llvm-dis.cpp revision 231057 
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"
34using namespace llvm;
35
36static cl::opt<std::string>
37InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
38
39static cl::opt<std::string>
40OutputFilename("o", cl::desc("Override output filename"),
41               cl::value_desc("filename"));
42
43static cl::opt<bool>
44Force("f", cl::desc("Enable binary output on terminals"));
45
46static cl::opt<bool>
47DontPrint("disable-output", cl::desc("Don't output the .ll file"), cl::Hidden);
48
49static cl::opt<bool>
50ShowAnnotations("show-annotations",
51                cl::desc("Add informational comments to the .ll file"));
52
53namespace {
54
55static 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}
65class CommentWriter : public AssemblyAnnotationWriter {
66public:
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
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::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
187