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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 . flagword flags;
302 . {* A pointer to the section to which this symbol is
303 . relative. This will always be non NULL, there are special
304 . sections for undefined and absolute symbols. *}
305 . struct bfd_section *section;
307 . {* Back end special data. *}
308 . union
310 . void *p;
311 . bfd_vma i;
313 . udata;
315 .asymbol;
319 #include "sysdep.h"
320 #include "bfd.h"
321 #include "libbfd.h"
322 #include "safe-ctype.h"
323 #include "bfdlink.h"
324 #include "aout/stab_gnu.h"
327 DOCDD
328 INODE
329 symbol handling functions, , typedef asymbol, Symbols
330 SUBSECTION
331 Symbol handling functions
335 FUNCTION
336 bfd_get_symtab_upper_bound
338 DESCRIPTION
339 Return the number of bytes required to store a vector of pointers
340 to <<asymbols>> for all the symbols in the BFD @var{abfd},
341 including a terminal NULL pointer. If there are no symbols in
342 the BFD, then return 0. If an error occurs, return -1.
344 .#define bfd_get_symtab_upper_bound(abfd) \
345 . BFD_SEND (abfd, _bfd_get_symtab_upper_bound, (abfd))
350 FUNCTION
351 bfd_is_local_label
353 SYNOPSIS
354 bfd_boolean bfd_is_local_label (bfd *abfd, asymbol *sym);
356 DESCRIPTION
357 Return TRUE if the given symbol @var{sym} in the BFD @var{abfd} is
358 a compiler generated local label, else return FALSE.
361 bfd_boolean
362 bfd_is_local_label (bfd *abfd, asymbol *sym)
364 /* The BSF_SECTION_SYM check is needed for IA-64, where every label that
365 starts with '.' is local. This would accidentally catch section names
366 if we didn't reject them here. */
367 if ((sym->flags & (BSF_GLOBAL | BSF_WEAK | BSF_FILE | BSF_SECTION_SYM)) != 0)
368 return FALSE;
369 if (sym->name == NULL)
370 return FALSE;
371 return bfd_is_local_label_name (abfd, sym->name);
375 FUNCTION
376 bfd_is_local_label_name
378 SYNOPSIS
379 bfd_boolean bfd_is_local_label_name (bfd *abfd, const char *name);
381 DESCRIPTION
382 Return TRUE if a symbol with the name @var{name} in the BFD
383 @var{abfd} is a compiler generated local label, else return
384 FALSE. This just checks whether the name has the form of a
385 local label.
387 .#define bfd_is_local_label_name(abfd, name) \
388 . BFD_SEND (abfd, _bfd_is_local_label_name, (abfd, name))
393 FUNCTION
394 bfd_is_target_special_symbol
396 SYNOPSIS
397 bfd_boolean bfd_is_target_special_symbol (bfd *abfd, asymbol *sym);
399 DESCRIPTION
400 Return TRUE iff a symbol @var{sym} in the BFD @var{abfd} is something
401 special to the particular target represented by the BFD. Such symbols
402 should normally not be mentioned to the user.
404 .#define bfd_is_target_special_symbol(abfd, sym) \
405 . BFD_SEND (abfd, _bfd_is_target_special_symbol, (abfd, sym))
410 FUNCTION
411 bfd_canonicalize_symtab
413 DESCRIPTION
414 Read the symbols from the BFD @var{abfd}, and fills in
415 the vector @var{location} with pointers to the symbols and
416 a trailing NULL.
417 Return the actual number of symbol pointers, not
418 including the NULL.
420 .#define bfd_canonicalize_symtab(abfd, location) \
421 . BFD_SEND (abfd, _bfd_canonicalize_symtab, (abfd, location))
426 FUNCTION
427 bfd_set_symtab
429 SYNOPSIS
430 bfd_boolean bfd_set_symtab
431 (bfd *abfd, asymbol **location, unsigned int count);
433 DESCRIPTION
434 Arrange that when the output BFD @var{abfd} is closed,
435 the table @var{location} of @var{count} pointers to symbols
436 will be written.
