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 "llvm/Object/Archive.h"
26 #include "llvm/Object/COFFImportFile.h"
27 #include "llvm/Object/ELFObjectFile.h"
28 #include "llvm/Object/MachOUniversal.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/ScopedPrinter.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   // -mips-options
172   cl::opt<bool> MipsOptions("mips-options",
173                             cl::desc("Display the MIPS .MIPS.options section"));
174 
175   // -coff-imports
176   cl::opt<bool>
177   COFFImports("coff-imports", cl::desc("Display the PE/COFF import table"));
178 
179   // -coff-exports
180   cl::opt<bool>
181   COFFExports("coff-exports", cl::desc("Display the PE/COFF export table"));
182 
183   // -coff-directives
184   cl::opt<bool>
185   COFFDirectives("coff-directives",
186                  cl::desc("Display the PE/COFF .drectve section"));
187 
188   // -coff-basereloc
189   cl::opt<bool>
190   COFFBaseRelocs("coff-basereloc",
191                  cl::desc("Display the PE/COFF .reloc section"));
192 
193   // -macho-data-in-code
194   cl::opt<bool>
195   MachODataInCode("macho-data-in-code",
196                   cl::desc("Display MachO Data in Code command"));
197 
198   // -macho-indirect-symbols
199   cl::opt<bool>
200   MachOIndirectSymbols("macho-indirect-symbols",
201                   cl::desc("Display MachO indirect symbols"));
202 
203   // -macho-linker-options
204   cl::opt<bool>
205   MachOLinkerOptions("macho-linker-options",
206                   cl::desc("Display MachO linker options"));
207 
208   // -macho-segment
209   cl::opt<bool>
210   MachOSegment("macho-segment",
211                   cl::desc("Display MachO Segment command"));
212 
213   // -macho-version-min
214   cl::opt<bool>
215   MachOVersionMin("macho-version-min",
216                   cl::desc("Display MachO version min command"));
217 
218   // -macho-dysymtab
219   cl::opt<bool>
220   MachODysymtab("macho-dysymtab",
221                   cl::desc("Display MachO Dysymtab command"));
222 
223   // -stackmap
224   cl::opt<bool>
225   PrintStackMap("stackmap",
226                 cl::desc("Display contents of stackmap section"));
227 
228   // -version-info
229   cl::opt<bool>
230       VersionInfo("version-info",
231                   cl::desc("Display ELF version sections (if present)"));
232   cl::alias VersionInfoShort("V", cl::desc("Alias for -version-info"),
233                              cl::aliasopt(VersionInfo));
234 
235   cl::opt<bool> SectionGroups("elf-section-groups",
236                               cl::desc("Display ELF section group contents"));
237   cl::alias SectionGroupsShort("g", cl::desc("Alias for -elf-sections-groups"),
238                                cl::aliasopt(SectionGroups));
239   cl::opt<bool> HashHistogram(
240       "elf-hash-histogram",
241       cl::desc("Display bucket list histogram for hash sections"));
242   cl::alias HashHistogramShort("I", cl::desc("Alias for -elf-hash-histogram"),
243                                cl::aliasopt(HashHistogram));
244 
245   cl::opt<OutputStyleTy>
246       Output("elf-output-style", cl::desc("Specify ELF dump style"),
247              cl::values(clEnumVal(LLVM, "LLVM default style"),
248                         clEnumVal(GNU, "GNU readelf style"), clEnumValEnd),
249              cl::init(LLVM));
250 } // namespace opts
251 
252 namespace llvm {
253 
254 LLVM_ATTRIBUTE_NORETURN void reportError(Twine Msg) {
255   errs() << "\nError reading file: " << Msg << ".\n";
256   errs().flush();
257   exit(1);
258 }
259 
260 void error(std::error_code EC) {
261   if (!EC)
262     return;
263 
264   reportError(EC.message());
265 }
266 
267 bool relocAddressLess(RelocationRef a, RelocationRef b) {
268   return a.getOffset() < b.getOffset();
269 }
270 
271 } // namespace llvm
272 
273 static void reportError(StringRef Input, std::error_code EC) {
274   if (Input == "-")
275     Input = "<stdin>";
276 
277   reportError(Twine(Input) + ": " + EC.message());
278 }
279 
280 static void reportError(StringRef Input, StringRef Message) {
281   if (Input == "-")
282     Input = "<stdin>";
283 
284   reportError(Twine(Input) + ": " + Message);
285 }
286 
287 static bool isMipsArch(unsigned Arch) {
288   switch (Arch) {
289   case llvm::Triple::mips:
290   case llvm::Triple::mipsel:
291   case llvm::Triple::mips64:
292   case llvm::Triple::mips64el:
293     return true;
294   default:
295     return false;
296   }
297 }
298 
299 /// @brief Creates an format-specific object file dumper.
