Support -Wabi warning about backward compatibility.
gcc/c-family/
* c.opt (Wabi=, fabi-compat-version): New.
* c-opts.c (c_common_handle_option): Handle -Wabi=.
(c_common_post_options): Handle flag_abi_compat_version default.
Disallow -fabi-compat-version=1.
* c-common.h (abi_version_crosses): New.
gcc/cp/
* call.c (convert_arg_to_ellipsis): Use abi_version_crosses.
* cvt.c (type_promotes_to): Likewise.
* mangle.c (write_type, write_expression): Likewise.
(write_name, write_template_arg): Likewise.
(mangle_decl): Make alias based on flag_abi_compat_version.
Emit -Wabi warning here.
(finish_mangling_internal): Not here. Drop warn parm.
(finish_mangling_get_identifier, finish_mangling): Adjust.
(mangle_type_string, mangle_special_for_type): Adjust.
(mangle_ctor_vtbl_for_type, mangle_thunk): Adjust.
(mangle_guard_variable, mangle_tls_init_fn): Adjust.
(mangle_tls_wrapper_fn, mangle_ref_init_variable): Adjust.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@211594
138bc75d-0d04-0410-961f-
82ee72b054a4