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"
33 struct DOTGraphTraits<const Function*> : public DefaultDOTGraphTraits {
34 static std::string getGraphName(const Function *F) {
35 return "CFG for '" + F->getNameStr() + "' function";
38 static std::string getNodeLabel(const BasicBlock *Node,
39 const Function *Graph,
41 if (ShortNames && !Node->getName().empty())
42 return Node->getNameStr() + ":";
45 raw_string_ostream OS(Str);
48 WriteAsOperand(OS, Node, false);
52 if (Node->getName().empty()) {
53 WriteAsOperand(OS, Node, false);
58 std::string OutStr = OS.str();
59 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
61 // Process string output to make it nicer...
62 for (unsigned i = 0; i != OutStr.length(); ++i)
63 if (OutStr[i] == '\n') { // Left justify
65 OutStr.insert(OutStr.begin()+i+1, 'l');
66 } else if (OutStr[i] == ';') { // Delete comments!
67 unsigned Idx = OutStr.find('\n', i+1); // Find end of line
68 OutStr.erase(OutStr.begin()+i, OutStr.begin()+Idx);
75 static std::string getEdgeSourceLabel(const BasicBlock *Node,
76 succ_const_iterator I) {
77 // Label source of conditional branches with "T" or "F"
78 if (const BranchInst *BI = dyn_cast<BranchInst>(Node->getTerminator()))
79 if (BI->isConditional())
80 return (I == succ_begin(Node)) ? "T" : "F";
87 struct VISIBILITY_HIDDEN CFGViewer : public FunctionPass {
88 static char ID; // Pass identifcation, replacement for typeid
89 CFGViewer() : FunctionPass(&ID) {}
91 virtual bool runOnFunction(Function &F) {
96 void print(raw_ostream &OS, const Module* = 0) const {}
98 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
104 char CFGViewer::ID = 0;
105 static RegisterPass<CFGViewer>
106 V0("view-cfg", "View CFG of function", false, true);
109 struct VISIBILITY_HIDDEN CFGOnlyViewer : public FunctionPass {
110 static char ID; // Pass identifcation, replacement for typeid
111 CFGOnlyViewer() : FunctionPass(&ID) {}
113 virtual bool runOnFunction(Function &F) {
118 void print(raw_ostream &OS, const Module* = 0) const {}
120 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
121 AU.setPreservesAll();
126 char CFGOnlyViewer::ID = 0;
127 static RegisterPass<CFGOnlyViewer>
129 "View CFG of function (with no function bodies)", false, true);
132 struct VISIBILITY_HIDDEN CFGPrinter : public FunctionPass {
133 static char ID; // Pass identification, replacement for typeid
134 CFGPrinter() : FunctionPass(&ID) {}
135 explicit CFGPrinter(void *pid) : FunctionPass(pid) {}
137 virtual bool runOnFunction(Function &F) {
138 std::string Filename = "cfg." + F.getNameStr() + ".dot";
139 cerr << "Writing '" << Filename << "'...";
140 std::ofstream File(Filename.c_str());
143 WriteGraph(File, (const Function*)&F);
145 cerr << " error opening file for writing!";
150 void print(raw_ostream &OS, const Module* = 0) const {}
152 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
153 AU.setPreservesAll();
158 char CFGPrinter::ID = 0;
159 static RegisterPass<CFGPrinter>
160 P1("dot-cfg", "Print CFG of function to 'dot' file", false, true);
163 struct VISIBILITY_HIDDEN CFGOnlyPrinter : public FunctionPass {
164 static char ID; // Pass identification, replacement for typeid
165 CFGOnlyPrinter() : FunctionPass(&ID) {}
166 explicit CFGOnlyPrinter(void *pid) : FunctionPass(pid) {}
167 virtual bool runOnFunction(Function &F) {
168 std::string Filename = "cfg." + F.getNameStr() + ".dot";
169 cerr << "Writing '" << Filename << "'...";
170 std::ofstream File(Filename.c_str());
173 WriteGraph(File, (const Function*)&F, true);
175 cerr << " error opening file for writing!";
179 void print(raw_ostream &OS, const Module* = 0) const {}
181 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
182 AU.setPreservesAll();
187 char CFGOnlyPrinter::ID = 0;
188 static RegisterPass<CFGOnlyPrinter>
190 "Print CFG of function to 'dot' file (with no function bodies)", false, true);
192 /// viewCFG - This function is meant for use from the debugger. You can just
193 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
194 /// program, displaying the CFG of the current function. This depends on there
195 /// being a 'dot' and 'gv' program in your path.
197 void Function::viewCFG() const {
198 ViewGraph(this, "cfg" + getNameStr());
201 /// viewCFGOnly - This function is meant for use from the debugger. It works
202 /// just like viewCFG, but it does not include the contents of basic blocks
203 /// into the nodes, just the label. If you are only interested in the CFG t
204 /// his can make the graph smaller.
206 void Function::viewCFGOnly() const {
207 ViewGraph(this, "cfg" + getNameStr(), true);
210 FunctionPass *llvm::createCFGPrinterPass () {
211 return new CFGPrinter();
214 FunctionPass *llvm::createCFGOnlyPrinterPass () {
215 return new CFGOnlyPrinter();