This slackbuild provides a convenient way to install the BlocksRuntime
library from the compiler-rt project (see http://compiler-rt.llvm.org/).
Several systems (Linux, FreeBSD, MacPorts, etc.) provide the clang
compiler either preinstalled or as an available package which has
Blocks support (provided the -fblocks compiler option is used).
Unfortunately, those installer packages do not provide the Blocks
runtime library, since this is a non-standard extension by Apple to
Clang.
This SBo is inspired by the work of:
https://github.com/mackyle/blocksruntime/
edf41f9650