mirror of
https://github.com/capstone-engine/llvm-capstone.git
synced 2024-12-07 22:27:13 +00:00
82e95a3c79
llvm-svn: 222335
2093 lines
74 KiB
C++
2093 lines
74 KiB
C++
//=- AnalysisBasedWarnings.cpp - Sema warnings based on libAnalysis -*- C++ -*-=//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines analysis_warnings::[Policy,Executor].
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// Together they are used by Sema to issue warnings based on inexpensive
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// static analysis algorithms in libAnalysis.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/Sema/AnalysisBasedWarnings.h"
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#include "clang/AST/DeclCXX.h"
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#include "clang/AST/DeclObjC.h"
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#include "clang/AST/EvaluatedExprVisitor.h"
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#include "clang/AST/ExprCXX.h"
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#include "clang/AST/ExprObjC.h"
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#include "clang/AST/ParentMap.h"
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#include "clang/AST/RecursiveASTVisitor.h"
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#include "clang/AST/StmtCXX.h"
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#include "clang/AST/StmtObjC.h"
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#include "clang/AST/StmtVisitor.h"
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#include "clang/Analysis/Analyses/CFGReachabilityAnalysis.h"
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#include "clang/Analysis/Analyses/Consumed.h"
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#include "clang/Analysis/Analyses/ReachableCode.h"
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#include "clang/Analysis/Analyses/ThreadSafety.h"
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#include "clang/Analysis/Analyses/UninitializedValues.h"
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#include "clang/Analysis/AnalysisContext.h"
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#include "clang/Analysis/CFG.h"
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#include "clang/Analysis/CFGStmtMap.h"
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#include "clang/Basic/SourceLocation.h"
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#include "clang/Basic/SourceManager.h"
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#include "clang/Lex/Lexer.h"
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#include "clang/Lex/Preprocessor.h"
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#include "clang/Sema/ScopeInfo.h"
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#include "clang/Sema/SemaInternal.h"
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#include "llvm/ADT/ArrayRef.h"
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#include "llvm/ADT/BitVector.h"
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#include "llvm/ADT/FoldingSet.h"
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#include "llvm/ADT/ImmutableMap.h"
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#include "llvm/ADT/MapVector.h"
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#include "llvm/ADT/PostOrderIterator.h"
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#include "llvm/ADT/SmallString.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/StringRef.h"
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#include "llvm/Support/Casting.h"
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#include <algorithm>
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#include <deque>
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#include <iterator>
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#include <vector>
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using namespace clang;
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//===----------------------------------------------------------------------===//
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// Unreachable code analysis.
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//===----------------------------------------------------------------------===//
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namespace {
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class UnreachableCodeHandler : public reachable_code::Callback {
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Sema &S;
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public:
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UnreachableCodeHandler(Sema &s) : S(s) {}
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void HandleUnreachable(reachable_code::UnreachableKind UK,
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SourceLocation L,
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SourceRange SilenceableCondVal,
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SourceRange R1,
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SourceRange R2) override {
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unsigned diag = diag::warn_unreachable;
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switch (UK) {
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case reachable_code::UK_Break:
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diag = diag::warn_unreachable_break;
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break;
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case reachable_code::UK_Return:
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diag = diag::warn_unreachable_return;
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break;
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case reachable_code::UK_Loop_Increment:
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diag = diag::warn_unreachable_loop_increment;
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break;
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case reachable_code::UK_Other:
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break;
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}
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S.Diag(L, diag) << R1 << R2;
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SourceLocation Open = SilenceableCondVal.getBegin();
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if (Open.isValid()) {
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SourceLocation Close = SilenceableCondVal.getEnd();
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Close = S.getLocForEndOfToken(Close);
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if (Close.isValid()) {
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S.Diag(Open, diag::note_unreachable_silence)
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<< FixItHint::CreateInsertion(Open, "/* DISABLES CODE */ (")
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<< FixItHint::CreateInsertion(Close, ")");
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}
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}
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}
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};
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}
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/// CheckUnreachable - Check for unreachable code.
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static void CheckUnreachable(Sema &S, AnalysisDeclContext &AC) {
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// As a heuristic prune all diagnostics not in the main file. Currently
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// the majority of warnings in headers are false positives. These
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// are largely caused by configuration state, e.g. preprocessor
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// defined code, etc.
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//
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// Note that this is also a performance optimization. Analyzing
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// headers many times can be expensive.
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if (!S.getSourceManager().isInMainFile(AC.getDecl()->getLocStart()))
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return;
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UnreachableCodeHandler UC(S);
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reachable_code::FindUnreachableCode(AC, S.getPreprocessor(), UC);
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}
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/// \brief Warn on logical operator errors in CFGBuilder
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class LogicalErrorHandler : public CFGCallback {
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Sema &S;
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public:
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LogicalErrorHandler(Sema &S) : CFGCallback(), S(S) {}
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static bool HasMacroID(const Expr *E) {
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if (E->getExprLoc().isMacroID())
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return true;
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// Recurse to children.
