[Piglit] [PATCH] Change expected behavior for #if with undefined macros.

[Anuj Phogat]

On Fri, Feb 22, 2013 at 1:21 PM, Carl Worth <cworth at cworth.org> wrote:
> The GLSL 1.30 specification deviated from the standard behavior of C
> preprocessors everwhere by making an undefined macro an error rather
> than treating it as a value of 0. This was not actually useful, and
> this exception to the standard behavior is dropped in GLSL 4.30.
>
> In the meantime, popular implementations have been ignoring the
> specified behavior and implementing the standard behavior anyway. So
> expect that.
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=51631
> ---
>  .../preprocessor/if/if-arg-must-be-defined-01.frag   |   14 +++++++++++---
>  .../preprocessor/if/if-arg-must-be-defined-02.frag   |   18 +++++++++++++++---
>  2 files changed, 26 insertions(+), 6 deletions(-)
>
> diff --git a/tests/spec/glsl-1.30/preprocessor/if/if-arg-must-be-defined-01.frag b/tests/spec/glsl-1.30/preprocessor/if/if-arg-must-be-defined-01.frag
> index 019104d..4fd5d87 100644
> --- a/tests/spec/glsl-1.30/preprocessor/if/if-arg-must-be-defined-01.frag
> +++ b/tests/spec/glsl-1.30/preprocessor/if/if-arg-must-be-defined-01.frag
> @@ -1,15 +1,23 @@
>  // [config]
> -// expect_result: fail
> +// expect_result:pass
>  // glsl_version: 1.30
>  // [end config]
>  //
> -// Check that the compiler raises an error when an undefined macro is used as
> +// Check that the compiler treats an undefined macro as 0 when used as
>  // an argument to the #if directive.
>  //
> -// From page 11 (17 of pdf) of the GLSL 1.30 spec:
> +// Older GLSL specifications (such as GLSL 1.30) had the following language:
> +//
>  //     "It is an error to use #if or #elif on expressions containing
>  //     undefined macro names, other than as arguments to the
>  //     defined operator."
> +//
> +//     [Page 11 (17 of pdf) of the GLSL 1.30 spec]
> +//
> +// But GLSL 4.30 drops this, so that un undefined macro should be
> +// treated as 0 just as is standard for C preprocessors. Many
> +// implementations have been doing this already as it's what is
> +// standard for C preprocessors, so is expected by users.
>
>  #version 130
>
> diff --git a/tests/spec/glsl-1.30/preprocessor/if/if-arg-must-be-defined-02.frag b/tests/spec/glsl-1.30/preprocessor/if/if-arg-must-be-defined-02.frag
> index 520344a..0aef7de 100644
> --- a/tests/spec/glsl-1.30/preprocessor/if/if-arg-must-be-defined-02.frag
> +++ b/tests/spec/glsl-1.30/preprocessor/if/if-arg-must-be-defined-02.frag
> @@ -1,15 +1,23 @@
>  // [config]
> -// expect_result: fail
> +// expect_result: pass
>  // glsl_version: 1.30
>  // [end config]
>  //
> -// Check that the compiler raises an error when an undefined macro is used as
> +// Check that the compiler treats an undefined macro as 0 when used as
>  // an argument to the #elif directive.
>  //
> -// From page 11 (17 of pdf) of the GLSL 1.30 spec:
> +// Older GLSL specifications (such as GLSL 1.30) had the following language:
> +//
>  //     "It is an error to use #if or #elif on expressions containing
>  //     undefined macro names, other than as arguments to the
>  //     defined operator."
> +//
> +//     [Page 11 (17 of pdf) of the GLSL 1.30 spec]
> +//
> +// But GLSL 4.30 drops this, so that un undefined macro should be
> +// treated as 0 just as is standard for C preprocessors. Many
> +// implementations have been doing this already as it's what is
> +// standard for C preprocessors, so is expected by users.
>
>  #version 130
>
> @@ -19,6 +27,10 @@
>  #      define JUNK 1
>  #endif
>
> +#if defined JUNK
> +#error Undefined macro should be treated as 0.
> +#endif
> +
>  int f()
>  {
>         return 0;
> --
> 1.7.10.4
>
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Sounds reasonable to me.
Reviewed-by: Anuj Phogat <anuj.phogat at gmail.com>