Re: cross-compiling textproc/icu

[Brook Milligan <brook%nmsu.edu@localhost>]

> On Sep 21, 2023, at 11:08 AM, Taylor R Campbell <campbell+netbsd-tech-pkg%mumble.net@localhost> wrote:
> 
>> Date: Thu, 14 Sep 2023 14:42:33 -0600
>> From: Brook Milligan <brook%nmsu.edu@localhost>
>> 
>> To cross-compile, textproc/icu must be configured with
>> —with-cross-build= pointing to a pre-compiled native version
>> of the icu source tree.  Thus, two compilations are required: (i) a
>> native build and (ii) a cross build.
> 
> I haven't tried cross-building textproc/icu before, it seems.  Does
> the installation prefix have enough for the cross-build, or is it
> necessary to actually use a native build's work directory?

Yes, it really requires the built work directory.  Specifically, ${WRKSRC}/source.  In the case of cross-builds, there are configure checks for a *.mk file there.

>> Should the cross build extract twice and build twice?
> 
> If icu really requires the native build's work directory, then I'm
> afraid we might have to do something like that.
> 
> (I'll take a closer look when I have some time.)

All comments I can find on the web indicate that building twice is necessary.  I have succeeded in cross-building boost-libs (which depends on icu) by first building  icu natively and storing the ${WRKSRC}/source directory somewhere, cleaning it, and then cross-building boost-libs, which cross-builds icu.  All that is needed for the latter is the —with-cross-build= pointing to the native icu stuff, which is easy to make happen with a make conditional dependent on USE_CROSS_COMPILER (see below).

However, I have not yet figured out how to make a build of icu with USE_CROSS_COMPILER=yes build itself twice.  For example, my naive try adding the following to the icu/Makefile does not work:

.if !empty(USE_CROSS_COMPILE:M[yY][eE][sS])
CONFIGURE_ARGS+=        --with-cross-build=/tmp/icu_source-native
.endif

.if !empty(USE_CROSS_COMPILE:M[yY][eE][sS])
pre-extract:
        ${MAKE} ${BUILD_TARGET} USE_CROSS_COMPILE=no
        ${MV} ${WRKSRC}/source ${WRKDIR}/icu_source-native
        ${MAKE} clean
.endif

Please suggest ways to build a package twice, once each with two different sets of CONFIGURE_ARGS.

Thanks a lot.

Cheers,
Brook