Re: [C++ PATCH] Battle of the comptypes (PR c++/35049)

[Paolo Bonzini <bonzini@gnu.org>]

> The fun comes in where the C/C++ common bits call comptypes with 2
> arguments (as they should), but that ends up calling the C++
> comptypes... with random data for the "strict" argument.

Summing up, we have:

C comptypes => C++ same_type_p

C lang_hooks.types_compatible_p => C++ 
same_type_ignoring_top_level_qualifiers_p

C++ lang_hooks.types_compatible_p => equivalence between pointers and 
reference + same_type_ignoring_top_level_qualifiers_p


So I have an alternate plan:

1) bulk-rename the calls to comptypes in the C front-end to same_type_p

2) add an argument to the C comptypes that will always be COMPARE_STRICT 
for C

3) move same_type_p, same_type_ignoring_top_level_qualifiers_p, 
COMPARE_STRICT from cp-tree.h to c-common.h

I'm testing a patch.

For 4.4, additionally, we can add the C++ lang_hooks.types_compatible_p 
special casing of pointers & references to the C langhook, thus killing 
the C++ lang_hooks.types_compatible_p

Paolo