ELFDynObjReader.cpp revision 6f75755c9204b1d8817ae5a65a2f7e5af0ec3f70 
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/LinkerConfig.h>
12#include <mcld/IRBuilder.h>
13#include <mcld/LD/ELFReader.h>
14#include <mcld/MC/MCLDInput.h>
15#include <mcld/Support/MemoryRegion.h>
16#include <mcld/Target/GNULDBackend.h>
17
18#include <llvm/ADT/Twine.h>
19#include <llvm/ADT/OwningPtr.h>
20#include <llvm/Support/ErrorHandling.h>
21
22#include <string>
23
24using namespace mcld;
25
26//===----------------------------------------------------------------------===//
27// ELFDynObjReader
28//===----------------------------------------------------------------------===//
29ELFDynObjReader::ELFDynObjReader(GNULDBackend& pBackend,
30                                 IRBuilder& pBuilder,
31                                 const LinkerConfig& pConfig)
32  : DynObjReader(),
33    m_pELFReader(0),
34    m_Builder(pBuilder) {
35  if (pConfig.targets().is32Bits() && pConfig.targets().isLittleEndian())
36    m_pELFReader = new ELFReader<32, true>(pBackend);
37  else if (pConfig.targets().is64Bits() && pConfig.targets().isLittleEndian())
38    m_pELFReader = new ELFReader<64, true>(pBackend);
39}
40
41ELFDynObjReader::~ELFDynObjReader()
42{
43  delete m_pELFReader;
44}
45
46/// isMyFormat
47bool ELFDynObjReader::isMyFormat(Input &pInput) const
48{
49  assert(pInput.hasMemArea());
50
51  // Don't warning about the frequently requests.
52  // MemoryArea has a list of cache to handle this.
53  size_t hdr_size = m_pELFReader->getELFHeaderSize();
54  MemoryRegion* region = pInput.memArea()->request(pInput.fileOffset(),
55                                                   hdr_size);
56
57  uint8_t* ELF_hdr = region->start();
58  bool result = true;
59  if (!m_pELFReader->isELF(ELF_hdr))
60    result = false;
61  else if (!m_pELFReader->isMyEndian(ELF_hdr))
62    result = false;
63  else if (!m_pELFReader->isMyMachine(ELF_hdr))
64    result = false;
65  else if (Input::DynObj != m_pELFReader->fileType(ELF_hdr))
66    result = false;
67  pInput.memArea()->release(region);
68  return result;
69}
70
71/// readHeader
72bool ELFDynObjReader::readHeader(Input& pInput)
73{
74  assert(pInput.hasMemArea());
75
76  size_t hdr_size = m_pELFReader->getELFHeaderSize();
77  MemoryRegion* region = pInput.memArea()->request(pInput.fileOffset(),
78                                                   hdr_size);
79  uint8_t* ELF_hdr = region->start();
80
81  bool shdr_result = m_pELFReader->readSectionHeaders(pInput, ELF_hdr);
82  pInput.memArea()->release(region);
83
84  // read .dynamic to get the correct SONAME
85  bool dyn_result = m_pELFReader->readDynamic(pInput);
86
87  return (shdr_result && dyn_result);
88}
89
90/// readSymbols
91bool ELFDynObjReader::readSymbols(Input& pInput)
92{
93  assert(pInput.hasMemArea());
94
95  LDSection* symtab_shdr = pInput.context()->getSection(".dynsym");
96  if (NULL == symtab_shdr) {
97    note(diag::note_has_no_symtab) << pInput.name()
98                                   << pInput.path()
99                                   << ".dynsym";
100    return true;
101  }
102
103  LDSection* strtab_shdr = symtab_shdr->getLink();
104  if (NULL == strtab_shdr) {
105    fatal(diag::fatal_cannot_read_strtab) << pInput.name()
106                                          << pInput.path()
107                                          << ".dynsym";
108    return false;
109  }
110
111  MemoryRegion* symtab_region = pInput.memArea()->request(
112              pInput.fileOffset() + symtab_shdr->offset(), symtab_shdr->size());
113
114  MemoryRegion* strtab_region = pInput.memArea()->request(
115              pInput.fileOffset() + strtab_shdr->offset(), strtab_shdr->size());
116  char* strtab = reinterpret_cast<char*>(strtab_region->start());
117  bool result = m_pELFReader->readSymbols(pInput, m_Builder,
118                                          *symtab_region, strtab);
119  pInput.memArea()->release(symtab_region);
120  pInput.memArea()->release(strtab_region);
121
122  return result;
123}
124
125