1 /* sb.c - string buffer manipulation routines
2 Copyright (C) 1994-2014 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 3, 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 #include "as.h"
25 #include "sb.h"
26
27 #ifdef HAVE_LIMITS_H
28 #include <limits.h>
29 #endif
30 #ifndef CHAR_BIT
31 #define CHAR_BIT 8
32 #endif
33
34 /* These routines are about manipulating strings.
35
36 They are managed in things called `sb's which is an abbreviation
37 for string buffers. An sb has to be created, things can be glued
38 on to it, and at the end of it's life it should be freed. The
39 contents should never be pointed at whilst it is still growing,
40 since it could be moved at any time
41
42 eg:
43 sb_new (&foo);
44 sb_grow... (&foo,...);
45 use foo->ptr[*];
46 sb_kill (&foo); */
47
48 /* Buffers start at INIT_ALLOC size, and roughly double each time we
49 go over the current allocation. MALLOC_OVERHEAD is a guess at the
50 system malloc overhead. We aim to not waste any memory in the
51 underlying page/chunk allocated by the system malloc. */
52 #define MALLOC_OVERHEAD (2 * sizeof (size_t))
53 #define INIT_ALLOC (64 - MALLOC_OVERHEAD - 1)
54
55 static void sb_check (sb *, size_t);
56
57 /* Initializes an sb. */
58
59 void
sb_build(sb * ptr,size_t size)60 sb_build (sb *ptr, size_t size)
61 {
62 ptr->ptr = xmalloc (size + 1);
63 ptr->max = size;
64 ptr->len = 0;
65 }
66
67 void
sb_new(sb * ptr)68 sb_new (sb *ptr)
69 {
70 sb_build (ptr, INIT_ALLOC);
71 }
72
73 /* Deallocate the sb at ptr. */
74
75 void
sb_kill(sb * ptr)76 sb_kill (sb *ptr)
77 {
78 free (ptr->ptr);
79 }
80
81 /* Add the sb at s to the end of the sb at ptr. */
82
83 void
sb_add_sb(sb * ptr,sb * s)84 sb_add_sb (sb *ptr, sb *s)
85 {
86 sb_check (ptr, s->len);
87 memcpy (ptr->ptr + ptr->len, s->ptr, s->len);
88 ptr->len += s->len;
89 }
90
91 /* Helper for sb_scrub_and_add_sb. */
92
93 static sb *sb_to_scrub;
94 static char *scrub_position;
95 static size_t
scrub_from_sb(char * buf,size_t buflen)96 scrub_from_sb (char *buf, size_t buflen)
97 {
98 size_t copy;
99 copy = sb_to_scrub->len - (scrub_position - sb_to_scrub->ptr);
100 if (copy > buflen)
101 copy = buflen;
102 memcpy (buf, scrub_position, copy);
103 scrub_position += copy;
104 return copy;
105 }
106
107 /* Run the sb at s through do_scrub_chars and add the result to the sb
108 at ptr. */
109
110 void
sb_scrub_and_add_sb(sb * ptr,sb * s)111 sb_scrub_and_add_sb (sb *ptr, sb *s)
112 {
113 sb_to_scrub = s;
114 scrub_position = s->ptr;
115
116 sb_check (ptr, s->len);
117 ptr->len += do_scrub_chars (scrub_from_sb, ptr->ptr + ptr->len, s->len);
118
119 sb_to_scrub = 0;
120 scrub_position = 0;
121 }
122
123 /* Make sure that the sb at ptr has room for another len characters,
124 and grow it if it doesn't. */
125
126 static void
sb_check(sb * ptr,size_t len)127 sb_check (sb *ptr, size_t len)
128 {
129 size_t want = ptr->len + len;
130
131 if (want > ptr->max)
132 {
133 size_t max;
134
135 want += MALLOC_OVERHEAD + 1;
136 if ((ssize_t) want < 0)
137 as_fatal ("string buffer overflow");
138 #if GCC_VERSION >= 3004
139 max = (size_t) 1 << (CHAR_BIT * sizeof (want)
140 - (sizeof (want) <= sizeof (long)
141 ? __builtin_clzl ((long) want)
142 : __builtin_clzll ((long long) want)));
143 #else
144 max = 128;
145 while (want > max)
146 max <<= 1;
147 #endif
148 max -= MALLOC_OVERHEAD + 1;
149 ptr->max = max;
150 ptr->ptr = xrealloc (ptr->ptr, max + 1);
151 }
152 }
153
154 /* Make the sb at ptr point back to the beginning. */
155
156 void
sb_reset(sb * ptr)157 sb_reset (sb *ptr)
158 {
159 ptr->len = 0;
160 }
161
162 /* Add character c to the end of the sb at ptr. */
163
164 void
sb_add_char(sb * ptr,size_t c)165 sb_add_char (sb *ptr, size_t c)
166 {
167 sb_check (ptr, 1);
168 ptr->ptr[ptr->len++] = c;
169 }
170
171 /* Add null terminated string s to the end of sb at ptr. */
172
173 void
sb_add_string(sb * ptr,const char * s)174 sb_add_string (sb *ptr, const char *s)
175 {
176 size_t len = strlen (s);
177 sb_check (ptr, len);
178 memcpy (ptr->ptr + ptr->len, s, len);
179 ptr->len += len;
180 }
181
182 /* Add string at s of length len to sb at ptr */
183
184 void
sb_add_buffer(sb * ptr,const char * s,size_t len)185 sb_add_buffer (sb *ptr, const char *s, size_t len)
186 {
187 sb_check (ptr, len);
188 memcpy (ptr->ptr + ptr->len, s, len);
189 ptr->len += len;
190 }
191
192 /* Write terminating NUL and return string. */
193
194 char *
sb_terminate(sb * in)195 sb_terminate (sb *in)
196 {
197 in->ptr[in->len] = 0;
198 return in->ptr;
199 }
200
201 /* Start at the index idx into the string in sb at ptr and skip
202 whitespace. return the index of the first non whitespace character. */
203
204 size_t
sb_skip_white(size_t idx,sb * ptr)205 sb_skip_white (size_t idx, sb *ptr)
206 {
207 while (idx < ptr->len
208 && (ptr->ptr[idx] == ' '
209 || ptr->ptr[idx] == '\t'))
210 idx++;
211 return idx;
212 }
213
214 /* Start at the index idx into the sb at ptr. skips whitespace,
215 a comma and any following whitespace. returns the index of the
216 next character. */
217
218 size_t
sb_skip_comma(size_t idx,sb * ptr)219 sb_skip_comma (size_t idx, sb *ptr)
220 {
221 while (idx < ptr->len
222 && (ptr->ptr[idx] == ' '
223 || ptr->ptr[idx] == '\t'))
224 idx++;
225
226 if (idx < ptr->len
227 && ptr->ptr[idx] == ',')
228 idx++;
229
230 while (idx < ptr->len
231 && (ptr->ptr[idx] == ' '
232 || ptr->ptr[idx] == '\t'))
233 idx++;
234
235 return idx;
236 }
237