1 /*
2  * Copyright 2011, The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ELF_SECTION_HEADER_TABLE_HXX
18 #define ELF_SECTION_HEADER_TABLE_HXX
19 
20 #include "ELFHeader.h"
21 #include "ELFObject.h"
22 #include "ELFSectionHeader.h"
23 
24 #include "utils/rsl_assert.h"
25 
26 template <unsigned Bitwidth>
~ELFSectionHeaderTable()27 ELFSectionHeaderTable<Bitwidth>::~ELFSectionHeaderTable() {
28   for (size_t i = 0; i < table.size(); ++i) {
29     delete table[i];
30   }
31 }
32 
33 template <unsigned Bitwidth>
34 template <typename Archiver>
35 inline ELFSectionHeaderTable<Bitwidth> *
read(Archiver & AR,ELFObjectTy * owner)36 ELFSectionHeaderTable<Bitwidth>::read(Archiver &AR, ELFObjectTy *owner) {
37   if (!AR) {
38     // Archiver is in bad state before calling read function.
39     // Return NULL and do nothing.
40     return 0;
41   }
42 
43   // Allocate a new section header table and assign the owner.
44   std::unique_ptr<ELFSectionHeaderTable> tab(new ELFSectionHeaderTable());
45 
46   // Get ELF header
47   ELFHeaderTy const *header = owner->getHeader();
48 
49   rsl_assert(header->getSectionHeaderEntrySize() ==
50          TypeTraits<ELFSectionHeaderTy>::size);
51 
52   // Seek to the address of section header
53   AR.seek(header->getSectionHeaderTableOffset(), true);
54 
55   for (size_t i = 0; i < header->getSectionHeaderNum(); ++i) {
56     std::unique_ptr<ELFSectionHeaderTy> sh(
57       ELFSectionHeaderTy::read(AR, owner, i));
58 
59     if (!sh) {
60       // Something wrong while reading the section header.
61       return 0;
62     }
63 
64     tab->table.push_back(sh.release());
65   }
66 
67   return tab.release();
68 }
69 
70 template <unsigned Bitwidth>
print() const71 inline void ELFSectionHeaderTable<Bitwidth>::print() const {
72   using namespace llvm;
73 
74   out() << '\n' << fillformat('=', 79) << '\n';
75   out().changeColor(raw_ostream::WHITE, true);
76   out() << "ELF Section Header Table" << '\n';
77   out().resetColor();
78 
79   for (size_t i = 0; i < table.size(); ++i) {
80     (*this)[i]->print();
81   }
82 
83   out() << fillformat('=', 79) << '\n';
84 }
85 
86 template <unsigned Bitwidth>
buildNameMap()87 inline void ELFSectionHeaderTable<Bitwidth>::buildNameMap() {
88   for (size_t i = 0; i < table.size(); ++i) {
89     ELFSectionHeaderTy *sh = table[i];
90     if ( sh ) {
91       name_map[sh->getName()] = sh;
92     }
93   }
94 }
95 
96 template <unsigned Bitwidth>
97 inline ELFSectionHeader<Bitwidth> const *
getByName(const std::string & name) const98 ELFSectionHeaderTable<Bitwidth>::getByName(const std::string &name) const {
99   typename llvm::StringMap<ELFSectionHeaderTy *>::const_iterator sh =
100     name_map.find(name);
101   if (sh == name_map.end()) {
102     // Return SHN_UNDEF section header;
103     return table[0];
104   }
105   return sh->getValue();
106 }
107 
108 template <unsigned Bitwidth>
109 inline ELFSectionHeader<Bitwidth> *
getByName(const std::string & name)110 ELFSectionHeaderTable<Bitwidth>::getByName(const std::string &name) {
111   ELFSectionHeaderTableTy const *const_this = this;
112   ELFSectionHeaderTy const *shptr = const_this->getByName(name);
113   // Const cast for the same API's const and non-const versions.
114   return const_cast<ELFSectionHeaderTy *>(shptr);
115 }
116 
117 #endif // ELF_SECTION_HEADER_TABLE_HXX
118