diff options
Diffstat (limited to 'contrib/llvm/tools/clang/lib/Analysis/ThreadSafety.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/Analysis/ThreadSafety.cpp | 1641 |
1 files changed, 1121 insertions, 520 deletions
diff --git a/contrib/llvm/tools/clang/lib/Analysis/ThreadSafety.cpp b/contrib/llvm/tools/clang/lib/Analysis/ThreadSafety.cpp index 2f7e794..5954682 100644 --- a/contrib/llvm/tools/clang/lib/Analysis/ThreadSafety.cpp +++ b/contrib/llvm/tools/clang/lib/Analysis/ThreadSafety.cpp @@ -26,6 +26,7 @@ #include "clang/AST/StmtVisitor.h" #include "clang/Basic/SourceManager.h" #include "clang/Basic/SourceLocation.h" +#include "clang/Basic/OperatorKinds.h" #include "llvm/ADT/BitVector.h" #include "llvm/ADT/FoldingSet.h" #include "llvm/ADT/ImmutableMap.h" @@ -45,8 +46,15 @@ ThreadSafetyHandler::~ThreadSafetyHandler() {} namespace { -/// \brief A MutexID object uniquely identifies a particular mutex, and -/// is built from an Expr* (i.e. calling a lock function). +/// SExpr implements a simple expression language that is used to store, +/// compare, and pretty-print C++ expressions. Unlike a clang Expr, a SExpr +/// does not capture surface syntax, and it does not distinguish between +/// C++ concepts, like pointers and references, that have no real semantic +/// differences. This simplicity allows SExprs to be meaningfully compared, +/// e.g. +/// (x) = x +/// (*this).foo = this->foo +/// *&a = a /// /// Thread-safety analysis works by comparing lock expressions. Within the /// body of a function, an expression such as "x->foo->bar.mu" will resolve to @@ -59,41 +67,194 @@ namespace { /// /// The current implementation assumes, but does not verify, that multiple uses /// of the same lock expression satisfies these criteria. -/// -/// Clang introduces an additional wrinkle, which is that it is difficult to -/// derive canonical expressions, or compare expressions directly for equality. -/// Thus, we identify a mutex not by an Expr, but by the list of named -/// declarations that are referenced by the Expr. In other words, -/// x->foo->bar.mu will be a four element vector with the Decls for -/// mu, bar, and foo, and x. The vector will uniquely identify the expression -/// for all practical purposes. Null is used to denote 'this'. -/// -/// Note we will need to perform substitution on "this" and function parameter -/// names when constructing a lock expression. -/// -/// For example: -/// class C { Mutex Mu; void lock() EXCLUSIVE_LOCK_FUNCTION(this->Mu); }; -/// void myFunc(C *X) { ... X->lock() ... } -/// The original expression for the mutex acquired by myFunc is "this->Mu", but -/// "X" is substituted for "this" so we get X->Mu(); -/// -/// For another example: -/// foo(MyList *L) EXCLUSIVE_LOCKS_REQUIRED(L->Mu) { ... } -/// MyList *MyL; -/// foo(MyL); // requires lock MyL->Mu to be held -class MutexID { - SmallVector<NamedDecl*, 2> DeclSeq; - - /// Build a Decl sequence representing the lock from the given expression. +class SExpr { +private: + enum ExprOp { + EOP_Nop, //< No-op + EOP_Wildcard, //< Matches anything. + EOP_This, //< This keyword. + EOP_NVar, //< Named variable. + EOP_LVar, //< Local variable. + EOP_Dot, //< Field access + EOP_Call, //< Function call + EOP_MCall, //< Method call + EOP_Index, //< Array index + EOP_Unary, //< Unary operation + EOP_Binary, //< Binary operation + EOP_Unknown //< Catchall for everything else + }; + + + class SExprNode { + private: + unsigned char Op; //< Opcode of the root node + unsigned char Flags; //< Additional opcode-specific data + unsigned short Sz; //< Number of child nodes + const void* Data; //< Additional opcode-specific data + + public: + SExprNode(ExprOp O, unsigned F, const void* D) + : Op(static_cast<unsigned char>(O)), + Flags(static_cast<unsigned char>(F)), Sz(1), Data(D) + { } + + unsigned size() const { return Sz; } + void setSize(unsigned S) { Sz = S; } + + ExprOp kind() const { return static_cast<ExprOp>(Op); } + + const NamedDecl* getNamedDecl() const { + assert(Op == EOP_NVar || Op == EOP_LVar || Op == EOP_Dot); + return reinterpret_cast<const NamedDecl*>(Data); + } + + const NamedDecl* getFunctionDecl() const { + assert(Op == EOP_Call || Op == EOP_MCall); + return reinterpret_cast<const NamedDecl*>(Data); + } + + bool isArrow() const { return Op == EOP_Dot && Flags == 1; } + void setArrow(bool A) { Flags = A ? 1 : 0; } + + unsigned arity() const { + switch (Op) { + case EOP_Nop: return 0; + case EOP_Wildcard: return 0; + case EOP_NVar: return 0; + case EOP_LVar: return 0; + case EOP_This: return 0; + case EOP_Dot: return 1; + case EOP_Call: return Flags+1; // First arg is function. + case EOP_MCall: return Flags+1; // First arg is implicit obj. + case EOP_Index: return 2; + case EOP_Unary: return 1; + case EOP_Binary: return 2; + case EOP_Unknown: return Flags; + } + return 0; + } + + bool operator==(const SExprNode& Other) const { + // Ignore flags and size -- they don't matter. + return (Op == Other.Op && + Data == Other.Data); + } + + bool operator!=(const SExprNode& Other) const { + return !(*this == Other); + } + + bool matches(const SExprNode& Other) const { + return (*this == Other) || + (Op == EOP_Wildcard) || + (Other.Op == EOP_Wildcard); + } + }; + + + /// \brief Encapsulates the lexical context of a function call. The lexical + /// context includes the arguments to the call, including the implicit object + /// argument. When an attribute containing a mutex expression is attached to + /// a method, the expression may refer to formal parameters of the method. + /// Actual arguments must be substituted for formal parameters to derive + /// the appropriate mutex expression in the lexical context where the function + /// is called. PrevCtx holds the context in which the arguments themselves + /// should be evaluated; multiple calling contexts can be chained together + /// by the lock_returned attribute. + struct CallingContext { + const NamedDecl* AttrDecl; // The decl to which the attribute is attached. + Expr* SelfArg; // Implicit object argument -- e.g. 'this' + bool SelfArrow; // is Self referred to with -> or .? + unsigned NumArgs; // Number of funArgs + Expr** FunArgs; // Function arguments + CallingContext* PrevCtx; // The previous context; or 0 if none. + + CallingContext(const NamedDecl *D = 0, Expr *S = 0, + unsigned N = 0, Expr **A = 0, CallingContext *P = 0) + : AttrDecl(D), SelfArg(S), SelfArrow(false), + NumArgs(N), FunArgs(A), PrevCtx(P) + { } + }; + + typedef SmallVector<SExprNode, 4> NodeVector; + +private: + // A SExpr is a list of SExprNodes in prefix order. The Size field allows + // the list to be traversed as a tree. + NodeVector NodeVec; + +private: + unsigned makeNop() { + NodeVec.push_back(SExprNode(EOP_Nop, 0, 0)); + return NodeVec.size()-1; + } + + unsigned makeWildcard() { + NodeVec.push_back(SExprNode(EOP_Wildcard, 0, 0)); + return NodeVec.size()-1; + } + + unsigned makeNamedVar(const NamedDecl *D) { + NodeVec.push_back(SExprNode(EOP_NVar, 0, D)); + return NodeVec.size()-1; + } + + unsigned makeLocalVar(const NamedDecl *D) { + NodeVec.push_back(SExprNode(EOP_LVar, 0, D)); + return NodeVec.size()-1; + } + + unsigned makeThis() { + NodeVec.push_back(SExprNode(EOP_This, 0, 0)); + return NodeVec.size()-1; + } + + unsigned makeDot(const NamedDecl *D, bool Arrow) { + NodeVec.push_back(SExprNode(EOP_Dot, Arrow ? 1 : 0, D)); + return NodeVec.size()-1; + } + + unsigned makeCall(unsigned NumArgs, const NamedDecl *D) { + NodeVec.push_back(SExprNode(EOP_Call, NumArgs, D)); + return NodeVec.size()-1; + } + + unsigned makeMCall(unsigned NumArgs, const NamedDecl *D) { + NodeVec.push_back(SExprNode(EOP_MCall, NumArgs, D)); + return NodeVec.size()-1; + } + + unsigned makeIndex() { + NodeVec.push_back(SExprNode(EOP_Index, 0, 0)); + return NodeVec.size()-1; + } + + unsigned makeUnary() { + NodeVec.push_back(SExprNode(EOP_Unary, 0, 0)); + return NodeVec.size()-1; + } + + unsigned makeBinary() { + NodeVec.push_back(SExprNode(EOP_Binary, 0, 0)); + return NodeVec.size()-1; + } + + unsigned makeUnknown(unsigned Arity) { + NodeVec.push_back(SExprNode(EOP_Unknown, Arity, 0)); + return NodeVec.size()-1; + } + + /// Build an SExpr from the given C++ expression. /// Recursive function that terminates on DeclRefExpr. - /// Note: this function merely creates a MutexID; it does not check to + /// Note: this function merely creates a SExpr; it does not check to /// ensure that the original expression is a valid mutex expression. - void buildMutexID(Expr *Exp, const NamedDecl *D, Expr *Parent, - unsigned NumArgs, Expr **FunArgs) { - if (!Exp) { - DeclSeq.clear(); - return; - } + /// + /// NDeref returns the number of Derefence and AddressOf operations + /// preceeding the Expr; this is used to decide whether to pretty-print + /// SExprs with . or ->. + unsigned buildSExpr(Expr *Exp, CallingContext* CallCtx, int* NDeref = 0) { + if (!Exp) + return 0; if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Exp)) { NamedDecl *ND = cast<NamedDecl>(DRE->getDecl()->getCanonicalDecl()); @@ -103,144 +264,246 @@ class MutexID { cast<FunctionDecl>(PV->getDeclContext())->getCanonicalDecl(); unsigned i = PV->getFunctionScopeIndex(); - if (FunArgs && FD == D->getCanonicalDecl()) { + if (CallCtx && CallCtx->FunArgs && + FD == CallCtx->AttrDecl->getCanonicalDecl()) { // Substitute call arguments for references to function parameters - assert(i < NumArgs); - buildMutexID(FunArgs[i], D, 0, 0, 0); - return; + assert(i < CallCtx->NumArgs); + return buildSExpr(CallCtx->FunArgs[i], CallCtx->PrevCtx, NDeref); } // Map the param back to the param of the original function declaration. - DeclSeq.push_back(FD->getParamDecl(i)); - return; + makeNamedVar(FD->getParamDecl(i)); + return 1; } // Not a function parameter -- just store the reference. - DeclSeq.push_back(ND); - } else if (MemberExpr *ME = dyn_cast<MemberExpr>(Exp)) { - NamedDecl *ND = ME->getMemberDecl(); - DeclSeq.push_back(ND); - buildMutexID(ME->getBase(), D, Parent, NumArgs, FunArgs); + makeNamedVar(ND); + return 1; } else if (isa<CXXThisExpr>(Exp)) { - if (Parent) - buildMutexID(Parent, D, 0, 0, 0); + // Substitute parent for 'this' + if (CallCtx && CallCtx->SelfArg) { + if (!CallCtx->SelfArrow && NDeref) + // 'this' is a pointer, but self is not, so need to take address. + --(*NDeref); + return buildSExpr(CallCtx->SelfArg, CallCtx->PrevCtx, NDeref); + } else { - DeclSeq.push_back(0); // Use 0 to represent 'this'. - return; // mutexID is still valid in this case + makeThis(); + return 1; } + } else if (MemberExpr *ME = dyn_cast<MemberExpr>(Exp)) { + NamedDecl *ND = ME->getMemberDecl(); + int ImplicitDeref = ME->isArrow() ? 