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/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/Signals.h"
38 #include "llvm/Support/TargetRegistry.h"
39 #include "llvm/Support/TargetSelect.h"
40 #include <string>
41 #include <system_error>
42 
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   // -symbols, -t
95   cl::opt<bool> Symbols("symbols",
96     cl::desc("Display the symbol table"));
97   cl::alias SymbolsShort("t",
98     cl::desc("Alias for --symbols"),
99     cl::aliasopt(Symbols));
100 
101   // -dyn-symbols, -dt
102   cl::opt<bool> DynamicSymbols("dyn-symbols",
103     cl::desc("Display the dynamic symbol table"));
104   cl::alias DynamicSymbolsShort("dt",
105     cl::desc("Alias for --dyn-symbols"),
106     cl::aliasopt(DynamicSymbols));
107 
108   // -unwind, -u
109   cl::opt<bool> UnwindInfo("unwind",
110     cl::desc("Display unwind information"));
111   cl::alias UnwindInfoShort("u",
112     cl::desc("Alias for --unwind"),
113     cl::aliasopt(UnwindInfo));
114 
115   // -dynamic-table
116   cl::opt<bool> DynamicTable("dynamic-table",
117     cl::desc("Display the ELF .dynamic section table"));
118 
119   // -needed-libs
120   cl::opt<bool> NeededLibraries("needed-libs",
121     cl::desc("Display the needed libraries"));
122 
123   // -program-headers
124   cl::opt<bool> ProgramHeaders("program-headers",
125     cl::desc("Display ELF program headers"));
126 
127   // -expand-relocs
128   cl::opt<bool> ExpandRelocs("expand-relocs",
129     cl::desc("Expand each shown relocation to multiple lines"));
130 
131   // -codeview
132   cl::opt<bool> CodeView("codeview",
133                          cl::desc("Display CodeView debug information"));
134 
135   // -codeview-subsection-bytes
136   cl::opt<bool> CodeViewSubsectionBytes(
137       "codeview-subsection-bytes",
138       cl::desc("Dump raw contents of codeview debug sections and records"));
139 
140   // -arm-attributes, -a
141   cl::opt<bool> ARMAttributes("arm-attributes",
142                               cl::desc("Display the ARM attributes section"));
143   cl::alias ARMAttributesShort("-a", cl::desc("Alias for --arm-attributes"),
144                                cl::aliasopt(ARMAttributes));
145 
146   // -mips-plt-got
147   cl::opt<bool>
148   MipsPLTGOT("mips-plt-got",
149              cl::desc("Display the MIPS GOT and PLT GOT sections"));
150 
151   // -coff-imports
152   cl::opt<bool>
153   COFFImports("coff-imports", cl::desc("Display the PE/COFF import table"));
154 
155   // -coff-exports
156   cl::opt<bool>
157   COFFExports("coff-exports", cl::desc("Display the PE/COFF export table"));
158 
159   // -coff-directives
160   cl::opt<bool>
161   COFFDirectives("coff-directives",
162                  cl::desc("Display the PE/COFF .drectve section"));
163 
164   // -coff-basereloc
165   cl::opt<bool>
166   COFFBaseRelocs("coff-basereloc",
167                  cl::desc("Display the PE/COFF .reloc section"));
168 } // namespace opts
169 
170 static int ReturnValue = EXIT_SUCCESS;
171 
172 namespace llvm {
173 
174 bool error(std::error_code EC) {
175   if (!EC)
176     return false;
177 
178   ReturnValue = EXIT_FAILURE;
179   outs() << "\nError reading file: " << EC.message() << ".\n";
180   outs().flush();
181   return true;
182 }
183 
184 bool relocAddressLess(RelocationRef a, RelocationRef b) {
185   uint64_t a_addr, b_addr;
186   if (error(a.getOffset(a_addr))) exit(ReturnValue);
187   if (error(b.getOffset(b_addr))) exit(ReturnValue);
188   return a_addr < b_addr;
189 }
190 
191 } // namespace llvm
192 
193 static void reportError(StringRef Input, std::error_code EC) {
194   if (Input == "-")
195     Input = "<stdin>";
196 
197   errs() << Input << ": " << EC.message() << "\n";
198   errs().flush();
199   ReturnValue = EXIT_FAILURE;
200 }
201 
202 static void reportError(StringRef Input, StringRef Message) {
203   if (Input == "-")
204     Input = "<stdin>";
205 
206   errs() << Input << ": " << Message << "\n";
207   ReturnValue = EXIT_FAILURE;
208 }
209 
210 static bool isMipsArch(unsigned Arch) {
211   switch (Arch) {
212   case llvm::Triple::mips:
213   case llvm::Triple::mipsel:
214   case llvm::Triple::mips64:
215   case llvm::Triple::mips64el:
216     return true;
217   default:
218     return false;
219   }
220 }
221 
222 /// @brief Creates an format-specific object file dumper.
