ia64 eh, part 5

[Alexandre Oliva]

On Mar 28, 2001, Richard Henderson <rth@redhat.com> wrote:

> ! cs-tconfig.h: Makefile $(GCONFIG_H) insn-flags.h except.h
>   	HEADERS="$(xm_file)" DEFINES="$(xm_defines)" \
>   	TARGET_CPU_DEFAULT="" \
>   	$(SHELL) $(srcdir)/mkconfig.sh tconfig.h
> + # ??? Need extra help to get this definition copied to where libgcc can
> + # see it.  It shouldn't matter which compiler we use to get there.
> + 	echo '#include "config.h"' > conftest.c
> + 	echo '#include "except.h"' >> conftest.c
> + 	echo 'xyzzy USING_SJLJ_EXCEPTIONS' >> conftest.c
> + 	$(HOST_CC) -E conftest.c $(HOST_CFLAGS) $(INCLUDES) > conftest.out
> + 	sed -e 's/xyzzy/#define USING_SJLJ_EXCEPTIONS/' -e '/#define/p' \
> + 		-e d conftest.out >> tconfig.h
> + 	rm conftest.*

I'd rather see this test moved into mkconfig.sh.  We might even use
autoconf (2.50)'s AC_PLAIN_SCRIPT to be able to use AC_TRY_CPP.
Probably not worth the effort, though.

In any case, it's generally preferred to grep the output of the
preprocessor than to sed its output.  Probably just tradition, since
they're pretty much equivalent.

An autoconf test in mkconfig.sh would probably expand to something
like this:

cat > conftest.c << EOF
#include "config.h"
#include "except.h"

#if USING_SJLJ_EXCEPTIONS
use sjlj exceptions
#endif

if ${CC} $(CPPFLAGS) -E conftest.c | grep "use sjlj exceptions"; then
  echo '#define USING_SJLJ_EXCEPTIONS 1' >> $output.T
fi

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer                  aoliva@{cygnus.com, redhat.com}
CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist    *Please* write to mailing lists, not to me