1 /* OS ABI variant handling for GDB.
3 Copyright (C) 2001-2023 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/>. */
23 #include "arch-utils.h"
30 #ifndef GDB_OSABI_DEFAULT
31 #define GDB_OSABI_DEFAULT GDB_OSABI_UNKNOWN
34 /* State for the "set osabi" command. */
35 static enum { osabi_auto
, osabi_default
, osabi_user
} user_osabi_state
;
36 static enum gdb_osabi user_selected_osabi
;
37 static const char *gdb_osabi_available_names
[GDB_OSABI_INVALID
+ 3] = {
43 static const char *set_osabi_string
;
45 /* Names associated with each osabi. */
49 /* The "pretty" name. */
53 /* The triplet regexp, or NULL if not known. */
58 /* This table matches the indices assigned to enum gdb_osabi. Keep
60 static const struct osabi_names gdb_osabi_names
[] =
68 { "GNU/Linux", "linux(-gnu[^-]*)?" },
72 { "WindowsCE", NULL
},
74 { "QNX-Neutrino", NULL
},
81 { "LynxOS178", NULL
},
90 gdbarch_osabi_name (enum gdb_osabi osabi
)
92 if (osabi
>= GDB_OSABI_UNKNOWN
&& osabi
< GDB_OSABI_INVALID
)
93 return gdb_osabi_names
[osabi
].pretty
;
95 return gdb_osabi_names
[GDB_OSABI_INVALID
].pretty
;
101 osabi_triplet_regexp (enum gdb_osabi osabi
)
103 if (osabi
>= GDB_OSABI_UNKNOWN
&& osabi
< GDB_OSABI_INVALID
)
104 return gdb_osabi_names
[osabi
].regexp
;
106 return gdb_osabi_names
[GDB_OSABI_INVALID
].regexp
;
109 /* Lookup the OS ABI corresponding to the specified target description
113 osabi_from_tdesc_string (const char *name
)
117 for (i
= 0; i
< ARRAY_SIZE (gdb_osabi_names
); i
++)
118 if (strcmp (name
, gdb_osabi_names
[i
].pretty
) == 0)
120 /* See note above: the name table matches the indices assigned
121 to enum gdb_osabi. */
122 enum gdb_osabi osabi
= (enum gdb_osabi
) i
;
124 if (osabi
== GDB_OSABI_INVALID
)
125 return GDB_OSABI_UNKNOWN
;
130 return GDB_OSABI_UNKNOWN
;
133 /* Handler for a given architecture/OS ABI pair. There should be only
134 one handler for a given OS ABI each architecture family. */
135 struct gdb_osabi_handler
137 struct gdb_osabi_handler
*next
;
138 const struct bfd_arch_info
*arch_info
;
139 enum gdb_osabi osabi
;
140 void (*init_osabi
)(struct gdbarch_info
, struct gdbarch
*);
143 static struct gdb_osabi_handler
*gdb_osabi_handler_list
;
146 gdbarch_register_osabi (enum bfd_architecture arch
, unsigned long machine
,
147 enum gdb_osabi osabi
,
148 void (*init_osabi
)(struct gdbarch_info
,
151 struct gdb_osabi_handler
**handler_p
;
152 const struct bfd_arch_info
*arch_info
= bfd_lookup_arch (arch
, machine
);
153 const char **name_ptr
;
155 /* Registering an OS ABI handler for "unknown" is not allowed. */
156 if (osabi
== GDB_OSABI_UNKNOWN
)
159 (_("gdbarch_register_osabi: An attempt to register a handler for "
160 "OS ABI \"%s\" for architecture %s was made. The handler will "
161 "not be registered"),
162 gdbarch_osabi_name (osabi
),
163 bfd_printable_arch_mach (arch
, machine
));
167 gdb_assert (arch_info
);
169 for (handler_p
= &gdb_osabi_handler_list
; *handler_p
!= NULL
;
170 handler_p
= &(*handler_p
)->next
)
172 if ((*handler_p
)->arch_info
== arch_info
173 && (*handler_p
)->osabi
== osabi
)
176 (_("gdbarch_register_osabi: A handler for OS ABI \"%s\" "
177 "has already been registered for architecture %s"),
178 gdbarch_osabi_name (osabi
),
179 arch_info
->printable_name
);
180 /* If user wants to continue, override previous definition. */
181 (*handler_p
)->init_osabi
= init_osabi
;
186 (*handler_p
) = XNEW (struct gdb_osabi_handler
);
187 (*handler_p
)->next
= NULL
;
188 (*handler_p
)->arch_info
= arch_info
;
189 (*handler_p
)->osabi
= osabi
;
190 (*handler_p
)->init_osabi
= init_osabi
;
192 /* Add this OS ABI to the list of enum values for "set osabi", if it isn't
194 for (name_ptr
= gdb_osabi_available_names
; *name_ptr
; name_ptr
++)
196 if (*name_ptr
== gdbarch_osabi_name (osabi
))
199 *name_ptr
++ = gdbarch_osabi_name (osabi
);
204 /* Sniffer to find the OS ABI for a given file's architecture and flavour.
