[Bug c/78568] [5/6/7 Regression] Wtype-limits warning regression

[joseph at codesourcery dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78568

--- Comment #5 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
c_fully_fold should not be asked to fold the same expression more than 
once.  When a subexpression is folded during parsing, for whatever reason, 
the result should be wrapped in a tree code that c_fully_fold does not 
recurse into, using c_wrap_maybe_const if no other such tree code is 
involved.

Thus, warning from c_fully_fold should be OK without generating duplicate 
warnings (if duplicates occur, that suggests something is failing to 
prevent multiple calls to c_fully_fold for the same expression).