1# This shell script emits a C file. -*- C -*-
2#   Copyright (C) 2004-2016 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;
37
38static void
39mips_after_parse (void)
40{
41  /* .gnu.hash and the MIPS ABI require .dynsym to be sorted in different
42     ways.  .gnu.hash needs symbols to be grouped by hash code whereas the
43     MIPS ABI requires a mapping between the GOT and the symbol table.  */
44  if (link_info.emit_gnu_hash)
45    {
46      einfo ("%X%P: .gnu.hash is incompatible with the MIPS ABI\n");
47      link_info.emit_hash = TRUE;
48      link_info.emit_gnu_hash = FALSE;
49    }
50  gld${EMULATION_NAME}_after_parse ();
51}
52
53struct hook_stub_info
54{
55  lang_statement_list_type add;
56  asection *input_section;
57};
58
59/* Traverse the linker tree to find the spot where the stub goes.  */
60
61static bfd_boolean
62hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
63{
64  lang_statement_union_type *l;
65  bfd_boolean ret;
66
67  for (; (l = *lp) != NULL; lp = &l->header.next)
68    {
69      switch (l->header.type)
70	{
71	case lang_constructors_statement_enum:
72	  ret = hook_in_stub (info, &constructor_list.head);
73	  if (ret)
74	    return ret;
75	  break;
76
77	case lang_output_section_statement_enum:
78	  ret = hook_in_stub (info,
79			      &l->output_section_statement.children.head);
80	  if (ret)
81	    return ret;
82	  break;
83
84	case lang_wild_statement_enum:
85	  ret = hook_in_stub (info, &l->wild_statement.children.head);
86	  if (ret)
87	    return ret;
88	  break;
89
90	case lang_group_statement_enum:
91	  ret = hook_in_stub (info, &l->group_statement.children.head);
92	  if (ret)
93	    return ret;
94	  break;
95
96	case lang_input_section_enum:
97	  if (info->input_section == NULL
98	      || l->input_section.section == info->input_section)
99	    {
100	      /* We've found our section.  Insert the stub immediately
101		 before its associated input section.  */
102	      *lp = info->add.head;
103	      *(info->add.tail) = l;
104	      return TRUE;
105	    }
106	  break;
107
108	case lang_data_statement_enum:
109	case lang_reloc_statement_enum:
110	case lang_object_symbols_statement_enum:
111	case lang_output_statement_enum:
112	case lang_target_statement_enum:
113	case lang_input_statement_enum:
114	case lang_assignment_statement_enum:
115	case lang_padding_statement_enum:
116	case lang_address_statement_enum:
117	case lang_fill_statement_enum:
118	  break;
119
120	default:
121	  FAIL ();
122	  break;
123	}
124    }
125  return FALSE;
126}
127
128/* Create a new stub section called STUB_SEC_NAME and arrange for it to
129   be linked in OUTPUT_SECTION.  The section should go at the beginning of
130   OUTPUT_SECTION if INPUT_SECTION is null, otherwise it must go immediately
131   before INPUT_SECTION.  */
132
133static asection *
134mips_add_stub_section (const char *stub_sec_name, asection *input_section,
135		       asection *output_section)
136{
137  asection *stub_sec;
138  flagword flags;
139  lang_output_section_statement_type *os;
140  struct hook_stub_info info;
141
142  /* PR 12845: If the input section has been garbage collected it will
143     not have its output section set to *ABS*.  */
144  if (bfd_is_abs_section (output_section))
145    return NULL;
146
147  /* Create the stub file, if we haven't already.  */
148  if (stub_file == NULL)
149    {
150      stub_file = lang_add_input_file ("linker stubs",
151				       lang_input_file_is_fake_enum,
152				       NULL);
153      stub_bfd = bfd_create ("linker stubs", link_info.output_bfd);
154      if (stub_bfd == NULL
155	  || !bfd_set_arch_mach (stub_bfd,
156				 bfd_get_arch (link_info.output_bfd),
157				 bfd_get_mach (link_info.output_bfd)))
