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 #include "Error.h"
24 #include "ObjDumper.h"
25 #include "StreamWriter.h"
26 #include "llvm/Object/Archive.h"
27 #include "llvm/Object/COFFImportFile.h"
28 #include "llvm/Object/ELFObjectFile.h"
29 #include "llvm/Object/MachOUniversal.h"
30 #include "llvm/Object/ObjectFile.h"
31 #include "llvm/Support/Casting.h"
32 #include "llvm/Support/CommandLine.h"
33 #include "llvm/Support/DataTypes.h"
34 #include "llvm/Support/Debug.h"
35 #include "llvm/Support/FileSystem.h"
36 #include "llvm/Support/ManagedStatic.h"
37 #include "llvm/Support/PrettyStackTrace.h"
38 #include "llvm/Support/Signals.h"
39 #include "llvm/Support/TargetRegistry.h"
40 #include "llvm/Support/TargetSelect.h"
41 #include <string>
42 #include <system_error>
43 
44 using namespace llvm;
45 using namespace llvm::object;
46 
47 namespace opts {
48   cl::list<std::string> InputFilenames(cl::Positional,
49     cl::desc("<input object files>"),
50     cl::ZeroOrMore);
51 
52   // -file-headers, -h
53   cl::opt<bool> FileHeaders("file-headers",
54     cl::desc("Display file headers "));
55   cl::alias FileHeadersShort("h",
56     cl::desc("Alias for --file-headers"),
57     cl::aliasopt(FileHeaders));
58 
59   // -sections, -s
60   cl::opt<bool> Sections("sections",
61     cl::desc("Display all sections."));
62   cl::alias SectionsShort("s",
63     cl::desc("Alias for --sections"),
64     cl::aliasopt(Sections));
65 
66   // -section-relocations, -sr
67   cl::opt<bool> SectionRelocations("section-relocations",
68     cl::desc("Display relocations for each section shown."));
69   cl::alias SectionRelocationsShort("sr",
70     cl::desc("Alias for --section-relocations"),
71     cl::aliasopt(SectionRelocations));
72 
73   // -section-symbols, -st
74   cl::opt<bool> SectionSymbols("section-symbols",
75     cl::desc("Display symbols for each section shown."));
76   cl::alias SectionSymbolsShort("st",
77     cl::desc("Alias for --section-symbols"),
78     cl::aliasopt(SectionSymbols));
79 
80   // -section-data, -sd
81   cl::opt<bool> SectionData("section-data",
82     cl::desc("Display section data for each section shown."));
83   cl::alias SectionDataShort("sd",
84     cl::desc("Alias for --section-data"),
85     cl::aliasopt(SectionData));
86 
87   // -relocations, -r
88   cl::opt<bool> Relocations("relocations",
89     cl::desc("Display the relocation entries in the file"));
90   cl::alias RelocationsShort("r",
91     cl::desc("Alias for --relocations"),
92     cl::aliasopt(Relocations));
93 
94   // -dyn-relocations
95   cl::opt<bool> DynRelocs("dyn-relocations",
96     cl::desc("Display the dynamic relocation entries in the file"));
97 
98   // -symbols, -t
99   cl::opt<bool> Symbols("symbols",
100     cl::desc("Display the symbol table"));
101   cl::alias SymbolsShort("t",
102     cl::desc("Alias for --symbols"),
103     cl::aliasopt(Symbols));
104 
105   // -dyn-symbols, -dt
106   cl::opt<bool> DynamicSymbols("dyn-symbols",
107     cl::desc("Display the dynamic symbol table"));
108   cl::alias DynamicSymbolsShort("dt",
109     cl::desc("Alias for --dyn-symbols"),
110     cl::aliasopt(DynamicSymbols));
111 
112   // -unwind, -u
113   cl::opt<bool> UnwindInfo("unwind",
114     cl::desc("Display unwind information"));
115   cl::alias UnwindInfoShort("u",
116     cl::desc("Alias for --unwind"),
117     cl::aliasopt(UnwindInfo));
118 
119   // -dynamic-table
120   cl::opt<bool> DynamicTable("dynamic-table",
121     cl::desc("Display the ELF .dynamic section table"));
122 
123   // -needed-libs
124   cl::opt<bool> NeededLibraries("needed-libs",
125     cl::desc("Display the needed libraries"));
126 
127   // -program-headers
128   cl::opt<bool> ProgramHeaders("program-headers",
129     cl::desc("Display ELF program headers"));
130 
131   // -hash-table
132   cl::opt<bool> HashTable("hash-table",
133     cl::desc("Display ELF hash table"));
134 
135   // -gnu-hash-table
136   cl::opt<bool> GnuHashTable("gnu-hash-table",
