[OE-core] bug 1169 eglibc doesn't depend on gcc version correctly

[Robert Yang]

Hi experts,

There is a bug 1169: eglibc doesn't depend on gcc version correctly,

The produce steps are:

1) In the first build dir(e.g, build_1), edit conf/local.conf:
    SSTATE_DIR = /path/to/share_sstate

    $ bitbake meta-toolchain

2) In the second build dir(e.g, build_2), edit local.conf:
    SSTATE_DIR = /path/to/share_sstate
    SDKGCCVERSION="4.5.1"
    GCCVERSION="4.5.1"

    $ bitbake meta-toolchain

Then we will notice the error:
| error: Failed dependencies:
|       libgcc1 >= 4.6.0 is needed by eglibc-utils-2.13-r1+svnr14157.armv5te

The reason is a little complicated:
As we can see that eglibc's RDPENDS should have 'libgcc', but eglibc's
DEPENDS(not RDEPENDS) can't have libgcc, otherwise there would be loop
dependencies(since libgcc already DEPENDS on eglibc), this causes
eglibc.do_package can't detect that the version of libgcc or gcc
has been changed from 4.6 to 4.5.1, so it would mirror the
sstate-eglibc-xxx_package.tgz(which is stored by gcc 4.6) from the
SSTATE_DIR, and then it would do_package_write_rpm from the data
of sstate-eglibc-xxx_package.tgz, but the objdump can find that the
binary file depends on the special version of libgcc, and it would
write the data( libgcc1 >= 4.6.0) to eglibc.spec, but the current
version of libgcc is 4.5.1, so there would be dependencies error when
do_rootfs.

I don't know how to fix this, maybe we should not mirror the tarball of
sstate-xxx_package.tgz(which is mirrored according to the DEPENDS) from the
SSTATE_DIR, but only mirror the tarball of sstate-xxx_deploy-rpm.tgz(which
is mirrored according to the RDEPENDS, the RDEPENDS is what the binary
rpm package really cares), the similar to ipk and deb.

-- 
Thanks

Robert