https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99576
--- Comment #13 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Adrian Perl from comment #12)
> I have sent the patch and tests to gcc-patc...@gcc.gnu.org
As noted there, the patch causes regressions in more complex library code (e.g.
some tests in folly) where CONSTRUCTOR trees might have nested await
expressions.
I mentioned that the real problem is to determine if a temporary should be
promoted - and, in the case of PR95736, the issue is that we promote a
temporary for a target expression that is subsequently elided; we can see this
clearly if we print the object addresses in the test case:
START TASK
Foo() 0x600001004071
IN LAMBDA
~Foo() 0x600001004070 << corresponds to the elided target expression.
~Foo() 0x600001004071
so this:
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index ce7cf971e03..1bad509233c 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -2830,6 +2830,7 @@ find_interesting_subtree (tree *expr_p, int *dosub, void
*d)
}
}
else if (tmp_target_expr_p (expr)
+ && !TARGET_EXPR_ELIDING_P (expr)
&& !p->temps_used->contains (expr))
{
p->entry = expr_p;
fixes that specific problem - but regresses other test cases (no detailed
analysis yet). Needs more thought ....
