[Bug c/51712] -Wtype-limits should not trigger for types of implementation-defined signedness

[joseph at codesourcery dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51712

--- Comment #6 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2012-04-23 21:11:33 UTC ---
On Tue, 17 Apr 2012, manu at gcc dot gnu.org wrote:

> Unfortunately, I cannot see any way to know that FOO is a constant that comes
> from an enum. Joseph, is this possible to do in the C FE? 

The original types of expressions that came from enums are already tracked 
for use of -Wc++-compat (checking if C code is compatible with stricter 
C++ rules for enums).  (This is what c-typeck.c:build_external_ref uses 
the type pointer for: storing the original type of an enum.)  So the 
information is available in at least parts of the C front end.