1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                              E X P _ C H 3                               --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--          Copyright (C) 1992-2012, Free Software Foundation, Inc.         --
10--                                                                          --
11-- GNAT is free software;  you can  redistribute it  and/or modify it under --
12-- terms of the  GNU General Public License as published  by the Free Soft- --
13-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
14-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
15-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
16-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
17-- for  more details.  You should have  received  a copy of the GNU General --
18-- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
19-- http://www.gnu.org/licenses for a complete copy of the license.          --
20--                                                                          --
21-- GNAT was originally developed  by the GNAT team at  New York University. --
22-- Extensive contributions were provided by Ada Core Technologies Inc.      --
23--                                                                          --
24------------------------------------------------------------------------------
25
26--  Expand routines for chapter 3 constructs
27
28with Types;  use Types;
29with Elists; use Elists;
30with Uintp;  use Uintp;
31
32package Exp_Ch3 is
33
34   procedure Expand_N_Object_Declaration         (N : Node_Id);
35   procedure Expand_N_Subtype_Indication         (N : Node_Id);
36   procedure Expand_N_Variant_Part               (N : Node_Id);
37   procedure Expand_N_Full_Type_Declaration      (N : Node_Id);
38
39   procedure Expand_Previous_Access_Type (Def_Id : Entity_Id);
40   --  For a full type declaration that contains tasks, or that is a task,
41   --  check whether there exists an access type whose designated type is an
42   --  incomplete declarations for the current composite type. If so, build the
43   --  master for that access type, now that it is known to denote an object
44   --  with tasks.
45
46   procedure Expand_Record_Extension (T : Entity_Id; Def : Node_Id);
47   --  Add a field _parent in the extension part of the record
48
49   procedure Build_Discr_Checking_Funcs (N : Node_Id);
50   --  Builds function which checks whether the component name is consistent
51   --  with the current discriminants. N is the full type declaration node,
52   --  and the discriminant checking functions are inserted after this node.
53
54   function Build_Initialization_Call
55     (Loc               : Source_Ptr;
56      Id_Ref            : Node_Id;
57      Typ               : Entity_Id;
58      In_Init_Proc      : Boolean := False;
59      Enclos_Type       : Entity_Id := Empty;
60      Discr_Map         : Elist_Id := New_Elmt_List;
61      With_Default_Init : Boolean := False;
62      Constructor_Ref   : Node_Id := Empty) return List_Id;
63   --  Builds a call to the initialization procedure for the base type of Typ,
64   --  passing it the object denoted by Id_Ref, plus additional parameters as
65   --  appropriate for the type (the _Master, for task types, for example).
66   --  Loc is the source location for the constructed tree. In_Init_Proc has
67   --  to be set to True when the call is itself in an init proc in order to
68   --  enable the use of discriminals. Enclos_Type is the enclosing type when
69   --  initializing a component in an outer init proc, and it is used for
70   --  various expansion cases including the case where Typ is a task type
71   --  which is an array component, the indexes of the enclosing type are
72   --  used to build the string that identifies each task at runtime.
73   --
74   --  Discr_Map is used to replace discriminants by their discriminals in
75   --  expressions used to constrain record components. In the presence of
76   --  entry families bounded by discriminants, protected type discriminants
77   --  can appear within expressions in array bounds (not as stand-alone
78   --  identifiers) and a general replacement is necessary.
79   --
80   --  Ada 2005 (AI-287): With_Default_Init is used to indicate that the
81   --  initialization call corresponds to a default initialized component
82   --  of an aggregate.
83   --
84   --  Constructor_Ref is a call to a constructor subprogram. It is currently
85   --  used only to support C++ constructors.
86
87   function Freeze_Type (N : Node_Id) return Boolean;
88   --  This function executes the freezing actions associated with the given
89   --  freeze type node N and returns True if the node is to be deleted. We
90   --  delete the node if it is present just for front end purpose and we don't
91   --  want Gigi to see the node. This function can't delete the node itself
92   --  since it would confuse any remaining processing of the freeze node.
93
94   procedure Init_Secondary_Tags
95     (Typ            : Entity_Id;
96      Target         : Node_Id;
97      Stmts_List     : List_Id;
98      Fixed_Comps    : Boolean := True;
99      Variable_Comps : Boolean := True);
100   --  Ada 2005 (AI-251): Initialize the tags of the secondary dispatch tables
101   --  of Typ. The generated code referencing tag fields of Target is appended
102   --  to Stmts_List. If Fixed_Comps is True then the tag components located at
103   --  fixed positions of Target are initialized; if Variable_Comps is True
104   --  then tags components located at variable positions of Target are
105   --  initialized.
106
107   function Needs_Simple_Initialization
108     (T           : Entity_Id;
109      Consider_IS : Boolean := True) return Boolean;
110   --  Certain types need initialization even though there is no specific
111   --  initialization routine:
112   --    Access types (which need initializing to null)
113   --    All scalar types if Normalize_Scalars mode set
114   --    Descendents of standard string types if Normalize_Scalars mode set
115   --    Scalar types having a Default_Value attribute
116   --  Regarding Initialize_Scalars mode, this is ignored if Consider_IS is
117   --  set to False, but if Consider_IS is set to True, then the cases above
118   --  mentioning Normalize_Scalars also apply for Initialize_Scalars mode.
119
120   function Get_Simple_Init_Val
121     (T    : Entity_Id;
122      N    : Node_Id;
123      Size : Uint := No_Uint) return Node_Id;
124   --  For a type which Needs_Simple_Initialization (see above), prepares the
125   --  tree for an expression representing the required initial value. N is a
126   --  node whose source location used in constructing this tree which is
127   --  returned as the result of the call. The Size parameter indicates the
128   --  target size of the object if it is known (indicated by a value that is
129   --  not No_Uint and is greater than zero). If Size is not given (Size set to
130   --  No_Uint, or non-positive), then the Esize of T is used as an estimate of
131   --  the Size. The object size is needed to prepare a known invalid value for
132   --  use by Normalize_Scalars. A call to this routine where T is a scalar
133   --  type is only valid if we are in Normalize_Scalars or Initialize_Scalars
134   --  mode, or if N is the node for a 'Invalid_Value attribute node.
135
136end Exp_Ch3;
137