File : s-secsta-static.ads
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S Y S T E M . S E C O N D A R Y _ S T A C K --
6 -- --
7 -- S p e c --
8 -- --
9 -- Copyright (C) 1992-2012, 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 static version of this package spec, for use with runtimes
33 -- that don't use dynamic allocation (such as zfp or minimal)
34
35 with System.Storage_Elements;
36
37 package System.Secondary_Stack is
38
39 package SSE renames System.Storage_Elements;
40
41 Default_Secondary_Stack_Size : constant := 10 * 1024;
42 -- Default size of a secondary stack
43
44 procedure SS_Init
45 (Stk : System.Address;
46 Size : Natural := Default_Secondary_Stack_Size);
47 -- Initialize the secondary stack with a main stack of the given Size.
48 --
49 -- Stk is an "in" parameter that is already pointing to a memory area of
50 -- size Size.
51 --
52 -- The secondary stack is fixed, and any attempt to allocate more than the
53 -- initial size will result in a Storage_Error being raised.
54
55 procedure SS_Allocate
56 (Address : out System.Address;
57 Storage_Size : SSE.Storage_Count);
58 -- Allocate enough space for a 'Storage_Size' bytes object with Maximum
59 -- alignment. The address of the allocated space is returned in 'Address'
60
61 type Mark_Id is private;
62 -- Type used to mark the stack
63
64 function SS_Mark return Mark_Id;
65 -- Return the Mark corresponding to the current state of the stack
66
67 procedure SS_Release (M : Mark_Id);
68 -- Restore the state of the stack corresponding to the mark M. If an
69 -- additional chunk have been allocated, it will never be freed during a
70
71 private
72
73 SS_Pool : Integer;
74 -- Unused entity that is just present to ease the sharing of the pool
75 -- mechanism for specific allocation/deallocation in the compiler
76
77 type Mark_Address is new SSE.Integer_Address;
78
79 type Mark_Id is record
80 Mark_Addr : Mark_Address;
81 Unused : System.Address;
82 end record;
83 -- A Mark_Id value contains the address of the mark point in the secondary
84 -- stack. This type is defined as two addresses for compatibility with the
85 -- the standard version of the secondary stack, even though the second
86 -- address is unused in this version. The GNAAMP back end generates calls
87 -- to SS_Mark and SS_Release in certain cases and the calling sequences
88 -- must be compatible.
89
90 end System.Secondary_Stack;