gas/sb.c

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