Compiler blacklist 'shorthand'

[Ryan Schmidt]

On May 6, 2018, at 05:18, Rainer Müller wrote:

> 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}

I didn't say it was intuitive; I just said that's how it is right now.

Such a portgroup could be created, but I dislike the proliferation of portgroups.