Hi
>What I can think of is to hide the stale source location when it no
>longer have
>defined meaning:
>Index: cgraphunit.c
>===================================================================
>--- cgraphunit.c (revision 202352)
>+++ cgraphunit.c (working copy)
>@@ -913,6 +913,7 @@ analyze_functions (void)
>
> bitmap_obstack_initialize (NULL);
> cgraph_state = CGRAPH_STATE_CONSTRUCTION;
>+ input_location = UNKNOWN_LOCATION;
>
>/* Ugly, but the fixup can not happen at a time same body alias is
>created;
> C++ FE is confused about the COMDAT groups being right. */
>
>but of course this just leads to:
>jh@gcc10:~/trunk/build7/gcc$ ./xgcc -B ./ -O2
>../../gcc/testsuite/g++.dg/template/cond2.C
>../../gcc/testsuite/g++.dg/template/cond2.C: In instantiation of 'int
>test(c<(X ? : Y)>&) [with int X = 0; int Y = 2]':
>:0:0: required from here
>../../gcc/testsuite/g++.dg/template/cond2.C:6:28: error: omitted middle
>operand to '?:' operand cannot be mangled
>template<int X, int Y> int test(c<X ? : Y>&); // { dg-error "omitted" }
Actually this kind of change makes a lot of sense to me (cmp clang too): since
at that point we do *not* really know the location of the "required from" bit,
just plainly admit it. Would it be possible in such cases to have a conditional
in the diagnostic machinery and avoid the output of that bit completely when
the location is UNKNOWN? I don't think there are existing cases where it's sane
to say :0:0 as "required from"!?!
Short term at least, it would seem a good enough solution to me + a comment in
testcase too.
Then indeed as you explained in your last message before leaving (enjoy Pisa!
All in all I spent there ~10 years!) we should audit, avoid as much as possible
such late diagnostic, etc.
What do you think?
Paolo
