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[binutils.git] / bfd / syms.c
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1 /* Generic symbol-table support for the BFD library.
2 Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004, 2007
4 Free Software Foundation, Inc.
5 Written by Cygnus Support.
7 This file is part of BFD, the Binary File Descriptor library.
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.
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.
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. */
25 SECTION
26 Symbols
28 BFD tries to maintain as much symbol information as it can when
29 it moves information from file to file. BFD passes information
30 to applications though the <<asymbol>> structure. When the
31 application requests the symbol table, BFD reads the table in
32 the native form and translates parts of it into the internal
33 format. To maintain more than the information passed to
34 applications, some targets keep some information ``behind the
35 scenes'' in a structure only the particular back end knows
36 about. For example, the coff back end keeps the original
37 symbol table structure as well as the canonical structure when
38 a BFD is read in. On output, the coff back end can reconstruct
39 the output symbol table so that no information is lost, even
40 information unique to coff which BFD doesn't know or
41 understand. If a coff symbol table were read, but were written
42 through an a.out back end, all the coff specific information
43 would be lost. The symbol table of a BFD
44 is not necessarily read in until a canonicalize request is
45 made. Then the BFD back end fills in a table provided by the
46 application with pointers to the canonical information. To
47 output symbols, the application provides BFD with a table of
48 pointers to pointers to <<asymbol>>s. This allows applications
49 like the linker to output a symbol as it was read, since the ``behind
50 the scenes'' information will be still available.
51 @menu
52 @* Reading Symbols::
53 @* Writing Symbols::
54 @* Mini Symbols::
55 @* typedef asymbol::
56 @* symbol handling functions::
57 @end menu
59 INODE
60 Reading Symbols, Writing Symbols, Symbols, Symbols
61 SUBSECTION
62 Reading symbols
64 There are two stages to reading a symbol table from a BFD:
65 allocating storage, and the actual reading process. This is an
66 excerpt from an application which reads the symbol table:
68 | long storage_needed;
69 | asymbol **symbol_table;
70 | long number_of_symbols;
71 | long i;
73 | storage_needed = bfd_get_symtab_upper_bound (abfd);
75 | if (storage_needed < 0)
76 | FAIL
78 | if (storage_needed == 0)
79 | return;
81 | symbol_table = xmalloc (storage_needed);
82 | ...
83 | number_of_symbols =
84 | bfd_canonicalize_symtab (abfd, symbol_table);
86 | if (number_of_symbols < 0)
87 | FAIL
89 | for (i = 0; i < number_of_symbols; i++)
90 | process_symbol (symbol_table[i]);
92 All storage for the symbols themselves is in an objalloc
93 connected to the BFD; it is freed when the BFD is closed.
95 INODE
96 Writing Symbols, Mini Symbols, Reading Symbols, Symbols
97 SUBSECTION
98 Writing symbols
100 Writing of a symbol table is automatic when a BFD open for
101 writing is closed. The application attaches a vector of
102 pointers to pointers to symbols to the BFD being written, and
103 fills in the symbol count. The close and cleanup code reads
104 through the table provided and performs all the necessary
105 operations. The BFD output code must always be provided with an
106 ``owned'' symbol: one which has come from another BFD, or one
107 which has been created using <<bfd_make_empty_symbol>>. Here is an
108 example showing the creation of a symbol table with only one element:
110 | #include "bfd.h"
111 | int main (void)
113 | bfd *abfd;
114 | asymbol *ptrs[2];
115 | asymbol *new;
117 | abfd = bfd_openw ("foo","a.out-sunos-big");
118 | bfd_set_format (abfd, bfd_object);
119 | new = bfd_make_empty_symbol (abfd);
120 | new->name = "dummy_symbol";
121 | new->section = bfd_make_section_old_way (abfd, ".text");
122 | new->flags = BSF_GLOBAL;
123 | new->value = 0x12345;
125 | ptrs[0] = new;
126 | ptrs[1] = 0;
128 | bfd_set_symtab (abfd, ptrs, 1);
129 | bfd_close (abfd);
130 | return 0;
133 | ./makesym
134 | nm foo
135 | 00012345 A dummy_symbol
137 Many formats cannot represent arbitrary symbol information; for
138 instance, the <<a.out>> object format does not allow an
139 arbitrary number of sections. A symbol pointing to a section
140 which is not one of <<.text>>, <<.data>> or <<.bss>> cannot
141 be described.
143 INODE
144 Mini Symbols, typedef asymbol, Writing Symbols, Symbols
145 SUBSECTION
146 Mini Symbols
148 Mini symbols provide read-only access to the symbol table.
149 They use less memory space, but require more time to access.
150 They can be useful for tools like nm or objdump, which may
151 have to handle symbol tables of extremely large executables.
153 The <<bfd_read_minisymbols>> function will read the symbols
154 into memory in an internal form. It will return a <<void *>>
155 pointer to a block of memory, a symbol count, and the size of
156 each symbol. The pointer is allocated using <<malloc>>, and
157 should be freed by the caller when it is no longer needed.
159 The function <<bfd_minisymbol_to_symbol>> will take a pointer
160 to a minisymbol, and a pointer to a structure returned by
161 <<bfd_make_empty_symbol>>, and return a <<asymbol>> structure.
162 The return value may or may not be the same as the value from
163 <<bfd_make_empty_symbol>> which was passed in.
