2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * @(#)memalloc.c 8.3 (Berkeley) 5/4/95
37 * $FreeBSD: src/bin/sh/memalloc.c,v 1.27 2005/10/28 10:45:19 stefanf Exp $
38 * $DragonFly: src/bin/sh/memalloc.c,v 1.5 2007/01/14 04:59:57 pavalos Exp $
41 #include <sys/param.h>
52 * Like malloc, but returns an error when out of space.
64 error("Out of space");
74 ckrealloc(pointer p
, int nbytes
)
77 p
= realloc(p
, nbytes
);
80 error("Out of space");
94 * Make a copy of a string in safe storage.
98 savestr(const char *s
)
102 p
= ckmalloc(strlen(s
) + 1);
109 * Parse trees for commands are allocated in lifo order, so we use a stack
110 * to make this more efficient, and also to avoid all sorts of exception
111 * handling code to handle interrupts in the middle of a parse.
113 * The size 496 was chosen because with 16-byte alignment the total size
114 * for the allocated block is 512.
117 #define MINSIZE 496 /* minimum size of a block. */
121 struct stack_block
*prev
;
124 #define SPACE(sp) ((char*)(sp) + ALIGN(sizeof(struct stack_block)))
126 STATIC
struct stack_block
*stackp
;
127 STATIC
struct stackmark
*markp
;
135 stnewblock(int nbytes
)
137 struct stack_block
*sp
;
140 if (nbytes
< MINSIZE
)
143 allocsize
= ALIGN(sizeof(struct stack_block
)) + ALIGN(nbytes
);
146 sp
= ckmalloc(allocsize
);
148 stacknxt
= SPACE(sp
);
149 stacknleft
= allocsize
- (stacknxt
- (char*)sp
);
160 nbytes
= ALIGN(nbytes
);
161 if (nbytes
> stacknleft
)
165 stacknleft
-= nbytes
;
173 if (p
== NULL
) { /*DEBUG */
174 write(STDERR_FILENO
, "stunalloc\n", 10);
177 stacknleft
+= stacknxt
- (char *)p
;
184 setstackmark(struct stackmark
*mark
)
186 mark
->stackp
= stackp
;
187 mark
->stacknxt
= stacknxt
;
188 mark
->stacknleft
= stacknleft
;
189 mark
->marknext
= markp
;
195 popstackmark(struct stackmark
*mark
)
197 struct stack_block
*sp
;
200 markp
= mark
->marknext
;
201 while (stackp
!= mark
->stackp
) {
206 stacknxt
= mark
->stacknxt
;
207 stacknleft
= mark
->stacknleft
;
213 * When the parser reads in a string, it wants to stick the string on the
214 * stack and only adjust the stack pointer when it knows how big the
215 * string is. Stackblock (defined in stack.h) returns a pointer to a block
216 * of space on top of the stack and stackblocklen returns the length of
217 * this block. Growstackblock will grow this space by at least one byte,
218 * possibly moving it (like realloc). Grabstackblock actually allocates the
219 * part of the block that has been used.
229 struct stack_block
*sp
;
230 struct stack_block
*oldstackp
;
231 struct stackmark
*xmark
;
233 newlen
= (stacknleft
== 0) ? MINSIZE
: stacknleft
* 2 + 100;
234 newlen
= ALIGN(newlen
);
238 if (stackp
!= NULL
&& stacknxt
== SPACE(stackp
)) {
241 stackp
= oldstackp
->prev
;
242 sp
= ckrealloc((pointer
)oldstackp
, newlen
);
245 stacknxt
= SPACE(sp
);
246 stacknleft
= newlen
- (stacknxt
- (char*)sp
);
249 * Stack marks pointing to the start of the old block
250 * must be relocated to point to the new block
253 while (xmark
!= NULL
&& xmark
->stackp
== oldstackp
) {
254 xmark
->stackp
= stackp
;
255 xmark
->stacknxt
= stacknxt
;
256 xmark
->stacknleft
= stacknleft
;
257 xmark
= xmark
->marknext
;
263 memcpy(p
, oldspace
, oldlen
);
271 grabstackblock(int len
)
281 * The following routines are somewhat easier to use that the above.
282 * The user declares a variable of type STACKSTR, which may be declared
283 * to be a register. The macro STARTSTACKSTR initializes things. Then
284 * the user uses the macro STPUTC to add characters to the string. In
285 * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is
286 * grown as necessary. When the user is done, she can just leave the
287 * string there and refer to it using stackblock(). Or she can allocate
288 * the space for it using grabstackstr(). If it is necessary to allow
289 * someone else to use the stack temporarily and then continue to grow
290 * the string, the user should use grabstack to allocate the space, and
291 * then call ungrabstr(p) to return to the previous mode of operation.
293 * USTPUTC is like STPUTC except that it doesn't check for overflow.
294 * CHECKSTACKSPACE can be called before USTPUTC to ensure that there
295 * is space for at least one character.
304 len
= stackblocksize();
305 if (herefd
>= 0 && len
>= 1024) {
306 xwrite(herefd
, stackblock(), len
);
311 sstrnleft
= stackblocksize() - len
- 1;
312 return stackblock() + len
;
317 * Called from CHECKSTRSPACE.
325 len
= stackblocksize() - sstrnleft
;
327 sstrnleft
= stackblocksize() - len
;
328 return stackblock() + len
;
334 ungrabstackstr(char *s
, char *p
)
336 stacknleft
+= stacknxt
- s
;
338 sstrnleft
= stacknleft
- (p
- s
);