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 { "Windows CE", NULL },
75 { "HP/UX ELF", NULL },
76 { "HP/UX SOM", NULL },
77 { "QNX Neutrino", NULL },
84 { "LynxOS178", NULL },
92 gdbarch_osabi_name (enum gdb_osabi osabi)
94 if (osabi >= GDB_OSABI_UNKNOWN && osabi < GDB_OSABI_INVALID)
95 return gdb_osabi_names[osabi].pretty;
97 return gdb_osabi_names[GDB_OSABI_INVALID].pretty;
103 osabi_triplet_regexp (enum gdb_osabi osabi)
105 if (osabi >= GDB_OSABI_UNKNOWN && osabi < GDB_OSABI_INVALID)
106 return gdb_osabi_names[osabi].regexp;
108 return gdb_osabi_names[GDB_OSABI_INVALID].regexp;
111 /* Lookup the OS ABI corresponding to the specified target description
115 osabi_from_tdesc_string (const char *name)
119 for (i = 0; i < ARRAY_SIZE (gdb_osabi_names); i++)
120 if (strcmp (name, gdb_osabi_names[i].pretty) == 0)
122 /* See note above: the name table matches the indices assigned
123 to enum gdb_osabi. */
124 enum gdb_osabi osabi = (enum gdb_osabi) i;
126 if (osabi == GDB_OSABI_INVALID)
127 return GDB_OSABI_UNKNOWN;
132 return GDB_OSABI_UNKNOWN;
135 /* Handler for a given architecture/OS ABI pair. There should be only
136 one handler for a given OS ABI each architecture family. */
137 struct gdb_osabi_handler
139 struct gdb_osabi_handler *next;
140 const struct bfd_arch_info *arch_info;
141 enum gdb_osabi osabi;
142 void (*init_osabi)(struct gdbarch_info, struct gdbarch *);
145 static struct gdb_osabi_handler *gdb_osabi_handler_list;
148 gdbarch_register_osabi (enum bfd_architecture arch, unsigned long machine,
149 enum gdb_osabi osabi,
150 void (*init_osabi)(struct gdbarch_info,
153 struct gdb_osabi_handler **handler_p;
154 const struct bfd_arch_info *arch_info = bfd_lookup_arch (arch, machine);
155 const char **name_ptr;
157 /* Registering an OS ABI handler for "unknown" is not allowed. */
158 if (osabi == GDB_OSABI_UNKNOWN)
162 _("gdbarch_register_osabi: An attempt to register a handler for "
163 "OS ABI \"%s\" for architecture %s was made. The handler will "
164 "not be registered"),
165 gdbarch_osabi_name (osabi),
166 bfd_printable_arch_mach (arch, machine));
170 gdb_assert (arch_info);
172 for (handler_p = &gdb_osabi_handler_list; *handler_p != NULL;
173 handler_p = &(*handler_p)->next)
175 if ((*handler_p)->arch_info == arch_info
176 && (*handler_p)->osabi == osabi)
180 _("gdbarch_register_osabi: A handler for OS ABI \"%s\" "
181 "has already been registered for architecture %s"),
182 gdbarch_osabi_name (osabi),
183 arch_info->printable_name);
184 /* If user wants to continue, override previous definition. */
185 (*handler_p)->init_osabi = init_osabi;
190 (*handler_p) = XNEW (struct gdb_osabi_handler);
191 (*handler_p)->next = NULL;
192 (*handler_p)->arch_info = arch_info;
193 (*handler_p)->osabi = osabi;
194 (*handler_p)->init_osabi = init_osabi;
196 /* Add this OS ABI to the list of enum values for "set osabi", if it isn't
198 for (name_ptr = gdb_osabi_available_names; *name_ptr; name_ptr ++)
200 if (*name_ptr == gdbarch_osabi_name (osabi))
203 *name_ptr++ = gdbarch_osabi_name (osabi);
208 /* Sniffer to find the OS ABI for a given file's architecture and flavour.
