1 /* frags.h - Header file for the frag concept. 2 Copyright (C) 1987-2016 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 #ifndef FRAGS_H 22 #define FRAGS_H 23 24 struct obstack; 25 26 /* A code fragment (frag) is some known number of chars, followed by some 27 unknown number of chars. Typically the unknown number of chars is an 28 instruction address whose size is yet unknown. We always know the greatest 29 possible size the unknown number of chars may become, and reserve that 30 much room at the end of the frag. 31 Once created, frags do not change address during assembly. 32 We chain the frags in (a) forward-linked list(s). The object-file address 33 of the 1st char of a frag is generally not known until after relax(). 34 Many things at assembly time describe an address by {object-file-address 35 of a particular frag}+offset. 36 37 BUG: it may be smarter to have a single pointer off to various different 38 notes for different frag kinds. See how code pans. */ 39 40 struct frag { 41 /* Object file address (as an octet offset). */ 42 addressT fr_address; 43 /* When relaxing multiple times, remember the address the frag had 44 in the last relax pass. */ 45 addressT last_fr_address; 46 47 /* (Fixed) number of octets we know we have. May be 0. */ 48 offsetT fr_fix; 49 /* May be used for (Variable) number of octets after above. 50 The generic frag handling code no longer makes any use of fr_var. */ 51 offsetT fr_var; 52 /* For variable-length tail. */ 53 offsetT fr_offset; 54 /* For variable-length tail. */ 55 symbolS *fr_symbol; 56 /* Points to opcode low addr byte, for relaxation. */ 57 char *fr_opcode; 58 59 /* Chain forward; ascending address order. Rooted in frch_root. */ 60 struct frag *fr_next; 61 62 /* Where the frag was created, or where it became a variant frag. */ 63 const char *fr_file; 64 unsigned int fr_line; 65 66 #ifndef NO_LISTING 67 struct list_info_struct *line; 68 #endif 69 70 /* A serial number for a sequence of frags having at most one alignment 71 or org frag, and that at the tail of the sequence. */ 72 unsigned int region:16; 73 74 /* Flipped each relax pass so we can easily determine whether 75 fr_address has been adjusted. */ 76 unsigned int relax_marker:1; 77 78 /* Used to ensure that all insns are emitted on proper address 79 boundaries. */ 80 unsigned int has_code:1; 81 unsigned int insn_addr:6; 82 83 /* What state is my tail in? */ 84 relax_stateT fr_type; 85 relax_substateT fr_subtype; 86 87 #ifdef USING_CGEN 88 /* Don't include this unless using CGEN to keep frag size down. */ 89 struct { 90 /* CGEN_INSN entry for this instruction. */ 91 const struct cgen_insn *insn; 92 /* Index into operand table. */ 93 int opindex; 94 /* Target specific data, usually reloc number. */ 95 int opinfo; 96 } fr_cgen; 97 #endif 98 99 #ifdef TC_FRAG_TYPE 100 TC_FRAG_TYPE tc_frag_data; 101 #endif 102 #ifdef OBJ_FRAG_TYPE 103 OBJ_FRAG_TYPE obj_frag_data; 104 #endif 105 106 /* Data begins here. */ 107 char fr_literal[1]; 108 }; 109 110 #define SIZEOF_STRUCT_FRAG \ 111 ((char *) zero_address_frag.fr_literal - (char *) &zero_address_frag) 112 /* We want to say fr_literal[0] above. */ 113 114 /* Current frag we are building. This frag is incomplete. It is, 115 however, included in frchain_now. The fr_fix field is bogus; 116 instead, use frag_now_fix (). */ 117 COMMON fragS *frag_now; 118 extern addressT frag_now_fix (void); 119 extern addressT frag_now_fix_octets (void); 120 121 /* For foreign-segment symbol fixups. */ 122 COMMON fragS zero_address_frag; 123 COMMON fragS predefined_address_frag; 124 125 extern void frag_append_1_char (int); 126 #define FRAG_APPEND_1_CHAR(X) frag_append_1_char (X) 127 128 void frag_init (void); 129 fragS *frag_alloc (struct obstack *); 130 void frag_grow (size_t nchars); 131 char *frag_more (size_t nchars); 132 void frag_align (int alignment, int fill_character, int max); 133 void frag_align_pattern (int alignment, const char *fill_pattern, 134 size_t n_fill, int max); 135 void frag_align_code (int alignment, int max); 136 void frag_new (size_t old_frags_var_max_size); 137 void frag_wane (fragS * fragP); 138 size_t frag_room (void); 139 140 char *frag_variant (relax_stateT type, 141 size_t max_chars, 142 size_t var, 143 relax_substateT subtype, 144 symbolS * symbol, 145 offsetT offset, 146 char *opcode); 147 148 char *frag_var (relax_stateT type, 149 size_t max_chars, 150 size_t var, 151 relax_substateT subtype, 152 symbolS * symbol, 153 offsetT offset, 154 char *opcode); 155 156 bfd_boolean frag_offset_fixed_p (const fragS *, const fragS *, offsetT *); 157 158 int get_frag_count (void); 159 void clear_frag_count (void); 160 161 #endif /* FRAGS_H */ 162
