DR 1402

	DR 1402
	* method.c (synthesized_method_walk): Replace uses of msg with diag.
	Correct handling of virtual bases with move operations.
	(process_subob_fn, walk_field_subobs): Replace uses of msg with diag.

From-SVN: r189426

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index a59cefe..fd2ba73 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,10 @@
+2012-07-11  Jason Merrill  <jason@redhat.com>
+
+       DR 1402
+       * method.c (synthesized_method_walk): Replace uses of msg with diag.
+       Correct handling of virtual bases with move operations.
+       (process_subob_fn, walk_field_subobs): Replace uses of msg with diag.
+
 2012-07-11  Steven Bosscher  <steven@gcc.gnu.org>
 
        * method.c: Do not include tree-pass.h.

diff --git a/gcc/cp/method.c b/gcc/cp/method.c
index 9481aa7..bd0792f 100644 (file)
--- a/gcc/cp/method.c
+++ b/gcc/cp/method.c
@@ -922,7 +922,7 @@ get_copy_assign (tree type)
 static void
 process_subob_fn (tree fn, bool move_p, tree *spec_p, bool *trivial_p,
                  bool *deleted_p, bool *constexpr_p, bool *no_implicit_p,
-                 const char *msg, tree arg)
+                 bool diag, tree arg)
 {
   if (!fn || fn == error_mark_node)
     goto bad;
@@ -942,7 +942,7 @@ process_subob_fn (tree fn, bool move_p, tree *spec_p, bool *trivial_p,
        {
          if (deleted_p)
            *deleted_p = true;
-         if (msg)
+         if (diag)
            error ("union member %q+D with non-trivial %qD", arg, fn);
        }
     }
@@ -955,7 +955,7 @@ process_subob_fn (tree fn, bool move_p, tree *spec_p, bool *trivial_p,
   if (constexpr_p && !DECL_DECLARED_CONSTEXPR_P (fn))
     {
       *constexpr_p = false;
-      if (msg)
+      if (diag)
        {
          inform (0, "defaulted constructor calls non-constexpr "
                  "%q+D", fn);
@@ -978,7 +978,7 @@ walk_field_subobs (tree fields, tree fnname, special_function_kind sfk,
                   int quals, bool copy_arg_p, bool move_p,
                   bool assign_p, tree *spec_p, bool *trivial_p,
                   bool *deleted_p, bool *constexpr_p, bool *no_implicit_p,
-                  const char *msg, int flags, tsubst_flags_t complain)
+                  bool diag, int flags, tsubst_flags_t complain)
 {
   tree field;
   for (field = fields; field; field = DECL_CHAIN (field))
@@ -995,13 +995,13 @@ walk_field_subobs (tree fields, tree fnname, special_function_kind sfk,
          bool bad = true;
          if (CP_TYPE_CONST_P (mem_type) && !CLASS_TYPE_P (mem_type))
            {
-             if (msg)
+             if (diag)
                error ("non-static const member %q#D, can%'t use default "
                       "assignment operator", field);
            }
          else if (TREE_CODE (mem_type) == REFERENCE_TYPE)
            {
-             if (msg)
+             if (diag)
                error ("non-static reference member %q#D, can%'t use "
                       "default assignment operator", field);
            }
@@ -1017,7 +1017,7 @@ walk_field_subobs (tree fields, tree fnname, special_function_kind sfk,
 
