[Mesa-dev] [PATCH] glsl: allow duplicate layout-qualifier-names

[Matt Turner]

On Wed, Jan 13, 2016 at 9:26 PM, Timothy Arceri
<timothy.arceri at collabora.com> wrote:
> The special case from detecting stream duplicates is also
> removed, as testing never trigged this error.
>
> From the ARB_shading_language_420pack spec:
>
>    "More than one layout qualifier may appear in a single
>    declaration. If the same layout-qualifier-name occurs in
>    multiple layout qualifiers for the same declaration, the
>    last one overrides the former ones."
>
> While the extension spec is taking about multiple layout
> qualifiers we interpret that to mean layout-qualifier-names
> can also occur multiple times within a single layout qualifier.
>
> In Section 4.4 (Layout Qualifiers) of the GLSL 4.40 spec it
> clarifies this:
>
>    "More than one layout qualifier may appear in a single
>    declaration. Additionally, the same layout-qualifier-name
>    can occur multiple times within a layout qualifier or across
>    multiple layout qualifiers in the  same declaration"
> ---

As I said in reply to the piglit tests, I don't think this should be
interpreted as a clarification but as an actual behavioral change in
GLSL 4.40/ARB_enhanced_layouts.