ppc64elf.em revision 104834
1# This shell script emits a C file. -*- C -*- 2# Copyright 2002 Free Software Foundation, Inc. 3# 4# This file is part of GLD, the Gnu Linker. 5# 6# This program is free software; you can redistribute it and/or modify 7# it under the terms of the GNU General Public License as published by 8# the Free Software Foundation; either version 2 of the License, or 9# (at your option) any later version. 10# 11# This program is distributed in the hope that it will be useful, 12# but WITHOUT ANY WARRANTY; without even the implied warranty of 13# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14# GNU General Public License for more details. 15# 16# You should have received a copy of the GNU General Public License 17# along with this program; if not, write to the Free Software 18# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 19# 20 21# This file is sourced from elf32.em, and defines extra powerpc64-elf 22# specific routines. 23# 24cat >>e${EMULATION_NAME}.c <<EOF 25 26#include "ldctor.h" 27#include "libbfd.h" 28#include "elf64-ppc.h" 29 30/* Fake input file for stubs. */ 31static lang_input_statement_type *stub_file; 32 33/* Whether we need to call ppc_layout_sections_again. */ 34static int need_laying_out = 0; 35 36/* Maximum size of a group of input sections that can be handled by 37 one stub section. A value of +/-1 indicates the bfd back-end 38 should use a suitable default size. */ 39static bfd_signed_vma group_size = 1; 40 41/* Whether to add ".foo" entries for each "foo" in a version script. */ 42static int dotsyms = 1; 43 44static void ppc_create_output_section_statements PARAMS ((void)); 45static void ppc_after_open PARAMS ((void)); 46static asection *ppc_add_stub_section PARAMS ((const char *, asection *)); 47static void ppc_layout_sections_again PARAMS ((void)); 48static void gld${EMULATION_NAME}_after_allocation PARAMS ((void)); 49static void build_section_lists PARAMS ((lang_statement_union_type *)); 50static struct bfd_elf_version_expr *gld${EMULATION_NAME}_new_vers_pattern 51 PARAMS ((struct bfd_elf_version_expr *)); 52 53/* This is called before the input files are opened. We create a new 54 fake input file to hold the stub sections. */ 55 56static void 57ppc_create_output_section_statements () 58{ 59 stub_file = lang_add_input_file ("linker stubs", 60 lang_input_file_is_fake_enum, 61 NULL); 62 stub_file->the_bfd = bfd_create ("linker stubs", output_bfd); 63 if (stub_file->the_bfd == NULL 64 || !bfd_set_arch_mach (stub_file->the_bfd, 65 bfd_get_arch (output_bfd), 66 bfd_get_mach (output_bfd))) 67 { 68 einfo ("%X%P: can not create BFD %E\n"); 69 return; 70 } 71 72 ldlang_add_file (stub_file); 73} 74 75static void 76ppc_after_open () 77{ 78 if (!ppc64_elf_mark_entry_syms (&link_info)) 79 { 80 einfo ("%X%P: can not mark entry symbols %E\n"); 81 return; 82 } 83 84 gld${EMULATION_NAME}_after_open (); 85} 86 87struct hook_stub_info 88{ 89 lang_statement_list_type add; 90 asection *input_section; 91}; 92 93/* Traverse the linker tree to find the spot where the stub goes. */ 94 95static boolean hook_in_stub 96 PARAMS ((struct hook_stub_info *, lang_statement_union_type **)); 97 98static boolean 99hook_in_stub (info, lp) 100 struct hook_stub_info *info; 101 lang_statement_union_type **lp; 102{ 103 lang_statement_union_type *l; 104 boolean ret; 105 106 for (; (l = *lp) != NULL; lp = &l->header.next) 107 { 108 switch (l->header.type) 109 { 110 case lang_constructors_statement_enum: 111 ret = hook_in_stub (info, &constructor_list.head); 112 if (ret) 113 return ret; 114 break; 115 116 case lang_output_section_statement_enum: 