439 bfd_boolean
440 bfd_set_symtab (bfd *abfd, asymbol **location, unsigned int symcount)
442 if (abfd->format != bfd_object || bfd_read_p (abfd))
444 bfd_set_error (bfd_error_invalid_operation);
445 return FALSE;
448 bfd_get_outsymbols (abfd) = location;
449 bfd_get_symcount (abfd) = symcount;
450 return TRUE;
454 FUNCTION
455 bfd_print_symbol_vandf
457 SYNOPSIS
458 void bfd_print_symbol_vandf (bfd *abfd, void *file, asymbol *symbol);
460 DESCRIPTION
461 Print the value and flags of the @var{symbol} supplied to the
462 stream @var{file}.
464 void
465 bfd_print_symbol_vandf (bfd *abfd, void *arg, asymbol *symbol)
467 FILE *file = arg;
469 flagword type = symbol->flags;
471 if (symbol->section != NULL)
472 bfd_fprintf_vma (abfd, file, symbol->value + symbol->section->vma);
473 else
474 bfd_fprintf_vma (abfd, file, symbol->value);
476 /* This presumes that a symbol can not be both BSF_DEBUGGING and
477 BSF_DYNAMIC, nor more than one of BSF_FUNCTION, BSF_FILE, and
478 BSF_OBJECT. */
479 fprintf (file, " %c%c%c%c%c%c%c",
480 ((type & BSF_LOCAL)
481 ? (type & BSF_GLOBAL) ? '!' : 'l'
482 : (type & BSF_GLOBAL) ? 'g' : ' '),
483 (type & BSF_WEAK) ? 'w' : ' ',
484 (type & BSF_CONSTRUCTOR) ? 'C' : ' ',
485 (type & BSF_WARNING) ? 'W' : ' ',
486 (type & BSF_INDIRECT) ? 'I' : ' ',
487 (type & BSF_DEBUGGING) ? 'd' : (type & BSF_DYNAMIC) ? 'D' : ' ',
488 ((type & BSF_FUNCTION)
489 ? 'F'
490 : ((type & BSF_FILE)
491 ? 'f'
492 : ((type & BSF_OBJECT) ? 'O' : ' '))));
496 FUNCTION
497 bfd_make_empty_symbol
499 DESCRIPTION
500 Create a new <<asymbol>> structure for the BFD @var{abfd}
501 and return a pointer to it.
503 This routine is necessary because each back end has private
504 information surrounding the <<asymbol>>. Building your own
505 <<asymbol>> and pointing to it will not create the private
506 information, and will cause problems later on.
508 .#define bfd_make_empty_symbol(abfd) \
509 . BFD_SEND (abfd, _bfd_make_empty_symbol, (abfd))
514 FUNCTION
515 _bfd_generic_make_empty_symbol
517 SYNOPSIS
518 asymbol *_bfd_generic_make_empty_symbol (bfd *);
520 DESCRIPTION
521 Create a new <<asymbol>> structure for the BFD @var{abfd}
522 and return a pointer to it. Used by core file routines,
523 binary back-end and anywhere else where no private info
524 is needed.
527 asymbol *
528 _bfd_generic_make_empty_symbol (bfd *abfd)
530 bfd_size_type amt = sizeof (asymbol);
531 asymbol *new = bfd_zalloc (abfd, amt);
532 if (new)
533 new->the_bfd = abfd;
534 return new;
538 FUNCTION
539 bfd_make_debug_symbol
541 DESCRIPTION
542 Create a new <<asymbol>> structure for the BFD @var{abfd},
543 to be used as a debugging symbol. Further details of its use have
544 yet to be worked out.
546 .#define bfd_make_debug_symbol(abfd,ptr,size) \
547 . BFD_SEND (abfd, _bfd_make_debug_symbol, (abfd, ptr, size))
551 struct section_to_type
553 const char *section;
554 char type;
557 /* Map section names to POSIX/BSD single-character symbol types.
