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Diffstat (limited to 'gcc/ada/s-memory.adb')
| -rw-r--r-- | gcc/ada/s-memory.adb | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/gcc/ada/s-memory.adb b/gcc/ada/s-memory.adb new file mode 100644 index 00000000000..4f11aeca738 --- /dev/null +++ b/gcc/ada/s-memory.adb @@ -0,0 +1,142 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT RUN-TIME COMPONENTS -- +-- -- +-- S Y S T E M . M E M O R Y -- +-- -- +-- S p e c -- +-- -- +-- $Revision: 1.2 $ +-- -- +-- Copyright (C) 2001 Free Software Foundation, Inc. -- +-- -- +-- This specification is derived from the Ada Reference Manual for use with -- +-- GNAT. The copyright notice above, and the license provisions that follow -- +-- apply solely to the contents of the part following the private keyword. -- +-- -- +-- 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, 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. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- +-- -- +------------------------------------------------------------------------------ + +-- This is the default implementation of this package. + +-- This implementation assumes that the underlying malloc/free/realloc +-- implementation is thread safe, and thus, no additional lock is required. +-- Note that we still need to defer abortion because on most systems, +-- an asynchronous signal (as used for implementing asynchronous abortion +-- of task) cannot safely be handled while malloc is executing. + +-- If you are not using Ada constructs containing the "abort" keyword, +-- then you can remove the calls to Abort_Defer.all and Abort_Undefer.all +-- from this unit. + +with Ada.Exceptions; +with System.Soft_Links; + +package body System.Memory is + + use Ada.Exceptions; + use System.Soft_Links; + + function c_malloc (Size : size_t) return System.Address; + pragma Import (C, c_malloc, "malloc"); + + procedure c_free (Ptr : System.Address); + pragma Import (C, c_free, "free"); + + function c_realloc + (Ptr : System.Address; Size : size_t) return System.Address; + pragma Import (C, c_realloc, "realloc"); + + ----------- + -- Alloc -- + ----------- + + function Alloc (Size : size_t) return System.Address is + Result : System.Address; + Actual_Size : size_t := Size; + + begin + if Size = size_t'Last then + Raise_Exception (Storage_Error'Identity, "object too large"); + end if; + + -- Change size from zero to non-zero. We still want a proper pointer + -- for the zero case because pointers to zero length objects have to + -- be distinct, but we can't just go ahead and allocate zero bytes, + -- since some malloc's return zero for a zero argument. + + if Size = 0 then + Actual_Size := 1; + end if; + + Abort_Defer.all; + Result := c_malloc (Actual_Size); + Abort_Undefer.all; + + if Result = System.Null_Address then + Raise_Exception (Storage_Error'Identity, "heap exhausted"); + end if; + + return Result; + end Alloc; + + ---------- + -- Free -- + ---------- + + procedure Free (Ptr : System.Address) is + begin + Abort_Defer.all; + c_free (Ptr); + Abort_Undefer.all; + end Free; + + ------------- + -- Realloc -- + ------------- + + function Realloc + (Ptr : System.Address; + Size : size_t) + return System.Address + is + Result : System.Address; + Actual_Size : size_t := Size; + + begin + if Size = size_t'Last then + Raise_Exception (Storage_Error'Identity, "object too large"); + end if; + + Abort_Defer.all; + Result := c_realloc (Ptr, Actual_Size); + Abort_Undefer.all; + + if Result = System.Null_Address then + Raise_Exception (Storage_Error'Identity, "heap exhausted"); + end if; + + return Result; + end Realloc; + +end System.Memory; |