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 1.15.2.2 2002/07/19 04:38:51 tjr Exp $
38 * $DragonFly: src/bin/sh/memalloc.c,v 1.4 2004/01/28 16:25:29 joerg Exp $
52 * Like malloc, but returns an error when out of space.
60 if ((p = malloc(nbytes)) == NULL)
61 error("Out of space");
71 ckrealloc(pointer p, int nbytes)
73 if ((p = realloc(p, nbytes)) == NULL)
74 error("Out of space");
80 * Make a copy of a string in safe storage.
84 savestr(const char *s)
88 p = ckmalloc(strlen(s) + 1);
95 * Parse trees for commands are allocated in lifo order, so we use a stack
96 * to make this more efficient, and also to avoid all sorts of exception
97 * handling code to handle interrupts in the middle of a parse.
99 * The size 504 was chosen because the Ultrix malloc handles that size
103 #define MINSIZE 504 /* minimum size of a block */
107 struct stack_block *prev;
111 STATIC struct stack_block stackbase;
112 STATIC struct stack_block *stackp = &stackbase;
113 STATIC struct stackmark *markp;
114 char *stacknxt = stackbase.space;
115 int stacknleft = MINSIZE;
126 nbytes = ALIGN(nbytes);
127 if (nbytes > stacknleft) {
129 struct stack_block *sp;
132 if (blocksize < MINSIZE)
135 sp = ckmalloc(sizeof(struct stack_block) - MINSIZE +
138 stacknxt = sp->space;
139 stacknleft = blocksize;
145 stacknleft -= nbytes;
153 if (p == NULL) { /*DEBUG */
154 write(STDERR_FILENO, "stunalloc\n", 10);
157 stacknleft += stacknxt - (char *)p;
164 setstackmark(struct stackmark *mark)
166 mark->stackp = stackp;
167 mark->stacknxt = stacknxt;
168 mark->stacknleft = stacknleft;
169 mark->marknext = markp;
175 popstackmark(struct stackmark *mark)
177 struct stack_block *sp;
180 markp = mark->marknext;
181 while (stackp != mark->stackp) {
186 stacknxt = mark->stacknxt;
187 stacknleft = mark->stacknleft;
193 * When the parser reads in a string, it wants to stick the string on the
194 * stack and only adjust the stack pointer when it knows how big the
195 * string is. Stackblock (defined in stack.h) returns a pointer to a block
196 * of space on top of the stack and stackblocklen returns the length of
197 * this block. Growstackblock will grow this space by at least one byte,
198 * possibly moving it (like realloc). Grabstackblock actually allocates the
199 * part of the block that has been used.
209 struct stack_block *sp;
210 struct stack_block *oldstackp;
212 newlen = ALIGN(stacknleft * 2 + 100);
216 if (stacknxt == stackp->space && stackp != &stackbase) {
221 sp = ckrealloc((pointer)sp, sizeof(struct stack_block) -
225 stacknxt = sp->space;
228 /* Stack marks pointing to the start of the old block
229 * must be relocated to point to the new block
231 struct stackmark *xmark;
233 while (xmark != NULL && xmark->stackp == oldstackp) {
234 xmark->stackp = stackp;
235 xmark->stacknxt = stacknxt;
236 xmark->stacknleft = stacknleft;
237 xmark = xmark->marknext;
243 memcpy(p, oldspace, oldlen);
244 stacknxt = p; /* free the space */
245 stacknleft += newlen; /* we just allocated */
252 grabstackblock(int len)
262 * The following routines are somewhat easier to use that the above.
263 * The user declares a variable of type STACKSTR, which may be declared
264 * to be a register. The macro STARTSTACKSTR initializes things. Then
265 * the user uses the macro STPUTC to add characters to the string. In
266 * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is
267 * grown as necessary. When the user is done, she can just leave the
268 * string there and refer to it using stackblock(). Or she can allocate
269 * the space for it using grabstackstr(). If it is necessary to allow
270 * someone else to use the stack temporarily and then continue to grow
271 * the string, the user should use grabstack to allocate the space, and
272 * then call ungrabstr(p) to return to the previous mode of operation.
274 * USTPUTC is like STPUTC except that it doesn't check for overflow.
275 * CHECKSTACKSPACE can be called before USTPUTC to ensure that there
276 * is space for at least one character.
285 len = stackblocksize();
286 if (herefd >= 0 && len >= 1024) {
287 xwrite(herefd, stackblock(), len);
292 sstrnleft = stackblocksize() - len - 1;
293 return stackblock() + len;
298 * Called from CHECKSTRSPACE.
306 len = stackblocksize() - sstrnleft;
308 sstrnleft = stackblocksize() - len;
309 return stackblock() + len;
315 ungrabstackstr(char *s, char *p)
317 stacknleft += stacknxt - s;
319 sstrnleft = stacknleft - (p - s);