1 // defstd.cc -- define standard symbols for gold. 2 3 // Copyright (C) 2006-2016 Free Software Foundation, Inc. 4 // Written by Ian Lance Taylor <iant (at) google.com>. 5 6 // This file is part of gold. 7 8 // This program is free software; you can redistribute it and/or modify 9 // it under the terms of the GNU General Public License as published by 10 // the Free Software Foundation; either version 3 of the License, or 11 // (at your option) any later version. 12 13 // This program is distributed in the hope that it will be useful, 14 // but WITHOUT ANY WARRANTY; without even the implied warranty of 15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 // GNU General Public License for more details. 17 18 // You should have received a copy of the GNU General Public License 19 // along with this program; if not, write to the Free Software 20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 21 // MA 02110-1301, USA. 22 23 #include "gold.h" 24 25 #include "symtab.h" 26 #include "layout.h" 27 #include "defstd.h" 28 29 // This is a simple file which defines the standard symbols like 30 // "_end". 31 32 namespace 33 { 34 35 using namespace gold; 36 37 const Define_symbol_in_section in_section[] = 38 { 39 { 40 "__preinit_array_start", // name 41 ".preinit_array", // output_section 42 0, // value 43 0, // size 44 elfcpp::STT_NOTYPE, // type 45 elfcpp::STB_GLOBAL, // binding 46 elfcpp::STV_HIDDEN, // visibility 47 0, // nonvis 48 false, // offset_is_from_end 49 true // only_if_ref 50 }, 51 { 52 "__preinit_array_end", // name 53 ".preinit_array", // output_section 54 0, // value 55 0, // size 56 elfcpp::STT_NOTYPE, // type 57 elfcpp::STB_GLOBAL, // binding 58 elfcpp::STV_HIDDEN, // visibility 59 0, // nonvis 60 true, // offset_is_from_end 61 true // only_if_ref 62 }, 63 { 64 "__init_array_start", // name 65 ".init_array", // output_section 66 0, // value 67 0, // size 68 elfcpp::STT_NOTYPE, // type 69 elfcpp::STB_GLOBAL, // binding 70 elfcpp::STV_HIDDEN, // visibility 71 0, // nonvis 72 false, // offset_is_from_end 73 true // only_if_ref 74 }, 75 { 76 "__init_array_end", // name 77 ".init_array", // output_section 78 0, // value 79 0, // size 80 elfcpp::STT_NOTYPE, // type 81 elfcpp::STB_GLOBAL, // binding 82 elfcpp::STV_HIDDEN, // visibility 83 0, // nonvis 84 true, // offset_is_from_end 85 true // only_if_ref 86 }, 87 { 88 "__fini_array_start", // name 89 ".fini_array", // output_section 90 0, // value 91 0, // size 92 elfcpp::STT_NOTYPE, // type 93 elfcpp::STB_GLOBAL, // binding 94 elfcpp::STV_HIDDEN, // visibility 95 0, // nonvis 96 false, // offset_is_from_end 97 true // only_if_ref 98 }, 99 { 100 "__fini_array_end", // name 101 ".fini_array", // output_section 102 0, // value 103 0, // size 104 elfcpp::STT_NOTYPE, // type 105 elfcpp::STB_GLOBAL, // binding 106 elfcpp::STV_HIDDEN, // visibility 107 0, // nonvis 108 true, // offset_is_from_end 109 true // only_if_ref 110 }, 111 { 112 "__stack", // name 113 ".stack", // output_section 114 0, // value 115 0, // size 116 elfcpp::STT_NOTYPE, // type 117 elfcpp::STB_GLOBAL, // binding 118 elfcpp::STV_DEFAULT, // visibility 119 0, // nonvis 120 false, // offset_is_from_end 121 true // only_if_ref 122 }, 123 }; 124 125 const int in_section_count = sizeof in_section / sizeof in_section[0]; 126 127 const Define_symbol_in_segment in_segment[] = 128 { 129 { 130 "__executable_start", // name 131 elfcpp::PT_LOAD, // segment_type 132 elfcpp::PF(0), // segment_flags_set 133 elfcpp::PF(0), // segment_flags_clear 134 0, // value 135 0, // size 136 elfcpp::STT_NOTYPE, // type 137 elfcpp::STB_GLOBAL, // binding 138 elfcpp::STV_DEFAULT, // visibility 139 0, // nonvis 140 Symbol::SEGMENT_START, // offset_from_base 141 true // only_if_ref 142 }, 143 { 144 "__ehdr_start", // name 145 elfcpp::PT_LOAD, // segment_type 146 elfcpp::PF(0), // segment_flags_set 