Re: [PATCH 7/7] d3dcompiler: Store the "array" field in struct hlsl_deref as a struct hlsl_deref pointer.

[Matteo Bruni]

On Sat, Mar 7, 2020 at 12:25 AM Zebediah Figura  wrote:
> Signed-off-by: Zebediah Figura
>
> dlls/d3dcompiler_43/d3dcompiler_private.h |  2 +-
>  dlls/d3dcompiler_43/hlsl.y                | 25 ++++++++++++++++++++---
>  dlls/d3dcompiler_43/utils.c               |  6 +++++-
>  3 files changed, 28 insertions(+), 5 deletions(-)
>
> diff --git a/dlls/d3dcompiler_43/d3dcompiler_private.h b/dlls/d3dcompiler_43/d3dcompiler_private.h
> index d221d1056fa..f4f68b9e4cf 100644
> --- a/dlls/d3dcompiler_43/d3dcompiler_private.h
> +++ b/dlls/d3dcompiler_43/d3dcompiler_private.h
> @@ -907,7 +907,7 @@ struct hlsl_deref
>          struct hlsl_ir_var *var;
>          struct
>          {
> -
>        struct hlsl_ir_node *array;
> -
>        struct hlsl_deref *array;
>        struct hlsl_ir_node *index;
>    } array;
>    struct
>
> diff --git a/dlls/d3dcompiler_43/hlsl.y b/dlls/d3dcompiler_43/hlsl.y
> index 40159c60dcc..11dd8026c16 100644
> --- a/dlls/d3dcompiler_43/hlsl.y
> +++ b/dlls/d3dcompiler_43/hlsl.y
> @@ -2114,8 +2114,17 @@ postfix_expr:             primary_expr
>                                  /* This may be an array dereference or a vector/matrix
>                                   * subcomponent access.
>                                   * We store it as an array dereference in any case. */
> -
>                            struct hlsl_ir_deref *deref = d3dcompiler_alloc(sizeof(*deref));
> -
>                            struct hlsl_type *expr_type = node_from_list($1)->data_type;
> -
>                            struct hlsl_ir_deref *deref = d3dcompiler_alloc(sizeof(*deref)), *src;
> -
>                            struct hlsl_ir_node *node = node_from_list($1);
> -
>                            struct hlsl_type *expr_type = node->data_type;
> -
> -
>                            if (node->type != HLSL_IR_DEREF)
> -
>                            {
> -
>                                FIXME("Unimplemented index of node type %s.\n",
> -
>                                        debug_node_type(node->type));
> -
>                                YYABORT;
> -
>                            }
> -
>                            src = deref_from_node(node);

It looks like it's legal in HLSL to array dereference an arbitrary
vector expression. E.g.:

uniform int i;
uniform float4 b;
...
float4 a = {0.25, 0.5, 0.75, 1.0};
float r = (a * b)[i];

How do you plan to handle that? Mostly wondering if this patch would
have to be effectively reverted in the future or you have something
else in mind.