memalloc.c revision 18018
11556Srgrimes/*- 21556Srgrimes * Copyright (c) 1991, 1993 31556Srgrimes * The Regents of the University of California. All rights reserved. 41556Srgrimes * 51556Srgrimes * This code is derived from software contributed to Berkeley by 61556Srgrimes * Kenneth Almquist. 71556Srgrimes * 81556Srgrimes * Redistribution and use in source and binary forms, with or without 91556Srgrimes * modification, are permitted provided that the following conditions 101556Srgrimes * are met: 111556Srgrimes * 1. Redistributions of source code must retain the above copyright 121556Srgrimes * notice, this list of conditions and the following disclaimer. 131556Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 141556Srgrimes * notice, this list of conditions and the following disclaimer in the 151556Srgrimes * documentation and/or other materials provided with the distribution. 161556Srgrimes * 3. All advertising materials mentioning features or use of this software 171556Srgrimes * must display the following acknowledgement: 181556Srgrimes * This product includes software developed by the University of 191556Srgrimes * California, Berkeley and its contributors. 201556Srgrimes * 4. Neither the name of the University nor the names of its contributors 211556Srgrimes * may be used to endorse or promote products derived from this software 221556Srgrimes * without specific prior written permission. 231556Srgrimes * 241556Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 251556Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 261556Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 271556Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 281556Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 291556Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 301556Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 311556Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 321556Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 331556Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 341556Srgrimes * SUCH DAMAGE. 353044Sdg * 3618018Speter * $Id: memalloc.c,v 1.3 1996/09/01 10:20:42 peter Exp $ 371556Srgrimes */ 381556Srgrimes 391556Srgrimes#ifndef lint 4017987Speterstatic char sccsid[] = "@(#)memalloc.c 8.3 (Berkeley) 5/4/95"; 411556Srgrimes#endif /* not lint */ 421556Srgrimes 431556Srgrimes#include "shell.h" 441556Srgrimes#include "output.h" 451556Srgrimes#include "memalloc.h" 461556Srgrimes#include "error.h" 471556Srgrimes#include "machdep.h" 481556Srgrimes#include "mystring.h" 4917987Speter#include <stdlib.h> 5017987Speter#include <unistd.h> 511556Srgrimes 521556Srgrimes/* 531556Srgrimes * Like malloc, but returns an error when out of space. 541556Srgrimes */ 551556Srgrimes 561556Srgrimespointer 5717987Speterckmalloc(nbytes) 5817987Speter int nbytes; 5917987Speter{ 601556Srgrimes register pointer p; 611556Srgrimes 621556Srgrimes if ((p = malloc(nbytes)) == NULL) 631556Srgrimes error("Out of space"); 641556Srgrimes return p; 651556Srgrimes} 661556Srgrimes 671556Srgrimes 681556Srgrimes/* 691556Srgrimes * Same for realloc. 701556Srgrimes */ 711556Srgrimes 721556Srgrimespointer 731556Srgrimesckrealloc(p, nbytes) 741556Srgrimes register pointer p; 7517987Speter int nbytes; 7617987Speter{ 771556Srgrimes 781556Srgrimes if ((p = realloc(p, nbytes)) == NULL) 791556Srgrimes error("Out of space"); 801556Srgrimes return p; 811556Srgrimes} 821556Srgrimes 831556Srgrimes 841556Srgrimes/* 851556Srgrimes * Make a copy of a string in safe storage. 