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a2fb1b05 ILT |
1 | // layout.h -- lay out output file sections for gold -*- C++ -*- |
2 | ||
10b4f102 | 3 | // Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. |
6cb15b7f ILT |
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 | #ifndef GOLD_LAYOUT_H |
24 | #define GOLD_LAYOUT_H | |
25 | ||
e94cf127 | 26 | #include <cstring> |
a2fb1b05 | 27 | #include <list> |
1ef4d87f | 28 | #include <map> |
a2fb1b05 ILT |
29 | #include <string> |
30 | #include <utility> | |
31 | #include <vector> | |
32 | ||
e5756efb | 33 | #include "script.h" |
a2fb1b05 ILT |
34 | #include "workqueue.h" |
35 | #include "object.h" | |
14b31740 | 36 | #include "dynobj.h" |
a2fb1b05 ILT |
37 | #include "stringpool.h" |
38 | ||
39 | namespace gold | |
40 | { | |
41 | ||
ead1e424 | 42 | class General_options; |
3ce2c28e | 43 | class Incremental_inputs; |
cdc29364 | 44 | class Incremental_binary; |
54dc6425 | 45 | class Input_objects; |
7d9e3d98 | 46 | class Mapfile; |
75f65a3e | 47 | class Symbol_table; |
ead1e424 | 48 | class Output_section_data; |
a2fb1b05 | 49 | class Output_section; |
75f65a3e | 50 | class Output_section_headers; |
20e6d0d6 DK |
51 | class Output_segment_headers; |
52 | class Output_file_header; | |
a2fb1b05 | 53 | class Output_segment; |
54dc6425 | 54 | class Output_data; |
3a44184e | 55 | class Output_data_reloc_generic; |
a3ad94ed | 56 | class Output_data_dynamic; |
d491d34e | 57 | class Output_symtab_xindex; |
62b01cb5 ILT |
58 | class Output_reduced_debug_abbrev_section; |
59 | class Output_reduced_debug_info_section; | |
730cdc88 | 60 | class Eh_frame; |
61ba1cf9 | 61 | class Target; |
09ec0418 | 62 | struct Timespec; |
a2fb1b05 | 63 | |
a2e47362 CC |
64 | // Return TRUE if SECNAME is the name of a compressed debug section. |
65 | extern bool | |
66 | is_compressed_debug_section(const char* secname); | |
67 | ||
cdc29364 CC |
68 | // Maintain a list of free space within a section, segment, or file. |
69 | // Used for incremental update links. | |
70 | ||
71 | class Free_list | |
72 | { | |
73 | public: | |
8ea8cd50 CC |
74 | struct Free_list_node |
75 | { | |
76 | Free_list_node(off_t start, off_t end) | |
77 | : start_(start), end_(end) | |
78 | { } | |
79 | off_t start_; | |
80 | off_t end_; | |
81 | }; | |
82 | typedef std::list<Free_list_node>::const_iterator Const_iterator; | |
83 | ||
cdc29364 | 84 | Free_list() |
8ea8cd50 CC |
85 | : list_(), last_remove_(list_.begin()), extend_(false), length_(0), |
86 | min_hole_(0) | |
cdc29364 CC |
87 | { } |
88 | ||
8ea8cd50 CC |
89 | // Initialize the free list for a section of length LEN. |
90 | // If EXTEND is true, free space may be allocated past the end. | |
cdc29364 CC |
91 | void |
92 | init(off_t len, bool extend); | |
93 | ||
8ea8cd50 CC |
94 | // Set the minimum hole size that is allowed when allocating |
95 | // from the free list. | |
96 | void | |
97 | set_min_hole_size(off_t min_hole) | |
98 | { this->min_hole_ = min_hole; } | |
99 | ||
100 | // Remove a chunk from the free list. | |
cdc29364 CC |
101 | void |
102 | remove(off_t start, off_t end); | |
103 | ||
8ea8cd50 CC |
104 | // Allocate a chunk of space from the free list of length LEN, |
105 | // with alignment ALIGN, and minimum offset MINOFF. | |
cdc29364 CC |
106 | off_t |
107 | allocate(off_t len, uint64_t align, off_t minoff); | |
108 | ||
8ea8cd50 CC |
109 | // Return an iterator for the beginning of the free list. |
110 | Const_iterator | |
111 | begin() const | |
112 | { return this->list_.begin(); } | |
113 | ||
114 | // Return an iterator for the end of the free list. | |
115 | Const_iterator | |
116 | end() const | |
117 | { return this->list_.end(); } | |
118 | ||
119 | // Dump the free list (for debugging). | |
cdc29364 CC |
120 | void |
121 | dump(); | |
122 | ||
8ea8cd50 | 123 | // Print usage statistics. |
cdc29364 CC |
124 | static void |
125 | print_stats(); | |
126 | ||
127 | private: | |
cdc29364 CC |
128 | typedef std::list<Free_list_node>::iterator Iterator; |
129 | ||
130 | // The free list. | |
131 | std::list<Free_list_node> list_; | |
132 | ||
133 | // The last node visited during a remove operation. | |
134 | Iterator last_remove_; | |
135 | ||
136 | // Whether we can extend past the original length. | |
137 | bool extend_; | |
138 | ||
139 | // The total length of the section, segment, or file. | |
140 | off_t length_; | |
141 | ||
8ea8cd50 CC |
142 | // The minimum hole size allowed. When allocating from the free list, |
143 | // we must not leave a hole smaller than this. | |
144 | off_t min_hole_; | |
145 | ||
cdc29364 CC |
146 | // Statistics: |
147 | // The total number of free lists used. | |
148 | static unsigned int num_lists; | |
149 | // The total number of free list nodes used. | |
150 | static unsigned int num_nodes; | |
151 | // The total number of calls to Free_list::remove. | |
152 | static unsigned int num_removes; | |
153 | // The total number of nodes visited during calls to Free_list::remove. | |
154 | static unsigned int num_remove_visits; | |
155 | // The total number of calls to Free_list::allocate. | |
156 | static unsigned int num_allocates; | |
157 | // The total number of nodes visited during calls to Free_list::allocate. | |
158 | static unsigned int num_allocate_visits; | |
159 | }; | |
160 | ||
92e059d8 ILT |
161 | // This task function handles mapping the input sections to output |
162 | // sections and laying them out in memory. | |
a2fb1b05 | 163 | |
92e059d8 | 164 | class Layout_task_runner : public Task_function_runner |
a2fb1b05 ILT |
165 | { |
166 | public: | |
167 | // OPTIONS is the command line options, INPUT_OBJECTS is the list of | |
92e059d8 ILT |
168 | // input objects, SYMTAB is the symbol table, LAYOUT is the layout |
169 | // object. | |
170 | Layout_task_runner(const General_options& options, | |
171 | const Input_objects* input_objects, | |
172 | Symbol_table* symtab, | |
8851ecca | 173 | Target* target, |
7d9e3d98 ILT |
174 | Layout* layout, |
175 | Mapfile* mapfile) | |
75f65a3e | 176 | : options_(options), input_objects_(input_objects), symtab_(symtab), |
7d9e3d98 | 177 | target_(target), layout_(layout), mapfile_(mapfile) |
a2fb1b05 ILT |
178 | { } |
179 | ||
92e059d8 | 180 | // Run the operation. |
a2fb1b05 | 181 | void |
17a1d0a9 | 182 | run(Workqueue*, const Task*); |
a2fb1b05 ILT |
183 | |
184 | private: | |
92e059d8 ILT |
185 | Layout_task_runner(const Layout_task_runner&); |
186 | Layout_task_runner& operator=(const Layout_task_runner&); | |
a2fb1b05 ILT |
187 | |
188 | const General_options& options_; | |
54dc6425 | 189 | const Input_objects* input_objects_; |
75f65a3e | 190 | Symbol_table* symtab_; |
8851ecca | 191 | Target* target_; |
12e14209 | 192 | Layout* layout_; |
7d9e3d98 | 193 | Mapfile* mapfile_; |
a2fb1b05 ILT |
194 | }; |
195 | ||
1ef4d87f ILT |
196 | // This class holds information about the comdat group or |
197 | // .gnu.linkonce section that will be kept for a given signature. | |
8a4c0b0d | 198 | |
1ef4d87f | 199 | class Kept_section |
8a4c0b0d | 200 | { |
1ef4d87f ILT |
201 | private: |
202 | // For a comdat group, we build a mapping from the name of each | |
203 | // section in the group to the section index and the size in object. | |
204 | // When we discard a group in some other object file, we use this | |
205 | // map to figure out which kept section the discarded section is | |
206 | // associated with. We then use that mapping when processing relocs | |
207 | // against discarded sections. | |
208 | struct Comdat_section_info | |
209 | { | |
210 | // The section index. | |
211 | unsigned int shndx; | |
212 | // The section size. | |
213 | uint64_t size; | |
214 | ||
