[Bug c/60018] Bogus conversion warning with optimization flag -O1

[manu at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60018

Manuel López-Ibáñez <manu at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |manu at gcc dot gnu.org

--- Comment #3 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
(In reply to Marek Polacek from comment #2)
> The issue is that at -O0 conversion_warning gets (fn3(), 0) || 0 and doesn't
> call unsafe_conversion_p on it, while on -O fold_binary folds away the || 0
> part and conversion_warning sees COMPOUND_EXPR, it then calls
> unsafe_conversion_p on it.

But in any case, it should look to the last operand of (... , ...) and see that
it is a constant 0. I think there is a duplicate already about -Wconversion not
recursing into compound expressions.