ELFDynObjReader.cpp revision 22add6ff3426df1a85089fe6a6e1597ee3b6f300 
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 <llvm/ADT/Twine.h>
10#include <llvm/ADT/OwningPtr.h>
11#include <llvm/Support/ErrorHandling.h>
12
13#include <mcld/LD/ELFDynObjReader.h>
14#include <mcld/LD/ELFReader.h>
15#include <mcld/MC/MCLDInput.h>
16#include <mcld/Fragment/FragmentLinker.h>
17#include <mcld/Target/GNULDBackend.h>
18#include <mcld/Support/MemoryRegion.h>
19
20#include <string>
21
22using namespace mcld;
23
24//===----------------------------------------------------------------------===//
25// ELFDynObjReader
26//===----------------------------------------------------------------------===//
27ELFDynObjReader::ELFDynObjReader(GNULDBackend& pBackend, FragmentLinker& pLinker)
28  : DynObjReader(),
29    m_pELFReader(0),
30    m_Linker(pLinker) {
31  if (32 == pBackend.bitclass() && pBackend.isLittleEndian())
32    m_pELFReader = new ELFReader<32, true>(pBackend);
33}
34
35ELFDynObjReader::~ELFDynObjReader()
36{
37  delete m_pELFReader;
38}
39
40/// isMyFormat
41bool ELFDynObjReader::isMyFormat(Input &pInput) const
42{
43  assert(pInput.hasMemArea());
44
45  // Don't warning about the frequently requests.
46  // MemoryArea has a list of cache to handle this.
47  size_t hdr_size = m_pELFReader->getELFHeaderSize();
48  MemoryRegion* region = pInput.memArea()->request(pInput.fileOffset(),
49                                                   hdr_size);
50
51  uint8_t* ELF_hdr = region->start();
52  bool result = true;
53  if (!m_pELFReader->isELF(ELF_hdr))
54    result = false;
55  else if (!m_pELFReader->isMyEndian(ELF_hdr))
56    result = false;
57  else if (!m_pELFReader->isMyMachine(ELF_hdr))
58    result = false;
59  else if (Input::DynObj != m_pELFReader->fileType(ELF_hdr))
60    result = false;
61  pInput.memArea()->release(region);
62  return result;
63}
64
65/// readHeader
66bool ELFDynObjReader::readHeader(Input& pInput)
67{
68  assert(pInput.hasMemArea());
69
70  size_t hdr_size = m_pELFReader->getELFHeaderSize();
71  MemoryRegion* region = pInput.memArea()->request(pInput.fileOffset(),
72                                                   hdr_size);
73  uint8_t* ELF_hdr = region->start();
74
75  bool shdr_result = m_pELFReader->readSectionHeaders(pInput, ELF_hdr);
76  pInput.memArea()->release(region);
77
78  // read .dynamic to get the correct SONAME
79  bool dyn_result = m_pELFReader->readDynamic(pInput);
80
81  return (shdr_result && dyn_result);
82}
83
84/// readSymbols
85bool ELFDynObjReader::readSymbols(Input& pInput)
86{
87  assert(pInput.hasMemArea());
88
89  LDSection* symtab_shdr = pInput.context()->getSection(".dynsym");
90  if (NULL == symtab_shdr) {
91    note(diag::note_has_no_symtab) << pInput.name()
92                                   << pInput.path()
93                                   << ".dynsym";
94    return true;
95  }
96
97  LDSection* strtab_shdr = symtab_shdr->getLink();
98  if (NULL == strtab_shdr) {
99    fatal(diag::fatal_cannot_read_strtab) << pInput.name()
100                                          << pInput.path()
101                                          << ".dynsym";
102    return false;
103  }
104
105  MemoryRegion* symtab_region = pInput.memArea()->request(
106              pInput.fileOffset() + symtab_shdr->offset(), symtab_shdr->size());
107
108  MemoryRegion* strtab_region = pInput.memArea()->request(
109              pInput.fileOffset() + strtab_shdr->offset(), strtab_shdr->size());
110  char* strtab = reinterpret_cast<char*>(strtab_region->start());
111  bool result = m_pELFReader->readSymbols(pInput, m_Linker, *symtab_region,
112                                            strtab);
113  pInput.memArea()->release(symtab_region);
114  pInput.memArea()->release(strtab_region);
115
116  return result;
117}
118
119