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/IR/LLVMContext.h"
  20 #include "llvm/Bitcode/ReaderWriter.h"
  21 #include "llvm/IR/AssemblyAnnotationWriter.h"
  22 #include "llvm/IR/DebugInfo.h"
  23 #include "llvm/IR/DiagnosticInfo.h"
  24 #include "llvm/IR/DiagnosticPrinter.h"
  25 #include "llvm/IR/IntrinsicInst.h"
  26 #include "llvm/IR/Module.h"
  27 #include "llvm/IR/Type.h"
  28 #include "llvm/Support/CommandLine.h"
  29 #include "llvm/Support/DataStream.h"
  30 #include "llvm/Support/FileSystem.h"
  31 #include "llvm/Support/FormattedStream.h"
  32 #include "llvm/Support/ManagedStatic.h"
  33 #include "llvm/Support/MemoryBuffer.h"
  34 #include "llvm/Support/PrettyStackTrace.h"
  35 #include "llvm/Support/Signals.h"
  36 #include "llvm/Support/ToolOutputFile.h"
  37 #include <system_error>
  38 using namespace llvm;
  39
  40 static cl::opt<std::string>
  41 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
  42
  43 static cl::opt<std::string>
  44 OutputFilename("o", cl::desc("Override output filename"),
  45                cl::value_desc("filename"));
  46
  47 static cl::opt<bool>
  48 Force("f", cl::desc("Enable binary output on terminals"));
  49
  50 static cl::opt<bool>
  51 DontPrint("disable-output", cl::desc("Don't output the .ll file"), cl::Hidden);
  52
  53 static cl::opt<bool>
  54 ShowAnnotations("show-annotations",
  55                 cl::desc("Add informational comments to the .ll file"));
  56
  57 static cl::opt<bool> PreserveAssemblyUseListOrder(
  58     "preserve-ll-uselistorder",
  59     cl::desc("Preserve use-list order when writing LLVM assembly."),
  60     cl::init(false), cl::Hidden);
  61
  62 namespace {
  63
  64 static void printDebugLoc(const DebugLoc &DL, formatted_raw_ostream &OS) {
  65   OS << DL.getLine() << ":" << DL.getCol();
  66   if (DILocation *IDL = DL.getInlinedAt()) {
  67     OS << "@";
  68     printDebugLoc(IDL, OS);
  69   }
  70 }
  71 class CommentWriter : public AssemblyAnnotationWriter {
  72 public:
  73   void emitFunctionAnnot(const Function *F,
  74                          formatted_raw_ostream &OS) override {
  75     OS << "; [#uses=" << F->getNumUses() << ']';  // Output # uses
  76     OS << '\n';
  77   }
  78   void printInfoComment(const Value &V, formatted_raw_ostream &OS) override {
  79     bool Padded = false;
  80     if (!V.getType()->isVoidTy()) {
  81       OS.PadToColumn(50);
  82       Padded = true;
  83       // Output # uses and type
  84       OS << "; [#uses=" << V.getNumUses() << " type=" << *V.getType() << "]";
  85     }
  86     if (const Instruction *I = dyn_cast<Instruction>(&V)) {
  87       if (const DebugLoc &DL = I->getDebugLoc()) {
  88         if (!Padded) {
  89           OS.PadToColumn(50);
  90           Padded = true;
  91           OS << ";";
  92         }
  93         OS << " [debug line = ";
  94         printDebugLoc(DL,OS);
  95         OS << "]";
  96       }
  97       if (const DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(I)) {
  98         if (!Padded) {
  99           OS.PadToColumn(50);
 100           OS << ";";
 101         }
 102         OS << " [debug variable = " << DDI->getVariable()->getName() << "]";
 103       }
 104       else if (const DbgValueInst *DVI = dyn_cast<DbgValueInst>(I)) {
 105         if (!Padded) {
 106           OS.PadToColumn(50);
 107           OS << ";";
 108         }
 109         OS << " [debug variable = " << DVI->getVariable()->getName() << "]";
 110       }
 111     }
 112   }
 113 };
 114
 115 } // end anon namespace
 116
 117 static void diagnosticHandler(const DiagnosticInfo &DI, void *Context) {
 118   raw_ostream &OS = errs();
 119   OS << (char *)Context << ": ";
 120   switch (DI.getSeverity()) {
 121   case DS_Error: OS << "error: "; break;
 122   case DS_Warning: OS << "warning: "; break;
 123   case DS_Remark: OS << "remark: "; break;
 124   case DS_Note: OS << "note: "; break;
 125   }
 126
 127   DiagnosticPrinterRawOStream DP(OS);
 128   DI.print(DP);
 129   OS << '\n';
 130
 131   if (DI.getSeverity() == DS_Error)
 132     exit(1);
 133 }
 134
 135 int main(int argc, char **argv) {
 136   // Print a stack trace if we signal out.
 137   sys::PrintStackTraceOnErrorSignal();
 138   PrettyStackTraceProgram X(argc, argv);
 139
 140   LLVMContext &Context = getGlobalContext();
 141   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
 142
 143   Context.setDiagnosticHandler(diagnosticHandler, argv[0]);
 144
 145   cl::ParseCommandLineOptions(argc, argv, "llvm .bc -> .ll disassembler\n");
 146
 147   std::string ErrorMessage;
 148   std::unique_ptr<Module> M;
 149
 150   // Use the bitcode streaming interface
 151   std::unique_ptr<DataStreamer> Streamer =
 152       getDataFileStreamer(InputFilename, &ErrorMessage);
 153   if (Streamer) {
 154     std::string DisplayFilename;
 155     if (InputFilename == "-")
 156       DisplayFilename = "<stdin>";
 157     else
 158       DisplayFilename = InputFilename;
 159     ErrorOr<std::unique_ptr<Module>> MOrErr =
 160         getStreamedBitcodeModule(DisplayFilename, std::move(Streamer), Context);
 161     M = std::move(*MOrErr);
 162     M->materializeAllPermanently();
 163   } else {
 164     errs() << argv[0] << ": " << ErrorMessage << '\n';
 165     return 1;
 166   }
 167
 168   // Just use stdout.  We won't actually print anything on it.
 169   if (DontPrint)
 170     OutputFilename = "-";
 171
 172   if (OutputFilename.empty()) { // Unspecified output, infer it.
 173     if (InputFilename == "-") {
 174       OutputFilename = "-";
 175     } else {
 176       StringRef IFN = InputFilename;
 177       OutputFilename = (IFN.endswith(".bc") ? IFN.drop_back(3) : IFN).str();
 178       OutputFilename += ".ll";
 179     }
 180   }
 181
 182   std::error_code EC;
 183   std::unique_ptr<tool_output_file> Out(
 184       new tool_output_file(OutputFilename, EC, sys::fs::F_None));
 185   if (EC) {
 186     errs() << EC.message() << '\n';
 187     return 1;
 188   }
 189
 190   std::unique_ptr<AssemblyAnnotationWriter> Annotator;
 191   if (ShowAnnotations)
 192     Annotator.reset(new CommentWriter());
 193
 194   // All that llvm-dis does is write the assembly to a file.
 195   if (!DontPrint)
 196     M->print(Out->os(), Annotator.get(), PreserveAssemblyUseListOrder);
 197
 198   // Declare success.
 199   Out->keep();
 200
 201   return 0;
 202 }