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 <ctype.h>
  26 #include "glcpp.h"
  27
  28 void
  29 glcpp_error (YYLTYPE *locp, glcpp_parser_t *parser, const char *fmt, ...)
  30 {
  31         parser->error = 1;
  32         parser->info_log = talloc_asprintf_append(parser->info_log,
  33                                                   "%u:%u(%u): "
  34                                                   "preprocessor error: ",
  35                                                   locp->source,
  36                                                   locp->first_line,
  37                                                   locp->first_column);
  38         va_list ap;
  39         va_start(ap, fmt);
  40         parser->info_log = talloc_vasprintf_append(parser->info_log, fmt, ap);
  41         va_end(ap);
  42         parser->info_log = talloc_strdup_append(parser->info_log, "\n");
  43 }
  44
  45 void
  46 glcpp_warning (YYLTYPE *locp, glcpp_parser_t *parser, const char *fmt, ...)
  47 {
  48         parser->info_log = talloc_asprintf_append(parser->info_log,
  49                                                   "%u:%u(%u): "
  50                                                   "preprocessor warning: ",
  51                                                   locp->source,
  52                                                   locp->first_line,
  53                                                   locp->first_column);
  54         va_list ap;
  55         va_start(ap, fmt);
  56         parser->info_log = talloc_vasprintf_append(parser->info_log, fmt, ap);
  57         va_end(ap);
  58         parser->info_log = talloc_strdup_append(parser->info_log, "\n");
  59 }
  60
  61 /* Searches backwards for '^ *#' from a given starting point. */
  62 static int
  63 in_directive(const char *shader, const char *ptr)
  64 {
  65         assert(ptr >= shader);
  66
  67         /* Search backwards for '#'. If we find a \n first, it doesn't count */
  68         for (; ptr >= shader && *ptr != '#'; ptr--) {
  69                 if (*ptr == '\n')
  70                         return 0;
  71         }
  72         if (ptr >= shader) {
  73                 /* Found '#'...look for spaces preceded by a newline */
  74                 for (ptr--; ptr >= shader && isblank(*ptr); ptr--);
  75                 // FIXME: I don't think the '\n' case can happen
  76                 if (ptr < shader || *ptr == '\n')
  77                         return 1;
  78         }
  79         return 0;
  80 }
  81
  82 /* Remove any line continuation characters in preprocessing directives.
  83  * However, ignore any in GLSL code, as "There is no line continuation
  84  * character" (1.30 page 9) in GLSL.
  85  */
  86 static char *
  87 remove_line_continuations(glcpp_parser_t *ctx, const char *shader)
  88 {
  89         int in_continued_line = 0;
  90         int extra_newlines = 0;
  91         char *clean = talloc_strdup(ctx, "");
  92         const char *search_start = shader;
  93         const char *newline;
  94         while ((newline = strchr(search_start, '\n')) != NULL) {
  95                 const char *backslash = NULL;
  96                 /* Find the preceding '\', if it exists */
  97                 if (newline[-1] == '\\') {
  98                         backslash = newline - 1;
  99                 } else if (newline[-1] == '\r' && newline[-2] == '\\') {
 100                         backslash = newline - 2;
 101                 }
 102                 /* Double backslashes don't count (the backslash is escaped) */
 103                 if (backslash != NULL && backslash[-1] == '\\') {
 104                         backslash = NULL;
 105                 }
 106
 107                 if (backslash != NULL) {
 108                         /* We found a line continuation, but do we care? */
 109                         if (!in_continued_line) {
 110                                 if (in_directive(shader, backslash)) {
 111                                         in_continued_line = 1;
 112                                         extra_newlines = 0;
 113                                 }
 114                         }
 115                         if (in_continued_line) {
 116                                 /* Copy everything before the \ */
 117                                 clean = talloc_strndup_append(clean, shader, backslash - shader);
 118                                 shader = newline + 1;
 119                                 extra_newlines++;
 120                         }
 121                 } else if (in_continued_line) {
 122                         /* Copy everything up to and including the \n */
 123                         clean = talloc_strndup_append(clean, shader, newline - shader + 1);
 124                         shader = newline + 1;
 125                         /* Output extra newlines to make line numbers match */
 126                         for (; extra_newlines > 0; extra_newlines--)
 127                                 clean = talloc_strdup_append(clean, "\n");
 128                         in_continued_line = 0;
 129                 }
 130                 search_start = newline + 1;
 131         }
 132         clean = talloc_strdup_append(clean, shader);
 133         return clean;
 134 }
 135
 136 extern int
 137 preprocess(void *talloc_ctx, const char **shader, char **info_log,
 138            const struct gl_extensions *extensions)
 139 {
 140         int errors;
 141         glcpp_parser_t *parser = glcpp_parser_create (extensions);
 142         *shader = remove_line_continuations(parser, *shader);
 143
 144         glcpp_lex_set_source_string (parser, *shader);
 145
 146         glcpp_parser_parse (parser);
 147
 148         *info_log = talloc_strdup_append(*info_log, parser->info_log);
 149
 150         talloc_steal(talloc_ctx, parser->output);
 151         *shader = parser->output;
 152
 153         errors = parser->error;
 154         glcpp_parser_destroy (parser);
 155         return errors;
 156 }