1 //=- AnalysisBasedWarnings.cpp - Sema warnings based on libAnalysis -*- C++ -*-=//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines analysis_warnings::[Policy,Executor].
11 // Together they are used by Sema to issue warnings based on inexpensive
12 // static analysis algorithms in libAnalysis.
14 //===----------------------------------------------------------------------===//
16 #include "clang/Sema/AnalysisBasedWarnings.h"
17 #include "clang/AST/DeclCXX.h"
18 #include "clang/AST/DeclObjC.h"
19 #include "clang/AST/EvaluatedExprVisitor.h"
20 #include "clang/AST/ExprCXX.h"
21 #include "clang/AST/ExprObjC.h"
22 #include "clang/AST/ParentMap.h"
23 #include "clang/AST/RecursiveASTVisitor.h"
24 #include "clang/AST/StmtCXX.h"
25 #include "clang/AST/StmtObjC.h"
26 #include "clang/AST/StmtVisitor.h"
27 #include "clang/Analysis/Analyses/CFGReachabilityAnalysis.h"
28 #include "clang/Analysis/Analyses/Consumed.h"
29 #include "clang/Analysis/Analyses/ReachableCode.h"
30 #include "clang/Analysis/Analyses/ThreadSafety.h"
31 #include "clang/Analysis/Analyses/UninitializedValues.h"
32 #include "clang/Analysis/AnalysisContext.h"
33 #include "clang/Analysis/CFG.h"
34 #include "clang/Analysis/CFGStmtMap.h"
35 #include "clang/Basic/SourceLocation.h"
36 #include "clang/Basic/SourceManager.h"
37 #include "clang/Lex/Lexer.h"
38 #include "clang/Lex/Preprocessor.h"
39 #include "clang/Sema/ScopeInfo.h"
40 #include "clang/Sema/SemaInternal.h"
41 #include "llvm/ADT/ArrayRef.h"
42 #include "llvm/ADT/BitVector.h"
43 #include "llvm/ADT/FoldingSet.h"
44 #include "llvm/ADT/ImmutableMap.h"
45 #include "llvm/ADT/MapVector.h"
46 #include "llvm/ADT/PostOrderIterator.h"
47 #include "llvm/ADT/SmallString.h"
48 #include "llvm/ADT/SmallVector.h"
49 #include "llvm/ADT/StringRef.h"
50 #include "llvm/Support/Casting.h"
56 using namespace clang;
58 //===----------------------------------------------------------------------===//
59 // Unreachable code analysis.
60 //===----------------------------------------------------------------------===//
63 class UnreachableCodeHandler : public reachable_code::Callback {
66 UnreachableCodeHandler(Sema &s) : S(s) {}
68 void HandleUnreachable(reachable_code::UnreachableKind UK,
70 SourceRange SilenceableCondVal,
72 SourceRange R2) override {
73 unsigned diag = diag::warn_unreachable;
75 case reachable_code::UK_Break:
76 diag = diag::warn_unreachable_break;
78 case reachable_code::UK_Return:
79 diag = diag::warn_unreachable_return;
81 case reachable_code::UK_Loop_Increment:
82 diag = diag::warn_unreachable_loop_increment;
84 case reachable_code::UK_Other:
88 S.Diag(L, diag) << R1 << R2;
90 SourceLocation Open = SilenceableCondVal.getBegin();
92 SourceLocation Close = SilenceableCondVal.getEnd();
93 Close = S.getLocForEndOfToken(Close);
94 if (Close.isValid()) {
95 S.Diag(Open, diag::note_unreachable_silence)
96 << FixItHint::CreateInsertion(Open, "/* DISABLES CODE */ (")
97 << FixItHint::CreateInsertion(Close, ")");
104 /// CheckUnreachable - Check for unreachable code.
105 static void CheckUnreachable(Sema &S, AnalysisDeclContext &AC) {
106 // As a heuristic prune all diagnostics not in the main file. Currently
107 // the majority of warnings in headers are false positives. These
108 // are largely caused by configuration state, e.g. preprocessor
109 // defined code, etc.
111 // Note that this is also a performance optimization. Analyzing
112 // headers many times can be expensive.
113 if (!S.getSourceManager().isInMainFile(AC.getDecl()->getLocStart()))
116 UnreachableCodeHandler UC(S);
117 reachable_code::FindUnreachableCode(AC, S.getPreprocessor(), UC);
121 /// \brief Warn on logical operator errors in CFGBuilder
122 class LogicalErrorHandler : public CFGCallback {
126 LogicalErrorHandler(Sema &S) : CFGCallback(), S(S) {}
128 static bool HasMacroID(const Expr *E) {
129 if (E->getExprLoc().isMacroID())
132 // Recurse to children.
133 for (const Stmt *SubStmt : E->children())
134 if (const Expr *SubExpr = dyn_cast_or_null<Expr>(SubStmt))
135 if (HasMacroID(SubExpr))
141 void compareAlwaysTrue(const BinaryOperator *B, bool isAlwaysTrue) override {
145 SourceRange DiagRange = B->getSourceRange();
146 S.Diag(B->getExprLoc(), diag::warn_tautological_overlap_comparison)
147 << DiagRange << isAlwaysTrue;
150 void compareBitwiseEquality(const BinaryOperator *B,
151 bool isAlwaysTrue) override {
155 SourceRange DiagRange = B->getSourceRange();
156 S.Diag(B->getExprLoc(), diag::warn_comparison_bitwise_always)
157 << DiagRange << isAlwaysTrue;
162 //===----------------------------------------------------------------------===//
163 // Check for infinite self-recursion in functions
164 //===----------------------------------------------------------------------===//
166 // All blocks are in one of three states. States are ordered so that blocks
167 // can only move to higher states.
168 enum RecursiveState {
171 FoundPathWithNoRecursiveCall
174 static void checkForFunctionCall(Sema &S, const FunctionDecl *FD,
175 CFGBlock &Block, unsigned ExitID,
176 llvm::SmallVectorImpl<RecursiveState> &States,
177 RecursiveState State) {
178 unsigned ID = Block.getBlockID();
180 // A block's state can only move to a higher state.
181 if (States[ID] >= State)
186 // Found a path to the exit node without a recursive call.
187 if (ID == ExitID && State == FoundPathWithNoRecursiveCall)
190 if (State == FoundPathWithNoRecursiveCall) {
191 // If the current state is FoundPathWithNoRecursiveCall, the successors
192 // will be either FoundPathWithNoRecursiveCall or FoundPath. To determine
193 // which, process all the Stmt's in this block to find any recursive calls.
194 for (const auto &B : Block) {
195 if (B.getKind() != CFGElement::Statement)
198 const CallExpr *CE = dyn_cast<CallExpr>(B.getAs<CFGStmt>()->getStmt());
199 if (CE && CE->getCalleeDecl() &&
200 CE->getCalleeDecl()->getCanonicalDecl() == FD) {
202 // Skip function calls which are qualified with a templated class.
203 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(
204 CE->getCallee()->IgnoreParenImpCasts())) {
205 if (NestedNameSpecifier *NNS = DRE->getQualifier()) {
206 if (NNS->getKind() == NestedNameSpecifier::TypeSpec &&
207 isa<TemplateSpecializationType>(NNS->getAsType())) {
213 if (const CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(CE)) {
214 if (isa<CXXThisExpr>(MCE->getImplicitObjectArgument()) ||
215 !MCE->getMethodDecl()->isVirtual()) {
227 for (CFGBlock::succ_iterator I = Block.succ_begin(), E = Block.succ_end();
230 checkForFunctionCall(S, FD, **I, ExitID, States, State);
233 static void checkRecursiveFunction(Sema &S, const FunctionDecl *FD,
235 AnalysisDeclContext &AC) {
236 FD = FD->getCanonicalDecl();
238 // Only run on non-templated functions and non-templated members of
239 // templated classes.
240 if (FD->getTemplatedKind() != FunctionDecl::TK_NonTemplate &&
241 FD->getTemplatedKind() != FunctionDecl::TK_MemberSpecialization)
244 CFG *cfg = AC.getCFG();
247 // If the exit block is unreachable, skip processing the function.
248 if (cfg->getExit().pred_empty())
251 // Mark all nodes as FoundNoPath, then begin processing the entry block.
252 llvm::SmallVector<RecursiveState, 16> states(cfg->getNumBlockIDs(),
254 checkForFunctionCall(S, FD, cfg->getEntry(), cfg->getExit().getBlockID(),
255 states, FoundPathWithNoRecursiveCall);
257 // Check that the exit block is reachable. This prevents triggering the
258 // warning on functions that do not terminate.
259 if (states[cfg->getExit().getBlockID()] == FoundPath)
260 S.Diag(Body->getLocStart(), diag::warn_infinite_recursive_function);
263 //===----------------------------------------------------------------------===//
264 // Check for missing return value.
265 //===----------------------------------------------------------------------===//
267 enum ControlFlowKind {
272 NeverFallThroughOrReturn
275 /// CheckFallThrough - Check that we don't fall off the end of a
276 /// Statement that should return a value.
278 /// \returns AlwaysFallThrough iff we always fall off the end of the statement,
279 /// MaybeFallThrough iff we might or might not fall off the end,
280 /// NeverFallThroughOrReturn iff we never fall off the end of the statement or
281 /// return. We assume NeverFallThrough iff we never fall off the end of the
282 /// statement but we may return. We assume that functions not marked noreturn
284 static ControlFlowKind CheckFallThrough(AnalysisDeclContext &AC) {
285 CFG *cfg = AC.getCFG();
286 if (!cfg) return UnknownFallThrough;
288 // The CFG leaves in dead things, and we don't want the dead code paths to
289 // confuse us, so we mark all live things first.
