xref: /dragonfly/contrib/binutils-2.34/ld/ldlang.h (revision 8af44722)
1 /* ldlang.h - linker command language support
2    Copyright (C) 1991-2020 Free Software Foundation, Inc.
3 
4    This file is part of the GNU Binutils.
5 
6    This program is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as published by
8    the Free Software Foundation; either version 3 of the License, or
9    (at your option) any later version.
10 
11    This program is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14    GNU General Public License for more details.
15 
16    You should have received a copy of the GNU General Public License
17    along with this program; if not, write to the Free Software
18    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19    MA 02110-1301, USA.  */
20 
21 #ifndef LDLANG_H
22 #define LDLANG_H
23 
24 #define DEFAULT_MEMORY_REGION   "*default*"
25 
26 typedef enum
27 {
28   lang_input_file_is_l_enum,
29   lang_input_file_is_symbols_only_enum,
30   lang_input_file_is_marker_enum,
31   lang_input_file_is_fake_enum,
32   lang_input_file_is_search_file_enum,
33   lang_input_file_is_file_enum
34 } lang_input_file_enum_type;
35 
36 struct _fill_type
37 {
38   size_t size;
39   unsigned char data[1];
40 };
41 
42 typedef struct statement_list
43 {
44   union lang_statement_union *  head;
45   union lang_statement_union ** tail;
46 } lang_statement_list_type;
47 
48 typedef struct memory_region_name_struct
49 {
50   const char * name;
51   struct memory_region_name_struct * next;
52 } lang_memory_region_name;
53 
54 typedef struct memory_region_struct
55 {
56   lang_memory_region_name name_list;
57   struct memory_region_struct *next;
58   union etree_union *origin_exp;
59   bfd_vma origin;
60   bfd_size_type length;
61   union etree_union *length_exp;
62   bfd_vma current;
63   union lang_statement_union *last_os;
64   flagword flags;
65   flagword not_flags;
66   bfd_boolean had_full_message;
67 } lang_memory_region_type;
68 
69 enum statement_enum
70 {
71   lang_address_statement_enum,
72   lang_assignment_statement_enum,
73   lang_data_statement_enum,
74   lang_fill_statement_enum,
75   lang_group_statement_enum,
76   lang_input_section_enum,
77   lang_input_statement_enum,
78   lang_insert_statement_enum,
79   lang_output_section_statement_enum,
80   lang_output_statement_enum,
81   lang_padding_statement_enum,
82   lang_reloc_statement_enum,
83   lang_target_statement_enum,
84   lang_wild_statement_enum,
85   lang_constructors_statement_enum,
86   lang_object_symbols_statement_enum
87 };
88 
89 typedef struct lang_statement_header_struct
90 {
91   /* Next pointer for statement_list statement list.  */
92   union lang_statement_union *next;
93   enum statement_enum type;
94 } lang_statement_header_type;
95 
96 typedef struct
97 {
98   lang_statement_header_type header;
99   union etree_union *exp;
100 } lang_assignment_statement_type;
101 
102 typedef struct lang_target_statement_struct
103 {
104   lang_statement_header_type header;
105   const char *target;
106 } lang_target_statement_type;
107 
108 typedef struct lang_output_statement_struct
109 {
110   lang_statement_header_type header;
111   const char *name;
112 } lang_output_statement_type;
113 
114 /* Section types specified in a linker script.  */
115 
116 enum section_type
117 {
118   normal_section,
119   first_overlay_section,
120   overlay_section,
121   noload_section,
122   noalloc_section
123 };
124 
125 /* This structure holds a list of program headers describing
126    segments in which this section should be placed.  */
127 
128 typedef struct lang_output_section_phdr_list
129 {
130   struct lang_output_section_phdr_list *next;
131   const char *name;
132   bfd_boolean used;
133 } lang_output_section_phdr_list;
134 
135 typedef struct lang_output_section_statement_struct
136 {
137   lang_statement_header_type header;
138   lang_statement_list_type children;
139   struct lang_output_section_statement_struct *next;
140   struct lang_output_section_statement_struct *prev;
141   const char *name;
142   asection *bfd_section;
143   lang_memory_region_type *region;
144   lang_memory_region_type *lma_region;
145   fill_type *fill;
146   union etree_union *addr_tree;
147   union etree_union *load_base;
148   union etree_union *section_alignment;
149   union etree_union *subsection_alignment;
150 
151   /* If non-null, an expression to evaluate after setting the section's
152      size.  The expression is evaluated inside REGION (above) with '.'
