llvm/tools/opt/PrintSCC.cpp
Chandler Carruth df13080481 [PM] Remove the underspecified 'getRoot' method from CallGraph. It's
only user was an ancient SCC printing bit of the opt tool which really
should be walking the call graph the same way the CGSCC pass manager
does.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195800 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-27 01:32:17 +00:00

113 lines
3.9 KiB
C++

//===- PrintSCC.cpp - Enumerate SCCs in some key graphs -------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides passes to print out SCCs in a CFG or a CallGraph.
// Normally, you would not use these passes; instead, you would use the
// scc_iterator directly to enumerate SCCs and process them in some way. These
// passes serve three purposes:
//
// (1) As a reference for how to use the scc_iterator.
// (2) To print out the SCCs for a CFG or a CallGraph:
// analyze -print-cfg-sccs to print the SCCs in each CFG of a module.
// analyze -print-cfg-sccs -stats to print the #SCCs and the maximum SCC size.
// analyze -print-cfg-sccs -debug > /dev/null to watch the algorithm in action.
//
// and similarly:
// analyze -print-callgraph-sccs [-stats] [-debug] to print SCCs in the CallGraph
//
// (3) To test the scc_iterator.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/SCCIterator.h"
#include "llvm/Analysis/CallGraph.h"
#include "llvm/IR/Module.h"
#include "llvm/Pass.h"
#include "llvm/Support/CFG.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
struct CFGSCC : public FunctionPass {
static char ID; // Pass identification, replacement for typeid
CFGSCC() : FunctionPass(ID) {}
bool runOnFunction(Function& func);
void print(raw_ostream &O, const Module* = 0) const { }
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
}
};
struct CallGraphSCC : public ModulePass {
static char ID; // Pass identification, replacement for typeid
CallGraphSCC() : ModulePass(ID) {}
// run - Print out SCCs in the call graph for the specified module.
bool runOnModule(Module &M);
void print(raw_ostream &O, const Module* = 0) const { }
// getAnalysisUsage - This pass requires the CallGraph.
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.addRequired<CallGraphWrapperPass>();
}
};
}
char CFGSCC::ID = 0;
static RegisterPass<CFGSCC>
Y("print-cfg-sccs", "Print SCCs of each function CFG");
char CallGraphSCC::ID = 0;
static RegisterPass<CallGraphSCC>
Z("print-callgraph-sccs", "Print SCCs of the Call Graph");
bool CFGSCC::runOnFunction(Function &F) {
unsigned sccNum = 0;
errs() << "SCCs for Function " << F.getName() << " in PostOrder:";
for (scc_iterator<Function*> SCCI = scc_begin(&F),
E = scc_end(&F); SCCI != E; ++SCCI) {
std::vector<BasicBlock*> &nextSCC = *SCCI;
errs() << "\nSCC #" << ++sccNum << " : ";
for (std::vector<BasicBlock*>::const_iterator I = nextSCC.begin(),
E = nextSCC.end(); I != E; ++I)
errs() << (*I)->getName() << ", ";
if (nextSCC.size() == 1 && SCCI.hasLoop())
errs() << " (Has self-loop).";
}
errs() << "\n";
return true;
}
// run - Print out SCCs in the call graph for the specified module.
bool CallGraphSCC::runOnModule(Module &M) {
CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
unsigned sccNum = 0;
errs() << "SCCs for the program in PostOrder:";
for (scc_iterator<CallGraph*> SCCI = scc_begin(&CG),
E = scc_end(&CG); SCCI != E; ++SCCI) {
const std::vector<CallGraphNode*> &nextSCC = *SCCI;
errs() << "\nSCC #" << ++sccNum << " : ";
for (std::vector<CallGraphNode*>::const_iterator I = nextSCC.begin(),
E = nextSCC.end(); I != E; ++I)
errs() << ((*I)->getFunction() ? (*I)->getFunction()->getName()
: "external node") << ", ";
if (nextSCC.size() == 1 && SCCI.hasLoop())
errs() << " (Has self-loop).";
}
errs() << "\n";
return true;
}