1#ifndef _FRAGS_H_
2#define _FRAGS_H_
3/* frags.h - Header file for the frag concept.
4   Copyright (C) 1987 Free Software Foundation, Inc.
5
6This file is part of GAS, the GNU Assembler.
7
8GAS is free software; you can redistribute it and/or modify
9it under the terms of the GNU General Public License as published by
10the Free Software Foundation; either version 1, or (at your option)
11any later version.
12
13GAS is distributed in the hope that it will be useful,
14but WITHOUT ANY WARRANTY; without even the implied warranty of
15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16GNU General Public License for more details.
17
18You should have received a copy of the GNU General Public License
19along with GAS; see the file COPYING.  If not, write to
20the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
21
22#import "as.h"
23#import "relax.h"
24#import "struc-symbol.h"
25
26/*
27 * A code fragment (frag) is some known number of chars, followed by some
28 * unknown number of chars. Typically the unknown number of chars is an
29 * instruction address whose size is yet unknown. We always know the greatest
30 * possible size the unknown number of chars may become, and reserve that
31 * much room at the end of the frag.
32 * Once created, frags do not change address during assembly.
33 * We chain the frags in (a) forward-linked list(s). The object-file address
34 * of the 1st char of a frag is generally not known until after relax().
35 * Many things at assembly time describe an address by {object-file-address
36 * of a particular frag}+offset.
37
38 BUG: it may be smarter to have a single pointer off to various different
39notes for different frag kinds. See how code pans out.
40
41 */
42struct frag			/* a code fragment */
43{
44    uint64_t fr_address;	/* Object file address. */
45    uint64_t last_fr_address;	/* When relaxing multiple times, remember the */
46				/* address the frag had in the last relax pass*/
47    struct frag *fr_next;	/* Chain forward; ascending address order. */
48				/* Rooted in frch_root. */
49
50    int32_t fr_fix;		/* (Fixed) number of chars we know we have. */
51				/* May be 0. */
52    int32_t fr_var;		/* (Variable) number of chars after above. */
53				/* May be 0. */
54    struct symbol *fr_symbol;	/* For variable-length tail. */
55    int32_t fr_offset;		/* For variable-length tail. */
56    char *fr_opcode;		/* ->opcode low addr byte,for relax()ation*/
57    relax_stateT fr_type;	/* What state is my tail in? */
58    relax_substateT fr_subtype;	/* Used to index in to md_relax_table for */
59				/*  fr_type == rs_machine_dependent frags. */
60#ifdef ARM
61    /* Where the frag was created, or where it became a variant frag.  */
62    char *fr_file;
63    unsigned int fr_line;
64    /* Flipped each relax pass so we can easily determine whether
65       fr_address has been adjusted.  */
66    unsigned int relax_marker:1,
67		 pad:31;
68#endif /* ARM */
69    char fr_literal[1];		/* Chars begin here. */
70				/* One day we will compile fr_literal[0]. */
71};
72
73/* We want to say fr_literal[0] below */
74#define SIZEOF_STRUCT_FRAG \
75 ((uintptr_t)zero_address_frag.fr_literal - (uintptr_t)&zero_address_frag)
76
77/*
78 * frag_now points at the current frag we are building. This frag is incomplete.
79 * It is, however, included in frchain_now. Frag_now->fr_fix is not the total
80 * bytes in use for the frag.  For that use:
81 * frag_now->fr_fix + obstack_next_free(&frags) - frag_now->fr_literal.
82 */
83extern fragS *frag_now;
84extern addressT frag_now_fix (void);
85extern addressT frag_now_fix_octets (void);
86
87/*
88 * Frags ONLY live in this obstack.  We use obstack_next_free() macro
89 * so please don't put any other objects on this stack!
90 */
91extern struct obstack frags;
92
93/* For foreign-segment symbol fixups. */
94extern fragS zero_address_frag;
95
96void frag_grow (unsigned int nchars);
97extern void frag_new(
98    int old_frags_var_max_size);
99extern char * frag_more(
100    int nchars);
101extern char *frag_var(
102    relax_stateT type,
103    int max_chars,
104    int var,
105    relax_substateT subtype,
106    symbolS *symbol,
107    int32_t offset,
108    char *opcode);
109extern void frag_wane(
110    fragS *fragP);
111extern void frag_align(
112    int power_of_2_alignment,
113    char *fill,
114    int fill_size,
115    int max_bytes_to_fill);
116
117/*
118 * A macro to speed up appending exactly 1 char
119 * to current frag.
120 */
121/* JF changed < 1 to <= 1 to avoid a race conditon */
122#define FRAG_APPEND_1_CHAR(datum)	\
123{					\
124	if (obstack_room( &frags ) <= 1) {\
125		frag_wane (frag_now);	\
126		frag_new (0);		\
127	}				\
128	(void)obstack_1grow( &frags, datum );	\
129}
130#endif /* _FRAGS_H_ */
131