290 llvm::BitVector live(cfg->getNumBlockIDs());
291 unsigned count = reachable_code::ScanReachableFromBlock(&cfg->getEntry(),
294 bool AddEHEdges = AC.getAddEHEdges();
295 if (!AddEHEdges && count != cfg->getNumBlockIDs())
296 // When there are things remaining dead, and we didn't add EH edges
297 // from CallExprs to the catch clauses, we have to go back and
298 // mark them as live.
299 for (const auto *B : *cfg) {
300 if (!live[B->getBlockID()]) {
301 if (B->pred_begin() == B->pred_end()) {
302 if (B->getTerminator() && isa<CXXTryStmt>(B->getTerminator()))
303 // When not adding EH edges from calls, catch clauses
304 // can otherwise seem dead. Avoid noting them as dead.
305 count += reachable_code::ScanReachableFromBlock(B, live);
311 // Now we know what is live, we check the live precessors of the exit block
312 // and look for fall through paths, being careful to ignore normal returns,
313 // and exceptional paths.
314 bool HasLiveReturn = false;
315 bool HasFakeEdge = false;
316 bool HasPlainEdge = false;
317 bool HasAbnormalEdge = false;
319 // Ignore default cases that aren't likely to be reachable because all
320 // enums in a switch(X) have explicit case statements.
321 CFGBlock::FilterOptions FO;
322 FO.IgnoreDefaultsWithCoveredEnums = 1;
324 for (CFGBlock::filtered_pred_iterator
325 I = cfg->getExit().filtered_pred_start_end(FO); I.hasMore(); ++I) {
326 const CFGBlock& B = **I;
327 if (!live[B.getBlockID()])
330 // Skip blocks which contain an element marked as no-return. They don't
331 // represent actually viable edges into the exit block, so mark them as
333 if (B.hasNoReturnElement()) {
334 HasAbnormalEdge = true;
338 // Destructors can appear after the 'return' in the CFG. This is
339 // normal. We need to look pass the destructors for the return
340 // statement (if it exists).
341 CFGBlock::const_reverse_iterator ri = B.rbegin(), re = B.rend();
343 for ( ; ri != re ; ++ri)
344 if (ri->getAs<CFGStmt>())
347 // No more CFGElements in the block?
349 if (B.getTerminator() && isa<CXXTryStmt>(B.getTerminator())) {
350 HasAbnormalEdge = true;
353 // A labeled empty statement, or the entry block...
358 CFGStmt CS = ri->castAs<CFGStmt>();
359 const Stmt *S = CS.getStmt();
360 if (isa<ReturnStmt>(S)) {
361 HasLiveReturn = true;
364 if (isa<ObjCAtThrowStmt>(S)) {
368 if (isa<CXXThrowExpr>(S)) {
372 if (isa<MSAsmStmt>(S)) {
373 // TODO: Verify this is correct.
375 HasLiveReturn = true;
378 if (isa<CXXTryStmt>(S)) {
379 HasAbnormalEdge = true;
382 if (std::find(B.succ_begin(), B.succ_end(), &cfg->getExit())
384 HasAbnormalEdge = true;
392 return NeverFallThrough;
393 return NeverFallThroughOrReturn;
395 if (HasAbnormalEdge || HasFakeEdge || HasLiveReturn)
396 return MaybeFallThrough;
397 // This says AlwaysFallThrough for calls to functions that are not marked
398 // noreturn, that don't return. If people would like this warning to be more
399 // accurate, such functions should be marked as noreturn.
400 return AlwaysFallThrough;
405 struct CheckFallThroughDiagnostics {
406 unsigned diag_MaybeFallThrough_HasNoReturn;
407 unsigned diag_MaybeFallThrough_ReturnsNonVoid;
408 unsigned diag_AlwaysFallThrough_HasNoReturn;
409 unsigned diag_AlwaysFallThrough_ReturnsNonVoid;
410 unsigned diag_NeverFallThroughOrReturn;
411 enum { Function, Block, Lambda } funMode;
412 SourceLocation FuncLoc;
414 static CheckFallThroughDiagnostics MakeForFunction(const Decl *Func) {
415 CheckFallThroughDiagnostics D;
416 D.FuncLoc = Func->getLocation();
417 D.diag_MaybeFallThrough_HasNoReturn =
418 diag::warn_falloff_noreturn_function;
419 D.diag_MaybeFallThrough_ReturnsNonVoid =
420 diag::warn_maybe_falloff_nonvoid_function;
421 D.diag_AlwaysFallThrough_HasNoReturn =
422 diag::warn_falloff_noreturn_function;
423 D.diag_AlwaysFallThrough_ReturnsNonVoid =
424 diag::warn_falloff_nonvoid_function;
426 // Don't suggest that virtual functions be marked "noreturn", since they
427 // might be overridden by non-noreturn functions.
428 bool isVirtualMethod = false;
429 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Func))
430 isVirtualMethod = Method->isVirtual();
432 // Don't suggest that template instantiations be marked "noreturn"
433 bool isTemplateInstantiation = false;
434 if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(Func))
435 isTemplateInstantiation = Function->isTemplateInstantiation();
437 if (!isVirtualMethod && !isTemplateInstantiation)
438 D.diag_NeverFallThroughOrReturn =
439 diag::warn_suggest_noreturn_function;
441 D.diag_NeverFallThroughOrReturn = 0;
443 D.funMode = Function;
447 static CheckFallThroughDiagnostics MakeForBlock() {
448 CheckFallThroughDiagnostics D;
449 D.diag_MaybeFallThrough_HasNoReturn =
450 diag::err_noreturn_block_has_return_expr;
451 D.diag_MaybeFallThrough_ReturnsNonVoid =
452 diag::err_maybe_falloff_nonvoid_block;
453 D.diag_AlwaysFallThrough_HasNoReturn =
454 diag::err_noreturn_block_has_return_expr;
455 D.diag_AlwaysFallThrough_ReturnsNonVoid =
456 diag::err_falloff_nonvoid_block;
457 D.diag_NeverFallThroughOrReturn = 0;
462 static CheckFallThroughDiagnostics MakeForLambda() {
463 CheckFallThroughDiagnostics D;
464 D.diag_MaybeFallThrough_HasNoReturn =
465 diag::err_noreturn_lambda_has_return_expr;
466 D.diag_MaybeFallThrough_ReturnsNonVoid =
467 diag::warn_maybe_falloff_nonvoid_lambda;
468 D.diag_AlwaysFallThrough_HasNoReturn =
469 diag::err_noreturn_lambda_has_return_expr;
470 D.diag_AlwaysFallThrough_ReturnsNonVoid =
471 diag::warn_falloff_nonvoid_lambda;
472 D.diag_NeverFallThroughOrReturn = 0;
477 bool checkDiagnostics(DiagnosticsEngine &D, bool ReturnsVoid,
478 bool HasNoReturn) const {
479 if (funMode == Function) {
480 return (ReturnsVoid ||
481 D.isIgnored(diag::warn_maybe_falloff_nonvoid_function,
484 D.isIgnored(diag::warn_noreturn_function_has_return_expr,
487 D.isIgnored(diag::warn_suggest_noreturn_block, FuncLoc));
490 // For blocks / lambdas.
491 return ReturnsVoid && !HasNoReturn;
497 /// CheckFallThroughForFunctionDef - Check that we don't fall off the end of a
498 /// function that should return a value. Check that we don't fall off the end
499 /// of a noreturn function. We assume that functions and blocks not marked
500 /// noreturn will return.
501 static void CheckFallThroughForBody(Sema &S, const Decl *D, const Stmt *Body,
502 const BlockExpr *blkExpr,
503 const CheckFallThroughDiagnostics& CD,
504 AnalysisDeclContext &AC) {
506 bool ReturnsVoid = false;
507 bool HasNoReturn = false;
509 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
510 ReturnsVoid = FD->getReturnType()->isVoidType();
511 HasNoReturn = FD->isNoReturn();
513 else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) {
514 ReturnsVoid = MD->getReturnType()->isVoidType();
515 HasNoReturn = MD->hasAttr<NoReturnAttr>();
517 else if (isa<BlockDecl>(D)) {
518 QualType BlockTy = blkExpr->getType();
519 if (const FunctionType *FT =
520 BlockTy->getPointeeType()->getAs<FunctionType>()) {
521 if (FT->getReturnType()->isVoidType())
523 if (FT->getNoReturnAttr())
528 DiagnosticsEngine &Diags = S.getDiagnostics();
530 // Short circuit for compilation speed.
531 if (CD.checkDiagnostics(Diags, ReturnsVoid, HasNoReturn))
534 SourceLocation LBrace = Body->getLocStart(), RBrace = Body->getLocEnd();
535 // Either in a function body compound statement, or a function-try-block.
536 switch (CheckFallThrough(AC)) {
537 case UnknownFallThrough:
540 case MaybeFallThrough:
542 S.Diag(RBrace, CD.diag_MaybeFallThrough_HasNoReturn);
543 else if (!ReturnsVoid)
544 S.Diag(RBrace, CD.diag_MaybeFallThrough_ReturnsNonVoid);
546 case AlwaysFallThrough:
548 S.Diag(RBrace, CD.diag_AlwaysFallThrough_HasNoReturn);
549 else if (!ReturnsVoid)
550 S.Diag(RBrace, CD.diag_AlwaysFallThrough_ReturnsNonVoid);
552 case NeverFallThroughOrReturn:
553 if (ReturnsVoid && !HasNoReturn && CD.diag_NeverFallThroughOrReturn) {
554 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
555 S.Diag(LBrace, CD.diag_NeverFallThroughOrReturn) << 0 << FD;
556 } else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) {
557 S.Diag(LBrace, CD.diag_NeverFallThroughOrReturn) << 1 << MD;
559 S.Diag(LBrace, CD.diag_NeverFallThroughOrReturn);
563 case NeverFallThrough:
568 //===----------------------------------------------------------------------===//
570 //===----------------------------------------------------------------------===//
573 /// ContainsReference - A visitor class to search for references to
574 /// a particular declaration (the needle) within any evaluated component of an
575 /// expression (recursively).
