xref: /netbsd-src/external/gpl3/binutils/dist/ld/ldlang.h (revision b49cc1491953ef2348eff9c84520ffd0678a5c8d)
1 /* ldlang.h - linker command language support
2    Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
4    Free Software Foundation, Inc.
5 
6    This file is part of the GNU Binutils.
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 
23 #ifndef LDLANG_H
24 #define LDLANG_H
25 
26 #define DEFAULT_MEMORY_REGION   "*default*"
27 
28 typedef enum
29 {
30   lang_input_file_is_l_enum,
31   lang_input_file_is_symbols_only_enum,
32   lang_input_file_is_marker_enum,
33   lang_input_file_is_fake_enum,
34   lang_input_file_is_search_file_enum,
35   lang_input_file_is_file_enum
36 } lang_input_file_enum_type;
37 
38 struct _fill_type
39 {
40   size_t size;
41   unsigned char data[1];
42 };
43 
44 typedef struct statement_list
45 {
46   union lang_statement_union *head;
47   union lang_statement_union **tail;
48 } lang_statement_list_type;
49 
50 typedef struct memory_region_struct
51 {
52   char *name;
53   struct memory_region_struct *next;
54   bfd_vma origin;
55   bfd_size_type length;
56   bfd_vma current;
57   union lang_statement_union *last_os;
58   flagword flags;
59   flagword not_flags;
60   bfd_boolean had_full_message;
61 } lang_memory_region_type;
62 
63 typedef struct lang_statement_header_struct
64 {
65   union lang_statement_union *next;
66   enum statement_enum
67   {
68     lang_output_section_statement_enum,
69     lang_assignment_statement_enum,
70     lang_input_statement_enum,
71     lang_address_statement_enum,
72     lang_wild_statement_enum,
73     lang_input_section_enum,
74     lang_object_symbols_statement_enum,
75     lang_fill_statement_enum,
76     lang_data_statement_enum,
77     lang_reloc_statement_enum,
78     lang_target_statement_enum,
79     lang_output_statement_enum,
80     lang_padding_statement_enum,
81     lang_group_statement_enum,
82     lang_insert_statement_enum,
83     lang_constructors_statement_enum
84   } type;
85 } lang_statement_header_type;
86 
87 typedef struct
88 {
89   lang_statement_header_type header;
90   union etree_union *exp;
91 } lang_assignment_statement_type;
92 
93 typedef struct lang_target_statement_struct
94 {
95   lang_statement_header_type header;
96   const char *target;
97 } lang_target_statement_type;
98 
99 typedef struct lang_output_statement_struct
100 {
101   lang_statement_header_type header;
102   const char *name;
103 } lang_output_statement_type;
104 
105 /* Section types specified in a linker script.  */
106 
107 enum section_type
108 {
109   normal_section,
110   overlay_section,
111   noload_section,
112   noalloc_section
113 };
114 
115 /* This structure holds a list of program headers describing
116    segments in which this section should be placed.  */
117 
118 typedef struct lang_output_section_phdr_list
119 {
120   struct lang_output_section_phdr_list *next;
121   const char *name;
122   bfd_boolean used;
123 } lang_output_section_phdr_list;
124 
125 typedef struct lang_output_section_statement_struct
126 {
127   lang_statement_header_type header;
128   lang_statement_list_type children;
129   struct lang_output_section_statement_struct *next;
130   struct lang_output_section_statement_struct *prev;
131   const char *name;
132   asection *bfd_section;
133   lang_memory_region_type *region;
134   lang_memory_region_type *lma_region;
135   fill_type *fill;
136   union etree_union *addr_tree;
137   union etree_union *load_base;
138 
139   /* If non-null, an expression to evaluate after setting the section's
140      size.  The expression is evaluated inside REGION (above) with '.'
