Re: [Mesa3d-dev] Mesa: regression (with --enable-debug only!) caused by c76d4db25260dd68684bf784efacd7323c7cab8b

[Brian P. <bri...@gm...>]

On Sun, Feb 28, 2010 at 3:44 AM, Magnus Kessler <Mag...@gm...> wrote:
> Here's an interesting regression caused by Mesa commit
> c76d4db25260dd68684bf784efacd7323c7cab8b
> (http://cgit.freedesktop.org/mesa/mesa/commit/?id=c76d4db25260dd68684bf784efacd7323c7cab8b).
> It shows itself only when Mesa is configured with --enable-debug. In this case
> the i965_dri.so driver can't be loaded due to a missing symbol CLAMP:
>
> libGL error: dlopen /usr/lib64/dri/i965_dri.so failed
> (/usr/lib64/dri/i965_dri.so: undefined symbol: CLAMP)
>
> I tracked this down to the removal of the inclusion of "main/macros.h" in
> gen6_cc.c. In color_calc_state_create_from_key() (gen6_cc.c line 220), the
> macro UNCLAMPED_FLOAT_TO_UBYTE is used. This macro is defined in
> "main/imports.h". Unfortunately, for the debug case, this macro calls upon the
> CLAMP macro defined in "main/macros.h", which is no longer included into
> gen6_cc.so.
>
> My feeling is that the macro declaration in "main/imports.h" is at fault. This
> file is included into "main/macros.h", but clearly depends on a macro (CLAMP)
> in there, causing a circular dependency.
>
> To me it sounds like the best way to fix the root cause is to move the
> UNCLAMPED_FLOAT_TO_UBYTE macro to "main/macros.h" where it would sit next to
> other similar macros. gen6_cc.c as a user of this macro would then of course
> include "main/macros.h" again. The minimum fix is just to revert part of
> c76d4db25260dd68684bf784efacd7323c7cab8b for gen6_cc.c
>
> I hope this analysis is useful to you.

I think I'll just undo the change to gen6_cc.c for now.

-Brian