dblaikie added a comment. In D146986#4225192 <https://reviews.llvm.org/D146986#4225192>, @aaron.ballman wrote:
> In D146986#4225121 <https://reviews.llvm.org/D146986#4225121>, @dblaikie > wrote: > >> From the discussion on the issue: >> >>> Do we want this loosening of the restriction to apply to *only* `std` and >>> the same followed by a number, or to any reserved identifier used in a >>> module? e.g., >>> >>> module std; // error today, but will become a warning >>> module _Test; // error today, but do we want this to become a warning as >>> well? >>> >>> my thinking is we probably want all of these to be warnings because it'd be >>> hard to explain why `std` is reserved but with a warning while `_Test` is >>> reserved but with an error. >> >> Yeah, I'd treat them equally - while we could subset the reserved names and >> allow implementations to only use a subset (while leaving the rest as an >> error for both implementations and consumers alike) that doesn't feel in >> keeping with the purpose of these names - to be usable by /someone/ and so >> necessary to allow them to be used. >> >> (hmm - there's some discussion in the description about the fact that this >> error was already suppressed in "system headers" - why was that suppression >> inadequate for system implementation modules? (& does that suppression for >> reserved names risk being over-broad, since every third party library >> installed on a system is generally considered a "system header", even if >> they aren't part of the implementation?)) > > We currently use line markers to "enter" a system header and that's quite > fragile. I mentioned we could use `#pragma clang system_header`, but > @ChuanqiXu didn't think that was appropriate because these are not headers, > they're modules, and we should have some separation between "system headers" > and "system modules". > (https://github.com/llvm/llvm-project/issues/61446#issuecomment-1473029776) > As for being over-broad, it might be, but this is the approach we usually > take (anything that's a "system header" is considered special and gets less > diagnostics because the user isn't typically able to change the contents of > the header file anyway). Presumably adding an alias for `#pragma clang system_header` called `system_module` wouldn't be too hard? (though the pragma is also being removed from libc++ soon, I think, in favor of `-isystem` usage, so maybe that's a sign the pragma's not a great way to do) Presumably the line marker issue would be less significant for a module? Since there's no complex line marking, inclusion, etc, going on - it's just where the actual .cppm file is located/how it's found? (though yeah, that might get weird for building .pcms - since you're going to name the source file directly on the command line, it's not going to be found via any isystem lookup, etc... ) Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D146986/new/ https://reviews.llvm.org/D146986 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