141      set to the end of the section.  Used in the last overlay section
142      to move '.' past all the overlaid sections.  */
143   union etree_union *update_dot_tree;
144 
145   lang_output_section_phdr_list *phdrs;
146 
147   unsigned int block_value;
148   int subsection_alignment;	/* Alignment of components.  */
149   int section_alignment;	/* Alignment of start of section.  */
150   int constraint;
151   flagword flags;
152   enum section_type sectype;
153   unsigned int processed_vma : 1;
154   unsigned int processed_lma : 1;
155   unsigned int all_input_readonly : 1;
156   /* If this section should be ignored.  */
157   unsigned int ignored : 1;
158   /* If there is a symbol relative to this section.  */
159   unsigned int section_relative_symbol : 1;
160 } lang_output_section_statement_type;
161 
162 typedef struct
163 {
164   lang_statement_header_type header;
165 } lang_common_statement_type;
166 
167 typedef struct
168 {
169   lang_statement_header_type header;
170 } lang_object_symbols_statement_type;
171 
172 typedef struct
173 {
174   lang_statement_header_type header;
175   fill_type *fill;
176   int size;
177   asection *output_section;
178 } lang_fill_statement_type;
179 
180 typedef struct
181 {
182   lang_statement_header_type header;
183   unsigned int type;
184   union etree_union *exp;
185   bfd_vma value;
186   asection *output_section;
187   bfd_vma output_offset;
188 } lang_data_statement_type;
189 
190 /* Generate a reloc in the output file.  */
191 
192 typedef struct
193 {
194   lang_statement_header_type header;
195 
196   /* Reloc to generate.  */
197   bfd_reloc_code_real_type reloc;
198 
199   /* Reloc howto structure.  */
200   reloc_howto_type *howto;
201 
202   /* Section to generate reloc against.
203      Exactly one of section and name must be NULL.  */
204   asection *section;
205 
206   /* Name of symbol to generate reloc against.
207      Exactly one of section and name must be NULL.  */
208   const char *name;
209 
210   /* Expression for addend.  */
211   union etree_union *addend_exp;
212 
213   /* Resolved addend.  */
214   bfd_vma addend_value;
215 
216   /* Output section where reloc should be performed.  */
217   asection *output_section;
218 
219   /* Offset within output section.  */
220   bfd_vma output_offset;
221 } lang_reloc_statement_type;
222 
223 typedef struct lang_input_statement_struct
224 {
225   lang_statement_header_type header;
226   /* Name of this file.  */
227   const char *filename;
228   /* Name to use for the symbol giving address of text start.
229      Usually the same as filename, but for a file spec'd with
230      -l this is the -l switch itself rather than the filename.  */
231   const char *local_sym_name;
232 
233   bfd *the_bfd;
234 
235   /* Point to the next file - whatever it is, wanders up and down
236      archives */
237   union lang_statement_union *next;
238 
239   /* Point to the next file, but skips archive contents.  */
240   union lang_statement_union *next_real_file;
241 
242   const char *target;
243 
244   unsigned int is_archive : 1;
245 
246   /* 1 means search a set of directories for this file.  */
247   unsigned int search_dirs_flag : 1;
248 
249   /* 1 means this was found in a search directory marked as sysrooted,
250      if search_dirs_flag is false, otherwise, that it should be
251      searched in ld_sysroot before any other location, as long as it
252      starts with a slash.  */
253   unsigned int sysrooted : 1;
254 
255   /* 1 means this is base file of incremental load.
