rjmccall added inline comments.
================ Comment at: clang/include/clang/Basic/DiagnosticGroups.td:269 +def CXXPre2BCompatPedantic : + DiagGroup<"c++98-c++11-c++14-c++17-c++20-compat-pedantic", [CXXPre2BCompat]>; ---------------- Quuxplusone wrote: > aaron.ballman wrote: > > rjmccall wrote: > > > Uh, I think we're a couple standard releases past the point at which we > > > should have reconsidered this schema. I guess the problem is that we > > > can't say `-Wpre-c++23-compat` without jumping the gun. Is there a > > > problem with `-Wc++20-compat` and then having the earlier warning groups > > > imply the later ones? That seems to be what we do with `-Wc++98-compat`; > > > did we abandon that approach intentionally? > > @rsmith may have more background here. I was following the pattern already > > in the file, but I tend to agree that this pattern is not leading us > > somewhere good. FWIW, I ran into a similar situation with this on the C > > side of things in D95396, so we should probably be consistent there too. > My understanding is that the //command-line user// is expected to pass > - `clang++ -std=c++20 -Wc++11-compat` to indicate "I want //actually// to > compile in C++20 mode, but give me warnings about anything that would prevent > compiling in C++11 mode" > - `clang++ -std=c++17 -Wc++14-compat` to indicate "I want //actually// to > compile in C++17 mode, but give me warnings about anything that would prevent > compiling in C++14 mode" > - `clang++ -std=c++14 -Wc++20-compat` to indicate "I want //actually// to > compile in C++14 mode, but give me warnings about anything that would prevent > compiling in C++20 mode" — EXCEPT that I think this is not supported. My > impression is that forward-compatibility warnings are generally just rolled > into `-Wall` and not handled separately beyond that? > > I don't think any human user is expected to pass > `-Wc++98-c++11-c++14-c++17-c++20-compat` by hand; it's just an internal name > for a particular subset of `-Wc++98-compat`. > > IOW, we could choose a new naming scheme for it, but that would be a purely > internal change that won't affect how command-line users interact with Clang > at all (for better and for worse). Diagnostic groups can both directly contain diagnostics and imply other diagnostic groups, so I don't think there's any reason to make a dedicated group just to contain the new diagnostics in e.g. `-Wc++14-compat` except to allow someone turn on those warnings separately. And it does show up to users as the warning group under `-fdiagnostics-show-option` (which is the default). Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D95691/new/ https://reviews.llvm.org/D95691 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
