1 /* OS ABI variant handling for GDB.
3 Copyright (C) 2001-2015 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"
29 #ifndef GDB_OSABI_DEFAULT
30 #define GDB_OSABI_DEFAULT GDB_OSABI_UNKNOWN
33 /* State for the "set osabi" command. */
34 static enum { osabi_auto, osabi_default, osabi_user } user_osabi_state;
35 static enum gdb_osabi user_selected_osabi;
36 static const char *gdb_osabi_available_names[GDB_OSABI_INVALID + 3] = {
42 static const char *set_osabi_string;
44 /* Names associated with each osabi. */
48 /* The "pretty" name. */
52 /* The triplet regexp, or NULL if not known. */
57 /* This table matches the indices assigned to enum gdb_osabi. Keep
59 static const struct osabi_names gdb_osabi_names[] =
66 { "GNU/Linux", "linux(-gnu)?" },
67 { "FreeBSD a.out", NULL },
68 { "FreeBSD ELF", NULL },
69 { "NetBSD a.out", NULL },
70 { "NetBSD ELF", NULL },
71 { "OpenBSD ELF", NULL },
72 { "DragonFly", NULL },
73 { "Windows CE", NULL },
76 { "HP/UX ELF", NULL },
77 { "HP/UX SOM", NULL },
78 { "QNX Neutrino", NULL },
85 { "LynxOS178", NULL },
93 gdbarch_osabi_name (enum gdb_osabi osabi)
95 if (osabi >= GDB_OSABI_UNKNOWN && osabi < GDB_OSABI_INVALID)
96 return gdb_osabi_names[osabi].pretty;
98 return gdb_osabi_names[GDB_OSABI_INVALID].pretty;
104 osabi_triplet_regexp (enum gdb_osabi osabi)
106 if (osabi >= GDB_OSABI_UNKNOWN && osabi < GDB_OSABI_INVALID)
107 return gdb_osabi_names[osabi].regexp;
109 return gdb_osabi_names[GDB_OSABI_INVALID].regexp;
112 /* Lookup the OS ABI corresponding to the specified target description
116 osabi_from_tdesc_string (const char *name)
120 for (i = 0; i < ARRAY_SIZE (gdb_osabi_names); i++)
121 if (strcmp (name, gdb_osabi_names[i].pretty) == 0)
123 /* See note above: the name table matches the indices assigned
124 to enum gdb_osabi. */
125 enum gdb_osabi osabi = (enum gdb_osabi) i;
127 if (osabi == GDB_OSABI_INVALID)
128 return GDB_OSABI_UNKNOWN;
133 return GDB_OSABI_UNKNOWN;
136 /* Handler for a given architecture/OS ABI pair. There should be only
137 one handler for a given OS ABI each architecture family. */
138 struct gdb_osabi_handler
140 struct gdb_osabi_handler *next;
141 const struct bfd_arch_info *arch_info;
142 enum gdb_osabi osabi;
143 void (*init_osabi)(struct gdbarch_info, struct gdbarch *);
146 static struct gdb_osabi_handler *gdb_osabi_handler_list;
149 gdbarch_register_osabi (enum bfd_architecture arch, unsigned long machine,
150 enum gdb_osabi osabi,
151 void (*init_osabi)(struct gdbarch_info,
154 struct gdb_osabi_handler **handler_p;
155 const struct bfd_arch_info *arch_info = bfd_lookup_arch (arch, machine);
156 const char **name_ptr;
158 /* Registering an OS ABI handler for "unknown" is not allowed. */
159 if (osabi == GDB_OSABI_UNKNOWN)
163 _("gdbarch_register_osabi: An attempt to register a handler for "
164 "OS ABI \"%s\" for architecture %s was made. The handler will "
165 "not be registered"),
166 gdbarch_osabi_name (osabi),
167 bfd_printable_arch_mach (arch, machine));
171 gdb_assert (arch_info);
173 for (handler_p = &gdb_osabi_handler_list; *handler_p != NULL;
174 handler_p = &(*handler_p)->next)
176 if ((*handler_p)->arch_info == arch_info
177 && (*handler_p)->osabi == osabi)
181 _("gdbarch_register_osabi: A handler for OS ABI \"%s\" "
182 "has already been registered for architecture %s"),
183 gdbarch_osabi_name (osabi),
184 arch_info->printable_name);
185 /* If user wants to continue, override previous definition. */
186 (*handler_p)->init_osabi = init_osabi;
192 = (struct gdb_osabi_handler *) xmalloc (sizeof (struct gdb_osabi_handler));
193 (*handler_p)->next = NULL;
194 (*handler_p)->arch_info = arch_info;
195 (*handler_p)->osabi = osabi;
196 (*handler_p)->init_osabi = init_osabi;
198 /* Add this OS ABI to the list of enum values for "set osabi", if it isn't
200 for (name_ptr = gdb_osabi_available_names; *name_ptr; name_ptr ++)
202 if (*name_ptr == gdbarch_osabi_name (osabi))
205 *name_ptr++ = gdbarch_osabi_name (osabi);
210 /* Sniffer to find the OS ABI for a given file's architecture and flavour.