117 ret = hook_in_stub (info, 118 &l->output_section_statement.children.head); 119 if (ret) 120 return ret; 121 break; 122 123 case lang_wild_statement_enum: 124 ret = hook_in_stub (info, &l->wild_statement.children.head); 125 if (ret) 126 return ret; 127 break; 128 129 case lang_group_statement_enum: 130 ret = hook_in_stub (info, &l->group_statement.children.head); 131 if (ret) 132 return ret; 133 break; 134 135 case lang_input_section_enum: 136 if (l->input_section.section == info->input_section) 137 { 138 /* We've found our section. Insert the stub immediately 139 before its associated input section. */ 140 *lp = info->add.head; 141 *(info->add.tail) = l; 142 return true; 143 } 144 break; 145 146 case lang_data_statement_enum: 147 case lang_reloc_statement_enum: 148 case lang_object_symbols_statement_enum: 149 case lang_output_statement_enum: 150 case lang_target_statement_enum: 151 case lang_input_statement_enum: 152 case lang_assignment_statement_enum: 153 case lang_padding_statement_enum: 154 case lang_address_statement_enum: 155 case lang_fill_statement_enum: 156 break; 157 158 default: 159 FAIL (); 160 break; 161 } 162 } 163 return false; 164} 165 166 167/* Call-back for ppc64_elf_size_stubs. */ 168 169/* Create a new stub section, and arrange for it to be linked 170 immediately before INPUT_SECTION. */ 171 172static asection * 173ppc_add_stub_section (stub_sec_name, input_section) 174 const char *stub_sec_name; 175 asection *input_section; 176{ 177 asection *stub_sec; 178 flagword flags; 179 asection *output_section; 180 const char *secname; 181 lang_output_section_statement_type *os; 182 struct hook_stub_info info; 183 184 stub_sec = bfd_make_section_anyway (stub_file->the_bfd, stub_sec_name); 185 if (stub_sec == NULL) 186 goto err_ret; 187 188 flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE 189 | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP); 190 if (!bfd_set_section_flags (stub_file->the_bfd, stub_sec, flags)) 191 goto err_ret; 192 193 output_section = input_section->output_section; 194 secname = bfd_get_section_name (output_section->owner, output_section); 195 os = lang_output_section_find (secname); 196 197 info.input_section = input_section; 198 lang_list_init (&info.add); 199 lang_add_section (&info.add, stub_sec, os, stub_file); 200 201 if (info.add.head == NULL) 202 goto err_ret; 203 204 if (hook_in_stub (&info, &os->children.head)) 205 return stub_sec; 206 207 err_ret: 208 einfo ("%X%P: can not make stub section: %E\n"); 209 return NULL; 210} 211 212 213/* Another call-back for ppc64_elf_size_stubs. */ 214 215static void 216ppc_layout_sections_again () 217{ 218 /* If we have changed sizes of the stub sections, then we need 219 to recalculate all the section offsets. This may mean we need to 220 add even more stubs. */ 221 need_laying_out = 0; 222 223 lang_reset_memory_regions (); 224 225 /* Resize the sections. */ 226 lang_size_sections (stat_ptr->head, abs_output_section, 227 &stat_ptr->head, 0, (bfd_vma) 0, NULL); 228 229 /* Recalculate TOC base. */ 230 ldemul_after_allocation (); 231 232 /* Do the assignments again. */ 233 lang_do_assignments (stat_ptr->head, abs_output_section, 234 (fill_type *) 0, (bfd_vma) 0); 235} 236 237 238/* Call the back-end function to set TOC base after we have placed all 239 the sections. */ 240static void 241gld${EMULATION_NAME}_after_allocation () 242{ 243 if (!link_info.relocateable) 244 _bfd_set_gp_value (output_bfd, ppc64_elf_toc (output_bfd)); 245} 246 247 248static void 249build_section_lists (statement) 250 lang_statement_union_type *statement; 251{ 