1# This shell script emits a C file. -*- C -*-
2#   Copyright (C) 2013-2016 Free Software Foundation, Inc.
3#
4# This file is part of GNU Binutils.
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 3 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,
19# MA 02110-1301, USA.
20#
21
22# This file is sourced from elf32.em, and defines extra Nios II ELF
23# specific routines. Taken from metagelf.em.
24#
25fragment <<EOF
26
27#include "ldctor.h"
28#include "elf32-nios2.h"
29
30
31/* Fake input file for stubs.  */
32static lang_input_statement_type *stub_file;
33
34/* Whether we need to call nios2_layout_sections_again.  */
35static int need_laying_out = 0;
36
37
38/* This is called before the input files are opened.  We create a new
39   fake input file to hold the stub sections.  */
40
41static void
42nios2elf_create_output_section_statements (void)
43{
44  extern const bfd_target nios2_elf32_le_vec, nios2_elf32_be_vec;
45
46  if (link_info.output_bfd->xvec != &nios2_elf32_le_vec
47      && link_info.output_bfd->xvec != &nios2_elf32_be_vec)
48    return;
49
50  /* If --no-relax was not explicitly specified by the user, enable
51     relaxation.  If it's not enabled (either explicitly or by default),
52     we're done, as we won't need to create any stubs.  */
53  if (!bfd_link_relocatable (&link_info) && RELAXATION_DISABLED_BY_DEFAULT)
54    ENABLE_RELAXATION;
55  if (!RELAXATION_ENABLED)
56    return;
57
58  stub_file = lang_add_input_file ("linker stubs",
59				   lang_input_file_is_fake_enum,
60				   NULL);
61  stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);
62  if (stub_file->the_bfd == NULL
63      || ! bfd_set_arch_mach (stub_file->the_bfd,
64			      bfd_get_arch (link_info.output_bfd),
65			      bfd_get_mach (link_info.output_bfd)))
66    {
67      einfo ("%X%P: can not create BFD %E\n");
68      return;
69    }
70
71  stub_file->the_bfd->flags |= BFD_LINKER_CREATED;
72  ldlang_add_file (stub_file);
73}
74
75
76struct hook_stub_info
77{
78  lang_statement_list_type add;
79  asection *input_section;
80};
81
82/* Traverse the linker tree to find the spot where the stub goes.  */
83
84static bfd_boolean
85hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp,
86	      bfd_boolean afterp)
87{
88  lang_statement_union_type *l;
89  bfd_boolean ret;
90
91  for (; (l = *lp) != NULL; lp = &l->header.next)
92    {
93      switch (l->header.type)
94	{
95	case lang_constructors_statement_enum:
96	  ret = hook_in_stub (info, &constructor_list.head, afterp);
97	  if (ret)
98	    return ret;
99	  break;
100
101	case lang_output_section_statement_enum:
102	  ret = hook_in_stub (info,
103			      &l->output_section_statement.children.head,
104			      afterp);
105	  if (ret)
106	    return ret;
107	  break;
108
109	case lang_wild_statement_enum:
110	  ret = hook_in_stub (info, &l->wild_statement.children.head, afterp);
111	  if (ret)
112	    return ret;
113	  break;
114
115	case lang_group_statement_enum:
116	  ret = hook_in_stub (info, &l->group_statement.children.head, afterp);
117	  if (ret)
118	    return ret;
119	  break;
120
121	case lang_input_section_enum:
122	  if (l->input_section.section == info->input_section)
123	    {
124	      /* We've found our section.  Insert the stub immediately
125		 before or after its associated input section.  */
126	      if (afterp)
127		{
128		  *(info->add.tail) = l->header.next;
129		  l->header.next = info->add.head;
130		}
131	      else
132		{
133		  *lp = info->add.head;
134		  *(info->add.tail) = l;
135		}
136	      return TRUE;
137	    }
138	  break;
139
140	case lang_data_statement_enum:
141	case lang_reloc_statement_enum:
142	case lang_object_symbols_statement_enum:
143	case lang_output_statement_enum:
144	case lang_target_statement_enum:
145	case lang_input_statement_enum:
146	case lang_assignment_statement_enum:
147	case lang_padding_statement_enum:
148	case lang_address_statement_enum:
149	case lang_fill_statement_enum:
150	  break;
151
152	default:
153	  FAIL ();
154	  break;
155	}
156    }
157  return FALSE;
158}
159
160/* Call-back for elf32_nios2_size_stubs.  */
161
162/* Create a new stub section, and arrange for it to be linked
163   immediately before or after INPUT_SECTION, according to AFTERP.  */
164
165static asection *
166nios2elf_add_stub_section (const char *stub_sec_name, asection *input_section,
167			   bfd_boolean afterp)
168{
169  asection *stub_sec;
170  flagword flags;
171  asection *output_section;
172  const char *secname;