211 It is legal to have multiple sniffers for each arch/flavour pair, to
212 disambiguate one OS's a.out from another, for example. The first sniffer
213 to return something other than GDB_OSABI_UNKNOWN wins, so a sniffer should
214 be careful to claim a file only if it knows for sure what it is. */
215 struct gdb_osabi_sniffer
217 struct gdb_osabi_sniffer *next;
218 enum bfd_architecture arch; /* bfd_arch_unknown == wildcard */
219 enum bfd_flavour flavour;
220 enum gdb_osabi (*sniffer)(bfd *);
223 static struct gdb_osabi_sniffer *gdb_osabi_sniffer_list;
226 gdbarch_register_osabi_sniffer (enum bfd_architecture arch,
227 enum bfd_flavour flavour,
228 enum gdb_osabi (*sniffer_fn)(bfd *))
230 struct gdb_osabi_sniffer *sniffer;
233 (struct gdb_osabi_sniffer *) xmalloc (sizeof (struct gdb_osabi_sniffer));
234 sniffer->arch = arch;
235 sniffer->flavour = flavour;
236 sniffer->sniffer = sniffer_fn;
238 sniffer->next = gdb_osabi_sniffer_list;
239 gdb_osabi_sniffer_list = sniffer;
244 gdbarch_lookup_osabi (bfd *abfd)
246 struct gdb_osabi_sniffer *sniffer;
247 enum gdb_osabi osabi, match;
250 /* If we aren't in "auto" mode, return the specified OS ABI. */
251 if (user_osabi_state == osabi_user)
252 return user_selected_osabi;
254 /* If we don't have a binary, just return unknown. The caller may
255 have other sources the OSABI can be extracted from, e.g., the
256 target description. */
258 return GDB_OSABI_UNKNOWN;
260 match = GDB_OSABI_UNKNOWN;
263 for (sniffer = gdb_osabi_sniffer_list; sniffer != NULL;
264 sniffer = sniffer->next)
266 if ((sniffer->arch == bfd_arch_unknown /* wildcard */
267 || sniffer->arch == bfd_get_arch (abfd))
268 && sniffer->flavour == bfd_get_flavour (abfd))
270 osabi = (*sniffer->sniffer) (abfd);
271 if (osabi < GDB_OSABI_UNKNOWN || osabi >= GDB_OSABI_INVALID)
275 _("gdbarch_lookup_osabi: invalid OS ABI (%d) from sniffer "
276 "for architecture %s flavour %d"),
278 bfd_printable_arch_mach (bfd_get_arch (abfd), 0),
279 (int) bfd_get_flavour (abfd));
281 else if (osabi != GDB_OSABI_UNKNOWN)
283 /* A specific sniffer always overrides a generic sniffer.
