2010-04-25 Eric Botcazou <ebotcazou@adacore.com>
+ * exp_dbug.ads: Fix outdated description. Mention link between XVS
+ and XVZ objects.
+ * gcc-interface/decl.c (gnat_to_gnu_entity) <E_Record_Subtype>: Set
+ XVZ variable as unit size of XVS type.
+ (maybe_pad_type): Likewise.
+
+2010-04-25 Eric Botcazou <ebotcazou@adacore.com>
+
* gcc-interface/trans.c (gnat_to_gnu) <N_Assignment_Statement>: Do not
use memmove if the array type is bit-packed.
-- --
-- S p e c --
-- --
--- Copyright (C) 1996-2009, Free Software Foundation, Inc. --
+-- Copyright (C) 1996-2010, 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- --
-- The size of the objects typed as x should be obtained from the
-- structure of x (and x___XVE, if applicable) as for ordinary types
-- unless there is a variable named x___XVZ, which, if present, will
- -- hold the size (in bytes) of x.
+ -- hold the size (in bytes) of x; in this latter case, the size of the
+ -- x___XVS type will not be a constant but a reference to x___XVZ.
-- The type x will either be a subtype of y (see also Subtypes of
- -- Variant Records, below) or will contain no fields at all. The layout,
- -- types, and positions of these fields will be accurate, if present.
- -- (Currently, however, the GDB debugger makes no use of x except to
- -- determine its size).
+ -- Variant Records, below) or will contain a single field of type y,
+ -- or no fields at all. The layout, types, and positions of these
+ -- fields will be accurate, if present. (Currently, however, the GDB
+ -- debugger makes no use of x except to determine its size).
- -- Among other uses, XVS types are sometimes used to encode
- -- unconstrained types. For example, given
+ -- Among other uses, XVS types are used to encode unconstrained types.
+ -- For example, given:
--
-- subtype Int is INTEGER range 0..10;
-- type T1 (N: Int := 0) is record
-- the element type for AT1 might have a type defined as if it had
-- been written:
--
- -- type at1___PAD is record null; end record;
+ -- type at1___PAD is record F : T1; end record;
-- for at1___PAD'Size use 16 * 8;
--
- -- and there would also be
+ -- and there would also be:
--
- -- type at1___PAD___XVS is record t1: Integer; end record;
+ -- type at1___PAD___XVS is record t1: reft1; end record;
-- type t1 is ...
+ -- type reft1 is <reference to t1>
--
-- Had the subtype Int been dynamic:
--
if (definition
&& TREE_CODE (gnu_size_unit) != INTEGER_CST
&& !CONTAINS_PLACEHOLDER_P (gnu_size_unit))
- create_var_decl (create_concat_name (gnat_entity, "XVZ"),
- NULL_TREE, sizetype, gnu_size_unit, false,
- false, false, false, NULL, gnat_entity);
+ TYPE_SIZE_UNIT (gnu_subtype_marker)
+ = create_var_decl (create_concat_name (gnat_entity,
+ "XVZ"),
+ NULL_TREE, sizetype, gnu_size_unit,
+ false, false, false, false, NULL,
+ gnat_entity);
}
/* Now we can finalize it. */
add_parallel_type (TYPE_STUB_DECL (record), marker);
if (definition && size && TREE_CODE (size) != INTEGER_CST)
- create_var_decl (concat_name (name, "XVZ"), NULL_TREE, sizetype,
- TYPE_SIZE_UNIT (record), false, false, false,
- false, NULL, gnat_entity);
+ TYPE_SIZE_UNIT (marker)
+ = create_var_decl (concat_name (name, "XVZ"), NULL_TREE, sizetype,
+ TYPE_SIZE_UNIT (record), false, false, false,
+ false, NULL, gnat_entity);
}
rest_of_record_type_compilation (record);