90 lines
2.2 KiB
C
90 lines
2.2 KiB
C
/* Copyright (c) 1990, 1991 UNIX System Laboratories, Inc. */
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/* Copyright (c) 1984, 1986, 1987, 1988, 1989, 1990 AT&T */
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/* All Rights Reserved */
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/* THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF */
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/* UNIX System Laboratories, Inc. */
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/* The copyright notice above does not evidence any */
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/* actual or intended publication of such source code. */
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#ident "@(#)sh:stak.h 1.7.4.1"
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/*
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* UNIX shell
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*/
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/* To use stack as temporary workspace across
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* possible storage allocation (eg name lookup)
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* a) get ptr from `relstak'
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* b) can now use `pushstak'
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* c) then reset with `setstak'
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* d) `absstak' gives real address if needed
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*/
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#define relstak() (staktop-stakbot)
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#define absstak(x) (stakbot+Rcheat(x))
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#define setstak(x) (staktop=absstak(x))
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#define pushstak(c) (*staktop++=(c))
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#define zerostak() (*staktop=0)
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/* Used to address an item left on the top of
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* the stack (very temporary)
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*/
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#define curstak() (staktop)
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/* `usestak' before `pushstak' then `fixstak'
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* These routines are safe against heap
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* being allocated.
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*/
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#define usestak() {locstak();}
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/* for local use only since it hands
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* out a real address for the stack top
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*/
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extern unsigned char *locstak();
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/* Will allocate the item being used and return its
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* address (safe now).
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*/
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#define fixstak() endstak(staktop)
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/* For use after `locstak' to hand back
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* new stack top and then allocate item
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*/
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extern unsigned char *endstak();
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/* Copy a string onto the stack and
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* allocate the space.
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*/
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#ifdef __STDC__
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extern void *cpystak();
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#else
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extern unsigned char *cpystak();
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#endif
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/* Allocate given ammount of stack space */
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#ifdef __STDC__
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extern void *getstak();
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#else
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extern unsigned char *getstak();
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#endif
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/* A chain of ptrs of stack blocks that
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* have become covered by heap allocation.
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* `tdystak' will return them to the heap.
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*/
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extern struct blk *stakbsy;
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/* Base of the entire stack */
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extern unsigned char *stakbas;
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/* Top of entire stack */
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extern unsigned char *brkend;
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/* Base of current item */
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extern unsigned char *stakbot;
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/* Top of current item */
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extern unsigned char *staktop;
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/* Used with tdystak */
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extern unsigned char *savstak();
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