
1071  AnnotatedCnt = 0;
1072 
1073  std::deque<const CFGBlock*> BlockQueue(B.pred_begin(), B.pred_end());
1074  while (!BlockQueue.empty()) {
1075  const CFGBlock *P = BlockQueue.front();
1076  BlockQueue.pop_front();
1077  if (!P) continue;
1078 
1079  const Stmt *Term = P->getTerminator();
1080  if (Term && isa<SwitchStmt>(Term))
1081  continue; // Switch statement, good.
1082 
1083  const SwitchCase *SW = dyn_cast_or_null<SwitchCase>(P->getLabel());
1084  if (SW && SW->getSubStmt() == B.getLabel() && P->begin() == P->end())
1085  continue; // Previous case label has no statements, good.
1086 
1087  const LabelStmt *L = dyn_cast_or_null<LabelStmt>(P->getLabel());
1088  if (L && L->getSubStmt() == B.getLabel() && P->begin() == P->end())
1089  continue; // Case label is preceded with a normal label, good.
1090 
1091  if (!ReachableBlocks.count(P)) {
1092  for (CFGBlock::const_reverse_iterator ElemIt = P->rbegin(),
1093  ElemEnd = P->rend();
1094  ElemIt != ElemEnd; ++ElemIt) {
1095  if (Optional<CFGStmt> CS = ElemIt->getAs<CFGStmt>()) {
1096  if (const AttributedStmt *AS = asFallThroughAttr(CS->getStmt())) {
1097  // Don't issue a warning for an unreachable fallthrough
1098  // attribute in template instantiations as it may not be
1099  // unreachable in all instantiations of the template.
1100  if (!IsTemplateInstantiation)
1101  S.Diag(AS->getBeginLoc(),
1102  diag::warn_fallthrough_attr_unreachable);
1103  markFallthroughVisited(AS);
1104  ++AnnotatedCnt;
1105  break;
1106  }
1107  // Don't care about other unreachable statements.
1108  }
1109  }
1110  // If there are no unreachable statements, this may be a special
1111  // case in CFG:
1112  // case X: {
1113  // A a; // A has a destructor.
1114  // break;
1115  // }
1116  // // <<<< This place is represented by a 'hanging' CFG block.
1117  // case Y:
1118  continue;
1119  }
1120 
1121  const Stmt *LastStmt = getLastStmt(*P);
1122  if (const AttributedStmt *AS = asFallThroughAttr(LastStmt)) {
1123  markFallthroughVisited(AS);
1124  ++AnnotatedCnt;
1125  continue; // Fallthrough annotation, good.
1126  }
1127 
1128  if (!LastStmt) { // This block contains no executable statements.
1129  // Traverse its predecessors.
1130  std::copy(P->pred_begin(), P->pred_end(),
1131  std::back_inserter(BlockQueue));
1132  continue;
1133  }
1134 
1135  ++UnannotatedCnt;
1136  }
1137  return !!UnannotatedCnt;
1138  }
1139 
1140  // RecursiveASTVisitor setup.
1141  bool shouldWalkTypesOfTypeLocs() const { return false; }
1142 
1143  bool VisitAttributedStmt(AttributedStmt *S) {
1144  if (asFallThroughAttr(S))
1145  FallthroughStmts.insert(S);
1146  return true;
1147  }
1148 
1149  bool VisitSwitchStmt(SwitchStmt *S) {
1150  FoundSwitchStatements = true;
1151  return true;
1152  }
1153 
1154  // We don't want to traverse local type declarations. We analyze their
1155  // methods separately.
1156  bool TraverseDecl(Decl *D) { return true; }
1157 
1158  // We analyze lambda bodies separately. Skip them here.
1159  bool TraverseLambdaExpr(LambdaExpr *LE) {
1160  // Traverse the captures, but not the body.
1161  for (const auto &C : zip(LE->captures(), LE->capture_inits()))
1162  TraverseLambdaCapture(LE, &std::get<0>(C), std::get<1>(C));
1163  return true;
1164  }
1165 
1166  private:
1167 
1168  static const AttributedStmt *asFallThroughAttr(const Stmt *S) {
1169  if (const AttributedStmt *AS = dyn_cast_or_null<AttributedStmt>(S)) {
1170  if (hasSpecificAttr<FallThroughAttr>(AS->getAttrs()))
1171  return AS;
1172  }
1173  return nullptr;
1174  }
1175 
1176  static const Stmt *getLastStmt(const CFGBlock &B) {
1177  if (const Stmt *Term = B.getTerminator())
1178  return Term;
1179  for (CFGBlock::const_reverse_iterator ElemIt = B.rbegin(),
1180  ElemEnd = B.rend();
1181  ElemIt != ElemEnd; ++ElemIt) {
1182  if (Optional<CFGStmt> CS = ElemIt->getAs<CFGStmt>())
1183  return CS->getStmt();
1184  }
1185  // Workaround to detect a statement thrown out by CFGBuilder:
1186  // case X: {} case Y:
1187  // case X: ; case Y:
1188  if (const SwitchCase *SW = dyn_cast_or_null<SwitchCase>(B.getLabel()))
1189  if (!isa<SwitchCase>(SW->getSubStmt()))
1190  return SW->getSubStmt();
1191 
1192  return nullptr;
1193  }
1194 
1195  bool FoundSwitchStatements;
1196  AttrStmts FallthroughStmts;
1197  Sema &S;
1198  llvm::SmallPtrSet<const CFGBlock *, 16> ReachableBlocks;
1199  };
1200 } // anonymous namespace
1201 
1203  SourceLocation Loc) {
1204  TokenValue FallthroughTokens[] = {
1205  tok::l_square, tok::l_square,
1206  PP.getIdentifierInfo("fallthrough"),
1207  tok::r_square, tok::r_square
1208  };
1209 
1210  TokenValue ClangFallthroughTokens[] = {
1211  tok::l_square, tok::l_square, PP.getIdentifierInfo("clang"),
1212  tok::coloncolon, PP.getIdentifierInfo("fallthrough"),
1213  tok::r_square, tok::r_square
1214  };
1215 
1216  bool PreferClangAttr = !PP.getLangOpts().CPlusPlus17;
1217 
1218  StringRef MacroName;
1219  if (PreferClangAttr)
1220  MacroName = PP.getLastMacroWithSpelling(Loc, ClangFallthroughTokens);
1221  if (MacroName.empty())
1222  MacroName = PP.getLastMacroWithSpelling(Loc, FallthroughTokens);
1223  if (MacroName.empty() && !PreferClangAttr)
1224  MacroName = PP.getLastMacroWithSpelling(Loc, ClangFallthroughTokens);
1225  if (MacroName.empty())
1226  MacroName = PreferClangAttr ? "[[clang::fallthrough]]" : "[[fallthrough]]";
1227  return MacroName;
1228 }
1229 
1231  bool PerFunction) {
1232  // Only perform this analysis when using [[]] attributes. There is no good
1233  // workflow for this warning when not using C++11. There is no good way to
1234  // silence the warning (no attribute is available) unless we are using
1235  // [[]] attributes. One could use pragmas to silence the warning, but as a
1236  // general solution that is gross and not in the spirit of this warning.
1237  //
1238  // NOTE: This an intermediate solution. There are on-going discussions on
1239  // how to properly support this warning outside of C++11 with an annotation.
1240  if (!AC.getASTContext().getLangOpts().DoubleSquareBracketAttributes)
1241  return;
1242 
1243  FallthroughMapper FM(S);
1244  FM.TraverseStmt(AC.getBody());
1245 
1246  if (!FM.foundSwitchStatements())
1247  return;
1248 
1249  if (PerFunction && FM.getFallthroughStmts().empty())
1250  return;
1251 
1252  CFG *Cfg = AC.getCFG();
1253 
1254  if (!Cfg)
1255  return;
1256 
1257  FM.fillReachableBlocks(Cfg);
1258 
1259  for (const CFGBlock *B : llvm::reverse(*Cfg)) {
1260  const Stmt *Label = B->getLabel();
1261 
1262  if (!Label || !isa<SwitchCase>(Label))
1263  continue;
1264 
1265  int AnnotatedCnt;
1266 
1267  bool IsTemplateInstantiation = false;
1268  if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(AC.getDecl()))
1269  IsTemplateInstantiation = Function->isTemplateInstantiation();
1270  if (!FM.checkFallThroughIntoBlock(*B, AnnotatedCnt,
1271  IsTemplateInstantiation))
1272  continue;
1273 
1274  S.Diag(Label->getBeginLoc(),
1275  PerFunction ? diag::warn_unannotated_fallthrough_per_function
1276  : diag::warn_unannotated_fallthrough);
1277 
1278  if (!AnnotatedCnt) {
1279  SourceLocation L = Label->getBeginLoc();
1280  if (L.isMacroID())
1281  continue;
1282  if (S.getLangOpts().CPlusPlus11) {
1283  const Stmt *Term = B->getTerminator();
1284  // Skip empty cases.
