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
25 namespace mcld {
26
27 //===----------------------------------------------------------------------===//
28 // ELFDynObjReader
29 //===----------------------------------------------------------------------===//
ELFDynObjReader(GNULDBackend & pBackend,IRBuilder & pBuilder,const LinkerConfig & pConfig)30 ELFDynObjReader::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
~ELFDynObjReader()40 ELFDynObjReader::~ELFDynObjReader() {
41 delete m_pELFReader;
42 }
43
44 /// isMyFormat
isMyFormat(Input & pInput,bool & pContinue) const45 bool 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
readHeader(Input & pInput)76 bool 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
readSymbols(Input & pInput)93 bool 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