168 DOCDD
169 INODE
170 typedef asymbol, symbol handling functions, Mini Symbols, Symbols
174 SUBSECTION
175 typedef asymbol
177 An <<asymbol>> has the form:
182 CODE_FRAGMENT
185 .typedef struct bfd_symbol
187 . {* A pointer to the BFD which owns the symbol. This information
188 . is necessary so that a back end can work out what additional
189 . information (invisible to the application writer) is carried
190 . with the symbol.
192 . This field is *almost* redundant, since you can use section->owner
193 . instead, except that some symbols point to the global sections
194 . bfd_{abs,com,und}_section. This could be fixed by making
195 . these globals be per-bfd (or per-target-flavor). FIXME. *}
196 . struct bfd *the_bfd; {* Use bfd_asymbol_bfd(sym) to access this field. *}
198 . {* The text of the symbol. The name is left alone, and not copied; the
199 . application may not alter it. *}
200 . const char *name;
202 . {* The value of the symbol. This really should be a union of a
203 . numeric value with a pointer, since some flags indicate that
204 . a pointer to another symbol is stored here. *}
205 . symvalue value;
207 . {* Attributes of a symbol. *}
208 .#define BSF_NO_FLAGS 0x00
210 . {* The symbol has local scope; <<static>> in <<C>>. The value
211 . is the offset into the section of the data. *}
212 .#define BSF_LOCAL 0x01
214 . {* The symbol has global scope; initialized data in <<C>>. The
215 . value is the offset into the section of the data. *}
216 .#define BSF_GLOBAL 0x02
218 . {* The symbol has global scope and is exported. The value is
219 . the offset into the section of the data. *}
220 .#define BSF_EXPORT BSF_GLOBAL {* No real difference. *}
222 . {* A normal C symbol would be one of:
223 . <<BSF_LOCAL>>, <<BSF_FORT_COMM>>, <<BSF_UNDEFINED>> or
224 . <<BSF_GLOBAL>>. *}
226 . {* The symbol is a debugging record. The value has an arbitrary
227 . meaning, unless BSF_DEBUGGING_RELOC is also set. *}
228 .#define BSF_DEBUGGING 0x08
230 . {* The symbol denotes a function entry point. Used in ELF,
231 . perhaps others someday. *}
232 .#define BSF_FUNCTION 0x10
234 . {* Used by the linker. *}
235 .#define BSF_KEEP 0x20
236 .#define BSF_KEEP_G 0x40
238 . {* A weak global symbol, overridable without warnings by
239 . a regular global symbol of the same name. *}
240 .#define BSF_WEAK 0x80
242 . {* This symbol was created to point to a section, e.g. ELF's
243 . STT_SECTION symbols. *}
244 .#define BSF_SECTION_SYM 0x100
246 . {* The symbol used to be a common symbol, but now it is
247 . allocated. *}
248 .#define BSF_OLD_COMMON 0x200
250 . {* The default value for common data. *}
251 .#define BFD_FORT_COMM_DEFAULT_VALUE 0
253 . {* In some files the type of a symbol sometimes alters its
254 . location in an output file - ie in coff a <<ISFCN>> symbol
255 . which is also <<C_EXT>> symbol appears where it was
256 . declared and not at the end of a section. This bit is set
257 . by the target BFD part to convey this information. *}
258 .#define BSF_NOT_AT_END 0x400
260 . {* Signal that the symbol is the label of constructor section. *}
261 .#define BSF_CONSTRUCTOR 0x800
263 . {* Signal that the symbol is a warning symbol. The name is a
264 . warning. The name of the next symbol is the one to warn about;
265 . if a reference is made to a symbol with the same name as the next
266 . symbol, a warning is issued by the linker. *}
267 .#define BSF_WARNING 0x1000
269 . {* Signal that the symbol is indirect. This symbol is an indirect
270 . pointer to the symbol with the same name as the next symbol. *}
271 .#define BSF_INDIRECT 0x2000
273 . {* BSF_FILE marks symbols that contain a file name. This is used
274 . for ELF STT_FILE symbols. *}
275 .#define BSF_FILE 0x4000
277 . {* Symbol is from dynamic linking information. *}
278 .#define BSF_DYNAMIC 0x8000
280 . {* The symbol denotes a data object. Used in ELF, and perhaps
281 . others someday. *}
282 .#define BSF_OBJECT 0x10000
284 . {* This symbol is a debugging symbol. The value is the offset
285 . into the section of the data. BSF_DEBUGGING should be set
286 . as well. *}
287 .#define BSF_DEBUGGING_RELOC 0x20000
289 . {* This symbol is thread local. Used in ELF. *}
290 .#define BSF_THREAD_LOCAL 0x40000
292 . {* This symbol represents a complex relocation expression,
293 . with the expression tree serialized in the symbol name. *}
294 .#define BSF_RELC 0x80000
296 . {* This symbol represents a signed complex relocation expression,
297 . with the expression tree serialized in the symbol name. *}
298 .#define BSF_SRELC 0x100000
300 . {* This symbol was created by bfd_get_synthetic_symtab. *}
301 .#define BSF_SYNTHETIC 0x200000
303 . flagword flags;
305 . {* A pointer to the section to which this symbol is
306 . relative. This will always be non NULL, there are special
307 . sections for undefined and absolute symbols. *}
308 . struct bfd_section *section;
310 . {* Back end special data. *}
311 . union
313 . void *p;
314 . bfd_vma i;
316 . udata;
318 .asymbol;
322 #include "sysdep.h"
323 #include "bfd.h"
324 #include "libbfd.h"
325 #include "safe-ctype.h"
326 #include "bfdlink.h"
327 #include "aout/stab_gnu.h"
330 DOCDD
331 INODE
332 symbol handling functions, , typedef asymbol, Symbols
333 SUBSECTION
334 Symbol handling functions
338 FUNCTION
339 bfd_get_symtab_upper_bound
341 DESCRIPTION
342 Return the number of bytes required to store a vector of pointers
343 to <<asymbols>> for all the symbols in the BFD @var{abfd},
344 including a terminal NULL pointer. If there are no symbols in
345 the BFD, then return 0. If an error occurs, return -1.