1285  while (B->empty() && !Term && B->succ_size() == 1) {
1286  B = *B->succ_begin();
1287  Term = B->getTerminator();
1288  }
1289  if (!(B->empty() && Term && isa<BreakStmt>(Term))) {
1290  Preprocessor &PP = S.getPreprocessor();
1291  StringRef AnnotationSpelling = getFallthroughAttrSpelling(PP, L);
1292  SmallString<64> TextToInsert(AnnotationSpelling);
1293  TextToInsert += "; ";
1294  S.Diag(L, diag::note_insert_fallthrough_fixit) <<
1295  AnnotationSpelling <<
1296  FixItHint::CreateInsertion(L, TextToInsert);
1297  }
1298  }
1299  S.Diag(L, diag::note_insert_break_fixit) <<
1300  FixItHint::CreateInsertion(L, "break; ");
1301  }
1302  }
1303 
1304  for (const auto *F : FM.getFallthroughStmts())
1305  S.Diag(F->getBeginLoc(), diag::err_fallthrough_attr_invalid_placement);
1306 }
1307 
1308 static bool isInLoop(const ASTContext &Ctx, const ParentMap &PM,
1309  const Stmt *S) {
1310  assert(S);
1311 
1312  do {
1313  switch (S->getStmtClass()) {
1314  case Stmt::ForStmtClass:
1315  case Stmt::WhileStmtClass:
1316  case Stmt::CXXForRangeStmtClass:
1317  case Stmt::ObjCForCollectionStmtClass:
1318  return true;
1319  case Stmt::DoStmtClass: {
1321  if (!cast<DoStmt>(S)->getCond()->EvaluateAsInt(Result, Ctx))
1322  return true;
1323  return Result.Val.getInt().getBoolValue();
1324  }
1325  default:
1326  break;
1327  }
1328  } while ((S = PM.getParent(S)));
1329 
1330  return false;
1331 }
1332 
1334  const sema::FunctionScopeInfo *CurFn,
1335  const Decl *D,
1336  const ParentMap &PM) {
1337  typedef sema::FunctionScopeInfo::WeakObjectProfileTy WeakObjectProfileTy;
1338  typedef sema::FunctionScopeInfo::WeakObjectUseMap WeakObjectUseMap;
1339  typedef sema::FunctionScopeInfo::WeakUseVector WeakUseVector;
1340  typedef std::pair<const Stmt *, WeakObjectUseMap::const_iterator>
1341  StmtUsesPair;
1342 
1343  ASTContext &Ctx = S.getASTContext();
1344 
1345  const WeakObjectUseMap &WeakMap = CurFn->getWeakObjectUses();
1346 
1347  // Extract all weak objects that are referenced more than once.
1348  SmallVector<StmtUsesPair, 8> UsesByStmt;
1349  for (WeakObjectUseMap::const_iterator I = WeakMap.begin(), E = WeakMap.end();
1350  I != E; ++I) {
1351  const WeakUseVector &Uses = I->second;
1352 
1353  // Find the first read of the weak object.
1354  WeakUseVector::const_iterator UI = Uses.begin(), UE = Uses.end();
1355  for ( ; UI != UE; ++UI) {
1356  if (UI->isUnsafe())
1357  break;
1358  }
1359 
1360  // If there were only writes to this object, don't warn.
1361  if (UI == UE)
1362  continue;
1363 
1364  // If there was only one read, followed by any number of writes, and the
1365  // read is not within a loop, don't warn. Additionally, don't warn in a
1366  // loop if the base object is a local variable -- local variables are often
1367  // changed in loops.
1368  if (UI == Uses.begin()) {
1369  WeakUseVector::const_iterator UI2 = UI;
1370  for (++UI2; UI2 != UE; ++UI2)
1371  if (UI2->isUnsafe())
1372  break;
1373 
1374  if (UI2 == UE) {
1375  if (!isInLoop(Ctx, PM, UI->getUseExpr()))
1376  continue;
1377 
1378  const WeakObjectProfileTy &Profile = I->first;
1379  if (!Profile.isExactProfile())
1380  continue;
1381 
1382  const NamedDecl *Base = Profile.getBase();
1383  if (!Base)
1384  Base = Profile.getProperty();
1385  assert(Base && "A profile always has a base or property.");
1386 
1387  if (const VarDecl *BaseVar = dyn_cast<VarDecl>(Base))
1388  if (BaseVar->hasLocalStorage() && !isa<ParmVarDecl>(Base))
1389  continue;
1390  }
1391  }
1392 
1393  UsesByStmt.push_back(StmtUsesPair(UI->getUseExpr(), I));
1394  }
1395 
1396  if (UsesByStmt.empty())
1397  return;
1398 
1399  // Sort by first use so that we emit the warnings in a deterministic order.
1401  llvm::sort(UsesByStmt,
1402  [&SM](const StmtUsesPair &LHS, const StmtUsesPair &RHS) {
1403  return SM.isBeforeInTranslationUnit(LHS.first->getBeginLoc(),
1404  RHS.first->getBeginLoc());
1405  });
1406 
1407  // Classify the current code body for better warning text.
1408  // This enum should stay in sync with the cases in
1409  // warn_arc_repeated_use_of_weak and warn_arc_possible_repeated_use_of_weak.
1410  // FIXME: Should we use a common classification enum and the same set of
1411  // possibilities all throughout Sema?
1412  enum {
1413  Function,
1414  Method,
1415  Block,
1416  Lambda
1417  } FunctionKind;
1418 
1419  if (isa<sema::BlockScopeInfo>(CurFn))
1420  FunctionKind = Block;
1421  else if (isa<sema::LambdaScopeInfo>(CurFn))
1422  FunctionKind = Lambda;
1423  else if (isa<ObjCMethodDecl>(D))
1424  FunctionKind = Method;
1425  else
1426  FunctionKind = Function;
1427 
1428  // Iterate through the sorted problems and emit warnings for each.
1429  for (const auto &P : UsesByStmt) {
1430  const Stmt *FirstRead = P.first;
1431  const WeakObjectProfileTy &Key = P.second->first;
1432  const WeakUseVector &Uses = P.second->second;
1433 
1434  // For complicated expressions like 'a.b.c' and 'x.b.c', WeakObjectProfileTy
1435  // may not contain enough information to determine that these are different
1436  // properties. We can only be 100% sure of a repeated use in certain cases,
1437  // and we adjust the diagnostic kind accordingly so that the less certain
1438  // case can be turned off if it is too noisy.
1439  unsigned DiagKind;
1440  if (Key.isExactProfile())
1441  DiagKind = diag::warn_arc_repeated_use_of_weak;
1442  else
1443  DiagKind = diag::warn_arc_possible_repeated_use_of_weak;
1444 
1445  // Classify the weak object being accessed for better warning text.
1446  // This enum should stay in sync with the cases in
1447  // warn_arc_repeated_use_of_weak and warn_arc_possible_repeated_use_of_weak.
1448  enum {
1449  Variable,
1450  Property,
1451  ImplicitProperty,
1452  Ivar
1453  } ObjectKind;
1454 
1455  const NamedDecl *KeyProp = Key.getProperty();
1456  if (isa<VarDecl>(KeyProp))
1457  ObjectKind = Variable;
1458  else if (isa<ObjCPropertyDecl>(KeyProp))
1459  ObjectKind = Property;
1460  else if (isa<ObjCMethodDecl>(KeyProp))
1461  ObjectKind = ImplicitProperty;
1462  else if (isa<ObjCIvarDecl>(KeyProp))
1463  ObjectKind = Ivar;
1464  else
1465  llvm_unreachable("Unexpected weak object kind!");
1466 
1467  // Do not warn about IBOutlet weak property receivers being set to null
1468  // since they are typically only used from the main thread.
1469  if (const ObjCPropertyDecl *Prop = dyn_cast<ObjCPropertyDecl>(KeyProp))
1470  if (Prop->hasAttr<IBOutletAttr>())
1471  continue;
1472 
1473  // Show the first time the object was read.
1474  S.Diag(FirstRead->getBeginLoc(), DiagKind)
1475  << int(ObjectKind) << KeyProp << int(FunctionKind)
1476  << FirstRead->getSourceRange();
1477 
1478  // Print all the other accesses as notes.
1479  for (const auto &Use : Uses) {
1480  if (Use.getUseExpr() == FirstRead)
1481  continue;
1482  S.Diag(Use.getUseExpr()->getBeginLoc(),
1483  diag::note_arc_weak_also_accessed_here)
1484  << Use.getUseExpr()->getSourceRange();
1485  }
1486  }
1487 }
1488 
1489 namespace {
1490 class UninitValsDiagReporter : public UninitVariablesHandler {
1491  Sema &S;
1492  typedef SmallVector<UninitUse, 2> UsesVec;
1493  typedef llvm::PointerIntPair<UsesVec *, 1, bool> MappedType;
1494  // Prefer using MapVector to DenseMap, so that iteration order will be
1495  // the same as insertion order. This is needed to obtain a deterministic
1496  // order of diagnostics when calling flushDiagnostics().
