1 /* Mach-O object file format
2 Copyright 2009, 2011 Free Software Foundation, Inc.
4 This file is part of GAS, the GNU Assembler.
6 GAS is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as
8 published by the Free Software Foundation; either version 3,
9 or (at your option) any later version.
11 GAS is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
14 the GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GAS; see the file COPYING. If not, write to the Free
18 Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
21 /* Here we handle the mach-o directives that are common to all architectures.
23 Most significant are mach-o named sections and a variety of symbol type
26 /* Mach-O supports multiple, named segments each of which may contain
27 multiple named sections. Thus the concept of subsectioning is
28 handled by (say) having a __TEXT segment with appropriate flags from
29 which subsections are generated like __text, __const etc.
31 The well-known as short-hand section switch directives like .text, .data
32 etc. are mapped onto predefined segment/section pairs using facilites
33 supplied by the mach-o port of bfd.
35 A number of additional mach-o short-hand section switch directives are
38 #define OBJ_HEADER "obj-macho.h"
45 #include "mach-o/loader.h"
46 #include "obj-macho.h"
48 /* TODO: Implement "-dynamic"/"-static" command line options. */
50 static int obj_mach_o_is_static;
52 /* Allow for special re-ordering on output. */
54 static int seen_objc_section;
56 /* Remember the subsections_by_symbols state in case we need to reset
58 static int obj_mach_o_subsections_by_symbols;
61 obj_mach_o_weak (int ignore ATTRIBUTE_UNUSED)
69 /* Get symbol name. */
70 name = input_line_pointer;
71 c = get_symbol_end ();
72 symbolP = symbol_find_or_make (name);
74 *input_line_pointer = c;
82 while (*input_line_pointer != '\n');
83 demand_empty_rest_of_line ();
86 /* This will put at most 16 characters (terminated by a ',' or newline) from
87 the input stream into dest. If there are more than 16 chars before the
88 delimiter, a warning is given and the string is truncated. On completion of
89 this function, input_line_pointer will point to the char after the ',' or
92 It trims leading and trailing space. */
95 collect_16char_name (char *dest, const char *msg, int require_comma)
100 namstart = input_line_pointer;
102 while ( (c = *input_line_pointer) != ','
103 && !is_end_of_line[(unsigned char) c])
104 input_line_pointer++;
107 int len = input_line_pointer - namstart; /* could be zero. */
108 /* lose any trailing space. */
109 while (len > 0 && namstart[len-1] == ' ')
113 *input_line_pointer = '\0'; /* make a temp string. */
114 as_bad (_("the %s name '%s' is too long (maximum 16 characters)"),
116 *input_line_pointer = c; /* restore for printing. */
120 memcpy (dest, namstart, len);
123 if (c != ',' && require_comma)
125 as_bad (_("expected a %s name followed by a `,'"), msg);
134 The '.section' specification syntax looks like:
135 .section <segment> , <section> [, type [, attribs [, size]]]
