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Diffstat (limited to 'gcc/ada/libgnat/s-memory.ads')
| -rw-r--r-- | gcc/ada/libgnat/s-memory.ads | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/gcc/ada/libgnat/s-memory.ads b/gcc/ada/libgnat/s-memory.ads new file mode 100644 index 0000000..a911ce7 --- /dev/null +++ b/gcc/ada/libgnat/s-memory.ads @@ -0,0 +1,107 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT RUN-TIME COMPONENTS -- +-- -- +-- S Y S T E M . M E M O R Y -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 2001-2017, Free Software Foundation, Inc. -- +-- -- +-- 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 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/>. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +-- This package provides the low level memory allocation/deallocation +-- mechanisms used by GNAT. + +-- To provide an alternate implementation, simply recompile the modified +-- body of this package with gnatmake -u -a -g s-memory.adb and make sure +-- that the ali and object files for this unit are found in the object +-- search path. + +-- This unit may be used directly from an application program by providing +-- an appropriate WITH, and the interface can be expected to remain stable. + +pragma Compiler_Unit_Warning; + +package System.Memory is + pragma Elaborate_Body; + + type size_t is mod 2 ** Standard'Address_Size; + -- Note: the reason we redefine this here instead of using the + -- definition in Interfaces.C is that we do not want to drag in + -- all of Interfaces.C just because System.Memory is used. + + function Alloc (Size : size_t) return System.Address; + -- This is the low level allocation routine. Given a size in storage + -- units, it returns the address of a maximally aligned block of + -- memory. The implementation of this routine is guaranteed to be + -- task safe, and also aborts are deferred if necessary. + -- + -- If Size is set to size_t'Last on entry, then a Storage_Error + -- exception is raised with a message "object too large". + -- + -- If Size is set to zero on entry, then a minimal (but non-zero) + -- size block is allocated. + -- + -- Note: this is roughly equivalent to the standard C malloc call + -- with the additional semantics as described above. + + procedure Free (Ptr : System.Address); + -- This is the low level free routine. It frees a block previously + -- allocated with a call to Alloc. As in the case of Alloc, this + -- call is guaranteed task safe, and aborts are deferred. + -- + -- Note: this is roughly equivalent to the standard C free call + -- with the additional semantics as described above. + + function Realloc + (Ptr : System.Address; + Size : size_t) return System.Address; + -- This is the low level reallocation routine. It takes an existing + -- block address returned by a previous call to Alloc or Realloc, + -- and reallocates the block. The size can either be increased or + -- decreased. If possible the reallocation is done in place, so that + -- the returned result is the same as the value of Ptr on entry. + -- However, it may be necessary to relocate the block to another + -- address, in which case the information is copied to the new + -- block, and the old block is freed. The implementation of this + -- routine is guaranteed to be task safe, and also aborts are + -- deferred as necessary. + -- + -- If Size is set to size_t'Last on entry, then a Storage_Error + -- exception is raised with a message "object too large". + -- + -- If Size is set to zero on entry, then a minimal (but non-zero) + -- size block is allocated. + -- + -- Note: this is roughly equivalent to the standard C realloc call + -- with the additional semantics as described above. + +private + + -- The following names are used from the generated compiler code + + pragma Export (C, Alloc, "__gnat_malloc"); + pragma Export (C, Free, "__gnat_free"); + pragma Export (C, Realloc, "__gnat_realloc"); + +end System.Memory; |