| ------------------------------------------------------------------------------ |
| -- -- |
| -- 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; |
