On 9/13/24 11:06 AM, Simon Martin wrote:
Hi Jason,
On 12 Sep 2024, at 16:48, Jason Merrill wrote:
On 9/12/24 7:23 AM, Simon Martin wrote:
Hi,
While looking at more open PRs, I have discovered that the problem
reported in PR109790 is very similar to that in PR100632, so I’m
combining both in a single patch attached here. The fix is similar to
the one I initially submitted, only more general and I believe
better.
We currently crash upon mangling members that have an anonymous union
or a template type.
The problem is that before calling write_unqualified_name,
write_member_name has an assert that assumes that it has an
IDENTIFIER_NODE in its hand. However it's incorrect: it has an
anonymous union in PR100632, and a template in PR109790.
The assert does not assume it has an IDENTIFIER_NODE; it assumes it
has a _DECL, and expects its DECL_NAME to be an IDENTIFIER_NODE.
!identifier_p will always be true for a _DECL, making the assert useless.
Indeed, my bad. Thanks for catching and explaining this!
How about checking !DECL_NAME (member) instead of !identifier_p?
Unfortunately it does not fix PR100632, that actually involves
legitimate operators.
I checked why the assert was added in the first place (via r11-6301),
and the idea was to catch any case where we’d be missing the “on”
marker - PR100632 contains such cases.
I assume you mean 109790?
So I took the approach to refactor write_member_name a bit to first
write the marker in all the cases required, and then actually write the
member name; and the assert is not needed anymore there.
Refactoring code in mangle.cc is tricky given the intent to retain
backward bug-compatibility.
Specifically, adding the "on" in ABI v11 is wrong since GCC 10 (ABI v10)
didn't emit it for the 109790 testcase; we can add it for v16, since GCC
11 ICEd on the testcase.
I would prefer to fix the bug locally rather than refactor.
Jason
