source: trunk/libs/newlib/src/include/bfdlink.h @ 666

Last change on this file since 666 was 444, checked in by satin@…, 6 years ago

add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc

File size: 30.7 KB
Line 
1/* bfdlink.h -- header file for BFD link routines
2   Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
3   2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
4   Free Software Foundation, Inc.
5   Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support.
6
7   This file is part of BFD, the Binary File Descriptor library.
8
9   This program is free software; you can redistribute it and/or modify
10   it under the terms of the GNU General Public License as published by
11   the Free Software Foundation; either version 3 of the License, or
12   (at your option) any later version.
13
14   This program is distributed in the hope that it will be useful,
15   but WITHOUT ANY WARRANTY; without even the implied warranty of
16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17   GNU General Public License for more details.
18
19   You should have received a copy of the GNU General Public License
20   along with this program; if not, write to the Free Software
21   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22   MA 02110-1301, USA.  */
23
24#ifndef BFDLINK_H
25#define BFDLINK_H
26
27/* Which symbols to strip during a link.  */
28enum bfd_link_strip
29{
30  strip_none,           /* Don't strip any symbols.  */
31  strip_debugger,       /* Strip debugging symbols.  */
32  strip_some,           /* keep_hash is the list of symbols to keep.  */
33  strip_all             /* Strip all symbols.  */
34};
35
36/* Which local symbols to discard during a link.  This is irrelevant
37   if strip_all is used.  */
38enum bfd_link_discard
39{
40  discard_sec_merge,    /* Discard local temporary symbols in SEC_MERGE
41                           sections.  */
42  discard_none,         /* Don't discard any locals.  */
43  discard_l,            /* Discard local temporary symbols.  */
44  discard_all           /* Discard all locals.  */
45};
46
47/* Describes the type of hash table entry structure being used.
48   Different hash table structure have different fields and so
49   support different linking features.  */
50enum bfd_link_hash_table_type
51  {
52    bfd_link_generic_hash_table,
53    bfd_link_elf_hash_table
54  };
55
56/* These are the possible types of an entry in the BFD link hash
57   table.  */
58
59enum bfd_link_hash_type
60{
61  bfd_link_hash_new,            /* Symbol is new.  */
62  bfd_link_hash_undefined,      /* Symbol seen before, but undefined.  */
63  bfd_link_hash_undefweak,      /* Symbol is weak and undefined.  */
64  bfd_link_hash_defined,        /* Symbol is defined.  */
65  bfd_link_hash_defweak,        /* Symbol is weak and defined.  */
66  bfd_link_hash_common,         /* Symbol is common.  */
67  bfd_link_hash_indirect,       /* Symbol is an indirect link.  */
68  bfd_link_hash_warning         /* Like indirect, but warn if referenced.  */
69};
70
71enum bfd_link_common_skip_ar_symbols
72{
73  bfd_link_common_skip_none,
74  bfd_link_common_skip_text,
75  bfd_link_common_skip_data,
76  bfd_link_common_skip_all
77};
78
79struct bfd_link_hash_common_entry
80  {
81    unsigned int alignment_power;       /* Alignment.  */
82    asection *section;          /* Symbol section.  */
83  };
84
85/* The linking routines use a hash table which uses this structure for
86   its elements.  */
87
88struct bfd_link_hash_entry
89{
90  /* Base hash table entry structure.  */
91  struct bfd_hash_entry root;
92
93  /* Type of this entry.  */
94  ENUM_BITFIELD (bfd_link_hash_type) type : 8;
95
96  unsigned int non_ir_ref : 1;
97
98  /* A union of information depending upon the type.  */
99  union
100    {
101      /* Nothing is kept for bfd_hash_new.  */
102      /* bfd_link_hash_undefined, bfd_link_hash_undefweak.  */
103      struct
104        {
105          /* Undefined and common symbols are kept in a linked list through
106             this field.  This field is present in all of the union element
107             so that we don't need to remove entries from the list when we
108             change their type.  Removing entries would either require the
109             list to be doubly linked, which would waste more memory, or
110             require a traversal.  When an undefined or common symbol is
111             created, it should be added to this list, the head of which is in
112             the link hash table itself.  As symbols are defined, they need
113             not be removed from the list; anything which reads the list must
114             doublecheck the symbol type.
