gas/sb.c

   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 }