[v2] libcamera: egl: Don't redefine EGL_NO_X11

28452 diff mbox series

Mesa built without the X11 platform exports -DEGL_NO_X11 via egl.pc
Cflags, from mesa!2226 (19.3) until mesa!18848 (22.3) moved Xlib
inclusion behind USE_X11. This affects non-glvnd builds, where egl.pc
comes from Mesa rather than libglvnd, e.g. the PowerVR mesa-pvr (22.1)
used on StarFive JH7110.

The -D defines the macro as 1, so the unconditional empty define in
egl.h is a redefinition, which is an error with -Werror:

  include/libcamera/internal/egl.h:23:9: error: 'EGL_NO_X11' redefined [-Werror]

The define is still needed for EGL headers predating
KhronosGroup/EGL-Registry#130, which otherwise pull in Xlib.h, so only
define it when it isn't already set.

Signed-off-by: Joel Winarske <joel.winarske@linux.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
---
Changes in v2:
- Expand commit message: Mesa versions/MRs, non-glvnd, why the define is kept
- Collect Reviewed-by tags

 include/libcamera/internal/egl.h | 2 ++
 1 file changed, 2 insertions(+)

On Wed, Oct 14, 2026 at 09:48:59AM -0700, Joel Winarske wrote:
> Mesa built without the X11 platform exports -DEGL_NO_X11 via egl.pc
> Cflags, from mesa!2226 (19.3) until mesa!18848 (22.3) moved Xlib

Merge request numbers are not a good way to identify versions, they're
not available in the git history. You could use the commit ID, but let's
just drop that as you have tags: "from 19.3 until 22.3".

> inclusion behind USE_X11. This affects non-glvnd builds, where egl.pc
> comes from Mesa rather than libglvnd, e.g. the PowerVR mesa-pvr (22.1)
> used on StarFive JH7110.
> 
> The -D defines the macro as 1, so the unconditional empty define in
> egl.h is a redefinition, which is an error with -Werror:

Where do you see it defined as 1 ?

>   include/libcamera/internal/egl.h:23:9: error: 'EGL_NO_X11' redefined [-Werror]
> 
> The define is still needed for EGL headers predating
> KhronosGroup/EGL-Registry#130, which otherwise pull in Xlib.h, so only
> define it when it isn't already set.
> 
> Signed-off-by: Joel Winarske <joel.winarske@linux.com>
> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
> Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
> ---
> Changes in v2:
> - Expand commit message: Mesa versions/MRs, non-glvnd, why the define is kept
> - Collect Reviewed-by tags
> 
>  include/libcamera/internal/egl.h | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/include/libcamera/internal/egl.h b/include/libcamera/internal/egl.h
> index 7d062b32d..9d2c9b5bc 100644
> --- a/include/libcamera/internal/egl.h
> +++ b/include/libcamera/internal/egl.h
> @@ -21,7 +21,9 @@
>   * Workaround for build issues on Mesa <= 22.2, see
>   * https://github.com/KhronosGroup/EGL-Registry/pull/130
>   */
> +#ifndef EGL_NO_X11
>  #define EGL_NO_X11
> +#endif
>  
>  #define EGL_EGLEXT_PROTOTYPES
>  #include <EGL/egl.h>

> Merge request numbers are not a good way to identify versions, they're
> not available in the git history. You could use the commit ID, but let's
> just drop that as you have tags: "from 19.3 until 22.3".

Copy that

> Where do you see it defined as 1 ?

-D without a value defines it as 1, per the GCC docs: "-D name: Predefine
name as a macro, with definition 1." The redefinition warning comes from
the empty #define not matching that. An identical redefinition is silent:

  $ printf '#define EGL_NO_X11\n' > a.c; gcc -DEGL_NO_X11 -Werror -c a.c
  a.c:1:9: error: 'EGL_NO_X11' redefined [-Werror]
  $ printf '#define EGL_NO_X11 1\n' > b.c; gcc -DEGL_NO_X11 -Werror -c b.c
  $

On Wed, Oct 14, 2026 at 11:45 AM Laurent Pinchart <
laurent.pinchart@ideasonboard.com> wrote:

> On Wed, Oct 14, 2026 at 09:48:59AM -0700, Joel Winarske wrote:
> > Mesa built without the X11 platform exports -DEGL_NO_X11 via egl.pc
> > Cflags, from mesa!2226 (19.3) until mesa!18848 (22.3) moved Xlib
>
> Merge request numbers are not a good way to identify versions, they're
> not available in the git history. You could use the commit ID, but let's
> just drop that as you have tags: "from 19.3 until 22.3".
>
> > inclusion behind USE_X11. This affects non-glvnd builds, where egl.pc
> > comes from Mesa rather than libglvnd, e.g. the PowerVR mesa-pvr (22.1)
> > used on StarFive JH7110.
> >
> > The -D defines the macro as 1, so the unconditional empty define in
> > egl.h is a redefinition, which is an error with -Werror:
>
> Where do you see it defined as 1 ?
>
> >   include/libcamera/internal/egl.h:23:9: error: 'EGL_NO_X11' redefined
> [-Werror]
> >
> > The define is still needed for EGL headers predating
> > KhronosGroup/EGL-Registry#130, which otherwise pull in Xlib.h, so only
> > define it when it isn't already set.
> >
> > Signed-off-by: Joel Winarske <joel.winarske@linux.com>
> > Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
> > Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
> > ---
> > Changes in v2:
> > - Expand commit message: Mesa versions/MRs, non-glvnd, why the define is
> kept
> > - Collect Reviewed-by tags
> >
> >  include/libcamera/internal/egl.h | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/include/libcamera/internal/egl.h
> b/include/libcamera/internal/egl.h
> > index 7d062b32d..9d2c9b5bc 100644
> > --- a/include/libcamera/internal/egl.h
> > +++ b/include/libcamera/internal/egl.h
> > @@ -21,7 +21,9 @@
> >   * Workaround for build issues on Mesa <= 22.2, see
> >   * https://github.com/KhronosGroup/EGL-Registry/pull/130
> >   */
> > +#ifndef EGL_NO_X11
> >  #define EGL_NO_X11
> > +#endif
> >
> >  #define EGL_EGLEXT_PROTOTYPES
> >  #include <EGL/egl.h>
>
> --
> Regards,
>
> Laurent Pinchart
>