576 class ContainsReference : public ConstEvaluatedExprVisitor<ContainsReference> {
578 const DeclRefExpr *Needle;
581 typedef ConstEvaluatedExprVisitor<ContainsReference> Inherited;
583 ContainsReference(ASTContext &Context, const DeclRefExpr *Needle)
584 : Inherited(Context), FoundReference(false), Needle(Needle) {}
586 void VisitExpr(const Expr *E) {
587 // Stop evaluating if we already have a reference.
591 Inherited::VisitExpr(E);
594 void VisitDeclRefExpr(const DeclRefExpr *E) {
596 FoundReference = true;
598 Inherited::VisitDeclRefExpr(E);
601 bool doesContainReference() const { return FoundReference; }
605 static bool SuggestInitializationFixit(Sema &S, const VarDecl *VD) {
606 QualType VariableTy = VD->getType().getCanonicalType();
607 if (VariableTy->isBlockPointerType() &&
608 !VD->hasAttr<BlocksAttr>()) {
609 S.Diag(VD->getLocation(), diag::note_block_var_fixit_add_initialization)
611 << FixItHint::CreateInsertion(VD->getLocation(), "__block ");
615 // Don't issue a fixit if there is already an initializer.
619 // Don't suggest a fixit inside macros.
620 if (VD->getLocEnd().isMacroID())
623 SourceLocation Loc = S.getLocForEndOfToken(VD->getLocEnd());
625 // Suggest possible initialization (if any).
626 std::string Init = S.getFixItZeroInitializerForType(VariableTy, Loc);
630 S.Diag(Loc, diag::note_var_fixit_add_initialization) << VD->getDeclName()
631 << FixItHint::CreateInsertion(Loc, Init);
635 /// Create a fixit to remove an if-like statement, on the assumption that its
636 /// condition is CondVal.
637 static void CreateIfFixit(Sema &S, const Stmt *If, const Stmt *Then,
638 const Stmt *Else, bool CondVal,
639 FixItHint &Fixit1, FixItHint &Fixit2) {
641 // If condition is always true, remove all but the 'then'.
642 Fixit1 = FixItHint::CreateRemoval(
643 CharSourceRange::getCharRange(If->getLocStart(),
644 Then->getLocStart()));
646 SourceLocation ElseKwLoc = Lexer::getLocForEndOfToken(
647 Then->getLocEnd(), 0, S.getSourceManager(), S.getLangOpts());
648 Fixit2 = FixItHint::CreateRemoval(
649 SourceRange(ElseKwLoc, Else->getLocEnd()));
652 // If condition is always false, remove all but the 'else'.
654 Fixit1 = FixItHint::CreateRemoval(
655 CharSourceRange::getCharRange(If->getLocStart(),
656 Else->getLocStart()));
658 Fixit1 = FixItHint::CreateRemoval(If->getSourceRange());
662 /// DiagUninitUse -- Helper function to produce a diagnostic for an
663 /// uninitialized use of a variable.
664 static void DiagUninitUse(Sema &S, const VarDecl *VD, const UninitUse &Use,
665 bool IsCapturedByBlock) {
666 bool Diagnosed = false;
668 switch (Use.getKind()) {
669 case UninitUse::Always:
670 S.Diag(Use.getUser()->getLocStart(), diag::warn_uninit_var)
671 << VD->getDeclName() << IsCapturedByBlock
672 << Use.getUser()->getSourceRange();
675 case UninitUse::AfterDecl:
676 case UninitUse::AfterCall:
677 S.Diag(VD->getLocation(), diag::warn_sometimes_uninit_var)
678 << VD->getDeclName() << IsCapturedByBlock
679 << (Use.getKind() == UninitUse::AfterDecl ? 4 : 5)
680 << const_cast<DeclContext*>(VD->getLexicalDeclContext())
681 << VD->getSourceRange();
682 S.Diag(Use.getUser()->getLocStart(), diag::note_uninit_var_use)
683 << IsCapturedByBlock << Use.getUser()->getSourceRange();
686 case UninitUse::Maybe:
687 case UninitUse::Sometimes:
688 // Carry on to report sometimes-uninitialized branches, if possible,
689 // or a 'may be used uninitialized' diagnostic otherwise.
693 // Diagnose each branch which leads to a sometimes-uninitialized use.
694 for (UninitUse::branch_iterator I = Use.branch_begin(), E = Use.branch_end();
696 assert(Use.getKind() == UninitUse::Sometimes);
698 const Expr *User = Use.getUser();
699 const Stmt *Term = I->Terminator;
701 // Information used when building the diagnostic.
706 // FixIts to suppress the diagnostic by removing the dead condition.
707 // For all binary terminators, branch 0 is taken if the condition is true,
708 // and branch 1 is taken if the condition is false.
709 int RemoveDiagKind = -1;
710 const char *FixitStr =
711 S.getLangOpts().CPlusPlus ? (I->Output ? "true" : "false")
712 : (I->Output ? "1" : "0");
713 FixItHint Fixit1, Fixit2;
715 switch (Term ? Term->getStmtClass() : Stmt::DeclStmtClass) {
717 // Don't know how to report this. Just fall back to 'may be used
718 // uninitialized'. FIXME: Can this happen?
721 // "condition is true / condition is false".
722 case Stmt::IfStmtClass: {
723 const IfStmt *IS = cast<IfStmt>(Term);
726 Range = IS->getCond()->getSourceRange();
728 CreateIfFixit(S, IS, IS->getThen(), IS->getElse(),
729 I->Output, Fixit1, Fixit2);
732 case Stmt::ConditionalOperatorClass: {
733 const ConditionalOperator *CO = cast<ConditionalOperator>(Term);
736 Range = CO->getCond()->getSourceRange();
738 CreateIfFixit(S, CO, CO->getTrueExpr(), CO->getFalseExpr(),
739 I->Output, Fixit1, Fixit2);
742 case Stmt::BinaryOperatorClass: {
743 const BinaryOperator *BO = cast<BinaryOperator>(Term);
744 if (!BO->isLogicalOp())
747 Str = BO->getOpcodeStr();
748 Range = BO->getLHS()->getSourceRange();
750 if ((BO->getOpcode() == BO_LAnd && I->Output) ||
751 (BO->getOpcode() == BO_LOr && !I->Output))
752 // true && y -> y, false || y -> y.
753 Fixit1 = FixItHint::CreateRemoval(SourceRange(BO->getLocStart(),
754 BO->getOperatorLoc()));
756 // false && y -> false, true || y -> true.
757 Fixit1 = FixItHint::CreateReplacement(BO->getSourceRange(), FixitStr);
761 // "loop is entered / loop is exited".
762 case Stmt::WhileStmtClass:
765 Range = cast<WhileStmt>(Term)->getCond()->getSourceRange();
767 Fixit1 = FixItHint::CreateReplacement(Range, FixitStr);
769 case Stmt::ForStmtClass:
772 Range = cast<ForStmt>(Term)->getCond()->getSourceRange();
775 Fixit1 = FixItHint::CreateRemoval(Range);
777 Fixit1 = FixItHint::CreateReplacement(Range, FixitStr);
779 case Stmt::CXXForRangeStmtClass:
780 if (I->Output == 1) {
781 // The use occurs if a range-based for loop's body never executes.
782 // That may be impossible, and there's no syntactic fix for this,
783 // so treat it as a 'may be uninitialized' case.
788 Range = cast<CXXForRangeStmt>(Term)->getRangeInit()->getSourceRange();
791 // "condition is true / loop is exited".
792 case Stmt::DoStmtClass:
795 Range = cast<DoStmt>(Term)->getCond()->getSourceRange();
797 Fixit1 = FixItHint::CreateReplacement(Range, FixitStr);
800 // "switch case is taken".
801 case Stmt::CaseStmtClass:
804 Range = cast<CaseStmt>(Term)->getLHS()->getSourceRange();
806 case Stmt::DefaultStmtClass:
809 Range = cast<DefaultStmt>(Term)->getDefaultLoc();
813 S.Diag(Range.getBegin(), diag::warn_sometimes_uninit_var)
814 << VD->getDeclName() << IsCapturedByBlock << DiagKind
815 << Str << I->Output << Range;
816 S.Diag(User->getLocStart(), diag::note_uninit_var_use)
817 << IsCapturedByBlock << User->getSourceRange();
818 if (RemoveDiagKind != -1)
819 S.Diag(Fixit1.RemoveRange.getBegin(), diag::note_uninit_fixit_remove_cond)
820 << RemoveDiagKind << Str << I->Output << Fixit1 << Fixit2;
826 S.Diag(Use.getUser()->getLocStart(), diag::warn_maybe_uninit_var)
827 << VD->getDeclName() << IsCapturedByBlock
828 << Use.getUser()->getSourceRange();
831 /// DiagnoseUninitializedUse -- Helper function for diagnosing uses of an
832 /// uninitialized variable. This manages the different forms of diagnostic
833 /// emitted for particular types of uses. Returns true if the use was diagnosed
834 /// as a warning. If a particular use is one we omit warnings for, returns
836 static bool DiagnoseUninitializedUse(Sema &S, const VarDecl *VD,
837 const UninitUse &Use,
838 bool alwaysReportSelfInit = false) {
840 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Use.getUser())) {
841 // Inspect the initializer of the variable declaration which is
842 // being referenced prior to its initialization. We emit
843 // specialized diagnostics for self-initialization, and we
844 // specifically avoid warning about self references which take the
849 // This is used to indicate to GCC that 'x' is intentionally left
850 // uninitialized. Proven code paths which access 'x' in
851 // an uninitialized state after this will still warn.