137     cl::desc("Display ELF .gnu.hash section"));
138 
139   // -expand-relocs
140   cl::opt<bool> ExpandRelocs("expand-relocs",
141     cl::desc("Expand each shown relocation to multiple lines"));
142 
143   // -codeview
144   cl::opt<bool> CodeView("codeview",
145                          cl::desc("Display CodeView debug information"));
146 
147   // -codeview-subsection-bytes
148   cl::opt<bool> CodeViewSubsectionBytes(
149       "codeview-subsection-bytes",
150       cl::desc("Dump raw contents of codeview debug sections and records"));
151 
152   // -arm-attributes, -a
153   cl::opt<bool> ARMAttributes("arm-attributes",
154                               cl::desc("Display the ARM attributes section"));
155   cl::alias ARMAttributesShort("-a", cl::desc("Alias for --arm-attributes"),
156                                cl::aliasopt(ARMAttributes));
157 
158   // -mips-plt-got
159   cl::opt<bool>
160   MipsPLTGOT("mips-plt-got",
161              cl::desc("Display the MIPS GOT and PLT GOT sections"));
162 
163   // -mips-abi-flags
164   cl::opt<bool> MipsABIFlags("mips-abi-flags",
165                              cl::desc("Display the MIPS.abiflags section"));
166 
167   // -mips-reginfo
168   cl::opt<bool> MipsReginfo("mips-reginfo",
169                             cl::desc("Display the MIPS .reginfo section"));
170 
171   // -coff-imports
172   cl::opt<bool>
173   COFFImports("coff-imports", cl::desc("Display the PE/COFF import table"));
174 
175   // -coff-exports
176   cl::opt<bool>
177   COFFExports("coff-exports", cl::desc("Display the PE/COFF export table"));
178 
179   // -coff-directives
180   cl::opt<bool>
181   COFFDirectives("coff-directives",
182                  cl::desc("Display the PE/COFF .drectve section"));
183 
184   // -coff-basereloc
185   cl::opt<bool>
186   COFFBaseRelocs("coff-basereloc",
187                  cl::desc("Display the PE/COFF .reloc section"));
188 
189   // -macho-data-in-code
190   cl::opt<bool>
191   MachODataInCode("macho-data-in-code",
192                   cl::desc("Display MachO Data in Code command"));
193 
194   // -macho-indirect-symbols
195   cl::opt<bool>
196   MachOIndirectSymbols("macho-indirect-symbols",
197                   cl::desc("Display MachO indirect symbols"));
198 
199   // -macho-linker-options
200   cl::opt<bool>
201   MachOLinkerOptions("macho-linker-options",
202                   cl::desc("Display MachO linker options"));
203 
204   // -macho-segment
205   cl::opt<bool>
206   MachOSegment("macho-segment",
207                   cl::desc("Display MachO Segment command"));
208 
209   // -macho-version-min
210   cl::opt<bool>
211   MachOVersionMin("macho-version-min",
212                   cl::desc("Display MachO version min command"));
213 
214   // -macho-dysymtab
215   cl::opt<bool>
216   MachODysymtab("macho-dysymtab",
217                   cl::desc("Display MachO Dysymtab command"));
218 
219   // -stackmap
220   cl::opt<bool>
221   PrintStackMap("stackmap",
222                 cl::desc("Display contents of stackmap section"));
223 
224   // -version-info
225   cl::opt<bool>
226       VersionInfo("version-info",
227                   cl::desc("Display ELF version sections (if present)"));
228   cl::alias VersionInfoShort("V", cl::desc("Alias for -version-info"),
229                              cl::aliasopt(VersionInfo));
230 
231   cl::opt<bool> SectionGroups("elf-section-groups",
232                               cl::desc("Display ELF section group contents"));
233   cl::alias SectionGroupsShort("g", cl::desc("Alias for -elf-sections-groups"),
234                                cl::aliasopt(SectionGroups));
235   cl::opt<bool> HashHistogram(
236       "elf-hash-histogram",
237       cl::desc("Display bucket list histogram for hash sections"));
238   cl::alias HashHistogramShort("I", cl::desc("Alias for -elf-hash-histogram"),
239                                cl::aliasopt(HashHistogram));
240 
241   cl::opt<OutputStyleTy>
242       Output("elf-output-style", cl::desc("Specify ELF dump style"),
