1 /* OS ABI variant handling for GDB.
3 Copyright (C) 2001-2004, 2007-2012 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 /* Lookup the OS ABI corresponding to the specified target description
92 osabi_from_tdesc_string (const char *name
)
96 for (i
= 0; i
< ARRAY_SIZE (gdb_osabi_names
); i
++)
97 if (strcmp (name
, gdb_osabi_names
[i
]) == 0)
99 /* See note above: the name table matches the indices assigned
100 to enum gdb_osabi. */
101 enum gdb_osabi osabi
= (enum gdb_osabi
) i
;
103 if (osabi
== GDB_OSABI_INVALID
)
104 return GDB_OSABI_UNKNOWN
;
109 return GDB_OSABI_UNKNOWN
;
112 /* Handler for a given architecture/OS ABI pair. There should be only
113 one handler for a given OS ABI each architecture family. */
114 struct gdb_osabi_handler
116 struct gdb_osabi_handler
*next
;
117 const struct bfd_arch_info
*arch_info
;
118 enum gdb_osabi osabi
;
119 void (*init_osabi
)(struct gdbarch_info
, struct gdbarch
*);
122 static struct gdb_osabi_handler
*gdb_osabi_handler_list
;
125 gdbarch_register_osabi (enum bfd_architecture arch
, unsigned long machine
,
126 enum gdb_osabi osabi
,
127 void (*init_osabi
)(struct gdbarch_info
,
130 struct gdb_osabi_handler
**handler_p
;
131 const struct bfd_arch_info
*arch_info
= bfd_lookup_arch (arch
, machine
);
132 const char **name_ptr
;
134 /* Registering an OS ABI handler for "unknown" is not allowed. */
135 if (osabi
== GDB_OSABI_UNKNOWN
)
139 _("gdbarch_register_osabi: An attempt to register a handler for "
140 "OS ABI \"%s\" for architecture %s was made. The handler will "
141 "not be registered"),
142 gdbarch_osabi_name (osabi
),
143 bfd_printable_arch_mach (arch
, machine
));
147 gdb_assert (arch_info
);
149 for (handler_p
= &gdb_osabi_handler_list
; *handler_p
!= NULL
;
150 handler_p
= &(*handler_p
)->next
)
152 if ((*handler_p
)->arch_info
== arch_info
153 && (*handler_p
)->osabi
== osabi
)
157 _("gdbarch_register_osabi: A handler for OS ABI \"%s\" "
158 "has already been registered for architecture %s"),
159 gdbarch_osabi_name (osabi
),
160 arch_info
->printable_name
);
161 /* If user wants to continue, override previous definition. */
162 (*handler_p
)->init_osabi
= init_osabi
;
168 = (struct gdb_osabi_handler
*) xmalloc (sizeof (struct gdb_osabi_handler
));
169 (*handler_p
)->next
= NULL
;
170 (*handler_p
)->arch_info
= arch_info
;
171 (*handler_p
)->osabi
= osabi
;
172 (*handler_p
)->init_osabi
= init_osabi
;
174 /* Add this OS ABI to the list of enum values for "set osabi", if it isn't
176 for (name_ptr
= gdb_osabi_available_names
; *name_ptr
; name_ptr
++)
178 if (*name_ptr
== gdbarch_osabi_name (osabi
))
181 *name_ptr
++ = gdbarch_osabi_name (osabi
);
186 /* Sniffer to find the OS ABI for a given file's architecture and flavour.
