+++ /dev/null
-------------------------------------------------------------------------------
--- --
--- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
--- --
--- S Y S T E M . S T A C K _ C H E C K I N G --
--- --
--- S p e c --
--- --
--- $Revision: 1.1.16.1 $
--- --
--- Copyright (C) 1999-2001 Free Software Foundation, Inc. --
--- --
--- GNARL 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. GNARL 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 GNARL; see file COPYING. If not, write --
--- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
--- MA 02111-1307, 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. --
--- --
--- GNARL was developed by the GNARL team at Florida State University. --
--- Extensive contributions were provided by Ada Core Technologies Inc. --
--- --
-------------------------------------------------------------------------------
-
--- This package provides a system-independent implementation of stack
--- checking using comparison with stack base and limit.
-
-with System.Storage_Elements;
-
-pragma Polling (Off);
--- Turn off polling, we do not want polling to take place during stack
--- checking operations. It causes infinite loops and other problems.
-
-package System.Stack_Checking is
- type Stack_Info is record
- Limit : System.Address := System.Null_Address;
- Base : System.Address := System.Null_Address;
- Size : System.Storage_Elements.Storage_Offset := 0;
- end record;
- -- This record may be part of a larger data structure like the
- -- task control block in the tasking case.
- -- This specific layout has the advantage of being compatible with the
- -- Intel x86 BOUNDS instruction.
-
- type Stack_Access is access all Stack_Info;
- -- Unique local storage associated with a specific task. This storage is
- -- used for the stack base and limit, and is returned by Checked_Self.
- -- Only self may write this information, it may be read by any task.
- -- At no time the address range Limit .. Base (or Base .. Limit for
- -- upgrowing stack) may contain any address that is part of another stack.
- -- The Stack_Access may be part of a larger data structure.
-
- Multi_Processor : constant Boolean := False; -- Not supported yet
-
- ----------------------
- -- Client Interface --
- ----------------------
-
- procedure Set_Stack_Size
- (Stack_Size : System.Storage_Elements.Storage_Offset);
- -- Specify the stack size for the current task.
-
- procedure Update_Stack_Cache (Stack : Stack_Access);
- -- Set the stack cache for the current task. Note that this is only
- -- for optimization purposes, nothing can be assumed about the
- -- contents of the cache at any time, see Set_Stack_Info.
-
- procedure Invalidate_Stack_Cache (Any_Stack : Stack_Access);
- -- Invalidate cache entries for the task T that owns Any_Stack.
- -- This causes the Set_Stack_Info function to be called during
- -- the next stack check done by T. This can be used to interrupt
- -- task T asynchronously.
- -- Stack_Check should be called in loops for this to work reliably.
-
- function Stack_Check (Stack_Address : System.Address) return Stack_Access;
- -- This version of Stack_Check should not be inlined.
-
-private
-
- Null_Stack_Info : aliased Stack_Info :=
- (Limit => System.Null_Address,
- Base => System.Null_Address,
- Size => 0);
- -- Use explicit assignment to avoid elaboration code (call to _init_proc).
-
- Null_Stack : constant Stack_Access := Null_Stack_Info'Access;
- -- Stack_Access value that will return a Stack_Base and Stack_Limit
- -- that fail any stack check.
-
- Cache : aliased Stack_Access := Null_Stack;
-
- pragma Export (C, Cache, "_gnat_stack_cache");
- pragma Export (C, Stack_Check, "_gnat_stack_check");
-
-end System.Stack_Checking;
projects / msp430-gcc.git / blobdiff