Re: [PATCH iproute2] iproute: build more easily on Android

On Mon, Oct 2, 2017 at 10:36 AM, Stephen Hemminger
[off-list ref] wrote:

On Tue,  3 Oct 2017 02:03:37 +0900
Lorenzo Colitti [off-list ref] wrote:

quoted

iproute2 contains a bunch of kernel headers, including uapi ones.
Android's libc uses uapi headers almost directly, and uses a
script to fix kernel types that don't match what userspace
expects.

For example: https://issuetracker.google.com/36987220 reports
that our struct ip_mreq_source contains "__be32 imr_multiaddr"
rather than "struct in_addr imr_multiaddr". The script addresses
this by replacing the uapi struct definition with a #include
<bits/ip_mreq.h> which contains the traditional userspace
definition.

Unfortunately, when we compile iproute2, this definition
conflicts with the one in iproute2's linux/in.h.

Historically we've just solved this problem by running "git rm"
on all the iproute2 include/linux headers that break Android's
libc.  However, deleting the files in this way makes it harder to
keep up with upstream, because every upstream change to
an include file causes a merge conflict with the delete.

This patch fixes the problem by moving the iproute2 linux headers
from include/linux to include/uapi/linux.

Tested: compiles on ubuntu trusty (glibc)

Signed-off-by: Elliott Hughes <redacted>
Signed-off-by: Lorenzo Colitti <redacted>

Rather than moving everything, why not make kernel headers directory
configurable as part of the configure script setup process.

the problem is that C libraries with their our own uapi headers still
need your app-specific headers. to build iproute2 we need to put
iproute2's include/ on our include path, but then the fact that your
different uapi headers are *under* that directory causes the conflict.
separating your headers from your copy of the uapi headers is a
necessary part of any fix.

-- 
Elliott Hughes - http://who/enh - http://jessies.org/~enh/
Android native code/tools questions? Mail me/drop by/add me as a reviewer.