| /* subsegs.c - subsegments - |
| Copyright (C) 1987-2024 Free Software Foundation, Inc. |
| |
| This file is part of GAS, the GNU Assembler. |
| |
| 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. |
| |
| 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. |
| |
| 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. */ |
| |
| /* Segments & sub-segments. */ |
| |
| #include "as.h" |
| |
| #include "subsegs.h" |
| #include "obstack.h" |
| |
| frchainS *frchain_now; |
| |
| static struct obstack frchains; |
| |
| static fragS dummy_frag; |
| |
| |
| void |
| subsegs_begin (void) |
| { |
| obstack_begin (&frchains, chunksize); |
| #if __GNUC__ >= 2 |
| obstack_alignment_mask (&frchains) = __alignof__ (frchainS) - 1; |
| #endif |
| |
| frchain_now = NULL; /* Warn new_subseg() that we are booting. */ |
| frag_now = &dummy_frag; |
| } |
| |
| void |
| subsegs_end (struct obstack **obs) |
| { |
| for (; *obs; obs++) |
| _obstack_free (*obs, NULL); |
| _obstack_free (&frchains, NULL); |
| bfd_set_section_userdata (bfd_abs_section_ptr, NULL); |
| bfd_set_section_userdata (bfd_und_section_ptr, NULL); |
| } |
| |
| static void |
| alloc_seginfo (segT seg) |
| { |
| segment_info_type *seginfo; |
| |
| seginfo = obstack_alloc (¬es, sizeof (*seginfo)); |
| memset (seginfo, 0, sizeof (*seginfo)); |
| bfd_set_section_userdata (seg, seginfo); |
| } |
| /* |
| * 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 (segT seg, int subseg) |
| { |
| now_seg = seg; |
| now_subseg = subseg; |
| |
| if (!seg_info (seg)) |
| alloc_seginfo (seg); |
| } |
| |
| 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; |
| |
| mri_common_symbol = NULL; |
| |
| if (frag_now && frchain_now) |
| frchain_now->frch_frag_now = frag_now; |
| |
| gas_assert (frchain_now == 0 |
| || frchain_now->frch_last == frag_now); |
| |
| subseg_change (seg, (int) subseg); |
| |
| seginfo = seg_info (seg); |
| |
| /* Should the section symbol be kept? */ |
| if (bfd_keep_unused_section_symbols (stdoutput)) |
| seg->symbol->flags |= BSF_SECTION_SYM_USED; |
| |
| /* 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; |
| |
| if (frcP == NULL || frcP->frch_subseg != subseg) |
| { |
| /* This should be the only code that creates a frchainS. */ |
| |
| 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; |
| newP->frch_ginsn_data = NULL; |
| |
| newP->frch_root = newP->frch_last = newP->frch_frag_now; |
| |
| *lastPP = newP; |
| newP->frch_next = frcP; |
| frcP = newP; |
| } |
| |
| frchain_now = frcP; |
| frag_now = frcP->frch_frag_now; |
| |
| gas_assert (frchain_now->frch_last == frag_now); |
| } |
| |
| /* |
| * 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. |
| */ |
| |
| segT |
| subseg_get (const char *segname, int force_new) |
| { |
| segT secptr; |
| const char *now_seg_name = now_seg ? bfd_section_name (now_seg) : 0; |
| |
| if (!force_new |
| && now_seg_name |
| && (now_seg_name == segname |
| || !strcmp (now_seg_name, segname))) |
| return now_seg; |
| |
| if (!force_new) |
| secptr = bfd_make_section_old_way (stdoutput, segname); |
| else |
| secptr = bfd_make_section_anyway (stdoutput, segname); |
| |
| if (!seg_info (secptr)) |
| { |
| secptr->output_section = secptr; |
| alloc_seginfo (secptr); |
| } |
| return secptr; |
| } |
| |
| segT |
| subseg_new (const char *segname, subsegT subseg) |
| { |
| segT secptr; |
| |
| secptr = subseg_get (segname, 0); |
| subseg_set_rest (secptr, subseg); |
| return secptr; |
| } |
| |
| /* 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; |
| |
| secptr = subseg_get (segname, 1); |
| subseg_set_rest (secptr, subseg); |
| return secptr; |
| } |
| |
| void |
| subseg_set (segT secptr, subsegT subseg) |
| { |
| if (! (secptr == now_seg && subseg == now_subseg)) |
| subseg_set_rest (secptr, subseg); |
| mri_common_symbol = NULL; |
| } |
| |
| #ifndef obj_sec_sym_ok_for_reloc |
| #define obj_sec_sym_ok_for_reloc(SEC) 0 |
| #endif |
| |
| symbolS * |
| section_symbol (segT sec) |
| { |
| segment_info_type *seginfo = seg_info (sec); |
| symbolS *s; |
| |
| if (seginfo == 0) |
| abort (); |
| if (seginfo->sym) |
| return seginfo->sym; |
| |
| #ifndef EMIT_SECTION_SYMBOLS |
| #define EMIT_SECTION_SYMBOLS 1 |
| #endif |
| |
| 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, &zero_address_frag, 0); |
| } |
| 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, &zero_address_frag, 0); |
| else if (seg == undefined_section) |
| { |
| S_SET_SEGMENT (s, sec); |
| symbol_set_frag (s, &zero_address_frag); |
| } |
| } |
| |
| S_CLEAR_EXTERNAL (s); |
| |
| /* 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; |
| |
| seginfo->sym = s; |
| return s; |
| } |
| |
| /* Return whether the specified segment is thought to hold text. */ |
| |
| int |
| subseg_text_p (segT sec) |
| { |
| return (bfd_section_flags (sec) & SEC_CODE) != 0; |
| } |
| |
| /* 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. */ |
| |
| int |
| seg_not_empty_p (segT sec ATTRIBUTE_UNUSED) |
| { |
| segment_info_type *seginfo = seg_info (sec); |
| frchainS *chain; |
| fragS *frag; |
| |
| if (!seginfo) |
| return 0; |
| |
| 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; |
| } |
| |
| void |
| subsegs_print_statistics (FILE *file) |
| { |
| frchainS *frchp; |
| asection *s; |
| |
| /* PR 20897 - check to see if the output bfd was actually created. */ |
| if (stdoutput == NULL) |
| return; |
| |
| fprintf (file, "frag chains:\n"); |
| for (s = stdoutput->sections; s; s = s->next) |
| { |
| segment_info_type *seginfo; |
| |
| /* Skip gas-internal sections. */ |
| if (segment_name (s)[0] == '*') |
| continue; |
| |
| seginfo = seg_info (s); |
| if (!seginfo) |
| continue; |
| |
| for (frchp = seginfo->frchainP; frchp; frchp = frchp->frch_next) |
| { |
| int count = 0; |
| fragS *fragp; |
| |
| for (fragp = frchp->frch_root; fragp; fragp = fragp->fr_next) |
| count++; |
| |
| fprintf (file, "\n"); |
| fprintf (file, "\t%p %-10s\t%10d frags\n", (void *) frchp, |
| segment_name (s), count); |
| } |
| } |
| } |
| |
| /* end of subsegs.c */ |