1 /* OS ABI variant handling for GDB.
3 Copyright (C) 2001, 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
5 This file is part of GDB.
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 3 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, see <http://www.gnu.org/licenses/>. */
22 #include "gdb_assert.h"
23 #include "gdb_string.h"
26 #include "arch-utils.h"
32 #ifndef GDB_OSABI_DEFAULT
33 #define GDB_OSABI_DEFAULT GDB_OSABI_UNKNOWN
36 /* State for the "set osabi" command. */
37 static enum { osabi_auto
, osabi_default
, osabi_user
} user_osabi_state
;
38 static enum gdb_osabi user_selected_osabi
;
39 static const char *gdb_osabi_available_names
[GDB_OSABI_INVALID
+ 3] = {
45 static const char *set_osabi_string
;
47 /* This table matches the indices assigned to enum gdb_osabi. Keep
49 static const char * const gdb_osabi_names
[] =
80 gdbarch_osabi_name (enum gdb_osabi osabi
)
82 if (osabi
>= GDB_OSABI_UNKNOWN
&& osabi
< GDB_OSABI_INVALID
)
83 return gdb_osabi_names
[osabi
];
85 return gdb_osabi_names
[GDB_OSABI_INVALID
];
88 /* Handler for a given architecture/OS ABI pair. There should be only
89 one handler for a given OS ABI each architecture family. */
90 struct gdb_osabi_handler
92 struct gdb_osabi_handler
*next
;
93 const struct bfd_arch_info
*arch_info
;
95 void (*init_osabi
)(struct gdbarch_info
, struct gdbarch
*);
98 static struct gdb_osabi_handler
*gdb_osabi_handler_list
;
101 gdbarch_register_osabi (enum bfd_architecture arch
, unsigned long machine
,
102 enum gdb_osabi osabi
,
103 void (*init_osabi
)(struct gdbarch_info
,
106 struct gdb_osabi_handler
**handler_p
;
107 const struct bfd_arch_info
*arch_info
= bfd_lookup_arch (arch
, machine
);
108 const char **name_ptr
;
110 /* Registering an OS ABI handler for "unknown" is not allowed. */
111 if (osabi
== GDB_OSABI_UNKNOWN
)
115 _("gdbarch_register_osabi: An attempt to register a handler for "
116 "OS ABI \"%s\" for architecture %s was made. The handler will "
117 "not be registered"),
118 gdbarch_osabi_name (osabi
),
119 bfd_printable_arch_mach (arch
, machine
));
123 gdb_assert (arch_info
);
125 for (handler_p
= &gdb_osabi_handler_list
; *handler_p
!= NULL
;
126 handler_p
= &(*handler_p
)->next
)
128 if ((*handler_p
)->arch_info
== arch_info
129 && (*handler_p
)->osabi
== osabi
)
133 _("gdbarch_register_osabi: A handler for OS ABI \"%s\" "
134 "has already been registered for architecture %s"),
135 gdbarch_osabi_name (osabi
),
136 arch_info
->printable_name
);
137 /* If user wants to continue, override previous definition. */
138 (*handler_p
)->init_osabi
= init_osabi
;
144 = (struct gdb_osabi_handler
*) xmalloc (sizeof (struct gdb_osabi_handler
));
145 (*handler_p
)->next
= NULL
;
146 (*handler_p
)->arch_info
= arch_info
;
147 (*handler_p
)->osabi
= osabi
;
148 (*handler_p
)->init_osabi
= init_osabi
;
150 /* Add this OS ABI to the list of enum values for "set osabi", if it isn't
152 for (name_ptr
= gdb_osabi_available_names
; *name_ptr
; name_ptr
++)
154 if (*name_ptr
== gdbarch_osabi_name (osabi
))
157 *name_ptr
++ = gdbarch_osabi_name (osabi
);
162 /* Sniffer to find the OS ABI for a given file's architecture and flavour.
