LLVM API Documentation

 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Groups Pages
CFGPrinter.cpp
Go to the documentation of this file.
1 //===- CFGPrinter.cpp - DOT printer for the control flow graph ------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
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.
13 //
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
16 // on the CFG.
17 //
18 //===----------------------------------------------------------------------===//
19 
21 #include "llvm/Pass.h"
22 using namespace llvm;
23 
24 namespace {
25  struct CFGViewer : public FunctionPass {
26  static char ID; // Pass identifcation, replacement for typeid
27  CFGViewer() : FunctionPass(ID) {
29  }
30 
31  virtual bool runOnFunction(Function &F) {
32  F.viewCFG();
33  return false;
34  }
35 
36  void print(raw_ostream &OS, const Module* = 0) const {}
37 
38  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
39  AU.setPreservesAll();
40  }
41  };
42 }
43 
44 char CFGViewer::ID = 0;
45 INITIALIZE_PASS(CFGViewer, "view-cfg", "View CFG of function", false, true)
46 
47 namespace {
48  struct CFGOnlyViewer : public FunctionPass {
49  static char ID; // Pass identifcation, replacement for typeid
50  CFGOnlyViewer() : FunctionPass(ID) {
52  }
53 
54  virtual bool runOnFunction(Function &F) {
55  F.viewCFGOnly();
56  return false;
57  }
58 
59  void print(raw_ostream &OS, const Module* = 0) const {}
60 
61  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
62  AU.setPreservesAll();
63  }
64  };
65 }
66 
67 char CFGOnlyViewer::ID = 0;
68 INITIALIZE_PASS(CFGOnlyViewer, "view-cfg-only",
69  "View CFG of function (with no function bodies)", false, true)
70 
71 namespace {
72  struct CFGPrinter : public FunctionPass {
73  static char ID; // Pass identification, replacement for typeid
74  CFGPrinter() : FunctionPass(ID) {
76  }
77 
78  virtual bool runOnFunction(Function &F) {
79  std::string Filename = "cfg." + F.getName().str() + ".dot";
80  errs() << "Writing '" << Filename << "'...";
81 
82  std::string ErrorInfo;
83  raw_fd_ostream File(Filename.c_str(), ErrorInfo);
84 
85  if (ErrorInfo.empty())
86  WriteGraph(File, (const Function*)&F);
87  else
88  errs() << " error opening file for writing!";
89  errs() << "\n";
90  return false;
91  }
92 
93  void print(raw_ostream &OS, const Module* = 0) const {}
94 
95  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
96  AU.setPreservesAll();
97  }
98  };
99 }
100 
101 char CFGPrinter::ID = 0;
102 INITIALIZE_PASS(CFGPrinter, "dot-cfg", "Print CFG of function to 'dot' file",
103  false, true)
104 
105 namespace {
106  struct CFGOnlyPrinter : public FunctionPass {
107  static char ID; // Pass identification, replacement for typeid
108  CFGOnlyPrinter() : FunctionPass(ID) {
110  }
111 
112  virtual bool runOnFunction(Function &F) {
113  std::string Filename = "cfg." + F.getName().str() + ".dot";
114  errs() << "Writing '" << Filename << "'...";
115 
116  std::string ErrorInfo;
117  raw_fd_ostream File(Filename.c_str(), ErrorInfo);
118 
119  if (ErrorInfo.empty())
120  WriteGraph(File, (const Function*)&F, true);
121  else
122  errs() << " error opening file for writing!";
123  errs() << "\n";
124  return false;
125  }
126  void print(raw_ostream &OS, const Module* = 0) const {}
127 
128  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
129  AU.setPreservesAll();
130  }
131  };
132 }
133 
134 char CFGOnlyPrinter::ID = 0;
135 INITIALIZE_PASS(CFGOnlyPrinter, "dot-cfg-only",
136  "Print CFG of function to 'dot' file (with no function bodies)",
137  false, true)
138 
139 /// viewCFG - This function is meant for use from the debugger. You can just
140 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
141 /// program, displaying the CFG of the current function. This depends on there
142 /// being a 'dot' and 'gv' program in your path.
143 ///
144 void Function::viewCFG() const {
145  ViewGraph(this, "cfg" + getName());
146 }
147 
148 /// viewCFGOnly - This function is meant for use from the debugger. It works
149 /// just like viewCFG, but it does not include the contents of basic blocks
150 /// into the nodes, just the label. If you are only interested in the CFG t
151 /// his can make the graph smaller.
152 ///
153 void Function::viewCFGOnly() const {
154  ViewGraph(this, "cfg" + getName(), true);
155 }
156 
158  return new CFGPrinter();
159 }
160 
162  return new CFGOnlyPrinter();
163 }
164 
void viewCFGOnly() const
raw_ostream & errs()
static PassRegistry * getPassRegistry()
The main container class for the LLVM Intermediate Representation.
Definition: Module.h:112
raw_ostream & WriteGraph(raw_ostream &O, const EdgeBundles &G, bool ShortNames=false, const Twine &Title="")
Specialize WriteGraph, the standard implementation won't work.
Definition: EdgeBundles.cpp:78
std::string str() const
str - Get the contents as an std::string.
Definition: StringRef.h:181
F(f)
StringRef getName() const
Definition: Value.cpp:167
void viewCFG() const
ID
LLVM Calling Convention Representation.
Definition: CallingConv.h:26
FunctionPass * createCFGPrinterPass()
Definition: CFGPrinter.cpp:157
void initializeCFGOnlyPrinterPass(PassRegistry &)
INITIALIZE_PASS(CFGOnlyViewer,"view-cfg-only","View CFG of function (with no function bodies)", false, true) namespace
Definition: CFGPrinter.cpp:68
void ViewGraph(const GraphType &G, const Twine &Name, bool ShortNames=false, const Twine &Title="", GraphProgram::Name Program=GraphProgram::DOT)
Definition: GraphWriter.h:346
void initializeCFGPrinterPass(PassRegistry &)
void initializeCFGOnlyViewerPass(PassRegistry &)
std::string getName(ID id, ArrayRef< Type * > Tys=None)
Definition: Function.cpp:400
FunctionPass * createCFGOnlyPrinterPass()
Definition: CFGPrinter.cpp:161