1 /* BFD back-end data structures for a.out (and similar) files.
2 Copyright 1990, 1991, 1992 Free Software Foundation, Inc.
3 Written by Cygnus Support.
5 This file is part of BFD, the Binary File Descriptor library.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
24 /* We try to encapsulate the differences in the various a.out file
25 variants in a few routines, and otherwise share large masses of code.
26 This means we only have to fix bugs in one place, most of the time. */
30 /* Parameterize the a.out code based on whether it is being built
31 for a 32-bit architecture or a 64-bit architecture. */
33 #define GET_WORD bfd_h_get_64
34 #define GET_SWORD bfd_h_get_signed_64
35 #define PUT_WORD bfd_h_put_64
37 #define NAME(x,y) CAT3(x,_64_,y)
39 #define JNAME(x) CAT(x,_64)
40 #define BYTES_IN_WORD 8
41 #else /* ARCH_SIZE == 32 */
42 #define GET_WORD bfd_h_get_32
43 #define GET_SWORD bfd_h_get_signed_32
44 #define PUT_WORD bfd_h_put_32
46 #define NAME(x,y) CAT3(x,_32_,y)
48 #define JNAME(x) CAT(x,_32)
49 #define BYTES_IN_WORD 4
50 #endif /* ARCH_SIZE==32 */
52 /* Declare at file level, since used in parameter lists, which have
55 struct external_nlist;
56 struct reloc_ext_external;
57 struct reloc_std_external;
59 /* a.out backend linker hash table entries. */
61 struct aout_link_hash_entry
63 struct bfd_link_hash_entry root;
64 /* Whether this symbol has been written out. */
66 /* Symbol index in output file. */
70 /* a.out backend linker hash table. */
72 struct aout_link_hash_table
74 struct bfd_link_hash_table root;
77 /* Look up an entry in an a.out link hash table. */
79 #define aout_link_hash_lookup(table, string, create, copy, follow) \
80 ((struct aout_link_hash_entry *) \
81 bfd_link_hash_lookup (&(table)->root, (string), (create), (copy), (follow)))
83 /* Traverse an a.out link hash table. */
85 #define aout_link_hash_traverse(table, func, info) \
86 (bfd_link_hash_traverse \
88 (boolean (*) PARAMS ((struct bfd_link_hash_entry *, PTR))) (func), \
91 /* Get the a.out link hash table from the info structure. This is
94 #define aout_hash_table(p) ((struct aout_link_hash_table *) ((p)->hash))
96 /* Back-end information for various a.out targets. */
97 struct aout_backend_data
99 /* Are ZMAGIC files mapped contiguously? If so, the text section may
100 need more padding, if the segment size (granularity for memory access
101 control) is larger than the page size. */
102 unsigned char zmagic_mapped_contiguous;
103 /* If this flag is set, ZMAGIC/NMAGIC file headers get mapped in with the
104 text section, which starts immediately after the file header.
105 If not, the text section starts on the next page. */
106 unsigned char text_includes_header;
108 /* The value to pass to N_SET_FLAGS. */
109 unsigned char exec_hdr_flags;
111 /* If the text section VMA isn't specified, and we need an absolute
112 address, use this as the default. If we're producing a relocatable
113 file, zero is always used. */
114 /* ?? Perhaps a callback would be a better choice? Will this do anything
115 reasonable for a format that handles multiple CPUs with different
116 load addresses for each? */
117 bfd_vma default_text_vma;
119 /* Callback for setting the page and segment sizes, if they can't be
120 trivially determined from the architecture. */
121 boolean (*set_sizes) PARAMS ((bfd *));
123 /* zmagic files only. For go32, the length of the exec header contributes
124 to the size of the text section in the file for alignment purposes but
125 does *not* get counted in the length of the text section. */
126 unsigned char exec_header_not_counted;
128 /* Callback from the add symbols phase of the linker code to handle
130 boolean (*add_dynamic_symbols) PARAMS ((bfd *, struct bfd_link_info *));
132 /* Callback from the add symbols phase of the linker code to handle
133 adding a single symbol to the global linker hash table. */
134 boolean (*add_one_symbol) PARAMS ((struct bfd_link_info *, bfd *,
135 const char *, flagword, asection *,
136 bfd_vma, const char *, boolean,
138 struct bfd_link_hash_entry **));
140 /* Called to handle linking a dynamic object. */
141 boolean (*link_dynamic_object) PARAMS ((struct bfd_link_info *, bfd *));
143 /* Called for each global symbol being written out by the linker.
