gas/sb.c

   1 /* sb.c - string buffer manipulation routines
   2    Copyright 1994, 1995, 2000, 2003, 2006 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, 51 Franklin Street - Fifth Floor, Boston, MA
  22    02110-1301, USA.  */
  23
  24 #include "as.h"
  25 #include "sb.h"
  26
  27 /* These routines are about manipulating strings.
  28
  29    They are managed in things called `sb's which is an abbreviation
  30    for string buffers.  An sb has to be created, things can be glued
  31    on to it, and at the end of it's life it should be freed.  The
  32    contents should never be pointed at whilst it is still growing,
  33    since it could be moved at any time
  34
  35    eg:
  36    sb_new (&foo);
  37    sb_grow... (&foo,...);
  38    use foo->ptr[*];
  39    sb_kill (&foo);  */
  40
  41 static int dsize = 5;
  42 static void sb_check (sb *, int);
  43
  44 /* Statistics of sb structures.  */
  45 static int string_count[sb_max_power_two];
  46
  47 /* Free list of sb structures.  */
  48 static struct
  49 {
  50   sb_element *size[sb_max_power_two];
  51 } free_list;
  52
  53 /* Initializes an sb.  */
  54
  55 static void
  56 sb_build (sb *ptr, int size)
  57 {
  58   /* See if we can find one to allocate.  */
  59   sb_element *e;
  60
  61   assert (size < sb_max_power_two);
  62
  63   e = free_list.size[size];
  64   if (!e)
  65     {
  66       /* Nothing there, allocate one and stick into the free list.  */
  67       e = (sb_element *) xmalloc (sizeof (sb_element) + (1 << size));
  68       e->next = free_list.size[size];
  69       e->size = 1 << size;
  70       free_list.size[size] = e;
  71       string_count[size]++;
  72     }
  73
  74   /* Remove from free list.  */
  75   free_list.size[size] = e->next;
  76
  77   /* Copy into callers world.  */
  78   ptr->ptr = e->data;
  79   ptr->pot = size;
  80   ptr->len = 0;
  81   ptr->item = e;
  82 }
  83
  84 void
  85 sb_new (sb *ptr)
  86 {
  87   sb_build (ptr, dsize);
  88 }
  89
  90 /* Deallocate the sb at ptr.  */
  91
  92 void
  93 sb_kill (sb *ptr)
  94 {
  95   /* Return item to free list.  */
  96   ptr->item->next = free_list.size[ptr->pot];
  97   free_list.size[ptr->pot] = ptr->item;
  98 }
  99
 100 /* Add the sb at s to the end of the sb at ptr.  */
 101
 102 void
 103 sb_add_sb (sb *ptr, sb *s)
 104 {
 105   sb_check (ptr, s->len);
 106   memcpy (ptr->ptr + ptr->len, s->ptr, s->len);
 107   ptr->len += s->len;
 108 }
 109
 110 /* Helper for sb_scrub_and_add_sb.  */
 111
 112 static sb *sb_to_scrub;
 113 static char *scrub_position;
 114 static int
 115 scrub_from_sb (char *buf, int buflen)
 116 {
 117   int copy;
 118   copy = sb_to_scrub->len - (scrub_position - sb_to_scrub->ptr);
 119   if (copy > buflen)
 120     copy = buflen;
 121   memcpy (buf, scrub_position, copy);
 122   scrub_position += copy;
 123   return copy;
 124 }
 125
 126 /* Run the sb at s through do_scrub_chars and add the result to the sb
 127    at ptr.  */
 128
 129 void
 130 sb_scrub_and_add_sb (sb *ptr, sb *s)
 131 {
 132   sb_to_scrub = s;
 133   scrub_position = s->ptr;
 134
 135   sb_check (ptr, s->len);
 136   ptr->len += do_scrub_chars (scrub_from_sb, ptr->ptr + ptr->len, s->len);
 137
 138   sb_to_scrub = 0;
 139   scrub_position = 0;
 140 }
 141
 142 /* Make sure that the sb at ptr has room for another len characters,
 143    and grow it if it doesn't.  */
 144
 145 static void
 146 sb_check (sb *ptr, int len)
 147 {
 148   if (ptr->len + len >= 1 << ptr->pot)
 149     {
 150       sb tmp;
 151       int pot = ptr->pot;
 152
 153       while (ptr->len + len >= 1 << pot)
 154         pot++;
 155       sb_build (&tmp, pot);
 156       sb_add_sb (&tmp, ptr);
 157       sb_kill (ptr);
 158       *ptr = tmp;
 159     }
 160 }
 161
 162 /* Make the sb at ptr point back to the beginning.  */
 163
 164 void
 165 sb_reset (sb *ptr)
 166 {
 167   ptr->len = 0;
 168 }
 169
 170 /* Add character c to the end of the sb at ptr.  */
 171
 172 void
 173 sb_add_char (sb *ptr, int c)
 174 {
 175   sb_check (ptr, 1);
 176   ptr->ptr[ptr->len++] = c;
 177 }
 178
 179 /* Add null terminated string s to the end of sb at ptr.  */
 180
 181 void
 182 sb_add_string (sb *ptr, const char *s)
 183 {
 184   int len = strlen (s);
 185   sb_check (ptr, len);
 186   memcpy (ptr->ptr + ptr->len, s, len);
 187   ptr->len += len;
 188 }
 189
 190 /* Add string at s of length len to sb at ptr */
 191
 192 void
 193 sb_add_buffer (sb *ptr, const char *s, int len)
 194 {
 195   sb_check (ptr, len);
 196   memcpy (ptr->ptr + ptr->len, s, len);
 197   ptr->len += len;
 198 }
 199
 200 /* Like sb_name, but don't include the null byte in the string.  */
 201
 202 char *
 203 sb_terminate (sb *in)
 204 {
 205   sb_add_char (in, 0);
 206   --in->len;
 207   return in->ptr;
 208 }
 209
 210 /* Start at the index idx into the string in sb at ptr and skip
 211    whitespace. return the index of the first non whitespace character.  */
 212
 213 int
 214 sb_skip_white (int idx, sb *ptr)
 215 {
 216   while (idx < ptr->len
 217          && (ptr->ptr[idx] == ' '
 218              || ptr->ptr[idx] == '\t'))
 219     idx++;
 220   return idx;
 221 }
 222
 223 /* Start at the index idx into the sb at ptr. skips whitespace,
 224    a comma and any following whitespace. returns the index of the
 225    next character.  */
 226
 227 int
 228 sb_skip_comma (int idx, sb *ptr)
 229 {
 230   while (idx < ptr->len
 231          && (ptr->ptr[idx] == ' '
 232              || ptr->ptr[idx] == '\t'))
 233     idx++;
 234
 235   if (idx < ptr->len
 236       && ptr->ptr[idx] == ',')
 237     idx++;
 238
 239   while (idx < ptr->len
 240          && (ptr->ptr[idx] == ' '
 241              || ptr->ptr[idx] == '\t'))
 242     idx++;
 243
 244   return idx;
 245 }