diff options
Diffstat (limited to 'contrib/llvm/tools/clang/lib/Sema/AnalysisBasedWarnings.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/Sema/AnalysisBasedWarnings.cpp | 200 |
1 files changed, 184 insertions, 16 deletions
diff --git a/contrib/llvm/tools/clang/lib/Sema/AnalysisBasedWarnings.cpp b/contrib/llvm/tools/clang/lib/Sema/AnalysisBasedWarnings.cpp index a987a8c..f83baa7 100644 --- a/contrib/llvm/tools/clang/lib/Sema/AnalysisBasedWarnings.cpp +++ b/contrib/llvm/tools/clang/lib/Sema/AnalysisBasedWarnings.cpp @@ -279,6 +279,159 @@ static void checkRecursiveFunction(Sema &S, const FunctionDecl *FD, } //===----------------------------------------------------------------------===// +// Check for throw in a non-throwing function. +//===----------------------------------------------------------------------===// +enum ThrowState { + FoundNoPathForThrow, + FoundPathForThrow, + FoundPathWithNoThrowOutFunction, +}; + +static bool isThrowCaught(const CXXThrowExpr *Throw, + const CXXCatchStmt *Catch) { + const Type *ThrowType = nullptr; + if (Throw->getSubExpr()) + ThrowType = Throw->getSubExpr()->getType().getTypePtrOrNull(); + if (!ThrowType) + return false; + const Type *CaughtType = Catch->getCaughtType().getTypePtrOrNull(); + if (!CaughtType) + return true; + if (ThrowType->isReferenceType()) + ThrowType = ThrowType->castAs<ReferenceType>() + ->getPointeeType() + ->getUnqualifiedDesugaredType(); + if (CaughtType->isReferenceType()) + CaughtType = CaughtType->castAs<ReferenceType>() + ->getPointeeType() + ->getUnqualifiedDesugaredType(); + if (ThrowType->isPointerType() && CaughtType->isPointerType()) { + ThrowType = ThrowType->getPointeeType()->getUnqualifiedDesugaredType(); + CaughtType = CaughtType->getPointeeType()->getUnqualifiedDesugaredType(); + } + if (CaughtType == ThrowType) + return true; + const CXXRecordDecl *CaughtAsRecordType = + CaughtType->getAsCXXRecordDecl(); + const CXXRecordDecl *ThrowTypeAsRecordType = ThrowType->getAsCXXRecordDecl(); + if (CaughtAsRecordType && ThrowTypeAsRecordType) + return ThrowTypeAsRecordType->isDerivedFrom(CaughtAsRecordType); + return false; +} + +static bool isThrowCaughtByHandlers(const CXXThrowExpr *CE, + const CXXTryStmt *TryStmt) { + for (unsigned H = 0, E = TryStmt->getNumHandlers(); H < E; ++H) { + if (isThrowCaught(CE, TryStmt->getHandler(H))) + return true; + } + return false; +} + +static bool doesThrowEscapePath(CFGBlock Block, SourceLocation &OpLoc) { + for (const auto &B : Block) { + if (B.getKind() != CFGElement::Statement) + continue; + const auto *CE = dyn_cast<CXXThrowExpr>(B.getAs<CFGStmt>()->getStmt()); + if (!CE) + continue; + + OpLoc = CE->getThrowLoc(); + for (const auto &I : Block.succs()) { + if (!I.isReachable()) + continue; + if (const auto *Terminator = + dyn_cast_or_null<CXXTryStmt>(I->getTerminator())) + if (isThrowCaughtByHandlers(CE, Terminator)) + return false; + } + return true; + } + return false; +} + +static bool hasThrowOutNonThrowingFunc(SourceLocation &OpLoc, CFG *BodyCFG) { + + unsigned ExitID = BodyCFG->getExit().getBlockID(); + + SmallVector<ThrowState, 16> States(BodyCFG->getNumBlockIDs(), + FoundNoPathForThrow); + States[BodyCFG->getEntry().getBlockID()] = FoundPathWithNoThrowOutFunction; + + SmallVector<CFGBlock *, 16> Stack; + Stack.push_back(&BodyCFG->getEntry()); + while (!Stack.empty()) { + CFGBlock *CurBlock = Stack.back(); + Stack.pop_back(); + + unsigned ID = CurBlock->getBlockID(); + ThrowState CurState = States[ID]; + if (CurState == FoundPathWithNoThrowOutFunction) { + if (ExitID == ID) + continue; + + if (doesThrowEscapePath(*CurBlock, OpLoc)) + CurState = FoundPathForThrow; + } + + // Loop over successor blocks and add them to the Stack if their state + // changes. + for (const auto &I : CurBlock->succs()) + if (I.isReachable()) { + unsigned NextID = I->getBlockID(); + if (NextID == ExitID && CurState == FoundPathForThrow) { + States[NextID] = CurState; + } else if (States[NextID] < CurState) { + States[NextID] = CurState; + Stack.push_back(I); + } + } + } + // Return true if the exit node is reachable, and only reachable through + // a throw expression. + return States[ExitID] == FoundPathForThrow; +} + +static void EmitDiagForCXXThrowInNonThrowingFunc(Sema &S, SourceLocation OpLoc, + const FunctionDecl *FD) { + if (!S.getSourceManager().isInSystemHeader(OpLoc) && + FD->getTypeSourceInfo()) { + S.Diag(OpLoc, diag::warn_throw_in_noexcept_func) << FD; + if (S.getLangOpts().CPlusPlus11 && + (isa<CXXDestructorDecl>(FD) || + FD->getDeclName().getCXXOverloadedOperator() == OO_Delete || + FD->getDeclName().getCXXOverloadedOperator() == OO_Array_Delete)) { + if (const auto *Ty = FD->getTypeSourceInfo()->getType()-> + getAs<FunctionProtoType>()) + S.Diag(FD->getLocation(), diag::note_throw_in_dtor) + << !isa<CXXDestructorDecl>(FD) << !Ty->hasExceptionSpec() + << FD->getExceptionSpecSourceRange(); + } else + S.Diag(FD->getLocation(), diag::note_throw_in_function) + << FD->getExceptionSpecSourceRange(); + } +} + +static void checkThrowInNonThrowingFunc(Sema &S, const FunctionDecl *FD, + AnalysisDeclContext &AC) { + CFG *BodyCFG = AC.getCFG(); + if (!BodyCFG) + return; + if (BodyCFG->getExit().pred_empty()) + return; + SourceLocation OpLoc; + if (hasThrowOutNonThrowingFunc(OpLoc, BodyCFG)) + EmitDiagForCXXThrowInNonThrowingFunc(S, OpLoc, FD); +} + +static bool isNoexcept(const FunctionDecl *FD) { + const auto *FPT = FD->getType()->castAs<FunctionProtoType>(); + if (FPT->isNothrow(FD->getASTContext())) + return true; + return false; +} + +//===----------------------------------------------------------------------===// // Check for missing return value. //===----------------------------------------------------------------------===// @@ -542,6 +695,7 @@ static void CheckFallThroughForBody(Sema &S, const Decl *D, const Stmt *Body, bool ReturnsVoid = false; bool HasNoReturn = false; + bool IsCoroutine = S.getCurFunction() && S.getCurFunction()->isCoroutine(); if (const auto *FD = dyn_cast<FunctionDecl>(D)) { if (const auto *CBody = dyn_cast<CoroutineBodyStmt>(Body)) @@ -570,8 +724,13 @@ static void CheckFallThroughForBody(Sema &S, const Decl *D, const Stmt *Body, // Short circuit for compilation speed. if (CD.checkDiagnostics(Diags, ReturnsVoid, HasNoReturn)) return; - SourceLocation LBrace = Body->getLocStart(), RBrace = Body->getLocEnd(); + auto EmitDiag = [&](SourceLocation Loc, unsigned DiagID) { + if (IsCoroutine) + S.Diag(Loc, DiagID) << S.getCurFunction()->CoroutinePromise->getType(); + else + S.Diag(Loc, DiagID); + }; // Either in a function body compound statement, or a function-try-block. switch (CheckFallThrough(AC)) { case UnknownFallThrough: @@ -579,15 +738,15 @@ static void CheckFallThroughForBody(Sema &S, const Decl *D, const Stmt *Body, case MaybeFallThrough: if (HasNoReturn) - S.Diag(RBrace, CD.diag_MaybeFallThrough_HasNoReturn); + EmitDiag(RBrace, CD.diag_MaybeFallThrough_HasNoReturn); else