memalloc.c revision 3044
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 * 363044Sdg * $Id$ 371556Srgrimes */ 381556Srgrimes 391556Srgrimes#ifndef lint 401556Srgrimesstatic char sccsid[] = "@(#)memalloc.c 8.1 (Berkeley) 5/31/93"; 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" 491556Srgrimes 501556Srgrimes/* 511556Srgrimes * Like malloc, but returns an error when out of space. 521556Srgrimes */ 531556Srgrimes 541556Srgrimespointer 551556Srgrimesckmalloc(nbytes) { 561556Srgrimes register pointer p; 571556Srgrimes pointer malloc(); 581556Srgrimes 591556Srgrimes if ((p = malloc(nbytes)) == NULL) 601556Srgrimes error("Out of space"); 611556Srgrimes return p; 621556Srgrimes} 631556Srgrimes 641556Srgrimes 651556Srgrimes/* 661556Srgrimes * Same for realloc. 671556Srgrimes */ 681556Srgrimes 691556Srgrimespointer 701556Srgrimesckrealloc(p, nbytes) 711556Srgrimes register pointer p; 721556Srgrimes { 731556Srgrimes pointer realloc(); 741556Srgrimes 751556Srgrimes if ((p = realloc(p, nbytes)) == NULL) 761556Srgrimes error("Out of space"); 771556Srgrimes return p; 781556Srgrimes} 791556Srgrimes 801556Srgrimes 811556Srgrimes/* 821556Srgrimes * Make a copy of a string in safe storage. 831556Srgrimes */ 841556Srgrimes 851556Srgrimeschar * 861556Srgrimessavestr(s) 871556Srgrimes char *s; 881556Srgrimes { 891556Srgrimes register char *p; 901556Srgrimes 911556Srgrimes p = ckmalloc(strlen(s) + 1); 921556Srgrimes scopy(s, p); 931556Srgrimes return p; 941556Srgrimes} 951556Srgrimes 961556Srgrimes 971556Srgrimes/* 981556Srgrimes * Parse trees for commands are allocated in lifo order, so we use a stack 991556Srgrimes * to make this more efficient, and also to avoid all sorts of exception 1001556Srgrimes * handling code to handle interrupts in the middle of a parse. 1011556Srgrimes * 1021556Srgrimes * The size 504 was chosen because the Ultrix malloc handles that size 1031556Srgrimes * well. 1041556Srgrimes */ 1051556Srgrimes 1061556Srgrimes#define MINSIZE 504 /* minimum size of a block */ 1071556Srgrimes 1081556Srgrimes 1091556Srgrimesstruct stack_block { 1101556Srgrimes struct stack_block *prev; 1111556Srgrimes char space[MINSIZE]; 1121556Srgrimes}; 1131556Srgrimes 1141556Srgrimesstruct stack_block stackbase; 1151556Srgrimesstruct stack_block *stackp = &stackbase; 1161556Srgrimeschar *stacknxt = stackbase.space; 1171556Srgrimesint stacknleft = MINSIZE; 1181556Srgrimesint sstrnleft; 1191556Srgrimesint herefd = -1; 1201556Srgrimes 1211556Srgrimes 1221556Srgrimes 1231556Srgrimespointer 1241556Srgrimesstalloc(nbytes) { 1251556Srgrimes register char *p; 1261556Srgrimes 1271556Srgrimes nbytes = ALIGN(nbytes); 1281556Srgrimes if (nbytes > stacknleft) { 1291556Srgrimes int blocksize; 1301556Srgrimes struct stack_block *sp; 1311556Srgrimes 1321556Srgrimes blocksize = nbytes; 1331556Srgrimes if (blocksize < MINSIZE) 1341556Srgrimes blocksize = MINSIZE; 1351556Srgrimes INTOFF; 1361556Srgrimes sp = ckmalloc(sizeof(struct stack_block) - MINSIZE + blocksize); 1371556Srgrimes sp->prev = stackp; 1381556Srgrimes stacknxt = sp->space; 1391556Srgrimes stacknleft = blocksize; 1401556Srgrimes stackp = sp; 1411556Srgrimes INTON; 1421556Srgrimes } 1431556Srgrimes p = stacknxt; 1441556Srgrimes stacknxt += nbytes; 1451556Srgrimes stacknleft -= nbytes; 1461556Srgrimes return p; 1471556Srgrimes} 1481556Srgrimes 1491556Srgrimes 1501556Srgrimesvoid 1511556Srgrimesstunalloc(p) 1521556Srgrimes pointer p; 1531556Srgrimes { 1541556Srgrimes if (p == NULL) { /*DEBUG */ 1551556Srgrimes write(2, "stunalloc\n", 10); 1561556Srgrimes abort(); 1571556Srgrimes } 1581556Srgrimes stacknleft += stacknxt - (char *)p; 1591556Srgrimes stacknxt = p; 1601556Srgrimes} 1611556Srgrimes 1621556Srgrimes 1631556Srgrimes 1641556Srgrimesvoid 1651556Srgrimessetstackmark(mark) 1661556Srgrimes struct stackmark *mark; 1671556Srgrimes { 1681556Srgrimes mark->stackp = stackp; 1691556Srgrimes mark->stacknxt = stacknxt; 1701556Srgrimes mark->stacknleft = stacknleft; 1711556Srgrimes} 1721556Srgrimes 1731556Srgrimes 1741556Srgrimesvoid 1751556Srgrimespopstackmark(mark) 1761556Srgrimes struct stackmark *mark; 1771556Srgrimes { 1781556Srgrimes struct stack_block *sp; 1791556Srgrimes 1801556Srgrimes INTOFF; 1811556Srgrimes while (stackp != mark->stackp) { 1821556Srgrimes sp = stackp; 1831556Srgrimes stackp = sp->prev; 1841556Srgrimes ckfree(sp); 1851556Srgrimes } 1861556Srgrimes