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a2fb1b05 ILT |
1 | // layout.cc -- lay out output file sections for gold |
2 | ||
6cb15b7f ILT |
3 | // Copyright 2006, 2007 Free Software Foundation, Inc. |
4 | // Written by Ian Lance Taylor <iant@google.com>. | |
5 | ||
6 | // This file is part of gold. | |
7 | ||
8 | // This program is free software; you can redistribute it and/or modify | |
9 | // it under the terms of the GNU General Public License as published by | |
10 | // the Free Software Foundation; either version 3 of the License, or | |
11 | // (at your option) any later version. | |
12 | ||
13 | // This program is distributed in the hope that it will be useful, | |
14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | // GNU General Public License for more details. | |
17 | ||
18 | // You should have received a copy of the GNU General Public License | |
19 | // along with this program; if not, write to the Free Software | |
20 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
21 | // MA 02110-1301, USA. | |
22 | ||
a2fb1b05 ILT |
23 | #include "gold.h" |
24 | ||
a2fb1b05 | 25 | #include <cstring> |
54dc6425 | 26 | #include <algorithm> |
a2fb1b05 ILT |
27 | #include <iostream> |
28 | #include <utility> | |
29 | ||
7e1edb90 | 30 | #include "parameters.h" |
a2fb1b05 | 31 | #include "output.h" |
f6ce93d6 | 32 | #include "symtab.h" |
a3ad94ed | 33 | #include "dynobj.h" |
3151305a | 34 | #include "ehframe.h" |
a2fb1b05 ILT |
35 | #include "layout.h" |
36 | ||
37 | namespace gold | |
38 | { | |
39 | ||
92e059d8 | 40 | // Layout_task_runner methods. |
a2fb1b05 ILT |
41 | |
42 | // Lay out the sections. This is called after all the input objects | |
43 | // have been read. | |
44 | ||
45 | void | |
92e059d8 | 46 | Layout_task_runner::run(Workqueue* workqueue) |
a2fb1b05 | 47 | { |
12e14209 ILT |
48 | off_t file_size = this->layout_->finalize(this->input_objects_, |
49 | this->symtab_); | |
61ba1cf9 ILT |
50 | |
51 | // Now we know the final size of the output file and we know where | |
52 | // each piece of information goes. | |
c51e6221 ILT |
53 | Output_file* of = new Output_file(this->options_, |
54 | this->input_objects_->target()); | |
61ba1cf9 ILT |
55 | of->open(file_size); |
56 | ||
57 | // Queue up the final set of tasks. | |
58 | gold::queue_final_tasks(this->options_, this->input_objects_, | |
12e14209 | 59 | this->symtab_, this->layout_, workqueue, of); |
a2fb1b05 ILT |
60 | } |
61 | ||
62 | // Layout methods. | |
63 | ||
54dc6425 | 64 | Layout::Layout(const General_options& options) |
a3ad94ed | 65 | : options_(options), namepool_(), sympool_(), dynpool_(), signatures_(), |
61ba1cf9 | 66 | section_name_map_(), segment_list_(), section_list_(), |
a3ad94ed | 67 | unattached_section_list_(), special_output_list_(), |
14b31740 | 68 | tls_segment_(NULL), symtab_section_(NULL), |
3151305a | 69 | dynsym_section_(NULL), dynamic_section_(NULL), dynamic_data_(NULL), |
35cdfc9a ILT |
70 | eh_frame_section_(NULL), output_file_size_(-1), |
71 | input_requires_executable_stack_(false), | |
72 | input_with_gnu_stack_note_(false), | |
73 | input_without_gnu_stack_note_(false) | |
54dc6425 ILT |
74 | { |
75 | // Make space for more than enough segments for a typical file. | |
76 | // This is just for efficiency--it's OK if we wind up needing more. | |
a3ad94ed ILT |
77 | this->segment_list_.reserve(12); |
78 | ||
79 | // We expect three unattached Output_data objects: the file header, | |
80 | // the segment headers, and the section headers. | |
81 | this->special_output_list_.reserve(3); | |
54dc6425 ILT |
82 | } |
83 | ||
a2fb1b05 ILT |
84 | // Hash a key we use to look up an output section mapping. |
85 | ||
86 | size_t | |
87 | Layout::Hash_key::operator()(const Layout::Key& k) const | |
88 | { | |
f0641a0b | 89 | return k.first + k.second.first + k.second.second; |
a2fb1b05 ILT |
90 | } |
91 | ||
9e2dcb77 ILT |
92 | // Return whether PREFIX is a prefix of STR. |
93 | ||
94 | static inline bool | |
95 | is_prefix_of(const char* prefix, const char* str) | |
96 | { | |
97 | return strncmp(prefix, str, strlen(prefix)) == 0; | |
98 | } | |
99 | ||
a2fb1b05 ILT |
100 | // Whether to include this section in the link. |
101 | ||
102 | template<int size, bool big_endian> | |
103 | bool | |
9e2dcb77 | 104 | Layout::include_section(Object*, const char* name, |
a2fb1b05 ILT |
105 | const elfcpp::Shdr<size, big_endian>& shdr) |
106 | { | |
107 | // Some section types are never linked. Some are only linked when | |
108 | // doing a relocateable link. | |
109 | switch (shdr.get_sh_type()) | |
110 | { | |
111 | case elfcpp::SHT_NULL: | |
112 | case elfcpp::SHT_SYMTAB: | |
113 | case elfcpp::SHT_DYNSYM: | |
114 | case elfcpp::SHT_STRTAB: | |
115 | case elfcpp::SHT_HASH: | |
116 | case elfcpp::SHT_DYNAMIC: | |
117 | case elfcpp::SHT_SYMTAB_SHNDX: | |
118 | return false; | |
119 | ||
120 | case elfcpp::SHT_RELA: | |
121 | case elfcpp::SHT_REL: | |
122 | case elfcpp::SHT_GROUP: | |
7e1edb90 | 123 | return parameters->output_is_object(); |
a2fb1b05 | 124 | |
9e2dcb77 ILT |
125 | case elfcpp::SHT_PROGBITS: |
126 | if (parameters->strip_debug() | |
127 | && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0) | |
128 | { | |
129 | // Debugging sections can only be recognized by name. | |
130 | if (is_prefix_of(".debug", name) | |
131 | || is_prefix_of(".gnu.linkonce.wi.", name) | |
132 | || is_prefix_of(".line", name) | |
133 | || is_prefix_of(".stab", name)) | |
134 | return false; | |
135 | } | |
136 | return true; | |
137 | ||
a2fb1b05 | 138 | default: |
a2fb1b05 ILT |
139 | return true; |
140 | } | |
141 | } | |
142 | ||
ead1e424 | 143 | // Return an output section named NAME, or NULL if there is none. |
a2fb1b05 | 144 | |
a2fb1b05 | 145 | Output_section* |
ead1e424 | 146 | Layout::find_output_section(const char* name) const |
a2fb1b05 | 147 | { |
ead1e424 ILT |
148 | for (Section_name_map::const_iterator p = this->section_name_map_.begin(); |
149 | p != this->section_name_map_.end(); | |
150 | ++p) | |
f0641a0b | 151 | if (strcmp(p->second->name(), name) == 0) |
ead1e424 ILT |
152 | return p->second; |
153 | return NULL; | |
154 | } | |
a2fb1b05 | 155 | |
ead1e424 ILT |
156 | // Return an output segment of type TYPE, with segment flags SET set |
157 | // and segment flags CLEAR clear. Return NULL if there is none. | |
a2fb1b05 | 158 | |
ead1e424 ILT |
159 | Output_segment* |
160 | Layout::find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set, | |
161 | elfcpp::Elf_Word clear) const | |
162 | { | |
163 | for (Segment_list::const_iterator p = this->segment_list_.begin(); | |
164 | p != this->segment_list_.end(); | |
165 | ++p) | |
166 | if (static_cast<elfcpp::PT>((*p)->type()) == type | |
167 | && ((*p)->flags() & set) == set | |
168 | && ((*p)->flags() & clear) == 0) | |
169 | return *p; | |
170 | return NULL; | |
171 | } | |
a2fb1b05 | 172 | |
ead1e424 ILT |
173 | // Return the output section to use for section NAME with type TYPE |
174 | // and section flags FLAGS. | |
a2fb1b05 | 175 | |
ead1e424 | 176 | Output_section* |
f0641a0b ILT |
177 | Layout::get_output_section(const char* name, Stringpool::Key name_key, |
178 | elfcpp::Elf_Word type, elfcpp::Elf_Xword flags) | |
ead1e424 ILT |
179 | { |
180 | // We should ignore some flags. | |
181 | flags &= ~ (elfcpp::SHF_INFO_LINK | |
182 | | elfcpp::SHF_LINK_ORDER | |
b8e6aad9 ILT |
183 | | elfcpp::SHF_GROUP |
184 | | elfcpp::SHF_MERGE | |
185 | | elfcpp::SHF_STRINGS); | |
a2fb1b05 | 186 | |
f0641a0b | 187 | const Key key(name_key, std::make_pair(type, flags)); |
a2fb1b05 ILT |
188 | const std::pair<Key, Output_section*> v(key, NULL); |
189 | std::pair<Section_name_map::iterator, bool> ins( | |
190 | this->section_name_map_.insert(v)); | |
191 | ||
a2fb1b05 | 192 | if (!ins.second) |
ead1e424 | 193 | return ins.first->second; |
a2fb1b05 ILT |
194 | else |
195 | { | |
196 | // This is the first time we've seen this name/type/flags | |
197 | // combination. | |
ead1e424 | 198 | Output_section* os = this->make_output_section(name, type, flags); |
a2fb1b05 | 199 | ins.first->second = os; |
ead1e424 | 200 | return os; |
a2fb1b05 | 201 | } |
ead1e424 ILT |
202 | } |
203 | ||
204 | // Return the output section to use for input section SHNDX, with name | |
205 | // NAME, with header HEADER, from object OBJECT. Set *OFF to the | |
206 | // offset of this input section without the output section. | |
207 | ||
208 | template<int size, bool big_endian> | |
209 | Output_section* | |
f6ce93d6 | 210 | Layout::layout(Relobj* object, unsigned int shndx, const char* name, |
ead1e424 ILT |
211 | const elfcpp::Shdr<size, big_endian>& shdr, off_t* off) |
212 | { | |
213 | if (!this->include_section(object, name, shdr)) | |
214 | return NULL; | |
215 | ||
216 | // If we are not doing a relocateable link, choose the name to use | |
217 | // for the output section. | |
218 | size_t len = strlen(name); | |
7e1edb90 | 219 | if (!parameters->output_is_object()) |
ead1e424 ILT |
220 | name = Layout::output_section_name(name, &len); |
221 | ||
222 | // FIXME: Handle SHF_OS_NONCONFORMING here. | |
223 | ||
224 | // Canonicalize the section name. | |
f0641a0b | 225 | Stringpool::Key name_key; |
cfd73a4e | 226 | name = this->namepool_.add_prefix(name, len, &name_key); |
ead1e424 ILT |
227 | |
228 | // Find the output section. The output section is selected based on | |
229 | // the section name, type, and flags. | |
