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 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., 51 Franklin Street, Fifth Floor,
20 Boston, MA 02110-1301, USA. */
24 #include "gdb_assert.h"
25 #include "gdb_string.h"
28 #include "arch-utils.h"
34 #ifndef GDB_OSABI_DEFAULT
35 #define GDB_OSABI_DEFAULT GDB_OSABI_UNKNOWN
38 /* State for the "set osabi" command. */
39 static enum { osabi_auto
, osabi_default
, osabi_user
} user_osabi_state
;
40 static enum gdb_osabi user_selected_osabi
;
41 static const char *gdb_osabi_available_names
[GDB_OSABI_INVALID
+ 3] = {
47 static const char *set_osabi_string
;
49 /* This table matches the indices assigned to enum gdb_osabi. Keep
51 static const char * const gdb_osabi_names
[] =
81 gdbarch_osabi_name (enum gdb_osabi osabi
)
83 if (osabi
>= GDB_OSABI_UNKNOWN
&& osabi
< GDB_OSABI_INVALID
)
84 return gdb_osabi_names
[osabi
];
86 return gdb_osabi_names
[GDB_OSABI_INVALID
];
89 /* Handler for a given architecture/OS ABI pair. There should be only
90 one handler for a given OS ABI each architecture family. */
91 struct gdb_osabi_handler
93 struct gdb_osabi_handler
*next
;
94 const struct bfd_arch_info
*arch_info
;
96 void (*init_osabi
)(struct gdbarch_info
, struct gdbarch
*);
99 static struct gdb_osabi_handler
*gdb_osabi_handler_list
;
102 gdbarch_register_osabi (enum bfd_architecture arch
, unsigned long machine
,
103 enum gdb_osabi osabi
,
104 void (*init_osabi
)(struct gdbarch_info
,
107 struct gdb_osabi_handler
**handler_p
;
108 const struct bfd_arch_info
*arch_info
= bfd_lookup_arch (arch
, machine
);
109 const char **name_ptr
;
111 /* Registering an OS ABI handler for "unknown" is not allowed. */
112 if (osabi
== GDB_OSABI_UNKNOWN
)
116 _("gdbarch_register_osabi: An attempt to register a handler for "
117 "OS ABI \"%s\" for architecture %s was made. The handler will "
118 "not be registered"),
119 gdbarch_osabi_name (osabi
),
120 bfd_printable_arch_mach (arch
, machine
));
124 gdb_assert (arch_info
);
126 for (handler_p
= &gdb_osabi_handler_list
; *handler_p
!= NULL
;
127 handler_p
= &(*handler_p
)->next
)
129 if ((*handler_p
)->arch_info
== arch_info
130 && (*handler_p
)->osabi
== osabi
)
134 _("gdbarch_register_osabi: A handler for OS ABI \"%s\" "
135 "has already been registered for architecture %s"),
136 gdbarch_osabi_name (osabi
),
137 arch_info
->printable_name
);
138 /* If user wants to continue, override previous definition. */
139 (*handler_p
)->init_osabi
= init_osabi
;
145 = (struct gdb_osabi_handler
*) xmalloc (sizeof (struct gdb_osabi_handler
));
146 (*handler_p
)->next
= NULL
;
147 (*handler_p
)->arch_info
= arch_info
;
148 (*handler_p
)->osabi
= osabi
;
149 (*handler_p
)->init_osabi
= init_osabi
;
151 /* Add this OS ABI to the list of enum values for "set osabi", if it isn't
153 for (name_ptr
= gdb_osabi_available_names
; *name_ptr
; name_ptr
++)
155 if (*name_ptr
== gdbarch_osabi_name (osabi
))
158 *name_ptr
++ = gdbarch_osabi_name (osabi
);
163 /* Sniffer to find the OS ABI for a given file's architecture and flavour.
