src/glsl/glcpp/pp.c

   1 /*
   2  * Copyright © 2010 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 #include <assert.h>
  25 #include <string.h>
  26 #include <ctype.h>
  27 #include "glcpp.h"
  28 #include "main/core.h" /* for isblank() on MSVC */
  29
  30 void
  31 glcpp_error (YYLTYPE *locp, glcpp_parser_t *parser, const char *fmt, ...)
  32 {
  33         va_list ap;
  34
  35         parser->error = 1;
  36         ralloc_asprintf_rewrite_tail(&parser->info_log,
  37                                      &parser->info_log_length,
  38                                      "%u:%u(%u): "
  39                                      "preprocessor error: ",
  40                                      locp->source,
  41                                      locp->first_line,
  42                                      locp->first_column);
  43         va_start(ap, fmt);
  44         ralloc_vasprintf_rewrite_tail(&parser->info_log,
  45                                       &parser->info_log_length,
  46                                       fmt, ap);
  47         va_end(ap);
  48         ralloc_asprintf_rewrite_tail(&parser->info_log,
  49                                      &parser->info_log_length, "\n");
  50 }
  51
  52 void
  53 glcpp_warning (YYLTYPE *locp, glcpp_parser_t *parser, const char *fmt, ...)
  54 {
  55         va_list ap;
  56
  57         ralloc_asprintf_rewrite_tail(&parser->info_log,
  58                                      &parser->info_log_length,
  59                                      "%u:%u(%u): "
  60                                      "preprocessor warning: ",
  61                                      locp->source,
  62                                      locp->first_line,
  63                                      locp->first_column);
  64         va_start(ap, fmt);
  65         ralloc_vasprintf_rewrite_tail(&parser->info_log,
  66                                       &parser->info_log_length,
  67                                       fmt, ap);
  68         va_end(ap);
  69         ralloc_asprintf_rewrite_tail(&parser->info_log,
  70                                      &parser->info_log_length, "\n");
  71 }
  72
  73 /* Remove any line continuation characters in the shader, (whether in
  74  * preprocessing directives or in GLSL code).
  75  */
  76 static char *
  77 remove_line_continuations(glcpp_parser_t *ctx, const char *shader)
  78 {
  79         char *clean = ralloc_strdup(ctx, "");
  80         const char *backslash, *newline;
  81         int collapsed_newlines = 0;
  82
  83         while (true) {
  84                 backslash = strchr(shader, '\\');
  85
  86                 /* If we have previously collapsed any line-continuations,
  87                  * then we want to insert additional newlines at the next
  88                  * occurrence of a newline character to avoid changing any
  89                  * line numbers.
  90                  */
  91                 if (collapsed_newlines) {
  92                         newline = strchr(shader, '\n');
  93                         if (newline &&
  94                             (backslash == NULL || newline < backslash))
  95                         {
  96                                 ralloc_strncat(&clean, shader,
  97                                                newline - shader + 1);
  98                                 while (collapsed_newlines--)
  99                                         ralloc_strcat(&clean, "\n");
 100                                 shader = newline + 1;
 101                         }
 102                 }
 103
 104                 if (backslash == NULL)
 105                         break;
 106
 107                 /* At each line continuation, (backslash followed by a
 108                  * newline), copy all preceding text to the output, then
 109                  * advance the shader pointer to the character after the
 110                  * newline.
 111                  */
 112                 if (backslash[1] == '\n' ||
 113                     (backslash[1] == '\r' && backslash[2] == '\n'))
 114                 {
 115                         collapsed_newlines++;
 116                         ralloc_strncat(&clean, shader, backslash - shader);
 117                         if (backslash[1] == '\n')
 118                                 shader = backslash + 2;
 119                         else
 120                                 shader = backslash + 3;
 121                 }
 122         }
 123
 124         ralloc_strcat(&clean, shader);
 125
 126         return clean;
 127 }
 128
 129 int
 130 glcpp_preprocess(void *ralloc_ctx, const char **shader, char **info_log,
 131            const struct gl_extensions *extensions, int api)
 132 {
 133         int errors;
 134         glcpp_parser_t *parser = glcpp_parser_create (extensions, api);
 135         *shader = remove_line_continuations(parser, *shader);
 136
 137         glcpp_lex_set_source_string (parser, *shader);
 138
 139         glcpp_parser_parse (parser);
 140
 141         if (parser->skip_stack)
 142                 glcpp_error (&parser->skip_stack->loc, parser, "Unterminated #if\n");
 143
 144         ralloc_strcat(info_log, parser->info_log);
 145
 146         ralloc_steal(ralloc_ctx, parser->output);
 147         *shader = parser->output;
 148
 149         errors = parser->error;
 150         glcpp_parser_destroy (parser);
 151         return errors;
 152 }