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_ANALYSIS_CALLGRAPHSCCPASS_H 22#define LLVM_ANALYSIS_CALLGRAPHSCCPASS_H 23 24#include "llvm/Analysis/CallGraph.h" 25#include "llvm/Pass.h" 26 27namespace llvm { 28 29class CallGraphNode; 30class CallGraph; 31class PMStack; 32class CallGraphSCC; 33 34class CallGraphSCCPass : public Pass { 35public: 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, 41 const std::string &Banner) const override; 42 43 using llvm::Pass::doInitialization; 44 using llvm::Pass::doFinalization; 45 46 /// doInitialization - This method is called before the SCC's of the program 47 /// has been processed, allowing the pass to do initialization as necessary. 48 virtual bool doInitialization(CallGraph &CG) { 49 return false; 50 } 51 52 /// runOnSCC - This method should be implemented by the subclass to perform 53 /// whatever action is necessary for the specified SCC. Note that 54 /// non-recursive (or only self-recursive) functions will have an SCC size of 55 /// 1, where recursive portions of the call graph will have SCC size > 1. 56 /// 57 /// SCC passes that add or delete functions to the SCC are required to update 58 /// the SCC list, otherwise stale pointers may be dereferenced. 59 /// 60 virtual bool runOnSCC(CallGraphSCC &SCC) = 0; 61 62 /// doFinalization - This method is called after the SCC's of the program has 63 /// been processed, allowing the pass to do final cleanup as necessary. 64 virtual bool doFinalization(CallGraph &CG) { 65 return false; 66 } 67 68 /// Assign pass manager to manager this pass 69 void assignPassManager(PMStack &PMS, PassManagerType PMT) override; 70 71 /// Return what kind of Pass Manager can manage this pass. 72 PassManagerType getPotentialPassManagerType() const override { 73 return PMT_CallGraphPassManager; 74 } 75 76 /// getAnalysisUsage - For this class, we declare that we require and preserve 77 /// the call graph. If the derived class implements this method, it should 78 /// always explicitly call the implementation here. 79 void getAnalysisUsage(AnalysisUsage &Info) const override; 80}; 81 82/// CallGraphSCC - This is a single SCC that a CallGraphSCCPass is run on. 83class CallGraphSCC { 84 void *Context; // The CGPassManager object that is vending this. 85 std::vector<CallGraphNode*> Nodes; 86 87public: 88 CallGraphSCC(void *context) : Context(context) {} 89 90 void initialize(CallGraphNode *const *I, CallGraphNode *const *E) { 91 Nodes.assign(I, E); 92 } 93 94 bool isSingular() const { return Nodes.size() == 1; } 95 unsigned size() const { return Nodes.size(); } 96 97 /// ReplaceNode - This informs the SCC and the pass manager that the specified 98 /// Old node has been deleted, and New is to be used in its place. 99 void ReplaceNode(CallGraphNode *Old, CallGraphNode *New); 100 101 typedef std::vector<CallGraphNode *>::const_iterator iterator; 102 iterator begin() const { return Nodes.begin(); } 103 iterator end() const { return Nodes.end(); } 104}; 105 106} // End llvm namespace 107 108#endif 109