558 This table is probably incomplete. It is sorted for convenience of
559 adding entries. Since it is so short, a linear search is used. */
560 static const struct section_to_type stt[] =
562 {".bss", 'b'},
563 {"code", 't'}, /* MRI .text */
564 {".data", 'd'},
565 {"*DEBUG*", 'N'},
566 {".debug", 'N'}, /* MSVC's .debug (non-standard debug syms) */
567 {".drectve", 'i'}, /* MSVC's .drective section */
568 {".edata", 'e'}, /* MSVC's .edata (export) section */
569 {".fini", 't'}, /* ELF fini section */
570 {".idata", 'i'}, /* MSVC's .idata (import) section */
571 {".init", 't'}, /* ELF init section */
572 {".pdata", 'p'}, /* MSVC's .pdata (stack unwind) section */
573 {".rdata", 'r'}, /* Read only data. */
574 {".rodata", 'r'}, /* Read only data. */
575 {".sbss", 's'}, /* Small BSS (uninitialized data). */
576 {".scommon", 'c'}, /* Small common. */
577 {".sdata", 'g'}, /* Small initialized data. */
578 {".text", 't'},
579 {"vars", 'd'}, /* MRI .data */
580 {"zerovars", 'b'}, /* MRI .bss */
581 {0, 0}
584 /* Return the single-character symbol type corresponding to
585 section S, or '?' for an unknown COFF section.
587 Check for any leading string which matches, so .text5 returns
588 't' as well as .text */
590 static char
591 coff_section_type (const char *s)
593 const struct section_to_type *t;
595 for (t = &stt[0]; t->section; t++)
596 if (!strncmp (s, t->section, strlen (t->section)))
597 return t->type;
599 return '?';
602 /* Return the single-character symbol type corresponding to section
603 SECTION, or '?' for an unknown section. This uses section flags to
604 identify sections.
606 FIXME These types are unhandled: c, i, e, p. If we handled these also,
607 we could perhaps obsolete coff_section_type. */
609 static char
610 decode_section_type (const struct bfd_section *section)
612 if (section->flags & SEC_CODE)
613 return 't';
614 if (section->flags & SEC_DATA)
616 if (section->flags & SEC_READONLY)
617 return 'r';
618 else if (section->flags & SEC_SMALL_DATA)
619 return 'g';
620 else
621 return 'd';
623 if ((section->flags & SEC_HAS_CONTENTS) == 0)
625 if (section->flags & SEC_SMALL_DATA)
626 return 's';
627 else
628 return 'b';
630 if (section->flags & SEC_DEBUGGING)
631 return 'N';
632 if ((section->flags & SEC_HAS_CONTENTS) && (section->flags & SEC_READONLY))
633 return 'n';
635 return '?';
639 FUNCTION
640 bfd_decode_symclass
642 DESCRIPTION
643 Return a character corresponding to the symbol
644 class of @var{symbol}, or '?' for an unknown class.
646 SYNOPSIS
647 int bfd_decode_symclass (asymbol *symbol);
650 bfd_decode_symclass (asymbol *symbol)
652 char c;
654 if (symbol->section && bfd_is_com_section (symbol->section))
655 return 'C';
656 if (bfd_is_und_section (symbol->section))
658 if (symbol->flags & BSF_WEAK)
660 /* If weak, determine if it's specifically an object
661 or non-object weak. */
662 if (symbol->flags & BSF_OBJECT)
663 return 'v';
664 else
665 return 'w';
667 else
668 return 'U';
670 if (bfd_is_ind_section (symbol->section))
671 return 'I';
672 if (symbol->flags & BSF_WEAK)
674 /* If weak, determine if it's specifically an object
675 or non-object weak. */
676 if (symbol->flags & BSF_OBJECT)
677 return 'V';
678 else
679 return 'W';
681 if (!(symbol->flags & (BSF_GLOBAL | BSF_LOCAL)))
682 return '?';
684 if (bfd_is_abs_section (symbol->section))
685 c = 'a';
686 else if (symbol->section)
688 c = coff_section_type (symbol->section->name);
689 if (c == '?')
690 c = decode_section_type (symbol->section);
692 else
693 return '?';
694 if (symbol->flags & BSF_GLOBAL)
695 c = TOUPPER (c);
696 return c;
698 /* We don't have to handle these cases just yet, but we will soon:
699 N_SETV: 'v';
700 N_SETA: 'l';
701 N_SETT: 'x';
702 N_SETD: 'z';
703 N_SETB: 's';
704 N_INDR: 'i';
709 FUNCTION
710 bfd_is_undefined_symclass
712 DESCRIPTION
713 Returns non-zero if the class symbol returned by
714 bfd_decode_symclass represents an undefined symbol.
