1 /* OS ABI variant handling for GDB.
3 Copyright (C) 2001, 2002, 2003, 2004 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[] =
82 gdbarch_osabi_name (enum gdb_osabi osabi)
84 if (osabi >= GDB_OSABI_UNKNOWN && osabi < GDB_OSABI_INVALID)
85 return gdb_osabi_names[osabi];
87 return gdb_osabi_names[GDB_OSABI_INVALID];
90 /* Handler for a given architecture/OS ABI pair. There should be only
91 one handler for a given OS ABI each architecture family. */
92 struct gdb_osabi_handler
94 struct gdb_osabi_handler *next;
95 const struct bfd_arch_info *arch_info;
97 void (*init_osabi)(struct gdbarch_info, struct gdbarch *);
100 static struct gdb_osabi_handler *gdb_osabi_handler_list;
103 gdbarch_register_osabi (enum bfd_architecture arch, unsigned long machine,
104 enum gdb_osabi osabi,
105 void (*init_osabi)(struct gdbarch_info,
108 struct gdb_osabi_handler **handler_p;
109 const struct bfd_arch_info *arch_info = bfd_lookup_arch (arch, machine);
110 const char **name_ptr;
112 /* Registering an OS ABI handler for "unknown" is not allowed. */
113 if (osabi == GDB_OSABI_UNKNOWN)
117 _("gdbarch_register_osabi: An attempt to register a handler for "
118 "OS ABI \"%s\" for architecture %s was made. The handler will "
119 "not be registered"),
120 gdbarch_osabi_name (osabi),
121 bfd_printable_arch_mach (arch, machine));
125 gdb_assert (arch_info);
127 for (handler_p = &gdb_osabi_handler_list; *handler_p != NULL;
128 handler_p = &(*handler_p)->next)
130 if ((*handler_p)->arch_info == arch_info
131 && (*handler_p)->osabi == osabi)
135 _("gdbarch_register_osabi: A handler for OS ABI \"%s\" "
136 "has already been registered for architecture %s"),
137 gdbarch_osabi_name (osabi),
138 arch_info->printable_name);
139 /* If user wants to continue, override previous definition. */
140 (*handler_p)->init_osabi = init_osabi;
146 = (struct gdb_osabi_handler *) xmalloc (sizeof (struct gdb_osabi_handler));
147 (*handler_p)->next = NULL;
148 (*handler_p)->arch_info = arch_info;
149 (*handler_p)->osabi = osabi;
150 (*handler_p)->init_osabi = init_osabi;
152 /* Add this OS ABI to the list of enum values for "set osabi", if it isn't
154 for (name_ptr = gdb_osabi_available_names; *name_ptr; name_ptr ++)
156 if (*name_ptr == gdbarch_osabi_name (osabi))
159 *name_ptr++ = gdbarch_osabi_name (osabi);
164 /* Sniffer to find the OS ABI for a given file's architecture and flavour.
165 It is legal to have multiple sniffers for each arch/flavour pair, to
166 disambiguate one OS's a.out from another, for example. The first sniffer
167 to return something other than GDB_OSABI_UNKNOWN wins, so a sniffer should
168 be careful to claim a file only if it knows for sure what it is. */
169 struct gdb_osabi_sniffer
171 struct gdb_osabi_sniffer *next;
172 enum bfd_architecture arch; /* bfd_arch_unknown == wildcard */
173 enum bfd_flavour flavour;
174 enum gdb_osabi (*sniffer)(bfd *);
177 static struct gdb_osabi_sniffer *gdb_osabi_sniffer_list;
180 gdbarch_register_osabi_sniffer (enum bfd_architecture arch,
181 enum bfd_flavour flavour,
182 enum gdb_osabi (*sniffer_fn)(bfd *))
184 struct gdb_osabi_sniffer *sniffer;
187 (struct gdb_osabi_sniffer *) xmalloc (sizeof (struct gdb_osabi_sniffer));
188 sniffer->arch = arch;
189 sniffer->flavour = flavour;
190 sniffer->sniffer = sniffer_fn;
192 sniffer->next = gdb_osabi_sniffer_list;
193 gdb_osabi_sniffer_list = sniffer;
198 gdbarch_lookup_osabi (bfd *abfd)
200 struct gdb_osabi_sniffer *sniffer;
201 enum gdb_osabi osabi, match;
204 /* If we aren't in "auto" mode, return the specified OS ABI. */
205 if (user_osabi_state == osabi_user)
206 return user_selected_osabi;
208 /* If we don't have a binary, return the default OS ABI (if set) or
209 an inconclusive result (otherwise). */
212 if (GDB_OSABI_DEFAULT != GDB_OSABI_UNKNOWN)
213 return GDB_OSABI_DEFAULT;
215 return GDB_OSABI_UNINITIALIZED;
218 match = GDB_OSABI_UNKNOWN;
221 for (sniffer = gdb_osabi_sniffer_list; sniffer != NULL;
222 sniffer = sniffer->next)
224 if ((sniffer->arch == bfd_arch_unknown /* wildcard */
225 || sniffer->arch == bfd_get_arch (abfd))
226 && sniffer->flavour == bfd_get_flavour (abfd))
228 osabi = (*sniffer->sniffer) (abfd);
229 if (osabi < GDB_OSABI_UNKNOWN || osabi >= GDB_OSABI_INVALID)
233 _("gdbarch_lookup_osabi: invalid OS ABI (%d) from sniffer "
234 "for architecture %s flavour %d"),
236 bfd_printable_arch_mach (bfd_get_arch (abfd), 0),
237 (int) bfd_get_flavour (abfd));
239 else if (osabi != GDB_OSABI_UNKNOWN)
241 /* A specific sniffer always overrides a generic sniffer.
