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 "llvm/Function.h"
21 #include "llvm/Instructions.h"
22 #include "llvm/Pass.h"
23 #include "llvm/Analysis/CFGPrinter.h"
24 #include "llvm/Assembly/Writer.h"
25 #include "llvm/Support/CFG.h"
26 #include "llvm/Support/GraphWriter.h"
31 /// CFGOnly flag - This is used to control whether or not the CFG graph printer
32 /// prints out the contents of basic blocks or not. This is acceptable because
33 /// this code is only really used for debugging purposes.
35 static bool CFGOnly = false;
39 struct DOTGraphTraits<const Function*> : public DefaultDOTGraphTraits {
40 static std::string getGraphName(const Function *F) {
41 return "CFG for '" + F->getName() + "' function";
44 static std::string getNodeLabel(const BasicBlock *Node,
45 const Function *Graph) {
46 if (CFGOnly && !Node->getName().empty())
47 return Node->getName() + ":";
49 std::ostringstream Out;
51 WriteAsOperand(Out, Node, false, true);
55 if (Node->getName().empty()) {
56 WriteAsOperand(Out, Node, false, true);
61 std::string OutStr = Out.str();
62 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
64 // Process string output to make it nicer...
65 for (unsigned i = 0; i != OutStr.length(); ++i)
66 if (OutStr[i] == '\n') { // Left justify
68 OutStr.insert(OutStr.begin()+i+1, 'l');
69 } else if (OutStr[i] == ';') { // Delete comments!
70 unsigned Idx = OutStr.find('\n', i+1); // Find end of line
71 OutStr.erase(OutStr.begin()+i, OutStr.begin()+Idx);
78 static std::string getEdgeSourceLabel(const BasicBlock *Node,
79 succ_const_iterator I) {
80 // Label source of conditional branches with "T" or "F"
81 if (const BranchInst *BI = dyn_cast<BranchInst>(Node->getTerminator()))
82 if (BI->isConditional())
83 return (I == succ_begin(Node)) ? "T" : "F";
90 struct CFGPrinter : public FunctionPass {
91 virtual bool runOnFunction(Function &F) {
92 std::string Filename = "cfg." + F.getName() + ".dot";
93 std::cerr << "Writing '" << Filename << "'...";
94 std::ofstream File(Filename.c_str());
97 WriteGraph(File, (const Function*)&F);
99 std::cerr << " error opening file for writing!";
104 void print(std::ostream &OS, const Module* = 0) const {}
106 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
107 AU.setPreservesAll();
111 RegisterAnalysis<CFGPrinter> P1("print-cfg",
112 "Print CFG of function to 'dot' file");
114 struct CFGOnlyPrinter : public CFGPrinter {
115 virtual bool runOnFunction(Function &F) {
116 bool OldCFGOnly = CFGOnly;
118 CFGPrinter::runOnFunction(F);
119 CFGOnly = OldCFGOnly;
122 void print(std::ostream &OS, const Module* = 0) const {}
124 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
125 AU.setPreservesAll();
129 RegisterAnalysis<CFGOnlyPrinter>
131 "Print CFG of function to 'dot' file (with no function bodies)");
134 /// viewCFG - This function is meant for use from the debugger. You can just
135 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
136 /// program, displaying the CFG of the current function. This depends on there
137 /// being a 'dot' and 'gv' program in your path.
139 void Function::viewCFG() const {
140 std::string Filename = "/tmp/cfg." + getName() + ".dot";
141 std::cerr << "Writing '" << Filename << "'... ";
142 std::ofstream F(Filename.c_str());
145 std::cerr << " error opening file for writing!\n";
153 std::cerr << "Running 'dot' program... " << std::flush;
154 if (system(("dot -Tps -Nfontname=Courier -Gsize=7.5,10 " + Filename
155 + " > /tmp/cfg.tempgraph.ps").c_str())) {
156 std::cerr << "Error running dot: 'dot' not in path?\n";
159 system("gv /tmp/cfg.tempgraph.ps");
161 system(("rm " + Filename + " /tmp/cfg.tempgraph.ps").c_str());
164 /// viewCFGOnly - This function is meant for use from the debugger. It works
165 /// just like viewCFG, but it does not include the contents of basic blocks
166 /// into the nodes, just the label. If you are only interested in the CFG t
167 /// his can make the graph smaller.
169 void Function::viewCFGOnly() const {
175 FunctionPass *llvm::createCFGPrinterPass () {
176 return new CFGPrinter();
179 FunctionPass *llvm::createCFGOnlyPrinterPass () {
180 return new CFGOnlyPrinter();