ThreadSafety.h revision 879a4334e4c4cab0c22ba91492ffc2838bbc21fc
1ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com//===- ThreadSafety.h ------------------------------------------*- C++ --*-===// 28a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com// 3ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com// The LLVM Compiler Infrastructure 48a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com// 5ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com// This file is distributed under the University of Illinois Open Source 6ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com// License. See LICENSE.TXT for details. 78a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com// 88a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com//===----------------------------------------------------------------------===// 9ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com// 108a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com// 118a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com// A intra-procedural analysis for thread safety (e.g. deadlocks and race 128a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com// conditions), based off of an annotation system. 138a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com// 148a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com// See http://clang.llvm.org/docs/LanguageExtensions.html#threadsafety for more 1557212f9469c8056bab3c85243dbb904e386eab95reed@google.com// information. 1657212f9469c8056bab3c85243dbb904e386eab95reed@google.com// 1757212f9469c8056bab3c85243dbb904e386eab95reed@google.com//===----------------------------------------------------------------------===// 1857212f9469c8056bab3c85243dbb904e386eab95reed@google.com 1957212f9469c8056bab3c85243dbb904e386eab95reed@google.com#ifndef LLVM_CLANG_THREADSAFETY_H 2057212f9469c8056bab3c85243dbb904e386eab95reed@google.com#define LLVM_CLANG_THREADSAFETY_H 2157212f9469c8056bab3c85243dbb904e386eab95reed@google.com 2257212f9469c8056bab3c85243dbb904e386eab95reed@google.com#include "clang/Analysis/AnalysisContext.h" 2357212f9469c8056bab3c85243dbb904e386eab95reed@google.com#include "clang/Basic/SourceLocation.h" 2457212f9469c8056bab3c85243dbb904e386eab95reed@google.com#include "llvm/ADT/StringRef.h" 2557212f9469c8056bab3c85243dbb904e386eab95reed@google.com 2657212f9469c8056bab3c85243dbb904e386eab95reed@google.comnamespace clang { 2757212f9469c8056bab3c85243dbb904e386eab95reed@google.comnamespace thread_safety { 2857212f9469c8056bab3c85243dbb904e386eab95reed@google.com 2957212f9469c8056bab3c85243dbb904e386eab95reed@google.com/// This enum distinguishes between different kinds of operations that may 3057212f9469c8056bab3c85243dbb904e386eab95reed@google.com/// need to be protected by locks. We use this enum in error handling. 3157212f9469c8056bab3c85243dbb904e386eab95reed@google.comenum ProtectedOperationKind { 3257212f9469c8056bab3c85243dbb904e386eab95reed@google.com POK_VarDereference, /// Dereferencing a variable (e.g. p in *p = 5;) 3357212f9469c8056bab3c85243dbb904e386eab95reed@google.com POK_VarAccess, /// Reading or writing a variable (e.g. x in x = 5;) 3457212f9469c8056bab3c85243dbb904e386eab95reed@google.com POK_FunctionCall /// Making a function call (e.g. fool()) 3557212f9469c8056bab3c85243dbb904e386eab95reed@google.com}; 3657212f9469c8056bab3c85243dbb904e386eab95reed@google.com 3757212f9469c8056bab3c85243dbb904e386eab95reed@google.com/// This enum distinguishes between different kinds of lock actions. For 3857212f9469c8056bab3c85243dbb904e386eab95reed@google.com/// example, it is an error to write a variable protected by shared version of a 3957212f9469c8056bab3c85243dbb904e386eab95reed@google.com/// mutex. 4057212f9469c8056bab3c85243dbb904e386eab95reed@google.comenum LockKind { 414b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com LK_Shared, /// Shared/reader lock of a mutex 428a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com LK_Exclusive /// Exclusive/writer lock of a mutex 430f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org}; 440f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org 450f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org/// This enum distinguishes between different ways to access (read or write) a 460f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org/// variable. 470f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.orgenum AccessKind { 480f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org AK_Read, /// Reading a variable 490f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org AK_Written /// Writing a variable 50f7927dd60761ca45f26059a8ab434018676cb2e7skia.committer@gmail.com}; 510f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org 520f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org/// This enum distinguishes between different situations where we warn due to 530f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org/// inconsistent locking. 540f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org/// \enum SK_LockedSomeLoopIterations -- a mutex is locked for some but not all 550f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org/// loop iterations. 560f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org/// \enum SK_LockedSomePredecessors -- a mutex is locked in some but not all 570f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org/// predecessors of a CFGBlock. 