tools/llvm-dis/llvm-dis.cpp

   1 //===-- llvm-dis.cpp - The low-level LLVM disassembler --------------------===//
   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 // This utility may be invoked in the following manner:
  11 //  llvm-dis [options]      - Read LLVM bitcode from stdin, write asm to stdout
  12 //  llvm-dis [options] x.bc - Read LLVM bitcode from the x.bc file, write asm
  13 //                            to the x.ll file.
  14 //  Options:
  15 //      --help   - Output information about command line switches
  16 //
  17 //===----------------------------------------------------------------------===//
  18
  19 #include "llvm/Module.h"
  20 #include "llvm/PassManager.h"
  21 #include "llvm/Bitcode/ReaderWriter.h"
  22 #include "llvm/Assembly/PrintModulePass.h"
  23 #include "llvm/Support/CommandLine.h"
  24 #include "llvm/Support/ManagedStatic.h"
  25 #include "llvm/Support/MemoryBuffer.h"
  26 #include "llvm/Support/Streams.h"
  27 #include "llvm/System/Signals.h"
  28 #include <iostream>
  29 #include <fstream>
  30 #include <memory>
  31 using namespace llvm;
  32
  33 static cl::opt<std::string>
  34 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
  35
  36 static cl::opt<std::string>
  37 OutputFilename("o", cl::desc("Override output filename"),
  38                cl::value_desc("filename"));
  39
  40 static cl::opt<bool>
  41 Force("f", cl::desc("Overwrite output files"));
  42
  43 static cl::opt<bool>
  44 DontPrint("disable-output", cl::desc("Don't output the .ll file"), cl::Hidden);
  45
  46 int main(int argc, char **argv) {
  47   llvm_shutdown_obj X;  // Call llvm_shutdown() on exit.
  48   try {
  49     cl::ParseCommandLineOptions(argc, argv, " llvm .bc -> .ll disassembler\n");
  50     sys::PrintStackTraceOnErrorSignal();
  51
  52     std::ostream *Out = &std::cout;  // Default to printing to stdout.
  53     std::string ErrorMessage;
  54
  55     std::auto_ptr<Module> M;
  56
  57     if (MemoryBuffer *Buffer
  58            = MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage)) {
  59       M.reset(ParseBitcodeFile(Buffer, &ErrorMessage));
  60       delete Buffer;
  61     }
  62
  63     if (M.get() == 0) {
  64       cerr << argv[0] << ": ";
  65       if (ErrorMessage.size())
  66         cerr << ErrorMessage << "\n";
  67       else
  68         cerr << "bitcode didn't read correctly.\n";
  69       return 1;
  70     }
  71
  72     if (DontPrint) {
  73       // Just use stdout.  We won't actually print anything on it.
  74     } else if (OutputFilename != "") {   // Specified an output filename?
  75       if (OutputFilename != "-") { // Not stdout?
  76         if (!Force && std::ifstream(OutputFilename.c_str())) {
  77           // If force is not specified, make sure not to overwrite a file!
  78           cerr << argv[0] << ": error opening '" << OutputFilename
  79                << "': file exists! Sending to standard output.\n";
  80         } else {
  81           Out = new std::ofstream(OutputFilename.c_str());
  82         }
  83       }
  84     } else {
  85       if (InputFilename == "-") {
  86         OutputFilename = "-";
  87       } else {
  88         std::string IFN = InputFilename;
  89         int Len = IFN.length();
  90         if (IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
  91           // Source ends in .bc
  92           OutputFilename = std::string(IFN.begin(), IFN.end()-3)+".ll";
  93         } else {
  94           OutputFilename = IFN+".ll";
  95         }
  96
  97         if (!Force && std::ifstream(OutputFilename.c_str())) {
  98           // If force is not specified, make sure not to overwrite a file!
  99           cerr << argv[0] << ": error opening '" << OutputFilename
 100                << "': file exists! Sending to standard output.\n";
 101         } else {
 102           Out = new std::ofstream(OutputFilename.c_str());
 103
 104           // Make sure that the Out file gets unlinked from the disk if we get a
 105           // SIGINT
 106           sys::RemoveFileOnSignal(sys::Path(OutputFilename));
 107         }
 108       }
 109     }
 110
 111     if (!Out->good()) {
 112       cerr << argv[0] << ": error opening " << OutputFilename
 113            << ": sending to stdout instead!\n";
 114       Out = &std::cout;
 115     }
 116
 117     // All that llvm-dis does is write the assembly to a file.
 118     if (!DontPrint) {
 119       PassManager Passes;
 120       OStream L(*Out);
 121       Passes.add(new PrintModulePass(&L));
 122       Passes.run(*M.get());
 123     }
 124
 125     if (Out != &std::cout) {
 126       ((std::ofstream*)Out)->close();
 127       delete Out;
 128     }
 129     return 0;
 130   } catch (const std::string& msg) {
 131     cerr << argv[0] << ": " << msg << "\n";
 132   } catch (...) {
 133     cerr << argv[0] << ": Unexpected unknown exception occurred.\n";
 134   }
 135
 136   return 1;
 137 }
 138