1 : 0; + unsigned Root = makeDot(ND, false); + unsigned Sz = buildSExpr(ME->getBase(), CallCtx, &ImplicitDeref); + NodeVec[Root].setArrow(ImplicitDeref > 0); + NodeVec[Root].setSize(Sz + 1); + return Sz + 1; } else if (CXXMemberCallExpr *CMCE = dyn_cast<CXXMemberCallExpr>(Exp)) { - DeclSeq.push_back(CMCE->getMethodDecl()->getCanonicalDecl()); - buildMutexID(CMCE->getImplicitObjectArgument(), - D, Parent, NumArgs, FunArgs); + // When calling a function with a lock_returned attribute, replace + // the function call with the expression in lock_returned. + if (LockReturnedAttr* At = + CMCE->getMethodDecl()->getAttr<LockReturnedAttr>()) { + CallingContext LRCallCtx(CMCE->getMethodDecl()); + LRCallCtx.SelfArg = CMCE->getImplicitObjectArgument(); + LRCallCtx.SelfArrow = + dyn_cast<MemberExpr>(CMCE->getCallee())->isArrow(); + LRCallCtx.NumArgs = CMCE->getNumArgs(); + LRCallCtx.FunArgs = CMCE->getArgs(); + LRCallCtx.PrevCtx = CallCtx; + return buildSExpr(At->getArg(), &LRCallCtx); + } + // Hack to treat smart pointers and iterators as pointers; + // ignore any method named get(). + if (CMCE->getMethodDecl()->getNameAsString() == "get" && + CMCE->getNumArgs() == 0) { + if (NDeref && dyn_cast<MemberExpr>(CMCE->getCallee())->isArrow()) + ++(*NDeref); + return buildSExpr(CMCE->getImplicitObjectArgument(), CallCtx, NDeref); + } unsigned NumCallArgs = CMCE->getNumArgs(); + unsigned Root = + makeMCall(NumCallArgs, CMCE->getMethodDecl()->getCanonicalDecl()); + unsigned Sz = buildSExpr(CMCE->getImplicitObjectArgument(), CallCtx); Expr** CallArgs = CMCE->getArgs(); for (unsigned i = 0; i < NumCallArgs; ++i) { - buildMutexID(CallArgs[i], D, Parent, NumArgs, FunArgs); + Sz += buildSExpr(CallArgs[i], CallCtx); } + NodeVec[Root].setSize(Sz + 1); + return Sz + 1; } else if (CallExpr *CE = dyn_cast<CallExpr>(Exp)) { - buildMutexID(CE->getCallee(), D, Parent, NumArgs, FunArgs); + if (LockReturnedAttr* At = + CE->getDirectCallee()->getAttr<LockReturnedAttr>()) { + CallingContext LRCallCtx(CE->getDirectCallee()); + LRCallCtx.NumArgs = CE->getNumArgs(); + LRCallCtx.FunArgs = CE->getArgs(); + LRCallCtx.PrevCtx = CallCtx; + return buildSExpr(At->getArg(), &LRCallCtx); + } + // Treat smart pointers and iterators as pointers; + // ignore the * and -> operators. + if (CXXOperatorCallExpr *OE = dyn_cast<CXXOperatorCallExpr>(CE)) { + OverloadedOperatorKind k = OE->getOperator(); + if (k == OO_Star) { + if (NDeref) ++(*NDeref); + return buildSExpr(OE->getArg(0), CallCtx, NDeref); + } + else if (k == OO_Arrow) { + return buildSExpr(OE->getArg(0), CallCtx, NDeref); + } + } unsigned NumCallArgs = CE->getNumArgs(); + unsigned Root = makeCall(NumCallArgs, 0); + unsigned Sz = buildSExpr(CE->getCallee(), CallCtx); Expr** CallArgs = CE->getArgs(); for (unsigned i = 0; i < NumCallArgs; ++i) { - buildMutexID(CallArgs[i], D, Parent, NumArgs, FunArgs); + Sz += buildSExpr(CallArgs[i], CallCtx); } + NodeVec[Root].setSize(Sz+1); + return Sz+1; } else if (BinaryOperator *BOE = dyn_cast<BinaryOperator>(Exp)) { - buildMutexID(BOE->getLHS(), D, Parent, NumArgs, FunArgs); - buildMutexID(BOE->getRHS(), D, Parent, NumArgs, FunArgs); + unsigned Root = makeBinary(); + unsigned Sz = buildSExpr(BOE->getLHS(), CallCtx); + Sz += buildSExpr(BOE->getRHS(), CallCtx); + NodeVec[Root].setSize(Sz); + return Sz; } else if (UnaryOperator *UOE = dyn_cast<UnaryOperator>(Exp)) { - buildMutexID(UOE->getSubExpr(), D, Parent, NumArgs, FunArgs); + // Ignore & and * operators -- they're no-ops. + // However, we try to figure out whether the expression is a pointer, + // so we can use . and -> appropriately in error messages. + if (UOE->getOpcode() == UO_Deref) { + if (NDeref) ++(*NDeref); + return buildSExpr(UOE->getSubExpr(), CallCtx, NDeref); + } + if (UOE->getOpcode() == UO_AddrOf) { + if (DeclRefExpr* DRE = dyn_cast<DeclRefExpr>(UOE->getSubExpr())) { + if (DRE->getDecl()->isCXXInstanceMember()) { + // This is a pointer-to-member expression, e.g. &MyClass::mu_. + // We interpret this syntax specially, as a wildcard. + unsigned Root = makeDot(DRE->getDecl(), false); + makeWildcard(); + NodeVec[Root].setSize(2); + return 2; + } + } + if (NDeref) --(*NDeref); + return buildSExpr(UOE->getSubExpr(), CallCtx, NDeref); + } + unsigned Root = makeUnary(); + unsigned Sz = buildSExpr(UOE->getSubExpr(), CallCtx); + NodeVec[Root].setSize(Sz); + return Sz; } else if (ArraySubscriptExpr *ASE = dyn_cast<ArraySubscriptExpr>(Exp)) { - buildMutexID(ASE->getBase(), D, Parent, NumArgs, FunArgs); - buildMutexID(ASE->getIdx(), D, Parent, NumArgs, FunArgs); + unsigned Root = makeIndex(); + unsigned Sz = buildSExpr(ASE->getBase(), CallCtx); + Sz += buildSExpr(ASE->getIdx(), CallCtx); + NodeVec[Root].setSize(Sz); + return Sz; } else if (AbstractConditionalOperator *CE = - dyn_cast<AbstractConditionalOperator>(Exp)) { - buildMutexID(CE->getCond(), D, Parent, NumArgs, FunArgs); - buildMutexID(CE->getTrueExpr(), D, Parent, NumArgs, FunArgs); - buildMutexID(CE->getFalseExpr(), D, Parent, NumArgs, FunArgs); + dyn_cast<AbstractConditionalOperator>(Exp)) { + unsigned Root = makeUnknown(3); + unsigned Sz = buildSExpr(CE->getCond(), CallCtx); + Sz += buildSExpr(CE->getTrueExpr(), CallCtx); + Sz += buildSExpr(CE->getFalseExpr(), CallCtx); + NodeVec[Root].setSize(Sz); + return Sz; } else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(Exp)) { - buildMutexID(CE->getCond(), D, Parent, NumArgs, FunArgs); - buildMutexID(CE->getLHS(), D, Parent, NumArgs, FunArgs); - buildMutexID(CE->getRHS(), D, Parent, NumArgs, FunArgs); + unsigned Root = makeUnknown(3); + unsigned Sz = buildSExpr(CE->getCond(), CallCtx); + Sz += buildSExpr(CE->getLHS(), CallCtx); + Sz += buildSExpr(CE->getRHS(), CallCtx); + NodeVec[Root].setSize(Sz); + return Sz; } else if (CastExpr *CE = dyn_cast<CastExpr>(Exp)) { - buildMutexID(CE->getSubExpr(), D, Parent, NumArgs, FunArgs); + return buildSExpr(CE->getSubExpr(), CallCtx, NDeref); } else if (ParenExpr *PE = dyn_cast<ParenExpr>(Exp)) { - buildMutexID(PE->getSubExpr(), D, Parent, NumArgs, FunArgs); + return buildSExpr(PE->getSubExpr(), CallCtx, NDeref); + } else if (ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(Exp)) { + return buildSExpr(EWC->getSubExpr(), CallCtx, NDeref); + } else if (CXXBindTemporaryExpr *E = dyn_cast<CXXBindTemporaryExpr>(Exp)) { + return buildSExpr(E->getSubExpr(), CallCtx, NDeref); } else if (isa<CharacterLiteral>(Exp) || - isa<CXXNullPtrLiteralExpr>(Exp) || - isa<GNUNullExpr>(Exp) || - isa<CXXBoolLiteralExpr>(Exp) || - isa<FloatingLiteral>(Exp) || - isa<ImaginaryLiteral>(Exp) || - isa<IntegerLiteral>(Exp) || - isa<StringLiteral>(Exp) || - isa<ObjCStringLiteral>(Exp)) { - return; // FIXME: Ignore literals for now + isa<CXXNullPtrLiteralExpr>(Exp) || + isa<GNUNullExpr>(Exp) || + isa<CXXBoolLiteralExpr>(Exp) || + isa<FloatingLiteral>(Exp) || + isa<ImaginaryLiteral>(Exp) || + isa<IntegerLiteral>(Exp) || + isa<StringLiteral>(Exp) || + isa<ObjCStringLiteral>(Exp)) { + makeNop(); + return 1; // FIXME: Ignore literals for now } else { - // Ignore. FIXME: mark as invalid expression? + makeNop(); + return 1; // Ignore. FIXME: mark as invalid expression? } } - /// \brief Construct a MutexID from an expression. + /// \brief Construct a SExpr from an expression. /// \param MutexExp The original mutex expression within an attribute /// \param DeclExp An expression involving the Decl on which the attribute /// occurs. /// \param D The declaration to which the lock/unlock attribute is attached. - void buildMutexIDFromExp(Expr *MutexExp, Expr *DeclExp, const NamedDecl *D) { - Expr *Parent = 0; - unsigned NumArgs = 0; - Expr **FunArgs = 0; + void buildSExprFromExpr(Expr *MutexExp, Expr *DeclExp, const NamedDecl *D) { + CallingContext CallCtx(D); // If we are processing a raw attribute expression, with no substitutions. if (DeclExp == 0) { - buildMutexID(MutexExp, D, 0, 0, 0); + buildSExpr(MutexExp, 0); return; } - // Examine DeclExp to find Parent and FunArgs, which are used to substitute + // Examine DeclExp to find SelfArg and FunArgs, which are used to substitute // for formal parameters when we call buildMutexID later. if (MemberExpr *ME = dyn_cast<MemberExpr>(DeclExp)) { - Parent = ME->getBase(); + CallCtx.SelfArg = ME->getBase(); + CallCtx.SelfArrow = ME->isArrow(); } else if (CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(DeclExp)) { - Parent = CE->getImplicitObjectArgument(); - NumArgs = CE->getNumArgs(); - FunArgs = CE->getArgs(); + CallCtx.SelfArg = CE->getImplicitObjectArgument(); + CallCtx.SelfArrow = dyn_cast<MemberExpr>(CE->getCallee())->isArrow(); + CallCtx.NumArgs = CE->getNumArgs(); + CallCtx.FunArgs = CE->getArgs(); } else if (CallExpr *CE = dyn_cast<CallExpr>(DeclExp)) { - NumArgs = CE->getNumArgs(); - FunArgs = CE->getArgs(); + CallCtx.NumArgs = CE->getNumArgs(); + CallCtx.FunArgs = CE->getArgs(); } else if (CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(DeclExp)) { - Parent = 0; // FIXME -- get the parent from DeclStmt - NumArgs = CE->getNumArgs(); - FunArgs = CE->getArgs(); + CallCtx.SelfArg = 0; // FIXME -- get the parent from DeclStmt + CallCtx.NumArgs = CE->getNumArgs(); + CallCtx.FunArgs = CE->getArgs(); } else if (D && isa<CXXDestructorDecl>(D)) { // There's no such thing as a "destructor call" in the AST. - Parent = DeclExp; + CallCtx.SelfArg = DeclExp; } // If the attribute has no arguments, then assume the argument is "this". if (MutexExp == 0) { - buildMutexID(Parent, D, 0, 0, 0); + buildSExpr(CallCtx.SelfArg, 0); return; } - buildMutexID(MutexExp, D, Parent, NumArgs, FunArgs); + // For most attributes. + buildSExpr(MutexExp, &CallCtx); } -public: - explicit MutexID(clang::Decl::EmptyShell e) { - DeclSeq.clear(); + /// \brief Get index of next sibling of node i. + unsigned getNextSibling(unsigned i) const { + return i + NodeVec[i].size(); } +public: + explicit SExpr(clang::Decl::EmptyShell e) { NodeVec.clear(); } + /// \param MutexExp The original mutex expression within an attribute /// \param DeclExp An expression involving the Decl on which the attribute /// occurs. /// \param D The declaration to which the lock/unlock attribute is attached. /// Caller must check isValid() after construction. - MutexID(Expr* MutexExp, Expr *DeclExp, const NamedDecl* D) { - buildMutexIDFromExp(MutexExp, DeclExp, D); + SExpr(Expr* MutexExp, Expr *DeclExp, const NamedDecl* D) { + buildSExprFromExpr(MutexExp, DeclExp, D); } /// Return true if this is a valid decl sequence. /// Caller must call this by hand after construction to handle errors. bool isValid() const { - return !DeclSeq.empty(); + return !NodeVec.empty(); } /// Issue a warning about an invalid lock expression @@ -255,44 +518,144 @@ public: Handler.handleInvalidLockExp(Loc); } - bool operator==(const MutexID &other) const { - return DeclSeq == other.DeclSeq; + bool operator==(const SExpr &other) const { + return NodeVec == other.NodeVec; } - bool operator!=(const MutexID &other) const { + bool operator!=(const SExpr &other) const { return !(*this == other); } - // SmallVector overloads Operator< to do lexicographic ordering. Note that - // we use pointer equality (and <) to compare NamedDecls. This means the order - // of MutexIDs in a lockset is nondeterministic. In order to output - // diagnostics in a deterministic ordering, we must order all diagnostics to - // output by SourceLocation when iterating through this lockset. - bool operator<(const MutexID &other) const { - return DeclSeq < other.DeclSeq; + bool matches(const SExpr &Other, unsigned i = 0, unsigned j = 0) const { + if (NodeVec[i].matches(Other.NodeVec[j])) { + unsigned n = NodeVec[i].arity(); + bool Result = true; + unsigned ci = i+1; // first child of i + unsigned cj = j+1; // first child of j + for (unsigned k = 0; k < n; + ++k, ci=getNextSibling(ci), cj = Other.getNextSibling(cj)) { + Result = Result && matches(Other, ci, cj); + } + return Result; + } + return false; } - /// \brief Returns the name of the first Decl in the list for a given MutexID; - /// e.g. the lock expression foo.bar() has name "bar". - /// The caret will point unambiguously to the lock expression, so using this - /// name in diagnostics is a way to get simple, and consistent, mutex names. - /// We do not want to output the entire expression text for security reasons. - std::string getName() const { + /// \brief Pretty print a lock expression for use in error messages. + std::string toString(unsigned i = 0) const { assert(isValid()); - if (!DeclSeq.front()) - return "this"; // Use 0 to represent 'this'. - return DeclSeq.front()->getNameAsString(); + if (i >= NodeVec.size()) + return ""; + + const SExprNode* N = &NodeVec[i]; + switch (N->kind()) { + case EOP_Nop: + return "_"; + case EOP_Wildcard: + return "(?)"; + case EOP_This: + return "this"; + case EOP_NVar: + case EOP_LVar: { + return N->getNamedDecl()->getNameAsString(); + } + case EOP_Dot: { + if (NodeVec[i+1].kind() == EOP_Wildcard) { + std::string S = "&"; + S += N->getNamedDecl()->getQualifiedNameAsString(); + return S; + } + std::string FieldName = N->getNamedDecl()->getNameAsString(); + if (NodeVec[i+1].kind() == EOP_This) + return FieldName; + + std::string S = toString(i+1); + if (N->isArrow()) + return S + "->" + FieldName; + else + return S + "." + FieldName; + } + case EOP_Call: { + std::string S = toString(i+1) + "("; + unsigned NumArgs = N->arity()-1; + unsigned ci = getNextSibling(i+1); + for (unsigned k=0; k<NumArgs; ++k, ci = getNextSibling(ci)) { + S += toString(ci); + if (k+1 < NumArgs) S += ","; + } + S += ")"; + return S; + } + case EOP_MCall: { + std::string S = ""; + if (NodeVec[i+1].kind() != EOP_This) + S = toString(i+1) + "."; + if (const NamedDecl *D = N->getFunctionDecl()) + S += D->getNameAsString() + "("; + else + S += "#("; + unsigned NumArgs = N->arity()-1; + unsigned ci = getNextSibling(i+1); + for (unsigned k=0; k<NumArgs; ++k, ci = getNextSibling(ci)) { + S += toString(ci); + if (k+1 < NumArgs) S += ","; + } + S += ")"; + return S; + } + case EOP_Index: { + std::string S1 = toString(i+1); + std::string S2 = toString(i+1 + NodeVec[i+1].size()); + return S1 + "[" + S2 + "]"; + } + case EOP_Unary: { + std::string S = toString(i+1); + return "#" + S; + } + case EOP_Binary: { + std::string S1 = toString(i+1); + std::string S2 = toString(i+1 + NodeVec[i+1].size()); + return "(" + S1 + "#" + S2 + ")"; + } + case EOP_Unknown: { + unsigned NumChildren = N->arity(); + if (NumChildren == 0) + return "(...)"; + std::string S = "("; + unsigned ci = i+1; + for (unsigned j = 0; j < NumChildren; ++j, ci = getNextSibling(ci)) { + S += toString(ci); + if (j+1 < NumChildren) S += "#"; + } + S += ")"; + return S; + } + } + return ""; } +}; - void Profile(llvm::FoldingSetNodeID &ID) const { - for (SmallVectorImpl<NamedDecl*>::const_iterator I = DeclSeq.begin(), - E = DeclSeq.end(); I != E; ++I) { - ID.AddPointer(*I); - } + + +/// \brief A short list of SExprs +class MutexIDList : public SmallVector<SExpr, 3> { +public: + /// \brief Return true if the list contains the specified SExpr + /// Performs a linear search, because these lists are almost always very small. + bool contains(const SExpr& M) { + for (iterator I=begin(),E=end(); I != E; ++I) + if ((*I) == M) return true; + return false; + } + + /// \brief Push M onto list, bud discard duplicates + void push_back_nodup(const SExpr& M) { + if (!contains(M)) push_back(M); } }; + /// \brief This is a helper class that stores info about the most recent /// accquire of a Lock. /// @@ -307,14 +670,18 @@ struct LockData { /// /// FIXME: add support for re-entrant locking and lock up/downgrading LockKind LKind; - MutexID UnderlyingMutex; // for ScopedLockable objects + bool Managed; // for ScopedLockable objects + SExpr UnderlyingMutex; // for ScopedLockable objects - LockData(SourceLocation AcquireLoc, LockKind LKind) - : AcquireLoc(AcquireLoc), LKind(LKind), UnderlyingMutex(Decl::EmptyShell()) + LockData(SourceLocation AcquireLoc, LockKind LKind, bool M = false) + : AcquireLoc(AcquireLoc), LKind(LKind), Managed(M), + UnderlyingMutex(Decl::EmptyShell()) {} - LockData(SourceLocation AcquireLoc, LockKind LKind, const MutexID &Mu) - : AcquireLoc(AcquireLoc), LKind(LKind), UnderlyingMutex(Mu) {} + LockData(SourceLocation AcquireLoc, LockKind LKind, const SExpr &Mu) + : AcquireLoc(AcquireLoc), LKind(LKind), Managed(false), + UnderlyingMutex(Mu) + {} bool operator==(const LockData &other) const { return AcquireLoc == other.AcquireLoc && LKind == other.LKind; @@ -331,10 +698,102 @@ struct LockData { }; -/// A Lockset maps each MutexID (defined above) to information about how it has +/// \brief A FactEntry stores a single fact that is known at a particular point +/// in the program execution. Currently, this is information regarding a lock +/// that is held at that point. +struct FactEntry { + SExpr MutID; + LockData LDat; + + FactEntry(const SExpr& M, const LockData& L) + : MutID(M), LDat(L) + { } +}; + + +typedef unsigned short FactID; + +/// \brief FactManager manages the memory for all facts that are created during +/// the analysis of a single routine. +class FactManager { +private: + std::vector<FactEntry> Facts; + +public: + FactID newLock(const SExpr& M, const LockData& L) { + Facts.push_back(FactEntry(M,L)); + return static_cast<unsigned short>(Facts.size() - 1); + } + + const FactEntry& operator[](FactID F) const { return Facts[F]; } + FactEntry& operator[](FactID F) { return Facts[F]; } +}; + + +/// \brief A FactSet is the set of facts that are known to be true at a +/// particular program point. FactSets must be small, because they are +/// frequently copied, and are thus implemented as a set of indices into a +/// table maintained by a FactManager. A typical FactSet only holds 1 or 2 +/// locks, so we can get away with doing a linear search for lookup. Note +/// that a hashtable or map is inappropriate in this case, because lookups +/// may involve partial pattern matches, rather than exact matches. +class FactSet { +private: + typedef SmallVector<FactID, 4> FactVec; + + FactVec FactIDs; + +public: + typedef FactVec::iterator iterator; + typedef FactVec::const_iterator const_iterator; + + iterator begin() { return FactIDs.begin(); } + const_iterator begin() const { return FactIDs.begin(); } + + iterator end() { return FactIDs.end(); } + const_iterator end() const { return