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/Streams.h"
  29 #include "llvm/Support/raw_ostream.h"
  30 #include "llvm/System/Signals.h"
  31 #include <memory>
  32 using namespace llvm;
  33
  34 static cl::opt<std::string>
  35 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
  36
  37 static cl::opt<std::string>
  38 OutputFilename("o", cl::desc("Override output filename"),
  39                cl::value_desc("filename"));
  40
  41 static cl::opt<bool>
  42 Force("f", cl::desc("Overwrite output files"));
  43
  44 static cl::opt<bool>
  45 DontPrint("disable-output", cl::desc("Don't output the .ll file"), cl::Hidden);
  46
  47 int main(int argc, char **argv) {
  48   // Print a stack trace if we signal out.
  49   sys::PrintStackTraceOnErrorSignal();
  50   PrettyStackTraceProgram X(argc, argv);
  51
  52   LLVMContext &Context = getGlobalContext();
  53   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
  54   try {
  55     cl::ParseCommandLineOptions(argc, argv, "llvm .bc -> .ll disassembler\n");
  56
  57     raw_ostream *Out = &outs();  // 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, Context, &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         std::string ErrorInfo;
  82         Out = new raw_fd_ostream(OutputFilename.c_str(), /*Binary=*/false,
  83                                  Force, ErrorInfo);
  84         if (!ErrorInfo.empty()) {
  85           errs() << ErrorInfo << '\n';
  86           if (!Force)
  87             errs() << "Use -f command line argument to force output\n";
  88           delete Out;
  89           return 1;
  90         }
  91       }
  92     } else {
  93       if (InputFilename == "-") {
  94         OutputFilename = "-";
  95       } else {
  96         std::string IFN = InputFilename;
  97         int Len = IFN.length();
  98         if (IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
  99           // Source ends in .bc
 100           OutputFilename = std::string(IFN.begin(), IFN.end()-3)+".ll";
 101         } else {
 102           OutputFilename = IFN+".ll";
 103         }
 104
 105         std::string ErrorInfo;
 106         Out = new raw_fd_ostream(OutputFilename.c_str(), /*Binary=*/false,
 107                                  Force, ErrorInfo);
 108         if (!ErrorInfo.empty()) {
 109           errs() << ErrorInfo << '\n';
 110           if (!Force)
 111             errs() << "Use -f command line argument to force output\n";
 112           delete Out;
 113           return 1;
 114         }
 115
 116         // Make sure that the Out file gets unlinked from the disk if we get a
 117         // SIGINT
 118         sys::RemoveFileOnSignal(sys::Path(OutputFilename));
 119       }
 120     }
 121
 122     // All that llvm-dis does is write the assembly to a file.
 123     if (!DontPrint) {
 124       PassManager Passes;
 125       Passes.add(createPrintModulePass(Out));
 126       Passes.run(*M.get());
 127     }
 128
 129     if (Out != &outs())
 130       delete Out;
 131     return 0;
 132   } catch (const std::string& msg) {
 133     cerr << argv[0] << ": " << msg << "\n";
 134   } catch (...) {
 135     cerr << argv[0] << ": Unexpected unknown exception occurred.\n";
 136   }
 137
 138   return 1;
 139 }
 140