stor-layout.c (skip_simple_constant_arithmetic): New function.

	* stor-layout.c (skip_simple_constant_arithmetic): New function.
	(self_referential_size): Use it instead of skip_simple_arithmetic.

From-SVN: r165716

gcc/ChangeLog

+2010-10-20  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* stor-layout.c (skip_simple_constant_arithmetic): New function.
+	(self_referential_size): Use it instead of skip_simple_arithmetic.
+
 2010-10-20  Olivier Hainque  <hainque@adacore.com>
 
 	* config/rs6000/rs6000.c (rs6000_reg_live_or_pic_offset_p):

gcc/stor-layout.c

@@ -173,6 +173,32 @@ variable_size (tree size)
 /* An array of functions used for self-referential size computation.  */
 static GTY(()) VEC (tree, gc) *size_functions;
 
+/* Look inside EXPR into simple arithmetic operations involving constants.
+   Return the outermost non-arithmetic or non-constant node.  */
+
+static tree
+skip_simple_constant_arithmetic (tree expr)
+{
+  while (true)
+    {
+      if (UNARY_CLASS_P (expr))
+	expr = TREE_OPERAND (expr, 0);
+      else if (BINARY_CLASS_P (expr))
+	{
+	  if (TREE_CONSTANT (TREE_OPERAND (expr, 1)))
+	    expr = TREE_OPERAND (expr, 0);
+	  else if (TREE_CONSTANT (TREE_OPERAND (expr, 0)))
+	    expr = TREE_OPERAND (expr, 1);
+	  else
+	    break;
+	}
+      else
+	break;
+    }
+
+  return expr;
+}
+
 /* Similar to copy_tree_r but do not copy component references involving
    PLACEHOLDER_EXPRs.  These nodes are spotted in find_placeholder_in_expr
    and substituted in substitute_in_expr.  */
@@ -241,7 +267,7 @@ self_referential_size (tree size)
   VEC(tree,gc) *args = NULL;
 
   /* Do not factor out simple operations.  */
-  t = skip_simple_arithmetic (size);
+  t = skip_simple_constant_arithmetic (size);
   if (TREE_CODE (t) == CALL_EXPR)
     return size;
 

gcc/testsuite/ChangeLog

+2010-10-20  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gnat.dg/discr25.adb: New test.
+	* gnat.dg/discr25_pkg.ad[sb]: New helper.
+
 2010-10-20  Olivier Hainque  <hainque@adacore.com>
 
 	* gcc.target/powerpc/ehreturn.c: New test.

gcc/testsuite/gnat.dg/discr25.adb

+-- { dg-do compile }
+
+with Discr25_Pkg;
+
+procedure Discr25 (N : Natural) is
+
+  package Test_Set is new Discr25_Pkg (N);
+
+begin
+  null;
+end;

gcc/testsuite/gnat.dg/discr25_pkg.adb

+package body Discr25_Pkg is
+
+  type Arr1 is array (Natural range <>) of Integer;
+
+  B : constant Boolean := N > 0;
+
+  type Arr2 is array (True .. B) of Integer;
+
+  type Obj_T (Size_Max : Natural) is record
+    A2 : Arr2;
+    A1 : Arr1 (0 .. Size_Max);
+  end record;
+
+  procedure Proc1 (Set : in out T) is
+  begin
+    Set := new Obj_T'(Set.all);
+  end;
+
+  procedure Proc2 (Obj : in out T; L : Natural) is
+  begin
+    Obj := new Obj_T (L);
+  end;
+
+end Discr25_Pkg;

gcc/testsuite/gnat.dg/discr25_pkg.ads

+generic
+
+  N : Natural;
+
+package Discr25_Pkg is
+
+  type T is private;
+
+  procedure Proc1 (Set : in out T);
+
+private
+  type Obj_T (Size_Max : Natural);
+  type T is access Obj_T;
+
+end Discr25_Pkg;