215 | Comdat_section_info(unsigned int a_shndx, uint64_t a_size) | |
216 | : shndx(a_shndx), size(a_size) | |
217 | { } | |
218 | }; | |
219 | ||
220 | // Most comdat groups have only one or two sections, so we use a | |
221 | // std::map rather than an Unordered_map to optimize for that case | |
222 | // without paying too heavily for groups with more sections. | |
223 | typedef std::map<std::string, Comdat_section_info> Comdat_group; | |
224 | ||
225 | public: | |
8a4c0b0d | 226 | Kept_section() |
1ef4d87f ILT |
227 | : object_(NULL), shndx_(0), is_comdat_(false), is_group_name_(false) |
228 | { this->u_.linkonce_size = 0; } | |
229 | ||
230 | // We need to support copies for the signature map in the Layout | |
231 | // object, but we should never copy an object after it has been | |
232 | // marked as a comdat section. | |
233 | Kept_section(const Kept_section& k) | |
234 | : object_(k.object_), shndx_(k.shndx_), is_comdat_(false), | |
235 | is_group_name_(k.is_group_name_) | |
236 | { | |
237 | gold_assert(!k.is_comdat_); | |
238 | this->u_.linkonce_size = 0; | |
239 | } | |
240 | ||
241 | ~Kept_section() | |
242 | { | |
243 | if (this->is_comdat_) | |
244 | delete this->u_.group_sections; | |
245 | } | |
246 | ||
247 | // The object where this section lives. | |
248 | Relobj* | |
249 | object() const | |
250 | { return this->object_; } | |
8a4c0b0d | 251 | |
1ef4d87f ILT |
252 | // Set the object. |
253 | void | |
2ea97941 | 254 | set_object(Relobj* object) |
1ef4d87f ILT |
255 | { |
256 | gold_assert(this->object_ == NULL); | |
2ea97941 | 257 | this->object_ = object; |
1ef4d87f ILT |
258 | } |
259 | ||
260 | // The section index. | |
261 | unsigned int | |
262 | shndx() const | |
263 | { return this->shndx_; } | |
264 | ||
265 | // Set the section index. | |
266 | void | |
2ea97941 | 267 | set_shndx(unsigned int shndx) |
1ef4d87f ILT |
268 | { |
269 | gold_assert(this->shndx_ == 0); | |
2ea97941 | 270 | this->shndx_ = shndx; |
1ef4d87f ILT |
271 | } |
272 | ||
273 | // Whether this is a comdat group. | |
274 | bool | |
275 | is_comdat() const | |
276 | { return this->is_comdat_; } | |
277 | ||
278 | // Set that this is a comdat group. | |
279 | void | |
280 | set_is_comdat() | |
281 | { | |
282 | gold_assert(!this->is_comdat_); | |
283 | this->is_comdat_ = true; | |
284 | this->u_.group_sections = new Comdat_group(); | |
285 | } | |
8a4c0b0d | 286 | |
1ef4d87f ILT |
287 | // Whether this is associated with the name of a group or section |
288 | // rather than the symbol name derived from a linkonce section. | |
289 | bool | |
290 | is_group_name() const | |
291 | { return this->is_group_name_; } | |
292 | ||
293 | // Note that this represents a comdat group rather than a single | |
294 | // linkonce section. | |
295 | void | |
296 | set_is_group_name() | |
297 | { this->is_group_name_ = true; } | |
298 | ||
299 | // Add a section to the group list. | |
300 | void | |
2ea97941 | 301 | add_comdat_section(const std::string& name, unsigned int shndx, |
1ef4d87f ILT |
302 | uint64_t size) |
303 | { | |
304 | gold_assert(this->is_comdat_); | |
2ea97941 | 305 | Comdat_section_info sinfo(shndx, size); |
1ef4d87f ILT |
306 | this->u_.group_sections->insert(std::make_pair(name, sinfo)); |
307 | } | |
308 | ||
309 | // Look for a section name in the group list, and return whether it | |
310 | // was found. If found, returns the section index and size. | |
311 | bool | |
ca09d69a NC |
312 | find_comdat_section(const std::string& name, unsigned int* pshndx, |
313 | uint64_t* psize) const | |
1ef4d87f ILT |
314 | { |
315 | gold_assert(this->is_comdat_); | |
316 | Comdat_group::const_iterator p = this->u_.group_sections->find(name); | |
317 | if (p == this->u_.group_sections->end()) | |
318 | return false; | |
319 | *pshndx = p->second.shndx; | |
320 | *psize = p->second.size; | |
321 | return true; | |
322 | } | |
323 | ||
324 | // If there is only one section in the group list, return true, and | |
325 | // return the section index and size. | |
326 | bool | |
ca09d69a | 327 | find_single_comdat_section(unsigned int* pshndx, uint64_t* psize) const |
1ef4d87f ILT |
328 | { |
329 | gold_assert(this->is_comdat_); | |
330 | if (this->u_.group_sections->size() != 1) | |
331 | return false; | |
332 | Comdat_group::const_iterator p = this->u_.group_sections->begin(); | |
333 | *pshndx = p->second.shndx; | |
334 | *psize = p->second.size; | |
335 | return true; | |
336 | } | |
337 | ||
338 | // Return the size of a linkonce section. | |
339 | uint64_t | |
340 | linkonce_size() const | |
341 | { | |
342 | gold_assert(!this->is_comdat_); | |
343 | return this->u_.linkonce_size; | |
344 | } | |
345 | ||
346 | // Set the size of a linkonce section. | |
347 | void | |
348 | set_linkonce_size(uint64_t size) | |
349 | { | |
350 | gold_assert(!this->is_comdat_); | |
351 | this->u_.linkonce_size = size; | |
352 | } | |
353 | ||
354 | private: | |
355 | // No assignment. | |
356 | Kept_section& operator=(const Kept_section&); | |
357 | ||
358 | // The object containing the comdat group or .gnu.linkonce section. | |
359 | Relobj* object_; | |
360 | // Index of the group section for comdats and the section itself for | |
8a4c0b0d | 361 | // .gnu.linkonce. |
1ef4d87f ILT |
362 | unsigned int shndx_; |
363 | // True if this is for a comdat group rather than a .gnu.linkonce | |
364 | // section. | |
365 | bool is_comdat_; | |
8a4c0b0d ILT |
366 | // The Kept_sections are values of a mapping, that maps names to |
367 | // them. This field is true if this struct is associated with the | |
368 | // name of a comdat or .gnu.linkonce, false if it is associated with | |
369 | // the name of a symbol obtained from the .gnu.linkonce.* name | |
370 | // through some heuristics. | |
1ef4d87f ILT |
371 | bool is_group_name_; |
372 | union | |
373 | { | |
374 | // If the is_comdat_ field is true, this holds a map from names of | |
375 | // the sections in the group to section indexes in object_ and to | |
376 | // section sizes. | |
377 | Comdat_group* group_sections; | |
378 | // If the is_comdat_ field is false, this holds the size of the | |
379 | // single section. | |
380 | uint64_t linkonce_size; | |
381 | } u_; | |
8a4c0b0d ILT |
382 | }; |
383 | ||
22f0da72 ILT |
384 | // The ordering for output sections. This controls how output |
385 | // sections are ordered within a PT_LOAD output segment. | |
386 | ||
387 | enum Output_section_order | |
388 | { | |
389 | // Unspecified. Used for non-load segments. Also used for the file | |
390 | // and segment headers. | |
391 | ORDER_INVALID, | |
392 | ||
393 | // The PT_INTERP section should come first, so that the dynamic | |
394 | // linker can pick it up quickly. | |
395 | ORDER_INTERP, | |
396 | ||
397 | // Loadable read-only note sections come next so that the PT_NOTE | |
398 | // segment is on the first page of the executable. | |
399 | ORDER_RO_NOTE, | |
400 | ||
401 | // Put read-only sections used by the dynamic linker early in the | |
402 | // executable to minimize paging. | |
403 | ORDER_DYNAMIC_LINKER, | |
404 | ||
405 | // Put reloc sections used by the dynamic linker after other | |
406 | // sections used by the dynamic linker; otherwise, objcopy and strip | |
407 | // get confused. | |
408 | ORDER_DYNAMIC_RELOCS, | |
409 | ||
410 | // Put the PLT reloc section after the other dynamic relocs; | |
9a2743de | 411 | // otherwise, prelink gets confused. |
22f0da72 ILT |
412 | ORDER_DYNAMIC_PLT_RELOCS, |
413 | ||
414 | // The .init section. | |
415 | ORDER_INIT, | |
416 | ||
417 | // The PLT. | |
418 | ORDER_PLT, | |
419 | ||
420 | // The regular text sections. | |
421 | ORDER_TEXT, | |
422 | ||
423 | // The .fini section. | |
424 | ORDER_FINI, | |
425 | ||
426 | // The read-only sections. | |