115
116             Weak symbols are not kept on this list.
117
118             Defined and defweak symbols use this field as a reference marker.
119             If the field is not NULL, or this structure is the tail of the
120             undefined symbol list, the symbol has been referenced.  If the
121             symbol is undefined and becomes defined, this field will
122             automatically be non-NULL since the symbol will have been on the
123             undefined symbol list.  */
124          struct bfd_link_hash_entry *next;
125          bfd *abfd;            /* BFD symbol was found in.  */
126        } undef;
127      /* bfd_link_hash_defined, bfd_link_hash_defweak.  */
128      struct
129        {
130          struct bfd_link_hash_entry *next;
131          asection *section;    /* Symbol section.  */
132          bfd_vma value;        /* Symbol value.  */
133        } def;
134      /* bfd_link_hash_indirect, bfd_link_hash_warning.  */
135      struct
136        {
137          struct bfd_link_hash_entry *next;
138          struct bfd_link_hash_entry *link;     /* Real symbol.  */
139          const char *warning;  /* Warning (bfd_link_hash_warning only).  */
140        } i;
141      /* bfd_link_hash_common.  */
142      struct
143        {
144          struct bfd_link_hash_entry *next;
145          /* The linker needs to know three things about common
146             symbols: the size, the alignment, and the section in
147             which the symbol should be placed.  We store the size
148             here, and we allocate a small structure to hold the
149             section and the alignment.  The alignment is stored as a
150             power of two.  We don't store all the information
151             directly because we don't want to increase the size of
152             the union; this structure is a major space user in the
153             linker.  */
154          struct bfd_link_hash_common_entry *p;
155          bfd_size_type size;   /* Common symbol size.  */
156        } c;
157    } u;
158};
159
160/* This is the link hash table.  It is a derived class of
161   bfd_hash_table.  */
162
163struct bfd_link_hash_table
164{
165  /* The hash table itself.  */
166  struct bfd_hash_table table;
167  /* A linked list of undefined and common symbols, linked through the
168     next field in the bfd_link_hash_entry structure.  */
169  struct bfd_link_hash_entry *undefs;
170  /* Entries are added to the tail of the undefs list.  */
171  struct bfd_link_hash_entry *undefs_tail;
172  /* The type of the link hash table.  */
173  enum bfd_link_hash_table_type type;
174};
175
176/* Look up an entry in a link hash table.  If FOLLOW is TRUE, this
177   follows bfd_link_hash_indirect and bfd_link_hash_warning links to
178   the real symbol.  */
179extern struct bfd_link_hash_entry *bfd_link_hash_lookup
180  (struct bfd_link_hash_table *, const char *, bfd_boolean create,
181   bfd_boolean copy, bfd_boolean follow);
182
183/* Look up an entry in the main linker hash table if the symbol might
184   be wrapped.  This should only be used for references to an
185   undefined symbol, not for definitions of a symbol.  */
186
187extern struct bfd_link_hash_entry *bfd_wrapped_link_hash_lookup
188  (bfd *, struct bfd_link_info *, const char *, bfd_boolean,
189   bfd_boolean, bfd_boolean);
190
191/* Traverse a link hash table.  */
192extern void bfd_link_hash_traverse
193  (struct bfd_link_hash_table *,
194    bfd_boolean (*) (struct bfd_link_hash_entry *, void *),
195    void *);
196
197/* Add an entry to the undefs list.  */
198extern void bfd_link_add_undef
199  (struct bfd_link_hash_table *, struct bfd_link_hash_entry *);
200
201/* Remove symbols from the undefs list that don't belong there.  */
202extern void bfd_link_repair_undef_list
203  (struct bfd_link_hash_table *table);
204
205/* Read symbols and cache symbol pointer array in outsymbols.  */
206extern bfd_boolean bfd_generic_link_read_symbols (bfd *);
207
208struct bfd_sym_chain
209{
210  struct bfd_sym_chain *next;
211  const char *name;
212};
213
214/* How to handle unresolved symbols.