242 Croak on multiple match if the two matches are of the
243 same class. If the user wishes to continue, we'll use
245 if (match != GDB_OSABI_UNKNOWN)
247 if ((match_specific && sniffer->arch != bfd_arch_unknown)
248 || (!match_specific && sniffer->arch == bfd_arch_unknown))
252 _("gdbarch_lookup_osabi: multiple %sspecific OS ABI "
253 "match for architecture %s flavour %d: first "
254 "match \"%s\", second match \"%s\""),
255 match_specific ? "" : "non-",
256 bfd_printable_arch_mach (bfd_get_arch (abfd), 0),
257 (int) bfd_get_flavour (abfd),
258 gdbarch_osabi_name (match),
259 gdbarch_osabi_name (osabi));
261 else if (sniffer->arch != bfd_arch_unknown)
270 if (sniffer->arch != bfd_arch_unknown)
277 /* If we didn't find a match, but a default was specified at configure
278 time, return the default. */
279 if (GDB_OSABI_DEFAULT != GDB_OSABI_UNKNOWN && match == GDB_OSABI_UNKNOWN)
280 return GDB_OSABI_DEFAULT;
286 /* Return non-zero if architecture A can run code written for
289 can_run_code_for (const struct bfd_arch_info *a, const struct bfd_arch_info *b)
291 /* BFD's 'A->compatible (A, B)' functions return zero if A and B are
292 incompatible. But if they are compatible, it returns the 'more
293 featureful' of the two arches. That is, if A can run code
294 written for B, but B can't run code written for A, then it'll
297 struct bfd_arch_info objects are singletons: that is, there's
298 supposed to be exactly one instance for a given machine. So you
299 can tell whether two are equivalent by comparing pointers. */
300 return (a == b || a->compatible (a, b) == a);
305 gdbarch_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
307 struct gdb_osabi_handler *handler;
309 if (info.osabi == GDB_OSABI_UNKNOWN)
311 /* Don't complain about an unknown OSABI. Assume the user knows
312 what they are doing. */
316 for (handler = gdb_osabi_handler_list; handler != NULL;
317 handler = handler->next)
319 if (handler->osabi != info.osabi)
322 /* If the architecture described by ARCH_INFO can run code for
323 the architcture we registered the handler for, then the
324 handler is applicable. Note, though, that if the handler is
325 for an architecture that is a superset of ARCH_INFO, we can't
326 use that --- it would be perfectly correct for it to install
327 gdbarch methods that refer to registers / instructions /
328 other facilities ARCH_INFO doesn't have.
330 NOTE: kettenis/20021027: There may be more than one machine
331 type that is compatible with the desired machine type. Right
332 now we simply return the first match, which is fine for now.