284 Croak on multiple match if the two matches are of the
285 same class. If the user wishes to continue, we'll use
287 if (match != GDB_OSABI_UNKNOWN)
289 if ((match_specific && sniffer->arch != bfd_arch_unknown)
290 || (!match_specific && sniffer->arch == bfd_arch_unknown))
294 _("gdbarch_lookup_osabi: multiple %sspecific OS ABI "
295 "match for architecture %s flavour %d: first "
296 "match \"%s\", second match \"%s\""),
297 match_specific ? "" : "non-",
298 bfd_printable_arch_mach (bfd_get_arch (abfd), 0),
299 (int) bfd_get_flavour (abfd),
300 gdbarch_osabi_name (match),
301 gdbarch_osabi_name (osabi));
303 else if (sniffer->arch != bfd_arch_unknown)
312 if (sniffer->arch != bfd_arch_unknown)
323 /* Return non-zero if architecture A can run code written for
326 can_run_code_for (const struct bfd_arch_info *a, const struct bfd_arch_info *b)
328 /* BFD's 'A->compatible (A, B)' functions return zero if A and B are
329 incompatible. But if they are compatible, it returns the 'more
330 featureful' of the two arches. That is, if A can run code
331 written for B, but B can't run code written for A, then it'll
334 struct bfd_arch_info objects are singletons: that is, there's
335 supposed to be exactly one instance for a given machine. So you
336 can tell whether two are equivalent by comparing pointers. */
337 return (a == b || a->compatible (a, b) == a);
342 gdbarch_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
344 struct gdb_osabi_handler *handler;
346 if (info.osabi == GDB_OSABI_UNKNOWN)
348 /* Don't complain about an unknown OSABI. Assume the user knows
349 what they are doing. */
353 for (handler = gdb_osabi_handler_list; handler != NULL;
354 handler = handler->next)
356 if (handler->osabi != info.osabi)
359 /* If the architecture described by ARCH_INFO can run code for
360 the architcture we registered the handler for, then the
361 handler is applicable. Note, though, that if the handler is
362 for an architecture that is a superset of ARCH_INFO, we can't
363 use that --- it would be perfectly correct for it to install
364 gdbarch methods that refer to registers / instructions /
365 other facilities ARCH_INFO doesn't have.
367 NOTE: kettenis/20021027: There may be more than one machine
368 type that is compatible with the desired machine type. Right
369 now we simply return the first match, which is fine for now.
370 However, we might want to do something smarter in the future. */
371 /* NOTE: cagney/2003-10-23: The code for "a can_run_code_for b"
372 is implemented using BFD's compatible method (a->compatible
373 (b) == a -- the lowest common denominator between a and b is
374 a). That method's definition of compatible may not be as you
375 expect. For instance the test "amd64 can run code for i386"
376 (or more generally "64-bit ISA can run code for the 32-bit
377 ISA"). BFD doesn't normally consider 32-bit and 64-bit
378 "compatible" so it doesn't succeed. */
379 if (can_run_code_for (info.bfd_arch_info, handler->arch_info))
381 (*handler->init_osabi) (info, gdbarch);
387 ("A handler for the OS ABI \"%s\" is not built into this configuration\n"
388 "of GDB. Attempting to continue with the default %s settings.\n",
389 gdbarch_osabi_name (info.osabi),
390 info.bfd_arch_info->printable_name);
393 /* Limit on the amount of data to be read. */
394 #define MAX_NOTESZ 128
396 /* Return non-zero if NOTE matches NAME, DESCSZ and TYPE. If
397 *SECTSIZE is non-zero, then this reads that many bytes from
398 the start of the section and clears *SECTSIZE. */
401 check_note (bfd *abfd, asection *sect, char *note, unsigned int *sectsize,