205 It is legal to have multiple sniffers for each arch/flavour pair, to
206 disambiguate one OS's a.out from another, for example. The first sniffer
207 to return something other than GDB_OSABI_UNKNOWN wins, so a sniffer should
208 be careful to claim a file only if it knows for sure what it is. */
209 struct gdb_osabi_sniffer
211 struct gdb_osabi_sniffer
*next
;
212 enum bfd_architecture arch
; /* bfd_arch_unknown == wildcard */
213 enum bfd_flavour flavour
;
214 enum gdb_osabi (*sniffer
)(bfd
*);
217 static struct gdb_osabi_sniffer
*gdb_osabi_sniffer_list
;
220 gdbarch_register_osabi_sniffer (enum bfd_architecture arch
,
221 enum bfd_flavour flavour
,
222 enum gdb_osabi (*sniffer_fn
)(bfd
*))
224 struct gdb_osabi_sniffer
*sniffer
;
226 sniffer
= XNEW (struct gdb_osabi_sniffer
);
227 sniffer
->arch
= arch
;
228 sniffer
->flavour
= flavour
;
229 sniffer
->sniffer
= sniffer_fn
;
231 sniffer
->next
= gdb_osabi_sniffer_list
;
232 gdb_osabi_sniffer_list
= sniffer
;
237 gdbarch_lookup_osabi (bfd
*abfd
)
239 struct gdb_osabi_sniffer
*sniffer
;
240 enum gdb_osabi osabi
, match
;
243 /* If we aren't in "auto" mode, return the specified OS ABI. */
244 if (user_osabi_state
== osabi_user
)
245 return user_selected_osabi
;
247 /* If we don't have a binary, just return unknown. The caller may
248 have other sources the OSABI can be extracted from, e.g., the
249 target description. */
251 return GDB_OSABI_UNKNOWN
;
253 match
= GDB_OSABI_UNKNOWN
;
256 for (sniffer
= gdb_osabi_sniffer_list
; sniffer
!= NULL
;
257 sniffer
= sniffer
->next
)
259 if ((sniffer
->arch
== bfd_arch_unknown
/* wildcard */
260 || sniffer
->arch
== bfd_get_arch (abfd
))
261 && sniffer
->flavour
== bfd_get_flavour (abfd
))
263 osabi
= (*sniffer
->sniffer
) (abfd
);
264 if (osabi
< GDB_OSABI_UNKNOWN
|| osabi
>= GDB_OSABI_INVALID
)
267 (_("gdbarch_lookup_osabi: invalid OS ABI (%d) from sniffer "
268 "for architecture %s flavour %d"),
270 bfd_printable_arch_mach (bfd_get_arch (abfd
), 0),
271 (int) bfd_get_flavour (abfd
));
273 else if (osabi
!= GDB_OSABI_UNKNOWN
)
275 /* A specific sniffer always overrides a generic sniffer.