333 However, we might want to do something smarter in the future. */
334 /* NOTE: cagney/2003-10-23: The code for "a can_run_code_for b"
335 is implemented using BFD's compatible method (a->compatible
336 (b) == a -- the lowest common denominator between a and b is
337 a). That method's definition of compatible may not be as you
338 expect. For instance the test "amd64 can run code for i386"
339 (or more generally "64-bit ISA can run code for the 32-bit
340 ISA"). BFD doesn't normally consider 32-bit and 64-bit
341 "compatible" so it doesn't succeed. */
342 if (can_run_code_for (info.bfd_arch_info, handler->arch_info))
344 (*handler->init_osabi) (info, gdbarch);
350 ("A handler for the OS ABI \"%s\" is not built into this configuration\n"
351 "of GDB. Attempting to continue with the default %s settings.\n",
352 gdbarch_osabi_name (info.osabi),
353 info.bfd_arch_info->printable_name);
356 /* Limit on the amount of data to be read. */
357 #define MAX_NOTESZ 128
359 /* Return non-zero if NOTE matches NAME, DESCSZ and TYPE. */
362 check_note (bfd *abfd, asection *sect, const char *note,
363 const char *name, unsigned long descsz, unsigned long type)
365 unsigned long notesz;
367 /* Calculate the size of this note. */
368 notesz = strlen (name) + 1;
369 notesz = ((notesz + 3) & ~3);
371 notesz = ((notesz + 3) & ~3);
373 /* If this assertion triggers, increase MAX_NOTESZ. */
374 gdb_assert (notesz <= MAX_NOTESZ);
376 /* Check whether SECT is big enough to comtain the complete note. */
377 if (notesz > bfd_section_size (abfd, sect))
380 /* Check the note name. */
381 if (bfd_h_get_32 (abfd, note) != (strlen (name) + 1)
382 || strcmp (note + 12, name) != 0)
385 /* Check the descriptor size. */
386 if (bfd_h_get_32 (abfd, note + 4) != descsz)
389 /* Check the note type. */
390 if (bfd_h_get_32 (abfd, note + 8) != type)
396 /* Generic sniffer for ELF flavoured files. */
399 generic_elf_osabi_sniff_abi_tag_sections (bfd *abfd, asection *sect, void *obj)
401 enum gdb_osabi *osabi = obj;
403 unsigned int sectsize;
406 name = bfd_get_section_name (abfd, sect);
407 sectsize = bfd_section_size (abfd, sect);
409 /* Limit the amount of data to read. */
410 if (sectsize > MAX_NOTESZ)
411 sectsize = MAX_NOTESZ;
413 note = alloca (sectsize);
414 bfd_get_section_contents (abfd, sect, note, 0, sectsize);
416 /* .note.ABI-tag notes, used by GNU/Linux and FreeBSD. */
417 if (strcmp (name, ".note.ABI-tag") == 0)
420 if (check_note (abfd, sect, note, "GNU", 16, NT_GNU_ABI_TAG))
422 unsigned int abi_tag = bfd_h_get_32 (abfd, note + 16);
426 case GNU_ABI_TAG_LINUX:
427 *osabi = GDB_OSABI_LINUX;
430 case GNU_ABI_TAG_HURD:
431 *osabi = GDB_OSABI_HURD;
434 case GNU_ABI_TAG_SOLARIS:
435 *osabi = GDB_OSABI_SOLARIS;
438 case GNU_ABI_TAG_FREEBSD:
439 *osabi = GDB_OSABI_FREEBSD_ELF;
442 case GNU_ABI_TAG_NETBSD:
443 *osabi = GDB_OSABI_NETBSD_ELF;
447 internal_error (__FILE__, __LINE__, _("\
448 generic_elf_osabi_sniff_abi_tag_sections: unknown OS number %d"),
455 if (check_note (abfd, sect, note, "FreeBSD", 4, NT_FREEBSD_ABI_TAG))
457 /* There is no need to check the version yet. */
458 *osabi = GDB_OSABI_FREEBSD_ELF;
465 /* .note.netbsd.ident notes, used by NetBSD. */
466 if (strcmp (name, ".note.netbsd.ident") == 0
467 && check_note (abfd, sect, note, "NetBSD", 4, NT_NETBSD_IDENT))
469 /* There is no need to check the version yet. */
470 *osabi = GDB_OSABI_NETBSD_ELF;
474 /* .note.openbsd.ident notes, used by OpenBSD. */
475 if (strcmp (name, ".note.openbsd.ident") == 0
476 && check_note (abfd, sect, note, "OpenBSD", 4, NT_OPENBSD_IDENT))
478 /* There is no need to check the version yet. */
479 *osabi = GDB_OSABI_OPENBSD_ELF;
483 /* .note.netbsdcore.procinfo notes, used by NetBSD. */
484 if (strcmp (name, ".note.netbsdcore.procinfo") == 0)
486 *osabi = GDB_OSABI_NETBSD_ELF;
