blob: 667e1715775faa00afb4f109269161c994064299 [file] [log] [blame]
//===- CallGraphSCCPass.h - Pass that operates BU on call graph -*- C++ -*-===//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
// This file defines the CallGraphSCCPass class, which is used for passes which
// are implemented as bottom-up traversals on the call graph. Because there may
// be cycles in the call graph, passes of this type operate on the call-graph in
// SCC order: that is, they process function bottom-up, except for recursive
// functions, which they process all at once.
// These passes are inherently interprocedural, and are required to keep the
// call graph up-to-date if they do anything which could modify it.
#include "llvm/Analysis/CallGraph.h"
#include "llvm/Pass.h"
namespace llvm {
class CallGraphNode;
class CallGraph;
class PMStack;
class CallGraphSCC;
class CallGraphSCCPass : public Pass {
explicit CallGraphSCCPass(char &pid) : Pass(PT_CallGraphSCC, pid) {}
/// createPrinterPass - Get a pass that prints the Module
/// corresponding to a CallGraph.
Pass *createPrinterPass(raw_ostream &O,
const std::string &Banner) const override;
using llvm::Pass::doInitialization;
using llvm::Pass::doFinalization;
/// doInitialization - This method is called before the SCC's of the program
/// has been processed, allowing the pass to do initialization as necessary.
virtual bool doInitialization(CallGraph &CG) {
return false;
/// runOnSCC - This method should be implemented by the subclass to perform
/// whatever action is necessary for the specified SCC. Note that
/// non-recursive (or only self-recursive) functions will have an SCC size of
/// 1, where recursive portions of the call graph will have SCC size > 1.
/// SCC passes that add or delete functions to the SCC are required to update
/// the SCC list, otherwise stale pointers may be dereferenced.
virtual bool runOnSCC(CallGraphSCC &SCC) = 0;
/// doFinalization - This method is called after the SCC's of the program has
/// been processed, allowing the pass to do final cleanup as necessary.
virtual bool doFinalization(CallGraph &CG) {
return false;
/// Assign pass manager to manager this pass
void assignPassManager(PMStack &PMS, PassManagerType PMT) override;
/// Return what kind of Pass Manager can manage this pass.
PassManagerType getPotentialPassManagerType() const override {
return PMT_CallGraphPassManager;
/// getAnalysisUsage - For this class, we declare that we require and preserve
/// the call graph. If the derived class implements this method, it should
/// always explicitly call the implementation here.
void getAnalysisUsage(AnalysisUsage &Info) const override;
/// CallGraphSCC - This is a single SCC that a CallGraphSCCPass is run on.
class CallGraphSCC {
void *Context; // The CGPassManager object that is vending this.
std::vector<CallGraphNode*> Nodes;
CallGraphSCC(void *context) : Context(context) {}
void initialize(CallGraphNode*const*I, CallGraphNode*const*E) {
Nodes.assign(I, E);
bool isSingular() const { return Nodes.size() == 1; }
unsigned size() const { return Nodes.size(); }
/// ReplaceNode - This informs the SCC and the pass manager that the specified
/// Old node has been deleted, and New is to be used in its place.
void ReplaceNode(CallGraphNode *Old, CallGraphNode *New);
typedef std::vector<CallGraphNode*>::const_iterator iterator;
iterator begin() const { return Nodes.begin(); }
iterator end() const { return Nodes.end(); }
} // End llvm namespace