276 Croak on multiple match if the two matches are of the
277 same class. If the user wishes to continue, we'll use
279 if (match
!= GDB_OSABI_UNKNOWN
)
281 if ((match_specific
&& sniffer
->arch
!= bfd_arch_unknown
)
282 || (!match_specific
&& sniffer
->arch
== bfd_arch_unknown
))
285 (_("gdbarch_lookup_osabi: multiple %sspecific OS ABI "
286 "match for architecture %s flavour %d: first "
287 "match \"%s\", second match \"%s\""),
288 match_specific
? "" : "non-",
289 bfd_printable_arch_mach (bfd_get_arch (abfd
), 0),
290 (int) bfd_get_flavour (abfd
),
291 gdbarch_osabi_name (match
),
292 gdbarch_osabi_name (osabi
));
294 else if (sniffer
->arch
!= bfd_arch_unknown
)
303 if (sniffer
->arch
!= bfd_arch_unknown
)
314 /* Return non-zero if architecture A can run code written for
317 can_run_code_for (const struct bfd_arch_info
*a
, const struct bfd_arch_info
*b
)
319 /* BFD's 'A->compatible (A, B)' functions return zero if A and B are
320 incompatible. But if they are compatible, it returns the 'more
321 featureful' of the two arches. That is, if A can run code
322 written for B, but B can't run code written for A, then it'll
325 struct bfd_arch_info objects are singletons: that is, there's
326 supposed to be exactly one instance for a given machine. So you
327 can tell whether two are equivalent by comparing pointers. */
328 return (a
== b
|| a
->compatible (a
, b
) == a
);
331 /* Return OS ABI handler for INFO. */
333 static struct gdb_osabi_handler
*
334 gdbarch_osabi_handler (struct gdbarch_info info
)
336 struct gdb_osabi_handler
*handler
;
338 gdb_assert (info
.osabi
!= GDB_OSABI_UNKNOWN
);
340 for (handler
= gdb_osabi_handler_list
; handler
!= NULL
;
341 handler
= handler
->next
)
343 if (handler
->osabi
!= info
.osabi
)
346 /* If the architecture described by ARCH_INFO can run code for
347 the architecture we registered the handler for, then the
348 handler is applicable. Note, though, that if the handler is
349 for an architecture that is a superset of ARCH_INFO, we can't
350 use that --- it would be perfectly correct for it to install
351 gdbarch methods that refer to registers / instructions /
352 other facilities ARCH_INFO doesn't have.
354 NOTE: kettenis/20021027: There may be more than one machine
355 type that is compatible with the desired machine type. Right
356 now we simply return the first match, which is fine for now.
357 However, we might want to do something smarter in the future. */
358 /* NOTE: cagney/2003-10-23: The code for "a can_run_code_for b"
359 is implemented using BFD's compatible method (a->compatible
360 (b) == a -- the lowest common denominator between a and b is
361 a). That method's definition of compatible may not be as you
362 expect. For instance the test "amd64 can run code for i386"
363 (or more generally "64-bit ISA can run code for the 32-bit
364 ISA"). BFD doesn't normally consider 32-bit and 64-bit
365 "compatible" so it doesn't succeed. */
366 if (can_run_code_for (info
.bfd_arch_info
, handler
->arch_info
))
376 has_gdb_osabi_handler (struct gdbarch_info info
)
378 return gdbarch_osabi_handler (info
) != nullptr;
382 gdbarch_init_osabi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
384 struct gdb_osabi_handler
*handler
;
386 gdb_assert (info
.osabi
!= GDB_OSABI_UNKNOWN
);
387 handler
= gdbarch_osabi_handler (info
);
389 if (handler
!= nullptr)
391 (*handler
->init_osabi
) (info
, gdbarch
);
395 if (info
.osabi
== GDB_OSABI_NONE
)
397 /* Don't complain about no OSABI. Assume the user knows
398 what they are doing. */
403 ("A handler for the OS ABI \"%s\" is not built into this configuration\n"
404 "of GDB. Attempting to continue with the default %s settings.\n",
405 gdbarch_osabi_name (info
.osabi
),
406 info
.bfd_arch_info
->printable_name
);
