Mesa (master): glsl: Only warn for macro names containing __

[Ian Romanick]

Module: Mesa
Branch: master
Commit: 2c85fd5a964a78c9f7a93994fb79f1723c6f45b5
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=2c85fd5a964a78c9f7a93994fb79f1723c6f45b5

Author: Ian Romanick <ian.d.romanick at intel.com>
Date:   Tue Feb 18 09:36:08 2014 -0800

glsl: Only warn for macro names containing __

>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."

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.  Names simply containing __ are dangerous to use, but should
be allowed.

Per the Khronos bug mentioned below, a future version of the GLSL
specification will clarify this.

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Cc: "9.2 10.0 10.1" <mesa-stable at lists.freedesktop.org>
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
Tested-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Anuj Phogat <anuj.phogat at gmail.com>
Tested-by: Darius Spitznagel <d.spitznagel at goodbytez.de>
Cc: Tapani Pälli <lemody at gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=71870
Bugzilla: Khronos #11702

---

 src/glsl/ast_to_hir.cpp |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
index 6de73f4..6549ca7 100644
--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -2928,10 +2928,17 @@ validate_identifier(const char *identifier, YYLTYPE loc,
        *     "In addition, all identifiers containing two
        *      consecutive underscores (__) are reserved as
        *      possible future keywords."
+       *
+       * 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.  Names simply containing __ are dangerous to use,
+       * but should be allowed.
+       *
+       * A future version of the GLSL specification will clarify this.
        */
-      _mesa_glsl_error(&loc, state,
-                       "identifier `%s' uses reserved `__' string",
-                       identifier);
+      _mesa_glsl_warning(&loc, state,
+                         "identifier `%s' uses reserved `__' string",
+                         identifier);
    }
 }