gcc/ada/g-enblsp-vms-ia64.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --         G N A T . E X P E C T . N O N _ B L O C K I N G _ S P A W N      --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --                    Copyright (C) 2005-2010, AdaCore                      --
  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 --  This package provides a target dependent non-blocking spawn function
  33 --  for use by the VMS GNAT.Expect package (g-expect-vms.adb). This package
  34 --  should not be directly with'ed by an application program.
  35
  36 --  This version is for IA64/VMS
  37
  38 separate (GNAT.Expect)
  39 procedure Non_Blocking_Spawn
  40   (Descriptor  : out Process_Descriptor'Class;
  41    Command     : String;
  42    Args        : GNAT.OS_Lib.Argument_List;
  43    Buffer_Size : Natural := 4096;
  44    Err_To_Out  : Boolean := False)
  45 is
  46    function Alloc_Vfork_Blocks return Integer;
  47    pragma Import (C, Alloc_Vfork_Blocks, "decc$$alloc_vfork_blocks");
  48
  49    function Get_Vfork_Jmpbuf return System.Address;
  50    pragma Import (C, Get_Vfork_Jmpbuf, "decc$$get_vfork_jmpbuf");
  51
  52    function Setjmp1 (Addr : System.Address) return Process_Id;
  53    pragma Import (C, Setjmp1, "decc$setjmp1");
  54
  55    Pipe1, Pipe2, Pipe3 : aliased Pipe_Type;
  56
  57    Arg      : String_Access;
  58    Arg_List : aliased array (1 .. Args'Length + 2) of System.Address;
  59
  60    Command_With_Path : String_Access;
  61
  62 begin
  63    --  Create the rest of the pipes
  64
  65    Set_Up_Communications
  66      (Descriptor, Err_To_Out, Pipe1'Access, Pipe2'Access, Pipe3'Access);
  67
  68    Command_With_Path := Locate_Exec_On_Path (Command);
  69
  70    if Command_With_Path = null then
  71       raise Invalid_Process;
  72    end if;
  73
  74    --  Fork a new process (it is not possible to do this in a subprogram)
  75
  76    Descriptor.Pid :=
  77      (if Alloc_Vfork_Blocks >= 0 then Setjmp1 (Get_Vfork_Jmpbuf) else -1);
  78
  79    --  Are we now in the child
  80
  81    if Descriptor.Pid = Null_Pid then
  82
  83       --  Prepare an array of arguments to pass to C
  84
  85       Arg   := new String (1 .. Command_With_Path'Length + 1);
  86       Arg (1 .. Command_With_Path'Length) := Command_With_Path.all;
  87       Arg (Arg'Last)        := ASCII.NUL;
  88       Arg_List (1)          := Arg.all'Address;
  89
  90       for J in Args'Range loop
  91          Arg                     := new String (1 .. Args (J)'Length + 1);
  92          Arg (1 .. Args (J)'Length)  := Args (J).all;
  93          Arg (Arg'Last)              := ASCII.NUL;
  94          Arg_List (J + 2 - Args'First) := Arg.all'Address;
  95       end loop;
  96
  97       Arg_List (Arg_List'Last) := System.Null_Address;
  98
  99       --  This does not return on Unix systems
 100
 101       Set_Up_Child_Communications
 102         (Descriptor, Pipe1, Pipe2, Pipe3, Command_With_Path.all,
 103          Arg_List'Address);
 104    end if;
 105
 106    Free (Command_With_Path);
 107
 108    --  Did we have an error when spawning the child ?
 109
 110    if Descriptor.Pid < Null_Pid then
 111       raise Invalid_Process;
 112    else
 113       --  We are now in the parent process
 114
 115       Set_Up_Parent_Communications (Descriptor, Pipe1, Pipe2, Pipe3);
 116    end if;
 117
 118    --  Create the buffer
 119
 120    Descriptor.Buffer_Size := Buffer_Size;
 121
 122    if Buffer_Size /= 0 then
 123       Descriptor.Buffer := new String (1 .. Positive (Buffer_Size));
 124    end if;
 125 end Non_Blocking_Spawn;