409 /* Limit on the amount of data to be read. */
410 #define MAX_NOTESZ 128
412 /* Return non-zero if NOTE matches NAME, DESCSZ and TYPE. If
413 *SECTSIZE is non-zero, then this reads that many bytes from
414 the start of the section and clears *SECTSIZE. */
417 check_note (bfd
*abfd
, asection
*sect
, char *note
, unsigned int *sectsize
,
418 const char *name
, unsigned long descsz
, unsigned long type
)
420 unsigned long notesz
;
424 if (!bfd_get_section_contents (abfd
, sect
, note
, 0, *sectsize
))
429 /* Calculate the size of this note. */
430 notesz
= strlen (name
) + 1;
431 notesz
= ((notesz
+ 3) & ~3);
433 notesz
= ((notesz
+ 3) & ~3);
435 /* If this assertion triggers, increase MAX_NOTESZ. */
436 gdb_assert (notesz
<= MAX_NOTESZ
);
438 /* Check whether SECT is big enough to contain the complete note. */
439 if (notesz
> bfd_section_size (sect
))
442 /* Check the note name. */
443 if (bfd_h_get_32 (abfd
, note
) != (strlen (name
) + 1)
444 || strcmp (note
+ 12, name
) != 0)
447 /* Check the descriptor size. */
448 if (bfd_h_get_32 (abfd
, note
+ 4) != descsz
)
451 /* Check the note type. */
452 if (bfd_h_get_32 (abfd
, note
+ 8) != type
)
458 /* Generic sniffer for ELF flavoured files. */
461 generic_elf_osabi_sniff_abi_tag_sections (bfd
*abfd
, asection
*sect
,
462 enum gdb_osabi
*osabi
)
465 unsigned int sectsize
;
468 name
= bfd_section_name (sect
);
469 sectsize
= bfd_section_size (sect
);
471 /* Limit the amount of data to read. */
472 if (sectsize
> MAX_NOTESZ
)
473 sectsize
= MAX_NOTESZ
;
475 /* We lazily read the section data here. Since we use
476 BFD_DECOMPRESS, we can't use bfd_get_section_contents on a
477 compressed section. But, since note sections are not compressed,
478 deferring the reading until we recognize the section avoids any
480 note
= (char *) alloca (sectsize
);
482 /* .note.ABI-tag notes, used by GNU/Linux and FreeBSD. */
483 if (strcmp (name
, ".note.ABI-tag") == 0)
486 if (check_note (abfd
, sect
, note
, §size
, "GNU", 16, NT_GNU_ABI_TAG
))
488 unsigned int abi_tag
= bfd_h_get_32 (abfd
, note
+ 16);
492 case GNU_ABI_TAG_LINUX
:
493 *osabi
= GDB_OSABI_LINUX
;
496 case GNU_ABI_TAG_HURD
:
497 *osabi
= GDB_OSABI_HURD
;
500 case GNU_ABI_TAG_SOLARIS
:
501 *osabi
= GDB_OSABI_SOLARIS
;
504 case GNU_ABI_TAG_FREEBSD
:
505 *osabi
= GDB_OSABI_FREEBSD
;
508 case GNU_ABI_TAG_NETBSD
:
509 *osabi
= GDB_OSABI_NETBSD
;
513 warning (_("GNU ABI tag value %u unrecognized."), abi_tag
);
520 if (check_note (abfd
, sect
, note
, §size
, "FreeBSD", 4,
523 /* There is no need to check the version yet. */
524 *osabi
= GDB_OSABI_FREEBSD
;
531 /* .note.netbsd.ident notes, used by NetBSD. */
532 if (strcmp (name
, ".note.netbsd.ident") == 0
533 && check_note (abfd
, sect
, note
, §size
, "NetBSD", 4, NT_NETBSD_IDENT
))
535 /* There is no need to check the version yet. */
536 *osabi
= GDB_OSABI_NETBSD
;
540 /* .note.openbsd.ident notes, used by OpenBSD. */
541 if (strcmp (name
, ".note.openbsd.ident") == 0
542 && check_note (abfd
, sect
, note
, §size
, "OpenBSD", 4,
545 /* There is no need to check the version yet. */
546 *osabi
= GDB_OSABI_OPENBSD
;
550 /* .note.netbsdcore.procinfo notes, used by NetBSD. */
551 if (strcmp (name
, ".note.netbsdcore.procinfo") == 0)
553 *osabi
= GDB_OSABI_NETBSD
;
558 static enum gdb_osabi
559 generic_elf_osabi_sniffer (bfd
*abfd
)
561 unsigned int elfosabi
;
562 enum gdb_osabi osabi
= GDB_OSABI_UNKNOWN
;
564 elfosabi
= elf_elfheader (abfd
)->e_ident
[EI_OSABI
];
571 /* When the EI_OSABI field in the ELF header is ELFOSABI_NONE
572 (0), then the ELF structures in the file are conforming to
573 the base specification for that machine (there are no
574 OS-specific extensions). In order to determine the real OS
575 in use, we must look for OS-specific notes.