1497  typedef llvm::MapVector<const VarDecl *, MappedType> UsesMap;
1498  UsesMap uses;
1499 
1500 public:
1501  UninitValsDiagReporter(Sema &S) : S(S) {}
1502  ~UninitValsDiagReporter() override { flushDiagnostics(); }
1503 
1504  MappedType &getUses(const VarDecl *vd) {
1505  MappedType &V = uses[vd];
1506  if (!V.getPointer())
1507  V.setPointer(new UsesVec());
1508  return V;
1509  }
1510 
1511  void handleUseOfUninitVariable(const VarDecl *vd,
1512  const UninitUse &use) override {
1513  getUses(vd).getPointer()->push_back(use);
1514  }
1515 
1516  void handleSelfInit(const VarDecl *vd) override {
1517  getUses(vd).setInt(true);
1518  }
1519 
1520  void flushDiagnostics() {
1521  for (const auto &P : uses) {
1522  const VarDecl *vd = P.first;
1523  const MappedType &V = P.second;
1524 
1525  UsesVec *vec = V.getPointer();
1526  bool hasSelfInit = V.getInt();
1527 
1528  // Specially handle the case where we have uses of an uninitialized
1529  // variable, but the root cause is an idiomatic self-init. We want
1530  // to report the diagnostic at the self-init since that is the root cause.
1531  if (!vec->empty() && hasSelfInit && hasAlwaysUninitializedUse(vec))
1534  /* isAlwaysUninit */ true),
1535  /* alwaysReportSelfInit */ true);
1536  else {
1537  // Sort the uses by their SourceLocations. While not strictly
1538  // guaranteed to produce them in line/column order, this will provide
1539  // a stable ordering.
1540  llvm::sort(vec->begin(), vec->end(),
1541  [](const UninitUse &a, const UninitUse &b) {
1542  // Prefer a more confident report over a less confident one.
1543  if (a.getKind() != b.getKind())
1544  return a.getKind() > b.getKind();
1545  return a.getUser()->getBeginLoc() < b.getUser()->getBeginLoc();
1546  });
1547 
1548  for (const auto &U : *vec) {
1549  // If we have self-init, downgrade all uses to 'may be uninitialized'.
1550  UninitUse Use = hasSelfInit ? UninitUse(U.getUser(), false) : U;
1551 
1552  if (DiagnoseUninitializedUse(S, vd, Use))
1553  // Skip further diagnostics for this variable. We try to warn only
1554  // on the first point at which a variable is used uninitialized.
1555  break;
1556  }
1557  }
1558 
1559  // Release the uses vector.
1560  delete vec;
1561  }
1562 
1563  uses.clear();
1564  }
1565 
1566 private:
1567  static bool hasAlwaysUninitializedUse(const UsesVec* vec) {
1568  return std::any_of(vec->begin(), vec->end(), [](const UninitUse &U) {
1569  return U.getKind() == UninitUse::Always ||
1570  U.getKind() == UninitUse::AfterCall ||
1571  U.getKind() == UninitUse::AfterDecl;
1572  });
1573  }
1574 };
1575 } // anonymous namespace
1576 
1577 namespace clang {
1578 namespace {
1580 typedef std::pair<PartialDiagnosticAt, OptionalNotes> DelayedDiag;
1581 typedef std::list<DelayedDiag> DiagList;
1582 
1583 struct SortDiagBySourceLocation {
1585  SortDiagBySourceLocation(SourceManager &SM) : SM(SM) {}
1586 
1587  bool operator()(const DelayedDiag &left, const DelayedDiag &right) {
1588  // Although this call will be slow, this is only called when outputting
1589  // multiple warnings.
1590  return SM.isBeforeInTranslationUnit(left.first.first, right.first.first);
1591  }
1592 };
1593 } // anonymous namespace
1594 } // namespace clang
1595 
1596 //===----------------------------------------------------------------------===//
1597 // -Wthread-safety
1598 //===----------------------------------------------------------------------===//
1599 namespace clang {
1600 namespace threadSafety {
1601 namespace {
1602 class ThreadSafetyReporter : public clang::threadSafety::ThreadSafetyHandler {
1603  Sema &S;
1604  DiagList Warnings;
1605  SourceLocation FunLocation, FunEndLocation;
1606 
1607  const FunctionDecl *CurrentFunction;
1608  bool Verbose;
1609 
1610  OptionalNotes getNotes() const {
1611  if (Verbose && CurrentFunction) {
1612  PartialDiagnosticAt FNote(CurrentFunction->getBody()->getBeginLoc(),
1613  S.PDiag(diag::note_thread_warning_in_fun)
1614  << CurrentFunction);
1615  return OptionalNotes(1, FNote);
1616  }
1617  return OptionalNotes();
1618  }
1619 
1620  OptionalNotes getNotes(const PartialDiagnosticAt &Note) const {
1621  OptionalNotes ONS(1, Note);
1622  if (Verbose && CurrentFunction) {
1623  PartialDiagnosticAt FNote(CurrentFunction->getBody()->getBeginLoc(),
1624  S.PDiag(diag::note_thread_warning_in_fun)
1625  << CurrentFunction);
1626  ONS.push_back(std::move(FNote));
1627  }
1628  return ONS;
1629  }
1630 
1631  OptionalNotes getNotes(const PartialDiagnosticAt &Note1,
1632  const PartialDiagnosticAt &Note2) const {
1633  OptionalNotes ONS;
1634  ONS.push_back(Note1);
1635  ONS.push_back(Note2);
1636  if (Verbose && CurrentFunction) {
1637  PartialDiagnosticAt FNote(CurrentFunction->getBody()->getBeginLoc(),
1638  S.PDiag(diag::note_thread_warning_in_fun)
1639  << CurrentFunction);
1640  ONS.push_back(std::move(FNote));
1641  }
1642  return ONS;
1643  }
1644 
1645  public:
1646  ThreadSafetyReporter(Sema &S, SourceLocation FL, SourceLocation FEL)
1647  : S(S), FunLocation(FL), FunEndLocation(FEL),
1648  CurrentFunction(nullptr), Verbose(false) {}
1649 
1650  void setVerbose(bool b) { Verbose = b; }
1651 
1652  /// Emit all buffered diagnostics in order of sourcelocation.
1653  /// We need to output diagnostics produced while iterating through
1654  /// the lockset in deterministic order, so this function orders diagnostics
1655  /// and outputs them.
1656  void emitDiagnostics() {
1657  Warnings.sort(SortDiagBySourceLocation(S.getSourceManager()));
1658  for (const auto &Diag : Warnings) {
1659  S.Diag(Diag.first.first, Diag.first.second);
1660  for (const auto &Note : Diag.second)
1661  S.Diag(Note.first, Note.second);
1662  }
1663  }
1664 
1665  void handleInvalidLockExp(StringRef Kind, SourceLocation Loc) override {
1666  PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_cannot_resolve_lock)
1667  << Loc);
1668  Warnings.emplace_back(std::move(Warning), getNotes());
1669  }
1670 
1671  void handleUnmatchedUnlock(StringRef Kind, Name LockName,
1672  SourceLocation Loc) override {
1673  if (Loc.isInvalid())
1674  Loc = FunLocation;
1675  PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_unlock_but_no_lock)
1676  << Kind << LockName);
1677  Warnings.emplace_back(std::move(Warning), getNotes());
1678  }
1679 
1680  void handleIncorrectUnlockKind(StringRef Kind, Name LockName,
1681  LockKind Expected, LockKind Received,
1682  SourceLocation Loc) override {
1683  if (Loc.isInvalid())
1684  Loc = FunLocation;
1685  PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_unlock_kind_mismatch)
1686  << Kind << LockName << Received
1687  << Expected);
1688  Warnings.emplace_back(std::move(Warning), getNotes());
1689  }
1690 
1691  void handleDoubleLock(StringRef Kind, Name LockName, SourceLocation LocLocked,
1692  SourceLocation Loc) override {
1693  if (Loc.isInvalid())
1694  Loc = FunLocation;
1695  PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_double_lock)
1696  << Kind << LockName);
1697  OptionalNotes Notes =
1698  LocLocked.isValid()
1699  ? getNotes(PartialDiagnosticAt(
1700  LocLocked, S.PDiag(diag::note_locked_here) << Kind))
1701  : getNotes();
1702  Warnings.emplace_back(std::move(Warning), std::move(Notes));
1703  }
1704 
1705  void handleMutexHeldEndOfScope(StringRef Kind, Name LockName,
1706  SourceLocation LocLocked,
1707  SourceLocation LocEndOfScope,
1708  LockErrorKind LEK) override {
1709  unsigned DiagID = 0;
1710  switch (LEK) {
1712  DiagID = diag::warn_lock_some_predecessors;
1713  break;
1715  DiagID = diag::warn_expecting_lock_held_on_loop;
1716  break;
1718  DiagID = diag::warn_no_unlock;
1719  break;
1721  DiagID = diag::warn_expecting_locked;
1722  break;
1723  }
1724  if (LocEndOfScope.isInvalid())
1725  LocEndOfScope = FunEndLocation;
1726 
1727  PartialDiagnosticAt Warning(LocEndOfScope, S.PDiag(DiagID) << Kind
1728  << LockName);
1729  if (LocLocked.isValid()) {
1730  PartialDiagnosticAt Note(LocLocked, S.PDiag(diag::note_locked_here)
1731  << Kind);
1732  Warnings.emplace_back(std::move(Warning), getNotes(Note));
1733  return;
1734  }
1735  Warnings.emplace_back(std::move(Warning), getNotes());
1736  }
1737 
1738  void handleExclusiveAndShared(StringRef Kind, Name LockName,
1739  SourceLocation Loc1,
1740  SourceLocation Loc2) override {
1742  S.PDiag(diag::warn_lock_exclusive_and_shared)
1743  << Kind << LockName);
1744  PartialDiagnosticAt Note(Loc2, S.PDiag(diag::note_lock_exclusive_and_shared)
1745  << Kind << LockName);
1746  Warnings.emplace_back(std::move(Warning), getNotes(Note));
1747  }
1748 
1749  void handleNoMutexHeld(StringRef Kind, const NamedDecl *D,
1751  SourceLocation Loc) override {
1752  assert((POK == POK_VarAccess || POK == POK_VarDereference) &&
1753  "Only works for variables");
1754  unsigned DiagID = POK == POK_VarAccess?
