//===- CFGPrinter.cpp - DOT printer for the control flow graph ------------===// // // The LLVM Compiler Infrastructure // // This file was developed by the LLVM research group and is distributed under // the University of Illinois Open Source License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file defines a '-print-cfg' analysis pass, which emits the // cfg.<fnname>.dot file for each function in the program, with a graph of the // CFG for that function. // // The other main feature of this file is that it implements the // Function::viewCFG method, which is useful for debugging passes which operate // on the CFG. // //===----------------------------------------------------------------------===// #include "llvm/Function.h" #include "llvm/Instructions.h" #include "llvm/Pass.h" #include "llvm/Analysis/CFGPrinter.h" #include "llvm/Assembly/Writer.h" #include "llvm/Support/CFG.h" #include "llvm/Support/GraphWriter.h" #include "llvm/Config/config.h" #include <sstream> #include <fstream> using namespace llvm; /// CFGOnly flag - This is used to control whether or not the CFG graph printer /// prints out the contents of basic blocks or not. This is acceptable because /// this code is only really used for debugging purposes. /// static bool CFGOnly = false; namespace llvm { template<> struct DOTGraphTraits<const Function*> : public DefaultDOTGraphTraits { static std::string getGraphName(const Function *F) { return "CFG for '" + F->getName() + "' function"; } static std::string getNodeLabel(const BasicBlock *Node, const Function *Graph) { if (CFGOnly && !Node->getName().empty()) return Node->getName() + ":"; std::ostringstream Out; if (CFGOnly) { WriteAsOperand(Out, Node, false, true); return Out.str(); } if (Node->getName().empty()) { WriteAsOperand(Out, Node, false, true); Out << ":"; } Out << *Node; std::string OutStr = Out.str(); if (OutStr[0] == '\n') OutStr.erase(OutStr.begin()); // Process string output to make it nicer... for (unsigned i = 0; i != OutStr.length(); ++i) if (OutStr[i] == '\n') { // Left justify OutStr[i] = '\\'; OutStr.insert(OutStr.begin()+i+1, 'l'); } else if (OutStr[i] == ';') { // Delete comments! unsigned Idx = OutStr.find('\n', i+1); // Find end of line OutStr.erase(OutStr.begin()+i, OutStr.begin()+Idx); --i; } return OutStr; } static std::string getEdgeSourceLabel(const BasicBlock *Node, succ_const_iterator I) { // Label source of conditional branches with "T" or "F" if (const BranchInst *BI = dyn_cast<BranchInst>(Node->getTerminator())) if (BI->isConditional()) return (I == succ_begin(Node)) ? "T" : "F"; return ""; } }; } namespace { struct CFGPrinter : public FunctionPass { virtual bool runOnFunction(Function &F) { std::string Filename = "cfg." + F.getName() + ".dot"; std::cerr << "Writing '" << Filename << "'..."; std::ofstream File(Filename.c_str()); if (File.good()) WriteGraph(File, (const Function*)&F); else std::cerr << " error opening file for writing!"; std::cerr << "\n"; return false; } void print(std::ostream &OS, const Module* = 0) const {} virtual void getAnalysisUsage(AnalysisUsage &AU) const { AU.setPreservesAll(); } }; RegisterAnalysis<CFGPrinter> P1("print-cfg", "Print CFG of function to 'dot' file"); struct CFGOnlyPrinter : public CFGPrinter { virtual bool runOnFunction(Function &F) { bool OldCFGOnly = CFGOnly; CFGOnly = true; CFGPrinter::runOnFunction(F); CFGOnly = OldCFGOnly; return false; } void print(std::ostream &OS, const Module* = 0) const {} virtual void getAnalysisUsage(AnalysisUsage &AU) const { AU.setPreservesAll(); } }; RegisterAnalysis<CFGOnlyPrinter> P2("print-cfg-only", "Print CFG of function to 'dot' file (with no function bodies)"); } /// viewCFG - This function is meant for use from the debugger. You can just /// say 'call F->viewCFG()' and a ghostview window should pop up from the /// program, displaying the CFG of the current function. This depends on there /// being a 'dot' and 'gv' program in your path. /// void Function::viewCFG() const { #ifndef NDEBUG std::string Filename = "/tmp/cfg." + getName() + ".dot"; std::cerr << "Writing '" << Filename << "'... "; std::ofstream F(Filename.c_str()); if (!F.good()) { std::cerr << " error opening file for writing!\n"; return; } WriteGraph(F, this); F.close(); std::cerr << "\n"; #ifdef HAVE_GRAPHVIZ std::cerr << "Running 'Graphviz' program... " << std::flush; if (system((LLVM_PATH_GRAPHVIZ " " + Filename).c_str())) { std::cerr << "Error viewing graph: 'Graphviz' not in path?\n"; } else { system(("rm " + Filename).c_str()); return; } #endif // HAVE_GRAPHVIZ #ifdef HAVE_GV std::cerr << "Running 'dot' program... " << std::flush; if (system(("dot -Tps -Nfontname=Courier -Gsize=7.5,10 " + Filename + " > /tmp/cfg.tempgraph.ps").c_str())) { std::cerr << "Error running dot: 'dot' not in path?\n"; } else { std::cerr << "\n"; system("gv /tmp/cfg.tempgraph.ps"); } system(("rm " + Filename + " /tmp/cfg.tempgraph.ps").c_str()); return; #endif // HAVE_GV #endif // NDEBUG std::cerr << "Function::viewCFG is only available in debug builds on " << "systems with Graphviz or gv!\n"; #ifndef NDEBUG system(("rm " + Filename).c_str()); #endif } /// viewCFGOnly - This function is meant for use from the debugger. It works /// just like viewCFG, but it does not include the contents of basic blocks /// into the nodes, just the label. If you are only interested in the CFG t /// his can make the graph smaller. /// void Function::viewCFGOnly() const { CFGOnly = true; viewCFG(); CFGOnly = false; } FunctionPass *llvm::createCFGPrinterPass () { return new CFGPrinter(); } FunctionPass *llvm::createCFGOnlyPrinterPass () { return new CFGOnlyPrinter(); }