memalloc.c revision 36150
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 3836150Scharnier#if 0 3936150Scharnierstatic char sccsid[] = "@(#)memalloc.c 8.3 (Berkeley) 5/4/95"; 4036150Scharnier#endif 4136150Scharnierstatic const char rcsid[] = 4236150Scharnier "$Id$"; 431556Srgrimes#endif /* not lint */ 441556Srgrimes 451556Srgrimes#include "shell.h" 461556Srgrimes#include "output.h" 471556Srgrimes#include "memalloc.h" 481556Srgrimes#include "error.h" 491556Srgrimes#include "machdep.h" 501556Srgrimes#include "mystring.h" 5117987Speter#include <stdlib.h> 5217987Speter#include <unistd.h> 531556Srgrimes 541556Srgrimes/* 551556Srgrimes * Like malloc, but returns an error when out of space. 561556Srgrimes */ 571556Srgrimes 581556Srgrimespointer 5920425Ssteveckmalloc(nbytes) 6017987Speter int nbytes; 6117987Speter{ 6225222Ssteve pointer p; 631556Srgrimes 641556Srgrimes if ((p = malloc(nbytes)) == NULL) 651556Srgrimes error("Out of space"); 661556Srgrimes return p; 671556Srgrimes} 681556Srgrimes 691556Srgrimes 701556Srgrimes/* 711556Srgrimes * Same for realloc. 721556Srgrimes */ 731556Srgrimes 741556Srgrimespointer 751556Srgrimesckrealloc(p, nbytes) 7625222Ssteve pointer p; 7717987Speter int nbytes; 7817987Speter{ 791556Srgrimes 801556Srgrimes if ((p = realloc(p, nbytes)) == NULL) 811556Srgrimes error("Out of space"); 821556Srgrimes return p; 831556Srgrimes} 841556Srgrimes 851556Srgrimes 861556Srgrimes/* 871556Srgrimes * Make a copy of a string in safe storage. 881556Srgrimes */ 891556Srgrimes 901556Srgrimeschar * 911556Srgrimessavestr(s) 921556Srgrimes char *s; 931556Srgrimes { 9425222Ssteve char *p; 951556Srgrimes 961556Srgrimes p = ckmalloc(strlen(s) + 1); 971556Srgrimes scopy(s, p); 981556Srgrimes return p; 991556Srgrimes} 1001556Srgrimes 1011556Srgrimes 1021556Srgrimes/* 1031556Srgrimes * Parse trees for commands are allocated in lifo order, so we use a stack 1041556Srgrimes * to make this more efficient, and also to avoid all sorts of exception 1051556Srgrimes * handling code to handle interrupts in the middle of a parse. 1061556Srgrimes * 1071556Srgrimes * The size 504 was chosen because the Ultrix malloc handles that size 1081556Srgrimes * well. 1091556Srgrimes */ 1101556Srgrimes 1111556Srgrimes#define MINSIZE 504 /* minimum size of a block */ 1121556Srgrimes 1131556Srgrimes 1141556Srgrimesstruct stack_block { 1151556Srgrimes struct stack_block *prev; 1161556Srgrimes char space[MINSIZE]; 1171556Srgrimes}; 1181556Srgrimes 1191556Srgrimesstruct stack_block stackbase; 1201556Srgrimesstruct stack_block *stackp = &stackbase; 1211556Srgrimeschar *stacknxt = stackbase.space; 1221556Srgrimesint stacknleft = MINSIZE; 1231556Srgrimesint sstrnleft; 1241556Srgrimesint herefd = -1; 1251556Srgrimes 1261556Srgrimes 1271556Srgrimes 1281556Srgrimespointer 12920425Sstevestalloc(nbytes) 13017987Speter int nbytes; 13117987Speter{ 13225222Ssteve char *p; 1331556Srgrimes 1341556Srgrimes nbytes = ALIGN(nbytes); 1351556Srgrimes if (nbytes > stacknleft) { 1361556Srgrimes int blocksize; 1371556Srgrimes