FactIDs.end(); } + + bool isEmpty() const { return FactIDs.size() == 0; } + + FactID addLock(FactManager& FM, const SExpr& M, const LockData& L) { + FactID F = FM.newLock(M, L); + FactIDs.push_back(F); + return F; + } + + bool removeLock(FactManager& FM, const SExpr& M) { + unsigned n = FactIDs.size(); + if (n == 0) + return false; + + for (unsigned i = 0; i < n-1; ++i) { + if (FM[FactIDs[i]].MutID.matches(M)) { + FactIDs[i] = FactIDs[n-1]; + FactIDs.pop_back(); + return true; + } + } + if (FM[FactIDs[n-1]].MutID.matches(M)) { + FactIDs.pop_back(); + return true; + } + return false; + } + + LockData* findLock(FactManager& FM, const SExpr& M) const { + for (const_iterator I=begin(), E=end(); I != E; ++I) { + if (FM[*I].MutID.matches(M)) return &FM[*I].LDat; + } + return 0; + } +}; + + + +/// A Lockset maps each SExpr (defined above) to information about how it has /// been locked. -typedef llvm::ImmutableMap<MutexID, LockData> Lockset; -typedef llvm::ImmutableMap<NamedDecl*, unsigned> LocalVarContext; +typedef llvm::ImmutableMap<SExpr, LockData> Lockset; +typedef llvm::ImmutableMap<const NamedDecl*, unsigned> LocalVarContext; class LocalVariableMap; @@ -345,15 +804,15 @@ enum CFGBlockSide { CBS_Entry, CBS_Exit }; /// maintained for each block in the CFG. See LocalVariableMap for more /// information about the contexts. struct CFGBlockInfo { - Lockset EntrySet; // Lockset held at entry to block - Lockset ExitSet; // Lockset held at exit from block + FactSet EntrySet; // Lockset held at entry to block + FactSet ExitSet; // Lockset held at exit from block LocalVarContext EntryContext; // Context held at entry to block LocalVarContext ExitContext; // Context held at exit from block SourceLocation EntryLoc; // Location of first statement in block SourceLocation ExitLoc; // Location of last statement in block. unsigned EntryIndex; // Used to replay contexts later - const Lockset &getSet(CFGBlockSide Side) const { + const FactSet &getSet(CFGBlockSide Side) const { return Side == CBS_Entry ? EntrySet : ExitSet; } SourceLocation getLocation(CFGBlockSide Side) const { @@ -361,14 +820,12 @@ struct CFGBlockInfo { } private: - CFGBlockInfo(Lockset EmptySet, LocalVarContext EmptyCtx) - : EntrySet(EmptySet), ExitSet(EmptySet), - EntryContext(EmptyCtx), ExitContext(EmptyCtx) + CFGBlockInfo(LocalVarContext EmptyCtx) + : EntryContext(EmptyCtx), ExitContext(EmptyCtx) { } public: - static CFGBlockInfo getEmptyBlockInfo(Lockset::Factory &F, - LocalVariableMap &M); + static CFGBlockInfo getEmptyBlockInfo(LocalVariableMap &M); }; @@ -398,21 +855,21 @@ public: public: friend class LocalVariableMap; - NamedDecl *Dec; // The original declaration for this variable. - Expr *Exp; // The expression for this variable, OR - unsigned Ref; // Reference to another VarDefinition - Context Ctx; // The map with which Exp should be interpreted. + const NamedDecl *Dec; // The original declaration for this variable. + const Expr *Exp; // The expression for this variable, OR + unsigned Ref; // Reference to another VarDefinition + Context Ctx; // The map with which Exp should be interpreted. bool isReference() { return !Exp; } private: // Create ordinary variable definition - VarDefinition(NamedDecl *D, Expr *E, Context C) + VarDefinition(const NamedDecl *D, const Expr *E, Context C) : Dec(D), Exp(E), Ref(0), Ctx(C) { } // Create reference to previous definition - VarDefinition(NamedDecl *D, unsigned R, Context C) + VarDefinition(const NamedDecl *D, unsigned R, Context C) : Dec(D), Exp(0), Ref(R), Ctx(C) { } }; @@ -430,7 +887,7 @@ public: } /// Look up a definition, within the given context. - const VarDefinition* lookup(NamedDecl *D, Context Ctx) { + const VarDefinition* lookup(const NamedDecl *D, Context Ctx) { const unsigned *i = Ctx.lookup(D); if (!i) return 0; @@ -441,7 +898,7 @@ public: /// Look up the definition for D within the given context. Returns /// NULL if the expression is not statically known. If successful, also /// modifies Ctx to hold the context of the return Expr. - Expr* lookupExpr(NamedDecl *D, Context &Ctx) { + const Expr* lookupExpr(const NamedDecl *D, Context &Ctx) { const unsigned *P = Ctx.lookup(D); if (!P) return 0; @@ -476,7 +933,7 @@ public: llvm::errs() << "Undefined"; return; } - NamedDecl *Dec = VarDefinitions[i].Dec; + const NamedDecl *Dec = VarDefinitions[i].Dec; if (!Dec) { llvm::errs() << "<<NULL>>"; return; @@ -488,7 +945,7 @@ public: /// Dumps an ASCII representation of the variable map to llvm::errs() void dump() { for (unsigned i = 1, e = VarDefinitions.size(); i < e; ++i) { - Expr *Exp = VarDefinitions[i].Exp; + const Expr *Exp = VarDefinitions[i].Exp; unsigned Ref = VarDefinitions[i].Ref; dumpVarDefinitionName(i); @@ -504,7 +961,7 @@ public: /// Dumps an ASCII representation of a Context to llvm::errs() void dumpContext(Context C) { for (Context::iterator I = C.begin(), E = C.end(); I != E; ++I) { - NamedDecl *D = I.getKey(); + const NamedDecl *D = I.getKey(); D->printName(llvm::errs()); const unsigned *i = C.lookup(D); llvm::errs() << " -> "; @@ -528,7 +985,7 @@ protected: // Adds a new definition to the given context, and returns a new context. // This method should be called when declaring a new variable. - Context addDefinition(NamedDecl *D, Expr *Exp, Context Ctx) { + Context addDefinition(const NamedDecl *D, Expr *Exp, Context Ctx) { assert(!Ctx.contains(D)); unsigned newID = VarDefinitions.size(); Context NewCtx = ContextFactory.add(Ctx, D, newID); @@ -537,7 +994,7 @@ protected: } // Add a new reference to an existing definition. - Context addReference(NamedDecl *D, unsigned i, Context Ctx) { + Context addReference(const NamedDecl *D, unsigned i, Context Ctx) { unsigned newID = VarDefinitions.size(); Context NewCtx = ContextFactory.add(Ctx, D, newID); VarDefinitions.push_back(VarDefinition(D, i, Ctx)); @@ -546,7 +1003,7 @@ protected: // Updates a definition only if that definition is already in the map. // This method should be called when assigning to an existing variable. - Context updateDefinition(NamedDecl *D, Expr *Exp, Context Ctx) { + Context updateDefinition(const NamedDecl *D, Expr *Exp, Context Ctx) { if (Ctx.contains(D)) { unsigned newID = VarDefinitions.size(); Context NewCtx = ContextFactory.remove(Ctx, D); @@ -559,7 +1016,7 @@ protected: // Removes a definition from the context, but keeps the variable name // as a valid variable. The index 0 is a placeholder for cleared definitions. - Context clearDefinition(NamedDecl *D, Context Ctx) { + Context clearDefinition(const NamedDecl *D, Context Ctx) { Context NewCtx = Ctx; if (NewCtx.contains(D)) { NewCtx = ContextFactory.remove(NewCtx, D); @@ -569,7 +1026,7 @@ protected: } // Remove a definition entirely frmo the context. - Context removeDefinition(NamedDecl *D, Context Ctx) { + Context removeDefinition(const NamedDecl *D, Context Ctx) { Context NewCtx = Ctx; if (NewCtx.contains(D)) { NewCtx = ContextFactory.remove(NewCtx, D); @@ -586,9 +1043,8 @@ protected: // This has to be defined after LocalVariableMap. -CFGBlockInfo CFGBlockInfo::getEmptyBlockInfo(Lockset::Factory &F, - LocalVariableMap &M) { - return CFGBlockInfo(F.getEmptyMap(), M.getEmptyContext()); +CFGBlockInfo CFGBlockInfo::getEmptyBlockInfo(LocalVariableMap &M) { + return CFGBlockInfo(M.getEmptyContext()); } @@ -655,7 +1111,7 @@ LocalVariableMap::Context LocalVariableMap::intersectContexts(Context C1, Context C2) { Context Result = C1; for (Context::iterator I = C1.begin(), E = C1.end(); I != E; ++I) { - NamedDecl *Dec = I.getKey(); + const NamedDecl *Dec = I.getKey(); unsigned i1 = I.getData(); const unsigned *i2 = C2.lookup(Dec); if (!i2) // variable doesn't exist on second path @@ -672,7 +1128,7 @@ LocalVariableMap::intersectContexts(Context C1, Context C2) { LocalVariableMap::Context LocalVariableMap::createReferenceContext(Context C) { Context Result = getEmptyContext(); for (Context::iterator I = C.begin(), E = C.end(); I != E; ++I) { - NamedDecl *Dec = I.getKey(); + const NamedDecl *Dec = I.getKey(); unsigned i = I.getData(); Result = addReference(Dec, i, Result); } @@ -684,7 +1140,7 @@ LocalVariableMap::Context LocalVariableMap::createReferenceContext(Context C) { // createReferenceContext. void LocalVariableMap::intersectBackEdge(Context C1, Context C2) { for (Context::iterator I = C1.begin(), E = C1.end(); I != E; ++I) { - NamedDecl *Dec = I.getKey(); + const NamedDecl *Dec = I.getKey(); unsigned i1 = I.getData(); VarDefinition *VDef = &VarDefinitions[i1]; assert(VDef->isReference()); @@ -725,7 +1181,7 @@ void LocalVariableMap::intersectBackEdge(Context C1, Context C2) { // incoming back edge, it duplicates the context, creating new definitions // that refer back to the originals. (These correspond to places where SSA // might have to insert a phi node.) On the second pass, these definitions are -// set to NULL if the the variable has changed on the back-edge (i.e. a phi +// set to NULL if the variable has changed on the back-edge (i.e. a phi // node was actually required.) E.g. // // { Context | VarDefinitions } @@ -869,24 +1325,294 @@ static void findBlockLocations(CFG *CFGraph, class ThreadSafetyAnalyzer { friend class BuildLockset; - ThreadSafetyHandler &Handler; - Lockset::Factory LocksetFactory; - LocalVariableMap LocalVarMap; + ThreadSafetyHandler &Handler; + LocalVariableMap LocalVarMap; + FactManager FactMan; + std::vector<CFGBlockInfo> BlockInfo; public: ThreadSafetyAnalyzer(ThreadSafetyHandler &H) : Handler(H) {} - Lockset intersectAndWarn(const CFGBlockInfo &Block1, CFGBlockSide Side1, - const CFGBlockInfo &Block2, CFGBlockSide Side2, - LockErrorKind LEK); + void addLock(FactSet &FSet, const SExpr &Mutex, const LockData &LDat); + void removeLock(FactSet &FSet, const SExpr &Mutex, + SourceLocation UnlockLoc, bool FullyRemove=false); + + template <typename AttrType> + void getMutexIDs(MutexIDList &Mtxs, AttrType *Attr, Expr *Exp, + const NamedDecl *D); - Lockset addLock(Lockset &LSet, Expr *MutexExp, const NamedDecl *D, - LockKind LK, SourceLocation Loc); + template <class AttrType> + void getMutexIDs(MutexIDList &Mtxs, AttrType *Attr, Expr *Exp, + const NamedDecl *D, + const CFGBlock *PredBlock, const CFGBlock *CurrBlock, + Expr *BrE, bool Neg); + + const CallExpr* getTrylockCallExpr(const Stmt *Cond, LocalVarContext C, + bool &Negate); + + void getEdgeLockset(FactSet &Result, const FactSet &ExitSet, + const CFGBlock* PredBlock, + const CFGBlock *CurrBlock); + + void intersectAndWarn(FactSet &FSet1, const FactSet &FSet2, + SourceLocation JoinLoc, + LockErrorKind LEK1, LockErrorKind LEK2, + bool Modify=true); + + void intersectAndWarn(FactSet &FSet1, const FactSet &FSet2, + SourceLocation JoinLoc, LockErrorKind LEK1, + bool Modify=true) { + intersectAndWarn(FSet1, FSet2, JoinLoc, LEK1, LEK1, Modify); + } void runAnalysis(AnalysisDeclContext &AC); }; +/// \brief Add a new lock to the lockset, warning if the lock is already there. +/// \param Mutex -- the Mutex expression for the lock +/// \param LDat -- the LockData for the lock +void ThreadSafetyAnalyzer::addLock(FactSet &FSet, const SExpr &Mutex, + const LockData &LDat) { + // FIXME: deal with acquired before/after annotations. + // FIXME: Don't always warn when we have support for reentrant locks. + if (FSet.findLock(FactMan, Mutex)) { + Handler.handleDoubleLock(Mutex.toString(), LDat.AcquireLoc); + } else { + FSet.addLock(FactMan, Mutex, LDat); + } +} + + +/// \brief Remove a lock from the lockset, warning if the lock is not there. +/// \param LockExp The lock expression corresponding to the lock to be removed +/// \param UnlockLoc The source location of the unlock (only used in error msg) +void ThreadSafetyAnalyzer::removeLock(FactSet &FSet, + const SExpr &Mutex, + SourceLocation UnlockLoc, + bool FullyRemove) { + const LockData *LDat = FSet.findLock(FactMan, Mutex); + if (!LDat) { + Handler.handleUnmatchedUnlock(Mutex.toString(), UnlockLoc); + return; + } + + if (LDat->UnderlyingMutex.isValid()) { + // This is scoped lockable object, which manages the real mutex. + if (FullyRemove) { + // We're destroying the managing object. + // Remove the underlying mutex if it exists; but don't warn. + if (FSet.findLock(FactMan, LDat->UnderlyingMutex)) + FSet.removeLock(FactMan, LDat->UnderlyingMutex); + } else { + // We're releasing the underlying mutex, but not destroying the + // managing object. Warn on dual release. + if (!FSet.findLock(FactMan, LDat->UnderlyingMutex)) { + Handler.handleUnmatchedUnlock(LDat->UnderlyingMutex.toString(), + UnlockLoc); + } + FSet.removeLock(FactMan, LDat->UnderlyingMutex); + return; + } + } + FSet.removeLock(FactMan, Mutex); +} + + +/// \brief Extract the list of mutexIDs from the attribute on an expression, +/// and push them onto Mtxs, discarding any duplicates. +template <typename AttrType> +void ThreadSafetyAnalyzer::getMutexIDs(MutexIDList &Mtxs, AttrType *Attr, + Expr *Exp, const NamedDecl *D) { + typedef typename AttrType::args_iterator iterator_type; + + if (Attr->args_size() == 0) { + // The mutex held is the "this" object. + SExpr Mu(0, Exp, D); + if (!Mu.isValid()) + SExpr::warnInvalidLock(Handler, 0, Exp, D); + else + Mtxs.push_back_nodup(Mu); + return; + } + + for (iterator_type I=Attr->args_begin(), E=Attr->args_end(); I != E; ++I) { + SExpr Mu(*I, Exp, D); + if (!Mu.isValid()) + SExpr::warnInvalidLock(Handler, *I, Exp, D); + else + Mtxs.push_back_nodup(Mu); + } +} + + +/// \brief Extract the list of mutexIDs from a trylock attribute. If the +/// trylock applies to the given edge, then push them onto Mtxs, discarding +/// any duplicates. +template <class AttrType> +void ThreadSafetyAnalyzer::getMutexIDs(MutexIDList &Mtxs, AttrType *Attr, + Expr *Exp, const NamedDecl *D, + const CFGBlock *PredBlock, + const CFGBlock *CurrBlock, + Expr *BrE, bool Neg) { + // Find out which branch has the lock + bool branch = 0; + if (CXXBoolLiteralExpr *BLE = dyn_cast_or_null<CXXBoolLiteralExpr>(BrE)) { + branch = BLE->getValue(); + } + else if (IntegerLiteral *ILE = dyn_cast_or_null<IntegerLiteral>(BrE)) { + branch = ILE->getValue().getBoolValue(); + } + int branchnum = branch ? 0 : 1; + if (Neg) branchnum = !branchnum; + + // If we've taken the trylock branch, then add the lock + int i = 0; + for (CFGBlock::const_succ_iterator SI = PredBlock->succ_begin(), + SE = PredBlock->succ_end(); SI != SE && i < 2; ++SI, ++i) { + if (*SI == CurrBlock && i == branchnum) { + getMutexIDs(Mtxs, Attr, Exp, D); + } + } +} + + +bool getStaticBooleanValue(Expr* E, bool& TCond) { + if (isa<CXXNullPtrLiteralExpr>(E) || isa<GNUNullExpr>(E)) { + TCond = false; + return true; + } else if (CXXBoolLiteralExpr *BLE = dyn_cast<CXXBoolLiteralExpr>(E)) { + TCond = BLE->getValue(); + return true; + } else if (IntegerLiteral *ILE = dyn_cast<IntegerLiteral>(E)) { + TCond = ILE->getValue().getBoolValue(); + return true; + } else if (ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E)) { + return getStaticBooleanValue(CE->getSubExpr(), TCond); + } + return false; +} + + +// If Cond can be traced back to a function call, return the call expression. +// The negate variable should be called with false, and will be set to true +// if the function call is negated, e.g. if (!mu.tryLock(...)) +const CallExpr* ThreadSafetyAnalyzer::getTrylockCallExpr(const Stmt *Cond, + LocalVarContext C, + bool &Negate) { + if (!Cond) + return 0; + + if (const CallExpr *CallExp = dyn_cast<CallExpr>(Cond)) { + return CallExp; + } + else if (const ParenExpr *PE = dyn_cast<ParenExpr>(Cond)) { + return getTrylockCallExpr(PE->getSubExpr(), C, Negate); + } + else if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(Cond)) { + return getTrylockCallExpr(CE->getSubExpr(), C, Negate); + } + else if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Cond)) { + const Expr *E = LocalVarMap.lookupExpr(DRE->getDecl(), C); + return getTrylockCallExpr(E, C, Negate); + } + else if (const UnaryOperator *UOP = dyn_cast<UnaryOperator>(Cond)) { + if (UOP->getOpcode() == UO_LNot) { + Negate = !Negate; + return getTrylockCallExpr(UOP->getSubExpr(), C, Negate); + } + return 0; + } + else if (const BinaryOperator *BOP = dyn_cast<BinaryOperator>(Cond)) { + if (BOP->getOpcode() == BO_EQ || BOP->getOpcode() == BO_NE) { + if (BOP->getOpcode() == BO_NE) + Negate = !Negate; + + bool TCond = false; + if (getStaticBooleanValue(BOP->getRHS(), TCond)) { + if (!TCond) Negate = !Negate; + return getTrylockCallExpr(BOP->getLHS(), C, Negate); + } + else if (getStaticBooleanValue(BOP->getLHS(), TCond)) { + if (!TCond) Negate = !Negate; + return getTrylockCallExpr(BOP->getRHS(), C, Negate); + } + return 0; + } + return 0; + } + // FIXME -- handle && and || as well. + return 0; +} + + +/// \brief Find the lockset that holds on the edge between PredBlock +/// and CurrBlock. The edge set is the exit set of PredBlock (passed +/// as the ExitSet parameter) plus any trylocks, which are conditionally held. +void ThreadSafetyAnalyzer::getEdgeLockset(FactSet& Result, + const FactSet &ExitSet, + const CFGBlock *PredBlock, + const CFGBlock *CurrBlock) { + Result = ExitSet; + + if (!PredBlock->getTerminatorCondition()) + return; + + bool Negate = false; + const Stmt *Cond = PredBlock->getTerminatorCondition(); + const CFGBlockInfo *PredBlockInfo = &BlockInfo[PredBlock->getBlockID()]; + const LocalVarContext &LVarCtx = PredBlockInfo->ExitContext; + + CallExpr *Exp = + const_cast<CallExpr*>(getTrylockCallExpr(Cond, LVarCtx, Negate)); + if (!Exp) + return; + + NamedDecl *FunDecl = dyn_cast_or_null<NamedDecl>(Exp->getCalleeDecl()); + if(!FunDecl || !FunDecl->hasAttrs()) + return; + + + MutexIDList ExclusiveLocksToAdd; + MutexIDList SharedLocksToAdd; + + // If the condition is a call to a Trylock function, then grab the attributes + AttrVec &ArgAttrs = FunDecl->getAttrs(); + for (unsigned i = 0; i < ArgAttrs.size(); ++i) { + Attr *Attr = ArgAttrs[i]; + switch (Attr->getKind()) { + case attr::ExclusiveTrylockFunction: { + ExclusiveTrylockFunctionAttr *A = + cast<ExclusiveTrylockFunctionAttr>(Attr); + getMutexIDs(ExclusiveLocksToAdd, A, Exp, FunDecl, + PredBlock, CurrBlock, A->getSuccessValue(), Negate); + break; + } + case attr::SharedTrylockFunction: { + SharedTrylockFunctionAttr *A = + cast<SharedTrylockFunctionAttr>(Attr); + getMutexIDs(ExclusiveLocksToAdd, A, Exp, FunDecl, + PredBlock, CurrBlock, A->getSuccessValue(), Negate); + break; + } + default: + break; + } + } + + // Add and remove locks. + SourceLocation Loc = Exp->getExprLoc(); + for (unsigned i=0,n=ExclusiveLocksToAdd.size(); i<n; ++i) { + addLock(Result, ExclusiveLocksToAdd[i], + LockData(Loc, LK_Exclusive)); + } + for (unsigned i=0,n=SharedLocksToAdd.size(); i<n; ++i) { + addLock(Result, SharedLocksToAdd[i], + LockData(Loc, LK_Shared)); + } +} + + /// \brief We use this class to visit different types of expressions in /// CFGBlocks, and build up the lockset. /// An expression may cause us to add or remove locks from the lockset, or else @@ -895,50 +1621,31 @@ public: class BuildLockset : public StmtVisitor<BuildLockset> { friend class ThreadSafetyAnalyzer; - ThreadSafetyHandler &Handler; - Lockset::Factory &LocksetFactory; - LocalVariableMap &LocalVarMap; - - Lockset LSet; + ThreadSafetyAnalyzer *Analyzer; + FactSet FSet; LocalVariableMap::Context LVarCtx; unsigned CtxIndex; // Helper functions - void addLock(const MutexID &Mutex, const LockData &LDat); - void