347 .#define bfd_get_symtab_upper_bound(abfd) \
348 . BFD_SEND (abfd, _bfd_get_symtab_upper_bound, (abfd))
353 FUNCTION
354 bfd_is_local_label
356 SYNOPSIS
357 bfd_boolean bfd_is_local_label (bfd *abfd, asymbol *sym);
359 DESCRIPTION
360 Return TRUE if the given symbol @var{sym} in the BFD @var{abfd} is
361 a compiler generated local label, else return FALSE.
364 bfd_boolean
365 bfd_is_local_label (bfd *abfd, asymbol *sym)
367 /* The BSF_SECTION_SYM check is needed for IA-64, where every label that
368 starts with '.' is local. This would accidentally catch section names
369 if we didn't reject them here. */
370 if ((sym->flags & (BSF_GLOBAL | BSF_WEAK | BSF_FILE | BSF_SECTION_SYM)) != 0)
371 return FALSE;
372 if (sym->name == NULL)
373 return FALSE;
374 return bfd_is_local_label_name (abfd, sym->name);
378 FUNCTION
379 bfd_is_local_label_name
381 SYNOPSIS
382 bfd_boolean bfd_is_local_label_name (bfd *abfd, const char *name);
384 DESCRIPTION
385 Return TRUE if a symbol with the name @var{name} in the BFD
386 @var{abfd} is a compiler generated local label, else return
387 FALSE. This just checks whether the name has the form of a
388 local label.
390 .#define bfd_is_local_label_name(abfd, name) \
391 . BFD_SEND (abfd, _bfd_is_local_label_name, (abfd, name))
396 FUNCTION
397 bfd_is_target_special_symbol
399 SYNOPSIS
400 bfd_boolean bfd_is_target_special_symbol (bfd *abfd, asymbol *sym);
402 DESCRIPTION
403 Return TRUE iff a symbol @var{sym} in the BFD @var{abfd} is something
404 special to the particular target represented by the BFD. Such symbols
405 should normally not be mentioned to the user.
407 .#define bfd_is_target_special_symbol(abfd, sym) \
408 . BFD_SEND (abfd, _bfd_is_target_special_symbol, (abfd, sym))
413 FUNCTION
414 bfd_canonicalize_symtab
416 DESCRIPTION
417 Read the symbols from the BFD @var{abfd}, and fills in
418 the vector @var{location} with pointers to the symbols and
419 a trailing NULL.
420 Return the actual number of symbol pointers, not
421 including the NULL.
423 .#define bfd_canonicalize_symtab(abfd, location) \
424 . BFD_SEND (abfd, _bfd_canonicalize_symtab, (abfd, location))
429 FUNCTION
430 bfd_set_symtab
432 SYNOPSIS
433 bfd_boolean bfd_set_symtab
434 (bfd *abfd, asymbol **location, unsigned int count);
436 DESCRIPTION
437 Arrange that when the output BFD @var{abfd} is closed,
438 the table @var{location} of @var{count} pointers to symbols
439 will be written.
442 bfd_boolean
443 bfd_set_symtab (bfd *abfd, asymbol **location, unsigned int symcount)
445 if (abfd->format != bfd_object || bfd_read_p (abfd))
447 bfd_set_error (bfd_error_invalid_operation);
448 return FALSE;
451 bfd_get_outsymbols (abfd) = location;
452 bfd_get_symcount (abfd) = symcount;
453 return TRUE;
457 FUNCTION
458 bfd_print_symbol_vandf
460 SYNOPSIS
461 void bfd_print_symbol_vandf (bfd *abfd, void *file, asymbol *symbol);
463 DESCRIPTION
464 Print the value and flags of the @var{symbol} supplied to the
465 stream @var{file}.
467 void
468 bfd_print_symbol_vandf (bfd *abfd, void *arg, asymbol *symbol)
470 FILE *file = arg;
472 flagword type = symbol->flags;
474 if (symbol->section != NULL)
475 bfd_fprintf_vma (abfd, file, symbol->value + symbol->section->vma);
476 else
477 bfd_fprintf_vma (abfd, file, symbol->value);
479 /* This presumes that a symbol can not be both BSF_DEBUGGING and
480 BSF_DYNAMIC, nor more than one of BSF_FUNCTION, BSF_FILE, and
481 BSF_OBJECT. */
482 fprintf (file, " %c%c%c%c%c%c%c",
483 ((type & BSF_LOCAL)
484 ? (type & BSF_GLOBAL) ? '!' : 'l'
485 : (type & BSF_GLOBAL) ? 'g' : ' '),
486 (type & BSF_WEAK) ? 'w' : ' ',
487 (type & BSF_CONSTRUCTOR) ? 'C' : ' ',
488 (type & BSF_WARNING) ? 'W' : ' ',
489 (type & BSF_INDIRECT) ? 'I' : ' ',
490 (type & BSF_DEBUGGING) ? 'd' : (type & BSF_DYNAMIC) ? 'D' : ' ',
491 ((type & BSF_FUNCTION)
492 ? 'F'
493 : ((type & BSF_FILE)
494 ? 'f'
495 : ((type & BSF_OBJECT) ? 'O' : ' '))));
499 FUNCTION
500 bfd_make_empty_symbol
502 DESCRIPTION
503 Create a new <<asymbol>> structure for the BFD @var{abfd}
504 and return a pointer to it.
