Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1 | //===- ThreadSafety.cpp ----------------------------------------*- 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 | // A intra-procedural analysis for thread safety (e.g. deadlocks and race |
| 11 | // conditions), based off of an annotation system. |
| 12 | // |
Caitlin Sadowski | 1990346 | 2011-09-14 20:05:09 +0000 | [diff] [blame] | 13 | // See http://clang.llvm.org/docs/LanguageExtensions.html#threadsafety for more |
| 14 | // information. |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 15 | // |
| 16 | //===----------------------------------------------------------------------===// |
| 17 | |
| 18 | #include "clang/Analysis/Analyses/ThreadSafety.h" |
Ted Kremenek | 439ed16 | 2011-10-22 02:14:27 +0000 | [diff] [blame] | 19 | #include "clang/Analysis/Analyses/PostOrderCFGView.h" |
Caitlin Sadowski | d5b1605 | 2011-09-09 23:00:59 +0000 | [diff] [blame] | 20 | #include "clang/Analysis/AnalysisContext.h" |
| 21 | #include "clang/Analysis/CFG.h" |
| 22 | #include "clang/Analysis/CFGStmtMap.h" |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 23 | #include "clang/AST/DeclCXX.h" |
| 24 | #include "clang/AST/ExprCXX.h" |
| 25 | #include "clang/AST/StmtCXX.h" |
| 26 | #include "clang/AST/StmtVisitor.h" |
Caitlin Sadowski | d5b1605 | 2011-09-09 23:00:59 +0000 | [diff] [blame] | 27 | #include "clang/Basic/SourceManager.h" |
| 28 | #include "clang/Basic/SourceLocation.h" |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 29 | #include "llvm/ADT/BitVector.h" |
| 30 | #include "llvm/ADT/FoldingSet.h" |
| 31 | #include "llvm/ADT/ImmutableMap.h" |
| 32 | #include "llvm/ADT/PostOrderIterator.h" |
| 33 | #include "llvm/ADT/SmallVector.h" |
| 34 | #include "llvm/ADT/StringRef.h" |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 35 | #include "llvm/Support/raw_ostream.h" |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 36 | #include <algorithm> |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 37 | #include <utility> |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 38 | #include <vector> |
| 39 | |
| 40 | using namespace clang; |
| 41 | using namespace thread_safety; |
| 42 | |
Caitlin Sadowski | 1990346 | 2011-09-14 20:05:09 +0000 | [diff] [blame] | 43 | // Key method definition |
| 44 | ThreadSafetyHandler::~ThreadSafetyHandler() {} |
| 45 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 46 | namespace { |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 47 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 48 | /// \brief A MutexID object uniquely identifies a particular mutex, and |
| 49 | /// is built from an Expr* (i.e. calling a lock function). |
| 50 | /// |
| 51 | /// Thread-safety analysis works by comparing lock expressions. Within the |
| 52 | /// body of a function, an expression such as "x->foo->bar.mu" will resolve to |
| 53 | /// a particular mutex object at run-time. Subsequent occurrences of the same |
| 54 | /// expression (where "same" means syntactic equality) will refer to the same |
| 55 | /// run-time object if three conditions hold: |
| 56 | /// (1) Local variables in the expression, such as "x" have not changed. |
| 57 | /// (2) Values on the heap that affect the expression have not changed. |
| 58 | /// (3) The expression involves only pure function calls. |
DeLesley Hutchins | e0eaa85 | 2011-10-21 18:06:53 +0000 | [diff] [blame] | 59 | /// |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 60 | /// The current implementation assumes, but does not verify, that multiple uses |
| 61 | /// of the same lock expression satisfies these criteria. |
| 62 | /// |
| 63 | /// Clang introduces an additional wrinkle, which is that it is difficult to |
| 64 | /// derive canonical expressions, or compare expressions directly for equality. |
DeLesley Hutchins | 4bda3ec | 2012-02-16 17:03:24 +0000 | [diff] [blame] | 65 | /// Thus, we identify a mutex not by an Expr, but by the list of named |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 66 | /// declarations that are referenced by the Expr. In other words, |
| 67 | /// x->foo->bar.mu will be a four element vector with the Decls for |
| 68 | /// mu, bar, and foo, and x. The vector will uniquely identify the expression |
DeLesley Hutchins | 4bda3ec | 2012-02-16 17:03:24 +0000 | [diff] [blame] | 69 | /// for all practical purposes. Null is used to denote 'this'. |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 70 | /// |
| 71 | /// Note we will need to perform substitution on "this" and function parameter |
| 72 | /// names when constructing a lock expression. |
| 73 | /// |
| 74 | /// For example: |
| 75 | /// class C { Mutex Mu; void lock() EXCLUSIVE_LOCK_FUNCTION(this->Mu); }; |
| 76 | /// void myFunc(C *X) { ... X->lock() ... } |
| 77 | /// The original expression for the mutex acquired by myFunc is "this->Mu", but |
| 78 | /// "X" is substituted for "this" so we get X->Mu(); |
| 79 | /// |
| 80 | /// For another example: |
| 81 | /// foo(MyList *L) EXCLUSIVE_LOCKS_REQUIRED(L->Mu) { ... } |
| 82 | /// MyList *MyL; |
| 83 | /// foo(MyL); // requires lock MyL->Mu to be held |
| 84 | class MutexID { |
| 85 | SmallVector<NamedDecl*, 2> DeclSeq; |
| 86 | |
| 87 | /// Build a Decl sequence representing the lock from the given expression. |
DeLesley Hutchins | e0eaa85 | 2011-10-21 18:06:53 +0000 | [diff] [blame] | 88 | /// Recursive function that terminates on DeclRefExpr. |
| 89 | /// Note: this function merely creates a MutexID; it does not check to |
| 90 | /// ensure that the original expression is a valid mutex expression. |
DeLesley Hutchins | e03b2b3 | 2012-01-20 23:24:41 +0000 | [diff] [blame] | 91 | void buildMutexID(Expr *Exp, const NamedDecl *D, Expr *Parent, |
| 92 | unsigned NumArgs, Expr **FunArgs) { |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 93 | if (!Exp) { |
| 94 | DeclSeq.clear(); |
| 95 | return; |
| 96 | } |
| 97 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 98 | if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Exp)) { |
| 99 | NamedDecl *ND = cast<NamedDecl>(DRE->getDecl()->getCanonicalDecl()); |
DeLesley Hutchins | e03b2b3 | 2012-01-20 23:24:41 +0000 | [diff] [blame] | 100 | ParmVarDecl *PV = dyn_cast_or_null<ParmVarDecl>(ND); |
| 101 | if (PV) { |
| 102 | FunctionDecl *FD = |
| 103 | cast<FunctionDecl>(PV->getDeclContext())->getCanonicalDecl(); |
| 104 | unsigned i = PV->getFunctionScopeIndex(); |
| 105 | |
| 106 | if (FunArgs && FD == D->getCanonicalDecl()) { |
| 107 | // Substitute call arguments for references to function parameters |
| 108 | assert(i < NumArgs); |
| 109 | buildMutexID(FunArgs[i], D, 0, 0, 0); |
| 110 | return; |
| 111 | } |
| 112 | // Map the param back to the param of the original function declaration. |
| 113 | DeclSeq.push_back(FD->getParamDecl(i)); |
| 114 | return; |
| 115 | } |
| 116 | // Not a function parameter -- just store the reference. |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 117 | DeclSeq.push_back(ND); |
| 118 | } else if (MemberExpr *ME = dyn_cast<MemberExpr>(Exp)) { |
| 119 | NamedDecl *ND = ME->getMemberDecl(); |
| 120 | DeclSeq.push_back(ND); |
DeLesley Hutchins | e03b2b3 | 2012-01-20 23:24:41 +0000 | [diff] [blame] | 121 | buildMutexID(ME->getBase(), D, Parent, NumArgs, FunArgs); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 122 | } else if (isa<CXXThisExpr>(Exp)) { |
Caitlin Sadowski | 194418f | 2011-09-14 20:00:24 +0000 | [diff] [blame] | 123 | if (Parent) |
DeLesley Hutchins | e03b2b3 | 2012-01-20 23:24:41 +0000 | [diff] [blame] | 124 | buildMutexID(Parent, D, 0, 0, 0); |
DeLesley Hutchins | 4bda3ec | 2012-02-16 17:03:24 +0000 | [diff] [blame] | 125 | else { |
| 126 | DeclSeq.push_back(0); // Use 0 to represent 'this'. |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 127 | return; // mutexID is still valid in this case |
DeLesley Hutchins | 4bda3ec | 2012-02-16 17:03:24 +0000 | [diff] [blame] | 128 | } |
DeLesley Hutchins | e0eaa85 | 2011-10-21 18:06:53 +0000 | [diff] [blame] | 129 | } else if (UnaryOperator *UOE = dyn_cast<UnaryOperator>(Exp)) |
DeLesley Hutchins | e03b2b3 | 2012-01-20 23:24:41 +0000 | [diff] [blame] | 130 | buildMutexID(UOE->getSubExpr(), D, Parent, NumArgs, FunArgs); |
DeLesley Hutchins | e0eaa85 | 2011-10-21 18:06:53 +0000 | [diff] [blame] | 131 | else if (CastExpr *CE = dyn_cast<CastExpr>(Exp)) |
DeLesley Hutchins | e03b2b3 | 2012-01-20 23:24:41 +0000 | [diff] [blame] | 132 | buildMutexID(CE->getSubExpr(), D, Parent, NumArgs, FunArgs); |
Caitlin Sadowski | 99107eb | 2011-09-09 16:21:55 +0000 | [diff] [blame] | 133 | else |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 134 | DeclSeq.clear(); // Mark as invalid lock expression. |
| 135 | } |
| 136 | |
| 137 | /// \brief Construct a MutexID from an expression. |
| 138 | /// \param MutexExp The original mutex expression within an attribute |
| 139 | /// \param DeclExp An expression involving the Decl on which the attribute |
| 140 | /// occurs. |
| 141 | /// \param D The declaration to which the lock/unlock attribute is attached. |
| 142 | void buildMutexIDFromExp(Expr *MutexExp, Expr *DeclExp, const NamedDecl *D) { |
| 143 | Expr *Parent = 0; |
DeLesley Hutchins | 8121639 | 2011-10-17 21:38:02 +0000 | [diff] [blame] | 144 | unsigned NumArgs = 0; |
| 145 | Expr **FunArgs = 0; |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 146 | |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 147 | // If we are processing a raw attribute expression, with no substitutions. |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 148 | if (DeclExp == 0) { |
DeLesley Hutchins | e03b2b3 | 2012-01-20 23:24:41 +0000 | [diff] [blame] | 149 | buildMutexID(MutexExp, D, 0, 0, 0); |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 150 | return; |
| 151 | } |
| 152 | |
DeLesley Hutchins | e0eaa85 | 2011-10-21 18:06:53 +0000 | [diff] [blame] | 153 | // Examine DeclExp to find Parent and FunArgs, which are used to substitute |
| 154 | // for formal parameters when we call buildMutexID later. |
DeLesley Hutchins | 8121639 | 2011-10-17 21:38:02 +0000 | [diff] [blame] | 155 | if (MemberExpr *ME = dyn_cast<MemberExpr>(DeclExp)) { |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 156 | Parent = ME->getBase(); |
DeLesley Hutchins | 8121639 | 2011-10-17 21:38:02 +0000 | [diff] [blame] | 157 | } else if (CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(DeclExp)) { |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 158 | Parent = CE->getImplicitObjectArgument(); |
DeLesley Hutchins | 8121639 | 2011-10-17 21:38:02 +0000 | [diff] [blame] | 159 | NumArgs = CE->getNumArgs(); |
| 160 | FunArgs = CE->getArgs(); |
DeLesley Hutchins | df49782 | 2011-12-29 00:56:48 +0000 | [diff] [blame] | 161 | } else if (CallExpr *CE = dyn_cast<CallExpr>(DeclExp)) { |
| 162 | NumArgs = CE->getNumArgs(); |
| 163 | FunArgs = CE->getArgs(); |
DeLesley Hutchins | e0eaa85 | 2011-10-21 18:06:53 +0000 | [diff] [blame] | 164 | } else if (CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(DeclExp)) { |
| 165 | Parent = 0; // FIXME -- get the parent from DeclStmt |
| 166 | NumArgs = CE->getNumArgs(); |
| 167 | FunArgs = CE->getArgs(); |
DeLesley Hutchins | 6db51f7 | 2011-10-21 20:51:27 +0000 | [diff] [blame] | 168 | } else if (D && isa<CXXDestructorDecl>(D)) { |
| 169 | // There's no such thing as a "destructor call" in the AST. |
| 170 | Parent = DeclExp; |