209 It is legal to have multiple sniffers for each arch/flavour pair, to
210 disambiguate one OS's a.out from another, for example. The first sniffer
211 to return something other than GDB_OSABI_UNKNOWN wins, so a sniffer should
212 be careful to claim a file only if it knows for sure what it is. */
213 struct gdb_osabi_sniffer
215 struct gdb_osabi_sniffer *next;
216 enum bfd_architecture arch; /* bfd_arch_unknown == wildcard */
217 enum bfd_flavour flavour;
218 enum gdb_osabi (*sniffer)(bfd *);
221 static struct gdb_osabi_sniffer *gdb_osabi_sniffer_list;
224 gdbarch_register_osabi_sniffer (enum bfd_architecture arch,
225 enum bfd_flavour flavour,
226 enum gdb_osabi (*sniffer_fn)(bfd *))
228 struct gdb_osabi_sniffer *sniffer;
230 sniffer = XNEW (struct gdb_osabi_sniffer);
231 sniffer->arch = arch;
232 sniffer->flavour = flavour;
233 sniffer->sniffer = sniffer_fn;
235 sniffer->next = gdb_osabi_sniffer_list;
236 gdb_osabi_sniffer_list = sniffer;
241 gdbarch_lookup_osabi (bfd *abfd)
243 struct gdb_osabi_sniffer *sniffer;
244 enum gdb_osabi osabi, match;
247 /* If we aren't in "auto" mode, return the specified OS ABI. */
248 if (user_osabi_state == osabi_user)
249 return user_selected_osabi;
251 /* If we don't have a binary, just return unknown. The caller may
252 have other sources the OSABI can be extracted from, e.g., the
253 target description. */
255 return GDB_OSABI_UNKNOWN;
257 match = GDB_OSABI_UNKNOWN;
260 for (sniffer = gdb_osabi_sniffer_list; sniffer != NULL;
261 sniffer = sniffer->next)
263 if ((sniffer->arch == bfd_arch_unknown /* wildcard */
264 || sniffer->arch == bfd_get_arch (abfd))
265 && sniffer->flavour == bfd_get_flavour (abfd))
267 osabi = (*sniffer->sniffer) (abfd);
268 if (osabi < GDB_OSABI_UNKNOWN || osabi >= GDB_OSABI_INVALID)
272 _("gdbarch_lookup_osabi: invalid OS ABI (%d) from sniffer "
273 "for architecture %s flavour %d"),
275 bfd_printable_arch_mach (bfd_get_arch (abfd), 0),
276 (int) bfd_get_flavour (abfd));
278 else if (osabi != GDB_OSABI_UNKNOWN)
280 /* A specific sniffer always overrides a generic sniffer.