580f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org/// \enum SK_LockedAtEndOfFunction -- a mutex is still locked at the end of a 590f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org/// function. 600f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.orgenum LockErrorKind { 610f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org LEK_LockedSomeLoopIterations, 620f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org LEK_LockedSomePredecessors, 630f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org LEK_LockedAtEndOfFunction, 640f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org LEK_NotLockedAtEndOfFunction 650f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org}; 660f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org 670f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org/// Handler class for thread safety warnings. 680f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.orgclass ThreadSafetyHandler { 690f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.orgpublic: 700f1fef834c73cb4f38023de0f98d05562d24f2bccommit-bot@chromium.org typedef llvm::StringRef Name; 714b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com virtual ~ThreadSafetyHandler(); 724b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com 738a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// Warn about lock expressions which fail to resolve to lockable objects. 7444d37d9d7228e7409f4feea722c26f570434b8fdreed@google.com /// \param Loc -- the SourceLocation of the unresolved expression. 757729534da419436ea6127545e9f79b0b47ccffb4reed@google.com virtual void handleInvalidLockExp(SourceLocation Loc) {} 767729534da419436ea6127545e9f79b0b47ccffb4reed@google.com 777729534da419436ea6127545e9f79b0b47ccffb4reed@google.com /// Warn about unlock function calls that do not have a prior matching lock 787729534da419436ea6127545e9f79b0b47ccffb4reed@google.com /// expression. 797729534da419436ea6127545e9f79b0b47ccffb4reed@google.com /// \param LockName -- A StringRef name for the lock expression, to be printed 807729534da419436ea6127545e9f79b0b47ccffb4reed@google.com /// in the error message. 817729534da419436ea6127545e9f79b0b47ccffb4reed@google.com /// \param Loc -- The SourceLocation of the Unlock 827729534da419436ea6127545e9f79b0b47ccffb4reed@google.com virtual void handleUnmatchedUnlock(Name LockName, SourceLocation Loc) {} 837729534da419436ea6127545e9f79b0b47ccffb4reed@google.com 847729534da419436ea6127545e9f79b0b47ccffb4reed@google.com /// Warn about lock function calls for locks which are already held. 857729534da419436ea6127545e9f79b0b47ccffb4reed@google.com /// \param LockName -- A StringRef name for the lock expression, to be printed 867729534da419436ea6127545e9f79b0b47ccffb4reed@google.com /// in the error message. 873a2682a77f996f649de7699c9f7bee046c6d4f17mtklein /// \param Loc -- The location of the second lock expression. 885c341d1ff1b58cc2b88c52f4ee41faf53a2a7578reed@google.com virtual void handleDoubleLock(Name LockName, SourceLocation Loc) {} 895c341d1ff1b58cc2b88c52f4ee41faf53a2a7578reed@google.com 905c341d1ff1b58cc2b88c52f4ee41faf53a2a7578reed@google.com /// Warn about situations where a mutex is sometimes held and sometimes not. 915c341d1ff1b58cc2b88c52f4ee41faf53a2a7578reed@google.com /// The three situations are: 927729534da419436ea6127545e9f79b0b47ccffb4reed@google.com /// 1. a mutex is locked on an "if" branch but not the "else" branch, 937729534da419436ea6127545e9f79b0b47ccffb4reed@google.com /// 2, or a mutex is only held at the start of some loop iterations, 947729534da419436ea6127545e9f79b0b47ccffb4reed@google.com /// 3. or when a mutex is locked but not unlocked inside a function. 954b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com /// \param LockName -- A StringRef name for the lock expression, to be printed 96eebf5cb6c0f5ed2630de2e7712d61b4ec1d49015reed@android.com /// in the error message. 974b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com /// \param LocLocked -- The location of the lock expression where the mutex is 984b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com /// locked 994b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com /// \param LocEndOfScope -- The location of the end of the scope where the 1008a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// mutex is no longer held 1018a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// \param LEK -- which of the three above cases we should warn for 1028a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com virtual void handleMutexHeldEndOfScope(Name LockName, 1038a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com SourceLocation LocLocked, 1048a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com SourceLocation LocEndOfScope, 1054b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com LockErrorKind LEK){} 1064b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com 1074b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com /// Warn when a mutex is held exclusively and shared at the same point. For 1084b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com /// example, if a mutex is locked exclusively during an if branch and shared 1094b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com /// during the else branch. 