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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_ANALYSIS_CALLGRAPHSCCPASS_H
22 #define LLVM_ANALYSIS_CALLGRAPHSCCPASS_H
24 #include "llvm/Analysis/CallGraph.h"
25 #include "llvm/Pass.h"
34 class CallGraphSCCPass
: public Pass
{
36 explicit CallGraphSCCPass(char &pid
) : Pass(PT_CallGraphSCC
, pid
) {}
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
;
43 using llvm::Pass::doInitialization
;
44 using llvm::Pass::doFinalization
;
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
) {
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.
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.
60 virtual bool runOnSCC(CallGraphSCC
&SCC
) = 0;
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
) {
68 /// Assign pass manager to manager this pass
69 void assignPassManager(PMStack
&PMS
, PassManagerType PMT
) override
;
71 /// Return what kind of Pass Manager can manage this pass.
72 PassManagerType
getPotentialPassManagerType() const override
{
73 return PMT_CallGraphPassManager
;
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
;
82 /// CallGraphSCC - This is a single SCC that a CallGraphSCCPass is run on.
84 void *Context
; // The CGPassManager object that is vending this.
85 std::vector
<CallGraphNode
*> Nodes
;
87 CallGraphSCC(void *context
) : Context(context
) {}
89 void initialize(CallGraphNode
*const*I
, CallGraphNode
*const*E
) {
93 bool isSingular() const { return Nodes
.size() == 1; }
94 unsigned size() const { return Nodes
.size(); }
96 /// ReplaceNode - This informs the SCC and the pass manager that the specified
97 /// Old node has been deleted, and New is to be used in its place.
98 void ReplaceNode(CallGraphNode
*Old
, CallGraphNode
*New
);
100 typedef std::vector
<CallGraphNode
*>::const_iterator iterator
;
101 iterator
begin() const { return Nodes
.begin(); }
102 iterator
end() const { return Nodes
.end(); }
105 } // End llvm namespace