[OE-core] [PATCH 3/4] cross.bbclass: add virtclass handler

[Richard Purdie]

On Tue, 2012-02-07 at 21:09 +0000, Otavio Salvador wrote:
> Allow use of BBCLASSEXTEND with 'cross' and use of virtclass-cross in
> recipes.
> 
> Signed-off-by: Otavio Salvador <otavio at ossystems.com.br>
> ---
>  meta/classes/cross.bbclass |   39 +++++++++++++++++++++++++++++++++++++++
>  1 files changed, 39 insertions(+), 0 deletions(-)
> 
> diff --git a/meta/classes/cross.bbclass b/meta/classes/cross.bbclass
> index 5681ab9..a764902 100644
> --- a/meta/classes/cross.bbclass
> +++ b/meta/classes/cross.bbclass
> @@ -55,6 +55,45 @@ libexecdir = "${exec_prefix}/libexec/${CROSS_TARGET_SYS_DIR}"
>  
>  do_populate_sysroot[sstate-inputdirs] = "${SYSROOT_DESTDIR}/${STAGING_DIR_NATIVE}"
>  
> +python cross_virtclass_handler () {
> +    if not isinstance(e, bb.event.RecipePreFinalise):
> +        return
> +
> +    classextend = e.data.getVar('BBCLASSEXTEND', True) or ""
> +    if "cross" not in classextend:
> +        return
> +
> +    pn = e.data.getVar("PN", True)
> +    if not pn.endswith("-cross"):
> +        return
> +
> +    def map_dependencies(varname, d, suffix = ""):
> +        if suffix:
> +            varname = varname + "_" + suffix
> +        deps = d.getVar(varname, True)
> +        if not deps:
> +            return
> +        deps = bb.utils.explode_deps(deps)
> +        newdeps = []
> +        for dep in deps:
> +            if dep.endswith("-cross"):
> +                newdeps.append(dep)
> +            else:
> +                newdeps.append(dep + "-cross")
> +        bb.data.setVar(varname, " ".join(newdeps), d)
> +
> +    for pkg in (e.data.getVar("PACKAGES", True).split() + [""]):
> +        map_dependencies("RDEPENDS", e.data, pkg)
> +        map_dependencies("RRECOMMENDS", e.data, pkg)
> +        map_dependencies("RSUGGESTS", e.data, pkg)
> +        map_dependencies("RPROVIDES", e.data, pkg)
> +        map_dependencies("RREPLACES", e.data, pkg)

I want to highlight what this code does and I don't understand when it
would do something that makes sense. If for example we have a recipe
which:

RDEPENDS = "libc zlib"

it will now:

RDEPENDS = "lib-cross zlib-cross"

or a native recipe which had:

RDEPENDS = "pkgconfig-native"

will now:

RDEPENDS = "pkgconfig-native-cross"

Can you point me at the recipe you're using this in? I suspect we should
just remove the map_dependencies() pieces from this class entirely and
handle dependency issues with the override manually. I think at this
point all the BBCLASSEXTEND is going to give you is the removal of the
need to add a separate .bb file with "inherit cross" in it and enable an
override for your to use. I'm not sure we can write generic dependency
mapping code that would work for -cross.

Cheers,

Richard