Re: libtool and gcj

[Per Bothner]

Anthony Green wrote:
> The other bad thing I should mention is the test to see if gcj can use
> both -c and -o.  This test is failing for some unknown reason, causing
> bad problems for my project.   I don't think libtool should even perform
> this test.  gcj is known to always handle -c and -o.

The reason it is failing is because to compile the test program it
uses the value of teh valraivle ac_compile, which is $CC -c $CFLAGS
$CPPFLAGS conftest.$ac_ext', and where CC=gcj CFLAGS="-g -O2"
CPPFLAGS="".  Notice there is no -o option.  However, just above,
GCJFLAGS is set to include the needed -o flag.  So the problem
is that ac_compile has the wrong value.  In comparison, when we
see if g++ supports -c -o, ac_compile has the value:
'$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext'.

The actula bug is presumably in the definition of 
AC_LIBTOOL_LANG_GCJ_CONFIG in libtool.m4.  The corresponding
AC_LIBTOOL_LANG_CXX_CONFIG uses the same AC_LIBTOOL_PROG_CC_C_O($1),
but the preamble of AC_LIBTOOL_LANG_CXX_CONFIG is substantially
different from AC_LIBTOOL_LANG_GCJ_CONFIG.  Specifically, the
former sets ac_compile in the comamnds generated by:
AC_LANG_PUSH(C++)

Unfortuntely, autoconf 2.52 does not define 'Java' as a language.
But that can probably be worked around.

More later.
--
        --Per Bothner
address@hidden   http://www.bothner.com/per/