llvm-readobj.cpp revision 1c8dfa5e90fa7ba5d351d2e2511dc1495c83f6fd 
1//===- llvm-readobj.cpp - Dump contents of an Object File -----------------===//
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 is a tool similar to readelf, except it works on multiple object file
11// formats. The main purpose of this tool is to provide detailed output suitable
12// for FileCheck.
13//
14// Flags should be similar to readelf where supported, but the output format
15// does not need to be identical. The point is to not make users learn yet
16// another set of flags.
17//
18// Output should be specialized for each format where appropriate.
19//
20//===----------------------------------------------------------------------===//
21
22#include "llvm-readobj.h"
23
24#include "Error.h"
25#include "ObjDumper.h"
26#include "StreamWriter.h"
27
28#include "llvm/Object/Archive.h"
29#include "llvm/Object/ObjectFile.h"
30#include "llvm/Support/Casting.h"
31#include "llvm/Support/CommandLine.h"
32#include "llvm/Support/DataTypes.h"
33#include "llvm/Support/Debug.h"
34#include "llvm/Support/FileSystem.h"
35#include "llvm/Support/ManagedStatic.h"
36#include "llvm/Support/PrettyStackTrace.h"
37#include "llvm/Support/Signals.h"
38#include "llvm/Support/TargetRegistry.h"
39#include "llvm/Support/TargetSelect.h"
40#include "llvm/Support/system_error.h"
41
42#include <string>
43
44
45using namespace llvm;
46using namespace llvm::object;
47
48namespace opts {
49  cl::list<std::string> InputFilenames(cl::Positional,
50    cl::desc("<input object files>"),
51    cl::ZeroOrMore);
52
53  // -file-headers, -h
54  cl::opt<bool> FileHeaders("file-headers",
55    cl::desc("Display file headers "));
56  cl::alias FileHeadersShort("h",
57    cl::desc("Alias for --file-headers"),
58    cl::aliasopt(FileHeaders));
59
60  // -sections, -s
61  cl::opt<bool> Sections("sections",
62    cl::desc("Display all sections."));
63  cl::alias SectionsShort("s",
64    cl::desc("Alias for --sections"),
65    cl::aliasopt(Sections));
66
67  // -section-relocations, -sr
68  cl::opt<bool> SectionRelocations("section-relocations",
69    cl::desc("Display relocations for each section shown."));
70  cl::alias SectionRelocationsShort("sr",
71    cl::desc("Alias for --section-relocations"),
72    cl::aliasopt(SectionRelocations));
73
74  // -section-symbols, -st
75  cl::opt<bool> SectionSymbols("section-symbols",
76    cl::desc("Display symbols for each section shown."));
77  cl::alias SectionSymbolsShort("st",
78    cl::desc("Alias for --section-symbols"),
79    cl::aliasopt(SectionSymbols));
80
81  // -section-data, -sd
82  cl::opt<bool> SectionData("section-data",
83    cl::desc("Display section data for each section shown."));
84  cl::alias SectionDataShort("sd",
85    cl::desc("Alias for --section-data"),
86    cl::aliasopt(SectionData));
87
88  // -relocations, -r
89  cl::opt<bool> Relocations("relocations",
90    cl::desc("Display the relocation entries in the file"));
91  cl::alias RelocationsShort("r",
92    cl::desc("Alias for --relocations"),
93    cl::aliasopt(Relocations));
94
95  // -symbols, -t
96  cl::opt<bool> Symbols("symbols",
97    cl::desc("Display the symbol table"));
98  cl::alias SymbolsShort("t",
99    cl::desc("Alias for --symbols"),
100    cl::aliasopt(Symbols));
101
102  // -dyn-symbols, -dt
103  cl::opt<bool> DynamicSymbols("dyn-symbols",
104    cl::desc("Display the dynamic symbol table"));
105  cl::alias DynamicSymbolsShort("dt",
106    cl::desc("Alias for --dyn-symbols"),
107    cl::aliasopt(DynamicSymbols));
108
109  // -unwind, -u
110  cl::opt<bool> UnwindInfo("unwind",
111    cl::desc("Display unwind information"));
112  cl::alias UnwindInfoShort("u",
113    cl::desc("Alias for --unwind"),
114    cl::aliasopt(UnwindInfo));
115
116  // -dynamic-table
117  cl::opt<bool> DynamicTable("dynamic-table",
118    cl::desc("Display the ELF .dynamic section table"));
119
120  // -needed-libs
121  cl::opt<bool> NeededLibraries("needed-libs",
122    cl::desc("Display the needed libraries"));
123
124  // -expand-relocs
125  cl::opt<bool> ExpandRelocs("expand-relocs",
126    cl::desc("Expand each shown relocation to multiple lines"));
127} // namespace opts
128
129namespace llvm {
130
131bool error(error_code EC) {
132  if (!EC)
133    return false;
134
135  outs() << "\nError reading file: " << EC.message() << ".\n";
136  outs().flush();
137  return true;
138}
139
140bool relocAddressLess(RelocationRef a, RelocationRef b) {
141  uint64_t a_addr, b_addr;
142  if (error(a.getAddress(a_addr))) return false;
143  if (error(b.getAddress(b_addr))) return false;
144  return a_addr < b_addr;
145}
146
147} // namespace llvm
148
149
150static void reportError(StringRef Input, error_code EC) {
151  if (Input == "-")
152    Input = "<stdin>";
153
154  errs() << Input << ": " << EC.message() << "\n";
155  errs().flush();
156}
157
158static void reportError(StringRef Input, StringRef Message) {
159  if (Input == "-")
160    Input = "<stdin>";
161
162  errs() << Input << ": " << Message << "\n";
163}
164
165/// @brief Creates an format-specific object file dumper.
