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Diffstat (limited to 'contrib/llvm/tools/clang/lib/Sema/AnalysisBasedWarnings.cpp')
-rw-r--r-- | contrib/llvm/tools/clang/lib/Sema/AnalysisBasedWarnings.cpp | 1837 |
1 files changed, 1837 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/Sema/AnalysisBasedWarnings.cpp b/contrib/llvm/tools/clang/lib/Sema/AnalysisBasedWarnings.cpp new file mode 100644 index 0000000..93e3ecf --- /dev/null +++ b/contrib/llvm/tools/clang/lib/Sema/AnalysisBasedWarnings.cpp @@ -0,0 +1,1837 @@ +//=- AnalysisBasedWarnings.cpp - Sema warnings based on libAnalysis -*- C++ -*-=// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file defines analysis_warnings::[Policy,Executor]. +// Together they are used by Sema to issue warnings based on inexpensive +// static analysis algorithms in libAnalysis. +// +//===----------------------------------------------------------------------===// + +#include "clang/Sema/AnalysisBasedWarnings.h" +#include "clang/AST/DeclCXX.h" +#include "clang/AST/DeclObjC.h" +#include "clang/AST/EvaluatedExprVisitor.h" +#include "clang/AST/ExprCXX.h" +#include "clang/AST/ExprObjC.h" +#include "clang/AST/ParentMap.h" +#include "clang/AST/RecursiveASTVisitor.h" +#include "clang/AST/StmtCXX.h" +#include "clang/AST/StmtObjC.h" +#include "clang/AST/StmtVisitor.h" +#include "clang/Analysis/Analyses/CFGReachabilityAnalysis.h" +#include "clang/Analysis/Analyses/Consumed.h" +#include "clang/Analysis/Analyses/ReachableCode.h" +#include "clang/Analysis/Analyses/ThreadSafety.h" +#include "clang/Analysis/Analyses/UninitializedValues.h" +#include "clang/Analysis/AnalysisContext.h" +#include "clang/Analysis/CFG.h" +#include "clang/Analysis/CFGStmtMap.h" +#include "clang/Basic/SourceLocation.h" +#include "clang/Basic/SourceManager.h" +#include "clang/Lex/Lexer.h" +#include "clang/Lex/Preprocessor.h" +#include "clang/Sema/ScopeInfo.h" +#include "clang/Sema/SemaInternal.h" +#include "llvm/ADT/ArrayRef.h" +#include "llvm/ADT/BitVector.h" +#include "llvm/ADT/FoldingSet.h" +#include "llvm/ADT/ImmutableMap.h" +#include "llvm/ADT/MapVector.h" +#include "llvm/ADT/PostOrderIterator.h" +#include "llvm/ADT/SmallString.h" +#include "llvm/ADT/SmallVector.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/Support/Casting.h" +#include <algorithm> +#include <deque> +#include <iterator> +#include <vector> + +using namespace clang; + +//===----------------------------------------------------------------------===// +// Unreachable code analysis. +//===----------------------------------------------------------------------===// + +namespace { + class UnreachableCodeHandler : public reachable_code::Callback { + Sema &S; + public: + UnreachableCodeHandler(Sema &s) : S(s) {} + + void HandleUnreachable(SourceLocation L, SourceRange R1, SourceRange R2) { + S.Diag(L, diag::warn_unreachable) << R1 << R2; + } + }; +} + +/// CheckUnreachable - Check for unreachable code. +static void CheckUnreachable(Sema &S, AnalysisDeclContext &AC) { + UnreachableCodeHandler UC(S); + reachable_code::FindUnreachableCode(AC, UC); +} + +//===----------------------------------------------------------------------===// +// Check for missing return value. +//===----------------------------------------------------------------------===// + +enum ControlFlowKind { + UnknownFallThrough, + NeverFallThrough, + MaybeFallThrough, + AlwaysFallThrough, + NeverFallThroughOrReturn +}; + +/// CheckFallThrough - Check that we don't fall off the end of a +/// Statement that should return a value. +/// +/// \returns AlwaysFallThrough iff we always fall off the end of the statement, +/// MaybeFallThrough iff we might or might not fall off the end, +/// NeverFallThroughOrReturn iff we never fall off the end of the statement or +/// return. We assume NeverFallThrough iff we never fall off the end of the +/// statement but we may return. We assume that functions not marked noreturn +/// will return. +static ControlFlowKind CheckFallThrough(AnalysisDeclContext &AC) { + CFG *cfg = AC.getCFG(); + if (cfg == 0) return UnknownFallThrough; + + // The CFG leaves in dead things, and we don't want the dead code paths to + // confuse us, so we mark all live things first. + llvm::BitVector live(cfg->getNumBlockIDs()); + unsigned count = reachable_code::ScanReachableFromBlock(&cfg->getEntry(), + live); + + bool AddEHEdges = AC.getAddEHEdges(); + if (!AddEHEdges && count != cfg->getNumBlockIDs()) + // When there are things remaining dead, and we didn't add EH edges + // from CallExprs to the catch clauses, we have to go back and + // mark them as live. + for (CFG::iterator I = cfg->begin(), E = cfg->end(); I != E; ++I) { + CFGBlock &b = **I; + if (!live[b.getBlockID()]) { + if (b.pred_begin() == b.pred_end()) { + if (b.getTerminator() && isa<CXXTryStmt>(b.getTerminator())) + // When not adding EH edges from calls, catch clauses + // can otherwise seem dead. Avoid noting them as dead. + count += reachable_code::ScanReachableFromBlock(&b, live); + continue; + } + } + } + + // Now we know what is live, we check the live precessors of the exit block + // and look for fall through paths, being careful to ignore normal returns, + // and exceptional paths. + bool HasLiveReturn = false; + bool HasFakeEdge = false; + bool HasPlainEdge = false; + bool HasAbnormalEdge = false; + + // Ignore default cases that aren't likely to be reachable because all + // enums in a switch(X) have explicit case statements. + CFGBlock::FilterOptions FO; + FO.IgnoreDefaultsWithCoveredEnums = 1; + + for (CFGBlock::filtered_pred_iterator + I = cfg->getExit().filtered_pred_start_end(FO); I.hasMore(); ++I) { + const CFGBlock& B = **I; + if (!live[B.getBlockID()]) + continue; + + // Skip blocks which contain an element marked as no-return. They don't + // represent actually viable edges into the exit block, so mark them as + // abnormal. + if (B.hasNoReturnElement()) { + HasAbnormalEdge = true; + continue; + } + + // Destructors can appear after the 'return' in the CFG. This is + // normal. We need to look pass the destructors for the return + // statement (if it exists). + CFGBlock::const_reverse_iterator ri = B.rbegin(), re = B.rend(); + + for ( ; ri != re ; ++ri) + if (ri->getAs<CFGStmt>()) + break; + + // No more CFGElements in the block? + if (ri == re) { + if (B.getTerminator() && isa<CXXTryStmt>(B.getTerminator())) { + HasAbnormalEdge = true; + continue; + } + // A labeled empty statement, or the entry block... + HasPlainEdge = true; + continue; + } + + CFGStmt CS = ri->castAs<CFGStmt>(); + const Stmt *S = CS.getStmt(); + if (isa<ReturnStmt>(S)) { + HasLiveReturn = true; + continue; + } + if (isa<ObjCAtThrowStmt>(S)) { + HasFakeEdge = true; + continue; + } + if (isa<CXXThrowExpr>(S)) { + HasFakeEdge = true; + continue; + } + if (isa<MSAsmStmt>(S)) { + // TODO: Verify this is correct. + HasFakeEdge = true; + HasLiveReturn = true; + continue; + } + if (isa<CXXTryStmt>(S)) { + HasAbnormalEdge = true; + continue; + } + if (std::find(B.succ_begin(), B.succ_end(), &cfg->getExit()) + == B.succ_end()) { + HasAbnormalEdge = true; + continue; + } + + HasPlainEdge = true; + } + if (!HasPlainEdge) { + if (HasLiveReturn) + return NeverFallThrough; + return NeverFallThroughOrReturn; + } + if (HasAbnormalEdge || HasFakeEdge || HasLiveReturn) + return MaybeFallThrough; + // This says AlwaysFallThrough for calls to functions that are not marked + // noreturn, that don't return. If people would like this warning to be more + // accurate, such functions should