struct stack_block *sp; 1381556Srgrimes 1391556Srgrimes blocksize = nbytes; 1401556Srgrimes if (blocksize < MINSIZE) 1411556Srgrimes blocksize = MINSIZE; 1421556Srgrimes INTOFF; 1431556Srgrimes sp = ckmalloc(sizeof(struct stack_block) - MINSIZE + blocksize); 1441556Srgrimes sp->prev = stackp; 1451556Srgrimes stacknxt = sp->space; 1461556Srgrimes stacknleft = blocksize; 1471556Srgrimes stackp = sp; 1481556Srgrimes INTON; 1491556Srgrimes } 1501556Srgrimes p = stacknxt; 1511556Srgrimes stacknxt += nbytes; 1521556Srgrimes stacknleft -= nbytes; 1531556Srgrimes return p; 1541556Srgrimes} 1551556Srgrimes 1561556Srgrimes 1571556Srgrimesvoid 1581556Srgrimesstunalloc(p) 1591556Srgrimes pointer p; 1601556Srgrimes { 1611556Srgrimes if (p == NULL) { /*DEBUG */ 1621556Srgrimes write(2, "stunalloc\n", 10); 1631556Srgrimes abort(); 1641556Srgrimes } 1651556Srgrimes stacknleft += stacknxt - (char *)p; 1661556Srgrimes stacknxt = p; 1671556Srgrimes} 1681556Srgrimes 1691556Srgrimes 1701556Srgrimes 1711556Srgrimesvoid 1721556Srgrimessetstackmark(mark) 1731556Srgrimes struct stackmark *mark; 1741556Srgrimes { 1751556Srgrimes mark->stackp = stackp; 1761556Srgrimes mark->stacknxt = stacknxt; 1771556Srgrimes mark->stacknleft = stacknleft; 1781556Srgrimes} 1791556Srgrimes 1801556Srgrimes 1811556Srgrimesvoid 1821556Srgrimespopstackmark(mark) 1831556Srgrimes struct stackmark *mark; 1841556Srgrimes { 1851556Srgrimes struct stack_block *sp; 1861556Srgrimes 1871556Srgrimes INTOFF; 1881556Srgrimes while (stackp != mark->stackp) { 1891556Srgrimes sp = stackp; 1901556Srgrimes stackp = sp->prev; 1911556Srgrimes ckfree(sp); 1921556Srgrimes } 1931556Srgrimes stacknxt = mark->stacknxt; 1941556Srgrimes stacknleft = mark->stacknleft; 1951556Srgrimes INTON; 1961556Srgrimes} 1971556Srgrimes 1981556Srgrimes 1991556Srgrimes/* 2001556Srgrimes * When the parser reads in a string, it wants to stick the string on the 2011556Srgrimes * stack and only adjust the stack pointer when it knows how big the 2021556Srgrimes * string is. Stackblock (defined in stack.h) returns a pointer to a block 2031556Srgrimes * of space on top of the stack and stackblocklen returns the length of 2041556Srgrimes * this block. Growstackblock will grow this space by at least one byte, 2051556Srgrimes * possibly moving it (like realloc). Grabstackblock actually allocates the 2061556Srgrimes * part of the block that has been used. 2071556Srgrimes */ 2081556Srgrimes 2091556Srgrimesvoid 2101556Srgrimesgrowstackblock() { 2111556Srgrimes char *p; 21218018Speter int newlen = ALIGN(stacknleft * 2 + 100); 2131556Srgrimes char *oldspace = stacknxt; 2141556Srgrimes int oldlen = stacknleft; 2151556Srgrimes struct stack_block *sp; 2161556Srgrimes 2171556Srgrimes if (stacknxt == stackp->space && stackp != &stackbase) { 2181556Srgrimes INTOFF; 2191556Srgrimes sp = stackp; 2201556Srgrimes stackp = sp->prev; 2211556Srgrimes sp = ckrealloc((pointer)sp, sizeof(struct stack_block) - MINSIZE + newlen); 2221556Srgrimes sp->prev = stackp; 2231556Srgrimes stackp = sp; 