xref: /NextBSD/contrib/gdb/gdb/osabi.c (revision 95f7c2f56c7268d6ed9c2a56d357aeeac260363b)
1 /* OS ABI variant handling for GDB.
2    Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
3 
4    This file is part of GDB.
5 
6    This program is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as published by
8    the Free Software Foundation; either version 2 of the License, or
9    (at your option) any later version.
10 
11    This program is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14    GNU General Public License for more details.
15 
16    You should have received a copy of the GNU General Public License
17    along with this program; if not, write to the Free Software
18    Foundation, Inc., 59 Temple Place - Suite 330,
19    Boston, MA 02111-1307, USA.  */
20 
21 #include "defs.h"
22 
23 #include "gdb_assert.h"
24 #include "gdb_string.h"
25 
26 #include "osabi.h"
27 #include "arch-utils.h"
28 #include "gdbcmd.h"
29 #include "command.h"
30 
31 #include "elf-bfd.h"
32 
33 #ifndef GDB_OSABI_DEFAULT
34 #define GDB_OSABI_DEFAULT GDB_OSABI_UNKNOWN
35 #endif
36 
37 /* State for the "set osabi" command.  */
38 static enum { osabi_auto, osabi_default, osabi_user } user_osabi_state;
39 static enum gdb_osabi user_selected_osabi;
40 static const char *gdb_osabi_available_names[GDB_OSABI_INVALID + 3] = {
41   "auto",
42   "default",
43   "none",
44   NULL
45 };
46 static const char *set_osabi_string;
47 
48 /* This table matches the indices assigned to enum gdb_osabi.  Keep
49    them in sync.  */
50 static const char * const gdb_osabi_names[] =
51 {
52   "none",
53 
54   "SVR4",
55   "GNU/Hurd",
56   "Solaris",
57   "OSF/1",
58   "GNU/Linux",
59   "FreeBSD a.out",
60   "FreeBSD ELF",
61   "NetBSD a.out",
62   "NetBSD ELF",
63   "OpenBSD ELF",
64   "Windows CE",
65   "DJGPP",
66   "NetWare",
67   "Irix",
68   "LynxOS",
69   "Interix",
70   "HP/UX ELF",
71   "HP/UX SOM",
72 
73   "ARM EABI v1",
74   "ARM EABI v2",
75   "ARM APCS",
76   "QNX Neutrino",
77 
78   "Cygwin",
79 
80   "<invalid>"
81 };
82 
83 const char *
gdbarch_osabi_name(enum gdb_osabi osabi)84 gdbarch_osabi_name (enum gdb_osabi osabi)
85 {
86   if (osabi >= GDB_OSABI_UNKNOWN && osabi < GDB_OSABI_INVALID)
87     return gdb_osabi_names[osabi];
88 
89   return gdb_osabi_names[GDB_OSABI_INVALID];
90 }
91 
92 /* Handler for a given architecture/OS ABI pair.  There should be only
93    one handler for a given OS ABI each architecture family.  */
94 struct gdb_osabi_handler
95 {
96   struct gdb_osabi_handler *next;
97   const struct bfd_arch_info *arch_info;
98   enum gdb_osabi osabi;
99   void (*init_osabi)(struct gdbarch_info, struct gdbarch *);
100 };
101 
102 static struct gdb_osabi_handler *gdb_osabi_handler_list;
103 
104 void
gdbarch_register_osabi(enum bfd_architecture arch,unsigned long machine,enum gdb_osabi osabi,void (* init_osabi)(struct gdbarch_info,struct gdbarch *))105 gdbarch_register_osabi (enum bfd_architecture arch, unsigned long machine,
106 			enum gdb_osabi osabi,
107                         void (*init_osabi)(struct gdbarch_info,
108 					   struct gdbarch *))
109 {
110   struct gdb_osabi_handler **handler_p;
111   const struct bfd_arch_info *arch_info = bfd_lookup_arch (arch, machine);
112   const char **name_ptr;
113 
114   /* Registering an OS ABI handler for "unknown" is not allowed.  */
115   if (osabi == GDB_OSABI_UNKNOWN)
116     {
117       internal_error
118 	(__FILE__, __LINE__,
119 	 "gdbarch_register_osabi: An attempt to register a handler for "
120          "OS ABI \"%s\" for architecture %s was made.  The handler will "
121 	 "not be registered",
122 	 gdbarch_osabi_name (osabi),
123 	 bfd_printable_arch_mach (arch, machine));
124       return;
125     }
126 
127   gdb_assert (arch_info);
128 
129   for (handler_p = &gdb_osabi_handler_list; *handler_p != NULL;
130        handler_p = &(*handler_p)->next)
131     {
132       if ((*handler_p)->arch_info == arch_info
