Re: cross compiling libgcj for powerpc-linux?

[Jeff Sturm <jeff dot sturm at appnet dot com>]

Mathias Kiss wrote:
> But we didn't succeed in building the libgcj-2.95.1 using our cross-compiler
> for powerpc. Our questions are now:

I don't think libgcj can be cross-compiled without modifications.  The last time
I attempted it failed while configuring libffi.

Currently libffi/configure.in uses AC_CHECK_SIZEOF, which requires a native
test.  If you hack configure.in, pasting in the correct values for your target,
the rest might work.

> -Which options are needed (--target=... / --host=.. )?

You need to specify at least --target for cross compilation.  See the online
docs for more info:

http://gcc.gnu.org/onlinedocs/gcc_3.html#SEC56

> - Should we run 'make all' or 'make bootstrap'? What does 'make bootstrap'
> do?

'make bootstrap' tests the compiler by rebuilding with itself.  (You cannot
bootstrap a cross compiler.)

> powerpc-8xx-linux-gcc -DLINUX_THREADS=1 -D_REENTRANT=1 -DSILENT=1
> -DNO_SIGNALS=1
> -DNO_DEBUGGING=1 -DJAVA_FINALIZATION=1 -I.
> -I/cross/src/libgcj-2.95.1/boehm-gc
> -I././targ-include -I/cross/src/libgcj-2.95.1/boehm-gc/./libc/include
> -fno-built
> in -g -O2 -c /cross/src/libgcj-2.95.1/boehm-gc/allchblk.c -o allchblk.o
> In file included from /cross/src/libgcj-2.95.1/boehm-gc/allchblk.c:20:
> /cross/src/libgcj-2.95.1/boehm-gc/gc_priv.h:469: parse error before `--'
> make[1]: *** [allchblk.lo] Error 1
> make[1]: Leaving directory
> `/cross/powerpc/libgcj/powerpc-8xx-linux/boehm-gc'
> make: *** [all-target-boehm-gc] Error 2

You'll have to look at gc_priv.h for more clues.  (Chances are there is an
informative message on line 469, the `--' token is a common technique to force
an error.)

I don't have libgcj-2.95.1 on disk anymore, but IIRC the old boehm-gc did not
have a test_and_set for PPC Linux.  If that is the error, you can either build
without threads or get a newer gcj/libgcj.

--
Jeff Sturm
jeff.sturm@commerceone.com