          if (DECL_INITIAL (field))
            {
-             if (msg && DECL_INITIAL (field) == error_mark_node)
+             if (diag && DECL_INITIAL (field) == error_mark_node)
                inform (0, "initializer for %q+#D is invalid", field);
              if (trivial_p)
                *trivial_p = false;
@@ -1040,14 +1040,14 @@ walk_field_subobs (tree fields, tree fnname, special_function_kind sfk,
          if (CP_TYPE_CONST_P (mem_type)
              && default_init_uninitialized_part (mem_type))
            {
-             if (msg)
+             if (diag)
                error ("uninitialized non-static const member %q#D",
                       field);
              bad = true;
            }
          else if (TREE_CODE (mem_type) == REFERENCE_TYPE)
            {
-             if (msg)
+             if (diag)
                error ("uninitialized non-static reference member %q#D",
                       field);
              bad = true;
@@ -1063,7 +1063,7 @@ walk_field_subobs (tree fields, tree fnname, special_function_kind sfk,
              && TREE_CODE (DECL_CONTEXT (field)) != UNION_TYPE)
            {
              *constexpr_p = false;
-             if (msg)
+             if (diag)
                inform (0, "defaulted default constructor does not "
                        "initialize %q+#D", field);
            }
@@ -1077,7 +1077,7 @@ walk_field_subobs (tree fields, tree fnname, special_function_kind sfk,
          walk_field_subobs (TYPE_FIELDS (mem_type), fnname, sfk, quals,
                             copy_arg_p, move_p, assign_p, spec_p, trivial_p,
                             deleted_p, constexpr_p, no_implicit_p,
-                            msg, flags, complain);
+                            diag, flags, complain);
          continue;
        }
 
@@ -1094,7 +1094,7 @@ walk_field_subobs (tree fields, tree fnname, special_function_kind sfk,
       rval = locate_fn_flags (mem_type, fnname, argtype, flags, complain);
 
       process_subob_fn (rval, move_p, spec_p, trivial_p, deleted_p,
-                       constexpr_p, no_implicit_p, msg, field);
+                       constexpr_p, no_implicit_p, diag, field);
     }
 }
 
@@ -1115,7 +1115,6 @@ synthesized_method_walk (tree ctype, special_function_kind sfk, bool const_p,
   VEC(tree,gc) *vbases;
   int i, quals, flags;
   tsubst_flags_t complain;
-  const char *msg;
   bool ctor_p;
 
   if (spec_p)
@@ -1239,25 +1238,21 @@ synthesized_method_walk (tree ctype, special_function_kind sfk, bool const_p,
     quals = TYPE_UNQUALIFIED;
   argtype = NULL_TREE;
 
-  if (!diag)
-    msg = NULL;
-  else if (assign_p)
-    msg = ("base %qT does not have a move assignment operator or trivial "
-          "copy assignment operator");
-  else
-    msg = ("base %qT does not have a move constructor or trivial "
-          "copy constructor");
-
   for (binfo = TYPE_BINFO (ctype), i = 0;
        BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
     {
       tree basetype = BINFO_TYPE (base_binfo);
+
+      if (!assign_p && BINFO_VIRTUAL_P (base_binfo))
+       /* We'll handle virtual bases below.  */
+       continue;
+
       if (copy_arg_p)
        argtype = build_stub_type (basetype, quals, move_p);
       rval = locate_fn_flags (base_binfo, fnname, argtype, flags, complain);
 
       process_subob_fn (rval, move_p, spec_p, trivial_p, deleted_p,
-                       constexpr_p, no_implicit_p, msg, basetype);
+                       constexpr_p, no_implicit_p, diag, basetype);
       if (ctor_p && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype))
        {
          /* In a constructor we also need to check the subobject
@@ -1270,7 +1265,7 @@ synthesized_method_walk (tree ctype, special_function_kind sfk, bool const_p,
             throw) or exception-specification (a throw from one of the
             dtors would be a double-fault).  */
          process_subob_fn (rval, false, NULL, NULL,
-                           deleted_p, NULL, NULL, NULL,
+                           deleted_p, NULL, NULL, false,
                            basetype);
        }
 
@@ -1287,21 +1282,31 @@ synthesized_method_walk (tree ctype, special_function_kind sfk, bool const_p,
     }
 