133 	  && (*handler_p)->osabi == osabi)
134 	{
135 	  internal_error
136 	    (__FILE__, __LINE__,
137 	     "gdbarch_register_osabi: A handler for OS ABI \"%s\" "
138 	     "has already been registered for architecture %s",
139 	     gdbarch_osabi_name (osabi),
140 	     arch_info->printable_name);
141 	  /* If user wants to continue, override previous definition.  */
142 	  (*handler_p)->init_osabi = init_osabi;
143 	  return;
144 	}
145     }
146 
147   (*handler_p)
148     = (struct gdb_osabi_handler *) xmalloc (sizeof (struct gdb_osabi_handler));
149   (*handler_p)->next = NULL;
150   (*handler_p)->arch_info = arch_info;
151   (*handler_p)->osabi = osabi;
152   (*handler_p)->init_osabi = init_osabi;
153 
154   /* Add this OS ABI to the list of enum values for "set osabi", if it isn't
155      already there.  */
156   for (name_ptr = gdb_osabi_available_names; *name_ptr; name_ptr ++)
157     {
158       if (*name_ptr == gdbarch_osabi_name (osabi))
159 	return;
160     }
161   *name_ptr++ = gdbarch_osabi_name (osabi);
162   *name_ptr = NULL;
163 }
164 
165 
166 /* Sniffer to find the OS ABI for a given file's architecture and flavour.
167    It is legal to have multiple sniffers for each arch/flavour pair, to
168    disambiguate one OS's a.out from another, for example.  The first sniffer
169    to return something other than GDB_OSABI_UNKNOWN wins, so a sniffer should
170    be careful to claim a file only if it knows for sure what it is.  */
171 struct gdb_osabi_sniffer
172 {
173   struct gdb_osabi_sniffer *next;
174   enum bfd_architecture arch;   /* bfd_arch_unknown == wildcard */
175   enum bfd_flavour flavour;
176   enum gdb_osabi (*sniffer)(bfd *);
177 };
178 
179 static struct gdb_osabi_sniffer *gdb_osabi_sniffer_list;
180 
181 void
gdbarch_register_osabi_sniffer(enum bfd_architecture arch,enum bfd_flavour flavour,enum gdb_osabi (* sniffer_fn)(bfd *))182 gdbarch_register_osabi_sniffer (enum bfd_architecture arch,
183                                 enum bfd_flavour flavour,
184 				enum gdb_osabi (*sniffer_fn)(bfd *))
185 {
186   struct gdb_osabi_sniffer *sniffer;
187 
188   sniffer =
189     (struct gdb_osabi_sniffer *) xmalloc (sizeof (struct gdb_osabi_sniffer));
190   sniffer->arch = arch;
191   sniffer->flavour = flavour;
192   sniffer->sniffer = sniffer_fn;
193 
194   sniffer->next = gdb_osabi_sniffer_list;
195   gdb_osabi_sniffer_list = sniffer;
196 }
197 
198 
199 enum gdb_osabi
gdbarch_lookup_osabi(bfd * abfd)200 gdbarch_lookup_osabi (bfd *abfd)
201 {
202   struct gdb_osabi_sniffer *sniffer;
203   enum gdb_osabi osabi, match;
204   int match_specific;
205 
206   /* If we aren't in "auto" mode, return the specified OS ABI.  */
207   if (user_osabi_state == osabi_user)
208     return user_selected_osabi;
209 
210   /* If we don't have a binary, return the default OS ABI (if set) or
211      an inconclusive result (otherwise).  */
212   if (abfd == NULL)
213     {
214       if (GDB_OSABI_DEFAULT != GDB_OSABI_UNKNOWN)
215 	return GDB_OSABI_DEFAULT;
216       else
217 	return GDB_OSABI_UNINITIALIZED;
218     }
219 
220   match = GDB_OSABI_UNKNOWN;
221   match_specific = 0;
222 
223   for (sniffer = gdb_osabi_sniffer_list; sniffer != NULL;
224        sniffer = sniffer->next)
225     {
226       if ((sniffer->arch == bfd_arch_unknown /* wildcard */
227 	   || sniffer->arch == bfd_get_arch (abfd))
228 	  && sniffer->flavour == bfd_get_flavour (abfd))
229 	{
230 	  osabi = (*sniffer->sniffer) (abfd);
231 	  if (osabi < GDB_OSABI_UNKNOWN || osabi >= GDB_OSABI_INVALID)
232 	    {
233 	      internal_error
234 		(__FILE__, __LINE__,
235 		 "gdbarch_lookup_osabi: invalid OS ABI (%d) from sniffer "
236 		 "for architecture %s flavour %d",
237 		 (int) osabi,
238 		 bfd_printable_arch_mach (bfd_get_arch (abfd), 0),
239 		 (int) bfd_get_flavour (abfd));
240 	    }
241 	  else if (osabi != GDB_OSABI_UNKNOWN)
242 	    {
243 	      /* A specific sniffer always overrides a generic sniffer.