256      Do not load this file's text or data.
257      Also default text_start to after this file's bss.  */
258   unsigned int just_syms_flag : 1;
259 
260   /* Whether to search for this entry as a dynamic archive.  */
261   unsigned int dynamic : 1;
262 
263   /* Whether DT_NEEDED tags should be added for dynamic libraries in
264      DT_NEEDED tags from this entry.  */
265   unsigned int add_needed : 1;
266 
267   /* Whether this entry should cause a DT_NEEDED tag only when
268      satisfying references from regular files, or always.  */
269   unsigned int as_needed : 1;
270 
271   /* Whether to include the entire contents of an archive.  */
272   unsigned int whole_archive : 1;
273 
274   unsigned int loaded : 1;
275 
276   unsigned int real : 1;
277 } lang_input_statement_type;
278 
279 typedef struct
280 {
281   lang_statement_header_type header;
282   asection *section;
283 } lang_input_section_type;
284 
285 typedef struct lang_wild_statement_struct lang_wild_statement_type;
286 
287 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
288 			    asection *, lang_input_statement_type *, void *);
289 
290 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
291 					     lang_input_statement_type *,
292 					     callback_t callback,
293 					     void *data);
294 
295 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
296 						 bfd *, const asection *);
297 
298 /* Binary search tree structure to efficiently sort sections by
299    name.  */
300 typedef struct lang_section_bst
301 {
302   asection *section;
303   struct lang_section_bst *left;
304   struct lang_section_bst *right;
305 } lang_section_bst_type;
306 
307 struct lang_wild_statement_struct
308 {
309   lang_statement_header_type header;
310   const char *filename;
311   bfd_boolean filenames_sorted;
312   struct wildcard_list *section_list;
313   bfd_boolean keep_sections;
314   lang_statement_list_type children;
315 
316   walk_wild_section_handler_t walk_wild_section_handler;
317   struct wildcard_list *handler_data[4];
318   lang_section_bst_type *tree;
319 };
320 
321 typedef struct lang_address_statement_struct
322 {
323   lang_statement_header_type header;
324   const char *section_name;
325   union etree_union *address;
326   const segment_type *segment;
327 } lang_address_statement_type;
328 
329 typedef struct
330 {
331   lang_statement_header_type header;
332   bfd_vma output_offset;
333   size_t size;
334   asection *output_section;
335   fill_type *fill;
336 } lang_padding_statement_type;
337 
338 /* A group statement collects a set of libraries together.  The
339    libraries are searched multiple times, until no new undefined
340    symbols are found.  The effect is to search a group of libraries as
341    though they were a single library.  */
342 
343 typedef struct
344 {
345   lang_statement_header_type header;
346   lang_statement_list_type children;
347 } lang_group_statement_type;
348 
349 typedef struct
350 {
351   lang_statement_header_type header;
352   const char *where;
353   bfd_boolean is_before;
354 } lang_insert_statement_type;
355 
356 typedef union lang_statement_union
357 {
358   lang_statement_header_type header;
359   lang_wild_statement_type wild_statement;
360   lang_data_statement_type data_statement;
361   lang_reloc_statement_type reloc_statement;
362   lang_address_statement_type address_statement;
363   lang_output_section_statement_type output_section_statement;
364   lang_assignment_statement_type assignment_statement;
365   lang_input_statement_type input_statement;
366   lang_target_statement_type target_statement;
367   lang_output_statement_type output_statement;
368   lang_input_section_type input_section;
369   lang_common_statement_type common_statement;
370   lang_object_symbols_statement_type object_symbols_statement;
371   lang_fill_statement_type fill_statement;
372   lang_padding_statement_type padding_statement;
373   lang_group_statement_type group_statement;
374   lang_insert_statement_type insert_statement;
375 } lang_statement_union_type;
376 
377 /* This structure holds information about a program header, from the
378    PHDRS command in the linker script.  */
379 
380 struct lang_phdr
381 {
382   struct lang_phdr *next;
383   const char *name;
384   unsigned long type;
385   bfd_boolean filehdr;
386   bfd_boolean phdrs;