be marked as noreturn. + return AlwaysFallThrough; +} + +namespace { + +struct CheckFallThroughDiagnostics { + unsigned diag_MaybeFallThrough_HasNoReturn; + unsigned diag_MaybeFallThrough_ReturnsNonVoid; + unsigned diag_AlwaysFallThrough_HasNoReturn; + unsigned diag_AlwaysFallThrough_ReturnsNonVoid; + unsigned diag_NeverFallThroughOrReturn; + enum { Function, Block, Lambda } funMode; + SourceLocation FuncLoc; + + static CheckFallThroughDiagnostics MakeForFunction(const Decl *Func) { + CheckFallThroughDiagnostics D; + D.FuncLoc = Func->getLocation(); + D.diag_MaybeFallThrough_HasNoReturn = + diag::warn_falloff_noreturn_function; + D.diag_MaybeFallThrough_ReturnsNonVoid = + diag::warn_maybe_falloff_nonvoid_function; + D.diag_AlwaysFallThrough_HasNoReturn = + diag::warn_falloff_noreturn_function; + D.diag_AlwaysFallThrough_ReturnsNonVoid = + diag::warn_falloff_nonvoid_function; + + // Don't suggest that virtual functions be marked "noreturn", since they + // might be overridden by non-noreturn functions. + bool isVirtualMethod = false; + if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Func)) + isVirtualMethod = Method->isVirtual(); + + // Don't suggest that template instantiations be marked "noreturn" + bool isTemplateInstantiation = false; + if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(Func)) + isTemplateInstantiation = Function->isTemplateInstantiation(); + + if (!isVirtualMethod && !isTemplateInstantiation) + D.diag_NeverFallThroughOrReturn = + diag::warn_suggest_noreturn_function; + else + D.diag_NeverFallThroughOrReturn = 0; + + D.funMode = Function; + return D; + } + + static CheckFallThroughDiagnostics MakeForBlock() { + CheckFallThroughDiagnostics D; + D.diag_MaybeFallThrough_HasNoReturn = + diag::err_noreturn_block_has_return_expr; + D.diag_MaybeFallThrough_ReturnsNonVoid = + diag::err_maybe_falloff_nonvoid_block; + D.diag_AlwaysFallThrough_HasNoReturn = + diag::err_noreturn_block_has_return_expr; + D.diag_AlwaysFallThrough_ReturnsNonVoid = + diag::err_falloff_nonvoid_block; + D.diag_NeverFallThroughOrReturn = + diag::warn_suggest_noreturn_block; + D.funMode = Block; + return D; + } + + static CheckFallThroughDiagnostics MakeForLambda() { + CheckFallThroughDiagnostics D; + D.diag_MaybeFallThrough_HasNoReturn = + diag::err_noreturn_lambda_has_return_expr; + D.diag_MaybeFallThrough_ReturnsNonVoid = + diag::warn_maybe_falloff_nonvoid_lambda; + D.diag_AlwaysFallThrough_HasNoReturn = + diag::err_noreturn_lambda_has_return_expr; + D.diag_AlwaysFallThrough_ReturnsNonVoid = + diag::warn_falloff_nonvoid_lambda; + D.diag_NeverFallThroughOrReturn = 0; + D.funMode = Lambda; + return D; + } + + bool checkDiagnostics(DiagnosticsEngine &D, bool ReturnsVoid, + bool HasNoReturn) const { + if (funMode == Function) { + return (ReturnsVoid || + D.getDiagnosticLevel(diag::warn_maybe_falloff_nonvoid_function, + FuncLoc) == DiagnosticsEngine::Ignored) + && (!HasNoReturn || + D.getDiagnosticLevel(diag::warn_noreturn_function_has_return_expr, + FuncLoc) == DiagnosticsEngine::Ignored) + && (!ReturnsVoid || + D.getDiagnosticLevel(diag::warn_suggest_noreturn_block, FuncLoc) + == DiagnosticsEngine::Ignored); + } + + // For blocks / lambdas. + return ReturnsVoid && !HasNoReturn + && ((funMode == Lambda) || + D.getDiagnosticLevel(diag::warn_suggest_noreturn_block, FuncLoc) + == DiagnosticsEngine::Ignored); + } +}; + +} + +/// CheckFallThroughForFunctionDef - Check that we don't fall off the end of a +/// function that should return a value. Check that we don't fall off the end +/// of a noreturn function. We assume that functions and blocks not marked +/// noreturn will return. +static void CheckFallThroughForBody(Sema &S, const Decl *D, const Stmt *Body, + const BlockExpr *blkExpr, + const CheckFallThroughDiagnostics& CD, + AnalysisDeclContext &AC) { + + bool ReturnsVoid = false; + bool HasNoReturn = false; + + if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { + ReturnsVoid = FD->getResultType()->isVoidType(); + HasNoReturn = FD->isNoReturn(); + } + else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { + ReturnsVoid = MD->getResultType()->isVoidType(); + HasNoReturn = MD->hasAttr<NoReturnAttr>(); + } + else if (isa<BlockDecl>(D)) { + QualType BlockTy = blkExpr->getType(); + if (const FunctionType *FT = + BlockTy->getPointeeType()->getAs<FunctionType>()) { + if (FT->getResultType()->isVoidType()) + ReturnsVoid = true; + if (FT->getNoReturnAttr()) + HasNoReturn = true; + } + } + + DiagnosticsEngine &Diags = S.getDiagnostics(); + + // Short circuit for compilation speed. + if (CD.checkDiagnostics(Diags, ReturnsVoid, HasNoReturn)) + return; + + // FIXME: Function try block + if (const CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) { + switch (CheckFallThrough(AC)) { + case UnknownFallThrough: + break; + + case MaybeFallThrough: + if (HasNoReturn) + S.Diag(Compound->getRBracLoc(), + CD.diag_MaybeFallThrough_HasNoReturn); + else if (!ReturnsVoid) + S.Diag(Compound->getRBracLoc(), + CD.diag_MaybeFallThrough_ReturnsNonVoid); + break; + case AlwaysFallThrough: + if (HasNoReturn) + S.Diag(Compound->getRBracLoc(), + CD.diag_AlwaysFallThrough_HasNoReturn); + else if (!ReturnsVoid) + S.Diag(Compound->getRBracLoc(), + CD.diag_AlwaysFallThrough_ReturnsNonVoid); + break; + case NeverFallThroughOrReturn: + if (ReturnsVoid && !HasNoReturn && CD.diag_NeverFallThroughOrReturn) { + if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { + S.Diag(Compound->getLBracLoc(), CD.diag_NeverFallThroughOrReturn) + << 0 << FD; + } else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { + S.Diag(Compound->getLBracLoc(), CD.diag_NeverFallThroughOrReturn) + << 1 << MD; + } else { + S.Diag(Compound->getLBracLoc(), CD.diag_NeverFallThroughOrReturn); + } + } + break; + case NeverFallThrough: + break; + } + } +} + +//===----------------------------------------------------------------------===// +// -Wuninitialized +//===----------------------------------------------------------------------===// + +namespace { +/// ContainsReference - A visitor class to search for references to +/// a particular declaration (the needle) within any evaluated component of an +/// expression (recursively). +class ContainsReference : public EvaluatedExprVisitor<ContainsReference> { + bool FoundReference; + const DeclRefExpr *Needle; + +public: + ContainsReference(ASTContext &Context, const DeclRefExpr *Needle) + : EvaluatedExprVisitor<ContainsReference>(Context), + FoundReference(false), Needle(Needle) {} + + void VisitExpr(Expr *E) { + // Stop evaluating if we already have a reference. + if (FoundReference) + return; + + EvaluatedExprVisitor<ContainsReference>::VisitExpr(E); + } + + void VisitDeclRefExpr(DeclRefExpr *E) { + if (E == Needle) + FoundReference = true; + else + EvaluatedExprVisitor<ContainsReference>::VisitDeclRefExpr(E); + } + + bool doesContainReference() const { return FoundReference; } +}; +} + +static bool SuggestInitializationFixit(Sema &S, const VarDecl *VD) { + QualType VariableTy = VD->getType().getCanonicalType(); + if (VariableTy->isBlockPointerType() && + !VD->hasAttr<BlocksAttr>()) { + S.Diag(VD->getLocation(), diag::note_block_var_fixit_add_initialization) << VD->getDeclName() + << FixItHint::CreateInsertion(VD->getLocation(), "__block "); + return true; + } + + // Don't issue a fixit if there is already an initializer. + if (VD->getInit()) + return false; + + // Don't suggest a fixit inside macros. + if (VD->getLocEnd().isMacroID()) + return false; + + SourceLocation Loc = S.PP.getLocForEndOfToken(VD->getLocEnd()); + + // Suggest possible initialization (if any). + std::string Init = S.getFixItZeroInitializerForType(VariableTy, Loc); + if (Init.empty()) + return false; + + S.Diag(Loc, diag::note_var_fixit_add_initialization) << VD->getDeclName() + << FixItHint::CreateInsertion(Loc, Init); + return true; +} + +/// Create a fixit to remove an if-like statement, on the assumption that its +/// condition is CondVal. +static void CreateIfFixit(Sema &S, const Stmt *If, const Stmt *Then, + const Stmt *Else, bool CondVal, + FixItHint &Fixit1, FixItHint &Fixit2) { + if (CondVal) { + // If condition is always true, remove all but the 'then'. + Fixit1 = FixItHint::CreateRemoval( + CharSourceRange::getCharRange(If->getLocStart(), + Then->getLocStart())); + if (Else) { + SourceLocation ElseKwLoc = Lexer::getLocForEndOfToken( + Then->getLocEnd(), 0, S.getSourceManager(), S.getLangOpts()); + Fixit2 = FixItHint::CreateRemoval( + SourceRange(ElseKwLoc, Else->getLocEnd())); + } + } else { + // If condition is always false, remove all but the 'else'. + if (Else) + Fixit1 = FixItHint::CreateRemoval( + CharSourceRange::getCharRange(If->getLocStart(), + Else->getLocStart())); + else + Fixit1 = FixItHint::CreateRemoval(If->getSourceRange()); + } +} + +/// DiagUninitUse -- Helper function to produce a diagnostic for an +/// uninitialized use of a variable. +static void DiagUninitUse(Sema &S, const VarDecl *VD, const UninitUse &Use, + bool IsCapturedByBlock) { + bool Diagnosed = false; + + switch (Use.getKind()) { + case UninitUse::Always: + S.Diag(Use.getUser()->getLocStart(), diag::warn_uninit_var) + << VD->getDeclName() << IsCapturedByBlock + << Use.getUser()->getSourceRange(); + return; + + case UninitUse::AfterDecl: + case UninitUse::AfterCall: + S.Diag(VD->getLocation(), diag::warn_sometimes_uninit_var) + << VD->getDeclName() << IsCapturedByBlock + << (Use.getKind() == UninitUse::AfterDecl ? 4 : 5) + << const_cast<DeclContext*>(VD->getLexicalDeclContext()) + << VD->getSourceRange(); + S.Diag(Use.getUser()->getLocStart(), diag::note_uninit_var_use) + << IsCapturedByBlock << Use.getUser()->getSourceRange(); + return; + + case UninitUse::Maybe: + case UninitUse::Sometimes: + // Carry on to report sometimes-uninitialized branches, if possible, + // or a 'may be used uninitialized' diagnostic otherwise. + break; + } + + // Diagnose each branch which leads to a sometimes-uninitialized use. + for (UninitUse::branch_iterator I = Use.branch_begin(), E = Use.branch_end(); + I != E; ++I) { + assert(Use.getKind() == UninitUse::Sometimes); + + const Expr *User = Use.getUser(); + const Stmt *Term = I->Terminator; + + // Information used when building the diagnostic. + unsigned DiagKind; + StringRef Str; + SourceRange Range; + + // FixIts to suppress the diagnostic by removing the dead condition. + // For all binary terminators, branch 0 is taken if the condition is true, + // and branch 1 is taken if the condition is false. + int RemoveDiagKind = -1; + const char *FixitStr = + S.getLangOpts().CPlusPlus ? (I->Output ? "true" : "false") + : (I->Output ? "1" : "0"); + FixItHint Fixit1, Fixit2; + + switch (Term ? Term->getStmtClass() : Stmt::DeclStmtClass) { + default: + // Don't know how to report this. Just fall back to 'may be used + // uninitialized'. FIXME: Can this happen? + continue; + + // "condition is true / condition is false". + case Stmt::IfStmtClass: { + const IfStmt *IS = cast<IfStmt>(Term); + DiagKind = 0; + Str = "if"; + Range = IS->getCond()->getSourceRange(); + RemoveDiagKind = 0; + CreateIfFixit(S, IS, IS->getThen(), IS->getElse(), + I->Output, Fixit1, Fixit2); + break; + } + case Stmt::ConditionalOperatorClass: { + const ConditionalOperator *CO = cast<ConditionalOperator>(Term); + DiagKind = 0; + Str = "?:"; + Range = CO->getCond()->getSourceRange(); + RemoveDiagKind = 0; + CreateIfFixit(S, CO, CO->getTrueExpr(), CO->getFalseExpr(), + I->Output, Fixit1, Fixit2); + break; + } + case Stmt::BinaryOperatorClass: { + const BinaryOperator *BO = cast<BinaryOperator>(Term); + if (!BO->isLogicalOp()) + continue; + DiagKind = 0; + Str = BO->getOpcodeStr(); + Range = BO->getLHS()->getSourceRange(); + RemoveDiagKind = 0; + if ((BO->getOpcode() == BO_LAnd && I->Output) || + (BO->getOpcode() == BO_LOr && !I->Output)) + // true && y -> y, false || y -> y. + Fixit1 = FixItHint::CreateRemoval(SourceRange(BO->getLocStart(), + BO->getOperatorLoc())); + else + // false && y -> false, true || y -> true. + Fixit1 = FixItHint::CreateReplacement(BO->getSourceRange(), FixitStr); + break; + } + + // "loop is entered / loop is exited". + case Stmt::WhileStmtClass: + DiagKind = 1; + Str = "while"; + Range = cast<WhileStmt>(Term)->getCond()->getSourceRange(); + RemoveDiagKind = 1; + Fixit1 = FixItHint::CreateReplacement(Range, FixitStr); + break; + case Stmt::ForStmtClass: + DiagKind = 1; + Str = "for"; + Range = cast<ForStmt>(Term)->getCond()->getSourceRange(); + RemoveDiagKind = 1; + if (I->Output) + Fixit1 = FixItHint::CreateRemoval(Range); + else + Fixit1 = FixItHint::CreateReplacement(Range, FixitStr); + break; + case Stmt::CXXForRangeStmtClass: + if (I->Output == 1) { + // The use occurs if a range-based for loop's body never executes. + // That may be impossible, and there's no syntactic fix for this, + // so treat it as a 'may be uninitialized' case. + continue; + } + DiagKind = 1; + Str = "for"; + Range = cast<CXXForRangeStmt>(Term)->getRangeInit()->getSourceRange(); + break; + + // "condition is true / loop is exited". + case Stmt::DoStmtClass: + DiagKind = 2; + Str = "do"; + Range = cast<DoStmt>(Term)->getCond()->getSourceRange(); + RemoveDiagKind = 1; + Fixit1 = FixItHint::CreateReplacement(Range, FixitStr); + break; + + // "switch case is taken". + case Stmt::CaseStmtClass: + DiagKind = 3; + Str = "case"; + Range = cast<CaseStmt>(Term)->getLHS()->getSourceRange(); + break; + case Stmt::DefaultStmtClass: + DiagKind = 3; + Str = "default"; + Range = cast<DefaultStmt>(Term)->getDefaultLoc(); + break; + } + + S.Diag(Range.getBegin(), diag::warn_sometimes_uninit_var) + << VD->getDeclName() << IsCapturedByBlock << DiagKind + << Str << I->Output << Range; + S.Diag(User->getLocStart(), diag::note_uninit_var_use) + << IsCapturedByBlock << User->getSourceRange(); + if (RemoveDiagKind != -1) + S.Diag(Fixit1.RemoveRange.getBegin(), diag::note_uninit_fixit_remove_cond) + << RemoveDiagKind << Str << I->Output << Fixit1 << Fixit2; + + Diagnosed = true; + } + + if (!Diagnosed) + S.Diag(Use.getUser()->getLocStart(), diag::warn_maybe_uninit_var) + << VD->getDeclName() << IsCapturedByBlock + << Use.getUser()->getSourceRange(); +} + +/// DiagnoseUninitializedUse -- Helper function for diagnosing uses of an +/// uninitialized variable. This manages the different forms of diagnostic +/// emitted for particular types of uses. Returns true if the use was diagnosed +/// as a warning. If a particular use is one we omit warnings for, returns +/// false. +static bool DiagnoseUninitializedUse(Sema &S, const VarDecl *VD, + const UninitUse &Use, + bool alwaysReportSelfInit = false) { + + if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Use.getUser())) { + // Inspect the initializer of the variable declaration which is + // being referenced prior to its initialization. We emit + // specialized diagnostics for self-initialization, and we + // specifically avoid warning about self references which take the + // form of: + // + // int x = x; + // + // This is used to indicate to GCC that 'x' is