1# This shell script emits a C file. -*- C -*-
2#   Copyright 2002, 2003, 2004, 2005 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., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, 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 "elf-bfd.h"
29#include "elf64-ppc.h"
30
31/* Fake input file for stubs.  */
32static lang_input_statement_type *stub_file;
33static int stub_added = 0;
34
35/* Whether we need to call ppc_layout_sections_again.  */
36static int need_laying_out = 0;
37
38/* Maximum size of a group of input sections that can be handled by
39   one stub section.  A value of +/-1 indicates the bfd back-end
40   should use a suitable default size.  */
41static bfd_signed_vma group_size = 1;
42
43/* Whether to add ".foo" entries for each "foo" in a version script.  */
44static int dotsyms = 1;
45
46/* Whether to run tls optimization.  */
47static int no_tls_opt = 0;
48
49/* Whether to run opd optimization.  */
50static int no_opd_opt = 0;
51
52/* Whether to run toc optimization.  */
53static int no_toc_opt = 0;
54
55/* Whether to allow multiple toc sections.  */
56static int no_multi_toc = 0;
57
58/* Whether to emit symbols for stubs.  */
59static int emit_stub_syms = 0;
60
61static asection *toc_section = 0;
62
63/* Whether to canonicalize .opd so that there are no overlapping
64   .opd entries.  */
65static int non_overlapping_opd = 0;
66
67/* This is called before the input files are opened.  We create a new
68   fake input file to hold the stub sections.  */
69
70static void
71ppc_create_output_section_statements (void)
72{
73  extern const bfd_target bfd_elf64_powerpc_vec;
74  extern const bfd_target bfd_elf64_powerpcle_vec;
75  asection *sect;
76
77  if (link_info.hash->creator != &bfd_elf64_powerpc_vec
78      && link_info.hash->creator != &bfd_elf64_powerpcle_vec)
79    return;
80
81  link_info.wrap_char = '.';
82
83  stub_file = lang_add_input_file ("linker stubs",
84				   lang_input_file_is_fake_enum,
85				   NULL);
86  stub_file->the_bfd = bfd_create ("linker stubs", output_bfd);
87  if (stub_file->the_bfd == NULL
88      || !bfd_set_arch_mach (stub_file->the_bfd,
89			     bfd_get_arch (output_bfd),
90			     bfd_get_mach (output_bfd)))
91    {
92      einfo ("%F%P: can not create BFD %E\n");
93      return;
94    }
95
96  if (bfd_get_section_by_name (stub_file->the_bfd, ".note.GNU-stack") == NULL)
97    sect = bfd_make_section (stub_file->the_bfd, ".note.GNU-stack");
98  stub_file->the_bfd->flags |= BFD_LINKER_CREATED;
99  ldlang_add_file (stub_file);
100  ppc64_elf_init_stub_bfd (stub_file->the_bfd, &link_info);
101}
102
103static void
104ppc_before_allocation (void)
105{
106  if (stub_file != NULL)
107    {
108      if (!ppc64_elf_edit_opd (output_bfd, &link_info, no_opd_opt,
109			       non_overlapping_opd))
110	einfo ("%X%P: can not edit %s %E\n", "opd");
111
112      if (ppc64_elf_tls_setup (output_bfd, &link_info) && !no_tls_opt)
113	{
114	  /* Size the sections.  This is premature, but we want to know the
115	     TLS segment layout so that certain optimizations can be done.  */
116	  expld.phase = lang_mark_phase_enum;
117	  expld.dataseg.phase = exp_dataseg_none;
118	  one_lang_size_sections_pass (NULL, TRUE);
119
120	  if (!ppc64_elf_tls_optimize (output_bfd, &link_info))
121	    einfo ("%X%P: TLS problem %E\n");
122
123	  /* We must not cache anything from the preliminary sizing.  */
124	  lang_reset_memory_regions ();
125	}
126
127      if (!no_toc_opt
128	  && !link_info.relocatable
129	  && !ppc64_elf_edit_toc (output_bfd, &link_info))
130	einfo ("%X%P: can not edit %s %E\n", "toc");
131    }
132
133  gld${EMULATION_NAME}_before_allocation ();
134}
135
136struct hook_stub_info
137{
138  lang_statement_list_type add;