387   etree_type *at;
388   etree_type *flags;
389 };
390 
391 extern struct lang_phdr *lang_phdr_list;
392 
393 /* This structure is used to hold a list of sections which may not
394    cross reference each other.  */
395 
396 typedef struct lang_nocrossref
397 {
398   struct lang_nocrossref *next;
399   const char *name;
400 } lang_nocrossref_type;
401 
402 /* The list of nocrossref lists.  */
403 
404 struct lang_nocrossrefs
405 {
406   struct lang_nocrossrefs *next;
407   lang_nocrossref_type *list;
408 };
409 
410 extern struct lang_nocrossrefs *nocrossref_list;
411 
412 /* This structure is used to hold a list of input section names which
413    will not match an output section in the linker script.  */
414 
415 struct unique_sections
416 {
417   struct unique_sections *next;
418   const char *name;
419 };
420 
421 /* This structure records symbols for which we need to keep track of
422    definedness for use in the DEFINED () test.  */
423 
424 struct lang_definedness_hash_entry
425 {
426   struct bfd_hash_entry root;
427   int iteration;
428 };
429 
430 /* Used by place_orphan to keep track of orphan sections and statements.  */
431 
432 struct orphan_save {
433   const char *name;
434   flagword flags;
435   lang_output_section_statement_type *os;
436   asection **section;
437   lang_statement_union_type **stmt;
438   lang_output_section_statement_type **os_tail;
439 };
440 
441 extern lang_output_section_statement_type *abs_output_section;
442 extern lang_statement_list_type lang_output_section_statement;
443 extern bfd_boolean lang_has_input_file;
444 extern etree_type *base;
445 extern lang_statement_list_type *stat_ptr;
446 extern bfd_boolean delete_output_file_on_failure;
447 
448 extern struct bfd_sym_chain entry_symbol;
449 extern const char *entry_section;
450 extern bfd_boolean entry_from_cmdline;
451 extern lang_statement_list_type file_chain;
452 extern lang_statement_list_type input_file_chain;
453 
454 extern int lang_statement_iteration;
455 
456 extern void lang_init
457   (void);
458 extern void lang_finish
459   (void);
460 extern lang_memory_region_type *lang_memory_region_lookup
461   (const char *const, bfd_boolean);
462 extern lang_memory_region_type *lang_memory_region_default
463   (asection *);
464 extern void lang_map
465   (void);
466 extern void lang_set_flags
467   (lang_memory_region_type *, const char *, int);
468 extern void lang_add_output
469   (const char *, int from_script);
470 extern lang_output_section_statement_type *lang_enter_output_section_statement
471   (const char *output_section_statement_name,
472    etree_type *address_exp,
473    enum section_type sectype,
474    etree_type *align,
475    etree_type *subalign,
476    etree_type *, int);
477 extern void lang_final
478   (void);
479 extern void lang_process
480   (void);
481 extern void lang_section_start
482   (const char *, union etree_union *, const segment_type *);
483 extern void lang_add_entry
484   (const char *, bfd_boolean);
485 extern void lang_default_entry
486   (const char *);
487 extern void lang_add_target
488   (const char *);
489 extern void lang_add_wild
490   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
491 extern void lang_add_map
492   (const char *);
493 extern void lang_add_fill
494   (fill_type *);
495 extern lang_assignment_statement_type *lang_add_assignment
496   (union etree_union *);
497 extern void lang_add_attribute
498   (enum statement_enum);
499 extern void lang_startup
500   (const char *);
501 extern void lang_float
502   (bfd_boolean);
503 extern void lang_leave_output_section_statement
504   (fill_type *, const char *, lang_output_section_phdr_list *,
505    const char *);
506 extern void lang_abs_symbol_at_end_of
507   (const char *, const char *);
508 extern void lang_abs_symbol_at_beginning_of
509   (const char *, const char *);
510 extern void lang_statement_append
511   (lang_statement_list_type *, lang_statement_union_type *,
512    lang_statement_union_type **);
513 extern void lang_for_each_input_file
514   (void (*dothis) (lang_input_statement_type *));
515 extern void lang_for_each_file
516   (void (*dothis) (lang_input_statement_type *));
517 extern void lang_reset_memory_regions
518   (void);
519 extern void lang_do_assignments
520   (void);
521 
