sb.h revision 33965 
1/* sb.h - header file for string buffer manipulation routines
2   Copyright (C) 1994, 1995 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, 59 Temple Place - Suite 330, Boston, MA
22   02111-1307, USA. */
23
24#ifndef SB_H
25
26#define SB_H
27
28#include <stdio.h>
29#include "ansidecl.h"
30
31/* string blocks
32
33   I had a couple of choices when deciding upon this data structure.
34   gas uses null terminated strings for all its internal work.  This
35   often means that parts of the program that want to examine
36   substrings have to manipulate the data in the string to do the
37   right thing (a common operation is to single out a bit of text by
38   saving away the character after it, nulling it out, operating on
39   the substring and then replacing the character which was under the
40   null).  This is a pain and I remember a load of problems that I had with
41   code in gas which almost got this right.  Also, it's harder to grow and
42   allocate null terminated strings efficiently.
43
44   Obstacks provide all the functionality needed, but are too
45   complicated, hence the sb.
46
47   An sb is allocated by the caller, and is initialzed to point to an
48   sb_element.  sb_elements are kept on a free lists, and used when
49   needed, replaced onto the free list when unused.
50 */
51
52#define sb_max_power_two    30	/* don't allow strings more than
53			           2^sb_max_power_two long */
54/* structure of an sb */
55typedef struct sb
56  {
57    char *ptr;			/* points to the current block. */
58    int len;			/* how much is used. */
59    int pot;			/* the maximum length is 1<<pot */
60    struct le *item;
61  }
62sb;
63
64/* Structure of the free list object of an sb */
65typedef struct le
66  {
67    struct le *next;
68    int size;
69    char data[1];
70  }
71sb_element;
72
73/* The free list */
74typedef struct
75  {
76    sb_element *size[sb_max_power_two];
77  } sb_list_vector;
78
79extern int string_count[sb_max_power_two];
80
81extern void sb_build PARAMS ((sb *, int));
82extern void sb_new PARAMS ((sb *));
83extern void sb_kill PARAMS ((sb *));
84extern void sb_add_sb PARAMS ((sb *, sb *));
85extern void sb_reset PARAMS ((sb *));
86extern void sb_add_char PARAMS ((sb *, int));
87extern void sb_add_string PARAMS ((sb *, const char *));
88extern void sb_add_buffer PARAMS ((sb *, const char *, int));
89extern void sb_print PARAMS ((FILE *, sb *));
90extern void sb_print_at PARAMS ((FILE *, int, sb *));
91extern char *sb_name PARAMS ((sb *));
92extern char *sb_terminate PARAMS ((sb *));
93extern int sb_skip_white PARAMS ((int, sb *));
94extern int sb_skip_comma PARAMS ((int, sb *));
95
96/* Actually in input-scrub.c.  */
97extern void input_scrub_include_sb PARAMS ((sb *, char *));
98
99#endif /* SB_H */
100