1//===------ utils/elf2yaml.cpp - obj2yaml conversion tool -------*- C++ -*-===//
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#include "Error.h"
11#include "obj2yaml.h"
12#include "llvm/ADT/STLExtras.h"
13#include "llvm/Object/ELFObjectFile.h"
14#include "llvm/Object/ELFYAML.h"
15#include "llvm/Support/ErrorHandling.h"
16#include "llvm/Support/YAMLTraits.h"
17
18using namespace llvm;
19
20namespace {
21
22template <class ELFT>
23class ELFDumper {
24  typedef object::Elf_Sym_Impl<ELFT> Elf_Sym;
25  typedef typename object::ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
26  typedef typename object::ELFFile<ELFT>::Elf_Word Elf_Word;
27
28  const object::ELFFile<ELFT> &Obj;
29  ArrayRef<Elf_Word> ShndxTable;
30
31  std::error_code dumpSymbol(const Elf_Sym *Sym, const Elf_Shdr *SymTab,
32                             StringRef StrTable, ELFYAML::Symbol &S);
33  std::error_code dumpCommonSection(const Elf_Shdr *Shdr, ELFYAML::Section &S);
34  std::error_code dumpCommonRelocationSection(const Elf_Shdr *Shdr,
35                                              ELFYAML::RelocationSection &S);
36  template <class RelT>
37  std::error_code dumpRelocation(const RelT *Rel, const Elf_Shdr *SymTab,
38                                 ELFYAML::Relocation &R);
39
40  ErrorOr<ELFYAML::RelocationSection *> dumpRelSection(const Elf_Shdr *Shdr);
41  ErrorOr<ELFYAML::RelocationSection *> dumpRelaSection(const Elf_Shdr *Shdr);
42  ErrorOr<ELFYAML::RawContentSection *>
43  dumpContentSection(const Elf_Shdr *Shdr);
44  ErrorOr<ELFYAML::NoBitsSection *> dumpNoBitsSection(const Elf_Shdr *Shdr);
45  ErrorOr<ELFYAML::Group *> dumpGroup(const Elf_Shdr *Shdr);
46  ErrorOr<ELFYAML::MipsABIFlags *> dumpMipsABIFlags(const Elf_Shdr *Shdr);
47
48public:
49  ELFDumper(const object::ELFFile<ELFT> &O);
50  ErrorOr<ELFYAML::Object *> dump();
51};
52
53}
54
55template <class ELFT>
56ELFDumper<ELFT>::ELFDumper(const object::ELFFile<ELFT> &O)
57    : Obj(O) {}
58
59template <class ELFT>
60ErrorOr<ELFYAML::Object *> ELFDumper<ELFT>::dump() {
61  auto Y = make_unique<ELFYAML::Object>();
62
63  // Dump header
64  Y->Header.Class = ELFYAML::ELF_ELFCLASS(Obj.getHeader()->getFileClass());
65  Y->Header.Data = ELFYAML::ELF_ELFDATA(Obj.getHeader()->getDataEncoding());
66  Y->Header.OSABI = Obj.getHeader()->e_ident[ELF::EI_OSABI];
67  Y->Header.Type = Obj.getHeader()->e_type;
68  Y->Header.Machine = Obj.getHeader()->e_machine;
69  Y->Header.Flags = Obj.getHeader()->e_flags;
70  Y->Header.Entry = Obj.getHeader()->e_entry;
71
72  const Elf_Shdr *Symtab = nullptr;
73
74  // Dump sections
75  for (const Elf_Shdr &Sec : Obj.sections()) {
76    switch (Sec.sh_type) {
77    case ELF::SHT_NULL:
78    case ELF::SHT_DYNSYM:
79    case ELF::SHT_STRTAB:
80      // Do not dump these sections.