522 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)			\
523   lang_input_statement_type *statement;					\
524   for (statement = (lang_input_statement_type *) file_chain.head;	\
525        statement != (lang_input_statement_type *) NULL;			\
526        statement = (lang_input_statement_type *) statement->next)	\
527 
528 #define lang_output_section_find(NAME) \
529   lang_output_section_statement_lookup (NAME, 0, FALSE)
530 
531 extern void lang_process
532   (void);
533 extern void ldlang_add_file
534   (lang_input_statement_type *);
535 extern lang_output_section_statement_type *lang_output_section_find_by_flags
536   (const asection *, lang_output_section_statement_type **,
537    lang_match_sec_type_func);
538 extern lang_output_section_statement_type *lang_insert_orphan
539   (asection *, const char *, int, lang_output_section_statement_type *,
540    struct orphan_save *, etree_type *, lang_statement_list_type *);
541 extern lang_input_statement_type *lang_add_input_file
542   (const char *, lang_input_file_enum_type, const char *);
543 extern void lang_add_keepsyms_file
544   (const char *);
545 extern lang_output_section_statement_type *lang_output_section_statement_lookup
546   (const char *const, int, bfd_boolean);
547 extern void ldlang_add_undef
548   (const char *const);
549 extern void lang_add_output_format
550   (const char *, const char *, const char *, int);
551 extern void lang_list_init
552   (lang_statement_list_type *);
553 extern void push_stat_ptr
554   (lang_statement_list_type *);
555 extern void pop_stat_ptr
556   (void);
557 extern void lang_add_data
558   (int type, union etree_union *);
559 extern void lang_add_reloc
560   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
561    union etree_union *);
562 extern void lang_for_each_statement
563   (void (*) (lang_statement_union_type *));
564 extern void *stat_alloc
565   (size_t);
566 extern void strip_excluded_output_sections
567   (void);
568 extern void dprint_statement
569   (lang_statement_union_type *, int);
570 extern void lang_size_sections
571   (bfd_boolean *, bfd_boolean);
572 extern void one_lang_size_sections_pass
573   (bfd_boolean *, bfd_boolean);
574 extern void lang_add_insert
575   (const char *, int);
576 extern void lang_enter_group
577   (void);
578 extern void lang_leave_group
579   (void);
580 extern void lang_add_section
581   (lang_statement_list_type *, asection *,
582    lang_output_section_statement_type *);
583 extern void lang_new_phdr
584   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
585    etree_type *);
586 extern void lang_add_nocrossref
587   (lang_nocrossref_type *);
588 extern void lang_enter_overlay
589   (etree_type *, etree_type *);
590 extern void lang_enter_overlay_section
591   (const char *);
592 extern void lang_leave_overlay_section
593   (fill_type *, lang_output_section_phdr_list *);
594 extern void lang_leave_overlay
595   (etree_type *, int, fill_type *, const char *,
596    lang_output_section_phdr_list *, const char *);
597 
598 extern struct bfd_elf_version_tree *lang_elf_version_info;
599 
600 extern struct bfd_elf_version_expr *lang_new_vers_pattern
601   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
602 extern struct bfd_elf_version_tree *lang_new_vers_node
603   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
604 extern struct bfd_elf_version_deps *lang_add_vers_depend
605   (struct bfd_elf_version_deps *, const char *);
606 extern void lang_register_vers_node
607   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
608 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
609 extern void lang_append_dynamic_list_cpp_typeinfo (void);
610 extern void lang_append_dynamic_list_cpp_new (void);
611 extern void lang_add_unique
612   (const char *);
613 extern const char *lang_get_output_target
614   (void);
615 extern void lang_track_definedness (const char *);
616 extern int lang_symbol_definition_iteration (const char *);
617 extern void lang_update_definedness
618   (const char *, struct bfd_link_hash_entry *);
619 
620 extern void add_excluded_libs (const char *);
621 extern bfd_boolean load_symbols
622   (lang_input_statement_type *, lang_statement_list_type *);
623 
624 extern bfd_boolean
625 ldlang_override_segment_assignment
626   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
627 
628 #endif
629