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[analyzer] lock_guard and unique_lock extension for BlockInCriticalSection checker 

A patch by zdtorok (Zoltán Dániel Török)!

Differential Revision: https://reviews.llvm.org/D33729

llvm-svn: 316892
This commit is contained in:
Gabor Horvath 2017-10-30 10:09:55 +00:00
parent d0208b4b1c
commit 9a8c8bf60d
2 changed files with 85 additions and 11 deletions
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54
clang/lib/StaticAnalyzer/Checkers/BlockInCriticalSectionChecker.cpp
View File

@ -26,15 +26,22 @@ using namespace ento;
namespace {
class BlockInCriticalSectionChecker : public Checker<check::PostCall,
check::PreCall> {
class BlockInCriticalSectionChecker : public Checker<check::PostCall> {
mutable IdentifierInfo *IILockGuard, *IIUniqueLock;
CallDescription LockFn, UnlockFn, SleepFn, GetcFn, FgetsFn, ReadFn, RecvFn,
PthreadLockFn, PthreadTryLockFn, PthreadUnlockFn,
MtxLock, MtxTimedLock, MtxTryLock, MtxUnlock;
StringRef ClassLockGuard, ClassUniqueLock;
mutable bool IdentifierInfoInitialized;
std::unique_ptr<BugType> BlockInCritSectionBugType;
void initIdentifierInfo(ASTContext &Ctx) const;
void reportBlockInCritSection(SymbolRef FileDescSym,
const CallEvent &call,
CheckerContext &C) const;
@ -46,13 +53,10 @@ public:
bool isLockFunction(const CallEvent &Call) const;
bool isUnlockFunction(const CallEvent &Call) const;
void checkPreCall(const CallEvent &Call, CheckerContext &C) const;
/// Process unlock.
/// Process lock.
/// Process blocking functions (sleep, getc, fgets, read, recv)
void checkPostCall(const CallEvent &Call, CheckerContext &C) const;
};
} // end anonymous namespace
@ -60,7 +64,8 @@ public:
REGISTER_TRAIT_WITH_PROGRAMSTATE(MutexCounter, unsigned)
BlockInCriticalSectionChecker::BlockInCriticalSectionChecker()
: LockFn("lock"), UnlockFn("unlock"), SleepFn("sleep"), GetcFn("getc"),
: IILockGuard(nullptr), IIUniqueLock(nullptr),
LockFn("lock"), UnlockFn("unlock"), SleepFn("sleep"), GetcFn("getc"),
FgetsFn("fgets"), ReadFn("read"), RecvFn("recv"),
PthreadLockFn("pthread_mutex_lock"),
PthreadTryLockFn("pthread_mutex_trylock"),
@ -68,13 +73,29 @@ BlockInCriticalSectionChecker::BlockInCriticalSectionChecker()
MtxLock("mtx_lock"),
MtxTimedLock("mtx_timedlock"),
MtxTryLock("mtx_trylock"),
MtxUnlock("mtx_unlock") {
MtxUnlock("mtx_unlock"),
ClassLockGuard("lock_guard"),
ClassUniqueLock("unique_lock"),
IdentifierInfoInitialized(false) {
// Initialize the bug type.
BlockInCritSectionBugType.reset(
new BugType(this, "Call to blocking function in critical section",
"Blocking Error"));
}
void BlockInCriticalSectionChecker::initIdentifierInfo(ASTContext &Ctx) const {
if (!IdentifierInfoInitialized) {
/* In case of checking C code, or when the corresponding headers are not
* included, we might end up query the identifier table every time when this
* function is called instead of early returning it. To avoid this, a bool
* variable (IdentifierInfoInitialized) is used and the function will be run
* only once. */
IILockGuard = &Ctx.Idents.get(ClassLockGuard);
IIUniqueLock = &Ctx.Idents.get(ClassUniqueLock);
IdentifierInfoInitialized = true;
}
}
bool BlockInCriticalSectionChecker::isBlockingFunction(const CallEvent &Call) const {
if (Call.isCalled(SleepFn)
|| Call.isCalled(GetcFn)
@ -87,6 +108,12 @@ bool BlockInCriticalSectionChecker::isBlockingFunction(const CallEvent &Call) co
}
bool BlockInCriticalSectionChecker::isLockFunction(const CallEvent &Call) const {
if (const auto *Ctor = dyn_cast<CXXConstructorCall>(&Call)) {
auto IdentifierInfo = Ctor->getDecl()->getParent()->getIdentifier();
if (IdentifierInfo == IILockGuard || IdentifierInfo == IIUniqueLock)
return true;
}
if (Call.isCalled(LockFn)
|| Call.isCalled(PthreadLockFn)
|| Call.isCalled(PthreadTryLockFn)
@ -99,6 +126,13 @@ bool BlockInCriticalSectionChecker::isLockFunction(const CallEvent &Call) const
}
bool BlockInCriticalSectionChecker::isUnlockFunction(const CallEvent &Call) const {
if (const auto *Dtor = dyn_cast<CXXDestructorCall>(&Call)) {
const auto *DRecordDecl = dyn_cast<CXXRecordDecl>(Dtor->getDecl()->getParent());
auto IdentifierInfo = DRecordDecl->getIdentifier();
if (IdentifierInfo == IILockGuard || IdentifierInfo == IIUniqueLock)
return true;
}
if (Call.isCalled(UnlockFn)
|| Call.isCalled(PthreadUnlockFn)
|| Call.isCalled(MtxUnlock)) {
@ -107,12 +141,10 @@ bool BlockInCriticalSectionChecker::isUnlockFunction(const CallEvent &Call) cons
return false;
}
void BlockInCriticalSectionChecker::checkPreCall(const CallEvent &Call,
CheckerContext &C) const {
}
void BlockInCriticalSectionChecker::checkPostCall(const CallEvent &Call,
CheckerContext &C) const {
initIdentifierInfo(C.getASTContext());
if (!isBlockingFunction(Call)
&& !isLockFunction(Call)
&& !isUnlockFunction(Call))