81      break;
82    case ELF::SHT_SYMTAB:
83      Symtab = &Sec;
84      break;
85    case ELF::SHT_SYMTAB_SHNDX: {
86      ErrorOr<ArrayRef<Elf_Word>> TableOrErr = Obj.getSHNDXTable(Sec);
87      if (std::error_code EC = TableOrErr.getError())
88        return EC;
89      ShndxTable = *TableOrErr;
90      break;
91    }
92    case ELF::SHT_RELA: {
93      ErrorOr<ELFYAML::RelocationSection *> S = dumpRelaSection(&Sec);
94      if (std::error_code EC = S.getError())
95        return EC;
96      Y->Sections.push_back(std::unique_ptr<ELFYAML::Section>(S.get()));
97      break;
98    }
99    case ELF::SHT_REL: {
100      ErrorOr<ELFYAML::RelocationSection *> S = dumpRelSection(&Sec);
101      if (std::error_code EC = S.getError())
102        return EC;
103      Y->Sections.push_back(std::unique_ptr<ELFYAML::Section>(S.get()));
104      break;
105    }
106    case ELF::SHT_GROUP: {
107      ErrorOr<ELFYAML::Group *> G = dumpGroup(&Sec);
108      if (std::error_code EC = G.getError())
109        return EC;
110      Y->Sections.push_back(std::unique_ptr<ELFYAML::Section>(G.get()));
111      break;
112    }
113    case ELF::SHT_MIPS_ABIFLAGS: {
114      ErrorOr<ELFYAML::MipsABIFlags *> G = dumpMipsABIFlags(&Sec);
115      if (std::error_code EC = G.getError())
116        return EC;
117      Y->Sections.push_back(std::unique_ptr<ELFYAML::Section>(G.get()));
118      break;
119    }
120    case ELF::SHT_NOBITS: {
121      ErrorOr<ELFYAML::NoBitsSection *> S = dumpNoBitsSection(&Sec);
122      if (std::error_code EC = S.getError())
123        return EC;
124      Y->Sections.push_back(std::unique_ptr<ELFYAML::Section>(S.get()));
125      break;
126    }
127    default: {
128      ErrorOr<ELFYAML::RawContentSection *> S = dumpContentSection(&Sec);
129      if (std::error_code EC = S.getError())
130        return EC;
131      Y->Sections.push_back(std::unique_ptr<ELFYAML::Section>(S.get()));
132    }
133    }
134  }
135
136  // Dump symbols
137  ErrorOr<StringRef> StrTableOrErr = Obj.getStringTableForSymtab(*Symtab);
138  if (std::error_code EC = StrTableOrErr.getError())
139    return EC;
140  StringRef StrTable = *StrTableOrErr;
141
142  bool IsFirstSym = true;
143  for (const Elf_Sym &Sym : Obj.symbols(Symtab)) {
144    if (IsFirstSym) {
145      IsFirstSym = false;
146      continue;
147    }
148
149    ELFYAML::Symbol S;
150    if (std::error_code EC =
151            ELFDumper<ELFT>::dumpSymbol(&Sym, Symtab, StrTable, S))
152      return EC;
153
154    switch (Sym.getBinding())
155    {
156    case ELF::STB_LOCAL:
157      Y->Symbols.Local.push_back(S);
158      break;
159    case ELF::STB_GLOBAL:
160      Y->Symbols.Global.push_back(S);
161      break;
162    case ELF::STB_WEAK:
163      Y->Symbols.Weak.push_back(S);
164      break;
165    default:
166      llvm_unreachable("Unknown ELF symbol binding");
167    }
168  }
169
170  return Y.release();
171}
172
173template <class ELFT>
174std::error_code
175ELFDumper<ELFT>::dumpSymbol(const Elf_Sym *Sym, const Elf_Shdr *SymTab,
176                            StringRef StrTable, ELFYAML::Symbol &S) {