153      set to the end of the section.  Used in the last overlay section
154      to move '.' past all the overlaid sections.  */
155   union etree_union *update_dot_tree;
156 
157   lang_output_section_phdr_list *phdrs;
158 
159   unsigned int block_value;
160   int constraint;
161   flagword flags;
162   enum section_type sectype;
163   unsigned int processed_vma : 1;
164   unsigned int processed_lma : 1;
165   unsigned int all_input_readonly : 1;
166   /* If this section should be ignored.  */
167   unsigned int ignored : 1;
168   /* If this section should update "dot".  Prevents section being ignored.  */
169   unsigned int update_dot : 1;
170   /* If this section is after assignment to _end.  */
171   unsigned int after_end : 1;
172   /* If this section uses the alignment of its input sections.  */
173   unsigned int align_lma_with_input : 1;
174 } lang_output_section_statement_type;
175 
176 typedef struct
177 {
178   lang_statement_header_type header;
179   fill_type *fill;
180   int size;
181   asection *output_section;
182 } lang_fill_statement_type;
183 
184 typedef struct
185 {
186   lang_statement_header_type header;
187   unsigned int type;
188   union etree_union *exp;
189   bfd_vma value;
190   asection *output_section;
191   bfd_vma output_offset;
192 } lang_data_statement_type;
193 
194 /* Generate a reloc in the output file.  */
195 
196 typedef struct
197 {
198   lang_statement_header_type header;
199 
200   /* Reloc to generate.  */
201   bfd_reloc_code_real_type reloc;
202 
203   /* Reloc howto structure.  */
204   reloc_howto_type *howto;
205 
206   /* Section to generate reloc against.
207      Exactly one of section and name must be NULL.  */
208   asection *section;
209 
210   /* Name of symbol to generate reloc against.
211      Exactly one of section and name must be NULL.  */
212   const char *name;
213 
214   /* Expression for addend.  */
215   union etree_union *addend_exp;
216 
217   /* Resolved addend.  */
218   bfd_vma addend_value;
219 
220   /* Output section where reloc should be performed.  */
221   asection *output_section;
222 
223   /* Offset within output section.  */
224   bfd_vma output_offset;
225 } lang_reloc_statement_type;
226 
227 struct lang_input_statement_flags
228 {
229   /* 1 means this file was specified in a -l option.  */
230   unsigned int maybe_archive : 1;
231 
232   /* 1 means this file was specified in a -l:namespec option.  */
233   unsigned int full_name_provided : 1;
234 
235   /* 1 means search a set of directories for this file.  */
236   unsigned int search_dirs : 1;
237 
238   /* 1 means this was found when processing a script in the sysroot.  */
239   unsigned int sysrooted : 1;
240 
241   /* 1 means this is base file of incremental load.
242      Do not load this file's text or data.
243      Also default text_start to after this file's bss.  */
244   unsigned int just_syms : 1;
245 
246   /* Whether to search for this entry as a dynamic archive.  */
247   unsigned int dynamic : 1;
248 
249   /* Set if a DT_NEEDED tag should be added not just for the dynamic library
250      explicitly given by this entry but also for any dynamic libraries in
251      this entry's needed list.  */
252   unsigned int add_DT_NEEDED_for_dynamic : 1;
253 
254   /* Set if this entry should cause a DT_NEEDED tag only when some
255      regular file references its symbols (ie. --as-needed is in effect).  */
256   unsigned int add_DT_NEEDED_for_regular : 1;
257 
258   /* Whether to include the entire contents of an archive.  */
259   unsigned int whole_archive : 1;
260 
261   /* Set when bfd opening is successful.  */
262   unsigned int loaded : 1;
263 
264   unsigned int real : 1;
265 
266   /* Set if the file does not exist.  */
267   unsigned int missing_file : 1;
268 
269   /* Set if reloading an archive or --as-needed lib.  */
270   unsigned int reload : 1;
271 
272 #ifdef ENABLE_PLUGINS
273   /* Set if the file was claimed by a plugin.  */
274   unsigned int claimed : 1;
275 
276   /* Set if the file was claimed from an archive.  */
277   unsigned int claim_archive : 1;
278 
279   /* Set if added by the lto plugin add_input_file callback.  */
280   unsigned int lto_output : 1;
281 #endif /* ENABLE_PLUGINS */
282 
283   /* Head of list of pushed flags.  */
284   struct lang_input_statement_flags *pushed;
285 };
286 
287 typedef struct lang_input_statement_struct
288 {
289   lang_statement_header_type header;
290   /* Name of this file.  */
291   const char *filename;
292   /* Name to use for the symbol giving address of text start.
