0,0 → 1,330 |
/* subsegs.c - subsegments - |
Copyright 1987, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, |
1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009 |
Free Software Foundation, Inc. |
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This file is part of GAS, the GNU Assembler. |
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GAS is free software; you can redistribute it and/or modify |
it under the terms of the GNU General Public License as published by |
the Free Software Foundation; either version 3, or (at your option) |
any later version. |
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GAS is distributed in the hope that it will be useful, |
but WITHOUT ANY WARRANTY; without even the implied warranty of |
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
GNU General Public License for more details. |
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You should have received a copy of the GNU General Public License |
along with GAS; see the file COPYING. If not, write to the Free |
Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA |
02110-1301, USA. */ |
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/* Segments & sub-segments. */ |
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#include "as.h" |
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#include "subsegs.h" |
#include "obstack.h" |
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frchainS *frchain_now; |
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static struct obstack frchains; |
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static fragS dummy_frag; |
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void |
subsegs_begin (void) |
{ |
obstack_begin (&frchains, chunksize); |
#if __GNUC__ >= 2 |
obstack_alignment_mask (&frchains) = __alignof__ (frchainS) - 1; |
#endif |
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frchain_now = NULL; /* Warn new_subseg() that we are booting. */ |
frag_now = &dummy_frag; |
} |
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/* |
* subseg_change() |
* |
* Change the subsegment we are in, BUT DO NOT MAKE A NEW FRAG for the |
* subsegment. If we are already in the correct subsegment, change nothing. |
* This is used eg as a worker for subseg_set [which does make a new frag_now] |
* and for changing segments after we have read the source. We construct eg |
* fixSs even after the source file is read, so we do have to keep the |
* segment context correct. |
*/ |
void |
subseg_change (register segT seg, register int subseg) |
{ |
segment_info_type *seginfo = seg_info (seg); |
now_seg = seg; |
now_subseg = subseg; |
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if (! seginfo) |
{ |
seginfo = (segment_info_type *) xcalloc (1, sizeof (*seginfo)); |
seginfo->bfd_section = seg; |
bfd_set_section_userdata (stdoutput, seg, seginfo); |
} |
} |
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static void |
subseg_set_rest (segT seg, subsegT subseg) |
{ |
frchainS *frcP; /* crawl frchain chain */ |
frchainS **lastPP; /* address of last pointer */ |
frchainS *newP; /* address of new frchain */ |
segment_info_type *seginfo; |
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mri_common_symbol = NULL; |
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if (frag_now && frchain_now) |
frchain_now->frch_frag_now = frag_now; |
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gas_assert (frchain_now == 0 |
|| frchain_now->frch_last == frag_now); |
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subseg_change (seg, (int) subseg); |
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seginfo = seg_info (seg); |
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/* Attempt to find or make a frchain for that subsection. |
We keep the list sorted by subsection number. */ |
for (frcP = *(lastPP = &seginfo->frchainP); |
frcP != NULL; |
frcP = *(lastPP = &frcP->frch_next)) |
if (frcP->frch_subseg >= subseg) |
break; |
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if (frcP == NULL || frcP->frch_subseg != subseg) |
{ |
/* This should be the only code that creates a frchainS. */ |
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newP = (frchainS *) obstack_alloc (&frchains, sizeof (frchainS)); |
newP->frch_subseg = subseg; |
newP->fix_root = NULL; |
newP->fix_tail = NULL; |
obstack_begin (&newP->frch_obstack, chunksize); |
#if __GNUC__ >= 2 |
obstack_alignment_mask (&newP->frch_obstack) = __alignof__ (fragS) - 1; |
#endif |
newP->frch_frag_now = frag_alloc (&newP->frch_obstack); |
newP->frch_frag_now->fr_type = rs_fill; |
newP->frch_cfi_data = NULL; |
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newP->frch_root = newP->frch_last = newP->frch_frag_now; |
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*lastPP = newP; |
newP->frch_next = frcP; |
frcP = newP; |
} |
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frchain_now = frcP; |
frag_now = frcP->frch_frag_now; |
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gas_assert (frchain_now->frch_last == frag_now); |
} |
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/* |
* subseg_set(segT, subsegT) |
* |
* If you attempt to change to the current subsegment, nothing happens. |
* |
* In: segT, subsegT code for new subsegment. |
* frag_now -> incomplete frag for current subsegment. |
* If frag_now==NULL, then there is no old, incomplete frag, so |
* the old frag is not closed off. |
* |
* Out: now_subseg, now_seg updated. |
* Frchain_now points to the (possibly new) struct frchain for this |
* sub-segment. |
*/ |
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segT |
subseg_get (const char *segname, int force_new) |
