Re: 2.0.11 on OS X 10.9 / Xcode 5.1

[Taylan Ulrich Bayirli/Kammer <taylanbayirli@gmail.com>]

Mark H Weaver <mhw@netris.org> writes:

> What does (sin -0.0) evaluate to?
>
> My first guess is that at the C level, sin(-0.0) => 0.0 on your system,
> although IEEE 754 and C11 (F.10.1.6) specify that sin(-0.0) => -0.0.
>
> If my guess is incorrect, then please put a breakpoint in
> 'scm_c_make_polar' and see what's going wrong.  Both 'ang' and 's'
> should be -0.0, and then it should pass -0.0 as the second argument to
> 'scm_c_make_rectangular'.
>
>     Thanks,
>       Mark

Update:

(As mentioned on IRC, (sin -0.0) evaluates to -0.0, also via sin() on
the C level in a minimal test-case compiled with the same compiler.
However...)

While trying to get the MacPorts-provided GCC 4.8 to build Guile with
debugging symbols (and not succeeding), I noticed that adding -g or
-ggdb to CFLAGS hides the issue, making #i1@-0 => 1.0-0.0i.  It seems to
be enough to recompile numbers.c (I touch it and re-run make with or
without CFLAGS+="-g").

Interestingly even with -g or -ggdb the ".debug_info" of the installed
guile executable is empty as per dwarfdump(1).  I wonder if, by the time
I actually manage to build with debug symbols, I'll be able to reproduce
the bug.

I wonder if I should concentrate on getting Guile to build with the
native compiler of OS X 10.9 / Xcode 5.1 instead (clang).  I don't have
too much time for Guile at work anyway, and otherwise no OS X system.

Taylan