https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63764
--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to jos...@codesourcery.com from comment #9) > On Tue, 18 Nov 2014, jakub at gcc dot gnu.org wrote: > > So, shall we convert_vector_to_pointer_for_subscript add something like > > if (!lvalue_p (*vecp)) > > error_at (...); ? > > What wording for it? > > I'd think it's reasonable to subscript a non-lvalue vector (including e.g. > the return value of a function with vector return type) - this might of > course need to create a temporary object, as with non-lvalue arrays. For rhs yes, supposedly. But not for lhs. So, perhaps if *vecp is not an lvalue, assign to temporary and take address of that, but then in the end wrap the result of the subscripting into NON_LVALUE_EXPR, so that we actually error out on the testcase?
