File : a-comlin.adb


   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                     A D A . C O M M A N D _ L I N E                      --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2013, 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.                                     --
  17 --                                                                          --
  18 --                                                                          --
  19 --                                                                          --
  20 --                                                                          --
  21 --                                                                          --
  22 -- You should have received a copy of the GNU General Public License and    --
  23 -- a copy of the GCC Runtime Library Exception along with this program;     --
  24 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  25 -- <http://www.gnu.org/licenses/>.                                          --
  26 --                                                                          --
  27 -- GNAT was originally developed  by the GNAT team at  New York University. --
  28 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31 
  32 pragma Compiler_Unit_Warning;
  33 
  34 with System; use System;
  35 
  36 package body Ada.Command_Line is
  37 
  38    function Arg_Count return Natural;
  39    pragma Import (C, Arg_Count, "__gnat_arg_count");
  40 
  41    procedure Fill_Arg (A : System.Address; Arg_Num : Integer);
  42    pragma Import (C, Fill_Arg, "__gnat_fill_arg");
  43 
  44    function Len_Arg (Arg_Num : Integer) return Integer;
  45    pragma Import (C, Len_Arg, "__gnat_len_arg");
  46 
  47    -----------------------
  48    -- Local Subprograms --
  49    -----------------------
  50 
  51    function Initialized return Boolean;
  52    --  Checks to ensure that gnat_argc and gnat_argv have been properly
  53    --  initialized.  Returns false if not, or if argv / argc are
  54    --  unsupported on the target (e.g. VxWorks).
  55 
  56    --------------
  57    -- Argument --
  58    --------------
  59 
  60    function Argument (Number : Positive) return String is
  61       Num : Positive;
  62 
  63    begin
  64       if Number > Argument_Count then
  65          raise Constraint_Error;
  66       end if;
  67 
  68       if Remove_Args = null then
  69          Num := Number;
  70       else
  71          Num := Remove_Args (Number);
  72       end if;
  73 
  74       declare
  75          Arg : aliased String (1 .. Len_Arg (Num));
  76       begin
  77          Fill_Arg (Arg'Address, Num);
  78          return Arg;
  79       end;
  80    end Argument;
  81 
  82    --------------------
  83    -- Argument_Count --
  84    --------------------
  85 
  86    function Argument_Count return Natural is
  87    begin
  88       if not Initialized then
  89          --  RM A.15 (11)
  90          return 0;
  91       end if;
  92 
  93       if Remove_Args = null then
  94          return Arg_Count - 1;
  95       else
  96          return Remove_Count;
  97       end if;
  98    end Argument_Count;
  99 
 100    -----------------
 101    -- Initialized --
 102    -----------------
 103 
 104    function Initialized return Boolean is
 105       gnat_argv : System.Address;
 106       pragma Import (C, gnat_argv, "gnat_argv");
 107 
 108    begin
 109       return gnat_argv /= System.Null_Address;
 110    end Initialized;
 111 
 112    ------------------
 113    -- Command_Name --
 114    ------------------
 115 
 116    function Command_Name return String is
 117    begin
 118       if not Initialized then
 119          return "";
 120       end if;
 121 
 122       declare
 123          Arg : aliased String (1 .. Len_Arg (0));
 124 
 125       begin
 126          Fill_Arg (Arg'Address, 0);
 127          return Arg;
 128       end;
 129    end Command_Name;
 130 
 131 end Ada.Command_Line;