intentionally left + // uninitialized. Proven code paths which access 'x' in + // an uninitialized state after this will still warn. + if (const Expr *Initializer = VD->getInit()) { + if (!alwaysReportSelfInit && DRE == Initializer->IgnoreParenImpCasts()) + return false; + + ContainsReference CR(S.Context, DRE); + CR.Visit(const_cast<Expr*>(Initializer)); + if (CR.doesContainReference()) { + S.Diag(DRE->getLocStart(), + diag::warn_uninit_self_reference_in_init) + << VD->getDeclName() << VD->getLocation() << DRE->getSourceRange(); + return true; + } + } + + DiagUninitUse(S, VD, Use, false); + } else { + const BlockExpr *BE = cast<BlockExpr>(Use.getUser()); + if (VD->getType()->isBlockPointerType() && !VD->hasAttr<BlocksAttr>()) + S.Diag(BE->getLocStart(), + diag::warn_uninit_byref_blockvar_captured_by_block) + << VD->getDeclName(); + else + DiagUninitUse(S, VD, Use, true); + } + + // Report where the variable was declared when the use wasn't within + // the initializer of that declaration & we didn't already suggest + // an initialization fixit. + if (!SuggestInitializationFixit(S, VD)) + S.Diag(VD->getLocStart(), diag::note_uninit_var_def) + << VD->getDeclName(); + + return true; +} + +namespace { + class FallthroughMapper : public RecursiveASTVisitor<FallthroughMapper> { + public: + FallthroughMapper(Sema &S) + : FoundSwitchStatements(false), + S(S) { + } + + bool foundSwitchStatements() const { return FoundSwitchStatements; } + + void markFallthroughVisited(const AttributedStmt *Stmt) { + bool Found = FallthroughStmts.erase(Stmt); + assert(Found); + (void)Found; + } + + typedef llvm::SmallPtrSet<const AttributedStmt*, 8> AttrStmts; + + const AttrStmts &getFallthroughStmts() const { + return FallthroughStmts; + } + + void fillReachableBlocks(CFG *Cfg) { + assert(ReachableBlocks.empty() && "ReachableBlocks already filled"); + std::deque<const CFGBlock *> BlockQueue; + + ReachableBlocks.insert(&Cfg->getEntry()); + BlockQueue.push_back(&Cfg->getEntry()); + // Mark all case blocks reachable to avoid problems with switching on + // constants, covered enums, etc. + // These blocks can contain fall-through annotations, and we don't want to + // issue a warn_fallthrough_attr_unreachable for them. + for (CFG::iterator I = Cfg->begin(), E = Cfg->end(); I != E; ++I) { + const CFGBlock *B = *I; + const Stmt *L = B->getLabel(); + if (L && isa<SwitchCase>(L) && ReachableBlocks.insert(B)) + BlockQueue.push_back(B); + } + + while (!BlockQueue.empty()) { + const CFGBlock *P = BlockQueue.front(); + BlockQueue.pop_front(); + for (CFGBlock::const_succ_iterator I = P->succ_begin(), + E = P->succ_end(); + I != E; ++I) { + if (*I && ReachableBlocks.insert(*I)) + BlockQueue.push_back(*I); + } + } + } + + bool checkFallThroughIntoBlock(const CFGBlock &B, int &AnnotatedCnt) { + assert(!ReachableBlocks.empty() && "ReachableBlocks empty"); + + int UnannotatedCnt = 0; + AnnotatedCnt = 0; + + std::deque<const CFGBlock*> BlockQueue; + + std::copy(B.pred_begin(), B.pred_end(), std::back_inserter(BlockQueue)); + + while (!BlockQueue.empty()) { + const CFGBlock *P = BlockQueue.front(); + BlockQueue.pop_front(); + + const Stmt *Term = P->getTerminator(); + if (Term && isa<SwitchStmt>(Term)) + continue; // Switch statement, good. + + const SwitchCase *SW = dyn_cast_or_null<SwitchCase>(P->getLabel()); + if (SW && SW->getSubStmt() == B.getLabel() && P->begin() == P->end()) + continue; // Previous case label has no statements, good. + + const LabelStmt *L = dyn_cast_or_null<LabelStmt>(P->getLabel()); + if (L && L->getSubStmt() == B.getLabel() && P->begin() == P->end()) + continue; // Case label is preceded with a normal label, good. + + if (!ReachableBlocks.count(P)) { + for (CFGBlock::const_reverse_iterator ElemIt = P->rbegin(), + ElemEnd = P->rend(); + 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); + markFallthroughVisited(AS); + ++AnnotatedCnt; + break; + } + // Don't care about other unreachable statements. + } + } + // If there are no unreachable statements, this may be a special + // case in CFG: + // case X: { + // A a; // A has a destructor. + // break; + // } + // // <<<< This place is represented by a 'hanging' CFG block. + // case Y: + continue; + } + + const Stmt *LastStmt = getLastStmt(*P); + if (const AttributedStmt *AS = asFallThroughAttr(LastStmt)) { + markFallthroughVisited(AS); + ++AnnotatedCnt; + continue; // Fallthrough annotation, good. + } + + if (!LastStmt) { // This block contains no executable statements. + // Traverse its predecessors. + std::copy(P->pred_begin(), P->pred_end(), + std::back_inserter(BlockQueue)); + continue; + } + + ++UnannotatedCnt; + } + return !!UnannotatedCnt; + } + + // RecursiveASTVisitor setup. + bool shouldWalkTypesOfTypeLocs() const { return false; } + + bool VisitAttributedStmt(AttributedStmt *S) { + if (asFallThroughAttr(S)) + FallthroughStmts.insert(S); + return true; + } + + bool VisitSwitchStmt(SwitchStmt *S) { + FoundSwitchStatements = true; + return true; + } + + // We don't want to traverse local type declarations. We analyze their + // methods separately. + bool TraverseDecl(Decl *D) { return true; } + + private: + + static const AttributedStmt *asFallThroughAttr(const Stmt *S) { + if (const AttributedStmt *AS = dyn_cast_or_null<AttributedStmt>(S)) { + if (hasSpecificAttr<FallThroughAttr>(AS->getAttrs())) + return AS; + } + return 0; + } + + static const Stmt *getLastStmt(const CFGBlock &B) { + if (const Stmt *Term = B.getTerminator()) + return Term; + for (CFGBlock::const_reverse_iterator ElemIt = B.rbegin(), + ElemEnd = B.rend(); + ElemIt != ElemEnd; ++ElemIt) { + if (Optional<CFGStmt> CS = ElemIt->getAs<CFGStmt>()) + return CS->getStmt(); + } + // Workaround to detect a statement thrown out by CFGBuilder: + // case X: {} case Y: + // case X: ; case Y: + if (const SwitchCase *SW = dyn_cast_or_null<SwitchCase>(B.getLabel())) + if (!isa<SwitchCase>(SW->getSubStmt())) + return SW->getSubStmt(); + + return 0; + } + + bool FoundSwitchStatements; + AttrStmts FallthroughStmts; + Sema &S; + llvm::SmallPtrSet<const CFGBlock *, 16> ReachableBlocks; + }; +} + +static void DiagnoseSwitchLabelsFallthrough(Sema &S, AnalysisDeclContext &AC, + bool PerFunction) { + // Only perform this analysis when using C++11. There is no good workflow + // for this warning when not using C++11. There is no good way to silence + // the warning (no attribute is available) unless we are using C++11's support + // for generalized attributes. Once could use pragmas to silence the warning, + // but as a general solution that is gross and not in the spirit of this + // warning. + // + // NOTE: This an intermediate solution. There are on-going discussions on + // how to properly support this warning outside of C++11 with an annotation. + if (!AC.getASTContext().getLangOpts().CPlusPlus11) + return; + + FallthroughMapper FM(S); + FM.TraverseStmt(AC.getBody()); + + if (!FM.foundSwitchStatements()) + return; + + if (PerFunction && FM.getFallthroughStmts().empty()) + return; + + CFG *Cfg = AC.getCFG(); + + if (!Cfg) + return; + + FM.fillReachableBlocks(Cfg); + + for (CFG::reverse_iterator I = Cfg->rbegin(), E = Cfg->rend(); I != E; ++I) { + const CFGBlock *B = *I; + const Stmt *Label = B->getLabel(); + + if (!Label || !isa<SwitchCase>(Label)) + continue; + + int AnnotatedCnt; + + if (!FM.checkFallThroughIntoBlock(*B, AnnotatedCnt)) + continue; + + S.Diag(Label->getLocStart(), + PerFunction ? diag::warn_unannotated_fallthrough_per_function + : diag::warn_unannotated_fallthrough); + + if (!AnnotatedCnt) { + SourceLocation L = Label->getLocStart(); + if (L.isMacroID()) + continue; + if (S.getLangOpts().CPlusPlus11) { + const Stmt *Term = B->getTerminator(); + // Skip empty cases. + while (B->empty() && !Term && B->succ_size() == 1) { + B = *B->succ_begin(); + Term = B->getTerminator(); + } + if (!