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for (ConstStmtRange SubStmts = E->children(); SubStmts; ++SubStmts)
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if (*SubStmts)
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if (const Expr *SubExpr = dyn_cast<Expr>(*SubStmts))
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if (HasMacroID(SubExpr))
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return true;
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return false;
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}
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void compareAlwaysTrue(const BinaryOperator *B, bool isAlwaysTrue) {
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if (HasMacroID(B))
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return;
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SourceRange DiagRange = B->getSourceRange();
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S.Diag(B->getExprLoc(), diag::warn_tautological_overlap_comparison)
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<< DiagRange << isAlwaysTrue;
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}
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void compareBitwiseEquality(const BinaryOperator *B, bool isAlwaysTrue) {
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if (HasMacroID(B))
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return;
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SourceRange DiagRange = B->getSourceRange();
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S.Diag(B->getExprLoc(), diag::warn_comparison_bitwise_always)
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<< DiagRange << isAlwaysTrue;
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}
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};
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//===----------------------------------------------------------------------===//
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// Check for infinite self-recursion in functions
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//===----------------------------------------------------------------------===//
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// All blocks are in one of three states. States are ordered so that blocks
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// can only move to higher states.
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enum RecursiveState {
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FoundNoPath,
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FoundPath,
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FoundPathWithNoRecursiveCall
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};
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static void checkForFunctionCall(Sema &S, const FunctionDecl *FD,
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CFGBlock &Block, unsigned ExitID,
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llvm::SmallVectorImpl<RecursiveState> &States,
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RecursiveState State) {
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unsigned ID = Block.getBlockID();
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// A block's state can only move to a higher state.
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if (States[ID] >= State)
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return;
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States[ID] = State;
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// Found a path to the exit node without a recursive call.
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if (ID == ExitID && State == FoundPathWithNoRecursiveCall)
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return;
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if (State == FoundPathWithNoRecursiveCall) {
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// If the current state is FoundPathWithNoRecursiveCall, the successors
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// will be either FoundPathWithNoRecursiveCall or FoundPath. To determine
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// which, process all the Stmt's in this block to find any recursive calls.
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for (const auto &B : Block) {
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if (B.getKind() != CFGElement::Statement)
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continue;
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const CallExpr *CE = dyn_cast<CallExpr>(B.getAs<CFGStmt>()->getStmt());
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if (CE && CE->getCalleeDecl() &&
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CE->getCalleeDecl()->getCanonicalDecl() == FD) {
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// Skip function calls which are qualified with a templated class.
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if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(
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CE->getCallee()->IgnoreParenImpCasts())) {
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if (NestedNameSpecifier *NNS = DRE->getQualifier()) {
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if (NNS->getKind() == NestedNameSpecifier::TypeSpec &&
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isa<TemplateSpecializationType>(NNS->getAsType())) {
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continue;
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}
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}
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}
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if (const CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(CE)) {
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if (isa<CXXThisExpr>(MCE->getImplicitObjectArgument()) ||
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!MCE->getMethodDecl()->isVirtual()) {
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State = FoundPath;
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break;
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}
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} else {
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State = FoundPath;
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break;
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}
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}
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}
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}
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for (CFGBlock::succ_iterator I = Block.succ_begin(), E = Block.succ_end();
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I != E; ++I)
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if (*I)
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checkForFunctionCall(S, FD, **I, ExitID, States, State);
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}
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static void checkRecursiveFunction(Sema &S, const FunctionDecl *FD,
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const Stmt *Body,
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AnalysisDeclContext &AC) {
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FD = FD->getCanonicalDecl();
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// Only run on non-templated functions and non-templated members of
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// templated classes.
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if (FD->getTemplatedKind() != FunctionDecl::TK_NonTemplate &&
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FD->getTemplatedKind() != FunctionDecl::TK_MemberSpecialization)
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return;
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CFG *cfg = AC.getCFG();
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if (!cfg) return;
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// If the exit block is unreachable, skip processing the function.
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if (cfg->getExit().pred_empty())
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return;
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// Mark all nodes as FoundNoPath, then begin processing the entry block.
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llvm::SmallVector<RecursiveState, 16> states(cfg->getNumBlockIDs(),
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FoundNoPath);
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checkForFunctionCall(S, FD, cfg->getEntry(), cfg->getExit().getBlockID(),
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states, FoundPathWithNoRecursiveCall);
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// Check that the exit block is reachable. This prevents triggering the
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// warning on functions that do not terminate.
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if (states[cfg->getExit().getBlockID()] == FoundPath)
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S.Diag(Body->getLocStart(), diag::warn_infinite_recursive_function);
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}
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//===----------------------------------------------------------------------===//
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// Check for missing return value.