187 It is legal to have multiple sniffers for each arch/flavour pair, to
188 disambiguate one OS's a.out from another, for example. The first sniffer
189 to return something other than GDB_OSABI_UNKNOWN wins, so a sniffer should
190 be careful to claim a file only if it knows for sure what it is. */
191 struct gdb_osabi_sniffer
193 struct gdb_osabi_sniffer
*next
;
194 enum bfd_architecture arch
; /* bfd_arch_unknown == wildcard */
195 enum bfd_flavour flavour
;
196 enum gdb_osabi (*sniffer
)(bfd
*);
199 static struct gdb_osabi_sniffer
*gdb_osabi_sniffer_list
;
202 gdbarch_register_osabi_sniffer (enum bfd_architecture arch
,
203 enum bfd_flavour flavour
,
204 enum gdb_osabi (*sniffer_fn
)(bfd
*))
206 struct gdb_osabi_sniffer
*sniffer
;
209 (struct gdb_osabi_sniffer
*) xmalloc (sizeof (struct gdb_osabi_sniffer
));
210 sniffer
->arch
= arch
;
211 sniffer
->flavour
= flavour
;
212 sniffer
->sniffer
= sniffer_fn
;
214 sniffer
->next
= gdb_osabi_sniffer_list
;
215 gdb_osabi_sniffer_list
= sniffer
;
220 gdbarch_lookup_osabi (bfd
*abfd
)
222 struct gdb_osabi_sniffer
*sniffer
;
223 enum gdb_osabi osabi
, match
;
226 /* If we aren't in "auto" mode, return the specified OS ABI. */
227 if (user_osabi_state
== osabi_user
)
228 return user_selected_osabi
;
230 /* If we don't have a binary, just return unknown. The caller may
231 have other sources the OSABI can be extracted from, e.g., the
232 target description. */
234 return GDB_OSABI_UNKNOWN
;
236 match
= GDB_OSABI_UNKNOWN
;
239 for (sniffer
= gdb_osabi_sniffer_list
; sniffer
!= NULL
;
240 sniffer
= sniffer
->next
)
242 if ((sniffer
->arch
== bfd_arch_unknown
/* wildcard */
243 || sniffer
->arch
== bfd_get_arch (abfd
))
244 && sniffer
->flavour
== bfd_get_flavour (abfd
))
246 osabi
= (*sniffer
->sniffer
) (abfd
);
247 if (osabi
< GDB_OSABI_UNKNOWN
|| osabi
>= GDB_OSABI_INVALID
)
251 _("gdbarch_lookup_osabi: invalid OS ABI (%d) from sniffer "
252 "for architecture %s flavour %d"),
254 bfd_printable_arch_mach (bfd_get_arch (abfd
), 0),
255 (int) bfd_get_flavour (abfd
));
257 else if (osabi
!= GDB_OSABI_UNKNOWN
)
259 /* A specific sniffer always overrides a generic sniffer.
260 Croak on multiple match if the two matches are of the
261 same class. If the user wishes to continue, we'll use
263 if (match
!= GDB_OSABI_UNKNOWN
)
265 if ((match_specific
&& sniffer
->arch
!= bfd_arch_unknown
)
266 || (!match_specific
&& sniffer
->arch
== bfd_arch_unknown
))
270 _("gdbarch_lookup_osabi: multiple %sspecific OS ABI "
271 "match for architecture %s flavour %d: first "
272 "match \"%s\", second match \"%s\""),
273 match_specific
? "" : "non-",
274 bfd_printable_arch_mach (bfd_get_arch (abfd
), 0),
275 (int) bfd_get_flavour (abfd
),
276 gdbarch_osabi_name (match
),
277 gdbarch_osabi_name (osabi
));
279 else if (sniffer
->arch
!= bfd_arch_unknown
)
288 if (sniffer
->arch
!= bfd_arch_unknown
)
299 /* Return non-zero if architecture A can run code written for
302 can_run_code_for (const struct bfd_arch_info
*a
, const struct bfd_arch_info
*b
)
304 /* BFD's 'A->compatible (A, B)' functions return zero if A and B are
305 incompatible. But if they are compatible, it returns the 'more
306 featureful' of the two arches. That is, if A can run code
307 written for B, but B can't run code written for A, then it'll
310 struct bfd_arch_info objects are singletons: that is, there's
311 supposed to be exactly one instance for a given machine. So you
312 can tell whether two are equivalent by comparing pointers. */
313 return (a
== b
|| a
->compatible (a
, b
) == a
);
318 gdbarch_init_osabi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
320 struct gdb_osabi_handler
*handler
;
322 if (info
.osabi
== GDB_OSABI_UNKNOWN
)
324 /* Don't complain about an unknown OSABI. Assume the user knows
325 what they are doing. */
329 for (handler
= gdb_osabi_handler_list
; handler
!= NULL
;
330 handler
= handler
->next
)
332 if (handler
->osabi
!= info
.osabi
)
335 /* If the architecture described by ARCH_INFO can run code for
336 the architcture we registered the handler for, then the
337 handler is applicable. Note, though, that if the handler is
338 for an architecture that is a superset of ARCH_INFO, we can't
339 use that --- it would be perfectly correct for it to install
340 gdbarch methods that refer to registers / instructions /
341 other facilities ARCH_INFO doesn't have.