223 static std::error_code createDumper(const ObjectFile *Obj, StreamWriter &Writer,
224                                     std::unique_ptr<ObjDumper> &Result) {
225   if (!Obj)
226     return readobj_error::unsupported_file_format;
227 
228   if (Obj->isCOFF())
229     return createCOFFDumper(Obj, Writer, Result);
230   if (Obj->isELF())
231     return createELFDumper(Obj, Writer, Result);
232   if (Obj->isMachO())
233     return createMachODumper(Obj, Writer, Result);
234 
235   return readobj_error::unsupported_obj_file_format;
236 }
237 
238 static StringRef getLoadName(const ObjectFile *Obj) {
239   if (auto *ELF = dyn_cast<ELF32LEObjectFile>(Obj))
240     return ELF->getLoadName();
241   if (auto *ELF = dyn_cast<ELF64LEObjectFile>(Obj))
242     return ELF->getLoadName();
243   if (auto *ELF = dyn_cast<ELF32BEObjectFile>(Obj))
244     return ELF->getLoadName();
245   if (auto *ELF = dyn_cast<ELF64BEObjectFile>(Obj))
246     return ELF->getLoadName();
247   llvm_unreachable("Not ELF");
248 }
249 
250 /// @brief Dumps the specified object file.
251 static void dumpObject(const ObjectFile *Obj) {
252   StreamWriter Writer(outs());
253   std::unique_ptr<ObjDumper> Dumper;
254   if (std::error_code EC = createDumper(Obj, Writer, Dumper)) {
255     reportError(Obj->getFileName(), EC);
256     return;
257   }
258 
259   outs() << '\n';
260   outs() << "File: " << Obj->getFileName() << "\n";
261   outs() << "Format: " << Obj->getFileFormatName() << "\n";
262   outs() << "Arch: "
263          << Triple::getArchTypeName((llvm::Triple::ArchType)Obj->getArch())
264          << "\n";
265   outs() << "AddressSize: " << (8*Obj->getBytesInAddress()) << "bit\n";
266   if (Obj->isELF())
267     outs() << "LoadName: " << getLoadName(Obj) << "\n";
268 
269   if (opts::FileHeaders)
270     Dumper->printFileHeaders();
271   if (opts::Sections)
272     Dumper->printSections();
273   if (opts::Relocations)
274     Dumper->printRelocations();
275   if (opts::Symbols)
276     Dumper->printSymbols();
277   if (opts::DynamicSymbols)
278     Dumper->printDynamicSymbols();
279   if (opts::UnwindInfo)
280     Dumper->printUnwindInfo();
281   if (opts::DynamicTable)
282     Dumper->printDynamicTable();
283   if (opts::NeededLibraries)
284     Dumper->printNeededLibraries();
285   if (opts::ProgramHeaders)
286     Dumper->printProgramHeaders();
287   if (Obj->getArch() == llvm::Triple::arm && Obj->isELF())
288     if (opts::ARMAttributes)
289       Dumper->printAttributes();
290   if (isMipsArch(Obj->getArch()) && Obj->isELF())
291     if (opts::MipsPLTGOT)
292       Dumper->printMipsPLTGOT();
293   if (opts::COFFImports)
294     Dumper->printCOFFImports();
295   if (opts::COFFExports)
296     Dumper->printCOFFExports();
297   if (opts::COFFDirectives)
298     Dumper->printCOFFDirectives();
299   if (opts::COFFBaseRelocs)
300     Dumper->printCOFFBaseReloc();
301 }
302 
303 
304 /// @brief Dumps each object file in \a Arc;
305 static void dumpArchive(const Archive *Arc) {
306   for (Archive::child_iterator ArcI = Arc->child_begin(),
307                                ArcE = Arc->child_end();
308                                ArcI != ArcE; ++ArcI) {
309     ErrorOr<std::unique_ptr<Binary>> ChildOrErr = ArcI->getAsBinary();
310     if (std::error_code EC = ChildOrErr.getError()) {
311       // Ignore non-object files.
