libgfortran/runtime/string.c

   1 /* Copyright (C) 2002-2021 Free Software Foundation, Inc.
   2    Contributed by Paul Brook
   3
   4 This file is part of the GNU Fortran runtime library (libgfortran).
   5
   6 Libgfortran is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 3, or (at your option)
   9 any later version.
  10
  11 Libgfortran is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 Under Section 7 of GPL version 3, you are granted additional
  17 permissions described in the GCC Runtime Library Exception, version
  18 3.1, as published by the Free Software Foundation.
  19
  20 You should have received a copy of the GNU General Public License and
  21 a copy of the GCC Runtime Library Exception along with this program;
  22 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 <http://www.gnu.org/licenses/>.  */
  24
  25 #include "libgfortran.h"
  26 #include <string.h>
  27 #include <strings.h>
  28
  29
  30 /* Given a fortran string, return its length exclusive of the trailing
  31    spaces.  */
  32
  33 gfc_charlen_type
  34 fstrlen (const char *string, gfc_charlen_type len)
  35 {
  36   for (; len > 0; len--)
  37     if (string[len-1] != ' ')
  38       break;
  39
  40   return len;
  41 }
  42
  43
  44 /* Copy a Fortran string (not null-terminated, hence length arguments
  45    for both source and destination strings. Returns the non-padded
  46    length of the destination.  */
  47
  48 gfc_charlen_type
  49 fstrcpy (char *dest, gfc_charlen_type destlen,
  50          const char *src, gfc_charlen_type srclen)
  51 {
  52   if (srclen >= destlen)
  53     {
  54       /* This will truncate if too long.  */
  55       memcpy (dest, src, destlen);
  56       return destlen;
  57     }
  58   else
  59     {
  60       memcpy (dest, src, srclen);
  61       /* Pad with spaces.  */
  62       memset (&dest[srclen], ' ', destlen - srclen);
  63       return srclen;
  64     }
  65 }
  66
  67
  68 /* Copy a null-terminated C string to a non-null-terminated Fortran
  69    string. Returns the non-padded length of the destination string.  */
  70
  71 gfc_charlen_type
  72 cf_strcpy (char *dest, gfc_charlen_type dest_len, const char *src)
  73 {
  74   size_t src_len;
  75
  76   src_len = strlen (src);
  77
  78   if (src_len >= (size_t) dest_len)
  79     {
  80       /* This will truncate if too long.  */
  81       memcpy (dest, src, dest_len);
  82       return dest_len;
  83     }
  84   else
  85     {
  86       memcpy (dest, src, src_len);
  87       /* Pad with spaces.  */
  88       memset (&dest[src_len], ' ', dest_len - src_len);
  89       return src_len;
  90     }
  91 }
  92
  93
  94 #ifndef HAVE_STRNLEN
  95 static size_t
  96 strnlen (const char *s, size_t maxlen)
  97 {
  98   for (size_t ii = 0; ii < maxlen; ii++)
  99     {
 100       if (s[ii] == '\0')
 101         return ii;
 102     }
 103   return maxlen;
 104 }
 105 #endif
 106
 107
 108 #ifndef HAVE_STRNDUP
 109 static char *
 110 strndup (const char *s, size_t n)
 111 {
 112   size_t len = strnlen (s, n);
 113   char *p = malloc (len + 1);
 114   if (!p)
 115     return NULL;
 116   memcpy (p, s, len);
 117   p[len] = '\0';
 118   return p;
 119 }
 120 #endif
 121
 122
 123 /* Duplicate a non-null-terminated Fortran string to a malloced
 124    null-terminated C string.  */
 125
 126 char *
 127 fc_strdup (const char *src, gfc_charlen_type src_len)
 128 {
 129   gfc_charlen_type n = fstrlen (src, src_len);
 130   char *p = strndup (src, n);
 131   if (!p)
 132     os_error ("Memory allocation failed in fc_strdup");
 133   return p;
 134 }
 135
 136
 137 /* Duplicate a non-null-terminated Fortran string to a malloced
 138    null-terminated C string, without getting rid of trailing
 139    blanks.  */
 140
 141 char *
 142 fc_strdup_notrim (const char *src, gfc_charlen_type src_len)
 143 {
 144   char *p = strndup (src, src_len);
 145   if (!p)
 146     os_error ("Memory allocation failed in fc_strdup");
 147   return p;
 148 }
 149
 150
 151 /* Given a fortran string and an array of st_option structures, search through
 152    the array to find a match.  If the option is not found, we generate an error
 153    if no default is provided.  */
 154
 155 int
 156 find_option (st_parameter_common *cmp, const char *s1, gfc_charlen_type s1_len,
 157              const st_option * opts, const char *error_message)
 158 {
 159   /* Strip trailing blanks from the Fortran string.  */
 160   size_t len = (size_t) fstrlen (s1, s1_len);
 161
 162   for (; opts->name; opts++)
 163     if (len == strlen(opts->name) && strncasecmp (s1, opts->name, len) == 0)
 164       return opts->value;
 165
 166   generate_error (cmp, LIBERROR_BAD_OPTION, error_message);
 167
 168   return -1;
 169 }
 170
 171
 172 /* Integer to decimal conversion.
 173
 174    This function is much more restricted than the widespread (but
 175    non-standard) itoa() function.  This version has the following
 176    characteristics:
 177
 178      - it takes only non-negative arguments
 179      - it is async-signal-safe (we use it runtime/backtrace.c)
 180      - it works in base 10 (see xtoa, otoa, btoa functions
 181        in io/write.c for other radices)
 182  */
 183
 184 const char *
 185 gfc_itoa (GFC_UINTEGER_LARGEST n, char *buffer, size_t len)
 186 {
 187   char *p;
 188
 189   if (len < GFC_ITOA_BUF_SIZE)
 190     sys_abort ();
 191
 192   if (n == 0)
 193     return "0";
 194
 195   p = buffer + GFC_ITOA_BUF_SIZE - 1;
 196   *p = '\0';
 197
 198   while (n != 0)
 199     {
 200       *--p = '0' + (n % 10);
 201       n /= 10;
 202     }
 203
 204   return p;
 205 }