usr/src/cmd/sh/stak.h

   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();