aaron.ballman added inline comments.
================ Comment at: clang-tools-extra/test/clang-tidy/bugprone-dynamic-static-initializers.hpp:33-35 + // This may work fine when optimization is enabled because bar() can + // be turned into a constant 7. But without optimization, it can + // cause problems. Therefore, we must err on the side of conservatism. ---------------- czhang wrote: > aaron.ballman wrote: > > czhang wrote: > > > aaron.ballman wrote: > > > > What problems can be caused here? Typically, dynamic init is only > > > > problematic when it happens before main() is executed (because of > > > > initialization order dependencies), but that doesn't apply to local > > > > statics. > > > Consider the case when synchronization is disabled for static > > > initialization, and two threads call `foo2` for the first time. It may be > > > the case that they both try and initialize the static variable at the > > > same time with different values (since the dynamic initializer may not be > > > pure), creating a race condition. > > > Consider the case when synchronization is disabled for static > > > initialization > > > > This is a compiler bug, though: http://eel.is/c++draft/stmt.dcl#4.sentence-3 > Sorry, I guess I didn't make it clear enough in the rst documentation file, > but this check is for those who explicitly enable the -fno-threadsafe-statics > flag because they provide their own synchronization. Then they would like to > check if the headers they didn't write may possibly run into this issue when > compiling with this flag. Ah! Thank you for the explanation. In that case, this behavior makes more sense, but I think you should only warn if the user has enabled that feature flag rather than always warning. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D62829/new/ https://reviews.llvm.org/D62829 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits