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Re: Wrong configure test for PCH ?
On Tue, Sep 30, 2003 at 08:50:37AM -0500, Benjamin Kosnik wrote:
>
> >AC_DEFUN(GLIBCXX_ENABLE_PCH, [
> >...
> >
> > echo '#include <math.h>' > conftest.h
> > if $CXX $CXXFLAGS $CPPFLAGS -x c++-header conftest.h \
> > -o conftest.h.gch 1>&5 2>&1 &&
> >...
> >
> >I think there is a '-c' missing there.
>
> No, not with -x c++-header.
>
> %/mnt/hd/bld/gcc/gcc/xgcc -B/mnt/hd/bld/gcc/gcc/ -B/mnt/hd/bld/H-x86-gcc/i686-pc-linux-gnu/bin/ -B/mnt/hd/bld/H-x86-gcc/i686-pc-linux-gnu/lib/ -x c++ config.h -o config.h.gch
> /usr/lib/crt1.o(.text+0x18): In function `_start':
> : undefined reference to `main'
> collect2: ld returned 1 exit status
>
>
> %/mnt/hd/bld/gcc/gcc/xgcc -B/mnt/hd/bld/gcc/gcc/ -B/mnt/hd/bld/H-x86-gcc/i686-pc-linux-gnu/bin/ -B/mnt/hd/bld/H-x86-gcc/i686-pc-linux-gnu/lib/ -x c++-header config.h -o config.h.gch
>
>
> This configure test is correct.
Then why do I get:
$ cat conftest.h
#include <math.h>
$ g++-cvs-3.4 -g -fno-exceptions -pipe -x c++-header conftest.h -o conftest.h.gch
/usr/lib/crt1.o(.text+0x18): In function `_start':
../sysdeps/i386/elf/start.S:77: undefined reference to `main'
collect2: ld returned 1 exit status
Adding a '-c' makes it work.
--
Carlo Wood <carlo@alinoe.com>