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
   8 it 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,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU 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
  23 #include "config.h"
  24 #include "system.h"
  25 #include "dyn-string.h"
  26
  27 /* Create a new dynamic string capable of holding at least SPACE characters,
  28    including the terminating NUL.  If SPACE is 0, it will be silently
  29    increased to 1.  */
  30
  31 dyn_string_t
  32 dyn_string_new (space)
  33      int space;
  34 {
  35   dyn_string_t result = (dyn_string_t) xmalloc (sizeof (struct dyn_string));
  36
  37   /* We need at least one byte in which to store the terminating NUL.  */
  38   if (space == 0)
  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 necessary.  */
  60
  61 dyn_string_t
  62 dyn_string_append (ds, s)
  63      dyn_string_t ds;
  64      const char *s;
  65 {
  66   int len = strlen (s);
  67
  68   /* The new length is the old length plus the size of our string, plus
  69      one for the null at the end.  */
  70   dyn_string_resize (ds, ds->length + len + 1);
  71   strcpy (ds->s + ds->length, s);
  72   ds->length += len;
  73
  74   return ds;
  75 }
  76
  77 /* Increase the capacity of DS so it can hold at least SPACE characters,
  78    including the terminating NUL.  This function will not (at present)
  79    reduce the capacity of DS.  */
  80
  81 dyn_string_t
  82 dyn_string_resize (ds, space)
  83      dyn_string_t ds;
  84      int space;
  85 {
  86   int new_allocated = ds->allocated;
  87
  88   while (space > new_allocated)
  89     new_allocated *= 2;
  90
  91   if (new_allocated != ds->allocated)
  92     {
  93       /* We actually need more space.  */
  94       ds->allocated = new_allocated;
  95       ds->s = (char *) xrealloc (ds->s, ds->allocated);
  96     }
  97
  98   return ds;
  99 }