1//=== CXXSelfAssignmentChecker.cpp -----------------------------*- C++ -*--===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines CXXSelfAssignmentChecker, which tests all custom defined
11// copy and move assignment operators for the case of self assignment, thus
12// where the parameter refers to the same location where the this pointer
13// points to. The checker itself does not do any checks at all, but it
14// causes the analyzer to check every copy and move assignment operator twice:
15// once for when 'this' aliases with the parameter and once for when it may not.
16// It is the task of the other enabled checkers to find the bugs in these two
17// different cases.
18//
19//===----------------------------------------------------------------------===//
20
21#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
22#include "clang/StaticAnalyzer/Core/Checker.h"
23#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
24
25using namespace clang;
26using namespace ento;
27
28namespace {
29
30class CXXSelfAssignmentChecker : public Checker<check::BeginFunction> {
31public:
32 CXXSelfAssignmentChecker();
33 void checkBeginFunction(CheckerContext &C) const;
34};
35}
36
37CXXSelfAssignmentChecker::CXXSelfAssignmentChecker() {}
38
39void CXXSelfAssignmentChecker::checkBeginFunction(CheckerContext &C) const {
40 if (!C.inTopFrame())
41 return;
42 const auto *LCtx = C.getLocationContext();
43 const auto *MD = dyn_cast<CXXMethodDecl>(LCtx->getDecl());
44 if (!MD)
45 return;
46 if (!MD->isCopyAssignmentOperator() && !MD->isMoveAssignmentOperator())
47 return;
48 auto &State = C.getState();
49 auto &SVB = C.getSValBuilder();
50 auto ThisVal =
51 State->getSVal(SVB.getCXXThis(MD, LCtx->getStackFrame()));
52 auto Param = SVB.makeLoc(State->getRegion(MD->getParamDecl(0), LCtx));
53 auto ParamVal = State->getSVal(Param);
54 ProgramStateRef SelfAssignState = State->bindLoc(Param, ThisVal, LCtx);
55 C.addTransition(SelfAssignState);
56 ProgramStateRef NonSelfAssignState = State->bindLoc(Param, ParamVal, LCtx);
57 C.addTransition(NonSelfAssignState);
58}
59
60void ento::registerCXXSelfAssignmentChecker(CheckerManager &Mgr) {
61 Mgr.registerChecker<CXXSelfAssignmentChecker>();
62}