--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gdc.dg/pr94777b.d	Mon May 25 07:50:57 2020 +0900
@@ -0,0 +1,181 @@
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94777
+// { dg-additional-options "-fmain -funittest" }
+// { dg-do run { target hw } }
+// { dg-skip-if "needs gcc/config.d" { ! d_runtime } }
+
+void testVariadic(T)(int nargs, ...)
+{
+    import core.stdc.stdarg;
+    foreach(i; 0 .. nargs)
+    {
+        auto arg = va_arg!T(_argptr);
+        static if (__traits(compiles, arg.value))
+        {
+            assert(arg.value == i);
+        }
+        else static if (__traits(compiles, arg[0]))
+        {
+            foreach (value; arg)
+                assert(value == i);
+        }
+        else
+        {
+            assert(arg == T.init);
+        }
+    }
+}
+
+/******************************************/
+
+struct Constructor
+{
+    static int count;
+    int value;
+    this(int v) { count++; this.value = v; }
+}
+
+unittest
+{
+    auto a0 = Constructor(0);
+    auto a1 = Constructor(1);
+    auto a2 = Constructor(2);
+    testVariadic!Constructor(3, a0, a1, a2);
+    assert(Constructor.count == 3);
+}
+
+/******************************************/
+
+struct Postblit
+{
+    static int count = 0;
+    int value;
+    this(this) { count++; }
+}
+
+unittest
+{
+    auto a0 = Postblit(0);
+    auto a1 = Postblit(1);
+    auto a2 = Postblit(2);
+    testVariadic!Postblit(3, a0, a1, a2);
+    assert(Postblit.count == 3);
+}
+
+/******************************************/
+
+struct Destructor
+{
+    static int count = 0;
+    int value;
+    ~this() { count++; }
+}
+
+unittest
+{
+    {
+        auto a0 = Destructor(0);
+        auto a1 = Destructor(1);
+        auto a2 = Destructor(2);
+        static assert(!__traits(compiles, testVariadic!Destructor(3, a0, a1, a2)));
+    }
+    assert(Destructor.count == 3);
+}
+
+/******************************************/
+
+struct CopyConstructor 
+{
+    static int count = 0;
+    int value;
+    this(int v) { this.value = v; }
+    this(ref typeof(this) other) { count++; this.value = other.value; }
+}
+
+unittest
+{
+    auto a0 = CopyConstructor(0);
+    auto a1 = CopyConstructor(1);
+    auto a2 = CopyConstructor(2);
+    testVariadic!CopyConstructor(3, a0, a1, a2);
+    // NOTE: Cpctors are not implemented yet.
+    assert(CopyConstructor.count == 0 || CopyConstructor.count == 3);
+}
+
+/******************************************/
+
+unittest
+{
+    struct Nested
+    {
+        int value;
+    }
+
+    auto a0 = Nested(0);
+    auto a1 = Nested(1);
+    auto a2 = Nested(2);
+    testVariadic!Nested(3, a0, a1, a2);
+}
+
+/******************************************/
+
+unittest
+{
+    struct Nested2
+    {
+        int value;
+    }
+
+    void testVariadic2(int nargs, ...)
+    {
+        import core.stdc.stdarg;
+        foreach(i; 0 .. nargs)
+        {
+            auto arg = va_arg!Nested2(_argptr);
+            assert(arg.value == i);
+        }
+    }
+
+    auto a0 = Nested2(0);
+    auto a1 = Nested2(1);
+    auto a2 = Nested2(2);
+    testVariadic2(3, a0, a1, a2);
+}
+
+/******************************************/
+
+struct EmptyStruct
+{
+}
+
+unittest
+{
+    auto a0 = EmptyStruct();
+    auto a1 = EmptyStruct();
+    auto a2 = EmptyStruct();
+    testVariadic!EmptyStruct(3, a0, a1, a2);
+}
+
+/******************************************/
+
+alias StaticArray = int[4];
+
+unittest
+{
+    StaticArray a0 = 0;
+    StaticArray a1 = 1;
+    StaticArray a2 = 2;
+    // XBUG: Front-end rewrites static arrays as dynamic arrays.
+    //testVariadic!StaticArray(3, a0, a1, a2);
+}
+
+/******************************************/
+
+alias EmptyArray = void[0];
+
+unittest
+{
+    auto a0 = EmptyArray.init;
+    auto a1 = EmptyArray.init;
+    auto a2 = EmptyArray.init;
+    testVariadic!EmptyArray(3, a0, a1, a2);
+}