144 This should write out the dynamic symbol information. */
145 boolean (*write_dynamic_symbol) PARAMS ((bfd *, struct bfd_link_info *,
146 struct aout_link_hash_entry *));
148 /* This callback is called by the linker for each reloc against an
149 external symbol. RELOC is a pointer to the unswapped reloc. If
150 *SKIP is set to true, the reloc will be skipped. */
151 boolean (*check_dynamic_reloc) PARAMS ((struct bfd_link_info *info,
153 asection *input_section,
154 struct aout_link_hash_entry *h,
155 PTR reloc, boolean *skip));
157 /* Called at the end of a link to finish up any dynamic linking
159 boolean (*finish_dynamic_link) PARAMS ((bfd *, struct bfd_link_info *));
161 #define aout_backend_info(abfd) \
162 ((CONST struct aout_backend_data *)((abfd)->xvec->backend_data))
164 /* This is the layout in memory of a "struct exec" while we process it.
165 All 'lengths' are given as a number of bytes.
166 All 'alignments' are for relinkable files only; an alignment of
167 'n' indicates the corresponding segment must begin at an
168 address that is a multiple of (2**n). */
172 long a_info; /* Magic number and flags, packed */
173 bfd_vma a_text; /* length of text, in bytes */
174 bfd_vma a_data; /* length of data, in bytes */
175 bfd_vma a_bss; /* length of uninitialized data area in mem */
176 bfd_vma a_syms; /* length of symbol table data in file */
177 bfd_vma a_entry; /* start address */
178 bfd_vma a_trsize; /* length of text's relocation info, in bytes */
179 bfd_vma a_drsize; /* length of data's relocation info, in bytes */
181 bfd_vma a_tload; /* Text runtime load address */
182 bfd_vma a_dload; /* Data runtime load address */
183 unsigned char a_talign; /* Alignment of text segment */
184 unsigned char a_dalign; /* Alignment of data segment */
185 unsigned char a_balign; /* Alignment of bss segment */
186 char a_relaxable; /* Enough info for linker relax */
189 /* Magic number is written
191 3130292827262524232221201918171615141312111009080706050403020100
192 < FLAGS >< MACHINE TYPE >< MAGIC NUMBER >
194 /* Magic number for NetBSD is
196 3130292827262524232221201918171615141312111009080706050403020100
197 < FLAGS >< >< MAGIC NUMBER >
205 /* skip a bunch so we don't run into any of suns numbers */
207 M_29K = 101, /* AMD 29000 */
208 M_386_DYNIX = 102, /* Sequent running dynix */
209 M_386_NETBSD = 134, /* NetBSD/386 binary */
210 M_MIPS1 = 151, /* MIPS R2000/R3000 binary */
211 M_MIPS2 = 152, /* MIPS R4000/R6000 binary */
212 M_HP200 = 200, /* HP 200 (68010) BSD binary */
213 M_HP300 = (300 % 256), /* HP 300 (68020+68881) BSD binary */
214 M_HPUX = (0x20c % 256)/* HP 200/300 HPUX binary */
217 #define N_DYNAMIC(exec) ((exec).a_info & 0x80000000)
220 # define N_MAGIC(exec) ((exec).a_info & 0xffff)
224 # define N_MACHTYPE(exec) ((enum machine_type)(((exec).a_info >> 16) & 0xff))
228 # define N_FLAGS(exec) (((exec).a_info >> 24) & 0xff)
232 # define N_SET_INFO(exec, magic, type, flags) \
233 ((exec).a_info = ((magic) & 0xffff) \
234 | (((int)(type) & 0xff) << 16) \
235 | (((flags) & 0xff) << 24))
238 #ifndef N_SET_DYNAMIC
239 # define N_SET_DYNAMIC(exec, dynamic) \
240 ((exec).a_info = (dynamic) ? ((exec).a_info | 0x80000000) : \
241 ((exec).a_info & 0x7fffffff))
245 # define N_SET_MAGIC(exec, magic) \
246 ((exec).a_info = (((exec).a_info & 0xffff0000) | ((magic) & 0xffff)))
249 #ifndef N_SET_MACHTYPE
250 # define N_SET_MACHTYPE(exec, machtype) \
252 ((exec).a_info&0xff00ffff) | ((((int)(machtype))&0xff) << 16))
256 # define N_SET_FLAGS(exec, flags) \
258 ((exec).a_info&0x00ffffff) | (((flags) & 0xff) << 24))
261 typedef struct aout_symbol {
268 /* The `tdata' struct for all a.out-like object file formats.
269 Various things depend on this struct being around any time an a.out
270 file is being handled. An example is dbxread.c in GDB. */
273 struct internal_exec *hdr; /* exec file header */
274 aout_symbol_type *symbols; /* symtab for input bfd */
276 /* For ease, we do this */
281 /* We remember these offsets so that after check_file_format, we have
282 no dependencies on the particular format of the exec_hdr. */
283 file_ptr sym_filepos;
284 file_ptr str_filepos;
286 /* Size of a relocation entry in external form */
287 unsigned reloc_entry_size;
289 /* Size of a symbol table entry in external form */
290 unsigned symbol_entry_size;
292 /* Page size - needed for alignment of demand paged files. */
293 unsigned long page_size;
295 /* Segment size - needed for alignment of demand paged files. */
296 unsigned long segment_size;
298 unsigned exec_bytes_size;
299 unsigned vma_adjusted : 1;
301 /* used when a bfd supports several highly similar formats */
305 /* Used on HP 9000/300 running HP/UX. See hp300hpux.c. */
307 /* Used on Linux, 386BSD, etc. See include/aout/aout64.h. */
319 /* The external symbol information. */
320 struct external_nlist *external_syms;
321 bfd_size_type external_sym_count;
322 char *external_strings;
323 bfd_size_type external_string_size;
324 struct aout_link_hash_entry **sym_hashes;
326 /* A pointer for shared library information. */
330 struct aout_data_struct {
332 struct internal_exec e;
335 #define adata(bfd) ((bfd)->tdata.aout_data->a)
336 #define exec_hdr(bfd) (adata(bfd).hdr)
337 #define obj_aout_symbols(bfd) (adata(bfd).symbols)
338 #define obj_textsec(bfd) (adata(bfd).textsec)
339 #define obj_datasec(bfd) (adata(bfd).datasec)
340 #define obj_bsssec(bfd) (adata(bfd).bsssec)
341 #define obj_sym_filepos(bfd) (adata(bfd).sym_filepos)
342 #define obj_str_filepos(bfd) (adata(bfd).str_filepos)
343 #define obj_reloc_entry_size(bfd) (adata(bfd).reloc_entry_size)
344 #define obj_symbol_entry_size(bfd) (adata(bfd).symbol_entry_size)
345 #define obj_aout_subformat(bfd) (adata(bfd).subformat)
346 #define obj_aout_external_syms(bfd) (adata(bfd).external_syms)
347 #define obj_aout_external_sym_count(bfd) (adata(bfd).external_sym_count)
348 #define obj_aout_external_strings(bfd) (adata(bfd).external_strings)
