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d871d478 | 1 | /* Emulation code used by all ELF targets. |
b3adc24a | 2 | Copyright (C) 1991-2020 Free Software Foundation, Inc. |
d871d478 AM |
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 | ||
21 | #include "sysdep.h" | |
22 | #include "bfd.h" | |
0b4453c7 | 23 | #include "bfdlink.h" |
1ff6de03 | 24 | #include "ctf-api.h" |
d871d478 AM |
25 | #include "ld.h" |
26 | #include "ldmain.h" | |
27 | #include "ldmisc.h" | |
28 | #include "ldexp.h" | |
29 | #include "ldlang.h" | |
30 | #include "elf-bfd.h" | |
31 | #include "ldelfgen.h" | |
32 | ||
33 | void | |
34 | ldelf_map_segments (bfd_boolean need_layout) | |
35 | { | |
36 | int tries = 10; | |
37 | ||
38 | do | |
39 | { | |
40 | lang_relax_sections (need_layout); | |
41 | need_layout = FALSE; | |
42 | ||
43 | if (link_info.output_bfd->xvec->flavour == bfd_target_elf_flavour | |
44 | && !bfd_link_relocatable (&link_info)) | |
45 | { | |
46 | bfd_size_type phdr_size; | |
47 | ||
48 | phdr_size = elf_program_header_size (link_info.output_bfd); | |
49 | /* If we don't have user supplied phdrs, throw away any | |
50 | previous linker generated program headers. */ | |
51 | if (lang_phdr_list == NULL) | |
52 | elf_seg_map (link_info.output_bfd) = NULL; | |
53 | if (!_bfd_elf_map_sections_to_segments (link_info.output_bfd, | |
54 | &link_info)) | |
55 | einfo (_("%F%P: map sections to segments failed: %E\n")); | |
56 | ||
57 | if (phdr_size != elf_program_header_size (link_info.output_bfd)) | |
58 | { | |
59 | if (tries > 6) | |
60 | /* The first few times we allow any change to | |
61 | phdr_size . */ | |
62 | need_layout = TRUE; | |
63 | else if (phdr_size | |
64 | < elf_program_header_size (link_info.output_bfd)) | |
65 | /* After that we only allow the size to grow. */ | |
66 | need_layout = TRUE; | |
67 | else | |
68 | elf_program_header_size (link_info.output_bfd) = phdr_size; | |
69 | } | |
70 | } | |
71 | } | |
72 | while (need_layout && --tries); | |
73 | ||
74 | if (tries == 0) | |
75 | einfo (_("%F%P: looping in map_segments")); | |
6f6fd151 L |
76 | |
77 | if (link_info.output_bfd->xvec->flavour == bfd_target_elf_flavour | |
78 | && lang_phdr_list == NULL) | |
79 | { | |
80 | /* If we don't have user supplied phdrs, strip zero-sized dynamic | |
81 | sections and regenerate program headers. */ | |
82 | const struct elf_backend_data *bed | |
83 | = get_elf_backend_data (link_info.output_bfd); | |
84 | if (bed->elf_backend_strip_zero_sized_dynamic_sections | |
85 | && !bed->elf_backend_strip_zero_sized_dynamic_sections | |
86 | (&link_info)) | |
87 | einfo (_("%F%P: failed to strip zero-sized dynamic sections")); | |
88 | } | |
d871d478 | 89 | } |
1ff6de03 | 90 | |
094e34f2 | 91 | #ifdef ENABLE_LIBCTF |
1ff6de03 NA |
92 | /* We want to emit CTF early if and only if we are not targetting ELF with this |
93 | invocation. */ | |
94 | ||
95 | int | |
96 | ldelf_emit_ctf_early (void) | |
97 | { | |
98 | if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour) | |
99 | return 0; | |
100 | return 1; | |
101 | } | |
102 | ||
103 | /* Callbacks used to map from bfd types to libctf types, under libctf's | |
104 | control. */ | |
105 | ||
106 | struct ctf_strsym_iter_cb_arg | |
107 | { | |
108 | struct elf_sym_strtab *syms; | |
109 | bfd_size_type symcount; | |
110 | struct elf_strtab_hash *symstrtab; | |
111 | size_t next_i; | |
112 | size_t next_idx; | |
113 | }; | |
114 | ||
115 | /* Return strings from the strtab to libctf, one by one. Returns NULL when | |