removeLock(const MutexID &Mutex, SourceLocation UnlockLoc); + const ValueDecl *getValueDecl(Expr *Exp); - template <class AttrType> - void addLocksToSet(LockKind LK, AttrType *Attr, - Expr *Exp, NamedDecl *D, VarDecl *VD = 0); - void removeLocksFromSet(UnlockFunctionAttr *Attr, - Expr *Exp, NamedDecl* FunDecl); + void warnIfMutexNotHeld(const NamedDecl *D, Expr *Exp, AccessKind AK, + Expr *MutexExp, ProtectedOperationKind POK); - const ValueDecl *getValueDecl(Expr *Exp); - void warnIfMutexNotHeld (const NamedDecl *D, Expr *Exp, AccessKind AK, - Expr *MutexExp, ProtectedOperationKind POK); void checkAccess(Expr *Exp, AccessKind AK); void checkDereference(Expr *Exp, AccessKind AK); - void handleCall(Expr *Exp, NamedDecl *D, VarDecl *VD = 0); - - template <class AttrType> - void addTrylock(LockKind LK, AttrType *Attr, Expr *Exp, NamedDecl *FunDecl, - const CFGBlock* PredBlock, const CFGBlock *CurrBlock, - Expr *BrE, bool Neg); - CallExpr* getTrylockCallExpr(Stmt *Cond, LocalVariableMap::Context C, - bool &Negate); - void handleTrylock(Stmt *Cond, const CFGBlock* PredBlock, - const CFGBlock *CurrBlock); + void handleCall(Expr *Exp, const NamedDecl *D, VarDecl *VD = 0); /// \brief Returns true if the lockset contains a lock, regardless of whether /// the lock is held exclusively or shared. - bool locksetContains(const MutexID &Lock) const { - return LSet.lookup(Lock); + bool locksetContains(const SExpr &Mu) const { + return FSet.findLock(Analyzer->FactMan, Mu); } /// \brief Returns true if the lockset contains a lock with the passed in /// locktype. - bool locksetContains(const MutexID &Lock, LockKind KindRequested) const { - const LockData *LockHeld = LSet.lookup(Lock); + bool locksetContains(const SExpr &Mu, LockKind KindRequested) const { + const LockData *LockHeld = FSet.findLock(Analyzer->FactMan, Mu); return (LockHeld && KindRequested == LockHeld->LKind); } @@ -946,7 +1653,7 @@ class BuildLockset : public StmtVisitor<BuildLockset> { /// passed in locktype. So for example, if we pass in LK_Shared, this function /// returns true if the lock is held LK_Shared or LK_Exclusive. If we pass in /// LK_Exclusive, this function returns true if the lock is held LK_Exclusive. - bool locksetContainsAtLeast(const MutexID &Lock, + bool locksetContainsAtLeast(const SExpr &Lock, LockKind KindRequested) const { switch (KindRequested) { case LK_Shared: @@ -958,12 +1665,10 @@ class BuildLockset : public StmtVisitor<BuildLockset> { } public: - BuildLockset(ThreadSafetyAnalyzer *analyzer, CFGBlockInfo &Info) + BuildLockset(ThreadSafetyAnalyzer *Anlzr, CFGBlockInfo &Info) : StmtVisitor<BuildLockset>(), - Handler(analyzer->Handler), - LocksetFactory(analyzer->LocksetFactory), - LocalVarMap(analyzer->LocalVarMap), - LSet(Info.EntrySet), + Analyzer(Anlzr), + FSet(Info.EntrySet), LVarCtx(Info.EntryContext), CtxIndex(Info.EntryIndex) {} @@ -976,104 +1681,6 @@ public: void VisitDeclStmt(DeclStmt *S); }; -/// \brief Add a new lock to the lockset, warning if the lock is already there. -/// \param Mutex -- the Mutex expression for the lock -/// \param LDat -- the LockData for the lock -void BuildLockset::addLock(const MutexID &Mutex, const LockData& LDat) { - // FIXME: deal with acquired before/after annotations. - // FIXME: Don't always warn when we have support for reentrant locks. - if (locksetContains(Mutex)) - Handler.handleDoubleLock(Mutex.getName(), LDat.AcquireLoc); - else - LSet = LocksetFactory.add(LSet, Mutex, LDat); -} - -/// \brief Remove a lock from the lockset, warning if the lock is not there. -/// \param LockExp The lock expression corresponding to the lock to be removed -/// \param UnlockLoc The source location of the unlock (only used in error msg) -void BuildLockset::removeLock(const MutexID &Mutex, SourceLocation UnlockLoc) { - const LockData *LDat = LSet.lookup(Mutex); - if (!LDat) - Handler.handleUnmatchedUnlock(Mutex.getName(), UnlockLoc); - else { - // For scoped-lockable vars, remove the mutex associated with this var. - if (LDat->UnderlyingMutex.isValid()) - removeLock(LDat->UnderlyingMutex, UnlockLoc); - LSet = LocksetFactory.remove(LSet, Mutex); - } -} - -/// \brief This function, parameterized by an attribute type, is used to add a -/// set of locks specified as attribute arguments to the lockset. -template <typename AttrType> -void BuildLockset::addLocksToSet(LockKind LK, AttrType *Attr, - Expr *Exp, NamedDecl* FunDecl, VarDecl *VD) { - typedef typename AttrType::args_iterator iterator_type; - - SourceLocation ExpLocation = Exp->getExprLoc(); - - // Figure out if we're calling the constructor of scoped lockable class - bool isScopedVar = false; - if (VD) { - if (CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FunDecl)) { - CXXRecordDecl* PD = CD->getParent(); - if (PD && PD->getAttr<ScopedLockableAttr>()) - isScopedVar = true; - } - } - - if (Attr->args_size() == 0) { - // The mutex held is the "this" object. - MutexID Mutex(0, Exp, FunDecl); - if (!Mutex.isValid()) - MutexID::warnInvalidLock(Handler, 0, Exp, FunDecl); - else - addLock(Mutex, LockData(ExpLocation, LK)); - return; - } - - for (iterator_type I=Attr->args_begin(), E=Attr->args_end(); I != E; ++I) { - MutexID Mutex(*I, Exp, FunDecl); - if (!Mutex.isValid()) - MutexID::warnInvalidLock(Handler, *I, Exp, FunDecl); - else { - addLock(Mutex, LockData(ExpLocation, LK)); - if (isScopedVar) { - // For scoped lockable vars, map this var to its underlying mutex. - DeclRefExpr DRE(VD, false, VD->getType(), VK_LValue, VD->getLocation()); - MutexID SMutex(&DRE, 0, 0); - addLock(SMutex, LockData(VD->getLocation(), LK, Mutex)); - } - } - } -} - -/// \brief This function removes a set of locks specified as attribute -/// arguments from the lockset. -void BuildLockset::removeLocksFromSet(UnlockFunctionAttr *Attr, - Expr *Exp, NamedDecl* FunDecl) { - SourceLocation ExpLocation; - if (Exp) ExpLocation = Exp->getExprLoc(); - - if (Attr->args_size() == 0) { - // The mutex held is the "this" object. - MutexID Mu(0, Exp, FunDecl); - if (!Mu.isValid()) - MutexID::warnInvalidLock(Handler, 0, Exp, FunDecl); - else - removeLock(Mu, ExpLocation); - return; - } - - for (UnlockFunctionAttr::args_iterator I = Attr->args_begin(), - E = Attr->args_end(); I != E; ++I) { - MutexID Mutex(*I, Exp, FunDecl); - if (!Mutex.isValid()) - MutexID::warnInvalidLock(Handler, *I, Exp, FunDecl); - else - removeLock(Mutex, ExpLocation); - } -} /// \brief Gets the value decl pointer from DeclRefExprs or MemberExprs const ValueDecl *BuildLockset::getValueDecl(Expr *Exp) { @@ -1093,11 +1700,12 @@ void BuildLockset::warnIfMutexNotHeld(const NamedDecl *D, Expr *Exp, ProtectedOperationKind POK) { LockKind LK = getLockKindFromAccessKind(AK); - MutexID Mutex(MutexExp, Exp, D); + SExpr Mutex(MutexExp, Exp, D); if (!Mutex.isValid()) - MutexID::warnInvalidLock(Handler, MutexExp, Exp, D); + SExpr::warnInvalidLock(Analyzer->Handler, MutexExp, Exp, D); else if (!locksetContainsAtLeast(Mutex, LK)) - Handler.handleMutexNotHeld(D, POK, Mutex.getName(), LK, Exp->getExprLoc()); + Analyzer->Handler.handleMutexNotHeld(D, POK, Mutex.toString(), LK, + Exp->getExprLoc()); } /// \brief This method identifies variable dereferences and checks pt_guarded_by @@ -1116,8 +1724,9 @@ void BuildLockset::checkDereference(Expr *Exp, AccessKind AK) { if(!D || !D->hasAttrs()) return; - if (D->getAttr<PtGuardedVarAttr>() && LSet.isEmpty()) - Handler.handleNoMutexHeld(D, POK_VarDereference, AK, Exp->getExprLoc()); + if (D->getAttr<PtGuardedVarAttr>() && FSet.isEmpty()) + Analyzer->Handler.handleNoMutexHeld(D, POK_VarDereference, AK, + Exp->getExprLoc()); const AttrVec &ArgAttrs = D->getAttrs(); for(unsigned i = 0, Size = ArgAttrs.size(); i < Size; ++i) @@ -1134,8 +1743,9 @@ void BuildLockset::checkAccess(Expr *Exp, AccessKind AK) { if(!D || !D->hasAttrs()) return; - if (D->getAttr<GuardedVarAttr>() && LSet.isEmpty()) - Handler.handleNoMutexHeld(D, POK_VarAccess, AK, Exp->getExprLoc()); + if (D->getAttr<GuardedVarAttr>() && FSet.isEmpty()) + Analyzer->Handler.handleNoMutexHeld(D, POK_VarAccess, AK, + Exp->getExprLoc()); const AttrVec &ArgAttrs = D->getAttrs(); for(unsigned i = 0, Size = ArgAttrs.size(); i < Size; ++i) @@ -1153,68 +1763,68 @@ void BuildLockset::checkAccess(Expr *Exp, AccessKind AK) { /// and check that the appropriate locks are held. Non-const method calls with /// the same signature as const method calls can be also treated as reads. /// -/// FIXME: We need to also visit CallExprs to catch/check global functions. -/// -/// FIXME: Do not flag an error for member variables accessed in constructors/ -/// destructors -void BuildLockset::handleCall(Expr *Exp, NamedDecl *D, VarDecl *VD) { - AttrVec &ArgAttrs = D->getAttrs(); +void BuildLockset::handleCall(Expr *Exp, const NamedDecl *D, VarDecl *VD) { + const AttrVec &ArgAttrs = D->getAttrs(); + MutexIDList ExclusiveLocksToAdd; + MutexIDList SharedLocksToAdd; + MutexIDList LocksToRemove; + for(unsigned i = 0; i < ArgAttrs.size(); ++i) { - Attr *Attr = ArgAttrs[i]; - switch (Attr->getKind()) { + Attr *At = const_cast<Attr*>(ArgAttrs[i]); + switch (At->getKind()) { // When we encounter an exclusive lock function, we need to add the lock // to our lockset with kind exclusive. case attr::ExclusiveLockFunction: { - ExclusiveLockFunctionAttr *A = cast<ExclusiveLockFunctionAttr>(Attr); - addLocksToSet(LK_Exclusive, A, Exp, D, VD); + ExclusiveLockFunctionAttr *A = cast<ExclusiveLockFunctionAttr>(At); + Analyzer->getMutexIDs(ExclusiveLocksToAdd, A, Exp, D); break; } // When we encounter a shared lock function, we need to add the lock // to our lockset with kind shared. case attr::SharedLockFunction: { - SharedLockFunctionAttr *A = cast<SharedLockFunctionAttr>(Attr); - addLocksToSet(LK_Shared, A, Exp, D, VD); + SharedLockFunctionAttr *A = cast<SharedLockFunctionAttr>(At); + Analyzer->getMutexIDs(SharedLocksToAdd, A, Exp, D); break; } // When we encounter an unlock function, we need to remove unlocked // mutexes from the lockset, and flag a warning if they are not there. case attr::UnlockFunction: { - UnlockFunctionAttr *UFAttr = cast<UnlockFunctionAttr>(Attr); - removeLocksFromSet(UFAttr, Exp, D); + UnlockFunctionAttr *A = cast<UnlockFunctionAttr>(At); + Analyzer->getMutexIDs(LocksToRemove, A, Exp, D); break; } case attr::ExclusiveLocksRequired: { - ExclusiveLocksRequiredAttr *ELRAttr = - cast<ExclusiveLocksRequiredAttr>(Attr); + ExclusiveLocksRequiredAttr *A = cast<ExclusiveLocksRequiredAttr>(At); for (ExclusiveLocksRequiredAttr::args_iterator - I = ELRAttr->args_begin(), E = ELRAttr->args_end(); I != E; ++I) + I = A->args_begin(), E = A->args_end(); I != E; ++I) warnIfMutexNotHeld(D, Exp, AK_Written, *I, POK_FunctionCall); break; } case attr::SharedLocksRequired: { - SharedLocksRequiredAttr *SLRAttr = cast<SharedLocksRequiredAttr>(Attr); + SharedLocksRequiredAttr *A = cast<SharedLocksRequiredAttr>(At); - for (SharedLocksRequiredAttr::args_iterator I = SLRAttr->args_begin(), - E = SLRAttr->args_end(); I != E; ++I) + for (SharedLocksRequiredAttr::args_iterator I = A->args_begin(), + E = A->args_end(); I != E; ++I) warnIfMutexNotHeld(D, Exp, AK_Read, *I, POK_FunctionCall); break; } case attr::LocksExcluded: { - LocksExcludedAttr *LEAttr = cast<LocksExcludedAttr>(Attr); - for (LocksExcludedAttr::args_iterator I = LEAttr->args_begin(), - E = LEAttr->args_end(); I != E; ++I) { - MutexID Mutex(*I, Exp, D); + LocksExcludedAttr *A = cast<LocksExcludedAttr>(At); + for (LocksExcludedAttr::args_iterator I = A->args_begin(), + E = A->args_end(); I != E; ++I) { + SExpr Mutex(*I, Exp, D); if (!Mutex.isValid()) - MutexID::warnInvalidLock(Handler, *I, Exp, D); + SExpr::warnInvalidLock(Analyzer->Handler, *I, Exp, D); else if (locksetContains(Mutex)) - Handler.handleFunExcludesLock(D->getName(), Mutex.getName(), - Exp->getExprLoc()); + Analyzer->Handler.handleFunExcludesLock(D->getName(), + Mutex.toString(), + Exp->getExprLoc()); } break; } @@ -1224,102 +1834,50 @@ void BuildLockset::handleCall(Expr *Exp, NamedDecl *D, VarDecl *VD) { break; } } -} - - -/// \brief Add lock to set, if the current block is in the taken branch of a -/// trylock. -template <class AttrType> -void BuildLockset::addTrylock(LockKind LK, AttrType *Attr, Expr *Exp, - NamedDecl *FunDecl, const CFGBlock *PredBlock, - const CFGBlock *CurrBlock, Expr *BrE, bool Neg) { - // Find out which branch has the lock - bool branch = 0; - if (CXXBoolLiteralExpr *BLE = dyn_cast_or_null<CXXBoolLiteralExpr>(BrE)) { - branch = BLE->getValue(); - } - else if (IntegerLiteral *ILE = dyn_cast_or_null<IntegerLiteral>(BrE)) { - branch = ILE->getValue().getBoolValue(); - } - int branchnum = branch ? 0 : 1; - if (Neg) branchnum = !branchnum; - // If we've taken the trylock branch, then add the lock - int i = 0; - for (CFGBlock::const_succ_iterator SI = PredBlock->succ_begin(), - SE = PredBlock->succ_end(); SI != SE && i < 2; ++SI, ++i) { - if (*SI == CurrBlock && i == branchnum) { - addLocksToSet(LK, Attr, Exp, FunDecl, 0); + // Figure out if we're calling the constructor of scoped lockable class + bool isScopedVar = false; + if (VD) { + if (const CXXConstructorDecl *CD = dyn_cast<const CXXConstructorDecl>(D)) { + const CXXRecordDecl* PD = CD->getParent(); + if (PD && PD->getAttr<ScopedLockableAttr>()) + isScopedVar = true; } } -} - -// If Cond can be traced back to a function call, return the call expression. -// The negate variable should be called with false, and will be set to true -// if the function call is negated, e.g. if (!mu.tryLock(...)) -CallExpr* BuildLockset::getTrylockCallExpr(Stmt *Cond, - LocalVariableMap::Context C, - bool &Negate) { - if (!Cond) - return 0; - - if (CallExpr *CallExp = dyn_cast<CallExpr>(Cond)) { - return CallExp; - } - else if (ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(Cond)) { - return getTrylockCallExpr(CE->getSubExpr(), C, Negate); + // Add locks. + SourceLocation Loc = Exp->getExprLoc(); + for (unsigned i=0,n=ExclusiveLocksToAdd.size(); i<n; ++i) { + Analyzer->addLock(FSet, ExclusiveLocksToAdd[i], + LockData(Loc, LK_Exclusive, isScopedVar)); } - else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Cond)) { - Expr *E = LocalVarMap.lookupExpr(DRE->getDecl(), C); - return getTrylockCallExpr(E, C, Negate); - } - else if (UnaryOperator *UOP = dyn_cast<UnaryOperator>(Cond)) { - if (UOP->getOpcode() == UO_LNot) { - Negate = !Negate; - return getTrylockCallExpr(UOP->getSubExpr(), C, Negate); - } + for (unsigned i=0,n=SharedLocksToAdd.size(); i<n; ++i) { + Analyzer->addLock(FSet, SharedLocksToAdd[i], + LockData(Loc, LK_Shared, isScopedVar)); } - // FIXME -- handle && and || as well. - return NULL; -} - - -/// \brief Process a conditional branch from a previous block to the current -/// block, looking for trylock calls. -void BuildLockset::handleTrylock(Stmt *Cond, const CFGBlock *PredBlock, - const CFGBlock *CurrBlock) { - bool Negate = false; - CallExpr *Exp = getTrylockCallExpr(Cond, LVarCtx, Negate); - if (!Exp) - return; - NamedDecl *FunDecl = dyn_cast_or_null<NamedDecl>(Exp->getCalleeDecl()); - if(!FunDecl || !FunDecl->hasAttrs()) - return; + // Add the managing object as a dummy mutex, mapped to the underlying mutex. + // FIXME -- this doesn't work if we acquire multiple locks. + if (isScopedVar) { + SourceLocation MLoc = VD->getLocation(); + DeclRefExpr DRE(VD, false, VD->getType(), VK_LValue, VD->getLocation()); + SExpr SMutex(&DRE, 0, 0); - // If the condition is a call to a Trylock function, then grab the attributes - AttrVec &ArgAttrs = FunDecl->getAttrs(); - for (unsigned i = 0; i < ArgAttrs.size(); ++i) { - Attr *Attr = ArgAttrs[i]; - switch (Attr->getKind()) { - case attr::ExclusiveTrylockFunction: { - ExclusiveTrylockFunctionAttr *A = - cast<ExclusiveTrylockFunctionAttr>(Attr); - addTrylock(LK_Exclusive, A, Exp, FunDecl, PredBlock, CurrBlock, - A->getSuccessValue(), Negate); - break; - } - case attr::SharedTrylockFunction: { - SharedTrylockFunctionAttr *A = - cast<SharedTrylockFunctionAttr>(Attr); - addTrylock(LK_Shared, A, Exp, FunDecl, PredBlock, CurrBlock, - A->getSuccessValue(), Negate); - break; - } - default: - break; + for (unsigned i=0,n=ExclusiveLocksToAdd.size(); i<n; ++i) { + Analyzer->addLock(FSet, SMutex, LockData(MLoc, LK_Exclusive, + ExclusiveLocksToAdd[i])); } + for (unsigned i=0,n=SharedLocksToAdd.size(); i<n; ++i) { + Analyzer->addLock(FSet, SMutex, LockData(MLoc, LK_Shared, + SharedLocksToAdd[i])); + } + } + + // Remove locks. + // FIXME -- should only fully remove if the attribute refers to 'this'. + bool Dtor = isa<CXXDestructorDecl>(D); + for (unsigned i=0,n=LocksToRemove.size(); i<n; ++i) { + Analyzer->removeLock(FSet, LocksToRemove[i], Loc, Dtor); } } @@ -1351,7 +1909,7 @@ void BuildLockset::VisitBinaryOperator(BinaryOperator *BO) { return; // adjust the context - LVarCtx = LocalVarMap.getNextContext(CtxIndex, BO, LVarCtx); + LVarCtx = Analyzer->LocalVarMap.getNextContext(CtxIndex, BO, LVarCtx); Expr *LHSExp = BO->getLHS()->IgnoreParenCasts(); checkAccess(LHSExp, AK_Written); @@ -1383,13 +1941,17 @@ void BuildLockset::VisitCXXConstructExpr(CXXConstructExpr *Exp) { void BuildLockset::VisitDeclStmt(DeclStmt *S) { // adjust the context - LVarCtx = LocalVarMap.getNextContext(CtxIndex, S, LVarCtx); + LVarCtx = Analyzer->LocalVarMap.getNextContext(CtxIndex, S, LVarCtx); DeclGroupRef DGrp = S->getDeclGroup(); for (DeclGroupRef::iterator I = DGrp.begin(), E = DGrp.end(); I != E; ++I) { Decl *D = *I; if (VarDecl *VD = dyn_cast_or_null<VarDecl>(D)) { Expr *E = VD->getInit(); + // handle constructors that involve temporaries + if (ExprWithCleanups *EWC = dyn_cast_or_null<ExprWithCleanups>(E)) + E = EWC->getSubExpr(); + if (CXXConstructExpr *CE = dyn_cast_or_null<CXXConstructExpr>(E)) { NamedDecl *CtorD = dyn_cast_or_null<NamedDecl>(CE->getConstructor()); if (!CtorD || !CtorD->hasAttrs()) @@ -1401,6 +1963,7 @@ void BuildLockset::VisitDeclStmt(DeclStmt *S) { } + /// \brief Compute the intersection of two locksets and issue warnings for any /// locks in the symmetric difference. /// @@ -1409,58 +1972,80 @@ void BuildLockset::VisitDeclStmt(DeclStmt *S) { /// A; if () then B; else C; D; we need to check that the lockset after B and C /// are the same. In the event of a difference, we use the intersection of these /// two locksets at the start of D. -Lockset ThreadSafetyAnalyzer::intersectAndWarn(const CFGBlockInfo &Block1, - CFGBlockSide Side1, - const CFGBlockInfo &Block2, - CFGBlockSide Side2, - LockErrorKind LEK) { - Lockset LSet1 = Block1.getSet(Side1); - Lockset LSet2 = Block2.getSet(Side2); - - Lockset Intersection = LSet1; - for (Lockset::iterator I = LSet2.begin(), E = LSet2.end(); I != E; ++I) { - const MutexID &LSet2Mutex = I.getKey(); - const LockData &LSet2LockData = I.getData(); - if (const LockData *LD = LSet1.lookup(LSet2Mutex)) { - if (LD->LKind != LSet2LockData.LKind) { - Handler.handleExclusiveAndShared(LSet2Mutex.getName(), - LSet2LockData.AcquireLoc, - LD->AcquireLoc); - if (LD->LKind != LK_Exclusive) - Intersection = LocksetFactory.add(Intersection, LSet2Mutex, - LSet2LockData); +/// +/// \param LSet1 The first lockset. +/// \param LSet2 The second lockset. +/// \param JoinLoc The location of the join point for error reporting +/// \param LEK1 The error message to report if a mutex is missing from LSet1 +/// \param LEK2 The error message to report if a mutex is missing