1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 2000-2011, Free Software Foundation, Inc. --
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. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 -- Subprograms to set, get and cache external references, to be used as
27 -- External functions in project files.
29 with GNAT.Dynamic_HTables;
33 -------------------------
34 -- External References --
35 -------------------------
37 -- External references influence the way a project tree is processed (in
38 -- particular they provide the values for the typed string variables that
39 -- are then used in case constructions).
41 -- External references are project-tree specific, so that when multiple
42 -- trees are loaded in parallel we can have different scenarios (or even
43 -- load the same tree twice and see different views of it).
45 type External_References is private;
46 No_External_Refs : constant External_References;
49 (Self : out External_References;
50 Copy_From : External_References := No_External_Refs);
51 -- Initialize Self, and copy all values from Copy_From if needed.
52 -- This has no effect if Self was already initialized.
54 procedure Free (Self : in out External_References);
55 -- Free memory used by Self
58 (Self : External_References;
59 External_Name : String;
61 -- Add an external reference (or modify an existing one)
64 (Self : External_References;
65 External_Name : Name_Id;
66 With_Default : Name_Id := No_Name)
68 -- Get the value of an external reference, and cache it for future uses
71 (Self : External_References;
72 Declaration : String) return Boolean;
73 -- Check that an external declaration <external>=<value> is correct.
74 -- If it is correct, the external reference is Added.
76 procedure Reset (Self : External_References);
77 -- Clear the internal data structure that stores the external references
78 -- and free any allocated memory.
82 -- Use a Static_HTable, not a Simple_HTable.
83 -- The issue is that we need to be able to copy the contents of the table
84 -- (in Initialize), but this isn't doable for Simple_HTable for which
85 -- iterators do not return the key.
88 type Name_To_Name_Ptr is access all Name_To_Name;
89 type Name_To_Name is record
92 Next : Name_To_Name_Ptr;
95 procedure Set_Next (E : Name_To_Name_Ptr; Next : Name_To_Name_Ptr);
96 function Next (E : Name_To_Name_Ptr) return Name_To_Name_Ptr;
97 function Get_Key (E : Name_To_Name_Ptr) return Name_Id;
99 package Name_To_Name_HTable is new GNAT.Dynamic_HTables.Static_HTable
100 (Header_Num => Header_Num,
101 Element => Name_To_Name,
102 Elmt_Ptr => Name_To_Name_Ptr,
104 Set_Next => Set_Next,
110 -- General type for htables associating name_id to name_id. This is in
111 -- particular used to store the values of external references.
113 type Instance_Access is access all Name_To_Name_HTable.Instance;
115 type External_References is record
116 Refs : Instance_Access;
117 -- External references are stored in this hash table (and manipulated
118 -- through subprogrames in prj-ext.ads). External references are
119 -- project-tree specific so that one can load the same tree twice but
120 -- have two views of it, for instance.
123 No_External_Refs : constant External_References := (Refs => null);