rsmith requested changes to this revision. rsmith added a comment. This revision now requires changes to proceed.
This is not a conforming extension. We are explicitly not allowed to make standard library functions `constexpr` if the standard doesn't say they are; see [constexpr.functions] (17.6.5.6) in the C++ standard. Clang previously used to allow constant-folding `strlen` calls, but we removed that support intentionally for this reason. It would seem reasonable for this constant-folding to be enabled for `strlen` if the callee was explicitly marked as `constexpr` in the source code. That way, if the standard library chooses to mark it as `constexpr` as a (currently) non-conforming extension, we would provide an optimized implementation. Repository: rL LLVM https://reviews.llvm.org/D23692 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
