File : s-parame.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S Y S T E M . P A R A M E T E R S --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1995-2013, 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 is the default (used on all native platforms) version of this package
33
34 pragma Compiler_Unit_Warning;
35
36 package body System.Parameters is
37
38 -------------------------
39 -- Adjust_Storage_Size --
40 -------------------------
41
42 function Adjust_Storage_Size (Size : Size_Type) return Size_Type is
43 begin
44 if Size = Unspecified_Size then
45 return Default_Stack_Size;
46 elsif Size < Minimum_Stack_Size then
47 return Minimum_Stack_Size;
48 else
49 return Size;
50 end if;
51 end Adjust_Storage_Size;
52
53 ------------------------
54 -- Default_Stack_Size --
55 ------------------------
56
57 function Default_Stack_Size return Size_Type is
58 Default_Stack_Size : Integer;
59 pragma Import (C, Default_Stack_Size, "__gl_default_stack_size");
60 begin
61 if Default_Stack_Size = -1 then
62 return 2 * 1024 * 1024;
63 else
64 return Size_Type (Default_Stack_Size);
65 end if;
66 end Default_Stack_Size;
67
68 ------------------------
69 -- Minimum_Stack_Size --
70 ------------------------
71
72 function Minimum_Stack_Size return Size_Type is
73 begin
74 -- 12K is required for stack-checking to work reliably on most platforms
75 -- when using the GCC scheme to propagate an exception in the ZCX case.
76 -- 16K is the value of PTHREAD_STACK_MIN under Linux, so is a reasonable
77 -- default.
78
79 return 16 * 1024;
80 end Minimum_Stack_Size;
81
82 end System.Parameters;