-
Notifications
You must be signed in to change notification settings - Fork 11.8k
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
[analyzer] Opt-in C Style Cast Checker for OSObject pointers
Differential Revision: https://reviews.llvm.org/D57261 llvm-svn: 353566
- Loading branch information
George Karpenkov
committed
Feb 8, 2019
1 parent
fcb63c4
commit 2add627
Showing
4 changed files
with
138 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -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; | ||
} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,39 @@ | ||
// RUN: %clang_analyze_cc1 -analyzer-checker=optin.osx.OSObjectCStyleCast %s -verify | ||
#include "os_object_base.h" | ||
|
||
struct OSArray : public OSObject { | ||
unsigned getCount(); | ||
}; | ||
|
||
struct A { | ||
int x; | ||
}; | ||
struct B : public A { | ||
unsigned getCount(); | ||
}; | ||
|
||
unsigned warn_on_explicit_downcast(OSObject * obj) { | ||
OSArray *a = (OSArray *) obj; // expected-warning{{C-style cast of OSObject. Use OSDynamicCast instead}} | ||
return a->getCount(); | ||
} | ||
|
||
void no_warn_on_upcast(OSArray *arr) { | ||
OSObject *obj = (OSObject *) arr; | ||
obj->retain(); | ||
obj->release(); | ||
} | ||
|
||
unsigned no_warn_on_dynamic_cast(OSObject *obj) { | ||
OSArray *a = OSDynamicCast(OSArray, obj); | ||
return a->getCount(); | ||
} | ||
|
||
unsigned long no_warn_on_primitive_conversion(OSArray *arr) { | ||
return (unsigned long) arr; | ||
} | ||
|
||
unsigned no_warn_on_other_type_cast(A *a) { | ||
B *b = (B *) a; | ||
return b->getCount(); | ||
} | ||
|