1 //===- CallGraphSCCPass.h - Pass that operates BU on call graph -*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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.
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.
19 //===----------------------------------------------------------------------===//
21 #ifndef LLVM_CALL_GRAPH_SCC_PASS_H
22 #define LLVM_CALL_GRAPH_SCC_PASS_H
24 #include "llvm/Pass.h"
25 #include "llvm/Analysis/CallGraph.h"
34 class CallGraphSCCPass : public Pass {
36 explicit CallGraphSCCPass(intptr_t pid) : Pass(PT_CallGraphSCC, pid) {}
37 explicit CallGraphSCCPass(void *pid) : Pass(PT_CallGraphSCC, pid) {}
39 /// createPrinterPass - Get a pass that prints the Module
40 /// corresponding to a CallGraph.
41 Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const;
43 /// doInitialization - This method is called before the SCC's of the program
44 /// has been processed, allowing the pass to do initialization as necessary.
45 virtual bool doInitialization(CallGraph &CG) {
49 /// runOnSCC - This method should be implemented by the subclass to perform
50 /// whatever action is necessary for the specified SCC. Note that
51 /// non-recursive (or only self-recursive) functions will have an SCC size of
52 /// 1, where recursive portions of the call graph will have SCC size > 1.
54 /// SCC passes that add or delete functions to the SCC are required to update
55 /// the SCC list, otherwise stale pointers may be dereferenced.
57 virtual bool runOnSCC(CallGraphSCC &SCC) = 0;
59 /// doFinalization - This method is called after the SCC's of the program has
60 /// been processed, allowing the pass to do final cleanup as necessary.
61 virtual bool doFinalization(CallGraph &CG) {
65 /// Assign pass manager to manager this pass
66 virtual void assignPassManager(PMStack &PMS,
67 PassManagerType PMT =PMT_CallGraphPassManager);
69 /// Return what kind of Pass Manager can manage this pass.
70 virtual PassManagerType getPotentialPassManagerType() const {
71 return PMT_CallGraphPassManager;
74 /// getAnalysisUsage - For this class, we declare that we require and preserve
75 /// the call graph. If the derived class implements this method, it should
76 /// always explicitly call the implementation here.
77 virtual void getAnalysisUsage(AnalysisUsage &Info) const;
80 /// CallGraphSCC - This is a single SCC that a CallGraphSCCPass is run on.
82 void *Context; // The CGPassManager object that is vending this.
83 std::vector<CallGraphNode*> Nodes;
85 CallGraphSCC(void *context) : Context(context) {}
87 void initialize(CallGraphNode*const*I, CallGraphNode*const*E) {
91 bool isSingular() const { return Nodes.size() == 1; }
92 unsigned size() const { return Nodes.size(); }
94 /// ReplaceNode - This informs the SCC and the pass manager that the specified
95 /// Old node has been deleted, and New is to be used in its place.
96 void ReplaceNode(CallGraphNode *Old, CallGraphNode *New);
98 typedef std::vector<CallGraphNode*>::const_iterator iterator;
99 iterator begin() const { return Nodes.begin(); }
100 iterator end() const { return Nodes.end(); }
103 } // End llvm namespace