173  lang_output_section_statement_type *os;
174  struct hook_stub_info info;
175
176  flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
177	   | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
178  stub_sec = bfd_make_section_anyway_with_flags (stub_file->the_bfd,
179						 stub_sec_name, flags);
180  if (stub_sec == NULL)
181    goto err_ret;
182
183  output_section = input_section->output_section;
184  secname = bfd_get_section_name (output_section->owner, output_section);
185  os = lang_output_section_find (secname);
186
187  info.input_section = input_section;
188  lang_list_init (&info.add);
189  lang_add_section (&info.add, stub_sec, NULL, os);
190
191  if (info.add.head == NULL)
192    goto err_ret;
193
194  if (hook_in_stub (&info, &os->children.head, afterp))
195    return stub_sec;
196
197 err_ret:
198  einfo ("%X%P: can not make stub section: %E\n");
199  return NULL;
200}
201
202
203/* Another call-back for elf32_nios2_size_stubs.  */
204
205static void
206nios2elf_layout_sections_again (void)
207{
208  /* If we have changed sizes of the stub sections, then we need
209     to recalculate all the section offsets.  This may mean we need to
210     add even more stubs.  */
211  gld${EMULATION_NAME}_map_segments (TRUE);
212  need_laying_out = -1;
213}
214
215
216static void
217build_section_lists (lang_statement_union_type *statement)
218{
219  if (statement->header.type == lang_input_section_enum)
220    {
221      asection *i = statement->input_section.section;
222
223      if (i->sec_info_type != SEC_INFO_TYPE_JUST_SYMS
224	  && (i->flags & SEC_EXCLUDE) == 0
225	  && i->output_section != NULL
226	  && i->output_section->owner == link_info.output_bfd)
227	{
228	  nios2_elf32_next_input_section (&link_info, i);
229	}
230    }
231}
232
233
234/* For Nios II we use this opportunity to build linker stubs.  */
235
236static void
237gld${EMULATION_NAME}_after_allocation (void)
238{
239  int ret;
240
241  /* bfd_elf_discard_info just plays with data and debugging sections,
242     ie. doesn't affect code size, so we can delay resizing the
243     sections.  It's likely we'll resize everything in the process of
244     adding stubs.  */
245  ret = bfd_elf_discard_info (link_info.output_bfd, &link_info);
246  if (ret < 0)
247    {
248      einfo ("%X%P: .eh_frame/.stab edit: %E\n");
249      return;
250    }
251  else if (ret > 0)
252    need_laying_out = 1;
253
254  /* If generating a relocatable output file, then we don't
255     have to examine the relocs.  */
256  if (stub_file != NULL
257      && !bfd_link_relocatable (&link_info)
258      && RELAXATION_ENABLED)
259    {
260      ret = nios2_elf32_setup_section_lists (link_info.output_bfd, &link_info);
261      if (ret != 0)
262	{
263	  if (ret < 0)
264	    {
265	      einfo ("%X%P: can not size stub section: %E\n");
266	      return;
267	    }
268
269	  lang_for_each_statement (build_section_lists);
270
271	  /* Call into the BFD backend to do the real work.  */
272	  if (! nios2_elf32_size_stubs (link_info.output_bfd,
273					stub_file->the_bfd,
274					&link_info,
275					&nios2elf_add_stub_section,
276					&nios2elf_layout_sections_again))
277	    {
278	      einfo ("%X%P: can not size stub section: %E\n");
279	      return;
280	    }
281	}
282    }
283
284  if (need_laying_out != -1)
285    gld${EMULATION_NAME}_map_segments (need_laying_out);
286
287  if (!bfd_link_relocatable (&link_info) && RELAXATION_ENABLED)
288    {
289      /* Now build the linker stubs.  */
290      if (stub_file != NULL && stub_file->the_bfd->sections != NULL)
291	{
292	  if (! nios2_elf32_build_stubs (&link_info))
293	    einfo ("%X%P: can not build stubs: %E\n");
294	}
295    }
296}
297
298
299/* Avoid processing the fake stub_file in vercheck, stat_needed and
300   check_needed routines.  */
301
302static void (*real_func) (lang_input_statement_type *);
303
304static void nios2_for_each_input_file_wrapper (lang_input_statement_type *l)
305{
306  if (l != stub_file)
307    (*real_func) (l);
308}
309
310static void
311nios2_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
312{
313  real_func = func;
314  lang_for_each_input_file (&nios2_for_each_input_file_wrapper);
315}
316
317#define lang_for_each_input_file nios2_lang_for_each_input_file
318
319EOF
320
321
322# Put these extra nios2elf routines in ld_${EMULATION_NAME}_emulation
323#
324LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation
325LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=nios2elf_create_output_section_statements
326