852 if (const Expr *Initializer = VD->getInit()) {
853 if (!alwaysReportSelfInit && DRE == Initializer->IgnoreParenImpCasts())
856 ContainsReference CR(S.Context, DRE);
857 CR.Visit(Initializer);
858 if (CR.doesContainReference()) {
859 S.Diag(DRE->getLocStart(),
860 diag::warn_uninit_self_reference_in_init)
861 << VD->getDeclName() << VD->getLocation() << DRE->getSourceRange();
866 DiagUninitUse(S, VD, Use, false);
868 const BlockExpr *BE = cast<BlockExpr>(Use.getUser());
869 if (VD->getType()->isBlockPointerType() && !VD->hasAttr<BlocksAttr>())
870 S.Diag(BE->getLocStart(),
871 diag::warn_uninit_byref_blockvar_captured_by_block)
872 << VD->getDeclName();
874 DiagUninitUse(S, VD, Use, true);
877 // Report where the variable was declared when the use wasn't within
878 // the initializer of that declaration & we didn't already suggest
879 // an initialization fixit.
880 if (!SuggestInitializationFixit(S, VD))
881 S.Diag(VD->getLocStart(), diag::note_uninit_var_def)
882 << VD->getDeclName();
888 class FallthroughMapper : public RecursiveASTVisitor<FallthroughMapper> {
890 FallthroughMapper(Sema &S)
891 : FoundSwitchStatements(false),
895 bool foundSwitchStatements() const { return FoundSwitchStatements; }
897 void markFallthroughVisited(const AttributedStmt *Stmt) {
898 bool Found = FallthroughStmts.erase(Stmt);
903 typedef llvm::SmallPtrSet<const AttributedStmt*, 8> AttrStmts;
905 const AttrStmts &getFallthroughStmts() const {
906 return FallthroughStmts;
909 void fillReachableBlocks(CFG *Cfg) {
910 assert(ReachableBlocks.empty() && "ReachableBlocks already filled");
911 std::deque<const CFGBlock *> BlockQueue;
913 ReachableBlocks.insert(&Cfg->getEntry());
914 BlockQueue.push_back(&Cfg->getEntry());
915 // Mark all case blocks reachable to avoid problems with switching on
916 // constants, covered enums, etc.
917 // These blocks can contain fall-through annotations, and we don't want to
918 // issue a warn_fallthrough_attr_unreachable for them.
919 for (const auto *B : *Cfg) {
920 const Stmt *L = B->getLabel();
921 if (L && isa<SwitchCase>(L) && ReachableBlocks.insert(B).second)
922 BlockQueue.push_back(B);
925 while (!BlockQueue.empty()) {
926 const CFGBlock *P = BlockQueue.front();
927 BlockQueue.pop_front();
928 for (CFGBlock::const_succ_iterator I = P->succ_begin(),
931 if (*I && ReachableBlocks.insert(*I).second)
932 BlockQueue.push_back(*I);
937 bool checkFallThroughIntoBlock(const CFGBlock &B, int &AnnotatedCnt) {
938 assert(!ReachableBlocks.empty() && "ReachableBlocks empty");
940 int UnannotatedCnt = 0;
943 std::deque<const CFGBlock*> BlockQueue(B.pred_begin(), B.pred_end());
944 while (!BlockQueue.empty()) {
945 const CFGBlock *P = BlockQueue.front();
946 BlockQueue.pop_front();
949 const Stmt *Term = P->getTerminator();
950 if (Term && isa<SwitchStmt>(Term))
951 continue; // Switch statement, good.
953 const SwitchCase *SW = dyn_cast_or_null<SwitchCase>(P->getLabel());
954 if (SW && SW->getSubStmt() == B.getLabel() && P->begin() == P->end())
955 continue; // Previous case label has no statements, good.
957 const LabelStmt *L = dyn_cast_or_null<LabelStmt>(P->getLabel());
958 if (L && L->getSubStmt() == B.getLabel() && P->begin() == P->end())
959 continue; // Case label is preceded with a normal label, good.
961 if (!ReachableBlocks.count(P)) {
962 for (CFGBlock::const_reverse_iterator ElemIt = P->rbegin(),
964 ElemIt != ElemEnd; ++ElemIt) {
965 if (Optional<CFGStmt> CS = ElemIt->getAs<CFGStmt>()) {
966 if (const AttributedStmt *AS = asFallThroughAttr(CS->getStmt())) {
967 S.Diag(AS->getLocStart(),
968 diag::warn_fallthrough_attr_unreachable);
969 markFallthroughVisited(AS);
973 // Don't care about other unreachable statements.
976 // If there are no unreachable statements, this may be a special
979 // A a; // A has a destructor.
982 // // <<<< This place is represented by a 'hanging' CFG block.
987 const Stmt *LastStmt = getLastStmt(*P);
988 if (const AttributedStmt *AS = asFallThroughAttr(LastStmt)) {
989 markFallthroughVisited(AS);
991 continue; // Fallthrough annotation, good.
994 if (!LastStmt) { // This block contains no executable statements.
995 // Traverse its predecessors.
996 std::copy(P->pred_begin(), P->pred_end(),
997 std::back_inserter(BlockQueue));
1003 return !!UnannotatedCnt;
1006 // RecursiveASTVisitor setup.
1007 bool shouldWalkTypesOfTypeLocs() const { return false; }
1009 bool VisitAttributedStmt(AttributedStmt *S) {
1010 if (asFallThroughAttr(S))
1011 FallthroughStmts.insert(S);
1015 bool VisitSwitchStmt(SwitchStmt *S) {
1016 FoundSwitchStatements = true;
1020 // We don't want to traverse local type declarations. We analyze their
1021 // methods separately.
1022 bool TraverseDecl(Decl *D) { return true; }
1024 // We analyze lambda bodies separately. Skip them here.
1025 bool TraverseLambdaBody(LambdaExpr *LE) { return true; }
1029 static const AttributedStmt *asFallThroughAttr(const Stmt *S) {
1030 if (const AttributedStmt *AS = dyn_cast_or_null<AttributedStmt>(S)) {
1031 if (hasSpecificAttr<FallThroughAttr>(AS->getAttrs()))
1037 static const Stmt *getLastStmt(const CFGBlock &B) {
1038 if (const Stmt *Term = B.getTerminator())
1040 for (CFGBlock::const_reverse_iterator ElemIt = B.rbegin(),
1042 ElemIt != ElemEnd; ++ElemIt) {
1043 if (Optional<CFGStmt> CS = ElemIt->getAs<CFGStmt>())
1044 return CS->getStmt();
1046 // Workaround to detect a statement thrown out by CFGBuilder:
1047 // case X: {} case Y:
1048 // case X: ; case Y:
1049 if (const SwitchCase *SW = dyn_cast_or_null<SwitchCase>(B.getLabel()))
1050 if (!isa<SwitchCase>(SW->getSubStmt()))
1051 return SW->getSubStmt();
1056 bool FoundSwitchStatements;
1057 AttrStmts FallthroughStmts;
1059 llvm::SmallPtrSet<const CFGBlock *, 16> ReachableBlocks;
1063 static void DiagnoseSwitchLabelsFallthrough(Sema &S, AnalysisDeclContext &AC,
1065 // Only perform this analysis when using C++11. There is no good workflow
1066 // for this warning when not using C++11. There is no good way to silence
1067 // the warning (no attribute is available) unless we are using C++11's support
1068 // for generalized attributes. Once could use pragmas to silence the warning,
1069 // but as a general solution that is gross and not in the spirit of this
1072 // NOTE: This an intermediate solution. There are on-going discussions on
1073 // how to properly support this warning outside of C++11 with an annotation.
1074 if (!AC.getASTContext().getLangOpts().CPlusPlus11)
1077 FallthroughMapper FM(S);
1078 FM.TraverseStmt(AC.getBody());
1080 if (!FM.foundSwitchStatements())
1083 if (PerFunction && FM.getFallthroughStmts().empty())
1086 CFG *Cfg = AC.getCFG();
1091 FM.fillReachableBlocks(Cfg);
1093 for (CFG::reverse_iterator I = Cfg->rbegin(), E = Cfg->rend(); I != E; ++I) {
1094 const CFGBlock *B = *I;
1095 const Stmt *Label = B->getLabel();
1097 if (!Label || !isa<SwitchCase>(Label))
1102 if (!FM.checkFallThroughIntoBlock(*B, AnnotatedCnt))
1105 S.Diag(Label->getLocStart(),
1106 PerFunction ? diag::warn_unannotated_fallthrough_per_function
1107 : diag::warn_unannotated_fallthrough);
1109 if (!AnnotatedCnt) {
1110 SourceLocation L = Label->getLocStart();
1113 if (S.getLangOpts().CPlusPlus11) {
1114 const Stmt *Term = B->getTerminator();
1115 // Skip empty cases.
