/* $OpenBSD: memalloc.c,v 1.3 1996/06/23 14:21:21 deraadt Exp $ */ /* $NetBSD: memalloc.c,v 1.17 1996/05/20 14:49:32 cgd 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. */ #ifndef lint #if 0 static char sccsid[] = "@(#)memalloc.c 8.3 (Berkeley) 5/4/95"; #else static char rcsid[] = "$OpenBSD: memalloc.c,v 1.3 1996/06/23 14:21:21 deraadt 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; { register pointer p; if ((p = malloc(nbytes)) == NULL) error("Out of space"); return p; } /* * Same for realloc. */ pointer ckrealloc(p, nbytes) register 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; { register 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; { register 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); }