715 Returns zero otherwise.
717 SYNOPSIS
718 bfd_boolean bfd_is_undefined_symclass (int symclass);
721 bfd_boolean
722 bfd_is_undefined_symclass (int symclass)
724 return symclass == 'U' || symclass == 'w' || symclass == 'v';
728 FUNCTION
729 bfd_symbol_info
731 DESCRIPTION
732 Fill in the basic info about symbol that nm needs.
733 Additional info may be added by the back-ends after
734 calling this function.
736 SYNOPSIS
737 void bfd_symbol_info (asymbol *symbol, symbol_info *ret);
740 void
741 bfd_symbol_info (asymbol *symbol, symbol_info *ret)
743 ret->type = bfd_decode_symclass (symbol);
745 if (bfd_is_undefined_symclass (ret->type))
746 ret->value = 0;
747 else
748 ret->value = symbol->value + symbol->section->vma;
750 ret->name = symbol->name;
754 FUNCTION
755 bfd_copy_private_symbol_data
757 SYNOPSIS
758 bfd_boolean bfd_copy_private_symbol_data
759 (bfd *ibfd, asymbol *isym, bfd *obfd, asymbol *osym);
761 DESCRIPTION
762 Copy private symbol information from @var{isym} in the BFD
763 @var{ibfd} to the symbol @var{osym} in the BFD @var{obfd}.
764 Return <<TRUE>> on success, <<FALSE>> on error. Possible error
765 returns are:
767 o <<bfd_error_no_memory>> -
768 Not enough memory exists to create private data for @var{osec}.
770 .#define bfd_copy_private_symbol_data(ibfd, isymbol, obfd, osymbol) \
771 . BFD_SEND (obfd, _bfd_copy_private_symbol_data, \
772 . (ibfd, isymbol, obfd, osymbol))
776 /* The generic version of the function which returns mini symbols.
777 This is used when the backend does not provide a more efficient
778 version. It just uses BFD asymbol structures as mini symbols. */
780 long
781 _bfd_generic_read_minisymbols (bfd *abfd,
782 bfd_boolean dynamic,
783 void **minisymsp,
784 unsigned int *sizep)
786 long storage;
787 asymbol **syms = NULL;
788 long symcount;
790 if (dynamic)
791 storage = bfd_get_dynamic_symtab_upper_bound (abfd);
792 else
793 storage = bfd_get_symtab_upper_bound (abfd);
794 if (storage < 0)
795 goto error_return;
796 if (storage == 0)
797 return 0;
799 syms = bfd_malloc (storage);
800 if (syms == NULL)
801 goto error_return;
803 if (dynamic)
804 symcount = bfd_canonicalize_dynamic_symtab (abfd, syms);
805 else
806 symcount = bfd_canonicalize_symtab (abfd, syms);
807 if (symcount < 0)
808 goto error_return;
810 *minisymsp = syms;
811 *sizep = sizeof (asymbol *);
812 return symcount;
814 error_return:
815 bfd_set_error (bfd_error_no_symbols);
816 if (syms != NULL)
817 free (syms);
818 return -1;
821 /* The generic version of the function which converts a minisymbol to
822 an asymbol. We don't worry about the sym argument we are passed;
823 we just return the asymbol the minisymbol points to. */
825 asymbol *
826 _bfd_generic_minisymbol_to_symbol (bfd *abfd ATTRIBUTE_UNUSED,
827 bfd_boolean dynamic ATTRIBUTE_UNUSED,
828 const void *minisym,
829 asymbol *sym ATTRIBUTE_UNUSED)
831 return *(asymbol **) minisym;
834 /* Look through stabs debugging information in .stab and .stabstr
835 sections to find the source file and line closest to a desired
836 location. This is used by COFF and ELF targets. It sets *pfound
837 to TRUE if it finds some information. The *pinfo field is used to
838 pass cached information in and out of this routine; this first time
839 the routine is called for a BFD, *pinfo should be NULL. The value
840 placed in *pinfo should be saved with the BFD, and passed back each
841 time this function is called. */
843 /* We use a cache by default. */
845 #define ENABLE_CACHING
847 /* We keep an array of indexentry structures to record where in the
848 stabs section we should look to find line number information for a
849 particular address. */
851 struct indexentry
853 bfd_vma val;
854 bfd_byte *stab;
855 bfd_byte *str;
856 char *directory_name;
857 char *file_name;
