mcgrathr added a comment. In https://reviews.llvm.org/D53787#1282975, @rsmith wrote:
> These symbols really are special. Other symbols are introduced explicitly by > a declaration, whereas these are declared implicitly by the compiler. The implicit declaration is the only difference that actually makes sense to me. > Other symbols must have exactly one definition (modulo the permission for > duplicate identical definitions for some cases), but these ones have a > default definition that is designed to be overridable by a different > definition appearing anywhere in the program. I don't understand this claim. These are symbols like any others at link time. A single definition must be supplied as for any other function. > Other symbols are generally provided in one library and consumed by users of > that library, whereas these symbols are typically provided by the main binary > and consumed by the libraries that it uses. And so on. I don't understand this claim. These symbols are normally defined in libc++.so and nowhere else. >> It is especially bizarre to me that explicit attributes on the definition >> sites are silently ignored for these functions and no others. > > Do you have a testcase? That's not the behavior I'm seeing. What I see is > that we get a hard error for an explicit attribute on the definition site, > because the prior compiler-generated declaration has default visibility. Eg: You're right. It's been quite a while since I was fighting with this originally. It might have been GCC that ignored explicit attributes. Repository: rC Clang https://reviews.llvm.org/D53787 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