861556Srgrimes */ 871556Srgrimes 881556Srgrimeschar * 891556Srgrimessavestr(s) 901556Srgrimes char *s; 911556Srgrimes { 921556Srgrimes register char *p; 931556Srgrimes 941556Srgrimes p = ckmalloc(strlen(s) + 1); 951556Srgrimes scopy(s, p); 961556Srgrimes return p; 971556Srgrimes} 981556Srgrimes 991556Srgrimes 1001556Srgrimes/* 1011556Srgrimes * Parse trees for commands are allocated in lifo order, so we use a stack 1021556Srgrimes * to make this more efficient, and also to avoid all sorts of exception 1031556Srgrimes * handling code to handle interrupts in the middle of a parse. 1041556Srgrimes * 1051556Srgrimes * The size 504 was chosen because the Ultrix malloc handles that size 1061556Srgrimes * well. 1071556Srgrimes */ 1081556Srgrimes 1091556Srgrimes#define MINSIZE 504 /* minimum size of a block */ 1101556Srgrimes 1111556Srgrimes 1121556Srgrimesstruct stack_block { 1131556Srgrimes struct stack_block *prev; 1141556Srgrimes char space[MINSIZE]; 1151556Srgrimes}; 1161556Srgrimes 1171556Srgrimesstruct stack_block stackbase; 1181556Srgrimesstruct stack_block *stackp = &stackbase; 1191556Srgrimeschar *stacknxt = stackbase.space; 1201556Srgrimesint stacknleft = MINSIZE; 1211556Srgrimesint sstrnleft; 1221556Srgrimesint herefd = -1; 1231556Srgrimes 1241556Srgrimes 1251556Srgrimes 1261556Srgrimespointer 12717987Speterstalloc(nbytes) 12817987Speter int nbytes; 12917987Speter{ 1301556Srgrimes register char *p; 1311556Srgrimes 1321556Srgrimes nbytes = ALIGN(nbytes); 1331556Srgrimes if (nbytes > stacknleft) { 1341556Srgrimes int blocksize; 1351556Srgrimes struct stack_block *sp; 1361556Srgrimes 1371556Srgrimes blocksize = nbytes; 1381556Srgrimes if (blocksize < MINSIZE) 1391556Srgrimes blocksize = MINSIZE; 1401556Srgrimes INTOFF; 1411556Srgrimes sp = ckmalloc(sizeof(struct stack_block) - MINSIZE + blocksize); 1421556Srgrimes sp->prev = stackp; 1431556Srgrimes stacknxt = sp->space; 1441556Srgrimes stacknleft = blocksize; 1451556Srgrimes stackp = sp; 1461556Srgrimes INTON; 1471556Srgrimes } 1481556Srgrimes p = stacknxt; 1491556Srgrimes stacknxt += nbytes; 1501556Srgrimes stacknleft -= nbytes; 1511556Srgrimes return p; 1521556Srgrimes} 1531556Srgrimes 1541556Srgrimes 1551556Srgrimesvoid 1561556Srgrimesstunalloc(p) 1571556Srgrimes pointer p; 1581556Srgrimes { 1591556Srgrimes if (p == NULL) { /*DEBUG */ 1601556Srgrimes write(2, "stunalloc\n", 10); 1611556Srgrimes abort(); 1621556Srgrimes } 1631556Srgrimes stacknleft += stacknxt - (char *)p; 1641556Srgrimes stacknxt = p; 1651556Srgrimes} 1661556Srgrimes 1671556Srgrimes 1681556Srgrimes 1691556Srgrimesvoid 1701556Srgrimessetstackmark(mark) 1711556Srgrimes struct stackmark *mark; 1721556Srgrimes { 1731556Srgrimes mark->stackp = stackp; 1741556Srgrimes mark->stacknxt = stacknxt; 1751556Srgrimes mark->stacknleft = stacknleft; 1761556Srgrimes} 1771556Srgrimes 1781556Srgrimes 1791556Srgrimesvoid 1801556Srgrimespopstackmark(mark) 1811556Srgrimes struct stackmark *mark; 1821556Srgrimes { 1831556Srgrimes struct stack_block *sp; 1841556Srgrimes 1851556Srgrimes INTOFF; 1861556Srgrimes while (stackp != mark->stackp) { 1871556Srgrimes sp = stackp; 1881556Srgrimes stackp = sp->prev; 1891556Srgrimes ckfree(sp); 1901556Srgrimes } 1911556Srgrimes stacknxt = mark->stacknxt; 1921556Srgrimes stacknleft = mark->stacknleft; 1931556Srgrimes INTON; 1941556Srgrimes} 1951556Srgrimes 1961556Srgrimes 1971556Srgrimes/* 1981556Srgrimes * When the parser reads in a string, it wants to stick the string on the 1991556Srgrimes * stack and only adjust the stack pointer when it knows how big the 2001556Srgrimes * string is. Stackblock (defined in stack.h) returns a pointer to a block 2011556Srgrimes * of space on top of the stack and stackblocklen returns the length of 2021556Srgrimes * this block. Growstackblock will grow this space by at least one byte, 2031556Srgrimes * possibly moving it (like realloc). Grabstackblock actually allocates the 