libffi

Prepare

• autoreconf breaks build

Configure

• --disable-builddir prevents the build from running in a subdirectory
• Static exec trampolines are enabled by default since 3.4.2 and --disable-exec-static-tramp violates “Write XOR Execute (W^X)”, though it might be needed for ghc and gobject-introspection
• --disable-multi-os-directory on glaucus because multilib is disabled, and libffi is not being cross-compiled (also used on Arch, Void and OpenWRT for optimization, while Alpine uses --enable-portable-binary for portability as it disables optimizations)
• --enable-pax_emutramp is experimental and it requires pax kernel
• --enable-purify-safety is for debugging with purify

References

• https://github.com/libffi/libffi/pull/647