1/* An abstract string datatype.
2   Copyright (C) 1998, 1999 Free Software Foundation, Inc.
3   Contributed by Mark Mitchell (mark@markmitchell.com).
4
5This file is part of GNU CC.
6
7GNU CC is free software; you can redistribute it and/or modify it
8under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 2, or (at your option)
10any later version.
11
12GNU CC is distributed in the hope that it will be useful, but
13WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with GNU CC; see the file COPYING.  If not, write to
19the Free Software Foundation, 59 Temple Place - Suite 330,
20Boston, 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
30dyn_string_t
31dyn_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
51void
52dyn_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
62dyn_string_t
63dyn_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
79dyn_string_t
80dyn_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}
98