* Copyright (c) 1991 The Regents of the University of California.
* This code is derived from software contributed to Berkeley by
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* 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
static char sccsid
[] = "@(#)memalloc.c 5.2 (Berkeley) 3/13/91";
* Like malloc, but returns an error when out of space.
if ((p
= malloc(nbytes
)) == NULL
)
if ((p
= realloc(p
, nbytes
)) == NULL
)
* Make a copy of a string in safe storage.
p
= ckmalloc(strlen(s
) + 1);
* 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
#define MINSIZE 504 /* minimum size of a block */
struct stack_block
*prev
;
struct stack_block stackbase
;
struct stack_block
*stackp
= &stackbase
;
char *stacknxt
= stackbase
.space
;
int stacknleft
= MINSIZE
;
if (nbytes
> stacknleft
) {
sp
= ckmalloc(sizeof(struct stack_block
) - MINSIZE
+ blocksize
);
if (p
== NULL
) { /*DEBUG */
write(2, "stunalloc\n", 10);
stacknleft
+= stacknxt
- (char *)p
;
mark
->stacknxt
= stacknxt
;
mark
->stacknleft
= stacknleft
;
while (stackp
!= mark
->stackp
) {
stacknxt
= mark
->stacknxt
;
stacknleft
= mark
->stacknleft
;
* 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.
int newlen
= stacknleft
* 2 + 100;
char *oldspace
= stacknxt
;
if (stacknxt
== stackp
->space
&& stackp
!= &stackbase
) {
sp
= ckrealloc((pointer
)sp
, sizeof(struct stack_block
) - MINSIZE
+ newlen
);
bcopy(oldspace
, p
, oldlen
);
stacknxt
= p
; /* free the space */
stacknleft
+= newlen
; /* we just allocated */
* 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.
int len
= stackblocksize();
if (herefd
>= 0 && len
>= 1024) {
xwrite(herefd
, stackblock(), len
);
sstrnleft
= stackblocksize() - len
- 1;
return stackblock() + len
;
* Called from CHECKSTRSPACE.
int len
= stackblocksize() - sstrnleft
;
sstrnleft
= stackblocksize() - len
;
return stackblock() + len
;
stacknleft
+= stacknxt
- s
;
sstrnleft
= stacknleft
- (p
- s
);