DeLesley Hutchins | 8121639 | 2011-10-17 21:38:02 +0000 | [diff] [blame] | 171 | } |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 172 | |
| 173 | // If the attribute has no arguments, then assume the argument is "this". |
| 174 | if (MutexExp == 0) { |
DeLesley Hutchins | e03b2b3 | 2012-01-20 23:24:41 +0000 | [diff] [blame] | 175 | buildMutexID(Parent, D, 0, 0, 0); |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 176 | return; |
| 177 | } |
DeLesley Hutchins | 8121639 | 2011-10-17 21:38:02 +0000 | [diff] [blame] | 178 | |
DeLesley Hutchins | e03b2b3 | 2012-01-20 23:24:41 +0000 | [diff] [blame] | 179 | buildMutexID(MutexExp, D, Parent, NumArgs, FunArgs); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 180 | } |
| 181 | |
| 182 | public: |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 183 | explicit MutexID(clang::Decl::EmptyShell e) { |
| 184 | DeclSeq.clear(); |
| 185 | } |
| 186 | |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 187 | /// \param MutexExp The original mutex expression within an attribute |
| 188 | /// \param DeclExp An expression involving the Decl on which the attribute |
| 189 | /// occurs. |
| 190 | /// \param D The declaration to which the lock/unlock attribute is attached. |
| 191 | /// Caller must check isValid() after construction. |
| 192 | MutexID(Expr* MutexExp, Expr *DeclExp, const NamedDecl* D) { |
| 193 | buildMutexIDFromExp(MutexExp, DeclExp, D); |
Caitlin Sadowski | 194418f | 2011-09-14 20:00:24 +0000 | [diff] [blame] | 194 | } |
| 195 | |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 196 | /// Return true if this is a valid decl sequence. |
| 197 | /// Caller must call this by hand after construction to handle errors. |
Caitlin Sadowski | 194418f | 2011-09-14 20:00:24 +0000 | [diff] [blame] | 198 | bool isValid() const { |
| 199 | return !DeclSeq.empty(); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 200 | } |
| 201 | |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 202 | /// Issue a warning about an invalid lock expression |
| 203 | static void warnInvalidLock(ThreadSafetyHandler &Handler, Expr* MutexExp, |
| 204 | Expr *DeclExp, const NamedDecl* D) { |
| 205 | SourceLocation Loc; |
| 206 | if (DeclExp) |
| 207 | Loc = DeclExp->getExprLoc(); |
| 208 | |
| 209 | // FIXME: add a note about the attribute location in MutexExp or D |
| 210 | if (Loc.isValid()) |
| 211 | Handler.handleInvalidLockExp(Loc); |
| 212 | } |
| 213 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 214 | bool operator==(const MutexID &other) const { |
| 215 | return DeclSeq == other.DeclSeq; |
| 216 | } |
| 217 | |
| 218 | bool operator!=(const MutexID &other) const { |
| 219 | return !(*this == other); |
| 220 | } |
| 221 | |
| 222 | // SmallVector overloads Operator< to do lexicographic ordering. Note that |
| 223 | // we use pointer equality (and <) to compare NamedDecls. This means the order |
| 224 | // of MutexIDs in a lockset is nondeterministic. In order to output |
| 225 | // diagnostics in a deterministic ordering, we must order all diagnostics to |
| 226 | // output by SourceLocation when iterating through this lockset. |
| 227 | bool operator<(const MutexID &other) const { |
| 228 | return DeclSeq < other.DeclSeq; |
| 229 | } |
| 230 | |
| 231 | /// \brief Returns the name of the first Decl in the list for a given MutexID; |
| 232 | /// e.g. the lock expression foo.bar() has name "bar". |
| 233 | /// The caret will point unambiguously to the lock expression, so using this |
| 234 | /// name in diagnostics is a way to get simple, and consistent, mutex names. |
| 235 | /// We do not want to output the entire expression text for security reasons. |
| 236 | StringRef getName() const { |
Caitlin Sadowski | 194418f | 2011-09-14 20:00:24 +0000 | [diff] [blame] | 237 | assert(isValid()); |
DeLesley Hutchins | 4bda3ec | 2012-02-16 17:03:24 +0000 | [diff] [blame] | 238 | if (!DeclSeq.front()) |
| 239 | return "this"; // Use 0 to represent 'this'. |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 240 | return DeclSeq.front()->getName(); |
| 241 | } |
| 242 | |
| 243 | void Profile(llvm::FoldingSetNodeID &ID) const { |
| 244 | for (SmallVectorImpl<NamedDecl*>::const_iterator I = DeclSeq.begin(), |
| 245 | E = DeclSeq.end(); I != E; ++I) { |
| 246 | ID.AddPointer(*I); |
| 247 | } |
| 248 | } |
| 249 | }; |
| 250 | |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 251 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 252 | /// \brief This is a helper class that stores info about the most recent |
| 253 | /// accquire of a Lock. |
| 254 | /// |
| 255 | /// The main body of the analysis maps MutexIDs to LockDatas. |
| 256 | struct LockData { |
| 257 | SourceLocation AcquireLoc; |
| 258 | |
| 259 | /// \brief LKind stores whether a lock is held shared or exclusively. |
| 260 | /// Note that this analysis does not currently support either re-entrant |
| 261 | /// locking or lock "upgrading" and "downgrading" between exclusive and |
| 262 | /// shared. |
| 263 | /// |
| 264 | /// FIXME: add support for re-entrant locking and lock up/downgrading |
| 265 | LockKind LKind; |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 266 | MutexID UnderlyingMutex; // for ScopedLockable objects |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 267 | |
| 268 | LockData(SourceLocation AcquireLoc, LockKind LKind) |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 269 | : AcquireLoc(AcquireLoc), LKind(LKind), UnderlyingMutex(Decl::EmptyShell()) |
| 270 | {} |
| 271 | |
| 272 | LockData(SourceLocation AcquireLoc, LockKind LKind, const MutexID &Mu) |
| 273 | : AcquireLoc(AcquireLoc), LKind(LKind), UnderlyingMutex(Mu) {} |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 274 | |
| 275 | bool operator==(const LockData &other) const { |
| 276 | return AcquireLoc == other.AcquireLoc && LKind == other.LKind; |
| 277 | } |
| 278 | |
| 279 | bool operator!=(const LockData &other) const { |
| 280 | return !(*this == other); |
| 281 | } |
| 282 | |
| 283 | void Profile(llvm::FoldingSetNodeID &ID) const { |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 284 | ID.AddInteger(AcquireLoc.getRawEncoding()); |
| 285 | ID.AddInteger(LKind); |
| 286 | } |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 287 | }; |
| 288 | |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 289 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 290 | /// A Lockset maps each MutexID (defined above) to information about how it has |
| 291 | /// been locked. |
| 292 | typedef llvm::ImmutableMap<MutexID, LockData> Lockset; |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 293 | typedef llvm::ImmutableMap<NamedDecl*, unsigned> LocalVarContext; |
| 294 | |
| 295 | class LocalVariableMap; |
| 296 | |
Richard Smith | 2e51562 | 2012-02-03 04:45:26 +0000 | [diff] [blame] | 297 | /// A side (entry or exit) of a CFG node. |
| 298 | enum CFGBlockSide { CBS_Entry, CBS_Exit }; |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 299 | |
| 300 | /// CFGBlockInfo is a struct which contains all the information that is |
| 301 | /// maintained for each block in the CFG. See LocalVariableMap for more |
| 302 | /// information about the contexts. |
| 303 | struct CFGBlockInfo { |
| 304 | Lockset EntrySet; // Lockset held at entry to block |
| 305 | Lockset ExitSet; // Lockset held at exit from block |
| 306 | LocalVarContext EntryContext; // Context held at entry to block |
| 307 | LocalVarContext ExitContext; // Context held at exit from block |
Richard Smith | 2e51562 | 2012-02-03 04:45:26 +0000 | [diff] [blame] | 308 | SourceLocation EntryLoc; // Location of first statement in block |
| 309 | SourceLocation ExitLoc; // Location of last statement in block. |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 310 | unsigned EntryIndex; // Used to replay contexts later |
| 311 | |
Richard Smith | 2e51562 | 2012-02-03 04:45:26 +0000 | [diff] [blame] | 312 | const Lockset &getSet(CFGBlockSide Side) const { |
| 313 | return Side == CBS_Entry ? EntrySet : ExitSet; |
| 314 | } |
| 315 | SourceLocation getLocation(CFGBlockSide Side) const { |
| 316 | return Side == CBS_Entry ? EntryLoc : ExitLoc; |
| 317 | } |
| 318 | |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 319 | private: |
| 320 | CFGBlockInfo(Lockset EmptySet, LocalVarContext EmptyCtx) |
| 321 | : EntrySet(EmptySet), ExitSet(EmptySet), |
| 322 | EntryContext(EmptyCtx), ExitContext(EmptyCtx) |
| 323 | { } |
| 324 | |
| 325 | public: |
| 326 | static CFGBlockInfo getEmptyBlockInfo(Lockset::Factory &F, |
| 327 | LocalVariableMap &M); |
| 328 | }; |
| 329 | |
| 330 | |
| 331 | |
| 332 | // A LocalVariableMap maintains a map from local variables to their currently |
| 333 | // valid definitions. It provides SSA-like functionality when traversing the |
| 334 | // CFG. Like SSA, each definition or assignment to a variable is assigned a |
| 335 | // unique name (an integer), which acts as the SSA name for that definition. |
| 336 | // The total set of names is shared among all CFG basic blocks. |
| 337 | // Unlike SSA, we do not rewrite expressions to replace local variables declrefs |
| 338 | // with their SSA-names. Instead, we compute a Context for each point in the |
| 339 | // code, which maps local variables to the appropriate SSA-name. This map |
| 340 | // changes with each assignment. |
| 341 | // |
| 342 | // The map is computed in a single pass over the CFG. Subsequent analyses can |
| 343 | // then query the map to find the appropriate Context for a statement, and use |
| 344 | // that Context to look up the definitions of variables. |
| 345 | class LocalVariableMap { |
| 346 | public: |
| 347 | typedef LocalVarContext Context; |
| 348 | |
| 349 | /// A VarDefinition consists of an expression, representing the value of the |
| 350 | /// variable, along with the context in which that expression should be |
| 351 | /// interpreted. A reference VarDefinition does not itself contain this |
| 352 | /// information, but instead contains a pointer to a previous VarDefinition. |
| 353 | struct VarDefinition { |
| 354 | public: |
| 355 | friend class LocalVariableMap; |
| 356 | |
| 357 | NamedDecl *Dec; // The original declaration for this variable. |
| 358 | Expr *Exp; // The expression for this variable, OR |
| 359 | unsigned Ref; // Reference to another VarDefinition |
| 360 | Context Ctx; // The map with which Exp should be interpreted. |
| 361 | |
| 362 | bool isReference() { return !Exp; } |
| 363 | |
| 364 | private: |
| 365 | // Create ordinary variable definition |
| 366 | VarDefinition(NamedDecl *D, Expr *E, Context C) |
| 367 | : Dec(D), Exp(E), Ref(0), Ctx(C) |
| 368 | { } |
| 369 | |
| 370 | // Create reference to previous definition |
| 371 | VarDefinition(NamedDecl *D, unsigned R, Context C) |
| 372 | : Dec(D), Exp(0), Ref(R), Ctx(C) |
| 373 | { } |
| 374 | }; |
| 375 | |
| 376 | private: |
| 377 | Context::Factory ContextFactory; |
| 378 | std::vector<VarDefinition> VarDefinitions; |
| 379 | std::vector<unsigned> CtxIndices; |
| 380 | std::vector<std::pair<Stmt*, Context> > SavedContexts; |
| 381 | |
| 382 | public: |
| 383 | LocalVariableMap() { |
| 384 | // index 0 is a placeholder for undefined variables (aka phi-nodes). |
| 385 | VarDefinitions.push_back(VarDefinition(0, 0u, getEmptyContext())); |
| 386 | } |
| 387 | |
| 388 | /// Look up a definition, within the given context. |