312       if (EC != object_error::invalid_file_type)
313         reportError(Arc->getFileName(), EC.message());
314       continue;
315     }
316 
317     if (ObjectFile *Obj = dyn_cast<ObjectFile>(&*ChildOrErr.get()))
318       dumpObject(Obj);
319     else
320       reportError(Arc->getFileName(), readobj_error::unrecognized_file_format);
321   }
322 }
323 
324 /// @brief Dumps each object file in \a MachO Universal Binary;
325 static void dumpMachOUniversalBinary(const MachOUniversalBinary *UBinary) {
326   for (const MachOUniversalBinary::ObjectForArch &Obj : UBinary->objects()) {
327     ErrorOr<std::unique_ptr<MachOObjectFile>> ObjOrErr = Obj.getAsObjectFile();
328     if (ObjOrErr)
329       dumpObject(&*ObjOrErr.get());
330     else if (ErrorOr<std::unique_ptr<Archive>> AOrErr = Obj.getAsArchive())
331       dumpArchive(&*AOrErr.get());
332     else
333       reportError(UBinary->getFileName(), ObjOrErr.getError().message());
334   }
335 }
336 
337 /// @brief Opens \a File and dumps it.
338 static void dumpInput(StringRef File) {
339   // If file isn't stdin, check that it exists.
340   if (File != "-" && !sys::fs::exists(File)) {
341     reportError(File, readobj_error::file_not_found);
342     return;
343   }
344 
345   // Attempt to open the binary.
346   ErrorOr<OwningBinary<Binary>> BinaryOrErr = createBinary(File);
347   if (std::error_code EC = BinaryOrErr.getError()) {
348     reportError(File, EC);
349     return;
350   }
351   Binary &Binary = *BinaryOrErr.get().getBinary();
352 
353   if (Archive *Arc = dyn_cast<Archive>(&Binary))
354     dumpArchive(Arc);
355   else if (MachOUniversalBinary *UBinary =
356                dyn_cast<MachOUniversalBinary>(&Binary))
357     dumpMachOUniversalBinary(UBinary);
358   else if (ObjectFile *Obj = dyn_cast<ObjectFile>(&Binary))
359     dumpObject(Obj);
360   else
361     reportError(File, readobj_error::unrecognized_file_format);
362 }
363 
364 
365 int main(int argc, const char *argv[]) {
366   sys::PrintStackTraceOnErrorSignal();
367   PrettyStackTraceProgram X(argc, argv);
368   llvm_shutdown_obj Y;
369 
370   // Initialize targets.
371   llvm::InitializeAllTargetInfos();
372 
373   // Register the target printer for --version.
374   cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion);
375 
376   cl::ParseCommandLineOptions(argc, argv, "LLVM Object Reader\n");
377 
378   // Default to stdin if no filename is specified.
379   if (opts::InputFilenames.size() == 0)
380     opts::InputFilenames.push_back("-");
381 
382   std::for_each(opts::InputFilenames.begin(), opts::InputFilenames.end(),
383                 dumpInput);
384 
385   return ReturnValue;
386 }
387