[Mesa-dev] [PATCH 8/9] glsl: In later GLSL versions, sequence operator is cannot be a constant expression

[Matt Turner]

On Fri, Oct 9, 2015 at 6:53 PM, Ian Romanick <idr at freedesktop.org> wrote:
> From: Ian Romanick <ian.d.romanick at intel.com>
>
> Fixes:
>     ES3-CTS.shaders.negative.constant_sequence
>
>     spec/glsl-es-3.00/compiler/global-initializer/from-sequence.vert
>     spec/glsl-es-3.00/compiler/global-initializer/from-sequence.frag
>
> Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
> Cc: "10.6 11.0" <mesa-stable at lists.freedesktop.org>
> ---
>  src/glsl/ast_to_hir.cpp | 43 ++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 42 insertions(+), 1 deletion(-)
>
> diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
> index 6af0f80..f34cbe0 100644
> --- a/src/glsl/ast_to_hir.cpp
> +++ b/src/glsl/ast_to_hir.cpp
> @@ -3311,8 +3311,49 @@ process_initializer(ir_variable *var, ast_declaration *decl,
>        if (new_rhs != NULL) {
>           rhs = new_rhs;
>
> +         /* Section 4.3.3 (Constant Expressions) of the GLSL ES 3.00.4 spec
> +          * says:
> +          *
> +          *     "A constant expression is one of
> +          *
> +          *        ...
> +          *
> +          *        - an expression formed by an operator on operands that are
> +          *          all constant expressions, including getting an element of
> +          *          a constant array, or a field of a constant structure, or
> +          *          components of a constant vector.  However, the sequence
> +          *          operator ( , ) and the assignment operators ( =, +=, ...)
> +          *          are not included in the operators that can create a
> +          *          constant expression."
> +          *
> +          * Section 12.43 (Sequence operator and constant expressions) says:
> +          *
> +          *     "Should the following construct be allowed?
> +          *
> +          *         float a[2,3];
> +          *
> +          *     The expression within the brackets uses the sequence operator
> +          *     (',') and returns the integer 3 so the construct is decl aring

There's a space in the middle of "declaring"

> +          *     a single-dimensional array of size 3.  In some languages, the
> +          *     construct declares a two-dimensional array.  It would be
> +          *     preferable to make this construct illegal to avoid confusion.
> +          *
> +          *     One possibility is to change the definition of the sequence
> +          *     operator so that it does not return a constant- expression and

Presumably the space after the - comes from a line break and isn't intentional.