yihanaa added a comment. As far as I know, turning on the -fsanitizer=alignment options when calling __builtin_assume_aligned in C code, if the 1st arg has volatile qualifier, Clang will emit "call void @__ubsan_handle_alignment_assumption(...)" in CodeGen, else Clang will emit an warning and ignore "call void @__ubsan_handle_alignment_assumption(...)". But the same situation in C++, Clang will generate an error in Sema.
So I think, in order to keep this patch consistent with recent version of Clang and GCC behavior, when compile C code, Clang should not directly emit an error and exit in Sema, but should check the 1st arg's volatile qualifier in CodeGen and decide whether to emit "call void @__ubsan_handle_alignment_assumption(...)". But, I agree to use other ways to replace use getSubExprAsWritten() in CodeGen to check the 1st arg 'isVolatile', what do you all think about? For more information about UBSan, see https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html and search 'volatile' on this website. "The null, alignment, object-size, local-bounds, and vptr checks do not apply to pointers to types with the volatile qualifier." C https://godbolt.org/z/xv35fG14r C++ https://godbolt.org/z/qfje6sErE Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D131979/new/ https://reviews.llvm.org/D131979 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
