Compiler blacklist 'shorthand'

[Rainer Müller]

On 2018-05-06 12:07, Ryan Schmidt wrote:
> 
> On May 5, 2018, at 19:36, Craig Treleaven wrote:
> 
>> A couple of times recently, I’ve noticed boilerplate in ports that require C++14.  After including the compiler_blacklist_versions portgroup, they then do some gymnastics like:
>>
>> compiler.blacklist          *gcc-3.* *gcc-4.* {*gcc-5.[0-3]} \
>>                            {clang < 800} macports-clang-3.4 macports-clang-3.5 macports-clang-3.6 macports-clang-3.7
>>
>> Would it not be easier to use and maintain if we had some shorthand definitions.  Maybe something like:
>>
>> compiler.blacklist      ${min_cxx14}
>>
>> “min_cxx14” would be defined in the portgroup and then expand to the above...assuming the above actually does a good job of blacklisting compilers that don’t support C++14!
>>
>> A major advantage is that if our list of non-C++14 compilers ever changes, it only needs to be updated in one spot.
>>
>> I suspect there would be a few other shorthand lists that could be pre-defined.
>>
>> Thoughts?
> 
> Yes, we should have support for specifying the required language standard(s) in Portfile, so that MacPorts could then select a compatible compiler.
> 
> Until we have that, you need to blacklist incompatible compilers.
>
> If you require C++11, include the cxx11 1.1 portgroup which will do what's needed for you, including blacklisting incompatible compilers and ensuring the right C++ standard library is used.
> 
> If you require C++14, include the cxx11 1.1 portgroup and additionally use "compiler.blacklist-append {clang < 602}".

This does not seem very intuitive. Maybe that should be put into a
simple cxx14 port group acting as a thin wrapper as shown below?

# cxx14-1.1.tcl
PortGroup cxx11 1.1
compiler.blacklist-append {clang < 602}


Rainer