427 | ORDER_READONLY, | |
428 | ||
429 | // The exception frame sections. | |
430 | ORDER_EHFRAME, | |
431 | ||
432 | // The TLS sections come first in the data section. | |
433 | ORDER_TLS_DATA, | |
434 | ORDER_TLS_BSS, | |
435 | ||
436 | // Local RELRO (read-only after relocation) sections come before | |
437 | // non-local RELRO sections. This data will be fully resolved by | |
438 | // the prelinker. | |
439 | ORDER_RELRO_LOCAL, | |
440 | ||
441 | // Non-local RELRO sections are grouped together after local RELRO | |
442 | // sections. All RELRO sections must be adjacent so that they can | |
443 | // all be put into a PT_GNU_RELRO segment. | |
444 | ORDER_RELRO, | |
445 | ||
446 | // We permit marking exactly one output section as the last RELRO | |
447 | // section. We do this so that the read-only GOT can be adjacent to | |
448 | // the writable GOT. | |
449 | ORDER_RELRO_LAST, | |
450 | ||
451 | // Similarly, we permit marking exactly one output section as the | |
452 | // first non-RELRO section. | |
453 | ORDER_NON_RELRO_FIRST, | |
454 | ||
455 | // The regular data sections come after the RELRO sections. | |
456 | ORDER_DATA, | |
457 | ||
458 | // Large data sections normally go in large data segments. | |
459 | ORDER_LARGE_DATA, | |
460 | ||
461 | // Group writable notes so that we can have a single PT_NOTE | |
462 | // segment. | |
463 | ORDER_RW_NOTE, | |
464 | ||
465 | // The small data sections must be at the end of the data sections, | |
466 | // so that they can be adjacent to the small BSS sections. | |
467 | ORDER_SMALL_DATA, | |
468 | ||
469 | // The BSS sections start here. | |
470 | ||
471 | // The small BSS sections must be at the start of the BSS sections, | |
472 | // so that they can be adjacent to the small data sections. | |
473 | ORDER_SMALL_BSS, | |
474 | ||
475 | // The regular BSS sections. | |
476 | ORDER_BSS, | |
477 | ||
478 | // The large BSS sections come after the other BSS sections. | |
479 | ORDER_LARGE_BSS, | |
480 | ||
481 | // Maximum value. | |
482 | ORDER_MAX | |
483 | }; | |
484 | ||
a2fb1b05 ILT |
485 | // This class handles the details of laying out input sections. |
486 | ||
487 | class Layout | |
488 | { | |
489 | public: | |
e55bde5e | 490 | Layout(int number_of_input_files, Script_options*); |
54dc6425 | 491 | |
20e6d0d6 DK |
492 | ~Layout() |
493 | { | |
494 | delete this->relaxation_debug_check_; | |
495 | delete this->segment_states_; | |
496 | } | |
497 | ||
cdc29364 CC |
498 | // For incremental links, record the base file to be modified. |
499 | void | |
500 | set_incremental_base(Incremental_binary* base); | |
501 | ||
502 | Incremental_binary* | |
503 | incremental_base() | |
504 | { return this->incremental_base_; } | |
505 | ||
506 | // For incremental links, record the initial fixed layout of a section | |
507 | // from the base file, and return a pointer to the Output_section. | |
508 | template<int size, bool big_endian> | |
509 | Output_section* | |
510 | init_fixed_output_section(const char*, elfcpp::Shdr<size, big_endian>&); | |
511 | ||
ead1e424 ILT |
512 | // Given an input section SHNDX, named NAME, with data in SHDR, from |
513 | // the object file OBJECT, return the output section where this | |
730cdc88 ILT |
514 | // input section should go. RELOC_SHNDX is the index of a |
515 | // relocation section which applies to this section, or 0 if none, | |
516 | // or -1U if more than one. RELOC_TYPE is the type of the | |
517 | // relocation section if there is one. Set *OFFSET to the offset | |
518 | // within the output section. | |
a2fb1b05 ILT |
519 | template<int size, bool big_endian> |
520 | Output_section* | |
6fa2a40b | 521 | layout(Sized_relobj_file<size, big_endian> *object, unsigned int shndx, |
730cdc88 ILT |
522 | const char* name, const elfcpp::Shdr<size, big_endian>& shdr, |
523 | unsigned int reloc_shndx, unsigned int reloc_type, off_t* offset); | |
524 | ||
e9552f7e ST |
525 | bool |
526 | is_section_ordering_specified() | |
527 | { return this->section_ordering_specified_; } | |
528 | ||
529 | void | |
530 | set_section_ordering_specified() | |
531 | { this->section_ordering_specified_ = true; } | |
532 | ||
cdc29364 CC |
533 | // For incremental updates, allocate a block of memory from the |
534 | // free list. Find a block starting at or after MINOFF. | |
535 | off_t | |
536 | allocate(off_t len, uint64_t align, off_t minoff) | |
537 | { return this->free_list_.allocate(len, align, minoff); } | |
538 | ||
6e9ba2ca ST |
539 | unsigned int |
540 | find_section_order_index(const std::string&); | |
541 | ||
e9552f7e ST |
542 | // Read the sequence of input sections from the file specified with |
543 | // linker option --section-ordering-file. | |
6e9ba2ca ST |
544 | void |
545 | read_layout_from_file(); | |
546 | ||
6a74a719 ILT |
547 | // Layout an input reloc section when doing a relocatable link. The |
548 | // section is RELOC_SHNDX in OBJECT, with data in SHDR. | |
549 | // DATA_SECTION is the reloc section to which it refers. RR is the | |
550 | // relocatable information. | |
551 | template<int size, bool big_endian> | |
552 | Output_section* | |
6fa2a40b | 553 | layout_reloc(Sized_relobj_file<size, big_endian>* object, |
6a74a719 ILT |
554 | unsigned int reloc_shndx, |
555 | const elfcpp::Shdr<size, big_endian>& shdr, | |
556 | Output_section* data_section, | |
557 | Relocatable_relocs* rr); | |
558 | ||
559 | // Layout a group section when doing a relocatable link. | |
560 | template<int size, bool big_endian> | |
561 | void | |
562 | layout_group(Symbol_table* symtab, | |
6fa2a40b | 563 | Sized_relobj_file<size, big_endian>* object, |
6a74a719 ILT |
564 | unsigned int group_shndx, |
565 | const char* group_section_name, | |
566 | const char* signature, | |
567 | const elfcpp::Shdr<size, big_endian>& shdr, | |
8825ac63 ILT |
568 | elfcpp::Elf_Word flags, |
569 | std::vector<unsigned int>* shndxes); | |
6a74a719 | 570 | |
730cdc88 ILT |
571 | // Like layout, only for exception frame sections. OBJECT is an |
572 | // object file. SYMBOLS is the contents of the symbol table | |
573 | // section, with size SYMBOLS_SIZE. SYMBOL_NAMES is the contents of | |
574 | // the symbol name section, with size SYMBOL_NAMES_SIZE. SHNDX is a | |
575 | // .eh_frame section in OBJECT. SHDR is the section header. | |
576 | // RELOC_SHNDX is the index of a relocation section which applies to | |
577 | // this section, or 0 if none, or -1U if more than one. RELOC_TYPE | |
578 | // is the type of the relocation section if there is one. This | |
579 | // returns the output section, and sets *OFFSET to the offset. | |
580 | template<int size, bool big_endian> | |
581 | Output_section* | |
6fa2a40b | 582 | layout_eh_frame(Sized_relobj_file<size, big_endian>* object, |
730cdc88 ILT |
583 | const unsigned char* symbols, |
584 | off_t symbols_size, | |
585 | const unsigned char* symbol_names, | |
586 | off_t symbol_names_size, | |
587 | unsigned int shndx, | |
588 | const elfcpp::Shdr<size, big_endian>& shdr, | |
589 | unsigned int reloc_shndx, unsigned int reloc_type, | |
590 | off_t* offset); | |
a2fb1b05 | 591 | |
07a60597 ILT |
592 | // Add .eh_frame information for a PLT. The FDE must start with a |
593 | // 4-byte PC-relative reference to the start of the PLT, followed by | |
594 | // a 4-byte size of PLT. | |
595 | void | |
596 | add_eh_frame_for_plt(Output_data* plt, const unsigned char* cie_data, | |
597 | size_t cie_length, const unsigned char* fde_data, | |
598 | size_t fde_length); | |
599 | ||
35cdfc9a ILT |
600 | // Handle a GNU stack note. This is called once per input object |
601 | // file. SEEN_GNU_STACK is true if the object file has a | |
602 | // .note.GNU-stack section. GNU_STACK_FLAGS is the section flags | |
