1# This shell script emits a C file. -*- C -*-
2#   Copyright (C) 2004-2014 Free Software Foundation, Inc.
3#
4# This file is part of the 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
21fragment <<EOF
22
23#include "ldctor.h"
24#include "elf/mips.h"
25#include "elfxx-mips.h"
26
27#define is_mips_elf(bfd)				\
28  (bfd_get_flavour (bfd) == bfd_target_elf_flavour	\
29   && elf_tdata (bfd) != NULL				\
30   && elf_object_id (bfd) == MIPS_ELF_DATA)
31
32/* Fake input file for stubs.  */
33static lang_input_statement_type *stub_file;
34static bfd *stub_bfd;
35
36static bfd_boolean insn32;
37static bfd_boolean compact_branches;
38
39static void
40mips_after_parse (void)
41{
42  /* .gnu.hash and the MIPS ABI require .dynsym to be sorted in different
43     ways.  .gnu.hash needs symbols to be grouped by hash code whereas the
44     MIPS ABI requires a mapping between the GOT and the symbol table.  */
45  if (link_info.emit_gnu_hash)
46    {
47      einfo ("%X%P: .gnu.hash is incompatible with the MIPS ABI\n");
48      link_info.emit_hash = TRUE;
49      link_info.emit_gnu_hash = FALSE;
50    }
51  after_parse_default ();
52}
53
54struct hook_stub_info
55{
56  lang_statement_list_type add;
57  asection *input_section;
58};
59
60/* Traverse the linker tree to find the spot where the stub goes.  */
61
62static bfd_boolean
63hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
64{
65  lang_statement_union_type *l;
66  bfd_boolean ret;
67
68  for (; (l = *lp) != NULL; lp = &l->header.next)
69    {
70      switch (l->header.type)
71	{
72	case lang_constructors_statement_enum:
73	  ret = hook_in_stub (info, &constructor_list.head);
74	  if (ret)
75	    return ret;
76	  break;
77
78	case lang_output_section_statement_enum:
79	  ret = hook_in_stub (info,
80			      &l->output_section_statement.children.head);
81	  if (ret)
82	    return ret;
83	  break;
84
85	case lang_wild_statement_enum:
86	  ret = hook_in_stub (info, &l->wild_statement.children.head);
87	  if (ret)
88	    return ret;
89	  break;
90
91	case lang_group_statement_enum:
92	  ret = hook_in_stub (info, &l->group_statement.children.head);
93	  if (ret)
94	    return ret;
95	  break;
96
97	case lang_input_section_enum:
98	  if (info->input_section == NULL
99	      || l->input_section.section == info->input_section)
100	    {
101	      /* We've found our section.  Insert the stub immediately
102		 before its associated input section.  */
103	      *lp = info->add.head;
104	      *(info->add.tail) = l;
105	      return TRUE;
106	    }
107	  break;
108
109	case lang_data_statement_enum:
110	case lang_reloc_statement_enum:
111	case lang_object_symbols_statement_enum:
112	case lang_output_statement_enum:
113	case lang_target_statement_enum:
114	case lang_input_statement_enum:
115	case lang_assignment_statement_enum:
116	case lang_padding_statement_enum:
117	case lang_address_statement_enum:
118	case lang_fill_statement_enum:
119	  break;
120
121	default:
122	  FAIL ();
123	  break;
124	}
125    }
126  return FALSE;
127}
128
129/* Create a new stub section called STUB_SEC_NAME and arrange for it to
130   be linked in OUTPUT_SECTION.  The section should go at the beginning of
131   OUTPUT_SECTION if INPUT_SECTION is null, otherwise it must go immediately
132   before INPUT_SECTION.  */
133
134static asection *
135mips_add_stub_section (const char *stub_sec_name, asection *input_section,
136		       asection *output_section)
137{
138  asection *stub_sec;
139  flagword flags;
140  lang_output_section_statement_type *os;
141  struct hook_stub_info info;
142
143  /* PR 12845: If the input section has been garbage collected it will
144     not have its output section set to *ABS*.  */
145  if (bfd_is_abs_section (output_section))
146    return NULL;
147
148  /* Create the stub file, if we haven't already.  */
149  if (stub_file == NULL)
150    {
151      stub_file = lang_add_input_file ("linker stubs",
152				       lang_input_file_is_fake_enum,
153				       NULL);
154      stub_bfd = bfd_create ("linker stubs", link_info.output_bfd);
155      if (stub_bfd == NULL
156	  || !bfd_set_arch_mach (stub_bfd,
157				 bfd_get_arch (link_info.output_bfd),
158				 bfd_get_mach (link_info.output_bfd)))
159	{
160	  einfo ("%F%P: can not create BFD %E\n");
161	  return NULL;
162	}
163      stub_bfd->flags |= BFD_LINKER_CREATED;
