c++: anon union designated init [PR105925]

This testcase was failing because CONSTRUCTOR_IS_DESIGNATED_INIT wasn't
getting set on the introduced CONSTRUCTOR for the anonymous union, and
build_aggr_conv uses that flag to decide whether to pay attention to the
indexes of the CONSTRUCTOR.  So set the flag when we see a designator rather
than relying on copying it from another CONSTRUCTOR.

	PR c++/105925

gcc/cp/ChangeLog:

	* decl.cc (reshape_init_array_1): Set
	CONSTRUCTOR_IS_DESIGNATED_INIT here.
	(reshape_init_class): And here.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp2a/desig26.C: New test.
This commit is contained in:
Jason Merrill 2022-06-23 16:04:02 -04:00
parent b96b64bec3
commit db29b66193
2 changed files with 25 additions and 0 deletions

View File

@ -6503,6 +6503,8 @@ reshape_init_array_1 (tree elt_type, tree max_index, reshape_iter *d,
tree elt_init;
constructor_elt *old_cur = d->cur;
if (d->cur->index)
CONSTRUCTOR_IS_DESIGNATED_INIT (new_init) = true;
check_array_designated_initializer (d->cur, index);
elt_init = reshape_init_r (elt_type, d,
/*first_initializer_p=*/NULL_TREE,
@ -6670,6 +6672,7 @@ reshape_init_class (tree type, reshape_iter *d, bool first_initializer_p,
}
else if (TREE_CODE (d->cur->index) == IDENTIFIER_NODE)
{
CONSTRUCTOR_IS_DESIGNATED_INIT (new_init) = true;
field = get_class_binding (type, d->cur->index);
direct_desig = true;
}

View File

@ -0,0 +1,22 @@
// PR c++/105925
// { dg-do compile { target c++20 } }
struct V
{
int i;
double d;
};
struct X
{
union
{
int x;
V y;
};
};
X foo()
{
return {.y = {0, 0.0}};
}