X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=include%2Fllvm%2FAnalysis%2FCallGraph.h;h=591484dd278247db9400d4c833e3d977303aa9e1;hp=d8fadc1c5fbf4e6a5ec818810dbd5f816812e010;hb=0b8c9a80f20772c3793201ab5b251d3520b9cea3;hpb=7e70829632f82de15db187845666aaca6e04b792 diff --git a/include/llvm/Analysis/CallGraph.h b/include/llvm/Analysis/CallGraph.h index d8fadc1c5fb..591484dd278 100644 --- a/include/llvm/Analysis/CallGraph.h +++ b/include/llvm/Analysis/CallGraph.h @@ -1,39 +1,49 @@ -//===- CallGraph.h - Build a Module's call graph -----------------*- C++ -*--=// +//===- CallGraph.h - Build a Module's call graph ----------------*- C++ -*-===// // -// This interface is used to build and manipulate a call graph, which is a very +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This interface is used to build and manipulate a call graph, which is a very // useful tool for interprocedural optimization. // -// Every method in a module is represented as a node in the call graph. The -// callgraph node keeps track of which methods the are called by the method +// Every function in a module is represented as a node in the call graph. The +// callgraph node keeps track of which functions the are called by the function // corresponding to the node. // -// A call graph will contain nodes where the method that they correspond to is -// null. This 'external' node is used to represent control flow that is not -// represented (or analyzable) in the module. As such, the external node will -// have edges to methods with the following properties: -// 1. All methods in the module without internal linkage, since they could -// be called by methods outside of the our analysis capability. -// 2. All methods whose address is used for something more than a direct call, -// for example being stored into a memory location. Since they may be -// called by an unknown caller later, they must be tracked as such. +// A call graph may contain nodes where the function that they correspond to is +// null. These 'external' nodes are used to represent control flow that is not +// represented (or analyzable) in the module. In particular, this analysis +// builds one external node such that: +// 1. All functions in the module without internal linkage will have edges +// from this external node, indicating that they could be called by +// functions outside of the module. +// 2. All functions whose address is used for something more than a direct +// call, for example being stored into a memory location will also have an +// edge from this external node. Since they may be called by an unknown +// caller later, they must be tracked as such. // -// Similarly, methods have a call edge to the external node iff: -// 1. The method is external, reflecting the fact that they could call +// There is a second external node added for calls that leave this module. +// Functions have a call edge to the external node iff: +// 1. The function is external, reflecting the fact that they could call // anything without internal linkage or that has its address taken. -// 2. The method contains an indirect method call. +// 2. The function contains an indirect function call. // // As an extension in the future, there may be multiple nodes with a null -// method. These will be used when we can prove (through pointer analysis) that -// an indirect call site can call only a specific set of methods. +// function. These will be used when we can prove (through pointer analysis) +// that an indirect call site can call only a specific set of functions. // // Because of these properties, the CallGraph captures a conservative superset // of all of the caller-callee relationships, which is useful for // transformations. // // The CallGraph class also attempts to figure out what the root of the -// CallGraph is, which is currently does by looking for a method named 'main'. -// If no method named 'main' is found, the external node is used as the entry -// node, reflecting the fact that any method without internal linkage could +// CallGraph is, which it currently does by looking for a function named 'main'. +// If no function named 'main' is found, the external node is used as the entry +// node, reflecting the fact that any function without internal linkage could // be called into (which is common for libraries). // //===----------------------------------------------------------------------===// @@ -41,8 +51,17 @@ #ifndef LLVM_ANALYSIS_CALLGRAPH_H #define LLVM_ANALYSIS_CALLGRAPH_H -#include "Support/GraphTraits.h" +#include "llvm/ADT/GraphTraits.