File : s-memory-cert.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT RUN-TIME COMPONENTS --
4 -- --
5 -- S Y S T E M . M E M O R Y --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 2001-2014, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
17 -- --
18 -- --
19 -- --
20 -- --
21 -- --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
26 -- --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
29 -- --
30 ------------------------------------------------------------------------------
31
32 -- This implementation assumes that the underlying malloc/free/realloc
33 -- implementation is thread safe, and thus, no additional lock is required.
34
35 with Ada.Exceptions;
36
37 package body System.Memory is
38
39 use Ada.Exceptions;
40
41 function c_malloc (Size : size_t) return System.Address;
42 pragma Import (C, c_malloc, "malloc");
43
44 -----------
45 -- Alloc --
46 -----------
47
48 function Alloc (Size : size_t) return System.Address is
49 Result : System.Address;
50 Actual_Size : size_t := Size;
51
52 begin
53 if Size = size_t'Last then
54 Raise_Exception (Storage_Error'Identity, "object too large");
55 end if;
56
57 -- Change size from zero to non-zero. We still want a proper pointer
58 -- for the zero case because pointers to zero length objects have to
59 -- be distinct, but we can't just go ahead and allocate zero bytes,
60 -- since some malloc's return zero for a zero argument.
61
62 if Size = 0 then
63 Actual_Size := 1;
64 end if;
65
66 Result := c_malloc (Actual_Size);
67
68 if Result = System.Null_Address then
69 Raise_Exception (Storage_Error'Identity, "heap exhausted");
70 end if;
71
72 return Result;
73 end Alloc;
74
75 ----------
76 -- Free --
77 ----------
78
79 procedure Free (Ptr : System.Address) is
80 begin
81 raise Program_Error;
82 end Free;
83
84 end System.Memory;