603 | // from that section if there was one. | |
604 | void | |
83e17bd5 CC |
605 | layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags, |
606 | const Object*); | |
35cdfc9a | 607 | |
ead1e424 | 608 | // Add an Output_section_data to the layout. This is used for |
22f0da72 ILT |
609 | // special sections like the GOT section. ORDER is where the |
610 | // section should wind up in the output segment. IS_RELRO is true | |
611 | // for relro sections. | |
9f1d377b | 612 | Output_section* |
ead1e424 ILT |
613 | add_output_section_data(const char* name, elfcpp::Elf_Word type, |
614 | elfcpp::Elf_Xword flags, | |
22f0da72 ILT |
615 | Output_section_data*, Output_section_order order, |
616 | bool is_relro); | |
1a2dff53 ILT |
617 | |
618 | // Increase the size of the relro segment by this much. | |
619 | void | |
620 | increase_relro(unsigned int s) | |
621 | { this->increase_relro_ += s; } | |
ead1e424 | 622 | |
a3ad94ed ILT |
623 | // Create dynamic sections if necessary. |
624 | void | |
9b07f471 | 625 | create_initial_dynamic_sections(Symbol_table*); |
a3ad94ed | 626 | |
bfd58944 ILT |
627 | // Define __start and __stop symbols for output sections. |
628 | void | |
9b07f471 | 629 | define_section_symbols(Symbol_table*); |
bfd58944 | 630 | |
9c547ec3 ILT |
631 | // Create automatic note sections. |
632 | void | |
633 | create_notes(); | |
634 | ||
919ed24c ILT |
635 | // Create sections for linker scripts. |
636 | void | |
637 | create_script_sections() | |
638 | { this->script_options_->create_script_sections(this); } | |
639 | ||
e5756efb ILT |
640 | // Define symbols from any linker script. |
641 | void | |
9b07f471 ILT |
642 | define_script_symbols(Symbol_table* symtab) |
643 | { this->script_options_->add_symbols_to_table(symtab); } | |
e5756efb | 644 | |
755ab8af ILT |
645 | // Define symbols for group signatures. |
646 | void | |
647 | define_group_signatures(Symbol_table*); | |
648 | ||
61ba1cf9 ILT |
649 | // Return the Stringpool used for symbol names. |
650 | const Stringpool* | |
651 | sympool() const | |
652 | { return &this->sympool_; } | |
653 | ||
16649710 ILT |
654 | // Return the Stringpool used for dynamic symbol names and dynamic |
655 | // tags. | |
656 | const Stringpool* | |
657 | dynpool() const | |
658 | { return &this->dynpool_; } | |
659 | ||
7d172687 ILT |
660 | // Return the .dynamic output section. This is only valid after the |
661 | // layout has been finalized. | |
662 | Output_section* | |
663 | dynamic_section() const | |
664 | { return this->dynamic_section_; } | |
665 | ||
d491d34e ILT |
666 | // Return the symtab_xindex section used to hold large section |
667 | // indexes for the normal symbol table. | |
668 | Output_symtab_xindex* | |
669 | symtab_xindex() const | |
670 | { return this->symtab_xindex_; } | |
671 | ||
672 | // Return the dynsym_xindex section used to hold large section | |
673 | // indexes for the dynamic symbol table. | |
674 | Output_symtab_xindex* | |
675 | dynsym_xindex() const | |
676 | { return this->dynsym_xindex_; } | |
677 | ||
a2fb1b05 ILT |
678 | // Return whether a section is a .gnu.linkonce section, given the |
679 | // section name. | |
680 | static inline bool | |
681 | is_linkonce(const char* name) | |
682 | { return strncmp(name, ".gnu.linkonce", sizeof(".gnu.linkonce") - 1) == 0; } | |
683 | ||
d7bb5745 ILT |
684 | // Whether we have added an input section. |
685 | bool | |
686 | have_added_input_section() const | |
687 | { return this->have_added_input_section_; } | |
688 | ||
e94cf127 CC |
689 | // Return true if a section is a debugging section. |
690 | static inline bool | |
691 | is_debug_info_section(const char* name) | |
692 | { | |
693 | // Debugging sections can only be recognized by name. | |
694 | return (strncmp(name, ".debug", sizeof(".debug") - 1) == 0 | |
a2e47362 | 695 | || strncmp(name, ".zdebug", sizeof(".zdebug") - 1) == 0 |
8a4c0b0d | 696 | || strncmp(name, ".gnu.linkonce.wi.", |
e94cf127 CC |
697 | sizeof(".gnu.linkonce.wi.") - 1) == 0 |
698 | || strncmp(name, ".line", sizeof(".line") - 1) == 0 | |
699 | || strncmp(name, ".stab", sizeof(".stab") - 1) == 0); | |
700 | } | |
701 | ||
5393d741 ILT |
702 | // Return true if RELOBJ is an input file whose base name matches |
703 | // FILE_NAME. The base name must have an extension of ".o", and | |
704 | // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o". | |
705 | static bool | |
706 | match_file_name(const Relobj* relobj, const char* file_name); | |
707 | ||
487b39df ILT |
708 | // Return whether section SHNDX in RELOBJ is a .ctors/.dtors section |
709 | // with more than one word being mapped to a .init_array/.fini_array | |
710 | // section. | |
711 | bool | |
712 | is_ctors_in_init_array(Relobj* relobj, unsigned int shndx) const; | |
713 | ||
8a4c0b0d ILT |
714 | // Check if a comdat group or .gnu.linkonce section with the given |
715 | // NAME is selected for the link. If there is already a section, | |
716 | // *KEPT_SECTION is set to point to the signature and the function | |
1ef4d87f ILT |
717 | // returns false. Otherwise, OBJECT, SHNDX,IS_COMDAT, and |
718 | // IS_GROUP_NAME are recorded for this NAME in the layout object, | |
719 | // *KEPT_SECTION is set to the internal copy and the function return | |
720 | // false. | |
a2fb1b05 | 721 | bool |
1ef4d87f ILT |
722 | find_or_add_kept_section(const std::string& name, Relobj* object, |
723 | unsigned int shndx, bool is_comdat, | |
724 | bool is_group_name, Kept_section** kept_section); | |
a2fb1b05 | 725 | |
54dc6425 | 726 | // Finalize the layout after all the input sections have been added. |
75f65a3e | 727 | off_t |
8851ecca | 728 | finalize(const Input_objects*, Symbol_table*, Target*, const Task*); |
17a1d0a9 ILT |
729 | |
730 | // Return whether any sections require postprocessing. | |
731 | bool | |
732 | any_postprocessing_sections() const | |
733 | { return this->any_postprocessing_sections_; } | |
54dc6425 | 734 | |
e44fcf3b ILT |
735 | // Return the size of the output file. |
736 | off_t | |
737 | output_file_size() const | |
738 | { return this->output_file_size_; } | |
739 | ||
16649710 ILT |
740 | // Return the TLS segment. This will return NULL if there isn't |
741 | // one. | |
92e059d8 ILT |
742 | Output_segment* |
743 | tls_segment() const | |
744 | { return this->tls_segment_; } | |
745 | ||
16649710 ILT |
746 | // Return the normal symbol table. |
747 | Output_section* | |
748 | symtab_section() const | |
749 | { | |
750 | gold_assert(this->symtab_section_ != NULL); | |
751 | return this->symtab_section_; | |
752 | } | |
753 | ||
bec5b579 CC |
754 | // Return the file offset of the normal symbol table. |
755 | off_t | |
756 | symtab_section_offset() const; | |
757 | ||
886f533a ILT |
758 | // Return the section index of the normal symbol tabl.e |
759 | unsigned int | |
760 | symtab_section_shndx() const; | |
761 | ||
16649710 ILT |
762 | // Return the dynamic symbol table. |
763 | Output_section* | |
764 | dynsym_section() const | |
765 | { | |
766 | gold_assert(this->dynsym_section_ != NULL); | |
767 | return this->dynsym_section_; | |
768 | } | |
769 | ||
770 | // Return the dynamic tags. | |
771 | Output_data_dynamic* | |
772 | dynamic_data() const | |
773 | { return this->dynamic_data_; } | |
774 | ||
730cdc88 ILT |
775 | // Write out the output sections. |
776 | void | |
777 | write_output_sections(Output_file* of) const; | |
778 | ||
61ba1cf9 ILT |
779 | // Write out data not associated with an input file or the symbol |
780 | // table. | |
781 | void | |
9025d29d | 782 | write_data(const Symbol_table*, Output_file*) const; |
61ba1cf9 | 783 | |
730cdc88 ILT |
784 | // Write out output sections which can not be written until all the |
