Hi, > On 16 May 2012 19:53, Paolo Carlini <pcarl...@gmail.com> wrote: >>> - expr = build_new_op (loc, code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE, >>> + expr = build_new_op (LOC_OR_HERE (loc), code, LOOKUP_NORMAL, >>> + arg1, arg2, NULL_TREE, >>> overload, complain); >>> >>> This doesn't seem correct to me because of the reasons Jason gave. If >>> loc is unknown, you are changing the behaviour. >> >> If loc is UNKNOWN I'm passing down an input_location which seems a definite >> improvement to me in the light of your last message, given that the called >> function may immediately error out and try to use that location in the >> error_at. But I'm not going to insist. >> > > But then, this should have happened before, no? Or do we get > UNKNOWN_LOCATION now but not before? That would indicate something has > changed in an upper level that is not quite right. The point is that > some things may naturally have UNKNOWN_LOCATION, however, such things > should never be used in diagnostics. That indicates a bug. So, if the > caller is passing down loc == UNKNOWN_LOCATION here and this new > operation is never artificial, then the caller is wrongly passing down > UNKNOWN_LOCATION. > > In this particular case, you may have just uncovered a latent bug, and > use the LOC_OR_HERE trick to defer fixing it for later. That seems OK > to me, but then you should add a FIXME for such case, saying "This > should be just LOC but something is passing down UNKNOWN_LOCATION and > this breaks so and so"
To clarify: I didn't do that out of "empirical necessity", because not doing it caused regression, or I had a new testcase which required it. I did it for consistency with all the other build_x_* functions, because I gathered that we never ever want to pass an UNKNOWN_LOCATION to a diagnostic function. But really I'm not going to insist, I can as well only in this build_x_* not use the LOC_OR_HERE trick, just, hey, let's agree on something which is a small but clear improvement and move to the next step in this (long, I'm afraid) path. Paolo