164 It is legal to have multiple sniffers for each arch/flavour pair, to
165 disambiguate one OS's a.out from another, for example. The first sniffer
166 to return something other than GDB_OSABI_UNKNOWN wins, so a sniffer should
167 be careful to claim a file only if it knows for sure what it is. */
168 struct gdb_osabi_sniffer
170 struct gdb_osabi_sniffer
*next
;
171 enum bfd_architecture arch
; /* bfd_arch_unknown == wildcard */
172 enum bfd_flavour flavour
;
173 enum gdb_osabi (*sniffer
)(bfd
*);
176 static struct gdb_osabi_sniffer
*gdb_osabi_sniffer_list
;
179 gdbarch_register_osabi_sniffer (enum bfd_architecture arch
,
180 enum bfd_flavour flavour
,
181 enum gdb_osabi (*sniffer_fn
)(bfd
*))
183 struct gdb_osabi_sniffer
*sniffer
;
186 (struct gdb_osabi_sniffer
*) xmalloc (sizeof (struct gdb_osabi_sniffer
));
187 sniffer
->arch
= arch
;
188 sniffer
->flavour
= flavour
;
189 sniffer
->sniffer
= sniffer_fn
;
191 sniffer
->next
= gdb_osabi_sniffer_list
;
192 gdb_osabi_sniffer_list
= sniffer
;
197 gdbarch_lookup_osabi (bfd
*abfd
)
199 struct gdb_osabi_sniffer
*sniffer
;
200 enum gdb_osabi osabi
, match
;
203 /* If we aren't in "auto" mode, return the specified OS ABI. */
204 if (user_osabi_state
== osabi_user
)
205 return user_selected_osabi
;
207 /* If we don't have a binary, return the default OS ABI (if set) or
208 unknown (otherwise). */
210 return GDB_OSABI_DEFAULT
;
212 match
= GDB_OSABI_UNKNOWN
;
215 for (sniffer
= gdb_osabi_sniffer_list
; sniffer
!= NULL
;
216 sniffer
= sniffer
->next
)
218 if ((sniffer
->arch
== bfd_arch_unknown
/* wildcard */
219 || sniffer
->arch
== bfd_get_arch (abfd
))
220 && sniffer
->flavour
== bfd_get_flavour (abfd
))
222 osabi
= (*sniffer
->sniffer
) (abfd
);
223 if (osabi
< GDB_OSABI_UNKNOWN
|| osabi
>= GDB_OSABI_INVALID
)
227 _("gdbarch_lookup_osabi: invalid OS ABI (%d) from sniffer "
228 "for architecture %s flavour %d"),
230 bfd_printable_arch_mach (bfd_get_arch (abfd
), 0),
231 (int) bfd_get_flavour (abfd
));
233 else if (osabi
!= GDB_OSABI_UNKNOWN
)
235 /* A specific sniffer always overrides a generic sniffer.
236 Croak on multiple match if the two matches are of the
237 same class. If the user wishes to continue, we'll use
239 if (match
!= GDB_OSABI_UNKNOWN
)
241 if ((match_specific
&& sniffer
->arch
!= bfd_arch_unknown
)
242 || (!match_specific
&& sniffer
->arch
== bfd_arch_unknown
))
246 _("gdbarch_lookup_osabi: multiple %sspecific OS ABI "
247 "match for architecture %s flavour %d: first "
248 "match \"%s\", second match \"%s\""),
249 match_specific
? "" : "non-",
250 bfd_printable_arch_mach (bfd_get_arch (abfd
), 0),
251 (int) bfd_get_flavour (abfd
),
252 gdbarch_osabi_name (match
),
253 gdbarch_osabi_name (osabi
));
255 else if (sniffer
->arch
!= bfd_arch_unknown
)
264 if (sniffer
->arch
!= bfd_arch_unknown
)
271 /* If we didn't find a match, but a default was specified at configure
272 time, return the default. */
273 if (GDB_OSABI_DEFAULT
!= GDB_OSABI_UNKNOWN
&& match
== GDB_OSABI_UNKNOWN
)
274 return GDB_OSABI_DEFAULT
;
280 /* Return non-zero if architecture A can run code written for