785 | // input sections are complete. | |
786 | void | |
27bc2bce | 787 | write_sections_after_input_sections(Output_file* of); |
730cdc88 | 788 | |
ead1e424 ILT |
789 | // Return an output section named NAME, or NULL if there is none. |
790 | Output_section* | |
791 | find_output_section(const char* name) const; | |
792 | ||
793 | // Return an output segment of type TYPE, with segment flags SET set | |
794 | // and segment flags CLEAR clear. Return NULL if there is none. | |
795 | Output_segment* | |
796 | find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set, | |
797 | elfcpp::Elf_Word clear) const; | |
798 | ||
3802b2dd ILT |
799 | // Return the number of segments we expect to produce. |
800 | size_t | |
801 | expected_segment_count() const; | |
802 | ||
535890bb ILT |
803 | // Set a flag to indicate that an object file uses the static TLS model. |
804 | void | |
805 | set_has_static_tls() | |
806 | { this->has_static_tls_ = true; } | |
807 | ||
808 | // Return true if any object file uses the static TLS model. | |
809 | bool | |
810 | has_static_tls() const | |
811 | { return this->has_static_tls_; } | |
812 | ||
e5756efb ILT |
813 | // Return the options which may be set by a linker script. |
814 | Script_options* | |
815 | script_options() | |
816 | { return this->script_options_; } | |
817 | ||
818 | const Script_options* | |
819 | script_options() const | |
820 | { return this->script_options_; } | |
d391083d | 821 | |
3ce2c28e ILT |
822 | // Return the object managing inputs in incremental build. NULL in |
823 | // non-incremental builds. | |
824 | Incremental_inputs* | |
09ec0418 | 825 | incremental_inputs() const |
3ce2c28e ILT |
826 | { return this->incremental_inputs_; } |
827 | ||
ea715a34 ILT |
828 | // For the target-specific code to add dynamic tags which are common |
829 | // to most targets. | |
830 | void | |
831 | add_target_dynamic_tags(bool use_rel, const Output_data* plt_got, | |
832 | const Output_data* plt_rel, | |
3a44184e | 833 | const Output_data_reloc_generic* dyn_rel, |
612a8d3d | 834 | bool add_debug, bool dynrel_includes_plt); |
ea715a34 | 835 | |
8ed814a9 ILT |
836 | // Compute and write out the build ID if needed. |
837 | void | |
838 | write_build_id(Output_file*) const; | |
839 | ||
516cb3d0 ILT |
840 | // Rewrite output file in binary format. |
841 | void | |
842 | write_binary(Output_file* in) const; | |
843 | ||
7d9e3d98 ILT |
844 | // Print output sections to the map file. |
845 | void | |
846 | print_to_mapfile(Mapfile*) const; | |
847 | ||
ad8f37d1 ILT |
848 | // Dump statistical information to stderr. |
849 | void | |
850 | print_stats() const; | |
851 | ||
a445fddf | 852 | // A list of segments. |
54dc6425 ILT |
853 | |
854 | typedef std::vector<Output_segment*> Segment_list; | |
855 | ||
a445fddf | 856 | // A list of sections. |
54dc6425 | 857 | |
a3ad94ed | 858 | typedef std::vector<Output_section*> Section_list; |
54dc6425 ILT |
859 | |
860 | // The list of information to write out which is not attached to | |
861 | // either a section or a segment. | |
a3ad94ed | 862 | typedef std::vector<Output_data*> Data_list; |
54dc6425 | 863 | |
a445fddf ILT |
864 | // Store the allocated sections into the section list. This is used |
865 | // by the linker script code. | |
866 | void | |
867 | get_allocated_sections(Section_list*) const; | |
868 | ||
919ed24c ILT |
869 | // Make a section for a linker script to hold data. |
870 | Output_section* | |
1e5d2fb1 DK |
871 | make_output_section_for_script(const char* name, |
872 | Script_sections::Section_type section_type); | |
919ed24c | 873 | |
a445fddf ILT |
874 | // Make a segment. This is used by the linker script code. |
875 | Output_segment* | |
876 | make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags); | |
877 | ||
878 | // Return the number of segments. | |
879 | size_t | |
880 | segment_count() const | |
881 | { return this->segment_list_.size(); } | |
882 | ||
883 | // Map from section flags to segment flags. | |
884 | static elfcpp::Elf_Word | |
885 | section_flags_to_segment(elfcpp::Elf_Xword flags); | |
886 | ||
154e0e9a ILT |
887 | // Attach sections to segments. |
888 | void | |
889 | attach_sections_to_segments(); | |
890 | ||
20e6d0d6 DK |
891 | // For relaxation clean up, we need to know output section data created |
892 | // from a linker script. | |
893 | void | |
894 | new_output_section_data_from_script(Output_section_data* posd) | |
895 | { | |
896 | if (this->record_output_section_data_from_script_) | |
897 | this->script_output_section_data_list_.push_back(posd); | |
898 | } | |
899 | ||
c0a62865 DK |
900 | // Return section list. |
901 | const Section_list& | |
902 | section_list() const | |
903 | { return this->section_list_; } | |
904 | ||
a2fb1b05 ILT |
905 | private: |
906 | Layout(const Layout&); | |
907 | Layout& operator=(const Layout&); | |
908 | ||
dff16297 ILT |
909 | // Mapping from input section names to output section names. |
910 | struct Section_name_mapping | |
a2fb1b05 ILT |
911 | { |
912 | const char* from; | |
913 | int fromlen; | |
914 | const char* to; | |
ead1e424 | 915 | int tolen; |
a2fb1b05 | 916 | }; |
dff16297 ILT |
917 | static const Section_name_mapping section_name_mapping[]; |
918 | static const int section_name_mapping_count; | |
a2fb1b05 | 919 | |
755ab8af ILT |
920 | // During a relocatable link, a list of group sections and |
921 | // signatures. | |
922 | struct Group_signature | |
923 | { | |
924 | // The group section. | |
925 | Output_section* section; | |
926 | // The signature. | |
927 | const char* signature; | |
928 | ||
929 | Group_signature() | |
930 | : section(NULL), signature(NULL) | |
931 | { } | |
932 | ||
933 | Group_signature(Output_section* sectiona, const char* signaturea) | |
934 | : section(sectiona), signature(signaturea) | |
935 | { } | |
936 | }; | |
937 | typedef std::vector<Group_signature> Group_signatures; | |
938 | ||
ef4ab7a8 | 939 | // Create a note section, filling in the header. |
8ed814a9 | 940 | Output_section* |
ca09d69a | 941 | create_note(const char* name, int note_type, const char* section_name, |
ef4ab7a8 | 942 | size_t descsz, bool allocate, size_t* trailing_padding); |
8ed814a9 | 943 | |
ef4ab7a8 | 944 | // Create a note section for gold version. |
4f211c8b | 945 | void |
35cdfc9a ILT |
946 | create_gold_note(); |
947 | ||
948 | // Record whether the stack must be executable. | |
949 | void | |
9c547ec3 | 950 | create_executable_stack_info(); |
4f211c8b | 951 | |
8ed814a9 ILT |
952 | // Create a build ID note if needed. |
953 | void | |
954 | create_build_id(); | |
955 | ||
1518dc8f ILT |
956 | // Link .stab and .stabstr sections. |
957 | void | |
958 | link_stabs_sections(); | |
959 | ||
3ce2c28e ILT |
960 | // Create .gnu_incremental_inputs and .gnu_incremental_strtab sections needed |
961 | // for the next run of incremental linking to check what has changed. | |
962 | void | |
09ec0418 | 963 | create_incremental_info_sections(Symbol_table*); |
3ce2c28e | 964 | |
75f65a3e ILT |
965 | // Find the first read-only PT_LOAD segment, creating one if |
966 | // necessary. | |
967 | Output_segment* | |
968 | find_first_load_seg(); | |
969 | ||
7bf1f802 ILT |
970 | // Count the local symbols in the regular symbol table and the dynamic |
971 | // symbol table, and build the respective string pools. | |
972 | void | |
17a1d0a9 | 973 | count_local_symbols(const Task*, const Input_objects*); |
7bf1f802 | 974 | |
54dc6425 ILT |
975 | // Create the output sections for the symbol table. |
976 | void | |
d491d34e ILT |
977 | create_symtab_sections(const Input_objects*, Symbol_table*, |
978 | unsigned int, off_t*); | |
54dc6425 | 979 | |
75f65a3e ILT |