(B->empty() && Term && isa<BreakStmt>(Term))) { + Preprocessor &PP = S.getPreprocessor(); + TokenValue Tokens[] = { + tok::l_square, tok::l_square, PP.getIdentifierInfo("clang"), + tok::coloncolon, PP.getIdentifierInfo("fallthrough"), + tok::r_square, tok::r_square + }; + StringRef AnnotationSpelling = "[[clang::fallthrough]]"; + StringRef MacroName = PP.getLastMacroWithSpelling(L, Tokens); + if (!MacroName.empty()) + AnnotationSpelling = MacroName; + SmallString<64> TextToInsert(AnnotationSpelling); + TextToInsert += "; "; + S.Diag(L, diag::note_insert_fallthrough_fixit) << + AnnotationSpelling << + FixItHint::CreateInsertion(L, TextToInsert); + } + } + S.Diag(L, diag::note_insert_break_fixit) << + FixItHint::CreateInsertion(L, "break; "); + } + } + + const FallthroughMapper::AttrStmts &Fallthroughs = FM.getFallthroughStmts(); + for (FallthroughMapper::AttrStmts::const_iterator I = Fallthroughs.begin(), + E = Fallthroughs.end(); + I != E; ++I) { + S.Diag((*I)->getLocStart(), diag::warn_fallthrough_attr_invalid_placement); + } + +} + +namespace { +typedef std::pair<const Stmt *, + sema::FunctionScopeInfo::WeakObjectUseMap::const_iterator> + StmtUsesPair; + +class StmtUseSorter { + const SourceManager &SM; + +public: + explicit StmtUseSorter(const SourceManager &SM) : SM(SM) { } + + bool operator()(const StmtUsesPair &LHS, const StmtUsesPair &RHS) { + return SM.isBeforeInTranslationUnit(LHS.first->getLocStart(), + RHS.first->getLocStart()); + } +}; +} + +static bool isInLoop(const ASTContext &Ctx, const ParentMap &PM, + const Stmt *S) { + assert(S); + + do { + switch (S->getStmtClass()) { + case Stmt::ForStmtClass: + case Stmt::WhileStmtClass: + case Stmt::CXXForRangeStmtClass: + case Stmt::ObjCForCollectionStmtClass: + return true; + case Stmt::DoStmtClass: { + const Expr *Cond = cast<DoStmt>(S)->getCond(); + llvm::APSInt Val; + if (!Cond->EvaluateAsInt(Val, Ctx)) + return true; + return Val.getBoolValue(); + } + default: + break; + } + } while ((S = PM.getParent(S))); + + return false; +} + + +static void diagnoseRepeatedUseOfWeak(Sema &S, + const sema::FunctionScopeInfo *CurFn, + const Decl *D, + const ParentMap &PM) { + typedef sema::FunctionScopeInfo::WeakObjectProfileTy WeakObjectProfileTy; + typedef sema::FunctionScopeInfo::WeakObjectUseMap WeakObjectUseMap; + typedef sema::FunctionScopeInfo::WeakUseVector WeakUseVector; + + ASTContext &Ctx = S.getASTContext(); + + const WeakObjectUseMap &WeakMap = CurFn->getWeakObjectUses(); + + // Extract all weak objects that are referenced more than once. + SmallVector<StmtUsesPair, 8> UsesByStmt; + for (WeakObjectUseMap::const_iterator I = WeakMap.begin(), E = WeakMap.end(); + I != E; ++I) { + const WeakUseVector &Uses = I->second; + + // Find the first read of the weak object. + WeakUseVector::const_iterator UI = Uses.begin(), UE = Uses.end(); + for ( ; UI != UE; ++UI) { + if (UI->isUnsafe()) + break; + } + + // If there were only writes to this object, don't warn. + if (UI == UE) + continue; + + // If there was only one read, followed by any number of writes, and the + // read is not within a loop, don't warn. Additionally, don't warn in a + // loop if the base object is a local variable -- local variables are often + // changed in loops. + if (UI == Uses.begin()) { + WeakUseVector::const_iterator UI2 = UI; + for (++UI2; UI2 != UE; ++UI2) + if (UI2->isUnsafe()) + break; + + if (UI2 == UE) { + if (!isInLoop(Ctx, PM, UI->getUseExpr())) + continue; + + const WeakObjectProfileTy &Profile = I->first; + if (!Profile.isExactProfile()) + continue; + + const NamedDecl *Base = Profile.getBase(); + if (!Base) + Base = Profile.getProperty(); + assert(Base && "A profile always has a base or property."); + + if (const VarDecl *BaseVar = dyn_cast<VarDecl>(Base)) + if (BaseVar->hasLocalStorage() && !isa<ParmVarDecl>(Base)) + continue; + } + } + + UsesByStmt.push_back(StmtUsesPair(UI->getUseExpr(), I)); + } + + if (UsesByStmt.empty()) + return; + + // Sort by first use so that we emit the warnings in a deterministic order. + std::sort(UsesByStmt.begin(), UsesByStmt.end(), + StmtUseSorter(S.getSourceManager())); + + // Classify the current code body for better warning text. + // This enum should stay in sync with the cases in + // warn_arc_repeated_use_of_weak and warn_arc_possible_repeated_use_of_weak. + // FIXME: Should we use a common classification enum and the same set of + // possibilities all throughout Sema? + enum { + Function, + Method, + Block, + Lambda + } FunctionKind; + + if (isa<sema::BlockScopeInfo>(CurFn)) + FunctionKind = Block; + else if (isa<sema::LambdaScopeInfo>(CurFn)) + FunctionKind = Lambda; + else if (isa<ObjCMethodDecl>(D)) + FunctionKind = Method; + else + FunctionKind = Function; + + // Iterate through the sorted problems and emit warnings for each. + for (SmallVectorImpl<StmtUsesPair>::const_iterator I = UsesByStmt.begin(), + E = UsesByStmt.end(); + I != E; ++I) { + const Stmt *FirstRead = I->first; + const WeakObjectProfileTy &Key = I->second->first; + const WeakUseVector &Uses = I->second->second; + + // For complicated expressions like 'a.b.c' and 'x.b.c', WeakObjectProfileTy + // may not contain enough information to determine that these are different + // properties. We can only be 100% sure of a repeated use in certain cases, + // and we adjust the diagnostic kind accordingly so that the less certain + // case can be turned off if it is too noisy. + unsigned DiagKind; + if (Key.isExactProfile()) + DiagKind = diag::warn_arc_repeated_use_of_weak; + else + DiagKind = diag::warn_arc_possible_repeated_use_of_weak; + + // Classify the weak object being accessed for better warning text. + // This enum should stay in sync with the cases in + // warn_arc_repeated_use_of_weak and warn_arc_possible_repeated_use_of_weak. + enum { + Variable, + Property, + ImplicitProperty, + Ivar + } ObjectKind; + + const NamedDecl *D = Key.getProperty(); + if (isa<VarDecl>(D)) + ObjectKind = Variable; + else if (isa<ObjCPropertyDecl>(D)) + ObjectKind = Property; + else if (isa<ObjCMethodDecl>(D)) + ObjectKind = ImplicitProperty; + else if (isa<ObjCIvarDecl>(D)) + ObjectKind = Ivar; + else + llvm_unreachable("Unexpected weak object kind!"); + + // Show the first time the object was read. + S.Diag(FirstRead->getLocStart(), DiagKind) + << int(ObjectKind) << D << int(FunctionKind) + << FirstRead->getSourceRange(); + + // Print all the other accesses as notes. + for (WeakUseVector::const_iterator UI = Uses.begin(), UE = Uses.end(); + UI != UE; ++UI) { + if (UI->getUseExpr() == FirstRead) + continue; + S.Diag(UI->getUseExpr()->getLocStart(), + diag::note_arc_weak_also_accessed_here) + << UI->getUseExpr()->getSourceRange(); + } + } +} + + +namespace { +struct SLocSort { + bool operator()(const UninitUse &a, const UninitUse &b) { + // Prefer a more confident report over a less confident one. + if (a.getKind() != b.getKind()) + return a.getKind() > b.getKind(); + SourceLocation aLoc = a.getUser()->getLocStart(); + SourceLocation bLoc = b.getUser()->getLocStart(); + return aLoc.getRawEncoding() < bLoc.getRawEncoding(); + } +}; + +class UninitValsDiagReporter : public UninitVariablesHandler { + Sema &S; + typedef