1755  diag::warn_variable_requires_any_lock:
1756  diag::warn_var_deref_requires_any_lock;
1757  PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID)
1758  << D << getLockKindFromAccessKind(AK));
1759  Warnings.emplace_back(std::move(Warning), getNotes());
1760  }
1761 
1762  void handleMutexNotHeld(StringRef Kind, const NamedDecl *D,
1763  ProtectedOperationKind POK, Name LockName,
1764  LockKind LK, SourceLocation Loc,
1765  Name *PossibleMatch) override {
1766  unsigned DiagID = 0;
1767  if (PossibleMatch) {
1768  switch (POK) {
1769  case POK_VarAccess:
1770  DiagID = diag::warn_variable_requires_lock_precise;
1771  break;
1772  case POK_VarDereference:
1773  DiagID = diag::warn_var_deref_requires_lock_precise;
1774  break;
1775  case POK_FunctionCall:
1776  DiagID = diag::warn_fun_requires_lock_precise;
1777  break;
1778  case POK_PassByRef:
1779  DiagID = diag::warn_guarded_pass_by_reference;
1780  break;
1781  case POK_PtPassByRef:
1782  DiagID = diag::warn_pt_guarded_pass_by_reference;
1783  break;
1784  }
1785  PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID) << Kind
1786  << D
1787  << LockName << LK);
1788  PartialDiagnosticAt Note(Loc, S.PDiag(diag::note_found_mutex_near_match)
1789  << *PossibleMatch);
1790  if (Verbose && POK == POK_VarAccess) {
1791  PartialDiagnosticAt VNote(D->getLocation(),
1792  S.PDiag(diag::note_guarded_by_declared_here)
1793  << D->getNameAsString());
1794  Warnings.emplace_back(std::move(Warning), getNotes(Note, VNote));
1795  } else
1796  Warnings.emplace_back(std::move(Warning), getNotes(Note));
1797  } else {
1798  switch (POK) {
1799  case POK_VarAccess:
1800  DiagID = diag::warn_variable_requires_lock;
1801  break;
1802  case POK_VarDereference:
1803  DiagID = diag::warn_var_deref_requires_lock;
1804  break;
1805  case POK_FunctionCall:
1806  DiagID = diag::warn_fun_requires_lock;
1807  break;
1808  case POK_PassByRef:
1809  DiagID = diag::warn_guarded_pass_by_reference;
1810  break;
1811  case POK_PtPassByRef:
1812  DiagID = diag::warn_pt_guarded_pass_by_reference;
1813  break;
1814  }
1815  PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID) << Kind
1816  << D
1817  << LockName << LK);
1818  if (Verbose && POK == POK_VarAccess) {
1820  S.PDiag(diag::note_guarded_by_declared_here));
1821  Warnings.emplace_back(std::move(Warning), getNotes(Note));
1822  } else
1823  Warnings.emplace_back(std::move(Warning), getNotes());
1824  }
1825  }
1826 
1827  void handleNegativeNotHeld(StringRef Kind, Name LockName, Name Neg,
1828  SourceLocation Loc) override {
1830  S.PDiag(diag::warn_acquire_requires_negative_cap)
1831  << Kind << LockName << Neg);
1832  Warnings.emplace_back(std::move(Warning), getNotes());
1833  }
1834 
1835  void handleFunExcludesLock(StringRef Kind, Name FunName, Name LockName,
1836  SourceLocation Loc) override {
1837  PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_fun_excludes_mutex)
1838  << Kind << FunName << LockName);
1839  Warnings.emplace_back(std::move(Warning), getNotes());
1840  }
1841 
1842  void handleLockAcquiredBefore(StringRef Kind, Name L1Name, Name L2Name,
1843  SourceLocation Loc) override {
1845  S.PDiag(diag::warn_acquired_before) << Kind << L1Name << L2Name);
1846  Warnings.emplace_back(std::move(Warning), getNotes());
1847  }
1848 
1849  void handleBeforeAfterCycle(Name L1Name, SourceLocation Loc) override {
1851  S.PDiag(diag::warn_acquired_before_after_cycle) << L1Name);
1852  Warnings.emplace_back(std::move(Warning), getNotes());
1853  }
1854 
1855  void enterFunction(const FunctionDecl* FD) override {
1856  CurrentFunction = FD;
1857  }
1858 
1859  void leaveFunction(const FunctionDecl* FD) override {
1860  CurrentFunction = nullptr;
1861  }
1862 };
1863 } // anonymous namespace
1864 } // namespace threadSafety
1865 } // namespace clang
1866 
1867 //===----------------------------------------------------------------------===//
1868 // -Wconsumed
1869 //===----------------------------------------------------------------------===//
1870 
1871 namespace clang {
1872 namespace consumed {
1873 namespace {
1874 class ConsumedWarningsHandler : public ConsumedWarningsHandlerBase {
1875 
1876  Sema &S;
1877  DiagList Warnings;
1878 
1879 public:
1880 
1881  ConsumedWarningsHandler(Sema &S) : S(S) {}
1882 
1883  void emitDiagnostics() override {
1884  Warnings.sort(SortDiagBySourceLocation(S.getSourceManager()));
1885  for (const auto &Diag : Warnings) {
1886  S.Diag(Diag.first.first, Diag.first.second);
1887  for (const auto &Note : Diag.second)
1888  S.Diag(Note.first, Note.second);
1889  }
1890  }
1891 
1892  void warnLoopStateMismatch(SourceLocation Loc,
1893  StringRef VariableName) override {
1894  PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_loop_state_mismatch) <<
1895  VariableName);
1896 
1897  Warnings.emplace_back(std::move(Warning), OptionalNotes());
1898  }
1899 
1900  void warnParamReturnTypestateMismatch(SourceLocation Loc,
1901  StringRef VariableName,
1902  StringRef ExpectedState,
1903  StringRef ObservedState) override {
1904 
1906  diag::warn_param_return_typestate_mismatch) << VariableName <<
1907  ExpectedState << ObservedState);
1908 
1909  Warnings.emplace_back(std::move(Warning), OptionalNotes());
1910  }
1911 
1912  void warnParamTypestateMismatch(SourceLocation Loc, StringRef ExpectedState,
1913  StringRef ObservedState) override {
1914 
1916  diag::warn_param_typestate_mismatch) << ExpectedState << ObservedState);
1917 
1918  Warnings.emplace_back(std::move(Warning), OptionalNotes());
1919  }
1920 
1921  void warnReturnTypestateForUnconsumableType(SourceLocation Loc,
1922  StringRef TypeName) override {
1924  diag::warn_return_typestate_for_unconsumable_type) << TypeName);
1925 
1926  Warnings.emplace_back(std::move(Warning), OptionalNotes());
1927  }
1928 
1929  void warnReturnTypestateMismatch(SourceLocation Loc, StringRef ExpectedState,
1930  StringRef ObservedState) override {
1931 
1933  diag::warn_return_typestate_mismatch) << ExpectedState << ObservedState);
1934 
1935  Warnings.emplace_back(std::move(Warning), OptionalNotes());
1936  }
1937 
1938  void warnUseOfTempInInvalidState(StringRef MethodName, StringRef State,
1939  SourceLocation Loc) override {
1940 
1942  diag::warn_use_of_temp_in_invalid_state) << MethodName << State);
1943 
1944  Warnings.emplace_back(std::move(Warning), OptionalNotes());
1945  }
1946 
1947  void warnUseInInvalidState(StringRef MethodName, StringRef VariableName,
1948  StringRef State, SourceLocation Loc) override {
1949 
1950  PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_use_in_invalid_state) <<
1951  MethodName << VariableName << State);
1952 
1953  Warnings.emplace_back(std::move(Warning), OptionalNotes());
1954  }
1955 };
1956 } // anonymous namespace
1957 } // namespace consumed
1958 } // namespace clang
1959 
1960 //===----------------------------------------------------------------------===//
1961 // AnalysisBasedWarnings - Worker object used by Sema to execute analysis-based
1962 // warnings on a function, method, or block.
