summaryrefslogtreecommitdiff
path: root/tools/analyze/PrintSCC.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'tools/analyze/PrintSCC.cpp')
-rw-r--r--tools/analyze/PrintSCC.cpp93
1 files changed, 93 insertions, 0 deletions
diff --git a/tools/analyze/PrintSCC.cpp b/tools/analyze/PrintSCC.cpp
new file mode 100644
index 0000000000..70049d20c9
--- /dev/null
+++ b/tools/analyze/PrintSCC.cpp
@@ -0,0 +1,93 @@
+//===- PrintSCC.cpp - Enumerate SCCs in some key graphs ---------*- C++ -*-===//
+//
+// 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
+// TarjanSCCIterator directly to enumerate SCCs and process them in some way.
+// These passes serve three purposes:
+// (1) As a reference for how to use the TarjanSCCIterator.
+// (2) To print out the SCCs for a CFG or a CallGraph:
+// analyze -cfgscc to print the SCCs in each CFG of a module.
+// analyze -cfgscc -stats to print the #SCCs and the maximum SCC size.
+// analyze -cfgscc -debug > /dev/null to watch the algorithm in action.
+//
+// and similarly:
+// analyze -callscc [-stats] [-debug] to print SCCs in the CallGraph
+//
+// (3) To test the TarjanSCCIterator.
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Pass.h"
+#include "llvm/Module.h"
+#include "llvm/Function.h"
+#include "llvm/BasicBlock.h"
+#include "llvm/Analysis/CallGraph.h"
+#include "llvm/Support/CFG.h"
+#include "Support/TarjanSCCIterator.h"
+
+namespace {
+
+class CFGSCC: public FunctionPass {
+public:
+ bool runOnFunction(Function& func) {
+ unsigned long sccNum = 0;
+ const SCC<Function*>* nextSCC;
+ std::cout << "SCCs for Function " << func.getName() << " in PostOrder:";
+ for (TarjanSCC_iterator<Function*> tarjSCCiter = tarj_begin(&func);
+ (nextSCC = *tarjSCCiter); ++tarjSCCiter)
+ {
+ std::cout << "\nSCC #" << ++sccNum << " : ";
+ for (SCC<Function*>::const_iterator I=nextSCC->begin(),E=nextSCC->end();
+ I != E; ++I)
+ std::cout << (*I)->getName() << ", ";
+ if (nextSCC->size() == 1 && nextSCC->HasLoop())
+ std::cout << " (Has self-loop).";
+ }
+ std::cout << "\n";
+
+ return true;
+ }
+ void print(std::ostream &O) const { }
+};
+
+
+class CallGraphSCC: public Pass {
+public:
+ // run - Print out SCCs in the call graph for the specified module.
+ bool run(Module& M) {
+ CallGraphNode* rootNode = getAnalysis<CallGraph>().getRoot();
+ unsigned long sccNum = 0;
+ const SCC<CallGraphNode*>* nextSCC;
+ std::cout << "SCCs for the program in PostOrder:";
+ for (TarjanSCC_iterator<CallGraphNode*> tarjSCCiter = tarj_begin(rootNode);
+ (nextSCC = *tarjSCCiter); ++tarjSCCiter)
+ {
+ std::cout << "\nSCC #" << ++sccNum << " : ";
+ for (SCC<CallGraphNode*>::const_iterator I=nextSCC->begin(),
+ E=nextSCC->end(); I != E; ++I)
+ std::cout << ((*I)->getFunction()? (*I)->getFunction()->getName()
+ : std::string("Null CallGraph node"))
+ << ", ";
+ if (nextSCC->size() == 1 && nextSCC->HasLoop())
+ std::cout << " (Has self-loop).";
+ }
+ std::cout << "\n";
+
+ return true;
+ }
+
+ void print(std::ostream &O) const { }
+
+ // getAnalysisUsage - This pass requires the CallGraph.
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesAll();
+ AU.addRequired<CallGraph>();
+ }
+};
+
+static RegisterAnalysis<CFGSCC>
+Y("cfgscc", "Print SCCs of each function CFG");
+
+static RegisterAnalysis<CallGraphSCC>
+Z("callscc", "Print SCCs of the Call Graph");
+
+}