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/ObjectFile.h"
29 #include "llvm/Support/Casting.h"
30 #include "llvm/Support/CommandLine.h"
31 #include "llvm/Support/DataTypes.h"
32 #include "llvm/Support/Debug.h"
33 #include "llvm/Support/FileSystem.h"
34 #include "llvm/Support/ManagedStatic.h"
35 #include "llvm/Support/PrettyStackTrace.h"
36 #include "llvm/Support/Signals.h"
37 #include "llvm/Support/TargetRegistry.h"
38 #include "llvm/Support/TargetSelect.h"
39 #include <string>
40 #include <system_error>
41 
42 
43 using namespace llvm;
44 using namespace llvm::object;
45 
46 namespace opts {
47   cl::list<std::string> InputFilenames(cl::Positional,
48     cl::desc("<input object files>"),
49     cl::ZeroOrMore);
50 
51   // -file-headers, -h
52   cl::opt<bool> FileHeaders("file-headers",
53     cl::desc("Display file headers "));
54   cl::alias FileHeadersShort("h",
55     cl::desc("Alias for --file-headers"),
56     cl::aliasopt(FileHeaders));
57 
58   // -sections, -s
59   cl::opt<bool> Sections("sections",
60     cl::desc("Display all sections."));
61   cl::alias SectionsShort("s",
62     cl::desc("Alias for --sections"),
63     cl::aliasopt(Sections));
64 
65   // -section-relocations, -sr
66   cl::opt<bool> SectionRelocations("section-relocations",
67     cl::desc("Display relocations for each section shown."));
68   cl::alias SectionRelocationsShort("sr",
69     cl::desc("Alias for --section-relocations"),
70     cl::aliasopt(SectionRelocations));
71 
72   // -section-symbols, -st
73   cl::opt<bool> SectionSymbols("section-symbols",
74     cl::desc("Display symbols for each section shown."));
75   cl::alias SectionSymbolsShort("st",
76     cl::desc("Alias for --section-symbols"),
77     cl::aliasopt(SectionSymbols));
78 
79   // -section-data, -sd
80   cl::opt<bool> SectionData("section-data",
81     cl::desc("Display section data for each section shown."));
82   cl::alias SectionDataShort("sd",
83     cl::desc("Alias for --section-data"),
84     cl::aliasopt(SectionData));
85 
86   // -relocations, -r
87   cl::opt<bool> Relocations("relocations",
88     cl::desc("Display the relocation entries in the file"));
89   cl::alias RelocationsShort("r",
90     cl::desc("Alias for --relocations"),
91     cl::aliasopt(Relocations));
92 
93   // -symbols, -t
94   cl::opt<bool> Symbols("symbols",
95     cl::desc("Display the symbol table"));
96   cl::alias SymbolsShort("t",
97     cl::desc("Alias for --symbols"),
98     cl::aliasopt(Symbols));
99 
100   // -dyn-symbols, -dt
101   cl::opt<bool> DynamicSymbols("dyn-symbols",
102     cl::desc("Display the dynamic symbol table"));
103   cl::alias DynamicSymbolsShort("dt",
104     cl::desc("Alias for --dyn-symbols"),
105     cl::aliasopt(DynamicSymbols));
106 
107   // -unwind, -u
108   cl::opt<bool> UnwindInfo("unwind",
109     cl::desc("Display unwind information"));
110   cl::alias UnwindInfoShort("u",
111     cl::desc("Alias for --unwind"),
112     cl::aliasopt(UnwindInfo));
113 
114   // -dynamic-table
115   cl::opt<bool> DynamicTable("dynamic-table",
116     cl::desc("Display the ELF .dynamic section table"));
117 
118   // -needed-libs
119   cl::opt<bool> NeededLibraries("needed-libs",
120     cl::desc("Display the needed libraries"));
121 
122   // -program-headers
123   cl::opt<bool> ProgramHeaders("program-headers",
124     cl::desc("Display ELF program headers"));
125 
126   // -expand-relocs
127   cl::opt<bool> ExpandRelocs("expand-relocs",
128     cl::desc("Expand each shown relocation to multiple lines"));
129 
130   // -codeview
131   cl::opt<bool> CodeView("codeview",
132                          cl::desc("Display CodeView debug information"));
133 
134   // -codeview-subsection-bytes
