X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FAnalysis%2FCallGraph.h;h=d8b80df8fc776a7e93c1c0b77f626da93a0a87e4;hb=b09c146b116359616f6cbd4c8b3328607e00ff42;hp=f3bc052ff895126c4f052f34bc8ed1729317f70d;hpb=5636eec5fbd754e3b5595e7e8a1f9cb428b788dc;p=oota-llvm.git diff --git a/include/llvm/Analysis/CallGraph.h b/include/llvm/Analysis/CallGraph.h index f3bc052ff89..d8b80df8fc7 100644 --- a/include/llvm/Analysis/CallGraph.h +++ b/include/llvm/Analysis/CallGraph.h @@ -1,23 +1,33 @@ -//===- 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 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 function 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 functions with the following properties: -// 1. All functions in the module without internal linkage, since they could -// be called by functions outside of the our analysis capability. +// 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. Since they may -// be called by an unknown caller later, they must be tracked as such. +// 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, functions have a call edge to the external node iff: +// 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. @@ -31,7 +41,7 @@ // transformations. // // The CallGraph class also attempts to figure out what the root of the -// CallGraph is, which is currently does by looking for a function named 'main'. +// 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). @@ -41,9 +51,17 @@ #ifndef LLVM_ANALYSIS_CALLGRAPH_H #define LLVM_ANALYSIS_CALLGRAPH_H -#include "Support/GraphTraits.h" -#include "Support/STLExtras.h" +#include "llvm/ADT/GraphTraits.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/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; @@ -51,42 +69,30 @@ class CallGraphNode; //===----------------------------------------------------------------------===// // CallGraph class definition // -class CallGraph : public Pass { +class CallGraph { +protected: Module *Mod; // The module this call graph represents 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 FunctionMapTy::iterator iterator; typedef FunctionMapTy::const_iterator const_iterator; - // getExternalNode - Return the node that points to all functions that are - // accessable from outside of the current program. - // - CallGraphNode *getExternalNode() { return ExternalNode; } - const CallGraphNode *getExternalNode() const { return ExternalNode; } - - // getRoot - Return the root of the call graph, which is either main, or if - // main cannot be found, the external node. - // - CallGraphNode *getRoot() { return Root; } - const CallGraphNode *getRoot() const { return Root; } + /// 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 { @@ -100,138 +106,227 @@ public: return I->second; } + /// 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; } + //===--------------------------------------------------------------------- // Functions to keep a call graph up to date with a function that has been - // modified + // modified. // - void addFunctionToModule(Function *F); - - // 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. - // + /// 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]); } + /// 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... - // - CallGraph() : Root(0) {} - ~CallGraph() { destroy(); } - - // 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(); - } - - // releaseMemory - Data structures can be large, so free memory aggressively. - virtual void releaseMemory() { - destroy(); - } - - /// Print the types found in the module. If the optional Module parameter is - /// passed in, then the types are printed symbolically if possible, using the - /// symbol table from the module. + /// 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 print(std::ostream &o, const Module *M) const; + 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 functions 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 *F; - std::vector CalledFunctions; + 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; - // getFunction - Return the function that this call graph node represents... + // getFunction - Return the function that this call graph node represents. Function *getFunction() const { return F; } 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 unsigned size() const { return CalledFunctions.size(); } + inline bool empty() const { return CalledFunctions.empty(); } + inline unsigned size() const { return (unsigned)CalledFunctions.size(); } - // Subscripting operator - Return the i'th called function... + /// 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. // - CallGraphNode *operator[](unsigned i) const { return CalledFunctions[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 function that has been // modified // + /// removeAllCalledFunctions - As the name implies, this removes all edges + /// from this CallGraphNode to any functions it calls. void removeAllCalledFunctions() { - CalledFunctions.clear(); + 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 function... - inline CallGraphNode(Function *f) : F(f) {} + void removeCallEdge(iterator I) { + I->second->DropRef(); + *I = CalledFunctions.back(); + CalledFunctions.pop_back(); + } + - // addCalledFunction add a function to the list of functions called by this - // one - void addCalledFunction(CallGraphNode *M) { - CalledFunctions.push_back(M); + /// 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); + + /// 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 { @@ -245,7 +340,7 @@ template <> struct GraphTraits { template<> struct GraphTraits : public GraphTraits { static NodeType *getEntryNode(CallGraph *CGN) { - return CGN->getExternalNode(); // Start at the external node! + return CGN->getExternalCallingNode(); // Start at the external node! } typedef std::pair PairTy; typedef std::pointer_to_unary_function DerefFun; @@ -259,15 +354,15 @@ template<> struct GraphTraits : public GraphTraits { return map_iterator(CG->end(), DerefFun(CGdereference)); } - static CallGraphNode &CGdereference (std::pair P) { + static CallGraphNode &CGdereference(PairTy P) { return *P.second; } }; + template<> struct GraphTraits : public GraphTraits { static NodeType *getEntryNode(const CallGraph *CGN) { - return CGN->getExternalNode(); + return CGN->getExternalCallingNode(); } // nodes_iterator/begin/end - Allow iteration over all nodes in the graph typedef CallGraph::const_iterator nodes_iterator; @@ -275,4 +370,9 @@ template<> struct GraphTraits : static nodes_iterator nodes_end (const CallGraph *CG) { return CG->end(); } }; +} // End llvm namespace + +// Make sure that any clients of this file link in CallGraph.cpp +FORCE_DEFINING_FILE_TO_BE_LINKED(CallGraph) + #endif