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Diffstat (limited to 'gcc-4.4.3/gcc/ada/s-stchop.ads')
| -rw-r--r-- | gcc-4.4.3/gcc/ada/s-stchop.ads | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/gcc-4.4.3/gcc/ada/s-stchop.ads b/gcc-4.4.3/gcc/ada/s-stchop.ads new file mode 100644 index 000000000..014eddc41 --- /dev/null +++ b/gcc-4.4.3/gcc/ada/s-stchop.ads @@ -0,0 +1,82 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS -- +-- -- +-- S Y S T E M . S T A C K _ C H E C K I N G . O P E R A T I O N S -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 1999-2009, 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 3, 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. -- +-- -- +-- As a special exception under Section 7 of GPL version 3, you are granted -- +-- additional permissions described in the GCC Runtime Library Exception, -- +-- version 3.1, as published by the Free Software Foundation. -- +-- -- +-- You should have received a copy of the GNU General Public License and -- +-- a copy of the GCC Runtime Library Exception along with this program; -- +-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- +-- <http://www.gnu.org/licenses/>. -- +-- -- +-- GNARL was developed by the GNARL team at Florida State University. -- +-- Extensive contributions were provided by Ada Core Technologies, Inc. -- +-- -- +------------------------------------------------------------------------------ + +-- This package provides a implementation of stack checking operations using +-- comparison with stack base and limit. + +pragma Restrictions (No_Elaboration_Code); +-- We want to guarantee the absence of elaboration code because the binder +-- does not handle references to this package. + +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. + +with System.Storage_Elements; + +package System.Stack_Checking.Operations is + pragma Preelaborate; + + 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. + -- + -- The stack cache should contain the bounds of the current task. But + -- because the RTS is not aware of task switches, the stack cache may be + -- incorrect. So when the stack pointer is not within the bounds of the + -- stack cache, Stack_Check first update the cache (which is a costly + -- operation hence the need of a cache). + + 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 + + procedure Notify_Stack_Attributes + (Initial_SP : System.Address; + Size : System.Storage_Elements.Storage_Offset); + -- Register Initial_SP as the initial stack pointer value for the current + -- task when it starts and Size as the associated stack area size. This + -- should be called once, after the soft-links have been initialized and + -- prior to the first "Stack_Check" call. + +private + 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.Operations; |