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[binutils.git] / gas / frags.h
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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.
5 This file is part of GAS, the GNU Assembler.
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.
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.
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. */
22 #ifndef FRAGS_H
23 #define FRAGS_H
25 #ifdef ANSI_PROTOTYPES
26 struct obstack;
27 #endif
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.
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. */
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;
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;
62 /* Chain forward; ascending address order. Rooted in frch_root. */
63 struct frag *fr_next;
65 /* Where the frag was created, or where it became a variant frag. */
66 char *fr_file;
67 unsigned int fr_line;
69 #ifndef NO_LISTING
70 struct list_info_struct *line;
71 #endif
73 /* Flipped each relax pass so we can easily determine whether
74 fr_address has been adjusted. */
75 unsigned int relax_marker:1;
77 /* What state is my tail in? */
78 relax_stateT fr_type;
79 relax_substateT fr_subtype;
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
93 #ifdef TC_FRAG_TYPE
94 TC_FRAG_TYPE tc_frag_data;
95 #endif
97 /* Data begins here. */
98 char fr_literal[1];
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. */
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);
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;
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) \
122 if (obstack_room (&frags) <= 1) \
124 frag_wane (frag_now); \
125 frag_new (0); \
127 obstack_1grow (&frags, datum); \
129 #else
130 extern void frag_append_1_char (int);
131 #define FRAG_APPEND_1_CHAR(X) frag_append_1_char (X)
132 #endif
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 int frag_room (void);
146 char *frag_variant (relax_stateT type,
147 int max_chars,
148 int var,
149 relax_substateT subtype,
150 symbolS * symbol,
151 offsetT offset,
152 char *opcode);
154 char *frag_var (relax_stateT type,
155 int max_chars,
156 int var,
157 relax_substateT subtype,
158 symbolS * symbol,
159 offsetT offset,
160 char *opcode);
162 #endif /* FRAGS_H */