402 const char *name, unsigned long descsz, unsigned long type)
404 unsigned long notesz;
408 if (!bfd_get_section_contents (abfd, sect, note, 0, *sectsize))
413 /* Calculate the size of this note. */
414 notesz = strlen (name) + 1;
415 notesz = ((notesz + 3) & ~3);
417 notesz = ((notesz + 3) & ~3);
419 /* If this assertion triggers, increase MAX_NOTESZ. */
420 gdb_assert (notesz <= MAX_NOTESZ);
422 /* Check whether SECT is big enough to comtain the complete note. */
423 if (notesz > bfd_section_size (abfd, sect))
426 /* Check the note name. */
427 if (bfd_h_get_32 (abfd, note) != (strlen (name) + 1)
428 || strcmp (note + 12, name) != 0)
431 /* Check the descriptor size. */
432 if (bfd_h_get_32 (abfd, note + 4) != descsz)
435 /* Check the note type. */
436 if (bfd_h_get_32 (abfd, note + 8) != type)
442 /* Generic sniffer for ELF flavoured files. */
445 generic_elf_osabi_sniff_abi_tag_sections (bfd *abfd, asection *sect, void *obj)
447 enum gdb_osabi *osabi = obj;
449 unsigned int sectsize;
452 name = bfd_get_section_name (abfd, sect);
453 sectsize = bfd_section_size (abfd, sect);
455 /* Limit the amount of data to read. */
456 if (sectsize > MAX_NOTESZ)
457 sectsize = MAX_NOTESZ;
459 /* We lazily read the section data here. Since we use
460 BFD_DECOMPRESS, we can't use bfd_get_section_contents on a
461 compressed section. But, since note sections are not compressed,
462 deferring the reading until we recognize the section avoids any
464 note = alloca (sectsize);
466 /* .note.ABI-tag notes, used by GNU/Linux and FreeBSD. */
467 if (strcmp (name, ".note.ABI-tag") == 0)
470 if (check_note (abfd, sect, note, §size, "GNU", 16, NT_GNU_ABI_TAG))
472 unsigned int abi_tag = bfd_h_get_32 (abfd, note + 16);
476 case GNU_ABI_TAG_LINUX:
477 *osabi = GDB_OSABI_LINUX;
480 case GNU_ABI_TAG_HURD:
481 *osabi = GDB_OSABI_HURD;
484 case GNU_ABI_TAG_SOLARIS:
485 *osabi = GDB_OSABI_SOLARIS;
488 case GNU_ABI_TAG_FREEBSD:
489 *osabi = GDB_OSABI_FREEBSD_ELF;
492 case GNU_ABI_TAG_NETBSD:
493 *osabi = GDB_OSABI_NETBSD_ELF;
497 warning (_("GNU ABI tag value %u unrecognized."), abi_tag);
504 if (check_note (abfd, sect, note, §size, "FreeBSD", 4,
507 /* There is no need to check the version yet. */
508 *osabi = GDB_OSABI_FREEBSD_ELF;
513 if (check_note (abfd, sect, note, §size, "DragonFly", 4,
514 NT_DRAGONFLY_ABI_TAG))
516 /* There is no need to check the version yet. */
517 *osabi = GDB_OSABI_DRAGONFLY;
524 /* .note.netbsd.ident notes, used by NetBSD. */
525 if (strcmp (name, ".note.netbsd.ident") == 0
526 && check_note (abfd, sect, note, §size, "NetBSD", 4, NT_NETBSD_IDENT))
528 /* There is no need to check the version yet. */
529 *osabi = GDB_OSABI_NETBSD_ELF;
533 /* .note.openbsd.ident notes, used by OpenBSD. */
534 if (strcmp (name, ".note.openbsd.ident") == 0
535 && check_note (abfd, sect, note, §size, "OpenBSD", 4,
538 /* There is no need to check the version yet. */
539 *osabi = GDB_OSABI_OPENBSD_ELF;
543 /* .note.netbsdcore.procinfo notes, used by NetBSD. */
544 if (strcmp (name, ".note.netbsdcore.procinfo") == 0)
546 *osabi = GDB_OSABI_NETBSD_ELF;
551 static enum gdb_osabi
552 generic_elf_osabi_sniffer (bfd *abfd)
554 unsigned int elfosabi;
555 enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;
557 elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI];
563 /* When the EI_OSABI field in the ELF header is ELFOSABI_NONE
564 (0), then the ELF structures in the file are conforming to
565 the base specification for that machine (there are no
566 OS-specific extensions). In order to determine the real OS
567 in use, we must look for OS-specific notes.