858 char *function_name;
861 /* Compare two indexentry structures. This is called via qsort. */
863 static int
864 cmpindexentry (const void *a, const void *b)
866 const struct indexentry *contestantA = a;
867 const struct indexentry *contestantB = b;
869 if (contestantA->val < contestantB->val)
870 return -1;
871 else if (contestantA->val > contestantB->val)
872 return 1;
873 else
874 return 0;
877 /* A pointer to this structure is stored in *pinfo. */
879 struct stab_find_info
881 /* The .stab section. */
882 asection *stabsec;
883 /* The .stabstr section. */
884 asection *strsec;
885 /* The contents of the .stab section. */
886 bfd_byte *stabs;
887 /* The contents of the .stabstr section. */
888 bfd_byte *strs;
890 /* A table that indexes stabs by memory address. */
891 struct indexentry *indextable;
892 /* The number of entries in indextable. */
893 int indextablesize;
895 #ifdef ENABLE_CACHING
896 /* Cached values to restart quickly. */
897 struct indexentry *cached_indexentry;
898 bfd_vma cached_offset;
899 bfd_byte *cached_stab;
900 char *cached_file_name;
901 #endif
903 /* Saved ptr to malloc'ed filename. */
904 char *filename;
907 bfd_boolean
908 _bfd_stab_section_find_nearest_line (bfd *abfd,
909 asymbol **symbols,
910 asection *section,
911 bfd_vma offset,
912 bfd_boolean *pfound,
913 const char **pfilename,
914 const char **pfnname,
915 unsigned int *pline,
916 void **pinfo)
918 struct stab_find_info *info;
919 bfd_size_type stabsize, strsize;
920 bfd_byte *stab, *str;
921 bfd_byte *last_stab = NULL;
922 bfd_size_type stroff;
923 struct indexentry *indexentry;
924 char *file_name;
925 char *directory_name;
926 int saw_fun;
927 bfd_boolean saw_line, saw_func;
929 *pfound = FALSE;
930 *pfilename = bfd_get_filename (abfd);
931 *pfnname = NULL;
932 *pline = 0;
934 /* Stabs entries use a 12 byte format:
935 4 byte string table index
936 1 byte stab type
937 1 byte stab other field
938 2 byte stab desc field
939 4 byte stab value
940 FIXME: This will have to change for a 64 bit object format.
942 The stabs symbols are divided into compilation units. For the
943 first entry in each unit, the type of 0, the value is the length
944 of the string table for this unit, and the desc field is the
945 number of stabs symbols for this unit. */
947 #define STRDXOFF (0)
948 #define TYPEOFF (4)
949 #define OTHEROFF (5)
950 #define DESCOFF (6)
951 #define VALOFF (8)
952 #define STABSIZE (12)
954 info = *pinfo;
955 if (info != NULL)
957 if (info->stabsec == NULL || info->strsec == NULL)
959 /* No stabs debugging information. */
960 return TRUE;
963 stabsize = (info->stabsec->rawsize
964 ? info->stabsec->rawsize
965 : info->stabsec->size);
966 strsize = (info->strsec->rawsize
967 ? info->strsec->rawsize
968 : info->strsec->size);
970 else
972 long reloc_size, reloc_count;
973 arelent **reloc_vector;
974 int i;
975 char *name;
976 char *function_name;
977 bfd_size_type amt = sizeof *info;
979 info = bfd_zalloc (abfd, amt);
980 if (info == NULL)
981 return FALSE;
983 /* FIXME: When using the linker --split-by-file or
984 --split-by-reloc options, it is possible for the .stab and
985 .stabstr sections to be split. We should handle that. */
987 info->stabsec = bfd_get_section_by_name (abfd, ".stab");
988 info->strsec = bfd_get_section_by_name (abfd, ".stabstr");
990 if (info->stabsec == NULL || info->strsec == NULL)
992 /* No stabs debugging information. Set *pinfo so that we
993 can return quickly in the info != NULL case above. */
994 *pinfo = info;
995 return TRUE;
998 stabsize = (info->stabsec->rawsize
999 ? info->stabsec->rawsize
1000 : info->stabsec->size);
1001 strsize = (info->strsec->rawsize
1002 ? info->strsec->rawsize
1003 : info->strsec->size);
1005 info->stabs = bfd_alloc (abfd, stabsize);
1006 info->strs = bfd_alloc (abfd, strsize);
