1 /* subsegs.h -> subsegs.c 2 Copyright (C) 1987-2014 Free Software Foundation, Inc. 3 4 This file is part of GAS, the GNU Assembler. 5 6 GAS 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 3, or (at your option) 9 any later version. 10 11 GAS 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 GAS; see the file COPYING. If not, write to the Free 18 Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA 19 02110-1301, USA. */ 20 21 /* 22 * For every sub-segment the user mentions in the ASsembler program, 23 * we make one struct frchain. Each sub-segment has exactly one struct frchain 24 * and vice versa. 25 * 26 * Struct frchain's are forward chained (in ascending order of sub-segment 27 * code number). The chain runs through frch_next of each subsegment. 28 * This makes it hard to find a subsegment's frags 29 * if programmer uses a lot of them. Most programs only use text0 and 30 * data0, so they don't suffer. At least this way: 31 * (1) There are no "arbitrary" restrictions on how many subsegments 32 * can be programmed; 33 * (2) Subsegments' frchain-s are (later) chained together in the order in 34 * which they are emitted for object file viz text then data. 35 * 36 * From each struct frchain dangles a chain of struct frags. The frags 37 * represent code fragments, for that sub-segment, forward chained. 38 */ 39 40 #include "obstack.h" 41 42 struct frch_cfi_data; 43 44 struct frchain /* control building of a frag chain */ 45 { /* FRCH = FRagment CHain control */ 46 struct frag *frch_root; /* 1st struct frag in chain, or NULL */ 47 struct frag *frch_last; /* last struct frag in chain, or NULL */ 48 struct frchain *frch_next; /* next in chain of struct frchain-s */ 49 subsegT frch_subseg; /* subsegment number of this chain */ 50 fixS *fix_root; /* Root of fixups for this subsegment. */ 51 fixS *fix_tail; /* Last fixup for this subsegment. */ 52 struct obstack frch_obstack; /* for objects in this frag chain */ 53 fragS *frch_frag_now; /* frag_now for this subsegment */ 54 struct frch_cfi_data *frch_cfi_data; 55 }; 56 57 typedef struct frchain frchainS; 58 59 /* Frchain we are assembling into now. That is, the current segment's 60 frag chain, even if it contains no (complete) frags. */ 61 extern frchainS *frchain_now; 62 63 typedef struct segment_info_struct { 64 frchainS *frchainP; 65 unsigned int hadone : 1; 66 67 /* This field is set if this is a .bss section which does not really 68 have any contents. Once upon a time a .bss section did not have 69 any frags, but that is no longer true. This field prevent the 70 SEC_HAS_CONTENTS flag from being set for the section even if 71 there are frags. */ 72 unsigned int bss : 1; 73 74 int user_stuff; 75 76 /* Fixups for this segment. This is only valid after the frchains 77 are run together. */ 78 fixS *fix_root; 79 fixS *fix_tail; 80 81 symbolS *dot; 82 83 struct lineno_list *lineno_list_head; 84 struct lineno_list *lineno_list_tail; 85 86 /* Which BFD section does this gas segment correspond to? */ 87 asection *bfd_section; 88 89 /* NULL, or pointer to the gas symbol that is the section symbol for 90 this section. sym->bsym and bfd_section->symbol should be the same. */ 91 symbolS *sym; 92 93 /* Used by dwarf2dbg.c for this section's line table entries. */ 94 void *dwarf2_line_seg; 95 96 union { 97 /* Current size of section holding stabs strings. */ 98 unsigned long stab_string_size; 99 /* Initial frag for ELF. */ 100 char *p; 101 } 102 stabu; 103 104 #ifdef NEED_LITERAL_POOL 105 unsigned long literal_pool_size; 106 #endif 107 108 #ifdef TC_SEGMENT_INFO_TYPE 109 TC_SEGMENT_INFO_TYPE tc_segment_info_data; 110 #endif 111 } segment_info_type; 112 113 114 #define seg_info(sec) \ 115 ((segment_info_type *) bfd_get_section_userdata (stdoutput, sec)) 116 117 extern symbolS *section_symbol (segT); 118 119 extern void subsegs_print_statistics (FILE *); 120