| 389 | const VarDefinition* lookup(NamedDecl *D, Context Ctx) { |
| 390 | const unsigned *i = Ctx.lookup(D); |
| 391 | if (!i) |
| 392 | return 0; |
| 393 | assert(*i < VarDefinitions.size()); |
| 394 | return &VarDefinitions[*i]; |
| 395 | } |
| 396 | |
| 397 | /// Look up the definition for D within the given context. Returns |
DeLesley Hutchins | b4fa418 | 2012-01-06 19:16:50 +0000 | [diff] [blame] | 398 | /// NULL if the expression is not statically known. If successful, also |
| 399 | /// modifies Ctx to hold the context of the return Expr. |
| 400 | Expr* lookupExpr(NamedDecl *D, Context &Ctx) { |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 401 | const unsigned *P = Ctx.lookup(D); |
| 402 | if (!P) |
| 403 | return 0; |
| 404 | |
| 405 | unsigned i = *P; |
| 406 | while (i > 0) { |
DeLesley Hutchins | b4fa418 | 2012-01-06 19:16:50 +0000 | [diff] [blame] | 407 | if (VarDefinitions[i].Exp) { |
| 408 | Ctx = VarDefinitions[i].Ctx; |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 409 | return VarDefinitions[i].Exp; |
DeLesley Hutchins | b4fa418 | 2012-01-06 19:16:50 +0000 | [diff] [blame] | 410 | } |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 411 | i = VarDefinitions[i].Ref; |
| 412 | } |
| 413 | return 0; |
| 414 | } |
| 415 | |
| 416 | Context getEmptyContext() { return ContextFactory.getEmptyMap(); } |
| 417 | |
| 418 | /// Return the next context after processing S. This function is used by |
| 419 | /// clients of the class to get the appropriate context when traversing the |
| 420 | /// CFG. It must be called for every assignment or DeclStmt. |
| 421 | Context getNextContext(unsigned &CtxIndex, Stmt *S, Context C) { |
| 422 | if (SavedContexts[CtxIndex+1].first == S) { |
| 423 | CtxIndex++; |
| 424 | Context Result = SavedContexts[CtxIndex].second; |
| 425 | return Result; |
| 426 | } |
| 427 | return C; |
| 428 | } |
| 429 | |
| 430 | void dumpVarDefinitionName(unsigned i) { |
| 431 | if (i == 0) { |
| 432 | llvm::errs() << "Undefined"; |
| 433 | return; |
| 434 | } |
| 435 | NamedDecl *Dec = VarDefinitions[i].Dec; |
| 436 | if (!Dec) { |
| 437 | llvm::errs() << "<<NULL>>"; |
| 438 | return; |
| 439 | } |
| 440 | Dec->printName(llvm::errs()); |
| 441 | llvm::errs() << "." << i << " " << ((void*) Dec); |
| 442 | } |
| 443 | |
| 444 | /// Dumps an ASCII representation of the variable map to llvm::errs() |
| 445 | void dump() { |
| 446 | for (unsigned i = 1, e = VarDefinitions.size(); i < e; ++i) { |
| 447 | Expr *Exp = VarDefinitions[i].Exp; |
| 448 | unsigned Ref = VarDefinitions[i].Ref; |
| 449 | |
| 450 | dumpVarDefinitionName(i); |
| 451 | llvm::errs() << " = "; |
| 452 | if (Exp) Exp->dump(); |
| 453 | else { |
| 454 | dumpVarDefinitionName(Ref); |
| 455 | llvm::errs() << "\n"; |
| 456 | } |
| 457 | } |
| 458 | } |
| 459 | |
| 460 | /// Dumps an ASCII representation of a Context to llvm::errs() |
| 461 | void dumpContext(Context C) { |
| 462 | for (Context::iterator I = C.begin(), E = C.end(); I != E; ++I) { |
| 463 | NamedDecl *D = I.getKey(); |
| 464 | D->printName(llvm::errs()); |
| 465 | const unsigned *i = C.lookup(D); |
| 466 | llvm::errs() << " -> "; |
| 467 | dumpVarDefinitionName(*i); |
| 468 | llvm::errs() << "\n"; |
| 469 | } |
| 470 | } |
| 471 | |
| 472 | /// Builds the variable map. |
| 473 | void traverseCFG(CFG *CFGraph, PostOrderCFGView *SortedGraph, |
| 474 | std::vector<CFGBlockInfo> &BlockInfo); |
| 475 | |
| 476 | protected: |
| 477 | // Get the current context index |
| 478 | unsigned getContextIndex() { return SavedContexts.size()-1; } |
| 479 | |
| 480 | // Save the current context for later replay |
| 481 | void saveContext(Stmt *S, Context C) { |
| 482 | SavedContexts.push_back(std::make_pair(S,C)); |
| 483 | } |
| 484 | |
| 485 | // Adds a new definition to the given context, and returns a new context. |
| 486 | // This method should be called when declaring a new variable. |
| 487 | Context addDefinition(NamedDecl *D, Expr *Exp, Context Ctx) { |
| 488 | assert(!Ctx.contains(D)); |
| 489 | unsigned newID = VarDefinitions.size(); |
| 490 | Context NewCtx = ContextFactory.add(Ctx, D, newID); |
| 491 | VarDefinitions.push_back(VarDefinition(D, Exp, Ctx)); |
| 492 | return NewCtx; |
| 493 | } |
| 494 | |
| 495 | // Add a new reference to an existing definition. |
| 496 | Context addReference(NamedDecl *D, unsigned i, Context Ctx) { |
| 497 | unsigned newID = VarDefinitions.size(); |
| 498 | Context NewCtx = ContextFactory.add(Ctx, D, newID); |
| 499 | VarDefinitions.push_back(VarDefinition(D, i, Ctx)); |
| 500 | return NewCtx; |
| 501 | } |
| 502 | |
| 503 | // Updates a definition only if that definition is already in the map. |
| 504 | // This method should be called when assigning to an existing variable. |
| 505 | Context updateDefinition(NamedDecl *D, Expr *Exp, Context Ctx) { |
| 506 | if (Ctx.contains(D)) { |
| 507 | unsigned newID = VarDefinitions.size(); |
| 508 | Context NewCtx = ContextFactory.remove(Ctx, D); |
| 509 | NewCtx = ContextFactory.add(NewCtx, D, newID); |
| 510 | VarDefinitions.push_back(VarDefinition(D, Exp, Ctx)); |
| 511 | return NewCtx; |
| 512 | } |
| 513 | return Ctx; |
| 514 | } |
| 515 | |
| 516 | // Removes a definition from the context, but keeps the variable name |
| 517 | // as a valid variable. The index 0 is a placeholder for cleared definitions. |
| 518 | Context clearDefinition(NamedDecl *D, Context Ctx) { |
| 519 | Context NewCtx = Ctx; |
| 520 | if (NewCtx.contains(D)) { |
| 521 | NewCtx = ContextFactory.remove(NewCtx, D); |
| 522 | NewCtx = ContextFactory.add(NewCtx, D, 0); |
| 523 | } |
| 524 | return NewCtx; |
| 525 | } |
| 526 | |
| 527 | // Remove a definition entirely frmo the context. |
| 528 | Context removeDefinition(NamedDecl *D, Context Ctx) { |
| 529 | Context NewCtx = Ctx; |
| 530 | if (NewCtx.contains(D)) { |
| 531 | NewCtx = ContextFactory.remove(NewCtx, D); |
| 532 | } |
| 533 | return NewCtx; |
| 534 | } |
| 535 | |
| 536 | Context intersectContexts(Context C1, Context C2); |
| 537 | Context createReferenceContext(Context C); |
| 538 | void intersectBackEdge(Context C1, Context C2); |
| 539 | |
| 540 | friend class VarMapBuilder; |
| 541 | }; |
| 542 | |
| 543 | |
| 544 | // This has to be defined after LocalVariableMap. |
| 545 | CFGBlockInfo CFGBlockInfo::getEmptyBlockInfo(Lockset::Factory &F, |
| 546 | LocalVariableMap &M) { |
| 547 | return CFGBlockInfo(F.getEmptyMap(), M.getEmptyContext()); |
| 548 | } |
| 549 | |
| 550 | |
| 551 | /// Visitor which builds a LocalVariableMap |
| 552 | class VarMapBuilder : public StmtVisitor<VarMapBuilder> { |
| 553 | public: |
| 554 | LocalVariableMap* VMap; |
| 555 | LocalVariableMap::Context Ctx; |
| 556 | |
| 557 | VarMapBuilder(LocalVariableMap *VM, LocalVariableMap::Context C) |
| 558 | : VMap(VM), Ctx(C) {} |
| 559 | |
| 560 | void VisitDeclStmt(DeclStmt *S); |
| 561 | void VisitBinaryOperator(BinaryOperator *BO); |
| 562 | }; |
| 563 | |
| 564 | |
| 565 | // Add new local variables to the variable map |
| 566 | void VarMapBuilder::VisitDeclStmt(DeclStmt *S) { |
| 567 | bool modifiedCtx = false; |
| 568 | DeclGroupRef DGrp = S->getDeclGroup(); |
| 569 | for (DeclGroupRef::iterator I = DGrp.begin(), E = DGrp.end(); I != E; ++I) { |
| 570 | if (VarDecl *VD = dyn_cast_or_null<VarDecl>(*I)) { |
| 571 | Expr *E = VD->getInit(); |
| 572 | |
| 573 | // Add local variables with trivial type to the variable map |
| 574 | QualType T = VD->getType(); |
| 575 | if (T.isTrivialType(VD->getASTContext())) { |
| 576 | Ctx = VMap->addDefinition(VD, E, Ctx); |
| 577 | modifiedCtx = true; |
| 578 | } |
| 579 | } |
| 580 | } |
| 581 | if (modifiedCtx) |
| 582 | VMap->saveContext(S, Ctx); |
| 583 | } |
| 584 | |
| 585 | // Update local variable definitions in variable map |
| 586 | void VarMapBuilder::VisitBinaryOperator(BinaryOperator *BO) { |
| 587 | if (!BO->isAssignmentOp()) |
| 588 | return; |
| 589 | |
| 590 | Expr *LHSExp = BO->getLHS()->IgnoreParenCasts(); |
| 591 | |
| 592 | // Update the variable map and current context. |
| 593 | if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(LHSExp)) { |
| 594 | ValueDecl *VDec = DRE->getDecl(); |
| 595 | if (Ctx.lookup(VDec)) { |
| 596 | if (BO->getOpcode() == BO_Assign) |
| 597 | Ctx = VMap->updateDefinition(VDec, BO->getRHS(), Ctx); |
| 598 | else |
| 599 | // FIXME -- handle compound assignment operators |
| 600 | Ctx = VMap->clearDefinition(VDec, Ctx); |
| 601 | VMap->saveContext(BO, Ctx); |
| 602 | } |
| 603 | } |
| 604 | } |
| 605 | |
| 606 | |
| 607 | // Computes the intersection of two contexts. The intersection is the |
| 608 | // set of variables which have the same definition in both contexts; |
| 609 | // variables with different definitions are discarded. |
| 610 | LocalVariableMap::Context |
| 611 | LocalVariableMap::intersectContexts(Context C1, Context C2) { |
| 612 | Context Result = C1; |
| 613 | for (Context::iterator I = C1.begin(), E = C1.end(); I != E; ++I) { |
| 614 | NamedDecl *Dec = I.getKey(); |
| 615 | unsigned i1 = I.getData(); |
| 616 | const unsigned *i2 = C2.lookup(Dec); |
| 617 | if (!i2) // variable doesn't exist on second path |
| 618 | Result = removeDefinition(Dec, Result); |
| 619 | else if (*i2 != i1) // variable exists, but has different definition |
| 620 | Result = clearDefinition(Dec, Result); |
| 621 | } |
| 622 | return Result; |
| 623 | } |
| 624 | |
| 625 | // For every variable in C, create a new variable that refers to the |
| 626 | // definition in C. Return a new context that contains these new variables. |
| 627 | // (We use this for a naive implementation of SSA on loop back-edges.) |
| 628 | LocalVariableMap::Context LocalVariableMap::createReferenceContext(Context C) { |
| 629 | Context Result = getEmptyContext(); |
| 630 | for (Context::iterator I = C.begin(), E = C.end(); I != E; ++I) { |
| 631 | NamedDecl *Dec = I.getKey(); |
| 632 | unsigned i = I.getData(); |
| 633 | Result = addReference(Dec, i, Result); |
| 634 | } |
| 635 | return Result; |
| 636 | } |
| 637 | |
| 638 | // This routine also takes the intersection of C1 and C2, but it does so by |
| 639 | // altering the VarDefinitions. C1 must be the result of an earlier call to |
| 640 | // createReferenceContext. |
| 641 | void LocalVariableMap::intersectBackEdge(Context C1, Context C2) { |
| 642 | for (Context::iterator I = C1.begin(), E = C1.end(); I != E; ++I) { |
| 643 | NamedDecl *Dec = I.getKey(); |
| 644 | unsigned i1 = I.getData(); |
| 645 | VarDefinition *VDef = &VarDefinitions[i1]; |
| 646 | assert(VDef->isReference()); |
| 647 | |
| 648 | const unsigned *i2 = C2.lookup(Dec); |
| 649 | if (!i2 || (*i2 != i1)) |
| 650 | VDef->Ref = 0; // Mark this variable as undefined |
| 651 | } |
| 652 | } |
| 653 | |
| 654 | |
| 655 | // Traverse the CFG in topological order, so all predecessors of a block |
| 656 | // (excluding back-edges) are visited before the block itself. At |
| 657 | // each point in the code, we calculate a Context, which holds the set of |
| 658 | // variable definitions which are visible at that point in execution. |
| 659 | // Visible variables are mapped to their definitions using an array that |
| 660 | // contains all definitions. |
| 661 | // |
| 662 | // At join points in the CFG, the set is computed as the intersection of |
| 663 | // the incoming sets along each edge, E.g. |
| 664 | // |
| 665 | // { Context | VarDefinitions } |
