On 1/22/21 4:01 PM, Marek Polacek wrote:
On Thu, Jan 21, 2021 at 09:47:35PM -0500, Jason Merrill via Gcc-patches wrote:
On 1/21/21 5:45 PM, Marek Polacek wrote:
I discovered very strange code in inject_parm_decls:
if (args && is_this_parameter (args))
{
gcc_checking_assert (current_class_ptr == NULL_TREE);
current_class_ptr = NULL_TREE;
We are tripping up on the assert because when we call inject_parm_decls,
current_class_ptr is set to 'A'. It was set by inject_this_parameter
after we've parsed the parameter-declaration-clause of the member
function foo.
But then it should be restored (to null) by the ccp = save_ccp a few lines
later.
Indeed. I glossed over that. :(
It seems correct to set ccp/ccr to A::B when we're
late parsing the noexcept-specifiers of bar* functions in B, so that
this-> does the right thing.
Agreed.
Since inject_parm_decls can mess with
ccp/ccr, I think best if we properly restore it after the late parsing
of noexcept-specifiers.
pop_injected_parms clears them, which is restoring them if we keep the
assert.
It should also work to clear ccp before calling inject_parm_decls, and
removing the assignment following the assert, should the assert stay.
But why is it non-null before parsing the unparsed_noexcepts?
Now that I've taken another look I see that ccp/ccr are being set
in start_preparsed_function (around line 16566), when we parse the
body of foo in cp_parser_late_parsing_for_member. Therefore it's
sort of expected that it's still set when we get to B in foo.
Ah! Yes, it's set because we're parsing a local class of A::foo. This
all makes more sense to me now. So:
- gcc_checking_assert (current_class_ptr == NULL_TREE);
Let's keep the assert, and...
+ tree save_ccp = current_class_ptr;
+ tree save_ccr = current_class_ref;
...clear cc* after saving so the assert succeeds
vec_safe_truncate (unparsed_noexcepts, 0);
+ current_class_ptr = save_ccp;
+ current_class_ref = save_ccr;
No point restoring the original values (for A::foo) here, it won't be
usable for any DMI in a local class of A.
OK with those changes.
Jason