1963 //===----------------------------------------------------------------------===//
1964 
1966  enableCheckFallThrough = 1;
1967  enableCheckUnreachable = 0;
1968  enableThreadSafetyAnalysis = 0;
1969  enableConsumedAnalysis = 0;
1970 }
1971 
1972 static unsigned isEnabled(DiagnosticsEngine &D, unsigned diag) {
1973  return (unsigned)!D.isIgnored(diag, SourceLocation());
1974 }
1975 
1977  : S(s),
1978  NumFunctionsAnalyzed(0),
1979  NumFunctionsWithBadCFGs(0),
1980  NumCFGBlocks(0),
1981  MaxCFGBlocksPerFunction(0),
1982  NumUninitAnalysisFunctions(0),
1983  NumUninitAnalysisVariables(0),
1984  MaxUninitAnalysisVariablesPerFunction(0),
1985  NumUninitAnalysisBlockVisits(0),
1986  MaxUninitAnalysisBlockVisitsPerFunction(0) {
1987 
1988  using namespace diag;
1990 
1991  DefaultPolicy.enableCheckUnreachable =
1992  isEnabled(D, warn_unreachable) ||
1993  isEnabled(D, warn_unreachable_break) ||
1994  isEnabled(D, warn_unreachable_return) ||
1995  isEnabled(D, warn_unreachable_loop_increment);
1996 
1997  DefaultPolicy.enableThreadSafetyAnalysis =
1998  isEnabled(D, warn_double_lock);
1999 
2000  DefaultPolicy.enableConsumedAnalysis =
2001  isEnabled(D, warn_use_in_invalid_state);
2002 }
2003 
2004 static void flushDiagnostics(Sema &S, const sema::FunctionScopeInfo *fscope) {
2005  for (const auto &D : fscope->PossiblyUnreachableDiags)
2006  S.Diag(D.Loc, D.PD);
2007 }
2008 
2009 void clang::sema::
2011  sema::FunctionScopeInfo *fscope,
2012  const Decl *D, const BlockExpr *blkExpr) {
2013 
2014  // We avoid doing analysis-based warnings when there are errors for
2015  // two reasons:
2016  // (1) The CFGs often can't be constructed (if the body is invalid), so
2017  // don't bother trying.
2018  // (2) The code already has problems; running the analysis just takes more
2019  // time.
2020  DiagnosticsEngine &Diags = S.getDiagnostics();
2021 
2022  // Do not do any analysis if we are going to just ignore them.
2023  if (Diags.getIgnoreAllWarnings() ||
2024  (Diags.getSuppressSystemWarnings() &&
2026  return;
2027 
2028  // For code in dependent contexts, we'll do this at instantiation time.
2029  if (cast<DeclContext>(D)->isDependentContext())
2030  return;
2031 
2032  if (Diags.hasUncompilableErrorOccurred()) {
2033  // Flush out any possibly unreachable diagnostics.
2034  flushDiagnostics(S, fscope);
2035  return;
2036  }
2037 
2038  const Stmt *Body = D->getBody();
2039  assert(Body);
2040 
2041  // Construct the analysis context with the specified CFG build options.
2042  AnalysisDeclContext AC(/* AnalysisDeclContextManager */ nullptr, D);
2043 
2044  // Don't generate EH edges for CallExprs as we'd like to avoid the n^2
2045  // explosion for destructors that can result and the compile time hit.
2047  AC.getCFGBuildOptions().AddEHEdges = false;
2048  AC.getCFGBuildOptions().AddInitializers = true;
2053 
2054  // Force that certain expressions appear as CFGElements in the CFG. This
2055  // is used to speed up various analyses.
2056  // FIXME: This isn't the right factoring. This is here for initial
2057  // prototyping, but we need a way for analyses to say what expressions they
2058  // expect to always be CFGElements and then fill in the BuildOptions
2059  // appropriately. This is essentially a layering violation.
2060  if (P.enableCheckUnreachable || P.enableThreadSafetyAnalysis ||
2061  P.enableConsumedAnalysis) {
2062  // Unreachable code analysis and thread safety require a linearized CFG.
2064  }
2065  else {
2066  AC.getCFGBuildOptions()
2067  .setAlwaysAdd(Stmt::BinaryOperatorClass)
2068  .setAlwaysAdd(Stmt::CompoundAssignOperatorClass)
2069  .setAlwaysAdd(Stmt::BlockExprClass)
2070  .setAlwaysAdd(Stmt::CStyleCastExprClass)
2071  .setAlwaysAdd(Stmt::DeclRefExprClass)
2072  .setAlwaysAdd(Stmt::ImplicitCastExprClass)
2073  .setAlwaysAdd(Stmt::UnaryOperatorClass)
2074  .setAlwaysAdd(Stmt::AttributedStmtClass);
2075  }
2076 
2077  // Install the logical handler for -Wtautological-overlap-compare
2079  if (!Diags.isIgnored(diag::warn_tautological_overlap_comparison,
2080  D->getBeginLoc())) {
2081  LEH.emplace(S);
2082  AC.getCFGBuildOptions().Observer = &*LEH;
2083  }
2084 
2085  // Emit delayed diagnostics.
2086  if (!fscope->PossiblyUnreachableDiags.empty()) {
2087  bool analyzed = false;
2088 
2089  // Register the expressions with the CFGBuilder.
2090  for (const auto &D : fscope->PossiblyUnreachableDiags) {
2091  if (D.stmt)
2092  AC.registerForcedBlockExpression(D.stmt);
2093  }
2094 
2095  if (AC.getCFG()) {
2096  analyzed = true;
2097  for (const auto &D : fscope->PossiblyUnreachableDiags) {
2098  bool processed = false;
2099  if (D.stmt) {
2100  const CFGBlock *block = AC.getBlockForRegisteredExpression(D.stmt);
2103  // FIXME: We should be able to assert that block is non-null, but
2104  // the CFG analysis can skip potentially-evaluated expressions in
2105  // edge cases; see test/Sema/vla-2.c.
2106  if (block && cra) {
2107  // Can this block be reached from the entrance?
2108  if (cra->isReachable(&AC.getCFG()->getEntry(), block))
2109  S.Diag(D.Loc, D.PD);
2110  processed = true;
2111  }
2112  }
2113  if (!processed) {
2114  // Emit the warning anyway if we cannot map to a basic block.
2115  S.Diag(D.Loc, D.PD);
2116  }
2117  }
2118  }
2119 
2120  if (!analyzed)
2121  flushDiagnostics(S, fscope);
2122  }
2123 
2124  // Warning: check missing 'return'
2125  if (P.enableCheckFallThrough) {
2126  const CheckFallThroughDiagnostics &CD =
2127  (isa<BlockDecl>(D)
2128  ? CheckFallThroughDiagnostics::MakeForBlock()
2129  : (isa<CXXMethodDecl>(D) &&
2130  cast<CXXMethodDecl>(D)->getOverloadedOperator() == OO_Call &&
2131  cast<CXXMethodDecl>(D)->getParent()->isLambda())
2132  ? CheckFallThroughDiagnostics::MakeForLambda()
2133  : (fscope->isCoroutine()
2134  ? CheckFallThroughDiagnostics::MakeForCoroutine(D)
2135  : CheckFallThroughDiagnostics::MakeForFunction(D)));
2136  CheckFallThroughForBody(S, D, Body, blkExpr, CD, AC, fscope);
2137  }
2138 
2139  // Warning: check for unreachable code
2140  if (P.enableCheckUnreachable) {
2141  // Only check for unreachable code on non-template instantiations.
2142  // Different template instantiations can effectively change the control-flow
2143  // and it is very difficult to prove that a snippet of code in a template
2144  // is unreachable for all instantiations.
2145  bool isTemplateInstantiation = false;
2146  if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D))
2147  isTemplateInstantiation = Function->isTemplateInstantiation();
2148  if (!isTemplateInstantiation)
2149  CheckUnreachable(S, AC);
2150  }
2151 
2152  // Check for thread safety violations
2153  if (P.enableThreadSafetyAnalysis) {
2154  SourceLocation FL = AC.getDecl()->getLocation();
2155  SourceLocation FEL = AC.getDecl()->getEndLoc();
2156  threadSafety::ThreadSafetyReporter Reporter(S, FL, FEL);
2157  if (!Diags.isIgnored(diag::warn_thread_safety_beta, D->getBeginLoc()))
2158  Reporter.setIssueBetaWarnings(true);
2159  if (!Diags.isIgnored(diag::warn_thread_safety_verbose, D->getBeginLoc()))
2160  Reporter.setVerbose(true);
2161 
2164  Reporter.emitDiagnostics();
2165  }
2166 
2167  // Check for violations of consumed properties.