166static error_code createDumper(const ObjectFile *Obj,
167                               StreamWriter &Writer,
168                               OwningPtr<ObjDumper> &Result) {
169  if (!Obj)
170    return readobj_error::unsupported_file_format;
171
172  if (Obj->isCOFF())
173    return createCOFFDumper(Obj, Writer, Result);
174  if (Obj->isELF())
175    return createELFDumper(Obj, Writer, Result);
176  if (Obj->isMachO())
177    return createMachODumper(Obj, Writer, Result);
178
179  return readobj_error::unsupported_obj_file_format;
180}
181
182
183/// @brief Dumps the specified object file.
184static void dumpObject(const ObjectFile *Obj) {
185  StreamWriter Writer(outs());
186  OwningPtr<ObjDumper> Dumper;
187  if (error_code EC = createDumper(Obj, Writer, Dumper)) {
188    reportError(Obj->getFileName(), EC);
189    return;
190  }
191
192  outs() << '\n';
193  outs() << "File: " << Obj->getFileName() << "\n";
194  outs() << "Format: " << Obj->getFileFormatName() << "\n";
195  outs() << "Arch: "
196         << Triple::getArchTypeName((llvm::Triple::ArchType)Obj->getArch())
197         << "\n";
198  outs() << "AddressSize: " << (8*Obj->getBytesInAddress()) << "bit\n";
199  if (Obj->isELF())
200    outs() << "LoadName: " << Obj->getLoadName() << "\n";
201
202  if (opts::FileHeaders)
203    Dumper->printFileHeaders();
204  if (opts::Sections)
205    Dumper->printSections();
206  if (opts::Relocations)
207    Dumper->printRelocations();
208  if (opts::Symbols)
209    Dumper->printSymbols();
210  if (opts::DynamicSymbols)
211    Dumper->printDynamicSymbols();
212  if (opts::UnwindInfo)
213    Dumper->printUnwindInfo();
214  if (opts::DynamicTable)
215    Dumper->printDynamicTable();
216  if (opts::NeededLibraries)
217    Dumper->printNeededLibraries();
218}
219
220
221/// @brief Dumps each object file in \a Arc;
222static void dumpArchive(const Archive *Arc) {
223  for (Archive::child_iterator ArcI = Arc->begin_children(),
224                               ArcE = Arc->end_children();
225                               ArcI != ArcE; ++ArcI) {
226    OwningPtr<Binary> child;
227    if (error_code EC = ArcI->getAsBinary(child)) {
228      // Ignore non-object files.
229      if (EC != object_error::invalid_file_type)
230        reportError(Arc->getFileName(), EC.message());
231      continue;
232    }
233
234    if (ObjectFile *Obj = dyn_cast<ObjectFile>(child.get()))
235      dumpObject(Obj);
236    else
237      reportError(Arc->getFileName(), readobj_error::unrecognized_file_format);
238  }
239}
240
241
242/// @brief Opens \a File and dumps it.
243static void dumpInput(StringRef File) {
244  // If file isn't stdin, check that it exists.
245  if (File != "-" && !sys::fs::exists(File)) {
246    reportError(File, readobj_error::file_not_found);
247    return;
248  }
249
250  // Attempt to open the binary.
251  OwningPtr<Binary> Binary;
252  if (error_code EC = createBinary(File, Binary)) {
253    reportError(File, EC);
254    return;
255  }
256
257  if (Archive *Arc = dyn_cast<Archive>(Binary.get()))
258    dumpArchive(Arc);
259  else if (ObjectFile *Obj = dyn_cast<ObjectFile>(Binary.get()))
260    dumpObject(Obj);
261  else
262    reportError(File, readobj_error::unrecognized_file_format);
263}
264
265
266int main(int argc, const char *argv[]) {
267  sys::PrintStackTraceOnErrorSignal();
268  PrettyStackTraceProgram X(argc, argv);
269  llvm_shutdown_obj Y;
270
271  // Initialize targets.
272  llvm::InitializeAllTargetInfos();
273
274  // Register the target printer for --version.
275  cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion);
276
277  cl::ParseCommandLineOptions(argc, argv, "LLVM Object Reader\n");
278
279  // Default to stdin if no filename is specified.
280  if (opts::InputFilenames.size() == 0)
281    opts::InputFilenames.push_back("-");
282
283  std::for_each(opts::InputFilenames.begin(), opts::InputFilenames.end(),
284                dumpInput);
285
286  return 0;
287}
288