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/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/PrettyStackTrace.h"
  27 #include "llvm/Support/Streams.h"
  28 #include "llvm/Support/raw_ostream.h"
  29 #include "llvm/System/Signals.h"
  30 #include <iostream>
  31 #include <fstream>
  32 #include <memory>
  33 using namespace llvm;
  34
  35 static cl::opt<std::string>
  36 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
  37
  38 static cl::opt<std::string>
  39 OutputFilename("o", cl::desc("Override output filename"),
  40                cl::value_desc("filename"));
  41
  42 static cl::opt<bool>
  43 Force("f", cl::desc("Overwrite output files"));
  44
  45 static cl::opt<bool>
  46 DontPrint("disable-output", cl::desc("Don't output the .ll file"), cl::Hidden);
  47
  48 int main(int argc, char **argv) {
  49   // Print a stack trace if we signal out.
  50   sys::PrintStackTraceOnErrorSignal();
  51   PrettyStackTraceProgram X(argc, argv);
  52
  53   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
  54   try {
  55     cl::ParseCommandLineOptions(argc, argv, "llvm .bc -> .ll disassembler\n");
  56
  57     std::ostream *Out = &std::cout;  // Default to printing to stdout.
  58     std::string ErrorMessage;
  59
  60     std::auto_ptr<Module> M;
  61
  62     if (MemoryBuffer *Buffer
  63            = MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage)) {
  64       M.reset(ParseBitcodeFile(Buffer, &ErrorMessage));
  65       delete Buffer;
  66     }
  67
  68     if (M.get() == 0) {
  69       cerr << argv[0] << ": ";
  70       if (ErrorMessage.size())
  71         cerr << ErrorMessage << "\n";
  72       else
  73         cerr << "bitcode didn't read correctly.\n";
  74       return 1;
  75     }
  76
  77     if (DontPrint) {
  78       // Just use stdout.  We won't actually print anything on it.
  79     } else if (OutputFilename != "") {   // Specified an output filename?
  80       if (OutputFilename != "-") { // Not stdout?
  81         if (!Force && std::ifstream(OutputFilename.c_str())) {
  82           // If force is not specified, make sure not to overwrite a file!
  83           cerr << argv[0] << ": error opening '" << OutputFilename
  84                << "': file exists! Sending to standard output.\n";
  85         } else {
  86           Out = new std::ofstream(OutputFilename.c_str());
  87         }
  88       }
  89     } else {
  90       if (InputFilename == "-") {
  91         OutputFilename = "-";
  92       } else {
  93         std::string IFN = InputFilename;
  94         int Len = IFN.length();
  95         if (IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
  96           // Source ends in .bc
  97           OutputFilename = std::string(IFN.begin(), IFN.end()-3)+".ll";
  98         } else {
  99           OutputFilename = IFN+".ll";
 100         }
 101
 102         if (!Force && std::ifstream(OutputFilename.c_str())) {
 103           // If force is not specified, make sure not to overwrite a file!
 104           cerr << argv[0] << ": error opening '" << OutputFilename
 105                << "': file exists! Sending to standard output.\n";
 106         } else {
 107           Out = new std::ofstream(OutputFilename.c_str());
 108
 109           // Make sure that the Out file gets unlinked from the disk if we get a
 110           // SIGINT
 111           sys::RemoveFileOnSignal(sys::Path(OutputFilename));
 112         }
 113       }
 114     }
 115
 116     if (!Out->good()) {
 117       cerr << argv[0] << ": error opening " << OutputFilename
 118            << ": sending to stdout instead!\n";
 119       Out = &std::cout;
 120     }
 121
 122     // All that llvm-dis does is write the assembly to a file.
 123     if (!DontPrint) {
 124       PassManager Passes;
 125       raw_os_ostream L(*Out);
 126       Passes.add(createPrintModulePass(&L));
 127       Passes.run(*M.get());
 128     }
 129
 130     if (Out != &std::cout) {
 131       ((std::ofstream*)Out)->close();
 132       delete Out;
 133     }
 134     return 0;
 135   } catch (const std::string& msg) {
 136     cerr << argv[0] << ": " << msg << "\n";
 137   } catch (...) {
 138     cerr << argv[0] << ": Unexpected unknown exception occurred.\n";
 139   }
 140
 141   return 1;
 142 }
 143