1 /* subsegs.c - subsegments -
2 Copyright (C) 1987, 1990, 1991, 1992, 1993, 1994
3 Free Software Foundation, Inc.
5 This file is part of GAS, the GNU Assembler.
7 GAS 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, or (at your option)
12 GAS 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 GAS; see the file COPYING. If not, write to
19 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
22 * Segments & sub-segments.
30 frchainS
*frchain_root
, *frchain_now
;
34 segment_info_type segment_info
[SEG_MAXIMUM_ORDINAL
];
37 /* Commented in "subsegs.h". */
38 frchainS
*data0_frchainP
, *bss0_frchainP
;
40 #endif /* MANY_SEGMENTS */
41 char *const seg_name
[] =
45 "e0", "e1", "e2", "e3", "e4", "e5", "e6", "e7", "e8", "e9",
50 #endif /* MANY_SEGMENTS */
52 "ASSEMBLER-INTERNAL-LOGIC-ERROR!",
55 "transfert vector preload",
56 "transfert vector postload",
59 }; /* Used by error reporters, dumpers etc. */
60 #else /* BFD_ASSEMBLER */
62 /* Gas segment information for bfd_abs_section_ptr and
63 bfd_und_section_ptr. */
64 static segment_info_type
*abs_seg_info
;
65 static segment_info_type
*und_seg_info
;
67 #endif /* BFD_ASSEMBLER */
69 static void subseg_set_rest
PARAMS ((segT
, subsegT
));
74 /* Check table(s) seg_name[], seg_N_TYPE[] is in correct order */
75 #if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER)
76 know (SEG_ABSOLUTE
== 0);
80 know (SEG_UNKNOWN
== 4);
83 know (SEG_DEBUG
== 7);
86 know (SEG_REGISTER
== 10);
87 know (SEG_MAXIMUM_ORDINAL
== SEG_REGISTER
);
90 obstack_begin (&frags
, 5000);
92 frchain_now
= NULL
; /* Warn new_subseg() that we are booting. */
93 /* Fake up 1st frag. It won't be used=> is ok if obstack...
94 pads the end of it for alignment. */
95 frag_now
= (fragS
*) obstack_alloc (&frags
, SIZEOF_STRUCT_FRAG
);
96 memset (frag_now
, 0, SIZEOF_STRUCT_FRAG
);
99 /* This 1st frag will not be in any frchain.
100 We simply give subseg_new somewhere to scribble. */
101 now_subseg
= 42; /* Lie for 1st call to subseg_new. */
105 for (i
= SEG_E0
; i
< SEG_UNKNOWN
; i
++)
108 segment_info
[i
].frchainP
= frchain_now
;
112 subseg_set (SEG_DATA
, 0); /* .data 0 */
113 data0_frchainP
= frchain_now
;
115 subseg_set (SEG_BSS
, 0);
116 bss0_frchainP
= frchain_now
;
118 #endif /* ! MANY_SEGMENTS */
119 #endif /* ! BFD_ASSEMBLER */
126 * Change the subsegment we are in, BUT DO NOT MAKE A NEW FRAG for the
127 * subsegment. If we are already in the correct subsegment, change nothing.
128 * This is used eg as a worker for subseg_set [which does make a new frag_now]
129 * and for changing segments after we have read the source. We construct eg
130 * fixSs even after the source file is read, so we do have to keep the
131 * segment context correct.
134 subseg_change (seg
, subseg
)
143 segment_info_type
*seginfo
;
144 seginfo
= (segment_info_type
*) bfd_get_section_userdata (stdoutput
, seg
);
147 seginfo
= (segment_info_type
*) xmalloc (sizeof (*seginfo
));
148 memset ((PTR
) seginfo
, 0, sizeof (*seginfo
));
149 seginfo
->fix_root
= NULL
;
150 seginfo
->fix_tail
= NULL
;
151 seginfo
->bfd_section
= seg
;
153 if (seg
== bfd_abs_section_ptr
)
154 abs_seg_info
= seginfo
;
155 else if (seg
== bfd_und_section_ptr
)
156 und_seg_info
= seginfo
;
158 bfd_set_section_userdata (stdoutput
, seg
, (PTR
) seginfo
);
163 seg_fix_rootP
= &segment_info
[seg
].fix_root
;
164 seg_fix_tailP
= &segment_info
[seg
].fix_tail
;
168 seg_fix_rootP
= &data_fix_root
;
169 seg_fix_tailP
= &data_fix_tail
;
171 else if (seg
== SEG_TEXT
)
173 seg_fix_rootP
= &text_fix_root
;
174 seg_fix_tailP
= &text_fix_tail
;
178 know (seg
== SEG_BSS
);
179 seg_fix_rootP
= &bss_fix_root
;
180 seg_fix_tailP
= &bss_fix_tail
;
188 subseg_set_rest (seg
, subseg
)
192 long tmp
; /* JF for obstack alignment hacking */
193 register frchainS
*frcP
; /* crawl frchain chain */
194 register frchainS
**lastPP
; /* address of last pointer */
195 frchainS
*newP
; /* address of new frchain */
196 register fragS
*former_last_fragP
;
197 register fragS
*new_fragP
;
199 if (frag_now
) /* If not bootstrapping. */
201 frag_now
->fr_fix
= (char*) obstack_next_free (&frags
) - frag_now
->fr_literal
;
202 frag_wane (frag_now
); /* Close off any frag in old subseg. */
205 * It would be nice to keep an obstack for each subsegment, if we swap
206 * subsegments a lot. Hence we would have much fewer frag_wanes().
