[Mesa-dev] [PATCH] glsl: buffer variables can be readonly and writeonly

[Juan A. Suarez Romero]

On Fri, 2017-09-15 at 12:47 +0200, Samuel Pitoiset wrote:
> I guess this will break some piglits.
> 


Right. I'll check them and provide fixes

Thanks.

	J.A.



> On 09/15/2017 10:49 AM, Juan A. Suarez Romero wrote:
> > In GLSL ES 3.10 session 4.9 [Memory Access Qualifiers], it has the following description:
> > 
> > "A variable could be qualified as both readonly and writeonly, disallowing both read and write, but still be passed to
> > imageSize() to have the size queried.".
> > 
> > This is for image variable, but not for buffer variables.
> > 
> > According to https://github.com/KhronosGroup/OpenGL-API/issues/7 Khronos
> > intent is to allow both readonly and writeonly in buffer variables, and
> > as such it will update the GLSL specification.
> > 
> > This commit address this issue, and fixes:
> > 
> > KHR-GL{43,44,45}.shader_storage_buffer_object.basic-readonly-writeonly
> > KHR-GLES31.core.shader_storage_buffer_object.basic-readonly-writeonly
> > ---
> >   src/compiler/glsl/ast_to_hir.cpp | 5 -----
> >   1 file changed, 5 deletions(-)
> > 
> > diff --git a/src/compiler/glsl/ast_to_hir.cpp b/src/compiler/glsl/ast_to_hir.cpp
> > index 45c8ca2a5d..1a94c274b6 100644
> > --- a/src/compiler/glsl/ast_to_hir.cpp
> > +++ b/src/compiler/glsl/ast_to_hir.cpp
> > @@ -7254,11 +7254,6 @@ ast_process_struct_or_iface_block_members(exec_list *instructions,
> >               validate_matrix_layout_for_type(state, &loc, decl_type, NULL);
> >         }
> >   
> > -      if (qual->flags.q.read_only && qual->flags.q.write_only) {
> > -         _mesa_glsl_error(&loc, state, "buffer variable can't be both "
> > -                          "readonly and writeonly.");
> > -      }
> > -
> >         foreach_list_typed (ast_declaration, decl, link,
> >                             &decl_list->declarations) {
> >            YYLTYPE loc = decl->get_location();
> > 
> 
>