139  asection *input_section;
140};
141
142/* Traverse the linker tree to find the spot where the stub goes.  */
143
144static bfd_boolean
145hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
146{
147  lang_statement_union_type *l;
148  bfd_boolean ret;
149
150  for (; (l = *lp) != NULL; lp = &l->header.next)
151    {
152      switch (l->header.type)
153	{
154	case lang_constructors_statement_enum:
155	  ret = hook_in_stub (info, &constructor_list.head);
156	  if (ret)
157	    return ret;
158	  break;
159
160	case lang_output_section_statement_enum:
161	  ret = hook_in_stub (info,
162			      &l->output_section_statement.children.head);
163	  if (ret)
164	    return ret;
165	  break;
166
167	case lang_wild_statement_enum:
168	  ret = hook_in_stub (info, &l->wild_statement.children.head);
169	  if (ret)
170	    return ret;
171	  break;
172
173	case lang_group_statement_enum:
174	  ret = hook_in_stub (info, &l->group_statement.children.head);
175	  if (ret)
176	    return ret;
177	  break;
178
179	case lang_input_section_enum:
180	  if (l->input_section.section == info->input_section)
181	    {
182	      /* We've found our section.  Insert the stub immediately
183		 before its associated input section.  */
184	      *lp = info->add.head;
185	      *(info->add.tail) = l;
186	      return TRUE;
187	    }
188	  break;
189
190	case lang_data_statement_enum:
191	case lang_reloc_statement_enum:
192	case lang_object_symbols_statement_enum:
193	case lang_output_statement_enum:
194	case lang_target_statement_enum:
195	case lang_input_statement_enum:
196	case lang_assignment_statement_enum:
197	case lang_padding_statement_enum:
198	case lang_address_statement_enum:
199	case lang_fill_statement_enum:
200	  break;
201
202	default:
203	  FAIL ();
204	  break;
205	}
206    }
207  return FALSE;
208}
209
210
211/* Call-back for ppc64_elf_size_stubs.  */
212
213/* Create a new stub section, and arrange for it to be linked
214   immediately before INPUT_SECTION.  */
215
216static asection *
217ppc_add_stub_section (const char *stub_sec_name, asection *input_section)
218{
219  asection *stub_sec;
220  flagword flags;
221  asection *output_section;
222  const char *secname;
223  lang_output_section_statement_type *os;
224  struct hook_stub_info info;
225
226  stub_sec = bfd_make_section_anyway (stub_file->the_bfd, stub_sec_name);
227  if (stub_sec == NULL)
228    goto err_ret;
229
230  flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
231	   | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_KEEP);
232  if (!bfd_set_section_flags (stub_file->the_bfd, stub_sec, flags))
233    goto err_ret;
234
235  output_section = input_section->output_section;
236  secname = bfd_get_section_name (output_section->owner, output_section);
237  os = lang_output_section_find (secname);
238
239  info.input_section = input_section;
240  lang_list_init (&info.add);
241  lang_add_section (&info.add, stub_sec, os);
242
243  if (info.add.head == NULL)
244    goto err_ret;
245
246  stub_added = 1;
247  if (hook_in_stub (&info, &os->children.head))
248    return stub_sec;
249
250 err_ret:
251  einfo ("%X%P: can not make stub section: %E\n");
252  return NULL;
253}
254
255
256/* Another call-back for ppc64_elf_size_stubs.  */
257
258static void
259ppc_layout_sections_again (void)
260{
261  /* If we have changed sizes of the stub sections, then we need
262     to recalculate all the section offsets.  This may mean we need to
263     add even more stubs.  */
264  gld${EMULATION_NAME}_map_segments (TRUE);
265  need_laying_out = -1;
266}
267
268
269/* Call the back-end function to set TOC base after we have placed all
270   the sections.  */
271static void
272gld${EMULATION_NAME}_after_allocation (void)
273{
274  if (!link_info.relocatable)