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//===----------------------------------------------------------------------===//
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enum ControlFlowKind {
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UnknownFallThrough,
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NeverFallThrough,
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MaybeFallThrough,
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AlwaysFallThrough,
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NeverFallThroughOrReturn
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};
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/// CheckFallThrough - Check that we don't fall off the end of a
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/// Statement that should return a value.
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///
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/// \returns AlwaysFallThrough iff we always fall off the end of the statement,
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/// MaybeFallThrough iff we might or might not fall off the end,
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/// NeverFallThroughOrReturn iff we never fall off the end of the statement or
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/// return. We assume NeverFallThrough iff we never fall off the end of the
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/// statement but we may return. We assume that functions not marked noreturn
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/// will return.
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static ControlFlowKind CheckFallThrough(AnalysisDeclContext &AC) {
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CFG *cfg = AC.getCFG();
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if (!cfg) return UnknownFallThrough;
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// The CFG leaves in dead things, and we don't want the dead code paths to
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// confuse us, so we mark all live things first.
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llvm::BitVector live(cfg->getNumBlockIDs());
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unsigned count = reachable_code::ScanReachableFromBlock(&cfg->getEntry(),
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live);
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bool AddEHEdges = AC.getAddEHEdges();
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if (!AddEHEdges && count != cfg->getNumBlockIDs())
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// When there are things remaining dead, and we didn't add EH edges
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// from CallExprs to the catch clauses, we have to go back and
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// mark them as live.
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for (const auto *B : *cfg) {
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if (!live[B->getBlockID()]) {
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if (B->pred_begin() == B->pred_end()) {
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if (B->getTerminator() && isa<CXXTryStmt>(B->getTerminator()))
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// When not adding EH edges from calls, catch clauses
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// can otherwise seem dead. Avoid noting them as dead.
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count += reachable_code::ScanReachableFromBlock(B, live);
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continue;
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}
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}
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}
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// Now we know what is live, we check the live precessors of the exit block
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// and look for fall through paths, being careful to ignore normal returns,
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// and exceptional paths.
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bool HasLiveReturn = false;
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bool HasFakeEdge = false;
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bool HasPlainEdge = false;
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bool HasAbnormalEdge = false;
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// Ignore default cases that aren't likely to be reachable because all
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// enums in a switch(X) have explicit case statements.
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CFGBlock::FilterOptions FO;
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FO.IgnoreDefaultsWithCoveredEnums = 1;
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for (CFGBlock::filtered_pred_iterator
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I = cfg->getExit().filtered_pred_start_end(FO); I.hasMore(); ++I) {
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const CFGBlock& B = **I;
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if (!live[B.getBlockID()])
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continue;
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// Skip blocks which contain an element marked as no-return. They don't
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// represent actually viable edges into the exit block, so mark them as
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// abnormal.
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if (B.hasNoReturnElement()) {
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HasAbnormalEdge = true;
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continue;
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}
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// Destructors can appear after the 'return' in the CFG. This is
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// normal. We need to look pass the destructors for the return
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// statement (if it exists).
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CFGBlock::const_reverse_iterator ri = B.rbegin(), re = B.rend();
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for ( ; ri != re ; ++ri)
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if (ri->getAs<CFGStmt>())
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break;
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// No more CFGElements in the block?
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if (ri == re) {
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if (B.getTerminator() && isa<CXXTryStmt>(B.getTerminator())) {
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HasAbnormalEdge = true;
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continue;
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}
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// A labeled empty statement, or the entry block...
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HasPlainEdge = true;
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continue;
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}
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CFGStmt CS = ri->castAs<CFGStmt>();
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const Stmt *S = CS.getStmt();
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if (isa<ReturnStmt>(S)) {
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HasLiveReturn = true;
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continue;
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}
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if (isa<ObjCAtThrowStmt>(S)) {
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HasFakeEdge = true;
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continue;
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}
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if (isa<CXXThrowExpr>(S)) {
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HasFakeEdge = true;
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continue;
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}
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if (isa<MSAsmStmt>(S)) {
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// TODO: Verify this is correct.
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HasFakeEdge = true;
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HasLiveReturn = true;
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continue;
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}
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if (isa<CXXTryStmt>(S)) {
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HasAbnormalEdge = true;
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continue;
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}
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if (std::find(B.succ_begin(), B.succ_end(), &cfg->getExit())
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== B.succ_end()) {
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HasAbnormalEdge = true;
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continue;
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}
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HasPlainEdge = true;
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}
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if (!HasPlainEdge) {
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if (HasLiveReturn)
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return NeverFallThrough;
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return NeverFallThroughOrReturn;
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}
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if (HasAbnormalEdge || HasFakeEdge || HasLiveReturn)
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return MaybeFallThrough;
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// This says AlwaysFallThrough for calls to functions that are not marked
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// noreturn, that don't return. If people would like this warning to be more
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// accurate, such functions should be marked as noreturn.
