PR c++/28659

        * typeck.c (merge_types): If either of the types have the right
        attributes, return that one.

        * tree.c (cp_build_type_attribute_variant): Make sure we aren't
        doing this to class types.
        * typeck.c (original_type): Deal with type quals properly.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@116329 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 37 insertions, 2 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index fa7d6bc0e65..22dbdba6936 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,13 @@
+2006-08-22  Jason Merrill  <jason@redhat.com>
+
+	PR c++/28659
+	* typeck.c (merge_types): If either of the types have the right 
+	attributes, return that one.
+
+	* tree.c (cp_build_type_attribute_variant): Make sure we aren't
+	doing this to class types.
+	* typeck.c (original_type): Deal with type quals properly.
+
 2006-08-21  Jason Merrill  <jason@redhat.com>
 
 	PR c++/27115
diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index bb579a6f739..1cedec55f8d 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -1936,6 +1936,10 @@ cp_build_type_attribute_variant (tree type, tree attributes)
 	  != TYPE_RAISES_EXCEPTIONS (type)))
     new_type = build_exception_variant (new_type,
 					TYPE_RAISES_EXCEPTIONS (type));
+
+  /* Making a new main variant of a class type is broken.  */
+  gcc_assert (!CLASS_TYPE_P (type) || new_type == type);
+    
   return new_type;
 }
 
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index f337328cfcd..c07a78d1ef4 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -228,6 +228,7 @@ commonparms (tree p1, tree p2)
 static tree
 original_type (tree t)
 {
+  int quals = cp_type_quals (t);
   while (t != error_mark_node
 	 && TYPE_NAME (t) != NULL_TREE)
     {
@@ -239,7 +240,7 @@ original_type (tree t)
 	break;
       t = x;
     }
-  return t;
+  return cp_build_qualified_type (t, quals);
 }
 
 /* T1 and T2 are arithmetic or enumeration types.  Return the type
@@ -730,7 +731,13 @@ merge_types (tree t1, tree t2)
 
     default:;
     }
-  return cp_build_type_attribute_variant (t1, attributes);
+
+  if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
+    return t1;
+  else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
+    return t2;
+  else
+    return cp_build_type_attribute_variant (t1, attributes);
 }
 
 /* Return the common type of two types.
diff --git a/gcc/testsuite/g++.dg/ext/attrib26.C b/gcc/testsuite/g++.dg/ext/attrib26.C
new file mode 100644
index 00000000000..dedf43a0246
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/attrib26.C
@@ -0,0 +1,14 @@
+// PR c++/28659
+// The attribute was causing us to get confused in merge_types when
+// combining the template type with an uninstantiated version.
+
+template<class T>
+struct __attribute__((aligned(1))) A
+{
+  A& operator=(const A &t);
+};
+
+template<class T>
+A<T>& A<T>::operator=(const A<T> &t)
+{
+}