506 This routine is necessary because each back end has private
507 information surrounding the <<asymbol>>. Building your own
508 <<asymbol>> and pointing to it will not create the private
509 information, and will cause problems later on.
511 .#define bfd_make_empty_symbol(abfd) \
512 . BFD_SEND (abfd, _bfd_make_empty_symbol, (abfd))
517 FUNCTION
518 _bfd_generic_make_empty_symbol
520 SYNOPSIS
521 asymbol *_bfd_generic_make_empty_symbol (bfd *);
523 DESCRIPTION
524 Create a new <<asymbol>> structure for the BFD @var{abfd}
525 and return a pointer to it. Used by core file routines,
526 binary back-end and anywhere else where no private info
527 is needed.
530 asymbol *
531 _bfd_generic_make_empty_symbol (bfd *abfd)
533 bfd_size_type amt = sizeof (asymbol);
534 asymbol *new = bfd_zalloc (abfd, amt);
535 if (new)
536 new->the_bfd = abfd;
537 return new;
541 FUNCTION
542 bfd_make_debug_symbol
544 DESCRIPTION
545 Create a new <<asymbol>> structure for the BFD @var{abfd},
546 to be used as a debugging symbol. Further details of its use have
547 yet to be worked out.
549 .#define bfd_make_debug_symbol(abfd,ptr,size) \
550 . BFD_SEND (abfd, _bfd_make_debug_symbol, (abfd, ptr, size))
554 struct section_to_type
556 const char *section;
557 char type;
560 /* Map section names to POSIX/BSD single-character symbol types.
561 This table is probably incomplete. It is sorted for convenience of
562 adding entries. Since it is so short, a linear search is used. */
563 static const struct section_to_type stt[] =
565 {".bss", 'b'},
566 {"code", 't'}, /* MRI .text */
567 {".data", 'd'},
568 {"*DEBUG*", 'N'},
569 {".debug", 'N'}, /* MSVC's .debug (non-standard debug syms) */
570 {".drectve", 'i'}, /* MSVC's .drective section */
571 {".edata", 'e'}, /* MSVC's .edata (export) section */
572 {".fini", 't'}, /* ELF fini section */
573 {".idata", 'i'}, /* MSVC's .idata (import) section */
574 {".init", 't'}, /* ELF init section */
575 {".pdata", 'p'}, /* MSVC's .pdata (stack unwind) section */
576 {".rdata", 'r'}, /* Read only data. */
577 {".rodata", 'r'}, /* Read only data. */
578 {".sbss", 's'}, /* Small BSS (uninitialized data). */
579 {".scommon", 'c'}, /* Small common. */
580 {".sdata", 'g'}, /* Small initialized data. */
581 {".text", 't'},
582 {"vars", 'd'}, /* MRI .data */
583 {"zerovars", 'b'}, /* MRI .bss */
584 {0, 0}
587 /* Return the single-character symbol type corresponding to
588 section S, or '?' for an unknown COFF section.
590 Check for any leading string which matches, so .text5 returns
591 't' as well as .text */
593 static char
594 coff_section_type (const char *s)
596 const struct section_to_type *t;
598 for (t = &stt[0]; t->section; t++)
599 if (!strncmp (s, t->section, strlen (t->section)))
600 return t->type;
602 return '?';
605 /* Return the single-character symbol type corresponding to section
606 SECTION, or '?' for an unknown section. This uses section flags to
607 identify sections.
609 FIXME These types are unhandled: c, i, e, p. If we handled these also,
610 we could perhaps obsolete coff_section_type. */
612 static char
613 decode_section_type (const struct bfd_section *section)
615 if (section->flags & SEC_CODE)
616 return 't';
617 if (section->flags & SEC_DATA)
619 if (section->flags & SEC_READONLY)
620 return 'r';
621 else if (section->flags & SEC_SMALL_DATA)
622 return 'g';
623 else
624 return 'd';
626 if ((section->flags & SEC_HAS_CONTENTS) == 0)
628 if (section->flags & SEC_SMALL_DATA)
629 return 's';
630 else
631 return 'b';
633 if (section->flags & SEC_DEBUGGING)
634 return 'N';
635 if ((section->flags & SEC_HAS_CONTENTS) && (section->flags & SEC_READONLY))
636 return 'n';
638 return '?';
642 FUNCTION
643 bfd_decode_symclass
645 DESCRIPTION
646 Return a character corresponding to the symbol
647 class of @var{symbol}, or '?' for an unknown class.
649 SYNOPSIS
650 int bfd_decode_symclass (asymbol *symbol);
653 bfd_decode_symclass (asymbol *symbol)
655 char c;
657 if (symbol->section && bfd_is_com_section (symbol->section))
658 return 'C';
659 if (bfd_is_und_section (symbol->section))
661 if (symbol->flags & BSF_WEAK)
663 /* If weak, determine if it's specifically an object
664 or non-object weak. */
665 if (symbol->flags & BSF_OBJECT)
666 return 'v';
667 else
668 return 'w';
670 else
671 return 'U';
673 if (bfd_is_ind_section (symbol->section))
674 return 'I';
675 if (symbol->flags & BSF_WEAK)
677 /* If weak, determine if it's specifically an object
678 or non-object weak. */
679 if (symbol->flags & BSF_OBJECT)
680 return 'V';
681 else
682 return 'W';
684 if (!(symbol->flags & (BSF_GLOBAL | BSF_LOCAL)))
685 return '?';
687 if (bfd_is_abs_section (symbol->section))
688 c = 'a';
689 else if (symbol->section)
691 c = coff_section_type (symbol->section->name);
692 if (c == '?')
