1//===-- llvm-dis.cpp - The low-level LLVM disassembler --------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This utility may be invoked in the following manner:
10//  llvm-dis [options]      - Read LLVM bitcode from stdin, write asm to stdout
11//  llvm-dis [options] x.bc - Read LLVM bitcode from the x.bc file, write asm
12//                            to the x.ll file.
13//  Options:
14//      --help   - Output information about command line switches
15//
16//===----------------------------------------------------------------------===//
17
18#include "llvm/Bitcode/BitcodeReader.h"
19#include "llvm/IR/AssemblyAnnotationWriter.h"
20#include "llvm/IR/DebugInfo.h"
21#include "llvm/IR/DiagnosticInfo.h"
22#include "llvm/IR/DiagnosticPrinter.h"
23#include "llvm/IR/IntrinsicInst.h"
24#include "llvm/IR/LLVMContext.h"
25#include "llvm/IR/Module.h"
26#include "llvm/IR/ModuleSummaryIndex.h"
27#include "llvm/IR/Type.h"
28#include "llvm/Support/CommandLine.h"
29#include "llvm/Support/Error.h"
30#include "llvm/Support/FileSystem.h"
31#include "llvm/Support/FormattedStream.h"
32#include "llvm/Support/InitLLVM.h"
33#include "llvm/Support/MemoryBuffer.h"
34#include "llvm/Support/ToolOutputFile.h"
35#include "llvm/Support/WithColor.h"
36#include <system_error>
37using namespace llvm;
38
39static cl::OptionCategory DisCategory("Disassembler Options");
40
41static cl::list<std::string> InputFilenames(cl::Positional,
42                                            cl::desc("[input bitcode]..."),
43                                            cl::cat(DisCategory));
44
45static cl::opt<std::string> OutputFilename("o",
46                                           cl::desc("Override output filename"),
47                                           cl::value_desc("filename"),
48                                           cl::cat(DisCategory));
49
50static cl::opt<bool> Force("f", cl::desc("Enable binary output on terminals"),
51                           cl::cat(DisCategory));
52
53static cl::opt<bool> DontPrint("disable-output",
54                               cl::desc("Don't output the .ll file"),
55                               cl::Hidden, cl::cat(DisCategory));
56
57static cl::opt<bool>
58    SetImporting("set-importing",
59                 cl::desc("Set lazy loading to pretend to import a module"),
60                 cl::Hidden, cl::cat(DisCategory));
61
62static cl::opt<bool>
63    ShowAnnotations("show-annotations",
64                    cl::desc("Add informational comments to the .ll file"),
65                    cl::cat(DisCategory));
66
67static cl::opt<bool> PreserveAssemblyUseListOrder(
68    "preserve-ll-uselistorder",
69    cl::desc("Preserve use-list order when writing LLVM assembly."),
70    cl::init(false), cl::Hidden, cl::cat(DisCategory));
71
72static cl::opt<bool>
73    MaterializeMetadata("materialize-metadata",
74                        cl::desc("Load module without materializing metadata, "
75                                 "then materialize only the metadata"),
76                        cl::cat(DisCategory));
77
78static cl::opt<bool> PrintThinLTOIndexOnly(
79    "print-thinlto-index-only",
80    cl::desc("Only read thinlto index and print the index as LLVM assembly."),
81    cl::init(false), cl::Hidden, cl::cat(DisCategory));
82
83namespace {
84
85static void printDebugLoc(const DebugLoc &DL, formatted_raw_ostream &OS) {
86  OS << DL.getLine() << ":" << DL.getCol();
87  if (DILocation *IDL = DL.getInlinedAt()) {
88    OS << "@";
89    printDebugLoc(IDL, OS);
90  }
91}
92class CommentWriter : public AssemblyAnnotationWriter {
93public:
94  void emitFunctionAnnot(const Function *F,
95                         formatted_raw_ostream &OS) override {
96    OS << "; [#uses=" << F->getNumUses() << ']';  // Output # uses
97    OS << '\n';
98  }
99  void printInfoComment(const Value &V, formatted_raw_ostream &OS) override {
100    bool Padded = false;
101    if (!V.getType()->isVoidTy()) {
102      OS.PadToColumn(50);
103      Padded = true;
104      // Output # uses and type
105      OS << "; [#uses=" << V.getNumUses() << " type=" << *V.getType() << "]";
106    }
107    if (const Instruction *I = dyn_cast<Instruction>(&V)) {
108      if (const DebugLoc &DL = I->getDebugLoc()) {
109        if (!Padded) {
110          OS.PadToColumn(50);
111          Padded = true;
112          OS << ";";
113        }
114        OS << " [debug line = ";
115        printDebugLoc(DL,OS);
116        OS << "]";
117      }
118      if (const DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(I)) {
119        if (!Padded) {
120          OS.PadToColumn(50);
121          OS << ";";
122        }
