ayzhao added inline comments.
================ Comment at: clang/lib/Sema/SemaInit.cpp:5380 + } + InitExprs.push_back(ER.get()); + } ---------------- So the libc++ test compile failures are due to this line. One example of a failing unit test is [range.take.while/ctor.view.pass](https://github.com/llvm/llvm-project/blob/main/libcxx/test/std/ranges/range.adaptors/range.take.while/ctor.view.pass.cpp). Clang calls this function twice in `TreeTransform.h` - once with `VerifyOnly` set to `true`, once with it set to `false`. For some reason, when this function tries to value-initialize the member `MoveOnly mo` in `View`, `Seq.Failed()` returns false after `TryValueInitialization(...)`, but the resulting `ExprResult` is `nullptr`, causing the segfault we see when we push `nullptr` to `InitExprs` and pass `InitExprs` to the constructor of `CXXParenListInitExpr`. One way to be fix this is to move the line `ExprResult ER = Seq.Perform(...)` out of the `if (!VerifyOnly)` block and check for `ER.isInvalid()` instead of `Seq.Failed()`, but that results in test failures due to excess diagnostic messages in `Seq.Perform(...)` I'm still looking into this, but if anyone has any ideas, they would be very welcome. To repro the buildbot failures, just build clang with this patch, and then in a separate build directory, build the target `check-cxx` using the previously built clang. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D129531/new/ https://reviews.llvm.org/D129531 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