252 if (statement->header.type == lang_input_section_enum 253 && !statement->input_section.ifile->just_syms_flag 254 && statement->input_section.section->output_section != NULL 255 && statement->input_section.section->output_section->owner == output_bfd) 256 { 257 ppc64_elf_next_input_section (&link_info, 258 statement->input_section.section); 259 } 260} 261 262 263/* Final emulation specific call. */ 264 265static void 266gld${EMULATION_NAME}_finish () 267{ 268 int ret; 269 270 /* e_entry on PowerPC64 points to the function descriptor for 271 _start. If _start is missing, default to the first function 272 descriptor in the .opd section. */ 273 entry_section = ".opd"; 274 275 /* If generating a relocatable output file, then we don't have any 276 stubs. */ 277 if (link_info.relocateable) 278 return; 279 280 /* bfd_elf64_discard_info just plays with debugging sections, 281 ie. doesn't affect any code, so we can delay resizing the 282 sections. It's likely we'll resize everything in the process of 283 adding stubs. */ 284 if (bfd_elf${ELFSIZE}_discard_info (output_bfd, &link_info)) 285 need_laying_out = 1; 286 287 ret = ppc64_elf_setup_section_lists (output_bfd, &link_info); 288 if (ret != 0) 289 { 290 if (ret < 0) 291 { 292 einfo ("%X%P: can not size stub section: %E\n"); 293 return; 294 } 295 296 lang_for_each_statement (build_section_lists); 297 298 /* Call into the BFD backend to do the real work. */ 299 if (!ppc64_elf_size_stubs (output_bfd, 300 stub_file->the_bfd, 301 &link_info, 302 group_size, 303 &ppc_add_stub_section, 304 &ppc_layout_sections_again)) 305 { 306 einfo ("%X%P: can not size stub section: %E\n"); 307 return; 308 } 309 } 310 311 if (need_laying_out) 312 ppc_layout_sections_again (); 313 314 if (stub_file->the_bfd->sections != NULL) 315 { 316 if (!ppc64_elf_build_stubs (&link_info)) 317 einfo ("%X%P: can not build stubs: %E\n"); 318 } 319} 320 321 322/* Add a pattern matching ".foo" for every "foo" in a version script. 323 324 The reason for doing this is that many shared library version 325 scripts export a selected set of functions or data symbols, forcing 326 others local. eg. 327 328 . VERS_1 { 329 . global: 330 . this; that; some; thing; 331 . local: 332 . *; 333 . }; 334 335 To make the above work for PowerPC64, we need to export ".this", 336 ".that" and so on, otherwise only the function descriptor syms are 337 exported. Lack of an exported function code sym may cause a 338 definition to be pulled in from a static library. */ 339 340struct bfd_elf_version_expr * 341gld${EMULATION_NAME}_new_vers_pattern (entry) 342 struct bfd_elf_version_expr *entry; 343{ 344 struct bfd_elf_version_expr *dot_entry; 345 struct bfd_elf_version_expr *next; 346 unsigned int len; 347 char *dot_pat; 348 349 if (!dotsyms || entry->pattern[0] == '*') 350 return entry; 351 352 /* Is the script adding ".foo" explicitly? */ 353 if (entry->pattern[0] == '.') 354 { 355 /* We may have added this pattern automatically. Don't add it 356 again. Quadratic behaviour here is acceptable as the list 357 may be traversed for each input bfd symbol. */ 358 for (next = entry->next; next != NULL; next = next->next) 359 { 360 if (strcmp (next->pattern, entry->pattern) == 0 361 && next->match == entry->match) 362 { 363 next = entry->next; 364 free ((char *) entry->pattern); 365 free (entry); 366 return next; 367 } 368 } 369 return entry; 370 } 371 372 /* Don't add ".foo" if the script has already done so. */ 373 for (next = entry->next; next != NULL; next = next->next) 374 { 375 if (next->pattern[0] == '.' 