Re: [PATCH] Throw an exception when mutating read-only data

[Andy Wingo]

Hi :)

On Sun 02 Apr 2017 17:34, Derek Upham <address@hidden> writes:

> Andy Wingo <address@hidden> writes:
>
>> * libguile/init.c (scm_i_init_guile): Install the SIGSEGV handler unless
>>   GUILE_INSTALL_SIGSEGV_HANDLER is 0.
>> * libguile/loader.c
>>   (scm_maybe_throw_exception_for_mutation_of_read_only_data): New public
>>   function.
>>   (sigsegv_handler): New helper.
>>   (scm_install_sigsegv_handler): New public function.
>> * libguile/loader.h: Declare new API.
>
> That doesn’t support systems without HAVE_SIGACTION.  Do we assume
> HAVE_SIGACTION for all systems these days?

I think we use Gnulib to ensure that sigaction is available, at least as
a wrapper.  On the other hand apparently that doesn't ensure that
SA_SIGINFO is available on mingw :/  Too bad.

If we find a way to make this work reliably on POSIX I guess we could
have it work there but not yet on mingw.

> The handler setup code is outside of scmsig.c, so there will be
> conflicts with the save/restore mechanisms.  For example,
> scm_restore_signals won’t re-establish that handler.

Good point!  It seems this patch is but half-baked :)

Andy