42
clang/test/Analysis/block-in-critical-section.cpp
View File

@ -7,6 +7,20 @@ struct mutex {
void lock() {}
void unlock() {}
};
template<typename T>
struct lock_guard {
lock_guard<T>(std::mutex) {}
~lock_guard<T>() {}
};
template<typename T>
struct unique_lock {
unique_lock<T>(std::mutex) {}
~unique_lock<T>() {}
};
template<typename T>
struct not_real_lock {
not_real_lock<T>(std::mutex) {}
};
}
void getc() {}
@ -110,3 +124,31 @@ void testBlockInCriticalSectionUnexpectedUnlock() {
m.lock();
sleep(1); // expected-warning {{Call to blocking function 'sleep' inside of critical section}}
}
void testBlockInCriticalSectionLockGuard() {
std::mutex g_mutex;
std::not_real_lock<std::mutex> not_real_lock(g_mutex);
sleep(1); // no-warning
std::lock_guard<std::mutex> lock(g_mutex);
sleep(1); // expected-warning {{Call to blocking function 'sleep' inside of critical section}}
}
void testBlockInCriticalSectionLockGuardNested() {
testBlockInCriticalSectionLockGuard();
sleep(1); // no-warning
}
void testBlockInCriticalSectionUniqueLock() {
std::mutex g_mutex;
std::not_real_lock<std::mutex> not_real_lock(g_mutex);
sleep(1); // no-warning
std::unique_lock<std::mutex> lock(g_mutex);
sleep(1); // expected-warning {{Call to blocking function 'sleep' inside of critical section}}
}
void testBlockInCriticalSectionUniqueLockNested() {
testBlockInCriticalSectionUniqueLock();
sleep(1); // no-warning
}