376 && strcmp (next->pattern + 1, entry->pattern) == 0 377 && next->match == entry->match) 378 return entry; 379 } 380 381 dot_entry = (struct bfd_elf_version_expr *) xmalloc (sizeof *dot_entry); 382 dot_entry->next = entry; 383 len = strlen (entry->pattern) + 2; 384 dot_pat = xmalloc (len); 385 dot_pat[0] = '.'; 386 memcpy (dot_pat + 1, entry->pattern, len - 1); 387 dot_entry->pattern = dot_pat; 388 dot_entry->match = entry->match; 389 return dot_entry; 390} 391 392 393/* Avoid processing the fake stub_file in vercheck, stat_needed and 394 check_needed routines. */ 395 396static void ppc_for_each_input_file_wrapper 397 PARAMS ((lang_input_statement_type *)); 398static void ppc_lang_for_each_input_file 399 PARAMS ((void (*) (lang_input_statement_type *))); 400 401static void (*real_func) PARAMS ((lang_input_statement_type *)); 402 403static void ppc_for_each_input_file_wrapper (l) 404 lang_input_statement_type *l; 405{ 406 if (l != stub_file) 407 (*real_func) (l); 408} 409 410static void 411ppc_lang_for_each_input_file (func) 412 void (*func) PARAMS ((lang_input_statement_type *)); 413{ 414 real_func = func; 415 lang_for_each_input_file (&ppc_for_each_input_file_wrapper); 416} 417 418#define lang_for_each_input_file ppc_lang_for_each_input_file 419 420EOF 421 422# Define some shell vars to insert bits of code into the standard elf 423# parse_args and list_options functions. 424# 425PARSE_AND_LIST_PROLOGUE=' 426#define OPTION_STUBGROUP_SIZE 301 427#define OPTION_DOTSYMS (OPTION_STUBGROUP_SIZE + 1) 428#define OPTION_NO_DOTSYMS (OPTION_DOTSYMS + 1) 429' 430 431# The options are repeated below so that no abbreviations are allowed. 432# Otherwise -s matches stub-group-size 433PARSE_AND_LIST_LONGOPTS=' 434 { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE }, 435 { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE }, 436 { "dotsyms", no_argument, NULL, OPTION_DOTSYMS }, 437 { "dotsyms", no_argument, NULL, OPTION_DOTSYMS }, 438 { "no-dotsyms", no_argument, NULL, OPTION_NO_DOTSYMS }, 439 { "no-dotsyms", no_argument, NULL, OPTION_NO_DOTSYMS }, 440' 441 442PARSE_AND_LIST_OPTIONS=' 443 fprintf (file, _("\ 444 --stub-group-size=N Maximum size of a group of input sections that can be\n\ 445 handled by one stub section. A negative value\n\ 446 locates all stubs before their branches (with a\n\ 447 group size of -N), while a positive value allows\n\ 448 two groups of input sections, one before, and one\n\ 449 after each stub section. Values of +/-1 indicate\n\ 450 the linker should choose suitable defaults.\n" 451 )); 452 fprintf (file, _("\ 453 --dotsyms For every version pattern \"foo\" in a version script,\n\ 454 add \".foo\" so that function code symbols are\n\ 455 treated the same as function descriptor symbols.\n\ 456 Defaults to on.\n" 457 )); 458 fprintf (file, _("\ 459 --no-dotsyms Don'\''t do anything special in version scripts.\n" 460 )); 461' 462 463PARSE_AND_LIST_ARGS_CASES=' 464 case OPTION_STUBGROUP_SIZE: 465 { 466 const char *end; 467 group_size = bfd_scan_vma (optarg, &end, 0); 468 if (*end) 469 einfo (_("%P%F: invalid number `%s'\''\n"), optarg); 470 } 471 break; 472 473 case OPTION_DOTSYMS: 474 { 475 dotsyms = 1; 476 } 477 break; 478 479 case OPTION_NO_DOTSYMS: 480 { 481 dotsyms = 0; 482 } 483 break; 484' 485 486# Put these extra ppc64elf routines in ld_${EMULATION_NAME}_emulation 487# 488LDEMUL_AFTER_OPEN=ppc_after_open 489LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation 490LDEMUL_FINISH=gld${EMULATION_NAME}_finish 491LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=ppc_create_output_section_statements 492LDEMUL_NEW_VERS_PATTERN=gld${EMULATION_NAME}_new_vers_pattern 493