343 NOTE: kettenis/20021027: There may be more than one machine
344 type that is compatible with the desired machine type. Right
345 now we simply return the first match, which is fine for now.
346 However, we might want to do something smarter in the future. */
347 /* NOTE: cagney/2003-10-23: The code for "a can_run_code_for b"
348 is implemented using BFD's compatible method (a->compatible
349 (b) == a -- the lowest common denominator between a and b is
350 a). That method's definition of compatible may not be as you
351 expect. For instance the test "amd64 can run code for i386"
352 (or more generally "64-bit ISA can run code for the 32-bit
353 ISA"). BFD doesn't normally consider 32-bit and 64-bit
354 "compatible" so it doesn't succeed. */
355 if (can_run_code_for (info
.bfd_arch_info
, handler
->arch_info
))
357 (*handler
->init_osabi
) (info
, gdbarch
);
363 ("A handler for the OS ABI \"%s\" is not built into this configuration\n"
364 "of GDB. Attempting to continue with the default %s settings.\n",
365 gdbarch_osabi_name (info
.osabi
),
366 info
.bfd_arch_info
->printable_name
);
369 /* Limit on the amount of data to be read. */
370 #define MAX_NOTESZ 128
372 /* Return non-zero if NOTE matches NAME, DESCSZ and TYPE. */
375 check_note (bfd
*abfd
, asection
*sect
, const char *note
,
376 const char *name
, unsigned long descsz
, unsigned long type
)
378 unsigned long notesz
;
380 /* Calculate the size of this note. */
381 notesz
= strlen (name
) + 1;
382 notesz
= ((notesz
+ 3) & ~3);
384 notesz
= ((notesz
+ 3) & ~3);
386 /* If this assertion triggers, increase MAX_NOTESZ. */
387 gdb_assert (notesz
<= MAX_NOTESZ
);
389 /* Check whether SECT is big enough to comtain the complete note. */
390 if (notesz
> bfd_section_size (abfd
, sect
))
393 /* Check the note name. */
394 if (bfd_h_get_32 (abfd
, note
) != (strlen (name
) + 1)
395 || strcmp (note
+ 12, name
) != 0)
398 /* Check the descriptor size. */
399 if (bfd_h_get_32 (abfd
, note
+ 4) != descsz
)
402 /* Check the note type. */
403 if (bfd_h_get_32 (abfd
, note
+ 8) != type
)
409 /* Generic sniffer for ELF flavoured files. */
412 generic_elf_osabi_sniff_abi_tag_sections (bfd
*abfd
, asection
*sect
, void *obj
)
414 enum gdb_osabi
*osabi
= obj
;
416 unsigned int sectsize
;
419 name
= bfd_get_section_name (abfd
