------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- SYSTEM.MACHINE_STATE_OPERATIONS -- -- -- -- B o d y -- -- (Version for Alpha/Dec Unix) -- -- -- -- Copyright (C) 1999-2005, AdaCore -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 2, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING. If not, write -- -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- -- Boston, MA 02110-1301, USA. -- -- -- -- As a special exception, if other files instantiate generics from this -- -- unit, or you link this unit with other files to produce an executable, -- -- this unit does not by itself cause the resulting executable to be -- -- covered by the GNU General Public License. This exception does not -- -- however invalidate any other reasons why the executable file might be -- -- covered by the GNU Public License. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- This version of System.Machine_State_Operations is for use on -- Alpha systems running DEC Unix. with System.Memory; package body System.Machine_State_Operations is pragma Linker_Options ("-lexc"); -- Needed for definitions of exc_capture_context and exc_virtual_unwind ---------------------------- -- Allocate_Machine_State -- ---------------------------- function Allocate_Machine_State return Machine_State is use System.Storage_Elements; function c_machine_state_length return Storage_Offset; pragma Import (C, c_machine_state_length, "__gnat_machine_state_length"); begin return Machine_State (Memory.Alloc (Memory.size_t (c_machine_state_length))); end Allocate_Machine_State; ---------------- -- Fetch_Code -- ---------------- function Fetch_Code (Loc : Code_Loc) return Code_Loc is begin return Loc; end Fetch_Code; ------------------------ -- Free_Machine_State -- ------------------------ procedure Free_Machine_State (M : in out Machine_State) is begin Memory.Free (Address (M)); M := Machine_State (Null_Address); end Free_Machine_State; ------------------ -- Get_Code_Loc -- ------------------ function Get_Code_Loc (M : Machine_State) return Code_Loc is Asm_Call_Size : constant := 4; function c_get_code_loc (M : Machine_State) return Code_Loc; pragma Import (C, c_get_code_loc, "__gnat_get_code_loc"); -- Code_Loc returned by c_get_code_loc is the return point but here we -- want Get_Code_Loc to return the call point. Under DEC Unix a call -- asm instruction takes 4 bytes. So we must remove this value from -- c_get_code_loc to have the call point. Loc : constant Code_Loc := c_get_code_loc (M); begin if Loc = 0 then return 0; else return Loc - Asm_Call_Size; end if; end Get_Code_Loc; -------------------------- -- Machine_State_Length -- -------------------------- function Machine_State_Length return System.Storage_Elements.Storage_Offset is use System.Storage_Elements; function c_machine_state_length return Storage_Offset; pragma Import (C, c_machine_state_length, "__gnat_machine_state_length"); begin return c_machine_state_length; end Machine_State_Length; --------------- -- Pop_Frame -- --------------- procedure Pop_Frame (M : Machine_State) is procedure exc_virtual_unwind (Fcn : System.Address; M : Machine_State); pragma Import (C, exc_virtual_unwind, "exc_virtual_unwind"); function exc_lookup_function (Loc : Code_Loc) return System.Address; pragma Import (C, exc_lookup_function, "exc_lookup_function_entry"); procedure c_set_code_loc (M : Machine_State; Loc : Code_Loc); pragma Import (C, c_set_code_loc, "__gnat_set_code_loc"); -- Look for a code-range descriptor table containing the PC of the -- specified machine state. If we don't find any, attempting to unwind -- further would fail so we set the machine state's code location to a -- value indicating that the top of the call chain is reached. This -- happens when the function at the address pointed to by PC has not -- been registered with the unwinding machinery, as with the __istart -- functions generated by the linker in presence of initialization -- routines for example. Prf : constant System.Address := exc_lookup_function (Get_Code_Loc (M)); begin if Prf = System.Null_Address then c_set_code_loc (M, 0); else exc_virtual_unwind (Prf, M); end if; end Pop_Frame; ----------------------- -- Set_Machine_State -- ----------------------- procedure Set_Machine_State (M : Machine_State) is procedure c_capture_context (M : Machine_State); pragma Import (C, c_capture_context, "exc_capture_context"); begin c_capture_context (M); Pop_Frame (M); end Set_Machine_State; end System.Machine_State_Operations;