2241556Srgrimes stacknxt = sp->space; 2251556Srgrimes stacknleft = newlen; 2261556Srgrimes INTON; 2271556Srgrimes } else { 2281556Srgrimes p = stalloc(newlen); 22917987Speter memcpy(p, oldspace, oldlen); 2301556Srgrimes stacknxt = p; /* free the space */ 23118018Speter stacknleft += newlen; /* we just allocated */ 2321556Srgrimes } 2331556Srgrimes} 2341556Srgrimes 2351556Srgrimes 2361556Srgrimes 2371556Srgrimesvoid 23820425Sstevegrabstackblock(len) 23917987Speter int len; 24017987Speter{ 2411556Srgrimes len = ALIGN(len); 2421556Srgrimes stacknxt += len; 2431556Srgrimes stacknleft -= len; 2441556Srgrimes} 2451556Srgrimes 2461556Srgrimes 2471556Srgrimes 2481556Srgrimes/* 2491556Srgrimes * The following routines are somewhat easier to use that the above. 2501556Srgrimes * The user declares a variable of type STACKSTR, which may be declared 2511556Srgrimes * to be a register. The macro STARTSTACKSTR initializes things. Then 2521556Srgrimes * the user uses the macro STPUTC to add characters to the string. In 2531556Srgrimes * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is 2541556Srgrimes * grown as necessary. When the user is done, she can just leave the 2551556Srgrimes * string there and refer to it using stackblock(). Or she can allocate 2561556Srgrimes * the space for it using grabstackstr(). If it is necessary to allow 2571556Srgrimes * someone else to use the stack temporarily and then continue to grow 2581556Srgrimes * the string, the user should use grabstack to allocate the space, and 2591556Srgrimes * then call ungrabstr(p) to return to the previous mode of operation. 2601556Srgrimes * 2611556Srgrimes * USTPUTC is like STPUTC except that it doesn't check for overflow. 2621556Srgrimes * CHECKSTACKSPACE can be called before USTPUTC to ensure that there 2631556Srgrimes * is space for at least one character. 2641556Srgrimes */ 2651556Srgrimes 2661556Srgrimes 2671556Srgrimeschar * 2681556Srgrimesgrowstackstr() { 2691556Srgrimes int len = stackblocksize(); 2701556Srgrimes if (herefd >= 0 && len >= 1024) { 2711556Srgrimes xwrite(herefd, stackblock(), len); 2721556Srgrimes sstrnleft = len - 1; 2731556Srgrimes return stackblock(); 2741556Srgrimes } 2751556Srgrimes growstackblock(); 2761556Srgrimes sstrnleft = stackblocksize() - len - 1; 2771556Srgrimes return stackblock() + len; 2781556Srgrimes} 2791556Srgrimes 2801556Srgrimes 2811556Srgrimes/* 2821556Srgrimes * Called from CHECKSTRSPACE. 2831556Srgrimes */ 2841556Srgrimes 2851556Srgrimeschar * 2861556Srgrimesmakestrspace() { 2871556Srgrimes int len = stackblocksize() - sstrnleft; 2881556Srgrimes growstackblock(); 2891556Srgrimes sstrnleft = stackblocksize() - len; 2901556Srgrimes return stackblock() + len; 2911556Srgrimes} 2921556Srgrimes 2931556Srgrimes 2941556Srgrimes 2951556Srgrimesvoid 2961556Srgrimesungrabstackstr(s, p) 2971556Srgrimes char *s; 2981556Srgrimes char *p; 2991556Srgrimes { 3001556Srgrimes stacknleft += stacknxt - s; 3011556Srgrimes stacknxt = s; 3021556Srgrimes sstrnleft = stacknleft - (p - s); 3031556Srgrimes} 304