293      Usually the same as filename, but for a file spec'd with
294      -l this is the -l switch itself rather than the filename.  */
295   const char *local_sym_name;
296 
297   bfd *the_bfd;
298 
299   ctf_archive_t *the_ctf;
300 
301   struct flag_info *section_flag_list;
302 
303   /* Next pointer for file_chain statement list.  */
304   struct lang_input_statement_struct *next;
305 
306   /* Next pointer for input_file_chain statement list.  */
307   struct lang_input_statement_struct *next_real_file;
308 
309   const char *target;
310 
311   struct lang_input_statement_flags flags;
312 } lang_input_statement_type;
313 
314 typedef struct
315 {
316   lang_statement_header_type header;
317   asection *section;
318 } lang_input_section_type;
319 
320 struct map_symbol_def {
321   struct bfd_link_hash_entry *entry;
322   struct map_symbol_def *next;
323 };
324 
325 /* For input sections, when writing a map file: head / tail of a linked
326    list of hash table entries for symbols defined in this section.  */
327 typedef struct input_section_userdata_struct
328 {
329   struct map_symbol_def *map_symbol_def_head;
330   struct map_symbol_def **map_symbol_def_tail;
331   unsigned long map_symbol_def_count;
332 } input_section_userdata_type;
333 
334 static inline bfd_boolean
335 bfd_input_just_syms (const bfd *abfd)
336 {
337   lang_input_statement_type *is = bfd_usrdata (abfd);
338   return is != NULL && is->flags.just_syms;
339 }
340 
341 typedef struct lang_wild_statement_struct lang_wild_statement_type;
342 
343 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
344 			    asection *, struct flag_info *,
345 			    lang_input_statement_type *, void *);
346 
347 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
348 					     lang_input_statement_type *,
349 					     callback_t callback,
350 					     void *data);
351 
352 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
353 						 bfd *, const asection *);
354 
355 /* Binary search tree structure to efficiently sort sections by
356    name.  */
357 typedef struct lang_section_bst
358 {
359   asection *section;
360   struct lang_section_bst *left;
361   struct lang_section_bst *right;
362 } lang_section_bst_type;
363 
364 struct lang_wild_statement_struct
365 {
366   lang_statement_header_type header;
367   const char *filename;
368   bfd_boolean filenames_sorted;
369   struct wildcard_list *section_list;
370   bfd_boolean keep_sections;
371   lang_statement_list_type children;
372   struct name_list *exclude_name_list;
373 
374   walk_wild_section_handler_t walk_wild_section_handler;
375   struct wildcard_list *handler_data[4];
376   lang_section_bst_type *tree;
377   struct flag_info *section_flag_list;
378 };
379 
380 typedef struct lang_address_statement_struct
381 {
382   lang_statement_header_type header;
383   const char *section_name;
384   union etree_union *address;
385   const segment_type *segment;
386 } lang_address_statement_type;
387 
388 typedef struct
389 {
390   lang_statement_header_type header;
391   bfd_vma output_offset;
392   bfd_size_type size;
393   asection *output_section;
394   fill_type *fill;
395 } lang_padding_statement_type;
396 
397 /* A group statement collects a set of libraries together.  The
398    libraries are searched multiple times, until no new undefined
399    symbols are found.  The effect is to search a group of libraries as
400    though they were a single library.  */
401 
402 typedef struct
403 {
404   lang_statement_header_type header;
405   lang_statement_list_type children;
406 } lang_group_statement_type;
407 
408 typedef struct
409 {
410   lang_statement_header_type header;
411   const char *where;
412   bfd_boolean is_before;
413 } lang_insert_statement_type;
414 
415 typedef union lang_statement_union
416 {
417   lang_statement_header_type header;
418   lang_address_statement_type address_statement;
419   lang_assignment_statement_type assignment_statement;
420   lang_data_statement_type data_statement;
421   lang_fill_statement_type fill_statement;
422   lang_group_statement_type group_statement;
423   lang_input_section_type input_section;
424   lang_input_statement_type input_statement;
425   lang_insert_statement_type insert_statement;
426   lang_output_section_statement_type output_section_statement;
427   lang_output_statement_type output_statement;
428   lang_padding_statement_type padding_statement;
429   lang_reloc_statement_type reloc_statement;
430   lang_target_statement_type target_statement;
431   lang_wild_statement_type wild_statement;
432 } lang_statement_union_type;
433 
434 /* This structure holds information about a program header, from the