2168  if (P.enableConsumedAnalysis) {
2169  consumed::ConsumedWarningsHandler WarningHandler(S);
2170  consumed::ConsumedAnalyzer Analyzer(WarningHandler);
2171  Analyzer.run(AC);
2172  }
2173 
2174  if (!Diags.isIgnored(diag::warn_uninit_var, D->getBeginLoc()) ||
2175  !Diags.isIgnored(diag::warn_sometimes_uninit_var, D->getBeginLoc()) ||
2176  !Diags.isIgnored(diag::warn_maybe_uninit_var, D->getBeginLoc())) {
2177  if (CFG *cfg = AC.getCFG()) {
2178  UninitValsDiagReporter reporter(S);
2180  std::memset(&stats, 0, sizeof(UninitVariablesAnalysisStats));
2181  runUninitializedVariablesAnalysis(*cast<DeclContext>(D), *cfg, AC,
2182  reporter, stats);
2183 
2184  if (S.CollectStats && stats.NumVariablesAnalyzed > 0) {
2185  ++NumUninitAnalysisFunctions;
2186  NumUninitAnalysisVariables += stats.NumVariablesAnalyzed;
2187  NumUninitAnalysisBlockVisits += stats.NumBlockVisits;
2188  MaxUninitAnalysisVariablesPerFunction =
2189  std::max(MaxUninitAnalysisVariablesPerFunction,
2190  stats.NumVariablesAnalyzed);
2191  MaxUninitAnalysisBlockVisitsPerFunction =
2192  std::max(MaxUninitAnalysisBlockVisitsPerFunction,
2193  stats.NumBlockVisits);
2194  }
2195  }
2196  }
2197 
2198  bool FallThroughDiagFull =
2199  !Diags.isIgnored(diag::warn_unannotated_fallthrough, D->getBeginLoc());
2200  bool FallThroughDiagPerFunction = !Diags.isIgnored(
2201  diag::warn_unannotated_fallthrough_per_function, D->getBeginLoc());
2202  if (FallThroughDiagFull || FallThroughDiagPerFunction ||
2203  fscope->HasFallthroughStmt) {
2204  DiagnoseSwitchLabelsFallthrough(S, AC, !FallThroughDiagFull);
2205  }
2206 
2207  if (S.getLangOpts().ObjCWeak &&
2208  !Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, D->getBeginLoc()))
2209  diagnoseRepeatedUseOfWeak(S, fscope, D, AC.getParentMap());
2210 
2211 
2212  // Check for infinite self-recursion in functions
2213  if (!Diags.isIgnored(diag::warn_infinite_recursive_function,
2214  D->getBeginLoc())) {
2215  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
2216  checkRecursiveFunction(S, FD, Body, AC);
2217  }
2218  }
2219 
2220  // Check for throw out of non-throwing function.
2221  if (!Diags.isIgnored(diag::warn_throw_in_noexcept_func, D->getBeginLoc()))
2222  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
2223  if (S.getLangOpts().CPlusPlus && isNoexcept(FD))
2224  checkThrowInNonThrowingFunc(S, FD, AC);
2225 
2226  // If none of the previous checks caused a CFG build, trigger one here
2227  // for -Wtautological-overlap-compare
2228  if (!Diags.isIgnored(diag::warn_tautological_overlap_comparison,
2229  D->getBeginLoc())) {
2230  AC.getCFG();
2231  }
2232 
2233  // Collect statistics about the CFG if it was built.
2234  if (S.CollectStats && AC.isCFGBuilt()) {
2235  ++NumFunctionsAnalyzed;
2236  if (CFG *cfg = AC.getCFG()) {
2237  // If we successfully built a CFG for this context, record some more
2238  // detail information about it.
2239  NumCFGBlocks += cfg->getNumBlockIDs();
2240  MaxCFGBlocksPerFunction = std::max(MaxCFGBlocksPerFunction,
2241  cfg->getNumBlockIDs());
2242  } else {
2243  ++NumFunctionsWithBadCFGs;
2244  }
2245  }
2246 }
2247 
2249  llvm::errs() << "\n*** Analysis Based Warnings Stats:\n";
2250 
2251  unsigned NumCFGsBuilt = NumFunctionsAnalyzed - NumFunctionsWithBadCFGs;
2252  unsigned AvgCFGBlocksPerFunction =
2253  !NumCFGsBuilt ? 0 : NumCFGBlocks/NumCFGsBuilt;
2254  llvm::errs() << NumFunctionsAnalyzed << " functions analyzed ("
2255  << NumFunctionsWithBadCFGs << " w/o CFGs).\n"
2256  << " " << NumCFGBlocks << " CFG blocks built.\n"
2257  << " " << AvgCFGBlocksPerFunction
2258  << " average CFG blocks per function.\n"
2259  << " " << MaxCFGBlocksPerFunction
2260  << " max CFG blocks per function.\n";
2261 
2262  unsigned AvgUninitVariablesPerFunction = !NumUninitAnalysisFunctions ? 0
2263  : NumUninitAnalysisVariables/NumUninitAnalysisFunctions;
2264  unsigned AvgUninitBlockVisitsPerFunction = !NumUninitAnalysisFunctions ? 0
2265  : NumUninitAnalysisBlockVisits/NumUninitAnalysisFunctions;
2266  llvm::errs() << NumUninitAnalysisFunctions
2267  << " functions analyzed for uninitialiazed variables\n"
2268  << " " << NumUninitAnalysisVariables << " variables analyzed.\n"
2269  << " " << AvgUninitVariablesPerFunction
2270  << " average variables per function.\n"
2271  << " " << MaxUninitAnalysisVariablesPerFunction
2272  << " max variables per function.\n"
2273  << " " << NumUninitAnalysisBlockVisits << " block visits.\n"
2274  << " " << AvgUninitBlockVisitsPerFunction
2275  << " average block visits per function.\n"
2276  << " " << MaxUninitAnalysisBlockVisitsPerFunction
2277  << " max block visits per function.\n";
2278 }
static void DiagUninitUse(Sema &S, const VarDecl *VD, const UninitUse &Use, bool IsCapturedByBlock)
DiagUninitUse – Helper function to produce a diagnostic for an uninitialized use of a variable...
Represents a function declaration or definition.
Definition: Decl.h:1737
Passing a guarded variable by reference.
Definition: ThreadSafety.h:47
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.
pred_iterator pred_end()
Definition: CFG.h:733
A (possibly-)qualified type.
Definition: Type.h:634
bool isBlockPointerType() const
Definition: Type.h:6309
SourceLocation getExprLoc() const
Definition: Expr.h:3344
IdentifierInfo * getIdentifierInfo(StringRef Name) const
Return information about the specified preprocessor identifier token.
bool HasFallthroughStmt
Whether there is a fallthrough statement in this function.
Definition: ScopeInfo.h:126
const Expr * getSubExpr() const
Definition: ExprCXX.h:1036
const Stmt * getStmt() const
Definition: CFG.h:132
Stmt * getBody() const
Get the body of the Declaration.
succ_iterator succ_begin()
Definition: CFG.h:750
virtual Stmt * getBody() const
getBody - If this Decl represents a declaration for a body of code, such as a function or method defi...
Definition: DeclBase.h:981
Stmt - This represents one statement.
Definition: Stmt.h:65
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:3360
CFGBlock & getEntry()
Definition: CFG.h:1092
IfStmt - This represents an if/then/else.
Definition: Stmt.h:1706
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:505
Defines the SourceManager interface.
static void diagnoseRepeatedUseOfWeak(Sema &S, const sema::FunctionScopeInfo *CurFn, const Decl *D, const ParentMap &PM)
unsigned getBlockID() const
Definition: CFG.h:855
SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID)
Emit a diagnostic.
Definition: Sema.h:1343
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:86
Expr * getImplicitObjectArgument() const
Retrieves the implicit object argument for the member call.
Definition: ExprCXX.cpp:639
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: DeclBase.h:412
bool isVirtual() const
Definition: DeclCXX.h:2093
Opcode getOpcode() const
Definition: Expr.h:3348
StringRef P
OverloadedOperatorKind getCXXOverloadedOperator() const
If this name is the name of an overloadable operator in C++ (e.g., operator+), retrieve the kind of o...
Represents an attribute applied to a statement.
Definition: Stmt.h:1652
bool isBeforeInTranslationUnit(SourceLocation LHS, SourceLocation RHS) const
Determines the order of 2 source locations in the translation unit.
bool getAddEHEdges() const
getAddEHEdges - Return true iff we are adding exceptional edges from callExprs.
const WeakObjectUseMap & getWeakObjectUses() const
Definition: ScopeInfo.h:391
The use is uninitialized whenever a certain branch is taken.
Stmt * getParent(Stmt *) const
Definition: ParentMap.cpp:122
iterator begin()
Definition: CFG.h:702
StringRef getLastMacroWithSpelling(SourceLocation Loc, ArrayRef< TokenValue > Tokens) const
Return the name of the macro defined before Loc that has spelling Tokens.
SourceLocation getLocForEndOfToken(SourceLocation Loc, unsigned Offset=0)
Calls Lexer::getLocForEndOfToken()
Definition: Sema.cpp:45
SourceLocation getEndLoc() const LLVM_READONLY
Definition: DeclBase.h:416
T castAs() const
Convert to the specified CFGElement type, asserting that this CFGElement is of the desired type...
Definition: CFG.h:98
bool getSuppressSystemWarnings() const
Definition: Diagnostic.h:625
LockKind getLockKindFromAccessKind(AccessKind AK)
Helper function that returns a LockKind required for the given level of access.
unsigned IgnoreDefaultsWithCoveredEnums
Definition: CFG.h:778
static std::pair< const Stmt *, const CFGBlock * > getLastStmt(const ExplodedNode *Node)
ProtectedOperationKind
This enum distinguishes between different kinds of operations that may need to be protected by locks...
Definition: ThreadSafety.h:36
Retains information about a function, method, or block that is currently being parsed.
Definition: ScopeInfo.h:96
Represents a variable declaration or definition.
Definition: Decl.h:812
PartialDiagnostic PDiag(unsigned DiagID=0)
Build a partial diagnostic.
Definition: SemaInternal.h:24
ASTContext & getASTContext() const
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6761
ObjCMethodDecl - Represents an instance or class method declaration.
Definition: DeclObjC.h:138
The use might be uninitialized.
Stmt * getThen()
Definition: Stmt.h:1793
Defines the Objective-C statement AST node classes.
A C++ throw-expression (C++ [except.throw]).