283 can_run_code_for (const struct bfd_arch_info
*a
, const struct bfd_arch_info
*b
)
285 /* BFD's 'A->compatible (A, B)' functions return zero if A and B are
286 incompatible. But if they are compatible, it returns the 'more
287 featureful' of the two arches. That is, if A can run code
288 written for B, but B can't run code written for A, then it'll
291 struct bfd_arch_info objects are singletons: that is, there's
292 supposed to be exactly one instance for a given machine. So you
293 can tell whether two are equivalent by comparing pointers. */
294 return (a
== b
|| a
->compatible (a
, b
) == a
);
299 gdbarch_init_osabi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
301 struct gdb_osabi_handler
*handler
;
303 if (info
.osabi
== GDB_OSABI_UNKNOWN
)
305 /* Don't complain about an unknown OSABI. Assume the user knows
306 what they are doing. */
310 for (handler
= gdb_osabi_handler_list
; handler
!= NULL
;
311 handler
= handler
->next
)
313 if (handler
->osabi
!= info
.osabi
)
316 /* If the architecture described by ARCH_INFO can run code for
317 the architcture we registered the handler for, then the
318 handler is applicable. Note, though, that if the handler is
319 for an architecture that is a superset of ARCH_INFO, we can't
320 use that --- it would be perfectly correct for it to install
321 gdbarch methods that refer to registers / instructions /
322 other facilities ARCH_INFO doesn't have.
324 NOTE: kettenis/20021027: There may be more than one machine
325 type that is compatible with the desired machine type. Right
326 now we simply return the first match, which is fine for now.
327 However, we might want to do something smarter in the future. */
328 /* NOTE: cagney/2003-10-23: The code for "a can_run_code_for b"
329 is implemented using BFD's compatible method (a->compatible
330 (b) == a -- the lowest common denominator between a and b is
331 a). That method's definition of compatible may not be as you
332 expect. For instance the test "amd64 can run code for i386"
333 (or more generally "64-bit ISA can run code for the 32-bit
334 ISA"). BFD doesn't normally consider 32-bit and 64-bit
335 "compatible" so it doesn't succeed. */
336 if (can_run_code_for (info
.bfd_arch_info
, handler
->arch_info
))
338 (*handler
->init_osabi
) (info
, gdbarch
);
344 ("A handler for the OS ABI \"%s\" is not built into this configuration\n"
345 "of GDB. Attempting to continue with the default %s settings.\n",
346 gdbarch_osabi_name (info
.osabi
),
347 info
.bfd_arch_info
->printable_name
);
350 /* Limit on the amount of data to be read. */
351 #define MAX_NOTESZ 128
353 /* Return non-zero if NOTE matches NAME, DESCSZ and TYPE. */
356 check_note (bfd
*abfd
, asection
*sect
, const char *note
,
357 const char *name
, unsigned long descsz
, unsigned long type
)
359 unsigned long notesz
;
361 /* Calculate the size of this note. */
362 notesz
= strlen (name
) + 1;
363 notesz
= ((notesz
+ 3) & ~3);
365 notesz
= ((notesz
+ 3) & ~3);
367 /* If this assertion triggers, increase MAX_NOTESZ. */
368 gdb_assert (notesz
<= MAX_NOTESZ
);
370 /* Check whether SECT is big enough to comtain the complete note. */
