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/Error.h"
31 #include "llvm/Support/FileSystem.h"
32 #include "llvm/Support/FormattedStream.h"
33 #include "llvm/Support/ManagedStatic.h"
34 #include "llvm/Support/MemoryBuffer.h"
35 #include "llvm/Support/PrettyStackTrace.h"
36 #include "llvm/Support/Signals.h"
37 #include "llvm/Support/ToolOutputFile.h"
38 #include <system_error>
39 using namespace llvm;
40 
41 static cl::opt<std::string>
42 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
43 
44 static cl::opt<std::string>
45 OutputFilename("o", cl::desc("Override output filename"),
46                cl::value_desc("filename"));
47 
48 static cl::opt<bool>
49 Force("f", cl::desc("Enable binary output on terminals"));
50 
51 static cl::opt<bool>
52 DontPrint("disable-output", cl::desc("Don't output the .ll file"), cl::Hidden);
53 
54 static cl::opt<bool>
55 ShowAnnotations("show-annotations",
56                 cl::desc("Add informational comments to the .ll file"));
57 
58 static cl::opt<bool> PreserveAssemblyUseListOrder(
59     "preserve-ll-uselistorder",
60     cl::desc("Preserve use-list order when writing LLVM assembly."),
61     cl::init(false), cl::Hidden);
62 
63 static cl::opt<bool>
64     MaterializeMetadata("materialize-metadata",
65                         cl::desc("Load module without materializing metadata, "
66                                  "then materialize only the metadata"));
67 
68 namespace {
69 
printDebugLoc(const DebugLoc & DL,formatted_raw_ostream & OS)70 static void printDebugLoc(const DebugLoc &DL, formatted_raw_ostream &OS) {
71   OS << DL.getLine() << ":" << DL.getCol();
72   if (DILocation *IDL = DL.getInlinedAt()) {
73     OS << "@";
74     printDebugLoc(IDL, OS);
75   }
76 }
77 class CommentWriter : public AssemblyAnnotationWriter {
78 public:
emitFunctionAnnot(const Function * F,formatted_raw_ostream & OS)79   void emitFunctionAnnot(const Function *F,
80                          formatted_raw_ostream &OS) override {
81     OS << "; [#uses=" << F->getNumUses() << ']';  // Output # uses
82     OS << '\n';
83   }
printInfoComment(const Value & V,formatted_raw_ostream & OS)84   void printInfoComment(const Value &V, formatted_raw_ostream &OS) override {
85     bool Padded = false;
86     if (!V.getType()->isVoidTy()) {
87       OS.PadToColumn(50);
88       Padded = true;
89       // Output # uses and type
90       OS << "; [#uses=" << V.getNumUses() << " type=" << *V.getType() << "]";
91     }
92     if (const Instruction *I = dyn_cast<Instruction>(&V)) {
93       if (const DebugLoc &DL = I->getDebugLoc()) {
94         if (!Padded) {
95           OS.PadToColumn(50);
96           Padded = true;
97           OS << ";";
98         }
99         OS << " [debug line = ";
100         printDebugLoc(DL,OS);
101         OS << "]";
102       }
103       if (const DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(I)) {
104         if (!Padded) {
105           OS.PadToColumn(50);
106           OS << ";";
107         }
108         OS << " [debug variable = " << DDI->getVariable()->getName() << "]";
109       }
110       else if (const DbgValueInst *DVI = dyn_cast<DbgValueInst>(I)) {
111         if (!Padded) {
112           OS.PadToColumn(50);
113           OS << ";";
114         }
115         OS << " [debug variable = " << DVI->getVariable()->getName() << "]";
116       }
117     }
118   }
119 };
120 
121 } // end anon namespace
122 
diagnosticHandler(const DiagnosticInfo & DI,void * Context)123 static void diagnosticHandler(const DiagnosticInfo &DI, void *Context) {
124   raw_ostream &OS = errs();
125   OS << (char *)Context << ": ";
