1 //===- CFGPrinter.cpp - DOT printer for the control flow graph ------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines a '-print-cfg' analysis pass, which emits the
11 // cfg.<fnname>.dot file for each function in the program, with a graph of the
12 // CFG for that function.
14 // The other main feature of this file is that it implements the
15 // Function::viewCFG method, which is useful for debugging passes which operate
18 //===----------------------------------------------------------------------===//
20 #include "Support/GraphWriter.h"
21 #include "llvm/Pass.h"
22 #include "llvm/Function.h"
23 #include "llvm/iTerminators.h"
24 #include "llvm/Support/CFG.h"
28 /// CFGOnly flag - This is used to control whether or not the CFG graph printer
29 /// prints out the contents of basic blocks or not. This is acceptable because
30 /// this code is only really used for debugging purposes.
32 static bool CFGOnly = false;
35 struct DOTGraphTraits<const Function*> : public DefaultDOTGraphTraits {
36 static std::string getGraphName(const Function *F) {
37 return "CFG for '" + F->getName() + "' function";
40 static std::string getNodeLabel(const BasicBlock *Node,
41 const Function *Graph) {
42 if (CFGOnly) return Node->getName() + ":";
44 std::ostringstream Out;
46 std::string OutStr = Out.str();
47 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
49 // Process string output to make it nicer...
50 for (unsigned i = 0; i != OutStr.length(); ++i)
51 if (OutStr[i] == '\n') { // Left justify
53 OutStr.insert(OutStr.begin()+i+1, 'l');
54 } else if (OutStr[i] == ';') { // Delete comments!
55 unsigned Idx = OutStr.find('\n', i+1); // Find end of line
56 OutStr.erase(OutStr.begin()+i, OutStr.begin()+Idx);
63 static std::string getNodeAttributes(const BasicBlock *N) {
64 return "fontname=Courier";
67 static std::string getEdgeSourceLabel(const BasicBlock *Node,
68 succ_const_iterator I) {
69 // Label source of conditional branches with "T" or "F"
70 if (const BranchInst *BI = dyn_cast<BranchInst>(Node->getTerminator()))
71 if (BI->isConditional())
72 return (I == succ_begin(Node)) ? "T" : "F";
78 struct CFGPrinter : public FunctionPass {
79 virtual bool runOnFunction(Function &F) {
80 std::string Filename = "cfg." + F.getName() + ".dot";
81 std::cerr << "Writing '" << Filename << "'...";
82 std::ofstream File(Filename.c_str());
85 WriteGraph(File, (const Function*)&F);
87 std::cerr << " error opening file for writing!";
92 void print(std::ostream &OS) const {}
94 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
99 RegisterAnalysis<CFGPrinter> P1("print-cfg",
100 "Print CFG of function to 'dot' file");
106 /// viewCFG - This function is meant for use from the debugger. You can just
107 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
108 /// program, displaying the CFG of the current function. This depends on there
109 /// being a 'dot' and 'gv' program in your path.
111 void Function::viewCFG() const {
112 std::string Filename = "/tmp/cfg." + getName() + ".dot";
113 std::cerr << "Writing '" << Filename << "'... ";
114 std::ofstream F(Filename.c_str());
117 std::cerr << " error opening file for writing!\n";
125 std::cerr << "Running 'dot' program... " << std::flush;
126 if (system(("dot -Tps " + Filename + " > /tmp/cfg.tempgraph.ps").c_str())) {
127 std::cerr << "Error running dot: 'dot' not in path?\n";
130 system("gv /tmp/cfg.tempgraph.ps");
132 system(("rm " + Filename + " /tmp/cfg.tempgraph.ps").c_str());
135 /// viewCFGOnly - This function is meant for use from the debugger. It works
136 /// just like viewCFG, but it does not include the contents of basic blocks
137 /// into the nodes, just the label. If you are only interested in the CFG t
138 /// his can make the graph smaller.
140 void Function::viewCFGOnly() const {