281 Croak on multiple match if the two matches are of the
282 same class. If the user wishes to continue, we'll use
284 if (match != GDB_OSABI_UNKNOWN)
286 if ((match_specific && sniffer->arch != bfd_arch_unknown)
287 || (!match_specific && sniffer->arch == bfd_arch_unknown))
291 _("gdbarch_lookup_osabi: multiple %sspecific OS ABI "
292 "match for architecture %s flavour %d: first "
293 "match \"%s\", second match \"%s\""),
294 match_specific ? "" : "non-",
295 bfd_printable_arch_mach (bfd_get_arch (abfd), 0),
296 (int) bfd_get_flavour (abfd),
297 gdbarch_osabi_name (match),
298 gdbarch_osabi_name (osabi));
300 else if (sniffer->arch != bfd_arch_unknown)
309 if (sniffer->arch != bfd_arch_unknown)
320 /* Return non-zero if architecture A can run code written for
323 can_run_code_for (const struct bfd_arch_info *a, const struct bfd_arch_info *b)
325 /* BFD's 'A->compatible (A, B)' functions return zero if A and B are
326 incompatible. But if they are compatible, it returns the 'more
327 featureful' of the two arches. That is, if A can run code
328 written for B, but B can't run code written for A, then it'll
331 struct bfd_arch_info objects are singletons: that is, there's
332 supposed to be exactly one instance for a given machine. So you
333 can tell whether two are equivalent by comparing pointers. */
334 return (a == b || a->compatible (a, b) == a);
339 gdbarch_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
341 struct gdb_osabi_handler *handler;
343 if (info.osabi == GDB_OSABI_UNKNOWN)
345 /* Don't complain about an unknown OSABI. Assume the user knows
346 what they are doing. */
350 for (handler = gdb_osabi_handler_list; handler != NULL;
351 handler = handler->next)
353 if (handler->osabi != info.osabi)
356 /* If the architecture described by ARCH_INFO can run code for
357 the architcture we registered the handler for, then the
358 handler is applicable. Note, though, that if the handler is
359 for an architecture that is a superset of ARCH_INFO, we can't
360 use that --- it would be perfectly correct for it to install
361 gdbarch methods that refer to registers / instructions /
362 other facilities ARCH_INFO doesn't have.
364 NOTE: kettenis/20021027: There may be more than one machine
365 type that is compatible with the desired machine type. Right
366 now we simply return the first match, which is fine for now.
367 However, we might want to do something smarter in the future. */
368 /* NOTE: cagney/2003-10-23: The code for "a can_run_code_for b"
369 is implemented using BFD's compatible method (a->compatible
370 (b) == a -- the lowest common denominator between a and b is
371 a). That method's definition of compatible may not be as you
372 expect. For instance the test "amd64 can run code for i386"
373 (or more generally "64-bit ISA can run code for the 32-bit
374 ISA"). BFD doesn't normally consider 32-bit and 64-bit
375 "compatible" so it doesn't succeed. */
376 if (can_run_code_for (info.bfd_arch_info, handler->arch_info))
378 (*handler->init_osabi) (info, gdbarch);
384 ("A handler for the OS ABI \"%s\" is not built into this configuration\n"
385 "of GDB. Attempting to continue with the default %s settings.\n",
386 gdbarch_osabi_name (info.osabi),
387 info.bfd_arch_info->printable_name);
390 /* Limit on the amount of data to be read. */
391 #define MAX_NOTESZ 128
393 /* Return non-zero if NOTE matches NAME, DESCSZ and TYPE. If
394 *SECTSIZE is non-zero, then this reads that many bytes from
395 the start of the section and clears *SECTSIZE. */
