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/Type.h"
  22 #include "llvm/Bitcode/ReaderWriter.h"
  23 #include "llvm/Assembly/AssemblyAnnotationWriter.h"
  24 #include "llvm/Support/CommandLine.h"
  25 #include "llvm/Support/FormattedStream.h"
  26 #include "llvm/Support/ManagedStatic.h"
  27 #include "llvm/Support/MemoryBuffer.h"
  28 #include "llvm/Support/PrettyStackTrace.h"
  29 #include "llvm/Support/ToolOutputFile.h"
  30 #include "llvm/System/Signals.h"
  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 static cl::opt<bool>
  47 ShowAnnotations("show-annotations",
  48                 cl::desc("Add informational comments to the .ll file"));
  49
  50 namespace {
  51
  52 class CommentWriter : public AssemblyAnnotationWriter {
  53 public:
  54   void emitFunctionAnnot(const Function *F,
  55                          formatted_raw_ostream &OS) {
  56     OS << "; [#uses=" << F->getNumUses() << ']';  // Output # uses
  57     OS << '\n';
  58   }
  59   void printInfoComment(const Value &V, formatted_raw_ostream &OS) {
  60     if (V.getType()->isVoidTy()) return;
  61
  62     OS.PadToColumn(50);
  63     OS << "; [#uses=" << V.getNumUses() << ']';  // Output # uses
  64   }
  65 };
  66
  67 } // end anon namespace
  68
  69 int main(int argc, char **argv) {
  70   // Print a stack trace if we signal out.
  71   sys::PrintStackTraceOnErrorSignal();
  72   PrettyStackTraceProgram X(argc, argv);
  73
  74   LLVMContext &Context = getGlobalContext();
  75   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
  76
  77
  78   cl::ParseCommandLineOptions(argc, argv, "llvm .bc -> .ll disassembler\n");
  79
  80   std::string ErrorMessage;
  81   std::auto_ptr<Module> M;
  82
  83   if (MemoryBuffer *Buffer
  84          = MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage)) {
  85     M.reset(ParseBitcodeFile(Buffer, Context, &ErrorMessage));
  86     delete Buffer;
  87   }
  88
  89   if (M.get() == 0) {
  90     errs() << argv[0] << ": ";
  91     if (ErrorMessage.size())
  92       errs() << ErrorMessage << "\n";
  93     else
  94       errs() << "bitcode didn't read correctly.\n";
  95     return 1;
  96   }
  97
  98   // Just use stdout.  We won't actually print anything on it.
  99   if (DontPrint)
 100     OutputFilename = "-";
 101
 102   if (OutputFilename.empty()) { // Unspecified output, infer it.
 103     if (InputFilename == "-") {
 104       OutputFilename = "-";
 105     } else {
 106       const std::string &IFN = InputFilename;
 107       int Len = IFN.length();
 108       // If the source ends in .bc, strip it off.
 109       if (IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c')
 110         OutputFilename = std::string(IFN.begin(), IFN.end()-3)+".ll";
 111       else
 112         OutputFilename = IFN+".ll";
 113     }
 114   }
 115
 116   std::string ErrorInfo;
 117   OwningPtr<tool_output_file>
 118   Out(new tool_output_file(OutputFilename.c_str(), ErrorInfo,
 119                            raw_fd_ostream::F_Binary));
 120   if (!ErrorInfo.empty()) {
 121     errs() << ErrorInfo << '\n';
 122     return 1;
 123   }
 124
 125   OwningPtr<AssemblyAnnotationWriter> Annotator;
 126   if (ShowAnnotations)
 127     Annotator.reset(new CommentWriter());
 128
 129   // All that llvm-dis does is write the assembly to a file.
 130   if (!DontPrint)
 131     M->print(Out->os(), Annotator.get());
 132
 133   // Declare success.
 134   Out->keep();
 135
 136   return 0;
 137 }
 138