Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 1 | //===--- PthreadLockChecker.h - Undefined arguments checker ----*- C++ -*--===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This defines PthreadLockChecker, a simple lock -> unlock checker. Eventually |
Argyrios Kyrtzidis | d2592a3 | 2010-12-22 18:53:44 +0000 | [diff] [blame^] | 11 | // this shouldn't be registered with ExprEngineInternalChecks. |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 12 | // |
| 13 | //===----------------------------------------------------------------------===// |
| 14 | |
Argyrios Kyrtzidis | 98cabba | 2010-12-22 18:51:49 +0000 | [diff] [blame] | 15 | #include "clang/GR/PathSensitive/CheckerVisitor.h" |
| 16 | #include "clang/GR/BugReporter/BugReporter.h" |
| 17 | #include "clang/GR/PathSensitive/GRStateTrait.h" |
Argyrios Kyrtzidis | d2592a3 | 2010-12-22 18:53:44 +0000 | [diff] [blame^] | 18 | #include "ExprEngineExperimentalChecks.h" |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 19 | #include "llvm/ADT/ImmutableSet.h" |
| 20 | |
| 21 | using namespace clang; |
Argyrios Kyrtzidis | 5a4f98f | 2010-12-22 18:53:20 +0000 | [diff] [blame] | 22 | using namespace GR; |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 23 | |
| 24 | namespace { |
Kovarththanan Rajaratnam | ba5fb5a | 2009-11-28 06:07:30 +0000 | [diff] [blame] | 25 | class PthreadLockChecker |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 26 | : public CheckerVisitor<PthreadLockChecker> { |
| 27 | BugType *BT; |
| 28 | public: |
| 29 | PthreadLockChecker() : BT(0) {} |
| 30 | static void *getTag() { |
| 31 | static int x = 0; |
| 32 | return &x; |
| 33 | } |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 34 | void PostVisitCallExpr(CheckerContext &C, const CallExpr *CE); |
| 35 | |
| 36 | void AcquireLock(CheckerContext &C, const CallExpr *CE, |
| 37 | SVal lock, bool isTryLock); |
| 38 | |
| 39 | void ReleaseLock(CheckerContext &C, const CallExpr *CE, |
| 40 | SVal lock); |
| 41 | |
| 42 | }; |
| 43 | } // end anonymous namespace |
| 44 | |
| 45 | // GDM Entry for tracking lock state. |
Kovarththanan Rajaratnam | ba5fb5a | 2009-11-28 06:07:30 +0000 | [diff] [blame] | 46 | namespace { class LockSet {}; } |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 47 | namespace clang { |
Argyrios Kyrtzidis | 5a4f98f | 2010-12-22 18:53:20 +0000 | [diff] [blame] | 48 | namespace GR { |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 49 | template <> struct GRStateTrait<LockSet> : |
| 50 | public GRStatePartialTrait<llvm::ImmutableSet<const MemRegion*> > { |
| 51 | static void* GDMIndex() { return PthreadLockChecker::getTag(); } |
| 52 | }; |
Argyrios Kyrtzidis | 5a4f98f | 2010-12-22 18:53:20 +0000 | [diff] [blame] | 53 | } // end GR namespace |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 54 | } // end clang namespace |
| 55 | |
Argyrios Kyrtzidis | d2592a3 | 2010-12-22 18:53:44 +0000 | [diff] [blame^] | 56 | void GR::RegisterPthreadLockChecker(ExprEngine &Eng) { |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 57 | Eng.registerCheck(new PthreadLockChecker()); |
| 58 | } |
| 59 | |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 60 | |
| 61 | void PthreadLockChecker::PostVisitCallExpr(CheckerContext &C, |
| 62 | const CallExpr *CE) { |
| 63 | const GRState *state = C.getState(); |
| 64 | const Expr *Callee = CE->getCallee(); |
Ted Kremenek | eb1c7a0 | 2009-11-25 01:32:22 +0000 | [diff] [blame] | 65 | const FunctionTextRegion *R = |
Ted Kremenek | 1397663 | 2010-02-08 16:18:51 +0000 | [diff] [blame] | 66 | dyn_cast_or_null<FunctionTextRegion>(state->getSVal(Callee).getAsRegion()); |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 67 | |
| 68 | if (!R) |
| 69 | return; |
| 70 | |
Douglas Gregor | 90d26a4 | 2010-11-01 23:16:05 +0000 | [diff] [blame] | 71 | IdentifierInfo *II = R->getDecl()->getIdentifier(); |