243              cl::values(clEnumVal(LLVM, "LLVM default style"),
244                         clEnumVal(GNU, "GNU readelf style"), clEnumValEnd),
245              cl::init(LLVM));
246 } // namespace opts
247 
248 namespace llvm {
249 
250 LLVM_ATTRIBUTE_NORETURN void reportError(Twine Msg) {
251   errs() << "\nError reading file: " << Msg << ".\n";
252   errs().flush();
253   exit(1);
254 }
255 
256 void error(std::error_code EC) {
257   if (!EC)
258     return;
259 
260   reportError(EC.message());
261 }
262 
263 bool relocAddressLess(RelocationRef a, RelocationRef b) {
264   return a.getOffset() < b.getOffset();
265 }
266 
267 } // namespace llvm
268 
269 static void reportError(StringRef Input, std::error_code EC) {
270   if (Input == "-")
271     Input = "<stdin>";
272 
273   reportError(Twine(Input) + ": " + EC.message());
274 }
275 
276 static void reportError(StringRef Input, StringRef Message) {
277   if (Input == "-")
278     Input = "<stdin>";
279 
280   reportError(Twine(Input) + ": " + Message);
281 }
282 
283 static bool isMipsArch(unsigned Arch) {
284   switch (Arch) {
285   case llvm::Triple::mips:
286   case llvm::Triple::mipsel:
287   case llvm::Triple::mips64:
288   case llvm::Triple::mips64el:
289     return true;
290   default:
291     return false;
292   }
293 }
294 
295 /// @brief Creates an format-specific object file dumper.
296 static std::error_code createDumper(const ObjectFile *Obj, StreamWriter &Writer,
297                                     std::unique_ptr<ObjDumper> &Result) {
298   if (!Obj)
299     return readobj_error::unsupported_file_format;
300 
301   if (Obj->isCOFF())
302     return createCOFFDumper(Obj, Writer, Result);
303   if (Obj->isELF())
304     return createELFDumper(Obj, Writer, Result);
305   if (Obj->isMachO())
306     return createMachODumper(Obj, Writer, Result);
307 
308   return readobj_error::unsupported_obj_file_format;
309 }
310 
311 /// @brief Dumps the specified object file.
312 static void dumpObject(const ObjectFile *Obj) {
313   StreamWriter Writer(outs());
314   std::unique_ptr<ObjDumper> Dumper;
315   if (std::error_code EC = createDumper(Obj, Writer, Dumper))
316     reportError(Obj->getFileName(), EC);
317 
318   if (opts::Output == opts::LLVM) {
319     outs() << '\n';
320     outs() << "File: " << Obj->getFileName() << "\n";
321     outs() << "Format: " << Obj->getFileFormatName() << "\n";
322     outs() << "Arch: " << Triple::getArchTypeName(
323                               (llvm::Triple::ArchType)Obj->getArch()) << "\n";
324     outs() << "AddressSize: " << (8 * Obj->getBytesInAddress()) << "bit\n";
325     Dumper->printLoadName();
326   }
327 
328   if (opts::FileHeaders)
329     Dumper->printFileHeaders();
330   if (opts::Sections)
331     Dumper->printSections();
332   if (opts::Relocations)
333     Dumper->printRelocations();
334   if (opts::DynRelocs)
335     Dumper->printDynamicRelocations();
336   if (opts::Symbols)
337     Dumper->printSymbols();
338   if (opts::DynamicSymbols)
339     Dumper->printDynamicSymbols();
340   if (opts::UnwindInfo)
341     Dumper->printUnwindInfo();
342   if (opts::DynamicTable)
343     Dumper->printDynamicTable();
344   if (opts::NeededLibraries)
345     Dumper->printNeededLibraries();
346   if (opts::ProgramHeaders)
347     Dumper->printProgramHeaders();
348   if (opts::HashTable)
349     Dumper->printHashTable();
350   if (opts::GnuHashTable)
351     Dumper->printGnuHashTable();
352   if (opts::VersionInfo)
353     Dumper->printVersionInfo();
354   if (Obj->isELF()) {
355     if (Obj->getArch() == llvm::Triple::arm)
356       if (opts::ARMAttributes)
357         Dumper->printAttributes();
358     if (isMipsArch(Obj->getArch())) {
359       if (opts::MipsPLTGOT)
360         Dumper->printMipsPLTGOT();
361       if (opts::MipsABIFlags)
362         Dumper->printMipsABIFlags();
363       if (opts::MipsReginfo)
364         Dumper->printMipsReginfo();
365     }
366     if (opts::SectionGroups)
367       Dumper->printGroupSections();
