castxml: add variants for different versions of clang toolchain, use corresponding toolchain for compilation

[mamoll (Mark Moll)]

castxml needs to be compiled with clang 3.6 or higher. It also needs the full install of llvm that MacPorts provides (Xcode is not complete enough). The attached patch fixes compilation problems on older OSs and adds the option to use clang-3.7.

[stromnov (Andrey Stromnov)]

AFAIK, CastXML can be compiled with any compatible compiler (GCC/XCode Clang/Clang), but must be linked with full stack LLVM/Clang (we have only two compatible versions in macports tree: 3.6 and 3.7).

LLVM/Clang in MacPorts generally compiled via XCode, so, as far as I understant, it is far more safe (in terms of ABI) to compile CastXML using the same compiler toolchain.

[mamoll (Mark Moll)]

You mean the same compiler as was used to compile LLVM/Clang? CastXML requires a C++11 compiler. It is probably a good idea to "inherit" the compiler blacklist from clang 3.6/3.7 to avoid build problems like these: ​https://build.macports.org/builders/buildports-mtln-x86_64/builds/24158.

[ryandesign (Ryan Carsten Schmidt)]

Replying to mmoll@…:

CastXML requires a C++11 compiler. It is probably a good idea to "inherit" the compiler blacklist from clang 3.6/3.7

Then this port should use the cxx11-1.0 portgroup, and not set the blacklist manually.

[mamoll (Mark Moll)]

This was fixed a long time ago.