1//===- ELFDynObjReader.cpp ------------------------------------------------===//
2//
3//                     The MCLinker Project
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9#include "mcld/LD/ELFDynObjReader.h"
10
11#include "mcld/IRBuilder.h"
12#include "mcld/LinkerConfig.h"
13#include "mcld/LD/ELFReader.h"
14#include "mcld/LD/LDContext.h"
15#include "mcld/MC/Input.h"
16#include "mcld/Support/MemoryArea.h"
17#include "mcld/Target/GNULDBackend.h"
18
19#include <llvm/ADT/StringRef.h>
20#include <llvm/ADT/Twine.h>
21#include <llvm/Support/ErrorHandling.h>
22
23#include <string>
24
25namespace mcld {
26
27//===----------------------------------------------------------------------===//
28// ELFDynObjReader
29//===----------------------------------------------------------------------===//
30ELFDynObjReader::ELFDynObjReader(GNULDBackend& pBackend,
31                                 IRBuilder& pBuilder,
32                                 const LinkerConfig& pConfig)
33    : DynObjReader(), m_pELFReader(0), m_Builder(pBuilder) {
34  if (pConfig.targets().is32Bits() && pConfig.targets().isLittleEndian())
35    m_pELFReader = new ELFReader<32, true>(pBackend);
36  else if (pConfig.targets().is64Bits() && pConfig.targets().isLittleEndian())
37    m_pELFReader = new ELFReader<64, true>(pBackend);
38}
39
40ELFDynObjReader::~ELFDynObjReader() {
41  delete m_pELFReader;
42}
43
44/// isMyFormat
45bool ELFDynObjReader::isMyFormat(Input& pInput, bool& pContinue) const {
46  assert(pInput.hasMemArea());
47
48  // Don't warning about the frequently requests.
49  // MemoryArea has a list of cache to handle this.
50  size_t hdr_size = m_pELFReader->getELFHeaderSize();
51  if (pInput.memArea()->size() < hdr_size)
52    return false;
53
54  llvm::StringRef region =
55      pInput.memArea()->request(pInput.fileOffset(), hdr_size);
56
57  const char* ELF_hdr = region.begin();
58  bool result = true;
59  if (!m_pELFReader->isELF(ELF_hdr)) {
60    pContinue = true;
61    result = false;
62  } else if (Input::DynObj != m_pELFReader->fileType(ELF_hdr)) {
63    pContinue = true;
64    result = false;
65  } else if (!m_pELFReader->isMyEndian(ELF_hdr)) {
66    pContinue = false;
67    result = false;
68  } else if (!m_pELFReader->isMyMachine(ELF_hdr)) {
69    pContinue = false;
70    result = false;
71  }
72  return result;
73}
74
75/// readHeader
76bool ELFDynObjReader::readHeader(Input& pInput) {
77  assert(pInput.hasMemArea());
78
79  size_t hdr_size = m_pELFReader->getELFHeaderSize();
80  llvm::StringRef region =
81      pInput.memArea()->request(pInput.fileOffset(), hdr_size);
82  const char* ELF_hdr = region.begin();
83
84  bool shdr_result = m_pELFReader->readSectionHeaders(pInput, ELF_hdr);
85
86  // read .dynamic to get the correct SONAME
87  bool dyn_result = m_pELFReader->readDynamic(pInput);
88
89  return (shdr_result && dyn_result);
90}
91
92/// readSymbols
93bool ELFDynObjReader::readSymbols(Input& pInput) {
94  assert(pInput.hasMemArea());
95
96  LDSection* symtab_shdr = pInput.context()->getSection(".dynsym");
97  if (symtab_shdr == NULL) {
98    note(diag::note_has_no_symtab) << pInput.name() << pInput.path()
99                                   << ".dynsym";
100    return true;
101  }
102
103  LDSection* strtab_shdr = symtab_shdr->getLink();
104  if (strtab_shdr == NULL) {
105    fatal(diag::fatal_cannot_read_strtab) << pInput.name() << pInput.path()
106                                          << ".dynsym";
107    return false;
108  }
109
110  llvm::StringRef symtab_region = pInput.memArea()->request(
111      pInput.fileOffset() + symtab_shdr->offset(), symtab_shdr->size());
112
113  llvm::StringRef strtab_region = pInput.memArea()->request(
114      pInput.fileOffset() + strtab_shdr->offset(), strtab_shdr->size());
115  const char* strtab = strtab_region.begin();
116  bool result =
117      m_pELFReader->readSymbols(pInput, m_Builder, symtab_region, strtab);
118  return result;
119}
120
121}  // namespace mcld
122