300 static std::error_code createDumper(const ObjectFile *Obj,
301                                     ScopedPrinter &Writer,
302                                     std::unique_ptr<ObjDumper> &Result) {
303   if (!Obj)
304     return readobj_error::unsupported_file_format;
305 
306   if (Obj->isCOFF())
307     return createCOFFDumper(Obj, Writer, Result);
308   if (Obj->isELF())
309     return createELFDumper(Obj, Writer, Result);
310   if (Obj->isMachO())
311     return createMachODumper(Obj, Writer, Result);
312 
313   return readobj_error::unsupported_obj_file_format;
314 }
315 
316 /// @brief Dumps the specified object file.
317 static void dumpObject(const ObjectFile *Obj) {
318   ScopedPrinter Writer(outs());
319   std::unique_ptr<ObjDumper> Dumper;
320   if (std::error_code EC = createDumper(Obj, Writer, Dumper))
321     reportError(Obj->getFileName(), EC);
322 
323   if (opts::Output == opts::LLVM) {
324     outs() << '\n';
325     outs() << "File: " << Obj->getFileName() << "\n";
326     outs() << "Format: " << Obj->getFileFormatName() << "\n";
327     outs() << "Arch: " << Triple::getArchTypeName(
328                               (llvm::Triple::ArchType)Obj->getArch()) << "\n";
329     outs() << "AddressSize: " << (8 * Obj->getBytesInAddress()) << "bit\n";
330     Dumper->printLoadName();
331   }
332 
333   if (opts::FileHeaders)
334     Dumper->printFileHeaders();
335   if (opts::Sections)
336     Dumper->printSections();
337   if (opts::Relocations)
338     Dumper->printRelocations();
339   if (opts::DynRelocs)
340     Dumper->printDynamicRelocations();
341   if (opts::Symbols)
342     Dumper->printSymbols();
343   if (opts::DynamicSymbols)
344     Dumper->printDynamicSymbols();
345   if (opts::UnwindInfo)
346     Dumper->printUnwindInfo();
347   if (opts::DynamicTable)
348     Dumper->printDynamicTable();
349   if (opts::NeededLibraries)
350     Dumper->printNeededLibraries();
351   if (opts::ProgramHeaders)
352     Dumper->printProgramHeaders();
353   if (opts::HashTable)
354     Dumper->printHashTable();
355   if (opts::GnuHashTable)
356     Dumper->printGnuHashTable();
357   if (opts::VersionInfo)
358     Dumper->printVersionInfo();
359   if (Obj->isELF()) {
360     if (Obj->getArch() == llvm::Triple::arm)
361       if (opts::ARMAttributes)
362         Dumper->printAttributes();
363     if (isMipsArch(Obj->getArch())) {
364       if (opts::MipsPLTGOT)
365         Dumper->printMipsPLTGOT();
366       if (opts::MipsABIFlags)
367         Dumper->printMipsABIFlags();
368       if (opts::MipsReginfo)
369         Dumper->printMipsReginfo();
370       if (opts::MipsOptions)
371         Dumper->printMipsOptions();
372     }
373     if (opts::SectionGroups)
374       Dumper->printGroupSections();
375     if (opts::HashHistogram)
376       Dumper->printHashHistogram();
377   }
378   if (Obj->isCOFF()) {
379     if (opts::COFFImports)
380       Dumper->printCOFFImports();
381     if (opts::COFFExports)
382       Dumper->printCOFFExports();
383     if (opts::COFFDirectives)
384       Dumper->printCOFFDirectives();
385     if (opts::COFFBaseRelocs)
386       Dumper->printCOFFBaseReloc();
387     if (opts::CodeView)
388       Dumper->printCodeViewDebugInfo();
389   }
390   if (Obj->isMachO()) {
391     if (opts::MachODataInCode)
392       Dumper->printMachODataInCode();
393     if (opts::MachOIndirectSymbols)