Definition: ExprCXX.h:1014
Defines the clang::Expr interface and subclasses for C++ expressions.
branch_iterator branch_end() const
LabelStmt - Represents a label, which has a substatement.
Definition: Stmt.h:1612
LockKind
This enum distinguishes between different kinds of lock actions.
Definition: ThreadSafety.h:56
bool pred_empty() const
Definition: CFG.h:772
DeclarationName getDeclName() const
Get the actual, stored name of the declaration, which may be a special name.
Definition: Decl.h:297
Kind getKind() const
Get the kind of uninitialized use.
Expr * getFalseExpr() const
Definition: Expr.h:3651
SourceLocation getBegin() const
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:154
LineState State
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:263
branch_iterator branch_begin() const
Branches which inevitably result in the variable being used uninitialized.
AnalysisDeclContext contains the context data for the function or method under analysis.
threadSafety::BeforeSet * ThreadSafetyDeclCache
Definition: Sema.h:7715
static void DiagnoseSwitchLabelsFallthrough(Sema &S, AnalysisDeclContext &AC, bool PerFunction)
succ_range succs()
Definition: CFG.h:760
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Decl.h:738
const LangOptions & getLangOpts() const
Definition: Preprocessor.h:817
AdjacentBlocks::const_iterator const_succ_iterator
Definition: CFG.h:726
TextDiagnosticBuffer::DiagList DiagList
Stmt * getBody(const FunctionDecl *&Definition) const
Retrieve the body (definition) of the function.
Definition: Decl.cpp:2730
APValue Val
Val - This is the value the expression can be folded to.
Definition: Expr.h:575
bool AddCXXDefaultInitExprInCtors
Definition: CFG.h:1026
CFGReverseBlockReachabilityAnalysis * getCFGReachablityAnalysis()
CFGCallback * Observer
Definition: CFG.h:1015
child_range children()
Definition: Stmt.cpp:212
Concrete class used by the front-end to report problems and issues.
Definition: Diagnostic.h:148
A builtin binary operation expression such as "x + y" or "x <= y".
Definition: Expr.h:3313
void IssueWarnings(Policy P, FunctionScopeInfo *fscope, const Decl *D, const BlockExpr *blkExpr)
static StringRef getFallthroughAttrSpelling(Preprocessor &PP, SourceLocation Loc)
SourceLocation getThrowLoc() const
Definition: ExprCXX.h:1039
Expr * IgnoreParenCasts() LLVM_READONLY
Skip past any parentheses and casts which might surround this expression until reaching a fixed point...
Definition: Expr.cpp:2724
static void CheckUnreachable(Sema &S, AnalysisDeclContext &AC)
CheckUnreachable - Check for unreachable code.
DeclContext * getLexicalDeclContext()
getLexicalDeclContext - The declaration context where this Decl was lexically declared (LexicalDC)...
Definition: DeclBase.h:823
__DEVICE__ void * memset(void *__a, int __b, size_t __c)
A C++ lambda expression, which produces a function object (of unspecified type) that can be invoked l...
Definition: ExprCXX.h:1648
const LangOptions & getLangOpts() const
Definition: Sema.h:1266
SourceRange getExceptionSpecSourceRange() const
Attempt to compute an informative source range covering the function exception specification, if any.
Definition: Decl.cpp:3221
A class that does preorder or postorder depth-first traversal on the entire Clang AST and visits each...
virtual Decl * getCanonicalDecl()
Retrieves the "canonical" declaration of the given declaration.
Definition: DeclBase.h:872
reverse_iterator rend()
Definition: CFG.h:708
static bool SuggestInitializationFixit(Sema &S, const VarDecl *VD)
DiagnosticsEngine & getDiagnostics() const
Definition: Sema.h:1270
Passing a pt-guarded variable by reference.
Definition: ThreadSafety.h:50
bool hasAttr() const
Definition: DeclBase.h:533
ConditionalOperator - The ?: ternary operator.
Definition: Expr.h:3608
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:313
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3692
static bool DiagnoseUninitializedUse(Sema &S, const VarDecl *VD, const UninitUse &Use, bool alwaysReportSelfInit=false)
DiagnoseUninitializedUse – Helper function for diagnosing uses of an uninitialized variable...
Handler class for thread safety warnings.
Definition: ThreadSafety.h:93
static StringRef getOpcodeStr(Opcode Op)
getOpcodeStr - Turn an Opcode enum value into the punctuation char it corresponds to...
Definition: Expr.cpp:1887
Represents a single basic block in a source-level CFG.
Definition: CFG.h:551
static bool isInLoop(const ASTContext &Ctx, const ParentMap &PM, const Stmt *S)
SourceManager & SM
Dereferencing a variable (e.g. p in *p = 5;)
Definition: ThreadSafety.h:38
Expr * getCond() const
Definition: Expr.h:3642
This represents one expression.
Definition: Expr.h:108
std::string Label
Represents a source-level, intra-procedural CFG that represents the control-flow of a Stmt...
Definition: CFG.h:1002
bool isInSystemHeader(SourceLocation Loc) const
Returns if a SourceLocation is in a system header.
bool hasUncompilableErrorOccurred() const
Errors that actually prevent compilation, not those that are upgraded from a warning by -Werror...
Definition: Diagnostic.h:750
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6824
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:5381
Expr * getCallee()
Definition: Expr.h:2547
Defines the clang::Preprocessor interface.
bool isCPUDispatchMultiVersion() const
True if this function is a multiversioned dispatch function as a part of the cpu_specific/cpu_dispatc...
Definition: Decl.cpp:2955
Stores token information for comparing actual tokens with predefined values.
Definition: Preprocessor.h:85
void runUninitializedVariablesAnalysis(const DeclContext &dc, const CFG &cfg, AnalysisDeclContext &ac, UninitVariablesHandler &handler, UninitVariablesAnalysisStats &stats)
void FindUnreachableCode(AnalysisDeclContext &AC, Preprocessor &PP, Callback &CB)
unsigned ScanReachableFromBlock(const CFGBlock *Start, llvm::BitVector &Reachable)
ScanReachableFromBlock - Mark all blocks reachable from Start.
QualType getType() const
Definition: Expr.h:130
std::pair< PartialDiagnosticAt, OptionalNotes > DelayedDiag
Definition: Consumed.h:53
const CFGBlock * getBlockForRegisteredExpression(const Stmt *stmt)
bool handlerCanCatch(QualType HandlerType, QualType ExceptionType)
AccessKind
This enum distinguishes between different ways to access (read or write) a variable.
Definition: ThreadSafety.h:69
SourceLocation getEnd() const
Making a function call (e.g. fool())
Definition: ThreadSafety.h:44
CXXMethodDecl * getMethodDecl() const
Retrieves the declaration of the called method.
Definition: ExprCXX.cpp:651
Preprocessor & getPreprocessor() const
Definition: Sema.h:1272
Expr * getCond()
Definition: Stmt.h:1781
A use of a variable, which might be uninitialized.
The result type of a method or function.
bool isNull() const
Return true if this QualType doesn&#39;t point to a type yet.
Definition: Type.h:699
bool isTemplateInstantiation(TemplateSpecializationKind Kind)
Determine whether this template specialization kind refers to an instantiation of an entity (as oppos...
Definition: Specifiers.h:169
reverse_iterator rbegin()
Definition: CFG.h:707
VarDecl * CoroutinePromise
The promise object for this coroutine, if any.
Definition: ScopeInfo.h:192
SourceLocation getEndLoc() const LLVM_READONLY
Definition: Stmt.cpp:276
static CharSourceRange getCharRange(SourceRange R)
CharSourceRange RemoveRange
Code that should be replaced to correct the error.
Definition: Diagnostic.h:69
CFGTerminator getTerminator()
Definition: CFG.h:839
Kind
QualType getCanonicalType() const
Definition: Type.h:6116
Reading or writing a variable (e.g. x in x = 5;)
Definition: ThreadSafety.h:41
FunctionDecl * getAsFunction() LLVM_READONLY
Returns the function itself, or the templated function if this is a function template.
Definition: DeclBase.cpp:217
ASTContext & getASTContext() const
Definition: Sema.h:1273
Encodes a location in the source.
BuildOptions & setAlwaysAdd(Stmt::StmtClass stmtClass, bool val=true)
Definition: CFG.h:1036
static void visitReachableThrows(CFG *BodyCFG, llvm::function_ref< void(const CXXThrowExpr *, CFGBlock &)> Visit)
SourceLocation getOperatorLoc() const
Definition: Expr.h:3345
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Expr.h:5404
static void EmitDiagForCXXThrowInNonThrowingFunc(Sema &S, SourceLocation OpLoc, const FunctionDecl *FD)
Stmt * getLabel()
Definition: CFG.h:850
std::string getNameAsString() const
Get a human-readable name for the declaration, even if it is one of the special kinds of names (C++ c...
Definition: Decl.h:291
bool isReachable(const CFGBlock *Src, const CFGBlock *Dst)
Returns true if the block &#39;Dst&#39; can be reached from block &#39;Src&#39;.
Represents a call to a member function that may be written either with member call syntax (e...
Definition: ExprCXX.h:170
llvm::iterator_range< capture_init_iterator > capture_inits()
Retrieve the initialization expressions for this lambda&#39;s captures.