SmallVector<UninitUse, 2> UsesVec; + typedef llvm::PointerIntPair<UsesVec *, 1, bool> MappedType; + // Prefer using MapVector to DenseMap, so that iteration order will be + // the same as insertion order. This is needed to obtain a deterministic + // order of diagnostics when calling flushDiagnostics(). + typedef llvm::MapVector<const VarDecl *, MappedType> UsesMap; + UsesMap *uses; + +public: + UninitValsDiagReporter(Sema &S) : S(S), uses(0) {} + ~UninitValsDiagReporter() { + flushDiagnostics(); + } + + MappedType &getUses(const VarDecl *vd) { + if (!uses) + uses = new UsesMap(); + + MappedType &V = (*uses)[vd]; + if (!V.getPointer()) + V.setPointer(new UsesVec()); + + return V; + } + + void handleUseOfUninitVariable(const VarDecl *vd, const UninitUse &use) { + getUses(vd).getPointer()->push_back(use); + } + + void handleSelfInit(const VarDecl *vd) { + getUses(vd).setInt(true); + } + + void flushDiagnostics() { + if (!uses) + return; + + for (UsesMap::iterator i = uses->begin(), e = uses->end(); i != e; ++i) { + const VarDecl *vd = i->first; + const MappedType &V = i->second; + + UsesVec *vec = V.getPointer(); + bool hasSelfInit = V.getInt(); + + // Specially handle the case where we have uses of an uninitialized + // variable, but the root cause is an idiomatic self-init. We want + // to report the diagnostic at the self-init since that is the root cause. + if (!vec->empty() && hasSelfInit && hasAlwaysUninitializedUse(vec)) + DiagnoseUninitializedUse(S, vd, + UninitUse(vd->getInit()->IgnoreParenCasts(), + /* isAlwaysUninit */ true), + /* alwaysReportSelfInit */ true); + else { + // Sort the uses by their SourceLocations. While not strictly + // guaranteed to produce them in line/column order, this will provide + // a stable ordering. + std::sort(vec->begin(), vec->end(), SLocSort()); + + for (UsesVec::iterator vi = vec->begin(), ve = vec->end(); vi != ve; + ++vi) { + // If we have self-init, downgrade all uses to 'may be uninitialized'. + UninitUse Use = hasSelfInit ? UninitUse(vi->getUser(), false) : *vi; + + if (DiagnoseUninitializedUse(S, vd, Use)) + // Skip further diagnostics for this variable. We try to warn only + // on the first point at which a variable is used uninitialized. + break; + } + } + + // Release the uses vector. + delete vec; + } + delete uses; + } + +private: + static bool hasAlwaysUninitializedUse(const UsesVec* vec) { + for (UsesVec::const_iterator i = vec->begin(), e = vec->end(); i != e; ++i) { + if (i->getKind() == UninitUse::Always || + i->getKind() == UninitUse::AfterCall || + i->getKind() == UninitUse::AfterDecl) { + return true; + } + } + return false; +} +}; +} + +namespace clang { +namespace { +typedef SmallVector<PartialDiagnosticAt, 1> OptionalNotes; +typedef std::pair<PartialDiagnosticAt, OptionalNotes> DelayedDiag; +typedef std::list<DelayedDiag> DiagList; + +struct SortDiagBySourceLocation { + SourceManager &SM; + SortDiagBySourceLocation(SourceManager &SM) : SM(SM) {} + + bool operator()(const DelayedDiag &left, const DelayedDiag &right) { + // Although this call will be slow, this is only called when outputting + // multiple warnings. + return SM.isBeforeInTranslationUnit(left.first.first, right.first.first); + } +}; +}} + +//===----------------------------------------------------------------------===// +// -Wthread-safety +//===----------------------------------------------------------------------===// +namespace clang { +namespace thread_safety { +namespace { +class ThreadSafetyReporter : public clang::thread_safety::ThreadSafetyHandler { + Sema &S; + DiagList Warnings; + SourceLocation FunLocation, FunEndLocation; + + // Helper functions + void warnLockMismatch(unsigned DiagID, Name LockName, SourceLocation Loc) { + // Gracefully handle rare cases when the analysis can't get a more + // precise source location. + if (!Loc.isValid()) + Loc = FunLocation; + PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID) << LockName); + Warnings.push_back(DelayedDiag(Warning, OptionalNotes())); + } + + public: + ThreadSafetyReporter(Sema &S, SourceLocation FL, SourceLocation FEL) + : S(S), FunLocation(FL), FunEndLocation(FEL) {} + + /// \brief Emit all buffered diagnostics in order of sourcelocation. + /// We need to output diagnostics produced while iterating through + /// the lockset in deterministic order, so this function orders diagnostics + /// and outputs them. + void emitDiagnostics() { + Warnings.sort(SortDiagBySourceLocation(S.getSourceManager())); + for (DiagList::iterator I = Warnings.begin(), E = Warnings.end(); + I != E; ++I) { + S.Diag(I->first.first, I->first.second); + const OptionalNotes &Notes = I->second; + for (unsigned NoteI = 0, NoteN = Notes.size(); NoteI != NoteN; ++NoteI) + S.Diag(Notes[NoteI].first, Notes[NoteI].second); + } + } + + void handleInvalidLockExp(SourceLocation Loc) { + PartialDiagnosticAt Warning(Loc, + S.PDiag(diag::warn_cannot_resolve_lock) << Loc); + Warnings.push_back(DelayedDiag(Warning, OptionalNotes())); + } + void handleUnmatchedUnlock(Name LockName, SourceLocation Loc) { + warnLockMismatch(diag::warn_unlock_but_no_lock, LockName, Loc); + } + + void handleDoubleLock(Name LockName, SourceLocation Loc) { + warnLockMismatch(diag::warn_double_lock, LockName, Loc); + } + + void handleMutexHeldEndOfScope(Name LockName, SourceLocation LocLocked, + SourceLocation LocEndOfScope, + LockErrorKind LEK){ + unsigned DiagID = 0; + switch (LEK) { + case LEK_LockedSomePredecessors: + DiagID = diag::warn_lock_some_predecessors; + break; + case LEK_LockedSomeLoopIterations: + DiagID = diag::warn_expecting_lock_held_on_loop; + break; + case LEK_LockedAtEndOfFunction: + DiagID = diag::warn_no_unlock; + break; + case LEK_NotLockedAtEndOfFunction: + DiagID = diag::warn_expecting_locked; + break; + } + if (LocEndOfScope.isInvalid()) + LocEndOfScope = FunEndLocation; + + PartialDiagnosticAt Warning(LocEndOfScope, S.PDiag(DiagID) << LockName); + if (LocLocked.isValid()) { + PartialDiagnosticAt Note(LocLocked, S.PDiag(diag::note_locked_here)); + Warnings.push_back(DelayedDiag(Warning, OptionalNotes(1, Note))); + return; + } + Warnings.push_back(DelayedDiag(Warning, OptionalNotes())); + } + + + void handleExclusiveAndShared(Name LockName, SourceLocation Loc1, + SourceLocation Loc2) { + PartialDiagnosticAt Warning( + Loc1, S.PDiag(diag::warn_lock_exclusive_and_shared) << LockName); + PartialDiagnosticAt Note( + Loc2, S.PDiag(diag::note_lock_exclusive_and_shared) << LockName); + Warnings.push_back(DelayedDiag(Warning, OptionalNotes(1, Note))); + } + + void handleNoMutexHeld(const NamedDecl *D, ProtectedOperationKind POK, + AccessKind AK, SourceLocation Loc) { + assert((POK == POK_VarAccess || POK == POK_VarDereference) + && "Only works for variables"); + unsigned DiagID = POK == POK_VarAccess? + diag::warn_variable_requires_any_lock: + diag::warn_var_deref_requires_any_lock; + PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID) + << D->getNameAsString() << getLockKindFromAccessKind(AK)); + Warnings.push_back(DelayedDiag(Warning, OptionalNotes())); + } + + void handleMutexNotHeld(const NamedDecl *D, ProtectedOperationKind POK, + Name LockName, LockKind LK, SourceLocation Loc, + Name *PossibleMatch) { + unsigned DiagID = 0; + if (PossibleMatch) { + switch (POK) { + case POK_VarAccess: + DiagID = diag::warn_variable_requires_lock_precise; + break; + case POK_VarDereference: + DiagID = diag::warn_var_deref_requires_lock_precise; + break; + case POK_FunctionCall: + DiagID = diag::warn_fun_requires_lock_precise; + break; + } + PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID) + << D->getNameAsString() << LockName << LK); + PartialDiagnosticAt Note(Loc, S.PDiag(diag::note_found_mutex_near_match) + << *PossibleMatch); + Warnings.push_back(DelayedDiag(Warning, OptionalNotes(1, Note))); + } else { + switch (POK) { + case POK_VarAccess: + DiagID = diag::warn_variable_requires_lock; + break; + case POK_VarDereference: + DiagID = diag::warn_var_deref_requires_lock; + break; + case POK_FunctionCall: + DiagID = diag::warn_fun_requires_lock; + break; + } + PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID) + << D->getNameAsString() << LockName << LK); + Warnings.push_back(DelayedDiag(Warning, OptionalNotes())); + } + } + + void handleFunExcludesLock(Name FunName, Name LockName, SourceLocation Loc) { + PartialDiagnosticAt Warning(Loc, + S.PDiag(diag::warn_fun_excludes_mutex) << FunName << LockName); + Warnings.push_back(DelayedDiag(Warning, OptionalNotes())); + } +}; +} +} +} + +//===----------------------------------------------------------------------===// +// -Wconsumed +//===----------------------------------------------------------------------===// + +namespace clang { +namespace consumed { +namespace { +class ConsumedWarningsHandler : public ConsumedWarningsHandlerBase { + + Sema &S; + DiagList Warnings; + +public: + + ConsumedWarningsHandler(Sema &S) : S(S) {} + + void emitDiagnostics() { + Warnings.sort(SortDiagBySourceLocation(S.getSourceManager())); + + for (DiagList::iterator I = Warnings.begin(), E = Warnings.end(); + I != E; ++I) { + + const OptionalNotes &Notes = I->second; + S.Diag(I->first.first, I->first.second); + + for (unsigned NoteI = 0, NoteN = Notes.size(); NoteI != NoteN; ++NoteI) { + S.Diag(Notes[NoteI].first, Notes[NoteI].second); + } + } + } + + void warnLoopStateMismatch(SourceLocation Loc, StringRef VariableName) { + PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_loop_state_mismatch) << + VariableName); + + Warnings.push_back(DelayedDiag(Warning, OptionalNotes())); + } + + void warnParamReturnTypestateMismatch(SourceLocation Loc, + StringRef VariableName, + StringRef ExpectedState, + StringRef ObservedState) { + + PartialDiagnosticAt Warning(Loc, S.PDiag( + diag::warn_param_return_typestate_mismatch) << VariableName << + ExpectedState << ObservedState); + + Warnings.push_back(DelayedDiag(Warning, OptionalNotes())); + } + + void warnParamTypestateMismatch(SourceLocation Loc, StringRef ExpectedState, + StringRef ObservedState) { + + PartialDiagnosticAt Warning(Loc, S.PDiag( + diag::warn_param_typestate_mismatch) << ExpectedState << ObservedState); + + Warnings.push_back(DelayedDiag(Warning, OptionalNotes())); + } + + void warnReturnTypestateForUnconsumableType(SourceLocation Loc, + StringRef TypeName) { + PartialDiagnosticAt Warning(Loc, S.PDiag( + diag::warn_return_typestate_for_unconsumable_type) << TypeName); + + Warnings.push_back(DelayedDiag(Warning, OptionalNotes())); + } + + void warnReturnTypestateMismatch(SourceLocation Loc, StringRef ExpectedState, + StringRef ObservedState) { + + PartialDiagnosticAt Warning(Loc, S.PDiag( + diag::warn_return_typestate_mismatch) << ExpectedState << ObservedState); + + Warnings.push_back(DelayedDiag(Warning, OptionalNotes())); + } + + void warnUseOfTempInInvalidState(StringRef MethodName, StringRef State, + SourceLocation Loc) { + + PartialDiagnosticAt Warning(Loc, S.PDiag( + diag::warn_use_of_temp_in_invalid_state) << MethodName << State); + + Warnings.push_back(DelayedDiag(Warning, OptionalNotes())); + } + + void warnUseInInvalidState(StringRef MethodName, StringRef VariableName, + StringRef State, SourceLocation Loc) { + + PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_use_in_invalid_state) << + MethodName << VariableName << State); + + Warnings.push_back(DelayedDiag(Warning, OptionalNotes())); + } +}; +}}} + +//===----------------------------------------------------------------------===// +// AnalysisBasedWarnings - Worker object used by Sema to execute analysis-based +// warnings on a function, method, or block. +//===----------------------------------------------------------------------===// + +clang::sema::AnalysisBasedWarnings::Policy::Policy() { + enableCheckFallThrough = 1; + enableCheckUnreachable = 0; + enableThreadSafetyAnalysis = 0; + enableConsumedAnalysis = 0; +} + +clang::sema::AnalysisBasedWarnings::AnalysisBasedWarnings(Sema &s) + : S(s), + NumFunctionsAnalyzed(0), + NumFunctionsWithBadCFGs(0), + NumCFGBlocks(0), + MaxCFGBlocksPerFunction(0), + NumUninitAnalysisFunctions(0), + NumUninitAnalysisVariables(0), + MaxUninitAnalysisVariablesPerFunction(0), + NumUninitAnalysisBlockVisits(0), + MaxUninitAnalysisBlockVisitsPerFunction(0) { + DiagnosticsEngine &D = S.getDiagnostics(); + DefaultPolicy.enableCheckUnreachable = (unsigned) + (D.getDiagnosticLevel(diag::warn_unreachable, SourceLocation()) != + DiagnosticsEngine::Ignored); + DefaultPolicy.enableThreadSafetyAnalysis = (unsigned) + (D.getDiagnosticLevel(diag::warn_double_lock, SourceLocation()) != + DiagnosticsEngine::Ignored); + DefaultPolicy.enableConsumedAnalysis = (unsigned) + (D.getDiagnosticLevel(diag::warn_use_in_invalid_state, SourceLocation()) != + DiagnosticsEngine::Ignored); +} + +static void flushDiagnostics(Sema &S, sema::FunctionScopeInfo *fscope) { + for (SmallVectorImpl<sema::PossiblyUnreachableDiag>::iterator + i = fscope->PossiblyUnreachableDiags.begin(), + e = fscope->PossiblyUnreachableDiags.end(); + i != e; ++i) { + const sema::PossiblyUnreachableDiag &D = *i; + S.Diag(D.Loc, D.PD); + } +} + +void clang::sema:: +AnalysisBasedWarnings::IssueWarnings(sema::AnalysisBasedWarnings::Policy P, + sema::FunctionScopeInfo *fscope, + const Decl *D, const BlockExpr *blkExpr) { + + // We avoid doing analysis-based warnings when there are errors for + // two reasons: + // (1) The CFGs often can't be constructed (if the body is invalid), so + // don't bother trying. + // (2) The code already has problems; running the analysis just takes more + // time. + DiagnosticsEngine &Diags = S.getDiagnostics(); + + // Do not do any analysis for declarations in system headers if we are + // going to just ignore them. + if (Diags.getSuppressSystemWarnings() && + S.SourceMgr.isInSystemHeader(D->getLocation())) + return; + + // For code in dependent contexts, we'll do this at instantiation time. + if (cast<DeclContext>(D)->isDependentContext()) + return; + + if (Diags.hasUncompilableErrorOccurred() || Diags.hasFatalErrorOccurred()) { + // Flush out any possibly unreachable diagnostics. + flushDiagnostics(S, fscope); + return; + } + + const Stmt *Body = D->getBody(); + assert(Body); + + // Construct the analysis context with the specified CFG build options. + AnalysisDeclContext AC(/* AnalysisDeclContextManager */ 0, D); + + // Don't generate EH edges for CallExprs as we'd like to avoid the n^2 + // explosion for destructors that can result and the compile time hit. + AC.getCFGBuildOptions().PruneTriviallyFalseEdges = true; + AC.getCFGBuildOptions().AddEHEdges = false; + AC.getCFGBuildOptions().AddInitializers = true; + AC.getCFGBuildOptions().AddImplicitDtors = true; + AC.getCFGBuildOptions().AddTemporaryDtors = true; + + // Force that certain expressions appear as CFGElements in the CFG. This + // is used to speed up various analyses. + // FIXME: This isn't the right factoring. This is here for initial + // prototyping, but we need a way for analyses to say what expressions they + // expect to always be CFGElements and then