X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FAnalysis%2FCallGraph.h;h=de839694dc8a3d812635c6321eeab54683856d45;hb=b679de2a21f5ecbae81b444290d72af93aa5b0b3;hp=62b1846952ba0f3ce0ca9c7bd050b04a29573524;hpb=8bbc97905277859da8fad2ca7e9b5ce8a6b313c1;p=oota-llvm.git diff --git a/include/llvm/Analysis/CallGraph.h b/include/llvm/Analysis/CallGraph.h index 62b1846952b..de839694dc8 100644 --- a/include/llvm/Analysis/CallGraph.h +++ b/include/llvm/Analysis/CallGraph.h @@ -1,173 +1,326 @@ -//===- llvm/Analysis/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. // -// This call graph represents a dynamic method invocation as a null method node. -// A call graph may only have up to one null method node that represents all of -// the dynamic method invocations. +// 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 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. // -// Additionally, the 'root' node of a call graph represents the "entry point" -// node of the graph, which has an edge to every external method in the graph. -// This node has a null method pointer. +// 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 function contains an indirect function call. +// +// As an extension in the future, there may be multiple nodes with a null +// 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 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). // //===----------------------------------------------------------------------===// #ifndef LLVM_ANALYSIS_CALLGRAPH_H #define LLVM_ANALYSIS_CALLGRAPH_H -#include "llvm/Support/GraphTraits.h" +#include "llvm/ADT/GraphTraits.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/Pass.h" +#include "llvm/Support/CallSite.h" +#include "llvm/System/IncludeFile.h" #include -#include -class Method; + +namespace llvm { + +class Function; class Module; +class CallGraphNode; -namespace cfg { +//===----------------------------------------------------------------------===// +// CallGraph class definition +// +class CallGraph { +protected: + Module *Mod; // The module this call graph represents -class CallGraph; -class CallGraphNode { - Method *Meth; - vector CalledMethods; + typedef std::map FunctionMapTy; + FunctionMapTy FunctionMap; // Map from a function to its node - CallGraphNode(const CallGraphNode &); // Do not implement public: - typedef vector::iterator iterator; - typedef vector::const_iterator const_iterator; + static char ID; // Class identification, replacement for typeinfo + //===--------------------------------------------------------------------- + // Accessors... + // + typedef FunctionMapTy::iterator iterator; + typedef FunctionMapTy::const_iterator const_iterator; + + /// 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 + // function + inline const CallGraphNode *operator[](const Function *F) const { + 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 = FunctionMap.find(F); + assert(I != FunctionMap.end() && "Function not in callgraph!"); + return I->second; + } - // getMethod - Return the method that this call graph node represents... - Method *getMethod() const { return 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; } - 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(); } + /// 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; } - inline CallGraphNode *operator[](unsigned i) const { return CalledMethods[i];} + //===--------------------------------------------------------------------- + // Functions to keep a call graph up to date with a function that has been + // modified. + // - void removeAllCalledMethods() { - CalledMethods.clear(); + /// 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]); } -private: // Stuff to construct the node, used by CallGraph - friend class CallGraph; + /// changeFunction - This method changes the function associated with this + /// CallGraphNode, for use by transformations that need to change the + /// prototype of a Function (thus they must create a new Function and move the + /// old code over). + void changeFunction(Function *OldF, Function *NewF); - // CallGraphNode ctor - Create a node for the specified method... - inline CallGraphNode(Method *M) : Meth(M) {} - - // addCalledMethod add a method to the list of methods called by this one - void addCalledMethod(CallGraphNode *M) { - CalledMethods.push_back(M); - } -}; + /// 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); + //===--------------------------------------------------------------------- + // Pass infrastructure interface glue code... + // +protected: + CallGraph() {} -class CallGraph { - Module *Mod; // The module this call graph represents +public: + virtual ~CallGraph() { destroy(); } + + /// initialize - Call this method before calling other methods, + /// re/initializes the state of the CallGraph. + /// + void initialize(Module &M); - typedef map MethodMapTy; - MethodMapTy MethodMap; // Map from a method to its node + virtual void print(std::ostream &o, const Module *M) const; + void print(std::ostream *o, const Module *M) const { if (o) print(*o, M); } + void dump() const; + +protected: + // destroy - Release memory for the call graph + virtual void destroy(); +}; + +//===----------------------------------------------------------------------===// +// CallGraphNode class definition +// +class CallGraphNode { + Function *F; + typedef std::pair CallRecord; + std::vector CalledFunctions; - CallGraphNode *Root; + CallGraphNode(const CallGraphNode &); // Do not implement public: - CallGraph(Module *TheModule); - ~CallGraph(); - - typedef MethodMapTy::iterator iterator; - typedef MethodMapTy::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(); } - - inline const CallGraphNode *operator[](const Method *M) const { - const_iterator I = MethodMap.find(M); - assert(I != MethodMap.end() && "Method not in callgraph!"); - return I->second; - } - inline CallGraphNode *operator[](const Method *M) { - const_iterator I = MethodMap.find(M); - assert(I != MethodMap.end() && "Method not in callgraph!"); - return I->second; - } + typedef std::vector CalledFunctionsVector; - // Methods to keep a call graph up to date with a method that has been - // modified + //===--------------------------------------------------------------------- + // Accessor methods... // - void addMethodToModule(Method *Meth); // TODO IMPLEMENT + typedef std::vector::iterator iterator; + typedef std::vector::const_iterator const_iterator; + + // getFunction - Return the function that this call graph node represents... + Function *getFunction() const { return F; } - // 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. + 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 function... // - Method *removeMethodFromModule(CallGraphNode *CGN); - Method *removeMethodFromModule(Method *Meth) { - return removeMethodFromModule((*this)[Meth]); + CallGraphNode *operator[](unsigned i) const { + return CalledFunctions[i].second; } -private: // Implementation of CallGraph construction + /// dump - Print out this call graph node. + /// + void dump() const; + void print(std::ostream &OS) const; + void print(std::ostream *OS) const { if (OS) print(*OS); } - // getNodeFor - Return the node for the specified method or create one if it - // does not already exist. + //===--------------------------------------------------------------------- + // Methods to keep a call graph up to date with a function that has been + // modified // - CallGraphNode *getNodeFor(Method *M); - // addToCallGraph - Add a method to the call graph, and link the node to all - // of the methods that it calls. - // - void addToCallGraph(Method *M); -}; + /// removeAllCalledFunctions - As the name implies, this removes all edges + /// from this CallGraphNode to any functions it calls. + void removeAllCalledFunctions() { + CalledFunctions.clear(); + } + + /// addCalledFunction - Add a function to the list of functions called by this + /// one. + void addCalledFunction(CallSite CS, CallGraphNode *M) { + CalledFunctions.push_back(std::make_pair(CS, M)); + } -} // end namespace cfg + /// 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); + + /// replaceCallSite - Make the edge in the node for Old CallSite be for + /// New CallSite instead. Note that this method takes linear time, so it + /// should be used sparingly. + void replaceCallSite(CallSite Old, CallSite New); + + friend class CallGraph; + // CallGraphNode ctor - Create a node for the specified function. + inline CallGraphNode(Function *f) : F(f) {} +}; +//===----------------------------------------------------------------------===// +// GraphTraits specializations for call graphs so that they can be treated as +// graphs by the generic graph algorithms. +// // Provide graph traits for tranversing call graphs using standard graph // traversals. -template <> struct GraphTraits { - typedef cfg::CallGraphNode NodeType; - typedef NodeType::iterator ChildIteratorType; +template <> struct GraphTraits { + typedef CallGraphNode NodeType; + + typedef std::pair CGNPairTy; + typedef std::pointer_to_unary_function CGNDerefFun; + + static NodeType *getEntryNode(CallGraphNode *CGN) { return CGN; } + + 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; + } - static NodeType *getEntryNode(cfg::CallGraphNode *CGN) { return CGN; } - static inline ChildIteratorType child_begin(NodeType *N) { return N->begin();} - static inline ChildIteratorType child_end (NodeType *N) { return N->end(); } }; -template <> struct GraphTraits { - typedef const cfg::CallGraphNode NodeType; +template <> struct GraphTraits { + typedef const CallGraphNode NodeType; typedef NodeType::const_iterator ChildIteratorType; - static NodeType *getEntryNode(const cfg::CallGraphNode *CGN) { return CGN; } + static NodeType *getEntryNode(const CallGraphNode *CGN) { return CGN; } static inline ChildIteratorType child_begin(NodeType *N) { return N->begin();} static inline ChildIteratorType child_end (NodeType *N) { return N->end(); } }; +template<> struct GraphTraits : public GraphTraits { + static NodeType *getEntryNode(CallGraph *CGN) { + return CGN->getExternalCallingNode(); // Start at the external node! + } + typedef std::pair PairTy; + typedef std::pointer_to_unary_function DerefFun; -template<> struct GraphTraits : - public GraphTraits { - static NodeType *getEntryNode(cfg::CallGraph *CGN) { - return CGN->getRoot(); + // 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 cfg::CallGraph *CGN) { - return CGN->getRoot(); + +template<> struct GraphTraits : + public GraphTraits { + static NodeType *getEntryNode(const CallGraph *CGN) { + 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 -// Checks if a method contains any call instructions. -// Note that this uses the call graph only if one is provided. -// It does not build the call graph. -// -bool isLeafMethod(const Method* method, const cfg::CallGraph *callGraph = 0); +// Make sure that any clients of this file link in CallGraph.cpp +FORCE_DEFINING_FILE_TO_BE_LINKED(CallGraph) #endif