f0641a0b ILT |
230 | Output_section* os = this->get_output_section(name, name_key, |
231 | shdr.get_sh_type(), | |
ead1e424 | 232 | shdr.get_sh_flags()); |
a2fb1b05 | 233 | |
3151305a ILT |
234 | // Special GNU handling of sections named .eh_frame. |
235 | if (!parameters->output_is_object() | |
236 | && strcmp(name, ".eh_frame") == 0 | |
237 | && shdr.get_sh_size() > 0 | |
238 | && shdr.get_sh_type() == elfcpp::SHT_PROGBITS | |
239 | && shdr.get_sh_flags() == elfcpp::SHF_ALLOC) | |
240 | { | |
241 | this->layout_eh_frame(object, shndx, name, shdr, os, off); | |
242 | return os; | |
243 | } | |
244 | ||
a2fb1b05 ILT |
245 | // FIXME: Handle SHF_LINK_ORDER somewhere. |
246 | ||
ead1e424 | 247 | *off = os->add_input_section(object, shndx, name, shdr); |
a2fb1b05 ILT |
248 | |
249 | return os; | |
250 | } | |
251 | ||
3151305a ILT |
252 | // Special GNU handling of sections named .eh_frame. They will |
253 | // normally hold exception frame data. | |
254 | ||
255 | template<int size, bool big_endian> | |
256 | void | |
257 | Layout::layout_eh_frame(Relobj* object, | |
258 | unsigned int shndx, | |
259 | const char* name, | |
260 | const elfcpp::Shdr<size, big_endian>& shdr, | |
261 | Output_section* os, off_t* off) | |
262 | { | |
263 | if (this->eh_frame_section_ == NULL) | |
264 | { | |
265 | this->eh_frame_section_ = os; | |
266 | ||
267 | if (this->options_.create_eh_frame_hdr()) | |
268 | { | |
269 | Stringpool::Key hdr_name_key; | |
270 | const char* hdr_name = this->namepool_.add(".eh_frame_hdr", | |
cfd73a4e | 271 | false, |
3151305a ILT |
272 | &hdr_name_key); |
273 | Output_section* hdr_os = | |
274 | this->get_output_section(hdr_name, hdr_name_key, | |
275 | elfcpp::SHT_PROGBITS, | |
276 | elfcpp::SHF_ALLOC); | |
277 | ||
9025d29d | 278 | Eh_frame_hdr* hdr_posd = new Eh_frame_hdr(os); |
3151305a ILT |
279 | hdr_os->add_output_section_data(hdr_posd); |
280 | ||
281 | Output_segment* hdr_oseg = | |
282 | new Output_segment(elfcpp::PT_GNU_EH_FRAME, elfcpp::PF_R); | |
283 | this->segment_list_.push_back(hdr_oseg); | |
284 | hdr_oseg->add_output_section(hdr_os, elfcpp::PF_R); | |
285 | } | |
286 | } | |
287 | ||
288 | gold_assert(this->eh_frame_section_ == os); | |
289 | ||
290 | *off = os->add_input_section(object, shndx, name, shdr); | |
291 | } | |
292 | ||
ead1e424 ILT |
293 | // Add POSD to an output section using NAME, TYPE, and FLAGS. |
294 | ||
295 | void | |
296 | Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type, | |
297 | elfcpp::Elf_Xword flags, | |
298 | Output_section_data* posd) | |
299 | { | |
300 | // Canonicalize the name. | |
f0641a0b | 301 | Stringpool::Key name_key; |
cfd73a4e | 302 | name = this->namepool_.add(name, true, &name_key); |
ead1e424 | 303 | |
f0641a0b | 304 | Output_section* os = this->get_output_section(name, name_key, type, flags); |
ead1e424 ILT |
305 | os->add_output_section_data(posd); |
306 | } | |
307 | ||
a2fb1b05 ILT |
308 | // Map section flags to segment flags. |
309 | ||
310 | elfcpp::Elf_Word | |
311 | Layout::section_flags_to_segment(elfcpp::Elf_Xword flags) | |
312 | { | |
313 | elfcpp::Elf_Word ret = elfcpp::PF_R; | |
314 | if ((flags & elfcpp::SHF_WRITE) != 0) | |
315 | ret |= elfcpp::PF_W; | |
316 | if ((flags & elfcpp::SHF_EXECINSTR) != 0) | |
317 | ret |= elfcpp::PF_X; | |
318 | return ret; | |
319 | } | |
320 | ||
321 | // Make a new Output_section, and attach it to segments as | |
322 | // appropriate. | |
323 | ||
324 | Output_section* | |
325 | Layout::make_output_section(const char* name, elfcpp::Elf_Word type, | |
326 | elfcpp::Elf_Xword flags) | |
327 | { | |
b8e6aad9 | 328 | Output_section* os = new Output_section(name, type, flags); |
a3ad94ed | 329 | this->section_list_.push_back(os); |
a2fb1b05 ILT |
330 | |
331 | if ((flags & elfcpp::SHF_ALLOC) == 0) | |
a3ad94ed | 332 | this->unattached_section_list_.push_back(os); |
a2fb1b05 ILT |
333 | else |
334 | { | |
335 | // This output section goes into a PT_LOAD segment. | |
336 | ||
337 | elfcpp::Elf_Word seg_flags = Layout::section_flags_to_segment(flags); | |
338 | ||
339 | // The only thing we really care about for PT_LOAD segments is | |
340 | // whether or not they are writable, so that is how we search | |
341 | // for them. People who need segments sorted on some other | |
342 | // basis will have to wait until we implement a mechanism for | |
343 | // them to describe the segments they want. | |
344 | ||
345 | Segment_list::const_iterator p; | |
346 | for (p = this->segment_list_.begin(); | |
347 | p != this->segment_list_.end(); | |
348 | ++p) | |
349 | { | |
350 | if ((*p)->type() == elfcpp::PT_LOAD | |
351 | && ((*p)->flags() & elfcpp::PF_W) == (seg_flags & elfcpp::PF_W)) | |
352 | { | |
75f65a3e | 353 | (*p)->add_output_section(os, seg_flags); |
a2fb1b05 ILT |
354 | break; |
355 | } | |
356 | } | |
357 | ||
358 | if (p == this->segment_list_.end()) | |
359 | { | |
360 | Output_segment* oseg = new Output_segment(elfcpp::PT_LOAD, | |
361 | seg_flags); | |
362 | this->segment_list_.push_back(oseg); | |
75f65a3e | 363 | oseg->add_output_section(os, seg_flags); |
a2fb1b05 ILT |
364 | } |
365 | ||
366 | // If we see a loadable SHT_NOTE section, we create a PT_NOTE | |
367 | // segment. | |
368 | if (type == elfcpp::SHT_NOTE) | |
369 | { | |
370 | // See if we already have an equivalent PT_NOTE segment. | |
371 | for (p = this->segment_list_.begin(); | |
372 | p != segment_list_.end(); | |
373 | ++p) | |
374 | { | |
375 | if ((*p)->type() == elfcpp::PT_NOTE | |
376 | && (((*p)->flags() & elfcpp::PF_W) | |
377 | == (seg_flags & elfcpp::PF_W))) | |
378 | { | |
75f65a3e | 379 | (*p)->add_output_section(os, seg_flags); |
a2fb1b05 ILT |
380 | break; |
381 | } | |
382 | } | |
383 | ||
384 | if (p == this->segment_list_.end()) | |
385 | { | |
386 | Output_segment* oseg = new Output_segment(elfcpp::PT_NOTE, | |
387 | seg_flags); | |
388 | this->segment_list_.push_back(oseg); | |
75f65a3e | 389 | oseg->add_output_section(os, seg_flags); |
a2fb1b05 ILT |
390 | } |
391 | } | |
54dc6425 ILT |
392 | |
393 | // If we see a loadable SHF_TLS section, we create a PT_TLS | |
92e059d8 | 394 | // segment. There can only be one such segment. |
54dc6425 ILT |
395 | if ((flags & elfcpp::SHF_TLS) != 0) |
396 | { | |
92e059d8 | 397 | if (this->tls_segment_ == NULL) |
54dc6425 | 398 | { |
92e059d8 ILT |
399 | this->tls_segment_ = new Output_segment(elfcpp::PT_TLS, |
400 | seg_flags); | |
401 | this->segment_list_.push_back(this->tls_segment_); | |
54dc6425 | 402 | } |
92e059d8 | 403 | this->tls_segment_->add_output_section(os, seg_flags); |
54dc6425 | 404 | } |
a2fb1b05 ILT |
405 | } |
406 | ||
407 | return os; | |
408 | } | |
409 | ||
35cdfc9a ILT |
410 | // Handle the .note.GNU-stack section at layout time. SEEN_GNU_STACK |
411 | // is whether we saw a .note.GNU-stack section in the object file. | |
412 | // GNU_STACK_FLAGS is the section flags. The flags give the | |
413 | // protection required for stack memory. We record this in an | |
414 | // executable as a PT_GNU_STACK segment. If an object file does not | |
415 | // have a .note.GNU-stack segment, we must assume that it is an old | |
416 | // object. On some targets that will force an executable stack. | |
417 | ||
418 | void | |
419 | Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags) | |
420 | { | |
421 | if (!seen_gnu_stack) | |
422 | this->input_without_gnu_stack_note_ = true; | |
423 | else | |
424 | { | |
425 | this->input_with_gnu_stack_note_ = true; | |
426 | if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0) | |
427 | this->input_requires_executable_stack_ = true; | |
428 | } | |
429 | } | |
430 | ||
a3ad94ed ILT |
431 | // Create the dynamic sections which are needed before we read the |
432 | // relocs. | |
433 | ||
434 | void | |
435 | Layout::create_initial_dynamic_sections(const Input_objects* input_objects, | |
436 | Symbol_table* symtab) | |
437 | { | |
436ca963 | 438 | if (parameters->doing_static_link()) |
a3ad94ed ILT |
439 | return; |
440 | ||
cfd73a4e | 441 | const char* dynamic_name = this->namepool_.add(".dynamic", false, NULL); |
a3ad94ed ILT |
442 | this->dynamic_section_ = this->make_output_section(dynamic_name, |
443 | elfcpp::SHT_DYNAMIC, | |
444 | (elfcpp::SHF_ALLOC | |
445 | | elfcpp::SHF_WRITE)); | |
446 | ||
14b31740 | 447 | symtab->define_in_output_data(input_objects->target(), "_DYNAMIC", NULL, |
a3ad94ed ILT |
448 | this->dynamic_section_, 0, 0, |
449 | elfcpp::STT_OBJECT, elfcpp::STB_LOCAL, | |
450 | elfcpp::STV_HIDDEN, 0, false, false); | |
16649710 | 451 | |
9025d29d | 452 | this->dynamic_data_ = new Output_data_dynamic(&this->dynpool_); |
16649710 ILT |
453 | |
454 | this->dynamic_section_->add_output_section_data(this->dynamic_data_); | |
a3ad94ed ILT |
455 | } |
456 | ||
bfd58944 ILT |
457 | // For each output section whose name can be represented as C symbol, |
458 | // define __start and __stop symbols for the section. This is a GNU | |
459 | // extension. | |
460 | ||
461 | void | |
462 | Layout::define_section_symbols(Symbol_table* symtab, const Target* target) | |
463 | { | |
464 | for (Section_list::const_iterator p = this->section_list_.begin(); | |
465 | p != this->section_list_.end(); | |
466 | ++p) | |
467 | { | |
468 | const char* const name = (*p)->name(); | |
469 | if (name[strspn(name, | |
470 | ("0123456789" | |
471 | "ABCDEFGHIJKLMNOPWRSTUVWXYZ" | |
472 | "abcdefghijklmnopqrstuvwxyz" | |