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return AlwaysFallThrough;
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}
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namespace {
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struct CheckFallThroughDiagnostics {
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unsigned diag_MaybeFallThrough_HasNoReturn;
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unsigned diag_MaybeFallThrough_ReturnsNonVoid;
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unsigned diag_AlwaysFallThrough_HasNoReturn;
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unsigned diag_AlwaysFallThrough_ReturnsNonVoid;
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unsigned diag_NeverFallThroughOrReturn;
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enum { Function, Block, Lambda } funMode;
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SourceLocation FuncLoc;
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static CheckFallThroughDiagnostics MakeForFunction(const Decl *Func) {
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CheckFallThroughDiagnostics D;
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D.FuncLoc = Func->getLocation();
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D.diag_MaybeFallThrough_HasNoReturn =
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diag::warn_falloff_noreturn_function;
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D.diag_MaybeFallThrough_ReturnsNonVoid =
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diag::warn_maybe_falloff_nonvoid_function;
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D.diag_AlwaysFallThrough_HasNoReturn =
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diag::warn_falloff_noreturn_function;
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D.diag_AlwaysFallThrough_ReturnsNonVoid =
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diag::warn_falloff_nonvoid_function;
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// Don't suggest that virtual functions be marked "noreturn", since they
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// might be overridden by non-noreturn functions.
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bool isVirtualMethod = false;
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if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Func))
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isVirtualMethod = Method->isVirtual();
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// Don't suggest that template instantiations be marked "noreturn"
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bool isTemplateInstantiation = false;
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if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(Func))
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isTemplateInstantiation = Function->isTemplateInstantiation();
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if (!isVirtualMethod && !isTemplateInstantiation)
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D.diag_NeverFallThroughOrReturn =
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diag::warn_suggest_noreturn_function;
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else
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D.diag_NeverFallThroughOrReturn = 0;
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D.funMode = Function;
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return D;
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}
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static CheckFallThroughDiagnostics MakeForBlock() {
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CheckFallThroughDiagnostics D;
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D.diag_MaybeFallThrough_HasNoReturn =
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diag::err_noreturn_block_has_return_expr;
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D.diag_MaybeFallThrough_ReturnsNonVoid =
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diag::err_maybe_falloff_nonvoid_block;
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D.diag_AlwaysFallThrough_HasNoReturn =
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diag::err_noreturn_block_has_return_expr;
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D.diag_AlwaysFallThrough_ReturnsNonVoid =
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diag::err_falloff_nonvoid_block;
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D.diag_NeverFallThroughOrReturn = 0;
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D.funMode = Block;
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return D;
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}
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static CheckFallThroughDiagnostics MakeForLambda() {
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CheckFallThroughDiagnostics D;
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D.diag_MaybeFallThrough_HasNoReturn =
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diag::err_noreturn_lambda_has_return_expr;
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D.diag_MaybeFallThrough_ReturnsNonVoid =
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diag::warn_maybe_falloff_nonvoid_lambda;
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D.diag_AlwaysFallThrough_HasNoReturn =
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diag::err_noreturn_lambda_has_return_expr;
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D.diag_AlwaysFallThrough_ReturnsNonVoid =
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diag::warn_falloff_nonvoid_lambda;
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D.diag_NeverFallThroughOrReturn = 0;
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D.funMode = Lambda;
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return D;
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}
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bool checkDiagnostics(DiagnosticsEngine &D, bool ReturnsVoid,
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bool HasNoReturn) const {
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if (funMode == Function) {
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return (ReturnsVoid ||
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D.isIgnored(diag::warn_maybe_falloff_nonvoid_function,
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FuncLoc)) &&
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(!HasNoReturn ||
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D.isIgnored(diag::warn_noreturn_function_has_return_expr,
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FuncLoc)) &&
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(!ReturnsVoid ||
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D.isIgnored(diag::warn_suggest_noreturn_block, FuncLoc));
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}
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// For blocks / lambdas.
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return ReturnsVoid && !HasNoReturn;
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}
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};
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}
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/// 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->getReturnType()->isVoidType();
|
|
HasNoReturn = FD->isNoReturn();
|
|
}
|
|
else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) {
|
|
ReturnsVoid = MD->getReturnType()->isVoidType();
|
|
HasNoReturn = MD->hasAttr<NoReturnAttr>();
|
|
}
|
|
else if (isa<BlockDecl>(D)) {
|
|
QualType BlockTy = blkExpr->getType();
|
|
if (const FunctionType *FT =
|
|
BlockTy->getPointeeType()->getAs<FunctionType>()) {
|
|
if (FT->getReturnType()->isVoidType())
|
|
ReturnsVoid = true;
|
|
if (FT->getNoReturnAttr())
|
|
HasNoReturn = true;
|
|
}
|
|
}
|
|
|
|
DiagnosticsEngine &Diags = S.getDiagnostics();
|
|
|
|
// Short circuit for compilation speed.
|
|
if (CD.checkDiagnostics(Diags, ReturnsVoid, HasNoReturn))
|
|
return;
|
|
|
|
SourceLocation LBrace = Body->getLocStart(), RBrace = Body->getLocEnd();
|
|
// Either in a function body compound statement, or a function-try-block.
