On Tue, May 30, 2017 at 2:14 AM, Volker Reichelt <v.reich...@netcologne.de> wrote: > On 24 May, Jason Merrill wrote: >> On Mon, May 15, 2017 at 3:58 PM, Martin Sebor <mse...@gmail.com> wrote: >>>> So how about the following then? I stayed with the catch part and added >>>> a parameter to the warning to let the user decide on the warnings she/he >>>> wants to get: -Wcatch-value=n. >>>> -Wcatch-value=1 only warns for polymorphic classes that are caught by >>>> value (to avoid slicing), -Wcatch-value=2 warns for all classes that >>>> are caught by value (to avoid copies). And finally -Wcatch-value=3 >>>> warns for everything not caught by reference to find typos (like pointer >>>> instead of reference) and bad coding practices. >>> >>> It seems reasonable to me. I'm not too fond of multi-level >>> warnings since few users take advantage of anything but the >>> default, but this case is simple and innocuous enough that >>> I don't think it can do harm. >> >>>> Bootstrapped and regtested on x86_64-pc-linux-gnu. >>>> OK for trunk? >> >> OK. > > Committed. > >>>> If so, would it make sense to add -Wcatch-value=1 to -Wextra or even -Wall? >>>> I would do this in a seperate patch, becuase I haven't checked what that >>>> would mean for the testsuite. >>> >>> I can't think of a use case for polymorphic slicing that's not >>> harmful so unless there is a common one that escapes me, I'd say >>> -Wall. >> >> Agreed. But then you'll probably want to allow -Wno-catch-value to turn it >> off. > > So how about the following then? > Bootstrapped and regtested on x86_64-pc-linux-gnu. > OK for trunk?
OK, thanks. Jason