209 obstack_finish (&frags
);
211 * If we don't do the above, the next object we put on obstack frags
212 * will appear to start at the fr_literal of the current frag.
213 * Also, above ensures that the next object will begin on a
214 * address that is aligned correctly for the engine that runs
218 subseg_change (seg
, (int) subseg
);
220 * Attempt to find or make a frchain for that sub seg.
221 * Crawl along chain of frchainSs, begins @ frchain_root.
222 * If we need to make a frchainS, link it into correct
223 * position of chain rooted in frchain_root.
225 for (frcP
= *(lastPP
= &frchain_root
);
226 frcP
&& frcP
->frch_seg
<= seg
;
227 frcP
= *(lastPP
= &frcP
->frch_next
))
229 if (frcP
->frch_seg
== seg
230 && frcP
->frch_subseg
>= subseg
)
236 * frcP: Address of the 1st frchainS in correct segment with
237 * frch_subseg >= subseg.
238 * We want to either use this frchainS, or we want
239 * to insert a new frchainS just before it.
241 * If frcP==NULL, then we are at the end of the chain
242 * of frchainS-s. A NULL frcP means we fell off the end
243 * of the chain looking for a
244 * frch_subseg >= subseg, so we
245 * must make a new frchainS.
247 * If we ever maintain a pointer to
248 * the last frchainS in the chain, we change that pointer
249 * ONLY when frcP==NULL.
251 * lastPP: Address of the pointer with value frcP;
253 * May point to frchain_root.
257 || (frcP
->frch_seg
> seg
258 || frcP
->frch_subseg
> subseg
)) /* Kinky logic only works with 2 segments. */
261 * This should be the only code that creates a frchainS.
263 newP
= (frchainS
*) obstack_alloc (&frags
, sizeof (frchainS
));
264 memset (newP
, 0, sizeof (frchainS
));
265 /* This begines on a good boundary because a obstack_done()
266 preceeded it. It implies an obstack_done(), so we expect
267 the next object allocated to begin on a correct boundary. */
269 newP
->frch_next
= frcP
; /* perhaps NULL */
270 (frcP
= newP
)->frch_subseg
= subseg
;
271 newP
->frch_seg
= seg
;
272 newP
->frch_last
= NULL
;
274 newP
->fix_root
= NULL
;
275 newP
->fix_tail
= NULL
;
279 * Here with frcP ->ing to the frchainS for subseg.
283 * Make a fresh frag for the subsegment.
285 /* We expect this to happen on a correct boundary since it was
286 proceeded by a obstack_done(). */
287 tmp
= obstack_alignment_mask (&frags
); /* JF disable alignment */
288 obstack_alignment_mask (&frags
) = 0;
289 frag_now
= (fragS
*) obstack_alloc (&frags
, SIZEOF_STRUCT_FRAG
);
290 memset (frag_now
, 0, SIZEOF_STRUCT_FRAG
);
291 obstack_alignment_mask (&frags
) = tmp
;
292 /* But we want any more chars to come immediately after the
293 structure we just made. */
294 new_fragP
= frag_now
;
295 new_fragP
->fr_next
= NULL
;
297 * Append new frag to current frchain.
299 former_last_fragP
= frcP
->frch_last
;
300 if (former_last_fragP
)
302 know (former_last_fragP
->fr_next
== NULL
);
303 know (frchain_now
->frch_root
);
304 former_last_fragP
->fr_next
= new_fragP
;
308 frcP
->frch_root
= new_fragP
;
310 frcP
->frch_last
= new_fragP
;
314 * subseg_set(segT, subsegT)
316 * If you attempt to change to the current subsegment, nothing happens.
318 * In: segT, subsegT code for new subsegment.
319 * frag_now -> incomplete frag for current subsegment.
320 * If frag_now==NULL, then there is no old, incomplete frag, so
321 * the old frag is not closed off.
323 * Out: now_subseg, now_seg updated.
324 * Frchain_now points to the (possibly new) struct frchain for this
326 * Frchain_root updated if needed.
329 #ifndef BFD_ASSEMBLER
332 subseg_new (segname
, subseg
)
338 for (i
= 0; i
< (int) SEG_MAXIMUM_ORDINAL
; i
++)
342 s
= segment_name ((segT
) i
);
343 if (strcmp (segname
, s
) == 0
344 || (segname
[0] == '.'
