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/Input.h>
15 #include <mcld/Target/GNULDBackend.h>
16 #include <mcld/Support/MemoryArea.h>
17
18 #include <llvm/ADT/StringRef.h>
19 #include <llvm/ADT/Twine.h>
20 #include <llvm/Support/ErrorHandling.h>
21
22 #include <string>
23
24 using namespace mcld;
25
26 //===----------------------------------------------------------------------===//
27 // ELFDynObjReader
28 //===----------------------------------------------------------------------===//
ELFDynObjReader(GNULDBackend & pBackend,IRBuilder & pBuilder,const LinkerConfig & pConfig)29 ELFDynObjReader::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
~ELFDynObjReader()41 ELFDynObjReader::~ELFDynObjReader()
42 {
43 delete m_pELFReader;
44 }
45
46 /// isMyFormat
isMyFormat(Input & pInput,bool & pContinue) const47 bool ELFDynObjReader::isMyFormat(Input &pInput, bool &pContinue) 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 if (pInput.memArea()->size() < hdr_size)
55 return false;
56
57 llvm::StringRef region = pInput.memArea()->request(pInput.fileOffset(),
58 hdr_size);
59
60 const char* ELF_hdr = region.begin();
61 bool result = true;
62 if (!m_pELFReader->isELF(ELF_hdr)) {
63 pContinue = true;
64 result = false;
65 } else if (Input::DynObj != m_pELFReader->fileType(ELF_hdr)) {
66 pContinue = true;
67 result = false;
68 } else if (!m_pELFReader->isMyEndian(ELF_hdr)) {
69 pContinue = false;
70 result = false;
71 } else if (!m_pELFReader->isMyMachine(ELF_hdr)) {
72 pContinue = false;
73 result = false;
74 }
75 return result;
76 }
77
78 /// readHeader
readHeader(Input & pInput)79 bool ELFDynObjReader::readHeader(Input& pInput)
80 {
81 assert(pInput.hasMemArea());
82
83 size_t hdr_size = m_pELFReader->getELFHeaderSize();
84 llvm::StringRef region = pInput.memArea()->request(pInput.fileOffset(),
85 hdr_size);
86 const char* ELF_hdr = region.begin();
87
88 bool shdr_result = m_pELFReader->readSectionHeaders(pInput, ELF_hdr);
89
90 // read .dynamic to get the correct SONAME
91 bool dyn_result = m_pELFReader->readDynamic(pInput);
92
93 return (shdr_result && dyn_result);
94 }
95
96 /// readSymbols
readSymbols(Input & pInput)97 bool ELFDynObjReader::readSymbols(Input& pInput)
98 {
99 assert(pInput.hasMemArea());
100
101 LDSection* symtab_shdr = pInput.context()->getSection(".dynsym");
102 if (NULL == symtab_shdr) {
103 note(diag::note_has_no_symtab) << pInput.name()
104 << pInput.path()
105 << ".dynsym";
106 return true;
107 }
108
109 LDSection* strtab_shdr = symtab_shdr->getLink();
110 if (NULL == strtab_shdr) {
111 fatal(diag::fatal_cannot_read_strtab) << pInput.name()
112 << pInput.path()
113 << ".dynsym";
114 return false;
115 }
116
117 llvm::StringRef symtab_region = pInput.memArea()->request(
118 pInput.fileOffset() + symtab_shdr->offset(), symtab_shdr->size());
119
120 llvm::StringRef strtab_region = pInput.memArea()->request(
121 pInput.fileOffset() + strtab_shdr->offset(), strtab_shdr->size());
122 const char* strtab = strtab_region.begin();
123 bool result = m_pELFReader->readSymbols(pInput, m_Builder,
124 symtab_region, strtab);
125 return result;
126 }
127
128