| 1 | /* frags.h - Header file for the frag concept. |
| 2 | Copyright 1987, 1992, 1993, 1994, 1995, 1997, 1998, 1999, 2000, 2001 |
| 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, 59 Temple Place - Suite 330, Boston, MA |
| 20 | 02111-1307, USA. */ |
| 21 | |
| 22 | #ifndef FRAGS_H |
| 23 | #define FRAGS_H |
| 24 | |
| 25 | #ifdef ANSI_PROTOTYPES |
| 26 | struct obstack; |
| 27 | #endif |
| 28 | |
| 29 | /* A code fragment (frag) is some known number of chars, followed by some |
| 30 | unknown number of chars. Typically the unknown number of chars is an |
| 31 | instruction address whose size is yet unknown. We always know the greatest |
| 32 | possible size the unknown number of chars may become, and reserve that |
| 33 | much room at the end of the frag. |
| 34 | Once created, frags do not change address during assembly. |
| 35 | We chain the frags in (a) forward-linked list(s). The object-file address |
| 36 | of the 1st char of a frag is generally not known until after relax(). |
| 37 | Many things at assembly time describe an address by {object-file-address |
| 38 | of a particular frag}+offset. |
| 39 | |
| 40 | BUG: it may be smarter to have a single pointer off to various different |
| 41 | notes for different frag kinds. See how code pans. */ |
| 42 | |
| 43 | struct frag { |
| 44 | /* Object file address (as an octet offset). */ |
| 45 | addressT fr_address; |
| 46 | /* When relaxing multiple times, remember the address the frag had |
| 47 | in the last relax pass. */ |
| 48 | addressT last_fr_address; |
| 49 | |
| 50 | /* (Fixed) number of octets we know we have. May be 0. */ |
| 51 | offsetT fr_fix; |
| 52 | /* May be used for (Variable) number of octets after above. |
| 53 | The generic frag handling code no longer makes any use of fr_var. */ |
| 54 | offsetT fr_var; |
| 55 | /* For variable-length tail. */ |
| 56 | offsetT fr_offset; |
| 57 | /* For variable-length tail. */ |
| 58 | symbolS *fr_symbol; |
| 59 | /* Points to opcode low addr byte, for relaxation. */ |
| 60 | char *fr_opcode; |
| 61 | |
| 62 | /* Chain forward; ascending address order. Rooted in frch_root. */ |
| 63 | struct frag *fr_next; |
| 64 | |
| 65 | /* Where the frag was created, or where it became a variant frag. */ |
| 66 | char *fr_file; |
| 67 | unsigned int fr_line; |
| 68 | |
| 69 | #ifndef NO_LISTING |
| 70 | struct list_info_struct *line; |
| 71 | #endif |
| 72 | |
| 73 | /* Flipped each relax pass so we can easily determine whether |
| 74 | fr_address has been adjusted. */ |
| 75 | unsigned int relax_marker:1; |
| 76 | |
| 77 | /* What state is my tail in? */ |
| 78 | relax_stateT fr_type; |
| 79 | relax_substateT fr_subtype; |
| 80 | |
| 81 | #ifdef USING_CGEN |
| 82 | /* Don't include this unless using CGEN to keep frag size down. */ |
| 83 | struct { |
| 84 | /* CGEN_INSN entry for this instruction. */ |
| 85 | const struct cgen_insn *insn; |
| 86 | /* Index into operand table. */ |
| 87 | int opindex; |
| 88 | /* Target specific data, usually reloc number. */ |
| 89 | int opinfo; |
| 90 | } fr_cgen; |
| 91 | #endif |
| 92 | |
| 93 | #ifdef TC_FRAG_TYPE |
| 94 | TC_FRAG_TYPE tc_frag_data; |
| 95 | #endif |
| 96 | |
| 97 | /* Data begins here. */ |
| 98 | char fr_literal[1]; |
| 99 | }; |
| 100 | |
| 101 | #define SIZEOF_STRUCT_FRAG \ |
| 102 | ((char *) zero_address_frag.fr_literal - (char *) &zero_address_frag) |
| 103 | /* We want to say fr_literal[0] above. */ |
| 104 | |
| 105 | /* Current frag we are building. This frag is incomplete. It is, |
| 106 | however, included in frchain_now. The fr_fix field is bogus; |
| 107 | instead, use frag_now_fix (). */ |
| 108 | COMMON fragS *frag_now; |
| 109 | extern addressT frag_now_fix (void); |
| 110 | extern addressT frag_now_fix_octets (void); |
| 111 | |
| 112 | /* For foreign-segment symbol fixups. */ |
| 113 | COMMON fragS zero_address_frag; |
| 114 | /* For local common (N_BSS segment) fixups. */ |
| 115 | COMMON fragS bss_address_frag; |
| 116 | |
| 117 | #if 0 |
| 118 | /* A macro to speed up appending exactly 1 char to current frag. */ |
| 119 | /* JF changed < 1 to <= 1 to avoid a race condition. */ |
| 120 | #define FRAG_APPEND_1_CHAR(datum) \ |
| 121 | { \ |
| 122 | if (obstack_room (&frags) <= 1) \ |
| 123 | { \ |
| 124 | frag_wane (frag_now); \ |
| 125 | frag_new (0); \ |
| 126 | } \ |
| 127 | obstack_1grow (&frags, datum); \ |
| 128 | } |
| 129 | #else |
| 130 | extern void frag_append_1_char (int); |
| 131 | #define FRAG_APPEND_1_CHAR(X) frag_append_1_char (X) |
| 132 | #endif |
| 133 | |
| 134 | void frag_init (void); |
| 135 | fragS *frag_alloc (struct obstack *); |
| 136 | void frag_grow (unsigned int nchars); |
| 137 | char *frag_more (int nchars); |
| 138 | void frag_align (int alignment, int fill_character, int max); |
| 139 | void frag_align_pattern (int alignment, const char *fill_pattern, |
| 140 | int n_fill, int max); |
| 141 | void frag_align_code (int alignment, int max); |
| 142 | void frag_new (int old_frags_var_max_size); |
| 143 | void frag_wane (fragS * fragP); |
| 144 | |
| 145 | char *frag_variant (relax_stateT type, |
| 146 | int max_chars, |
| 147 | int var, |
| 148 | relax_substateT subtype, |
| 149 | symbolS * symbol, |
| 150 | offsetT offset, |
| 151 | char *opcode); |
| 152 | |
| 153 | char *frag_var (relax_stateT type, |
| 154 | int max_chars, |
| 155 | int var, |
| 156 | relax_substateT subtype, |
| 157 | symbolS * symbol, |
| 158 | offsetT offset, |
| 159 | char *opcode); |
| 160 | |
| 161 | #endif /* FRAGS_H */ |