116 | iteration is complete. */ | |
117 | ||
118 | static const char * | |
119 | ldelf_ctf_strtab_iter_cb (uint32_t *offset, void *arg_) | |
120 | { | |
121 | bfd_size_type off; | |
122 | const char *ret; | |
123 | ||
124 | struct ctf_strsym_iter_cb_arg *arg = | |
125 | (struct ctf_strsym_iter_cb_arg *) arg_; | |
126 | ||
127 | /* There is no zeroth string. */ | |
128 | if (arg->next_i == 0) | |
129 | arg->next_i = 1; | |
130 | ||
131 | if (arg->next_i >= _bfd_elf_strtab_len (arg->symstrtab)) | |
132 | { | |
133 | arg->next_i = 0; | |
134 | return NULL; | |
135 | } | |
136 | ||
137 | ret = _bfd_elf_strtab_str (arg->symstrtab, arg->next_i++, &off); | |
138 | *offset = off; | |
139 | ||
140 | /* If we've overflowed, we cannot share any further strings: the CTF | |
141 | format cannot encode strings with such high offsets. */ | |
142 | if (*offset != off) | |
143 | return NULL; | |
144 | ||
145 | return ret; | |
146 | } | |
147 | ||
148 | /* Return symbols from the symbol table to libctf, one by one. We assume (and | |
149 | assert) that the symbols in the elf_link_hash_table are in strictly ascending | |
150 | order, and that none will be added in between existing ones. Returns NULL | |
151 | when iteration is complete. */ | |
152 | ||
153 | static struct ctf_link_sym * | |
154 | ldelf_ctf_symbols_iter_cb (struct ctf_link_sym *dest, | |
155 | void *arg_) | |
156 | { | |
157 | struct ctf_strsym_iter_cb_arg *arg = | |
158 | (struct ctf_strsym_iter_cb_arg *) arg_; | |
159 | ||
160 | if (arg->next_i > arg->symcount) | |
161 | { | |
162 | arg->next_i = 0; | |
163 | arg->next_idx = 0; | |
164 | return NULL; | |
165 | } | |
166 | ||
167 | ASSERT (arg->syms[arg->next_i].dest_index == arg->next_idx); | |
168 | dest->st_name = _bfd_elf_strtab_str (arg->symstrtab, arg->next_i, NULL); | |
169 | dest->st_shndx = arg->syms[arg->next_i].sym.st_shndx; | |
170 | dest->st_type = ELF_ST_TYPE (arg->syms[arg->next_i].sym.st_info); | |
171 | dest->st_value = arg->syms[arg->next_i].sym.st_value; | |
172 | arg->next_i++; | |
173 | return dest; | |
174 | } | |
175 | ||
176 | void | |
177 | ldelf_examine_strtab_for_ctf | |
178 | (struct ctf_file *ctf_output, struct elf_sym_strtab *syms, | |
179 | bfd_size_type symcount, struct elf_strtab_hash *symstrtab) | |
180 | { | |
181 | struct ctf_strsym_iter_cb_arg args = { syms, symcount, symstrtab, | |
182 | 0, 0 }; | |
183 | if (!ctf_output) | |
184 | return; | |
185 | ||
186 | if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour | |
187 | && !bfd_link_relocatable (&link_info)) | |
188 | { | |
189 | if (ctf_link_add_strtab (ctf_output, ldelf_ctf_strtab_iter_cb, | |
190 | &args) < 0) | |
191 | einfo (_("%F%P: warning: CTF strtab association failed; strings will " | |
192 | "not be shared: %s\n"), | |
193 | ctf_errmsg (ctf_errno (ctf_output))); | |
194 | ||
195 | if (ctf_link_shuffle_syms (ctf_output, ldelf_ctf_symbols_iter_cb, | |
196 | &args) < 0) | |
197 | einfo (_("%F%P: warning: CTF symbol shuffling failed; slight space " | |
198 | "cost: %s\n"), ctf_errmsg (ctf_errno (ctf_output))); | |
199 | } | |
200 | } | |
094e34f2 NA |
201 | #else |
202 | extern int ldelf_emit_ctf_early (void) | |
203 | { | |
204 | return 0; | |
205 | } | |
206 | ||
207 | extern void ldelf_examine_strtab_for_ctf | |
208 | (struct ctf_file *ctf_output ATTRIBUTE_UNUSED, | |
209 | struct elf_sym_strtab *syms ATTRIBUTE_UNUSED, | |
210 | bfd_size_type symcount ATTRIBUTE_UNUSED, | |
211 | struct elf_strtab_hash *symstrtab ATTRIBUTE_UNUSED) | |
212 | {} | |
213 | #endif |