693 c = decode_section_type (symbol->section);
695 else
696 return '?';
697 if (symbol->flags & BSF_GLOBAL)
698 c = TOUPPER (c);
699 return c;
701 /* We don't have to handle these cases just yet, but we will soon:
702 N_SETV: 'v';
703 N_SETA: 'l';
704 N_SETT: 'x';
705 N_SETD: 'z';
706 N_SETB: 's';
707 N_INDR: 'i';
712 FUNCTION
713 bfd_is_undefined_symclass
715 DESCRIPTION
716 Returns non-zero if the class symbol returned by
717 bfd_decode_symclass represents an undefined symbol.
718 Returns zero otherwise.
720 SYNOPSIS
721 bfd_boolean bfd_is_undefined_symclass (int symclass);
724 bfd_boolean
725 bfd_is_undefined_symclass (int symclass)
727 return symclass == 'U' || symclass == 'w' || symclass == 'v';
731 FUNCTION
732 bfd_symbol_info
734 DESCRIPTION
735 Fill in the basic info about symbol that nm needs.
736 Additional info may be added by the back-ends after
737 calling this function.
739 SYNOPSIS
740 void bfd_symbol_info (asymbol *symbol, symbol_info *ret);
743 void
744 bfd_symbol_info (asymbol *symbol, symbol_info *ret)
746 ret->type = bfd_decode_symclass (symbol);
748 if (bfd_is_undefined_symclass (ret->type))
749 ret->value = 0;
750 else
751 ret->value = symbol->value + symbol->section->vma;
753 ret->name = symbol->name;
757 FUNCTION
758 bfd_copy_private_symbol_data
760 SYNOPSIS
761 bfd_boolean bfd_copy_private_symbol_data
762 (bfd *ibfd, asymbol *isym, bfd *obfd, asymbol *osym);
764 DESCRIPTION
765 Copy private symbol information from @var{isym} in the BFD
766 @var{ibfd} to the symbol @var{osym} in the BFD @var{obfd}.
767 Return <<TRUE>> on success, <<FALSE>> on error. Possible error
768 returns are:
770 o <<bfd_error_no_memory>> -
771 Not enough memory exists to create private data for @var{osec}.
773 .#define bfd_copy_private_symbol_data(ibfd, isymbol, obfd, osymbol) \
774 . BFD_SEND (obfd, _bfd_copy_private_symbol_data, \
775 . (ibfd, isymbol, obfd, osymbol))
779 /* The generic version of the function which returns mini symbols.
780 This is used when the backend does not provide a more efficient
781 version. It just uses BFD asymbol structures as mini symbols. */
783 long
784 _bfd_generic_read_minisymbols (bfd *abfd,
785 bfd_boolean dynamic,
786 void **minisymsp,
787 unsigned int *sizep)
789 long storage;
790 asymbol **syms = NULL;
791 long symcount;
793 if (dynamic)
794 storage = bfd_get_dynamic_symtab_upper_bound (abfd);
795 else
796 storage = bfd_get_symtab_upper_bound (abfd);
797 if (storage < 0)
798 goto error_return;
799 if (storage == 0)
800 return 0;
802 syms = bfd_malloc (storage);
803 if (syms == NULL)
804 goto error_return;
806 if (dynamic)
807 symcount = bfd_canonicalize_dynamic_symtab (abfd, syms);
808 else
809 symcount = bfd_canonicalize_symtab (abfd, syms);
810 if (symcount < 0)
811 goto error_return;
813 *minisymsp = syms;
814 *sizep = sizeof (asymbol *);
815 return symcount;
817 error_return:
818 bfd_set_error (bfd_error_no_symbols);
819 if (syms != NULL)
820 free (syms);
821 return -1;
824 /* The generic version of the function which converts a minisymbol to
825 an asymbol. We don't worry about the sym argument we are passed;
826 we just return the asymbol the minisymbol points to. */
828 asymbol *
829 _bfd_generic_minisymbol_to_symbol (bfd *abfd ATTRIBUTE_UNUSED,
830 bfd_boolean dynamic ATTRIBUTE_UNUSED,
831 const void *minisym,
832 asymbol *sym ATTRIBUTE_UNUSED)
834 return *(asymbol **) minisym;
837 /* Look through stabs debugging information in .stab and .stabstr
838 sections to find the source file and line closest to a desired
839 location. This is used by COFF and ELF targets. It sets *pfound
840 to TRUE if it finds some information. The *pinfo field is used to
841 pass cached information in and out of this routine; this first time
842 the routine is called for a BFD, *pinfo should be NULL. The value
843 placed in *pinfo should be saved with the BFD, and passed back each
844 time this function is called. */
846 /* We use a cache by default. */
848 #define ENABLE_CACHING
850 /* We keep an array of indexentry structures to record where in the
851 stabs section we should look to find line number information for a
852 particular address. */
854 struct indexentry
856 bfd_vma val;
857 bfd_byte *stab;
858 bfd_byte *str;
859 char *directory_name;
860 char *file_name;
861 char *function_name;
864 /* Compare two indexentry structures. This is called via qsort. */
866 static int
867 cmpindexentry (const void *a, const void *b)
869 const struct indexentry *contestantA = a;
870 const struct indexentry *contestantB = b;
872 if (contestantA->val < contestantB->val)
873 return -1;