fill in the BuildOptions + // appropriately. This is essentially a layering violation. + if (P.enableCheckUnreachable || P.enableThreadSafetyAnalysis || + P.enableConsumedAnalysis) { + // Unreachable code analysis and thread safety require a linearized CFG. + AC.getCFGBuildOptions().setAllAlwaysAdd(); + } + else { + AC.getCFGBuildOptions() + .setAlwaysAdd(Stmt::BinaryOperatorClass) + .setAlwaysAdd(Stmt::CompoundAssignOperatorClass) + .setAlwaysAdd(Stmt::BlockExprClass) + .setAlwaysAdd(Stmt::CStyleCastExprClass) + .setAlwaysAdd(Stmt::DeclRefExprClass) + .setAlwaysAdd(Stmt::ImplicitCastExprClass) + .setAlwaysAdd(Stmt::UnaryOperatorClass) + .setAlwaysAdd(Stmt::AttributedStmtClass); + } + + + // Emit delayed diagnostics. + if (!fscope->PossiblyUnreachableDiags.empty()) { + bool analyzed = false; + + // Register the expressions with the CFGBuilder. + for (SmallVectorImpl<sema::PossiblyUnreachableDiag>::iterator + i = fscope->PossiblyUnreachableDiags.begin(), + e = fscope->PossiblyUnreachableDiags.end(); + i != e; ++i) { + if (const Stmt *stmt = i->stmt) + AC.registerForcedBlockExpression(stmt); + } + + if (AC.getCFG()) { + analyzed = true; + for (SmallVectorImpl<sema::PossiblyUnreachableDiag>::iterator + i = fscope->PossiblyUnreachableDiags.begin(), + e = fscope->PossiblyUnreachableDiags.end(); + i != e; ++i) + { + const sema::PossiblyUnreachableDiag &D = *i; + bool processed = false; + if (const Stmt *stmt = i->stmt) { + const CFGBlock *block = AC.getBlockForRegisteredExpression(stmt); + CFGReverseBlockReachabilityAnalysis *cra = + AC.getCFGReachablityAnalysis(); + // FIXME: We should be able to assert that block is non-null, but + // the CFG analysis can skip potentially-evaluated expressions in + // edge cases; see test/Sema/vla-2.c. + if (block && cra) { + // Can this block be reached from the entrance? + if (cra->isReachable(&AC.getCFG()->getEntry(), block)) + S.Diag(D.Loc, D.PD); + processed = true; + } + } + if (!processed) { + // Emit the warning anyway if we cannot map to a basic block. + S.Diag(D.Loc, D.PD); + } + } + } + + if (!analyzed) + flushDiagnostics(S, fscope); + } + + + // Warning: check missing 'return' + if (P.enableCheckFallThrough) { + const CheckFallThroughDiagnostics &CD = + (isa<BlockDecl>(D) ? CheckFallThroughDiagnostics::MakeForBlock() + : (isa<CXXMethodDecl>(D) && + cast<CXXMethodDecl>(D)->getOverloadedOperator() == OO_Call && + cast<CXXMethodDecl>(D)->getParent()->isLambda()) + ? CheckFallThroughDiagnostics::MakeForLambda() + : CheckFallThroughDiagnostics::MakeForFunction(D)); + CheckFallThroughForBody(S, D, Body, blkExpr, CD, AC); + } + + // Warning: check for unreachable code + if (P.enableCheckUnreachable) { + // Only check for unreachable code on non-template instantiations. + // Different template instantiations can effectively change the control-flow + // and it is very difficult to prove that a snippet of code in a template + // is unreachable for all instantiations. + bool isTemplateInstantiation = false; + if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) + isTemplateInstantiation = Function->isTemplateInstantiation(); + if (!isTemplateInstantiation) + CheckUnreachable(S, AC); + } + + // Check for thread safety violations + if (P.enableThreadSafetyAnalysis) { + SourceLocation FL = AC.getDecl()->getLocation(); + SourceLocation FEL = AC.getDecl()->getLocEnd(); + thread_safety::ThreadSafetyReporter Reporter(S, FL, FEL); + if (Diags.getDiagnosticLevel(diag::warn_thread_safety_beta,D->getLocStart()) + != DiagnosticsEngine::Ignored) + Reporter.setIssueBetaWarnings(true); + + thread_safety::runThreadSafetyAnalysis(AC, Reporter); + Reporter.emitDiagnostics(); + } + + // Check for violations of consumed properties. + if (P.enableConsumedAnalysis) { + consumed::ConsumedWarningsHandler WarningHandler(S); + consumed::ConsumedAnalyzer Analyzer(WarningHandler); + Analyzer.run(AC); + } + + if (Diags.getDiagnosticLevel(diag::warn_uninit_var, D->getLocStart()) + != DiagnosticsEngine::Ignored || + Diags.getDiagnosticLevel(diag::warn_sometimes_uninit_var,D->getLocStart()) + != DiagnosticsEngine::Ignored || + Diags.getDiagnosticLevel(diag::warn_maybe_uninit_var, D->getLocStart()) + != DiagnosticsEngine::Ignored) { + if (CFG *cfg = AC.getCFG()) { + UninitValsDiagReporter reporter(S); + UninitVariablesAnalysisStats stats; + std::memset(&stats, 0, sizeof(UninitVariablesAnalysisStats)); + runUninitializedVariablesAnalysis(*cast<DeclContext>(D), *cfg, AC, + reporter, stats); + + if (S.CollectStats && stats.NumVariablesAnalyzed > 0) { + ++NumUninitAnalysisFunctions; + NumUninitAnalysisVariables += stats.NumVariablesAnalyzed; + NumUninitAnalysisBlockVisits += stats.NumBlockVisits; + MaxUninitAnalysisVariablesPerFunction = + std::max(MaxUninitAnalysisVariablesPerFunction, + stats.NumVariablesAnalyzed); + MaxUninitAnalysisBlockVisitsPerFunction = + std::max(MaxUninitAnalysisBlockVisitsPerFunction, + stats.NumBlockVisits); + } + } + } + + bool FallThroughDiagFull = + Diags.getDiagnosticLevel(diag::warn_unannotated_fallthrough, + D->getLocStart()) != DiagnosticsEngine::Ignored; + bool FallThroughDiagPerFunction = + Diags.getDiagnosticLevel(diag::warn_unannotated_fallthrough_per_function, + D->getLocStart()) != DiagnosticsEngine::Ignored; + if (FallThroughDiagFull || FallThroughDiagPerFunction) { + DiagnoseSwitchLabelsFallthrough(S, AC, !FallThroughDiagFull); + } + + if (S.getLangOpts().ObjCARCWeak && + Diags.getDiagnosticLevel(diag::warn_arc_repeated_use_of_weak, + D->getLocStart()) != DiagnosticsEngine::Ignored) + diagnoseRepeatedUseOfWeak(S, fscope, D, AC.getParentMap()); + + // Collect statistics about the CFG if it was built. + if (S.CollectStats && AC.isCFGBuilt()) { + ++NumFunctionsAnalyzed; + if (CFG *cfg = AC.getCFG()) { + // If we successfully built a CFG for this context, record some more + // detail information about it. + NumCFGBlocks += cfg->getNumBlockIDs(); + MaxCFGBlocksPerFunction = std::max(MaxCFGBlocksPerFunction, + cfg->getNumBlockIDs()); + } else { + ++NumFunctionsWithBadCFGs; + } + } +} + +void clang::sema::AnalysisBasedWarnings::PrintStats() const { + llvm::errs() << "\n*** Analysis Based Warnings Stats:\n"; + + unsigned NumCFGsBuilt = NumFunctionsAnalyzed - NumFunctionsWithBadCFGs; + unsigned AvgCFGBlocksPerFunction = + !NumCFGsBuilt ? 0 : NumCFGBlocks/NumCFGsBuilt; + llvm::errs() << NumFunctionsAnalyzed << " functions analyzed (" + << NumFunctionsWithBadCFGs << " w/o CFGs).\n" + << " " << NumCFGBlocks << " CFG blocks built.\n" + << " " << AvgCFGBlocksPerFunction + << " average CFG blocks per function.\n" + << " " << MaxCFGBlocksPerFunction + << " max CFG blocks per function.\n"; + + unsigned AvgUninitVariablesPerFunction = !NumUninitAnalysisFunctions ? 0 + : NumUninitAnalysisVariables/NumUninitAnalysisFunctions; + unsigned AvgUninitBlockVisitsPerFunction = !NumUninitAnalysisFunctions ? 0 + : NumUninitAnalysisBlockVisits/NumUninitAnalysisFunctions; + llvm::errs() << NumUninitAnalysisFunctions + << " functions analyzed for uninitialiazed variables\n" + << " " << NumUninitAnalysisVariables << " variables analyzed.\n" + << " " << AvgUninitVariablesPerFunction + << " average variables per function.\n" + << " " << MaxUninitAnalysisVariablesPerFunction + << " max variables per function.\n" + << " " << NumUninitAnalysisBlockVisits << " block visits.\n" + << " " << AvgUninitBlockVisitsPerFunction + << " average block visits per function.\n" + << " " << MaxUninitAnalysisBlockVisitsPerFunction + << " max block visits per function.\n"; +} |