On Sun, Apr 17, 2022 at 10:33 AM Ryan Schmidt <gnu...@ryandesign.com> wrote: > > On Apr 17, 2022, at 02:54, Paul Eggert wrote: > > > On 4/16/22 20:28, Jeffrey Walton wrote: > >> maybe you should define a couple of macros > >> like GNULIB_LLVM_CLANG_VER and GNULIB_APPLE_CLANG_VER > > > > I hope we don't need to do that. This is software archaeology (Mac OS X > > 10.7.5 is so old that neither the Subject: line nor my patch got its name > > right, and nobody mentioned the mistake :-) and these macros would clutter > > the code for little benefit. Most Clang-specific code nowadays shouldn't > > use Clang version numbers; it should use __has_builtin etc. > > I agree you should detect features if you can. If you can't, and you need to > look at the compiler version, you need to first establish whether you're > using Apple Clang or open source clang, since the two use different version > numbering schemes. If __clang__ is defined and __apple_build_version__ is > defined, you're using Apple Clang and you could inspect that constant > directly or you could look at __clang_major__, __clang_minor__, and/or > __clang_patchlevel__ interpreted as Apple Clang version numbers. If __clang__ > is defined and __apple_build_version__ is not defined, you're using open > source clang and can look at the __clang_*__ defines interpreted as open > source clang version numbers. > > > Some sample output from my system: > > $ clang -dM -E - < /dev/null | egrep '__(clang|apple)' > #define __apple_build_version__ 4250028 > #define __clang__ 1 > #define __clang_major__ 4 > #define __clang_minor__ 2 > #define __clang_patchlevel__ 0 > #define __clang_version__ "4.2 (clang-425.0.28)" > > $ clang -v > Apple LLVM version 4.2 (clang-425.0.28) (based on LLVM 3.2svn) > Target: x86_64-apple-darwin11.4.2 > Thread model: posix > > $ xcodebuild -version > Xcode 4.6.3 > Build version 4H1503 > > $ sw_vers > ProductName: Mac OS X > ProductVersion: 10.7.5 > BuildVersion: 11G63
One other thing that is helpful is this cross reference for version numbers: https://gist.github.com/yamaya/2924292 If you cut a feature in for LLVM Clang, then you can lookup the Apple Clang version if you don't have an Apple machine with the compiler handy. Jeff