398 check_note (bfd *abfd, asection *sect, char *note, unsigned int *sectsize,
399 const char *name, unsigned long descsz, unsigned long type)
401 unsigned long notesz;
405 if (!bfd_get_section_contents (abfd, sect, note, 0, *sectsize))
410 /* Calculate the size of this note. */
411 notesz = strlen (name) + 1;
412 notesz = ((notesz + 3) & ~3);
414 notesz = ((notesz + 3) & ~3);
416 /* If this assertion triggers, increase MAX_NOTESZ. */
417 gdb_assert (notesz <= MAX_NOTESZ);
419 /* Check whether SECT is big enough to comtain the complete note. */
420 if (notesz > bfd_section_size (abfd, sect))
423 /* Check the note name. */
424 if (bfd_h_get_32 (abfd, note) != (strlen (name) + 1)
425 || strcmp (note + 12, name) != 0)
428 /* Check the descriptor size. */
429 if (bfd_h_get_32 (abfd, note + 4) != descsz)
432 /* Check the note type. */
433 if (bfd_h_get_32 (abfd, note + 8) != type)
439 /* Generic sniffer for ELF flavoured files. */
442 generic_elf_osabi_sniff_abi_tag_sections (bfd *abfd, asection *sect, void *obj)
444 enum gdb_osabi *osabi = (enum gdb_osabi *) obj;
446 unsigned int sectsize;
449 name = bfd_get_section_name (abfd, sect);
450 sectsize = bfd_section_size (abfd, sect);
452 /* Limit the amount of data to read. */
453 if (sectsize > MAX_NOTESZ)
454 sectsize = MAX_NOTESZ;
456 /* We lazily read the section data here. Since we use
457 BFD_DECOMPRESS, we can't use bfd_get_section_contents on a
458 compressed section. But, since note sections are not compressed,
459 deferring the reading until we recognize the section avoids any
461 note = (char *) alloca (sectsize);
463 /* .note.ABI-tag notes, used by GNU/Linux and FreeBSD. */
464 if (strcmp (name, ".note.ABI-tag") == 0)
467 if (check_note (abfd, sect, note, §size, "GNU", 16, NT_GNU_ABI_TAG))
469 unsigned int abi_tag = bfd_h_get_32 (abfd, note + 16);
473 case GNU_ABI_TAG_LINUX:
474 *osabi = GDB_OSABI_LINUX;
477 case GNU_ABI_TAG_HURD:
478 *osabi = GDB_OSABI_HURD;
481 case GNU_ABI_TAG_SOLARIS:
482 *osabi = GDB_OSABI_SOLARIS;
485 case GNU_ABI_TAG_FREEBSD:
486 *osabi = GDB_OSABI_FREEBSD_ELF;
489 case GNU_ABI_TAG_NETBSD:
490 *osabi = GDB_OSABI_NETBSD_ELF;
494 warning (_("GNU ABI tag value %u unrecognized."), abi_tag);
501 if (check_note (abfd, sect, note, §size, "FreeBSD", 4,
504 /* There is no need to check the version yet. */
505 *osabi = GDB_OSABI_FREEBSD_ELF;
512 /* .note.netbsd.ident notes, used by NetBSD. */
513 if (strcmp (name, ".note.netbsd.ident") == 0
514 && check_note (abfd, sect, note, §size, "NetBSD", 4, NT_NETBSD_IDENT))
516 /* There is no need to check the version yet. */
517 *osabi = GDB_OSABI_NETBSD_ELF;
521 /* .note.openbsd.ident notes, used by OpenBSD. */
522 if (strcmp (name, ".note.openbsd.ident") == 0
523 && check_note (abfd, sect, note, §size, "OpenBSD", 4,
526 /* There is no need to check the version yet. */
527 *osabi = GDB_OSABI_OPENBSD_ELF;
531 /* .note.netbsdcore.procinfo notes, used by NetBSD. */
532 if (strcmp (name, ".note.netbsdcore.procinfo") == 0)
534 *osabi = GDB_OSABI_NETBSD_ELF;
539 static enum gdb_osabi
540 generic_elf_osabi_sniffer (bfd *abfd)
542 unsigned int elfosabi;
543 enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;
545 elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI];
551 /* When the EI_OSABI field in the ELF header is ELFOSABI_NONE
552 (0), then the ELF structures in the file are conforming to
553 the base specification for that machine (there are no
554 OS-specific extensions). In order to determine the real OS
555 in use, we must look for OS-specific notes.