1007 if (info->stabs == NULL || info->strs == NULL)
1008 return FALSE;
1010 if (! bfd_get_section_contents (abfd, info->stabsec, info->stabs,
1011 0, stabsize)
1012 || ! bfd_get_section_contents (abfd, info->strsec, info->strs,
1013 0, strsize))
1014 return FALSE;
1016 /* If this is a relocatable object file, we have to relocate
1017 the entries in .stab. This should always be simple 32 bit
1018 relocations against symbols defined in this object file, so
1019 this should be no big deal. */
1020 reloc_size = bfd_get_reloc_upper_bound (abfd, info->stabsec);
1021 if (reloc_size < 0)
1022 return FALSE;
1023 reloc_vector = bfd_malloc (reloc_size);
1024 if (reloc_vector == NULL && reloc_size != 0)
1025 return FALSE;
1026 reloc_count = bfd_canonicalize_reloc (abfd, info->stabsec, reloc_vector,
1027 symbols);
1028 if (reloc_count < 0)
1030 if (reloc_vector != NULL)
1031 free (reloc_vector);
1032 return FALSE;
1034 if (reloc_count > 0)
1036 arelent **pr;
1038 for (pr = reloc_vector; *pr != NULL; pr++)
1040 arelent *r;
1041 unsigned long val;
1042 asymbol *sym;
1044 r = *pr;
1045 /* Ignore R_*_NONE relocs. */
1046 if (r->howto->dst_mask == 0)
1047 continue;
1049 if (r->howto->rightshift != 0
1050 || r->howto->size != 2
1051 || r->howto->bitsize != 32
1052 || r->howto->pc_relative
1053 || r->howto->bitpos != 0
1054 || r->howto->dst_mask != 0xffffffff)
1056 (*_bfd_error_handler)
1057 (_("Unsupported .stab relocation"));
1058 bfd_set_error (bfd_error_invalid_operation);
1059 if (reloc_vector != NULL)
1060 free (reloc_vector);
1061 return FALSE;
1064 val = bfd_get_32 (abfd, info->stabs + r->address);
1065 val &= r->howto->src_mask;
1066 sym = *r->sym_ptr_ptr;
1067 val += sym->value + sym->section->vma + r->addend;
1068 bfd_put_32 (abfd, (bfd_vma) val, info->stabs + r->address);
1072 if (reloc_vector != NULL)
1073 free (reloc_vector);
1075 /* First time through this function, build a table matching
1076 function VM addresses to stabs, then sort based on starting
1077 VM address. Do this in two passes: once to count how many
1078 table entries we'll need, and a second to actually build the
1079 table. */
1081 info->indextablesize = 0;
1082 saw_fun = 1;
1083 for (stab = info->stabs; stab < info->stabs + stabsize; stab += STABSIZE)
1085 if (stab[TYPEOFF] == (bfd_byte) N_SO)
1087 /* N_SO with null name indicates EOF */
1088 if (bfd_get_32 (abfd, stab + STRDXOFF) == 0)
1089 continue;
1091 /* if we did not see a function def, leave space for one. */
1092 if (saw_fun == 0)
1093 ++info->indextablesize;
1095 saw_fun = 0;
1097 /* two N_SO's in a row is a filename and directory. Skip */
1098 if (stab + STABSIZE < info->stabs + stabsize
1099 && *(stab + STABSIZE + TYPEOFF) == (bfd_byte) N_SO)
1101 stab += STABSIZE;
1104 else if (stab[TYPEOFF] == (bfd_byte) N_FUN)
1106 saw_fun = 1;
1107 ++info->indextablesize;
1111 if (saw_fun == 0)
1112 ++info->indextablesize;
1114 if (info->indextablesize == 0)
1115 return TRUE;
1116 ++info->indextablesize;
1118 amt = info->indextablesize;
1119 amt *= sizeof (struct indexentry);
1120 info->indextable = bfd_alloc (abfd, amt);
1121 if (info->indextable == NULL)
1122 return FALSE;
1124 file_name = NULL;
1125 directory_name = NULL;
1126 saw_fun = 1;
1128 for (i = 0, stroff = 0, stab = info->stabs, str = info->strs;
1129 i < info->indextablesize && stab < info->stabs + stabsize;
1130 stab += STABSIZE)
1132 switch (stab[TYPEOFF])
1134 case 0:
1135 /* This is the first entry in a compilation unit. */
1136 if ((bfd_size_type) ((info->strs + strsize) - str) < stroff)
1137 break;
1138 str += stroff;
1139 stroff = bfd_get_32 (abfd, stab + VALOFF);
1140 break;
1142 case N_SO:
1143 /* The main file name. */
1145 /* The following code creates a new indextable entry with
1146 a NULL function name if there were no N_FUNs in a file.