137 White space is allowed everywhere between elements.
139 <segment> and <section> may be from 0 to 16 chars in length - they may
140 contain spaces but leading and trailing space will be trimmed. It is
141 mandatory that they be present (or that zero-length names are indicated
144 There is only a single section type for any entry.
146 There may be multiple attributes, they are delimited by `+'.
148 Not all section types and attributes are accepted by the Darwin system
149 assemblers as user-specifiable - although, at present, we do here. */
152 obj_mach_o_section (int ignore ATTRIBUTE_UNUSED)
156 unsigned int sectype = BFD_MACH_O_S_REGULAR;
157 unsigned int defsectype = BFD_MACH_O_S_REGULAR;
158 unsigned int sectype_given = 0;
159 unsigned int secattr = 0;
160 unsigned int defsecattr = 0;
161 int secattr_given = 0;
162 unsigned int secalign = 0;
163 offsetT sizeof_stub = 0;
164 const mach_o_section_name_xlat * xlat;
166 flagword oldflags, flags;
168 bfd_mach_o_section *msect;
172 #ifdef md_flush_pending_output
173 md_flush_pending_output ();
176 /* Zero-length segment and section names are allowed. */
177 /* Parse segment name. */
178 memset (segname, 0, sizeof(segname));
179 if (collect_16char_name (segname, "segment", 1))
181 ignore_rest_of_line ();
184 input_line_pointer++; /* Skip the terminating ',' */
186 /* Parse section name. */
187 memset (sectname, 0, sizeof(sectname));
188 collect_16char_name (sectname, "section", 0);
191 if (*input_line_pointer == ',')
195 input_line_pointer++;
197 p = input_line_pointer;
198 while ((c = *input_line_pointer) != ','
199 && !is_end_of_line[(unsigned char) c])
200 input_line_pointer++;
202 len = input_line_pointer - p;
203 /* strip trailing spaces. */
204 while (len > 0 && p[len-1] == ' ')
208 /* Temporarily make a string from the token. */
210 sectype = bfd_mach_o_get_section_type_from_name (stdoutput, p);
211 if (sectype > 255) /* Max Section ID == 255. */
213 as_bad (_("unknown or invalid section type '%s'"), p);
215 ignore_rest_of_line ();
224 TODO: check validity of attributes for section type. */
225 if (sectype_given && c == ',')
231 /* Skip initial `,' and subsequent `+'. */
232 input_line_pointer++;
234 p = input_line_pointer;
235 while ((c = *input_line_pointer) != '+'
237 && !is_end_of_line[(unsigned char) c])
238 input_line_pointer++;
240 len = input_line_pointer - p;
241 /* strip trailing spaces. */
242 while (len > 0 && p[len-1] == ' ')
246 /* Temporarily make a string from the token. */
248 attr = bfd_mach_o_get_section_attribute_from_name (p);
251 as_bad (_("unknown or invalid section attribute '%s'"), p);
253 ignore_rest_of_line ();
264 while (*input_line_pointer == '+');
266 /* Parse sizeof_stub. */
267 if (secattr_given && *input_line_pointer == ',')
269 if (sectype != BFD_MACH_O_S_SYMBOL_STUBS)
271 as_bad (_("unexpected section size information"));
272 ignore_rest_of_line ();
276 input_line_pointer++;
277 sizeof_stub = get_absolute_expression ();
279 else if (secattr_given && sectype == BFD_MACH_O_S_SYMBOL_STUBS)
281 as_bad (_("missing sizeof_stub expression"));
282 ignore_rest_of_line ();
288 flags = SEC_NO_FLAGS;
289 /* This provides default bfd flags and default mach-o section type and
290 attributes along with the canonical name. */
291 xlat = bfd_mach_o_section_data_for_mach_sect (stdoutput, segname, sectname);
294 name = xstrdup (xlat->bfd_name);
295 flags = xlat->bfd_flags;
296 defsectype = xlat->macho_sectype;
297 defsecattr = xlat->macho_secattr;
298 secalign = xlat->sectalign;
302 /* There is no normal BFD section name for this section. Create one.
303 The name created doesn't really matter as it will never be written
305 size_t seglen = strlen (segname);
306 size_t sectlen = strlen (sectname);
309 n = xmalloc (seglen + 1 + sectlen + 1);
310 memcpy (n, segname, seglen);
312 memcpy (n + seglen + 1, sectname, sectlen);
313 n[seglen + 1 + sectlen] = 0;
317 /* Sub-segments don't exists as is on Mach-O. */
318 sec = subseg_new (name, 0);
320 oldflags = bfd_get_section_flags (stdoutput, sec);
321 msect = bfd_mach_o_get_mach_o_section (sec);
322 if (oldflags == SEC_NO_FLAGS)
324 if (! bfd_set_section_flags (stdoutput, sec, flags))
325 as_warn (_("error setting flags for \"%s\": %s"),