473 | "_"))] | |
474 | == '\0') | |
475 | { | |
476 | const std::string name_string(name); | |
477 | const std::string start_name("__start_" + name_string); | |
478 | const std::string stop_name("__stop_" + name_string); | |
479 | ||
480 | symtab->define_in_output_data(target, | |
481 | start_name.c_str(), | |
482 | NULL, // version | |
483 | *p, | |
484 | 0, // value | |
485 | 0, // symsize | |
486 | elfcpp::STT_NOTYPE, | |
487 | elfcpp::STB_GLOBAL, | |
488 | elfcpp::STV_DEFAULT, | |
489 | 0, // nonvis | |
490 | false, // offset_is_from_end | |
491 | false); // only_if_ref | |
492 | ||
493 | symtab->define_in_output_data(target, | |
494 | stop_name.c_str(), | |
495 | NULL, // version | |
496 | *p, | |
497 | 0, // value | |
498 | 0, // symsize | |
499 | elfcpp::STT_NOTYPE, | |
500 | elfcpp::STB_GLOBAL, | |
501 | elfcpp::STV_DEFAULT, | |
502 | 0, // nonvis | |
503 | true, // offset_is_from_end | |
504 | false); // only_if_ref | |
505 | } | |
506 | } | |
507 | } | |
508 | ||
75f65a3e ILT |
509 | // Find the first read-only PT_LOAD segment, creating one if |
510 | // necessary. | |
54dc6425 | 511 | |
75f65a3e ILT |
512 | Output_segment* |
513 | Layout::find_first_load_seg() | |
54dc6425 | 514 | { |
75f65a3e ILT |
515 | for (Segment_list::const_iterator p = this->segment_list_.begin(); |
516 | p != this->segment_list_.end(); | |
517 | ++p) | |
518 | { | |
519 | if ((*p)->type() == elfcpp::PT_LOAD | |
520 | && ((*p)->flags() & elfcpp::PF_R) != 0 | |
521 | && ((*p)->flags() & elfcpp::PF_W) == 0) | |
522 | return *p; | |
523 | } | |
524 | ||
525 | Output_segment* load_seg = new Output_segment(elfcpp::PT_LOAD, elfcpp::PF_R); | |
526 | this->segment_list_.push_back(load_seg); | |
527 | return load_seg; | |
54dc6425 ILT |
528 | } |
529 | ||
530 | // Finalize the layout. When this is called, we have created all the | |
531 | // output sections and all the output segments which are based on | |
532 | // input sections. We have several things to do, and we have to do | |
533 | // them in the right order, so that we get the right results correctly | |
534 | // and efficiently. | |
535 | ||
536 | // 1) Finalize the list of output segments and create the segment | |
537 | // table header. | |
538 | ||
539 | // 2) Finalize the dynamic symbol table and associated sections. | |
540 | ||
541 | // 3) Determine the final file offset of all the output segments. | |
542 | ||
543 | // 4) Determine the final file offset of all the SHF_ALLOC output | |
544 | // sections. | |
545 | ||
75f65a3e ILT |
546 | // 5) Create the symbol table sections and the section name table |
547 | // section. | |
548 | ||
549 | // 6) Finalize the symbol table: set symbol values to their final | |
54dc6425 ILT |
550 | // value and make a final determination of which symbols are going |
551 | // into the output symbol table. | |
552 | ||
54dc6425 ILT |
553 | // 7) Create the section table header. |
554 | ||
555 | // 8) Determine the final file offset of all the output sections which | |
556 | // are not SHF_ALLOC, including the section table header. | |
557 | ||
558 | // 9) Finalize the ELF file header. | |
559 | ||
75f65a3e ILT |
560 | // This function returns the size of the output file. |
561 | ||
562 | off_t | |
563 | Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab) | |
54dc6425 | 564 | { |
5a6f7e2d | 565 | Target* const target = input_objects->target(); |
dbe717ef | 566 | |
7e1edb90 | 567 | target->finalize_sections(this); |
5a6f7e2d | 568 | |
35cdfc9a ILT |
569 | this->create_gold_note(); |
570 | this->create_executable_stack_info(target); | |
4f211c8b | 571 | |
dbe717ef | 572 | Output_segment* phdr_seg = NULL; |
436ca963 | 573 | if (!parameters->doing_static_link()) |
54dc6425 | 574 | { |
dbe717ef ILT |
575 | // There was a dynamic object in the link. We need to create |
576 | // some information for the dynamic linker. | |
577 | ||
578 | // Create the PT_PHDR segment which will hold the program | |
579 | // headers. | |
580 | phdr_seg = new Output_segment(elfcpp::PT_PHDR, elfcpp::PF_R); | |
581 | this->segment_list_.push_back(phdr_seg); | |
582 | ||
14b31740 ILT |
583 | // Create the dynamic symbol table, including the hash table. |
584 | Output_section* dynstr; | |
585 | std::vector<Symbol*> dynamic_symbols; | |
586 | unsigned int local_dynamic_count; | |
587 | Versions versions; | |
588 | this->create_dynamic_symtab(target, symtab, &dynstr, | |
589 | &local_dynamic_count, &dynamic_symbols, | |
590 | &versions); | |
dbe717ef ILT |
591 | |
592 | // Create the .interp section to hold the name of the | |
593 | // interpreter, and put it in a PT_INTERP segment. | |
a3ad94ed ILT |
594 | this->create_interp(target); |
595 | ||
596 | // Finish the .dynamic section to hold the dynamic data, and put | |
597 | // it in a PT_DYNAMIC segment. | |
16649710 | 598 | this->finish_dynamic_section(input_objects, symtab); |
14b31740 ILT |
599 | |
600 | // We should have added everything we need to the dynamic string | |
601 | // table. | |
602 | this->dynpool_.set_string_offsets(); | |
603 | ||
604 | // Create the version sections. We can't do this until the | |
605 | // dynamic string table is complete. | |
46fe1623 | 606 | this->create_version_sections(&versions, symtab, local_dynamic_count, |
14b31740 | 607 | dynamic_symbols, dynstr); |
54dc6425 ILT |
608 | } |
609 | ||
610 | // FIXME: Handle PT_GNU_STACK. | |
611 | ||
75f65a3e ILT |
612 | Output_segment* load_seg = this->find_first_load_seg(); |
613 | ||
614 | // Lay out the segment headers. | |
75f65a3e | 615 | Output_segment_headers* segment_headers; |
9025d29d | 616 | segment_headers = new Output_segment_headers(this->segment_list_); |
75f65a3e | 617 | load_seg->add_initial_output_data(segment_headers); |
61ba1cf9 | 618 | this->special_output_list_.push_back(segment_headers); |
dbe717ef ILT |
619 | if (phdr_seg != NULL) |
620 | phdr_seg->add_initial_output_data(segment_headers); | |
75f65a3e ILT |
621 | |
622 | // Lay out the file header. | |
623 | Output_file_header* file_header; | |
9025d29d | 624 | file_header = new Output_file_header(target, symtab, segment_headers); |
75f65a3e | 625 | load_seg->add_initial_output_data(file_header); |
61ba1cf9 | 626 | this->special_output_list_.push_back(file_header); |
75f65a3e | 627 | |
ead1e424 ILT |
628 | // We set the output section indexes in set_segment_offsets and |
629 | // set_section_offsets. | |
630 | unsigned int shndx = 1; | |
631 | ||
632 | // Set the file offsets of all the segments, and all the sections | |
633 | // they contain. | |
a3ad94ed | 634 | off_t off = this->set_segment_offsets(target, load_seg, &shndx); |
75f65a3e | 635 | |
dba5a01f ILT |
636 | // Set the file offsets of all the data sections not associated with |
637 | // segments. This makes sure that debug sections have their offsets | |
638 | // before symbols are finalized. | |
639 | off = this->set_section_offsets(off, &shndx, true); | |
640 | ||
75f65a3e | 641 | // Create the symbol table sections. |
9025d29d | 642 | this->create_symtab_sections(input_objects, symtab, &off); |
75f65a3e ILT |
643 | |
644 | // Create the .shstrtab section. | |
645 | Output_section* shstrtab_section = this->create_shstrtab(); | |
646 | ||
dba5a01f | 647 | // Set the file offsets of all the non-data sections not associated with |
75f65a3e | 648 | // segments. |
dba5a01f | 649 | off = this->set_section_offsets(off, &shndx, false); |
ead1e424 | 650 | |
75f65a3e | 651 | // Create the section table header. |
9025d29d | 652 | Output_section_headers* oshdrs = this->create_shdrs(&off); |
75f65a3e ILT |
653 | |
654 | file_header->set_section_info(oshdrs, shstrtab_section); | |
655 | ||
656 | // Now we know exactly where everything goes in the output file. | |
a3ad94ed | 657 | Output_data::layout_complete(); |
75f65a3e | 658 | |
e44fcf3b ILT |
659 | this->output_file_size_ = off; |
660 | ||
75f65a3e ILT |
661 | return off; |
662 | } | |
663 | ||
4f211c8b ILT |
664 | // Create a .note section for an executable or shared library. This |
665 | // records the version of gold used to create the binary. | |
666 | ||
667 | void | |
35cdfc9a | 668 | Layout::create_gold_note() |
4f211c8b ILT |
669 | { |
670 | if (parameters->output_is_object()) | |
671 | return; | |
672 | ||
e2305dc0 ILT |
673 | // Authorities all agree that the values in a .note field should |
674 | // be aligned on 4-byte boundaries for 32-bit binaries. However, | |
675 | // they differ on what the alignment is for 64-bit binaries. | |
676 | // The GABI says unambiguously they take 8-byte alignment: | |
677 | // http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section | |
678 | // Other documentation says alignment should always be 4 bytes: | |
679 | // http://www.netbsd.org/docs/kernel/elf-notes.html#note-format | |
680 | // GNU ld and GNU readelf both support the latter (at least as of | |
681 | // version 2.16.91), and glibc always generates the latter for | |
682 | // .note.ABI-tag (as of version 1.6), so that's the one we go with | |
683 | // here. | |
35cdfc9a | 684 | #ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION // This is not defined by default. |
4f211c8b | 685 | const int size = parameters->get_size(); |
e2305dc0 ILT |
686 | #else |
687 | const int size = 32; | |
688 | #endif | |
4f211c8b ILT |
689 | |
690 | // The contents of the .note section. | |
691 | const char* name = "GNU"; | |
692 | std::string desc(std::string("gold ") + gold::get_version_string()); | |