368     if (opts::HashHistogram)
369       Dumper->printHashHistogram();
370   }
371   if (Obj->isCOFF()) {
372     if (opts::COFFImports)
373       Dumper->printCOFFImports();
374     if (opts::COFFExports)
375       Dumper->printCOFFExports();
376     if (opts::COFFDirectives)
377       Dumper->printCOFFDirectives();
378     if (opts::COFFBaseRelocs)
379       Dumper->printCOFFBaseReloc();
380     if (opts::CodeView)
381       Dumper->printCodeViewDebugInfo();
382   }
383   if (Obj->isMachO()) {
384     if (opts::MachODataInCode)
385       Dumper->printMachODataInCode();
386     if (opts::MachOIndirectSymbols)
387       Dumper->printMachOIndirectSymbols();
388     if (opts::MachOLinkerOptions)
389       Dumper->printMachOLinkerOptions();
390     if (opts::MachOSegment)
391       Dumper->printMachOSegment();
392     if (opts::MachOVersionMin)
393       Dumper->printMachOVersionMin();
394     if (opts::MachODysymtab)
395       Dumper->printMachODysymtab();
396   }
397   if (opts::PrintStackMap)
398     Dumper->printStackMap();
399 }
400 
401 /// @brief Dumps each object file in \a Arc;
402 static void dumpArchive(const Archive *Arc) {
403   for (auto &ErrorOrChild : Arc->children()) {
404     if (std::error_code EC = ErrorOrChild.getError())
405       reportError(Arc->getFileName(), EC.message());
406     const auto &Child = *ErrorOrChild;
407     ErrorOr<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary();
408     if (std::error_code EC = ChildOrErr.getError()) {
409       // Ignore non-object files.
410       if (EC != object_error::invalid_file_type)
411         reportError(Arc->getFileName(), EC.message());
412       continue;
413     }
414 
415     if (ObjectFile *Obj = dyn_cast<ObjectFile>(&*ChildOrErr.get()))
416       dumpObject(Obj);
417     else
418       reportError(Arc->getFileName(), readobj_error::unrecognized_file_format);
419   }
420 }
421 
422 /// @brief Dumps each object file in \a MachO Universal Binary;
423 static void dumpMachOUniversalBinary(const MachOUniversalBinary *UBinary) {
424   for (const MachOUniversalBinary::ObjectForArch &Obj : UBinary->objects()) {
425     ErrorOr<std::unique_ptr<MachOObjectFile>> ObjOrErr = Obj.getAsObjectFile();
426     if (ObjOrErr)
427       dumpObject(&*ObjOrErr.get());
428     else if (ErrorOr<std::unique_ptr<Archive>> AOrErr = Obj.getAsArchive())
429       dumpArchive(&*AOrErr.get());
430     else
431       reportError(UBinary->getFileName(), ObjOrErr.getError().message());
432   }
433 }
434 
435 /// @brief Opens \a File and dumps it.
436 static void dumpInput(StringRef File) {
437 
438   // Attempt to open the binary.
439   Expected<OwningBinary<Binary>> BinaryOrErr = createBinary(File);
440   if (!BinaryOrErr)
441     reportError(File, errorToErrorCode(BinaryOrErr.takeError()));
442   Binary &Binary = *BinaryOrErr.get().getBinary();
443 
444   if (Archive *Arc = dyn_cast<Archive>(&Binary))
445     dumpArchive(Arc);
446   else if (MachOUniversalBinary *UBinary =
447                dyn_cast<MachOUniversalBinary>(&Binary))
448     dumpMachOUniversalBinary(UBinary);
449   else if (ObjectFile *Obj = dyn_cast<ObjectFile>(&Binary))
450     dumpObject(Obj);
451   else if (COFFImportFile *Import = dyn_cast<COFFImportFile>(&Binary))
452     dumpCOFFImportFile(Import);
453   else
454     reportError(File, readobj_error::unrecognized_file_format);
455 }
456 
457 int main(int argc, const char *argv[]) {
458   sys::PrintStackTraceOnErrorSignal();
459   PrettyStackTraceProgram X(argc, argv);
460   llvm_shutdown_obj Y;
461 
462   // Register the target printer for --version.
463   cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion);
464 
465   cl::ParseCommandLineOptions(argc, argv, "LLVM Object Reader\n");
466 
467   // Default to stdin if no filename is specified.
468   if (opts::InputFilenames.size() == 0)
469     opts::InputFilenames.push_back("-");
470 
471   std::for_each(opts::InputFilenames.begin(), opts::InputFilenames.end(),
472                 dumpInput);
473 
474   return 0;
475 }
476