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      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/IR/LLVMContext.h"
     20 #include "llvm/Assembly/AssemblyAnnotationWriter.h"
     21 #include "llvm/Bitcode/ReaderWriter.h"
     22 #include "llvm/DebugInfo.h"
     23 #include "llvm/IR/IntrinsicInst.h"
     24 #include "llvm/IR/Module.h"
     25 #include "llvm/IR/Type.h"
     26 #include "llvm/Support/CommandLine.h"
     27 #include "llvm/Support/DataStream.h"
     28 #include "llvm/Support/FormattedStream.h"
     29 #include "llvm/Support/ManagedStatic.h"
     30 #include "llvm/Support/MemoryBuffer.h"
     31 #include "llvm/Support/PrettyStackTrace.h"
     32 #include "llvm/Support/Signals.h"
     33 #include "llvm/Support/ToolOutputFile.h"
     34 #include "llvm/Support/system_error.h"
     35 using namespace llvm;
     36 
     37 static cl::opt<std::string>
     38 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
     39 
     40 static cl::opt<std::string>
     41 OutputFilename("o", cl::desc("Override output filename"),
     42                cl::value_desc("filename"));
     43 
     44 static cl::opt<bool>
     45 Force("f", cl::desc("Enable binary output on terminals"));
     46 
     47 static cl::opt<bool>
     48 DontPrint("disable-output", cl::desc("Don't output the .ll file"), cl::Hidden);
     49 
     50 static cl::opt<bool>
     51 ShowAnnotations("show-annotations",
     52                 cl::desc("Add informational comments to the .ll file"));
     53 
     54 namespace {
     55 
     56 static void printDebugLoc(const DebugLoc &DL, formatted_raw_ostream &OS) {
     57   OS << DL.getLine() << ":" << DL.getCol();
     58   if (MDNode *N = DL.getInlinedAt(getGlobalContext())) {
     59     DebugLoc IDL = DebugLoc::getFromDILocation(N);
     60     if (!IDL.isUnknown()) {
     61       OS << "@";
     62       printDebugLoc(IDL,OS);
     63     }
     64   }
     65 }
     66 class CommentWriter : public AssemblyAnnotationWriter {
     67 public:
     68   void emitFunctionAnnot(const Function *F,
     69                          formatted_raw_ostream &OS) {
     70     OS << "; [#uses=" << F->getNumUses() << ']';  // Output # uses
     71     OS << '\n';
     72   }
     73   void printInfoComment(const Value &V, formatted_raw_ostream &OS) {
     74     bool Padded = false;
     75     if (!V.getType()->isVoidTy()) {
     76       OS.PadToColumn(50);
     77       Padded = true;
     78       OS << "; [#uses=" << V.getNumUses() << " type=" << *V.getType() << "]";  // Output # uses and type
     79     }
     80     if (const Instruction *I = dyn_cast<Instruction>(&V)) {
     81       const DebugLoc &DL = I->getDebugLoc();
     82       if (!DL.isUnknown()) {
     83         if (!Padded) {
     84           OS.PadToColumn(50);
     85           Padded = true;
     86           OS << ";";
     87         }
     88         OS << " [debug line = ";
     89         printDebugLoc(DL,OS);
     90         OS << "]";
     91       }
     92       if (const DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(I)) {
     93         DIVariable Var(DDI->getVariable());
     94         if (!Padded) {
     95           OS.PadToColumn(50);
     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           OS << ";";
    105         }
    106         OS << " [debug variable = " << Var.getName() << "]";
    107       }
    108     }
    109   }
    110 };
    111 
    112 } // end anon namespace
    113 
    114 int main(int argc, char **argv) {
    115   // Print a stack trace if we signal out.
    116   sys::PrintStackTraceOnErrorSignal();
    117   PrettyStackTraceProgram X(argc, argv);
    118 
    119   LLVMContext &Context = getGlobalContext();
    120   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
    121 
    122 
    123   cl::ParseCommandLineOptions(argc, argv, "llvm .bc -> .ll disassembler\n");
    124 
    125   std::string ErrorMessage;
    126   std::auto_ptr<Module> M;
    127 
    128   // Use the bitcode streaming interface
    129   DataStreamer *streamer = getDataFileStreamer(InputFilename, &ErrorMessage);
    130   if (streamer) {
    131     std::string DisplayFilename;
    132     if (InputFilename == "-")
    133       DisplayFilename = "<stdin>";
    134     else
    135       DisplayFilename = InputFilename;
    136     M.reset(getStreamedBitcodeModule(DisplayFilename, streamer, Context,
    137                                      &ErrorMessage));
    138     if(M.get() != 0 && M->MaterializeAllPermanently(&ErrorMessage)) {
    139       M.reset();
    140     }
    141   }
    142 
    143   if (M.get() == 0) {
    144     errs() << argv[0] << ": ";
    145     if (ErrorMessage.size())
    146       errs() << ErrorMessage << "\n";
    147     else
    148       errs() << "bitcode didn't read correctly.\n";
    149     return 1;
    150   }
    151 
    152   // Just use stdout.  We won't actually print anything on it.
    153   if (DontPrint)
    154     OutputFilename = "-";
    155 
    156   if (OutputFilename.empty()) { // Unspecified output, infer it.
    157     if (InputFilename == "-") {
    158       OutputFilename = "-";
    159     } else {
    160       const std::string &IFN = InputFilename;
    161       int Len = IFN.length();
    162       // If the source ends in .bc, strip it off.
    163       if (IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c')
    164         OutputFilename = std::string(IFN.begin(), IFN.end()-3)+".ll";
    165       else
    166         OutputFilename = IFN+".ll";
    167     }
    168   }
    169 
    170   std::string ErrorInfo;
    171   OwningPtr<tool_output_file>
    172   Out(new tool_output_file(OutputFilename.c_str(), ErrorInfo,
    173                            raw_fd_ostream::F_Binary));
    174   if (!ErrorInfo.empty()) {
    175     errs() << ErrorInfo << '\n';
    176     return 1;
    177   }
    178 
    179   OwningPtr<AssemblyAnnotationWriter> Annotator;
    180   if (ShowAnnotations)
    181     Annotator.reset(new CommentWriter());
    182 
    183   // All that llvm-dis does is write the assembly to a file.
    184   if (!DontPrint)
    185     M->print(Out->os(), Annotator.get());
    186 
    187   // Declare success.
    188   Out->keep();
    189 
    190   return 0;
    191 }
    192