1116 while (B->empty() && !Term && B->succ_size() == 1) {
1117 B = *B->succ_begin();
1118 Term = B->getTerminator();
1120 if (!(B->empty() && Term && isa<BreakStmt>(Term))) {
1121 Preprocessor &PP = S.getPreprocessor();
1122 TokenValue Tokens[] = {
1123 tok::l_square, tok::l_square, PP.getIdentifierInfo("clang"),
1124 tok::coloncolon, PP.getIdentifierInfo("fallthrough"),
1125 tok::r_square, tok::r_square
1127 StringRef AnnotationSpelling = "[[clang::fallthrough]]";
1128 StringRef MacroName = PP.getLastMacroWithSpelling(L, Tokens);
1129 if (!MacroName.empty())
1130 AnnotationSpelling = MacroName;
1131 SmallString<64> TextToInsert(AnnotationSpelling);
1132 TextToInsert += "; ";
1133 S.Diag(L, diag::note_insert_fallthrough_fixit) <<
1134 AnnotationSpelling <<
1135 FixItHint::CreateInsertion(L, TextToInsert);
1138 S.Diag(L, diag::note_insert_break_fixit) <<
1139 FixItHint::CreateInsertion(L, "break; ");
1143 for (const auto *F : FM.getFallthroughStmts())
1144 S.Diag(F->getLocStart(), diag::warn_fallthrough_attr_invalid_placement);
1147 static bool isInLoop(const ASTContext &Ctx, const ParentMap &PM,
1152 switch (S->getStmtClass()) {
1153 case Stmt::ForStmtClass:
1154 case Stmt::WhileStmtClass:
1155 case Stmt::CXXForRangeStmtClass:
1156 case Stmt::ObjCForCollectionStmtClass:
1158 case Stmt::DoStmtClass: {
1159 const Expr *Cond = cast<DoStmt>(S)->getCond();
1161 if (!Cond->EvaluateAsInt(Val, Ctx))
1163 return Val.getBoolValue();
1168 } while ((S = PM.getParent(S)));
1174 static void diagnoseRepeatedUseOfWeak(Sema &S,
1175 const sema::FunctionScopeInfo *CurFn,
1177 const ParentMap &PM) {
1178 typedef sema::FunctionScopeInfo::WeakObjectProfileTy WeakObjectProfileTy;
1179 typedef sema::FunctionScopeInfo::WeakObjectUseMap WeakObjectUseMap;
1180 typedef sema::FunctionScopeInfo::WeakUseVector WeakUseVector;
1181 typedef std::pair<const Stmt *, WeakObjectUseMap::const_iterator>
1184 ASTContext &Ctx = S.getASTContext();
1186 const WeakObjectUseMap &WeakMap = CurFn->getWeakObjectUses();
1188 // Extract all weak objects that are referenced more than once.
1189 SmallVector<StmtUsesPair, 8> UsesByStmt;
1190 for (WeakObjectUseMap::const_iterator I = WeakMap.begin(), E = WeakMap.end();
1192 const WeakUseVector &Uses = I->second;
1194 // Find the first read of the weak object.
1195 WeakUseVector::const_iterator UI = Uses.begin(), UE = Uses.end();
1196 for ( ; UI != UE; ++UI) {
1201 // If there were only writes to this object, don't warn.
1205 // If there was only one read, followed by any number of writes, and the
1206 // read is not within a loop, don't warn. Additionally, don't warn in a
1207 // loop if the base object is a local variable -- local variables are often
1208 // changed in loops.
1209 if (UI == Uses.begin()) {
1210 WeakUseVector::const_iterator UI2 = UI;
1211 for (++UI2; UI2 != UE; ++UI2)
1212 if (UI2->isUnsafe())
1216 if (!isInLoop(Ctx, PM, UI->getUseExpr()))
1219 const WeakObjectProfileTy &Profile = I->first;
1220 if (!Profile.isExactProfile())
1223 const NamedDecl *Base = Profile.getBase();
1225 Base = Profile.getProperty();
1226 assert(Base && "A profile always has a base or property.");
1228 if (const VarDecl *BaseVar = dyn_cast<VarDecl>(Base))
1229 if (BaseVar->hasLocalStorage() && !isa<ParmVarDecl>(Base))
1234 UsesByStmt.push_back(StmtUsesPair(UI->getUseExpr(), I));
1237 if (UsesByStmt.empty())
1240 // Sort by first use so that we emit the warnings in a deterministic order.
1241 SourceManager &SM = S.getSourceManager();
1242 std::sort(UsesByStmt.begin(), UsesByStmt.end(),
1243 [&SM](const StmtUsesPair &LHS, const StmtUsesPair &RHS) {
1244 return SM.isBeforeInTranslationUnit(LHS.first->getLocStart(),
1245 RHS.first->getLocStart());
1248 // Classify the current code body for better warning text.
1249 // This enum should stay in sync with the cases in
1250 // warn_arc_repeated_use_of_weak and warn_arc_possible_repeated_use_of_weak.
1251 // FIXME: Should we use a common classification enum and the same set of
1252 // possibilities all throughout Sema?
1260 if (isa<sema::BlockScopeInfo>(CurFn))
1261 FunctionKind = Block;
1262 else if (isa<sema::LambdaScopeInfo>(CurFn))
1263 FunctionKind = Lambda;
1264 else if (isa<ObjCMethodDecl>(D))
1265 FunctionKind = Method;
1267 FunctionKind = Function;
1269 // Iterate through the sorted problems and emit warnings for each.
1270 for (const auto &P : UsesByStmt) {
1271 const Stmt *FirstRead = P.first;
1272 const WeakObjectProfileTy &Key = P.second->first;
1273 const WeakUseVector &Uses = P.second->second;
1275 // For complicated expressions like 'a.b.c' and 'x.b.c', WeakObjectProfileTy
1276 // may not contain enough information to determine that these are different
1277 // properties. We can only be 100% sure of a repeated use in certain cases,
1278 // and we adjust the diagnostic kind accordingly so that the less certain
1279 // case can be turned off if it is too noisy.
1281 if (Key.isExactProfile())
1282 DiagKind = diag::warn_arc_repeated_use_of_weak;
1284 DiagKind = diag::warn_arc_possible_repeated_use_of_weak;
1286 // Classify the weak object being accessed for better warning text.
1287 // This enum should stay in sync with the cases in
1288 // warn_arc_repeated_use_of_weak and warn_arc_possible_repeated_use_of_weak.
1296 const NamedDecl *D = Key.getProperty();
1297 if (isa<VarDecl>(D))
1298 ObjectKind = Variable;
1299 else if (isa<ObjCPropertyDecl>(D))
1300 ObjectKind = Property;
1301 else if (isa<ObjCMethodDecl>(D))
1302 ObjectKind = ImplicitProperty;
1303 else if (isa<ObjCIvarDecl>(D))
1306 llvm_unreachable("Unexpected weak object kind!");
1308 // Show the first time the object was read.
1309 S.Diag(FirstRead->getLocStart(), DiagKind)
1310 << int(ObjectKind) << D << int(FunctionKind)
1311 << FirstRead->getSourceRange();
1313 // Print all the other accesses as notes.
1314 for (const auto &Use : Uses) {
1315 if (Use.getUseExpr() == FirstRead)
1317 S.Diag(Use.getUseExpr()->getLocStart(),
1318 diag::note_arc_weak_also_accessed_here)
1319 << Use.getUseExpr()->getSourceRange();
1325 class UninitValsDiagReporter : public UninitVariablesHandler {
1327 typedef SmallVector<UninitUse, 2> UsesVec;
1328 typedef llvm::PointerIntPair<UsesVec *, 1, bool> MappedType;
1329 // Prefer using MapVector to DenseMap, so that iteration order will be
1330 // the same as insertion order. This is needed to obtain a deterministic
1331 // order of diagnostics when calling flushDiagnostics().
1332 typedef llvm::MapVector<const VarDecl *, MappedType> UsesMap;
1336 UninitValsDiagReporter(Sema &S) : S(S), uses(nullptr) {}
1337 ~UninitValsDiagReporter() override { flushDiagnostics(); }
1339 MappedType &getUses(const VarDecl *vd) {
1341 uses = new UsesMap();
1343 MappedType &V = (*uses)[vd];
1344 if (!V.getPointer())
1345 V.setPointer(new UsesVec());
1350 void handleUseOfUninitVariable(const VarDecl *vd,
1351 const UninitUse &use) override {
1352 getUses(vd).getPointer()->push_back(use);
1355 void handleSelfInit(const VarDecl *vd) override {
1356 getUses(vd).setInt(true);
1359 void flushDiagnostics() {
1363 for (const auto &P : *uses) {
1364 const VarDecl *vd = P.first;
1365 const MappedType &V = P.second;
1367 UsesVec *vec = V.getPointer();
1368 bool hasSelfInit = V.getInt();
1370 // Specially handle the case where we have uses of an uninitialized
1371 // variable, but the root cause is an idiomatic self-init. We want
1372 // to report the diagnostic at the self-init since that is the root cause.
1373 if (!vec->empty() && hasSelfInit && hasAlwaysUninitializedUse(vec))
1374 DiagnoseUninitializedUse(S, vd,
1375 UninitUse(vd->getInit()->IgnoreParenCasts(),
1376 /* isAlwaysUninit */ true),
1377 /* alwaysReportSelfInit */ true);
1379 // Sort the uses by their SourceLocations. While not strictly
1380 // guaranteed to produce them in line/column order, this will provide
1381 // a stable ordering.
1382 std::sort(vec->begin(), vec->end(),
1383 [](const UninitUse &a, const UninitUse &b) {
1384 // Prefer a more confident report over a less confident one.
1385 if (a.getKind() != b.getKind())
1386 return a.getKind() > b.getKind();
1387 return a.getUser()->getLocStart() < b.getUser()->getLocStart();
1390 for (const auto &U : *vec) {
1391 // If we have self-init, downgrade all uses to 'may be uninitialized'.
