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