135   cl::opt<bool> CodeViewSubsectionBytes(
136       "codeview-subsection-bytes",
137       cl::desc("Dump raw contents of codeview debug sections and records"));
138 
139   // -arm-attributes, -a
140   cl::opt<bool> ARMAttributes("arm-attributes",
141                               cl::desc("Display the ARM attributes section"));
142   cl::alias ARMAttributesShort("-a", cl::desc("Alias for --arm-attributes"),
143                                cl::aliasopt(ARMAttributes));
144 
145   // -mips-plt-got
146   cl::opt<bool>
147   MipsPLTGOT("mips-plt-got",
148              cl::desc("Display the MIPS GOT and PLT GOT sections"));
149 
150   // -coff-imports
151   cl::opt<bool>
152   COFFImports("coff-imports", cl::desc("Display the PE/COFF import table"));
153 
154   // -coff-exports
155   cl::opt<bool>
156   COFFExports("coff-exports", cl::desc("Display the PE/COFF export table"));
157 
158   // -coff-directives
159   cl::opt<bool>
160   COFFDirectives("coff-directives",
161                  cl::desc("Display the PE/COFF .drectve section"));
162 
163   // -coff-basereloc
164   cl::opt<bool>
165   COFFBaseRelocs("coff-basereloc",
166                  cl::desc("Display the PE/COFF .reloc section"));
167 } // namespace opts
168 
169 static int ReturnValue = EXIT_SUCCESS;
170 
171 namespace llvm {
172 
173 bool error(std::error_code EC) {
174   if (!EC)
175     return false;
176 
177   ReturnValue = EXIT_FAILURE;
178   outs() << "\nError reading file: " << EC.message() << ".\n";
179   outs().flush();
180   return true;
181 }
182 
183 bool relocAddressLess(RelocationRef a, RelocationRef b) {
184   uint64_t a_addr, b_addr;
185   if (error(a.getOffset(a_addr))) exit(ReturnValue);
186   if (error(b.getOffset(b_addr))) exit(ReturnValue);
187   return a_addr < b_addr;
188 }
189 
190 } // namespace llvm
191 
192 static void reportError(StringRef Input, std::error_code EC) {
193   if (Input == "-")
194     Input = "<stdin>";
195 
196   errs() << Input << ": " << EC.message() << "\n";
197   errs().flush();
198   ReturnValue = EXIT_FAILURE;
199 }
200 
201 static void reportError(StringRef Input, StringRef Message) {
202   if (Input == "-")
203     Input = "<stdin>";
204 
205   errs() << Input << ": " << Message << "\n";
206   ReturnValue = EXIT_FAILURE;
207 }
208 
209 static bool isMipsArch(unsigned Arch) {
210   switch (Arch) {
211   case llvm::Triple::mips:
212   case llvm::Triple::mipsel:
213   case llvm::Triple::mips64:
214   case llvm::Triple::mips64el:
215     return true;
216   default:
217     return false;
218   }
219 }
220 
221 /// @brief Creates an format-specific object file dumper.
222 static std::error_code createDumper(const ObjectFile *Obj, StreamWriter &Writer,
223                                     std::unique_ptr<ObjDumper> &Result) {
224   if (!Obj)
225     return readobj_error::unsupported_file_format;
226 
227   if (Obj->isCOFF())
228     return createCOFFDumper(Obj, Writer, Result);
229   if (Obj->isELF())
230     return createELFDumper(Obj, Writer, Result);
231   if (Obj->isMachO())
232     return createMachODumper(Obj, Writer, Result);
233 
234   return readobj_error::unsupported_obj_file_format;
235 }
236 
237 static StringRef getLoadName(const ObjectFile *Obj) {
238   if (auto *ELF = dyn_cast<ELF32LEObjectFile>(Obj))
239     return ELF->getLoadName();
240   if (auto *ELF = dyn_cast<ELF64LEObjectFile>(Obj))
241     return ELF->getLoadName();
242   if (auto *ELF = dyn_cast<ELF32BEObjectFile>(Obj))
243     return ELF->getLoadName();
244   if (auto *ELF = dyn_cast<ELF64BEObjectFile>(Obj))
245     return ELF->getLoadName();
246   llvm_unreachable("Not ELF");
247 }
248 
249 /// @brief Dumps the specified object file.