, sect
);
420 sectsize
= bfd_section_size (abfd
, sect
);
422 /* Limit the amount of data to read. */
423 if (sectsize
> MAX_NOTESZ
)
424 sectsize
= MAX_NOTESZ
;
426 note
= alloca (sectsize
);
427 bfd_get_section_contents (abfd
, sect
, note
, 0, sectsize
);
429 /* .note.ABI-tag notes, used by GNU/Linux and FreeBSD. */
430 if (strcmp (name
, ".note.ABI-tag") == 0)
433 if (check_note (abfd
, sect
, note
, "GNU", 16, NT_GNU_ABI_TAG
))
435 unsigned int abi_tag
= bfd_h_get_32 (abfd
, note
+ 16);
439 case GNU_ABI_TAG_LINUX
:
440 *osabi
= GDB_OSABI_LINUX
;
443 case GNU_ABI_TAG_HURD
:
444 *osabi
= GDB_OSABI_HURD
;
447 case GNU_ABI_TAG_SOLARIS
:
448 *osabi
= GDB_OSABI_SOLARIS
;
451 case GNU_ABI_TAG_FREEBSD
:
452 *osabi
= GDB_OSABI_FREEBSD_ELF
;
455 case GNU_ABI_TAG_NETBSD
:
456 *osabi
= GDB_OSABI_NETBSD_ELF
;
460 internal_error (__FILE__
, __LINE__
,
461 _("generic_elf_osabi_sniff_abi_tag_sections: "
462 "unknown OS number %d"),
469 if (check_note (abfd
, sect
, note
, "FreeBSD", 4, NT_FREEBSD_ABI_TAG
))
471 /* There is no need to check the version yet. */
472 *osabi
= GDB_OSABI_FREEBSD_ELF
;
479 /* .note.netbsd.ident notes, used by NetBSD. */
480 if (strcmp (name
, ".note.netbsd.ident") == 0
481 && check_note (abfd
, sect
, note
, "NetBSD", 4, NT_NETBSD_IDENT
))
483 /* There is no need to check the version yet. */
484 *osabi
= GDB_OSABI_NETBSD_ELF
;
488 /* .note.openbsd.ident notes, used by OpenBSD. */
489 if (strcmp (name
, ".note.openbsd.ident") == 0
490 && check_note (abfd
, sect
, note
, "OpenBSD", 4, NT_OPENBSD_IDENT
))
492 /* There is no need to check the version yet. */
493 *osabi
= GDB_OSABI_OPENBSD_ELF
;
497 /* .note.netbsdcore.procinfo notes, used by NetBSD. */
498 if (strcmp (name
, ".note.netbsdcore.procinfo") == 0)
500 *osabi
= GDB_OSABI_NETBSD_ELF
;
505 static enum gdb_osabi
506 generic_elf_osabi_sniffer (bfd
*abfd
)
508 unsigned int elfosabi
;
509 enum gdb_osabi osabi
= GDB_OSABI_UNKNOWN
;
511 elfosabi
= elf_elfheader (abfd
)->e_ident
[EI_OSABI
];
517 /* When the EI_OSABI field in the ELF header is ELFOSABI_NONE
518 (0), then the ELF structures in the file are conforming to
519 the base specification for that machine (there are no
520 OS-specific extensions). In order to determine the real OS
521 in use, we must look for OS-specific notes.