326 bfd_section_name (stdoutput, sec),
327 bfd_errmsg (bfd_get_error ()));
328 strncpy (msect->segname, segname, sizeof (msect->segname));
329 msect->segname[16] = 0;
330 strncpy (msect->sectname, sectname, sizeof (msect->sectname));
331 msect->sectname[16] = 0;
332 msect->align = secalign;
335 msect->flags = sectype;
337 msect->flags |= secattr;
339 msect->flags |= defsecattr;
342 msect->flags = defsectype | defsecattr;
343 msect->reserved2 = sizeof_stub;
345 else if (flags != SEC_NO_FLAGS)
347 if (flags != oldflags
348 || msect->flags != (secattr | sectype))
349 as_warn (_("Ignoring changed section attributes for %s"), name);
351 demand_empty_rest_of_line ();
355 obj_mach_o_segT_from_bfd_name (const char *nam, int must_succeed)
357 const mach_o_section_name_xlat *xlat;
361 /* BFD has tables of flags and default attributes for all the sections that
362 have a 'canonical' name. */
363 xlat = bfd_mach_o_section_data_for_bfd_name (stdoutput, nam, &segn);
367 as_fatal (_("BFD is out of sync with GAS, "
368 "unhandled well-known section type `%s'"), nam);
372 sec = bfd_get_section_by_name (stdoutput, nam);
375 bfd_mach_o_section *msect;
377 sec = subseg_force_new (xlat->bfd_name, 0);
379 /* Set default type, attributes and alignment. */
380 msect = bfd_mach_o_get_mach_o_section (sec);
381 msect->flags = xlat->macho_sectype | xlat->macho_secattr;
382 msect->align = xlat->sectalign;
384 if ((msect->flags & BFD_MACH_O_SECTION_TYPE_MASK)
385 == BFD_MACH_O_S_ZEROFILL)
386 seg_info (sec)->bss = 1;
392 static const char * const known_sections[] =
397 /* 2 */ ".static_const",
401 /* 6 */ ".literal16",
402 /* 7 */ ".constructor",
403 /* 8 */ ".destructor",
406 /* 10 */ ".const_data",
407 /* 11 */ ".static_data",
408 /* 12 */ ".mod_init_func",
409 /* 13 */ ".mod_term_func",
414 /* Interface for a known non-optional section directive. */
417 obj_mach_o_known_section (int sect_index)
421 #ifdef md_flush_pending_output
422 md_flush_pending_output ();
425 section = obj_mach_o_segT_from_bfd_name (known_sections[sect_index], 1);
427 subseg_set (section, 0);
429 /* else, we leave the section as it was; there was a fatal error anyway. */
432 static const char * const objc_sections[] =
435 /* 1 */ ".objc_class",
436 /* 2 */ ".objc_meta_class",
437 /* 3 */ ".objc_cat_cls_meth",
438 /* 4 */ ".objc_cat_inst_meth",
439 /* 5 */ ".objc_protocol",
440 /* 6 */ ".objc_string_object",
441 /* 7 */ ".objc_cls_meth",
442 /* 8 */ ".objc_inst_meth",
443 /* 9 */ ".objc_cls_refs",
444 /* 10 */ ".objc_message_refs",
445 /* 11 */ ".objc_symbols",
446 /* 12 */ ".objc_category",
447 /* 13 */ ".objc_class_vars",
448 /* 14 */ ".objc_instance_vars",
449 /* 15 */ ".objc_module_info",
450 /* 16 */ ".cstring", /* objc_class_names Alias for .cstring */
451 /* 17 */ ".cstring", /* Alias objc_meth_var_types for .cstring */
452 /* 18 */ ".cstring", /* objc_meth_var_names Alias for .cstring */
453 /* 19 */ ".objc_selector_strs",
454 /* 20 */ ".objc_image_info", /* extension. */
455 /* 21 */ ".objc_selector_fixup", /* extension. */
456 /* 22 */ ".objc1_class_ext", /* ObjC-1 extension. */
457 /* 23 */ ".objc1_property_list", /* ObjC-1 extension. */
458 /* 24 */ ".objc1_protocol_ext" /* ObjC-1 extension. */
461 /* This currently does the same as known_sections, but kept separate for
462 ease of maintenance. */
465 obj_mach_o_objc_section (int sect_index)
469 #ifdef md_flush_pending_output
470 md_flush_pending_output ();
473 section = obj_mach_o_segT_from_bfd_name (objc_sections[sect_index], 1);
476 seen_objc_section = 1; /* We need to ensure that certain sections are
477 present and in the right order. */
478 subseg_set (section, 0);
481 /* else, we leave the section as it was; there was a fatal error anyway. */
484 /* Debug section directives. */
486 static const char * const debug_sections[] =
490 /* 1 */ ".debug_frame",
491 /* 2 */ ".debug_info",
492 /* 3 */ ".debug_abbrev",
493 /* 4 */ ".debug_aranges",
494 /* 5 */ ".debug_macinfo",
495 /* 6 */ ".debug_line",
496 /* 7 */ ".debug_loc",
497 /* 8 */ ".debug_pubnames",
498 /* 9 */ ".debug_pubtypes",
499 /* 10 */ ".debug_str",
500 /* 11 */ ".debug_ranges",
501 /* 12 */ ".debug_macro"
504 /* ??? Maybe these should be conditional on gdwarf-*.
