src/compiler/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
  29 void
  30 glcpp_error (YYLTYPE *locp, glcpp_parser_t *parser, const char *fmt, ...)
  31 {
  32         va_list ap;
  33
  34         parser->error = 1;
  35         ralloc_asprintf_rewrite_tail(&parser->info_log,
  36                                      &parser->info_log_length,
  37                                      "%u:%u(%u): "
  38                                      "preprocessor error: ",
  39                                      locp->source,
  40                                      locp->first_line,
  41                                      locp->first_column);
  42         va_start(ap, fmt);
  43         ralloc_vasprintf_rewrite_tail(&parser->info_log,
  44                                       &parser->info_log_length,
  45                                       fmt, ap);
  46         va_end(ap);
  47         ralloc_asprintf_rewrite_tail(&parser->info_log,
  48                                      &parser->info_log_length, "\n");
  49 }
  50
  51 void
  52 glcpp_warning (YYLTYPE *locp, glcpp_parser_t *parser, const char *fmt, ...)
  53 {
  54         va_list ap;
  55
  56         ralloc_asprintf_rewrite_tail(&parser->info_log,
  57                                      &parser->info_log_length,
  58                                      "%u:%u(%u): "
  59                                      "preprocessor warning: ",
  60                                      locp->source,
  61                                      locp->first_line,
  62                                      locp->first_column);
  63         va_start(ap, fmt);
  64         ralloc_vasprintf_rewrite_tail(&parser->info_log,
  65                                       &parser->info_log_length,
  66                                       fmt, ap);
  67         va_end(ap);
  68         ralloc_asprintf_rewrite_tail(&parser->info_log,
  69                                      &parser->info_log_length, "\n");
  70 }
  71
  72 /* Given str, (that's expected to start with a newline terminator of some
  73  * sort), return a pointer to the first character in str after the newline.
  74  *
  75  * A newline terminator can be any of the following sequences:
  76  *
  77  *      "\r\n"
  78  *      "\n\r"
  79  *      "\n"
  80  *      "\r"
  81  *
  82  * And the longest such sequence will be skipped.
  83  */
  84 static const char *
  85 skip_newline (const char *str)
  86 {
  87         const char *ret = str;
  88
  89         if (ret == NULL)
  90                 return ret;
  91
  92         if (*ret == '\0')
  93                 return ret;
  94
  95         if (*ret == '\r') {
  96                 ret++;
  97                 if (*ret && *ret == '\n')
  98                         ret++;
  99         } else if (*ret == '\n') {
 100                 ret++;
 101                 if (*ret && *ret == '\r')
 102                         ret++;
 103         }
 104
 105         return ret;
 106 }
 107
 108 /* Remove any line continuation characters in the shader, (whether in
 109  * preprocessing directives or in GLSL code).
 110  */
 111 static char *
 112 remove_line_continuations(glcpp_parser_t *ctx, const char *shader)
 113 {
 114         char *clean = ralloc_strdup(ctx, "");
 115         const char *backslash, *newline, *search_start;
 116         const char *cr, *lf;
 117         char newline_separator[3];
 118         int collapsed_newlines = 0;
 119
 120         backslash = strchr(shader, '\\');
 121
 122         /* No line continuations were found in this shader, our job is done */
 123         if (backslash == NULL)
 124                 return (char *) shader;
 125
 126         search_start = shader;
 127
 128         /* Determine what flavor of newlines this shader is using. GLSL
 129          * provides for 4 different possible ways to separate lines, (using
 130          * one or two characters):
 131          *
 132          *      "\n" (line-feed, like Linux, Unix, and new Mac OS)
 133          *      "\r" (carriage-return, like old Mac files)
 134          *      "\r\n" (carriage-return + line-feed, like DOS files)
 135          *      "\n\r" (line-feed + carriage-return, like nothing, really)
 136          *
 137          * This code explicitly supports a shader that uses a mixture of
 138          * newline terminators and will properly handle line continuation
 139          * backslashes followed by any of the above.
