Atlas update

[Ryan Schmidt]

On Feb 22, 2014, at 08:28, Vincent Habchi wrote:

> By the way, I figured out it is not very wise to change the default compiler from macports-clang-3.3 to XCode-clang, since a lot of people out here run Atlas on old machine that have not the last Xcode installed. 
> 
> So I’m going to make it conditional. For the people that have Xcode 5 installed, clang Xcode is going to be the default, but it will be macports-clang-3.4 for the others.
> 
> Now, does some guru out there remember me how to test against Xcode version?

There is simply an ${xcodeversion} variable that you can test with [vercmp]. However, it would be incorrect to do so, since what you care about is the version of clang in the command line tools, and the command line tools can be updated by the user (or, more often, forgotten to be updated) independently of updating Xcode. So what you really want to test is the clang version. There is no variable for that.

The usual answer, if you need to prevent the use of old versions of clang (or another Xcode compiler), is to use the compiler_blacklist_versions portgroup and the compiler.blacklist variable. You would delete your clang* variants and let MacPorts handle the compiler selection for you. Since macports-clang-3.4 was not final when the last version of MacPorts was released, it is not in compiler.fallback, so until the next version of MacPorts is released you would have to add it in the portfile.