1108a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// \param LockName -- A StringRef name for the lock expression, to be printed 1118a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// in the error message. 1128a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// \param Loc1 -- The location of the first lock expression. 1138a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// \param Loc2 -- The location of the second lock expression. 1148a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com virtual void handleExclusiveAndShared(Name LockName, SourceLocation Loc1, 1158a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com SourceLocation Loc2) {} 1168a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 1178a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// Warn when a protected operation occurs while no locks are held. 1188a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// \param D -- The decl for the protected variable or function 1198a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// \param POK -- The kind of protected operation (e.g. variable access) 1208a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// \param AK -- The kind of access (i.e. read or write) that occurred 1218a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// \param Loc -- The location of the protected operation. 1224b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com virtual void handleNoMutexHeld(const NamedDecl *D, ProtectedOperationKind POK, 1234b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com AccessKind AK, SourceLocation Loc) {} 1244b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com 1254b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com /// Warn when a protected operation occurs while the specific mutex protecting 1264b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com /// the operation is not locked. 1278a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// \param D -- The decl for the protected variable or function 1288a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// \param POK -- The kind of protected operation (e.g. variable access) 1298a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// \param LockName -- A StringRef name for the lock expression, to be printed 1308a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// in the error message. 1318a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// \param LK -- The kind of access (i.e. read or write) that occurred 1324b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com /// \param Loc -- The location of the protected operation. 1334b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com virtual void handleMutexNotHeld(const NamedDecl *D, 1344b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com ProtectedOperationKind POK, Name LockName, 1354b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com LockKind LK, SourceLocation Loc) {} 1364b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com 1374b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com /// Warn when a function is called while an excluded mutex is locked. For 1384b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com /// example, the mutex may be locked inside the function. 1394b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com /// \param FunName -- The name of the function 1404b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com /// \param LockName -- A StringRef name for the lock expression, to be printed 1418a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// in the error message. 1428a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com /// \param Loc -- The location of the function call. 1438a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com virtual void handleFunExcludesLock(Name FunName, Name LockName, 1448a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com SourceLocation Loc) {} 1458a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com}; 1464b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com 1474b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com/// \brief Check a function's CFG for thread-safety violations. 1484b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com/// 149f2b98d67dcb6fcb3120feede9c72016fc7b3ead8reed@android.com/// We traverse the blocks in the CFG, compute the set of mutexes that are held 150f2b98d67dcb6fcb3120feede9c72016fc7b3ead8reed@android.com/// at the end of each block, and issue warnings for thread safety violations. 151f2b98d67dcb6fcb3120feede9c72016fc7b3ead8reed@android.com/// Each block in the CFG is traversed exactly once. 152f2b98d67dcb6fcb3120feede9c72016fc7b3ead8reed@android.comvoid runThreadSafetyAnalysis(AnalysisDeclContext &AC, 153f2b98d67dcb6fcb3120feede9c72016fc7b3ead8reed@android.com ThreadSafetyHandler &Handler); 1548a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com 1558a1c16ff38322f0210116fa7293eb8817c7e477ereed@android.com/// \brief Helper function that returns a LockKind required for the given level 1564b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com/// of access. 1574b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.comLockKind getLockKindFromAccessKind(AccessKind AK); 1584b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com 1594b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com}} // end namespace clang::thread_safety 1604b163ed2c22facbe8891616874ae07ba7827d9c9reed@google.com#endif 1612092c40a0d0a89a91cc4b6bb2b1b992fd4f02cd7george@mozilla.com