177  S.Type = Sym->getType();
178  S.Value = Sym->st_value;
179  S.Size = Sym->st_size;
180  S.Other = Sym->st_other;
181
182  ErrorOr<StringRef> NameOrErr = Sym->getName(StrTable);
183  if (std::error_code EC = NameOrErr.getError())
184    return EC;
185  S.Name = NameOrErr.get();
186
187  ErrorOr<const Elf_Shdr *> ShdrOrErr = Obj.getSection(Sym, SymTab, ShndxTable);
188  if (std::error_code EC = ShdrOrErr.getError())
189    return EC;
190  const Elf_Shdr *Shdr = *ShdrOrErr;
191  if (!Shdr)
192    return obj2yaml_error::success;
193
194  NameOrErr = Obj.getSectionName(Shdr);
195  if (std::error_code EC = NameOrErr.getError())
196    return EC;
197  S.Section = NameOrErr.get();
198
199  return obj2yaml_error::success;
200}
201
202template <class ELFT>
203template <class RelT>
204std::error_code ELFDumper<ELFT>::dumpRelocation(const RelT *Rel,
205                                                const Elf_Shdr *SymTab,
206                                                ELFYAML::Relocation &R) {
207  R.Type = Rel->getType(Obj.isMips64EL());
208  R.Offset = Rel->r_offset;
209  R.Addend = 0;
210
211  const Elf_Sym *Sym = Obj.getRelocationSymbol(Rel, SymTab);
212  ErrorOr<const Elf_Shdr *> StrTabSec = Obj.getSection(SymTab->sh_link);
213  if (std::error_code EC = StrTabSec.getError())
214    return EC;
215  ErrorOr<StringRef> StrTabOrErr = Obj.getStringTable(*StrTabSec);
216  if (std::error_code EC = StrTabOrErr.getError())
217    return EC;
218  StringRef StrTab = *StrTabOrErr;
219
220  ErrorOr<StringRef> NameOrErr = Sym->getName(StrTab);
221  if (std::error_code EC = NameOrErr.getError())
222    return EC;
223  R.Symbol = NameOrErr.get();
224
225  return obj2yaml_error::success;
226}
227
228template <class ELFT>
229std::error_code ELFDumper<ELFT>::dumpCommonSection(const Elf_Shdr *Shdr,
230                                                   ELFYAML::Section &S) {
231  S.Type = Shdr->sh_type;
232  S.Flags = Shdr->sh_flags;
233  S.Address = Shdr->sh_addr;
234  S.AddressAlign = Shdr->sh_addralign;
235
236  ErrorOr<StringRef> NameOrErr = Obj.getSectionName(Shdr);
237  if (std::error_code EC = NameOrErr.getError())
238    return EC;
239  S.Name = NameOrErr.get();
240
241  if (Shdr->sh_link != ELF::SHN_UNDEF) {
242    ErrorOr<const Elf_Shdr *> LinkSection = Obj.getSection(Shdr->sh_link);
243    if (std::error_code EC = LinkSection.getError())
244      return EC;
245    NameOrErr = Obj.getSectionName(*LinkSection);
246    if (std::error_code EC = NameOrErr.getError())
247      return EC;
248    S.Link = NameOrErr.get();
249  }
250
251  return obj2yaml_error::success;
252}
253
254template <class ELFT>
255std::error_code
256ELFDumper<ELFT>::dumpCommonRelocationSection(const Elf_Shdr *Shdr,
257                                             ELFYAML::RelocationSection &S) {
258  if (std::error_code EC = dumpCommonSection(Shdr, S))
259    return EC;
260
261  ErrorOr<const Elf_Shdr *> InfoSection = Obj.getSection(Shdr->sh_info);
262  if (std::error_code EC = InfoSection.getError())
263    return EC;
264