215   There are four possibilities which are enumerated below:  */
216enum report_method
217{
218  /* This is the initial value when then link_info structure is created.
219     It allows the various stages of the linker to determine whether they
220     allowed to set the value.  */
221  RM_NOT_YET_SET = 0,
222  RM_IGNORE,
223  RM_GENERATE_WARNING,
224  RM_GENERATE_ERROR
225};
226
227typedef enum {with_flags, without_flags} flag_type;
228
229/* A section flag list.  */
230struct flag_info_list
231{
232  flag_type with;
233  const char *name;
234  bfd_boolean valid;
235  struct flag_info_list *next;
236};
237
238/* Section flag info.  */
239struct flag_info
240{
241  flagword only_with_flags;
242  flagword not_with_flags;
243  struct flag_info_list *flag_list;
244  bfd_boolean flags_initialized;
245};
246
247struct bfd_elf_dynamic_list;
248struct bfd_elf_version_tree;
249
250/* This structure holds all the information needed to communicate
251   between BFD and the linker when doing a link.  */
252
253struct bfd_link_info
254{
255  /* TRUE if BFD should generate a shared object (or a pie).  */
256  unsigned int shared: 1;
257
258  /* TRUE if generating an executable, position independent or not.  */
259  unsigned int executable : 1;
260
261  /* TRUE if generating a position independent executable.  */
262  unsigned int pie: 1;
263
264  /* TRUE if BFD should generate a relocatable object file.  */
265  unsigned int relocatable: 1;
266
267  /* TRUE if BFD should pre-bind symbols in a shared object.  */
268  unsigned int symbolic: 1;
269
270  /* TRUE if executable should not contain copy relocs.
271     Setting this true may result in a non-sharable text segment.  */
272  unsigned int nocopyreloc: 1;
273
274  /* TRUE if BFD should export all symbols in the dynamic symbol table
275     of an executable, rather than only those used.  */
276  unsigned int export_dynamic: 1;
277
278  /* TRUE if a default symbol version should be created and used for
279     exported symbols.  */
280  unsigned int create_default_symver: 1;
281
282  /* TRUE if unreferenced sections should be removed.  */
283  unsigned int gc_sections: 1;
284
285  /* TRUE if every symbol should be reported back via the notice
286     callback.  */
287  unsigned int notice_all: 1;
288
289  /* TRUE if we are loading LTO outputs.  */
290  unsigned int loading_lto_outputs: 1;
291
292  /* TRUE if global symbols in discarded sections should be stripped.  */
293  unsigned int strip_discarded: 1;
294
295  /* TRUE if all data symbols should be dynamic.  */
296  unsigned int dynamic_data: 1;
297
298  /* Which symbols to strip.  */
299  ENUM_BITFIELD (bfd_link_strip) strip : 2;
300
301  /* Which local symbols to discard.  */
302  ENUM_BITFIELD (bfd_link_discard) discard : 2;
303
304  /* Criteria for skipping symbols when determining
305     whether to include an object from an archive. */
306  ENUM_BITFIELD (bfd_link_common_skip_ar_symbols) common_skip_ar_symbols : 2;
307
308  /* What to do with unresolved symbols in an object file.
309     When producing executables the default is GENERATE_ERROR.
310     When producing shared libraries the default is IGNORE.  The
311     assumption with shared libraries is that the reference will be
312     resolved at load/execution time.  */
313  ENUM_BITFIELD (report_method) unresolved_syms_in_objects : 2;
314
315  /* What to do with unresolved symbols in a shared library.