505 It`s also likely that we will need to be able to set them from the cfi
509 obj_mach_o_debug_section (int sect_index)
513 #ifdef md_flush_pending_output
514 md_flush_pending_output ();
517 section = obj_mach_o_segT_from_bfd_name (debug_sections[sect_index], 1);
519 subseg_set (section, 0);
521 /* else, we leave the section as it was; there was a fatal error anyway. */
524 /* This could be moved to the tc-xx files, but there is so little dependency
525 there, that the code might as well be shared. */
534 /* The extensions here are for specific sections that are generated by GCC
535 and Darwin system tools, but don't have directives in the `system as'. */
537 static const struct opt_tgt_sect tgt_sections[] =
539 /* 0 */ { NULL, 0, 0},
540 /* 1 */ { ".lazy_symbol_pointer", 0, 0},
541 /* 2 */ { ".lazy_symbol_pointer2", 0, 0}, /* X86 - extension */
542 /* 3 */ { ".lazy_symbol_pointer3", 0, 0}, /* X86 - extension */
543 /* 4 */ { ".non_lazy_symbol_pointer", 0, 0},
544 /* 5 */ { ".non_lazy_symbol_pointer_x86", 0, 0}, /* X86 - extension */
545 /* 6 */ { ".symbol_stub", 16, 20},
546 /* 7 */ { ".symbol_stub1", 0, 16}, /* PPC - extension */
547 /* 8 */ { ".picsymbol_stub", 26, 36},
548 /* 9 */ { ".picsymbol_stub1", 0, 32}, /* PPC - extension */
549 /* 10 */ { ".picsymbol_stub2", 25, 0}, /* X86 - extension */
550 /* 11 */ { ".picsymbol_stub3", 5, 0}, /* X86 - extension */
553 /* Interface for an optional section directive. */
556 obj_mach_o_opt_tgt_section (int sect_index)
558 const struct opt_tgt_sect *tgtsct = &tgt_sections[sect_index];
561 #ifdef md_flush_pending_output
562 md_flush_pending_output ();
565 section = obj_mach_o_segT_from_bfd_name (tgtsct->name, 0);
568 as_bad (_("%s is not used for the selected target"), tgtsct->name);
569 /* Leave the section as it is. */
573 bfd_mach_o_section *mo_sec = bfd_mach_o_get_mach_o_section (section);
574 subseg_set (section, 0);
575 #if defined (TC_I386)
576 mo_sec->reserved2 = tgtsct->x86_val;
577 #elif defined (TC_PPC)
578 mo_sec->reserved2 = tgtsct->ppc_val;
580 mo_sec->reserved2 = 0;
585 /* We don't necessarily have the three 'base' sections on mach-o.
586 Normally, we would start up with only the 'text' section defined.
587 However, even that can be suppressed with (TODO) c/l option "-n".
588 Thus, we have to be able to create all three sections on-demand. */
591 obj_mach_o_base_section (int sect_index)
595 #ifdef md_flush_pending_output
596 md_flush_pending_output ();
599 /* We don't support numeric (or any other) qualifications on the
600 well-known section shorthands. */
601 demand_empty_rest_of_line ();
605 /* Handle the three sections that are globally known within GAS.