244 		 Croak on multiple match if the two matches are of the
245 		 same class.  If the user wishes to continue, we'll use
246 		 the first match.  */
247 	      if (match != GDB_OSABI_UNKNOWN)
248 		{
249 		  if ((match_specific && sniffer->arch != bfd_arch_unknown)
250 		   || (!match_specific && sniffer->arch == bfd_arch_unknown))
251 		    {
252 		      internal_error
253 		        (__FILE__, __LINE__,
254 		         "gdbarch_lookup_osabi: multiple %sspecific OS ABI "
255 			 "match for architecture %s flavour %d: first "
256 			 "match \"%s\", second match \"%s\"",
257 			 match_specific ? "" : "non-",
258 		         bfd_printable_arch_mach (bfd_get_arch (abfd), 0),
259 		         (int) bfd_get_flavour (abfd),
260 		         gdbarch_osabi_name (match),
261 		         gdbarch_osabi_name (osabi));
262 		    }
263 		  else if (sniffer->arch != bfd_arch_unknown)
264 		    {
265 		      match = osabi;
266 		      match_specific = 1;
267 		    }
268 		}
269 	      else
270 		{
271 		  match = osabi;
272 		  if (sniffer->arch != bfd_arch_unknown)
273 		    match_specific = 1;
274 		}
275 	    }
276 	}
277     }
278 
279   /* If we didn't find a match, but a default was specified at configure
280      time, return the default.  */
281   if (GDB_OSABI_DEFAULT != GDB_OSABI_UNKNOWN && match == GDB_OSABI_UNKNOWN)
282     return GDB_OSABI_DEFAULT;
283   else
284     return match;
285 }
286 
287 
288 /* Return non-zero if architecture A can run code written for
289    architecture B.  */
290 static int
can_run_code_for(const struct bfd_arch_info * a,const struct bfd_arch_info * b)291 can_run_code_for (const struct bfd_arch_info *a, const struct bfd_arch_info *b)
292 {
293   /* BFD's 'A->compatible (A, B)' functions return zero if A and B are
294      incompatible.  But if they are compatible, it returns the 'more
295      featureful' of the two arches.  That is, if A can run code
296      written for B, but B can't run code written for A, then it'll
297      return A.
298 
299      struct bfd_arch_info objects are singletons: that is, there's
300      supposed to be exactly one instance for a given machine.  So you
301      can tell whether two are equivalent by comparing pointers.  */
302   return (a == b || a->compatible (a, b) == a);
303 }
304 
305 
306 void
gdbarch_init_osabi(struct gdbarch_info info,struct gdbarch * gdbarch)307 gdbarch_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
308 {
309   struct gdb_osabi_handler *handler;
310 
311   if (info.osabi == GDB_OSABI_UNKNOWN)
312     {
313       /* Don't complain about an unknown OSABI.  Assume the user knows
314          what they are doing.  */
315       return;
316     }
317 
318   for (handler = gdb_osabi_handler_list; handler != NULL;
319        handler = handler->next)
320     {
321       if (handler->osabi != info.osabi)
322 	continue;
323 
324       /* If the architecture described by ARCH_INFO can run code for
325          the architcture we registered the handler for, then the
326          handler is applicable.  Note, though, that if the handler is
327          for an architecture that is a superset of ARCH_INFO, we can't
328          use that --- it would be perfectly correct for it to install
329          gdbarch methods that refer to registers / instructions /
330          other facilities ARCH_INFO doesn't have.
331 
332          NOTE: kettenis/20021027: There may be more than one machine
333 	 type that is compatible with the desired machine type.  Right
334 	 now we simply return the first match, which is fine for now.