316     The same defaults apply.  */
317  ENUM_BITFIELD (report_method) unresolved_syms_in_shared_libs : 2;
318
319  /* TRUE if shared objects should be linked directly, not shared.  */
320  unsigned int static_link: 1;
321
322  /* TRUE if symbols should be retained in memory, FALSE if they
323     should be freed and reread.  */
324  unsigned int keep_memory: 1;
325
326  /* TRUE if BFD should generate relocation information in the final
327     executable.  */
328  unsigned int emitrelocations: 1;
329
330  /* TRUE if PT_GNU_RELRO segment should be created.  */
331  unsigned int relro: 1;
332
333  /* TRUE if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment
334     should be created.  */
335  unsigned int eh_frame_hdr: 1;
336
337  /* TRUE if we should warn when adding a DT_TEXTREL to a shared object.  */
338  unsigned int warn_shared_textrel: 1;
339
340  /* TRUE if we should error when adding a DT_TEXTREL.  */
341  unsigned int error_textrel: 1;
342
343  /* TRUE if .hash section should be created.  */
344  unsigned int emit_hash: 1;
345
346  /* TRUE if .gnu.hash section should be created.  */
347  unsigned int emit_gnu_hash: 1;
348
349  /* If TRUE reduce memory overheads, at the expense of speed. This will
350     cause map file generation to use an O(N^2) algorithm and disable
351     caching ELF symbol buffer.  */
352  unsigned int reduce_memory_overheads: 1;
353
354  /* TRUE if the output file should be in a traditional format.  This
355     is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag
356     on the output file, but may be checked when reading the input
357     files.  */
358  unsigned int traditional_format: 1;
359
360  /* TRUE if non-PLT relocs should be merged into one reloc section
361     and sorted so that relocs against the same symbol come together.  */
362  unsigned int combreloc: 1;
363
364  /* TRUE if a default symbol version should be created and used for
365     imported symbols.  */
366  unsigned int default_imported_symver: 1;
367
368  /* TRUE if the new ELF dynamic tags are enabled. */
369  unsigned int new_dtags: 1;
370
371  /* FALSE if .eh_frame unwind info should be generated for PLT and other
372     linker created sections, TRUE if it should be omitted.  */
373  unsigned int no_ld_generated_unwind_info: 1;
374
375  /* TRUE if BFD should generate a "task linked" object file,
376     similar to relocatable but also with globals converted to
377     statics.  */
378  unsigned int task_link: 1;
379
380  /* TRUE if ok to have multiple definition.  */
381  unsigned int allow_multiple_definition: 1;
382
383  /* TRUE if ok to have version with no definition.  */
384  unsigned int allow_undefined_version: 1;
385
386  /* TRUE if some symbols have to be dynamic, controlled by
387     --dynamic-list command line options.  */
388  unsigned int dynamic: 1;
389
390  /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X
391     flags.  */
392  unsigned int execstack: 1;
393
394  /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W
395     flags.  */
396  unsigned int noexecstack: 1;
397
398  /* TRUE if we want to produced optimized output files.  This might
399     need much more time and therefore must be explicitly selected.  */
400  unsigned int optimize: 1;
401
402  /* TRUE if user should be informed of removed unreferenced sections.  */
403  unsigned int print_gc_sections: 1;
404
405  /* TRUE if we should warn alternate ELF machine code.  */
406  unsigned int warn_alternate_em: 1;
407
408  /* TRUE if the linker script contained an explicit PHDRS command.  */
409  unsigned int user_phdrs: 1;
410
411  /* Char that may appear as the first char of a symbol, but should be
412     skipped (like symbol_leading_char) when looking up symbols in
413     wrap_hash.  Used by PowerPC Linux for 'dot' symbols.  */
414  char wrap_char;
415
416  /* Separator between archive and filename in linker script filespecs.  */
417  char path_separator;
418
419  /* Default stack size.  Zero means default (often zero itself), -1
420     means explicitly zero-sized.  */
421  bfd_signed_vma stacksize;
422
423  /* Enable or disable target specific optimizations.
424
425     Not all targets have optimizations to enable.
426
427     Normally these optimizations are disabled by default but some targets
428     prefer to enable them by default.  So this field is a tri-state variable.
429     The values are:
430     
431     zero: Enable the optimizations (either from --relax being specified on
432       the command line or the backend's before_allocation emulation function.
433       
434     positive: The user has requested that these optimizations be disabled.
435       (Via the --no-relax command line option).
