llvm/clang/lib/StaticAnalyzer/Checkers/RunLoopAutoreleaseLeakChecker.cpp

//=- RunLoopAutoreleaseLeakChecker.cpp --------------------------*- C++ -*-==//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//
//===----------------------------------------------------------------------===//
//
// A checker for detecting leaks resulting from allocating temporary
// autoreleased objects before starting the main run loop.
//
// Checks for two antipatterns:
// 1. ObjCMessageExpr followed by [[NSRunLoop mainRunLoop] run] in the same
// autorelease pool.
// 2. ObjCMessageExpr followed by [[NSRunLoop mainRunLoop] run] in no
// autorelease pool.
//
// Any temporary objects autoreleased in code called in those expressions
// will not be deallocated until the program exits, and are effectively leaks.
//
//===----------------------------------------------------------------------===//
//

#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclObjC.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"

usingnamespaceclang;
usingnamespaceento;
usingnamespaceast_matchers;

namespace {

const char * RunLoopBind = …;
const char * RunLoopRunBind = …;
const char * OtherMsgBind = …;
const char * AutoreleasePoolBind = …;
const char * OtherStmtAutoreleasePoolBind = …;

class RunLoopAutoreleaseLeakChecker : public Checker<check::ASTCodeBody> { … };

} // end anonymous namespace

/// \return Whether @c A occurs before @c B in traversal of
/// @c Parent.
/// Conceptually a very incomplete/unsound approximation of happens-before
/// relationship (A is likely to be evaluated before B),
/// but useful enough in this case.
static bool seenBefore(const Stmt *Parent, const Stmt *A, const Stmt *B) { … }

static void emitDiagnostics(BoundNodes &Match,
                            const Decl *D,
                            BugReporter &BR,
                            AnalysisManager &AM,
                            const RunLoopAutoreleaseLeakChecker *Checker) { … }

static StatementMatcher getRunLoopRunM(StatementMatcher Extra = anything()) { … }

static StatementMatcher getOtherMessageSentM(StatementMatcher Extra = anything()) { … }

static void
checkTempObjectsInSamePool(const Decl *D, AnalysisManager &AM, BugReporter &BR,
                           const RunLoopAutoreleaseLeakChecker *Chkr) { … }

static void
checkTempObjectsInNoPool(const Decl *D, AnalysisManager &AM, BugReporter &BR,
                         const RunLoopAutoreleaseLeakChecker *Chkr) { … }

void RunLoopAutoreleaseLeakChecker::checkASTCodeBody(const Decl *D,
                        AnalysisManager &AM,
                        BugReporter &BR) const { … }

void ento::registerRunLoopAutoreleaseLeakChecker(CheckerManager &mgr) { … }

bool ento::shouldRegisterRunLoopAutoreleaseLeakChecker(const CheckerManager &mgr) { … }