394       Dumper->printMachOIndirectSymbols();
395     if (opts::MachOLinkerOptions)
396       Dumper->printMachOLinkerOptions();
397     if (opts::MachOSegment)
398       Dumper->printMachOSegment();
399     if (opts::MachOVersionMin)
400       Dumper->printMachOVersionMin();
401     if (opts::MachODysymtab)
402       Dumper->printMachODysymtab();
403   }
404   if (opts::PrintStackMap)
405     Dumper->printStackMap();
406 }
407 
408 /// @brief Dumps each object file in \a Arc;
409 static void dumpArchive(const Archive *Arc) {
410   for (auto &ErrorOrChild : Arc->children()) {
411     if (std::error_code EC = ErrorOrChild.getError())
412       reportError(Arc->getFileName(), EC.message());
413     const auto &Child = *ErrorOrChild;
414     ErrorOr<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary();
415     if (std::error_code EC = ChildOrErr.getError()) {
416       // Ignore non-object files.
417       if (EC != object_error::invalid_file_type)
418         reportError(Arc->getFileName(), EC.message());
419       continue;
420     }
421 
422     if (ObjectFile *Obj = dyn_cast<ObjectFile>(&*ChildOrErr.get()))
423       dumpObject(Obj);
424     else
425       reportError(Arc->getFileName(), readobj_error::unrecognized_file_format);
426   }
427 }
428 
429 /// @brief Dumps each object file in \a MachO Universal Binary;
430 static void dumpMachOUniversalBinary(const MachOUniversalBinary *UBinary) {
431   for (const MachOUniversalBinary::ObjectForArch &Obj : UBinary->objects()) {
432     ErrorOr<std::unique_ptr<MachOObjectFile>> ObjOrErr = Obj.getAsObjectFile();
433     if (ObjOrErr)
434       dumpObject(&*ObjOrErr.get());
435     else if (ErrorOr<std::unique_ptr<Archive>> AOrErr = Obj.getAsArchive())
436       dumpArchive(&*AOrErr.get());
437     else
438       reportError(UBinary->getFileName(), ObjOrErr.getError().message());
439   }
440 }
441 
442 /// @brief Opens \a File and dumps it.
443 static void dumpInput(StringRef File) {
444 
445   // Attempt to open the binary.
446   Expected<OwningBinary<Binary>> BinaryOrErr = createBinary(File);
447   if (!BinaryOrErr)
448     reportError(File, errorToErrorCode(BinaryOrErr.takeError()));
449   Binary &Binary = *BinaryOrErr.get().getBinary();
450 
451   if (Archive *Arc = dyn_cast<Archive>(&Binary))
452     dumpArchive(Arc);
453   else if (MachOUniversalBinary *UBinary =
454                dyn_cast<MachOUniversalBinary>(&Binary))
455     dumpMachOUniversalBinary(UBinary);
456   else if (ObjectFile *Obj = dyn_cast<ObjectFile>(&Binary))
457     dumpObject(Obj);
458   else if (COFFImportFile *Import = dyn_cast<COFFImportFile>(&Binary))
459     dumpCOFFImportFile(Import);
460   else
461     reportError(File, readobj_error::unrecognized_file_format);
462 }
463 
464 int main(int argc, const char *argv[]) {
465   sys::PrintStackTraceOnErrorSignal();
466   PrettyStackTraceProgram X(argc, argv);
467   llvm_shutdown_obj Y;
468 
469   // Register the target printer for --version.
470   cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion);
471 
472   cl::ParseCommandLineOptions(argc, argv, "LLVM Object Reader\n");
473 
474   // Default to stdin if no filename is specified.
475   if (opts::InputFilenames.size() == 0)
476     opts::InputFilenames.push_back("-");
477 
478   std::for_each(opts::InputFilenames.begin(), opts::InputFilenames.end(),
479                 dumpInput);
480 
481   return 0;
482 }
483