When manipulating bounded tree-based container objects, that do not otherwise
have any explicit initialization expression, the compiler would emit a warning
about the object not being initialized, because the Nodes component of the tree
type had not been given an initialization expression.
This warning is a false positive, because the logical state of the object is
empty, and other components of the tree record type are initialized, in a
manner that establishes the representation invariant of the object.
In order to eliminate the warning, the Nodes component of the tree type was
given an initialization expression.
Tested on x86_64-pc-linux-gnu, committed on trunk
2011-08-31 Matthew Heaney <hea...@adacore.com>
* a-crbltr.ads (Tree_Type): Default-initialize the Nodes component.
Index: a-crbltr.ads
===================================================================
--- a-crbltr.ads (revision 178358)
+++ a-crbltr.ads (working copy)
@@ -6,7 +6,7 @@
-- --
-- S p e c --
-- --
--- Copyright (C) 2004-2010, Free Software Foundation, Inc. --
+-- Copyright (C) 2004-2011, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
@@ -53,6 +53,13 @@
package Generic_Bounded_Tree_Types is
type Nodes_Type is array (Count_Type range <>) of Node_Type;
+ -- Note that objects of type Tree_Type are logically initialized (in the
+ -- sense that representation invariants of type are satisfied by dint of
+ -- default initialization), even without the Nodes component also having
+ -- its own initialization expression. We only initializae the Nodes
+ -- component here in order to prevent spurious compiler warnings about
+ -- the container object not being fully initialized.
+
type Tree_Type (Capacity : Count_Type) is tagged record
First : Count_Type := 0;
Last : Count_Type := 0;
@@ -61,7 +68,7 @@
Busy : Natural := 0;
Lock : Natural := 0;
Free : Count_Type'Base := -1;
- Nodes : Nodes_Type (1 .. Capacity);
+ Nodes : Nodes_Type (1 .. Capacity) := (others => <>);
end record;
end Generic_Bounded_Tree_Types;
