[PATCH v5 12/18] libcamera: Consolidate tracepoint header in libcamera_internal_headers

[Laurent Pinchart]

On Wed, Aug 07, 2024 at 12:19:17PM +0100, Kieran Bingham wrote:
> Quoting Laurent Pinchart (2024-08-05 15:36:48)
> > The libcamera_tracepoint_header variable stores the tracepoints.h header
> > custom target, for the sole purpose of being listed as a source of the
> > libcamera shared library, through the libcamera_internal_sources
> > variable.
> > 
> > Add the tracepoints.h header to libcamera_internal_headers instead of
> > libcamera_internal_sources, and list libcamera_internal_headers as a
> > source of the shared library, alongside libcamera_internal_sources. This
> > makes libcamera_internal_sources contain sources only, improving clarity
> > of the build system variables.
> > 
> > Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > ---
> >  include/libcamera/internal/meson.build | 16 +++++++++-------
> >  src/libcamera/meson.build              |  2 +-
> >  2 files changed, 10 insertions(+), 8 deletions(-)
> > 
> > diff --git a/include/libcamera/internal/meson.build b/include/libcamera/internal/meson.build
> > index f96cc5e37c23..39230facc8a4 100644
> > --- a/include/libcamera/internal/meson.build
> > +++ b/include/libcamera/internal/meson.build
> > @@ -2,13 +2,6 @@
> >  
> >  subdir('tracepoints')
> >  
> > -libcamera_tracepoint_header = custom_target(
> > -    'tp_header',
> > -    input : ['tracepoints.h.in', tracepoint_files],
> > -    output : 'tracepoints.h',
> > -    command : [gen_tracepoints_header, include_build_dir, '@OUTPUT@', '@INPUT@'],
> > -)
> > -
> >  libcamera_internal_headers = files([
> >      'bayer_format.h',
> >      'byte_stream_buffer.h',
> > @@ -51,5 +44,14 @@ libcamera_internal_headers = files([
> >      'yaml_parser.h',
> >  ])
> >  
> > +tracepoints_h = custom_target(
> > +    'tp_header',
> > +    input : ['tracepoints.h.in', tracepoint_files],
> > +    output : 'tracepoints.h',
> > +    command : [gen_tracepoints_header, include_build_dir, '@OUTPUT@', '@INPUT@'],
> > +)
> > +
> > +libcamera_internal_headers += tracepoints_h
> > +
> >  subdir('converter')
> >  subdir('software_isp')
> > diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
> > index 86e8b88cc1b2..6a7c9d77dfd8 100644
> > --- a/src/libcamera/meson.build
> > +++ b/src/libcamera/meson.build
> > @@ -55,7 +55,6 @@ libcamera_internal_sources = files([
> >  ])
> >  
> >  libcamera_public_sources += libcamera_public_headers
> > -libcamera_internal_sources += libcamera_tracepoint_header
> >  
> >  includes = [
> >      libcamera_includes,
> > @@ -196,6 +195,7 @@ libcamera = shared_library('libcamera',
> >                             [
> >                                 libcamera_public_sources,
> >                                 libcamera_ipa_headers,
> > +                               libcamera_internal_headers,
> 
> I think this brings in a set of the headers as dependencies now (a good
> thing). I wonder if this is where we had that 'breakage requiring a full
> clean rebuild' around v0.2.0 or v0.1.0 or such.

I don't think it will make a difference in practice. Meson handles
dependencies on static header automatically. If a static header changes,
the source files that include it (directly or indirectly) will be
recompiled, and so libcamera will be relinked. Adding the static headers
to the sources here shouldn't change anything.

The problems we encountered a while ago were due to missing dependencies
on generated files if I recall correctly.

> Anyway, it looks like a good thing to me.
> 
> Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> 
> >                                 libcamera_internal_sources,
> >                             ],
> >                             version : libcamera_version,

-- 
Regards,

Laurent Pinchart