874 else if (contestantA->val > contestantB->val)
875 return 1;
876 else
877 return 0;
880 /* A pointer to this structure is stored in *pinfo. */
882 struct stab_find_info
884 /* The .stab section. */
885 asection *stabsec;
886 /* The .stabstr section. */
887 asection *strsec;
888 /* The contents of the .stab section. */
889 bfd_byte *stabs;
890 /* The contents of the .stabstr section. */
891 bfd_byte *strs;
893 /* A table that indexes stabs by memory address. */
894 struct indexentry *indextable;
895 /* The number of entries in indextable. */
896 int indextablesize;
898 #ifdef ENABLE_CACHING
899 /* Cached values to restart quickly. */
900 struct indexentry *cached_indexentry;
901 bfd_vma cached_offset;
902 bfd_byte *cached_stab;
903 char *cached_file_name;
904 #endif
906 /* Saved ptr to malloc'ed filename. */
907 char *filename;
910 bfd_boolean
911 _bfd_stab_section_find_nearest_line (bfd *abfd,
912 asymbol **symbols,
913 asection *section,
914 bfd_vma offset,
915 bfd_boolean *pfound,
916 const char **pfilename,
917 const char **pfnname,
918 unsigned int *pline,
919 void **pinfo)
921 struct stab_find_info *info;
922 bfd_size_type stabsize, strsize;
923 bfd_byte *stab, *str;
924 bfd_byte *last_stab = NULL;
925 bfd_size_type stroff;
926 struct indexentry *indexentry;
927 char *file_name;
928 char *directory_name;
929 int saw_fun;
930 bfd_boolean saw_line, saw_func;
932 *pfound = FALSE;
933 *pfilename = bfd_get_filename (abfd);
934 *pfnname = NULL;
935 *pline = 0;
937 /* Stabs entries use a 12 byte format:
938 4 byte string table index
939 1 byte stab type
940 1 byte stab other field
941 2 byte stab desc field
942 4 byte stab value
943 FIXME: This will have to change for a 64 bit object format.
945 The stabs symbols are divided into compilation units. For the
946 first entry in each unit, the type of 0, the value is the length
947 of the string table for this unit, and the desc field is the
948 number of stabs symbols for this unit. */
950 #define STRDXOFF (0)
951 #define TYPEOFF (4)
952 #define OTHEROFF (5)
953 #define DESCOFF (6)
954 #define VALOFF (8)
955 #define STABSIZE (12)
957 info = *pinfo;
958 if (info != NULL)
960 if (info->stabsec == NULL || info->strsec == NULL)
962 /* No stabs debugging information. */
963 return TRUE;
966 stabsize = (info->stabsec->rawsize
967 ? info->stabsec->rawsize
968 : info->stabsec->size);
969 strsize = (info->strsec->rawsize
970 ? info->strsec->rawsize
971 : info->strsec->size);
973 else
975 long reloc_size, reloc_count;
976 arelent **reloc_vector;
977 int i;
978 char *name;
979 char *function_name;
980 bfd_size_type amt = sizeof *info;
982 info = bfd_zalloc (abfd, amt);
983 if (info == NULL)
984 return FALSE;
986 /* FIXME: When using the linker --split-by-file or
987 --split-by-reloc options, it is possible for the .stab and
988 .stabstr sections to be split. We should handle that. */
990 info->stabsec = bfd_get_section_by_name (abfd, ".stab");
991 info->strsec = bfd_get_section_by_name (abfd, ".stabstr");
993 if (info->stabsec == NULL || info->strsec == NULL)
995 /* Try SOM section names. */
996 info->stabsec = bfd_get_section_by_name (abfd, "$GDB_SYMBOLS$");
997 info->strsec = bfd_get_section_by_name (abfd, "$GDB_STRINGS$");
999 if (info->stabsec == NULL || info->strsec == NULL)
1001 /* No stabs debugging information. Set *pinfo so that we
1002 can return quickly in the info != NULL case above. */
1003 *pinfo = info;
1004 return TRUE;
1008 stabsize = (info->stabsec->rawsize
1009 ? info->stabsec->rawsize
1010 : info->stabsec->size);
1011 strsize = (info->strsec->rawsize
1012 ? info->strsec->rawsize
1013 : info->strsec->size);
1015 info->stabs = bfd_alloc (abfd, stabsize);
1016 info->strs = bfd_alloc (abfd, strsize);
1017 if (info->stabs == NULL || info->strs == NULL)
1018 return FALSE;
1020 if (! bfd_get_section_contents (abfd, info->stabsec, info->stabs,
1021 0, stabsize)
1022 || ! bfd_get_section_contents (abfd, info->strsec, info->strs,
1023 0, strsize))
1024 return FALSE;
1026 /* If this is a relocatable object file, we have to relocate
1027 the entries in .stab. This should always be simple 32 bit
1028 relocations against symbols defined in this object file, so
1029 this should be no big deal. */
1030 reloc_size = bfd_get_reloc_upper_bound (abfd, info->stabsec);
1031 if (reloc_size < 0)
1032 return FALSE;
1033 reloc_vector = bfd_malloc (reloc_size);
1034 if (reloc_vector == NULL && reloc_size != 0)
1035 return FALSE;
1036 reloc_count = bfd_canonicalize_reloc (abfd, info->stabsec, reloc_vector,
1037 symbols);
1038 if (reloc_count < 0)
1040 if (reloc_vector != NULL)