557 The same applies for ELFOSABI_GNU: this can mean GNU/Hurd,
558 GNU/Linux, and possibly more. */
559 bfd_map_over_sections (abfd,
560 generic_elf_osabi_sniff_abi_tag_sections,
564 case ELFOSABI_FREEBSD:
565 osabi = GDB_OSABI_FREEBSD_ELF;
568 case ELFOSABI_NETBSD:
569 osabi = GDB_OSABI_NETBSD_ELF;
572 case ELFOSABI_SOLARIS:
573 osabi = GDB_OSABI_SOLARIS;
577 /* For some reason the default value for the EI_OSABI field is
578 ELFOSABI_HPUX for all PA-RISC targets (with the exception of
579 GNU/Linux). We use HP-UX ELF as the default, but let any
580 OS-specific notes override this. */
581 osabi = GDB_OSABI_HPUX_ELF;
582 bfd_map_over_sections (abfd,
583 generic_elf_osabi_sniff_abi_tag_sections,
587 case ELFOSABI_OPENVMS:
588 osabi = GDB_OSABI_OPENVMS;
592 if (osabi == GDB_OSABI_UNKNOWN)
594 /* The FreeBSD folks have been naughty; they stored the string
595 "FreeBSD" in the padding of the e_ident field of the ELF
596 header to "brand" their ELF binaries in FreeBSD 3.x. */
597 if (memcmp (&elf_elfheader (abfd)->e_ident[8],
598 "FreeBSD", sizeof ("FreeBSD")) == 0)
599 osabi = GDB_OSABI_FREEBSD_ELF;
606 set_osabi (char *args, int from_tty, struct cmd_list_element *c)
608 struct gdbarch_info info;
610 if (strcmp (set_osabi_string, "auto") == 0)
611 user_osabi_state = osabi_auto;
612 else if (strcmp (set_osabi_string, "default") == 0)
614 user_selected_osabi = GDB_OSABI_DEFAULT;
615 user_osabi_state = osabi_user;
617 else if (strcmp (set_osabi_string, "none") == 0)
619 user_selected_osabi = GDB_OSABI_UNKNOWN;
620 user_osabi_state = osabi_user;
626 for (i = 1; i < GDB_OSABI_INVALID; i++)
628 enum gdb_osabi osabi = (enum gdb_osabi) i;
630 if (strcmp (set_osabi_string, gdbarch_osabi_name (osabi)) == 0)
632 user_selected_osabi = osabi;
633 user_osabi_state = osabi_user;
637 if (i == GDB_OSABI_INVALID)
638 internal_error (__FILE__, __LINE__,
639 _("Invalid OS ABI \"%s\" passed to command handler."),
643 /* NOTE: At some point (true multiple architectures) we'll need to be more
645 gdbarch_info_init (&info);
646 if (! gdbarch_update_p (info))
647 internal_error (__FILE__, __LINE__, _("Updating OS ABI failed."));
651 show_osabi (struct ui_file *file, int from_tty, struct cmd_list_element *c,
654 if (user_osabi_state == osabi_auto)
655 fprintf_filtered (file,
656 _("The current OS ABI is \"auto\" "
657 "(currently \"%s\").\n"),
658 gdbarch_osabi_name (gdbarch_osabi (get_current_arch ())));
660 fprintf_filtered (file, _("The current OS ABI is \"%s\".\n"),
661 gdbarch_osabi_name (user_selected_osabi));
663 if (GDB_OSABI_DEFAULT != GDB_OSABI_UNKNOWN)
664 fprintf_filtered (file, _("The default OS ABI is \"%s\".\n"),
665 gdbarch_osabi_name (GDB_OSABI_DEFAULT));
668 extern initialize_file_ftype _initialize_gdb_osabi; /* -Wmissing-prototype */
671 _initialize_gdb_osabi (void)
673 if (strcmp (gdb_osabi_names[GDB_OSABI_INVALID].pretty, "<invalid>") != 0)
676 _("_initialize_gdb_osabi: gdb_osabi_names[] is inconsistent"));
678 /* Register a generic sniffer for ELF flavoured files. */
679 gdbarch_register_osabi_sniffer (bfd_arch_unknown,
680 bfd_target_elf_flavour,
681 generic_elf_osabi_sniffer);
683 /* Register the "set osabi" command. */
684 add_setshow_enum_cmd ("osabi", class_support, gdb_osabi_available_names,
686 _("Set OS ABI of target."),
687 _("Show OS ABI of target."),
688 NULL, set_osabi, show_osabi,
689 &setlist, &showlist);
690 user_osabi_state = osabi_auto;