147 elfcpp::PF(0), // segment_flags_clear 148 0, // value 149 0, // size 150 elfcpp::STT_NOTYPE, // type 151 elfcpp::STB_GLOBAL, // binding 152 elfcpp::STV_HIDDEN, // visibility 153 0, // nonvis 154 Symbol::SEGMENT_START, // offset_from_base 155 true // only_if_ref 156 }, 157 { 158 "etext", // name 159 elfcpp::PT_LOAD, // segment_type 160 elfcpp::PF_X, // segment_flags_set 161 elfcpp::PF_W, // segment_flags_clear 162 0, // value 163 0, // size 164 elfcpp::STT_NOTYPE, // type 165 elfcpp::STB_GLOBAL, // binding 166 elfcpp::STV_DEFAULT, // visibility 167 0, // nonvis 168 Symbol::SEGMENT_END, // offset_from_base 169 true // only_if_ref 170 }, 171 { 172 "_etext", // name 173 elfcpp::PT_LOAD, // segment_type 174 elfcpp::PF_X, // segment_flags_set 175 elfcpp::PF_W, // segment_flags_clear 176 0, // value 177 0, // size 178 elfcpp::STT_NOTYPE, // type 179 elfcpp::STB_GLOBAL, // binding 180 elfcpp::STV_DEFAULT, // visibility 181 0, // nonvis 182 Symbol::SEGMENT_END, // offset_from_base 183 true // only_if_ref 184 }, 185 { 186 "__etext", // name 187 elfcpp::PT_LOAD, // segment_type 188 elfcpp::PF_X, // segment_flags_set 189 elfcpp::PF_W, // segment_flags_clear 190 0, // value 191 0, // size 192 elfcpp::STT_NOTYPE, // type 193 elfcpp::STB_GLOBAL, // binding 194 elfcpp::STV_DEFAULT, // visibility 195 0, // nonvis 196 Symbol::SEGMENT_END, // offset_from_base 197 true // only_if_ref 198 }, 199 { 200 "_edata", // name 201 elfcpp::PT_LOAD, // segment_type 202 elfcpp::PF_W, // segment_flags_set 203 elfcpp::PF(0), // segment_flags_clear 204 0, // value 205 0, // size 206 elfcpp::STT_NOTYPE, // type 207 elfcpp::STB_GLOBAL, // binding 208 elfcpp::STV_DEFAULT, // visibility 209 0, // nonvis 210 Symbol::SEGMENT_BSS, // offset_from_base 211 false // only_if_ref 212 }, 213 { 214 "edata", // name 215 elfcpp::PT_LOAD, // segment_type 216 elfcpp::PF_W, // segment_flags_set 217 elfcpp::PF(0), // segment_flags_clear 218 0, // value 219 0, // size 220 elfcpp::STT_NOTYPE, // type 221 elfcpp::STB_GLOBAL, // binding 222 elfcpp::STV_DEFAULT, // visibility 223 0, // nonvis 224 Symbol::SEGMENT_BSS, // offset_from_base 225 true // only_if_ref 226 }, 227 { 228 "__bss_start", // name 229 elfcpp::PT_LOAD, // segment_type 230 elfcpp::PF_W, // segment_flags_set 231 elfcpp::PF(0), // segment_flags_clear 232 0, // value 233 0, // size 234 elfcpp::STT_NOTYPE, // type 235 elfcpp::STB_GLOBAL, // binding 236 elfcpp::STV_DEFAULT, // visibility 237 0, // nonvis 238 Symbol::SEGMENT_BSS, // offset_from_base 239 false // only_if_ref 240 }, 241 { 242 "_end", // name 243 elfcpp::PT_LOAD, // segment_type 244 elfcpp::PF_W, // segment_flags_set 245 elfcpp::PF(0), // segment_flags_clear 246 0, // value 247 0, // size 248 elfcpp::STT_NOTYPE, // type 249 elfcpp::STB_GLOBAL, // binding 250 elfcpp::STV_DEFAULT, // visibility 251 0, // nonvis 252 Symbol::SEGMENT_END, // offset_from_base 253 false // only_if_ref 254 }, 255 { 256 "end", // name 257 elfcpp::PT_LOAD, // segment_type 258 elfcpp::PF_W, // segment_flags_set 259 elfcpp::PF(0), // segment_flags_clear 260 0, // value 261 0, // size 262 elfcpp::STT_NOTYPE, // type 263 elfcpp::STB_GLOBAL, // binding 264 elfcpp::STV_DEFAULT, // visibility 265 0, // nonvis 266 Symbol::SEGMENT_END, // offset_from_base 267 true // only_if_ref 268 } 269 }; 270 271 const int in_segment_count = sizeof in_segment / sizeof in_segment[0]; 272 273 } // End anonymous namespace. 274 275 namespace gold 276 { 277 278 void 279 define_standard_symbols(Symbol_table* symtab, const Layout* layout) 280 { 281 bool saw_sections_clause = layout->script_options()->saw_sections_clause(); 282 symtab->define_symbols(layout, in_section_count, in_section, 283 saw_sections_clause); 284 symtab->define_symbols(layout, in_segment_count, in_segment, 285 saw_sections_clause); 286 } 287 288 } // End namespace gold. 289