335 	 However, we might want to do something smarter in the future.  */
336       /* NOTE: cagney/2003-10-23: The code for "a can_run_code_for b"
337          is implemented using BFD's compatible method (a->compatible
338          (b) == a -- the lowest common denominator between a and b is
339          a).  That method's definition of compatible may not be as you
340          expect.  For instance the test "amd64 can run code for i386"
341          (or more generally "64-bit ISA can run code for the 32-bit
342          ISA").  BFD doesn't normally consider 32-bit and 64-bit
343          "compatible" so it doesn't succeed.  */
344       if (can_run_code_for (info.bfd_arch_info, handler->arch_info))
345 	{
346 	  (*handler->init_osabi) (info, gdbarch);
347 	  return;
348 	}
349     }
350 
351   warning
352     ("A handler for the OS ABI \"%s\" is not built into this configuration\n"
353      "of GDB.  Attempting to continue with the default %s settings.\n",
354      gdbarch_osabi_name (info.osabi),
355      info.bfd_arch_info->printable_name);
356 }
357 
358 /* Limit on the amount of data to be read.  */
359 #define MAX_NOTESZ	128
360 
361 /* Return non-zero if NOTE matches NAME, DESCSZ and TYPE.  */
362 
363 static int
check_note(bfd * abfd,asection * sect,const char * note,const char * name,unsigned long descsz,unsigned long type)364 check_note (bfd *abfd, asection *sect, const char *note,
365 	    const char *name, unsigned long descsz, unsigned long type)
366 {
367   unsigned long notesz;
368   unsigned long rdescsz;
369 
370   /* Calculate the size of this note.  */
371   notesz = 4 * 3;	/* namelen, optlen, type */
372   notesz += strlen (name) + 1;
373   notesz = ((notesz + 3) & ~3);
374 
375   /* If this assertion triggers, increase MAX_NOTESZ.  */
376   gdb_assert (notesz <= MAX_NOTESZ);
377 
378   /* Check whether SECT is big enough to comtain the complete note.  */
379   if (notesz > bfd_section_size (abfd, sect))
380     return 0;
381 
382   /* Check the note name.  */
383   if (bfd_h_get_32 (abfd, note) != (strlen (name) + 1)
384       || strcmp (note + 12, name) != 0)
385     return 0;
386 
387   /* Check the descriptor size.  */
388   rdescsz = bfd_h_get_32 (abfd, note + 4);
389   if (descsz != (unsigned long)-1 && rdescsz != descsz)
390     return 0;
391 
392   notesz += rdescsz;
393   notesz = ((notesz + 3) & ~3);
394 
395   /* Check whether SECT is big enough to comtain the complete note.  */
396   if (notesz > bfd_section_size (abfd, sect))
397     return 0;
398 
399   /* Check the note type.  */
400   if (bfd_h_get_32 (abfd, note + 8) != type)
401     return 0;
402 
403   return 1;
404 }
405 
406 /* Generic sniffer for ELF flavoured files.  */
407 
408 void
generic_elf_osabi_sniff_abi_tag_sections(bfd * abfd,asection * sect,void * obj)409 generic_elf_osabi_sniff_abi_tag_sections (bfd *abfd, asection *sect, void *obj)
410 {
411   enum gdb_osabi *osabi = obj;
412   const char *name;
413   unsigned int sectsize;
414   char *note;
415 
416   name = bfd_get_section_name (abfd, sect);
417   sectsize = bfd_section_size (abfd, sect);
418 
419   /* Limit the amount of data to read.  */
420   if (sectsize > MAX_NOTESZ)
421     sectsize = MAX_NOTESZ;
422 
423   note = alloca (sectsize);
424   bfd_get_section_contents (abfd, sect, note, 0, sectsize);
425 
426   /* .note.ABI-tag notes, used by GNU/Linux and FreeBSD.  */
427   if (strcmp (name, ".note.ABI-tag") == 0)
428     {
429       /* GNU.  */
430       if (check_note (abfd, sect, note, "GNU", 16, NT_GNU_ABI_TAG))
431 	{
432 	  unsigned int abi_tag = bfd_h_get_32 (abfd, note + 16);
433 
