trans.c (call_to_gnu): Also force the return slot opt for the call to a function whose return type was...

	* gcc-interface/trans.c (call_to_gnu): Also force the return slot opt
	for the call to a function whose return type was unconstrained.

From-SVN: r163648

4 files changed, 67 insertions, 7 deletions

diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index 5b427f8..076efea 100644
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,8 +1,13 @@
+2010-08-30  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc-interface/trans.c (call_to_gnu): Also force the return slot opt
+	for the call to a function whose return type was unconstrained.
+
 2010-08-30  Olivier Hainque  <hainque@adacore.com>
 
-        * gcc-interface/decl.c (FOREIGN_FORCE_REALIGN_STACK): New macro,
-        replacement for FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN.
-        (gnat_to_gnu_entity) <case ..., E_Procedure>: Use it.
+	* gcc-interface/decl.c (FOREIGN_FORCE_REALIGN_STACK): New macro,
+	replacement for FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN.
+	(gnat_to_gnu_entity) <case ..., E_Procedure>: Use it.
 
 2010-08-21  Eric Botcazou  <ebotcazou@adacore.com>
 
diff --git a/gcc/ada/gcc-interface/trans.c b/gcc/ada/gcc-interface/trans.c
index d32639a..b403189 100644
--- a/gcc/ada/gcc-interface/trans.c
+++ b/gcc/ada/gcc-interface/trans.c
@@ -2992,6 +2992,7 @@ call_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, tree gnu_target)
       if (gnu_target)
 	{
 	  Node_Id gnat_parent = Parent (gnat_node);
+	  tree gnu_result_type = TREE_TYPE (gnu_subprog_type);
 	  enum tree_code op_code;
 
 	  /* If range check is needed, emit code to generate it.  */
@@ -3002,11 +3003,15 @@ call_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, tree gnu_target)
 
 	  /* ??? If the return type has non-constant size, then force the
 	     return slot optimization as we would not be able to generate
-	     a temporary.  That's what has been done historically.  */
-	  if (TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (gnu_subprog_type))))
-	    op_code = MODIFY_EXPR;
-	  else
+	     a temporary.  Likewise if it was unconstrained as we would
+	     copy too much data.  That's what has been done historically.  */
+	  if (!TREE_CONSTANT (TYPE_SIZE (gnu_result_type))
+	      || (TYPE_IS_PADDING_P (gnu_result_type)
+		  && CONTAINS_PLACEHOLDER_P
+		     (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (gnu_result_type))))))
 	    op_code = INIT_EXPR;
+	  else
+	    op_code = MODIFY_EXPR;
 
 	  gnu_result
 	    = build_binary_op (op_code, NULL_TREE, gnu_target, gnu_result);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f01e477..55660ef 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2010-08-30  Thomas Quinot  <quinot@adacore.com>
+
+	* gnat.dg/discr24.adb: New test.
+
 2010-08-30  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/45449
diff --git a/gcc/testsuite/gnat.dg/discr24.adb b/gcc/testsuite/gnat.dg/discr24.adb
new file mode 100644
index 0000000..dcd67c4
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/discr24.adb
@@ -0,0 +1,46 @@
+-- { dg-do run }
+-- { dg-options "-gnatp" }
+
+procedure Discr24 is
+
+   type Family_Type is (Family_Inet, Family_Inet6);
+   type Port_Type is new Natural;
+
+   subtype Inet_Addr_Comp_Type is Natural range 0 .. 255;
+
+   type Inet_Addr_VN_Type is array (Natural range <>) of Inet_Addr_Comp_Type;
+
+   subtype Inet_Addr_V4_Type is Inet_Addr_VN_Type (1 ..  4);
+   subtype Inet_Addr_V6_Type is Inet_Addr_VN_Type (1 .. 16);
+
+   type Inet_Addr_Type (Family : Family_Type := Family_Inet) is record
+      case Family is
+         when Family_Inet =>
+            Sin_V4 : Inet_Addr_V4_Type := (others => 0);
+
+         when Family_Inet6 =>
+            Sin_V6 : Inet_Addr_V6_Type := (others => 0);
+      end case;
+   end record;
+
+   type Sock_Addr_Type (Family : Family_Type := Family_Inet) is record
+      Addr : Inet_Addr_Type (Family);
+      Port : Port_Type;
+   end record;
+
+   function F return Inet_Addr_Type is
+   begin
+      return Inet_Addr_Type'
+        (Family => Family_Inet, Sin_V4 => (192, 168, 169, 170));
+   end F;
+
+   SA : Sock_Addr_Type;
+
+begin
+   SA.Addr.Sin_V4 := (172, 16, 17, 18);
+   SA.Port := 1111;
+   SA.Addr := F;
+   if SA.Port /= 1111 then
+     raise Program_Error;
+   end if;
+end;