rjmccall added a comment. Please look into the history of that test case to see why we're specifically testing for the ability to redeclare this builtin.
We could certainly allow this builtin to be redeclared using the `const void*` type — that doesn't really reflect the generic nature of the builtin, but it would work for compatibility with other compilers in the vast preponderance of code — but if we don't really need to do it, let's not go down that road. ================ Comment at: clang/lib/Sema/SemaChecking.cpp:7651-7652 + Expr *FirstArg = TheCall->getArg(0); + if (auto *CE = dyn_cast<CastExpr>(FirstArg)) + FirstArg = CE->getSubExprAsWritten(); ---------------- yronglin wrote: > rjmccall wrote: > > rsmith wrote: > > > This looks very suspicious to me: this will remove a cast expression that > > > was written in the source code from the AST. That loses source fidelity, > > > can give the wrong answer if the cast changed the value (such as a C++ > > > derived-to-base conversion to a non-primary base class), and in any case > > > this is only done once where there could be multiple explicit casts > > > written on an argument to the builtin, so if it's necessary, then it's > > > not being done fully. > > > > > > Can this be removed? > > Somehow I missed this in my review. Yes, this line should be unnecessary, > > and as you say, it is definitely wrong. > CodeGen need real `user-written-type` to generate > `__ubsan_handle_alignment_assumption ` 's arg, but not `const void *` Because we're using custom type-checking here, there is no conversion to `const void *` in the first place; that conversion was an artifact of the earlier implementation. Also, if the previous code in CodeGen looked like this, then it was buggy: it is incorrect in the case that someone wrote `(const void*) foo` as the argument, because it would inappropriately look through the explicit, user-provided cast. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D133202/new/ https://reviews.llvm.org/D133202 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