434 	  switch (abi_tag)
435 	    {
436 	    case GNU_ABI_TAG_LINUX:
437 	      *osabi = GDB_OSABI_LINUX;
438 	      break;
439 
440 	    case GNU_ABI_TAG_HURD:
441 	      *osabi = GDB_OSABI_HURD;
442 	      break;
443 
444 	    case GNU_ABI_TAG_SOLARIS:
445 	      *osabi = GDB_OSABI_SOLARIS;
446 	      break;
447 
448 	    case GNU_ABI_TAG_FREEBSD:
449 	      *osabi = GDB_OSABI_FREEBSD_ELF;
450 	      break;
451 
452 	    case GNU_ABI_TAG_NETBSD:
453 	      *osabi = GDB_OSABI_NETBSD_ELF;
454 	      break;
455 
456 	    default:
457 	      internal_error (__FILE__, __LINE__, "\
458 generic_elf_osabi_sniff_abi_tag_sections: unknown OS number %d",
459 			      abi_tag);
460 	    }
461 	  return;
462 	}
463 
464       /* FreeBSD.  */
465       if (check_note (abfd, sect, note, "FreeBSD", 4, NT_FREEBSD_ABI_TAG))
466 	{
467 	  /* There is no need to check the version yet.  */
468 	  *osabi = GDB_OSABI_FREEBSD_ELF;
469 	  return;
470 	}
471 
472       return;
473     }
474 
475   /* .note.tag notes, used by FreeBSD.  */
476   if (strcmp (name, ".note.tag") == 0)
477    {
478       /* FreeBSD.  */
479       if (check_note (abfd, sect, note, "FreeBSD", 4, NT_FREEBSD_TAG))
480 	{
481 	  /* There is no need to check the version yet.  */
482 	  *osabi = GDB_OSABI_FREEBSD_ELF;
483 	  return;
484 	}
485       if (check_note (abfd, sect, note, "FreeBSD", 4, NT_FREEBSD_NOINIT_TAG))
486 	{
487 	  /* There is no need to check the version yet.  */
488 	  *osabi = GDB_OSABI_FREEBSD_ELF;
489 	  return;
490 	}
491       if (check_note (abfd, sect, note, "FreeBSD", -1, NT_FREEBSD_ARCH_TAG))
492 	{
493 	  /* There is no need to check the version yet.  */
494 	  *osabi = GDB_OSABI_FREEBSD_ELF;
495 	  return;
496 	}
497 
498       return;
499     }
500 
501   /* .note.netbsd.ident notes, used by NetBSD.  */
502   if (strcmp (name, ".note.netbsd.ident") == 0
503       && check_note (abfd, sect, note, "NetBSD", 4, NT_NETBSD_IDENT))
504     {
505       /* There is no need to check the version yet.  */
506       *osabi = GDB_OSABI_NETBSD_ELF;
507       return;
508     }
509 
510   /* .note.openbsd.ident notes, used by OpenBSD.  */
511   if (strcmp (name, ".note.openbsd.ident") == 0
512       && check_note (abfd, sect, note, "OpenBSD", 4, NT_OPENBSD_IDENT))
513     {
514       /* There is no need to check the version yet.  */
515       *osabi = GDB_OSABI_OPENBSD_ELF;
516       return;
517     }
518 
519   /* .note.netbsdcore.procinfo notes, used by NetBSD.  */
520   if (strcmp (name, ".note.netbsdcore.procinfo") == 0)
521     {
522       *osabi = GDB_OSABI_NETBSD_ELF;
523       return;
524     }
525 }
526 
527 static enum gdb_osabi
generic_elf_osabi_sniffer(bfd * abfd)528 generic_elf_osabi_sniffer (bfd *abfd)
529 {
530   unsigned int elfosabi;
531   enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;
532 
533   elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI];
534 
535   switch (elfosabi)
536     {
537     case ELFOSABI_NONE:
538       /* When elfosabi is ELFOSABI_NONE (0), then the ELF structures in the
539          file are conforming to the base specification for that machine
540 	 (there are no OS-specific extensions).  In order to determine the
541 	 real OS in use we must look for OS notes that have been added.  */
542       bfd_map_over_sections (abfd,
543 			     generic_elf_osabi_sniff_abi_tag_sections,
544 			     &osabi);
545       break;
546 
547     case ELFOSABI_FREEBSD:
548       osabi = GDB_OSABI_FREEBSD_ELF;
549       break;
550 
551     case ELFOSABI_NETBSD:
552       osabi = GDB_OSABI_NETBSD_ELF;
553       break;
554 
555     case ELFOSABI_LINUX:
