gcc/ada/5amastop.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                     SYSTEM.MACHINE_STATE_OPERATIONS                      --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                         (Version for Alpha/Dec Unix)                     --
   9 --                                                                          --
  10 --           Copyright (C) 1999-2002 Ada Core Technologies, Inc.            --
  11 --                                                                          --
  12 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  13 -- terms of the  GNU General Public License as published  by the Free Soft- --
  14 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  15 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  16 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  17 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  18 -- for  more details.  You should have  received  a copy of the GNU General --
  19 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  20 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  21 -- MA 02111-1307, USA.                                                      --
  22 --                                                                          --
  23 -- As a special exception,  if other files  instantiate  generics from this --
  24 -- unit, or you link  this unit with other files  to produce an executable, --
  25 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  26 -- covered  by the  GNU  General  Public  License.  This exception does not --
  27 -- however invalidate  any other reasons why  the executable file  might be --
  28 -- covered by the  GNU Public License.                                      --
  29 --                                                                          --
  30 -- GNAT was originally developed  by the GNAT team at  New York University. --
  31 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  32 --                                                                          --
  33 ------------------------------------------------------------------------------
  34
  35 --  This version of System.Machine_State_Operations is for use on
  36 --  Alpha systems running DEC Unix.
  37
  38 with System.Memory;
  39
  40 package body System.Machine_State_Operations is
  41
  42    use System.Exceptions;
  43
  44    pragma Linker_Options ("-lexc");
  45    --  Needed for definitions of exc_capture_context and exc_virtual_unwind
  46
  47    ----------------------------
  48    -- Allocate_Machine_State --
  49    ----------------------------
  50
  51    function Allocate_Machine_State return Machine_State is
  52       use System.Storage_Elements;
  53
  54       function c_machine_state_length return Storage_Offset;
  55       pragma Import (C, c_machine_state_length, "__gnat_machine_state_length");
  56
  57    begin
  58       return Machine_State
  59         (Memory.Alloc (Memory.size_t (c_machine_state_length)));
  60    end Allocate_Machine_State;
  61
  62    -------------------
  63    -- Enter_Handler --
  64    -------------------
  65
  66    procedure Enter_Handler (M : Machine_State; Handler : Handler_Loc) is
  67       procedure c_enter_handler (M : Machine_State; Handler : Handler_Loc);
  68       pragma Import (C, c_enter_handler, "__gnat_enter_handler");
  69
  70    begin
  71       c_enter_handler (M, Handler);
  72    end Enter_Handler;
  73
  74    ----------------
  75    -- Fetch_Code --
  76    ----------------
  77
  78    function Fetch_Code (Loc : Code_Loc) return Code_Loc is
  79    begin
  80       return Loc;
  81    end Fetch_Code;
  82
  83    ------------------------
  84    -- Free_Machine_State --
  85    ------------------------
  86
  87    procedure Free_Machine_State (M : in out Machine_State) is
  88    begin
  89       Memory.Free (Address (M));
  90       M := Machine_State (Null_Address);
  91    end Free_Machine_State;
  92
  93    ------------------
  94    -- Get_Code_Loc --
  95    ------------------
  96
  97    function Get_Code_Loc (M : Machine_State) return Code_Loc is
  98       Asm_Call_Size : constant := 4;
  99
 100       function c_get_code_loc (M : Machine_State) return Code_Loc;
 101       pragma Import (C, c_get_code_loc, "__gnat_get_code_loc");
 102
 103       --  Code_Loc returned by c_get_code_loc is the return point but here we
 104       --  want Get_Code_Loc to return the call point. Under DEC Unix a call
 105       --  asm instruction takes 4 bytes. So we must remove this value from
 106       --  c_get_code_loc to have the call point.
 107
 108       Loc : Code_Loc := c_get_code_loc (M);
 109    begin
 110       if Loc = 0 then
 111          return 0;
 112       else
 113          return Loc - Asm_Call_Size;
 114       end if;
 115    end Get_Code_Loc;
 116
 117    --------------------------
 118    -- Machine_State_Length --
 119    --------------------------
 120
 121    function Machine_State_Length
 122      return System.Storage_Elements.Storage_Offset
 123    is
 124       use System.Storage_Elements;
 125
 126       function c_machine_state_length return Storage_Offset;
 127       pragma Import (C, c_machine_state_length, "__gnat_machine_state_length");
 128
 129    begin
 130       return c_machine_state_length;
 131    end Machine_State_Length;
 132
 133    ---------------
 134    -- Pop_Frame --
 135    ---------------
 136
 137    procedure Pop_Frame
 138      (M    : Machine_State;
 139       Info : Subprogram_Info_Type)
 140    is
 141       pragma Warnings (Off, Info);
 142
 143       procedure exc_virtual_unwind
 144         (Fcn  : System.Address;
 145          M    : Machine_State);
 146       pragma Import (C, exc_virtual_unwind, "exc_virtual_unwind");
 147
 148    begin
 149       exc_virtual_unwind (System.Null_Address, M);
 150    end Pop_Frame;
 151
 152    -----------------------
 153    -- Set_Machine_State --
 154    -----------------------
 155
 156    procedure Set_Machine_State (M : Machine_State) is
 157       procedure c_capture_context (M : Machine_State);
 158       pragma Import (C, c_capture_context, "exc_capture_context");
 159
 160    begin
 161       c_capture_context (M);
 162       Pop_Frame (M, System.Null_Address);
 163    end Set_Machine_State;
 164
 165    ------------------------------
 166    -- Set_Signal_Machine_State --
 167    ------------------------------
 168
 169    procedure Set_Signal_Machine_State
 170      (M       : Machine_State;
 171       Context : System.Address)
 172    is
 173       pragma Warnings (Off, M);
 174       pragma Warnings (Off, Context);
 175
 176    begin
 177       null;
 178    end Set_Signal_Machine_State;
 179
 180 end System.Machine_State_Operations;