693 | size_t namesz = strlen(name) + 1; | |
694 | size_t aligned_namesz = align_address(namesz, size / 8); | |
695 | size_t descsz = desc.length() + 1; | |
696 | size_t aligned_descsz = align_address(descsz, size / 8); | |
697 | const int note_type = 4; | |
698 | ||
699 | size_t notesz = 3 * (size / 8) + aligned_namesz + aligned_descsz; | |
700 | ||
701 | unsigned char buffer[128]; | |
702 | gold_assert(sizeof buffer >= notesz); | |
703 | memset(buffer, 0, notesz); | |
704 | ||
705 | bool is_big_endian = parameters->is_big_endian(); | |
706 | ||
707 | if (size == 32) | |
708 | { | |
709 | if (!is_big_endian) | |
710 | { | |
711 | elfcpp::Swap<32, false>::writeval(buffer, namesz); | |
712 | elfcpp::Swap<32, false>::writeval(buffer + 4, descsz); | |
713 | elfcpp::Swap<32, false>::writeval(buffer + 8, note_type); | |
714 | } | |
715 | else | |
716 | { | |
717 | elfcpp::Swap<32, true>::writeval(buffer, namesz); | |
718 | elfcpp::Swap<32, true>::writeval(buffer + 4, descsz); | |
719 | elfcpp::Swap<32, true>::writeval(buffer + 8, note_type); | |
720 | } | |
721 | } | |
722 | else if (size == 64) | |
723 | { | |
724 | if (!is_big_endian) | |
725 | { | |
726 | elfcpp::Swap<64, false>::writeval(buffer, namesz); | |
727 | elfcpp::Swap<64, false>::writeval(buffer + 8, descsz); | |
728 | elfcpp::Swap<64, false>::writeval(buffer + 16, note_type); | |
729 | } | |
730 | else | |
731 | { | |
732 | elfcpp::Swap<64, true>::writeval(buffer, namesz); | |
733 | elfcpp::Swap<64, true>::writeval(buffer + 8, descsz); | |
734 | elfcpp::Swap<64, true>::writeval(buffer + 16, note_type); | |
735 | } | |
736 | } | |
737 | else | |
738 | gold_unreachable(); | |
739 | ||
740 | memcpy(buffer + 3 * (size / 8), name, namesz); | |
741 | memcpy(buffer + 3 * (size / 8) + aligned_namesz, desc.data(), descsz); | |
742 | ||
cfd73a4e | 743 | const char* note_name = this->namepool_.add(".note", false, NULL); |
4f211c8b ILT |
744 | Output_section* os = this->make_output_section(note_name, |
745 | elfcpp::SHT_NOTE, | |
746 | 0); | |
747 | Output_section_data* posd = new Output_data_const(buffer, notesz, | |
748 | size / 8); | |
749 | os->add_output_section_data(posd); | |
750 | } | |
751 | ||
35cdfc9a ILT |
752 | // Record whether the stack should be executable. This can be set |
753 | // from the command line using the -z execstack or -z noexecstack | |
754 | // options. Otherwise, if any input file has a .note.GNU-stack | |
755 | // section with the SHF_EXECINSTR flag set, the stack should be | |
756 | // executable. Otherwise, if at least one input file a | |
757 | // .note.GNU-stack section, and some input file has no .note.GNU-stack | |
758 | // section, we use the target default for whether the stack should be | |
759 | // executable. Otherwise, we don't generate a stack note. When | |
760 | // generating a object file, we create a .note.GNU-stack section with | |
761 | // the appropriate marking. When generating an executable or shared | |
762 | // library, we create a PT_GNU_STACK segment. | |
763 | ||
764 | void | |
765 | Layout::create_executable_stack_info(const Target* target) | |
766 | { | |
767 | bool is_stack_executable; | |
768 | if (this->options_.is_execstack_set()) | |
769 | is_stack_executable = this->options_.is_stack_executable(); | |
770 | else if (!this->input_with_gnu_stack_note_) | |
771 | return; | |
772 | else | |
773 | { | |
774 | if (this->input_requires_executable_stack_) | |
775 | is_stack_executable = true; | |
776 | else if (this->input_without_gnu_stack_note_) | |
777 | is_stack_executable = target->is_default_stack_executable(); | |
778 | else | |
779 | is_stack_executable = false; | |
780 | } | |
781 | ||
782 | if (parameters->output_is_object()) | |
783 | { | |
784 | const char* name = this->namepool_.add(".note.GNU-stack", false, NULL); | |
785 | elfcpp::Elf_Xword flags = 0; | |
786 | if (is_stack_executable) | |
787 | flags |= elfcpp::SHF_EXECINSTR; | |
788 | this->make_output_section(name, elfcpp::SHT_PROGBITS, flags); | |
789 | } | |
790 | else | |
791 | { | |
792 | int flags = elfcpp::PF_R | elfcpp::PF_W; | |
793 | if (is_stack_executable) | |
794 | flags |= elfcpp::PF_X; | |
795 | Output_segment* oseg = new Output_segment(elfcpp::PT_GNU_STACK, flags); | |
796 | this->segment_list_.push_back(oseg); | |
797 | } | |
798 | } | |
799 | ||
75f65a3e ILT |
800 | // Return whether SEG1 should be before SEG2 in the output file. This |
801 | // is based entirely on the segment type and flags. When this is | |
802 | // called the segment addresses has normally not yet been set. | |
803 | ||
804 | bool | |
805 | Layout::segment_precedes(const Output_segment* seg1, | |
806 | const Output_segment* seg2) | |
807 | { | |
808 | elfcpp::Elf_Word type1 = seg1->type(); | |
809 | elfcpp::Elf_Word type2 = seg2->type(); | |
810 | ||
811 | // The single PT_PHDR segment is required to precede any loadable | |
812 | // segment. We simply make it always first. | |
813 | if (type1 == elfcpp::PT_PHDR) | |
814 | { | |
a3ad94ed | 815 | gold_assert(type2 != elfcpp::PT_PHDR); |
75f65a3e ILT |
816 | return true; |
817 | } | |
818 | if (type2 == elfcpp::PT_PHDR) | |
819 | return false; | |
820 | ||
821 | // The single PT_INTERP segment is required to precede any loadable | |
822 | // segment. We simply make it always second. | |
823 | if (type1 == elfcpp::PT_INTERP) | |
824 | { | |
a3ad94ed | 825 | gold_assert(type2 != elfcpp::PT_INTERP); |
75f65a3e ILT |
826 | return true; |
827 | } | |
828 | if (type2 == elfcpp::PT_INTERP) | |
829 | return false; | |
830 | ||
831 | // We then put PT_LOAD segments before any other segments. | |
832 | if (type1 == elfcpp::PT_LOAD && type2 != elfcpp::PT_LOAD) | |
833 | return true; | |
834 | if (type2 == elfcpp::PT_LOAD && type1 != elfcpp::PT_LOAD) | |
835 | return false; | |
836 | ||
92e059d8 ILT |
837 | // We put the PT_TLS segment last, because that is where the dynamic |
838 | // linker expects to find it (this is just for efficiency; other | |
839 | // positions would also work correctly). | |
840 | if (type1 == elfcpp::PT_TLS && type2 != elfcpp::PT_TLS) | |
841 | return false; | |
842 | if (type2 == elfcpp::PT_TLS && type1 != elfcpp::PT_TLS) | |
843 | return true; | |
844 | ||
75f65a3e ILT |
845 | const elfcpp::Elf_Word flags1 = seg1->flags(); |
846 | const elfcpp::Elf_Word flags2 = seg2->flags(); | |
847 | ||
848 | // The order of non-PT_LOAD segments is unimportant. We simply sort | |
849 | // by the numeric segment type and flags values. There should not | |
850 | // be more than one segment with the same type and flags. | |
851 | if (type1 != elfcpp::PT_LOAD) | |
852 | { | |
853 | if (type1 != type2) | |
854 | return type1 < type2; | |
a3ad94ed | 855 | gold_assert(flags1 != flags2); |
75f65a3e ILT |
856 | return flags1 < flags2; |
857 | } | |
858 | ||
859 | // We sort PT_LOAD segments based on the flags. Readonly segments | |
860 | // come before writable segments. Then executable segments come | |
861 | // before non-executable segments. Then the unlikely case of a | |
862 | // non-readable segment comes before the normal case of a readable | |
863 | // segment. If there are multiple segments with the same type and | |
864 | // flags, we require that the address be set, and we sort by | |
865 | // virtual address and then physical address. | |
866 | if ((flags1 & elfcpp::PF_W) != (flags2 & elfcpp::PF_W)) | |
867 | return (flags1 & elfcpp::PF_W) == 0; | |
868 | if ((flags1 & elfcpp::PF_X) != (flags2 & elfcpp::PF_X)) | |
869 | return (flags1 & elfcpp::PF_X) != 0; | |
870 | if ((flags1 & elfcpp::PF_R) != (flags2 & elfcpp::PF_R)) | |
871 | return (flags1 & elfcpp::PF_R) == 0; | |
872 | ||
873 | uint64_t vaddr1 = seg1->vaddr(); | |
874 | uint64_t vaddr2 = seg2->vaddr(); | |
875 | if (vaddr1 != vaddr2) | |
876 | return vaddr1 < vaddr2; | |
877 | ||
878 | uint64_t paddr1 = seg1->paddr(); | |
879 | uint64_t paddr2 = seg2->paddr(); | |
a3ad94ed | 880 | gold_assert(paddr1 != paddr2); |
75f65a3e ILT |
881 | return paddr1 < paddr2; |
882 | } | |
883 | ||
ead1e424 ILT |
884 | // Set the file offsets of all the segments, and all the sections they |
885 | // contain. They have all been created. LOAD_SEG must be be laid out | |
886 | // first. Return the offset of the data to follow. | |
75f65a3e ILT |
887 | |
888 | off_t | |
ead1e424 ILT |
889 | Layout::set_segment_offsets(const Target* target, Output_segment* load_seg, |
890 | unsigned int *pshndx) | |
75f65a3e ILT |
891 | { |
892 | // Sort them into the final order. | |
54dc6425 ILT |
893 | std::sort(this->segment_list_.begin(), this->segment_list_.end(), |
894 | Layout::Compare_segments()); | |
895 | ||
75f65a3e ILT |
896 | // Find the PT_LOAD segments, and set their addresses and offsets |
897 | // and their section's addresses and offsets. | |
0c5e9c22 ILT |
898 | uint64_t addr; |
899 | if (options_.user_set_text_segment_address()) | |
900 | addr = options_.text_segment_address(); | |
901 | else | |
902 | addr = target->default_text_segment_address(); | |
75f65a3e ILT |
903 | off_t off = 0; |
904 | bool was_readonly = false; | |
905 | for (Segment_list::iterator p = this->segment_list_.begin(); | |
906 | p != this->segment_list_.end(); | |
907 | ++p) | |
908 | { | |
909 | if ((*p)->type() == elfcpp::PT_LOAD) | |
910 | { | |
911 | if (load_seg != NULL && load_seg != *p) | |
a3ad94ed | 912 | gold_unreachable(); |
75f65a3e ILT |
913 | load_seg = NULL; |