371 if (notesz
> bfd_section_size (abfd
, sect
))
374 /* Check the note name. */
375 if (bfd_h_get_32 (abfd
, note
) != (strlen (name
) + 1)
376 || strcmp (note
+ 12, name
) != 0)
379 /* Check the descriptor size. */
380 if (bfd_h_get_32 (abfd
, note
+ 4) != descsz
)
383 /* Check the note type. */
384 if (bfd_h_get_32 (abfd
, note
+ 8) != type
)
390 /* Generic sniffer for ELF flavoured files. */
393 generic_elf_osabi_sniff_abi_tag_sections (bfd
*abfd
, asection
*sect
, void *obj
)
395 enum gdb_osabi
*osabi
= obj
;
397 unsigned int sectsize
;
400 name
= bfd_get_section_name (abfd
, sect
);
401 sectsize
= bfd_section_size (abfd
, sect
);
403 /* Limit the amount of data to read. */
404 if (sectsize
> MAX_NOTESZ
)
405 sectsize
= MAX_NOTESZ
;
407 note
= alloca (sectsize
);
408 bfd_get_section_contents (abfd
, sect
, note
, 0, sectsize
);
410 /* .note.ABI-tag notes, used by GNU/Linux and FreeBSD. */
411 if (strcmp (name
, ".note.ABI-tag") == 0)
414 if (check_note (abfd
, sect
, note
, "GNU", 16, NT_GNU_ABI_TAG
))
416 unsigned int abi_tag
= bfd_h_get_32 (abfd
, note
+ 16);
420 case GNU_ABI_TAG_LINUX
:
421 *osabi
= GDB_OSABI_LINUX
;
424 case GNU_ABI_TAG_HURD
:
425 *osabi
= GDB_OSABI_HURD
;
428 case GNU_ABI_TAG_SOLARIS
:
429 *osabi
= GDB_OSABI_SOLARIS
;
432 case GNU_ABI_TAG_FREEBSD
:
433 *osabi
= GDB_OSABI_FREEBSD_ELF
;
436 case GNU_ABI_TAG_NETBSD
:
437 *osabi
= GDB_OSABI_NETBSD_ELF
;
441 internal_error (__FILE__
, __LINE__
, _("\
442 generic_elf_osabi_sniff_abi_tag_sections: unknown OS number %d"),
449 if (check_note (abfd
, sect
, note
, "FreeBSD", 4, NT_FREEBSD_ABI_TAG
))
451 /* There is no need to check the version yet. */
452 *osabi
= GDB_OSABI_FREEBSD_ELF
;
459 /* .note.netbsd.ident notes, used by NetBSD. */
460 if (strcmp (name
, ".note.netbsd.ident") == 0
461 && check_note (abfd
, sect
, note
, "NetBSD", 4, NT_NETBSD_IDENT
))
463 /* There is no need to check the version yet. */
464 *osabi
= GDB_OSABI_NETBSD_ELF
;
468 /* .note.openbsd.ident notes, used by OpenBSD. */
469 if (strcmp (name
, ".note.openbsd.ident") == 0
470 && check_note (abfd
, sect
, note
, "OpenBSD", 4, NT_OPENBSD_IDENT
))
472 /* There is no need to check the version yet. */
473 *osabi
= GDB_OSABI_OPENBSD_ELF
;
477 /* .note.netbsdcore.procinfo notes, used by NetBSD. */
478 if (strcmp (name
, ".note.netbsdcore.procinfo") == 0)
480 *osabi
= GDB_OSABI_NETBSD_ELF
;
485 static enum gdb_osabi
486 generic_elf_osabi_sniffer (bfd
*abfd
)
488 unsigned int elfosabi
;
489 enum gdb_osabi osabi
= GDB_OSABI_UNKNOWN
;
491 elfosabi
= elf_elfheader (abfd
)->e_ident
[EI_OSABI
];
496 /* When the EI_OSABI field in the ELF header is ELFOSABI_NONE
497 (0), then the ELF structures in the file are conforming to
498 the base specification for that machine (there are no
499 OS-specific extensions). In order to determine the real OS
500 in use we must look for OS-specific notes. */
501 bfd_map_over_sections (abfd
,
502 generic_elf_osabi_sniff_abi_tag_sections
,
506 case ELFOSABI_FREEBSD
:
507 osabi
= GDB_OSABI_FREEBSD_ELF
;
510 case ELFOSABI_NETBSD
:
511 osabi
= GDB_OSABI_NETBSD_ELF
;
515 osabi
