File : exp_ch3.ads
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- E X P _ C H 3 --
6 -- --
7 -- S p e c --
8 -- --
9 -- Copyright (C) 1992-2015, 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
28 with Types; use Types;
29 with Elists; use Elists;
30 with Uintp; use Uintp;
31
32 package 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 Make_Tag_Assignment (N : Node_Id) return Node_Id;
108 -- An object declaration that has an initialization for a tagged object
109 -- requires a separate reassignment of the tag of the given type, because
110 -- the expression may include an unchecked conversion. This tag assignment
111 -- is inserted after the declaration, but if the object has an address
112 -- clause the assignment is handled as part of the freezing of the object,
113 -- see Check_Address_Clause.
114
115 function Needs_Simple_Initialization
116 (T : Entity_Id;
117 Consider_IS : Boolean := True) return Boolean;
118 -- Certain types need initialization even though there is no specific
119 -- initialization routine:
120 -- Access types (which need initializing to null)
121 -- All scalar types if Normalize_Scalars mode set
122 -- Descendants of standard string types if Normalize_Scalars mode set
123 -- Scalar types having a Default_Value attribute
124 -- Regarding Initialize_Scalars mode, this is ignored if Consider_IS is
125 -- set to False, but if Consider_IS is set to True, then the cases above
126 -- mentioning Normalize_Scalars also apply for Initialize_Scalars mode.
127
128 function Get_Simple_Init_Val
129 (T : Entity_Id;
130 N : Node_Id;
131 Size : Uint := No_Uint) return Node_Id;
132 -- For a type which Needs_Simple_Initialization (see above), prepares the
133 -- tree for an expression representing the required initial value. N is a
134 -- node whose source location used in constructing this tree which is
135 -- returned as the result of the call. The Size parameter indicates the
136 -- target size of the object if it is known (indicated by a value that is
137 -- not No_Uint and is greater than zero). If Size is not given (Size set to
138 -- No_Uint, or non-positive), then the Esize of T is used as an estimate of
139 -- the Size. The object size is needed to prepare a known invalid value for
140 -- use by Normalize_Scalars. A call to this routine where T is a scalar
141 -- type is only valid if we are in Normalize_Scalars or Initialize_Scalars
142 -- mode, or if N is the node for a 'Invalid_Value attribute node.
143
144 end Exp_Ch3;