| 666 | // int x = 0; { x -> x1 | x1 = 0 } |
| 667 | // int y = 0; { x -> x1, y -> y1 | y1 = 0, x1 = 0 } |
| 668 | // if (b) x = 1; { x -> x2, y -> y1 | x2 = 1, y1 = 0, ... } |
| 669 | // else x = 2; { x -> x3, y -> y1 | x3 = 2, x2 = 1, ... } |
| 670 | // ... { y -> y1 (x is unknown) | x3 = 2, x2 = 1, ... } |
| 671 | // |
| 672 | // This is essentially a simpler and more naive version of the standard SSA |
| 673 | // algorithm. Those definitions that remain in the intersection are from blocks |
| 674 | // that strictly dominate the current block. We do not bother to insert proper |
| 675 | // phi nodes, because they are not used in our analysis; instead, wherever |
| 676 | // a phi node would be required, we simply remove that definition from the |
| 677 | // context (E.g. x above). |
| 678 | // |
| 679 | // The initial traversal does not capture back-edges, so those need to be |
| 680 | // handled on a separate pass. Whenever the first pass encounters an |
| 681 | // incoming back edge, it duplicates the context, creating new definitions |
| 682 | // that refer back to the originals. (These correspond to places where SSA |
| 683 | // might have to insert a phi node.) On the second pass, these definitions are |
| 684 | // set to NULL if the the variable has changed on the back-edge (i.e. a phi |
| 685 | // node was actually required.) E.g. |
| 686 | // |
| 687 | // { Context | VarDefinitions } |
| 688 | // int x = 0, y = 0; { x -> x1, y -> y1 | y1 = 0, x1 = 0 } |
| 689 | // while (b) { x -> x2, y -> y1 | [1st:] x2=x1; [2nd:] x2=NULL; } |
| 690 | // x = x+1; { x -> x3, y -> y1 | x3 = x2 + 1, ... } |
| 691 | // ... { y -> y1 | x3 = 2, x2 = 1, ... } |
| 692 | // |
| 693 | void LocalVariableMap::traverseCFG(CFG *CFGraph, |
| 694 | PostOrderCFGView *SortedGraph, |
| 695 | std::vector<CFGBlockInfo> &BlockInfo) { |
| 696 | PostOrderCFGView::CFGBlockSet VisitedBlocks(CFGraph); |
| 697 | |
| 698 | CtxIndices.resize(CFGraph->getNumBlockIDs()); |
| 699 | |
| 700 | for (PostOrderCFGView::iterator I = SortedGraph->begin(), |
| 701 | E = SortedGraph->end(); I!= E; ++I) { |
| 702 | const CFGBlock *CurrBlock = *I; |
| 703 | int CurrBlockID = CurrBlock->getBlockID(); |
| 704 | CFGBlockInfo *CurrBlockInfo = &BlockInfo[CurrBlockID]; |
| 705 | |
| 706 | VisitedBlocks.insert(CurrBlock); |
| 707 | |
| 708 | // Calculate the entry context for the current block |
| 709 | bool HasBackEdges = false; |
| 710 | bool CtxInit = true; |
| 711 | for (CFGBlock::const_pred_iterator PI = CurrBlock->pred_begin(), |
| 712 | PE = CurrBlock->pred_end(); PI != PE; ++PI) { |
| 713 | // if *PI -> CurrBlock is a back edge, so skip it |
| 714 | if (*PI == 0 || !VisitedBlocks.alreadySet(*PI)) { |
| 715 | HasBackEdges = true; |
| 716 | continue; |
| 717 | } |
| 718 | |
| 719 | int PrevBlockID = (*PI)->getBlockID(); |
| 720 | CFGBlockInfo *PrevBlockInfo = &BlockInfo[PrevBlockID]; |
| 721 | |
| 722 | if (CtxInit) { |
| 723 | CurrBlockInfo->EntryContext = PrevBlockInfo->ExitContext; |
| 724 | CtxInit = false; |
| 725 | } |
| 726 | else { |
| 727 | CurrBlockInfo->EntryContext = |
| 728 | intersectContexts(CurrBlockInfo->EntryContext, |
| 729 | PrevBlockInfo->ExitContext); |
| 730 | } |
| 731 | } |
| 732 | |
| 733 | // Duplicate the context if we have back-edges, so we can call |
| 734 | // intersectBackEdges later. |
| 735 | if (HasBackEdges) |
| 736 | CurrBlockInfo->EntryContext = |
| 737 | createReferenceContext(CurrBlockInfo->EntryContext); |
| 738 | |
| 739 | // Create a starting context index for the current block |
| 740 | saveContext(0, CurrBlockInfo->EntryContext); |
| 741 | CurrBlockInfo->EntryIndex = getContextIndex(); |
| 742 | |
| 743 | // Visit all the statements in the basic block. |
| 744 | VarMapBuilder VMapBuilder(this, CurrBlockInfo->EntryContext); |
| 745 | for (CFGBlock::const_iterator BI = CurrBlock->begin(), |
| 746 | BE = CurrBlock->end(); BI != BE; ++BI) { |
| 747 | switch (BI->getKind()) { |
| 748 | case CFGElement::Statement: { |
| 749 | const CFGStmt *CS = cast<CFGStmt>(&*BI); |
| 750 | VMapBuilder.Visit(const_cast<Stmt*>(CS->getStmt())); |
| 751 | break; |
| 752 | } |
| 753 | default: |
| 754 | break; |
| 755 | } |
| 756 | } |
| 757 | CurrBlockInfo->ExitContext = VMapBuilder.Ctx; |
| 758 | |
| 759 | // Mark variables on back edges as "unknown" if they've been changed. |
| 760 | for (CFGBlock::const_succ_iterator SI = CurrBlock->succ_begin(), |
| 761 | SE = CurrBlock->succ_end(); SI != SE; ++SI) { |
| 762 | // if CurrBlock -> *SI is *not* a back edge |
| 763 | if (*SI == 0 || !VisitedBlocks.alreadySet(*SI)) |
| 764 | continue; |
| 765 | |
| 766 | CFGBlock *FirstLoopBlock = *SI; |
| 767 | Context LoopBegin = BlockInfo[FirstLoopBlock->getBlockID()].EntryContext; |
| 768 | Context LoopEnd = CurrBlockInfo->ExitContext; |
| 769 | intersectBackEdge(LoopBegin, LoopEnd); |
| 770 | } |
| 771 | } |
| 772 | |
| 773 | // Put an extra entry at the end of the indexed context array |
| 774 | unsigned exitID = CFGraph->getExit().getBlockID(); |
| 775 | saveContext(0, BlockInfo[exitID].ExitContext); |
| 776 | } |
| 777 | |
Richard Smith | 2e51562 | 2012-02-03 04:45:26 +0000 | [diff] [blame] | 778 | /// Find the appropriate source locations to use when producing diagnostics for |
| 779 | /// each block in the CFG. |
| 780 | static void findBlockLocations(CFG *CFGraph, |
| 781 | PostOrderCFGView *SortedGraph, |
| 782 | std::vector<CFGBlockInfo> &BlockInfo) { |
| 783 | for (PostOrderCFGView::iterator I = SortedGraph->begin(), |
| 784 | E = SortedGraph->end(); I!= E; ++I) { |
| 785 | const CFGBlock *CurrBlock = *I; |
| 786 | CFGBlockInfo *CurrBlockInfo = &BlockInfo[CurrBlock->getBlockID()]; |
| 787 | |
| 788 | // Find the source location of the last statement in the block, if the |
| 789 | // block is not empty. |
| 790 | if (const Stmt *S = CurrBlock->getTerminator()) { |
| 791 | CurrBlockInfo->EntryLoc = CurrBlockInfo->ExitLoc = S->getLocStart(); |
| 792 | } else { |
| 793 | for (CFGBlock::const_reverse_iterator BI = CurrBlock->rbegin(), |
| 794 | BE = CurrBlock->rend(); BI != BE; ++BI) { |
| 795 | // FIXME: Handle other CFGElement kinds. |
| 796 | if (const CFGStmt *CS = dyn_cast<CFGStmt>(&*BI)) { |
| 797 | CurrBlockInfo->ExitLoc = CS->getStmt()->getLocStart(); |
| 798 | break; |
| 799 | } |
| 800 | } |
| 801 | } |
| 802 | |
| 803 | if (!CurrBlockInfo->ExitLoc.isInvalid()) { |
| 804 | // This block contains at least one statement. Find the source location |
| 805 | // of the first statement in the block. |
| 806 | for (CFGBlock::const_iterator BI = CurrBlock->begin(), |
| 807 | BE = CurrBlock->end(); BI != BE; ++BI) { |
| 808 | // FIXME: Handle other CFGElement kinds. |
| 809 | if (const CFGStmt *CS = dyn_cast<CFGStmt>(&*BI)) { |
| 810 | CurrBlockInfo->EntryLoc = CS->getStmt()->getLocStart(); |
| 811 | break; |
| 812 | } |
| 813 | } |
| 814 | } else if (CurrBlock->pred_size() == 1 && *CurrBlock->pred_begin() && |
| 815 | CurrBlock != &CFGraph->getExit()) { |
| 816 | // The block is empty, and has a single predecessor. Use its exit |
| 817 | // location. |
| 818 | CurrBlockInfo->EntryLoc = CurrBlockInfo->ExitLoc = |
| 819 | BlockInfo[(*CurrBlock->pred_begin())->getBlockID()].ExitLoc; |
| 820 | } |
| 821 | } |
| 822 | } |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 823 | |
| 824 | /// \brief Class which implements the core thread safety analysis routines. |
| 825 | class ThreadSafetyAnalyzer { |
| 826 | friend class BuildLockset; |
| 827 | |
| 828 | ThreadSafetyHandler &Handler; |
| 829 | Lockset::Factory LocksetFactory; |
| 830 | LocalVariableMap LocalVarMap; |
| 831 | |
| 832 | public: |
| 833 | ThreadSafetyAnalyzer(ThreadSafetyHandler &H) : Handler(H) {} |
| 834 | |
Richard Smith | 2e51562 | 2012-02-03 04:45:26 +0000 | [diff] [blame] | 835 | Lockset intersectAndWarn(const CFGBlockInfo &Block1, CFGBlockSide Side1, |
| 836 | const CFGBlockInfo &Block2, CFGBlockSide Side2, |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 837 | LockErrorKind LEK); |
| 838 | |
| 839 | Lockset addLock(Lockset &LSet, Expr *MutexExp, const NamedDecl *D, |
| 840 | LockKind LK, SourceLocation Loc); |
| 841 | |
| 842 | void runAnalysis(AnalysisDeclContext &AC); |
| 843 | }; |
| 844 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 845 | |
| 846 | /// \brief We use this class to visit different types of expressions in |
| 847 | /// CFGBlocks, and build up the lockset. |
| 848 | /// An expression may cause us to add or remove locks from the lockset, or else |
| 849 | /// output error messages related to missing locks. |
| 850 | /// FIXME: In future, we may be able to not inherit from a visitor. |
| 851 | class BuildLockset : public StmtVisitor<BuildLockset> { |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 852 | friend class ThreadSafetyAnalyzer; |
| 853 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 854 | ThreadSafetyHandler &Handler; |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 855 | Lockset::Factory &LocksetFactory; |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 856 | LocalVariableMap &LocalVarMap; |
| 857 | |
| 858 | Lockset LSet; |
| 859 | LocalVariableMap::Context LVarCtx; |
| 860 | unsigned CtxIndex; |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 861 | |
| 862 | // Helper functions |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 863 | void addLock(const MutexID &Mutex, const LockData &LDat); |
| 864 | void removeLock(const MutexID &Mutex, SourceLocation UnlockLoc); |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 865 | |
| 866 | template <class AttrType> |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 867 | void addLocksToSet(LockKind LK, AttrType *Attr, |
| 868 | Expr *Exp, NamedDecl *D, VarDecl *VD = 0); |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 869 | void removeLocksFromSet(UnlockFunctionAttr *Attr, |
| 870 | Expr *Exp, NamedDecl* FunDecl); |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 871 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 872 | const ValueDecl *getValueDecl(Expr *Exp); |
| 873 | void warnIfMutexNotHeld (const NamedDecl *D, Expr *Exp, AccessKind AK, |
| 874 | Expr *MutexExp, ProtectedOperationKind POK); |
| 875 | void checkAccess(Expr *Exp, AccessKind AK); |
| 876 | void checkDereference(Expr *Exp, AccessKind AK); |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 877 | void handleCall(Expr *Exp, NamedDecl *D, VarDecl *VD = 0); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 878 | |
DeLesley Hutchins | b4fa418 | 2012-01-06 19:16:50 +0000 | [diff] [blame] | 879 | template <class AttrType> |
| 880 | void addTrylock(LockKind LK, AttrType *Attr, Expr *Exp, NamedDecl *FunDecl, |
| 881 | const CFGBlock* PredBlock, const CFGBlock *CurrBlock, |
| 882 | Expr *BrE, bool Neg); |
| 883 | CallExpr* getTrylockCallExpr(Stmt *Cond, LocalVariableMap::Context C, |
| 884 | bool &Negate); |
| 885 | void handleTrylock(Stmt *Cond, const CFGBlock* PredBlock, |
| 886 | const CFGBlock *CurrBlock); |
| 887 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 888 | /// \brief Returns true if the lockset contains a lock, regardless of whether |
| 889 | /// the lock is held exclusively or shared. |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 890 | bool locksetContains(const MutexID &Lock) const { |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 891 | return LSet.lookup(Lock); |
| 892 | } |
| 893 | |
| 894 | /// \brief Returns true if the lockset contains a lock with the passed in |
