botan: add Python dependency and universal variant

[macports@…]

botan's configure script is written in Python, so we need an explicit build dependency. On IRC, jmr_mp and neverpanic both suggested adding a hard-coded dependency on python27 instead of a set of variants for different possible Python versions.

Moreover, since qt4-creator-mac +universal requires botan +universal, here's an attempt to enable a universal variant for botan.

[macports@…]

This patch should fix #39451.

[MarcusCalhoun-Lopez (Marcus Calhoun-Lopez)]

I do not know much about how botan works, but wouldn't disabling optimizations slow it down?

    configure.args-append --disable-asm --enable-modules=mp_generic \
                          --disable-modules=mp_x86_32,mp_x86_64,rdrand

The muniversal PortGroup was designed for just this problem.
Attached is another possible solution.

[MarcusCalhoun-Lopez (Marcus Calhoun-Lopez)]

Cc Me!

[macports@…]

Your patch looks good. Disabling inline assembly is not necessary after all. I had stumbled over some suspicious-looking compiler warnings related to inline assembly ("variable 'r' is uninitialized when used here"). However, the resulting machine code is indeed correct, so the warnings can be safely ignored.

I've updated my patch to include your changes.

[ryandesign (Ryan Carsten Schmidt)]

Instead of repeated if statements, a ​switch statement would be shorter. Even shorter would be just referencing the merger_configure_args array that you're defining anyway. See the openssl port for an example of how to do this.

[macports@…]

Thanks for the tips! I updated the patch accordingly.

[macports@…]

*bump*

[macports@…]

Updated patch v3

[macports@…]

New patch against current Portfile for version 1.10.6 attached.

[neverpanic (Clemens Lang)]

Oh wow, that took us a while. Anyway, in r125904 and thanks for the patch.