980 | // Create the .shstrtab section. |
981 | Output_section* | |
982 | create_shstrtab(); | |
983 | ||
984 | // Create the section header table. | |
27bc2bce | 985 | void |
d491d34e | 986 | create_shdrs(const Output_section* shstrtab_section, off_t*); |
54dc6425 | 987 | |
dbe717ef ILT |
988 | // Create the dynamic symbol table. |
989 | void | |
9b07f471 ILT |
990 | create_dynamic_symtab(const Input_objects*, Symbol_table*, |
991 | Output_section** pdynstr, | |
14b31740 ILT |
992 | unsigned int* plocal_dynamic_count, |
993 | std::vector<Symbol*>* pdynamic_symbols, | |
994 | Versions* versions); | |
dbe717ef | 995 | |
7bf1f802 ILT |
996 | // Assign offsets to each local portion of the dynamic symbol table. |
997 | void | |
998 | assign_local_dynsym_offsets(const Input_objects*); | |
999 | ||
a3ad94ed | 1000 | // Finish the .dynamic section and PT_DYNAMIC segment. |
dbe717ef | 1001 | void |
16649710 | 1002 | finish_dynamic_section(const Input_objects*, const Symbol_table*); |
dbe717ef | 1003 | |
f0ba79e2 ILT |
1004 | // Set the size of the _DYNAMIC symbol. |
1005 | void | |
1006 | set_dynamic_symbol_size(const Symbol_table*); | |
1007 | ||
dbe717ef ILT |
1008 | // Create the .interp section and PT_INTERP segment. |
1009 | void | |
1010 | create_interp(const Target* target); | |
1011 | ||
14b31740 ILT |
1012 | // Create the version sections. |
1013 | void | |
9025d29d | 1014 | create_version_sections(const Versions*, |
46fe1623 | 1015 | const Symbol_table*, |
14b31740 ILT |
1016 | unsigned int local_symcount, |
1017 | const std::vector<Symbol*>& dynamic_symbols, | |
1018 | const Output_section* dynstr); | |
1019 | ||
1020 | template<int size, bool big_endian> | |
1021 | void | |
1022 | sized_create_version_sections(const Versions* versions, | |
46fe1623 | 1023 | const Symbol_table*, |
14b31740 ILT |
1024 | unsigned int local_symcount, |
1025 | const std::vector<Symbol*>& dynamic_symbols, | |
7d1a9ebb | 1026 | const Output_section* dynstr); |
14b31740 | 1027 | |
a2fb1b05 ILT |
1028 | // Return whether to include this section in the link. |
1029 | template<int size, bool big_endian> | |
1030 | bool | |
6fa2a40b | 1031 | include_section(Sized_relobj_file<size, big_endian>* object, const char* name, |
a2fb1b05 ILT |
1032 | const elfcpp::Shdr<size, big_endian>&); |
1033 | ||
ead1e424 ILT |
1034 | // Return the output section name to use given an input section |
1035 | // name. Set *PLEN to the length of the name. *PLEN must be | |
1036 | // initialized to the length of NAME. | |
1037 | static const char* | |
5393d741 | 1038 | output_section_name(const Relobj*, const char* name, size_t* plen); |
ead1e424 | 1039 | |
d491d34e ILT |
1040 | // Return the number of allocated output sections. |
1041 | size_t | |
1042 | allocated_output_section_count() const; | |
1043 | ||
ead1e424 ILT |
1044 | // Return the output section for NAME, TYPE and FLAGS. |
1045 | Output_section* | |
f0641a0b | 1046 | get_output_section(const char* name, Stringpool::Key name_key, |
f5c870d2 | 1047 | elfcpp::Elf_Word type, elfcpp::Elf_Xword flags, |
22f0da72 | 1048 | Output_section_order order, bool is_relro); |
a2fb1b05 | 1049 | |
a445fddf ILT |
1050 | // Choose the output section for NAME in RELOBJ. |
1051 | Output_section* | |
1052 | choose_output_section(const Relobj* relobj, const char* name, | |
1053 | elfcpp::Elf_Word type, elfcpp::Elf_Xword flags, | |
22f0da72 ILT |
1054 | bool is_input_section, Output_section_order order, |
1055 | bool is_relro); | |
a445fddf | 1056 | |
a2fb1b05 ILT |
1057 | // Create a new Output_section. |
1058 | Output_section* | |
1059 | make_output_section(const char* name, elfcpp::Elf_Word type, | |
22f0da72 ILT |
1060 | elfcpp::Elf_Xword flags, Output_section_order order, |
1061 | bool is_relro); | |
a2fb1b05 | 1062 | |
4e2b1697 ILT |
1063 | // Attach a section to a segment. |
1064 | void | |
154e0e9a | 1065 | attach_section_to_segment(Output_section*); |
4e2b1697 | 1066 | |
22f0da72 ILT |
1067 | // Get section order. |
1068 | Output_section_order | |
1069 | default_section_order(Output_section*, bool is_relro_local); | |
1070 | ||
154e0e9a | 1071 | // Attach an allocated section to a segment. |
1650c4ff | 1072 | void |
154e0e9a | 1073 | attach_allocated_section_to_segment(Output_section*); |
1650c4ff | 1074 | |
07a60597 ILT |
1075 | // Make the .eh_frame section. |
1076 | Output_section* | |
1077 | make_eh_frame_section(const Relobj*); | |
1078 | ||
dbe717ef ILT |
1079 | // Set the final file offsets of all the segments. |
1080 | off_t | |
1081 | set_segment_offsets(const Target*, Output_segment*, unsigned int* pshndx); | |
1082 | ||
6a74a719 ILT |
1083 | // Set the file offsets of the sections when doing a relocatable |
1084 | // link. | |
1085 | off_t | |
1086 | set_relocatable_section_offsets(Output_data*, unsigned int* pshndx); | |
1087 | ||
86887060 | 1088 | // Set the final file offsets of all the sections not associated |
9a0910c3 ILT |
1089 | // with a segment. We set section offsets in three passes: the |
1090 | // first handles all allocated sections, the second sections that | |
17a1d0a9 ILT |
1091 | // require postprocessing, and the last the late-bound STRTAB |
1092 | // sections (probably only shstrtab, which is the one we care about | |
1093 | // because it holds section names). | |
9a0910c3 ILT |
1094 | enum Section_offset_pass |
1095 | { | |
1096 | BEFORE_INPUT_SECTIONS_PASS, | |
17a1d0a9 ILT |
1097 | POSTPROCESSING_SECTIONS_PASS, |
1098 | STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS | |
9a0910c3 | 1099 | }; |
dbe717ef | 1100 | off_t |
9a0910c3 ILT |
1101 | set_section_offsets(off_t, Section_offset_pass pass); |
1102 | ||
86887060 ILT |
1103 | // Set the final section indexes of all the sections not associated |
1104 | // with a segment. Returns the next unused index. | |
1105 | unsigned int | |
1106 | set_section_indexes(unsigned int pshndx); | |
dbe717ef | 1107 | |
a445fddf ILT |
1108 | // Set the section addresses when using a script. |
1109 | Output_segment* | |
1110 | set_section_addresses_from_script(Symbol_table*); | |
1111 | ||
20e6d0d6 DK |
1112 | // Find appropriate places or orphan sections in a script. |
1113 | void | |
1114 | place_orphan_sections_in_script(); | |
1115 | ||
a2fb1b05 | 1116 | // Return whether SEG1 comes before SEG2 in the output file. |
aecf301f | 1117 | bool |
b3168e9d | 1118 | segment_precedes(const Output_segment* seg1, const Output_segment* seg2); |
a2fb1b05 | 1119 | |
20e6d0d6 DK |
1120 | // Use to save and restore segments during relaxation. |
1121 | typedef Unordered_map<const Output_segment*, const Output_segment*> | |
1122 | Segment_states; | |
1123 | ||
1124 | // Save states of current output segments. | |
1125 | void | |
1126 | save_segments(Segment_states*); | |
1127 | ||
1128 | // Restore output segment states. | |
1129 | void | |
1130 | restore_segments(const Segment_states*); | |
1131 | ||
1132 | // Clean up after relaxation so that it is possible to lay out the | |
1133 | // sections and segments again. | |
1134 | void | |
1135 | clean_up_after_relaxation(); | |
1136 | ||
1137 | // Doing preparation work for relaxation. This is factored out to make | |
1138 | // Layout::finalized a bit smaller and easier to read. | |
1139 | void | |
1140 | prepare_for_relaxation(); | |
1141 | ||
1142 | // Main body of the relaxation loop, which lays out the section. | |
1143 | off_t | |
1144 | relaxation_loop_body(int, Target*, Symbol_table*, Output_segment**, | |
1145 | Output_segment*, Output_segment_headers*, | |
1146 | Output_file_header*, unsigned int*); | |
1147 | ||
8a4c0b0d | 1148 | // A mapping used for kept comdats/.gnu.linkonce group signatures. |
e94cf127 | 1149 | typedef Unordered_map<std::string, Kept_section> Signatures; |