123        OS << " [debug variable = " << DDI->getVariable()->getName() << "]";
124      }
125      else if (const DbgValueInst *DVI = dyn_cast<DbgValueInst>(I)) {
126        if (!Padded) {
127          OS.PadToColumn(50);
128          OS << ";";
129        }
130        OS << " [debug variable = " << DVI->getVariable()->getName() << "]";
131      }
132    }
133  }
134};
135
136struct LLVMDisDiagnosticHandler : public DiagnosticHandler {
137  char *Prefix;
138  LLVMDisDiagnosticHandler(char *PrefixPtr) : Prefix(PrefixPtr) {}
139  bool handleDiagnostics(const DiagnosticInfo &DI) override {
140    raw_ostream &OS = errs();
141    OS << Prefix << ": ";
142    switch (DI.getSeverity()) {
143      case DS_Error: WithColor::error(OS); break;
144      case DS_Warning: WithColor::warning(OS); break;
145      case DS_Remark: OS << "remark: "; break;
146      case DS_Note: WithColor::note(OS); break;
147    }
148
149    DiagnosticPrinterRawOStream DP(OS);
150    DI.print(DP);
151    OS << '\n';
152
153    if (DI.getSeverity() == DS_Error)
154      exit(1);
155    return true;
156  }
157};
158} // end anon namespace
159
160static ExitOnError ExitOnErr;
161
162int main(int argc, char **argv) {
163  InitLLVM X(argc, argv);
164
165  ExitOnErr.setBanner(std::string(argv[0]) + ": error: ");
166
167  cl::HideUnrelatedOptions({&DisCategory, &getColorCategory()});
168  cl::ParseCommandLineOptions(argc, argv, "llvm .bc -> .ll disassembler\n");
169
170  LLVMContext Context;
171  Context.setDiagnosticHandler(
172      std::make_unique<LLVMDisDiagnosticHandler>(argv[0]));
173
174  if (InputFilenames.size() < 1) {
175    InputFilenames.push_back("-");
176  } else if (InputFilenames.size() > 1 && !OutputFilename.empty()) {
177    errs()
178        << "error: output file name cannot be set for multiple input files\n";
179    return 1;
180  }
181
182  for (std::string InputFilename : InputFilenames) {
183    ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
184        MemoryBuffer::getFileOrSTDIN(InputFilename);
185    if (std::error_code EC = BufferOrErr.getError()) {
186      WithColor::error() << InputFilename << ": " << EC.message() << '\n';
187      return 1;
188    }
189    std::unique_ptr<MemoryBuffer> MB = std::move(BufferOrErr.get());
190
191    BitcodeFileContents IF = ExitOnErr(llvm::getBitcodeFileContents(*MB));
192
193    const size_t N = IF.Mods.size();
194
195    if (OutputFilename == "-" && N > 1)
196      errs() << "only single module bitcode files can be written to stdout\n";
197
198    for (size_t I = 0; I < N; ++I) {
199      BitcodeModule MB = IF.Mods[I];
200
201      std::unique_ptr<Module> M;
202
203      if (!PrintThinLTOIndexOnly) {
204        M = ExitOnErr(
205            MB.getLazyModule(Context, MaterializeMetadata, SetImporting));
206        if (MaterializeMetadata)
207          ExitOnErr(M->materializeMetadata());
208        else
209          ExitOnErr(M->materializeAll());
210      }
211
212      BitcodeLTOInfo LTOInfo = ExitOnErr(MB.getLTOInfo());
213      std::unique_ptr<ModuleSummaryIndex> Index;
214      if (LTOInfo.HasSummary)
215        Index = ExitOnErr(MB.getSummary());
216
217      std::string FinalFilename(OutputFilename);
218
219      // Just use stdout.  We won't actually print anything on it.
220      if (DontPrint)
221        FinalFilename = "-";
222
223      if (FinalFilename.empty()) { // Unspecified output, infer it.
224        if (InputFilename == "-") {
225          FinalFilename = "-";
226        } else {
227          StringRef IFN = InputFilename;
228          FinalFilename = (IFN.endswith(".bc") ? IFN.drop_back(3) : IFN).str();
229          if (N > 1)
230            FinalFilename += std::string(".") + std::to_string(I);
231          FinalFilename += ".ll";
232        }
233      } else {
234        if (N > 1)
235          FinalFilename += std::string(".") + std::to_string(I);
236      }
237
238      std::error_code EC;
239      std::unique_ptr<ToolOutputFile> Out(
240          new ToolOutputFile(FinalFilename, EC, sys::fs::OF_TextWithCRLF));
241      if (EC) {
242        errs() << EC.message() << '\n';
243        return 1;
244      }
245
246      std::unique_ptr<AssemblyAnnotationWriter> Annotator;
247      if (ShowAnnotations)
248        Annotator.reset(new CommentWriter());
249
250      // All that llvm-dis does is write the assembly to a file.
251      if (!DontPrint) {
252        if (M)
253          M->print(Out->os(), Annotator.get(), PreserveAssemblyUseListOrder);
254        if (Index)
255          Index->print(Out->os());
256      }
257
258      // Declare success.
259      Out->keep();
260    }
261  }
262
263  return 0;
264}
265