From: Ian Romanick <ian.d.roman...@intel.com>
Section 3.3 (Preprocessor) of the GLSL 1.30 spec (and later) and the
GLSL ES spec (all versions) say:
"All macro names containing two consecutive underscores ( __ ) are
reserved for future use as predefined macro names. All macro names
prefixed with "GL_" ("GL" followed by a single underscore) are also
reserved."
The intention is that names containing __ are reserved for internal use
by the implementation, and names prefixed with GL_ are reserved for use
by Khronos. Since every extension adds a name prefixed with GL_ (i.e.,
the name of the extension), that should be an error. Names simply
containing __ are dangerous to use, but should be allowed. In similar
cases, the C++ preprocessor specification says, "no diagnostic is
required."
Per the Khronos bug mentioned below, a future version of the GLSL
specification will clarify this.
Signed-off-by: Ian Romanick <ian.d.roman...@intel.com>
Cc: "9.2 10.0 10.1" <mesa-sta...@lists.freedesktop.org>
Cc: Tapani Pälli <lem...@gmail.com>
Cc: Kenneth Graunke <kenn...@whitecape.org>
Cc: Darius Spitznagel <d.spitzna...@goodbytez.de>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=71870
Bugzilla: Khronos #11702
---
src/glsl/glcpp/glcpp-parse.y | 22 +++++++++++++++++++---
.../tests/086-reserved-macro-names.c.expected | 4 ++--
2 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/src/glsl/glcpp/glcpp-parse.y b/src/glsl/glcpp/glcpp-parse.y
index 5bb2891..bdc598f 100644
--- a/src/glsl/glcpp/glcpp-parse.y
+++ b/src/glsl/glcpp/glcpp-parse.y
@@ -1770,11 +1770,27 @@ static void
_check_for_reserved_macro_name (glcpp_parser_t *parser, YYLTYPE *loc,
const char *identifier)
{
- /* According to the GLSL specification, macro names starting with "__"
- * or "GL_" are reserved for future use. So, don't allow them.
+ /* Section 3.3 (Preprocessor) of the GLSL 1.30 spec (and later) and
+ * the GLSL ES spec (all versions) say:
+ *
+ * "All macro names containing two consecutive underscores ( __ )
+ * are reserved for future use as predefined macro names. All
+ * macro names prefixed with "GL_" ("GL" followed by a single
+ * underscore) are also reserved."
+ *
+ * The intention is that names containing __ are reserved for internal
+ * use by the implementation, and names prefixed with GL_ are reserved
+ * for use by Khronos. Since every extension adds a name prefixed
+ * with GL_ (i.e., the name of the extension), that should be an
+ * error. Names simply containing __ are dangerous to use, but should
+ * be allowed.
+ *
+ * A future version of the GLSL specification will clarify this.
*/
if (strstr(identifier, "__")) {
- glcpp_error (loc, parser, "Macro names containing \"__\" are
reserved.\n");
+ glcpp_warning(loc, parser,
+ "Macro names containing \"__\" are reserved "
+ "for use by the implementation.\n");
}
if (strncmp(identifier, "GL_", 3) == 0) {
glcpp_error (loc, parser, "Macro names starting with \"GL_\" are
reserved.\n");
diff --git a/src/glsl/glcpp/tests/086-reserved-macro-names.c.expected
b/src/glsl/glcpp/tests/086-reserved-macro-names.c.expected
index d8aa9f0..5ca42a9 100644
--- a/src/glsl/glcpp/tests/086-reserved-macro-names.c.expected
+++ b/src/glsl/glcpp/tests/086-reserved-macro-names.c.expected
@@ -1,8 +1,8 @@
-0:1(10): preprocessor error: Macro names containing "__" are reserved.
+0:1(10): preprocessor warning: Macro names containing "__" are reserved for
use by the implementation.
0:2(9): preprocessor error: Macro names starting with "GL_" are reserved.
-0:3(9): preprocessor error: Macro names containing "__" are reserved.
+0:3(9): preprocessor warning: Macro names containing "__" are reserved for use
by the implementation.
