Check in LLVM r95781.
diff --git a/lib/Checker/PthreadLockChecker.cpp b/lib/Checker/PthreadLockChecker.cpp
new file mode 100644
index 0000000..74e266c
--- /dev/null
+++ b/lib/Checker/PthreadLockChecker.cpp
@@ -0,0 +1,141 @@
+//===--- PthreadLockChecker.h - Undefined arguments checker ----*- C++ -*--===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This defines PthreadLockChecker, a simple lock -> unlock checker. Eventually
+// this shouldn't be registered with GRExprEngineInternalChecks.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Checker/PathSensitive/CheckerVisitor.h"
+#include "clang/Checker/BugReporter/BugReporter.h"
+#include "clang/Checker/PathSensitive/GRStateTrait.h"
+#include "GRExprEngineExperimentalChecks.h"
+#include "llvm/ADT/ImmutableSet.h"
+
+using namespace clang;
+
+namespace {
+class PthreadLockChecker
+ : public CheckerVisitor<PthreadLockChecker> {
+ BugType *BT;
+public:
+ PthreadLockChecker() : BT(0) {}
+ static void *getTag() {
+ static int x = 0;
+ return &x;
+ }
+ void PostVisitCallExpr(CheckerContext &C, const CallExpr *CE);
+
+ void AcquireLock(CheckerContext &C, const CallExpr *CE,
+ SVal lock, bool isTryLock);
+
+ void ReleaseLock(CheckerContext &C, const CallExpr *CE,
+ SVal lock);
+
+};
+} // end anonymous namespace
+
+// GDM Entry for tracking lock state.
+namespace { class LockSet {}; }
+namespace clang {
+template <> struct GRStateTrait<LockSet> :
+ public GRStatePartialTrait<llvm::ImmutableSet<const MemRegion*> > {
+ static void* GDMIndex() { return PthreadLockChecker::getTag(); }
+};
+} // end clang namespace
+
+void clang::RegisterPthreadLockChecker(GRExprEngine &Eng) {
+ Eng.registerCheck(new PthreadLockChecker());
+}
+
+
+void PthreadLockChecker::PostVisitCallExpr(CheckerContext &C,
+ const CallExpr *CE) {
+ const GRState *state = C.getState();
+ const Expr *Callee = CE->getCallee();
+ const FunctionTextRegion *R =
+ dyn_cast_or_null<FunctionTextRegion>(state->getSVal(Callee).getAsRegion());
+
+ if (!R)
+ return;
+
+ llvm::StringRef FName = R->getDecl()->getName();
+
+ if (FName == "pthread_mutex_lock") {
+ if (CE->getNumArgs() != 1)
+ return;
+ AcquireLock(C, CE, state->getSVal(CE->getArg(0)), false);
+ }
+ else if (FName == "pthread_mutex_trylock") {
+ if (CE->getNumArgs() != 1)
+ return;
+ AcquireLock(C, CE, state->getSVal(CE->getArg(0)), true);
+ }
+ else if (FName == "pthread_mutex_unlock") {
+ if (CE->getNumArgs() != 1)
+ return;
+ ReleaseLock(C, CE, state->getSVal(CE->getArg(0)));
+ }
+}
+
+void PthreadLockChecker::AcquireLock(CheckerContext &C, const CallExpr *CE,
+ SVal lock, bool isTryLock) {
+
+ const MemRegion *lockR = lock.getAsRegion();
+ if (!lockR)
+ return;
+
+ const GRState *state = C.getState();
+
+ SVal X = state->getSVal(CE);
+ if (X.isUnknownOrUndef())
+ return;
+
+ DefinedSVal retVal = cast<DefinedSVal>(X);
+ const GRState *lockSucc = state;
+
+ if (isTryLock) {
+ // Bifurcate the state, and allow a mode where the lock acquisition fails.
+ const GRState *lockFail;
+ llvm::tie(lockFail, lockSucc) = state->Assume(retVal);
+ assert(lockFail && lockSucc);
+ C.addTransition(C.GenerateNode(CE, lockFail));
+ }
+ else {
+ // Assume that the return value was 0.
+ lockSucc = state->Assume(retVal, false);
+ assert(lockSucc);
+ }
+
+ // Record that the lock was acquired.
+ lockSucc = lockSucc->add<LockSet>(lockR);
+
+ C.addTransition(lockSucc != state ? C.GenerateNode(CE, lockSucc) :
+ C.getPredecessor());
+}
+
+void PthreadLockChecker::ReleaseLock(CheckerContext &C, const CallExpr *CE,
+ SVal lock) {
+
+ const MemRegion *lockR = lock.getAsRegion();
+ if (!lockR)
+ return;
+
+ const GRState *state = C.getState();
+
+ // Record that the lock was released.
+ // FIXME: Handle unlocking locks that were never acquired. This may
+ // require IPA for wrappers.
+ const GRState *unlockState = state->remove<LockSet>(lockR);
+
+ if (state == unlockState)
+ return;
+
+ C.addTransition(C.GenerateNode(CE, unlockState));
+}