1392 UninitUse Use = hasSelfInit ? UninitUse(U.getUser(), false) : U;
1394 if (DiagnoseUninitializedUse(S, vd, Use))
1395 // Skip further diagnostics for this variable. We try to warn only
1396 // on the first point at which a variable is used uninitialized.
1401 // Release the uses vector.
1408 static bool hasAlwaysUninitializedUse(const UsesVec* vec) {
1409 return std::any_of(vec->begin(), vec->end(), [](const UninitUse &U) {
1410 return U.getKind() == UninitUse::Always ||
1411 U.getKind() == UninitUse::AfterCall ||
1412 U.getKind() == UninitUse::AfterDecl;
1420 typedef SmallVector<PartialDiagnosticAt, 1> OptionalNotes;
1421 typedef std::pair<PartialDiagnosticAt, OptionalNotes> DelayedDiag;
1422 typedef std::list<DelayedDiag> DiagList;
1424 struct SortDiagBySourceLocation {
1426 SortDiagBySourceLocation(SourceManager &SM) : SM(SM) {}
1428 bool operator()(const DelayedDiag &left, const DelayedDiag &right) {
1429 // Although this call will be slow, this is only called when outputting
1430 // multiple warnings.
1431 return SM.isBeforeInTranslationUnit(left.first.first, right.first.first);
1436 //===----------------------------------------------------------------------===//
1438 //===----------------------------------------------------------------------===//
1440 namespace threadSafety {
1442 class ThreadSafetyReporter : public clang::threadSafety::ThreadSafetyHandler {
1445 SourceLocation FunLocation, FunEndLocation;
1447 const FunctionDecl *CurrentFunction;
1450 OptionalNotes getNotes() const {
1451 if (Verbose && CurrentFunction) {
1452 PartialDiagnosticAt FNote(CurrentFunction->getBody()->getLocStart(),
1453 S.PDiag(diag::note_thread_warning_in_fun)
1454 << CurrentFunction->getNameAsString());
1455 return OptionalNotes(1, FNote);
1457 return OptionalNotes();
1460 OptionalNotes getNotes(const PartialDiagnosticAt &Note) const {
1461 OptionalNotes ONS(1, Note);
1462 if (Verbose && CurrentFunction) {
1463 PartialDiagnosticAt FNote(CurrentFunction->getBody()->getLocStart(),
1464 S.PDiag(diag::note_thread_warning_in_fun)
1465 << CurrentFunction->getNameAsString());
1466 ONS.push_back(std::move(FNote));
1471 OptionalNotes getNotes(const PartialDiagnosticAt &Note1,
1472 const PartialDiagnosticAt &Note2) const {
1474 ONS.push_back(Note1);
1475 ONS.push_back(Note2);
1476 if (Verbose && CurrentFunction) {
1477 PartialDiagnosticAt FNote(CurrentFunction->getBody()->getLocStart(),
1478 S.PDiag(diag::note_thread_warning_in_fun)
1479 << CurrentFunction->getNameAsString());
1480 ONS.push_back(std::move(FNote));
1486 void warnLockMismatch(unsigned DiagID, StringRef Kind, Name LockName,
1487 SourceLocation Loc) {
1488 // Gracefully handle rare cases when the analysis can't get a more
1489 // precise source location.
1492 PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID) << Kind << LockName);
1493 Warnings.emplace_back(std::move(Warning), getNotes());
1497 ThreadSafetyReporter(Sema &S, SourceLocation FL, SourceLocation FEL)
1498 : S(S), FunLocation(FL), FunEndLocation(FEL),
1499 CurrentFunction(nullptr), Verbose(false) {}
1501 void setVerbose(bool b) { Verbose = b; }
1503 /// \brief Emit all buffered diagnostics in order of sourcelocation.
1504 /// We need to output diagnostics produced while iterating through
1505 /// the lockset in deterministic order, so this function orders diagnostics
1506 /// and outputs them.
1507 void emitDiagnostics() {
1508 Warnings.sort(SortDiagBySourceLocation(S.getSourceManager()));
1509 for (const auto &Diag : Warnings) {
1510 S.Diag(Diag.first.first, Diag.first.second);
1511 for (const auto &Note : Diag.second)
1512 S.Diag(Note.first, Note.second);
1516 void handleInvalidLockExp(StringRef Kind, SourceLocation Loc) override {
1517 PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_cannot_resolve_lock)
1519 Warnings.emplace_back(std::move(Warning), getNotes());
1522 void handleUnmatchedUnlock(StringRef Kind, Name LockName,
1523 SourceLocation Loc) override {
1524 warnLockMismatch(diag::warn_unlock_but_no_lock, Kind, LockName, Loc);
1527 void handleIncorrectUnlockKind(StringRef Kind, Name LockName,
1528 LockKind Expected, LockKind Received,
1529 SourceLocation Loc) override {
1530 if (Loc.isInvalid())
1532 PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_unlock_kind_mismatch)
1533 << Kind << LockName << Received
1535 Warnings.emplace_back(std::move(Warning), getNotes());
1538 void handleDoubleLock(StringRef Kind, Name LockName, SourceLocation Loc) override {
1539 warnLockMismatch(diag::warn_double_lock, Kind, LockName, Loc);
1542 void handleMutexHeldEndOfScope(StringRef Kind, Name LockName,
1543 SourceLocation LocLocked,
1544 SourceLocation LocEndOfScope,
1545 LockErrorKind LEK) override {
1546 unsigned DiagID = 0;
1548 case LEK_LockedSomePredecessors:
1549 DiagID = diag::warn_lock_some_predecessors;
1551 case LEK_LockedSomeLoopIterations:
1552 DiagID = diag::warn_expecting_lock_held_on_loop;
1554 case LEK_LockedAtEndOfFunction:
1555 DiagID = diag::warn_no_unlock;
1557 case LEK_NotLockedAtEndOfFunction:
1558 DiagID = diag::warn_expecting_locked;
1561 if (LocEndOfScope.isInvalid())
1562 LocEndOfScope = FunEndLocation;
1564 PartialDiagnosticAt Warning(LocEndOfScope, S.PDiag(DiagID) << Kind
1566 if (LocLocked.isValid()) {
1567 PartialDiagnosticAt Note(LocLocked, S.PDiag(diag::note_locked_here)
1569 Warnings.emplace_back(std::move(Warning), getNotes(Note));
1572 Warnings.emplace_back(std::move(Warning), getNotes());
1575 void handleExclusiveAndShared(StringRef Kind, Name LockName,
1576 SourceLocation Loc1,
1577 SourceLocation Loc2) override {
1578 PartialDiagnosticAt Warning(Loc1,
1579 S.PDiag(diag::warn_lock_exclusive_and_shared)
1580 << Kind << LockName);
1581 PartialDiagnosticAt Note(Loc2, S.PDiag(diag::note_lock_exclusive_and_shared)
1582 << Kind << LockName);
1583 Warnings.emplace_back(std::move(Warning), getNotes(Note));
1586 void handleNoMutexHeld(StringRef Kind, const NamedDecl *D,
1587 ProtectedOperationKind POK, AccessKind AK,
1588 SourceLocation Loc) override {
1589 assert((POK == POK_VarAccess || POK == POK_VarDereference) &&
1590 "Only works for variables");
1591 unsigned DiagID = POK == POK_VarAccess?