| 72 | if (!II) // if no identifier, not a simple C function |
| 73 | return; |
| 74 | llvm::StringRef FName = II->getName(); |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 75 | |
Ted Kremenek | fe37d04 | 2009-11-12 06:26:58 +0000 | [diff] [blame] | 76 | if (FName == "pthread_mutex_lock") { |
| 77 | if (CE->getNumArgs() != 1) |
| 78 | return; |
Ted Kremenek | 1397663 | 2010-02-08 16:18:51 +0000 | [diff] [blame] | 79 | AcquireLock(C, CE, state->getSVal(CE->getArg(0)), false); |
Ted Kremenek | fe37d04 | 2009-11-12 06:26:58 +0000 | [diff] [blame] | 80 | } |
| 81 | else if (FName == "pthread_mutex_trylock") { |
| 82 | if (CE->getNumArgs() != 1) |
| 83 | return; |
Ted Kremenek | 1397663 | 2010-02-08 16:18:51 +0000 | [diff] [blame] | 84 | AcquireLock(C, CE, state->getSVal(CE->getArg(0)), true); |
Ted Kremenek | fe37d04 | 2009-11-12 06:26:58 +0000 | [diff] [blame] | 85 | } |
| 86 | else if (FName == "pthread_mutex_unlock") { |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 87 | if (CE->getNumArgs() != 1) |
| 88 | return; |
Ted Kremenek | 1397663 | 2010-02-08 16:18:51 +0000 | [diff] [blame] | 89 | ReleaseLock(C, CE, state->getSVal(CE->getArg(0))); |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 90 | } |
| 91 | } |
| 92 | |
| 93 | void PthreadLockChecker::AcquireLock(CheckerContext &C, const CallExpr *CE, |
| 94 | SVal lock, bool isTryLock) { |
| 95 | |
| 96 | const MemRegion *lockR = lock.getAsRegion(); |
| 97 | if (!lockR) |
| 98 | return; |
| 99 | |
| 100 | const GRState *state = C.getState(); |
| 101 | |
Ted Kremenek | 1397663 | 2010-02-08 16:18:51 +0000 | [diff] [blame] | 102 | SVal X = state->getSVal(CE); |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 103 | if (X.isUnknownOrUndef()) |
| 104 | return; |
| 105 | |
| 106 | DefinedSVal retVal = cast<DefinedSVal>(X); |
| 107 | const GRState *lockSucc = state; |
| 108 | |
| 109 | if (isTryLock) { |
| 110 | // Bifurcate the state, and allow a mode where the lock acquisition fails. |
| 111 | const GRState *lockFail; |
Ted Kremenek | 28f47b9 | 2010-12-01 22:16:56 +0000 | [diff] [blame] | 112 | llvm::tie(lockFail, lockSucc) = state->assume(retVal); |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 113 | assert(lockFail && lockSucc); |
Ted Kremenek | d048c6e | 2010-12-20 21:19:09 +0000 | [diff] [blame] | 114 | C.addTransition(C.generateNode(CE, lockFail)); |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 115 | } |
| 116 | else { |
| 117 | // Assume that the return value was 0. |
Ted Kremenek | 28f47b9 | 2010-12-01 22:16:56 +0000 | [diff] [blame] | 118 | lockSucc = state->assume(retVal, false); |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 119 | assert(lockSucc); |
| 120 | } |
| 121 | |
| 122 | // Record that the lock was acquired. |
| 123 | lockSucc = lockSucc->add<LockSet>(lockR); |
| 124 | |
Ted Kremenek | d048c6e | 2010-12-20 21:19:09 +0000 | [diff] [blame] | 125 | C.addTransition(lockSucc != state ? C.generateNode(CE, lockSucc) : |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 126 | C.getPredecessor()); |
| 127 | } |
| 128 | |
| 129 | void PthreadLockChecker::ReleaseLock(CheckerContext &C, const CallExpr *CE, |
| 130 | SVal lock) { |
| 131 | |
| 132 | const MemRegion *lockR = lock.getAsRegion(); |
| 133 | if (!lockR) |
| 134 | return; |
| 135 | |
| 136 | const GRState *state = C.getState(); |
| 137 | |
| 138 | // Record that the lock was released. |
| 139 | // FIXME: Handle unlocking locks that were never acquired. This may |
| 140 | // require IPA for wrappers. |
| 141 | const GRState *unlockState = state->remove<LockSet>(lockR); |
| 142 | |
| 143 | if (state == unlockState) |
| 144 | return; |
| 145 | |
Ted Kremenek | d048c6e | 2010-12-20 21:19:09 +0000 | [diff] [blame] | 146 | C.addTransition(C.generateNode(CE, unlockState)); |
Ted Kremenek | ac9bea8 | 2009-11-12 06:17:47 +0000 | [diff] [blame] | 147 | } |