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 03:59:57 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);