1592 diag::warn_variable_requires_any_lock:
1593 diag::warn_var_deref_requires_any_lock;
1594 PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID)
1595 << D->getNameAsString() << getLockKindFromAccessKind(AK));
1596 Warnings.emplace_back(std::move(Warning), getNotes());
1599 void handleMutexNotHeld(StringRef Kind, const NamedDecl *D,
1600 ProtectedOperationKind POK, Name LockName,
1601 LockKind LK, SourceLocation Loc,
1602 Name *PossibleMatch) override {
1603 unsigned DiagID = 0;
1604 if (PossibleMatch) {
1607 DiagID = diag::warn_variable_requires_lock_precise;
1609 case POK_VarDereference:
1610 DiagID = diag::warn_var_deref_requires_lock_precise;
1612 case POK_FunctionCall:
1613 DiagID = diag::warn_fun_requires_lock_precise;
1616 DiagID = diag::warn_guarded_pass_by_reference;
1618 case POK_PtPassByRef:
1619 DiagID = diag::warn_pt_guarded_pass_by_reference;
1622 PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID) << Kind
1623 << D->getNameAsString()
1625 PartialDiagnosticAt Note(Loc, S.PDiag(diag::note_found_mutex_near_match)
1627 if (Verbose && POK == POK_VarAccess) {
1628 PartialDiagnosticAt VNote(D->getLocation(),
1629 S.PDiag(diag::note_guarded_by_declared_here)
1630 << D->getNameAsString());
1631 Warnings.emplace_back(std::move(Warning), getNotes(Note, VNote));
1633 Warnings.emplace_back(std::move(Warning), getNotes(Note));
1637 DiagID = diag::warn_variable_requires_lock;
1639 case POK_VarDereference:
1640 DiagID = diag::warn_var_deref_requires_lock;
1642 case POK_FunctionCall:
1643 DiagID = diag::warn_fun_requires_lock;
1646 DiagID = diag::warn_guarded_pass_by_reference;
1648 case POK_PtPassByRef:
1649 DiagID = diag::warn_pt_guarded_pass_by_reference;
1652 PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID) << Kind
1653 << D->getNameAsString()
1655 if (Verbose && POK == POK_VarAccess) {
1656 PartialDiagnosticAt Note(D->getLocation(),
1657 S.PDiag(diag::note_guarded_by_declared_here)
1658 << D->getNameAsString());
1659 Warnings.emplace_back(std::move(Warning), getNotes(Note));
1661 Warnings.emplace_back(std::move(Warning), getNotes());
1665 void handleNegativeNotHeld(StringRef Kind, Name LockName, Name Neg,
1666 SourceLocation Loc) override {
1667 PartialDiagnosticAt Warning(Loc,
1668 S.PDiag(diag::warn_acquire_requires_negative_cap)
1669 << Kind << LockName << Neg);
1670 Warnings.emplace_back(std::move(Warning), getNotes());
1674 void handleFunExcludesLock(StringRef Kind, Name FunName, Name LockName,
1675 SourceLocation Loc) override {
1676 PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_fun_excludes_mutex)
1677 << Kind << FunName << LockName);
1678 Warnings.emplace_back(std::move(Warning), getNotes());
1681 void handleLockAcquiredBefore(StringRef Kind, Name L1Name, Name L2Name,
1682 SourceLocation Loc) override {
1683 PartialDiagnosticAt Warning(Loc,
1684 S.PDiag(diag::warn_acquired_before) << Kind << L1Name << L2Name);
1685 Warnings.emplace_back(std::move(Warning), getNotes());
1688 void handleBeforeAfterCycle(Name L1Name, SourceLocation Loc) override {
1689 PartialDiagnosticAt Warning(Loc,
1690 S.PDiag(diag::warn_acquired_before_after_cycle) << L1Name);
1691 Warnings.emplace_back(std::move(Warning), getNotes());
1694 void enterFunction(const FunctionDecl* FD) override {
1695 CurrentFunction = FD;
1698 void leaveFunction(const FunctionDecl* FD) override {
1699 CurrentFunction = 0;
1703 } // namespace threadSafety
1704 } // namespace clang
1706 //===----------------------------------------------------------------------===//
1708 //===----------------------------------------------------------------------===//
1711 namespace consumed {
1713 class ConsumedWarningsHandler : public ConsumedWarningsHandlerBase {
1720 ConsumedWarningsHandler(Sema &S) : S(S) {}
1722 void emitDiagnostics() override {
1723 Warnings.sort(SortDiagBySourceLocation(S.getSourceManager()));
1724 for (const auto &Diag : Warnings) {
1725 S.Diag(Diag.first.first, Diag.first.second);
1726 for (const auto &Note : Diag.second)
1727 S.Diag(Note.first, Note.second);
1731 void warnLoopStateMismatch(SourceLocation Loc,
1732 StringRef VariableName) override {
1733 PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_loop_state_mismatch) <<
1736 Warnings.emplace_back(std::move(Warning), OptionalNotes());
1739 void warnParamReturnTypestateMismatch(SourceLocation Loc,
1740 StringRef VariableName,
1741 StringRef ExpectedState,
1742 StringRef ObservedState) override {
1744 PartialDiagnosticAt Warning(Loc, S.PDiag(
1745 diag::warn_param_return_typestate_mismatch) << VariableName <<
1746 ExpectedState << ObservedState);
1748 Warnings.emplace_back(std::move(Warning), OptionalNotes());
1751 void warnParamTypestateMismatch(SourceLocation Loc, StringRef ExpectedState,
1752 StringRef ObservedState) override {
1754 PartialDiagnosticAt Warning(Loc, S.PDiag(
1755 diag::warn_param_typestate_mismatch) << ExpectedState << ObservedState);
1757 Warnings.emplace_back(std::move(Warning), OptionalNotes());
1760 void warnReturnTypestateForUnconsumableType(SourceLocation Loc,
1761 StringRef TypeName) override {
1762 PartialDiagnosticAt Warning(Loc, S.PDiag(
1763 diag::warn_return_typestate_for_unconsumable_type) << TypeName);
1765 Warnings.emplace_back(std::move(Warning), OptionalNotes());
1768 void warnReturnTypestateMismatch(SourceLocation Loc, StringRef ExpectedState,
1769 StringRef ObservedState) override {
1771 PartialDiagnosticAt Warning(Loc, S.PDiag(
1772 diag::warn_return_typestate_mismatch) << ExpectedState << ObservedState);
1774 Warnings.emplace_back(std::move(Warning), OptionalNotes());
1777 void warnUseOfTempInInvalidState(StringRef MethodName, StringRef State,
1778 SourceLocation Loc) override {
1780 PartialDiagnosticAt Warning(Loc, S.PDiag(
1781 diag::warn_use_of_temp_in_invalid_state) << MethodName << State);
1783 Warnings.emplace_back(std::move(Warning), OptionalNotes());
1786 void warnUseInInvalidState(StringRef MethodName, StringRef VariableName,
1787 StringRef State, SourceLocation Loc) override {
1789 PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_use_in_invalid_state) <<
1790 MethodName << VariableName << State);
1792 Warnings.emplace_back(std::move(Warning), OptionalNotes());
1797 //===----------------------------------------------------------------------===//
1798 // AnalysisBasedWarnings - Worker object used by Sema to execute analysis-based
1799 // warnings on a function, method, or block.
1800 //===----------------------------------------------------------------------===//
1802 clang::sema::AnalysisBasedWarnings::Policy::Policy() {
1803 enableCheckFallThrough = 1;
1804 enableCheckUnreachable = 0;
1805 enableThreadSafetyAnalysis = 0;
1806 enableConsumedAnalysis = 0;
1809 static unsigned isEnabled(DiagnosticsEngine &D, unsigned diag) {
1810 return (unsigned)!D.isIgnored(diag, SourceLocation());
1813 clang::sema::AnalysisBasedWarnings::AnalysisBasedWarnings(Sema &s)
1815 NumFunctionsAnalyzed(0),
1816 NumFunctionsWithBadCFGs(0),
1818 MaxCFGBlocksPerFunction(0),
1819 NumUninitAnalysisFunctions(0),
1820 NumUninitAnalysisVariables(0),
1821 MaxUninitAnalysisVariablesPerFunction(0),
1822 NumUninitAnalysisBlockVisits(0),
1823 MaxUninitAnalysisBlockVisitsPerFunction(0) {
1825 using namespace diag;
1826 DiagnosticsEngine &D = S.getDiagnostics();
1828 DefaultPolicy.enableCheckUnreachable =
1829 isEnabled(D, warn_unreachable) ||
1830 isEnabled(D, warn_unreachable_break) ||
1831 isEnabled(D, warn_unreachable_return) ||
1832 isEnabled(D, warn_unreachable_loop_increment);
1834 DefaultPolicy.enableThreadSafetyAnalysis =
1835 isEnabled(D, warn_double_lock);
1837 DefaultPolicy.enableConsumedAnalysis =
1838 isEnabled(D, warn_use_in_invalid_state);
1841 static void flushDiagnostics(Sema &S, const sema::FunctionScopeInfo *fscope) {
1842 for (const auto &D : fscope->PossiblyUnreachableDiags)
1843 S.Diag(D.Loc, D.PD);
1847 AnalysisBasedWarnings::IssueWarnings(sema::AnalysisBasedWarnings::Policy P,
1848 sema::FunctionScopeInfo *fscope,
1849 const Decl *D, const BlockExpr *blkExpr) {
1851 // We avoid doing analysis-based warnings when there are errors for
1853 // (1) The CFGs often can't be constructed (if the body is invalid), so
1854 // don't bother trying.
1855 // (2) The code already has problems; running the analysis just takes more
1857 DiagnosticsEngine &Diags = S.getDiagnostics();
1859 // Do not do any analysis for declarations in system headers if we are
1860 // going to just ignore them.
1861 if (Diags.getSuppressSystemWarnings() &&
1862 S.SourceMgr.isInSystemHeader(D->getLocation()))
1865 // For code in dependent contexts, we'll do this at instantiation time.
1866 if (cast<DeclContext>(D)->isDependentContext())
1869 if (Diags.hasUncompilableErrorOccurred() || Diags.hasFatalErrorOccurred()) {
1870 // Flush out any possibly unreachable diagnostics.
1871 flushDiagnostics(S, fscope);
1875 const Stmt *Body = D->getBody();
1878 // Construct the analysis context with the specified CFG build options.
1879 AnalysisDeclContext AC(/* AnalysisDeclContextManager */ nullptr, D);
1881 // Don't generate EH edges for CallExprs as we'd like to avoid the n^2
1882 // explosion for destructors that can result and the compile time hit.
1883 AC.getCFGBuildOptions().PruneTriviallyFalseEdges = true;
1884 AC.getCFGBuildOptions().AddEHEdges = false;
1885 AC.getCFGBuildOptions().AddInitializers = true;
1886 AC.getCFGBuildOptions().AddImplicitDtors = true;
1887 AC.getCFGBuildOptions().AddTemporaryDtors = true;
1888 AC.getCFGBuildOptions().AddCXXNewAllocator = false;
1889 AC.getCFGBuildOptions().AddCXXDefaultInitExprInCtors = true;
1891 // Force that certain expressions appear as CFGElements in the CFG. This
1892 // is used to speed up various analyses.
1893 // FIXME: This isn't the right factoring. This is here for initial
1894 // prototyping, but we need a way for analyses to say what expressions they
1895 // expect to always be CFGElements and then fill in the BuildOptions
1896 // appropriately. This is essentially a layering violation.
1897 if (P.enableCheckUnreachable || P.enableThreadSafetyAnalysis ||
1898 P.enableConsumedAnalysis) {
1899 // Unreachable code analysis and thread safety require a linearized CFG.
