re PR c++/32992 (Incorrect code generated for anonymous union and return)

	PR c++/32992
	* typeck.c (check_return_expr): Don't NRV optimize vars in
	anonymous unions.
	* decl.c (finish_function): Comment fix.

	* g++.dg/opt/nrv14.C: New test.

From-SVN: r127510

gcc/cp/ChangeLog

+2007-08-15  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/32992
+	* typeck.c (check_return_expr): Don't NRV optimize vars in
+	anonymous unions.
+	* decl.c (finish_function): Comment fix.
+
 2007-08-15  Paolo Carlini  <pcarlini@suse.de>
 
 	PR c++/33035

gcc/cp/decl.c

@@ -11569,7 +11569,7 @@ finish_function (int flags)
   gcc_assert (stmts_are_full_exprs_p ());
 
   /* Set up the named return value optimization, if we can.  Candidate
-     variables are selected in check_return_value.  */
+     variables are selected in check_return_expr.  */
   if (current_function_return_value)
     {
       tree r = current_function_return_value;

gcc/cp/typeck.c

@@ -6703,6 +6703,7 @@ check_return_expr (tree retval, bool *no_warning)
      && TREE_CODE (retval) == VAR_DECL
      && DECL_CONTEXT (retval) == current_function_decl
      && ! TREE_STATIC (retval)
+     && ! DECL_ANON_UNION_VAR_P (retval)
      && (DECL_ALIGN (retval)
          >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
      /* The cv-unqualified type of the returned value must be the

gcc/testsuite/ChangeLog

+2007-08-15  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/32992
+	* g++.dg/opt/nrv14.C: New test.
+
 2007-08-15  Paolo Carlini  <pcarlini@suse.de>
 
 	PR c++/33035

gcc/testsuite/g++.dg/opt/nrv14.C

+// PR c++/32992
+// { dg-do run }
+// { dg-options "-O2" }
+
+extern "C" void abort (void);
+
+struct A
+{
+  long int a1;
+  long int a2;
+  long int a3;
+};
+
+struct B
+{
+  long int f[3];
+  operator A ()
+  {
+    union
+    {
+      long int t[3];
+      A a;
+    };
+    for (int i = 0; i < 3; i++)
+      t[i] = f[i];
+    return a;
+  }
+};
+
+int
+main ()
+{
+  B b = { {1, 3, 5} };
+  A a = b;
+
+  if (a.a1 != b.f[0] || a.a2 != b.f[1] || a.a3 != b.f[2])
+    abort ();
+  return 0;
+}