577 The same applies for ELFOSABI_GNU: this can mean GNU/Hurd,
578 GNU/Linux, and possibly more. */
580 /* And likewise ELFOSABI_HPUX. For some reason the default
581 value for the EI_OSABI field is ELFOSABI_HPUX for all PA-RISC
582 targets (with the exception of GNU/Linux). */
583 for (asection
*sect
: gdb_bfd_sections (abfd
))
584 generic_elf_osabi_sniff_abi_tag_sections (abfd
, sect
, &osabi
);
587 case ELFOSABI_FREEBSD
:
588 osabi
= GDB_OSABI_FREEBSD
;
591 case ELFOSABI_NETBSD
:
592 osabi
= GDB_OSABI_NETBSD
;
595 case ELFOSABI_SOLARIS
:
596 osabi
= GDB_OSABI_SOLARIS
;
599 case ELFOSABI_OPENVMS
:
600 osabi
= GDB_OSABI_OPENVMS
;
604 if (osabi
== GDB_OSABI_UNKNOWN
)
606 /* The FreeBSD folks have been naughty; they stored the string
607 "FreeBSD" in the padding of the e_ident field of the ELF
608 header to "brand" their ELF binaries in FreeBSD 3.x. */
609 if (memcmp (&elf_elfheader (abfd
)->e_ident
[8],
610 "FreeBSD", sizeof ("FreeBSD")) == 0)
611 osabi
= GDB_OSABI_FREEBSD
;
618 set_osabi (const char *args
, int from_tty
, struct cmd_list_element
*c
)
620 if (strcmp (set_osabi_string
, "auto") == 0)
621 user_osabi_state
= osabi_auto
;
622 else if (strcmp (set_osabi_string
, "default") == 0)
624 user_selected_osabi
= GDB_OSABI_DEFAULT
;
625 user_osabi_state
= osabi_user
;
631 for (i
= 1; i
< GDB_OSABI_INVALID
; i
++)
633 enum gdb_osabi osabi
= (enum gdb_osabi
) i
;
635 if (strcmp (set_osabi_string
, gdbarch_osabi_name (osabi
)) == 0)
637 user_selected_osabi
= osabi
;
638 user_osabi_state
= osabi_user
;
642 if (i
== GDB_OSABI_INVALID
)
643 internal_error (_("Invalid OS ABI \"%s\" passed to command handler."),
647 /* NOTE: At some point (true multiple architectures) we'll need to be more
650 if (! gdbarch_update_p (info
))
651 internal_error (_("Updating OS ABI failed."));
655 show_osabi (struct ui_file
*file
, int from_tty
, struct cmd_list_element
*c
,
658 if (user_osabi_state
== osabi_auto
)
660 _("The current OS ABI is \"auto\" "
661 "(currently \"%s\").\n"),
662 gdbarch_osabi_name (gdbarch_osabi (get_current_arch ())));
664 gdb_printf (file
, _("The current OS ABI is \"%s\".\n"),
665 gdbarch_osabi_name (user_selected_osabi
));
667 if (GDB_OSABI_DEFAULT
!= GDB_OSABI_UNKNOWN
)
668 gdb_printf (file
, _("The default OS ABI is \"%s\".\n"),
669 gdbarch_osabi_name (GDB_OSABI_DEFAULT
));
672 void _initialize_gdb_osabi ();
674 _initialize_gdb_osabi ()
676 if (strcmp (gdb_osabi_names
[GDB_OSABI_INVALID
].pretty
, "<invalid>") != 0)
678 (_("_initialize_gdb_osabi: gdb_osabi_names[] is inconsistent"));
680 /* Register a generic sniffer for ELF flavoured files. */
681 gdbarch_register_osabi_sniffer (bfd_arch_unknown
,
682 bfd_target_elf_flavour
,
683 generic_elf_osabi_sniffer
);
685 /* Register the "set osabi" command. */
686 user_osabi_state
= osabi_auto
;
687 set_osabi_string
= gdb_osabi_available_names
[0];
688 gdb_assert (strcmp (set_osabi_string
, "auto") == 0);
689 add_setshow_enum_cmd ("osabi", class_support
, gdb_osabi_available_names
,
691 _("Set OS ABI of target."),
692 _("Show OS ABI of target."),
693 NULL
, set_osabi
, show_osabi
,
694 &setlist
, &showlist
);