| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- P R J . E X T -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 2000-2011, 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); |
| -- 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. |
| |
| 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; |