556       osabi = GDB_OSABI_LINUX;
557       break;
558 
559     case ELFOSABI_HURD:
560       osabi = GDB_OSABI_HURD;
561       break;
562 
563     case ELFOSABI_SOLARIS:
564       osabi = GDB_OSABI_SOLARIS;
565       break;
566 
567     case ELFOSABI_HPUX:
568       osabi = GDB_OSABI_HPUX_ELF;
569       break;
570     }
571 
572   if (osabi == GDB_OSABI_UNKNOWN)
573     {
574       /* The FreeBSD folks have been naughty; they stored the string
575          "FreeBSD" in the padding of the e_ident field of the ELF
576          header to "brand" their ELF binaries in FreeBSD 3.x.  */
577       if (strcmp (&elf_elfheader (abfd)->e_ident[8], "FreeBSD") == 0)
578 	osabi = GDB_OSABI_FREEBSD_ELF;
579     }
580 
581   return osabi;
582 }
583 
584 static void
set_osabi(char * args,int from_tty,struct cmd_list_element * c)585 set_osabi (char *args, int from_tty, struct cmd_list_element *c)
586 {
587   struct gdbarch_info info;
588 
589   if (strcmp (set_osabi_string, "auto") == 0)
590     user_osabi_state = osabi_auto;
591   else if (strcmp (set_osabi_string, "default") == 0)
592     {
593       user_selected_osabi = GDB_OSABI_DEFAULT;
594       user_osabi_state = osabi_user;
595     }
596   else if (strcmp (set_osabi_string, "none") == 0)
597     {
598       user_selected_osabi = GDB_OSABI_UNKNOWN;
599       user_osabi_state = osabi_user;
600     }
601   else
602     {
603       int i;
604       for (i = 1; i < GDB_OSABI_INVALID; i++)
605 	if (strcmp (set_osabi_string, gdbarch_osabi_name (i)) == 0)
606 	  {
607 	    user_selected_osabi = i;
608 	    user_osabi_state = osabi_user;
609 	    break;
610 	  }
611       if (i == GDB_OSABI_INVALID)
612 	internal_error (__FILE__, __LINE__,
613 			"Invalid OS ABI \"%s\" passed to command handler.",
614 			set_osabi_string);
615     }
616 
617   /* NOTE: At some point (true multiple architectures) we'll need to be more
618      graceful here.  */
619   gdbarch_info_init (&info);
620   if (! gdbarch_update_p (info))
621     internal_error (__FILE__, __LINE__, "Updating OS ABI failed.");
622 }
623 
624 static void
show_osabi(char * args,int from_tty)625 show_osabi (char *args, int from_tty)
626 {
627   if (user_osabi_state == osabi_auto)
628     printf_filtered ("The current OS ABI is \"auto\" (currently \"%s\").\n",
629 		     gdbarch_osabi_name (gdbarch_osabi (current_gdbarch)));
630   else
631     printf_filtered ("The current OS ABI is \"%s\".\n",
632 		     gdbarch_osabi_name (user_selected_osabi));
633 
634   if (GDB_OSABI_DEFAULT != GDB_OSABI_UNKNOWN)
635     printf_filtered ("The default OS ABI is \"%s\".\n",
636 		     gdbarch_osabi_name (GDB_OSABI_DEFAULT));
637 }
638 
639 extern initialize_file_ftype _initialize_gdb_osabi; /* -Wmissing-prototype */
640 
641 void
_initialize_gdb_osabi(void)642 _initialize_gdb_osabi (void)
643 {
644   struct cmd_list_element *c;
645 
646   if (strcmp (gdb_osabi_names[GDB_OSABI_INVALID], "<invalid>") != 0)
647     internal_error
648       (__FILE__, __LINE__,
649        "_initialize_gdb_osabi: gdb_osabi_names[] is inconsistent");
650 
651   /* Register a generic sniffer for ELF flavoured files.  */
652   gdbarch_register_osabi_sniffer (bfd_arch_unknown,
653 				  bfd_target_elf_flavour,
654 				  generic_elf_osabi_sniffer);
655 
656   /* Register the "set osabi" command.  */
657   c = add_set_enum_cmd ("osabi", class_support, gdb_osabi_available_names,
658 			&set_osabi_string, "Set OS ABI of target.", &setlist);
659 
660   set_cmd_sfunc (c, set_osabi);
661   add_cmd ("osabi", class_support, show_osabi, "Show OS/ABI of target.",
662 	   &showlist);
663   user_osabi_state = osabi_auto;
664 }
665