gas/
[binutils.git] / gas / sb.c
blob8d5e8dde2fb8e8a9da2d3fb2d20471272132c9d6
1 /* sb.c - string buffer manipulation routines
2 Copyright 1994, 1995, 2000, 2003, 2005, 2006, 2007, 2009
3 Free Software Foundation, Inc.
5 Written by Steve and Judy Chamberlain of Cygnus Support,
6 sac@cygnus.com
8 This file is part of GAS, the GNU Assembler.
10 GAS is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
13 any later version.
15 GAS is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GAS; see the file COPYING. If not, write to the Free
22 Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
23 02110-1301, USA. */
25 #include "as.h"
26 #include "sb.h"
28 /* These routines are about manipulating strings.
30 They are managed in things called `sb's which is an abbreviation
31 for string buffers. An sb has to be created, things can be glued
32 on to it, and at the end of it's life it should be freed. The
33 contents should never be pointed at whilst it is still growing,
34 since it could be moved at any time
36 eg:
37 sb_new (&foo);
38 sb_grow... (&foo,...);
39 use foo->ptr[*];
40 sb_kill (&foo); */
42 static int dsize = 5;
43 static void sb_check (sb *, int);
45 /* Statistics of sb structures. */
46 static int string_count[sb_max_power_two];
48 /* Free list of sb structures. */
49 static struct
51 sb_element *size[sb_max_power_two];
52 } free_list;
54 /* Initializes an sb. */
56 static void
57 sb_build (sb *ptr, int size)
59 /* See if we can find one to allocate. */
60 sb_element *e;
62 gas_assert (size < sb_max_power_two);
64 e = free_list.size[size];
65 if (!e)
67 /* Nothing there, allocate one and stick into the free list. */
68 e = (sb_element *) xmalloc (sizeof (sb_element) + (1 << size));
69 e->next = free_list.size[size];
70 e->size = 1 << size;
71 free_list.size[size] = e;
72 string_count[size]++;
75 /* Remove from free list. */
76 free_list.size[size] = e->next;
78 /* Copy into callers world. */
79 ptr->ptr = e->data;
80 ptr->pot = size;
81 ptr->len = 0;
82 ptr->item = e;
85 void
86 sb_new (sb *ptr)
88 sb_build (ptr, dsize);
91 /* Deallocate the sb at ptr. */
93 void
94 sb_kill (sb *ptr)
96 /* Return item to free list. */
97 ptr->item->next = free_list.size[ptr->pot];
98 free_list.size[ptr->pot] = ptr->item;
101 /* Add the sb at s to the end of the sb at ptr. */
103 void
104 sb_add_sb (sb *ptr, sb *s)
106 sb_check (ptr, s->len);
107 memcpy (ptr->ptr + ptr->len, s->ptr, s->len);
108 ptr->len += s->len;
111 /* Helper for sb_scrub_and_add_sb. */
113 static sb *sb_to_scrub;
114 static char *scrub_position;
115 static int
116 scrub_from_sb (char *buf, int buflen)
118 int copy;
119 copy = sb_to_scrub->len - (scrub_position - sb_to_scrub->ptr);
120 if (copy > buflen)
121 copy = buflen;
122 memcpy (buf, scrub_position, copy);
123 scrub_position += copy;
124 return copy;
127 /* Run the sb at s through do_scrub_chars and add the result to the sb
128 at ptr. */
130 void
131 sb_scrub_and_add_sb (sb *ptr, sb *s)
133 sb_to_scrub = s;
134 scrub_position = s->ptr;
136 sb_check (ptr, s->len);
137 ptr->len += do_scrub_chars (scrub_from_sb, ptr->ptr + ptr->len, s->len);
139 sb_to_scrub = 0;
140 scrub_position = 0;
143 /* Make sure that the sb at ptr has room for another len characters,
144 and grow it if it doesn't. */
146 static void
147 sb_check (sb *ptr, int len)
149 if (ptr->len + len >= 1 << ptr->pot)
151 sb tmp;
152 int pot = ptr->pot;
154 while (ptr->len + len >= 1 << pot)
155 pot++;
156 sb_build (&tmp, pot);
157 sb_add_sb (&tmp, ptr);
158 sb_kill (ptr);
159 *ptr = tmp;
163 /* Make the sb at ptr point back to the beginning. */
165 void
166 sb_reset (sb *ptr)
168 ptr->len = 0;
171 /* Add character c to the end of the sb at ptr. */
173 void
174 sb_add_char (sb *ptr, int c)
176 sb_check (ptr, 1);
177 ptr->ptr[ptr->len++] = c;
180 /* Add null terminated string s to the end of sb at ptr. */
182 void
183 sb_add_string (sb *ptr, const char *s)
185 int len = strlen (s);
186 sb_check (ptr, len);
187 memcpy (ptr->ptr + ptr->len, s, len);
188 ptr->len += len;
191 /* Add string at s of length len to sb at ptr */
193 void
194 sb_add_buffer (sb *ptr, const char *s, int len)
196 sb_check (ptr, len);
197 memcpy (ptr->ptr + ptr->len, s, len);
198 ptr->len += len;
201 /* Like sb_name, but don't include the null byte in the string. */
203 char *
204 sb_terminate (sb *in)
206 sb_add_char (in, 0);
207 --in->len;
208 return in->ptr;
211 /* Start at the index idx into the string in sb at ptr and skip
212 whitespace. return the index of the first non whitespace character. */
215 sb_skip_white (int idx, sb *ptr)
217 while (idx < ptr->len
218 && (ptr->ptr[idx] == ' '
219 || ptr->ptr[idx] == '\t'))
220 idx++;
221 return idx;
224 /* Start at the index idx into the sb at ptr. skips whitespace,
225 a comma and any following whitespace. returns the index of the
226 next character. */
229 sb_skip_comma (int idx, sb *ptr)
231 while (idx < ptr->len
232 && (ptr->ptr[idx] == ' '
233 || ptr->ptr[idx] == '\t'))
234 idx++;
236 if (idx < ptr->len
237 && ptr->ptr[idx] == ',')
238 idx++;
240 while (idx < ptr->len
241 && (ptr->ptr[idx] == ' '
242 || ptr->ptr[idx] == '\t'))
243 idx++;
245 return idx;