|
|
switch (CheckFallThrough(AC)) {
|
|
case UnknownFallThrough:
|
|
break;
|
|
|
|
case MaybeFallThrough:
|
|
if (HasNoReturn)
|
|
S.Diag(RBrace, CD.diag_MaybeFallThrough_HasNoReturn);
|
|
else if (!ReturnsVoid)
|
|
S.Diag(RBrace, CD.diag_MaybeFallThrough_ReturnsNonVoid);
|
|
break;
|
|
case AlwaysFallThrough:
|
|
if (HasNoReturn)
|
|
S.Diag(RBrace, CD.diag_AlwaysFallThrough_HasNoReturn);
|
|
else if (!ReturnsVoid)
|
|
S.Diag(RBrace, CD.diag_AlwaysFallThrough_ReturnsNonVoid);
|
|
break;
|
|
case NeverFallThroughOrReturn:
|
|
if (ReturnsVoid && !HasNoReturn && CD.diag_NeverFallThroughOrReturn) {
|
|
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
|
|
S.Diag(LBrace, CD.diag_NeverFallThroughOrReturn) << 0 << FD;
|
|
} else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) {
|
|
S.Diag(LBrace, CD.diag_NeverFallThroughOrReturn) << 1 << MD;
|
|
} else {
|
|
S.Diag(LBrace, 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.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 (const auto *B : *Cfg) {
|
|
const Stmt *L = B->getLabel();
|
|
if (L && isa<SwitchCase>(L) && ReachableBlocks.insert(B).second)
|
|
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).second)
|
|
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(B.pred_begin(), B.pred_end());
|
|
while (!BlockQueue.empty()) {
|
|
const CFGBlock *P = BlockQueue.front();
|
|
BlockQueue.pop_front();
|
|
if (!P) continue;
|
|
|
|
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; }
|
|
|
|
// We analyze lambda bodies separately. Skip them here.
|
|
bool TraverseLambdaBody(LambdaExpr *LE) { 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 nullptr;
|
|
}
|
|
|
|
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 nullptr;
|
|
}
|
|
|
|
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; ");
|
|
}
|
|
}
|
|
|
|
for (const auto *F : FM.getFallthroughStmts())
|
|
S.Diag(F->getLocStart(), diag::warn_fallthrough_attr_invalid_placement);
|
|
}
|
|
|
|
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;
|
|
typedef std::pair<const Stmt *, WeakObjectUseMap::const_iterator>
|
|
StmtUsesPair;
|
|
|
|
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.
|
|
SourceManager &SM = S.getSourceManager();
|
|
std::sort(UsesByStmt.begin(), UsesByStmt.end(),
|
|
[&SM](const StmtUsesPair &LHS, const StmtUsesPair &RHS) {
|
|
return SM.isBeforeInTranslationUnit(LHS.first->getLocStart(),
|
|
RHS.first->getLocStart());
|
|
});
|
|
|
|
// 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 (const auto &P : UsesByStmt) {
|
|
const Stmt *FirstRead = P.first;
|
|
const WeakObjectProfileTy &Key = P.second->first;
|
|
const WeakUseVector &Uses = P.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 (const auto &Use : Uses) {
|
|
if (Use.getUseExpr() == FirstRead)
|
|
continue;
|
|
S.Diag(Use.getUseExpr()->getLocStart(),
|
|
diag::note_arc_weak_also_accessed_here)
|
|
<< Use.getUseExpr()->getSourceRange();
|
|
}
|
|
}
|
|
}
|
|
|
|
namespace {
|
|
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(nullptr) {}
|
|
~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) override {
|
|
getUses(vd).getPointer()->push_back(use);
|
|
}
|
|
|
|
void handleSelfInit(const VarDecl *vd) override {
|
|
getUses(vd).setInt(true);
|
|
}
|
|
|
|
void flushDiagnostics() {
|
|
if (!uses)
|
|
return;
|
|
|
|
for (const auto &P : *uses) {
|
|
const VarDecl *vd = P.first;
|
|
const MappedType &V = P.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(),
|
|
[](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();
|
|
return a.getUser()->getLocStart() < b.getUser()->getLocStart();
|
|
});
|
|
|
|
for (const auto &U : *vec) {
|
|
// If we have self-init, downgrade all uses to 'may be uninitialized'.
