aaron.ballman added inline comments. ================ Comment at: test/clang-tidy/google-global-names.cpp:13-14 @@ +12,4 @@ +// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: 'i' declared in the global namespace +extern int ii = 0; +// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: 'ii' declared in the global namespace + ---------------- bkramer wrote: > aaron.ballman wrote: > > This strikes me as being intentional enough to warrant not diagnosing > > because of the `extern` keyword. > The only case I see where this pattern is valuable is interfacing with C > code. Not sure yet if we want to allow that or enforce extern "C" instead. > Ideas? > > an extern global in the global namespace still feels like something we should > warn on :| Yet externs in the global namespace do happen for valid reasons (such as not breaking ABIs by putting the extern definition into a namespace or changing the language linkage) -- I'm trying to think of ways we can allow the user to silence this diagnostic in those cases. I feel like in cases where the user writes "extern", they're explicitly specifying their intent and that doesn't seem like a case to warn them about, in some regards. It would give us two ways to silence the diagnostic (well, three, but two are morally close enough):
1) Put it into a namespace 2) Slap `extern` on it if it is global for C++ compatibility (such as ABIs) 3) Slap `extern "C"` on it if it global for C compatibility I suppose we could require `extern "C++"` instead of `extern`, but I don't think that's a particularly common use of the language linkage specifier? https://reviews.llvm.org/D23130 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
