1/* subsegs.h -> subsegs.c 2 Copyright 1987, 1992, 1993, 1994, 1995, 1996, 1998, 2000, 2003, 2005, 3 2006 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 43struct frch_cfi_data; 44 45struct 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 subsegT frch_subseg; /* subsegment number of this chain */ 51 fixS *fix_root; /* Root of fixups for this subsegment. */ 52 fixS *fix_tail; /* Last fixup for this subsegment. */ 53 struct obstack frch_obstack; /* for objects in this frag chain */ 54 fragS *frch_frag_now; /* frag_now for this subsegment */ 55 struct frch_cfi_data *frch_cfi_data; 56}; 57 58typedef struct frchain frchainS; 59 60/* Frchain we are assembling into now. That is, the current segment's 61 frag chain, even if it contains no (complete) frags. */ 62extern frchainS *frchain_now; 63 64typedef struct segment_info_struct { 65 frchainS *frchainP; 66 unsigned int hadone : 1; 67 68 /* This field is set if this is a .bss section which does not really 69 have any contents. Once upon a time a .bss section did not have 70 any frags, but that is no longer true. This field prevent the 71 SEC_HAS_CONTENTS flag from being set for the section even if 72 there are frags. */ 73 unsigned int bss : 1; 74 75 int user_stuff; 76 77 /* Fixups for this segment. This is only valid after the frchains 78 are run together. */ 79 fixS *fix_root; 80 fixS *fix_tail; 81 82 symbolS *dot; 83 84 struct lineno_list *lineno_list_head; 85 struct lineno_list *lineno_list_tail; 86 87 /* Which BFD section does this gas segment correspond to? */ 88 asection *bfd_section; 89 90 /* NULL, or pointer to the gas symbol that is the section symbol for 91 this section. sym->bsym and bfd_section->symbol should be the same. */ 92 symbolS *sym; 93 94 union { 95 /* Current size of section holding stabs strings. */ 96 unsigned long stab_string_size; 97 /* Initial frag for ELF. */ 98 char *p; 99 } 100 stabu; 101 102#ifdef NEED_LITERAL_POOL 103 unsigned long literal_pool_size; 104#endif 105 106#ifdef TC_SEGMENT_INFO_TYPE 107 TC_SEGMENT_INFO_TYPE tc_segment_info_data; 108#endif 109} segment_info_type; 110 111 112#define seg_info(sec) \ 113 ((segment_info_type *) bfd_get_section_userdata (stdoutput, sec)) 114 115extern symbolS *section_symbol (segT); 116 117extern void subsegs_print_statistics (FILE *); 118