250 static void dumpObject(const ObjectFile *Obj) {
251   StreamWriter Writer(outs());
252   std::unique_ptr<ObjDumper> Dumper;
253   if (std::error_code EC = createDumper(Obj, Writer, Dumper)) {
254     reportError(Obj->getFileName(), EC);
255     return;
256   }
257 
258   outs() << '\n';
259   outs() << "File: " << Obj->getFileName() << "\n";
260   outs() << "Format: " << Obj->getFileFormatName() << "\n";
261   outs() << "Arch: "
262          << Triple::getArchTypeName((llvm::Triple::ArchType)Obj->getArch())
263          << "\n";
264   outs() << "AddressSize: " << (8*Obj->getBytesInAddress()) << "bit\n";
265   if (Obj->isELF())
266     outs() << "LoadName: " << getLoadName(Obj) << "\n";
267 
268   if (opts::FileHeaders)
269     Dumper->printFileHeaders();
270   if (opts::Sections)
271     Dumper->printSections();
272   if (opts::Relocations)
273     Dumper->printRelocations();
274   if (opts::Symbols)
275     Dumper->printSymbols();
276   if (opts::DynamicSymbols)
277     Dumper->printDynamicSymbols();
278   if (opts::UnwindInfo)
279     Dumper->printUnwindInfo();
280   if (opts::DynamicTable)
281     Dumper->printDynamicTable();
282   if (opts::NeededLibraries)
283     Dumper->printNeededLibraries();
284   if (opts::ProgramHeaders)
285     Dumper->printProgramHeaders();
286   if (Obj->getArch() == llvm::Triple::arm && Obj->isELF())
287     if (opts::ARMAttributes)
288       Dumper->printAttributes();
289   if (isMipsArch(Obj->getArch()) && Obj->isELF())
290     if (opts::MipsPLTGOT)
291       Dumper->printMipsPLTGOT();
292   if (opts::COFFImports)
293     Dumper->printCOFFImports();
294   if (opts::COFFExports)
295     Dumper->printCOFFExports();
296   if (opts::COFFDirectives)
297     Dumper->printCOFFDirectives();
298   if (opts::COFFBaseRelocs)
299     Dumper->printCOFFBaseReloc();
300 }
301 
302 
303 /// @brief Dumps each object file in \a Arc;
304 static void dumpArchive(const Archive *Arc) {
305   for (Archive::child_iterator ArcI = Arc->child_begin(),
306                                ArcE = Arc->child_end();
307                                ArcI != ArcE; ++ArcI) {
308     ErrorOr<std::unique_ptr<Binary>> ChildOrErr = ArcI->getAsBinary();
309     if (std::error_code EC = ChildOrErr.getError()) {
310       // Ignore non-object files.
311       if (EC != object_error::invalid_file_type)
312         reportError(Arc->getFileName(), EC.message());
313       continue;
314     }
315 
316     if (ObjectFile *Obj = dyn_cast<ObjectFile>(&*ChildOrErr.get()))
317       dumpObject(Obj);
318     else
319       reportError(Arc->getFileName(), readobj_error::unrecognized_file_format);
320   }
321 }
322 
323 
324 /// @brief Opens \a File and dumps it.
325 static void dumpInput(StringRef File) {
326   // If file isn't stdin, check that it exists.
327   if (File != "-" && !sys::fs::exists(File)) {
328     reportError(File, readobj_error::file_not_found);
329     return;
330   }
331 
332   // Attempt to open the binary.
333   ErrorOr<OwningBinary<Binary>> BinaryOrErr = createBinary(File);
334   if (std::error_code EC = BinaryOrErr.getError()) {
335     reportError(File, EC);
336     return;
337   }
338   Binary &Binary = *BinaryOrErr.get().getBinary();
339 
340   if (Archive *Arc = dyn_cast<Archive>(&Binary))
341     dumpArchive(Arc);
342   else if (ObjectFile *Obj = dyn_cast<ObjectFile>(&Binary))
343     dumpObject(Obj);
344   else
345     reportError(File, readobj_error::unrecognized_file_format);
346 }
347 
348 
349 int main(int argc, const char *argv[]) {
350   sys::PrintStackTraceOnErrorSignal();
351   PrettyStackTraceProgram X(argc, argv);
352   llvm_shutdown_obj Y;
353 
354   // Initialize targets.
355   llvm::InitializeAllTargetInfos();
356 
357   // Register the target printer for --version.
358   cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion);
359 
360   cl::ParseCommandLineOptions(argc, argv, "LLVM Object Reader\n");
361 
362   // Default to stdin if no filename is specified.
363   if (opts::InputFilenames.size() == 0)
364     opts::InputFilenames.push_back("-");
365 
366   std::for_each(opts::InputFilenames.begin(), opts::InputFilenames.end(),
367                 dumpInput);
368 
369   return ReturnValue;
370 }
371