llvm-dis.cpp revision 7c0e022c5c4be4b11e199a53f73bbdd84e34aa80 
1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// LLVM 'DIS' UTILITY
11//
12// This utility may be invoked in the following manner:
13//  llvm-dis [options]      - Read LLVM bytecode from stdin, write asm to stdout
14//  llvm-dis [options] x.bc - Read LLVM bytecode from the x.bc file, write asm
15//                            to the x.ll file.
16//  Options:
17//      --help   - Output information about command line switches
18//       -c      - Print C code instead of LLVM assembly
19//
20//===----------------------------------------------------------------------===//
21
22#include "llvm/Module.h"
23#include "llvm/PassManager.h"
24#include "llvm/Bytecode/Reader.h"
25#include "llvm/Assembly/CWriter.h"
26#include "llvm/Assembly/PrintModulePass.h"
27#include "Support/CommandLine.h"
28#include "Support/Signals.h"
29#include <fstream>
30#include <memory>
31
32// OutputMode - The different orderings to print basic blocks in...
33enum OutputMode {
34  llvm = 0,           // Generate LLVM assembly (the default)
35  c,                  // Generate C code
36};
37
38static cl::opt<std::string>
39InputFilename(cl::Positional, cl::desc("<input bytecode>"), cl::init("-"));
40
41static cl::opt<std::string>
42OutputFilename("o", cl::desc("Override output filename"),
43               cl::value_desc("filename"));
44
45static cl::opt<bool>
46Force("f", cl::desc("Overwrite output files"));
47
48static cl::opt<enum OutputMode>
49WriteMode(cl::desc("Specify the output format:"),
50          cl::values(clEnumVal(llvm, "Output LLVM assembly"),
51                     clEnumVal(c   , "Output C code for program"),
52                    0));
53
54int main(int argc, char **argv) {
55  cl::ParseCommandLineOptions(argc, argv, " llvm .bc -> .ll disassembler\n");
56  std::ostream *Out = &std::cout;  // Default to printing to stdout...
57  std::string ErrorMessage;
58
59  std::auto_ptr<Module> M(ParseBytecodeFile(InputFilename, &ErrorMessage));
60  if (M.get() == 0) {
61    std::cerr << argv[0] << ": ";
62    if (ErrorMessage.size())
63      std::cerr << ErrorMessage << "\n";
64    else
65      std::cerr << "bytecode didn't read correctly.\n";
66    return 1;
67  }
68
69  if (OutputFilename != "") {   // Specified an output filename?
70    if (OutputFilename != "-") { // Not stdout?
71      if (!Force && std::ifstream(OutputFilename.c_str())) {
72        // If force is not specified, make sure not to overwrite a file!
73        std::cerr << argv[0] << ": error opening '" << OutputFilename
74                  << "': file exists! Sending to standard output.\n";
75      } else {
76        Out = new std::ofstream(OutputFilename.c_str());
77      }
78    }
79  } else {
80    if (InputFilename == "-") {
81      OutputFilename = "-";
82    } else {
83      std::string IFN = InputFilename;
84      int Len = IFN.length();
85      if (IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
86	// Source ends in .bc
87	OutputFilename = std::string(IFN.begin(), IFN.end()-3);
88      } else {
89	OutputFilename = IFN;   // Append a .ll to it
90      }
91      if (WriteMode == c)
92        OutputFilename += ".c";
93      else
94        OutputFilename += ".ll";
95
96      if (!Force && std::ifstream(OutputFilename.c_str())) {
97        // If force is not specified, make sure not to overwrite a file!
98        std::cerr << argv[0] << ": error opening '" << OutputFilename
99                  << "': file exists! Sending to standard output.\n";
100      } else {
101        Out = new std::ofstream(OutputFilename.c_str());
102
103        // Make sure that the Out file gets unlinked from the disk if we get a
104        // SIGINT
105        RemoveFileOnSignal(OutputFilename);
106      }
107    }
108  }
109
110  if (!Out->good()) {
111    std::cerr << argv[0] << ": error opening " << OutputFilename
112              << ": sending to stdout instead!\n";
113    Out = &std::cout;
114  }
115
116  // All that dis does is write the assembly or C out to a file...
117  //
118  PassManager Passes;
119
120  switch (WriteMode) {
121  case llvm:           // Output LLVM assembly
122    Passes.add(new PrintModulePass(Out));
123    break;
124  case c:              // Convert LLVM to C
125    Passes.add(createWriteToCPass(*Out));
126    break;
127  }
128
129  Passes.run(*M.get());
130
131  if (Out != &std::cout) {
132    ((std::ofstream*)Out)->close();
133    delete Out;
134  }
135  return 0;
136}
137
138