158	{
159	  einfo ("%F%P: can not create BFD %E\n");
160	  return NULL;
161	}
162      stub_bfd->flags |= BFD_LINKER_CREATED;
163      stub_file->the_bfd = stub_bfd;
164      ldlang_add_file (stub_file);
165    }
166
167  /* Create the section.  */
168  stub_sec = bfd_make_section_anyway (stub_bfd, stub_sec_name);
169  if (stub_sec == NULL)
170    goto err_ret;
171
172  /* Set the flags.  */
173  flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
174	   | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_KEEP);
175  if (!bfd_set_section_flags (stub_bfd, stub_sec, flags))
176    goto err_ret;
177
178  os = lang_output_section_get (output_section);
179
180  /* Initialize a statement list that contains only the new statement.  */
181  lang_list_init (&info.add);
182  lang_add_section (&info.add, stub_sec, NULL, os);
183  if (info.add.head == NULL)
184    goto err_ret;
185
186  /* Insert the new statement in the appropriate place.  */
187  info.input_section = input_section;
188  if (hook_in_stub (&info, &os->children.head))
189    return stub_sec;
190
191 err_ret:
192  einfo ("%X%P: can not make stub section: %E\n");
193  return NULL;
194}
195
196/* This is called before the input files are opened.  */
197
198static void
199mips_create_output_section_statements (void)
200{
201  struct elf_link_hash_table *htab;
202
203  htab = elf_hash_table (&link_info);
204  if (is_elf_hash_table (htab) && is_mips_elf (link_info.output_bfd))
205    _bfd_mips_elf_insn32 (&link_info, insn32);
206
207  if (is_mips_elf (link_info.output_bfd))
208    _bfd_mips_elf_init_stubs (&link_info, mips_add_stub_section);
209}
210
211/* This is called after we have merged the private data of the input bfds.  */
212
213static void
214mips_before_allocation (void)
215{
216  flagword flags;
217
218  flags = elf_elfheader (link_info.output_bfd)->e_flags;
219  if (!bfd_link_pic (&link_info)
220      && !link_info.nocopyreloc
221      && (flags & (EF_MIPS_PIC | EF_MIPS_CPIC)) == EF_MIPS_CPIC)
222    _bfd_mips_elf_use_plts_and_copy_relocs (&link_info);
223
224  gld${EMULATION_NAME}_before_allocation ();
225}
226
227/* Avoid processing the fake stub_file in vercheck, stat_needed and
228   check_needed routines.  */
229
230static void (*real_func) (lang_input_statement_type *);
231
232static void mips_for_each_input_file_wrapper (lang_input_statement_type *l)
233{
234  if (l != stub_file)
235    (*real_func) (l);
236}
237
238static void
239mips_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
240{
241  real_func = func;
242  lang_for_each_input_file (&mips_for_each_input_file_wrapper);
243}
244
245#define lang_for_each_input_file mips_lang_for_each_input_file
246
247EOF
248
249# Define some shell vars to insert bits of code into the standard elf
250# parse_args and list_options functions.
251#
252PARSE_AND_LIST_PROLOGUE='
253enum
254  {
255    OPTION_INSN32 = 301,
256    OPTION_NO_INSN32
257  };
258'
259
260PARSE_AND_LIST_LONGOPTS='
261  { "insn32", no_argument, NULL, OPTION_INSN32 },
262  { "no-insn32", no_argument, NULL, OPTION_NO_INSN32 },
263'
264
265PARSE_AND_LIST_OPTIONS='
266  fprintf (file, _("\
267  --insn32                    Only generate 32-bit microMIPS instructions\n"
268		   ));
269  fprintf (file, _("\
270  --no-insn32                 Generate all microMIPS instructions\n"
271		   ));
272'
273
274PARSE_AND_LIST_ARGS_CASES='
275    case OPTION_INSN32:
276      insn32 = TRUE;
277      break;
278
279    case OPTION_NO_INSN32:
280      insn32 = FALSE;
281      break;
282'
283
284LDEMUL_AFTER_PARSE=mips_after_parse
285LDEMUL_BEFORE_ALLOCATION=mips_before_allocation
286LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=mips_create_output_section_statements
287