1147 Note that a N_SO without a file name is an EOF and
1148 there could be 2 N_SO following it with the new filename
1149 and directory. */
1150 if (saw_fun == 0)
1152 info->indextable[i].val = bfd_get_32 (abfd, last_stab + VALOFF);
1153 info->indextable[i].stab = last_stab;
1154 info->indextable[i].str = str;
1155 info->indextable[i].directory_name = directory_name;
1156 info->indextable[i].file_name = file_name;
1157 info->indextable[i].function_name = NULL;
1158 ++i;
1160 saw_fun = 0;
1162 file_name = (char *) str + bfd_get_32 (abfd, stab + STRDXOFF);
1163 if (*file_name == '\0')
1165 directory_name = NULL;
1166 file_name = NULL;
1167 saw_fun = 1;
1169 else
1171 last_stab = stab;
1172 if (stab + STABSIZE >= info->stabs + stabsize
1173 || *(stab + STABSIZE + TYPEOFF) != (bfd_byte) N_SO)
1175 directory_name = NULL;
1177 else
1179 /* Two consecutive N_SOs are a directory and a
1180 file name. */
1181 stab += STABSIZE;
1182 directory_name = file_name;
1183 file_name = ((char *) str
1184 + bfd_get_32 (abfd, stab + STRDXOFF));
1187 break;
1189 case N_SOL:
1190 /* The name of an include file. */
1191 file_name = (char *) str + bfd_get_32 (abfd, stab + STRDXOFF);
1192 break;
1194 case N_FUN:
1195 /* A function name. */
1196 saw_fun = 1;
1197 name = (char *) str + bfd_get_32 (abfd, stab + STRDXOFF);
1199 if (*name == '\0')
1200 name = NULL;
1202 function_name = name;
1204 if (name == NULL)
1205 continue;
1207 info->indextable[i].val = bfd_get_32 (abfd, stab + VALOFF);
1208 info->indextable[i].stab = stab;
1209 info->indextable[i].str = str;
1210 info->indextable[i].directory_name = directory_name;
1211 info->indextable[i].file_name = file_name;
1212 info->indextable[i].function_name = function_name;
1213 ++i;
1214 break;
1218 if (saw_fun == 0)
1220 info->indextable[i].val = bfd_get_32 (abfd, last_stab + VALOFF);
1221 info->indextable[i].stab = last_stab;
1222 info->indextable[i].str = str;
1223 info->indextable[i].directory_name = directory_name;
1224 info->indextable[i].file_name = file_name;
1225 info->indextable[i].function_name = NULL;
1226 ++i;
1229 info->indextable[i].val = (bfd_vma) -1;
1230 info->indextable[i].stab = info->stabs + stabsize;
1231 info->indextable[i].str = str;
1232 info->indextable[i].directory_name = NULL;
1233 info->indextable[i].file_name = NULL;
1234 info->indextable[i].function_name = NULL;
1235 ++i;
1237 info->indextablesize = i;
1238 qsort (info->indextable, (size_t) i, sizeof (struct indexentry),
1239 cmpindexentry);
1241 *pinfo = info;
1244 /* We are passed a section relative offset. The offsets in the
1245 stabs information are absolute. */
1246 offset += bfd_get_section_vma (abfd, section);
1248 #ifdef ENABLE_CACHING
1249 if (info->cached_indexentry != NULL
1250 && offset >= info->cached_offset
1251 && offset < (info->cached_indexentry + 1)->val)
1253 stab = info->cached_stab;
1254 indexentry = info->cached_indexentry;
1255 file_name = info->cached_file_name;
1257 else
1258 #endif
1260 long low, high;
1261 long mid = -1;
1263 /* Cache non-existent or invalid. Do binary search on
1264 indextable. */
1265 indexentry = NULL;