163 It is legal to have multiple sniffers for each arch/flavour pair, to
164 disambiguate one OS's a.out from another, for example. The first sniffer
165 to return something other than GDB_OSABI_UNKNOWN wins, so a sniffer should
166 be careful to claim a file only if it knows for sure what it is. */
167 struct gdb_osabi_sniffer
169 struct gdb_osabi_sniffer
*next
;
170 enum bfd_architecture arch
; /* bfd_arch_unknown == wildcard */
171 enum bfd_flavour flavour
;
172 enum gdb_osabi (*sniffer
)(bfd
*);
175 static struct gdb_osabi_sniffer
*gdb_osabi_sniffer_list
;
178 gdbarch_register_osabi_sniffer (enum bfd_architecture arch
,
179 enum bfd_flavour flavour
,
180 enum gdb_osabi (*sniffer_fn
)(bfd
*))
182 struct gdb_osabi_sniffer
*sniffer
;
185 (struct gdb_osabi_sniffer
*) xmalloc (sizeof (struct gdb_osabi_sniffer
));
186 sniffer
->arch
= arch
;
187 sniffer
->flavour
= flavour
;
188 sniffer
->sniffer
= sniffer_fn
;
190 sniffer
->next
= gdb_osabi_sniffer_list
;
191 gdb_osabi_sniffer_list
= sniffer
;
196 gdbarch_lookup_osabi (bfd
*abfd
)
198 struct gdb_osabi_sniffer
*sniffer
;
199 enum gdb_osabi osabi
, match
;
202 /* If we aren't in "auto" mode, return the specified OS ABI. */
203 if (user_osabi_state
== osabi_user
)
204 return user_selected_osabi
;
206 /* If we don't have a binary, return the default OS ABI (if set) or
207 unknown (otherwise). */
209 return GDB_OSABI_DEFAULT
;
211 match
= GDB_OSABI_UNKNOWN
;
214 for (sniffer
= gdb_osabi_sniffer_list
; sniffer
!= NULL
;
215 sniffer
= sniffer
->next
)
217 if ((sniffer
->arch
== bfd_arch_unknown
/* wildcard */
218 || sniffer
->arch
== bfd_get_arch (abfd
))
219 && sniffer
->flavour
== bfd_get_flavour (abfd
))
221 osabi
= (*sniffer
->sniffer
) (abfd
);
222 if (osabi
< GDB_OSABI_UNKNOWN
|| osabi
>= GDB_OSABI_INVALID
)
226 _("gdbarch_lookup_osabi: invalid OS ABI (%d) from sniffer "
227 "for architecture %s flavour %d"),
229 bfd_printable_arch_mach (bfd_get_arch (abfd
), 0),
230 (int) bfd_get_flavour (abfd
));
232 else if (osabi
!= GDB_OSABI_UNKNOWN
)
234 /* A specific sniffer always overrides a generic sniffer.
235 Croak on multiple match if the two matches are of the
236 same class. If the user wishes to continue, we'll use
238 if (match
!= GDB_OSABI_UNKNOWN
)
240 if ((match_specific
&& sniffer
->arch
!= bfd_arch_unknown
)
241 || (!match_specific
&& sniffer
->arch
== bfd_arch_unknown
))
245 _("gdbarch_lookup_osabi: multiple %sspecific OS ABI "
246 "match for architecture %s flavour %d: first "
247 "match \"%s\", second match \"%s\""),
248 match_specific
? "" : "non-",
249 bfd_printable_arch_mach (bfd_get_arch (abfd
), 0),
250 (int) bfd_get_flavour (abfd
),
251 gdbarch_osabi_name (match
),
252 gdbarch_osabi_name (osabi
));
254 else if (sniffer
->arch
!= bfd_arch_unknown
)
263 if (sniffer
->arch
!= bfd_arch_unknown
)
270 /* If we didn't find a match, but a default was specified at configure
271 time, return the default. */
272 if (GDB_OSABI_DEFAULT
!= GDB_OSABI_UNKNOWN
&& match
== GDB_OSABI_UNKNOWN
)
273 return GDB_OSABI_DEFAULT
;
279 /* Return non-zero if architecture A can run code written for
282 can_run_code_for (const struct bfd_arch_info
*a
, const struct bfd_arch_info
