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/IntrinsicInst.h"
  23 #include "llvm/Bitcode/ReaderWriter.h"
  24 #include "llvm/Analysis/DebugInfo.h"
  25 #include "llvm/Assembly/AssemblyAnnotationWriter.h"
  26 #include "llvm/Support/CommandLine.h"
  27 #include "llvm/Support/FormattedStream.h"
  28 #include "llvm/Support/ManagedStatic.h"
  29 #include "llvm/Support/MemoryBuffer.h"
  30 #include "llvm/Support/PrettyStackTrace.h"
  31 #include "llvm/Support/ToolOutputFile.h"
  32 #include "llvm/Support/Signals.h"
  33 #include "llvm/Support/system_error.h"
  34 using namespace llvm;
  35
  36 static cl::opt<std::string>
  37 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
  38
  39 static cl::opt<std::string>
  40 OutputFilename("o", cl::desc("Override output filename"),
  41                cl::value_desc("filename"));
  42
  43 static cl::opt<bool>
  44 Force("f", cl::desc("Enable binary output on terminals"));
  45
  46 static cl::opt<bool>
  47 DontPrint("disable-output", cl::desc("Don't output the .ll file"), cl::Hidden);
  48
  49 static cl::opt<bool>
  50 ShowAnnotations("show-annotations",
  51                 cl::desc("Add informational comments to the .ll file"));
  52
  53 namespace {
  54
  55 static void printDebugLoc(const DebugLoc &DL, formatted_raw_ostream &OS) {
  56   OS << DL.getLine() << ":" << DL.getCol();
  57   if (MDNode *N = DL.getInlinedAt(getGlobalContext())) {
  58     DebugLoc IDL = DebugLoc::getFromDILocation(N);
  59     if (!IDL.isUnknown()) {
  60       OS << "@";
  61       printDebugLoc(IDL,OS);
  62     }
  63   }
  64 }
  65 class CommentWriter : public AssemblyAnnotationWriter {
  66 public:
  67   void emitFunctionAnnot(const Function *F,
  68                          formatted_raw_ostream &OS) {
  69     OS << "; [#uses=" << F->getNumUses() << ']';  // Output # uses
  70     OS << '\n';
  71   }
  72   void printInfoComment(const Value &V, formatted_raw_ostream &OS) {
  73     bool Padded = false;
  74     if (!V.getType()->isVoidTy()) {
  75       OS.PadToColumn(50);
  76       Padded = true;
  77       OS << "; [#uses=" << V.getNumUses() << " type=" << *V.getType() << "]";  // Output # uses and type
  78     }
  79     if (const Instruction *I = dyn_cast<Instruction>(&V)) {
  80       const DebugLoc &DL = I->getDebugLoc();
  81       if (!DL.isUnknown()) {
  82         if (!Padded) {
  83           OS.PadToColumn(50);
  84           Padded = true;
  85           OS << ";";
  86         }
  87         OS << " [debug line = ";
  88         printDebugLoc(DL,OS);
  89         OS << "]";
  90       }
  91       if (const DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(I)) {
  92         DIVariable Var(DDI->getVariable());
  93         if (!Padded) {
  94           OS.PadToColumn(50);
  95           Padded = true;
  96           OS << ";";
  97         }
  98         OS << " [debug variable = " << Var.getName() << "]";
  99       }
 100       else if (const DbgValueInst *DVI = dyn_cast<DbgValueInst>(I)) {
 101         DIVariable Var(DVI->getVariable());
 102         if (!Padded) {
 103           OS.PadToColumn(50);
 104           Padded = true;
 105           OS << ";";
 106         }
 107         OS << " [debug variable = " << Var.getName() << "]";
 108       }
 109     }
 110   }
 111 };
 112
 113 } // end anon namespace
 114
 115 int main(int argc, char **argv) {
 116   // Print a stack trace if we signal out.
 117   sys::PrintStackTraceOnErrorSignal();
 118   PrettyStackTraceProgram X(argc, argv);
 119
 120   LLVMContext &Context = getGlobalContext();
 121   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
 122
 123
 124   cl::ParseCommandLineOptions(argc, argv, "llvm .bc -> .ll disassembler\n");
 125
 126   std::string ErrorMessage;
 127   std::auto_ptr<Module> M;
 128
 129   {
 130     OwningPtr<MemoryBuffer> BufferPtr;
 131     if (error_code ec = MemoryBuffer::getFileOrSTDIN(InputFilename, BufferPtr))
 132       ErrorMessage = ec.message();
 133     else
 134       M.reset(ParseBitcodeFile(BufferPtr.get(), Context, &ErrorMessage));
 135   }
 136
 137   if (M.get() == 0) {
 138     errs() << argv[0] << ": ";
 139     if (ErrorMessage.size())
 140       errs() << ErrorMessage << "\n";
 141     else
 142       errs() << "bitcode didn't read correctly.\n";
 143     return 1;
 144   }
 145
 146   // Just use stdout.  We won't actually print anything on it.
 147   if (DontPrint)
 148     OutputFilename = "-";
 149
 150   if (OutputFilename.empty()) { // Unspecified output, infer it.
 151     if (InputFilename == "-") {
 152       OutputFilename = "-";
 153     } else {
 154       const std::string &IFN = InputFilename;
 155       int Len = IFN.length();
 156       // If the source ends in .bc, strip it off.
 157       if (IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c')
 158         OutputFilename = std::string(IFN.begin(), IFN.end()-3)+".ll";
 159       else
 160         OutputFilename = IFN+".ll";
 161     }
 162   }
 163
 164   std::string ErrorInfo;
 165   OwningPtr<tool_output_file>
 166   Out(new tool_output_file(OutputFilename.c_str(), ErrorInfo,
 167                            raw_fd_ostream::F_Binary));
 168   if (!ErrorInfo.empty()) {
 169     errs() << ErrorInfo << '\n';
 170     return 1;
 171   }
 172
 173   OwningPtr<AssemblyAnnotationWriter> Annotator;
 174   if (ShowAnnotations)
 175     Annotator.reset(new CommentWriter());
 176
 177   // All that llvm-dis does is write the assembly to a file.
 178   if (!DontPrint)
 179     M->print(Out->os(), Annotator.get());
 180
 181   // Declare success.
 182   Out->keep();
 183
 184   return 0;
 185 }
 186