332 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			332 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*-
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|  * Copyright (c) 1991, 1993
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|  *	The Regents of the University of California.  All rights reserved.
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|  *
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|  * This code is derived from software contributed to Berkeley by
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|  * Kenneth Almquist.
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions
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|  * are met:
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|  * 1. Redistributions of source code must retain the above copyright
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|  *    notice, this list of conditions and the following disclaimer.
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|  * 2. Redistributions in binary form must reproduce the above copyright
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|  *    notice, this list of conditions and the following disclaimer in the
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|  *    documentation and/or other materials provided with the distribution.
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|  * 4. Neither the name of the University nor the names of its contributors
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|  *    may be used to endorse or promote products derived from this software
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|  *    without specific prior written permission.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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|  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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|  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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|  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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|  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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|  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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|  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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|  * SUCH DAMAGE.
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|  */
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| 
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| #ifndef lint
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| #if 0
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| static char sccsid[] = "@(#)memalloc.c	8.3 (Berkeley) 5/4/95";
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| #endif
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| #endif /* not lint */
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| /*
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| #include <sys/cdefs.h>
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| __FBSDID("$FreeBSD: src/bin/sh/memalloc.c,v 1.26 2004/04/06 20:06:51 markm Exp $");
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| */
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| 
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| #include "shell.h"
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| #include "output.h"
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| #include "machdep.h"
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| #include "memalloc.h"
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| #include "error.h"
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| #include "mystring.h"
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| #include "expand.h"
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| #include <stdlib.h>
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| #include <unistd.h>
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| 
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| /*
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|  * Like malloc, but returns an error when out of space.
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|  */
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| 
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| pointer
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| ckmalloc(int nbytes)
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| {
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| 	pointer p;
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| 
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| 	if ((p = malloc(nbytes)) == NULL)
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| 		error("Out of space");
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| 	return p;
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| }
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| 
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| 
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| /*
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|  * Same for realloc.
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|  */
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| 
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| pointer
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| ckrealloc(pointer p, int nbytes)
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| {
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| 	if ((p = realloc(p, nbytes)) == NULL)
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| 		error("Out of space");
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| 	return p;
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| }
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| 
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| 
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| /*
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|  * Make a copy of a string in safe storage.
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|  */
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| 
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| char *
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| savestr(const char *s)
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| {
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| 	char *p;
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| 
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| 	p = ckmalloc(strlen(s) + 1);
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| 	scopy(s, p);
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| 	return p;
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| }
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| 
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| 
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| /*
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|  * Parse trees for commands are allocated in lifo order, so we use a stack
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|  * to make this more efficient, and also to avoid all sorts of exception
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|  * handling code to handle interrupts in the middle of a parse.
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|  *
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|  * The size 496 was chosen because with 16-byte alignment the total size
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|  * for the allocated block is 512.
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|  */
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| 
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| #define MINSIZE 496		/* minimum size of a block. */
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| 
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| 
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| struct stack_block {
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| 	struct stack_block *prev;
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| 	/* Data follows */
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| };
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| #define SPACE(sp)	((char*)(sp) + ALIGN(sizeof(struct stack_block)))
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| 
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| STATIC struct stack_block *stackp;
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| STATIC struct stackmark *markp;
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| char *stacknxt;
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| int stacknleft;
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| int sstrnleft;
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| int herefd = -1;
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| 
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| 
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| static void
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| stnewblock(int nbytes)
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| {
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| 	struct stack_block *sp;
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| 	int allocsize;
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| 
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| 	if (nbytes < MINSIZE)
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| 		nbytes = MINSIZE;
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| 
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| 	allocsize = ALIGN(sizeof(struct stack_block)) + ALIGN(nbytes);
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| 
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| 	INTOFF;
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| 	sp = ckmalloc(allocsize);
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| 	sp->prev = stackp;
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| 	stacknxt = SPACE(sp);
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| 	stacknleft = allocsize - (stacknxt - (char*)sp);
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| 	stackp = sp;
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| 	INTON;
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| }
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| 
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| 
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| pointer
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| stalloc(int nbytes)
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| {
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| 	char *p;
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| 
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| 	nbytes = ALIGN(nbytes);
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| 	if (nbytes > stacknleft)
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| 		stnewblock(nbytes);
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| 	p = stacknxt;
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| 	stacknxt += nbytes;
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| 	stacknleft -= nbytes;
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| 	return p;
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| }
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| 
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| 
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| void
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| stunalloc(pointer p)
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| {
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| 	if (p == NULL) {		/*DEBUG */
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| 		write(STDERR_FILENO, "stunalloc\n", 10);
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| 		abort();
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| 	}
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| 	stacknleft += stacknxt - (char *)p;
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| 	stacknxt = p;
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| }
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| 
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| 
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| 
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| void
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| setstackmark(struct stackmark *mark)
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| {
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| 	mark->stackp = stackp;
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| 	mark->stacknxt = stacknxt;
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| 	mark->stacknleft = stacknleft;
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| 	mark->marknext = markp;
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| 	markp = mark;
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| }
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| 
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| 
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| void
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| popstackmark(struct stackmark *mark)
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| {
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| 	struct stack_block *sp;
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| 
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| 	INTOFF;
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| 	markp = mark->marknext;
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| 	while (stackp != mark->stackp) {
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| 		sp = stackp;
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| 		stackp = sp->prev;
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| 		ckfree(sp);
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| 	}
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| 	stacknxt = mark->stacknxt;
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| 	stacknleft = mark->stacknleft;
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| 	INTON;
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| }
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| 
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| 
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| /*
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|  * When the parser reads in a string, it wants to stick the string on the
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|  * stack and only adjust the stack pointer when it knows how big the
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|  * string is.  Stackblock (defined in stack.h) returns a pointer to a block
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|  * of space on top of the stack and stackblocklen returns the length of
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|  * this block.  Growstackblock will grow this space by at least one byte,
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|  * possibly moving it (like realloc).  Grabstackblock actually allocates the
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|  * part of the block that has been used.
