1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
|
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- P R J . E X T --
-- --
-- S p e c --
-- --
-- Copyright (C) 2000-2013, 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- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- Subprograms to set, get and cache external references, to be used as
-- External functions in project files.
with GNAT.Dynamic_HTables;
package Prj.Ext is
-------------------------
-- External References --
-------------------------
-- External references influence the way a project tree is processed (in
-- particular they provide the values for the typed string variables that
-- are then used in case constructions).
-- External references are project-tree specific, so that when multiple
-- trees are loaded in parallel we can have different scenarios (or even
-- load the same tree twice and see different views of it).
type External_References is private;
No_External_Refs : constant External_References;
procedure Initialize
(Self : out External_References;
Copy_From : External_References := No_External_Refs);
-- Initialize Self, and copy all values from Copy_From if needed.
-- This has no effect if Self was already initialized.
procedure Free (Self : in out External_References);
-- Free memory used by Self
type External_Source is
(From_Command_Line,
From_Environment,
From_External_Attribute);
-- Indicates where was the value of an external reference defined. They are
-- prioritized in that order, so that a user can always use the command
-- line to override a value coming from his environment, or an environment
-- variable to override a value defined in an aggregate project through the
-- "for External()..." attribute.
procedure Add
(Self : External_References;
External_Name : String;
Value : String;
Source : External_Source := External_Source'First;
Silent : Boolean := False);
-- Add an external reference (or modify an existing one). No overriding is
-- done if the Source's priority is less than the one used to previously
-- set the value of the variable. The default for Source is such that
-- overriding always occurs. When Silent is True, nothing is output even
-- with non default verbosity.
function Value_Of
(Self : External_References;
External_Name : Name_Id;
With_Default : Name_Id := No_Name)
return Name_Id;
-- Get the value of an external reference, and cache it for future uses
function Check
(Self : External_References;
Declaration : String) return Boolean;
-- Check that an external declaration <external>=<value> is correct.
-- If it is correct, the external reference is Added.
procedure Reset (Self : External_References);
-- Clear the internal data structure that stores the external references
-- and free any allocated memory.
private
-- Use a Static_HTable, rather than a Simple_HTable
-- The issue is that we need to be able to copy the contents of the table
-- (in Initialize), but this isn't doable for Simple_HTable for which
-- iterators do not return the key.
type Name_To_Name;
type Name_To_Name_Ptr is access all Name_To_Name;
type Name_To_Name is record
Key : Name_Id;
Value : Name_Id;
Source : External_Source;
Next : Name_To_Name_Ptr;
end record;
procedure Set_Next (E : Name_To_Name_Ptr; Next : Name_To_Name_Ptr);
function Next (E : Name_To_Name_Ptr) return Name_To_Name_Ptr;
function Get_Key (E : Name_To_Name_Ptr) return Name_Id;
package Name_To_Name_HTable is new GNAT.Dynamic_HTables.Static_HTable
(Header_Num => Header_Num,
Element => Name_To_Name,
Elmt_Ptr => Name_To_Name_Ptr,
Null_Ptr => null,
Set_Next => Set_Next,
Next => Next,
Key => Name_Id,
Get_Key => Get_Key,
Hash => Hash,
Equal => "=");
-- General type for htables associating name_id to name_id. This is in
-- particular used to store the values of external references.
type Instance_Access is access all Name_To_Name_HTable.Instance;
type External_References is record
Refs : Instance_Access;
-- External references are stored in this hash table (and manipulated
-- through subprogrames in prj-ext.ads). External references are
-- project-tree specific so that one can load the same tree twice but
-- have two views of it, for instance.
end record;
No_External_Refs : constant External_References := (Refs => null);
end Prj.Ext;
|
