gcc/ada/prj-ext.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                              P R J . E X T                               --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --             Copyright (C) 2000-2003 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 2,  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 COPYING.  If not, write --
  19 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  20 -- MA 02111-1307, USA.                                                      --
  21 --                                                                          --
  22 -- GNAT was originally developed  by the GNAT team at  New York University. --
  23 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  24 --                                                                          --
  25 ------------------------------------------------------------------------------
  26
  27 with Namet;   use Namet;
  28 with Osint;   use Osint;
  29 with Prj.Com; use Prj.Com;
  30 with Types;   use Types;
  31
  32 with GNAT.HTable;
  33 with GNAT.OS_Lib; use GNAT.OS_Lib;
  34
  35 package body Prj.Ext is
  36
  37    package Htable is new GNAT.HTable.Simple_HTable
  38      (Header_Num => Header_Num,
  39       Element    => Name_Id,
  40       No_Element => No_Name,
  41       Key        => Name_Id,
  42       Hash       => Hash,
  43       Equal      => "=");
  44    --  External references are stored in this hash table, either by procedure
  45    --  Add (directly or through a call to function Check) or by function
  46    --  Value_Of when an environment variable is found non empty. Value_Of
  47    --  first for external reference in this table, before checking the
  48    --  environment. Htable is emptied (reset) by procedure Reset.
  49
  50    ---------
  51    -- Add --
  52    ---------
  53
  54    procedure Add
  55      (External_Name : String;
  56       Value         : String)
  57    is
  58       The_Key   : Name_Id;
  59       The_Value : Name_Id;
  60
  61    begin
  62       Name_Len := Value'Length;
  63       Name_Buffer (1 .. Name_Len) := Value;
  64       The_Value := Name_Find;
  65       Name_Len := External_Name'Length;
  66       Name_Buffer (1 .. Name_Len) := External_Name;
  67       Canonical_Case_File_Name (Name_Buffer (1 .. Name_Len));
  68       The_Key := Name_Find;
  69       Htable.Set (The_Key, The_Value);
  70    end Add;
  71
  72    -----------
  73    -- Check --
  74    -----------
  75
  76    function Check (Declaration : String) return Boolean is
  77    begin
  78       for Equal_Pos in Declaration'Range loop
  79          if Declaration (Equal_Pos) = '=' then
  80             exit when Equal_Pos = Declaration'First;
  81             exit when Equal_Pos = Declaration'Last;
  82             Add
  83               (External_Name =>
  84                  Declaration (Declaration'First .. Equal_Pos - 1),
  85                Value =>
  86                  Declaration (Equal_Pos + 1 .. Declaration'Last));
  87             return True;
  88          end if;
  89       end loop;
  90
  91       return False;
  92    end Check;
  93
  94    -----------
  95    -- Reset --
  96    -----------
  97
  98    procedure Reset is
  99    begin
 100       Htable.Reset;
 101    end Reset;
 102
 103    --------------
 104    -- Value_Of --
 105    --------------
 106
 107    function Value_Of
 108      (External_Name : Name_Id;
 109       With_Default  : Name_Id := No_Name)
 110       return          Name_Id
 111    is
 112       The_Value : Name_Id;
 113       Name      : String := Get_Name_String (External_Name);
 114
 115    begin
 116       Canonical_Case_File_Name (Name);
 117       Name_Len := Name'Length;
 118       Name_Buffer (1 .. Name_Len) := Name;
 119       The_Value := Htable.Get (Name_Find);
 120
 121       if The_Value /= No_Name then
 122          return The_Value;
 123       end if;
 124
 125       --  Find if it is an environment.
 126       --  If it is, put the value in the hash table.
 127
 128       declare
 129          Env_Value : String_Access := Getenv (Name);
 130
 131       begin
 132          if Env_Value /= null and then Env_Value'Length > 0 then
 133             Name_Len := Env_Value'Length;
 134             Name_Buffer (1 .. Name_Len) := Env_Value.all;
 135             The_Value := Name_Find;
 136             Htable.Set (External_Name, The_Value);
 137             Free (Env_Value);
 138             return The_Value;
 139
 140          else
 141             Free (Env_Value);
 142             return With_Default;
 143          end if;
 144       end;
 145    end Value_Of;
 146
 147 end Prj.Ext;