435    PHDRS command in the linker script.  */
436 
437 struct lang_phdr
438 {
439   struct lang_phdr *next;
440   const char *name;
441   unsigned long type;
442   bfd_boolean filehdr;
443   bfd_boolean phdrs;
444   etree_type *at;
445   etree_type *flags;
446 };
447 
448 /* This structure is used to hold a list of sections which may not
449    cross reference each other.  */
450 
451 typedef struct lang_nocrossref
452 {
453   struct lang_nocrossref *next;
454   const char *name;
455 } lang_nocrossref_type;
456 
457 /* The list of nocrossref lists.  */
458 
459 struct lang_nocrossrefs
460 {
461   struct lang_nocrossrefs *next;
462   lang_nocrossref_type *list;
463   bfd_boolean onlyfirst;
464 };
465 
466 /* This structure is used to hold a list of input section names which
467    will not match an output section in the linker script.  */
468 
469 struct unique_sections
470 {
471   struct unique_sections *next;
472   const char *name;
473 };
474 
475 /* Used by place_orphan to keep track of orphan sections and statements.  */
476 
477 struct orphan_save
478 {
479   const char *name;
480   flagword flags;
481   lang_output_section_statement_type *os;
482   asection **section;
483   lang_statement_union_type **stmt;
484   lang_output_section_statement_type **os_tail;
485 };
486 
487 struct asneeded_minfo
488 {
489   struct asneeded_minfo *next;
490   const char *soname;
491   bfd *ref;
492   const char *name;
493 };
494 
495 extern struct lang_phdr *lang_phdr_list;
496 extern struct lang_nocrossrefs *nocrossref_list;
497 extern const char *output_target;
498 extern lang_output_section_statement_type *abs_output_section;
499 extern lang_statement_list_type lang_os_list;
500 extern struct lang_input_statement_flags input_flags;
501 extern bfd_boolean lang_has_input_file;
502 extern lang_statement_list_type *stat_ptr;
503 extern bfd_boolean delete_output_file_on_failure;
504 
505 extern struct bfd_sym_chain entry_symbol;
506 extern const char *entry_section;
507 extern bfd_boolean entry_from_cmdline;
508 extern lang_statement_list_type file_chain;
509 extern lang_statement_list_type input_file_chain;
510 
511 extern int lang_statement_iteration;
512 extern struct asneeded_minfo **asneeded_list_tail;
513 
514 extern void (*output_bfd_hash_table_free_fn) (struct bfd_link_hash_table *);
515 
516 extern void lang_init
517   (void);
518 extern void lang_finish
519   (void);
520 extern lang_memory_region_type * lang_memory_region_lookup
521   (const char * const, bfd_boolean);
522 extern void lang_memory_region_alias
523   (const char *, const char *);
524 extern void lang_map
525   (void);
526 extern void lang_set_flags
527   (lang_memory_region_type *, const char *, int);
528 extern void lang_add_output
529   (const char *, int from_script);
530 extern lang_output_section_statement_type *lang_enter_output_section_statement
531   (const char *, etree_type *, enum section_type, etree_type *, etree_type *,
532    etree_type *, int, int);
533 extern void lang_final
534   (void);
535 extern void lang_relax_sections
536   (bfd_boolean);
537 extern void lang_process
538   (void);
539 extern void lang_section_start
540   (const char *, union etree_union *, const segment_type *);
541 extern void lang_add_entry
542   (const char *, bfd_boolean);
543 extern void lang_default_entry
544   (const char *);
545 extern void lang_add_target
546   (const char *);
547 extern void lang_add_wild
548   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
549 extern void lang_add_map
550   (const char *);
551 extern void lang_add_fill
552   (fill_type *);
553 extern lang_assignment_statement_type *lang_add_assignment
554   (union etree_union *);
555 extern void lang_add_attribute
556   (enum statement_enum);
557 extern void lang_startup
558   (const char *);
559 extern void lang_float
560   (bfd_boolean);
561 extern void lang_leave_output_section_statement
562   (fill_type *, const char *, lang_output_section_phdr_list *,
563    const char *);
564 extern void lang_for_each_input_file
565   (void (*dothis) (lang_input_statement_type *));
566 extern void lang_for_each_file
567   (void (*dothis) (lang_input_statement_type *));
568 extern void lang_reset_memory_regions
569   (void);
570 extern void lang_do_assignments
571   (lang_phase_type);
572 extern asection *section_for_dot
573   (void);
574 
575 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)			\
576   lang_input_statement_type *statement;					\
577   for (statement = (lang_input_statement_type *) file_chain.head;	\
578        statement != NULL;						\
579        statement = statement->next)
580 
581 #define lang_output_section_find(NAME) \