2041556Srgrimes * part of the block that has been used. 2051556Srgrimes */ 2061556Srgrimes 2071556Srgrimesvoid 2081556Srgrimesgrowstackblock() { 2091556Srgrimes char *p; 21018018Speter int newlen = ALIGN(stacknleft * 2 + 100); 2111556Srgrimes char *oldspace = stacknxt; 2121556Srgrimes int oldlen = stacknleft; 2131556Srgrimes struct stack_block *sp; 2141556Srgrimes 2151556Srgrimes if (stacknxt == stackp->space && stackp != &stackbase) { 2161556Srgrimes INTOFF; 2171556Srgrimes sp = stackp; 2181556Srgrimes stackp = sp->prev; 2191556Srgrimes sp = ckrealloc((pointer)sp, sizeof(struct stack_block) - MINSIZE + newlen); 2201556Srgrimes sp->prev = stackp; 2211556Srgrimes stackp = sp; 2221556Srgrimes stacknxt = sp->space; 2231556Srgrimes stacknleft = newlen; 2241556Srgrimes INTON; 2251556Srgrimes } else { 2261556Srgrimes p = stalloc(newlen); 22717987Speter memcpy(p, oldspace, oldlen); 2281556Srgrimes stacknxt = p; /* free the space */ 22918018Speter stacknleft += newlen; /* we just allocated */ 2301556Srgrimes } 2311556Srgrimes} 2321556Srgrimes 2331556Srgrimes 2341556Srgrimes 2351556Srgrimesvoid 23617987Spetergrabstackblock(len) 23717987Speter int len; 23817987Speter{ 2391556Srgrimes len = ALIGN(len); 2401556Srgrimes stacknxt += len; 2411556Srgrimes stacknleft -= len; 2421556Srgrimes} 2431556Srgrimes 2441556Srgrimes 2451556Srgrimes 2461556Srgrimes/* 2471556Srgrimes * The following routines are somewhat easier to use that the above. 2481556Srgrimes * The user declares a variable of type STACKSTR, which may be declared 2491556Srgrimes * to be a register. The macro STARTSTACKSTR initializes things. Then 2501556Srgrimes * the user uses the macro STPUTC to add characters to the string. In 2511556Srgrimes * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is 2521556Srgrimes * grown as necessary. When the user is done, she can just leave the 2531556Srgrimes * string there and refer to it using stackblock(). Or she can allocate 2541556Srgrimes * the space for it using grabstackstr(). If it is necessary to allow 2551556Srgrimes * someone else to use the stack temporarily and then continue to grow 2561556Srgrimes * the string, the user should use grabstack to allocate the space, and 2571556Srgrimes * then call ungrabstr(p) to return to the previous mode of operation. 2581556Srgrimes * 2591556Srgrimes * USTPUTC is like STPUTC except that it doesn't check for overflow. 2601556Srgrimes * CHECKSTACKSPACE can be called before USTPUTC to ensure that there 2611556Srgrimes * is space for at least one character. 2621556Srgrimes */ 2631556Srgrimes 2641556Srgrimes 2651556Srgrimeschar * 2661556Srgrimesgrowstackstr() { 2671556Srgrimes int len = stackblocksize(); 2681556Srgrimes if (herefd >= 0 && len >= 1024) { 2691556Srgrimes xwrite(herefd, stackblock(), len); 2701556Srgrimes sstrnleft = len - 1; 2711556Srgrimes return stackblock(); 2721556Srgrimes } 2731556Srgrimes growstackblock(); 2741556Srgrimes sstrnleft = stackblocksize() - len - 1; 2751556Srgrimes return stackblock() + len; 2761556Srgrimes} 2771556Srgrimes 2781556Srgrimes 2791556Srgrimes/* 2801556Srgrimes * Called from CHECKSTRSPACE. 2811556Srgrimes */ 2821556Srgrimes 2831556Srgrimeschar * 2841556Srgrimesmakestrspace() { 2851556Srgrimes int len = stackblocksize() - sstrnleft; 2861556Srgrimes growstackblock(); 2871556Srgrimes sstrnleft = stackblocksize() - len; 2881556Srgrimes return stackblock() + len; 2891556Srgrimes} 2901556Srgrimes 2911556Srgrimes 2921556Srgrimes 2931556Srgrimesvoid 2941556Srgrimesungrabstackstr(s, p) 2951556Srgrimes char *s; 2961556Srgrimes char *p; 2971556Srgrimes { 2981556Srgrimes stacknleft += stacknxt - s; 2991556Srgrimes stacknxt = s; 3001556Srgrimes sstrnleft = stacknleft - (p - s); 3011556Srgrimes} 302