[libcamera-devel] [PATCH 4/5] libcamera: Document private members

[Laurent Pinchart]

Hello,

On Friday, 4 January 2019 18:47:30 EET Niklas Söderlund wrote:
> On 2019-01-03 18:38:58 +0100, Jacopo Mondi wrote:
> > The newly added MediaDevice::setLink() function is defined as private,
> > but it is worth being documented, as it is called from the friend method
> > MediaLink::setup().
> > 
> > In the library code base, several private methods and fields are
> > documented, but do not show up in the generated documentation output.
> > Change doxygen settings to output processed documentation for the
> > private fields and methods, when proper doxygen comments are applied to
> > them (and do not complain if private members are not documented at all).
> 
> I would split this to a separate commit.

I would also move documentation of setLink() to patch 3/5.

> > Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> > ---
> > 
> >  Documentation/Doxyfile.in      |  4 ++--
> >  src/libcamera/media_device.cpp | 22 ++++++++++++++++++++++
> >  2 files changed, 24 insertions(+), 2 deletions(-)
> > 
> > diff --git a/Documentation/Doxyfile.in b/Documentation/Doxyfile.in
> > index b1a70d3..16dcccd 100644
> > --- a/Documentation/Doxyfile.in
> > +++ b/Documentation/Doxyfile.in
> > @@ -442,7 +442,7 @@ EXTRACT_ALL            = NO
> > 
> >  # be included in the documentation.
> >  # The default value is: NO.
> > 
> > -EXTRACT_PRIVATE        = NO
> > +EXTRACT_PRIVATE        = YES
> > 
> >  # If the EXTRACT_PACKAGE tag is set to YES, all members with package or
> >  internal # scope will be included in the documentation.
> > 
> > @@ -487,7 +487,7 @@ EXTRACT_ANON_NSPACES   = NO
> > 
> >  # section is generated. This option has no effect if EXTRACT_ALL is
> >  enabled. # The default value is: NO.
> > 
> > -HIDE_UNDOC_MEMBERS     = NO
> > +HIDE_UNDOC_MEMBERS     = YES

This will remove doxygen warnings for undocumented private members, which 
achieves what you were trying to doc, but it will also remove those warnings 
for public members, which is really bad.

> >  # If the HIDE_UNDOC_CLASSES tag is set to YES, doxygen will hide all
> >  # undocumented classes that are normally visible in the class hierarchy.
> >  If set> 
> > diff --git a/src/libcamera/media_device.cpp
> > b/src/libcamera/media_device.cpp index b86d0c4..48aa805 100644
> > --- a/src/libcamera/media_device.cpp
> > +++ b/src/libcamera/media_device.cpp
> > @@ -641,6 +641,28 @@ bool MediaDevice::populateLinks(const struct
> > media_v2_topology &topology)
> >  	return true;
> >  }
> > 
> > +/**
> > + * \brief Apply \a flags to a link between two pads
> > + * \param source The source pad
> > + * \param sink The sink pad
> > + * \param flags The link flags
> > + *
> > + * Implements 'raw' link handling, as this functions applies \a flags,
> > + * (whose only accepted values are the ones defined by the Media
> > Controller + * APIs in MEDIA_LNK_FL_* macros) to a link between two pads.
> > No correctness + * checks on the link existence and validity of \a flags
> > is performed. The + * function assumes the \a source and \a sink pads are
> > connected, and the + * supplied \a flags applies to the link (ie.
> > immutable links cannot be + * disabled).
> > + *
> > + * This function wraps the raw MEDIA_IOC_SETUP_LINK ioctl, and shouldn't
> > be + * called directly by any other class or method but the
> > + * MediaLink::setup(bool enable) one, declared as friend for this reason.
> 
> I don't love this, make setLink() public :-)

I think there's value in avoiding potential problems, so keeping setLink() 
private with a friend is fine with me, but we need to find a solution for the 
doxygen issue pointed out above. We would need a HIDE_UNDOC_PRIVATE_MEMBERS 
directive, which doesn't seem to be available :-( If we have to choose between 
not generating documentation for private members and dropping warnings for all 
undocumented members, the former is unfortunately the only viable option.

> > + *
> > + * \sa MediaLink::setup(bool enable)
> > + *
> > + * \return 0 for success, negative error number otherwise
> > + */
> >  int MediaDevice::setLink(const MediaPad *source, const MediaPad *sink,
> >  			 unsigned int flags)
> >  {

-- 
Regards,

Laurent Pinchart