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/PassManager.h"
  22 #include "llvm/Bitcode/ReaderWriter.h"
  23 #include "llvm/Assembly/PrintModulePass.h"
  24 #include "llvm/Support/CommandLine.h"
  25 #include "llvm/Support/ManagedStatic.h"
  26 #include "llvm/Support/MemoryBuffer.h"
  27 #include "llvm/Support/PrettyStackTrace.h"
  28 #include "llvm/Support/raw_ostream.h"
  29 #include "llvm/System/Signals.h"
  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("Enable binary output on terminals"));
  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   // Print a stack trace if we signal out.
  48   sys::PrintStackTraceOnErrorSignal();
  49   PrettyStackTraceProgram X(argc, argv);
  50
  51   LLVMContext &Context = getGlobalContext();
  52   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
  53
  54
  55   cl::ParseCommandLineOptions(argc, argv, "llvm .bc -> .ll disassembler\n");
  56
  57   std::string ErrorMessage;
  58   std::auto_ptr<Module> M;
  59
  60   if (MemoryBuffer *Buffer
  61          = MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage)) {
  62     M.reset(ParseBitcodeFile(Buffer, Context, &ErrorMessage));
  63     delete Buffer;
  64   }
  65
  66   if (M.get() == 0) {
  67     errs() << argv[0] << ": ";
  68     if (ErrorMessage.size())
  69       errs() << ErrorMessage << "\n";
  70     else
  71       errs() << "bitcode didn't read correctly.\n";
  72     return 1;
  73   }
  74
  75   // Just use stdout.  We won't actually print anything on it.
  76   if (DontPrint)
  77     OutputFilename = "-";
  78
  79   if (OutputFilename.empty()) { // Unspecified output, infer it.
  80     if (InputFilename == "-") {
  81       OutputFilename = "-";
  82     } else {
  83       const std::string &IFN = InputFilename;
  84       int Len = IFN.length();
  85       // If the source ends in .bc, strip it off.
  86       if (IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c')
  87         OutputFilename = std::string(IFN.begin(), IFN.end()-3)+".ll";
  88       else
  89         OutputFilename = IFN+".ll";
  90     }
  91   }
  92
  93   // Make sure that the Out file gets unlinked from the disk if we get a
  94   // SIGINT.
  95   if (OutputFilename != "-")
  96     sys::RemoveFileOnSignal(sys::Path(OutputFilename));
  97
  98   std::string ErrorInfo;
  99   std::auto_ptr<raw_fd_ostream>
 100   Out(new raw_fd_ostream(OutputFilename.c_str(), ErrorInfo,
 101                          raw_fd_ostream::F_Binary));
 102   if (!ErrorInfo.empty()) {
 103     errs() << ErrorInfo << '\n';
 104     return 1;
 105   }
 106
 107   // All that llvm-dis does is write the assembly to a file.
 108   if (!DontPrint) {
 109     PassManager Passes;
 110     Passes.add(createPrintModulePass(Out.get()));
 111     Passes.run(*M.get());
 112   }
 113
 114   return 0;
 115 }
 116