sb.h revision 218822 
1/* sb.h - header file for string buffer manipulation routines
2   Copyright 1994, 1995, 2000, 2003, 2006 Free Software Foundation, Inc.
3
4   Written by Steve and Judy Chamberlain of Cygnus Support,
5      sac@cygnus.com
6
7   This file is part of GAS, the GNU Assembler.
8
9   GAS is free software; you can redistribute it and/or modify
10   it under the terms of the GNU General Public License as published by
11   the Free Software Foundation; either version 2, or (at your option)
12   any later version.
13
14   GAS is distributed in the hope that it will be useful,
15   but WITHOUT ANY WARRANTY; without even the implied warranty of
16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17   GNU General Public License for more details.
18
19   You should have received a copy of the GNU General Public License
20   along with GAS; see the file COPYING.  If not, write to the Free
21   Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
22   02110-1301, USA.  */
23
24#ifndef SB_H
25
26#define SB_H
27
28/* String blocks
29
30   I had a couple of choices when deciding upon this data structure.
31   gas uses null terminated strings for all its internal work.  This
32   often means that parts of the program that want to examine
33   substrings have to manipulate the data in the string to do the
34   right thing (a common operation is to single out a bit of text by
35   saving away the character after it, nulling it out, operating on
36   the substring and then replacing the character which was under the
37   null).  This is a pain and I remember a load of problems that I had with
38   code in gas which almost got this right.  Also, it's harder to grow and
39   allocate null terminated strings efficiently.
40
41   Obstacks provide all the functionality needed, but are too
42   complicated, hence the sb.
43
44   An sb is allocated by the caller, and is initialized to point to an
45   sb_element.  sb_elements are kept on a free lists, and used when
46   needed, replaced onto the free list when unused.  */
47
48#define sb_max_power_two    30	/* Don't allow strings more than
49			           2^sb_max_power_two long.  */
50
51typedef struct sb
52{
53  char *ptr;			/* Points to the current block.  */
54  int len;			/* How much is used.  */
55  int pot;			/* The maximum length is 1<<pot.  */
56  struct le *item;
57}
58sb;
59
60/* Structure of the free list object of a string block.  */
61
62typedef struct le
63{
64  struct le *next;
65  int size;
66  char data[1];
67}
68sb_element;
69
70extern void sb_new (sb *);
71extern void sb_kill (sb *);
72extern void sb_add_sb (sb *, sb *);
73extern void sb_scrub_and_add_sb (sb *, sb *);
74extern void sb_reset (sb *);
75extern void sb_add_char (sb *, int);
76extern void sb_add_string (sb *, const char *);
77extern void sb_add_buffer (sb *, const char *, int);
78extern char *sb_terminate (sb *);
79extern int sb_skip_white (int, sb *);
80extern int sb_skip_comma (int, sb *);
81
82/* Actually in input-scrub.c.  */
83extern void input_scrub_include_sb (sb *, char *, int);
84
85#endif /* SB_H */
86