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/IR/Function.h" #include "llvm/Pass.h" +#include "llvm/Support/CallSite.h" +#include "llvm/Support/IncludeFile.h" +#include "llvm/Support/ValueHandle.h" +#include + +namespace llvm { + class Function; class Module; class CallGraphNode; @@ -50,174 +69,264 @@ class CallGraphNode; //===----------------------------------------------------------------------===// // CallGraph class definition // -class CallGraph : public Pass { +class CallGraph { +protected: Module *Mod; // The module this call graph represents - typedef std::map MethodMapTy; - MethodMapTy MethodMap; // Map from a method to its node + typedef std::map FunctionMapTy; + FunctionMapTy FunctionMap; // Map from a function to its node - // Root is root of the call graph, or the external node if a 'main' function - // couldn't be found. ExternalNode is equivalent to (*this)[0]. - // - CallGraphNode *Root, *ExternalNode; public: - + static char ID; // Class identification, replacement for typeinfo //===--------------------------------------------------------------------- - // Accessors... + // Accessors. // - typedef MethodMapTy::iterator iterator; - typedef MethodMapTy::const_iterator const_iterator; + typedef FunctionMapTy::iterator iterator; + typedef FunctionMapTy::const_iterator const_iterator; - inline CallGraphNode *getRoot() { return Root; } - inline const CallGraphNode *getRoot() const { return Root; } - inline iterator begin() { return MethodMap.begin(); } - inline iterator end() { return MethodMap.end(); } - inline const_iterator begin() const { return MethodMap.begin(); } - inline const_iterator end() const { return MethodMap.end(); } + /// getModule - Return the module the call graph corresponds to. + /// + Module &getModule() const { return *Mod; } + inline iterator begin() { return FunctionMap.begin(); } + inline iterator end() { return FunctionMap.end(); } + inline const_iterator begin() const { return FunctionMap.begin(); } + inline const_iterator end() const { return FunctionMap.end(); } - // Subscripting operators, return the call graph node for the provided method + // Subscripting operators, return the call graph node for the provided + // function inline const CallGraphNode *operator[](const Function *F) const { - const_iterator I = MethodMap.find(F); - assert(I != MethodMap.end() && "Method not in callgraph!"); + const_iterator I = FunctionMap.find(F); + assert(I != FunctionMap.end() && "Function not in callgraph!"); return I->second; } inline CallGraphNode *operator[](const Function *F) { - const_iterator I = MethodMap.find(F); - assert(I != MethodMap.end() && "Method not in callgraph!"); + const_iterator I = FunctionMap.find(F); + assert(I != FunctionMap.end() && "Function not in callgraph!"); return I->second; } - //===--------------------------------------------------------------------- - // Methods to keep a call graph up to date with a method that has been - // modified - // - void addMethodToModule(Function *Meth); - - - // removeMethodFromModule - Unlink the method from this module, returning it. - // Because this removes the method from the module, the call graph node is - // destroyed. This is only valid if the method does not call any other - // methods (ie, there are no edges in it's CGN). The easiest way to do this - // is to dropAllReferences before calling this. - // - Function *removeMethodFromModule(CallGraphNode *CGN); - Function *removeMethodFromModule(Function *Meth) { - return removeMethodFromModule((*this)[Meth]); - } + /// Returns the CallGraphNode which is used to represent undetermined calls + /// into the callgraph. Override this if you want behavioral inheritance. + virtual CallGraphNode* getExternalCallingNode() const { return 0; } + virtual CallGraphNode* getCallsExternalNode() const { return 0; } + /// Return the root/main method in the module, or some other root node, such + /// as the externalcallingnode. Overload these if you behavioral + /// inheritance. + virtual CallGraphNode* getRoot() { return 0; } + virtual const CallGraphNode* getRoot() const { return 0; } //===--------------------------------------------------------------------- - // Pass infrastructure interface glue code... + // Functions to keep a call graph up to date with a function that has been + // modified. // - static AnalysisID ID; // We are an analysis, we must have an ID - - CallGraph(AnalysisID AID) : Root(0) { assert(AID == ID); } - ~CallGraph() { destroy(); } - - virtual const char *getPassName() const { return "Call Graph Construction"; } - - // run - Compute the call graph for the specified module. - virtual bool run(Module &M); - // getAnalysisUsage - This obviously provides a call graph - virtual void getAnalysisUsage(AnalysisUsage &AU) const { - AU.setPreservesAll(); - AU.addProvided(ID); + /// removeFunctionFromModule - Unlink the function from this module, returning + /// it. Because this removes the function from the module, the call graph + /// node is destroyed. This is only valid if the function does not call any + /// other functions (ie, there are no edges in it's CGN). The easiest way to + /// do this is to dropAllReferences before calling this. + /// + Function *removeFunctionFromModule(CallGraphNode *CGN); + Function *removeFunctionFromModule(Function *F) { + return removeFunctionFromModule((*this)[F]); } - // releaseMemory - Data structures can be large, so free memory aggressively. - virtual void releaseMemory() { - destroy(); - } + /// getOrInsertFunction - This method is identical to calling operator[], but + /// it will insert a new CallGraphNode for the specified function if one does + /// not already exist. + CallGraphNode *getOrInsertFunction(const Function *F); + + /// spliceFunction - Replace the function represented by this node by