1041 free (reloc_vector);
1042 return FALSE;
1044 if (reloc_count > 0)
1046 arelent **pr;
1048 for (pr = reloc_vector; *pr != NULL; pr++)
1050 arelent *r;
1051 unsigned long val;
1052 asymbol *sym;
1054 r = *pr;
1055 /* Ignore R_*_NONE relocs. */
1056 if (r->howto->dst_mask == 0)
1057 continue;
1059 if (r->howto->rightshift != 0
1060 || r->howto->size != 2
1061 || r->howto->bitsize != 32
1062 || r->howto->pc_relative
1063 || r->howto->bitpos != 0
1064 || r->howto->dst_mask != 0xffffffff)
1066 (*_bfd_error_handler)
1067 (_("Unsupported .stab relocation"));
1068 bfd_set_error (bfd_error_invalid_operation);
1069 if (reloc_vector != NULL)
1070 free (reloc_vector);
1071 return FALSE;
1074 val = bfd_get_32 (abfd, info->stabs + r->address);
1075 val &= r->howto->src_mask;
1076 sym = *r->sym_ptr_ptr;
1077 val += sym->value + sym->section->vma + r->addend;
1078 bfd_put_32 (abfd, (bfd_vma) val, info->stabs + r->address);
1082 if (reloc_vector != NULL)
1083 free (reloc_vector);
1085 /* First time through this function, build a table matching
1086 function VM addresses to stabs, then sort based on starting
1087 VM address. Do this in two passes: once to count how many
1088 table entries we'll need, and a second to actually build the
1089 table. */
1091 info->indextablesize = 0;
1092 saw_fun = 1;
1093 for (stab = info->stabs; stab < info->stabs + stabsize; stab += STABSIZE)
1095 if (stab[TYPEOFF] == (bfd_byte) N_SO)
1097 /* N_SO with null name indicates EOF */
1098 if (bfd_get_32 (abfd, stab + STRDXOFF) == 0)
1099 continue;
1101 /* if we did not see a function def, leave space for one. */
1102 if (saw_fun == 0)
1103 ++info->indextablesize;
1105 saw_fun = 0;
1107 /* two N_SO's in a row is a filename and directory. Skip */
1108 if (stab + STABSIZE < info->stabs + stabsize
1109 && *(stab + STABSIZE + TYPEOFF) == (bfd_byte) N_SO)
1111 stab += STABSIZE;
1114 else if (stab[TYPEOFF] == (bfd_byte) N_FUN)
1116 saw_fun = 1;
1117 ++info->indextablesize;
1121 if (saw_fun == 0)
1122 ++info->indextablesize;
1124 if (info->indextablesize == 0)
1125 return TRUE;
1126 ++info->indextablesize;
1128 amt = info->indextablesize;
1129 amt *= sizeof (struct indexentry);
1130 info->indextable = bfd_alloc (abfd, amt);
1131 if (info->indextable == NULL)
1132 return FALSE;
1134 file_name = NULL;
1135 directory_name = NULL;
1136 saw_fun = 1;
1138 for (i = 0, stroff = 0, stab = info->stabs, str = info->strs;
1139 i < info->indextablesize && stab < info->stabs + stabsize;
1140 stab += STABSIZE)
1142 switch (stab[TYPEOFF])
1144 case 0:
1145 /* This is the first entry in a compilation unit. */
1146 if ((bfd_size_type) ((info->strs + strsize) - str) < stroff)
1147 break;
1148 str += stroff;
1149 stroff = bfd_get_32 (abfd, stab + VALOFF);
1150 break;
1152 case N_SO:
1153 /* The main file name. */
1155 /* The following code creates a new indextable entry with
1156 a NULL function name if there were no N_FUNs in a file.
1157 Note that a N_SO without a file name is an EOF and
1158 there could be 2 N_SO following it with the new filename
1159 and directory. */
1160 if (saw_fun == 0)
1162 info->indextable[i].val = bfd_get_32 (abfd, last_stab + VALOFF);
1163 info->indextable[i].stab = last_stab;
1164 info->indextable[i].str = str;
1165 info->indextable[i].directory_name = directory_name;
1166 info->indextable[i].file_name = file_name;
1167 info->indextable[i].function_name = NULL;
1168 ++i;
1170 saw_fun = 0;
1172 file_name = (char *) str + bfd_get_32 (abfd, stab + STRDXOFF);
1173 if (*file_name == '\0')
1175 directory_name = NULL;
1176 file_name = NULL;
1177 saw_fun = 1;
1179 else
1181 last_stab = stab;
1182 if (stab + STABSIZE >= info->stabs + stabsize
1183 || *(stab + STABSIZE + TYPEOFF) != (bfd_byte) N_SO)
1185 directory_name = NULL;
1187 else
1189 /* Two consecutive N_SOs are a directory and a
1190 file name. */
1191 stab += STABSIZE;
1192 directory_name = file_name;
1193 file_name = ((char *) str
1194 + bfd_get_32 (abfd, stab + STRDXOFF));
1197 break;
1199 case N_SOL:
1200 /* The name of an include file. */
1201 file_name = (char *) str + bfd_get_32 (abfd, stab + STRDXOFF);
1202 break;
1204 case N_FUN:
1205 /* A function name. */
1206 saw_fun = 1;
1207 name = (char *) str + bfd_get_32 (abfd, stab + STRDXOFF);
1209 if (*name == '\0')
1210 name = NULL;
1212 function_name = name;
1214 if (name == NULL)
1215 continue;
1217 info->indextable[i].val = bfd_get_32 (abfd, stab + VALOFF);
1218 info->indextable[i].stab = stab;
1219 info->indextable[i].str = str;
1220 info->indextable[i].directory_name = directory_name;
1221 info->indextable[i].file_name = file_name;