914 | ||
915 | // If the last segment was readonly, and this one is not, | |
916 | // then skip the address forward one page, maintaining the | |
917 | // same position within the page. This lets us store both | |
918 | // segments overlapping on a single page in the file, but | |
919 | // the loader will put them on different pages in memory. | |
920 | ||
921 | uint64_t orig_addr = addr; | |
922 | uint64_t orig_off = off; | |
923 | ||
924 | uint64_t aligned_addr = addr; | |
925 | uint64_t abi_pagesize = target->abi_pagesize(); | |
0496d5e5 ILT |
926 | |
927 | // FIXME: This should depend on the -n and -N options. | |
928 | (*p)->set_minimum_addralign(target->common_pagesize()); | |
929 | ||
75f65a3e ILT |
930 | if (was_readonly && ((*p)->flags() & elfcpp::PF_W) != 0) |
931 | { | |
ead1e424 | 932 | uint64_t align = (*p)->addralign(); |
75f65a3e | 933 | |
ead1e424 | 934 | addr = align_address(addr, align); |
75f65a3e ILT |
935 | aligned_addr = addr; |
936 | if ((addr & (abi_pagesize - 1)) != 0) | |
937 | addr = addr + abi_pagesize; | |
938 | } | |
939 | ||
ead1e424 | 940 | unsigned int shndx_hold = *pshndx; |
75f65a3e | 941 | off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1)); |
ead1e424 | 942 | uint64_t new_addr = (*p)->set_section_addresses(addr, &off, pshndx); |
75f65a3e ILT |
943 | |
944 | // Now that we know the size of this segment, we may be able | |
945 | // to save a page in memory, at the cost of wasting some | |
946 | // file space, by instead aligning to the start of a new | |
947 | // page. Here we use the real machine page size rather than | |
948 | // the ABI mandated page size. | |
949 | ||
950 | if (aligned_addr != addr) | |
951 | { | |
952 | uint64_t common_pagesize = target->common_pagesize(); | |
953 | uint64_t first_off = (common_pagesize | |
954 | - (aligned_addr | |
955 | & (common_pagesize - 1))); | |
956 | uint64_t last_off = new_addr & (common_pagesize - 1); | |
957 | if (first_off > 0 | |
958 | && last_off > 0 | |
959 | && ((aligned_addr & ~ (common_pagesize - 1)) | |
960 | != (new_addr & ~ (common_pagesize - 1))) | |
961 | && first_off + last_off <= common_pagesize) | |
962 | { | |
ead1e424 ILT |
963 | *pshndx = shndx_hold; |
964 | addr = align_address(aligned_addr, common_pagesize); | |
75f65a3e | 965 | off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1)); |
ead1e424 | 966 | new_addr = (*p)->set_section_addresses(addr, &off, pshndx); |
75f65a3e ILT |
967 | } |
968 | } | |
969 | ||
970 | addr = new_addr; | |
971 | ||
972 | if (((*p)->flags() & elfcpp::PF_W) == 0) | |
973 | was_readonly = true; | |
974 | } | |
975 | } | |
976 | ||
977 | // Handle the non-PT_LOAD segments, setting their offsets from their | |
978 | // section's offsets. | |
979 | for (Segment_list::iterator p = this->segment_list_.begin(); | |
980 | p != this->segment_list_.end(); | |
981 | ++p) | |
982 | { | |
983 | if ((*p)->type() != elfcpp::PT_LOAD) | |
984 | (*p)->set_offset(); | |
985 | } | |
986 | ||
987 | return off; | |
988 | } | |
989 | ||
990 | // Set the file offset of all the sections not associated with a | |
991 | // segment. | |
992 | ||
993 | off_t | |
dba5a01f ILT |
994 | Layout::set_section_offsets(off_t off, |
995 | unsigned int* pshndx, | |
996 | bool do_bits_sections) | |
75f65a3e | 997 | { |
a3ad94ed ILT |
998 | for (Section_list::iterator p = this->unattached_section_list_.begin(); |
999 | p != this->unattached_section_list_.end(); | |
75f65a3e ILT |
1000 | ++p) |
1001 | { | |
dba5a01f ILT |
1002 | bool is_bits_section = ((*p)->type() == elfcpp::SHT_PROGBITS |
1003 | || (*p)->type() == elfcpp::SHT_NOBITS); | |
1004 | if (is_bits_section != do_bits_sections) | |
1005 | continue; | |
ead1e424 ILT |
1006 | (*p)->set_out_shndx(*pshndx); |
1007 | ++*pshndx; | |
61ba1cf9 ILT |
1008 | if ((*p)->offset() != -1) |
1009 | continue; | |
ead1e424 | 1010 | off = align_address(off, (*p)->addralign()); |
75f65a3e ILT |
1011 | (*p)->set_address(0, off); |
1012 | off += (*p)->data_size(); | |
1013 | } | |
1014 | return off; | |
1015 | } | |
1016 | ||
b8e6aad9 ILT |
1017 | // Create the symbol table sections. Here we also set the final |
1018 | // values of the symbols. At this point all the loadable sections are | |
1019 | // fully laid out. | |
75f65a3e ILT |
1020 | |
1021 | void | |
9025d29d | 1022 | Layout::create_symtab_sections(const Input_objects* input_objects, |
75f65a3e | 1023 | Symbol_table* symtab, |
16649710 | 1024 | off_t* poff) |
75f65a3e | 1025 | { |
61ba1cf9 ILT |
1026 | int symsize; |
1027 | unsigned int align; | |
9025d29d | 1028 | if (parameters->get_size() == 32) |
61ba1cf9 ILT |
1029 | { |
1030 | symsize = elfcpp::Elf_sizes<32>::sym_size; | |
1031 | align = 4; | |
1032 | } | |
9025d29d | 1033 | else if (parameters->get_size() == 64) |
61ba1cf9 ILT |
1034 | { |
1035 | symsize = elfcpp::Elf_sizes<64>::sym_size; | |
1036 | align = 8; | |
1037 | } | |
1038 | else | |
a3ad94ed | 1039 | gold_unreachable(); |
61ba1cf9 ILT |
1040 | |
1041 | off_t off = *poff; | |
ead1e424 | 1042 | off = align_address(off, align); |
61ba1cf9 ILT |
1043 | off_t startoff = off; |
1044 | ||
1045 | // Save space for the dummy symbol at the start of the section. We | |
1046 | // never bother to write this out--it will just be left as zero. | |
1047 | off += symsize; | |
c06b7b0b | 1048 | unsigned int local_symbol_index = 1; |
61ba1cf9 | 1049 | |
a3ad94ed ILT |
1050 | // Add STT_SECTION symbols for each Output section which needs one. |
1051 | for (Section_list::iterator p = this->section_list_.begin(); | |
1052 | p != this->section_list_.end(); | |
1053 | ++p) | |
1054 | { | |
1055 | if (!(*p)->needs_symtab_index()) | |
1056 | (*p)->set_symtab_index(-1U); | |
1057 | else | |
1058 | { | |
1059 | (*p)->set_symtab_index(local_symbol_index); | |
1060 | ++local_symbol_index; | |
1061 | off += symsize; | |
1062 | } | |
1063 | } | |
1064 | ||
f6ce93d6 ILT |
1065 | for (Input_objects::Relobj_iterator p = input_objects->relobj_begin(); |
1066 | p != input_objects->relobj_end(); | |
75f65a3e ILT |
1067 | ++p) |
1068 | { | |
1069 | Task_lock_obj<Object> tlo(**p); | |
c06b7b0b ILT |
1070 | unsigned int index = (*p)->finalize_local_symbols(local_symbol_index, |
1071 | off, | |
1072 | &this->sympool_); | |
1073 | off += (index - local_symbol_index) * symsize; | |
1074 | local_symbol_index = index; | |
75f65a3e ILT |
1075 | } |
1076 | ||
c06b7b0b | 1077 | unsigned int local_symcount = local_symbol_index; |
a3ad94ed | 1078 | gold_assert(local_symcount * symsize == off - startoff); |
61ba1cf9 | 1079 | |
16649710 ILT |
1080 | off_t dynoff; |
1081 | size_t dyn_global_index; | |
1082 | size_t dyncount; | |
1083 | if (this->dynsym_section_ == NULL) | |
1084 | { | |
1085 | dynoff = 0; | |
1086 | dyn_global_index = 0; | |
1087 | dyncount = 0; | |
1088 | } | |
1089 | else | |
1090 | { | |
1091 | dyn_global_index = this->dynsym_section_->info(); | |
1092 | off_t locsize = dyn_global_index * this->dynsym_section_->entsize(); | |
1093 | dynoff = this->dynsym_section_->offset() + locsize; | |
1094 | dyncount = (this->dynsym_section_->data_size() - locsize) / symsize; | |
f5c3f225 | 1095 | gold_assert(static_cast<off_t>(dyncount * symsize) |
16649710 ILT |
1096 | == this->dynsym_section_->data_size() - locsize); |
1097 | } | |
1098 | ||
1099 | off = symtab->finalize(local_symcount, off, dynoff, dyn_global_index, | |
1100 | dyncount, &this->sympool_); | |
75f65a3e | 1101 | |
9e2dcb77 ILT |
1102 | if (!parameters->strip_all()) |
1103 | { | |
1104 | this->sympool_.set_string_offsets(); | |
61ba1cf9 | 1105 | |
cfd73a4e | 1106 | const char* symtab_name = this->namepool_.add(".symtab", false, NULL); |
9e2dcb77 ILT |
1107 | Output_section* osymtab = this->make_output_section(symtab_name, |
1108 | elfcpp::SHT_SYMTAB, | |
1109 | 0); | |
1110 | this->symtab_section_ = osymtab; | |
a3ad94ed | 1111 | |
9e2dcb77 ILT |
1112 | Output_section_data* pos = new Output_data_space(off - startoff, |
1113 | align); | |
1114 | osymtab->add_output_section_data(pos); | |
61ba1cf9 | 1115 | |
cfd73a4e | 1116 | const char* strtab_name = this->namepool_.add(".strtab", false, NULL); |
9e2dcb77 ILT |
1117 | Output_section* ostrtab = this->make_output_section(strtab_name, |
1118 | elfcpp::SHT_STRTAB, | |
1119 | 0); | |
a3ad94ed | 1120 | |
9e2dcb77 ILT |
1121 | Output_section_data* pstr = new Output_data_strtab(&this->sympool_); |
1122 | ostrtab->add_output_section_data(pstr); | |
61ba1cf9 | 1123 | |
9e2dcb77 ILT |
1124 | osymtab->set_address(0, startoff); |
1125 | osymtab->set_link_section(ostrtab); | |
1126 | osymtab->set_info(local_symcount); | |
1127 | osymtab->set_entsize(symsize); | |
61ba1cf9 | 1128 | |
9e2dcb77 ILT |
1129 | *poff = off; |
1130 | } | |
75f65a3e ILT |
1131 | } |
1132 | ||
1133 | // Create the .shstrtab section, which holds the names of the | |
1134 | // sections. At the time this is called, we have created all the | |
1135 | // output sections except .shstrtab itself. | |
1136 | ||
1137 | Output_section* | |
1138 | Layout::create_shstrtab() | |
1139 | { | |
1140 | // FIXME: We don't need to create a .shstrtab section if we are | |
1141 | // stripping everything. | |
1142 | ||
cfd73a4e | 1143 | const char* name = this->namepool_.add(".shstrtab", false, NULL); |
75f65a3e | 1144 | |
61ba1cf9 ILT |
1145 | this->namepool_.set_string_offsets(); |
1146 | ||
a3ad94ed | 1147 | Output_section* os = this->make_output_section(name, elfcpp::SHT_STRTAB, 0); |
75f65a3e | 1148 | |