 140          *
 141          * But, since we must also insert additional newlines in the output
 142          * (for any collapsed lines) we attempt to maintain consistency by
 143          * examining the first encountered newline terminator, and using the
 144          * same terminator for any newlines we insert.
 145          */
 146         cr = strchr(search_start, '\r');
 147         lf = strchr(search_start, '\n');
 148
 149         newline_separator[0] = '\n';
 150         newline_separator[1] = '\0';
 151         newline_separator[2] = '\0';
 152
 153         if (cr == NULL) {
 154                 /* Nothing to do. */
 155         } else if (lf == NULL) {
 156                 newline_separator[0] = '\r';
 157         } else if (lf == cr + 1) {
 158                 newline_separator[0] = '\r';
 159                 newline_separator[1] = '\n';
 160         } else if (cr == lf + 1) {
 161                 newline_separator[0] = '\n';
 162                 newline_separator[1] = '\r';
 163         }
 164
 165         while (true) {
 166                 /* If we have previously collapsed any line-continuations,
 167                  * then we want to insert additional newlines at the next
 168                  * occurrence of a newline character to avoid changing any
 169                  * line numbers.
 170                  */
 171                 if (collapsed_newlines) {
 172                         cr = strchr (search_start, '\r');
 173                         lf = strchr (search_start, '\n');
 174                         if (cr && lf)
 175                                 newline = cr < lf ? cr : lf;
 176                         else if (cr)
 177                                 newline = cr;
 178                         else
 179                                 newline = lf;
 180                         if (newline &&
 181                             (backslash == NULL || newline < backslash))
 182                         {
 183                                 ralloc_strncat(&clean, shader,
 184                                                newline - shader + 1);
 185                                 while (collapsed_newlines) {
 186                                         ralloc_strcat(&clean, newline_separator);
 187                                         collapsed_newlines--;
 188                                 }
 189                                 shader = skip_newline (newline);
 190                                 search_start = shader;
 191                         }
 192                 }
 193
 194                 search_start = backslash + 1;
 195
 196                 if (backslash == NULL)
 197                         break;
 198
 199                 /* At each line continuation, (backslash followed by a
 200                  * newline), copy all preceding text to the output, then
 201                  * advance the shader pointer to the character after the
 202                  * newline.
 203                  */
 204                 if (backslash[1] == '\r' || backslash[1] == '\n')
 205                 {
 206                         collapsed_newlines++;
 207                         ralloc_strncat(&clean, shader, backslash - shader);
 208                         shader = skip_newline (backslash + 1);
 209                         search_start = shader;
 210                 }
 211
 212                 backslash = strchr(search_start, '\\');
 213         }
 214
 215         ralloc_strcat(&clean, shader);
 216
 217         return clean;
 218 }
 219
 220 int
 221 glcpp_preprocess(void *ralloc_ctx, const char **shader, char **info_log,
 222                  glcpp_extension_iterator extensions, void *state,
 223                  struct gl_context *gl_ctx)
 224 {
 225         int errors;
 226         glcpp_parser_t *parser =
 227                 glcpp_parser_create(&gl_ctx->Extensions, extensions, state, gl_ctx->API);
 228
 229         if (! gl_ctx->Const.DisableGLSLLineContinuations)
 230                 *shader = remove_line_continuations(parser, *shader);
 231
 232         glcpp_lex_set_source_string (parser, *shader);
 233
 234         glcpp_parser_parse (parser);
 235
 236         if (parser->skip_stack)
 237                 glcpp_error (&parser->skip_stack->loc, parser, "Unterminated #if\n");
 238
 239         glcpp_parser_resolve_implicit_version(parser);
 240
 241         ralloc_strcat(info_log, parser->info_log);
 242
 243         ralloc_steal(ralloc_ctx, parser->output);
 244         *shader = parser->output;
 245
 246         errors = parser->error;
 247         glcpp_parser_destroy (parser);
 248         return errors;
 249 }