{ |
segT secptr; |
segment_info_type *seginfo; |
const char *now_seg_name = (now_seg |
? bfd_get_section_name (stdoutput, now_seg) |
: 0); |
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if (!force_new |
&& now_seg_name |
&& (now_seg_name == segname |
|| !strcmp (now_seg_name, segname))) |
return now_seg; |
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if (!force_new) |
secptr = bfd_make_section_old_way (stdoutput, segname); |
else |
secptr = bfd_make_section_anyway (stdoutput, segname); |
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seginfo = seg_info (secptr); |
if (! seginfo) |
{ |
secptr->output_section = secptr; |
seginfo = (segment_info_type *) xcalloc (1, sizeof (*seginfo)); |
seginfo->bfd_section = secptr; |
bfd_set_section_userdata (stdoutput, secptr, seginfo); |
} |
return secptr; |
} |
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segT |
subseg_new (const char *segname, subsegT subseg) |
{ |
segT secptr; |
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secptr = subseg_get (segname, 0); |
subseg_set_rest (secptr, subseg); |
return secptr; |
} |
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/* Like subseg_new, except a new section is always created, even if |
a section with that name already exists. */ |
segT |
subseg_force_new (const char *segname, subsegT subseg) |
{ |
segT secptr; |
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secptr = subseg_get (segname, 1); |
subseg_set_rest (secptr, subseg); |
return secptr; |
} |
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void |
subseg_set (segT secptr, subsegT subseg) |
{ |
if (! (secptr == now_seg && subseg == now_subseg)) |
subseg_set_rest (secptr, subseg); |
mri_common_symbol = NULL; |
} |
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#ifndef obj_sec_sym_ok_for_reloc |
#define obj_sec_sym_ok_for_reloc(SEC) 0 |
#endif |
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symbolS * |
section_symbol (segT sec) |
{ |
segment_info_type *seginfo = seg_info (sec); |
symbolS *s; |
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if (seginfo == 0) |
abort (); |
if (seginfo->sym) |
return seginfo->sym; |
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#ifndef EMIT_SECTION_SYMBOLS |
#define EMIT_SECTION_SYMBOLS 1 |
#endif |
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if (! EMIT_SECTION_SYMBOLS || symbol_table_frozen) |
{ |
/* Here we know it won't be going into the symbol table. */ |
s = symbol_create (sec->symbol->name, sec, 0, &zero_address_frag); |
} |
else |
{ |
segT seg; |
s = symbol_find (sec->symbol->name); |
/* We have to make sure it is the right symbol when we |
have multiple sections with the same section name. */ |
if (s == NULL |
|| ((seg = S_GET_SEGMENT (s)) != sec |
&& seg != undefined_section)) |
s = symbol_new (sec->symbol->name, sec, 0, &zero_address_frag); |
else if (seg == undefined_section) |
{ |
S_SET_SEGMENT (s, sec); |
symbol_set_frag (s, &zero_address_frag); |
} |
} |
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S_CLEAR_EXTERNAL (s); |
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/* Use the BFD section symbol, if possible. */ |
if (obj_sec_sym_ok_for_reloc (sec)) |
symbol_set_bfdsym (s, sec->symbol); |
else |
symbol_get_bfdsym (s)->flags |= BSF_SECTION_SYM; |
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seginfo->sym = s; |
return s; |
} |
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/* Return whether the specified segment is thought to hold text. */ |
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int |
subseg_text_p (segT sec) |
{ |
return (bfd_get_section_flags (stdoutput, sec) & SEC_CODE) != 0; |
} |
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/* Return non zero if SEC has at least one byte of data. It is |
possible that we'll return zero even on a non-empty section because |
we don't know all the fragment types, and it is possible that an |
fr_fix == 0 one still contributes data. Think of this as |
seg_definitely_not_empty_p. */ |
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int |
seg_not_empty_p (segT sec ATTRIBUTE_UNUSED) |
{ |
segment_info_type *seginfo = seg_info (sec); |
frchainS *chain; |
fragS *frag; |
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if (!seginfo) |
return 0; |
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for (chain = seginfo->frchainP; chain; chain = chain->frch_next) |
{ |
for (frag = chain->frch_root; frag; frag = frag->fr_next) |
if (frag->fr_fix) |
return 1; |
if (obstack_next_free (&chain->frch_obstack) |
!= chain->frch_last->fr_literal) |
return 1; |
} |
return 0; |
} |
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void |
subsegs_print_statistics (FILE *file) |
{ |
frchainS *frchp; |
asection *s; |
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fprintf (file, "frag chains:\n"); |
for (s = stdoutput->sections; s; s = s->next) |
{ |
segment_info_type *seginfo; |
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/* Skip gas-internal sections. */ |
if (segment_name (s)[0] == '*') |
continue; |
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seginfo = seg_info (s); |
if (!seginfo) |
continue; |
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for (frchp = seginfo->frchainP; frchp; frchp = frchp->frch_next) |
{ |
int count = 0; |
fragS *fragp; |
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for (fragp = frchp->frch_root; fragp; fragp = fragp->fr_next) |
count++; |
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fprintf (file, "\n"); |
fprintf (file, "\t%p %-10s\t%10d frags\n", (void *) frchp, |
segment_name (s), count); |
} |
} |
} |
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/* end of subsegs.c */ |