275    _bfd_set_gp_value (output_bfd, ppc64_elf_toc (output_bfd));
276}
277
278
279static void
280build_toc_list (lang_statement_union_type *statement)
281{
282  if (statement->header.type == lang_input_section_enum)
283    {
284      asection *i = statement->input_section.section;
285
286      if (!((lang_input_statement_type *) i->owner->usrdata)->just_syms_flag
287	  && (i->flags & SEC_EXCLUDE) == 0
288	  && i->output_section == toc_section)
289	ppc64_elf_next_toc_section (&link_info, i);
290    }
291}
292
293
294static void
295build_section_lists (lang_statement_union_type *statement)
296{
297  if (statement->header.type == lang_input_section_enum)
298    {
299      asection *i = statement->input_section.section;
300
301      if (!((lang_input_statement_type *) i->owner->usrdata)->just_syms_flag
302	  && (i->flags & SEC_EXCLUDE) == 0
303	  && i->output_section != NULL
304	  && i->output_section->owner == output_bfd)
305	{
306	  if (!ppc64_elf_next_input_section (&link_info, i))
307	    einfo ("%X%P: can not size stub section: %E\n");
308	}
309    }
310}
311
312
313/* Final emulation specific call.  */
314
315static void
316gld${EMULATION_NAME}_finish (void)
317{
318  /* e_entry on PowerPC64 points to the function descriptor for
319     _start.  If _start is missing, default to the first function
320     descriptor in the .opd section.  */
321  entry_section = ".opd";
322
323  /* bfd_elf_discard_info just plays with debugging sections,
324     ie. doesn't affect any code, so we can delay resizing the
325     sections.  It's likely we'll resize everything in the process of
326     adding stubs.  */
327  if (bfd_elf_discard_info (output_bfd, &link_info))
328    need_laying_out = 1;
329
330  /* If generating a relocatable output file, then we don't have any
331     stubs.  */
332  if (stub_file != NULL && !link_info.relocatable)
333    {
334      int ret = ppc64_elf_setup_section_lists (output_bfd, &link_info,
335					       no_multi_toc);
336      if (ret < 0)
337	einfo ("%X%P: can not size stub section: %E\n");
338      else if (ret > 0)
339	{
340	  toc_section = bfd_get_section_by_name (output_bfd, ".got");
341	  if (toc_section != NULL)
342	    lang_for_each_statement (build_toc_list);
343
344	  ppc64_elf_reinit_toc (output_bfd, &link_info);
345
346	  lang_for_each_statement (build_section_lists);
347
348	  /* Call into the BFD backend to do the real work.  */
349	  if (!ppc64_elf_size_stubs (output_bfd,
350				     &link_info,
351				     group_size,
352				     &ppc_add_stub_section,
353				     &ppc_layout_sections_again))
354	    einfo ("%X%P: can not size stub section: %E\n");
355	}
356    }
357
358  if (need_laying_out != -1)
359    gld${EMULATION_NAME}_map_segments (need_laying_out);
360
361  if (link_info.relocatable)
362    {
363      asection *toc = bfd_get_section_by_name (output_bfd, ".toc");
364      if (toc != NULL
365	  && bfd_section_size (output_bfd, toc) > 0x10000)
366	einfo ("%X%P: TOC section size exceeds 64k\n");
367    }
368
369  if (stub_added)
370    {
371      char *msg = NULL;
372      char *line, *endline;
373
374      emit_stub_syms |= link_info.emitrelocations;
375      if (!ppc64_elf_build_stubs (emit_stub_syms, &link_info,
376				  config.stats ? &msg : NULL))
377	einfo ("%X%P: can not build stubs: %E\n");
378
379      for (line = msg; line != NULL; line = endline)
380	{
381	  endline = strchr (line, '\n');
382	  if (endline != NULL)
383	    *endline++ = '\0';
384	  fprintf (stderr, "%s: %s\n", program_name, line);
385	}
386      if (msg != NULL)
387	free (msg);
388    }
389
390  ppc64_elf_restore_symbols (&link_info);
391  finish_default ();
392}
393
394
395/* Add a pattern matching ".foo" for every "foo" in a version script.