164      stub_file->the_bfd = stub_bfd;
165      ldlang_add_file (stub_file);
166    }
167
168  /* Create the section.  */
169  stub_sec = bfd_make_section_anyway (stub_bfd, stub_sec_name);
170  if (stub_sec == NULL)
171    goto err_ret;
172
173  /* Set the flags.  */
174  flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
175	   | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_KEEP);
176  if (!bfd_set_section_flags (stub_bfd, stub_sec, flags))
177    goto err_ret;
178
179  os = lang_output_section_get (output_section);
180
181  /* Initialize a statement list that contains only the new statement.  */
182  lang_list_init (&info.add);
183  lang_add_section (&info.add, stub_sec, NULL, os);
184  if (info.add.head == NULL)
185    goto err_ret;
186
187  /* Insert the new statement in the appropriate place.  */
188  info.input_section = input_section;
189  if (hook_in_stub (&info, &os->children.head))
190    return stub_sec;
191
192 err_ret:
193  einfo ("%X%P: can not make stub section: %E\n");
194  return NULL;
195}
196
197/* This is called before the input files are opened.  */
198
199static void
200mips_create_output_section_statements (void)
201{
202  struct elf_link_hash_table *htab;
203
204  htab = elf_hash_table (&link_info);
205  if (is_elf_hash_table (htab) && is_mips_elf (link_info.output_bfd))
206    _bfd_mips_elf_insn32 (&link_info, insn32);
207
208  if (is_mips_elf (link_info.output_bfd))
209    {
210      _bfd_mips_elf_compact_branches (&link_info, compact_branches);
211      _bfd_mips_elf_init_stubs (&link_info, mips_add_stub_section);
212    }
213}
214
215/* This is called after we have merged the private data of the input bfds.  */
216
217static void
218mips_before_allocation (void)
219{
220  flagword flags;
221
222  flags = elf_elfheader (link_info.output_bfd)->e_flags;
223  if (!link_info.shared
224      && !link_info.nocopyreloc
225      && (flags & (EF_MIPS_PIC | EF_MIPS_CPIC)) == EF_MIPS_CPIC)
226    _bfd_mips_elf_use_plts_and_copy_relocs (&link_info);
227
228  gld${EMULATION_NAME}_before_allocation ();
229}
230
231/* Avoid processing the fake stub_file in vercheck, stat_needed and
232   check_needed routines.  */
233
234static void (*real_func) (lang_input_statement_type *);
235
236static void mips_for_each_input_file_wrapper (lang_input_statement_type *l)
237{
238  if (l != stub_file)
239    (*real_func) (l);
240}
241
242static void
243mips_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
244{
245  real_func = func;
246  lang_for_each_input_file (&mips_for_each_input_file_wrapper);
247}
248
249#define lang_for_each_input_file mips_lang_for_each_input_file
250
251EOF
252
253# Define some shell vars to insert bits of code into the standard elf
254# parse_args and list_options functions.
255#
256PARSE_AND_LIST_PROLOGUE='
257#define OPTION_INSN32			301
258#define OPTION_NO_INSN32		(OPTION_INSN32 + 1)
259#define OPTION_COMPACT_BRANCHES		(OPTION_NO_INSN32 + 1)
260#define OPTION_NO_COMPACT_BRANCHES	(OPTION_COMPACT_BRANCHES + 1)
261'
262
263PARSE_AND_LIST_LONGOPTS='
264  { "insn32", no_argument, NULL, OPTION_INSN32 },
265  { "no-insn32", no_argument, NULL, OPTION_NO_INSN32 },
266  { "compact-branches", no_argument, NULL, OPTION_COMPACT_BRANCHES },
267  { "no-compact-branches", no_argument, NULL, OPTION_NO_COMPACT_BRANCHES },
268'
269
270PARSE_AND_LIST_OPTIONS='
271  fprintf (file, _("\
272  --insn32                    Only generate 32-bit microMIPS instructions\n"
273		   ));
274  fprintf (file, _("\
275  --no-insn32                 Generate all microMIPS instructions\n"
276		   ));
277  fprintf (file, _("\
278  --compact-branches          Generate compact branches/jumps for MIPS R6\n"
279		   ));
280  fprintf (file, _("\
281  --no-compact-branches       Generate delay slot branches/jumps for MIPS R6\n"
282		   ));
283'
284
285PARSE_AND_LIST_ARGS_CASES='
286    case OPTION_INSN32:
287      insn32 = TRUE;
288      break;
289
290    case OPTION_NO_INSN32:
291      insn32 = FALSE;
292      break;
293
294    case OPTION_COMPACT_BRANCHES:
295      compact_branches = TRUE;
296      break;
297
298    case OPTION_NO_COMPACT_BRANCHES:
299      compact_branches = FALSE;
300      break;
301'
302
303LDEMUL_AFTER_PARSE=mips_after_parse
304LDEMUL_BEFORE_ALLOCATION=mips_before_allocation
305LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=mips_create_output_section_statements
306