gcc/ada/libgnat/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) 1992-2017, 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 -- As a special exception under Section 7 of GPL version 3, you are granted --
  19 -- additional permissions described in the GCC Runtime Library Exception,   --
  20 -- version 3.1, as published by the Free Software Foundation.               --
  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 with System; use System;
  33
  34 package body Ada.Command_Line is
  35
  36    function Arg_Count return Natural;
  37    pragma Import (C, Arg_Count, "__gnat_arg_count");
  38
  39    procedure Fill_Arg (A : System.Address; Arg_Num : Integer);
  40    pragma Import (C, Fill_Arg, "__gnat_fill_arg");
  41
  42    function Len_Arg (Arg_Num : Integer) return Integer;
  43    pragma Import (C, Len_Arg, "__gnat_len_arg");
  44
  45    -----------------------
  46    -- Local Subprograms --
  47    -----------------------
  48
  49    function Initialized return Boolean;
  50    --  Checks to ensure that gnat_argc and gnat_argv have been properly
  51    --  initialized.  Returns false if not, or if argv / argc are
  52    --  unsupported on the target (e.g. VxWorks).
  53
  54    --------------
  55    -- Argument --
  56    --------------
  57
  58    function Argument (Number : Positive) return String is
  59    begin
  60       if Number > Argument_Count then
  61          raise Constraint_Error;
  62       end if;
  63
  64       declare
  65          Num : constant Positive :=
  66                  (if Remove_Args = null then Number else Remove_Args (Number));
  67          Arg : aliased String (1 .. Len_Arg (Num));
  68       begin
  69          Fill_Arg (Arg'Address, Num);
  70          return Arg;
  71       end;
  72    end Argument;
  73
  74    --------------------
  75    -- Argument_Count --
  76    --------------------
  77
  78    function Argument_Count return Natural is
  79    begin
  80       if not Initialized then
  81          --  RM A.15 (11)
  82          return 0;
  83       end if;
  84
  85       if Remove_Args = null then
  86          return Arg_Count - 1;
  87       else
  88          return Remove_Count;
  89       end if;
  90    end Argument_Count;
  91
  92    -----------------
  93    -- Initialized --
  94    -----------------
  95
  96    function Initialized return Boolean is
  97       gnat_argv : System.Address;
  98       pragma Import (C, gnat_argv, "gnat_argv");
  99
 100    begin
 101       return gnat_argv /= System.Null_Address;
 102    end Initialized;
 103
 104    ------------------
 105    -- Command_Name --
 106    ------------------
 107
 108    function Command_Name return String is
 109    begin
 110       if not Initialized then
 111          return "";
 112       end if;
 113
 114       declare
 115          Arg : aliased String (1 .. Len_Arg (0));
 116
 117       begin
 118          Fill_Arg (Arg'Address, 0);
 119          return Arg;
 120       end;
 121    end Command_Name;
 122
 123 end Ada.Command_Line;