a3ad94ed ILT |
1149 | Output_section_data* posd = new Output_data_strtab(&this->namepool_); |
1150 | os->add_output_section_data(posd); | |
75f65a3e ILT |
1151 | |
1152 | return os; | |
1153 | } | |
1154 | ||
1155 | // Create the section headers. SIZE is 32 or 64. OFF is the file | |
1156 | // offset. | |
1157 | ||
1158 | Output_section_headers* | |
9025d29d | 1159 | Layout::create_shdrs(off_t* poff) |
75f65a3e ILT |
1160 | { |
1161 | Output_section_headers* oshdrs; | |
9025d29d | 1162 | oshdrs = new Output_section_headers(this, |
16649710 ILT |
1163 | &this->segment_list_, |
1164 | &this->unattached_section_list_, | |
61ba1cf9 | 1165 | &this->namepool_); |
ead1e424 | 1166 | off_t off = align_address(*poff, oshdrs->addralign()); |
75f65a3e | 1167 | oshdrs->set_address(0, off); |
61ba1cf9 ILT |
1168 | off += oshdrs->data_size(); |
1169 | *poff = off; | |
1170 | this->special_output_list_.push_back(oshdrs); | |
75f65a3e | 1171 | return oshdrs; |
54dc6425 ILT |
1172 | } |
1173 | ||
dbe717ef ILT |
1174 | // Create the dynamic symbol table. |
1175 | ||
1176 | void | |
14b31740 ILT |
1177 | Layout::create_dynamic_symtab(const Target* target, Symbol_table* symtab, |
1178 | Output_section **pdynstr, | |
1179 | unsigned int* plocal_dynamic_count, | |
1180 | std::vector<Symbol*>* pdynamic_symbols, | |
1181 | Versions* pversions) | |
dbe717ef | 1182 | { |
a3ad94ed ILT |
1183 | // Count all the symbols in the dynamic symbol table, and set the |
1184 | // dynamic symbol indexes. | |
dbe717ef | 1185 | |
a3ad94ed ILT |
1186 | // Skip symbol 0, which is always all zeroes. |
1187 | unsigned int index = 1; | |
dbe717ef | 1188 | |
a3ad94ed ILT |
1189 | // Add STT_SECTION symbols for each Output section which needs one. |
1190 | for (Section_list::iterator p = this->section_list_.begin(); | |
1191 | p != this->section_list_.end(); | |
1192 | ++p) | |
1193 | { | |
1194 | if (!(*p)->needs_dynsym_index()) | |
1195 | (*p)->set_dynsym_index(-1U); | |
1196 | else | |
1197 | { | |
1198 | (*p)->set_dynsym_index(index); | |
1199 | ++index; | |
1200 | } | |
1201 | } | |
1202 | ||
1203 | // FIXME: Some targets apparently require local symbols in the | |
1204 | // dynamic symbol table. Here is where we will have to count them, | |
1205 | // and set the dynamic symbol indexes, and add the names to | |
1206 | // this->dynpool_. | |
1207 | ||
1208 | unsigned int local_symcount = index; | |
14b31740 | 1209 | *plocal_dynamic_count = local_symcount; |
a3ad94ed ILT |
1210 | |
1211 | // FIXME: We have to tell set_dynsym_indexes whether the | |
1212 | // -E/--export-dynamic option was used. | |
35cdfc9a ILT |
1213 | index = symtab->set_dynsym_indexes(target, index, pdynamic_symbols, |
1214 | &this->dynpool_, pversions); | |
a3ad94ed ILT |
1215 | |
1216 | int symsize; | |
1217 | unsigned int align; | |
9025d29d | 1218 | const int size = parameters->get_size(); |
a3ad94ed ILT |
1219 | if (size == 32) |
1220 | { | |
1221 | symsize = elfcpp::Elf_sizes<32>::sym_size; | |
1222 | align = 4; | |
1223 | } | |
1224 | else if (size == 64) | |
1225 | { | |
1226 | symsize = elfcpp::Elf_sizes<64>::sym_size; | |
1227 | align = 8; | |
1228 | } | |
1229 | else | |
1230 | gold_unreachable(); | |
1231 | ||
14b31740 ILT |
1232 | // Create the dynamic symbol table section. |
1233 | ||
cfd73a4e | 1234 | const char* dynsym_name = this->namepool_.add(".dynsym", false, NULL); |
a3ad94ed ILT |
1235 | Output_section* dynsym = this->make_output_section(dynsym_name, |
1236 | elfcpp::SHT_DYNSYM, | |
1237 | elfcpp::SHF_ALLOC); | |
1238 | ||
1239 | Output_section_data* odata = new Output_data_space(index * symsize, | |
1240 | align); | |
1241 | dynsym->add_output_section_data(odata); | |
1242 | ||
1243 | dynsym->set_info(local_symcount); | |
1244 | dynsym->set_entsize(symsize); | |
1245 | dynsym->set_addralign(align); | |
1246 | ||
1247 | this->dynsym_section_ = dynsym; | |
1248 | ||
16649710 | 1249 | Output_data_dynamic* const odyn = this->dynamic_data_; |
a3ad94ed ILT |
1250 | odyn->add_section_address(elfcpp::DT_SYMTAB, dynsym); |
1251 | odyn->add_constant(elfcpp::DT_SYMENT, symsize); | |
1252 | ||
14b31740 ILT |
1253 | // Create the dynamic string table section. |
1254 | ||
cfd73a4e | 1255 | const char* dynstr_name = this->namepool_.add(".dynstr", false, NULL); |
a3ad94ed ILT |
1256 | Output_section* dynstr = this->make_output_section(dynstr_name, |
1257 | elfcpp::SHT_STRTAB, | |
1258 | elfcpp::SHF_ALLOC); | |
1259 | ||
1260 | Output_section_data* strdata = new Output_data_strtab(&this->dynpool_); | |
1261 | dynstr->add_output_section_data(strdata); | |
1262 | ||
16649710 ILT |
1263 | dynsym->set_link_section(dynstr); |
1264 | this->dynamic_section_->set_link_section(dynstr); | |
1265 | ||
a3ad94ed ILT |
1266 | odyn->add_section_address(elfcpp::DT_STRTAB, dynstr); |
1267 | odyn->add_section_size(elfcpp::DT_STRSZ, dynstr); | |
1268 | ||
14b31740 ILT |
1269 | *pdynstr = dynstr; |
1270 | ||
1271 | // Create the hash tables. | |
1272 | ||
a3ad94ed ILT |
1273 | // FIXME: We need an option to create a GNU hash table. |
1274 | ||
1275 | unsigned char* phash; | |
1276 | unsigned int hashlen; | |
9025d29d | 1277 | Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount, |
a3ad94ed ILT |
1278 | &phash, &hashlen); |
1279 | ||
cfd73a4e | 1280 | const char* hash_name = this->namepool_.add(".hash", false, NULL); |
a3ad94ed ILT |
1281 | Output_section* hashsec = this->make_output_section(hash_name, |
1282 | elfcpp::SHT_HASH, | |
1283 | elfcpp::SHF_ALLOC); | |
1284 | ||
1285 | Output_section_data* hashdata = new Output_data_const_buffer(phash, | |
1286 | hashlen, | |
1287 | align); | |
1288 | hashsec->add_output_section_data(hashdata); | |
1289 | ||
16649710 | 1290 | hashsec->set_link_section(dynsym); |
a3ad94ed | 1291 | hashsec->set_entsize(4); |
a3ad94ed ILT |
1292 | |
1293 | odyn->add_section_address(elfcpp::DT_HASH, hashsec); | |
dbe717ef ILT |
1294 | } |
1295 | ||
14b31740 ILT |
1296 | // Create the version sections. |
1297 | ||
1298 | void | |
9025d29d | 1299 | Layout::create_version_sections(const Versions* versions, |
46fe1623 | 1300 | const Symbol_table* symtab, |
14b31740 ILT |
1301 | unsigned int local_symcount, |
1302 | const std::vector<Symbol*>& dynamic_symbols, | |
1303 | const Output_section* dynstr) | |
1304 | { | |
1305 | if (!versions->any_defs() && !versions->any_needs()) | |
1306 | return; | |
1307 | ||
9025d29d | 1308 | if (parameters->get_size() == 32) |
14b31740 | 1309 | { |
9025d29d | 1310 | if (parameters->is_big_endian()) |
193a53d9 ILT |
1311 | { |
1312 | #ifdef HAVE_TARGET_32_BIG | |
1313 | this->sized_create_version_sections | |
1314 | SELECT_SIZE_ENDIAN_NAME(32, true)( | |
46fe1623 | 1315 | versions, symtab, local_symcount, dynamic_symbols, dynstr |
193a53d9 ILT |
1316 | SELECT_SIZE_ENDIAN(32, true)); |
1317 | #else | |
1318 | gold_unreachable(); | |
1319 | #endif | |
1320 | } | |
14b31740 | 1321 | else |
193a53d9 ILT |
1322 | { |
1323 | #ifdef HAVE_TARGET_32_LITTLE | |
1324 | this->sized_create_version_sections | |
1325 | SELECT_SIZE_ENDIAN_NAME(32, false)( | |
46fe1623 | 1326 | versions, symtab, local_symcount, dynamic_symbols, dynstr |
193a53d9 ILT |
1327 | SELECT_SIZE_ENDIAN(32, false)); |
1328 | #else | |
1329 | gold_unreachable(); | |
1330 | #endif | |
1331 | } | |
14b31740 | 1332 | } |
9025d29d | 1333 | else if (parameters->get_size() == 64) |
14b31740 | 1334 | { |
9025d29d | 1335 | if (parameters->is_big_endian()) |
193a53d9 ILT |
1336 | { |
1337 | #ifdef HAVE_TARGET_64_BIG | |
1338 | this->sized_create_version_sections | |
1339 | SELECT_SIZE_ENDIAN_NAME(64, true)( | |
46fe1623 | 1340 | versions, symtab, local_symcount, dynamic_symbols, dynstr |
193a53d9 ILT |
1341 | SELECT_SIZE_ENDIAN(64, true)); |
1342 | #else | |
1343 | gold_unreachable(); | |
1344 | #endif | |
1345 | } | |
14b31740 | 1346 | else |
193a53d9 ILT |
1347 | { |
1348 | #ifdef HAVE_TARGET_64_LITTLE | |
1349 | this->sized_create_version_sections | |
1350 | SELECT_SIZE_ENDIAN_NAME(64, false)( | |
46fe1623 | 1351 | versions, symtab, local_symcount, dynamic_symbols, dynstr |
193a53d9 ILT |
1352 | SELECT_SIZE_ENDIAN(64, false)); |
1353 | #else | |
1354 | gold_unreachable(); | |
1355 | #endif | |
1356 | } | |
14b31740 ILT |
1357 | } |
1358 | else | |
1359 | gold_unreachable(); | |
1360 | } | |
1361 | ||
1362 | // Create the version sections, sized version. | |
1363 | ||
1364 | template<int size, bool big_endian> | |
1365 | void | |
1366 | Layout::sized_create_version_sections( | |
1367 | const Versions* versions, | |
46fe1623 | 1368 | const Symbol_table* symtab, |
14b31740 ILT |
1369 | unsigned int local_symcount, |
1370 | const std::vector<Symbol*>& dynamic_symbols, | |
91da9340 ILT |
1371 | const Output_section* dynstr |
1372 | ACCEPT_SIZE_ENDIAN) | |
14b31740 | 1373 | { |
cfd73a4e | 1374 | const char* vname = this->namepool_.add(".gnu.version", false, NULL); |
14b31740 ILT |
1375 | Output_section* vsec = this->make_output_section(vname, |
1376 | elfcpp::SHT_GNU_versym, | |
1377 | elfcpp::SHF_ALLOC); | |
1378 | ||
1379 | unsigned char* vbuf; | |
1380 | unsigned int vsize; | |
91da9340 | 1381 | versions->symbol_section_contents SELECT_SIZE_ENDIAN_NAME(size, big_endian)( |
46fe1623 | 1382 | symtab, &this->dynpool_, local_symcount, dynamic_symbols, &vbuf, &vsize |
7e1edb90 | 1383 | SELECT_SIZE_ENDIAN(size, big_endian)); |
14b31740 ILT |
1384 | |
1385 | Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2); | |
