workbench/libs/mesa/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_append(&parser->info_log, "%u:%u(%u): "
  37                                                   "preprocessor error: ",
  38                                                   locp->source,
  39                                                   locp->first_line,
  40                                                   locp->first_column);
  41         va_start(ap, fmt);
  42         ralloc_vasprintf_append(&parser->info_log, fmt, ap);
  43         va_end(ap);
  44         ralloc_strcat(&parser->info_log, "\n");
  45 }
  46
  47 void
  48 glcpp_warning (YYLTYPE *locp, glcpp_parser_t *parser, const char *fmt, ...)
  49 {
  50         va_list ap;
  51
  52         ralloc_asprintf_append(&parser->info_log, "%u:%u(%u): "
  53                                                   "preprocessor warning: ",
  54                                                   locp->source,
  55                                                   locp->first_line,
  56                                                   locp->first_column);
  57         va_start(ap, fmt);
  58         ralloc_vasprintf_append(&parser->info_log, fmt, ap);
  59         va_end(ap);
  60         ralloc_strcat(&parser->info_log, "\n");
  61 }
  62
  63 /* Searches backwards for '^ *#' from a given starting point. */
  64 static int
  65 in_directive(const char *shader, const char *ptr)
  66 {
  67         assert(ptr >= shader);
  68
  69         /* Search backwards for '#'. If we find a \n first, it doesn't count */
  70         for (; ptr >= shader && *ptr != '#'; ptr--) {
  71                 if (*ptr == '\n')
  72                         return 0;
  73         }
  74         if (ptr >= shader) {
  75                 /* Found '#'...look for spaces preceded by a newline */
  76                 for (ptr--; ptr >= shader && isblank(*ptr); ptr--);
  77                 // FIXME: I don't think the '\n' case can happen
  78                 if (ptr < shader || *ptr == '\n')
  79                         return 1;
  80         }
  81         return 0;
  82 }
  83
  84 /* Remove any line continuation characters in preprocessing directives.
  85  * However, ignore any in GLSL code, as "There is no line continuation
  86  * character" (1.30 page 9) in GLSL.
  87  */
  88 static char *
  89 remove_line_continuations(glcpp_parser_t *ctx, const char *shader)
  90 {
  91         int in_continued_line = 0;
  92         int extra_newlines = 0;
  93         char *clean = ralloc_strdup(ctx, "");
  94         const char *search_start = shader;
  95         const char *newline;
  96         while ((newline = strchr(search_start, '\n')) != NULL) {
  97                 const char *backslash = NULL;
  98
  99                 /* # of characters preceding the newline. */
 100                 int n = newline - shader;
 101
 102                 /* Find the preceding '\', if it exists */
 103                 if (n >= 1 && newline[-1] == '\\')
 104                         backslash = newline - 1;
 105                 else if (n >= 2 && newline[-1] == '\r' && newline[-2] == '\\')
 106                         backslash = newline - 2;
 107
 108                 /* Double backslashes don't count (the backslash is escaped) */
 109                 if (backslash != NULL && backslash[-1] == '\\') {
 110                         backslash = NULL;
 111                 }
 112
 113                 if (backslash != NULL) {
 114                         /* We found a line continuation, but do we care? */
 115                         if (!in_continued_line) {
 116                                 if (in_directive(shader, backslash)) {
 117                                         in_continued_line = 1;
 118                                         extra_newlines = 0;
 119                                 }
 120                         }
 121                         if (in_continued_line) {
 122                                 /* Copy everything before the \ */
 123                                 ralloc_strncat(&clean, shader, backslash - shader);
 124                                 shader = newline + 1;
 125                                 extra_newlines++;
 126                         }
 127                 } else if (in_continued_line) {
 128                         /* Copy everything up to and including the \n */
 129                         ralloc_strncat(&clean, shader, newline - shader + 1);
 130                         shader = newline + 1;
 131                         /* Output extra newlines to make line numbers match */
 132                         for (; extra_newlines > 0; extra_newlines--)
 133                                 ralloc_strcat(&clean, "\n");
 134                         in_continued_line = 0;
 135                 }
 136                 search_start = newline + 1;
 137         }
 138         ralloc_strcat(&clean, shader);
 139         return clean;
 140 }
 141
 142 int
 143 preprocess(void *ralloc_ctx, const char **shader, char **info_log,
 144            const struct gl_extensions *extensions, int api)
 145 {
 146         int errors;
 147         glcpp_parser_t *parser = glcpp_parser_create (extensions, api);
 148         *shader = remove_line_continuations(parser, *shader);
 149
 150         glcpp_lex_set_source_string (parser, *shader);
 151
 152         glcpp_parser_parse (parser);
 153
 154         if (parser->skip_stack)
 155                 glcpp_error (&parser->skip_stack->loc, parser, "Unterminated #if\n");
 156
 157         ralloc_strcat(info_log, parser->info_log);
 158
 159         ralloc_steal(ralloc_ctx, parser->output);
 160         *shader = parser->output;
 161
 162         errors = parser->error;
 163         glcpp_parser_destroy (parser);
 164         return errors;
 165 }