diff options
Diffstat (limited to 'lib/StaticAnalyzer/Checkers/OSObjectCStyleCast.cpp')
-rw-r--r-- | lib/StaticAnalyzer/Checkers/OSObjectCStyleCast.cpp | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/lib/StaticAnalyzer/Checkers/OSObjectCStyleCast.cpp b/lib/StaticAnalyzer/Checkers/OSObjectCStyleCast.cpp new file mode 100644 index 0000000000..27dadd09d7 --- /dev/null +++ b/lib/StaticAnalyzer/Checkers/OSObjectCStyleCast.cpp @@ -0,0 +1,90 @@ +//===- OSObjectCStyleCast.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 OSObjectCStyleCast checker, which checks for C-style casts +// of OSObjects. Such casts almost always indicate a code smell, +// as an explicit static or dynamic cast should be used instead. +//===----------------------------------------------------------------------===// + +#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/Checker.h" +#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h" +#include "llvm/Support/Debug.h" + +using namespace clang; +using namespace ento; +using namespace ast_matchers; + +namespace { + +const char *WarnAtNode = "OSObjCast"; + +class OSObjectCStyleCastChecker : public Checker<check::ASTCodeBody> { +public: + void checkASTCodeBody(const Decl *D, + AnalysisManager &AM, + BugReporter &BR) const; +}; + +static void emitDiagnostics(const BoundNodes &Nodes, + BugReporter &BR, + AnalysisDeclContext *ADC, + const OSObjectCStyleCastChecker *Checker) { + const auto *CE = Nodes.getNodeAs<CastExpr>(WarnAtNode); + assert(CE); + + std::string Diagnostics; + llvm::raw_string_ostream OS(Diagnostics); + OS << "C-style cast of OSObject. Use OSDynamicCast instead."; + + BR.EmitBasicReport( + ADC->getDecl(), + Checker, + /*Name=*/"OSObject C-Style Cast", + /*Category=*/"Security", + OS.str(), + PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), ADC), + CE->getSourceRange()); +} + +static auto hasTypePointingTo(DeclarationMatcher DeclM) + -> decltype(hasType(pointerType())) { + return hasType(pointerType(pointee(hasDeclaration(DeclM)))); +} + +void OSObjectCStyleCastChecker::checkASTCodeBody(const Decl *D, AnalysisManager &AM, + BugReporter &BR) const { + + AnalysisDeclContext *ADC = AM.getAnalysisDeclContext(D); + + auto DynamicCastM = callExpr(callee(functionDecl(hasName("safeMetaCast")))); + + auto OSObjTypeM = hasTypePointingTo(cxxRecordDecl(isDerivedFrom("OSMetaClassBase"))); + auto OSObjSubclassM = hasTypePointingTo( + cxxRecordDecl(isDerivedFrom("OSObject"))); + + auto CastM = cStyleCastExpr( + allOf(hasSourceExpression(allOf(OSObjTypeM, unless(DynamicCastM))), + OSObjSubclassM)).bind(WarnAtNode); + + auto Matches = match(stmt(forEachDescendant(CastM)), *D->getBody(), AM.getASTContext()); + for (BoundNodes Match : Matches) + emitDiagnostics(Match, BR, ADC, this); +} +} + +void ento::registerOSObjectCStyleCast(CheckerManager &Mgr) { + Mgr.registerChecker<OSObjectCStyleCastChecker>(); +} + +bool ento::shouldRegisterOSObjectCStyleCast(const LangOptions &LO) { + return true; +} |