582   lang_output_section_statement_lookup (NAME, 0, FALSE)
583 
584 extern void lang_process
585   (void);
586 extern void ldlang_add_file
587   (lang_input_statement_type *);
588 extern lang_output_section_statement_type *lang_output_section_find_by_flags
589   (const asection *, flagword, lang_output_section_statement_type **,
590    lang_match_sec_type_func);
591 extern lang_output_section_statement_type *lang_insert_orphan
592   (asection *, const char *, int, lang_output_section_statement_type *,
593    struct orphan_save *, etree_type *, lang_statement_list_type *);
594 extern lang_input_statement_type *lang_add_input_file
595   (const char *, lang_input_file_enum_type, const char *);
596 extern void lang_add_keepsyms_file
597   (const char *);
598 extern lang_output_section_statement_type *lang_output_section_get
599   (const asection *);
600 extern lang_output_section_statement_type *lang_output_section_statement_lookup
601   (const char *, int, bfd_boolean);
602 extern lang_output_section_statement_type *next_matching_output_section_statement
603   (lang_output_section_statement_type *, int);
604 extern void ldlang_add_undef
605   (const char *const, bfd_boolean);
606 extern void ldlang_add_require_defined
607   (const char *const);
608 extern void lang_add_output_format
609   (const char *, const char *, const char *, int);
610 extern void lang_list_init
611   (lang_statement_list_type *);
612 extern void push_stat_ptr
613   (lang_statement_list_type *);
614 extern void pop_stat_ptr
615   (void);
616 extern void lang_add_data
617   (int type, union etree_union *);
618 extern void lang_add_reloc
619   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
620    union etree_union *);
621 extern void lang_for_each_statement
622   (void (*) (lang_statement_union_type *));
623 extern void lang_for_each_statement_worker
624   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
625 extern void *stat_alloc
626   (size_t);
627 extern void strip_excluded_output_sections
628   (void);
629 extern void lang_clear_os_map
630   (void);
631 extern void dprint_statement
632   (lang_statement_union_type *, int);
633 extern void lang_size_sections
634   (bfd_boolean *, bfd_boolean);
635 extern void one_lang_size_sections_pass
636   (bfd_boolean *, bfd_boolean);
637 extern void lang_add_insert
638   (const char *, int);
639 extern void lang_enter_group
640   (void);
641 extern void lang_leave_group
642   (void);
643 extern void lang_add_section
644   (lang_statement_list_type *, asection *,
645    struct flag_info *, lang_output_section_statement_type *);
646 extern void lang_new_phdr
647   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
648    etree_type *);
649 extern void lang_add_nocrossref
650   (lang_nocrossref_type *);
651 extern void lang_add_nocrossref_to
652   (lang_nocrossref_type *);
653 extern void lang_enter_overlay
654   (etree_type *, etree_type *);
655 extern void lang_enter_overlay_section
656   (const char *);
657 extern void lang_leave_overlay_section
658   (fill_type *, lang_output_section_phdr_list *);
659 extern void lang_leave_overlay
660   (etree_type *, int, fill_type *, const char *,
661    lang_output_section_phdr_list *, const char *);
662 
663 extern struct bfd_elf_version_expr *lang_new_vers_pattern
664   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
665 extern struct bfd_elf_version_tree *lang_new_vers_node
666   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
667 extern struct bfd_elf_version_deps *lang_add_vers_depend
668   (struct bfd_elf_version_deps *, const char *);
669 extern void lang_register_vers_node
670   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
671 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
672 extern void lang_append_dynamic_list_cpp_typeinfo (void);
673 extern void lang_append_dynamic_list_cpp_new (void);
674 extern void lang_add_unique
675   (const char *);
676 extern const char *lang_get_output_target
677   (void);
678 extern void add_excluded_libs (const char *);
679 extern bfd_boolean load_symbols
680   (lang_input_statement_type *, lang_statement_list_type *);
681 
682 struct elf_sym_strtab;
683 struct elf_strtab_hash;
684 extern void ldlang_ctf_apply_strsym
685   (struct elf_sym_strtab *, bfd_size_type, struct elf_strtab_hash *);
686 extern void ldlang_write_ctf_late
687   (void);
688 extern bfd_boolean
689 ldlang_override_segment_assignment
690   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
691 
692 extern void
693 lang_ld_feature (char *);
694 
695 extern void
696 lang_print_memory_usage (void);
697 
698 extern void
699 lang_add_gc_name (const char *);
700 
701 #endif
702