| 895 | /// locktype. |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 896 | bool locksetContains(const MutexID &Lock, LockKind KindRequested) const { |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 897 | const LockData *LockHeld = LSet.lookup(Lock); |
| 898 | return (LockHeld && KindRequested == LockHeld->LKind); |
| 899 | } |
| 900 | |
| 901 | /// \brief Returns true if the lockset contains a lock with at least the |
| 902 | /// passed in locktype. So for example, if we pass in LK_Shared, this function |
| 903 | /// returns true if the lock is held LK_Shared or LK_Exclusive. If we pass in |
| 904 | /// LK_Exclusive, this function returns true if the lock is held LK_Exclusive. |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 905 | bool locksetContainsAtLeast(const MutexID &Lock, |
| 906 | LockKind KindRequested) const { |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 907 | switch (KindRequested) { |
| 908 | case LK_Shared: |
| 909 | return locksetContains(Lock); |
| 910 | case LK_Exclusive: |
| 911 | return locksetContains(Lock, KindRequested); |
| 912 | } |
Benjamin Kramer | afc5b15 | 2011-09-10 21:52:04 +0000 | [diff] [blame] | 913 | llvm_unreachable("Unknown LockKind"); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 914 | } |
| 915 | |
| 916 | public: |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 917 | BuildLockset(ThreadSafetyAnalyzer *analyzer, CFGBlockInfo &Info) |
| 918 | : StmtVisitor<BuildLockset>(), |
| 919 | Handler(analyzer->Handler), |
| 920 | LocksetFactory(analyzer->LocksetFactory), |
| 921 | LocalVarMap(analyzer->LocalVarMap), |
| 922 | LSet(Info.EntrySet), |
| 923 | LVarCtx(Info.EntryContext), |
| 924 | CtxIndex(Info.EntryIndex) |
| 925 | {} |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 926 | |
| 927 | void VisitUnaryOperator(UnaryOperator *UO); |
| 928 | void VisitBinaryOperator(BinaryOperator *BO); |
| 929 | void VisitCastExpr(CastExpr *CE); |
DeLesley Hutchins | df49782 | 2011-12-29 00:56:48 +0000 | [diff] [blame] | 930 | void VisitCallExpr(CallExpr *Exp); |
DeLesley Hutchins | e0eaa85 | 2011-10-21 18:06:53 +0000 | [diff] [blame] | 931 | void VisitCXXConstructExpr(CXXConstructExpr *Exp); |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 932 | void VisitDeclStmt(DeclStmt *S); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 933 | }; |
| 934 | |
| 935 | /// \brief Add a new lock to the lockset, warning if the lock is already there. |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 936 | /// \param Mutex -- the Mutex expression for the lock |
| 937 | /// \param LDat -- the LockData for the lock |
| 938 | void BuildLockset::addLock(const MutexID &Mutex, const LockData& LDat) { |
| 939 | // FIXME: deal with acquired before/after annotations. |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 940 | // FIXME: Don't always warn when we have support for reentrant locks. |
| 941 | if (locksetContains(Mutex)) |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 942 | Handler.handleDoubleLock(Mutex.getName(), LDat.AcquireLoc); |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 943 | else |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 944 | LSet = LocksetFactory.add(LSet, Mutex, LDat); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 945 | } |
| 946 | |
| 947 | /// \brief Remove a lock from the lockset, warning if the lock is not there. |
| 948 | /// \param LockExp The lock expression corresponding to the lock to be removed |
| 949 | /// \param UnlockLoc The source location of the unlock (only used in error msg) |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 950 | void BuildLockset::removeLock(const MutexID &Mutex, SourceLocation UnlockLoc) { |
| 951 | const LockData *LDat = LSet.lookup(Mutex); |
| 952 | if (!LDat) |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 953 | Handler.handleUnmatchedUnlock(Mutex.getName(), UnlockLoc); |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 954 | else { |
| 955 | // For scoped-lockable vars, remove the mutex associated with this var. |
| 956 | if (LDat->UnderlyingMutex.isValid()) |
| 957 | removeLock(LDat->UnderlyingMutex, UnlockLoc); |
| 958 | LSet = LocksetFactory.remove(LSet, Mutex); |
| 959 | } |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 960 | } |
| 961 | |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 962 | /// \brief This function, parameterized by an attribute type, is used to add a |
| 963 | /// set of locks specified as attribute arguments to the lockset. |
| 964 | template <typename AttrType> |
| 965 | void BuildLockset::addLocksToSet(LockKind LK, AttrType *Attr, |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 966 | Expr *Exp, NamedDecl* FunDecl, VarDecl *VD) { |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 967 | typedef typename AttrType::args_iterator iterator_type; |
| 968 | |
| 969 | SourceLocation ExpLocation = Exp->getExprLoc(); |
| 970 | |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 971 | // Figure out if we're calling the constructor of scoped lockable class |
| 972 | bool isScopedVar = false; |
| 973 | if (VD) { |
| 974 | if (CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FunDecl)) { |
| 975 | CXXRecordDecl* PD = CD->getParent(); |
| 976 | if (PD && PD->getAttr<ScopedLockableAttr>()) |
| 977 | isScopedVar = true; |
| 978 | } |
| 979 | } |
| 980 | |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 981 | if (Attr->args_size() == 0) { |
| 982 | // The mutex held is the "this" object. |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 983 | MutexID Mutex(0, Exp, FunDecl); |
| 984 | if (!Mutex.isValid()) |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 985 | MutexID::warnInvalidLock(Handler, 0, Exp, FunDecl); |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 986 | else |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 987 | addLock(Mutex, LockData(ExpLocation, LK)); |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 988 | return; |
| 989 | } |
| 990 | |
| 991 | for (iterator_type I=Attr->args_begin(), E=Attr->args_end(); I != E; ++I) { |
| 992 | MutexID Mutex(*I, Exp, FunDecl); |
| 993 | if (!Mutex.isValid()) |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 994 | MutexID::warnInvalidLock(Handler, *I, Exp, FunDecl); |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 995 | else { |
| 996 | addLock(Mutex, LockData(ExpLocation, LK)); |
| 997 | if (isScopedVar) { |
| 998 | // For scoped lockable vars, map this var to its underlying mutex. |
| 999 | DeclRefExpr DRE(VD, VD->getType(), VK_LValue, VD->getLocation()); |
| 1000 | MutexID SMutex(&DRE, 0, 0); |
| 1001 | addLock(SMutex, LockData(VD->getLocation(), LK, Mutex)); |
| 1002 | } |
| 1003 | } |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 1004 | } |
| 1005 | } |
| 1006 | |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 1007 | /// \brief This function removes a set of locks specified as attribute |
| 1008 | /// arguments from the lockset. |
| 1009 | void BuildLockset::removeLocksFromSet(UnlockFunctionAttr *Attr, |
| 1010 | Expr *Exp, NamedDecl* FunDecl) { |
| 1011 | SourceLocation ExpLocation; |
| 1012 | if (Exp) ExpLocation = Exp->getExprLoc(); |
| 1013 | |
| 1014 | if (Attr->args_size() == 0) { |
| 1015 | // The mutex held is the "this" object. |
| 1016 | MutexID Mu(0, Exp, FunDecl); |
| 1017 | if (!Mu.isValid()) |
| 1018 | MutexID::warnInvalidLock(Handler, 0, Exp, FunDecl); |
| 1019 | else |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 1020 | removeLock(Mu, ExpLocation); |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 1021 | return; |
| 1022 | } |
| 1023 | |
| 1024 | for (UnlockFunctionAttr::args_iterator I = Attr->args_begin(), |
| 1025 | E = Attr->args_end(); I != E; ++I) { |
| 1026 | MutexID Mutex(*I, Exp, FunDecl); |
| 1027 | if (!Mutex.isValid()) |
| 1028 | MutexID::warnInvalidLock(Handler, *I, Exp, FunDecl); |
| 1029 | else |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 1030 | removeLock(Mutex, ExpLocation); |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 1031 | } |
| 1032 | } |
| 1033 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1034 | /// \brief Gets the value decl pointer from DeclRefExprs or MemberExprs |
| 1035 | const ValueDecl *BuildLockset::getValueDecl(Expr *Exp) { |
| 1036 | if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Exp)) |
| 1037 | return DR->getDecl(); |
| 1038 | |
| 1039 | if (const MemberExpr *ME = dyn_cast<MemberExpr>(Exp)) |
| 1040 | return ME->getMemberDecl(); |
| 1041 | |
| 1042 | return 0; |
| 1043 | } |
| 1044 | |
| 1045 | /// \brief Warn if the LSet does not contain a lock sufficient to protect access |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 1046 | /// of at least the passed in AccessKind. |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1047 | void BuildLockset::warnIfMutexNotHeld(const NamedDecl *D, Expr *Exp, |
| 1048 | AccessKind AK, Expr *MutexExp, |
| 1049 | ProtectedOperationKind POK) { |
| 1050 | LockKind LK = getLockKindFromAccessKind(AK); |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 1051 | |
| 1052 | MutexID Mutex(MutexExp, Exp, D); |
Caitlin Sadowski | 194418f | 2011-09-14 20:00:24 +0000 | [diff] [blame] | 1053 | if (!Mutex.isValid()) |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 1054 | MutexID::warnInvalidLock(Handler, MutexExp, Exp, D); |
Caitlin Sadowski | 194418f | 2011-09-14 20:00:24 +0000 | [diff] [blame] | 1055 | else if (!locksetContainsAtLeast(Mutex, LK)) |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1056 | Handler.handleMutexNotHeld(D, POK, Mutex.getName(), LK, Exp->getExprLoc()); |
| 1057 | } |
| 1058 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1059 | /// \brief This method identifies variable dereferences and checks pt_guarded_by |
| 1060 | /// and pt_guarded_var annotations. Note that we only check these annotations |
| 1061 | /// at the time a pointer is dereferenced. |
| 1062 | /// FIXME: We need to check for other types of pointer dereferences |
| 1063 | /// (e.g. [], ->) and deal with them here. |
| 1064 | /// \param Exp An expression that has been read or written. |
| 1065 | void BuildLockset::checkDereference(Expr *Exp, AccessKind AK) { |
| 1066 | UnaryOperator *UO = dyn_cast<UnaryOperator>(Exp); |
| 1067 | if (!UO || UO->getOpcode() != clang::UO_Deref) |
| 1068 | return; |
| 1069 | Exp = UO->getSubExpr()->IgnoreParenCasts(); |
| 1070 | |
| 1071 | const ValueDecl *D = getValueDecl(Exp); |
| 1072 | if(!D || !D->hasAttrs()) |
| 1073 | return; |
| 1074 | |
| 1075 | if (D->getAttr<PtGuardedVarAttr>() && LSet.isEmpty()) |
| 1076 | Handler.handleNoMutexHeld(D, POK_VarDereference, AK, Exp->getExprLoc()); |
| 1077 | |
| 1078 | const AttrVec &ArgAttrs = D->getAttrs(); |
| 1079 | for(unsigned i = 0, Size = ArgAttrs.size(); i < Size; ++i) |
| 1080 | if (PtGuardedByAttr *PGBAttr = dyn_cast<PtGuardedByAttr>(ArgAttrs[i])) |
| 1081 | warnIfMutexNotHeld(D, Exp, AK, PGBAttr->getArg(), POK_VarDereference); |
| 1082 | } |
| 1083 | |
| 1084 | /// \brief Checks guarded_by and guarded_var attributes. |
| 1085 | /// Whenever we identify an access (read or write) of a DeclRefExpr or |
| 1086 | /// MemberExpr, we need to check whether there are any guarded_by or |
| 1087 | /// guarded_var attributes, and make sure we hold the appropriate mutexes. |
| 1088 | void BuildLockset::checkAccess(Expr *Exp, AccessKind AK) { |
