Eric Sunshine a dit:
> On Sun, 28 Sep 2003 11:58:54 +0200 (CEST), Akim Demaille wrote:
>> Could you make the test case smaller? Are you sure all the tests were
>> run with the modified m4?
>
> I was able to narrow down the "failed with exit status: 139" error to the
> following tiny case:
>
> AC_INIT([crystal], [1], [someone])
> AC_ARG_ENABLE([cpu-specific-optimizations],
> [AC_HELP_STRING([--enable-cpu-specific-optimizations=level],
> [enable CPU-specific optimizations; recognized levels are no,
> minimum or min, maximum or max default MINIMUM; the minimum
> one processor will not work with earlier processors for example, Intel
> 686-specific code will not work with a 586])],
> [], [])
> AC_OUTPUT
I managed to make it even smaller, and I can now explain why the behavior
depends upon the arch. Running the following:
m4 <<\EOF
changequote([, ])
format([ %-23s ],
[[--enable-cpu-specific-optimizations=level],[enable CPU-specific
optimizations; recognized levels are no,
minimum or min, maximum or max default MINIMUM; the minimum
one processor will not work with earlier processors for example,
Intel
686-specific code will not work with a 586]])
EOF
gives a SEGV on Darwin, while on Debian GNU/Linux, I have the expected
output. But the implementation of format depends upon the arch: there
are two available. One when #ifdef HAVE_EFGCVT (my case), and the other
if not.
I'm not fond of fixing this issue which is addressed in newer M4. But
at least we learned a lot about this issue, and we can document it.
Anyway, people are very unlikely to find it again, now that AC_HELP_STRING
is fixed.
Thanks a lot!