1222 info->indextable[i].function_name = function_name;
1223 ++i;
1224 break;
1228 if (saw_fun == 0)
1230 info->indextable[i].val = bfd_get_32 (abfd, last_stab + VALOFF);
1231 info->indextable[i].stab = last_stab;
1232 info->indextable[i].str = str;
1233 info->indextable[i].directory_name = directory_name;
1234 info->indextable[i].file_name = file_name;
1235 info->indextable[i].function_name = NULL;
1236 ++i;
1239 info->indextable[i].val = (bfd_vma) -1;
1240 info->indextable[i].stab = info->stabs + stabsize;
1241 info->indextable[i].str = str;
1242 info->indextable[i].directory_name = NULL;
1243 info->indextable[i].file_name = NULL;
1244 info->indextable[i].function_name = NULL;
1245 ++i;
1247 info->indextablesize = i;
1248 qsort (info->indextable, (size_t) i, sizeof (struct indexentry),
1249 cmpindexentry);
1251 *pinfo = info;
1254 /* We are passed a section relative offset. The offsets in the
1255 stabs information are absolute. */
1256 offset += bfd_get_section_vma (abfd, section);
1258 #ifdef ENABLE_CACHING
1259 if (info->cached_indexentry != NULL
1260 && offset >= info->cached_offset
1261 && offset < (info->cached_indexentry + 1)->val)
1263 stab = info->cached_stab;
1264 indexentry = info->cached_indexentry;
1265 file_name = info->cached_file_name;
1267 else
1268 #endif
1270 long low, high;
1271 long mid = -1;
1273 /* Cache non-existent or invalid. Do binary search on
1274 indextable. */
1275 indexentry = NULL;
1277 low = 0;
1278 high = info->indextablesize - 1;
1279 while (low != high)
1281 mid = (high + low) / 2;
1282 if (offset >= info->indextable[mid].val
1283 && offset < info->indextable[mid + 1].val)
1285 indexentry = &info->indextable[mid];
1286 break;
1289 if (info->indextable[mid].val > offset)
1290 high = mid;
1291 else
1292 low = mid + 1;
1295 if (indexentry == NULL)
1296 return TRUE;
1298 stab = indexentry->stab + STABSIZE;
1299 file_name = indexentry->file_name;
1302 directory_name = indexentry->directory_name;
1303 str = indexentry->str;
1305 saw_line = FALSE;
1306 saw_func = FALSE;
1307 for (; stab < (indexentry+1)->stab; stab += STABSIZE)
1309 bfd_boolean done;
1310 bfd_vma val;
1312 done = FALSE;
1314 switch (stab[TYPEOFF])
1316 case N_SOL:
1317 /* The name of an include file. */
1318 val = bfd_get_32 (abfd, stab + VALOFF);
1319 if (val <= offset)
1321 file_name = (char *) str + bfd_get_32 (abfd, stab + STRDXOFF);
1322 *pline = 0;
1324 break;
1326 case N_SLINE:
1327 case N_DSLINE:
1328 case N_BSLINE:
1329 /* A line number. If the function was specified, then the value
1330 is relative to the start of the function. Otherwise, the
1331 value is an absolute address. */
1332 val = ((indexentry->function_name ? indexentry->val : 0)
1333 + bfd_get_32 (abfd, stab + VALOFF));
1334 /* If this line starts before our desired offset, or if it's
1335 the first line we've been able to find, use it. The
1336 !saw_line check works around a bug in GCC 2.95.3, which emits
1337 the first N_SLINE late. */
1338 if (!saw_line || val <= offset)
1340 *pline = bfd_get_16 (abfd, stab + DESCOFF);
1342 #ifdef ENABLE_CACHING
1343 info->cached_stab = stab;
1344 info->cached_offset = val;
1345 info->cached_file_name = file_name;
1346 info->cached_indexentry = indexentry;
1347 #endif
1349 if (val > offset)
1350 done = TRUE;
1351 saw_line = TRUE;
1352 break;
1354 case N_FUN:
1355 case N_SO:
1356 if (saw_func || saw_line)
1357 done = TRUE;
1358 saw_func = TRUE;
1359 break;
1362 if (done)
1363 break;
1366 *pfound = TRUE;
1368 if (file_name == NULL || IS_ABSOLUTE_PATH (file_name)
1369 || directory_name == NULL)
1370 *pfilename = file_name;
1371 else
1373 size_t dirlen;
1375 dirlen = strlen (directory_name);
1376 if (info->filename == NULL
1377 || strncmp (info->filename, directory_name, dirlen) != 0
1378 || strcmp (info->filename + dirlen, file_name) != 0)
1380 size_t len;
1382 if (info->filename != NULL)
1383 free (info->filename);
1384 len = strlen (file_name) + 1;
1385 info->filename = bfd_malloc (dirlen + len);
1386 if (info->filename == NULL)
1387 return FALSE;
1388 memcpy (info->filename, directory_name, dirlen);
1389 memcpy (info->filename + dirlen, file_name, len);
1392 *pfilename = info->filename;
1395 if (indexentry->function_name != NULL)
1397 char *s;
1399 /* This will typically be something like main:F(0,1), so we want
1400 to clobber the colon. It's OK to change the name, since the
1401 string is in our own local storage anyhow. */
1402 s = strchr (indexentry->function_name, ':');
1403 if (s != NULL)
1404 *s = '\0';
1406 *pfnname = indexentry->function_name;
1409 return TRUE;