265  ErrorOr<StringRef> NameOrErr = Obj.getSectionName(*InfoSection);
266  if (std::error_code EC = NameOrErr.getError())
267    return EC;
268  S.Info = NameOrErr.get();
269
270  return obj2yaml_error::success;
271}
272
273template <class ELFT>
274ErrorOr<ELFYAML::RelocationSection *>
275ELFDumper<ELFT>::dumpRelSection(const Elf_Shdr *Shdr) {
276  assert(Shdr->sh_type == ELF::SHT_REL && "Section type is not SHT_REL");
277  auto S = make_unique<ELFYAML::RelocationSection>();
278
279  if (std::error_code EC = dumpCommonRelocationSection(Shdr, *S))
280    return EC;
281
282  ErrorOr<const Elf_Shdr *> SymTabOrErr = Obj.getSection(Shdr->sh_link);
283  if (std::error_code EC = SymTabOrErr.getError())
284    return EC;
285  const Elf_Shdr *SymTab = *SymTabOrErr;
286
287  for (auto RI = Obj.rel_begin(Shdr), RE = Obj.rel_end(Shdr); RI != RE; ++RI) {
288    ELFYAML::Relocation R;
289    if (std::error_code EC = dumpRelocation(&*RI, SymTab, R))
290      return EC;
291    S->Relocations.push_back(R);
292  }
293
294  return S.release();
295}
296
297template <class ELFT>
298ErrorOr<ELFYAML::RelocationSection *>
299ELFDumper<ELFT>::dumpRelaSection(const Elf_Shdr *Shdr) {
300  assert(Shdr->sh_type == ELF::SHT_RELA && "Section type is not SHT_RELA");
301  auto S = make_unique<ELFYAML::RelocationSection>();
302
303  if (std::error_code EC = dumpCommonRelocationSection(Shdr, *S))
304    return EC;
305
306  ErrorOr<const Elf_Shdr *> SymTabOrErr = Obj.getSection(Shdr->sh_link);
307  if (std::error_code EC = SymTabOrErr.getError())
308    return EC;
309  const Elf_Shdr *SymTab = *SymTabOrErr;
310
311  for (auto RI = Obj.rela_begin(Shdr), RE = Obj.rela_end(Shdr); RI != RE;
312       ++RI) {
313    ELFYAML::Relocation R;
314    if (std::error_code EC = dumpRelocation(&*RI, SymTab, R))
315      return EC;
316    R.Addend = RI->r_addend;
317    S->Relocations.push_back(R);
318  }
319
320  return S.release();
321}
322
323template <class ELFT>
324ErrorOr<ELFYAML::RawContentSection *>
325ELFDumper<ELFT>::dumpContentSection(const Elf_Shdr *Shdr) {
326  auto S = make_unique<ELFYAML::RawContentSection>();
327
328  if (std::error_code EC = dumpCommonSection(Shdr, *S))
329    return EC;
330
331  ErrorOr<ArrayRef<uint8_t>> ContentOrErr = Obj.getSectionContents(Shdr);
332  if (std::error_code EC = ContentOrErr.getError())
333    return EC;
334  S->Content = yaml::BinaryRef(ContentOrErr.get());
335  S->Size = S->Content.binary_size();
336
337  return S.release();
338}
339
340template <class ELFT>
341ErrorOr<ELFYAML::NoBitsSection *>
342ELFDumper<ELFT>::dumpNoBitsSection(const Elf_Shdr *Shdr) {
343  auto S = make_unique<ELFYAML::NoBitsSection>();
344
345  if (std::error_code EC = dumpCommonSection(Shdr, *S))
346    return EC;
347  S->Size = Shdr->sh_size;
348
349  return S.release();
350}
351
352template <class ELFT>
353ErrorOr<ELFYAML::Group *> ELFDumper<ELFT>::dumpGroup(const Elf_Shdr *Shdr) {
354  auto S = make_unique<ELFYAML::Group>();
355
356  if (std::error_code EC = dumpCommonSection(Shdr, *S))
357    return EC;
358  // Get sh_info which is the signature.
