src/glsl/pp/sl_pp_extension.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 <stdlib.h>
  29 #include <string.h>
  30 #include "sl_pp_context.h"
  31 #include "sl_pp_process.h"
  32 #include "sl_pp_public.h"
  33
  34
  35 /**
  36  * Declare an extension to the preprocessor.  This tells the preprocessor
  37  * which extensions are supported by Mesa.
  38  * The shader still needs to have a "#extension name: behavior" line to enable
  39  * the extension.
  40  */
  41 int
  42 sl_pp_context_add_extension(struct sl_pp_context *context,
  43                             const char *name)
  44 {
  45    struct sl_pp_extension ext;
  46
  47    if (context->num_extensions == SL_PP_MAX_EXTENSIONS) {
  48       return -1;
  49    }
  50
  51    ext.name = sl_pp_context_add_unique_str(context, name);
  52    if (ext.name == -1) {
  53       return -1;
  54    }
  55
  56    ext.enabled = 0;
  57
  58    context->extensions[context->num_extensions++] = ext;
  59
  60    assert(context->num_extensions <= sizeof(context->extensions));
  61
  62    return 0;
  63 }
  64
  65 /**
  66  * Process a "#extension name: behavior" directive.
  67  */
  68 int
  69 sl_pp_process_extension(struct sl_pp_context *context,
  70                         const struct sl_pp_token_info *input,
  71                         unsigned int first,
  72                         unsigned int last,
  73                         struct sl_pp_process_state *state)
  74 {
  75    int extension_name = -1;
  76    int behavior = -1;
  77    struct sl_pp_token_info out;
  78    struct sl_pp_extension *extension = NULL;
  79
  80    /* Grab the extension name. */
  81    if (first < last && input[first].token == SL_PP_IDENTIFIER) {
  82       extension_name = input[first].data.identifier;
  83       first++;
  84    }
  85    if (extension_name == -1) {
  86       strcpy(context->error_msg, "expected identifier after `#extension'");
  87       return -1;
  88    }
  89
  90    /* Make sure the extension is supported. */
  91    if (extension_name == context->dict.all) {
  92       out.data.extension = extension_name;
  93    } else {
  94       unsigned int i;
  95
  96       out.data.extension = -1;
  97       for (i = 0; i < context->num_extensions; i++) {
  98          if (extension_name == context->extensions[i].name) {
  99             out.data.extension = extension_name;
 100             extension = &context->extensions[i];
 101             break;
 102          }
 103       }
 104    }
 105
 106    /* Grab the colon separating the extension name and behavior. */
 107    while (first < last && input[first].token == SL_PP_WHITESPACE) {
 108       first++;
 109    }
 110    if (first < last && input[first].token == SL_PP_COLON) {
 111       first++;
 112    } else {
 113       strcpy(context->error_msg, "expected `:' after extension name");
 114       return -1;
 115    }
 116    while (first < last && input[first].token == SL_PP_WHITESPACE) {
 117       first++;
 118    }
 119
 120    /* Grab the behavior name. */
 121    if (first < last && input[first].token == SL_PP_IDENTIFIER) {
 122       behavior = input[first].data.identifier;
 123       first++;
 124    }
 125    if (behavior == -1) {
 126       strcpy(context->error_msg, "expected identifier after `:'");
 127       return -1;
 128    }
 129
 130    if (behavior == context->dict.require) {
 131       if (out.data.extension == -1) {
 132          strcpy(context->error_msg, "the required extension is not supported");
 133          return -1;
 134       }
 135       if (out.data.extension == context->dict.all) {
 136          strcpy(context->error_msg, "invalid behavior for `all' extension: `require'");
 137          return -1;
 138       }
 139       out.token = SL_PP_EXTENSION_REQUIRE;
 140       extension->enabled = 1;
 141    } else if (behavior == context->dict.enable) {
 142       if (out.data.extension == -1) {
 143          /* Warning: the extension cannot be enabled. */
 144          return 0;
 145       }
 146       if (out.data.extension == context->dict.all) {
 147          strcpy(context->error_msg, "invalid behavior for `all' extension: `enable'");
 148          return -1;
 149       }
 150       out.token = SL_PP_EXTENSION_ENABLE;
 151       extension->enabled = 1;
 152    } else if (behavior == context->dict.warn) {
 153       if (out.data.extension == -1) {
 154          /* Warning: the extension is not supported. */
 155          return 0;
 156       }
 157       out.token = SL_PP_EXTENSION_WARN;
 158       extension->enabled = 0;
 159    } else if (behavior == context->dict.disable) {
 160       if (out.data.extension == -1) {
 161          /* Warning: the extension is not supported. */
 162          return 0;
 163       }
 164       out.token = SL_PP_EXTENSION_DISABLE;
 165       extension->enabled = 0;
 166    } else {
 167       strcpy(context->error_msg, "unrecognised behavior name");
 168       return -1;
 169    }
 170
 171    /* Grab the end of line. */
 172    while (first < last && input[first].token == SL_PP_WHITESPACE) {
 173       first++;
 174    }
 175    if (first < last) {
 176       strcpy(context->error_msg, "expected end of line after behavior name");
 177       return -1;
 178    }
 179
 180    if (sl_pp_process_out(state, &out)) {
 181       return -1;
 182    }
 183
 184    return 0;
 185 }