forked from OSchip/llvm-project
97 lines
3.3 KiB
C++
97 lines
3.3 KiB
C++
//== ObjCAtSyncChecker.cpp - nil mutex checker for @synchronized -*- 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 defines ObjCAtSyncChecker, a builtin check that checks for null pointers
|
|
// used as mutexes for @synchronized.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
|
|
#include "clang/AST/StmtObjC.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/CheckerContext.h"
|
|
#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
|
|
|
|
using namespace clang;
|
|
using namespace ento;
|
|
|
|
namespace {
|
|
class ObjCAtSyncChecker
|
|
: public Checker< check::PreStmt<ObjCAtSynchronizedStmt> > {
|
|
mutable std::unique_ptr<BuiltinBug> BT_null;
|
|
mutable std::unique_ptr<BuiltinBug> BT_undef;
|
|
|
|
public:
|
|
void checkPreStmt(const ObjCAtSynchronizedStmt *S, CheckerContext &C) const;
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
void ObjCAtSyncChecker::checkPreStmt(const ObjCAtSynchronizedStmt *S,
|
|
CheckerContext &C) const {
|
|
|
|
const Expr *Ex = S->getSynchExpr();
|
|
ProgramStateRef state = C.getState();
|
|
SVal V = C.getSVal(Ex);
|
|
|
|
// Uninitialized value used for the mutex?
|
|
if (V.getAs<UndefinedVal>()) {
|
|
if (ExplodedNode *N = C.generateErrorNode()) {
|
|
if (!BT_undef)
|
|
BT_undef.reset(new BuiltinBug(this, "Uninitialized value used as mutex "
|
|
"for @synchronized"));
|
|
auto report = std::make_unique<PathSensitiveBugReport>(
|
|
*BT_undef, BT_undef->getDescription(), N);
|
|
bugreporter::trackExpressionValue(N, Ex, *report);
|
|
C.emitReport(std::move(report));
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (V.isUnknown())
|
|
return;
|
|
|
|
// Check for null mutexes.
|
|
ProgramStateRef notNullState, nullState;
|
|
std::tie(notNullState, nullState) = state->assume(V.castAs<DefinedSVal>());
|
|
|
|
if (nullState) {
|
|
if (!notNullState) {
|
|
// Generate an error node. This isn't a sink since
|
|
// a null mutex just means no synchronization occurs.
|
|
if (ExplodedNode *N = C.generateNonFatalErrorNode(nullState)) {
|
|
if (!BT_null)
|
|
BT_null.reset(new BuiltinBug(
|
|
this, "Nil value used as mutex for @synchronized() "
|
|
"(no synchronization will occur)"));
|
|
auto report = std::make_unique<PathSensitiveBugReport>(
|
|
*BT_null, BT_null->getDescription(), N);
|
|
bugreporter::trackExpressionValue(N, Ex, *report);
|
|
|
|
C.emitReport(std::move(report));
|
|
return;
|
|
}
|
|
}
|
|
// Don't add a transition for 'nullState'. If the value is
|
|
// under-constrained to be null or non-null, assume it is non-null
|
|
// afterwards.
|
|
}
|
|
|
|
if (notNullState)
|
|
C.addTransition(notNullState);
|
|
}
|
|
|
|
void ento::registerObjCAtSyncChecker(CheckerManager &mgr) {
|
|
mgr.registerChecker<ObjCAtSyncChecker>();
|
|
}
|
|
|
|
bool ento::shouldRegisterObjCAtSyncChecker(const LangOptions &LO) {
|
|
return LO.ObjC;
|
|
}
|