| 1089 | const ValueDecl *D = getValueDecl(Exp); |
| 1090 | if(!D || !D->hasAttrs()) |
| 1091 | return; |
| 1092 | |
| 1093 | if (D->getAttr<GuardedVarAttr>() && LSet.isEmpty()) |
| 1094 | Handler.handleNoMutexHeld(D, POK_VarAccess, AK, Exp->getExprLoc()); |
| 1095 | |
| 1096 | const AttrVec &ArgAttrs = D->getAttrs(); |
| 1097 | for(unsigned i = 0, Size = ArgAttrs.size(); i < Size; ++i) |
| 1098 | if (GuardedByAttr *GBAttr = dyn_cast<GuardedByAttr>(ArgAttrs[i])) |
| 1099 | warnIfMutexNotHeld(D, Exp, AK, GBAttr->getArg(), POK_VarAccess); |
| 1100 | } |
| 1101 | |
DeLesley Hutchins | e0eaa85 | 2011-10-21 18:06:53 +0000 | [diff] [blame] | 1102 | /// \brief Process a function call, method call, constructor call, |
| 1103 | /// or destructor call. This involves looking at the attributes on the |
| 1104 | /// corresponding function/method/constructor/destructor, issuing warnings, |
| 1105 | /// and updating the locksets accordingly. |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1106 | /// |
| 1107 | /// FIXME: For classes annotated with one of the guarded annotations, we need |
| 1108 | /// to treat const method calls as reads and non-const method calls as writes, |
| 1109 | /// and check that the appropriate locks are held. Non-const method calls with |
| 1110 | /// the same signature as const method calls can be also treated as reads. |
| 1111 | /// |
| 1112 | /// FIXME: We need to also visit CallExprs to catch/check global functions. |
Caitlin Sadowski | 1748b12 | 2011-09-16 00:35:54 +0000 | [diff] [blame] | 1113 | /// |
| 1114 | /// FIXME: Do not flag an error for member variables accessed in constructors/ |
| 1115 | /// destructors |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 1116 | void BuildLockset::handleCall(Expr *Exp, NamedDecl *D, VarDecl *VD) { |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1117 | AttrVec &ArgAttrs = D->getAttrs(); |
| 1118 | for(unsigned i = 0; i < ArgAttrs.size(); ++i) { |
| 1119 | Attr *Attr = ArgAttrs[i]; |
| 1120 | switch (Attr->getKind()) { |
| 1121 | // When we encounter an exclusive lock function, we need to add the lock |
| 1122 | // to our lockset with kind exclusive. |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 1123 | case attr::ExclusiveLockFunction: { |
| 1124 | ExclusiveLockFunctionAttr *A = cast<ExclusiveLockFunctionAttr>(Attr); |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 1125 | addLocksToSet(LK_Exclusive, A, Exp, D, VD); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1126 | break; |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 1127 | } |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1128 | |
| 1129 | // When we encounter a shared lock function, we need to add the lock |
| 1130 | // to our lockset with kind shared. |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 1131 | case attr::SharedLockFunction: { |
| 1132 | SharedLockFunctionAttr *A = cast<SharedLockFunctionAttr>(Attr); |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 1133 | addLocksToSet(LK_Shared, A, Exp, D, VD); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1134 | break; |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 1135 | } |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1136 | |
| 1137 | // When we encounter an unlock function, we need to remove unlocked |
| 1138 | // mutexes from the lockset, and flag a warning if they are not there. |
| 1139 | case attr::UnlockFunction: { |
| 1140 | UnlockFunctionAttr *UFAttr = cast<UnlockFunctionAttr>(Attr); |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 1141 | removeLocksFromSet(UFAttr, Exp, D); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1142 | break; |
| 1143 | } |
| 1144 | |
| 1145 | case attr::ExclusiveLocksRequired: { |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1146 | ExclusiveLocksRequiredAttr *ELRAttr = |
| 1147 | cast<ExclusiveLocksRequiredAttr>(Attr); |
| 1148 | |
| 1149 | for (ExclusiveLocksRequiredAttr::args_iterator |
| 1150 | I = ELRAttr->args_begin(), E = ELRAttr->args_end(); I != E; ++I) |
| 1151 | warnIfMutexNotHeld(D, Exp, AK_Written, *I, POK_FunctionCall); |
| 1152 | break; |
| 1153 | } |
| 1154 | |
| 1155 | case attr::SharedLocksRequired: { |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1156 | SharedLocksRequiredAttr *SLRAttr = cast<SharedLocksRequiredAttr>(Attr); |
| 1157 | |
| 1158 | for (SharedLocksRequiredAttr::args_iterator I = SLRAttr->args_begin(), |
| 1159 | E = SLRAttr->args_end(); I != E; ++I) |
| 1160 | warnIfMutexNotHeld(D, Exp, AK_Read, *I, POK_FunctionCall); |
| 1161 | break; |
| 1162 | } |
| 1163 | |
| 1164 | case attr::LocksExcluded: { |
| 1165 | LocksExcludedAttr *LEAttr = cast<LocksExcludedAttr>(Attr); |
| 1166 | for (LocksExcludedAttr::args_iterator I = LEAttr->args_begin(), |
| 1167 | E = LEAttr->args_end(); I != E; ++I) { |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 1168 | MutexID Mutex(*I, Exp, D); |
Caitlin Sadowski | 194418f | 2011-09-14 20:00:24 +0000 | [diff] [blame] | 1169 | if (!Mutex.isValid()) |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 1170 | MutexID::warnInvalidLock(Handler, *I, Exp, D); |
Caitlin Sadowski | 194418f | 2011-09-14 20:00:24 +0000 | [diff] [blame] | 1171 | else if (locksetContains(Mutex)) |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1172 | Handler.handleFunExcludesLock(D->getName(), Mutex.getName(), |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 1173 | Exp->getExprLoc()); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1174 | } |
| 1175 | break; |
| 1176 | } |
| 1177 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1178 | // Ignore other (non thread-safety) attributes |
| 1179 | default: |
| 1180 | break; |
| 1181 | } |
| 1182 | } |
| 1183 | } |
| 1184 | |
DeLesley Hutchins | b4fa418 | 2012-01-06 19:16:50 +0000 | [diff] [blame] | 1185 | |
| 1186 | /// \brief Add lock to set, if the current block is in the taken branch of a |
| 1187 | /// trylock. |
| 1188 | template <class AttrType> |
| 1189 | void BuildLockset::addTrylock(LockKind LK, AttrType *Attr, Expr *Exp, |
| 1190 | NamedDecl *FunDecl, const CFGBlock *PredBlock, |
| 1191 | const CFGBlock *CurrBlock, Expr *BrE, bool Neg) { |
| 1192 | // Find out which branch has the lock |
| 1193 | bool branch = 0; |
| 1194 | if (CXXBoolLiteralExpr *BLE = dyn_cast_or_null<CXXBoolLiteralExpr>(BrE)) { |
| 1195 | branch = BLE->getValue(); |
| 1196 | } |
| 1197 | else if (IntegerLiteral *ILE = dyn_cast_or_null<IntegerLiteral>(BrE)) { |
| 1198 | branch = ILE->getValue().getBoolValue(); |
| 1199 | } |
| 1200 | int branchnum = branch ? 0 : 1; |
| 1201 | if (Neg) branchnum = !branchnum; |
| 1202 | |
| 1203 | // If we've taken the trylock branch, then add the lock |
| 1204 | int i = 0; |
| 1205 | for (CFGBlock::const_succ_iterator SI = PredBlock->succ_begin(), |
| 1206 | SE = PredBlock->succ_end(); SI != SE && i < 2; ++SI, ++i) { |
| 1207 | if (*SI == CurrBlock && i == branchnum) { |
| 1208 | addLocksToSet(LK, Attr, Exp, FunDecl, 0); |
| 1209 | } |
| 1210 | } |
| 1211 | } |
| 1212 | |
| 1213 | |
| 1214 | // If Cond can be traced back to a function call, return the call expression. |
| 1215 | // The negate variable should be called with false, and will be set to true |
| 1216 | // if the function call is negated, e.g. if (!mu.tryLock(...)) |
| 1217 | CallExpr* BuildLockset::getTrylockCallExpr(Stmt *Cond, |
| 1218 | LocalVariableMap::Context C, |
| 1219 | bool &Negate) { |
| 1220 | if (!Cond) |
| 1221 | return 0; |
| 1222 | |
| 1223 | if (CallExpr *CallExp = dyn_cast<CallExpr>(Cond)) { |
| 1224 | return CallExp; |
| 1225 | } |
| 1226 | else if (ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(Cond)) { |
| 1227 | return getTrylockCallExpr(CE->getSubExpr(), C, Negate); |
| 1228 | } |
| 1229 | else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Cond)) { |
| 1230 | Expr *E = LocalVarMap.lookupExpr(DRE->getDecl(), C); |
| 1231 | return getTrylockCallExpr(E, C, Negate); |
| 1232 | } |
| 1233 | else if (UnaryOperator *UOP = dyn_cast<UnaryOperator>(Cond)) { |
| 1234 | if (UOP->getOpcode() == UO_LNot) { |
| 1235 | Negate = !Negate; |
| 1236 | return getTrylockCallExpr(UOP->getSubExpr(), C, Negate); |
| 1237 | } |
| 1238 | } |
| 1239 | // FIXME -- handle && and || as well. |
| 1240 | return NULL; |
| 1241 | } |
| 1242 | |
| 1243 | |
| 1244 | /// \brief Process a conditional branch from a previous block to the current |
| 1245 | /// block, looking for trylock calls. |
| 1246 | void BuildLockset::handleTrylock(Stmt *Cond, const CFGBlock *PredBlock, |
| 1247 | const CFGBlock *CurrBlock) { |
| 1248 | bool Negate = false; |
| 1249 | CallExpr *Exp = getTrylockCallExpr(Cond, LVarCtx, Negate); |
| 1250 | if (!Exp) |
| 1251 | return; |
| 1252 | |
| 1253 | NamedDecl *FunDecl = dyn_cast_or_null<NamedDecl>(Exp->getCalleeDecl()); |
| 1254 | if(!FunDecl || !FunDecl->hasAttrs()) |
| 1255 | return; |
| 1256 | |
| 1257 | // If the condition is a call to a Trylock function, then grab the attributes |
| 1258 | AttrVec &ArgAttrs = FunDecl->getAttrs(); |
| 1259 | for (unsigned i = 0; i < ArgAttrs.size(); ++i) { |
| 1260 | Attr *Attr = ArgAttrs[i]; |
| 1261 | switch (Attr->getKind()) { |
| 1262 | case attr::ExclusiveTrylockFunction: { |
| 1263 | ExclusiveTrylockFunctionAttr *A = |
| 1264 | cast<ExclusiveTrylockFunctionAttr>(Attr); |
| 1265 | addTrylock(LK_Exclusive, A, Exp, FunDecl, PredBlock, CurrBlock, |
| 1266 | A->getSuccessValue(), Negate); |
| 1267 | break; |
| 1268 | } |
| 1269 | case attr::SharedTrylockFunction: { |
| 1270 | SharedTrylockFunctionAttr *A = |
| 1271 | cast<SharedTrylockFunctionAttr>(Attr); |
| 1272 | addTrylock(LK_Shared, A, Exp, FunDecl, PredBlock, CurrBlock, |
| 1273 | A->getSuccessValue(), Negate); |
| 1274 | break; |
| 1275 | } |
| 1276 | default: |
| 1277 | break; |
| 1278 | } |
| 1279 | } |
| 1280 | } |
| 1281 | |
| 1282 | |
DeLesley Hutchins | e0eaa85 | 2011-10-21 18:06:53 +0000 | [diff] [blame] | 1283 | /// \brief For unary operations which read and write a variable, we need to |
| 1284 | /// check whether we hold any required mutexes. Reads are checked in |
| 1285 | /// VisitCastExpr. |
| 1286 | void BuildLockset::VisitUnaryOperator(UnaryOperator *UO) { |
| 1287 | switch (UO->getOpcode()) { |
| 1288 | case clang::UO_PostDec: |
| 1289 | case clang::UO_PostInc: |
| 1290 | case clang::UO_PreDec: |
| 1291 | case clang::UO_PreInc: { |
| 1292 | Expr *SubExp = UO->getSubExpr()->IgnoreParenCasts(); |
| 1293 | checkAccess(SubExp, AK_Written); |
| 1294 | checkDereference(SubExp, AK_Written); |
| 1295 | break; |
| 1296 | } |
| 1297 | default: |
| 1298 | break; |
| 1299 | } |
| 1300 | } |
| 1301 | |
| 1302 | /// For binary operations which assign to a variable (writes), we need to check |
| 1303 | /// whether we hold any required mutexes. |
| 1304 | /// FIXME: Deal with non-primitive types. |
| 1305 | void BuildLockset::VisitBinaryOperator(BinaryOperator *BO) { |
| 1306 | if (!BO->isAssignmentOp()) |
| 1307 | return; |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 1308 | |
| 1309 | // adjust the context |
| 1310 | LVarCtx = LocalVarMap.getNextContext(CtxIndex, BO, LVarCtx); |
| 1311 | |
DeLesley Hutchins | e0eaa85 | 2011-10-21 18:06:53 +0000 | [diff] [blame] | 1312 | Expr *LHSExp = BO->getLHS()->IgnoreParenCasts(); |
| 1313 | checkAccess(LHSExp, AK_Written); |
| 1314 | checkDereference(LHSExp, AK_Written); |
| 1315 | } |
| 1316 | |