606 For Mach-O, these are created on demand rather than at startup. */
608 if (text_section == NULL)
609 text_section = obj_mach_o_segT_from_bfd_name (TEXT_SECTION_NAME, 1);
610 if (obj_mach_o_is_static)
612 bfd_mach_o_section *mo_sec
613 = bfd_mach_o_get_mach_o_section (text_section);
614 mo_sec->flags &= ~BFD_MACH_O_S_ATTR_PURE_INSTRUCTIONS;
616 section = text_section;
619 if (data_section == NULL)
620 data_section = obj_mach_o_segT_from_bfd_name (DATA_SECTION_NAME, 1);
621 section = data_section;
624 /* ??? maybe this achieves very little, as an addition. */
625 if (bss_section == NULL)
627 bss_section = obj_mach_o_segT_from_bfd_name (BSS_SECTION_NAME, 1);
628 seg_info (bss_section)->bss = 1;
630 section = bss_section;
633 as_fatal (_("internal error: base section index out of range"));
637 subseg_set (section, 0);
640 /* This finishes off parsing a .comm or .lcomm statement, which both can have
641 an (optional) alignment field. It also allows us to create the bss section
645 obj_mach_o_common_parse (int is_local, symbolS *symbolP,
650 /* Both comm and lcomm take an optional alignment, as a power
651 of two between 1 and 15. */
652 if (*input_line_pointer == ',')
654 /* We expect a power of 2. */
655 align = parse_align (0);
656 if (align == (addressT) -1)
660 as_warn (_("Alignment (%lu) too large: 15 assumed."),
661 (unsigned long)align);
668 /* Create the BSS section on demand. */
669 if (bss_section == NULL)
671 bss_section = obj_mach_o_segT_from_bfd_name (BSS_SECTION_NAME, 1);
672 seg_info (bss_section)->bss = 1;
674 bss_alloc (symbolP, size, align);
675 S_CLEAR_EXTERNAL (symbolP);
679 S_SET_VALUE (symbolP, size);
680 S_SET_ALIGN (symbolP, align);
681 S_SET_EXTERNAL (symbolP);
682 S_SET_SEGMENT (symbolP, bfd_com_section_ptr);
685 symbol_get_bfdsym (symbolP)->flags |= BSF_OBJECT;
691 obj_mach_o_comm (int is_local)
693 s_comm_internal (is_local, obj_mach_o_common_parse);
696 /* Set properties that apply to the whole file. At present, the only
697 one defined, is subsections_via_symbols. */
699 typedef enum obj_mach_o_file_properties {
700 OBJ_MACH_O_FILE_PROP_NONE = 0,
701 OBJ_MACH_O_FILE_PROP_SUBSECTS_VIA_SYMS,
702 OBJ_MACH_O_FILE_PROP_MAX
703 } obj_mach_o_file_properties;
706 obj_mach_o_fileprop (int prop)
708 if (prop < 0 || prop >= OBJ_MACH_O_FILE_PROP_MAX)
709 as_fatal (_("internal error: bad file property ID %d"), prop);
711 switch ((obj_mach_o_file_properties) prop)
713 case OBJ_MACH_O_FILE_PROP_SUBSECTS_VIA_SYMS:
714 obj_mach_o_subsections_by_symbols = 1;
715 if (!bfd_set_private_flags (stdoutput,
716 BFD_MACH_O_MH_SUBSECTIONS_VIA_SYMBOLS))
717 as_bad (_("failed to set subsections by symbols"));
718 demand_empty_rest_of_line ();
725 /* Dummy function to allow test-code to work while we are working
729 obj_mach_o_placeholder (int arg ATTRIBUTE_UNUSED)
731 ignore_rest_of_line ();
734 const pseudo_typeS mach_o_pseudo_table[] =
736 /* Section directives. */
737 { "comm", obj_mach_o_comm, 0 },
738 { "lcomm", obj_mach_o_comm, 1 },
740 { "text", obj_mach_o_base_section, 1},
741 { "data", obj_mach_o_base_section, 2},
742 { "bss", obj_mach_o_base_section, 3}, /* extension */
744 { "const", obj_mach_o_known_section, 1},
745 { "static_const", obj_mach_o_known_section, 2},
746 { "cstring", obj_mach_o_known_section, 3},
747 { "literal4", obj_mach_o_known_section, 4},
748 { "literal8", obj_mach_o_known_section, 5},
749 { "literal16", obj_mach_o_known_section, 6},
750 { "constructor", obj_mach_o_known_section, 7},
751 { "destructor", obj_mach_o_known_section, 8},
752 { "eh_frame", obj_mach_o_known_section, 9},
754 { "const_data", obj_mach_o_known_section, 10},
755 { "static_data", obj_mach_o_known_section, 11},
