c++: Handle ABI for non-polymorphic dynamic classes

The Itanium ABI has specific rules for when virtual tables for dynamic
classes should be emitted.  However we didn't consider structures with
virtual inheritance but no virtual members as dynamic classes for ABI
purposes; this patch fixes this.

gcc/cp/ChangeLog:

	* decl2.cc (import_export_class): Use TYPE_CONTAINS_VPTR_P
	instead of TYPE_POLYMORPHIC_P.
	(import_export_decl): Likewise.

gcc/testsuite/ChangeLog:

	* g++.dg/modules/virt-5_a.C: New test.
	* g++.dg/modules/virt-5_b.C: New test.

Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>

diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc
index a455eb481b1ad4ca3f768e41e2b3f719a9074a93..fa32ce35c8c43c899eef65088b46790d02cae272 100644 (file)
--- a/gcc/cp/decl2.cc
+++ b/gcc/cp/decl2.cc
@@ -2434,7 +2434,7 @@ import_export_class (tree ctype)
        translation unit, then export the class; otherwise, import
        it.  */
       import_export = -1;
-  else if (TYPE_POLYMORPHIC_P (ctype))
+  else if (TYPE_CONTAINS_VPTR_P (ctype))
     {
       tree cdecl = TYPE_NAME (ctype);
       if (DECL_LANG_SPECIFIC (cdecl) && DECL_MODULE_ATTACH_P (cdecl))
@@ -3530,7 +3530,7 @@ import_export_decl (tree decl)
          class_type = type;
          import_export_class (type);
          if (CLASSTYPE_INTERFACE_KNOWN (type)
-             && TYPE_POLYMORPHIC_P (type)
+             && TYPE_CONTAINS_VPTR_P (type)
              && CLASSTYPE_INTERFACE_ONLY (type)
              /* If -fno-rtti was specified, then we cannot be sure
                 that RTTI information will be emitted with the

diff --git a/gcc/testsuite/g++.dg/modules/virt-5_a.C b/gcc/testsuite/g++.dg/modules/virt-5_a.C
new file mode 100644 (file)
index 0000000..f4c6abe
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/virt-5_a.C
@@ -0,0 +1,16 @@
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi M }
+
+export module M;
+
+struct C {};
+struct B : virtual C {};
+
+// Despite no non-inline key function, this is still a dynamic class
+// and so by the Itanium ABI 5.2.3 should be uniquely emitted in this TU
+export struct A : B {
+  inline A (int) {}
+};
+
+// { dg-final { scan-assembler {_ZTTW1M1A:} } }
+// { dg-final { scan-assembler {_ZTVW1M1A:} } }

diff --git a/gcc/testsuite/g++.dg/modules/virt-5_b.C b/gcc/testsuite/g++.dg/modules/virt-5_b.C
new file mode 100644 (file)
index 0000000..785dd92
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/virt-5_b.C
@@ -0,0 +1,11 @@
+// { dg-module-do link }
+// { dg-additional-options "-fmodules-ts" }
+
+import M;
+
+int main() {
+  A a(0);
+}
+
+// { dg-final { scan-assembler-not {_ZTTW1M1A:} } }
+// { dg-final { scan-assembler-not {_ZTVW1M1A:} } }