Definition: ExprCXX.h:1782
Stmt * getElse()
Definition: Stmt.h:1802
bool PruneTriviallyFalseEdges
Definition: CFG.h:1016
std::pair< SourceLocation, PartialDiagnostic > PartialDiagnosticAt
A partial diagnostic along with the source location where this diagnostic occurs. ...
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:2048
bool isCFGBuilt() const
Returns true if we have built a CFG for this analysis context.
Represents a C++ nested name specifier, such as "\::std::vector<int>::".
bool CollectStats
Flag indicating whether or not to collect detailed statistics.
Definition: Sema.h:365
bool isInMainFile(SourceLocation Loc) const
Returns whether the PresumedLoc for a given SourceLocation is in the main file.
const Decl * getDecl() const
static void checkThrowInNonThrowingFunc(Sema &S, const FunctionDecl *FD, AnalysisDeclContext &AC)
Represents one property declaration in an Objective-C interface.
Definition: DeclObjC.h:728
unsigned getNumBlockIDs() const
Returns the total number of BlockIDs allocated (which start at 0).
Definition: CFG.h:1168
SourceRange getSourceRange() const override LLVM_READONLY
Source range that this declaration covers.
Definition: Decl.cpp:1957
static bool isLogicalOp(Opcode Opc)
Definition: Expr.h:3433
static void emitDiagnostics(BoundNodes &Match, const Decl *D, BugReporter &BR, AnalysisManager &AM, const ObjCAutoreleaseWriteChecker *Checker)
succ_iterator succ_end()
Definition: CFG.h:751
BuildOptions & setAllAlwaysAdd()
Definition: CFG.h:1041
The use is uninitialized the first time it is reached after we reach the variable&#39;s declaration...
Stmt * getSubStmt()
Definition: Stmt.h:1579
std::string getFixItZeroInitializerForType(QualType T, SourceLocation Loc) const
Get a string to suggest for zero-initialization of a type.
static unsigned isEnabled(DiagnosticsEngine &D, unsigned diag)
SourceLocation getExprLoc() const LLVM_READONLY
getExprLoc - Return the preferred location for the arrow when diagnosing a problem with a generic exp...
Definition: Expr.cpp:214
bool getIgnoreAllWarnings() const
Definition: Diagnostic.h:590
Optional< T > getAs() const
Convert to the specified CFGElement type, returning None if this CFGElement is not of the desired typ...
Definition: CFG.h:109
Expr * getLHS() const
Definition: Expr.h:3353
pred_iterator pred_begin()
Definition: CFG.h:732
SmallVectorImpl< Branch >::const_iterator branch_iterator
Dataflow Directional Tag Classes.
CFG::BuildOptions & getCFGBuildOptions()
Return the build options used to construct the CFG.
bool isValid() const
Return true if this is a valid SourceLocation object.
EvalResult is a struct with detailed info about an evaluated expression.
Definition: Expr.h:573
void runThreadSafetyAnalysis(AnalysisDeclContext &AC, ThreadSafetyHandler &Handler, BeforeSet **Bset)
Check a function&#39;s CFG for thread-safety violations.
static void CreateIfFixit(Sema &S, const Stmt *If, const Stmt *Then, const Stmt *Else, bool CondVal, FixItHint &Fixit1, FixItHint &Fixit2)
Create a fixit to remove an if-like statement, on the assumption that its condition is CondVal...
static FixItHint CreateRemoval(CharSourceRange RemoveRange)
Create a code modification hint that removes the given source range.
Definition: Diagnostic.h:117
const Expr * getInit() const
Definition: Decl.h:1219
static bool checkForRecursiveFunctionCall(const FunctionDecl *FD, CFG *cfg)
StmtClass getStmtClass() const
Definition: Stmt.h:1032
Represents a simple identification of a weak object.
Definition: ScopeInfo.h:243
A class that handles the analysis of uniqueness violations.
Definition: Consumed.h:240
ConstEvaluatedExprVisitor - This class visits &#39;const Expr *&#39;s.
static bool isNoexcept(const FunctionDecl *FD)
Expr * IgnoreParenImpCasts() LLVM_READONLY
Skip past any parentheses and implicit casts which might surround this expression until reaching a fi...
Definition: Expr.cpp:2719
bool isMacroID() const
SwitchStmt - This represents a &#39;switch&#39; stmt.
Definition: Stmt.h:1905
The standard open() call: int open(const char *path, int oflag, ...);.
UnreachableKind
Classifications of unreachable code.
Definition: ReachableCode.h:40
const Expr * getUser() const
Get the expression containing the uninitialized use.
The use is always uninitialized.
static void CheckFallThroughForBody(Sema &S, const Decl *D, const Stmt *Body, const BlockExpr *blkExpr, const CheckFallThroughDiagnostics &CD, AnalysisDeclContext &AC, sema::FunctionScopeInfo *FSI)
CheckFallThroughForBody - Check that we don&#39;t fall off the end of a function that should return a val...
TypeSourceInfo * getTypeSourceInfo() const
Definition: Decl.h:715
static bool throwEscapes(Sema &S, const CXXThrowExpr *E, CFGBlock &ThrowBlock, CFG *Body)
Determine whether an exception thrown by E, unwinding from ThrowBlock, can reach ExitBlock.
static void checkRecursiveFunction(Sema &S, const FunctionDecl *FD, const Stmt *Body, AnalysisDeclContext &AC)
static FixItHint CreateInsertion(SourceLocation InsertionLoc, StringRef Code, bool BeforePreviousInsertions=false)
Create a code modification hint that inserts the given code string at a specific location.
Definition: Diagnostic.h:91
static void flushDiagnostics(Sema &S, const sema::FunctionScopeInfo *fscope)
bool hasNoReturnElement() const
Definition: CFG.h:853
SmallVector< PartialDiagnosticAt, 1 > OptionalNotes
Definition: Consumed.h:52
Defines the C++ Decl subclasses, other than those for templates (found in DeclTemplate.h) and friends (in DeclFriend.h).
Defines the clang::SourceLocation class and associated facilities.
SmallVector< PossiblyUnreachableDiag, 4 > PossiblyUnreachableDiags
A list of PartialDiagnostics created but delayed within the current function scope.
Definition: ScopeInfo.h:214
CFGCallback defines methods that should be called when a logical operator error is found when buildin...
Definition: CFG.h:985
bool isValid() const
Expr * getTrueExpr() const
Definition: Expr.h:3646
void run(AnalysisDeclContext &AC)
Check a function&#39;s CFG for consumed violations.
Definition: Consumed.cpp:1304
Represents a top-level expression in a basic block.
Definition: CFG.h:55
static FixItHint CreateReplacement(CharSourceRange RemoveRange, StringRef Code)
Create a code modification hint that replaces the given source range with the given code string...
Definition: Diagnostic.h:128
capture_range captures() const
Retrieve this lambda&#39;s captures.
Definition: ExprCXX.cpp:1165
SourceManager & getSourceManager() const
Definition: Sema.h:1271
static ControlFlowKind CheckFallThrough(AnalysisDeclContext &AC)
CheckFallThrough - Check that we don&#39;t fall off the end of a Statement that should return a value...
SourceRange getSourceRange() const LLVM_READONLY
SourceLocation tokens are not useful in isolation - they are low level value objects created/interpre...
Definition: Stmt.cpp:251
The use is uninitialized the first time it is reached after the function is called.
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2429
void registerForcedBlockExpression(const Stmt *stmt)
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Expr.h:3358
__DEVICE__ int max(int __a, int __b)
llvm::SmallDenseMap< WeakObjectProfileTy, WeakUseVector, 8, WeakObjectProfileTy::DenseMapInfo > WeakObjectUseMap
Used to collect all uses of weak objects in a function body.
Definition: ScopeInfo.h:352
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1074
bool isIgnored(unsigned DiagID, SourceLocation Loc) const
Determine whether the diagnostic is known to be ignored.
Definition: Diagnostic.h:818
TemplatedKind getTemplatedKind() const
What kind of templated function this is.
Definition: Decl.cpp:3315
SourceManager & SourceMgr
Definition: Sema.h:362
Annotates a diagnostic with some code that should be inserted, removed, or replaced to fix the proble...
Definition: Diagnostic.h:65
Stmt * getSubStmt()
Definition: Stmt.h:1633
QualType getType() const
Definition: Decl.h:647
A trivial tuple used to represent a source range.
ASTContext & Context
Definition: Sema.h:359
FunctionDecl * getCanonicalDecl() override
Retrieves the "canonical" declaration of the given declaration.
Definition: Decl.cpp:2982
This represents a decl that may have a name.
Definition: Decl.h:248
iterator end()
Definition: CFG.h:703
APSInt & getInt()
Definition: APValue.h:257
Decl * getCalleeDecl()
Definition: Expr.h:2559
SourceLocation getBegin() const
const LangOptions & getLangOpts() const
Definition: ASTContext.h:706
static bool hasRecursiveCallInPath(const FunctionDecl *FD, CFGBlock &Block)
This class handles loading and caching of source files into memory.
SourceLocation getLocation() const
Definition: DeclBase.h:420
QualType getType() const
Return the type wrapped by this type source info.
Definition: Decl.h:97
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:124
CFGBlock & getExit()
Definition: CFG.h:1094