   vbases = CLASSTYPE_VBASECLASSES (ctype);
-  if (vbases && assign_p && move_p)
+  if (vbases == NULL)
+    /* No virtual bases to worry about.  */;
+  else if (assign_p && move_p && no_implicit_p)
     {
+      /* Don't implicitly declare a defaulted move assignment if a virtual
+        base has non-trivial move assignment, since moving the same base
+        more than once is dangerous.  */
       /* Should the spec be changed to allow vbases that only occur once?  */
-      if (diag)
-       error ("%qT has virtual bases, default move assignment operator "
-              "cannot be generated", ctype);
-      else if (deleted_p)
-       *deleted_p = true;
+      FOR_EACH_VEC_ELT (tree, vbases, i, base_binfo)
+       {
+         tree basetype = BINFO_TYPE (base_binfo);
+         if (copy_arg_p)
+           argtype = build_stub_type (basetype, quals, move_p);
+         rval = locate_fn_flags (base_binfo, fnname, argtype, flags, complain);
+         if (rval && rval != error_mark_node
+             && move_fn_p (rval) && !trivial_fn_p (rval))
+           {
+             *no_implicit_p = true;
+             break;
+           }
+       }
     }
   else if (!assign_p)
     {
-      if (diag)
-       msg = ("virtual base %qT does not have a move constructor "
-              "or trivial copy constructor");
-      if (vbases && constexpr_p)
+      if (constexpr_p)
        *constexpr_p = false;
       FOR_EACH_VEC_ELT (tree, vbases, i, base_binfo)
        {
@@ -1311,35 +1316,29 @@ synthesized_method_walk (tree ctype, special_function_kind sfk, bool const_p,
          rval = locate_fn_flags (base_binfo, fnname, argtype, flags, complain);
 
          process_subob_fn (rval, move_p, spec_p, trivial_p, deleted_p,
-                           constexpr_p, no_implicit_p, msg, basetype);
+                           constexpr_p, no_implicit_p, diag, basetype);
          if (ctor_p && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype))
            {
              rval = locate_fn_flags (base_binfo, complete_dtor_identifier,
                                      NULL_TREE, flags, complain);
              process_subob_fn (rval, false, NULL, NULL,
-                               deleted_p, NULL, NULL, NULL,
+                               deleted_p, NULL, NULL, false,
                                basetype);
            }
        }
     }
-  if (!diag)
-    /* Leave msg null. */;
-  else if (assign_p)
-    msg = ("non-static data member %qD does not have a move "
-          "assignment operator or trivial copy assignment operator");
-  else
-    msg = ("non-static data member %qD does not have a move "
-          "constructor or trivial copy constructor");
+
+  /* Now handle the non-static data members.  */
   walk_field_subobs (TYPE_FIELDS (ctype), fnname, sfk, quals,
                     copy_arg_p, move_p, assign_p, spec_p, trivial_p,
                     deleted_p, constexpr_p, no_implicit_p,
-                    msg, flags, complain);
+                    diag, flags, complain);
   if (ctor_p)
     walk_field_subobs (TYPE_FIELDS (ctype), complete_dtor_identifier,
                       sfk_destructor, TYPE_UNQUALIFIED, false,
                       false, false, NULL, NULL,
                       deleted_p, NULL,
-                      NULL, NULL, flags, complain);
+                      NULL, false, flags, complain);
 
   pop_scope (scope);
 

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index cd9d0a8..a82ac1c 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2012-07-11  Jason Merrill  <jason@redhat.com>
+
+       DR 1402
+       * g++.g/cpp0x/defaulted37.C: New.
+
 2012-07-11  Greta Yorsh  <Greta.Yorsh@arm.com>
 
        PR target/53859

diff --git a/gcc/testsuite/g++.dg/cpp0x/defaulted37.C b/gcc/testsuite/g++.dg/cpp0x/defaulted37.C
new file mode 100644 (file)
index 0000000..69105cc
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/defaulted37.C
@@ -0,0 +1,21 @@
+// DR 1402
+// { dg-do compile { target c++11 } }
+
+struct A
+{
+  int moved = 0;
+  A& operator=(A&&) { ++moved; }
+  ~A() { if (moved > 1) __builtin_abort(); }
+};
+
+struct B: virtual A { B& operator=(B&&) = default; };
+struct C: virtual A { };       // { dg-error "operator=.const A&" }
+
+int main()
+{
+  B b1, b2;
+  b2 = static_cast<B&&>(b1);
+
+  C c1, c2;
+  c2 = static_cast<C&&>(c1);   // { dg-error "operator=.const C&" }
+}