DW_AT_GNU_odr_signature

[Mark Wielaard]

Hi,

I saw that dwarf2out.c (generate_type_signature) does not just calculate
the complete type signature for use with DW_AT_signature, but also
outputs a DW_AT_GNU_odr_signature. The comment says:

/* First, compute a signature for just the type name (and its
   surrounding context, if any.  This is stored in the type unit DIE
   for link-time ODR (one-definition rule) checking.  */

I couldn't find where in the toolchain this link-time checking is done.
Does anybody have any pointers?

Thanks,

Mark