[Buildroot] [PATCH v5 02/36] package/libevas-generic-loaders: move to package directory

[Yann E. MORIN <yann.morin.1998@free.fr>]

Romain, All,

On 2015-10-25 20:21 +0100, Romain Naour spake thusly:
> Le 25/10/2015 13:56, Yann E. MORIN a ?crit :
> > On 2015-10-24 23:00 +0200, Romain Naour spake thusly:
> >> As for expedite package, there is no advantage for efl related
> >> packages to share the same version number anymore
> >> (except for efl and libelementary).
> >>
> >> Also, we usually do not have a sub-directory for a family of related
> >> packages which doen't share the same version number, so move
> >> libevas-generic-loaders to package directory.
> >> Libevas-generic-loaders appear now in "Libraries" -> "Graphics" in
> >> the Kconfig menu.
> >>
> >> While at it, remove BR2_USE_WCHAR dependency since the efl package
> >> already depend on it.
> > 
> > Are you sure that libevas-generic-loaders does not itself depend on
> > wchar?
> > 
> > If it does, then please keep the dependency, even if it is automatically
> > inherited through the dependency on EFL. This is so, in case EFL loses
> > its dependency on wchar, libevas-generic-loaders would still have its
> > own.
> 
> libevas-generic-loaders doesn't use wchar by itself, it's a reverse dependency
> that come from librsvg which is required for svg support only.

OK, so if libevas-generic-loader does not need it, and does not have to
inherit it through one of its select, then dropping is OK.

> So, IIUC when a package A select a package B, we must propagate all reverse
> dependencies of the package B when the package A already depends on them
> implicitly (i.e when using a depends on BR2_PACKAGE_C).

I'm not sure I groked what you wrote, so here's a litle example. Say you
have a pacakge foo that needs bar and bar needs threads; here's how
you'd express it:

    config foo
        bool "foo"
        depends on threads # bar
        select bar

    config bar
        bool "bar"
        depends on threads

Now, if package foo also needs threads for itself, here's how you'd
express it:

    config foo
        bool "foo"
        depends on threads
        select bar

    config bar
        bool "bar"
        depends on threads

Note that the threads dependency in foo no longer has the '# bar'
comment.

> Also, in the libevas-generic-loaders bump I removed two other dependencies for
> the same reason (BR2_TOOLCHAIN_HAS_THREADS and BR2_INSTALL_LIBSTDCPP):
> http://lists.busybox.net/pipermail/buildroot/2015-October/142950.html

Hmm... I may have missed properly checkign that. If libevas-generic-loader
does not need threads or C++, then you can indeed drop them. However, if
it needs it, you must depend on them, even if you inherit them from the
EFL dependency.

Looking at the libevas-generic-loader code, it seems there is no need
for threads, so you can drop it.

As for C++, evas-generic-loader needs it: first, tis configure.ac has
AC_PROG_CXX, and it has one C++ file, src/pdf/main.cpp. So you have to
keep the dependency on C++.

Regards,
Yann E. MORIN.

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