*b
)
284 /* BFD's 'A->compatible (A, B)' functions return zero if A and B are
285 incompatible. But if they are compatible, it returns the 'more
286 featureful' of the two arches. That is, if A can run code
287 written for B, but B can't run code written for A, then it'll
290 struct bfd_arch_info objects are singletons: that is, there's
291 supposed to be exactly one instance for a given machine. So you
292 can tell whether two are equivalent by comparing pointers. */
293 return (a
== b
|| a
->compatible (a
, b
) == a
);
298 gdbarch_init_osabi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
300 struct gdb_osabi_handler
*handler
;
302 if (info
.osabi
== GDB_OSABI_UNKNOWN
)
304 /* Don't complain about an unknown OSABI. Assume the user knows
305 what they are doing. */
309 for (handler
= gdb_osabi_handler_list
; handler
!= NULL
;
310 handler
= handler
->next
)
312 if (handler
->osabi
!= info
.osabi
)
315 /* If the architecture described by ARCH_INFO can run code for
316 the architcture we registered the handler for, then the
317 handler is applicable. Note, though, that if the handler is
318 for an architecture that is a superset of ARCH_INFO, we can't
319 use that --- it would be perfectly correct for it to install
320 gdbarch methods that refer to registers / instructions /
321 other facilities ARCH_INFO doesn't have.
323 NOTE: kettenis/20021027: There may be more than one machine
324 type that is compatible with the desired machine type. Right
325 now we simply return the first match, which is fine for now.
326 However, we might want to do something smarter in the future. */
327 /* NOTE: cagney/2003-10-23: The code for "a can_run_code_for b"
328 is implemented using BFD's compatible method (a->compatible
329 (b) == a -- the lowest common denominator between a and b is
330 a). That method's definition of compatible may not be as you
331 expect. For instance the test "amd64 can run code for i386"
332 (or more generally "64-bit ISA can run code for the 32-bit
333 ISA"). BFD doesn't normally consider 32-bit and 64-bit
334 "compatible" so it doesn't succeed. */
335 if (can_run_code_for (info
.bfd_arch_info
, handler
->arch_info
))
337 (*handler
->init_osabi
) (info
, gdbarch
);
343 ("A handler for the OS ABI \"%s\" is not built into this configuration\n"
344 "of GDB. Attempting to continue with the default %s settings.\n",
345 gdbarch_osabi_name (info
.osabi
),
346 info
.bfd_arch_info
->printable_name
);
349 /* Limit on the amount of data to be read. */
350 #define MAX_NOTESZ 128
352 /* Return non-zero if NOTE matches NAME, DESCSZ and TYPE. */
355 check_note (bfd
*abfd
, asection
*sect
, const char *note
,
356 const char *name
, unsigned long descsz
, unsigned long type
)
358 unsigned long notesz
;
360 /* Calculate the size of this note. */
361 notesz
= strlen (name
) + 1;
362 notesz
= ((notesz
+ 3) & ~3);
364 notesz
= ((notesz
+ 3) & ~3);
366 /* If this assertion triggers, increase MAX_NOTESZ. */
367 gdb_assert (notesz
<= MAX_NOTESZ
);
369 /* Check whether SECT is big enough to comtain the complete note. */
370 if (notesz
> bfd_section_size (abfd
, sect
))
373 /* Check the note name. */
374 if (bfd_h_get_32 (abfd