569 The same applies for ELFOSABI_GNU: this can mean GNU/Hurd,
570 GNU/Linux, and possibly more. */
571 bfd_map_over_sections (abfd,
572 generic_elf_osabi_sniff_abi_tag_sections,
576 case ELFOSABI_FREEBSD:
577 osabi = GDB_OSABI_FREEBSD_ELF;
580 case ELFOSABI_NETBSD:
581 osabi = GDB_OSABI_NETBSD_ELF;
584 case ELFOSABI_SOLARIS:
585 osabi = GDB_OSABI_SOLARIS;
589 /* For some reason the default value for the EI_OSABI field is
590 ELFOSABI_HPUX for all PA-RISC targets (with the exception of
591 GNU/Linux). We use HP-UX ELF as the default, but let any
592 OS-specific notes override this. */
593 osabi = GDB_OSABI_HPUX_ELF;
594 bfd_map_over_sections (abfd,
595 generic_elf_osabi_sniff_abi_tag_sections,
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_ELF;
618 set_osabi (char *args, int from_tty, struct cmd_list_element *c)
620 struct gdbarch_info info;
622 if (strcmp (set_osabi_string, "auto") == 0)
623 user_osabi_state = osabi_auto;
624 else if (strcmp (set_osabi_string, "default") == 0)
626 user_selected_osabi = GDB_OSABI_DEFAULT;
627 user_osabi_state = osabi_user;
629 else if (strcmp (set_osabi_string, "none") == 0)
631 user_selected_osabi = GDB_OSABI_UNKNOWN;
632 user_osabi_state = osabi_user;
638 for (i = 1; i < GDB_OSABI_INVALID; i++)
639 if (strcmp (set_osabi_string, gdbarch_osabi_name (i)) == 0)
641 user_selected_osabi = i;
642 user_osabi_state = osabi_user;
645 if (i == GDB_OSABI_INVALID)
646 internal_error (__FILE__, __LINE__,
647 _("Invalid OS ABI \"%s\" passed to command handler."),
651 /* NOTE: At some point (true multiple architectures) we'll need to be more
653 gdbarch_info_init (&info);
654 if (! gdbarch_update_p (info))
655 internal_error (__FILE__, __LINE__, _("Updating OS ABI failed."));
659 show_osabi (struct ui_file *file, int from_tty, struct cmd_list_element *c,
662 if (user_osabi_state == osabi_auto)
663 fprintf_filtered (file,
664 _("The current OS ABI is \"auto\" "
665 "(currently \"%s\").\n"),
666 gdbarch_osabi_name (gdbarch_osabi (get_current_arch ())));
668 fprintf_filtered (file, _("The current OS ABI is \"%s\".\n"),
669 gdbarch_osabi_name (user_selected_osabi));
671 if (GDB_OSABI_DEFAULT != GDB_OSABI_UNKNOWN)
672 fprintf_filtered (file, _("The default OS ABI is \"%s\".\n"),
673 gdbarch_osabi_name (GDB_OSABI_DEFAULT));
676 extern initialize_file_ftype _initialize_gdb_osabi; /* -Wmissing-prototype */
679 _initialize_gdb_osabi (void)
681 if (strcmp (gdb_osabi_names[GDB_OSABI_INVALID].pretty, "<invalid>") != 0)
684 _("_initialize_gdb_osabi: gdb_osabi_names[] is inconsistent"));
686 /* Register a generic sniffer for ELF flavoured files. */
687 gdbarch_register_osabi_sniffer (bfd_arch_unknown,
688 bfd_target_elf_flavour,
689 generic_elf_osabi_sniffer);
691 /* Register the "set osabi" command. */
692 add_setshow_enum_cmd ("osabi", class_support, gdb_osabi_available_names,
694 _("Set OS ABI of target."),
695 _("Show OS ABI of target."),
696 NULL, set_osabi, show_osabi,
697 &setlist, &showlist);
698 user_osabi_state = osabi_auto;