436
437     negative: The optimizations are disabled.  (Set when initializing the
438       args_type structure in ldmain.c:main.  */
439  signed int disable_target_specific_optimizations;
440
441  /* Function callbacks.  */
442  const struct bfd_link_callbacks *callbacks;
443
444  /* Hash table handled by BFD.  */
445  struct bfd_link_hash_table *hash;
446
447  /* Hash table of symbols to keep.  This is NULL unless strip is
448     strip_some.  */
449  struct bfd_hash_table *keep_hash;
450
451  /* Hash table of symbols to report back via the notice callback.  If
452     this is NULL, and notice_all is FALSE, then no symbols are
453     reported back.  */
454  struct bfd_hash_table *notice_hash;
455
456  /* Hash table of symbols which are being wrapped (the --wrap linker
457     option).  If this is NULL, no symbols are being wrapped.  */
458  struct bfd_hash_table *wrap_hash;
459
460  /* Hash table of symbols which may be left unresolved during
461     a link.  If this is NULL, no symbols can be left unresolved.  */
462  struct bfd_hash_table *ignore_hash;
463
464  /* The output BFD.  */
465  bfd *output_bfd;
466
467  /* The list of input BFD's involved in the link.  These are chained
468     together via the link_next field.  */
469  bfd *input_bfds;
470  bfd **input_bfds_tail;
471
472  /* If a symbol should be created for each input BFD, this is section
473     where those symbols should be placed.  It must be a section in
474     the output BFD.  It may be NULL, in which case no such symbols
475     will be created.  This is to support CREATE_OBJECT_SYMBOLS in the
476     linker command language.  */
477  asection *create_object_symbols_section;
478
479  /* List of global symbol names that are starting points for marking
480     sections against garbage collection.  */
481  struct bfd_sym_chain *gc_sym_list;
482
483  /* If a base output file is wanted, then this points to it */
484  void *base_file;
485
486  /* The function to call when the executable or shared object is
487     loaded.  */
488  const char *init_function;
489
490  /* The function to call when the executable or shared object is
491     unloaded.  */
492  const char *fini_function;
493
494  /* Number of relaxation passes.  Usually only one relaxation pass
495     is needed.  But a backend can have as many relaxation passes as
496     necessary.  During bfd_relax_section call, it is set to the
497     current pass, starting from 0.  */
498  int relax_pass;
499
500  /* Number of relaxation trips.  This number is incremented every
501     time the relaxation pass is restarted due to a previous
502     relaxation returning true in *AGAIN.  */
503  int relax_trip;
504
505  /* Non-zero if auto-import thunks for DATA items in pei386 DLLs
506     should be generated/linked against.  Set to 1 if this feature
507     is explicitly requested by the user, -1 if enabled by default.  */
508  int pei386_auto_import;
509
510  /* Non-zero if runtime relocs for DATA items with non-zero addends
511     in pei386 DLLs should be generated.  Set to 1 if this feature
512     is explicitly requested by the user, -1 if enabled by default.  */
513  int pei386_runtime_pseudo_reloc;
514
515  /* How many spare .dynamic DT_NULL entries should be added?  */
516  unsigned int spare_dynamic_tags;
517
518  /* May be used to set DT_FLAGS for ELF. */
519  bfd_vma flags;
520
521  /* May be used to set DT_FLAGS_1 for ELF. */
522  bfd_vma flags_1;
523
524  /* Start and end of RELRO region.  */
525  bfd_vma relro_start, relro_end;
526
527  /* List of symbols should be dynamic.  */
528  struct bfd_elf_dynamic_list *dynamic_list;
529
530  /* The version information.  */
531  struct bfd_elf_version_tree *version_info;
532};
533
534/* This structures holds a set of callback functions.  These are called
535   by the BFD linker routines.  Except for the info functions, the first
536   argument to each callback function is the bfd_link_info structure
537   being used and each function returns a boolean value.  If the
538   function returns FALSE, then the BFD function which called it should
539   return with a failure indication.  */
540
541struct bfd_link_callbacks
542{
543  /* A function which is called when an object is added from an
544     archive.  ABFD is the archive element being added.  NAME is the
545     name of the symbol which caused the archive element to be pulled
546     in.  This function may set *SUBSBFD to point to an alternative
547     BFD from which symbols should in fact be added in place of the
548     original BFD's symbols.  */
549  bfd_boolean (*add_archive_element)
550    (struct bfd_link_info *, bfd *abfd, const char *name, bfd **subsbfd);
551  /* A function which is called when a symbol is found with multiple
552     definitions.  H is the symbol which is defined multiple times.
