100 lines
3.2 KiB
C++
100 lines
3.2 KiB
C++
//=== UndefResultChecker.cpp ------------------------------------*- 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 defines UndefResultChecker, a builtin check in ExprEngine that
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// performs checks for undefined results of non-assignment binary operators.
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//
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//===----------------------------------------------------------------------===//
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#include "ClangSACheckers.h"
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#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
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#include "clang/StaticAnalyzer/Core/Checker.h"
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#include "clang/StaticAnalyzer/Core/CheckerManager.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
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#include "llvm/ADT/SmallString.h"
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#include "llvm/Support/raw_ostream.h"
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using namespace clang;
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using namespace ento;
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namespace {
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class UndefResultChecker
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: public Checker< check::PostStmt<BinaryOperator> > {
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mutable OwningPtr<BugType> BT;
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public:
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void checkPostStmt(const BinaryOperator *B, CheckerContext &C) const;
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};
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} // end anonymous namespace
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void UndefResultChecker::checkPostStmt(const BinaryOperator *B,
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CheckerContext &C) const {
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ProgramStateRef state = C.getState();
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const LocationContext *LCtx = C.getLocationContext();
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if (state->getSVal(B, LCtx).isUndef()) {
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// Do not report assignments of uninitialized values inside swap functions.
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// This should allow to swap partially uninitialized structs
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// (radar://14129997)
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if (const FunctionDecl *EnclosingFunctionDecl =
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dyn_cast<FunctionDecl>(C.getStackFrame()->getDecl()))
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if (C.getCalleeName(EnclosingFunctionDecl) == "swap")
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return;
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// Generate an error node.
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ExplodedNode *N = C.generateSink();
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if (!N)
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return;
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if (!BT)
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BT.reset(new BuiltinBug("Result of operation is garbage or undefined"));
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SmallString<256> sbuf;
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llvm::raw_svector_ostream OS(sbuf);
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const Expr *Ex = NULL;
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bool isLeft = true;
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if (state->getSVal(B->getLHS(), LCtx).isUndef()) {
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Ex = B->getLHS()->IgnoreParenCasts();
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isLeft = true;
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}
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else if (state->getSVal(B->getRHS(), LCtx).isUndef()) {
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Ex = B->getRHS()->IgnoreParenCasts();
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isLeft = false;
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}
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if (Ex) {
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OS << "The " << (isLeft ? "left" : "right")
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<< " operand of '"
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<< BinaryOperator::getOpcodeStr(B->getOpcode())
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<< "' is a garbage value";
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}
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else {
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// Neither operand was undefined, but the result is undefined.
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OS << "The result of the '"
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<< BinaryOperator::getOpcodeStr(B->getOpcode())
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<< "' expression is undefined";
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}
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BugReport *report = new BugReport(*BT, OS.str(), N);
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if (Ex) {
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report->addRange(Ex->getSourceRange());
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bugreporter::trackNullOrUndefValue(N, Ex, *report);
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}
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else
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bugreporter::trackNullOrUndefValue(N, B, *report);
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C.emitReport(report);
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}
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}
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void ento::registerUndefResultChecker(CheckerManager &mgr) {
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mgr.registerChecker<UndefResultChecker>();
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}
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