1386 | ||
1387 | vsec->add_output_section_data(vdata); | |
1388 | vsec->set_entsize(2); | |
1389 | vsec->set_link_section(this->dynsym_section_); | |
1390 | ||
1391 | Output_data_dynamic* const odyn = this->dynamic_data_; | |
1392 | odyn->add_section_address(elfcpp::DT_VERSYM, vsec); | |
1393 | ||
1394 | if (versions->any_defs()) | |
1395 | { | |
cfd73a4e | 1396 | const char* vdname = this->namepool_.add(".gnu.version_d", false, NULL); |
14b31740 ILT |
1397 | Output_section *vdsec; |
1398 | vdsec = this->make_output_section(vdname, elfcpp::SHT_GNU_verdef, | |
1399 | elfcpp::SHF_ALLOC); | |
1400 | ||
1401 | unsigned char* vdbuf; | |
1402 | unsigned int vdsize; | |
1403 | unsigned int vdentries; | |
91da9340 ILT |
1404 | versions->def_section_contents SELECT_SIZE_ENDIAN_NAME(size, big_endian)( |
1405 | &this->dynpool_, &vdbuf, &vdsize, &vdentries | |
1406 | SELECT_SIZE_ENDIAN(size, big_endian)); | |
14b31740 ILT |
1407 | |
1408 | Output_section_data* vddata = new Output_data_const_buffer(vdbuf, | |
1409 | vdsize, | |
1410 | 4); | |
1411 | ||
1412 | vdsec->add_output_section_data(vddata); | |
1413 | vdsec->set_link_section(dynstr); | |
1414 | vdsec->set_info(vdentries); | |
1415 | ||
1416 | odyn->add_section_address(elfcpp::DT_VERDEF, vdsec); | |
1417 | odyn->add_constant(elfcpp::DT_VERDEFNUM, vdentries); | |
1418 | } | |
1419 | ||
1420 | if (versions->any_needs()) | |
1421 | { | |
cfd73a4e | 1422 | const char* vnname = this->namepool_.add(".gnu.version_r", false, NULL); |
14b31740 ILT |
1423 | Output_section* vnsec; |
1424 | vnsec = this->make_output_section(vnname, elfcpp::SHT_GNU_verneed, | |
1425 | elfcpp::SHF_ALLOC); | |
1426 | ||
1427 | unsigned char* vnbuf; | |
1428 | unsigned int vnsize; | |
1429 | unsigned int vnentries; | |
91da9340 ILT |
1430 | versions->need_section_contents SELECT_SIZE_ENDIAN_NAME(size, big_endian) |
1431 | (&this->dynpool_, &vnbuf, &vnsize, &vnentries | |
1432 | SELECT_SIZE_ENDIAN(size, big_endian)); | |
14b31740 ILT |
1433 | |
1434 | Output_section_data* vndata = new Output_data_const_buffer(vnbuf, | |
1435 | vnsize, | |
1436 | 4); | |
1437 | ||
1438 | vnsec->add_output_section_data(vndata); | |
1439 | vnsec->set_link_section(dynstr); | |
1440 | vnsec->set_info(vnentries); | |
1441 | ||
1442 | odyn->add_section_address(elfcpp::DT_VERNEED, vnsec); | |
1443 | odyn->add_constant(elfcpp::DT_VERNEEDNUM, vnentries); | |
1444 | } | |
1445 | } | |
1446 | ||
dbe717ef ILT |
1447 | // Create the .interp section and PT_INTERP segment. |
1448 | ||
1449 | void | |
1450 | Layout::create_interp(const Target* target) | |
1451 | { | |
1452 | const char* interp = this->options_.dynamic_linker(); | |
1453 | if (interp == NULL) | |
1454 | { | |
1455 | interp = target->dynamic_linker(); | |
a3ad94ed | 1456 | gold_assert(interp != NULL); |
dbe717ef ILT |
1457 | } |
1458 | ||
1459 | size_t len = strlen(interp) + 1; | |
1460 | ||
1461 | Output_section_data* odata = new Output_data_const(interp, len, 1); | |
1462 | ||
cfd73a4e | 1463 | const char* interp_name = this->namepool_.add(".interp", false, NULL); |
dbe717ef ILT |
1464 | Output_section* osec = this->make_output_section(interp_name, |
1465 | elfcpp::SHT_PROGBITS, | |
1466 | elfcpp::SHF_ALLOC); | |
1467 | osec->add_output_section_data(odata); | |
1468 | ||
1469 | Output_segment* oseg = new Output_segment(elfcpp::PT_INTERP, elfcpp::PF_R); | |
1470 | this->segment_list_.push_back(oseg); | |
1471 | oseg->add_initial_output_section(osec, elfcpp::PF_R); | |
1472 | } | |
1473 | ||
a3ad94ed ILT |
1474 | // Finish the .dynamic section and PT_DYNAMIC segment. |
1475 | ||
1476 | void | |
1477 | Layout::finish_dynamic_section(const Input_objects* input_objects, | |
16649710 | 1478 | const Symbol_table* symtab) |
a3ad94ed | 1479 | { |
a3ad94ed ILT |
1480 | Output_segment* oseg = new Output_segment(elfcpp::PT_DYNAMIC, |
1481 | elfcpp::PF_R | elfcpp::PF_W); | |
1482 | this->segment_list_.push_back(oseg); | |
1483 | oseg->add_initial_output_section(this->dynamic_section_, | |
1484 | elfcpp::PF_R | elfcpp::PF_W); | |
1485 | ||
16649710 ILT |
1486 | Output_data_dynamic* const odyn = this->dynamic_data_; |
1487 | ||
a3ad94ed ILT |
1488 | for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin(); |
1489 | p != input_objects->dynobj_end(); | |
1490 | ++p) | |
1491 | { | |
1492 | // FIXME: Handle --as-needed. | |
1493 | odyn->add_string(elfcpp::DT_NEEDED, (*p)->soname()); | |
1494 | } | |
1495 | ||
1496 | // FIXME: Support --init and --fini. | |
1497 | Symbol* sym = symtab->lookup("_init"); | |
14b31740 | 1498 | if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj()) |
a3ad94ed ILT |
1499 | odyn->add_symbol(elfcpp::DT_INIT, sym); |
1500 | ||
1501 | sym = symtab->lookup("_fini"); | |
14b31740 | 1502 | if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj()) |
a3ad94ed ILT |
1503 | odyn->add_symbol(elfcpp::DT_FINI, sym); |
1504 | ||
1505 | // FIXME: Support DT_INIT_ARRAY and DT_FINI_ARRAY. | |
41f542e7 ILT |
1506 | |
1507 | // Add a DT_RPATH entry if needed. | |
1508 | const General_options::Dir_list& rpath(this->options_.rpath()); | |
1509 | if (!rpath.empty()) | |
1510 | { | |
1511 | std::string rpath_val; | |
1512 | for (General_options::Dir_list::const_iterator p = rpath.begin(); | |
1513 | p != rpath.end(); | |
1514 | ++p) | |
1515 | { | |
1516 | if (rpath_val.empty()) | |
ad2d6943 | 1517 | rpath_val = p->name(); |
41f542e7 ILT |
1518 | else |
1519 | { | |
1520 | // Eliminate duplicates. | |
1521 | General_options::Dir_list::const_iterator q; | |
1522 | for (q = rpath.begin(); q != p; ++q) | |
ad2d6943 | 1523 | if (q->name() == p->name()) |
41f542e7 ILT |
1524 | break; |
1525 | if (q == p) | |
1526 | { | |
1527 | rpath_val += ':'; | |
ad2d6943 | 1528 | rpath_val += p->name(); |
41f542e7 ILT |
1529 | } |
1530 | } | |
1531 | } | |
1532 | ||
1533 | odyn->add_string(elfcpp::DT_RPATH, rpath_val); | |
1534 | } | |
a3ad94ed ILT |
1535 | } |
1536 | ||
a2fb1b05 ILT |
1537 | // The mapping of .gnu.linkonce section names to real section names. |
1538 | ||
ead1e424 | 1539 | #define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 } |
a2fb1b05 ILT |
1540 | const Layout::Linkonce_mapping Layout::linkonce_mapping[] = |
1541 | { | |
1542 | MAPPING_INIT("d.rel.ro", ".data.rel.ro"), // Must be before "d". | |
1543 | MAPPING_INIT("t", ".text"), | |
1544 | MAPPING_INIT("r", ".rodata"), | |
1545 | MAPPING_INIT("d", ".data"), | |
1546 | MAPPING_INIT("b", ".bss"), | |
1547 | MAPPING_INIT("s", ".sdata"), | |
1548 | MAPPING_INIT("sb", ".sbss"), | |
1549 | MAPPING_INIT("s2", ".sdata2"), | |
1550 | MAPPING_INIT("sb2", ".sbss2"), | |
1551 | MAPPING_INIT("wi", ".debug_info"), | |
1552 | MAPPING_INIT("td", ".tdata"), | |
1553 | MAPPING_INIT("tb", ".tbss"), | |
1554 | MAPPING_INIT("lr", ".lrodata"), | |
1555 | MAPPING_INIT("l", ".ldata"), | |
1556 | MAPPING_INIT("lb", ".lbss"), | |
1557 | }; | |
1558 | #undef MAPPING_INIT | |
1559 | ||
1560 | const int Layout::linkonce_mapping_count = | |
1561 | sizeof(Layout::linkonce_mapping) / sizeof(Layout::linkonce_mapping[0]); | |
1562 | ||
1563 | // Return the name of the output section to use for a .gnu.linkonce | |
1564 | // section. This is based on the default ELF linker script of the old | |
1565 | // GNU linker. For example, we map a name like ".gnu.linkonce.t.foo" | |
ead1e424 ILT |
1566 | // to ".text". Set *PLEN to the length of the name. *PLEN is |
1567 | // initialized to the length of NAME. | |
a2fb1b05 ILT |
1568 | |
1569 | const char* | |
ead1e424 | 1570 | Layout::linkonce_output_name(const char* name, size_t *plen) |
a2fb1b05 ILT |
1571 | { |
1572 | const char* s = name + sizeof(".gnu.linkonce") - 1; | |
1573 | if (*s != '.') | |
1574 | return name; | |
1575 | ++s; | |
1576 | const Linkonce_mapping* plm = linkonce_mapping; | |
1577 | for (int i = 0; i < linkonce_mapping_count; ++i, ++plm) | |
1578 | { | |
1579 | if (strncmp(s, plm->from, plm->fromlen) == 0 && s[plm->fromlen] == '.') | |
ead1e424 ILT |
1580 | { |
1581 | *plen = plm->tolen; | |
1582 | return plm->to; | |
1583 | } | |
a2fb1b05 ILT |
1584 | } |
1585 | return name; | |
1586 | } | |
1587 | ||
ead1e424 ILT |
1588 | // Choose the output section name to use given an input section name. |
1589 | // Set *PLEN to the length of the name. *PLEN is initialized to the | |
1590 | // length of NAME. | |
1591 | ||
1592 | const char* | |
1593 | Layout::output_section_name(const char* name, size_t* plen) | |
1594 | { | |
1595 | if (Layout::is_linkonce(name)) | |
1596 | { | |
1597 | // .gnu.linkonce sections are laid out as though they were named | |
1598 | // for the sections are placed into. | |
1599 | return Layout::linkonce_output_name(name, plen); | |
1600 | } | |
1601 | ||
af4a8a83 ILT |
1602 | // gcc 4.3 generates the following sorts of section names when it |
1603 | // needs a section name specific to a function: | |
1604 | // .text.FN | |
1605 | // .rodata.FN | |
1606 | // .sdata2.FN | |
1607 | // .data.FN | |
1608 | // .data.rel.FN | |
1609 | // .data.rel.local.FN | |
1610 | // .data.rel.ro.FN | |
1611 | // .data.rel.ro.local.FN | |
1612 | // .sdata.FN | |
1613 | // .bss.FN | |
1614 | // .sbss.FN | |
1615 | // .tdata.FN | |
1616 | // .tbss.FN | |
1617 | ||
1618 | // The GNU linker maps all of those to the part before the .FN, | |
1619 | // except that .data.rel.local.FN is mapped to .data, and | |
1620 | // .data.rel.ro.local.FN is mapped to .data.rel.ro. The sections | |