= GDB_OSABI_LINUX
;
519 osabi
= GDB_OSABI_HURD
;
522 case ELFOSABI_SOLARIS
:
523 osabi
= GDB_OSABI_SOLARIS
;
527 /* For some reason the default value for the EI_OSABI field is
528 ELFOSABI_HPUX for all PA-RISC targets (with the exception of
529 GNU/Linux). We use HP-UX ELF as the default, but let any
530 OS-specific notes override this. */
531 osabi
= GDB_OSABI_HPUX_ELF
;
532 bfd_map_over_sections (abfd
,
533 generic_elf_osabi_sniff_abi_tag_sections
,
538 if (osabi
== GDB_OSABI_UNKNOWN
)
540 /* The FreeBSD folks have been naughty; they stored the string
541 "FreeBSD" in the padding of the e_ident field of the ELF
542 header to "brand" their ELF binaries in FreeBSD 3.x. */
543 if (memcmp (&elf_elfheader (abfd
)->e_ident
[8],
544 "FreeBSD", sizeof ("FreeBSD")) == 0)
545 osabi
= GDB_OSABI_FREEBSD_ELF
;
552 set_osabi (char *args
, int from_tty
, struct cmd_list_element
*c
)
554 struct gdbarch_info info
;
556 if (strcmp (set_osabi_string
, "auto") == 0)
557 user_osabi_state
= osabi_auto
;
558 else if (strcmp (set_osabi_string
, "default") == 0)
560 user_selected_osabi
= GDB_OSABI_DEFAULT
;
561 user_osabi_state
= osabi_user
;
563 else if (strcmp (set_osabi_string
, "none") == 0)
565 user_selected_osabi
= GDB_OSABI_UNKNOWN
;
566 user_osabi_state
= osabi_user
;
571 for (i
= 1; i
< GDB_OSABI_INVALID
; i
++)
572 if (strcmp (set_osabi_string
, gdbarch_osabi_name (i
)) == 0)
574 user_selected_osabi
= i
;
575 user_osabi_state
= osabi_user
;
578 if (i
== GDB_OSABI_INVALID
)
579 internal_error (__FILE__
, __LINE__
,
580 _("Invalid OS ABI \"%s\" passed to command handler."),
584 /* NOTE: At some point (true multiple architectures) we'll need to be more
586 gdbarch_info_init (&info
);
587 if (! gdbarch_update_p (info
))
588 internal_error (__FILE__
, __LINE__
, _("Updating OS ABI failed."));
592 show_osabi (struct ui_file
*file
, int from_tty
, struct cmd_list_element
*c
,
595 if (user_osabi_state
== osabi_auto
)
596 fprintf_filtered (file
,
597 _("The current OS ABI is \"auto\" (currently \"%s\").\n"),
598 gdbarch_osabi_name (gdbarch_osabi (current_gdbarch
)));
600 fprintf_filtered (file
, _("The current OS ABI is \"%s\".\n"),
601 gdbarch_osabi_name (user_selected_osabi
));
603 if (GDB_OSABI_DEFAULT
!= GDB_OSABI_UNKNOWN
)
604 fprintf_filtered (file
, _("The default OS ABI is \"%s\".\n"),
605 gdbarch_osabi_name (GDB_OSABI_DEFAULT
));
608 extern initialize_file_ftype _initialize_gdb_osabi
; /* -Wmissing-prototype */
611 _initialize_gdb_osabi (void)
613 struct cmd_list_element
*c
;
615 if (strcmp (gdb_osabi_names
[GDB_OSABI_INVALID
], "<invalid>") != 0)
618 _("_initialize_gdb_osabi: gdb_osabi_names[] is inconsistent"));
620 /* Register a generic sniffer for ELF flavoured files. */
621 gdbarch_register_osabi_sniffer (bfd_arch_unknown
,
622 bfd_target_elf_flavour
,
623 generic_elf_osabi_sniffer
);
625 /* Register the "set osabi" command. */
626 add_setshow_enum_cmd ("osabi", class_support
, gdb_osabi_available_names
,
627 &set_osabi_string
, _("\
628 Set OS ABI of target."), _("\
629 Show OS ABI of target."), NULL
,
632 &setlist
, &showlist
);
633 user_osabi_state
= osabi_auto
;