345 && strcmp (segname
+ 1, s
) == 0))
347 subseg_set ((segT
) i
, subseg
);
350 #ifdef obj_segment_name
351 s
= obj_segment_name ((segT
) i
);
352 if (strcmp (segname
, s
) == 0
353 || (segname
[0] == '.'
354 && strcmp (segname
+ 1, s
) == 0))
356 subseg_set ((segT
) i
, subseg
);
362 #ifdef obj_add_segment
365 new_seg
= obj_add_segment (segname
);
366 subseg_set (new_seg
, subseg
);
370 as_bad ("Attempt to switch to nonexistent segment \"%s\"", segname
);
376 subseg_set (seg
, subseg
) /* begin assembly for a new sub-segment */
377 register segT seg
; /* SEG_DATA or SEG_TEXT */
378 register subsegT subseg
;
380 #ifndef MANY_SEGMENTS
381 know (seg
== SEG_DATA
|| seg
== SEG_TEXT
|| seg
== SEG_BSS
);
384 if (seg
!= now_seg
|| subseg
!= now_subseg
)
385 { /* we just changed sub-segments */
386 subseg_set_rest (seg
, subseg
);
390 #else /* BFD_ASSEMBLER */
393 subseg_get (segname
, force_new
)
398 segment_info_type
*seginfo
;
399 const char *now_seg_name
= (now_seg
400 ? bfd_get_section_name (stdoutput
, now_seg
)
405 && (now_seg_name
== segname
406 || !strcmp (now_seg_name
, segname
)))
410 secptr
= bfd_make_section_old_way (stdoutput
, segname
);
412 secptr
= bfd_make_section_anyway (stdoutput
, segname
);
414 seginfo
= seg_info (secptr
);
417 /* Check whether output_section is set first because secptr may
418 be bfd_abs_section_ptr. */
419 if (secptr
->output_section
!= secptr
)
420 secptr
->output_section
= secptr
;
421 seginfo
= (segment_info_type
*) xmalloc (sizeof (*seginfo
));
422 memset ((PTR
) seginfo
, 0, sizeof (*seginfo
));
423 seginfo
->fix_root
= NULL
;
424 seginfo
->fix_tail
= NULL
;
425 seginfo
->bfd_section
= secptr
;
426 if (secptr
== bfd_abs_section_ptr
)
427 abs_seg_info
= seginfo
;
428 else if (secptr
== bfd_und_section_ptr
)
429 und_seg_info
= seginfo
;
431 bfd_set_section_userdata (stdoutput
, secptr
, (PTR
) seginfo
);
432 seginfo
->frchainP
= NULL
;
433 seginfo
->lineno_list_head
= seginfo
->lineno_list_tail
= NULL
;
441 subseg_new (segname
, subseg
)
446 segment_info_type
*seginfo
;
448 secptr
= subseg_get (segname
, 0);
449 subseg_set_rest (secptr
, subseg
);
450 seginfo
= seg_info (secptr
);
451 if (! seginfo
->frchainP
)
452 seginfo
->frchainP
= frchain_now
;
456 /* Like subseg_new, except a new section is always created, even if
457 a section with that name already exists. */
459 subseg_force_new (segname
, subseg
)
464 segment_info_type
*seginfo
;
466 secptr
= subseg_get (segname
, 1);
467 subseg_set_rest (secptr
, subseg
);
468 seginfo
= seg_info (secptr
);
469 if (! seginfo
->frchainP
)
470 seginfo
->frchainP
= frchain_now
;
475 subseg_set (secptr
, subseg
)
479 if (! (secptr
== now_seg
&& subseg
== now_subseg
))
480 subseg_set_rest (secptr
, subseg
);
483 #ifndef obj_sec_sym_ok_for_reloc
484 #define obj_sec_sym_ok_for_reloc(SEC) 0
487 /* Get the gas information we are storing for a section. */
493 if (sec
== bfd_abs_section_ptr
)
495 else if (sec
== bfd_und_section_ptr
)
498 return (segment_info_type
*) bfd_get_section_userdata (stdoutput
, sec
);
505 segment_info_type
*seginfo
= seg_info (sec
);
512 s
= symbol_find (sec
->name
);
515 #ifndef EMIT_SECTION_SYMBOLS
516 #define EMIT_SECTION_SYMBOLS 1
519 if (EMIT_SECTION_SYMBOLS
521 && symbol_table_frozen
524 s
= symbol_new (sec
->name
, sec
, 0, &zero_address_frag
);
526 s
= symbol_create (sec
->name
, sec
, 0, &zero_address_frag
);
527 S_CLEAR_EXTERNAL (s
);
529 /* Use the BFD section symbol, if possible. */
530 if (obj_sec_sym_ok_for_reloc (sec
))
531 s
->bsym
= sec
->symbol
;
537 #endif /* BFD_ASSEMBLER */
539 /* end of subsegs.c */