a2fb1b05 ILT |
1150 | |
1151 | // Mapping from input section name/type/flags to output section. We | |
1152 | // use canonicalized strings here. | |
1153 | ||
f0641a0b | 1154 | typedef std::pair<Stringpool::Key, |
a2fb1b05 ILT |
1155 | std::pair<elfcpp::Elf_Word, elfcpp::Elf_Xword> > Key; |
1156 | ||
1157 | struct Hash_key | |
1158 | { | |
1159 | size_t | |
1160 | operator()(const Key& k) const; | |
1161 | }; | |
1162 | ||
1163 | typedef Unordered_map<Key, Output_section*, Hash_key> Section_name_map; | |
1164 | ||
1165 | // A comparison class for segments. | |
1166 | ||
aecf301f | 1167 | class Compare_segments |
a2fb1b05 | 1168 | { |
aecf301f ILT |
1169 | public: |
1170 | Compare_segments(Layout* layout) | |
1171 | : layout_(layout) | |
1172 | { } | |
1173 | ||
a2fb1b05 ILT |
1174 | bool |
1175 | operator()(const Output_segment* seg1, const Output_segment* seg2) | |
aecf301f ILT |
1176 | { return this->layout_->segment_precedes(seg1, seg2); } |
1177 | ||
1178 | private: | |
1179 | Layout* layout_; | |
a2fb1b05 ILT |
1180 | }; |
1181 | ||
20e6d0d6 DK |
1182 | typedef std::vector<Output_section_data*> Output_section_data_list; |
1183 | ||
1184 | // Debug checker class. | |
1185 | class Relaxation_debug_check | |
1186 | { | |
1187 | public: | |
1188 | Relaxation_debug_check() | |
1189 | : section_infos_() | |
1190 | { } | |
1191 | ||
1192 | // Check that sections and special data are in reset states. | |
1193 | void | |
1194 | check_output_data_for_reset_values(const Layout::Section_list&, | |
1195 | const Layout::Data_list&); | |
1196 | ||
1197 | // Record information of a section list. | |
1198 | void | |
1199 | read_sections(const Layout::Section_list&); | |
1200 | ||
1201 | // Verify a section list with recorded information. | |
1202 | void | |
1203 | verify_sections(const Layout::Section_list&); | |
1204 | ||
1205 | private: | |
1206 | // Information we care about a section. | |
1207 | struct Section_info | |
1208 | { | |
1209 | // Output section described by this. | |
1210 | Output_section* output_section; | |
1211 | // Load address. | |
1212 | uint64_t address; | |
1213 | // Data size. | |
1214 | off_t data_size; | |
1215 | // File offset. | |
1216 | off_t offset; | |
1217 | }; | |
1218 | ||
1219 | // Section information. | |
1220 | std::vector<Section_info> section_infos_; | |
1221 | }; | |
1222 | ||
e55bde5e ILT |
1223 | // The number of input files, for sizing tables. |
1224 | int number_of_input_files_; | |
e5756efb ILT |
1225 | // Information set by scripts or by command line options. |
1226 | Script_options* script_options_; | |
a2fb1b05 ILT |
1227 | // The output section names. |
1228 | Stringpool namepool_; | |
75f65a3e ILT |
1229 | // The output symbol names. |
1230 | Stringpool sympool_; | |
a3ad94ed ILT |
1231 | // The dynamic strings, if needed. |
1232 | Stringpool dynpool_; | |
a2fb1b05 ILT |
1233 | // The list of group sections and linkonce sections which we have seen. |
1234 | Signatures signatures_; | |
1235 | // The mapping from input section name/type/flags to output sections. | |
1236 | Section_name_map section_name_map_; | |
1237 | // The list of output segments. | |
1238 | Segment_list segment_list_; | |
a3ad94ed ILT |
1239 | // The list of output sections. |
1240 | Section_list section_list_; | |
a2fb1b05 ILT |
1241 | // The list of output sections which are not attached to any output |
1242 | // segment. | |
a3ad94ed ILT |
1243 | Section_list unattached_section_list_; |
1244 | // The list of unattached Output_data objects which require special | |
1245 | // handling because they are not Output_sections. | |
61ba1cf9 | 1246 | Data_list special_output_list_; |
27bc2bce ILT |
1247 | // The section headers. |
1248 | Output_section_headers* section_headers_; | |
92e059d8 ILT |
1249 | // A pointer to the PT_TLS segment if there is one. |
1250 | Output_segment* tls_segment_; | |
9f1d377b ILT |
1251 | // A pointer to the PT_GNU_RELRO segment if there is one. |
1252 | Output_segment* relro_segment_; | |
10b4f102 ILT |
1253 | // A pointer to the PT_INTERP segment if there is one. |
1254 | Output_segment* interp_segment_; | |
1a2dff53 ILT |
1255 | // A backend may increase the size of the PT_GNU_RELRO segment if |
1256 | // there is one. This is the amount to increase it by. | |
1257 | unsigned int increase_relro_; | |
a3ad94ed ILT |
1258 | // The SHT_SYMTAB output section. |
1259 | Output_section* symtab_section_; | |
d491d34e ILT |
1260 | // The SHT_SYMTAB_SHNDX for the regular symbol table if there is one. |
1261 | Output_symtab_xindex* symtab_xindex_; | |
a3ad94ed ILT |
1262 | // The SHT_DYNSYM output section if there is one. |
1263 | Output_section* dynsym_section_; | |
d491d34e ILT |
1264 | // The SHT_SYMTAB_SHNDX for the dynamic symbol table if there is one. |
1265 | Output_symtab_xindex* dynsym_xindex_; | |
a3ad94ed ILT |
1266 | // The SHT_DYNAMIC output section if there is one. |
1267 | Output_section* dynamic_section_; | |
f0ba79e2 ILT |
1268 | // The _DYNAMIC symbol if there is one. |
1269 | Symbol* dynamic_symbol_; | |
16649710 ILT |
1270 | // The dynamic data which goes into dynamic_section_. |
1271 | Output_data_dynamic* dynamic_data_; | |
730cdc88 | 1272 | // The exception frame output section if there is one. |
3151305a | 1273 | Output_section* eh_frame_section_; |
730cdc88 ILT |
1274 | // The exception frame data for eh_frame_section_. |
1275 | Eh_frame* eh_frame_data_; | |
2c38906f ILT |
1276 | // Whether we have added eh_frame_data_ to the .eh_frame section. |
1277 | bool added_eh_frame_data_; | |
730cdc88 ILT |
1278 | // The exception frame header output section if there is one. |
1279 | Output_section* eh_frame_hdr_section_; | |
8ed814a9 ILT |
1280 | // The space for the build ID checksum if there is one. |
1281 | Output_section_data* build_id_note_; | |
62b01cb5 ILT |
1282 | // The output section containing dwarf abbreviations |
1283 | Output_reduced_debug_abbrev_section* debug_abbrev_; | |
1284 | // The output section containing the dwarf debug info tree | |
1285 | Output_reduced_debug_info_section* debug_info_; | |
755ab8af ILT |
1286 | // A list of group sections and their signatures. |
1287 | Group_signatures group_signatures_; | |
e44fcf3b ILT |
1288 | // The size of the output file. |
1289 | off_t output_file_size_; | |
d7bb5745 ILT |
1290 | // Whether we have added an input section to an output section. |
1291 | bool have_added_input_section_; | |
e55bde5e ILT |
1292 | // Whether we have attached the sections to the segments. |
1293 | bool sections_are_attached_; | |
35cdfc9a ILT |
1294 | // Whether we have seen an object file marked to require an |
1295 | // executable stack. | |
1296 | bool input_requires_executable_stack_; | |
1297 | // Whether we have seen at least one object file with an executable | |
1298 | // stack marker. | |
1299 | bool input_with_gnu_stack_note_; | |
1300 | // Whether we have seen at least one object file without an | |
1301 | // executable stack marker. | |
1302 | bool input_without_gnu_stack_note_; | |
535890bb ILT |
1303 | // Whether we have seen an object file that uses the static TLS model. |
1304 | bool has_static_tls_; | |
17a1d0a9 ILT |
1305 | // Whether any sections require postprocessing. |
1306 | bool any_postprocessing_sections_; | |
e55bde5e ILT |
1307 | // Whether we have resized the signatures_ hash table. |
1308 | bool resized_signatures_; | |
1518dc8f ILT |
1309 | // Whether we have created a .stab*str output section. |
1310 | bool have_stabstr_section_; | |
e9552f7e ST |
1311 | // True if the input sections in the output sections should be sorted |
1312 | // as specified in a section ordering file. | |
1313 | bool section_ordering_specified_; | |
3ce2c28e ILT |