126   switch (DI.getSeverity()) {
127   case DS_Error: OS << "error: "; break;
128   case DS_Warning: OS << "warning: "; break;
129   case DS_Remark: OS << "remark: "; break;
130   case DS_Note: OS << "note: "; break;
131   }
132 
133   DiagnosticPrinterRawOStream DP(OS);
134   DI.print(DP);
135   OS << '\n';
136 
137   if (DI.getSeverity() == DS_Error)
138     exit(1);
139 }
140 
openInputFile(LLVMContext & Context)141 static Expected<std::unique_ptr<Module>> openInputFile(LLVMContext &Context) {
142   if (MaterializeMetadata) {
143     ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
144         MemoryBuffer::getFileOrSTDIN(InputFilename);
145     if (!MBOrErr)
146       return errorCodeToError(MBOrErr.getError());
147     ErrorOr<std::unique_ptr<Module>> MOrErr =
148         getLazyBitcodeModule(std::move(*MBOrErr), Context,
149                              /*ShouldLazyLoadMetadata=*/true);
150     if (!MOrErr)
151       return errorCodeToError(MOrErr.getError());
152     (*MOrErr)->materializeMetadata();
153     return std::move(*MOrErr);
154   } else {
155     std::string ErrorMessage;
156     std::unique_ptr<DataStreamer> Streamer =
157         getDataFileStreamer(InputFilename, &ErrorMessage);
158     if (!Streamer)
159       return make_error<StringError>(ErrorMessage, inconvertibleErrorCode());
160     std::string DisplayFilename;
161     if (InputFilename == "-")
162       DisplayFilename = "<stdin>";
163     else
164       DisplayFilename = InputFilename;
165     ErrorOr<std::unique_ptr<Module>> MOrErr =
166         getStreamedBitcodeModule(DisplayFilename, std::move(Streamer), Context);
167     (*MOrErr)->materializeAll();
168     return std::move(*MOrErr);
169   }
170 }
171 
main(int argc,char ** argv)172 int main(int argc, char **argv) {
173   // Print a stack trace if we signal out.
174   sys::PrintStackTraceOnErrorSignal(argv[0]);
175   PrettyStackTraceProgram X(argc, argv);
176 
177   LLVMContext Context;
178   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
179 
180   Context.setDiagnosticHandler(diagnosticHandler, argv[0]);
181 
182   cl::ParseCommandLineOptions(argc, argv, "llvm .bc -> .ll disassembler\n");
183 
184   Expected<std::unique_ptr<Module>> MOrErr = openInputFile(Context);
185   if (!MOrErr) {
186     handleAllErrors(MOrErr.takeError(), [&](ErrorInfoBase &EIB) {
187       errs() << argv[0] << ": ";
188       EIB.log(errs());
189       errs() << '\n';
190     });
191     return 1;
192   }
193   std::unique_ptr<Module> M = std::move(*MOrErr);
194 
195   // Just use stdout.  We won't actually print anything on it.
196   if (DontPrint)
197     OutputFilename = "-";
198 
199   if (OutputFilename.empty()) { // Unspecified output, infer it.
200     if (InputFilename == "-") {
201       OutputFilename = "-";
202     } else {
203       StringRef IFN = InputFilename;
204       OutputFilename = (IFN.endswith(".bc") ? IFN.drop_back(3) : IFN).str();
205       OutputFilename += ".ll";
206     }
207   }
208 
209   std::error_code EC;
210   std::unique_ptr<tool_output_file> Out(
211       new tool_output_file(OutputFilename, EC, sys::fs::F_None));
212   if (EC) {
213     errs() << EC.message() << '\n';
214     return 1;
215   }
216 
217   std::unique_ptr<AssemblyAnnotationWriter> Annotator;
218   if (ShowAnnotations)
219     Annotator.reset(new CommentWriter());
220 
221   // All that llvm-dis does is write the assembly to a file.
222   if (!DontPrint)
223     M->print(Out->os(), Annotator.get(), PreserveAssemblyUseListOrder);
224 
225   // Declare success.
226   Out->keep();
227 
228   return 0;
229 }
230