| 1317 | /// Whenever we do an LValue to Rvalue cast, we are reading a variable and |
| 1318 | /// need to ensure we hold any required mutexes. |
| 1319 | /// FIXME: Deal with non-primitive types. |
| 1320 | void BuildLockset::VisitCastExpr(CastExpr *CE) { |
| 1321 | if (CE->getCastKind() != CK_LValueToRValue) |
| 1322 | return; |
| 1323 | Expr *SubExp = CE->getSubExpr()->IgnoreParenCasts(); |
| 1324 | checkAccess(SubExp, AK_Read); |
| 1325 | checkDereference(SubExp, AK_Read); |
| 1326 | } |
| 1327 | |
| 1328 | |
DeLesley Hutchins | df49782 | 2011-12-29 00:56:48 +0000 | [diff] [blame] | 1329 | void BuildLockset::VisitCallExpr(CallExpr *Exp) { |
DeLesley Hutchins | e0eaa85 | 2011-10-21 18:06:53 +0000 | [diff] [blame] | 1330 | NamedDecl *D = dyn_cast_or_null<NamedDecl>(Exp->getCalleeDecl()); |
| 1331 | if(!D || !D->hasAttrs()) |
| 1332 | return; |
| 1333 | handleCall(Exp, D); |
| 1334 | } |
| 1335 | |
| 1336 | void BuildLockset::VisitCXXConstructExpr(CXXConstructExpr *Exp) { |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 1337 | // FIXME -- only handles constructors in DeclStmt below. |
| 1338 | } |
| 1339 | |
| 1340 | void BuildLockset::VisitDeclStmt(DeclStmt *S) { |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 1341 | // adjust the context |
| 1342 | LVarCtx = LocalVarMap.getNextContext(CtxIndex, S, LVarCtx); |
| 1343 | |
DeLesley Hutchins | 1fa3c06 | 2011-12-08 20:23:06 +0000 | [diff] [blame] | 1344 | DeclGroupRef DGrp = S->getDeclGroup(); |
| 1345 | for (DeclGroupRef::iterator I = DGrp.begin(), E = DGrp.end(); I != E; ++I) { |
| 1346 | Decl *D = *I; |
| 1347 | if (VarDecl *VD = dyn_cast_or_null<VarDecl>(D)) { |
| 1348 | Expr *E = VD->getInit(); |
| 1349 | if (CXXConstructExpr *CE = dyn_cast_or_null<CXXConstructExpr>(E)) { |
| 1350 | NamedDecl *CtorD = dyn_cast_or_null<NamedDecl>(CE->getConstructor()); |
| 1351 | if (!CtorD || !CtorD->hasAttrs()) |
| 1352 | return; |
| 1353 | handleCall(CE, CtorD, VD); |
| 1354 | } |
| 1355 | } |
| 1356 | } |
DeLesley Hutchins | e0eaa85 | 2011-10-21 18:06:53 +0000 | [diff] [blame] | 1357 | } |
| 1358 | |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 1359 | |
Caitlin Sadowski | 4e4bc75 | 2011-09-15 17:25:19 +0000 | [diff] [blame] | 1360 | /// \brief Compute the intersection of two locksets and issue warnings for any |
| 1361 | /// locks in the symmetric difference. |
| 1362 | /// |
| 1363 | /// This function is used at a merge point in the CFG when comparing the lockset |
| 1364 | /// of each branch being merged. For example, given the following sequence: |
| 1365 | /// A; if () then B; else C; D; we need to check that the lockset after B and C |
| 1366 | /// are the same. In the event of a difference, we use the intersection of these |
| 1367 | /// two locksets at the start of D. |
Richard Smith | 2e51562 | 2012-02-03 04:45:26 +0000 | [diff] [blame] | 1368 | Lockset ThreadSafetyAnalyzer::intersectAndWarn(const CFGBlockInfo &Block1, |
| 1369 | CFGBlockSide Side1, |
| 1370 | const CFGBlockInfo &Block2, |
| 1371 | CFGBlockSide Side2, |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 1372 | LockErrorKind LEK) { |
Richard Smith | 2e51562 | 2012-02-03 04:45:26 +0000 | [diff] [blame] | 1373 | Lockset LSet1 = Block1.getSet(Side1); |
| 1374 | Lockset LSet2 = Block2.getSet(Side2); |
| 1375 | |
Caitlin Sadowski | 4e4bc75 | 2011-09-15 17:25:19 +0000 | [diff] [blame] | 1376 | Lockset Intersection = LSet1; |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1377 | for (Lockset::iterator I = LSet2.begin(), E = LSet2.end(); I != E; ++I) { |
| 1378 | const MutexID &LSet2Mutex = I.getKey(); |
| 1379 | const LockData &LSet2LockData = I.getData(); |
| 1380 | if (const LockData *LD = LSet1.lookup(LSet2Mutex)) { |
| 1381 | if (LD->LKind != LSet2LockData.LKind) { |
| 1382 | Handler.handleExclusiveAndShared(LSet2Mutex.getName(), |
| 1383 | LSet2LockData.AcquireLoc, |
| 1384 | LD->AcquireLoc); |
| 1385 | if (LD->LKind != LK_Exclusive) |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 1386 | Intersection = LocksetFactory.add(Intersection, LSet2Mutex, |
| 1387 | LSet2LockData); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1388 | } |
| 1389 | } else { |
| 1390 | Handler.handleMutexHeldEndOfScope(LSet2Mutex.getName(), |
Richard Smith | 2e51562 | 2012-02-03 04:45:26 +0000 | [diff] [blame] | 1391 | LSet2LockData.AcquireLoc, |
| 1392 | Block1.getLocation(Side1), LEK); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1393 | } |
| 1394 | } |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1395 | |
| 1396 | for (Lockset::iterator I = LSet1.begin(), E = LSet1.end(); I != E; ++I) { |
| 1397 | if (!LSet2.contains(I.getKey())) { |
| 1398 | const MutexID &Mutex = I.getKey(); |
| 1399 | const LockData &MissingLock = I.getData(); |
| 1400 | Handler.handleMutexHeldEndOfScope(Mutex.getName(), |
Richard Smith | 2e51562 | 2012-02-03 04:45:26 +0000 | [diff] [blame] | 1401 | MissingLock.AcquireLoc, |
| 1402 | Block2.getLocation(Side2), LEK); |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 1403 | Intersection = LocksetFactory.remove(Intersection, Mutex); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1404 | } |
| 1405 | } |
| 1406 | return Intersection; |
| 1407 | } |
| 1408 | |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 1409 | Lockset ThreadSafetyAnalyzer::addLock(Lockset &LSet, Expr *MutexExp, |
| 1410 | const NamedDecl *D, |
| 1411 | LockKind LK, SourceLocation Loc) { |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 1412 | MutexID Mutex(MutexExp, 0, D); |
Caitlin Sadowski | cb96751 | 2011-09-15 17:43:08 +0000 | [diff] [blame] | 1413 | if (!Mutex.isValid()) { |
DeLesley Hutchins | f1ac637 | 2011-10-21 18:10:14 +0000 | [diff] [blame] | 1414 | MutexID::warnInvalidLock(Handler, MutexExp, 0, D); |
Caitlin Sadowski | cb96751 | 2011-09-15 17:43:08 +0000 | [diff] [blame] | 1415 | return LSet; |
| 1416 | } |
| 1417 | LockData NewLock(Loc, LK); |
| 1418 | return LocksetFactory.add(LSet, Mutex, NewLock); |
| 1419 | } |
| 1420 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1421 | /// \brief Check a function's CFG for thread-safety violations. |
| 1422 | /// |
| 1423 | /// We traverse the blocks in the CFG, compute the set of mutexes that are held |
| 1424 | /// at the end of each block, and issue warnings for thread safety violations. |
| 1425 | /// Each block in the CFG is traversed exactly once. |
Ted Kremenek | 1d26f48 | 2011-10-24 01:32:45 +0000 | [diff] [blame] | 1426 | void ThreadSafetyAnalyzer::runAnalysis(AnalysisDeclContext &AC) { |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1427 | CFG *CFGraph = AC.getCFG(); |
| 1428 | if (!CFGraph) return; |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 1429 | const NamedDecl *D = dyn_cast_or_null<NamedDecl>(AC.getDecl()); |
| 1430 | |
| 1431 | if (!D) |
| 1432 | return; // Ignore anonymous functions for now. |
| 1433 | if (D->getAttr<NoThreadSafetyAnalysisAttr>()) |
| 1434 | return; |
DeLesley Hutchins | 2f13bec | 2012-02-16 17:13:43 +0000 | [diff] [blame] | 1435 | // FIXME: Do something a bit more intelligent inside constructor and |
| 1436 | // destructor code. Constructors and destructors must assume unique access |
| 1437 | // to 'this', so checks on member variable access is disabled, but we should |
| 1438 | // still enable checks on other objects. |
| 1439 | if (isa<CXXConstructorDecl>(D)) |
| 1440 | return; // Don't check inside constructors. |
| 1441 | if (isa<CXXDestructorDecl>(D)) |
| 1442 | return; // Don't check inside destructors. |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1443 | |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 1444 | std::vector<CFGBlockInfo> BlockInfo(CFGraph->getNumBlockIDs(), |
| 1445 | CFGBlockInfo::getEmptyBlockInfo(LocksetFactory, LocalVarMap)); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1446 | |
| 1447 | // We need to explore the CFG via a "topological" ordering. |
| 1448 | // That way, we will be guaranteed to have information about required |
| 1449 | // predecessor locksets when exploring a new block. |
Ted Kremenek | 439ed16 | 2011-10-22 02:14:27 +0000 | [diff] [blame] | 1450 | PostOrderCFGView *SortedGraph = AC.getAnalysis<PostOrderCFGView>(); |
| 1451 | PostOrderCFGView::CFGBlockSet VisitedBlocks(CFGraph); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1452 | |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 1453 | // Compute SSA names for local variables |
| 1454 | LocalVarMap.traverseCFG(CFGraph, SortedGraph, BlockInfo); |
| 1455 | |
Richard Smith | 2e51562 | 2012-02-03 04:45:26 +0000 | [diff] [blame] | 1456 | // Fill in source locations for all CFGBlocks. |
| 1457 | findBlockLocations(CFGraph, SortedGraph, BlockInfo); |
| 1458 | |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 1459 | // Add locks from exclusive_locks_required and shared_locks_required |
DeLesley Hutchins | 2f13bec | 2012-02-16 17:13:43 +0000 | [diff] [blame] | 1460 | // to initial lockset. Also turn off checking for lock and unlock functions. |
| 1461 | // FIXME: is there a more intelligent way to check lock/unlock functions? |
Ted Kremenek | 439ed16 | 2011-10-22 02:14:27 +0000 | [diff] [blame] | 1462 | if (!SortedGraph->empty() && D->hasAttrs()) { |
| 1463 | const CFGBlock *FirstBlock = *SortedGraph->begin(); |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 1464 | Lockset &InitialLockset = BlockInfo[FirstBlock->getBlockID()].EntrySet; |
Caitlin Sadowski | cb96751 | 2011-09-15 17:43:08 +0000 | [diff] [blame] | 1465 | const AttrVec &ArgAttrs = D->getAttrs(); |
DeLesley Hutchins | 2f13bec | 2012-02-16 17:13:43 +0000 | [diff] [blame] | 1466 | for (unsigned i = 0; i < ArgAttrs.size(); ++i) { |
Caitlin Sadowski | cb96751 | 2011-09-15 17:43:08 +0000 | [diff] [blame] | 1467 | Attr *Attr = ArgAttrs[i]; |
Caitlin Sadowski | 1748b12 | 2011-09-16 00:35:54 +0000 | [diff] [blame] | 1468 | SourceLocation AttrLoc = Attr->getLocation(); |
Caitlin Sadowski | cb96751 | 2011-09-15 17:43:08 +0000 | [diff] [blame] | 1469 | if (SharedLocksRequiredAttr *SLRAttr |
| 1470 | = dyn_cast<SharedLocksRequiredAttr>(Attr)) { |
| 1471 | for (SharedLocksRequiredAttr::args_iterator |
DeLesley Hutchins | 2f13bec | 2012-02-16 17:13:43 +0000 | [diff] [blame] | 1472 | SLRIter = SLRAttr->args_begin(), |
| 1473 | SLREnd = SLRAttr->args_end(); SLRIter != SLREnd; ++SLRIter) |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 1474 | InitialLockset = addLock(InitialLockset, |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 1475 | *SLRIter, D, LK_Shared, |
Caitlin Sadowski | 1748b12 | 2011-09-16 00:35:54 +0000 | [diff] [blame] | 1476 | AttrLoc); |
Caitlin Sadowski | cb96751 | 2011-09-15 17:43:08 +0000 | [diff] [blame] | 1477 | } else if (ExclusiveLocksRequiredAttr *ELRAttr |
| 1478 | = dyn_cast<ExclusiveLocksRequiredAttr>(Attr)) { |
| 1479 | for (ExclusiveLocksRequiredAttr::args_iterator |
DeLesley Hutchins | 2f13bec | 2012-02-16 17:13:43 +0000 | [diff] [blame] | 1480 | ELRIter = ELRAttr->args_begin(), |
| 1481 | ELREnd = ELRAttr->args_end(); ELRIter != ELREnd; ++ELRIter) |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 1482 | InitialLockset = addLock(InitialLockset, |
DeLesley Hutchins | 9f80a97 | 2011-10-17 21:33:35 +0000 | [diff] [blame] | 1483 | *ELRIter, D, LK_Exclusive, |
Caitlin Sadowski | 1748b12 | 2011-09-16 00:35:54 +0000 | [diff] [blame] | 1484 | AttrLoc); |
DeLesley Hutchins | 2f13bec | 2012-02-16 17:13:43 +0000 | [diff] [blame] | 1485 | } else if (isa<UnlockFunctionAttr>(Attr)) { |
