On 13 September 2018 at 12:08, Ville Voutilainen
<[email protected]> wrote:
> Curses.. the resetting is over-eager; we might have a non-trivial base
> or a member, and in those cases we shouldn't
> reset the triviality when we see a non-user-provided const copy. I
> think I'll hack around this with a non 0/1 value. :)
Testing the attached. I think it might need a comment, and I'm not
sure how to word it.
Here are some options:
1) /* Yo dawg, we heard you'd like another bit, so we added a second
bit to your bit
so you can read the other bit when you read your bit */
2) /* I'm vewy vewy sowwy */
3) /* We need to attach another bit to the TYPE_HAS_COMPLEX_COPY_CTOR
bit, so let's
quantum-entangle the additional bit and the actual bit */
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 50b60e8..ce6ac7f 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -13212,7 +13212,14 @@ grok_special_member_properties (tree decl)
default arguments. */
TYPE_HAS_COPY_CTOR (class_type) = 1;
if (user_provided_p (decl))
- TYPE_HAS_COMPLEX_COPY_CTOR (class_type) = 1;
+ {
+ if (ctor > 1)
+ TYPE_HAS_COMPLEX_COPY_CTOR (class_type) = 1;
+ else if (!TYPE_HAS_CONST_COPY_CTOR (class_type))
+ TYPE_HAS_COMPLEX_COPY_CTOR (class_type) += 2;
+ }
+ else if (ctor > 1 && TYPE_HAS_COMPLEX_COPY_CTOR (class_type) == 2)
+ TYPE_HAS_COMPLEX_COPY_CTOR (class_type) = 0;
if (ctor > 1)
TYPE_HAS_CONST_COPY_CTOR (class_type) = 1;
}
diff --git a/gcc/testsuite/g++.dg/ext/is_trivially_constructible7.C b/gcc/testsuite/g++.dg/ext/is_trivially_constructible7.C
new file mode 100644
index 0000000..177eb2e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/is_trivially_constructible7.C
@@ -0,0 +1,16 @@
+// { dg-do compile { target c++11 } }
+
+// PR c++/87051
+
+struct M {
+ M(const M&) = default;
+ M(M&);
+};
+
+struct M2 {
+ M2(M2&);
+ M2(const M2&) = default;
+};
+
+static_assert( __is_trivially_constructible(M, M&&), "");
+static_assert( __is_trivially_constructible(M2, M2&&), "");