|
|
UninitUse Use = hasSelfInit ? UninitUse(U.getUser(), false) : U;
|
|
|
|
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) {
|
|
return std::any_of(vec->begin(), vec->end(), [](const UninitUse &U) {
|
|
return U.getKind() == UninitUse::Always ||
|
|
U.getKind() == UninitUse::AfterCall ||
|
|
U.getKind() == UninitUse::AfterDecl;
|
|
});
|
|
}
|
|
};
|
|
}
|
|
|
|
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 threadSafety {
|
|
|
|
class ThreadSafetyReporter : public clang::threadSafety::ThreadSafetyHandler {
|
|
Sema &S;
|
|
DiagList Warnings;
|
|
SourceLocation FunLocation, FunEndLocation;
|
|
|
|
const FunctionDecl *CurrentFunction;
|
|
bool Verbose;
|
|
|
|
OptionalNotes getNotes() const {
|
|
if (Verbose && CurrentFunction) {
|
|
PartialDiagnosticAt FNote(CurrentFunction->getBody()->getLocStart(),
|
|
S.PDiag(diag::note_thread_warning_in_fun)
|
|
<< CurrentFunction->getNameAsString());
|
|
return OptionalNotes(1, FNote);
|
|
}
|
|
return OptionalNotes();
|
|
}
|
|
|
|
OptionalNotes getNotes(const PartialDiagnosticAt &Note) const {
|
|
OptionalNotes ONS(1, Note);
|
|
if (Verbose && CurrentFunction) {
|
|
PartialDiagnosticAt FNote(CurrentFunction->getBody()->getLocStart(),
|
|
S.PDiag(diag::note_thread_warning_in_fun)
|
|
<< CurrentFunction->getNameAsString());
|
|
ONS.push_back(FNote);
|
|
}
|
|
return ONS;
|
|
}
|
|
|
|
OptionalNotes getNotes(const PartialDiagnosticAt &Note1,
|
|
const PartialDiagnosticAt &Note2) const {
|
|
OptionalNotes ONS;
|
|
ONS.push_back(Note1);
|
|
ONS.push_back(Note2);
|
|
if (Verbose && CurrentFunction) {
|
|
PartialDiagnosticAt FNote(CurrentFunction->getBody()->getLocStart(),
|
|
S.PDiag(diag::note_thread_warning_in_fun)
|
|
<< CurrentFunction->getNameAsString());
|
|
ONS.push_back(FNote);
|
|
}
|
|
return ONS;
|
|
}
|
|
|
|
// Helper functions
|
|
void warnLockMismatch(unsigned DiagID, StringRef Kind, 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) << Kind << LockName);
|
|
Warnings.push_back(DelayedDiag(Warning, getNotes()));
|
|
}
|
|
|
|
public:
|
|
ThreadSafetyReporter(Sema &S, SourceLocation FL, SourceLocation FEL)
|
|
: S(S), FunLocation(FL), FunEndLocation(FEL),
|
|
CurrentFunction(nullptr), Verbose(false) {}
|
|
|
|
void setVerbose(bool b) { Verbose = b; }
|
|
|
|
/// \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 (const auto &Diag : Warnings) {
|
|
S.Diag(Diag.first.first, Diag.first.second);
|
|
for (const auto &Note : Diag.second)
|
|
S.Diag(Note.first, Note.second);
|
|
}
|
|
}
|
|
|
|
void handleInvalidLockExp(StringRef Kind, SourceLocation Loc) override {
|
|
PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_cannot_resolve_lock)
|
|
<< Loc);
|
|
Warnings.push_back(DelayedDiag(Warning, getNotes()));
|
|
}
|
|
|
|
void handleUnmatchedUnlock(StringRef Kind, Name LockName,
|
|
SourceLocation Loc) override {
|
|
warnLockMismatch(diag::warn_unlock_but_no_lock, Kind, LockName, Loc);
|
|
}
|
|
|
|
void handleIncorrectUnlockKind(StringRef Kind, Name LockName,
|
|
LockKind Expected, LockKind Received,
|
|
SourceLocation Loc) override {
|
|
if (Loc.isInvalid())
|
|
Loc = FunLocation;
|
|
PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_unlock_kind_mismatch)
|
|
<< Kind << LockName << Received
|
|
<< Expected);
|
|
Warnings.push_back(DelayedDiag(Warning, getNotes()));
|
|
}
|
|
|
|
void handleDoubleLock(StringRef Kind, Name LockName, SourceLocation Loc) override {
|
|
warnLockMismatch(diag::warn_double_lock, Kind, LockName, Loc);
|
|
}
|
|
|
|
void handleMutexHeldEndOfScope(StringRef Kind, Name LockName,
|
|
SourceLocation LocLocked,
|
|
SourceLocation LocEndOfScope,
|
|
LockErrorKind LEK) override {
|
|
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) << Kind
|
|
<< LockName);
|
|
if (LocLocked.isValid()) {
|
|
PartialDiagnosticAt Note(LocLocked, S.PDiag(diag::note_locked_here)
|
|
<< Kind);
|
|
Warnings.push_back(DelayedDiag(Warning, getNotes(Note)));
|
|
return;
|
|
}
|
|
Warnings.push_back(DelayedDiag(Warning, getNotes()));
|
|
}
|
|
|
|
void handleExclusiveAndShared(StringRef Kind, Name LockName,