from Lset2 +void ThreadSafetyAnalyzer::intersectAndWarn(FactSet &FSet1, + const FactSet &FSet2, + SourceLocation JoinLoc, + LockErrorKind LEK1, + LockErrorKind LEK2, + bool Modify) { + FactSet FSet1Orig = FSet1; + + for (FactSet::const_iterator I = FSet2.begin(), E = FSet2.end(); + I != E; ++I) { + const SExpr &FSet2Mutex = FactMan[*I].MutID; + const LockData &LDat2 = FactMan[*I].LDat; + + if (const LockData *LDat1 = FSet1.findLock(FactMan, FSet2Mutex)) { + if (LDat1->LKind != LDat2.LKind) { + Handler.handleExclusiveAndShared(FSet2Mutex.toString(), + LDat2.AcquireLoc, + LDat1->AcquireLoc); + if (Modify && LDat1->LKind != LK_Exclusive) { + FSet1.removeLock(FactMan, FSet2Mutex); + FSet1.addLock(FactMan, FSet2Mutex, LDat2); + } } } else { - Handler.handleMutexHeldEndOfScope(LSet2Mutex.getName(), - LSet2LockData.AcquireLoc, - Block1.getLocation(Side1), LEK); + if (LDat2.UnderlyingMutex.isValid()) { + if (FSet2.findLock(FactMan, LDat2.UnderlyingMutex)) { + // If this is a scoped lock that manages another mutex, and if the + // underlying mutex is still held, then warn about the underlying + // mutex. + Handler.handleMutexHeldEndOfScope(LDat2.UnderlyingMutex.toString(), + LDat2.AcquireLoc, + JoinLoc, LEK1); + } + } + else if (!LDat2.Managed) + Handler.handleMutexHeldEndOfScope(FSet2Mutex.toString(), + LDat2.AcquireLoc, + JoinLoc, LEK1); } } - for (Lockset::iterator I = LSet1.begin(), E = LSet1.end(); I != E; ++I) { - if (!LSet2.contains(I.getKey())) { - const MutexID &Mutex = I.getKey(); - const LockData &MissingLock = I.getData(); - Handler.handleMutexHeldEndOfScope(Mutex.getName(), - MissingLock.AcquireLoc, - Block2.getLocation(Side2), LEK); - Intersection = LocksetFactory.remove(Intersection, Mutex); + for (FactSet::const_iterator I = FSet1.begin(), E = FSet1.end(); + I != E; ++I) { + const SExpr &FSet1Mutex = FactMan[*I].MutID; + const LockData &LDat1 = FactMan[*I].LDat; + + if (!FSet2.findLock(FactMan, FSet1Mutex)) { + if (LDat1.UnderlyingMutex.isValid()) { + if (FSet1Orig.findLock(FactMan, LDat1.UnderlyingMutex)) { + // If this is a scoped lock that manages another mutex, and if the + // underlying mutex is still held, then warn about the underlying + // mutex. + Handler.handleMutexHeldEndOfScope(LDat1.UnderlyingMutex.toString(), + LDat1.AcquireLoc, + JoinLoc, LEK1); + } + } + else if (!LDat1.Managed) + Handler.handleMutexHeldEndOfScope(FSet1Mutex.toString(), + LDat1.AcquireLoc, + JoinLoc, LEK2); + if (Modify) + FSet1.removeLock(FactMan, FSet1Mutex); } } - return Intersection; } -Lockset ThreadSafetyAnalyzer::addLock(Lockset &LSet, Expr *MutexExp, - const NamedDecl *D, - LockKind LK, SourceLocation Loc) { - MutexID Mutex(MutexExp, 0, D); - if (!Mutex.isValid()) { - MutexID::warnInvalidLock(Handler, MutexExp, 0, D); - return LSet; - } - LockData NewLock(Loc, LK); - return LocksetFactory.add(LSet, Mutex, NewLock); -} + /// \brief Check a function's CFG for thread-safety violations. /// @@ -1472,6 +2057,8 @@ void ThreadSafetyAnalyzer::runAnalysis(AnalysisDeclContext &AC) { if (!CFGraph) return; const NamedDecl *D = dyn_cast_or_null<NamedDecl>(AC.getDecl()); + // AC.dumpCFG(true); + if (!D) return; // Ignore anonymous functions for now. if (D->getAttr<NoThreadSafetyAnalysisAttr>()) @@ -1485,8 +2072,8 @@ void ThreadSafetyAnalyzer::runAnalysis(AnalysisDeclContext &AC) { if (isa<CXXDestructorDecl>(D)) return; // Don't check inside destructors. - std::vector<CFGBlockInfo> BlockInfo(CFGraph->getNumBlockIDs(), - CFGBlockInfo::getEmptyBlockInfo(LocksetFactory, LocalVarMap)); + BlockInfo.resize(CFGraph->getNumBlockIDs(), + CFGBlockInfo::getEmptyBlockInfo(LocalVarMap)); // We need to explore the CFG via a "topological" ordering. // That way, we will be guaranteed to have information about required @@ -1505,27 +2092,22 @@ void ThreadSafetyAnalyzer::runAnalysis(AnalysisDeclContext &AC) { // FIXME: is there a more intelligent way to check lock/unlock functions? if (!SortedGraph->empty() && D->hasAttrs()) { const CFGBlock *FirstBlock = *SortedGraph->begin(); - Lockset &InitialLockset = BlockInfo[FirstBlock->getBlockID()].EntrySet; + FactSet &InitialLockset = BlockInfo[FirstBlock->getBlockID()].EntrySet; const AttrVec &ArgAttrs = D->getAttrs(); + + MutexIDList ExclusiveLocksToAdd; + MutexIDList SharedLocksToAdd; + + SourceLocation Loc = D->getLocation(); for (unsigned i = 0; i < ArgAttrs.size(); ++i) { Attr *Attr = ArgAttrs[i]; - SourceLocation AttrLoc = Attr->getLocation(); - if (SharedLocksRequiredAttr *SLRAttr - = dyn_cast<SharedLocksRequiredAttr>(Attr)) { - for (SharedLocksRequiredAttr::args_iterator - SLRIter = SLRAttr->args_begin(), - SLREnd = SLRAttr->args_end(); SLRIter != SLREnd; ++SLRIter) - InitialLockset = addLock(InitialLockset, - *SLRIter, D, LK_Shared, - AttrLoc); - } else if (ExclusiveLocksRequiredAttr *ELRAttr - = dyn_cast<ExclusiveLocksRequiredAttr>(Attr)) { - for (ExclusiveLocksRequiredAttr::args_iterator - ELRIter = ELRAttr->args_begin(), - ELREnd = ELRAttr->args_end(); ELRIter != ELREnd; ++ELRIter) - InitialLockset = addLock(InitialLockset, - *ELRIter, D, LK_Exclusive, - AttrLoc); + Loc = Attr->getLocation(); + if (ExclusiveLocksRequiredAttr *A + = dyn_cast<ExclusiveLocksRequiredAttr>(Attr)) { + getMutexIDs(ExclusiveLocksToAdd, A, (Expr*) 0, D); + } else if (SharedLocksRequiredAttr *A + = dyn_cast<SharedLocksRequiredAttr>(Attr)) { + getMutexIDs(SharedLocksToAdd, A, (Expr*) 0, D); } else if (isa<UnlockFunctionAttr>(Attr)) { // Don't try to check unlock functions for now return; @@ -1535,8 +2117,24 @@ void ThreadSafetyAnalyzer::runAnalysis(AnalysisDeclContext &AC) { } else if (isa<SharedLockFunctionAttr>(Attr)) { // Don't try to check lock functions for now return; + } else if (isa<ExclusiveTrylockFunctionAttr>(Attr)) { + // Don't try to check trylock functions for now + return; + } else if (isa<SharedTrylockFunctionAttr>(Attr)) { + // Don't try to check trylock functions for now + return; } } + + // FIXME -- Loc can be wrong here. + for (unsigned i=0,n=ExclusiveLocksToAdd.size(); i<n; ++i) { + addLock(InitialLockset, ExclusiveLocksToAdd[i], + LockData(Loc, LK_Exclusive)); + } + for (unsigned i=0,n=SharedLocksToAdd.size(); i<n; ++i) { + addLock(InitialLockset, SharedLocksToAdd[i], + LockData(Loc, LK_Shared)); + } } for (PostOrderCFGView::iterator I = SortedGraph->begin(), @@ -1587,15 +2185,16 @@ void ThreadSafetyAnalyzer::runAnalysis(AnalysisDeclContext &AC) { int PrevBlockID = (*PI)->getBlockID(); CFGBlockInfo *PrevBlockInfo = &BlockInfo[PrevBlockID]; + FactSet PrevLockset; + getEdgeLockset(PrevLockset, PrevBlockInfo->ExitSet, *PI, CurrBlock); if (!LocksetInitialized) { - CurrBlockInfo->EntrySet = PrevBlockInfo->ExitSet; + CurrBlockInfo->EntrySet = PrevLockset; LocksetInitialized = true; } else { - CurrBlockInfo->EntrySet = - intersectAndWarn(*CurrBlockInfo, CBS_Entry, - *PrevBlockInfo, CBS_Exit, - LEK_LockedSomePredecessors); + intersectAndWarn(CurrBlockInfo->EntrySet, PrevLockset, + CurrBlockInfo->EntryLoc, + LEK_LockedSomePredecessors); } } @@ -1619,23 +2218,20 @@ void ThreadSafetyAnalyzer::runAnalysis(AnalysisDeclContext &AC) { const Stmt *Terminator = PrevBlock->getTerminator(); bool IsLoop = Terminator && isa<ContinueStmt>(Terminator); + FactSet PrevLockset; + getEdgeLockset(PrevLockset, PrevBlockInfo->ExitSet, + PrevBlock, CurrBlock); + // Do not update EntrySet. - intersectAndWarn(*CurrBlockInfo, CBS_Entry, *PrevBlockInfo, CBS_Exit, + intersectAndWarn(CurrBlockInfo->EntrySet, PrevLockset, + PrevBlockInfo->ExitLoc, IsLoop ? LEK_LockedSomeLoopIterations - : LEK_LockedSomePredecessors); + : LEK_LockedSomePredecessors, + false); } } BuildLockset LocksetBuilder(this, *CurrBlockInfo); - CFGBlock::const_pred_iterator PI = CurrBlock->pred_begin(), - PE = CurrBlock->pred_end(); - if (PI != PE) { - // If the predecessor ended in a branch, then process any trylocks. - // FIXME -- check to make sure there's only one predecessor. - if (Stmt *TCE = (*PI)->getTerminatorCondition()) { - LocksetBuilder.handleTrylock(TCE, *PI, CurrBlock); - } - } // Visit all the statements in the basic block. for (CFGBlock::const_iterator BI = CurrBlock->begin(), @@ -1665,7 +2261,7 @@ void ThreadSafetyAnalyzer::runAnalysis(AnalysisDeclContext &AC) { break; } } - CurrBlockInfo->ExitSet = LocksetBuilder.LSet; + CurrBlockInfo->ExitSet = LocksetBuilder.FSet; // For every back edge from CurrBlock (the end of the loop) to another block // (FirstLoopBlock) we need to check that the Lockset of Block is equal to @@ -1679,19 +2275,24 @@ void ThreadSafetyAnalyzer::runAnalysis(AnalysisDeclContext &AC) { continue; CFGBlock *FirstLoopBlock = *SI; - CFGBlockInfo &PreLoop = BlockInfo[FirstLoopBlock->getBlockID()]; - CFGBlockInfo &LoopEnd = BlockInfo[CurrBlockID]; - intersectAndWarn(LoopEnd, CBS_Exit, PreLoop, CBS_Entry, - LEK_LockedSomeLoopIterations); + CFGBlockInfo *PreLoop = &BlockInfo[FirstLoopBlock->getBlockID()]; + CFGBlockInfo *LoopEnd = &BlockInfo[CurrBlockID]; + intersectAndWarn(LoopEnd->ExitSet, PreLoop->EntrySet, + PreLoop->EntryLoc, + LEK_LockedSomeLoopIterations, + false); } } - CFGBlockInfo &Initial = BlockInfo[CFGraph->getEntry().getBlockID()]; - CFGBlockInfo &Final = BlockInfo[CFGraph->getExit().getBlockID()]; + CFGBlockInfo *Initial = &BlockInfo[CFGraph->getEntry().getBlockID()]; + CFGBlockInfo *Final = &BlockInfo[CFGraph->getExit().getBlockID()]; // FIXME: Should we call this function for all blocks which exit the function? - intersectAndWarn(Initial, CBS_Entry, Final, CBS_Exit, - LEK_LockedAtEndOfFunction); + intersectAndWarn(Initial->EntrySet, Final->ExitSet, + Final->ExitLoc, + LEK_LockedAtEndOfFunction, + LEK_NotLockedAtEndOfFunction, + false); } } // end anonymous namespace |
