1 /* subsegs.h -> subsegs.c 2 Copyright 1987, 1992, 1993, 1994, 1995, 1996, 1998, 2000, 2003, 2005 3 Free Software Foundation, Inc. 4 5 This file is part of GAS, the GNU Assembler. 6 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) 10 any later version. 11 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. 16 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 the Free 19 Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA 20 02110-1301, USA. */ 21 22 /* 23 * For every sub-segment the user mentions in the ASsembler program, 24 * we make one struct frchain. Each sub-segment has exactly one struct frchain 25 * and vice versa. 26 * 27 * Struct frchain's are forward chained (in ascending order of sub-segment 28 * code number). The chain runs through frch_next of each subsegment. 29 * This makes it hard to find a subsegment's frags 30 * if programmer uses a lot of them. Most programs only use text0 and 31 * data0, so they don't suffer. At least this way: 32 * (1) There are no "arbitrary" restrictions on how many subsegments 33 * can be programmed; 34 * (2) Subsegments' frchain-s are (later) chained together in the order in 35 * which they are emitted for object file viz text then data. 36 * 37 * From each struct frchain dangles a chain of struct frags. The frags 38 * represent code fragments, for that sub-segment, forward chained. 39 */ 40 41 #include "obstack.h" 42 43 struct frch_cfi_data; 44 45 struct frchain /* control building of a frag chain */ 46 { /* FRCH = FRagment CHain control */ 47 struct frag *frch_root; /* 1st struct frag in chain, or NULL */ 48 struct frag *frch_last; /* last struct frag in chain, or NULL */ 49 struct frchain *frch_next; /* next in chain of struct frchain-s */ 50 segT frch_seg; /* SEG_TEXT or SEG_DATA. */ 51 subsegT frch_subseg; /* subsegment number of this chain */ 52 fixS *fix_root; /* Root of fixups for this subsegment. */ 53 fixS *fix_tail; /* Last fixup for this subsegment. */ 54 struct obstack frch_obstack; /* for objects in this frag chain */ 55 fragS *frch_frag_now; /* frag_now for this subsegment */ 56 struct frch_cfi_data *frch_cfi_data; 57 }; 58 59 typedef struct frchain frchainS; 60 61 /* All subsegments' chains hang off here. NULL means no frchains yet. */ 62 extern frchainS *frchain_root; 63 64 /* Frchain we are assembling into now. That is, the current segment's 65 frag chain, even if it contains no (complete) frags. */ 66 extern frchainS *frchain_now; 67 68 typedef struct segment_info_struct { 69 frchainS *frchainP; 70 unsigned int hadone : 1; 71 72 /* This field is set if this is a .bss section which does not really 73 have any contents. Once upon a time a .bss section did not have 74 any frags, but that is no longer true. This field prevent the 75 SEC_HAS_CONTENTS flag from being set for the section even if 76 there are frags. */ 77 unsigned int bss : 1; 78 79 int user_stuff; 80 81 /* Fixups for this segment. This is only valid after the frchains 82 are run together. */ 83 fixS *fix_root; 84 fixS *fix_tail; 85 86 symbolS *dot; 87 88 struct lineno_list *lineno_list_head; 89 struct lineno_list *lineno_list_tail; 90 91 /* Which BFD section does this gas segment correspond to? */ 92 asection *bfd_section; 93 94 /* NULL, or pointer to the gas symbol that is the section symbol for 95 this section. sym->bsym and bfd_section->symbol should be the same. */ 96 symbolS *sym; 97 98 union { 99 /* Current size of section holding stabs strings. */ 100 unsigned long stab_string_size; 101 /* Initial frag for ELF. */ 102 char *p; 103 } 104 stabu; 105 106 #ifdef NEED_LITERAL_POOL 107 unsigned long literal_pool_size; 108 #endif 109 110 #ifdef TC_SEGMENT_INFO_TYPE 111 TC_SEGMENT_INFO_TYPE tc_segment_info_data; 112 #endif 113 } segment_info_type; 114 115 extern segment_info_type *seg_info (segT); 116 extern symbolS *section_symbol (segT); 117 118 extern void subsegs_print_statistics (FILE *); 119