1267 low = 0;
1268 high = info->indextablesize - 1;
1269 while (low != high)
1271 mid = (high + low) / 2;
1272 if (offset >= info->indextable[mid].val
1273 && offset < info->indextable[mid + 1].val)
1275 indexentry = &info->indextable[mid];
1276 break;
1279 if (info->indextable[mid].val > offset)
1280 high = mid;
1281 else
1282 low = mid + 1;
1285 if (indexentry == NULL)
1286 return TRUE;
1288 stab = indexentry->stab + STABSIZE;
1289 file_name = indexentry->file_name;
1292 directory_name = indexentry->directory_name;
1293 str = indexentry->str;
1295 saw_line = FALSE;
1296 saw_func = FALSE;
1297 for (; stab < (indexentry+1)->stab; stab += STABSIZE)
1299 bfd_boolean done;
1300 bfd_vma val;
1302 done = FALSE;
1304 switch (stab[TYPEOFF])
1306 case N_SOL:
1307 /* The name of an include file. */
1308 val = bfd_get_32 (abfd, stab + VALOFF);
1309 if (val <= offset)
1311 file_name = (char *) str + bfd_get_32 (abfd, stab + STRDXOFF);
1312 *pline = 0;
1314 break;
1316 case N_SLINE:
1317 case N_DSLINE:
1318 case N_BSLINE:
1319 /* A line number. If the function was specified, then the value
1320 is relative to the start of the function. Otherwise, the
1321 value is an absolute address. */
1322 val = ((indexentry->function_name ? indexentry->val : 0)
1323 + bfd_get_32 (abfd, stab + VALOFF));
1324 /* If this line starts before our desired offset, or if it's
1325 the first line we've been able to find, use it. The
1326 !saw_line check works around a bug in GCC 2.95.3, which emits
1327 the first N_SLINE late. */
1328 if (!saw_line || val <= offset)
1330 *pline = bfd_get_16 (abfd, stab + DESCOFF);
1332 #ifdef ENABLE_CACHING
1333 info->cached_stab = stab;
1334 info->cached_offset = val;
1335 info->cached_file_name = file_name;
1336 info->cached_indexentry = indexentry;
1337 #endif
1339 if (val > offset)
1340 done = TRUE;
1341 saw_line = TRUE;
1342 break;
1344 case N_FUN:
1345 case N_SO:
1346 if (saw_func || saw_line)
1347 done = TRUE;
1348 saw_func = TRUE;
1349 break;
1352 if (done)
1353 break;
1356 *pfound = TRUE;
1358 if (file_name == NULL || IS_ABSOLUTE_PATH (file_name)
1359 || directory_name == NULL)
1360 *pfilename = file_name;
1361 else
1363 size_t dirlen;
1365 dirlen = strlen (directory_name);
1366 if (info->filename == NULL
1367 || strncmp (info->filename, directory_name, dirlen) != 0
1368 || strcmp (info->filename + dirlen, file_name) != 0)
1370 size_t len;
1372 if (info->filename != NULL)
1373 free (info->filename);
1374 len = strlen (file_name) + 1;
1375 info->filename = bfd_malloc (dirlen + len);
1376 if (info->filename == NULL)
1377 return FALSE;
1378 memcpy (info->filename, directory_name, dirlen);
1379 memcpy (info->filename + dirlen, file_name, len);
1382 *pfilename = info->filename;
1385 if (indexentry->function_name != NULL)
1387 char *s;
1389 /* This will typically be something like main:F(0,1), so we want
1390 to clobber the colon. It's OK to change the name, since the
1391 string is in our own local storage anyhow. */
1392 s = strchr (indexentry->function_name, ':');
1393 if (s != NULL)
1394 *s = '\0';
1396 *pfnname = indexentry->function_name;
1399 return TRUE;