added CACAO to IcedTea's build system

[Mark Wielaard]

Hi Christian,

On Thu, 2008-06-26 at 15:19 +0200, Christian Thalinger wrote:
> I finally integrated building CACAO to the IcedTea build system.  So,
> when you're now using --with-cacao, it downloads the latest release
> (0.99.1), builds it and the resulting libjvm.so is then used via
> ALT_HOTSPOT_IMPORT_PATH.

Awesome! This is really big!

You forgot to add the ChangeLog entry to the ChangeLog file. I have
added it for you:

2008-06-26 Christian Thalinger  <twisti at complang.tuwien.ac.at>

    * Makefile.am (stamps/cacao.stamp): Depend on stamps/extract.stamp.
    * Makefile.in: Regenerated.

2008-06-26 Christian Thalinger  <twisti at complang.tuwien.ac.at>

    * .hgignore: Added cacao.
    * Makefile.am (CACAO_VERSION, CACAO_MD5SUM, CACAO_URL, CACAO_SRC_ZIP):
    New variables.
    (distclean-local): Removed cacao directory.
    [WITH_CACAO] (ICEDTEA_ENV, ICEDTEA_ENV_ECJ): Use WITH_CACAO instead of
    CACAO.
    (stamps/download.stamp) [WITH_CACAO && !USE_SYSTEM_CACAO]: Download
    CACAO tarball.
    (clean-download): Removed CACAO tarball.
    (stamps/extract.stamp) [WITH_CACAO && !USE_SYSTEM_CACAO]: Extract
    CACAO tarball.
    (stamps/cacao.stamp): New target.
    (cacao): Likewise.
    * Makefile.in: Regenerated.
    * acinclude.m4 (AC_CHECK_WITH_CACAO): Renamed CACAO to WITH_CACAO.
    (AC_CHECK_WITH_CACAO_HOME): New function.
    (AC_CHECK_WITH_CACAO_SRC_ZIP): Likewise.
    * aclocal.m4: Regenerated.
    * configure: Likewise.
    * configure.ac (AC_CHECK_WITH_CACAO_HOME): Added.
    (AC_CHECK_WITH_CACAO_SRC_ZIP): Likewise.

I also added two dependencies. The icedtea-ecj target, which you use for
a completely clean bootstrap, needs cacao already build. cacao itself
needs the rt-classes available before it is build.

2008-06-29  Mark Wielaard  <mark at klomp.org>

    * Makefile.am (stamps/icedtea-ecj.stamp): Add dependency on
    stamps/cacao.stamp.
    (stamps/cacao.stamp): Add dependency on stamps/rt-class-files.stamp.
    * Makefile.in: Regenerated.

Finally on some GNU/Linux systems you will get:
LOG: [0xb80586c0] system_mmap_anonymous: mmap failed: Permission denied
somewhere in the middle of the build when the cacao is actually used for
the first time in the bootstrap build.

This seems to be caused by cacao trying to mmap a page at address zero.
Something that isn't allowed on some systems. A workaround is to do as
root: echo 0 > /proc/sys/vm/mmap_min_addr
Then things do work, but it would be nice if cacao didn't do this on
systems that don't allow it.

It seems you do this to catch null pointer dereferences. But on systems
that don't allow mmapping on address zero in the first place, you will
get a segv always anyway for such accesses.

Cheers,

Mark

P.S. Anybody know how we can now finally get rid of that extra
branch/head in the mercurial tree called cacao-b19. If we only have one
head then things like the fetch extension would work out of the box.