memalloc.c revision 1556
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. 351556Srgrimes */ 361556Srgrimes 371556Srgrimes#ifndef lint 381556Srgrimesstatic char sccsid[] = "@(#)memalloc.c 8.1 (Berkeley) 5/31/93"; 391556Srgrimes#endif /* not lint */ 401556Srgrimes 411556Srgrimes#include "shell.h" 421556Srgrimes#include "output.h" 431556Srgrimes#include "memalloc.h" 441556Srgrimes#include "error.h" 451556Srgrimes#include "machdep.h" 461556Srgrimes#include "mystring.h" 471556Srgrimes 481556Srgrimes/* 491556Srgrimes * Like malloc, but returns an error when out of space. 501556Srgrimes */ 511556Srgrimes 521556Srgrimespointer 531556Srgrimesckmalloc(nbytes) { 541556Srgrimes register pointer p; 551556Srgrimes pointer malloc(); 561556Srgrimes 571556Srgrimes if ((p = malloc(nbytes)) == NULL) 581556Srgrimes error("Out of space"); 591556Srgrimes return p; 601556Srgrimes} 611556Srgrimes 621556Srgrimes 631556Srgrimes/* 641556Srgrimes * Same for realloc. 651556Srgrimes */ 661556Srgrimes 671556Srgrimespointer 681556Srgrimesckrealloc(p, nbytes) 691556Srgrimes register pointer p; 701556Srgrimes { 711556Srgrimes pointer realloc(); 721556Srgrimes 731556Srgrimes if ((p = realloc(p, nbytes)) == NULL) 741556Srgrimes error("Out of space"); 751556Srgrimes return p; 761556Srgrimes} 771556Srgrimes 781556Srgrimes 791556Srgrimes/* 801556Srgrimes * Make a copy of a string in safe storage. 811556Srgrimes */ 821556Srgrimes 831556Srgrimeschar * 841556Srgrimessavestr(s) 851556Srgrimes char *s; 861556Srgrimes { 871556Srgrimes register char *p; 881556Srgrimes 891556Srgrimes p = ckmalloc(strlen(s) + 1); 901556Srgrimes scopy(s, p); 911556Srgrimes return p; 921556Srgrimes} 931556Srgrimes 941556Srgrimes 951556Srgrimes/* 961556Srgrimes * Parse trees for commands are allocated in lifo order, so we use a stack 971556Srgrimes * to make this more efficient, and also to avoid all sorts of exception 981556Srgrimes * handling code to handle interrupts in the middle of a parse. 991556Srgrimes * 1001556Srgrimes * The size 504 was chosen because the Ultrix malloc handles that size 1011556Srgrimes * well. 1021556Srgrimes */ 1031556Srgrimes 1041556Srgrimes#define MINSIZE 504 /* minimum size of a block */ 1051556Srgrimes 1061556Srgrimes 1071556Srgrimesstruct stack_block { 1081556Srgrimes struct stack_block *prev; 1091556Srgrimes char space[MINSIZE]; 1101556Srgrimes}; 1111556Srgrimes 1121556Srgrimesstruct stack_block stackbase; 1131556Srgrimesstruct stack_block *stackp = &stackbase; 1141556Srgrimeschar *stacknxt = stackbase.space; 1151556Srgrimesint stacknleft = MINSIZE; 1161556Srgrimesint sstrnleft; 1171556Srgrimesint herefd = -1; 1181556Srgrimes 1191556Srgrimes 1201556Srgrimes 1211556Srgrimespointer 1221556Srgrimesstalloc(nbytes) { 1231556Srgrimes register char *p; 1241556Srgrimes 1251556Srgrimes nbytes = ALIGN(nbytes); 1261556Srgrimes if (nbytes > stacknleft) { 1271556Srgrimes int blocksize; 1281556Srgrimes struct stack_block *sp; 1291556Srgrimes 1301556Srgrimes blocksize = nbytes; 1311556Srgrimes if (blocksize < MINSIZE) 1321556Srgrimes blocksize = MINSIZE; 1331556Srgrimes INTOFF; 1341556Srgrimes sp = ckmalloc(sizeof(struct stack_block) - MINSIZE + blocksize); 1351556Srgrimes sp->prev = stackp; 1361556Srgrimes stacknxt = sp->space; 1371556Srgrimes stacknleft = blocksize; 1381556Srgrimes stackp = sp; 1391556Srgrimes INTON; 1401556Srgrimes } 1411556Srgrimes p = stacknxt; 1421556Srgrimes stacknxt += nbytes; 1431556Srgrimes stacknleft -= nbytes; 1441556Srgrimes return p; 1451556Srgrimes} 1461556Srgrimes 1471556Srgrimes 1481556Srgrimesvoid 1491556Srgrimesstunalloc(p) 1501556Srgrimes pointer p; 1511556Srgrimes { 1521556Srgrimes if (p == NULL) { /*DEBUG */ 1531556Srgrimes write(2, "stunalloc\n", 10); 1541556Srgrimes abort(); 1551556Srgrimes } 1561556Srgrimes stacknleft += stacknxt - (char *)p; 1571556Srgrimes stacknxt = p; 1581556Srgrimes} 1591556Srgrimes 1601556Srgrimes 1611556Srgrimes 1621556Srgrimesvoid 1631556Srgrimessetstackmark(mark) 1641556Srgrimes struct stackmark *mark; 1651556Srgrimes { 1661556Srgrimes mark->stackp = stackp; 1671556Srgrimes mark->stacknxt = stacknxt; 1681556Srgrimes mark->stacknleft = stacknleft; 1691556Srgrimes} 1701556Srgrimes 1711556Srgrimes 1721556Srgrimesvoid 1731556Srgrimespopstackmark(mark) 1741556Srgrimes struct stackmark *mark; 1751556Srgrimes { 1761556Srgrimes struct stack_block *sp; 1771556Srgrimes 1781556Srgrimes INTOFF; 1791556Srgrimes while (stackp != mark->stackp) { 1801556Srgrimes sp = stackp; 