553     NBFD is the new BFD, NSEC is the new section, and NVAL is the new
554     value.  NSEC may be bfd_com_section or bfd_ind_section.  */
555  bfd_boolean (*multiple_definition)
556    (struct bfd_link_info *, struct bfd_link_hash_entry *h,
557     bfd *nbfd, asection *nsec, bfd_vma nval);
558  /* A function which is called when a common symbol is defined
559     multiple times.  H is the symbol appearing multiple times.
560     NBFD is the BFD of the new symbol.  NTYPE is the type of the new
561     symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or
562     bfd_link_hash_indirect.  If NTYPE is bfd_link_hash_common, NSIZE
563     is the size of the new symbol.  */
564  bfd_boolean (*multiple_common)
565    (struct bfd_link_info *, struct bfd_link_hash_entry *h,
566     bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize);
567  /* A function which is called to add a symbol to a set.  ENTRY is
568     the link hash table entry for the set itself (e.g.,
569     __CTOR_LIST__).  RELOC is the relocation to use for an entry in
570     the set when generating a relocatable file, and is also used to
571     get the size of the entry when generating an executable file.
572     ABFD, SEC and VALUE identify the value to add to the set.  */
573  bfd_boolean (*add_to_set)
574    (struct bfd_link_info *, struct bfd_link_hash_entry *entry,
575     bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value);
576  /* A function which is called when the name of a g++ constructor or
577     destructor is found.  This is only called by some object file
578     formats.  CONSTRUCTOR is TRUE for a constructor, FALSE for a
579     destructor.  This will use BFD_RELOC_CTOR when generating a
580     relocatable file.  NAME is the name of the symbol found.  ABFD,
581     SECTION and VALUE are the value of the symbol.  */
582  bfd_boolean (*constructor)
583    (struct bfd_link_info *, bfd_boolean constructor, const char *name,
584     bfd *abfd, asection *sec, bfd_vma value);
585  /* A function which is called to issue a linker warning.  For
586     example, this is called when there is a reference to a warning
587     symbol.  WARNING is the warning to be issued.  SYMBOL is the name
588     of the symbol which triggered the warning; it may be NULL if
589     there is none.  ABFD, SECTION and ADDRESS identify the location
590     which trigerred the warning; either ABFD or SECTION or both may
591     be NULL if the location is not known.  */
592  bfd_boolean (*warning)
593    (struct bfd_link_info *, const char *warning, const char *symbol,
594     bfd *abfd, asection *section, bfd_vma address);
595  /* A function which is called when a relocation is attempted against
596     an undefined symbol.  NAME is the symbol which is undefined.
597     ABFD, SECTION and ADDRESS identify the location from which the
598     reference is made. IS_FATAL indicates whether an undefined symbol is
599     a fatal error or not. In some cases SECTION may be NULL.  */
600  bfd_boolean (*undefined_symbol)
601    (struct bfd_link_info *, const char *name, bfd *abfd,
602     asection *section, bfd_vma address, bfd_boolean is_fatal);
603  /* A function which is called when a reloc overflow occurs. ENTRY is
604     the link hash table entry for the symbol the reloc is against.
605     NAME is the name of the local symbol or section the reloc is
606     against, RELOC_NAME is the name of the relocation, and ADDEND is
607     any addend that is used.  ABFD, SECTION and ADDRESS identify the
608     location at which the overflow occurs; if this is the result of a
609     bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
610     ABFD will be NULL.  */
611  bfd_boolean (*reloc_overflow)
612    (struct bfd_link_info *, struct bfd_link_hash_entry *entry,
613     const char *name, const char *reloc_name, bfd_vma addend,
614     bfd *abfd, asection *section, bfd_vma address);
615  /* A function which is called when a dangerous reloc is performed.