|
|
SourceLocation Loc1,
|
|
SourceLocation Loc2) override {
|
|
PartialDiagnosticAt Warning(Loc1,
|
|
S.PDiag(diag::warn_lock_exclusive_and_shared)
|
|
<< Kind << LockName);
|
|
PartialDiagnosticAt Note(Loc2, S.PDiag(diag::note_lock_exclusive_and_shared)
|
|
<< Kind << LockName);
|
|
Warnings.push_back(DelayedDiag(Warning, getNotes(Note)));
|
|
}
|
|
|
|
void handleNoMutexHeld(StringRef Kind, const NamedDecl *D,
|
|
ProtectedOperationKind POK, AccessKind AK,
|
|
SourceLocation Loc) override {
|
|
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, getNotes()));
|
|
}
|
|
|
|
void handleMutexNotHeld(StringRef Kind, const NamedDecl *D,
|
|
ProtectedOperationKind POK, Name LockName,
|
|
LockKind LK, SourceLocation Loc,
|
|
Name *PossibleMatch) override {
|
|
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;
|
|
case POK_PassByRef:
|
|
DiagID = diag::warn_guarded_pass_by_reference;
|
|
break;
|
|
case POK_PtPassByRef:
|
|
DiagID = diag::warn_pt_guarded_pass_by_reference;
|
|
break;
|
|
}
|
|
PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID) << Kind
|
|
<< D->getNameAsString()
|
|
<< LockName << LK);
|
|
PartialDiagnosticAt Note(Loc, S.PDiag(diag::note_found_mutex_near_match)
|
|
<< *PossibleMatch);
|
|
if (Verbose && POK == POK_VarAccess) {
|
|
PartialDiagnosticAt VNote(D->getLocation(),
|
|
S.PDiag(diag::note_guarded_by_declared_here)
|
|
<< D->getNameAsString());
|
|
Warnings.push_back(DelayedDiag(Warning, getNotes(Note, VNote)));
|
|
} else
|
|
Warnings.push_back(DelayedDiag(Warning, getNotes(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;
|
|
case POK_PassByRef:
|
|
DiagID = diag::warn_guarded_pass_by_reference;
|
|
break;
|
|
case POK_PtPassByRef:
|
|
DiagID = diag::warn_pt_guarded_pass_by_reference;
|
|
break;
|
|
}
|
|
PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID) << Kind
|
|
<< D->getNameAsString()
|
|
<< LockName << LK);
|
|
if (Verbose && POK == POK_VarAccess) {
|
|
PartialDiagnosticAt Note(D->getLocation(),
|
|
S.PDiag(diag::note_guarded_by_declared_here)
|
|
<< D->getNameAsString());
|
|
Warnings.push_back(DelayedDiag(Warning, getNotes(Note)));
|
|
} else
|
|
Warnings.push_back(DelayedDiag(Warning, getNotes()));
|
|
}
|
|
}
|
|
|
|
|
|
virtual void handleNegativeNotHeld(StringRef Kind, Name LockName, Name Neg,
|
|
SourceLocation Loc) override {
|
|
PartialDiagnosticAt Warning(Loc,
|
|
S.PDiag(diag::warn_acquire_requires_negative_cap)
|
|
<< Kind << LockName << Neg);
|
|
Warnings.push_back(DelayedDiag(Warning, getNotes()));
|
|
}
|
|
|
|
|
|
void handleFunExcludesLock(StringRef Kind, Name FunName, Name LockName,
|
|
SourceLocation Loc) override {
|
|
PartialDiagnosticAt Warning(Loc, S.PDiag(diag::warn_fun_excludes_mutex)
|
|
<< Kind << FunName << LockName);
|
|
Warnings.push_back(DelayedDiag(Warning, getNotes()));
|
|
}
|
|
|
|
void enterFunction(const FunctionDecl* FD) override {
|
|
CurrentFunction = FD;
|
|
}
|
|
|
|
void leaveFunction(const FunctionDecl* FD) override {
|
|
CurrentFunction = 0;
|
|
}
|
|
};
|
|
|
|
}
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// -Wconsumed
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
namespace clang {
|
|
namespace consumed {
|
|
namespace {
|
|
class ConsumedWarningsHandler : public ConsumedWarningsHandlerBase {
|
|
|
|
Sema &S;
|
|
DiagList Warnings;
|
|
|
|
public:
|
|
|
|
ConsumedWarningsHandler(Sema &S) : S(S) {}
|
|
|
|
void emitDiagnostics() override {
|
|
Warnings.sort(SortDiagBySourceLocation(S.getSourceManager()));
|
|
for (const auto &Diag : Warnings) {
|
|
S.Diag(Diag.first.first, Diag.first.second);
|
|
for (const auto &Note : Diag.second)
|
|
S.Diag(Note.first, Note.second);
|
|
}
|
|
}
|
|
|
|
void warnLoopStateMismatch(SourceLocation Loc,
|
|
StringRef VariableName) override {
|
|
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) override {
|
|
|
|
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) override {
|
|
|
|
PartialDiagnosticAt Warning(Loc, S.PDiag(
|
|
diag::warn_param_typestate_mismatch) << ExpectedState << ObservedState);