396
397   The reason for doing this is that many shared library version
398   scripts export a selected set of functions or data symbols, forcing
399   others local.  eg.
400
401   . VERS_1 {
402   .       global:
403   .               this; that; some; thing;
404   .       local:
405   .               *;
406   .   };
407
408   To make the above work for PowerPC64, we need to export ".this",
409   ".that" and so on, otherwise only the function descriptor syms are
410   exported.  Lack of an exported function code sym may cause a
411   definition to be pulled in from a static library.  */
412
413static struct bfd_elf_version_expr *
414gld${EMULATION_NAME}_new_vers_pattern (struct bfd_elf_version_expr *entry)
415{
416  struct bfd_elf_version_expr *dot_entry;
417  unsigned int len;
418  char *dot_pat;
419
420  if (!dotsyms
421      || (entry->pattern != NULL
422	  && (entry->pattern[0] == '*' || entry->pattern[0] == '.')))
423    return entry;
424
425  dot_entry = xmalloc (sizeof *dot_entry);
426  *dot_entry = *entry;
427  dot_entry->next = entry;
428  if (entry->pattern != NULL)
429    {
430      len = strlen (entry->pattern) + 2;
431      dot_pat = xmalloc (len);
432      dot_pat[0] = '.';
433      memcpy (dot_pat + 1, entry->pattern, len - 1);
434      dot_entry->pattern = dot_pat;
435    }
436  if (entry->symbol != NULL)
437    {
438      len = strlen (entry->symbol) + 2;
439      dot_pat = xmalloc (len);
440      dot_pat[0] = '.';
441      memcpy (dot_pat + 1, entry->symbol, len - 1);
442      dot_entry->symbol = dot_pat;
443    }
444  return dot_entry;
445}
446
447
448/* Avoid processing the fake stub_file in vercheck, stat_needed and
449   check_needed routines.  */
450
451static void (*real_func) (lang_input_statement_type *);
452
453static void ppc_for_each_input_file_wrapper (lang_input_statement_type *l)
454{
455  if (l != stub_file)
456    (*real_func) (l);
457}
458
459static void
460ppc_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
461{
462  real_func = func;
463  lang_for_each_input_file (&ppc_for_each_input_file_wrapper);
464}
465
466#define lang_for_each_input_file ppc_lang_for_each_input_file
467
468EOF
469
470if grep -q 'ld_elf32_spu_emulation' ldemul-list.h; then
471  cat >>e${EMULATION_NAME}.c <<EOF
472/* Special handling for embedded SPU executables.  */
473extern bfd_boolean embedded_spu_file (lang_input_statement_type *, const char *);
474static bfd_boolean gld${EMULATION_NAME}_load_symbols (lang_input_statement_type *);
475
476static bfd_boolean
477ppc64_recognized_file (lang_input_statement_type *entry)
478{
479  if (embedded_spu_file (entry, "-m64"))
480    return TRUE;
481
482  return gld${EMULATION_NAME}_load_symbols (entry);
483}
484EOF
485LDEMUL_RECOGNIZED_FILE=ppc64_recognized_file
486fi
487
488# Define some shell vars to insert bits of code into the standard elf
489# parse_args and list_options functions.
