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