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 is distributed under the University of Illinois Open Source
   6 // 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/LLVMContext.h"
  20 #include "llvm/Module.h"
  21 #include "llvm/Bitcode/ReaderWriter.h"
  22 #include "llvm/Support/CommandLine.h"
  23 #include "llvm/Support/ManagedStatic.h"
  24 #include "llvm/Support/MemoryBuffer.h"
  25 #include "llvm/Support/PrettyStackTrace.h"
  26 #include "llvm/Support/raw_ostream.h"
  27 #include "llvm/System/Signals.h"
  28 #include <memory>
  29 using namespace llvm;
  30
  31 static cl::opt<std::string>
  32 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
  33
  34 static cl::opt<std::string>
  35 OutputFilename("o", cl::desc("Override output filename"),
  36                cl::value_desc("filename"));
  37
  38 static cl::opt<bool>
  39 Force("f", cl::desc("Enable binary output on terminals"));
  40
  41 static cl::opt<bool>
  42 DontPrint("disable-output", cl::desc("Don't output the .ll file"), cl::Hidden);
  43
  44 int main(int argc, char **argv) {
  45   // Print a stack trace if we signal out.
  46   sys::PrintStackTraceOnErrorSignal();
  47   PrettyStackTraceProgram X(argc, argv);
  48
  49   LLVMContext &Context = getGlobalContext();
  50   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
  51
  52
  53   cl::ParseCommandLineOptions(argc, argv, "llvm .bc -> .ll disassembler\n");
  54
  55   std::string ErrorMessage;
  56   std::auto_ptr<Module> M;
  57
  58   if (MemoryBuffer *Buffer
  59          = MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage)) {
  60     M.reset(ParseBitcodeFile(Buffer, Context, &ErrorMessage));
  61     delete Buffer;
  62   }
  63
  64   if (M.get() == 0) {
  65     errs() << argv[0] << ": ";
  66     if (ErrorMessage.size())
  67       errs() << ErrorMessage << "\n";
  68     else
  69       errs() << "bitcode didn't read correctly.\n";
  70     return 1;
  71   }
  72
  73   // Just use stdout.  We won't actually print anything on it.
  74   if (DontPrint)
  75     OutputFilename = "-";
  76
  77   if (OutputFilename.empty()) { // Unspecified output, infer it.
  78     if (InputFilename == "-") {
  79       OutputFilename = "-";
  80     } else {
  81       const std::string &IFN = InputFilename;
  82       int Len = IFN.length();
  83       // If the source ends in .bc, strip it off.
  84       if (IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c')
  85         OutputFilename = std::string(IFN.begin(), IFN.end()-3)+".ll";
  86       else
  87         OutputFilename = IFN+".ll";
  88     }
  89   }
  90
  91   // Make sure that the Out file gets unlinked from the disk if we get a
  92   // SIGINT.
  93   if (OutputFilename != "-")
  94     sys::RemoveFileOnSignal(sys::Path(OutputFilename));
  95
  96   std::string ErrorInfo;
  97   std::auto_ptr<raw_fd_ostream>
  98   Out(new raw_fd_ostream(OutputFilename.c_str(), ErrorInfo,
  99                          raw_fd_ostream::F_Binary));
 100   if (!ErrorInfo.empty()) {
 101     errs() << ErrorInfo << '\n';
 102     return 1;
 103   }
 104
 105   // All that llvm-dis does is write the assembly to a file.
 106   if (!DontPrint)
 107     *Out << *M;
 108
 109   return 0;
 110 }
 111