, note
) != (strlen (name
) + 1)
375 || strcmp (note
+ 12, name
) != 0)
378 /* Check the descriptor size. */
379 if (bfd_h_get_32 (abfd
, note
+ 4) != descsz
)
382 /* Check the note type. */
383 if (bfd_h_get_32 (abfd
, note
+ 8) != type
)
389 /* Generic sniffer for ELF flavoured files. */
392 generic_elf_osabi_sniff_abi_tag_sections (bfd
*abfd
, asection
*sect
, void *obj
)
394 enum gdb_osabi
*osabi
= obj
;
396 unsigned int sectsize
;
399 name
= bfd_get_section_name (abfd
, sect
);
400 sectsize
= bfd_section_size (abfd
, sect
);
402 /* Limit the amount of data to read. */
403 if (sectsize
> MAX_NOTESZ
)
404 sectsize
= MAX_NOTESZ
;
406 note
= alloca (sectsize
);
407 bfd_get_section_contents (abfd
, sect
, note
, 0, sectsize
);
409 /* .note.ABI-tag notes, used by GNU/Linux and FreeBSD. */
410 if (strcmp (name
, ".note.ABI-tag") == 0)
413 if (check_note (abfd
, sect
, note
, "GNU", 16, NT_GNU_ABI_TAG
))
415 unsigned int abi_tag
= bfd_h_get_32 (abfd
, note
+ 16);
419 case GNU_ABI_TAG_LINUX
:
420 *osabi
= GDB_OSABI_LINUX
;
423 case GNU_ABI_TAG_HURD
:
424 *osabi
= GDB_OSABI_HURD
;
427 case GNU_ABI_TAG_SOLARIS
:
428 *osabi
= GDB_OSABI_SOLARIS
;
431 case GNU_ABI_TAG_FREEBSD
:
432 *osabi
= GDB_OSABI_FREEBSD_ELF
;
435 case GNU_ABI_TAG_NETBSD
:
436 *osabi
= GDB_OSABI_NETBSD_ELF
;
440 internal_error (__FILE__
, __LINE__
, _("\
441 generic_elf_osabi_sniff_abi_tag_sections: unknown OS number %d"),
448 if (check_note (abfd
, sect
, note
, "FreeBSD", 4, NT_FREEBSD_ABI_TAG
))
450 /* There is no need to check the version yet. */
451 *osabi
= GDB_OSABI_FREEBSD_ELF
;
456 if (check_note (abfd
, sect
, note
, "DragonFly", 4, NT_DRAGONFLY_ABI_TAG
))
458 /* There is no need to check the version yet. */
459 *osabi
= GDB_OSABI_DRAGONFLY_ELF
;
466 /* .note.netbsd.ident notes, used by NetBSD. */
467 if (strcmp (name
, ".note.netbsd.ident") == 0
468 && check_note (abfd
, sect
, note
, "NetBSD", 4, NT_NETBSD_IDENT
))
470 /* There is no need to check the version yet. */
471 *osabi
= GDB_OSABI_NETBSD_ELF
;
475 /* .note.openbsd.ident notes, used by OpenBSD. */
476 if (strcmp (name
, ".note.openbsd.ident") == 0
477 && check_note (abfd
, sect
, note
, "OpenBSD", 4, NT_OPENBSD_IDENT
))
479 /* There is no need to check the version yet. */
480 *osabi
= GDB_OSABI_OPENBSD_ELF
;
484 /* .note.netbsdcore.procinfo notes, used by NetBSD. */
485 if (strcmp (name
, ".note.netbsdcore.procinfo") == 0)
487 *osabi
= GDB_OSABI_NETBSD_ELF
;
492 static enum gdb_osabi
493 generic_elf_osabi_sniffer (bfd
*abfd
)
495 unsigned int elfosabi
;
496 enum gdb_osabi osabi
= GDB_OSABI_UNKNOWN
;
498 elfosabi
= elf_elfheader (abfd
)->e_ident
[EI_OSABI
];
503 /* When the EI_OSABI field in the ELF header is ELFOSABI_NONE
504 (0), then the ELF structures in the file are conforming to
505 the base specification for that machine (there are no
506 OS-specific extensions). In order to determine the real OS
507 in use we must look for OS-specific notes. */
508 bfd_map_over_sections (abfd
,
509 generic_elf_osabi_sniff_abi_tag_sections
,
513 case ELFOSABI_FREEBSD
:
514 /* XXX HACK we hijacked the FreeBSD osabi :/ */
515 osabi
= GDB_OSABI_DRAGONFLY_ELF
;
518 case ELFOSABI_NETBSD