616     MESSAGE is an appropriate message.
617     ABFD, SECTION and ADDRESS identify the location at which the
618     problem occurred; if this is the result of a
619     bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
620     ABFD will be NULL.  */
621  bfd_boolean (*reloc_dangerous)
622    (struct bfd_link_info *, const char *message,
623     bfd *abfd, asection *section, bfd_vma address);
624  /* A function which is called when a reloc is found to be attached
625     to a symbol which is not being written out.  NAME is the name of
626     the symbol.  ABFD, SECTION and ADDRESS identify the location of
627     the reloc; if this is the result of a
628     bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
629     ABFD will be NULL.  */
630  bfd_boolean (*unattached_reloc)
631    (struct bfd_link_info *, const char *name,
632     bfd *abfd, asection *section, bfd_vma address);
633  /* A function which is called when a symbol in notice_hash is
634     defined or referenced.  H is the symbol.  ABFD, SECTION and
635     ADDRESS are the (new) value of the symbol.  If SECTION is
636     bfd_und_section, this is a reference.  FLAGS are the symbol
637     BSF_* flags.  STRING is the name of the symbol to indirect to if
638     the sym is indirect, or the warning string if a warning sym.  */
639  bfd_boolean (*notice)
640    (struct bfd_link_info *, struct bfd_link_hash_entry *h,
641     bfd *abfd, asection *section, bfd_vma address, flagword flags,
642     const char *string);
643  /* Error or warning link info message.  */
644  void (*einfo)
645    (const char *fmt, ...);
646  /* General link info message.  */
647  void (*info)
648    (const char *fmt, ...);
649  /* Message to be printed in linker map file.  */
650  void (*minfo)
651    (const char *fmt, ...);
652  /* This callback provides a chance for users of the BFD library to
653     override its decision about whether to place two adjacent sections
654     into the same segment.  */
655  bfd_boolean (*override_segment_assignment)
656    (struct bfd_link_info *, bfd * abfd,
657     asection * current_section, asection * previous_section,
658     bfd_boolean new_segment);
659};
660
661/* The linker builds link_order structures which tell the code how to
662   include input data in the output file.  */
663
664/* These are the types of link_order structures.  */
665
666enum bfd_link_order_type
667{
668  bfd_undefined_link_order,     /* Undefined.  */
669  bfd_indirect_link_order,      /* Built from a section.  */
670  bfd_data_link_order,          /* Set to explicit data.  */
671  bfd_section_reloc_link_order, /* Relocate against a section.  */
672  bfd_symbol_reloc_link_order   /* Relocate against a symbol.  */
673};
674
675/* This is the link_order structure itself.  These form a chain
676   attached to the output section whose contents they are describing.  */
677
678struct bfd_link_order
679{
680  /* Next link_order in chain.  */
681  struct bfd_link_order *next;
682  /* Type of link_order.  */
683  enum bfd_link_order_type type;
684  /* Offset within output section.  */
685  bfd_vma offset;
686  /* Size within output section.  */
687  bfd_size_type size;
688  /* Type specific information.  */
689  union
690    {
691      struct
692        {
693          /* Section to include.  If this is used, then
694             section->output_section must be the section the
695             link_order is attached to, section->output_offset must
696             equal the link_order offset field, and section->size
697             must equal the link_order size field.  Maybe these
698             restrictions should be relaxed someday.  */
699          asection *section;
700        } indirect;
701      struct
702        {
703          /* Size of contents, or zero when contents should be filled by
704             the architecture-dependent fill function.
705             A non-zero value allows filling of the output section
706             with an arbitrary repeated pattern.  */
707          unsigned int size;
708          /* Data to put into file.  */
709          bfd_byte *contents;
710        } data;
711      struct
712        {
713          /* Description of reloc to generate.  Used for
714             bfd_section_reloc_link_order and
715             bfd_symbol_reloc_link_order.  */
716          struct bfd_link_order_reloc *p;
717        } reloc;
718    } u;
719};
720
721/* A linker order of type bfd_section_reloc_link_order or
722   bfd_symbol_reloc_link_order means to create a reloc against a
723   section or symbol, respectively.  This is used to implement -Ur to
724   generate relocs for the constructor tables.  The
725   bfd_link_order_reloc structure describes the reloc that BFD should
726   create.  It is similar to a arelent, but I didn't use arelent
727   because the linker does not know anything about most symbols, and
728   any asymbol structure it creates will be partially meaningless.