756 { "mod_init_func", obj_mach_o_known_section, 12},
757 { "mod_term_func", obj_mach_o_known_section, 13},
758 { "dyld", obj_mach_o_known_section, 14},
759 { "cfstring", obj_mach_o_known_section, 15},
761 { "objc_class", obj_mach_o_objc_section, 1},
762 { "objc_meta_class", obj_mach_o_objc_section, 2},
763 { "objc_cat_cls_meth", obj_mach_o_objc_section, 3},
764 { "objc_cat_inst_meth", obj_mach_o_objc_section, 4},
765 { "objc_protocol", obj_mach_o_objc_section, 5},
766 { "objc_string_object", obj_mach_o_objc_section, 6},
767 { "objc_cls_meth", obj_mach_o_objc_section, 7},
768 { "objc_inst_meth", obj_mach_o_objc_section, 8},
769 { "objc_cls_refs", obj_mach_o_objc_section, 9},
770 { "objc_message_refs", obj_mach_o_objc_section, 10},
771 { "objc_symbols", obj_mach_o_objc_section, 11},
772 { "objc_category", obj_mach_o_objc_section, 12},
773 { "objc_class_vars", obj_mach_o_objc_section, 13},
774 { "objc_instance_vars", obj_mach_o_objc_section, 14},
775 { "objc_module_info", obj_mach_o_objc_section, 15},
776 { "objc_class_names", obj_mach_o_objc_section, 16}, /* Alias for .cstring */
777 { "objc_meth_var_types", obj_mach_o_objc_section, 17}, /* Alias for .cstring */
778 { "objc_meth_var_names", obj_mach_o_objc_section, 18}, /* Alias for .cstring */
779 { "objc_selector_strs", obj_mach_o_objc_section, 19},
780 { "objc_image_info", obj_mach_o_objc_section, 20}, /* extension. */
781 { "objc_selector_fixup", obj_mach_o_objc_section, 21}, /* extension. */
782 { "objc1_class_ext", obj_mach_o_objc_section, 22}, /* ObjC-1 extension. */
783 { "objc1_property_list", obj_mach_o_objc_section, 23}, /* ObjC-1 extension. */
784 { "objc1_protocol_ext", obj_mach_o_objc_section, 24}, /* ObjC-1 extension. */
786 { "debug_frame", obj_mach_o_debug_section, 1}, /* extension. */
787 { "debug_info", obj_mach_o_debug_section, 2}, /* extension. */
788 { "debug_abbrev", obj_mach_o_debug_section, 3}, /* extension. */
789 { "debug_aranges", obj_mach_o_debug_section, 4}, /* extension. */
790 { "debug_macinfo", obj_mach_o_debug_section, 5}, /* extension. */
791 { "debug_line", obj_mach_o_debug_section, 6}, /* extension. */
792 { "debug_loc", obj_mach_o_debug_section, 7}, /* extension. */
793 { "debug_pubnames", obj_mach_o_debug_section, 8}, /* extension. */
794 { "debug_pubtypes", obj_mach_o_debug_section, 9}, /* extension. */
795 { "debug_str", obj_mach_o_debug_section, 10}, /* extension. */
796 { "debug_ranges", obj_mach_o_debug_section, 11}, /* extension. */
797 { "debug_macro", obj_mach_o_debug_section, 12}, /* extension. */
799 { "lazy_symbol_pointer", obj_mach_o_opt_tgt_section, 1},
800 { "lazy_symbol_pointer2", obj_mach_o_opt_tgt_section, 2}, /* extension. */
801 { "lazy_symbol_pointer3", obj_mach_o_opt_tgt_section, 3}, /* extension. */
802 { "non_lazy_symbol_pointer", obj_mach_o_opt_tgt_section, 4},
803 { "non_lazy_symbol_pointer_x86", obj_mach_o_opt_tgt_section, 5}, /* extension. */
804 { "symbol_stub", obj_mach_o_opt_tgt_section, 6},
805 { "symbol_stub1", obj_mach_o_opt_tgt_section, 7}, /* extension. */
806 { "picsymbol_stub", obj_mach_o_opt_tgt_section, 8}, /* extension. */
807 { "picsymbol_stub1", obj_mach_o_opt_tgt_section, 9}, /* extension. */
808 { "picsymbol_stub2", obj_mach_o_opt_tgt_section, 4}, /* extension. */
809 { "picsymbol_stub3", obj_mach_o_opt_tgt_section, 4}, /* extension. */
811 { "section", obj_mach_o_section, 0},
813 /* Symbol-related. */
814 { "indirect_symbol", obj_mach_o_placeholder, 0},
815 { "weak_definition", obj_mach_o_placeholder, 0},
816 { "private_extern", obj_mach_o_placeholder, 0},
817 { "weak", obj_mach_o_weak, 0}, /* extension */
820 { "subsections_via_symbols", obj_mach_o_fileprop,
821 OBJ_MACH_O_FILE_PROP_SUBSECTS_VIA_SYMS},