gcc/dyn-string.c

   1 /* An abstract string datatype.
   2    Copyright (C) 1998, 1999 Free Software Foundation, Inc.
   3    Contributed by Mark Mitchell (mark@markmitchell.com).
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC is free software; you can redistribute it and/or modify it
   8 under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU CC is distributed in the hope that it will be useful, but
  13 WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU CC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "dyn-string.h"
  25
  26 /* Create a new dynamic string capable of holding at least SPACE
  27    characters, including the terminating NUL.  If SPACE is 0, it
  28    will be silently increased to 1.  */
  29
  30 dyn_string_t
  31 dyn_string_new (space)
  32      int space;
  33 {
  34   dyn_string_t result = (dyn_string_t) xmalloc (sizeof (struct dyn_string));
  35
  36   if (space == 0)
  37     /* We need at least one byte in which to store the terminating
  38        NUL.  */
  39     space = 1;
  40
  41   result->allocated = space;
  42   result->s = (char*) xmalloc (space);
  43   result->length = 0;
  44   result->s[0] = '\0';
  45
  46   return result;
  47 }
  48
  49 /* Free the memory used by DS.  */
  50
  51 void
  52 dyn_string_delete (ds)
  53      dyn_string_t ds;
  54 {
  55   free (ds->s);
  56   free (ds);
  57 }
  58
  59 /* Append the NUL-terminated string S to DS, resizing DS if
  60    necessary.  */
  61
  62 dyn_string_t
  63 dyn_string_append (ds, s)
  64      dyn_string_t ds;
  65      const char *s;
  66 {
  67   int len = strlen (s);
  68   dyn_string_resize (ds, ds->length + len + 1 /* '\0' */);
  69   strcpy (ds->s + ds->length, s);
  70   ds->length += len;
  71
  72   return ds;
  73 }
  74
  75 /* Increase the capacity of DS so that it can hold at least SPACE
  76    characters, including the terminating NUL.  This function will not
  77    (at present) reduce the capacity of DS.  */
  78
  79 dyn_string_t
  80 dyn_string_resize (ds, space)
  81      dyn_string_t ds;
  82      int space;
  83 {
  84   int new_allocated = ds->allocated;
  85
  86   while (space > new_allocated)
  87     new_allocated *= 2;
  88
  89   if (new_allocated != ds->allocated)
  90     {
  91       /* We actually need more space.  */
  92       ds->allocated = new_allocated;
  93       ds->s = (char*) xrealloc (ds->s, ds->allocated);
  94     }
  95
  96   return ds;
  97 }