729   This information could logically be in the bfd_link_order struct,
730   but I didn't want to waste the space since these types of relocs
731   are relatively rare.  */
732
733struct bfd_link_order_reloc
734{
735  /* Reloc type.  */
736  bfd_reloc_code_real_type reloc;
737
738  union
739    {
740      /* For type bfd_section_reloc_link_order, this is the section
741         the reloc should be against.  This must be a section in the
742         output BFD, not any of the input BFDs.  */
743      asection *section;
744      /* For type bfd_symbol_reloc_link_order, this is the name of the
745         symbol the reloc should be against.  */
746      const char *name;
747    } u;
748
749  /* Addend to use.  The object file should contain zero.  The BFD
750     backend is responsible for filling in the contents of the object
751     file correctly.  For some object file formats (e.g., COFF) the
752     addend must be stored into in the object file, and for some
753     (e.g., SPARC a.out) it is kept in the reloc.  */
754  bfd_vma addend;
755};
756
757/* Allocate a new link_order for a section.  */
758extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *);
759
760/* These structures are used to describe version information for the
761   ELF linker.  These structures could be manipulated entirely inside
762   BFD, but it would be a pain.  Instead, the regular linker sets up
763   these structures, and then passes them into BFD.  */
764
765/* Glob pattern for a version.  */
766
767struct bfd_elf_version_expr
768{
769  /* Next glob pattern for this version.  */
770  struct bfd_elf_version_expr *next;
771  /* Glob pattern.  */
772  const char *pattern;
773  /* Set if pattern is not a glob.  */
774  unsigned int literal : 1;
775  /* Defined by ".symver".  */
776  unsigned int symver : 1;
777  /* Defined by version script.  */
778  unsigned int script : 1;
779  /* Pattern type.  */
780#define BFD_ELF_VERSION_C_TYPE          1
781#define BFD_ELF_VERSION_CXX_TYPE        2
782#define BFD_ELF_VERSION_JAVA_TYPE       4
783  unsigned int mask : 3;
784};
785
786struct bfd_elf_version_expr_head
787{
788  /* List of all patterns, both wildcards and non-wildcards.  */
789  struct bfd_elf_version_expr *list;
790  /* Hash table for non-wildcards.  */
791  void *htab;
792  /* Remaining patterns.  */
793  struct bfd_elf_version_expr *remaining;
794  /* What kind of pattern types are present in list (bitmask).  */
795  unsigned int mask;
796};
797
798/* Version dependencies.  */
799
800struct bfd_elf_version_deps
801{
802  /* Next dependency for this version.  */
803  struct bfd_elf_version_deps *next;
804  /* The version which this version depends upon.  */
805  struct bfd_elf_version_tree *version_needed;
806};
807
808/* A node in the version tree.  */
809
810struct bfd_elf_version_tree
811{
812  /* Next version.  */
813  struct bfd_elf_version_tree *next;
814  /* Name of this version.  */
815  const char *name;
816  /* Version number.  */
817  unsigned int vernum;
818  /* Regular expressions for global symbols in this version.  */
819  struct bfd_elf_version_expr_head globals;
820  /* Regular expressions for local symbols in this version.  */
821  struct bfd_elf_version_expr_head locals;
822  /* List of versions which this version depends upon.  */
823  struct bfd_elf_version_deps *deps;
824  /* Index of the version name.  This is used within BFD.  */
825  unsigned int name_indx;
826  /* Whether this version tree was used.  This is used within BFD.  */
827  int used;
828  /* Matching hook.  */
829  struct bfd_elf_version_expr *(*match)
830    (struct bfd_elf_version_expr_head *head,
831     struct bfd_elf_version_expr *prev, const char *sym);
832};
833
834struct bfd_elf_dynamic_list
835{
836  struct bfd_elf_version_expr_head head;
837  struct bfd_elf_version_expr *(*match)
838    (struct bfd_elf_version_expr_head *head,
839     struct bfd_elf_version_expr *prev, const char *sym);
840};
841
842#endif
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