if (!ReturnsVoid) - S.Diag(RBrace, CD.diag_MaybeFallThrough_ReturnsNonVoid); + EmitDiag(RBrace, CD.diag_MaybeFallThrough_ReturnsNonVoid); break; case AlwaysFallThrough: if (HasNoReturn) - S.Diag(RBrace, CD.diag_AlwaysFallThrough_HasNoReturn); + EmitDiag(RBrace, CD.diag_AlwaysFallThrough_HasNoReturn); else if (!ReturnsVoid) - S.Diag(RBrace, CD.diag_AlwaysFallThrough_ReturnsNonVoid); + EmitDiag(RBrace, CD.diag_AlwaysFallThrough_ReturnsNonVoid); break; case NeverFallThroughOrReturn: if (ReturnsVoid && !HasNoReturn && CD.diag_NeverFallThroughOrReturn) { @@ -972,7 +1131,8 @@ namespace { } } - bool checkFallThroughIntoBlock(const CFGBlock &B, int &AnnotatedCnt) { + bool checkFallThroughIntoBlock(const CFGBlock &B, int &AnnotatedCnt, + bool IsTemplateInstantiation) { assert(!ReachableBlocks.empty() && "ReachableBlocks empty"); int UnannotatedCnt = 0; @@ -1002,8 +1162,12 @@ namespace { ElemIt != ElemEnd; ++ElemIt) { if (Optional<CFGStmt> CS = ElemIt->getAs<CFGStmt>()) { if (const AttributedStmt *AS = asFallThroughAttr(CS->getStmt())) { - S.Diag(AS->getLocStart(), - diag::warn_fallthrough_attr_unreachable); + // Don't issue a warning for an unreachable fallthrough + // attribute in template instantiations as it may not be + // unreachable in all instantiations of the template. + if (!IsTemplateInstantiation) + S.Diag(AS->getLocStart(), + diag::warn_fallthrough_attr_unreachable); markFallthroughVisited(AS); ++AnnotatedCnt; break; @@ -1164,7 +1328,11 @@ static void DiagnoseSwitchLabelsFallthrough(Sema &S, AnalysisDeclContext &AC, int AnnotatedCnt; - if (!FM.checkFallThroughIntoBlock(*B, AnnotatedCnt)) + bool IsTemplateInstantiation = false; + if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(AC.getDecl())) + IsTemplateInstantiation = Function->isTemplateInstantiation(); + if (!FM.checkFallThroughIntoBlock(*B, AnnotatedCnt, + IsTemplateInstantiation)) continue; S.Diag(Label->getLocStart(), @@ -2018,12 +2186,6 @@ AnalysisBasedWarnings::IssueWarnings(sema::AnalysisBasedWarnings::Policy P, // Warning: check missing 'return' if (P.enableCheckFallThrough) { - auto IsCoro = [&]() { - if (auto *FD = dyn_cast<FunctionDecl>(D)) - if (FD->getBody() && isa<CoroutineBodyStmt>(FD->getBody())) - return true; - return false; - }; const CheckFallThroughDiagnostics &CD = (isa<BlockDecl>(D) ? CheckFallThroughDiagnostics::MakeForBlock() @@ -2031,7 +2193,7 @@ AnalysisBasedWarnings::IssueWarnings(sema::AnalysisBasedWarnings::Policy P, cast<CXXMethodDecl>(D)->getOverloadedOperator() == OO_Call && cast<CXXMethodDecl>(D)->getParent()->isLambda()) ? CheckFallThroughDiagnostics::MakeForLambda() - : (IsCoro() + : (fscope->isCoroutine() ? CheckFallThroughDiagnostics::MakeForCoroutine(D) : CheckFallThroughDiagnostics::MakeForFunction(D))); CheckFallThroughForBody(S, D, Body, blkExpr, CD, AC); @@ -2118,6 +2280,12 @@ AnalysisBasedWarnings::IssueWarnings(sema::AnalysisBasedWarnings::Policy P, } } + // Check for throw out of non-throwing function. + if (!Diags.isIgnored(diag::warn_throw_in_noexcept_func, D->getLocStart())) + if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) + if (S.getLangOpts().CPlusPlus && isNoexcept(FD)) + checkThrowInNonThrowingFunc(S, FD, AC); + // If none of the previous checks caused a CFG build, trigger one here // for -Wtautological-overlap-compare if (!Diags.isIgnored(diag::warn_tautological_overlap_comparison, |