1811556Srgrimes stackp = sp->prev; 1821556Srgrimes ckfree(sp); 1831556Srgrimes } 1841556Srgrimes stacknxt = mark->stacknxt; 1851556Srgrimes stacknleft = mark->stacknleft; 1861556Srgrimes INTON; 1871556Srgrimes} 1881556Srgrimes 1891556Srgrimes 1901556Srgrimes/* 1911556Srgrimes * When the parser reads in a string, it wants to stick the string on the 1921556Srgrimes * stack and only adjust the stack pointer when it knows how big the 1931556Srgrimes * string is. Stackblock (defined in stack.h) returns a pointer to a block 1941556Srgrimes * of space on top of the stack and stackblocklen returns the length of 1951556Srgrimes * this block. Growstackblock will grow this space by at least one byte, 1961556Srgrimes * possibly moving it (like realloc). Grabstackblock actually allocates the 1971556Srgrimes * part of the block that has been used. 1981556Srgrimes */ 1991556Srgrimes 2001556Srgrimesvoid 2011556Srgrimesgrowstackblock() { 2021556Srgrimes char *p; 2031556Srgrimes int newlen = stacknleft * 2 + 100; 2041556Srgrimes char *oldspace = stacknxt; 2051556Srgrimes int oldlen = stacknleft; 2061556Srgrimes struct stack_block *sp; 2071556Srgrimes 2081556Srgrimes if (stacknxt == stackp->space && stackp != &stackbase) { 2091556Srgrimes INTOFF; 2101556Srgrimes sp = stackp; 2111556Srgrimes stackp = sp->prev; 2121556Srgrimes sp = ckrealloc((pointer)sp, sizeof(struct stack_block) - MINSIZE + newlen); 2131556Srgrimes sp->prev = stackp; 2141556Srgrimes stackp = sp; 2151556Srgrimes stacknxt = sp->space; 2161556Srgrimes stacknleft = newlen; 2171556Srgrimes INTON; 2181556Srgrimes } else { 2191556Srgrimes p = stalloc(newlen); 2201556Srgrimes bcopy(oldspace, p, oldlen); 2211556Srgrimes stacknxt = p; /* free the space */ 2221556Srgrimes stacknleft += newlen; /* we just allocated */ 2231556Srgrimes } 2241556Srgrimes} 2251556Srgrimes 2261556Srgrimes 2271556Srgrimes 2281556Srgrimesvoid 2291556Srgrimesgrabstackblock(len) { 2301556Srgrimes len = ALIGN(len); 2311556Srgrimes stacknxt += len; 2321556Srgrimes stacknleft -= len; 2331556Srgrimes} 2341556Srgrimes 2351556Srgrimes 2361556Srgrimes 2371556Srgrimes/* 2381556Srgrimes * The following routines are somewhat easier to use that the above. 2391556Srgrimes * The user declares a variable of type STACKSTR, which may be declared 2401556Srgrimes * to be a register. The macro STARTSTACKSTR initializes things. Then 2411556Srgrimes * the user uses the macro STPUTC to add characters to the string. In 2421556Srgrimes * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is 2431556Srgrimes * grown as necessary. When the user is done, she can just leave the 2441556Srgrimes * string there and refer to it using stackblock(). Or she can allocate 2451556Srgrimes * the space for it using grabstackstr(). If it is necessary to allow 2461556Srgrimes * someone else to use the stack temporarily and then continue to grow 2471556Srgrimes * the string, the user should use grabstack to allocate the space, and 2481556Srgrimes * then call ungrabstr(p) to return to the previous mode of operation. 2491556Srgrimes * 2501556Srgrimes * USTPUTC is like STPUTC except that it doesn't check for overflow. 2511556Srgrimes * CHECKSTACKSPACE can be called before USTPUTC to ensure that there 2521556Srgrimes * is space for at least one character. 2531556Srgrimes */ 2541556Srgrimes 2551556Srgrimes 2561556Srgrimeschar * 2571556Srgrimesgrowstackstr() { 2581556Srgrimes int len = stackblocksize(); 2591556Srgrimes if (herefd >= 0 && len >= 1024) { 2601556Srgrimes xwrite(herefd, stackblock(), len); 2611556Srgrimes sstrnleft = len - 1; 2621556Srgrimes return stackblock(); 2631556Srgrimes } 2641556Srgrimes growstackblock(); 2651556Srgrimes sstrnleft = stackblocksize() - len - 1; 2661556Srgrimes return stackblock() + len; 2671556Srgrimes} 2681556Srgrimes 2691556Srgrimes 2701556Srgrimes/* 2711556Srgrimes * Called from CHECKSTRSPACE. 2721556Srgrimes */ 2731556Srgrimes 2741556Srgrimeschar * 2751556Srgrimesmakestrspace() { 2761556Srgrimes int len = stackblocksize() - sstrnleft; 2771556Srgrimes growstackblock(); 2781556Srgrimes sstrnleft = stackblocksize() - len; 2791556Srgrimes return stackblock() + len; 2801556Srgrimes} 2811556Srgrimes 2821556Srgrimes 2831556Srgrimes 2841556Srgrimesvoid 2851556Srgrimesungrabstackstr(s, p) 2861556Srgrimes char *s; 2871556Srgrimes char *p; 2881556Srgrimes { 2891556Srgrimes stacknleft += stacknxt - s; 2901556Srgrimes stacknxt = s; 2911556Srgrimes sstrnleft = stacknleft - (p - s); 2921556Srgrimes} 293