:
519 osabi
= GDB_OSABI_NETBSD_ELF
;
523 osabi
= GDB_OSABI_LINUX
;
527 osabi
= GDB_OSABI_HURD
;
530 case ELFOSABI_SOLARIS
:
531 osabi
= GDB_OSABI_SOLARIS
;
535 /* For some reason the default value for the EI_OSABI field is
536 ELFOSABI_HPUX for all PA-RISC targets (with the exception of
537 GNU/Linux). We use HP-UX ELF as the default, but let any
538 OS-specific notes override this. */
539 osabi
= GDB_OSABI_HPUX_ELF
;
540 bfd_map_over_sections (abfd
,
541 generic_elf_osabi_sniff_abi_tag_sections
,
546 if (osabi
== GDB_OSABI_UNKNOWN
)
548 /* The FreeBSD folks have been naughty; they stored the string
549 "FreeBSD" in the padding of the e_ident field of the ELF
550 header to "brand" their ELF binaries in FreeBSD 3.x. */
551 if (memcmp (&elf_elfheader (abfd
)->e_ident
[8],
552 "FreeBSD", sizeof ("FreeBSD")) == 0)
553 osabi
= GDB_OSABI_FREEBSD_ELF
;
560 set_osabi (char *args
, int from_tty
, struct cmd_list_element
*c
)
562 struct gdbarch_info info
;
564 if (strcmp (set_osabi_string
, "auto") == 0)
565 user_osabi_state
= osabi_auto
;
566 else if (strcmp (set_osabi_string
, "default") == 0)
568 user_selected_osabi
= GDB_OSABI_DEFAULT
;
569 user_osabi_state
= osabi_user
;
571 else if (strcmp (set_osabi_string
, "none") == 0)
573 user_selected_osabi
= GDB_OSABI_UNKNOWN
;
574 user_osabi_state
= osabi_user
;
579 for (i
= 1; i
< GDB_OSABI_INVALID
; i
++)
580 if (strcmp (set_osabi_string
, gdbarch_osabi_name (i
)) == 0)
582 user_selected_osabi
= i
;
583 user_osabi_state
= osabi_user
;
586 if (i
== GDB_OSABI_INVALID
)
587 internal_error (__FILE__
, __LINE__
,
588 _("Invalid OS ABI \"%s\" passed to command handler."),
592 /* NOTE: At some point (true multiple architectures) we'll need to be more
594 gdbarch_info_init (&info
);
595 if (! gdbarch_update_p (info
))
596 internal_error (__FILE__
, __LINE__
, _("Updating OS ABI failed."));
600 show_osabi (struct ui_file
*file
, int from_tty
, struct cmd_list_element
*c
,
603 if (user_osabi_state
== osabi_auto
)
604 fprintf_filtered (file
,
605 _("The current OS ABI is \"auto\" (currently \"%s\").\n"),
606 gdbarch_osabi_name (gdbarch_osabi (current_gdbarch
)));
608 fprintf_filtered (file
, _("The current OS ABI is \"%s\".\n"),
609 gdbarch_osabi_name (user_selected_osabi
));
611 if (GDB_OSABI_DEFAULT
!= GDB_OSABI_UNKNOWN
)
612 fprintf_filtered (file
, _("The default OS ABI is \"%s\".\n"),
613 gdbarch_osabi_name (GDB_OSABI_DEFAULT
));
616 extern initialize_file_ftype _initialize_gdb_osabi
; /* -Wmissing-prototype */
619 _initialize_gdb_osabi (void)
621 struct cmd_list_element
*c
;
623 if (strcmp (gdb_osabi_names
[GDB_OSABI_INVALID
], "<invalid>") != 0)
626 _("_initialize_gdb_osabi: gdb_osabi_names[] is inconsistent"));
628 /* Register a generic sniffer for ELF flavoured files. */
629 gdbarch_register_osabi_sniffer (bfd_arch_unknown
,
630 bfd_target_elf_flavour
,
631 generic_elf_osabi_sniffer
);
633 /* Register the "set osabi" command. */
634 add_setshow_enum_cmd ("osabi", class_support
, gdb_osabi_available_names
,
635 &set_osabi_string
, _("\
636 Set OS ABI of target."), _("\
637 Show OS ABI of target."), NULL
,
640 &setlist
, &showlist
);
641 user_osabi_state
= osabi_auto
;