491 static enum gdb_osabi
492 generic_elf_osabi_sniffer (bfd *abfd)
494 unsigned int elfosabi;
495 enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;
497 elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI];
502 /* When the EI_OSABI field in the ELF header is ELFOSABI_NONE
503 (0), then the ELF structures in the file are conforming to
504 the base specification for that machine (there are no
505 OS-specific extensions). In order to determine the real OS
506 in use we must look for OS-specific notes. */
507 bfd_map_over_sections (abfd,
508 generic_elf_osabi_sniff_abi_tag_sections,
512 case ELFOSABI_FREEBSD:
513 osabi = GDB_OSABI_FREEBSD_ELF;
516 case ELFOSABI_NETBSD:
517 osabi = GDB_OSABI_NETBSD_ELF;
521 osabi = GDB_OSABI_LINUX;
525 osabi = GDB_OSABI_HURD;
528 case ELFOSABI_SOLARIS:
529 osabi = GDB_OSABI_SOLARIS;
533 /* For some reason the default value for the EI_OSABI field is
534 ELFOSABI_HPUX for all PA-RISC targets (with the exception of
535 GNU/Linux). We use HP-UX ELF as the default, but let any
536 OS-specific notes override this. */
537 osabi = GDB_OSABI_HPUX_ELF;
538 bfd_map_over_sections (abfd,
539 generic_elf_osabi_sniff_abi_tag_sections,
544 if (osabi == GDB_OSABI_UNKNOWN)
546 /* The FreeBSD folks have been naughty; they stored the string
547 "FreeBSD" in the padding of the e_ident field of the ELF
548 header to "brand" their ELF binaries in FreeBSD 3.x. */
549 if (memcmp (&elf_elfheader (abfd)->e_ident[8],
550 "FreeBSD", sizeof ("FreeBSD")) == 0)
551 osabi = GDB_OSABI_FREEBSD_ELF;
558 set_osabi (char *args, int from_tty, struct cmd_list_element *c)
560 struct gdbarch_info info;
562 if (strcmp (set_osabi_string, "auto") == 0)
563 user_osabi_state = osabi_auto;
564 else if (strcmp (set_osabi_string, "default") == 0)
566 user_selected_osabi = GDB_OSABI_DEFAULT;
567 user_osabi_state = osabi_user;
569 else if (strcmp (set_osabi_string, "none") == 0)
571 user_selected_osabi = GDB_OSABI_UNKNOWN;
572 user_osabi_state = osabi_user;
577 for (i = 1; i < GDB_OSABI_INVALID; i++)
578 if (strcmp (set_osabi_string, gdbarch_osabi_name (i)) == 0)
580 user_selected_osabi = i;
581 user_osabi_state = osabi_user;
584 if (i == GDB_OSABI_INVALID)
585 internal_error (__FILE__, __LINE__,
586 _("Invalid OS ABI \"%s\" passed to command handler."),
590 /* NOTE: At some point (true multiple architectures) we'll need to be more
592 gdbarch_info_init (&info);
593 if (! gdbarch_update_p (info))
594 internal_error (__FILE__, __LINE__, _("Updating OS ABI failed."));
598 show_osabi (struct ui_file *file, int from_tty, struct cmd_list_element *c,
601 if (user_osabi_state == osabi_auto)
602 fprintf_filtered (file,
603 _("The current OS ABI is \"auto\" (currently \"%s\").\n"),
604 gdbarch_osabi_name (gdbarch_osabi (current_gdbarch)));
606 fprintf_filtered (file, _("The current OS ABI is \"%s\".\n"),
607 gdbarch_osabi_name (user_selected_osabi));
609 if (GDB_OSABI_DEFAULT != GDB_OSABI_UNKNOWN)
610 fprintf_filtered (file, _("The default OS ABI is \"%s\".\n"),
611 gdbarch_osabi_name (GDB_OSABI_DEFAULT));
614 extern initialize_file_ftype _initialize_gdb_osabi; /* -Wmissing-prototype */
617 _initialize_gdb_osabi (void)
619 struct cmd_list_element *c;
621 if (strcmp (gdb_osabi_names[GDB_OSABI_INVALID], "<invalid>") != 0)
624 _("_initialize_gdb_osabi: gdb_osabi_names[] is inconsistent"));
626 /* Register a generic sniffer for ELF flavoured files. */
627 gdbarch_register_osabi_sniffer (bfd_arch_unknown,
628 bfd_target_elf_flavour,
629 generic_elf_osabi_sniffer);
631 /* Register the "set osabi" command. */
632 add_setshow_enum_cmd ("osabi", class_support, gdb_osabi_available_names,
633 &set_osabi_string, _("\
634 Set OS ABI of target."), _("\
635 Show OS ABI of target."), NULL,
638 &setlist, &showlist);
639 user_osabi_state = osabi_auto;