|
|
|
|
Warnings.push_back(DelayedDiag(Warning, OptionalNotes()));
|
|
}
|
|
|
|
void warnReturnTypestateForUnconsumableType(SourceLocation Loc,
|
|
StringRef TypeName) override {
|
|
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) override {
|
|
|
|
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) override {
|
|
|
|
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) override {
|
|
|
|
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;
|
|
}
|
|
|
|
static unsigned isEnabled(DiagnosticsEngine &D, unsigned diag) {
|
|
return (unsigned)!D.isIgnored(diag, SourceLocation());
|
|
}
|
|
|
|
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) {
|
|
|
|
using namespace diag;
|
|
DiagnosticsEngine &D = S.getDiagnostics();
|
|
|
|
DefaultPolicy.enableCheckUnreachable =
|
|
isEnabled(D, warn_unreachable) ||
|
|
isEnabled(D, warn_unreachable_break) ||
|
|
isEnabled(D, warn_unreachable_return) ||
|
|
isEnabled(D, warn_unreachable_loop_increment);
|
|
|
|
DefaultPolicy.enableThreadSafetyAnalysis =
|
|
isEnabled(D, warn_double_lock);
|
|
|
|
DefaultPolicy.enableConsumedAnalysis =
|
|
isEnabled(D, warn_use_in_invalid_state);
|
|
}
|
|
|
|
static void flushDiagnostics(Sema &S, const sema::FunctionScopeInfo *fscope) {
|
|
for (const auto &D : fscope->PossiblyUnreachableDiags)
|
|
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 */ nullptr, 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;
|
|
AC.getCFGBuildOptions().AddCXXNewAllocator = false;
|
|
|
|
// 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);
|
|
}
|
|
|
|
// Install the logical handler for -Wtautological-overlap-compare
|
|
std::unique_ptr<LogicalErrorHandler> LEH;
|
|
if (!Diags.isIgnored(diag::warn_tautological_overlap_comparison,
|
|
D->getLocStart())) {
|
|
LEH.reset(new LogicalErrorHandler(S));
|
|
AC.getCFGBuildOptions().Observer = LEH.get();
|
|
}
|
|
|
|
// Emit delayed diagnostics.
|
|
if (!fscope->PossiblyUnreachableDiags.empty()) {
|
|
bool analyzed = false;
|
|
|
|
// Register the expressions with the CFGBuilder.
|
|
for (const auto &D : fscope->PossiblyUnreachableDiags) {
|
|
if (D.stmt)
|
|
AC.registerForcedBlockExpression(D.stmt);
|
|
}
|
|
|
|
if (AC.getCFG()) {
|
|
analyzed = true;
|
|
for (const auto &D : fscope->PossiblyUnreachableDiags) {
|
|
bool processed = false;
|
|
if (D.stmt) {
|
|
const CFGBlock *block = AC.getBlockForRegisteredExpression(D.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();
|
|
threadSafety::ThreadSafetyReporter Reporter(S, FL, FEL);
|
|
if (!Diags.isIgnored(diag::warn_thread_safety_beta, D->getLocStart()))
|
|
Reporter.setIssueBetaWarnings(true);
|
|
if (!Diags.isIgnored(diag::warn_thread_safety_verbose, D->getLocStart()))
|
|
Reporter.setVerbose(true);
|
|
|
|
threadSafety::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.isIgnored(diag::warn_uninit_var, D->getLocStart()) ||
|
|
!Diags.isIgnored(diag::warn_sometimes_uninit_var, D->getLocStart()) ||
|
|
!Diags.isIgnored(diag::warn_maybe_uninit_var, D->getLocStart())) {
|
|
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.isIgnored(diag::warn_unannotated_fallthrough, D->getLocStart());
|
|
bool FallThroughDiagPerFunction = !Diags.isIgnored(
|
|
diag::warn_unannotated_fallthrough_per_function, D->getLocStart());
|
|
if (FallThroughDiagFull || FallThroughDiagPerFunction) {
|
|
DiagnoseSwitchLabelsFallthrough(S, AC, !FallThroughDiagFull);
|
|
}
|
|
|
|
if (S.getLangOpts().ObjCARCWeak &&
|
|
!Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, D->getLocStart()))
|
|
diagnoseRepeatedUseOfWeak(S, fscope, D, AC.getParentMap());
|
|
|
|
|
|
// Check for infinite self-recursion in functions
|
|
if (!Diags.isIgnored(diag::warn_infinite_recursive_function,
|
|
D->getLocStart())) {
|
|
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
|
|
checkRecursiveFunction(S, FD, Body, 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,
|
|
D->getLocStart())) {
|
|
AC.getCFG();
|
|
}
|
|
|
|
// 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";
|
|
}
|