src/glsl/pp/sl_pp_version.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2009 VMware, Inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 #include "sl_pp_version.h"
  29
  30
  31 static int
  32 _parse_integer(const char *input,
  33                unsigned int *number)
  34 {
  35    unsigned int n = 0;
  36
  37    while (*input >= '0' && *input <= '9') {
  38       if (n * 10 < n) {
  39          /* Overflow. */
  40          return -1;
  41       }
  42
  43       n = n * 10 + (*input++ - '0');
  44    }
  45
  46    if (*input != '\0') {
  47       /* Invalid decimal number. */
  48       return -1;
  49    }
  50
  51    *number = n;
  52    return 0;
  53 }
  54
  55
  56 int
  57 sl_pp_version(struct sl_pp_context *context,
  58               const struct sl_pp_token_info *input,
  59               unsigned int *version,
  60               unsigned int *tokens_eaten)
  61 {
  62    unsigned int i = 0;
  63    unsigned int line = context->line;
  64
  65    /* Default values if `#version' is not present. */
  66    *version = 110;
  67    *tokens_eaten = 0;
  68
  69    /* There can be multiple `#version' directives present.
  70     * Accept the value of the last one.
  71     */
  72    for (;;) {
  73       int found_hash = 0;
  74       int found_version = 0;
  75       int found_number = 0;
  76       int found_end = 0;
  77
  78       /* Skip whitespace and newlines and seek for hash. */
  79       while (!found_hash) {
  80          switch (input[i].token) {
  81          case SL_PP_NEWLINE:
  82             line++;
  83             /* pass thru */
  84          case SL_PP_WHITESPACE:
  85             i++;
  86             break;
  87
  88          case SL_PP_HASH:
  89             i++;
  90             found_hash = 1;
  91             break;
  92
  93          default:
  94             return 0;
  95          }
  96       }
  97
  98       /* Skip whitespace and seek for `version'. */
  99       while (!found_version) {
 100          switch (input[i].token) {
 101          case SL_PP_WHITESPACE:
 102             i++;
 103             break;
 104
 105          case SL_PP_IDENTIFIER:
 106             {
 107                const char *id = sl_pp_context_cstr(context, input[i].data.identifier);
 108
 109                if (!id) {
 110                   return -1;
 111                }
 112                if (strcmp(id, "version")) {
 113                   return 0;
 114                }
 115                i++;
 116                found_version = 1;
 117             }
 118             break;
 119
 120          default:
 121             return 0;
 122          }
 123       }
 124
 125       /* Skip whitespace and seek for version number. */
 126       while (!found_number) {
 127          switch (input[i].token) {
 128          case SL_PP_WHITESPACE:
 129             i++;
 130             break;
 131
 132          case SL_PP_NUMBER:
 133             {
 134                const char *num = sl_pp_context_cstr(context, input[i].data.number);
 135
 136                if (!num) {
 137                   return -1;
 138                }
 139                if (_parse_integer(num, version)) {
 140                   /* Expected version number. */
 141                   return -1;
 142                }
 143                i++;
 144                found_number = 1;
 145             }
 146             break;
 147
 148          default:
 149             /* Expected version number. */
 150             return -1;
 151          }
 152       }
 153
 154       /* Skip whitespace and seek for either newline or eof. */
 155       while (!found_end) {
 156          switch (input[i].token) {
 157          case SL_PP_WHITESPACE:
 158             i++;
 159             break;
 160
 161          case SL_PP_NEWLINE:
 162             line++;
 163             /* pass thru */
 164          case SL_PP_EOF:
 165             i++;
 166             *tokens_eaten = i;
 167             context->line = line;
 168             found_end = 1;
 169             break;
 170
 171          default:
 172             /* Expected end of line. */
 173             return -1;
 174          }
 175       }
 176    }
 177
 178    /* Should not get here. */
 179 }