/* $NetBSD: memalloc.c,v 1.20 1997/07/04 21:02:08 christos Exp $ */
/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Kenneth Almquist.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)memalloc.c 8.3 (Berkeley) 5/4/95";
#else
__RCSID("$NetBSD: memalloc.c,v 1.20 1997/07/04 21:02:08 christos Exp $");
#endif
#endif /* not lint */
#include "shell.h"
#include "output.h"
#include "memalloc.h"
#include "error.h"
#include "machdep.h"
#include "mystring.h"
#include <stdlib.h>
#include <unistd.h>
/*
* Like malloc, but returns an error when out of space.
*/
pointer
ckmalloc(nbytes)
int nbytes;
{
pointer p;
if ((p = malloc(nbytes)) == NULL)
error("Out of space");
return p;
}
/*
* Same for realloc.
*/
pointer
ckrealloc(p, nbytes)
pointer p;
int nbytes;
{
if ((p = realloc(p, nbytes)) == NULL)
error("Out of space");
return p;
}
/*
* Make a copy of a string in safe storage.
*/
char *
savestr(s)
char *s;
{
char *p;
p = ckmalloc(strlen(s) + 1);
scopy(s, p);
return p;
}
/*
* Parse trees for commands are allocated in lifo order, so we use a stack
* to make this more efficient, and also to avoid all sorts of exception
* handling code to handle interrupts in the middle of a parse.
*
* The size 504 was chosen because the Ultrix malloc handles that size
* well.
*/
#define MINSIZE 504 /* minimum size of a block */
struct stack_block {
struct stack_block *prev;
char space[MINSIZE];
};
struct stack_block stackbase;
struct stack_block *stackp = &stackbase;
char *stacknxt = stackbase.space;
int stacknleft = MINSIZE;
int sstrnleft;
int herefd = -1;
pointer
stalloc(nbytes)
int nbytes;
{
char *p;
nbytes = ALIGN(nbytes);
if (nbytes > stacknleft) {
int blocksize;
struct stack_block *sp;
blocksize = nbytes;
if (blocksize < MINSIZE)
blocksize = MINSIZE;
INTOFF;
sp = ckmalloc(sizeof(struct stack_block) - MINSIZE + blocksize);
sp->prev = stackp;
stacknxt = sp->space;
stacknleft = blocksize;
stackp = sp;
INTON;
}
p = stacknxt;
stacknxt += nbytes;
stacknleft -= nbytes;
return p;
}
void
stunalloc(p)
pointer p;
{
if (p == NULL) { /*DEBUG */
write(2, "stunalloc\n", 10);
abort();
}
stacknleft += stacknxt - (char *)p;
stacknxt = p;
}
void
setstackmark(mark)
struct stackmark *mark;
{
mark->stackp = stackp;
mark->stacknxt = stacknxt;
mark->stacknleft = stacknleft;
}
void
popstackmark(mark)
struct stackmark *mark;
{
struct stack_block *sp;
INTOFF;
while (stackp != mark->stackp) {
sp = stackp;
stackp = sp->prev;
ckfree(sp);
}
stacknxt = mark->stacknxt;
stacknleft = mark->stacknleft;
INTON;
}
/*
* When the parser reads in a string, it wants to stick the string on the
* stack and only adjust the stack pointer when it knows how big the
* string is. Stackblock (defined in stack.h) returns a pointer to a block
* of space on top of the stack and stackblocklen returns the length of
* this block. Growstackblock will grow this space by at least one byte,
* possibly moving it (like realloc). Grabstackblock actually allocates the
* part of the block that has been used.
*/
void
growstackblock() {
char *p;
int newlen = ALIGN(stacknleft * 2 + 100);
char *oldspace = stacknxt;
int oldlen = stacknleft;
struct stack_block *sp;
if (stacknxt == stackp->space && stackp != &stackbase) {
INTOFF;
sp = stackp;
stackp = sp->prev;
sp = ckrealloc((pointer)sp, sizeof(struct stack_block) - MINSIZE + newlen);
sp->prev = stackp;
stackp = sp;
stacknxt = sp->space;
stacknleft = newlen;
INTON;
} else {
p = stalloc(newlen);
memcpy(p, oldspace, oldlen);
stacknxt = p; /* free the space */
stacknleft += newlen; /* we just allocated */
}
}
void
grabstackblock(len)
int len;
{
len = ALIGN(len);
stacknxt += len;
stacknleft -= len;
}
/*
* The following routines are somewhat easier to use that the above.
* The user declares a variable of type STACKSTR, which may be declared
* to be a register. The macro STARTSTACKSTR initializes things. Then
* the user uses the macro STPUTC to add characters to the string. In
* effect, STPUTC(c, p) is the same as *p++ = c except that the stack is
* grown as necessary. When the user is done, she can just leave the
* string there and refer to it using stackblock(). Or she can allocate
* the space for it using grabstackstr(). If it is necessary to allow
* someone else to use the stack temporarily and then continue to grow
* the string, the user should use grabstack to allocate the space, and
* then call ungrabstr(p) to return to the previous mode of operation.
*
* USTPUTC is like STPUTC except that it doesn't check for overflow.
* CHECKSTACKSPACE can be called before USTPUTC to ensure that there
* is space for at least one character.
*/
char *
growstackstr() {
int len = stackblocksize();
if (herefd >= 0 && len >= 1024) {
xwrite(herefd, stackblock(), len);
sstrnleft = len - 1;
return stackblock();
}
growstackblock();
sstrnleft = stackblocksize() - len - 1;
return stackblock() + len;
}
/*
* Called from CHECKSTRSPACE.
*/
char *
makestrspace() {
int len = stackblocksize() - sstrnleft;
growstackblock();
sstrnleft = stackblocksize() - len;
return stackblock() + len;
}
void
ungrabstackstr(s, p)
char *s;
char *p;
{
stacknleft += stacknxt - s;
stacknxt = s;
sstrnleft = stacknleft - (p - s);
}