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|  */
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| 
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| void
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| growstackblock(void)
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| {
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| 	char *p;
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| 	int newlen;
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| 	char *oldspace;
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| 	int oldlen;
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| 	struct stack_block *sp;
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| 	struct stack_block *oldstackp;
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| 	struct stackmark *xmark;
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| 
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| 	newlen = (stacknleft == 0) ? MINSIZE : stacknleft * 2 + 100;
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| 	newlen = ALIGN(newlen);
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| 	oldspace = stacknxt;
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| 	oldlen = stacknleft;
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| 
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| 	if (stackp != NULL && stacknxt == SPACE(stackp)) {
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| 		INTOFF;
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| 		oldstackp = stackp;
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| 		stackp = oldstackp->prev;
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| 		sp = ckrealloc((pointer)oldstackp, newlen);
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| 		sp->prev = stackp;
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| 		stackp = sp;
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| 		stacknxt = SPACE(sp);
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| 		stacknleft = newlen - (stacknxt - (char*)sp);
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| 
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| 		/*
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| 		 * Stack marks pointing to the start of the old block
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| 		 * must be relocated to point to the new block
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| 		 */
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| 		xmark = markp;
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| 		while (xmark != NULL && xmark->stackp == oldstackp) {
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| 			xmark->stackp = stackp;
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| 			xmark->stacknxt = stacknxt;
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| 			xmark->stacknleft = stacknleft;
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| 			xmark = xmark->marknext;
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| 		}
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| 		INTON;
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| 	} else {
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| 		p = stalloc(newlen);
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| 		if (oldlen != 0)
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| 			memcpy(p, oldspace, oldlen);
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| 		stunalloc(p);
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| 	}
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| }
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| 
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| 
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| 
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| void
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| grabstackblock(int len)
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| {
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| 	len = ALIGN(len);
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| 	stacknxt += len;
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| 	stacknleft -= len;
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| }
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| 
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| 
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| 
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| /*
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|  * The following routines are somewhat easier to use that the above.
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|  * The user declares a variable of type STACKSTR, which may be declared
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|  * to be a register.  The macro STARTSTACKSTR initializes things.  Then
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|  * the user uses the macro STPUTC to add characters to the string.  In
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|  * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is
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|  * grown as necessary.  When the user is done, she can just leave the
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|  * string there and refer to it using stackblock().  Or she can allocate
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|  * the space for it using grabstackstr().  If it is necessary to allow
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|  * someone else to use the stack temporarily and then continue to grow
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|  * the string, the user should use grabstack to allocate the space, and
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|  * then call ungrabstr(p) to return to the previous mode of operation.
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|  *
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|  * USTPUTC is like STPUTC except that it doesn't check for overflow.
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|  * CHECKSTACKSPACE can be called before USTPUTC to ensure that there
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|  * is space for at least one character.
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|  */
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| 
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| 
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| char *
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| growstackstr(void)
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| {
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| 	int len;
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| 
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| 	len = stackblocksize();
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| 	if (herefd >= 0 && len >= 1024) {
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| 		xwrite(herefd, stackblock(), len);
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| 		sstrnleft = len - 1;
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| 		return stackblock();
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| 	}
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| 	growstackblock();
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| 	sstrnleft = stackblocksize() - len - 1;
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| 	return stackblock() + len;
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| }
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| 
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| 
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| /*
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|  * Called from CHECKSTRSPACE.
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|  */
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| 
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| char *
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| makestrspace(void)
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| {
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| 	int len;
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| 
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| 	len = stackblocksize() - sstrnleft;
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| 	growstackblock();
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| 	sstrnleft = stackblocksize() - len;
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| 	return stackblock() + len;
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| }
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| 
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| 
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| 
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| void
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| ungrabstackstr(char *s, char *p)
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| {
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| 	stacknleft += stacknxt - s;
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| 	stacknxt = s;
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| 	sstrnleft = stacknleft - (p - s);
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| }
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| 
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| /*
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|  * $PchId: memalloc.c,v 1.5 2006/05/22 12:03:26 philip Exp $
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|  */
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