Hi!
The following testcase shows that we set TYPE_EMPTY_P just one of the
possibly many variants of an aggregate type.
On the testcase, in one case (in the callee) we check TYPE_EMPTY_P on X which is
the type variant for the using type, and in another case we check it on the
A<int> type instead, which has TYPE_EMPTY_P set.
Bootstrap/regtest pending on x86_64-linux and i686-linux, ok if it passes?
2018-02-21 Jakub Jelinek <ja...@redhat.com>
PR target/84502
* stor-layout.c (finalize_type_size): Propagate TYPE_EMPTY_P flag
to all type variants.
* g++.dg/torture/pr84502.C: New test.
--- gcc/stor-layout.c.jj 2018-02-13 21:23:29.187981310 +0100
+++ gcc/stor-layout.c 2018-02-21 21:43:24.783522853 +0100
@@ -1883,6 +1883,9 @@ finalize_type_size (tree type)
&& TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST)
TYPE_SIZE_UNIT (type) = variable_size (TYPE_SIZE_UNIT (type));
+ /* Handle empty records as per the x86-64 psABI. */
+ TYPE_EMPTY_P (type) = targetm.calls.empty_record_p (type);
+
/* Also layout any other variants of the type. */
if (TYPE_NEXT_VARIANT (type)
|| type != TYPE_MAIN_VARIANT (type))
@@ -1895,6 +1898,7 @@ finalize_type_size (tree type)
unsigned int precision = TYPE_PRECISION (type);
unsigned int user_align = TYPE_USER_ALIGN (type);
machine_mode mode = TYPE_MODE (type);
+ bool empty_p = TYPE_EMPTY_P (type);
/* Copy it into all variants. */
for (variant = TYPE_MAIN_VARIANT (type);
@@ -1911,11 +1915,9 @@ finalize_type_size (tree type)
SET_TYPE_ALIGN (variant, valign);
TYPE_PRECISION (variant) = precision;
SET_TYPE_MODE (variant, mode);
+ TYPE_EMPTY_P (variant) = empty_p;
}
}
-
- /* Handle empty records as per the x86-64 psABI. */
- TYPE_EMPTY_P (type) = targetm.calls.empty_record_p (type);
}
/* Return a new underlying object for a bitfield started with FIELD. */
--- gcc/testsuite/g++.dg/torture/pr84502.C.jj 2018-02-21 22:13:22.279420017
+0100
+++ gcc/testsuite/g++.dg/torture/pr84502.C 2018-02-21 22:13:03.727424362
+0100
@@ -0,0 +1,20 @@
+// PR target/84502
+// { dg-do run }
+
+template<typename T>
+struct A { };
+using X = A<int>;
+
+void
+foo (X, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
+{
+ if (a1 != 0 || a2 != 1 || a3 != 2 || a4 != 3
+ || a5 != 4 || a6 != 5 || a7 != 6 || a8 != 7)
+ __builtin_abort ();
+}
+
+int
+main ()
+{
+ foo (X{}, 0, 1, 2, 3, 4, 5, 6, 7);
+}
Jakub
