xref: /titanic_41/usr/src/cmd/sh/stak.h (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 /*
32  *	UNIX shell
33  */
34 
35 /* To use stack as temporary workspace across
36  * possible storage allocation (eg name lookup)
37  * a) get ptr from `relstak'
38  * b) can now use `pushstak'
39  * c) then reset with `setstak'
40  * d) `absstak' gives real address if needed
41  */
42 #define		relstak()	(staktop-stakbot)
43 #define		absstak(x)	(stakbot+Rcheat(x))
44 #define		setstak(x)	(staktop=absstak(x))
45 #define		pushstak(c)	(*staktop++=(c))
46 #define		zerostak()	(*staktop=0)
47 
48 /* Used to address an item left on the top of
49  * the stack (very temporary)
50  */
51 #define		curstak()	(staktop)
52 
53 /* `usestak' before `pushstak' then `fixstak'
54  * These routines are safe against heap
55  * being allocated.
56  */
57 #define		usestak()	{locstak();}
58 
59 /* for local use only since it hands
60  * out a real address for the stack top
61  */
62 extern unsigned char		*locstak();
63 
64 /* Will allocate the item being used and return its
65  * address (safe now).
66  */
67 #define		fixstak()	endstak(staktop)
68 
69 /* For use after `locstak' to hand back
70  * new stack top and then allocate item
71  */
72 extern unsigned char		*endstak();
73 
74 /* Copy a string onto the stack and
75  * allocate the space.
76  */
77 extern unsigned char		*cpystak();
78 
79 /* Copy a string onto the stack, checking for stack overflow
80  * as the copy is done.  Same calling sequence as "movstr".
81  */
82 extern unsigned char		*movstrstak();
83 
84 /* Move bytes onto the stack, checking for stack overflow
85  * as the copy is done.  Same calling sequence as the C
86  * library routine "memcpy".
87  */
88 extern unsigned char		*memcpystak();
89 
90 /* Allocate given ammount of stack space */
91 extern unsigned char		*getstak();
92 
93 /* Grow the data segment to include a given location */
94 extern void		growstak();
95 
96 /* A chain of ptrs of stack blocks that
97  * have become covered by heap allocation.
98  * `tdystak' will return them to the heap.
99  */
100 extern struct blk	*stakbsy;
101 
102 /* Base of the entire stack */
103 extern unsigned char		*stakbas;
104 
105 /* Top of entire stack */
106 extern unsigned char		*brkend;
107 
108 /* Base of current item */
109 extern unsigned char		*stakbot;
110 
111 /* Top of current item */
112 extern unsigned char		*staktop;
113 
114 /* Used with tdystak */
115 extern unsigned char		*savstak();
116