stacknxt = mark->stacknxt; 1871556Srgrimes stacknleft = mark->stacknleft; 1881556Srgrimes INTON; 1891556Srgrimes} 1901556Srgrimes 1911556Srgrimes 1921556Srgrimes/* 1931556Srgrimes * When the parser reads in a string, it wants to stick the string on the 1941556Srgrimes * stack and only adjust the stack pointer when it knows how big the 1951556Srgrimes * string is. Stackblock (defined in stack.h) returns a pointer to a block 1961556Srgrimes * of space on top of the stack and stackblocklen returns the length of 1971556Srgrimes * this block. Growstackblock will grow this space by at least one byte, 1981556Srgrimes * possibly moving it (like realloc). Grabstackblock actually allocates the 1991556Srgrimes * part of the block that has been used. 2001556Srgrimes */ 2011556Srgrimes 2021556Srgrimesvoid 2031556Srgrimesgrowstackblock() { 2041556Srgrimes char *p; 2051556Srgrimes int newlen = stacknleft * 2 + 100; 2061556Srgrimes char *oldspace = stacknxt; 2071556Srgrimes int oldlen = stacknleft; 2081556Srgrimes struct stack_block *sp; 2091556Srgrimes 2101556Srgrimes if (stacknxt == stackp->space && stackp != &stackbase) { 2111556Srgrimes INTOFF; 2121556Srgrimes sp = stackp; 2131556Srgrimes stackp = sp->prev; 2141556Srgrimes sp = ckrealloc((pointer)sp, sizeof(struct stack_block) - MINSIZE + newlen); 2151556Srgrimes sp->prev = stackp; 2161556Srgrimes stackp = sp; 2171556Srgrimes stacknxt = sp->space; 2181556Srgrimes stacknleft = newlen; 2191556Srgrimes INTON; 2201556Srgrimes } else { 2211556Srgrimes p = stalloc(newlen); 2221556Srgrimes bcopy(oldspace, p, oldlen); 2231556Srgrimes stacknxt = p; /* free the space */ 2241556Srgrimes stacknleft += newlen; /* we just allocated */ 2251556Srgrimes } 2261556Srgrimes} 2271556Srgrimes 2281556Srgrimes 2291556Srgrimes 2301556Srgrimesvoid 2311556Srgrimesgrabstackblock(len) { 2321556Srgrimes len = ALIGN(len); 2331556Srgrimes stacknxt += len; 2341556Srgrimes stacknleft -= len; 2351556Srgrimes} 2361556Srgrimes 2371556Srgrimes 2381556Srgrimes 2391556Srgrimes/* 2401556Srgrimes * The following routines are somewhat easier to use that the above. 2411556Srgrimes * The user declares a variable of type STACKSTR, which may be declared 2421556Srgrimes * to be a register. The macro STARTSTACKSTR initializes things. Then 2431556Srgrimes * the user uses the macro STPUTC to add characters to the string. In 2441556Srgrimes * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is 2451556Srgrimes * grown as necessary. When the user is done, she can just leave the 2461556Srgrimes * string there and refer to it using stackblock(). Or she can allocate 2471556Srgrimes * the space for it using grabstackstr(). If it is necessary to allow 2481556Srgrimes * someone else to use the stack temporarily and then continue to grow 2491556Srgrimes * the string, the user should use grabstack to allocate the space, and 2501556Srgrimes * then call ungrabstr(p) to return to the previous mode of operation. 2511556Srgrimes * 2521556Srgrimes * USTPUTC is like STPUTC except that it doesn't check for overflow. 2531556Srgrimes * CHECKSTACKSPACE can be called before USTPUTC to ensure that there 2541556Srgrimes * is space for at least one character. 2551556Srgrimes */ 2561556Srgrimes 2571556Srgrimes 2581556Srgrimeschar * 2591556Srgrimesgrowstackstr() { 2601556Srgrimes int len = stackblocksize(); 2611556Srgrimes if (herefd >= 0 && len >= 1024) { 2621556Srgrimes xwrite(herefd, stackblock(), len); 2631556Srgrimes sstrnleft = len - 1; 2641556Srgrimes return stackblock(); 2651556Srgrimes } 2661556Srgrimes growstackblock(); 2671556Srgrimes sstrnleft = stackblocksize() - len - 1; 2681556Srgrimes return stackblock() + len; 2691556Srgrimes} 2701556Srgrimes 2711556Srgrimes 2721556Srgrimes/* 2731556Srgrimes * Called from CHECKSTRSPACE. 2741556Srgrimes */ 2751556Srgrimes 2761556Srgrimeschar * 2771556Srgrimesmakestrspace() { 2781556Srgrimes int len = stackblocksize() - sstrnleft; 2791556Srgrimes growstackblock(); 2801556Srgrimes sstrnleft = stackblocksize() - len; 2811556Srgrimes return stackblock() + len; 2821556Srgrimes} 2831556Srgrimes 2841556Srgrimes 2851556Srgrimes 2861556Srgrimesvoid 2871556Srgrimesungrabstackstr(s, p) 2881556Srgrimes char *s; 2891556Srgrimes char *p; 2901556Srgrimes { 2911556Srgrimes stacknleft += stacknxt - s; 2921556Srgrimes stacknxt = s; 2931556Srgrimes sstrnleft = stacknleft - (p - s); 2941556Srgrimes} 295