349 #define obj_aout_external_string_size(bfd) (adata(bfd).external_string_size)
350 #define obj_aout_sym_hashes(bfd) (adata(bfd).sym_hashes)
351 #define obj_aout_dynamic_info(bfd) (adata(bfd).dynamic_info)
353 /* We take the address of the first element of an asymbol to ensure that the
354 macro is only ever applied to an asymbol */
355 #define aout_symbol(asymbol) ((aout_symbol_type *)(&(asymbol)->the_bfd))
357 /* Information we keep for each a.out section. This is currently only
358 used by the a.out backend linker. */
360 struct aout_section_data_struct
362 /* The unswapped relocation entries for this section. */
366 #define aout_section_data(s) \
367 ((struct aout_section_data_struct *) (s)->used_by_bfd)
369 /* Prototype declarations for functions defined in aoutx.h */
372 NAME(aout,squirt_out_relocs) PARAMS ((bfd *abfd, asection *section));
375 NAME(aout,make_sections) PARAMS ((bfd *));
378 NAME(aout,some_aout_object_p) PARAMS ((bfd *abfd,
379 struct internal_exec *execp,
380 bfd_target * (*callback)(bfd *)));
383 NAME(aout,mkobject) PARAMS ((bfd *abfd));
386 NAME(aout,machine_type) PARAMS ((enum bfd_architecture arch,
387 unsigned long machine,
391 NAME(aout,set_arch_mach) PARAMS ((bfd *abfd, enum bfd_architecture arch,
392 unsigned long machine));
395 NAME(aout,new_section_hook) PARAMS ((bfd *abfd, asection *newsect));
398 NAME(aout,set_section_contents) PARAMS ((bfd *abfd, sec_ptr section,
399 PTR location, file_ptr offset, bfd_size_type count));
402 NAME(aout,make_empty_symbol) PARAMS ((bfd *abfd));
405 NAME(aout,translate_symbol_table) PARAMS ((bfd *, aout_symbol_type *,
406 struct external_nlist *,
407 bfd_size_type, char *,
412 NAME(aout,slurp_symbol_table) PARAMS ((bfd *abfd));
415 NAME(aout,write_syms) PARAMS ((bfd *abfd));
418 NAME(aout,reclaim_symbol_table) PARAMS ((bfd *abfd));
421 NAME(aout,get_symtab_upper_bound) PARAMS ((bfd *abfd));
424 NAME(aout,get_symtab) PARAMS ((bfd *abfd, asymbol **location));
427 NAME(aout,swap_ext_reloc_in) PARAMS ((bfd *, struct reloc_ext_external *,
428 arelent *, asymbol **));
430 NAME(aout,swap_std_reloc_in) PARAMS ((bfd *, struct reloc_std_external *,
431 arelent *, asymbol **));
434 NAME(aout,slurp_reloc_table) PARAMS ((bfd *abfd, sec_ptr asect,
438 NAME(aout,canonicalize_reloc) PARAMS ((bfd *abfd, sec_ptr section,
439 arelent **relptr, asymbol **symbols));
442 NAME(aout,get_reloc_upper_bound) PARAMS ((bfd *abfd, sec_ptr asect));
445 NAME(aout,reclaim_reloc) PARAMS ((bfd *ignore_abfd, sec_ptr ignore));
448 NAME(aout,get_lineno) PARAMS ((bfd *ignore_abfd, asymbol *ignore_symbol));
451 NAME(aout,print_symbol) PARAMS ((bfd *ignore_abfd, PTR file,
452 asymbol *symbol, bfd_print_symbol_type how));
455 NAME(aout,get_symbol_info) PARAMS ((bfd *ignore_abfd,
456 asymbol *symbol, symbol_info *ret));
459 NAME(aout,find_nearest_line) PARAMS ((bfd *abfd, asection *section,
460 asymbol **symbols, bfd_vma offset, CONST char **filename_ptr,