1900 AC.getCFGBuildOptions().setAllAlwaysAdd();
1903 AC.getCFGBuildOptions()
1904 .setAlwaysAdd(Stmt::BinaryOperatorClass)
1905 .setAlwaysAdd(Stmt::CompoundAssignOperatorClass)
1906 .setAlwaysAdd(Stmt::BlockExprClass)
1907 .setAlwaysAdd(Stmt::CStyleCastExprClass)
1908 .setAlwaysAdd(Stmt::DeclRefExprClass)
1909 .setAlwaysAdd(Stmt::ImplicitCastExprClass)
1910 .setAlwaysAdd(Stmt::UnaryOperatorClass)
1911 .setAlwaysAdd(Stmt::AttributedStmtClass);
1914 // Install the logical handler for -Wtautological-overlap-compare
1915 std::unique_ptr<LogicalErrorHandler> LEH;
1916 if (!Diags.isIgnored(diag::warn_tautological_overlap_comparison,
1917 D->getLocStart())) {
1918 LEH.reset(new LogicalErrorHandler(S));
1919 AC.getCFGBuildOptions().Observer = LEH.get();
1922 // Emit delayed diagnostics.
1923 if (!fscope->PossiblyUnreachableDiags.empty()) {
1924 bool analyzed = false;
1926 // Register the expressions with the CFGBuilder.
1927 for (const auto &D : fscope->PossiblyUnreachableDiags) {
1929 AC.registerForcedBlockExpression(D.stmt);
1934 for (const auto &D : fscope->PossiblyUnreachableDiags) {
1935 bool processed = false;
1937 const CFGBlock *block = AC.getBlockForRegisteredExpression(D.stmt);
1938 CFGReverseBlockReachabilityAnalysis *cra =
1939 AC.getCFGReachablityAnalysis();
1940 // FIXME: We should be able to assert that block is non-null, but
1941 // the CFG analysis can skip potentially-evaluated expressions in
1942 // edge cases; see test/Sema/vla-2.c.
1944 // Can this block be reached from the entrance?
1945 if (cra->isReachable(&AC.getCFG()->getEntry(), block))
1946 S.Diag(D.Loc, D.PD);
1951 // Emit the warning anyway if we cannot map to a basic block.
1952 S.Diag(D.Loc, D.PD);
1958 flushDiagnostics(S, fscope);
1962 // Warning: check missing 'return'
1963 if (P.enableCheckFallThrough) {
1964 const CheckFallThroughDiagnostics &CD =
1965 (isa<BlockDecl>(D) ? CheckFallThroughDiagnostics::MakeForBlock()
1966 : (isa<CXXMethodDecl>(D) &&
1967 cast<CXXMethodDecl>(D)->getOverloadedOperator() == OO_Call &&
1968 cast<CXXMethodDecl>(D)->getParent()->isLambda())
1969 ? CheckFallThroughDiagnostics::MakeForLambda()
1970 : CheckFallThroughDiagnostics::MakeForFunction(D));
1971 CheckFallThroughForBody(S, D, Body, blkExpr, CD, AC);
1974 // Warning: check for unreachable code
1975 if (P.enableCheckUnreachable) {
1976 // Only check for unreachable code on non-template instantiations.
1977 // Different template instantiations can effectively change the control-flow
1978 // and it is very difficult to prove that a snippet of code in a template
1979 // is unreachable for all instantiations.
1980 bool isTemplateInstantiation = false;
1981 if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D))
1982 isTemplateInstantiation = Function->isTemplateInstantiation();
1983 if (!isTemplateInstantiation)
1984 CheckUnreachable(S, AC);
1987 // Check for thread safety violations
1988 if (P.enableThreadSafetyAnalysis) {
1989 SourceLocation FL = AC.getDecl()->getLocation();
1990 SourceLocation FEL = AC.getDecl()->getLocEnd();
1991 threadSafety::ThreadSafetyReporter Reporter(S, FL, FEL);
1992 if (!Diags.isIgnored(diag::warn_thread_safety_beta, D->getLocStart()))
1993 Reporter.setIssueBetaWarnings(true);
1994 if (!Diags.isIgnored(diag::warn_thread_safety_verbose, D->getLocStart()))
1995 Reporter.setVerbose(true);
1997 threadSafety::runThreadSafetyAnalysis(AC, Reporter,
1998 &S.ThreadSafetyDeclCache);
1999 Reporter.emitDiagnostics();
2002 // Check for violations of consumed properties.
2003 if (P.enableConsumedAnalysis) {
2004 consumed::ConsumedWarningsHandler WarningHandler(S);
2005 consumed::ConsumedAnalyzer Analyzer(WarningHandler);
2009 if (!Diags.isIgnored(diag::warn_uninit_var, D->getLocStart()) ||
2010 !Diags.isIgnored(diag::warn_sometimes_uninit_var, D->getLocStart()) ||
2011 !Diags.isIgnored(diag::warn_maybe_uninit_var, D->getLocStart())) {
2012 if (CFG *cfg = AC.getCFG()) {
2013 UninitValsDiagReporter reporter(S);
2014 UninitVariablesAnalysisStats stats;
2015 std::memset(&stats, 0, sizeof(UninitVariablesAnalysisStats));
2016 runUninitializedVariablesAnalysis(*cast<DeclContext>(D), *cfg, AC,
2019 if (S.CollectStats && stats.NumVariablesAnalyzed > 0) {
2020 ++NumUninitAnalysisFunctions;
2021 NumUninitAnalysisVariables += stats.NumVariablesAnalyzed;
2022 NumUninitAnalysisBlockVisits += stats.NumBlockVisits;
2023 MaxUninitAnalysisVariablesPerFunction =
2024 std::max(MaxUninitAnalysisVariablesPerFunction,
2025 stats.NumVariablesAnalyzed);
2026 MaxUninitAnalysisBlockVisitsPerFunction =
2027 std::max(MaxUninitAnalysisBlockVisitsPerFunction,
2028 stats.NumBlockVisits);
2033 bool FallThroughDiagFull =
2034 !Diags.isIgnored(diag::warn_unannotated_fallthrough, D->getLocStart());
2035 bool FallThroughDiagPerFunction = !Diags.isIgnored(
2036 diag::warn_unannotated_fallthrough_per_function, D->getLocStart());
2037 if (FallThroughDiagFull || FallThroughDiagPerFunction) {
2038 DiagnoseSwitchLabelsFallthrough(S, AC, !FallThroughDiagFull);
2041 if (S.getLangOpts().ObjCARCWeak &&
2042 !Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, D->getLocStart()))
2043 diagnoseRepeatedUseOfWeak(S, fscope, D, AC.getParentMap());
2046 // Check for infinite self-recursion in functions
2047 if (!Diags.isIgnored(diag::warn_infinite_recursive_function,
2048 D->getLocStart())) {
2049 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
2050 checkRecursiveFunction(S, FD, Body, AC);
2054 // If none of the previous checks caused a CFG build, trigger one here
2055 // for -Wtautological-overlap-compare
2056 if (!Diags.isIgnored(diag::warn_tautological_overlap_comparison,
2057 D->getLocStart())) {
2061 // Collect statistics about the CFG if it was built.
2062 if (S.CollectStats && AC.isCFGBuilt()) {
2063 ++NumFunctionsAnalyzed;
2064 if (CFG *cfg = AC.getCFG()) {
2065 // If we successfully built a CFG for this context, record some more
2066 // detail information about it.
2067 NumCFGBlocks += cfg->getNumBlockIDs();
2068 MaxCFGBlocksPerFunction = std::max(MaxCFGBlocksPerFunction,
2069 cfg->getNumBlockIDs());
2071 ++NumFunctionsWithBadCFGs;
2076 void clang::sema::AnalysisBasedWarnings::PrintStats() const {
2077 llvm::errs() << "\n*** Analysis Based Warnings Stats:\n";
2079 unsigned NumCFGsBuilt = NumFunctionsAnalyzed - NumFunctionsWithBadCFGs;
2080 unsigned AvgCFGBlocksPerFunction =
2081 !NumCFGsBuilt ? 0 : NumCFGBlocks/NumCFGsBuilt;
2082 llvm::errs() << NumFunctionsAnalyzed << " functions analyzed ("
2083 << NumFunctionsWithBadCFGs << " w/o CFGs).\n"
2084 << " " << NumCFGBlocks << " CFG blocks built.\n"
2085 << " " << AvgCFGBlocksPerFunction
2086 << " average CFG blocks per function.\n"
2087 << " " << MaxCFGBlocksPerFunction
2088 << " max CFG blocks per function.\n";
2090 unsigned AvgUninitVariablesPerFunction = !NumUninitAnalysisFunctions ? 0
2091 : NumUninitAnalysisVariables/NumUninitAnalysisFunctions;
2092 unsigned AvgUninitBlockVisitsPerFunction = !NumUninitAnalysisFunctions ? 0
2093 : NumUninitAnalysisBlockVisits/NumUninitAnalysisFunctions;
2094 llvm::errs() << NumUninitAnalysisFunctions
2095 << " functions analyzed for uninitialiazed variables\n"
2096 << " " << NumUninitAnalysisVariables << " variables analyzed.\n"
2097 << " " << AvgUninitVariablesPerFunction
2098 << " average variables per function.\n"
2099 << " " << MaxUninitAnalysisVariablesPerFunction
2100 << " max variables per function.\n"
2101 << " " << NumUninitAnalysisBlockVisits << " block visits.\n"
2102 << " " << AvgUninitBlockVisitsPerFunction
2103 << " average block visits per function.\n"
2104 << " " << MaxUninitAnalysisBlockVisitsPerFunction
2105 << " max block visits per function.\n";