359  ErrorOr<const Elf_Shdr *> SymtabOrErr = Obj.getSection(Shdr->sh_link);
360  if (std::error_code EC = SymtabOrErr.getError())
361    return EC;
362  const Elf_Shdr *Symtab = *SymtabOrErr;
363  const Elf_Sym *symbol = Obj.getSymbol(Symtab, Shdr->sh_info);
364  ErrorOr<StringRef> StrTabOrErr = Obj.getStringTableForSymtab(*Symtab);
365  if (std::error_code EC = StrTabOrErr.getError())
366    return EC;
367  StringRef StrTab = *StrTabOrErr;
368  auto sectionContents = Obj.getSectionContents(Shdr);
369  if (std::error_code ec = sectionContents.getError())
370    return ec;
371  ErrorOr<StringRef> symbolName = symbol->getName(StrTab);
372  if (std::error_code EC = symbolName.getError())
373    return EC;
374  S->Info = *symbolName;
375  const Elf_Word *groupMembers =
376      reinterpret_cast<const Elf_Word *>(sectionContents->data());
377  const long count = (Shdr->sh_size) / sizeof(Elf_Word);
378  ELFYAML::SectionOrType s;
379  for (int i = 0; i < count; i++) {
380    if (groupMembers[i] == llvm::ELF::GRP_COMDAT) {
381      s.sectionNameOrType = "GRP_COMDAT";
382    } else {
383      ErrorOr<const Elf_Shdr *> sHdr = Obj.getSection(groupMembers[i]);
384      if (std::error_code EC = sHdr.getError())
385        return EC;
386      ErrorOr<StringRef> sectionName = Obj.getSectionName(*sHdr);
387      if (std::error_code ec = sectionName.getError())
388        return ec;
389      s.sectionNameOrType = *sectionName;
390    }
391    S->Members.push_back(s);
392  }
393  return S.release();
394}
395
396template <class ELFT>
397ErrorOr<ELFYAML::MipsABIFlags *>
398ELFDumper<ELFT>::dumpMipsABIFlags(const Elf_Shdr *Shdr) {
399  assert(Shdr->sh_type == ELF::SHT_MIPS_ABIFLAGS &&
400         "Section type is not SHT_MIPS_ABIFLAGS");
401  auto S = make_unique<ELFYAML::MipsABIFlags>();
402  if (std::error_code EC = dumpCommonSection(Shdr, *S))
403    return EC;
404
405  ErrorOr<ArrayRef<uint8_t>> ContentOrErr = Obj.getSectionContents(Shdr);
406  if (std::error_code EC = ContentOrErr.getError())
407    return EC;
408
409  auto *Flags = reinterpret_cast<const object::Elf_Mips_ABIFlags<ELFT> *>(
410      ContentOrErr.get().data());
411  S->Version = Flags->version;
412  S->ISALevel = Flags->isa_level;
413  S->ISARevision = Flags->isa_rev;
414  S->GPRSize = Flags->gpr_size;
415  S->CPR1Size = Flags->cpr1_size;
416  S->CPR2Size = Flags->cpr2_size;
417  S->FpABI = Flags->fp_abi;
418  S->ISAExtension = Flags->isa_ext;
419  S->ASEs = Flags->ases;
420  S->Flags1 = Flags->flags1;
421  S->Flags2 = Flags->flags2;
422  return S.release();
423}
424
425template <class ELFT>
426static std::error_code elf2yaml(raw_ostream &Out,
427                                const object::ELFFile<ELFT> &Obj) {
428  ELFDumper<ELFT> Dumper(Obj);
429  ErrorOr<ELFYAML::Object *> YAMLOrErr = Dumper.dump();
430  if (std::error_code EC = YAMLOrErr.getError())
431    return EC;
432
433  std::unique_ptr<ELFYAML::Object> YAML(YAMLOrErr.get());
434  yaml::Output Yout(Out);
435  Yout << *YAML;
436
437  return std::error_code();
438}
439
440std::error_code elf2yaml(raw_ostream &Out, const object::ObjectFile &Obj) {
441  if (const auto *ELFObj = dyn_cast<object::ELF32LEObjectFile>(&Obj))
442    return elf2yaml(Out, *ELFObj->getELFFile());
443
444  if (const auto *ELFObj = dyn_cast<object::ELF32BEObjectFile>(&Obj))
445    return elf2yaml(Out, *ELFObj->getELFFile());
446
447  if (const auto *ELFObj = dyn_cast<object::ELF64LEObjectFile>(&Obj))
448    return elf2yaml(Out, *ELFObj->getELFFile());
449
450  if (const auto *ELFObj = dyn_cast<object::ELF64BEObjectFile>(&Obj))
451    return elf2yaml(Out, *ELFObj->getELFFile());
452
453  return obj2yaml_error::unsupported_obj_file_format;
454}
455