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

//===- ObjCAutoreleaseWriteChecker.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
//
//===----------------------------------------------------------------------===//
//
// This file defines ObjCAutoreleaseWriteChecker which warns against writes
// into autoreleased out parameters which cause crashes.
// An example of a problematic write is a write to @c error in the example
// below:
//
// - (BOOL) mymethod:(NSError *__autoreleasing *)error list:(NSArray*) list {
//     [list enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
//       NSString *myString = obj;
//       if ([myString isEqualToString:@"error"] && error)
//         *error = [NSError errorWithDomain:@"MyDomain" code:-1];
//     }];
//     return false;
// }
//
// Such code will crash on read from `*error` due to the autorelease pool
// in `enumerateObjectsUsingBlock` implementation freeing the error object
// on exit from the function.
//
//===----------------------------------------------------------------------===//

#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/Core/BugReporter/CommonBugCategories.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
#include "llvm/ADT/Twine.h"

usingnamespaceclang;
usingnamespaceento;
usingnamespaceast_matchers;

namespace {

const char *ProblematicWriteBind = …;
const char *CapturedBind = …;
const char *ParamBind = …;
const char *IsMethodBind = …;
const char *IsARPBind = …;

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

static inline std::vector<llvm::StringRef>
toRefs(const std::vector<std::string> &V) { … }

static decltype(auto)
callsNames(const std::vector<std::string> &FunctionNames) { … }

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

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

void ento::registerAutoreleaseWriteChecker(CheckerManager &Mgr) { … }

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