490#
491PARSE_AND_LIST_PROLOGUE='
492#define OPTION_STUBGROUP_SIZE		301
493#define OPTION_STUBSYMS			(OPTION_STUBGROUP_SIZE + 1)
494#define OPTION_DOTSYMS			(OPTION_STUBSYMS + 1)
495#define OPTION_NO_DOTSYMS		(OPTION_DOTSYMS + 1)
496#define OPTION_NO_TLS_OPT		(OPTION_NO_DOTSYMS + 1)
497#define OPTION_NO_OPD_OPT		(OPTION_NO_TLS_OPT + 1)
498#define OPTION_NO_TOC_OPT		(OPTION_NO_OPD_OPT + 1)
499#define OPTION_NO_MULTI_TOC		(OPTION_NO_TOC_OPT + 1)
500#define OPTION_NON_OVERLAPPING_OPD	(OPTION_NO_MULTI_TOC + 1)
501'
502
503PARSE_AND_LIST_LONGOPTS='
504  { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE },
505  { "emit-stub-syms", no_argument, NULL, OPTION_STUBSYMS },
506  { "dotsyms", no_argument, NULL, OPTION_DOTSYMS },
507  { "no-dotsyms", no_argument, NULL, OPTION_NO_DOTSYMS },
508  { "no-tls-optimize", no_argument, NULL, OPTION_NO_TLS_OPT },
509  { "no-opd-optimize", no_argument, NULL, OPTION_NO_OPD_OPT },
510  { "no-toc-optimize", no_argument, NULL, OPTION_NO_TOC_OPT },
511  { "no-multi-toc", no_argument, NULL, OPTION_NO_MULTI_TOC },
512  { "non-overlapping-opd", no_argument, NULL, OPTION_NON_OVERLAPPING_OPD },
513'
514
515PARSE_AND_LIST_OPTIONS='
516  fprintf (file, _("\
517  --stub-group-size=N   Maximum size of a group of input sections that can be\n\
518                          handled by one stub section.  A negative value\n\
519                          locates all stubs before their branches (with a\n\
520                          group size of -N), while a positive value allows\n\
521                          two groups of input sections, one before, and one\n\
522                          after each stub section.  Values of +/-1 indicate\n\
523                          the linker should choose suitable defaults.\n"
524		   ));
525  fprintf (file, _("\
526  --emit-stub-syms      Label linker stubs with a symbol.\n"
527		   ));
528  fprintf (file, _("\
529  --dotsyms             For every version pattern \"foo\" in a version script,\n\
530                          add \".foo\" so that function code symbols are\n\
531                          treated the same as function descriptor symbols.\n\
532                          Defaults to on.\n"
533		   ));
534  fprintf (file, _("\
535  --no-dotsyms          Don'\''t do anything special in version scripts.\n"
536		   ));
537  fprintf (file, _("\
538  --no-tls-optimize     Don'\''t try to optimize TLS accesses.\n"
539		   ));
540  fprintf (file, _("\
541  --no-opd-optimize     Don'\''t optimize the OPD section.\n"
542		   ));
543  fprintf (file, _("\
544  --no-toc-optimize     Don'\''t optimize the TOC section.\n"
545		   ));
546  fprintf (file, _("\
547  --no-multi-toc        Disallow automatic multiple toc sections.\n"
548		   ));
549  fprintf (file, _("\
550  --non-overlapping-opd Canonicalize .opd, so that there are no overlapping\n\
551                          .opd entries.\n"
552		   ));
553'
554
555PARSE_AND_LIST_ARGS_CASES='
556    case OPTION_STUBGROUP_SIZE:
557      {
558	const char *end;
559        group_size = bfd_scan_vma (optarg, &end, 0);
560        if (*end)
561	  einfo (_("%P%F: invalid number `%s'\''\n"), optarg);
562      }
563      break;
564
565    case OPTION_STUBSYMS:
566      emit_stub_syms = 1;
567      break;
568
569    case OPTION_DOTSYMS:
570      dotsyms = 1;
571      break;
572
573    case OPTION_NO_DOTSYMS:
574      dotsyms = 0;
575      break;
576
577    case OPTION_NO_TLS_OPT:
578      no_tls_opt = 1;
579      break;
580
581    case OPTION_NO_OPD_OPT:
582      no_opd_opt = 1;
583      break;
584
585    case OPTION_NO_TOC_OPT:
586      no_toc_opt = 1;
587      break;
588
589    case OPTION_NO_MULTI_TOC:
590      no_multi_toc = 1;
591      break;
592
593    case OPTION_NON_OVERLAPPING_OPD:
594      non_overlapping_opd = 1;
595      break;
596'
597
598# Put these extra ppc64elf routines in ld_${EMULATION_NAME}_emulation
599#
600LDEMUL_BEFORE_ALLOCATION=ppc_before_allocation
601LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation
602LDEMUL_FINISH=gld${EMULATION_NAME}_finish
603LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=ppc_create_output_section_statements
604LDEMUL_NEW_VERS_PATTERN=gld${EMULATION_NAME}_new_vers_pattern
605