523 The same applies for ELFOSABI_GNU: this can mean GNU/Hurd,
524 GNU/Linux, and possibly more. */
525 bfd_map_over_sections (abfd
,
526 generic_elf_osabi_sniff_abi_tag_sections
,
530 case ELFOSABI_FREEBSD
:
531 osabi
= GDB_OSABI_FREEBSD_ELF
;
534 case ELFOSABI_NETBSD
:
535 osabi
= GDB_OSABI_NETBSD_ELF
;
538 case ELFOSABI_SOLARIS
:
539 osabi
= GDB_OSABI_SOLARIS
;
543 /* For some reason the default value for the EI_OSABI field is
544 ELFOSABI_HPUX for all PA-RISC targets (with the exception of
545 GNU/Linux). We use HP-UX ELF as the default, but let any
546 OS-specific notes override this. */
547 osabi
= GDB_OSABI_HPUX_ELF
;
548 bfd_map_over_sections (abfd
,
549 generic_elf_osabi_sniff_abi_tag_sections
,
554 if (osabi
== GDB_OSABI_UNKNOWN
)
556 /* The FreeBSD folks have been naughty; they stored the string
557 "FreeBSD" in the padding of the e_ident field of the ELF
558 header to "brand" their ELF binaries in FreeBSD 3.x. */
559 if (memcmp (&elf_elfheader (abfd
)->e_ident
[8],
560 "FreeBSD", sizeof ("FreeBSD")) == 0)
561 osabi
= GDB_OSABI_FREEBSD_ELF
;
568 set_osabi (char *args
, int from_tty
, struct cmd_list_element
*c
)
570 struct gdbarch_info info
;
572 if (strcmp (set_osabi_string
, "auto") == 0)
573 user_osabi_state
= osabi_auto
;
574 else if (strcmp (set_osabi_string
, "default") == 0)
576 user_selected_osabi
= GDB_OSABI_DEFAULT
;
577 user_osabi_state
= osabi_user
;
579 else if (strcmp (set_osabi_string
, "none") == 0)
581 user_selected_osabi
= GDB_OSABI_UNKNOWN
;
582 user_osabi_state
= osabi_user
;
588 for (i
= 1; i
< GDB_OSABI_INVALID
; i
++)
589 if (strcmp (set_osabi_string
, gdbarch_osabi_name (i
)) == 0)
591 user_selected_osabi
= i
;
592 user_osabi_state
= osabi_user
;
595 if (i
== GDB_OSABI_INVALID
)
596 internal_error (__FILE__
, __LINE__
,
597 _("Invalid OS ABI \"%s\" passed to command handler."),
601 /* NOTE: At some point (true multiple architectures) we'll need to be more
603 gdbarch_info_init (&info
);
604 if (! gdbarch_update_p (info
))
605 internal_error (__FILE__
, __LINE__
, _("Updating OS ABI failed."));
609 show_osabi (struct ui_file
*file
, int from_tty
, struct cmd_list_element
*c
,
612 if (user_osabi_state
== osabi_auto
)
613 fprintf_filtered (file
,
614 _("The current OS ABI is \"auto\" "
615 "(currently \"%s\").\n"),
616 gdbarch_osabi_name (gdbarch_osabi (get_current_arch ())));
618 fprintf_filtered (file
, _("The current OS ABI is \"%s\".\n"),
619 gdbarch_osabi_name (user_selected_osabi
));
621 if (GDB_OSABI_DEFAULT
!= GDB_OSABI_UNKNOWN
)
622 fprintf_filtered (file
, _("The default OS ABI is \"%s\".\n"),
623 gdbarch_osabi_name (GDB_OSABI_DEFAULT
));
626 extern initialize_file_ftype _initialize_gdb_osabi
; /* -Wmissing-prototype */
629 _initialize_gdb_osabi (void)
631 if (strcmp (gdb_osabi_names
[GDB_OSABI_INVALID
], "<invalid>") != 0)
634 _("_initialize_gdb_osabi: gdb_osabi_names[] is inconsistent"));
636 /* Register a generic sniffer for ELF flavoured files. */
637 gdbarch_register_osabi_sniffer (bfd_arch_unknown
,
638 bfd_target_elf_flavour
,
639 generic_elf_osabi_sniffer
);
641 /* Register the "set osabi" command. */
642 add_setshow_enum_cmd ("osabi", class_support
, gdb_osabi_available_names
,
644 _("Set OS ABI of target."),
645 _("Show OS ABI of target."),
646 NULL
, set_osabi
, show_osabi
,
647 &setlist
, &showlist
);
648 user_osabi_state
= osabi_auto
;