mono/utils/parse.c

   1 /**
   2  * \file
   3  * Parsing for GC options.
   4  *
   5  * Copyright (C) 2015 Xamarin Inc
   6  *
   7  * Licensed under the MIT license. See LICENSE file in the project root for full license information.
   8  */
   9
  10 #include <config.h>
  11 #include <glib.h>
  12 #include <string.h>
  13 #include <errno.h>
  14 #include <ctype.h>
  15 #include <stdlib.h>
  16
  17 #include "parse.h"
  18
  19 /**
  20  * mono_gc_parse_environment_string_extract_number:
  21  * \param str points to the first digit of the number
  22  * \param out pointer to the variable that will receive the value
  23  * Tries to extract a number from the passed string, taking in to account m, k
  24  * and g suffixes
  25  * \returns TRUE if passing was successful
  26  */
  27 gboolean
  28 mono_gc_parse_environment_string_extract_number (const char *str, size_t *out)
  29 {
  30         char *endptr;
  31         int len = strlen (str), shift = 0;
  32         size_t val;
  33         gboolean is_suffix = FALSE;
  34         char suffix;
  35
  36         if (!len)
  37                 return FALSE;
  38
  39         suffix = str [len - 1];
  40
  41         switch (suffix) {
  42                 case 'g':
  43                 case 'G':
  44                         shift += 10;
  45                 case 'm':
  46                 case 'M':
  47                         shift += 10;
  48                 case 'k':
  49                 case 'K':
  50                         shift += 10;
  51                         is_suffix = TRUE;
  52                         break;
  53                 default:
  54                         if (!isdigit (suffix))
  55                                 return FALSE;
  56                         break;
  57         }
  58
  59         errno = 0;
  60         val = strtol (str, &endptr, 10);
  61
  62         if ((errno == ERANGE && (val == LONG_MAX || val == LONG_MIN))
  63                         || (errno != 0 && val == 0) || (endptr == str))
  64                 return FALSE;
  65
  66         if (is_suffix) {
  67                 size_t unshifted;
  68
  69                 if (*(endptr + 1)) /* Invalid string. */
  70                         return FALSE;
  71
  72                 unshifted = (size_t)val;
  73                 val <<= shift;
  74                 if (((size_t)val >> shift) != unshifted) /* value too large */
  75                         return FALSE;
  76         }
  77
  78         *out = val;
  79         return TRUE;
  80 }