| 1486 | // Don't try to check unlock functions for now |
| 1487 | return; |
| 1488 | } else if (isa<ExclusiveLockFunctionAttr>(Attr)) { |
| 1489 | // Don't try to check lock functions for now |
| 1490 | return; |
| 1491 | } else if (isa<SharedLockFunctionAttr>(Attr)) { |
| 1492 | // Don't try to check lock functions for now |
| 1493 | return; |
Caitlin Sadowski | cb96751 | 2011-09-15 17:43:08 +0000 | [diff] [blame] | 1494 | } |
| 1495 | } |
| 1496 | } |
| 1497 | |
Ted Kremenek | 439ed16 | 2011-10-22 02:14:27 +0000 | [diff] [blame] | 1498 | for (PostOrderCFGView::iterator I = SortedGraph->begin(), |
| 1499 | E = SortedGraph->end(); I!= E; ++I) { |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1500 | const CFGBlock *CurrBlock = *I; |
| 1501 | int CurrBlockID = CurrBlock->getBlockID(); |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 1502 | CFGBlockInfo *CurrBlockInfo = &BlockInfo[CurrBlockID]; |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1503 | |
| 1504 | // Use the default initial lockset in case there are no predecessors. |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 1505 | VisitedBlocks.insert(CurrBlock); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1506 | |
| 1507 | // Iterate through the predecessor blocks and warn if the lockset for all |
| 1508 | // predecessors is not the same. We take the entry lockset of the current |
| 1509 | // block to be the intersection of all previous locksets. |
| 1510 | // FIXME: By keeping the intersection, we may output more errors in future |
| 1511 | // for a lock which is not in the intersection, but was in the union. We |
| 1512 | // may want to also keep the union in future. As an example, let's say |
| 1513 | // the intersection contains Mutex L, and the union contains L and M. |
| 1514 | // Later we unlock M. At this point, we would output an error because we |
| 1515 | // never locked M; although the real error is probably that we forgot to |
| 1516 | // lock M on all code paths. Conversely, let's say that later we lock M. |
| 1517 | // In this case, we should compare against the intersection instead of the |
| 1518 | // union because the real error is probably that we forgot to unlock M on |
| 1519 | // all code paths. |
| 1520 | bool LocksetInitialized = false; |
Richard Smith | aacde71 | 2012-02-03 03:30:07 +0000 | [diff] [blame] | 1521 | llvm::SmallVector<CFGBlock*, 8> SpecialBlocks; |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1522 | for (CFGBlock::const_pred_iterator PI = CurrBlock->pred_begin(), |
| 1523 | PE = CurrBlock->pred_end(); PI != PE; ++PI) { |
| 1524 | |
| 1525 | // if *PI -> CurrBlock is a back edge |
| 1526 | if (*PI == 0 || !VisitedBlocks.alreadySet(*PI)) |
| 1527 | continue; |
| 1528 | |
Richard Smith | aacde71 | 2012-02-03 03:30:07 +0000 | [diff] [blame] | 1529 | // If the previous block ended in a 'continue' or 'break' statement, then |
| 1530 | // a difference in locksets is probably due to a bug in that block, rather |
| 1531 | // than in some other predecessor. In that case, keep the other |
| 1532 | // predecessor's lockset. |
| 1533 | if (const Stmt *Terminator = (*PI)->getTerminator()) { |
| 1534 | if (isa<ContinueStmt>(Terminator) || isa<BreakStmt>(Terminator)) { |
| 1535 | SpecialBlocks.push_back(*PI); |
| 1536 | continue; |
| 1537 | } |
| 1538 | } |
| 1539 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1540 | int PrevBlockID = (*PI)->getBlockID(); |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 1541 | CFGBlockInfo *PrevBlockInfo = &BlockInfo[PrevBlockID]; |
| 1542 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1543 | if (!LocksetInitialized) { |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 1544 | CurrBlockInfo->EntrySet = PrevBlockInfo->ExitSet; |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1545 | LocksetInitialized = true; |
| 1546 | } else { |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 1547 | CurrBlockInfo->EntrySet = |
Richard Smith | 2e51562 | 2012-02-03 04:45:26 +0000 | [diff] [blame] | 1548 | intersectAndWarn(*CurrBlockInfo, CBS_Entry, |
| 1549 | *PrevBlockInfo, CBS_Exit, |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 1550 | LEK_LockedSomePredecessors); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1551 | } |
| 1552 | } |
| 1553 | |
Richard Smith | aacde71 | 2012-02-03 03:30:07 +0000 | [diff] [blame] | 1554 | // Process continue and break blocks. Assume that the lockset for the |
| 1555 | // resulting block is unaffected by any discrepancies in them. |
| 1556 | for (unsigned SpecialI = 0, SpecialN = SpecialBlocks.size(); |
| 1557 | SpecialI < SpecialN; ++SpecialI) { |
| 1558 | CFGBlock *PrevBlock = SpecialBlocks[SpecialI]; |
| 1559 | int PrevBlockID = PrevBlock->getBlockID(); |
| 1560 | CFGBlockInfo *PrevBlockInfo = &BlockInfo[PrevBlockID]; |
| 1561 | |
| 1562 | if (!LocksetInitialized) { |
| 1563 | CurrBlockInfo->EntrySet = PrevBlockInfo->ExitSet; |
| 1564 | LocksetInitialized = true; |
| 1565 | } else { |
| 1566 | // Determine whether this edge is a loop terminator for diagnostic |
| 1567 | // purposes. FIXME: A 'break' statement might be a loop terminator, but |
| 1568 | // it might also be part of a switch. Also, a subsequent destructor |
| 1569 | // might add to the lockset, in which case the real issue might be a |
| 1570 | // double lock on the other path. |
| 1571 | const Stmt *Terminator = PrevBlock->getTerminator(); |
| 1572 | bool IsLoop = Terminator && isa<ContinueStmt>(Terminator); |
| 1573 | |
| 1574 | // Do not update EntrySet. |
Richard Smith | 2e51562 | 2012-02-03 04:45:26 +0000 | [diff] [blame] | 1575 | intersectAndWarn(*CurrBlockInfo, CBS_Entry, *PrevBlockInfo, CBS_Exit, |
Richard Smith | aacde71 | 2012-02-03 03:30:07 +0000 | [diff] [blame] | 1576 | IsLoop ? LEK_LockedSomeLoopIterations |
| 1577 | : LEK_LockedSomePredecessors); |
| 1578 | } |
| 1579 | } |
| 1580 | |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 1581 | BuildLockset LocksetBuilder(this, *CurrBlockInfo); |
DeLesley Hutchins | b4fa418 | 2012-01-06 19:16:50 +0000 | [diff] [blame] | 1582 | CFGBlock::const_pred_iterator PI = CurrBlock->pred_begin(), |
| 1583 | PE = CurrBlock->pred_end(); |
| 1584 | if (PI != PE) { |
| 1585 | // If the predecessor ended in a branch, then process any trylocks. |
| 1586 | // FIXME -- check to make sure there's only one predecessor. |
| 1587 | if (Stmt *TCE = (*PI)->getTerminatorCondition()) { |
| 1588 | LocksetBuilder.handleTrylock(TCE, *PI, CurrBlock); |
| 1589 | } |
| 1590 | } |
| 1591 | |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 1592 | // Visit all the statements in the basic block. |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1593 | for (CFGBlock::const_iterator BI = CurrBlock->begin(), |
| 1594 | BE = CurrBlock->end(); BI != BE; ++BI) { |
DeLesley Hutchins | 6db51f7 | 2011-10-21 20:51:27 +0000 | [diff] [blame] | 1595 | switch (BI->getKind()) { |
| 1596 | case CFGElement::Statement: { |
| 1597 | const CFGStmt *CS = cast<CFGStmt>(&*BI); |
| 1598 | LocksetBuilder.Visit(const_cast<Stmt*>(CS->getStmt())); |
| 1599 | break; |
| 1600 | } |
| 1601 | // Ignore BaseDtor, MemberDtor, and TemporaryDtor for now. |
| 1602 | case CFGElement::AutomaticObjectDtor: { |
| 1603 | const CFGAutomaticObjDtor *AD = cast<CFGAutomaticObjDtor>(&*BI); |
| 1604 | CXXDestructorDecl *DD = const_cast<CXXDestructorDecl*>( |
| 1605 | AD->getDestructorDecl(AC.getASTContext())); |
| 1606 | if (!DD->hasAttrs()) |
| 1607 | break; |
| 1608 | |
| 1609 | // Create a dummy expression, |
| 1610 | VarDecl *VD = const_cast<VarDecl*>(AD->getVarDecl()); |
| 1611 | DeclRefExpr DRE(VD, VD->getType(), VK_LValue, |
| 1612 | AD->getTriggerStmt()->getLocEnd()); |
| 1613 | LocksetBuilder.handleCall(&DRE, DD); |
| 1614 | break; |
| 1615 | } |
| 1616 | default: |
| 1617 | break; |
| 1618 | } |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1619 | } |
DeLesley Hutchins | b37d2b5 | 2012-01-06 18:36:09 +0000 | [diff] [blame] | 1620 | CurrBlockInfo->ExitSet = LocksetBuilder.LSet; |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1621 | |
| 1622 | // For every back edge from CurrBlock (the end of the loop) to another block |
| 1623 | // (FirstLoopBlock) we need to check that the Lockset of Block is equal to |
| 1624 | // the one held at the beginning of FirstLoopBlock. We can look up the |
| 1625 | // Lockset held at the beginning of FirstLoopBlock in the EntryLockSets map. |
| 1626 | for (CFGBlock::const_succ_iterator SI = CurrBlock->succ_begin(), |
| 1627 | SE = CurrBlock->succ_end(); SI != SE; ++SI) { |
| 1628 | |
| 1629 | // if CurrBlock -> *SI is *not* a back edge |
| 1630 | if (*SI == 0 || !VisitedBlocks.alreadySet(*SI)) |
| 1631 | continue; |
| 1632 | |
| 1633 | CFGBlock *FirstLoopBlock = *SI; |
Richard Smith | 2e51562 | 2012-02-03 04:45:26 +0000 | [diff] [blame] | 1634 | CFGBlockInfo &PreLoop = BlockInfo[FirstLoopBlock->getBlockID()]; |
| 1635 | CFGBlockInfo &LoopEnd = BlockInfo[CurrBlockID]; |
| 1636 | intersectAndWarn(LoopEnd, CBS_Exit, PreLoop, CBS_Entry, |
| 1637 | LEK_LockedSomeLoopIterations); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1638 | } |
| 1639 | } |
| 1640 | |
Richard Smith | 2e51562 | 2012-02-03 04:45:26 +0000 | [diff] [blame] | 1641 | CFGBlockInfo &Initial = BlockInfo[CFGraph->getEntry().getBlockID()]; |
| 1642 | CFGBlockInfo &Final = BlockInfo[CFGraph->getExit().getBlockID()]; |
Caitlin Sadowski | 1748b12 | 2011-09-16 00:35:54 +0000 | [diff] [blame] | 1643 | |
| 1644 | // FIXME: Should we call this function for all blocks which exit the function? |
Richard Smith | 2e51562 | 2012-02-03 04:45:26 +0000 | [diff] [blame] | 1645 | intersectAndWarn(Initial, CBS_Entry, Final, CBS_Exit, |
| 1646 | LEK_LockedAtEndOfFunction); |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 1647 | } |
| 1648 | |
| 1649 | } // end anonymous namespace |
| 1650 | |
| 1651 | |
| 1652 | namespace clang { |
| 1653 | namespace thread_safety { |
| 1654 | |
| 1655 | /// \brief Check a function's CFG for thread-safety violations. |
| 1656 | /// |
| 1657 | /// We traverse the blocks in the CFG, compute the set of mutexes that are held |
| 1658 | /// at the end of each block, and issue warnings for thread safety violations. |
| 1659 | /// Each block in the CFG is traversed exactly once. |
Ted Kremenek | 1d26f48 | 2011-10-24 01:32:45 +0000 | [diff] [blame] | 1660 | void runThreadSafetyAnalysis(AnalysisDeclContext &AC, |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 1661 | ThreadSafetyHandler &Handler) { |
| 1662 | ThreadSafetyAnalyzer Analyzer(Handler); |
| 1663 | Analyzer.runAnalysis(AC); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1664 | } |
| 1665 | |
| 1666 | /// \brief Helper function that returns a LockKind required for the given level |
| 1667 | /// of access. |
| 1668 | LockKind getLockKindFromAccessKind(AccessKind AK) { |
| 1669 | switch (AK) { |
| 1670 | case AK_Read : |
| 1671 | return LK_Shared; |
| 1672 | case AK_Written : |
| 1673 | return LK_Exclusive; |
| 1674 | } |
Benjamin Kramer | afc5b15 | 2011-09-10 21:52:04 +0000 | [diff] [blame] | 1675 | llvm_unreachable("Unknown AccessKind"); |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1676 | } |
DeLesley Hutchins | a60448d | 2011-10-21 16:14:33 +0000 | [diff] [blame] | 1677 | |
Caitlin Sadowski | 402aa06 | 2011-09-09 16:11:56 +0000 | [diff] [blame] | 1678 | }} // end namespace clang::thread_safety |