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/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/FileSystem.h"
29#include "llvm/Support/FormattedStream.h"
30#include "llvm/Support/ManagedStatic.h"
31#include "llvm/Support/MemoryBuffer.h"
32#include "llvm/Support/PrettyStackTrace.h"
33#include "llvm/Support/Signals.h"
34#include "llvm/Support/ToolOutputFile.h"
35#include <system_error>
36using namespace llvm;
37
38static cl::opt<std::string>
39InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
40
41static cl::opt<std::string>
42OutputFilename("o", cl::desc("Override output filename"),
43               cl::value_desc("filename"));
44
45static cl::opt<bool>
46Force("f", cl::desc("Enable binary output on terminals"));
47
48static cl::opt<bool>
49DontPrint("disable-output", cl::desc("Don't output the .ll file"), cl::Hidden);
50
51static cl::opt<bool>
52ShowAnnotations("show-annotations",
53                cl::desc("Add informational comments to the .ll file"));
54
55namespace {
56
57static void printDebugLoc(const DebugLoc &DL, formatted_raw_ostream &OS) {
58  OS << DL.getLine() << ":" << DL.getCol();
59  if (MDNode *N = DL.getInlinedAt(getGlobalContext())) {
60    DebugLoc IDL = DebugLoc::getFromDILocation(N);
61    if (!IDL.isUnknown()) {
62      OS << "@";
63      printDebugLoc(IDL,OS);
64    }
65  }
66}
67class CommentWriter : public AssemblyAnnotationWriter {
68public:
69  void emitFunctionAnnot(const Function *F,
70                         formatted_raw_ostream &OS) override {
71    OS << "; [#uses=" << F->getNumUses() << ']';  // Output # uses
72    OS << '\n';
73  }
74  void printInfoComment(const Value &V, formatted_raw_ostream &OS) override {
75    bool Padded = false;
76    if (!V.getType()->isVoidTy()) {
77      OS.PadToColumn(50);
78      Padded = true;
79      OS << "; [#uses=" << V.getNumUses() << " type=" << *V.getType() << "]";  // Output # uses and type
80    }
81    if (const Instruction *I = dyn_cast<Instruction>(&V)) {
82      const DebugLoc &DL = I->getDebugLoc();
83      if (!DL.isUnknown()) {
84        if (!Padded) {
85          OS.PadToColumn(50);
86          Padded = true;
87          OS << ";";
88        }
89        OS << " [debug line = ";
90        printDebugLoc(DL,OS);
91        OS << "]";
92      }
93      if (const DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(I)) {
94        DIVariable Var(DDI->getVariable());
95        if (!Padded) {
96          OS.PadToColumn(50);
97          OS << ";";
98        }
99        OS << " [debug variable = " << Var.getName() << "]";
100      }
101      else if (const DbgValueInst *DVI = dyn_cast<DbgValueInst>(I)) {
102        DIVariable Var(DVI->getVariable());
103        if (!Padded) {
104          OS.PadToColumn(50);
105          OS << ";";
106        }
107        OS << " [debug variable = " << Var.getName() << "]";
108      }
109    }
110  }
111};
112
113} // end anon namespace
114
115int 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::unique_ptr<Module> M;
128
129  // Use the bitcode streaming interface
130  DataStreamer *streamer = getDataFileStreamer(InputFilename, &ErrorMessage);
131  if (streamer) {
132    std::string DisplayFilename;
133    if (InputFilename == "-")
134      DisplayFilename = "<stdin>";
135    else
136      DisplayFilename = InputFilename;
137    M.reset(getStreamedBitcodeModule(DisplayFilename, streamer, Context,
138                                     &ErrorMessage));
139    if(M.get()) {
140      if (std::error_code EC = M->materializeAllPermanently()) {
141        ErrorMessage = EC.message();
142        M.reset();
143      }
144    }
145  }
146
147  if (!M.get()) {
148    errs() << argv[0] << ": ";
149    if (ErrorMessage.size())
150      errs() << ErrorMessage << "\n";
151    else
152      errs() << "bitcode didn't read correctly.\n";
153    return 1;
154  }
155
156  // Just use stdout.  We won't actually print anything on it.
157  if (DontPrint)
158    OutputFilename = "-";
159
160  if (OutputFilename.empty()) { // Unspecified output, infer it.
161    if (InputFilename == "-") {
162      OutputFilename = "-";
163    } else {
164      const std::string &IFN = InputFilename;
165      int Len = IFN.length();
166      // If the source ends in .bc, strip it off.
167      if (IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c')
168        OutputFilename = std::string(IFN.begin(), IFN.end()-3)+".ll";
169      else
170        OutputFilename = IFN+".ll";
171    }
172  }
173
174  std::string ErrorInfo;
175  std::unique_ptr<tool_output_file> Out(
176      new tool_output_file(OutputFilename.c_str(), ErrorInfo, sys::fs::F_None));
177  if (!ErrorInfo.empty()) {
178    errs() << ErrorInfo << '\n';
179    return 1;
180  }
181
182  std::unique_ptr<AssemblyAnnotationWriter> Annotator;
183  if (ShowAnnotations)
184    Annotator.reset(new CommentWriter());
185
186  // All that llvm-dis does is write the assembly to a file.
187  if (!DontPrint)
188    M->print(Out->os(), Annotator.get());
189
190  // Declare success.
191  Out->keep();
192
193  return 0;
194}
195