1 //===- CFGPrinter.cpp - DOT printer for the control flow graph ------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines a '-dot-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/Compiler.h"
27 #include "llvm/Support/GraphWriter.h"
28 #include "llvm/Config/config.h"
36 struct DOTGraphTraits<const Function*> : public DefaultDOTGraphTraits {
37 static std::string getGraphName(const Function *F) {
38 return "CFG for '" + F->getNameStr() + "' function";
41 static std::string getNodeLabel(const BasicBlock *Node,
42 const Function *Graph,
44 if (ShortNames && !Node->getName().empty())
45 return Node->getNameStr() + ":";
47 std::ostringstream Out;
49 WriteAsOperand(Out, Node, false);
53 if (Node->getName().empty()) {
54 WriteAsOperand(Out, Node, false);
59 std::string OutStr = Out.str();
60 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
62 // Process string output to make it nicer...
63 for (unsigned i = 0; i != OutStr.length(); ++i)
64 if (OutStr[i] == '\n') { // Left justify
66 OutStr.insert(OutStr.begin()+i+1, 'l');
67 } else if (OutStr[i] == ';') { // Delete comments!
68 unsigned Idx = OutStr.find('\n', i+1); // Find end of line
69 OutStr.erase(OutStr.begin()+i, OutStr.begin()+Idx);
76 static std::string getEdgeSourceLabel(const BasicBlock *Node,
77 succ_const_iterator I) {
78 // Label source of conditional branches with "T" or "F"
79 if (const BranchInst *BI = dyn_cast<BranchInst>(Node->getTerminator()))
80 if (BI->isConditional())
81 return (I == succ_begin(Node)) ? "T" : "F";
88 struct VISIBILITY_HIDDEN CFGViewer : public FunctionPass {
89 static char ID; // Pass identifcation, replacement for typeid
90 CFGViewer() : FunctionPass(&ID) {}
92 virtual bool runOnFunction(Function &F) {
97 void print(std::ostream &OS, const Module* = 0) const {}
99 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
100 AU.setPreservesAll();
105 char CFGViewer::ID = 0;
106 static RegisterPass<CFGViewer>
107 V0("view-cfg", "View CFG of function", false, true);
110 struct VISIBILITY_HIDDEN CFGOnlyViewer : public FunctionPass {
111 static char ID; // Pass identifcation, replacement for typeid
112 CFGOnlyViewer() : FunctionPass(&ID) {}
114 virtual bool runOnFunction(Function &F) {
119 void print(std::ostream &OS, const Module* = 0) const {}
121 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
122 AU.setPreservesAll();
127 char CFGOnlyViewer::ID = 0;
128 static RegisterPass<CFGOnlyViewer>
130 "View CFG of function (with no function bodies)", false, true);
133 struct VISIBILITY_HIDDEN CFGPrinter : public FunctionPass {
134 static char ID; // Pass identification, replacement for typeid
135 CFGPrinter() : FunctionPass(&ID) {}
136 explicit CFGPrinter(void *pid) : FunctionPass(pid) {}
138 virtual bool runOnFunction(Function &F) {
139 std::string Filename = "cfg." + F.getNameStr() + ".dot";
140 cerr << "Writing '" << Filename << "'...";
141 std::ofstream File(Filename.c_str());
144 WriteGraph(File, (const Function*)&F);
146 cerr << " error opening file for writing!";
151 void print(std::ostream &OS, const Module* = 0) const {}
153 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
154 AU.setPreservesAll();
159 char CFGPrinter::ID = 0;
160 static RegisterPass<CFGPrinter>
161 P1("dot-cfg", "Print CFG of function to 'dot' file", false, true);
164 struct VISIBILITY_HIDDEN CFGOnlyPrinter : public FunctionPass {
165 static char ID; // Pass identification, replacement for typeid
166 CFGOnlyPrinter() : FunctionPass(&ID) {}
167 explicit CFGOnlyPrinter(void *pid) : FunctionPass(pid) {}
168 virtual bool runOnFunction(Function &F) {
169 std::string Filename = "cfg." + F.getNameStr() + ".dot";
170 cerr << "Writing '" << Filename << "'...";
171 std::ofstream File(Filename.c_str());
174 WriteGraph(File, (const Function*)&F, true);
176 cerr << " error opening file for writing!";
180 void print(std::ostream &OS, const Module* = 0) const {}
182 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
183 AU.setPreservesAll();
188 char CFGOnlyPrinter::ID = 0;
189 static RegisterPass<CFGOnlyPrinter>
191 "Print CFG of function to 'dot' file (with no function bodies)", false, true);
193 /// viewCFG - This function is meant for use from the debugger. You can just
194 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
195 /// program, displaying the CFG of the current function. This depends on there
196 /// being a 'dot' and 'gv' program in your path.
198 void Function::viewCFG() const {
199 ViewGraph(this, "cfg" + getNameStr());
202 /// viewCFGOnly - This function is meant for use from the debugger. It works
203 /// just like viewCFG, but it does not include the contents of basic blocks
204 /// into the nodes, just the label. If you are only interested in the CFG t
205 /// his can make the graph smaller.
207 void Function::viewCFGOnly() const {
208 ViewGraph(this, "cfg" + getNameStr(), true);
211 FunctionPass *llvm::createCFGPrinterPass () {
212 return new CFGPrinter();
215 FunctionPass *llvm::createCFGOnlyPrinterPass () {
216 return new CFGOnlyPrinter();