1314 | // In incremental build, holds information check the inputs and build the |
1315 | // .gnu_incremental_inputs section. | |
1316 | Incremental_inputs* incremental_inputs_; | |
20e6d0d6 DK |
1317 | // Whether we record output section data created in script |
1318 | bool record_output_section_data_from_script_; | |
9b547ce6 | 1319 | // List of output data that needs to be removed at relaxation clean up. |
20e6d0d6 DK |
1320 | Output_section_data_list script_output_section_data_list_; |
1321 | // Structure to save segment states before entering the relaxation loop. | |
1322 | Segment_states* segment_states_; | |
1323 | // A relaxation debug checker. We only create one when in debugging mode. | |
1324 | Relaxation_debug_check* relaxation_debug_check_; | |
6e9ba2ca ST |
1325 | // Hash a pattern to its position in the section ordering file. |
1326 | Unordered_map<std::string, unsigned int> input_section_position_; | |
1327 | // Vector of glob only patterns in the section_ordering file. | |
1328 | std::vector<std::string> input_section_glob_; | |
cdc29364 CC |
1329 | // For incremental links, the base file to be modified. |
1330 | Incremental_binary* incremental_base_; | |
1331 | // For incremental links, a list of free space within the file. | |
1332 | Free_list free_list_; | |
61ba1cf9 ILT |
1333 | }; |
1334 | ||
730cdc88 ILT |
1335 | // This task handles writing out data in output sections which is not |
1336 | // part of an input section, or which requires special handling. When | |
1337 | // this is done, it unblocks both output_sections_blocker and | |
1338 | // final_blocker. | |
1339 | ||
1340 | class Write_sections_task : public Task | |
1341 | { | |
1342 | public: | |
1343 | Write_sections_task(const Layout* layout, Output_file* of, | |
1344 | Task_token* output_sections_blocker, | |
1345 | Task_token* final_blocker) | |
1346 | : layout_(layout), of_(of), | |
1347 | output_sections_blocker_(output_sections_blocker), | |
1348 | final_blocker_(final_blocker) | |
1349 | { } | |
1350 | ||
1351 | // The standard Task methods. | |
1352 | ||
17a1d0a9 ILT |
1353 | Task_token* |
1354 | is_runnable(); | |
730cdc88 | 1355 | |
17a1d0a9 ILT |
1356 | void |
1357 | locks(Task_locker*); | |
730cdc88 ILT |
1358 | |
1359 | void | |
1360 | run(Workqueue*); | |
1361 | ||
c7912668 ILT |
1362 | std::string |
1363 | get_name() const | |
1364 | { return "Write_sections_task"; } | |
1365 | ||
730cdc88 ILT |
1366 | private: |
1367 | class Write_sections_locker; | |
1368 | ||
1369 | const Layout* layout_; | |
1370 | Output_file* of_; | |
1371 | Task_token* output_sections_blocker_; | |
1372 | Task_token* final_blocker_; | |
1373 | }; | |
1374 | ||
61ba1cf9 ILT |
1375 | // This task handles writing out data which is not part of a section |
1376 | // or segment. | |
1377 | ||
1378 | class Write_data_task : public Task | |
1379 | { | |
1380 | public: | |
a3ad94ed | 1381 | Write_data_task(const Layout* layout, const Symbol_table* symtab, |
9025d29d ILT |
1382 | Output_file* of, Task_token* final_blocker) |
1383 | : layout_(layout), symtab_(symtab), of_(of), final_blocker_(final_blocker) | |
61ba1cf9 ILT |
1384 | { } |
1385 | ||
1386 | // The standard Task methods. | |
1387 | ||
17a1d0a9 ILT |
1388 | Task_token* |
1389 | is_runnable(); | |
61ba1cf9 | 1390 | |
17a1d0a9 ILT |
1391 | void |
1392 | locks(Task_locker*); | |
61ba1cf9 ILT |
1393 | |
1394 | void | |
1395 | run(Workqueue*); | |
1396 | ||
c7912668 ILT |
1397 | std::string |
1398 | get_name() const | |
1399 | { return "Write_data_task"; } | |
1400 | ||
61ba1cf9 ILT |
1401 | private: |
1402 | const Layout* layout_; | |
a3ad94ed | 1403 | const Symbol_table* symtab_; |
61ba1cf9 ILT |
1404 | Output_file* of_; |
1405 | Task_token* final_blocker_; | |
1406 | }; | |
1407 | ||
1408 | // This task handles writing out the global symbols. | |
1409 | ||
1410 | class Write_symbols_task : public Task | |
1411 | { | |
1412 | public: | |
d491d34e | 1413 | Write_symbols_task(const Layout* layout, const Symbol_table* symtab, |
9a2d6984 | 1414 | const Input_objects* input_objects, |
16649710 ILT |
1415 | const Stringpool* sympool, const Stringpool* dynpool, |
1416 | Output_file* of, Task_token* final_blocker) | |
d491d34e ILT |
1417 | : layout_(layout), symtab_(symtab), input_objects_(input_objects), |
1418 | sympool_(sympool), dynpool_(dynpool), of_(of), | |
1419 | final_blocker_(final_blocker) | |
61ba1cf9 ILT |
1420 | { } |
1421 | ||
1422 | // The standard Task methods. | |
1423 | ||
17a1d0a9 ILT |
1424 | Task_token* |
1425 | is_runnable(); | |
61ba1cf9 | 1426 | |
17a1d0a9 ILT |
1427 | void |
1428 | locks(Task_locker*); | |
61ba1cf9 ILT |
1429 | |
1430 | void | |
1431 | run(Workqueue*); | |
1432 | ||
c7912668 ILT |
1433 | std::string |
1434 | get_name() const | |
1435 | { return "Write_symbols_task"; } | |
1436 | ||
61ba1cf9 | 1437 | private: |
d491d34e | 1438 | const Layout* layout_; |
61ba1cf9 | 1439 | const Symbol_table* symtab_; |
9a2d6984 | 1440 | const Input_objects* input_objects_; |
61ba1cf9 | 1441 | const Stringpool* sympool_; |
16649710 | 1442 | const Stringpool* dynpool_; |
61ba1cf9 ILT |
1443 | Output_file* of_; |
1444 | Task_token* final_blocker_; | |
1445 | }; | |
1446 | ||
730cdc88 ILT |
1447 | // This task handles writing out data in output sections which can't |
1448 | // be written out until all the input sections have been handled. | |
1449 | // This is for sections whose contents is based on the contents of | |
1450 | // other output sections. | |
1451 | ||
1452 | class Write_after_input_sections_task : public Task | |
1453 | { | |
1454 | public: | |
27bc2bce | 1455 | Write_after_input_sections_task(Layout* layout, Output_file* of, |
730cdc88 ILT |
1456 | Task_token* input_sections_blocker, |
1457 | Task_token* final_blocker) | |
1458 | : layout_(layout), of_(of), | |
1459 | input_sections_blocker_(input_sections_blocker), | |
1460 | final_blocker_(final_blocker) | |
1461 | { } | |
1462 | ||
1463 | // The standard Task methods. | |
1464 | ||
17a1d0a9 ILT |
1465 | Task_token* |
1466 | is_runnable(); | |
730cdc88 | 1467 | |
17a1d0a9 ILT |
1468 | void |
1469 | locks(Task_locker*); | |
730cdc88 ILT |
1470 | |
1471 | void | |
1472 | run(Workqueue*); | |
1473 | ||
c7912668 ILT |
1474 | std::string |
1475 | get_name() const | |
1476 | { return "Write_after_input_sections_task"; } | |
1477 | ||
730cdc88 | 1478 | private: |
27bc2bce | 1479 | Layout* layout_; |
730cdc88 ILT |
1480 | Output_file* of_; |
1481 | Task_token* input_sections_blocker_; | |
1482 | Task_token* final_blocker_; | |
1483 | }; | |
1484 | ||
92e059d8 | 1485 | // This task function handles closing the file. |
61ba1cf9 | 1486 | |
92e059d8 | 1487 | class Close_task_runner : public Task_function_runner |
61ba1cf9 ILT |
1488 | { |
1489 | public: | |
516cb3d0 ILT |
1490 | Close_task_runner(const General_options* options, const Layout* layout, |
1491 | Output_file* of) | |
1492 | : options_(options), layout_(layout), of_(of) | |
61ba1cf9 ILT |
1493 | { } |
1494 | ||
92e059d8 | 1495 | // Run the operation. |
61ba1cf9 | 1496 | void |
17a1d0a9 | 1497 | run(Workqueue*, const Task*); |
61ba1cf9 ILT |
1498 | |
1499 | private: | |
516cb3d0 ILT |
1500 | const General_options* options_; |
1501 | const Layout* layout_; | |
61ba1cf9 | 1502 | Output_file* of_; |
a2fb1b05 ILT |
1503 | }; |
1504 | ||
ead1e424 ILT |
1505 | // A small helper function to align an address. |
1506 | ||
1507 | inline uint64_t | |
1508 | align_address(uint64_t address, uint64_t addralign) | |
1509 | { | |
1510 | if (addralign != 0) | |
1511 | address = (address + addralign - 1) &~ (addralign - 1); | |
1512 | return address; | |
1513 | } | |
1514 | ||
a2fb1b05 ILT |
1515 | } // End namespace gold. |
1516 | ||
1517 | #endif // !defined(GOLD_LAYOUT_H) |