Re: [B2-devel] config problems

[<gb...@di...>]

Hi,

> - the "extern "C" void exit(int) throw();" lines in the configure test
>   programs were interfering with a "extern void exit(int);"
>   declaration in SGI's unistd.h.  Deleting the " throw()"s fixed it.
>   (Note:  when I run autoconf 2.13 directly, it doesn't have this
>   problem.)

Hmm, I don't know where does this throw() comes from but I recently
realized it was added in autoconf for some Linux distributions...

> - the extended signal handlers test program was failing.  Eventually I
>   tracked it down to SGI's C++ compiler:  it was optimizing out one of
>   the writes to the page[] array, and moving the read of
>   handler_called above the writes.  Here's a patch which fixed it.
>   Just declaring the variables volatile doesn't seem to do it; I had
>   to insert the system call to force synchronization:

What about the test for a sigcontext subterfuge ?
[According to what you have said, I expect it to fail too]

> There's probably a cleaner way to do this... but it works.  I probably
> didn't see this problem before since I always ran configure with my
> local machine's environment instead of the official SGI freeware build
> environment, which may have changed the level of optimization used
> while configuring.

Thanks, your SGI compiler is definitely a really good optimizing
compiler. ;-)

I think we have to come up with a subterfuge to fool the compiler's data
flow analyzer. Something like a fake use after each write.

Brian, is your compiler still optimizing enough to inline a function
defined after its call is issued ? Let's have for example:

static void foo(int *);

int main() {
  int some_int;
  foo(&some_int);
}

void foo(int *) {
  printf("foo\n");
}

Is foo() inlined into the main() function ?

Thanks,
Gwenol=E9.