+
+void
+validate_identifier(const char *identifier, YYLTYPE loc,
+ struct _mesa_glsl_parse_state *state)
+{
+ /* From page 15 (page 21 of the PDF) of the GLSL 1.10 spec,
+ *
+ * "Identifiers starting with "gl_" are reserved for use by
+ * OpenGL, and may not be declared in a shader as either a
+ * variable or a function."
+ */
+ if (strncmp(identifier, "gl_", 3) == 0) {
+ _mesa_glsl_error(&loc, state,
+ "identifier `%s' uses reserved `gl_' prefix",
+ identifier);
+ } else if (strstr(identifier, "__")) {
+ /* From page 14 (page 20 of the PDF) of the GLSL 1.10
+ * spec:
+ *
+ * "In addition, all identifiers containing two
+ * consecutive underscores (__) are reserved as
+ * possible future keywords."
+ */
+ _mesa_glsl_error(&loc, state,
+ "identifier `%s' uses reserved `__' string",
+ identifier);
+ }
+}
+
+