1621 | // beginning with .data.rel.ro.local are grouped together. | |
1622 | ||
1623 | // For an anonymous namespace, the string FN can contain a '.'. | |
1624 | ||
1625 | // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the | |
1626 | // GNU linker maps to .rodata. | |
1627 | ||
1628 | // The .data.rel.ro sections enable a security feature triggered by | |
1629 | // the -z relro option. Section which need to be relocated at | |
1630 | // program startup time but which may be readonly after startup are | |
1631 | // grouped into .data.rel.ro. They are then put into a PT_GNU_RELRO | |
1632 | // segment. The dynamic linker will make that segment writable, | |
1633 | // perform relocations, and then make it read-only. FIXME: We do | |
1634 | // not yet implement this optimization. | |
1635 | ||
1636 | // It is hard to handle this in a principled way. | |
1637 | ||
1638 | // These are the rules we follow: | |
1639 | ||
1640 | // If the section name has no initial '.', or no dot other than an | |
1641 | // initial '.', we use the name unchanged (i.e., "mysection" and | |
1642 | // ".text" are unchanged). | |
1643 | ||
1644 | // If the name starts with ".data.rel.ro" we use ".data.rel.ro". | |
1645 | ||
1646 | // Otherwise, we drop the second '.' and everything that comes after | |
1647 | // it (i.e., ".text.XXX" becomes ".text"). | |
ead1e424 ILT |
1648 | |
1649 | const char* s = name; | |
af4a8a83 ILT |
1650 | if (*s != '.') |
1651 | return name; | |
1652 | ++s; | |
ead1e424 ILT |
1653 | const char* sdot = strchr(s, '.'); |
1654 | if (sdot == NULL) | |
1655 | return name; | |
1656 | ||
af4a8a83 ILT |
1657 | const char* const data_rel_ro = ".data.rel.ro"; |
1658 | if (strncmp(name, data_rel_ro, strlen(data_rel_ro)) == 0) | |
ead1e424 | 1659 | { |
af4a8a83 ILT |
1660 | *plen = strlen(data_rel_ro); |
1661 | return data_rel_ro; | |
ead1e424 ILT |
1662 | } |
1663 | ||
ead1e424 ILT |
1664 | *plen = sdot - name; |
1665 | return name; | |
1666 | } | |
1667 | ||
a2fb1b05 ILT |
1668 | // Record the signature of a comdat section, and return whether to |
1669 | // include it in the link. If GROUP is true, this is a regular | |
1670 | // section group. If GROUP is false, this is a group signature | |
1671 | // derived from the name of a linkonce section. We want linkonce | |
1672 | // signatures and group signatures to block each other, but we don't | |
1673 | // want a linkonce signature to block another linkonce signature. | |
1674 | ||
1675 | bool | |
1676 | Layout::add_comdat(const char* signature, bool group) | |
1677 | { | |
1678 | std::string sig(signature); | |
1679 | std::pair<Signatures::iterator, bool> ins( | |
ead1e424 | 1680 | this->signatures_.insert(std::make_pair(sig, group))); |
a2fb1b05 ILT |
1681 | |
1682 | if (ins.second) | |
1683 | { | |
1684 | // This is the first time we've seen this signature. | |
1685 | return true; | |
1686 | } | |
1687 | ||
1688 | if (ins.first->second) | |
1689 | { | |
1690 | // We've already seen a real section group with this signature. | |
1691 | return false; | |
1692 | } | |
1693 | else if (group) | |
1694 | { | |
1695 | // This is a real section group, and we've already seen a | |
a0fa0c07 | 1696 | // linkonce section with this signature. Record that we've seen |
a2fb1b05 ILT |
1697 | // a section group, and don't include this section group. |
1698 | ins.first->second = true; | |
1699 | return false; | |
1700 | } | |
1701 | else | |
1702 | { | |
1703 | // We've already seen a linkonce section and this is a linkonce | |
1704 | // section. These don't block each other--this may be the same | |
1705 | // symbol name with different section types. | |
1706 | return true; | |
1707 | } | |
1708 | } | |
1709 | ||
61ba1cf9 ILT |
1710 | // Write out data not associated with a section or the symbol table. |
1711 | ||
1712 | void | |
9025d29d | 1713 | Layout::write_data(const Symbol_table* symtab, Output_file* of) const |
61ba1cf9 | 1714 | { |
9e2dcb77 | 1715 | if (!parameters->strip_all()) |
a3ad94ed | 1716 | { |
9e2dcb77 ILT |
1717 | const Output_section* symtab_section = this->symtab_section_; |
1718 | for (Section_list::const_iterator p = this->section_list_.begin(); | |
1719 | p != this->section_list_.end(); | |
1720 | ++p) | |
a3ad94ed | 1721 | { |
9e2dcb77 ILT |
1722 | if ((*p)->needs_symtab_index()) |
1723 | { | |
1724 | gold_assert(symtab_section != NULL); | |
1725 | unsigned int index = (*p)->symtab_index(); | |
1726 | gold_assert(index > 0 && index != -1U); | |
1727 | off_t off = (symtab_section->offset() | |
1728 | + index * symtab_section->entsize()); | |
1729 | symtab->write_section_symbol(*p, of, off); | |
1730 | } | |
a3ad94ed ILT |
1731 | } |
1732 | } | |
1733 | ||
1734 | const Output_section* dynsym_section = this->dynsym_section_; | |
1735 | for (Section_list::const_iterator p = this->section_list_.begin(); | |
1736 | p != this->section_list_.end(); | |
1737 | ++p) | |
1738 | { | |
1739 | if ((*p)->needs_dynsym_index()) | |
1740 | { | |
1741 | gold_assert(dynsym_section != NULL); | |
1742 | unsigned int index = (*p)->dynsym_index(); | |
1743 | gold_assert(index > 0 && index != -1U); | |
1744 | off_t off = (dynsym_section->offset() | |
1745 | + index * dynsym_section->entsize()); | |
9025d29d | 1746 | symtab->write_section_symbol(*p, of, off); |
a3ad94ed ILT |
1747 | } |
1748 | } | |
1749 | ||
1750 | // Write out the Output_sections. Most won't have anything to | |
1751 | // write, since most of the data will come from input sections which | |
1752 | // are handled elsewhere. But some Output_sections do have | |
1753 | // Output_data. | |
1754 | for (Section_list::const_iterator p = this->section_list_.begin(); | |
1755 | p != this->section_list_.end(); | |
1756 | ++p) | |
1757 | (*p)->write(of); | |
1758 | ||
1759 | // Write out the Output_data which are not in an Output_section. | |
61ba1cf9 ILT |
1760 | for (Data_list::const_iterator p = this->special_output_list_.begin(); |
1761 | p != this->special_output_list_.end(); | |
1762 | ++p) | |
1763 | (*p)->write(of); | |
1764 | } | |
1765 | ||
1766 | // Write_data_task methods. | |
1767 | ||
1768 | // We can always run this task. | |
1769 | ||
1770 | Task::Is_runnable_type | |
1771 | Write_data_task::is_runnable(Workqueue*) | |
1772 | { | |
1773 | return IS_RUNNABLE; | |
1774 | } | |
1775 | ||
1776 | // We need to unlock FINAL_BLOCKER when finished. | |
1777 | ||
1778 | Task_locker* | |
1779 | Write_data_task::locks(Workqueue* workqueue) | |
1780 | { | |
1781 | return new Task_locker_block(*this->final_blocker_, workqueue); | |
1782 | } | |
1783 | ||
1784 | // Run the task--write out the data. | |
1785 | ||
1786 | void | |
1787 | Write_data_task::run(Workqueue*) | |
1788 | { | |
9025d29d | 1789 | this->layout_->write_data(this->symtab_, this->of_); |
61ba1cf9 ILT |
1790 | } |
1791 | ||
1792 | // Write_symbols_task methods. | |
1793 | ||
1794 | // We can always run this task. | |
1795 | ||
1796 | Task::Is_runnable_type | |
1797 | Write_symbols_task::is_runnable(Workqueue*) | |
1798 | { | |
1799 | return IS_RUNNABLE; | |
1800 | } | |
1801 | ||
1802 | // We need to unlock FINAL_BLOCKER when finished. | |
1803 | ||
1804 | Task_locker* | |
1805 | Write_symbols_task::locks(Workqueue* workqueue) | |
1806 | { | |
1807 | return new Task_locker_block(*this->final_blocker_, workqueue); | |
1808 | } | |
1809 | ||
1810 | // Run the task--write out the symbols. | |
1811 | ||
1812 | void | |
1813 | Write_symbols_task::run(Workqueue*) | |
1814 | { | |
16649710 ILT |
1815 | this->symtab_->write_globals(this->target_, this->sympool_, this->dynpool_, |
1816 | this->of_); | |
61ba1cf9 ILT |
1817 | } |
1818 | ||
92e059d8 | 1819 | // Close_task_runner methods. |
61ba1cf9 ILT |
1820 | |
1821 | // Run the task--close the file. | |
1822 | ||
1823 | void | |
92e059d8 | 1824 | Close_task_runner::run(Workqueue*) |
61ba1cf9 ILT |
1825 | { |
1826 | this->of_->close(); | |
1827 | } | |
1828 | ||
a2fb1b05 ILT |
1829 | // Instantiate the templates we need. We could use the configure |
1830 | // script to restrict this to only the ones for implemented targets. | |
1831 | ||
193a53d9 | 1832 | #ifdef HAVE_TARGET_32_LITTLE |
a2fb1b05 ILT |
1833 | template |
1834 | Output_section* | |
f6ce93d6 | 1835 | Layout::layout<32, false>(Relobj* object, unsigned int shndx, const char* name, |
a2fb1b05 | 1836 | const elfcpp::Shdr<32, false>& shdr, off_t*); |
193a53d9 | 1837 | #endif |
a2fb1b05 | 1838 | |
193a53d9 | 1839 | #ifdef HAVE_TARGET_32_BIG |
a2fb1b05 ILT |
1840 | template |
1841 | Output_section* | |
f6ce93d6 | 1842 | Layout::layout<32, true>(Relobj* object, unsigned int shndx, const char* name, |
a2fb1b05 | 1843 | const elfcpp::Shdr<32, true>& shdr, off_t*); |
193a53d9 | 1844 | #endif |
a2fb1b05 | 1845 | |
193a53d9 | 1846 | #ifdef HAVE_TARGET_64_LITTLE |
a2fb1b05 ILT |
1847 | template |
1848 | Output_section* | |
f6ce93d6 | 1849 | Layout::layout<64, false>(Relobj* object, unsigned int shndx, const char* name, |
a2fb1b05 | 1850 | const elfcpp::Shdr<64, false>& shdr, off_t*); |
193a53d9 | 1851 | #endif |
a2fb1b05 | 1852 | |
193a53d9 | 1853 | #ifdef HAVE_TARGET_64_BIG |
a2fb1b05 ILT |
1854 | template |
1855 | Output_section* | |
f6ce93d6 | 1856 | Layout::layout<64, true>(Relobj* object, unsigned int shndx, const char* name, |
a2fb1b05 | 1857 | const elfcpp::Shdr<64, true>& shdr, off_t*); |
193a53d9 | 1858 | #endif |
a2fb1b05 ILT |
1859 | |
1860 | ||
1861 | } // End namespace gold. |