ELFDynObjReader.cpp revision 67e37f1be98c926645219cfb47fab9e90d8c725c 
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/MC/MCLinker.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
26ELFDynObjReader::ELFDynObjReader(GNULDBackend& pBackend, MCLinker& pLinker)
27  : DynObjReader(),
28    m_pELFReader(0),
29    m_Linker(pLinker) {
30  if (32 == pBackend.bitclass() && pBackend.isLittleEndian())
31    m_pELFReader = new ELFReader<32, true>(pBackend);
32}
33
34ELFDynObjReader::~ELFDynObjReader()
35{
36  delete m_pELFReader;
37}
38
39/// isMyFormat
40bool ELFDynObjReader::isMyFormat(Input &pInput) const
41{
42  assert(pInput.hasMemArea());
43
44  // Don't warning about the frequently requests.
45  // MemoryArea has a list of cache to handle this.
46  size_t hdr_size = m_pELFReader->getELFHeaderSize();
47  MemoryRegion* region = pInput.memArea()->request(pInput.fileOffset(),
48                                                   hdr_size);
49
50  uint8_t* ELF_hdr = region->start();
51  bool result = true;
52  if (!m_pELFReader->isELF(ELF_hdr))
53    result = false;
54  else if (!m_pELFReader->isMyEndian(ELF_hdr))
55    result = false;
56  else if (!m_pELFReader->isMyMachine(ELF_hdr))
57    result = false;
58  else if (MCLDFile::DynObj != m_pELFReader->fileType(ELF_hdr))
59    result = false;
60  pInput.memArea()->release(region);
61  return result;
62}
63
64/// readDSO
65bool ELFDynObjReader::readDSO(Input& pInput)
66{
67  assert(pInput.hasMemArea());
68
69  size_t hdr_size = m_pELFReader->getELFHeaderSize();
70  MemoryRegion* region = pInput.memArea()->request(pInput.fileOffset(),
71                                                   hdr_size);
72  uint8_t* ELF_hdr = region->start();
73
74  bool shdr_result = m_pELFReader->readSectionHeaders(pInput, m_Linker, ELF_hdr);
75  pInput.memArea()->release(region);
76
77  // read .dynamic to get the correct SONAME
78  bool dyn_result = m_pELFReader->readDynamic(pInput);
79
80  return (shdr_result && dyn_result);
81}
82
83/// readSymbols
84bool ELFDynObjReader::readSymbols(Input& pInput)
85{
86  assert(pInput.hasMemArea());
87
88  LDSection* symtab_shdr = pInput.context()->getSection(".dynsym");
89  if (NULL == symtab_shdr) {
90    note(diag::note_has_no_symtab) << pInput.name()
91                                   << pInput.path()
92                                   << ".dynsym";
93    return true;
94  }
95
96  LDSection* strtab_shdr = symtab_shdr->getLink();
97  if (NULL == strtab_shdr) {
98    fatal(diag::fatal_cannot_read_strtab) << pInput.name()
99                                          << pInput.path()
100                                          << ".dynsym";
101    return false;
102  }
103
104  MemoryRegion* symtab_region = pInput.memArea()->request(
105              pInput.fileOffset() + symtab_shdr->offset(), symtab_shdr->size());
106
107  MemoryRegion* strtab_region = pInput.memArea()->request(
108              pInput.fileOffset() + strtab_shdr->offset(), strtab_shdr->size());
109  char* strtab = reinterpret_cast<char*>(strtab_region->start());
110  bool result = m_pELFReader->readSymbols(pInput, m_Linker, *symtab_region,
111                                            strtab);
112  pInput.memArea()->release(symtab_region);
113  pInput.memArea()->release(strtab_region);
114
115  return result;
116}
117
118