82 lines
3.1 KiB
C++
82 lines
3.1 KiB
C++
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//=== CXXSelfAssignmentChecker.cpp -----------------------------*- C++ -*--===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines CXXSelfAssignmentChecker, which tests all custom defined
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// copy and move assignment operators for the case of self assignment, thus
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// where the parameter refers to the same location where the this pointer
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// points to. The checker itself does not do any checks at all, but it
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// causes the analyzer to check every copy and move assignment operator twice:
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// once for when 'this' aliases with the parameter and once for when it may not.
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// It is the task of the other enabled checkers to find the bugs in these two
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// different cases.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
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#include "clang/StaticAnalyzer/Core/Checker.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.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 CXXSelfAssignmentChecker : public Checker<check::BeginFunction> {
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public:
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CXXSelfAssignmentChecker();
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void checkBeginFunction(CheckerContext &C) const;
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};
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}
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CXXSelfAssignmentChecker::CXXSelfAssignmentChecker() {}
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void CXXSelfAssignmentChecker::checkBeginFunction(CheckerContext &C) const {
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if (!C.inTopFrame())
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return;
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const auto *LCtx = C.getLocationContext();
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const auto *MD = dyn_cast<CXXMethodDecl>(LCtx->getDecl());
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if (!MD)
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return;
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if (!MD->isCopyAssignmentOperator() && !MD->isMoveAssignmentOperator())
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return;
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auto &State = C.getState();
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auto &SVB = C.getSValBuilder();
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auto ThisVal =
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State->getSVal(SVB.getCXXThis(MD, LCtx->getStackFrame()));
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auto Param = SVB.makeLoc(State->getRegion(MD->getParamDecl(0), LCtx));
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auto ParamVal = State->getSVal(Param);
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ProgramStateRef SelfAssignState = State->bindLoc(Param, ThisVal, LCtx);
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const NoteTag *SelfAssignTag =
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C.getNoteTag([MD](PathSensitiveBugReport &BR) -> std::string {
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SmallString<256> Msg;
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llvm::raw_svector_ostream Out(Msg);
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Out << "Assuming " << MD->getParamDecl(0)->getName() << " == *this";
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return std::string(Out.str());
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});
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C.addTransition(SelfAssignState, SelfAssignTag);
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ProgramStateRef NonSelfAssignState = State->bindLoc(Param, ParamVal, LCtx);
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const NoteTag *NonSelfAssignTag =
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C.getNoteTag([MD](PathSensitiveBugReport &BR) -> std::string {
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SmallString<256> Msg;
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llvm::raw_svector_ostream Out(Msg);
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Out << "Assuming " << MD->getParamDecl(0)->getName() << " != *this";
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return std::string(Out.str());
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});
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C.addTransition(NonSelfAssignState, NonSelfAssignTag);
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}
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void ento::registerCXXSelfAssignmentChecker(CheckerManager &Mgr) {
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Mgr.registerChecker<CXXSelfAssignmentChecker>();
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}
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bool ento::shouldRegisterCXXSelfAssignmentChecker(const CheckerManager &mgr) {
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return true;
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}
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