1 /* sb.c - string buffer manipulation routines 2 Copyright 1994, 1995, 2000, 2003, 2006, 2007 3 Free Software Foundation, Inc. 4 5 Written by Steve and Judy Chamberlain of Cygnus Support, 6 sac@cygnus.com 7 8 This file is part of GAS, the GNU Assembler. 9 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. 14 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. 19 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. */ 24 25 #include "as.h" 26 #include "sb.h" 27 28 /* These routines are about manipulating strings. 29 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 35 36 eg: 37 sb_new (&foo); 38 sb_grow... (&foo,...); 39 use foo->ptr[*]; 40 sb_kill (&foo); */ 41 42 static int dsize = 5; 43 static void sb_check (sb *, int); 44 45 /* Statistics of sb structures. */ 46 static int string_count[sb_max_power_two]; 47 48 /* Free list of sb structures. */ 49 static struct 50 { 51 sb_element *size[sb_max_power_two]; 52 } free_list; 53 54 /* Initializes an sb. */ 55 56 static void 57 sb_build (sb *ptr, int size) 58 { 59 /* See if we can find one to allocate. */ 60 sb_element *e; 61 62 assert (size < sb_max_power_two); 63 64 e = free_list.size[size]; 65 if (!e) 66 { 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]++; 73 } 74 75 /* Remove from free list. */ 76 free_list.size[size] = e->next; 77 78 /* Copy into callers world. */ 79 ptr->ptr = e->data; 80 ptr->pot = size; 81 ptr->len = 0; 82 ptr->item = e; 83 } 84 85 void 86 sb_new (sb *ptr) 87 { 88 sb_build (ptr, dsize); 89 } 90 91 /* Deallocate the sb at ptr. */ 92 93 void 94 sb_kill (sb *ptr) 95 { 96 /* Return item to free list. */ 97 ptr->item->next = free_list.size[ptr->pot]; 98 free_list.size[ptr->pot] = ptr->item; 99 } 100 101 /* Add the sb at s to the end of the sb at ptr. */ 102 103 void 104 sb_add_sb (sb *ptr, sb *s) 105 { 106 sb_check (ptr, s->len); 107 memcpy (ptr->ptr + ptr->len, s->ptr, s->len); 108 ptr->len += s->len; 109 } 110 111 /* Helper for sb_scrub_and_add_sb. */ 112 113 static sb *sb_to_scrub; 114 static char *scrub_position; 115 static int 116 scrub_from_sb (char *buf, int buflen) 117 { 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; 125 } 126 127 /* Run the sb at s through do_scrub_chars and add the result to the sb 128 at ptr. */ 129 130 void 131 sb_scrub_and_add_sb (sb *ptr, sb *s) 132 { 133 sb_to_scrub = s; 134 scrub_position = s->ptr; 135 136 sb_check (ptr, s->len); 137 ptr->len += do_scrub_chars (scrub_from_sb, ptr->ptr + ptr->len, s->len); 138 139 sb_to_scrub = 0; 140 scrub_position = 0; 141 } 142 143 /* Make sure that the sb at ptr has room for another len characters, 144 and grow it if it doesn't. */ 145 146 static void 147 sb_check (sb *ptr, int len) 148 { 149 if (ptr->len + len >= 1 << ptr->pot) 150 { 151 sb tmp; 152 int pot = ptr->pot; 153 154 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; 160 } 161 } 162 163 /* Make the sb at ptr point back to the beginning. */ 164 165 void 166 sb_reset (sb *ptr) 167 { 168 ptr->len = 0; 169 } 170 171 /* Add character c to the end of the sb at ptr. */ 172 173 void 174 sb_add_char (sb *ptr, int c) 175 { 176 sb_check (ptr, 1); 177 ptr->ptr[ptr->len++] = c; 178 } 179 180 /* Add null terminated string s to the end of sb at ptr. */ 181 182 void 183 sb_add_string (sb *ptr, const char *s) 184 { 185 int len = strlen (s); 186 sb_check (ptr, len); 187 memcpy (ptr->ptr + ptr->len, s, len); 188 ptr->len += len; 189 } 190 191 /* Add string at s of length len to sb at ptr */ 192 193 void 194 sb_add_buffer (sb *ptr, const char *s, int len) 195 { 196 sb_check (ptr, len); 197 memcpy (ptr->ptr + ptr->len, s, len); 198 ptr->len += len; 199 } 200 201 /* Like sb_name, but don't include the null byte in the string. */ 202 203 char * 204 sb_terminate (sb *in) 205 { 206 sb_add_char (in, 0); 207 --in->len; 208 return in->ptr; 209 } 210 211 /* 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. */ 213 214 int 215 sb_skip_white (int idx, sb *ptr) 216 { 217 while (idx < ptr->len 218 && (ptr->ptr[idx] == ' ' 219 || ptr->ptr[idx] == '\t')) 220 idx++; 221 return idx; 222 } 223 224 /* 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. */ 227 228 int 229 sb_skip_comma (int idx, sb *ptr) 230 { 231 while (idx < ptr->len 232 && (ptr->ptr[idx] == ' ' 233 || ptr->ptr[idx] == '\t')) 234 idx++; 235 236 if (idx < ptr->len 237 && ptr->ptr[idx] == ',') 238 idx++; 239 240 while (idx < ptr->len 241 && (ptr->ptr[idx] == ' ' 242 || ptr->ptr[idx] == '\t')) 243 idx++; 244 245 return idx; 246 } 247