another. + /// This does not rescan the body of the function, so it is suitable when + /// splicing the body of one function to another while also updating all + /// callers from the old function to the new. + /// + void spliceFunction(const Function *From, const Function *To); -private: //===--------------------------------------------------------------------- - // Implementation of CallGraph construction + // Pass infrastructure interface glue code. // +protected: + CallGraph() {} - // getNodeFor - Return the node for the specified function or create one if it - // does not already exist. - // - CallGraphNode *getNodeFor(Function *F); +public: + virtual ~CallGraph() { destroy(); } - // addToCallGraph - Add a function to the call graph, and link the node to all - // of the methods that it calls. - // - void addToCallGraph(Function *F); + /// initialize - Call this method before calling other methods, + /// re/initializes the state of the CallGraph. + /// + void initialize(Module &M); + void print(raw_ostream &o, Module *) const; + void dump() const; +protected: // destroy - Release memory for the call graph - void destroy(); + virtual void destroy(); }; - //===----------------------------------------------------------------------===// -// CallGraphNode class definition +// CallGraphNode class definition. // class CallGraphNode { - Function *Meth; - std::vector CalledMethods; + friend class CallGraph; + + AssertingVH F; - CallGraphNode(const CallGraphNode &); // Do not implement + // CallRecord - This is a pair of the calling instruction (a call or invoke) + // and the callgraph node being called. public: + typedef std::pair CallRecord; +private: + std::vector CalledFunctions; + + /// NumReferences - This is the number of times that this CallGraphNode occurs + /// in the CalledFunctions array of this or other CallGraphNodes. + unsigned NumReferences; + + CallGraphNode(const CallGraphNode &) LLVM_DELETED_FUNCTION; + void operator=(const CallGraphNode &) LLVM_DELETED_FUNCTION; + + void DropRef() { --NumReferences; } + void AddRef() { ++NumReferences; } +public: + typedef std::vector CalledFunctionsVector; + + + // CallGraphNode ctor - Create a node for the specified function. + inline CallGraphNode(Function *f) : F(f), NumReferences(0) {} + ~CallGraphNode() { + assert(NumReferences == 0 && "Node deleted while references remain"); + } + //===--------------------------------------------------------------------- - // Accessor methods... + // Accessor methods. // - typedef std::vector::iterator iterator; - typedef std::vector::const_iterator const_iterator; + typedef std::vector::iterator iterator; + typedef std::vector::const_iterator const_iterator; - // getMethod - Return the method that this call graph node represents... - Function *getMethod() const { return Meth; } + // getFunction - Return the function that this call graph node represents. + Function *getFunction() const { return F; } - inline iterator begin() { return CalledMethods.begin(); } - inline iterator end() { return CalledMethods.end(); } - inline const_iterator begin() const { return CalledMethods.begin(); } - inline const_iterator end() const { return CalledMethods.end(); } - inline unsigned size() const { return CalledMethods.size(); } + inline iterator begin() { return CalledFunctions.begin(); } + inline iterator end() { return CalledFunctions.end(); } + inline const_iterator begin() const { return CalledFunctions.begin(); } + inline const_iterator end() const { return CalledFunctions.end(); } + inline bool empty() const { return CalledFunctions.empty(); } + inline unsigned size() const { return (unsigned)CalledFunctions.size(); } - // Subscripting operator - Return the i'th called method... + /// getNumReferences - Return the number of other CallGraphNodes in this + /// CallGraph that reference this node in their callee list. + unsigned getNumReferences() const { return NumReferences; } + + // Subscripting operator - Return the i'th called function. // - inline CallGraphNode *operator[](unsigned i) const { return CalledMethods[i];} + CallGraphNode *operator[](unsigned i) const { + assert(i < CalledFunctions.size() && "Invalid index"); + return CalledFunctions[i].second; + } + /// dump - Print out this call graph node. + /// + void dump() const; + void print(raw_ostream &OS) const; //===--------------------------------------------------------------------- - // Methods to keep a call graph up to date with a method that has been + // Methods to keep a call graph up to date with a function that has been // modified // - void removeAllCalledMethods() { - CalledMethods.clear(); + /// removeAllCalledFunctions - As the name implies, this removes all edges + /// from this CallGraphNode to any functions it calls. + void removeAllCalledFunctions() { + while (!CalledFunctions.empty()) { + CalledFunctions.back().second->DropRef(); + CalledFunctions.pop_back(); + } + } + + /// stealCalledFunctionsFrom - Move all the callee information from N to this + /// node. + void stealCalledFunctionsFrom(CallGraphNode *N) { + assert(CalledFunctions.empty() && + "Cannot steal callsite information if I already have some"); + std::swap(CalledFunctions, N->CalledFunctions); } + -private: // Stuff to construct the node, used by CallGraph - friend class CallGraph; + /// addCalledFunction - Add a function to the list of functions called by this + /// one. + void addCalledFunction(CallSite CS, CallGraphNode *M) { + assert(!CS.getInstruction() || + !CS.getCalledFunction() || + !CS.getCalledFunction()->isIntrinsic()); + CalledFunctions.push_back(std::make_pair(CS.getInstruction(), M)); + M->AddRef(); + } - // CallGraphNode ctor - Create a node for the specified method... - inline CallGraphNode(Function *F) : Meth(F) {} + void removeCallEdge(iterator I) { + I->second->DropRef(); + *I = CalledFunctions.back(); + CalledFunctions.pop_back(); + } + + + /// removeCallEdgeFor - This method removes the edge in the node for the + /// specified call site. Note that this method takes linear time, so it + /// should be used sparingly. + void removeCallEdgeFor(CallSite CS); + + /// removeAnyCallEdgeTo - This method removes all call edges from this node + /// to the specified callee function. This takes more time to execute than + /// removeCallEdgeTo, so it should not be used unless necessary. + void removeAnyCallEdgeTo(CallGraphNode *Callee); + + /// removeOneAbstractEdgeTo - Remove one edge associated with a null callsite + /// from this node to the specified callee function. + void removeOneAbstractEdgeTo(CallGraphNode *Callee); - // addCalledMethod add a method to the list of methods called by this one - void addCalledMethod(CallGraphNode *M) { - CalledMethods.push_back(M); + /// replaceCallEdge - This method replaces the edge in the node for the + /// specified call site with a new one. Note that this method takes linear + /// time, so it should be used sparingly. + void replaceCallEdge(CallSite CS, CallSite NewCS, CallGraphNode *NewNode); + + /// allReferencesDropped - This is a special function that should only be + /// used by the CallGraph class. + void allReferencesDropped() { + NumReferences = 0; } }; - - //===----------------------------------------------------------------------===// // GraphTraits specializations for call graphs so that they can be treated as -// graphs by the generic graph algorithms... +// graphs by the generic graph algorithms. // // Provide graph traits for tranversing call graphs using standard graph // traversals. template <> struct GraphTraits { typedef CallGraphNode NodeType; - typedef NodeType::iterator ChildIteratorType; + + typedef CallGraphNode::CallRecord CGNPairTy; + typedef std::pointer_to_unary_function CGNDerefFun; static NodeType *getEntryNode(CallGraphNode *CGN) { return CGN; } - static inline ChildIteratorType child_begin(NodeType *N) { return N->begin();} - static inline ChildIteratorType child_end (NodeType *N) { return N->end(); } + + typedef mapped_iterator ChildIteratorType; + + static inline ChildIteratorType child_begin(NodeType *N) { + return map_iterator(N->begin(), CGNDerefFun(CGNDeref)); + } + static inline ChildIteratorType child_end (NodeType *N) { + return map_iterator(N->end(), CGNDerefFun(CGNDeref)); + } + + static CallGraphNode *CGNDeref(CGNPairTy P) { + return P.second; + } + }; template <> struct GraphTraits { @@ -229,35 +338,41 @@ template <> struct GraphTraits { static inline ChildIteratorType child_end (NodeType *N) { return N->end(); } }; - -template<> struct GraphTraits : - public GraphTraits { +template<> struct GraphTraits : public GraphTraits { static NodeType *getEntryNode(CallGraph *CGN) { - return CGN->getRoot(); + return CGN->getExternalCallingNode(); // Start at the external node! + } + typedef std::pair PairTy; + typedef std::pointer_to_unary_function DerefFun; + + // nodes_iterator/begin/end - Allow iteration over all nodes in the graph + typedef mapped_iterator nodes_iterator; + static nodes_iterator nodes_begin(CallGraph *CG) { + return map_iterator(CG->begin(), DerefFun(CGdereference)); + } + static nodes_iterator nodes_end (CallGraph *CG) { + return map_iterator(CG->end(), DerefFun(CGdereference)); + } + + static CallGraphNode &CGdereference(PairTy P) { + return *P.second; } }; + template<> struct GraphTraits : public GraphTraits { static NodeType *getEntryNode(const CallGraph *CGN) { - return CGN->getRoot(); + return CGN->getExternalCallingNode(); } + // nodes_iterator/begin/end - Allow iteration over all nodes in the graph + typedef CallGraph::const_iterator nodes_iterator; + static nodes_iterator nodes_begin(const CallGraph *CG) { return CG->begin(); } + static nodes_iterator nodes_end (const CallGraph *CG) { return CG->end(); } }; +} // End llvm namespace -//===----------------------------------------------------------------------===// -// Printing support for Call Graphs -// - -// Stuff for printing out a callgraph... - -void WriteToOutput(const CallGraph &, std::ostream &o); -inline std::ostream &operator <<(std::ostream &o, const CallGraph &CG) { - WriteToOutput(CG, o); return o; -} - -void WriteToOutput(const CallGraphNode *, std::ostream &o); -inline std::ostream &operator <<(std::ostream &o, const CallGraphNode *CGN) { - WriteToOutput(CGN, o); return o; -} +// Make sure that any clients of this file link in CallGraph.cpp +FORCE_DEFINING_FILE_TO_BE_LINKED(CallGraph) #endif