461 CONST char **functionname_ptr, unsigned int *line_ptr));
464 NAME(aout,sizeof_headers) PARAMS ((bfd *abfd, boolean exec));
467 NAME(aout,adjust_sizes_and_vmas) PARAMS ((bfd *abfd,
468 bfd_size_type *text_size, file_ptr *text_end));
471 NAME(aout,swap_exec_header_in) PARAMS ((bfd *abfd,
472 struct external_exec *raw_bytes, struct internal_exec *execp));
475 NAME(aout,swap_exec_header_out) PARAMS ((bfd *abfd,
476 struct internal_exec *execp, struct external_exec *raw_bytes));
478 struct bfd_hash_entry *
479 NAME(aout,link_hash_newfunc)
480 PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *, const char *));
483 NAME(aout,link_hash_table_init)
484 PARAMS ((struct aout_link_hash_table *, bfd *,
485 struct bfd_hash_entry *(*) (struct bfd_hash_entry *,
486 struct bfd_hash_table *,
489 struct bfd_link_hash_table *
490 NAME(aout,link_hash_table_create) PARAMS ((bfd *));
493 NAME(aout,link_add_symbols) PARAMS ((bfd *, struct bfd_link_info *));
496 NAME(aout,final_link) PARAMS ((bfd *, struct bfd_link_info *,
497 void (*) (bfd *, file_ptr *, file_ptr *,
501 NAME(aout,bfd_free_cached_info) PARAMS ((bfd *));
503 /* Prototypes for functions in stab-syms.c. */
506 aout_stab_name PARAMS ((int code));
508 /* A.out uses the generic versions of these routines... */
510 #define aout_32_get_section_contents _bfd_generic_get_section_contents
512 #define aout_64_get_section_contents _bfd_generic_get_section_contents
513 #ifndef NO_WRITE_HEADER_KLUDGE
514 #define NO_WRITE_HEADER_KLUDGE 0
517 #ifndef aout_32_bfd_is_local_label
518 #define aout_32_bfd_is_local_label bfd_generic_is_local_label
521 #ifndef WRITE_HEADERS
522 #define WRITE_HEADERS(abfd, execp) \
524 bfd_size_type text_size; /* dummy vars */ \
526 if (adata(abfd).magic == undecided_magic) \
527 NAME(aout,adjust_sizes_and_vmas) (abfd, &text_size, &text_end); \
529 execp->a_syms = bfd_get_symcount (abfd) * EXTERNAL_NLIST_SIZE; \
530 execp->a_entry = bfd_get_start_address (abfd); \
532 execp->a_trsize = ((obj_textsec (abfd)->reloc_count) * \
533 obj_reloc_entry_size (abfd)); \
534 execp->a_drsize = ((obj_datasec (abfd)->reloc_count) * \
535 obj_reloc_entry_size (abfd)); \
536 NAME(aout,swap_exec_header_out) (abfd, execp, &exec_bytes); \
538 if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) return false; \
539 if (bfd_write ((PTR) &exec_bytes, 1, EXEC_BYTES_SIZE, abfd) \
540 != EXEC_BYTES_SIZE) \
542 /* Now write out reloc info, followed by syms and strings */ \
544 if (bfd_get_outsymbols (abfd) != (asymbol **) NULL \
545 && bfd_get_symcount (abfd) != 0) \
547 if (bfd_seek (abfd, (file_ptr)(N_SYMOFF(*execp)), SEEK_SET) \
551 if (! NAME(aout,write_syms)(abfd)) return false; \
553 if (bfd_seek (abfd, (file_ptr)(N_TRELOFF(*execp)), SEEK_SET) \
557 if (!NAME(aout,squirt_out_relocs) (abfd, obj_textsec (abfd))) \
559 if (bfd_seek (abfd, (file_ptr)(N_DRELOFF(*execp)), SEEK_SET) \
563 if (!NAME(aout,squirt_out_relocs)(abfd, obj_datasec (abfd))) \
569 #endif /* ! defined (LIBAOUT_H) */