vkd3d-shader: Implement an initial pass-through HLSL preprocessor.

Signed-off-by: Zebediah Figura <zfigura@codeweavers.com>
Signed-off-by: Henri Verbeet <hverbeet@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

libs/vkd3d-shader/preproc.y

@@ -0,0 +1,60 @@
+/*
+ * HLSL preprocessor
+ *
+ * Copyright 2020 Zebediah Figura for CodeWeavers
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+%code requires
+{
+
+#include "vkd3d_shader_private.h"
+#include "preproc.h"
+
+}
+
+%code provides
+{
+
+int preproc_yylex(PREPROC_YYSTYPE *yylval_param, PREPROC_YYLTYPE *yylloc_param, void *scanner);
+
+}
+
+%code
+{
+
+static void yyerror(const YYLTYPE *loc, void *scanner, struct preproc_ctx *ctx, const char *string)
+{
+    FIXME("Error reporting is not implemented.\n");
+}
+
+}
+
+%define api.prefix {preproc_yy}
+%define api.pure full
+%define parse.error verbose
+%expect 0
+%locations
+%lex-param {yyscan_t scanner}
+%parse-param {void *scanner}
+%parse-param {struct preproc_ctx *ctx}
+
+%token T_TEXT
+
+%%
+
+shader_text
+    : %empty