1 //===- CallGraphSCCPass.h - Pass that operates BU on call graph -*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file defines the CallGraphSCCPass class, which is used for passes which 11 // are implemented as bottom-up traversals on the call graph. Because there may 12 // be cycles in the call graph, passes of this type operate on the call-graph in 13 // SCC order: that is, they process function bottom-up, except for recursive 14 // functions, which they process all at once. 15 // 16 // These passes are inherently interprocedural, and are required to keep the 17 // call graph up-to-date if they do anything which could modify it. 18 // 19 //===----------------------------------------------------------------------===// 20 21 #ifndef LLVM_CALL_GRAPH_SCC_PASS_H 22 #define LLVM_CALL_GRAPH_SCC_PASS_H 23 24 #include "llvm/Pass.h" 25 #include "llvm/Analysis/CallGraph.h" 26 27 namespace llvm { 28 29 class CallGraphNode; 30 class CallGraph; 31 class PMStack; 32 class CallGraphSCC; 33 34 class CallGraphSCCPass : public Pass { 35 public: 36 explicit CallGraphSCCPass(char &pid) : Pass(PT_CallGraphSCC, pid) {} 37 38 /// createPrinterPass - Get a pass that prints the Module 39 /// corresponding to a CallGraph. 40 Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const; 41 42 /// doInitialization - This method is called before the SCC's of the program 43 /// has been processed, allowing the pass to do initialization as necessary. 44 virtual bool doInitialization(CallGraph &CG) { 45 return false; 46 } 47 48 /// runOnSCC - This method should be implemented by the subclass to perform 49 /// whatever action is necessary for the specified SCC. Note that 50 /// non-recursive (or only self-recursive) functions will have an SCC size of 51 /// 1, where recursive portions of the call graph will have SCC size > 1. 52 /// 53 /// SCC passes that add or delete functions to the SCC are required to update 54 /// the SCC list, otherwise stale pointers may be dereferenced. 55 /// 56 virtual bool runOnSCC(CallGraphSCC &SCC) = 0; 57 58 /// doFinalization - This method is called after the SCC's of the program has 59 /// been processed, allowing the pass to do final cleanup as necessary. 60 virtual bool doFinalization(CallGraph &CG) { 61 return false; 62 } 63 64 /// Assign pass manager to manager this pass 65 virtual void assignPassManager(PMStack &PMS, 66 PassManagerType PMT); 67 68 /// Return what kind of Pass Manager can manage this pass. 69 virtual PassManagerType getPotentialPassManagerType() const { 70 return PMT_CallGraphPassManager; 71 } 72 73 /// getAnalysisUsage - For this class, we declare that we require and preserve 74 /// the call graph. If the derived class implements this method, it should 75 /// always explicitly call the implementation here. 76 virtual void getAnalysisUsage(AnalysisUsage &Info) const; 77 }; 78 79 /// CallGraphSCC - This is a single SCC that a CallGraphSCCPass is run on. 80 class CallGraphSCC { 81 void *Context; // The CGPassManager object that is vending this. 82 std::vector<CallGraphNode*> Nodes; 83 public: 84 CallGraphSCC(void *context) : Context(context) {} 85 86 void initialize(CallGraphNode*const*I, CallGraphNode*const*E) { 87 Nodes.assign(I, E); 88 } 89 90 bool isSingular() const { return Nodes.size() == 1; } 91 unsigned size() const { return Nodes.size(); } 92 93 /// ReplaceNode - This informs the SCC and the pass manager that the specified 94 /// Old node has been deleted, and New is to be used in its place. 95 void ReplaceNode(CallGraphNode *Old, CallGraphNode *New); 96 97 typedef std::vector<CallGraphNode*>::const_iterator iterator; 98 iterator begin() const { return Nodes.begin(); } 99 iterator end() const { return Nodes.end(); } 100 }; 101 102 } // End llvm namespace 103 104 #endif 105
