CFGPrinter.h revision 2f08e75a45b9fa698a49277f6cc11e041bf5fa51 
1//===-- CFGPrinter.h - CFG printer external interface -----------*- C++ -*-===//
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 external functions that can be called to explicitly
11// instantiate the CFG printer.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_ANALYSIS_CFGPRINTER_H
16#define LLVM_ANALYSIS_CFGPRINTER_H
17
18#include "llvm/Assembly/Writer.h"
19#include "llvm/IR/Constants.h"
20#include "llvm/IR/Function.h"
21#include "llvm/IR/Instructions.h"
22#include "llvm/Support/CFG.h"
23#include "llvm/Support/GraphWriter.h"
24
25namespace llvm {
26template<>
27struct DOTGraphTraits<const Function*> : public DefaultDOTGraphTraits {
28
29  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
30
31  static std::string getGraphName(const Function *F) {
32    return "CFG for '" + F->getName().str() + "' function";
33  }
34
35  static std::string getSimpleNodeLabel(const BasicBlock *Node,
36                                        const Function *) {
37    if (!Node->getName().empty())
38      return Node->getName().str();
39
40    std::string Str;
41    raw_string_ostream OS(Str);
42
43    WriteAsOperand(OS, Node, false);
44    return OS.str();
45  }
46
47  static std::string getCompleteNodeLabel(const BasicBlock *Node,
48                                          const Function *) {
49    enum { MaxColumns = 80 };
50    std::string Str;
51    raw_string_ostream OS(Str);
52
53    if (Node->getName().empty()) {
54      WriteAsOperand(OS, Node, false);
55      OS << ":";
56    }
57
58    OS << *Node;
59    std::string OutStr = OS.str();
60    if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
61
62    // Process string output to make it nicer...
63    unsigned ColNum = 0;
64    unsigned LastSpace = 0;
65    for (unsigned i = 0; i != OutStr.length(); ++i) {
66      if (OutStr[i] == '\n') {                            // Left justify
67        OutStr[i] = '\\';
68        OutStr.insert(OutStr.begin()+i+1, 'l');
69        ColNum = 0;
70        LastSpace = 0;
71      } else if (OutStr[i] == ';') {                      // Delete comments!
72        unsigned Idx = OutStr.find('\n', i+1);            // Find end of line
73        OutStr.erase(OutStr.begin()+i, OutStr.begin()+Idx);
74        --i;
75      } else if (ColNum == MaxColumns) {                  // Wrap lines.
76        if (LastSpace) {
77          OutStr.insert(LastSpace, "\\l...");
78          ColNum = i - LastSpace;
79          LastSpace = 0;
80          i += 3; // The loop will advance 'i' again.
81        }
82        // Else keep trying to find a space.
83      }
84      else
85        ++ColNum;
86      if (OutStr[i] == ' ')
87        LastSpace = i;
88    }
89    return OutStr;
90  }
91
92  std::string getNodeLabel(const BasicBlock *Node,
93                           const Function *Graph) {
94    if (isSimple())
95      return getSimpleNodeLabel(Node, Graph);
96    else
97      return getCompleteNodeLabel(Node, Graph);
98  }
99
100  static std::string getEdgeSourceLabel(const BasicBlock *Node,
101                                        succ_const_iterator I) {
102    // Label source of conditional branches with "T" or "F"
103    if (const BranchInst *BI = dyn_cast<BranchInst>(Node->getTerminator()))
104      if (BI->isConditional())
105        return (I == succ_begin(Node)) ? "T" : "F";
106
107    // Label source of switch edges with the associated value.
108    if (const SwitchInst *SI = dyn_cast<SwitchInst>(Node->getTerminator())) {
109      unsigned SuccNo = I.getSuccessorIndex();
110
111      if (SuccNo == 0) return "def";
112
113      std::string Str;
114      raw_string_ostream OS(Str);
115      SwitchInst::ConstCaseIt Case =
116          SwitchInst::ConstCaseIt::fromSuccessorIndex(SI, SuccNo);
117      OS << Case.getCaseValue()->getValue();
118      return OS.str();
119    }
120    return "";
121  }
122};
123} // End llvm namespace
124
125namespace llvm {
126  class FunctionPass;
127  FunctionPass *createCFGPrinterPass ();
128  FunctionPass *createCFGOnlyPrinterPass ();
129} // End llvm namespace
130
131#endif
132