memalloc.c revision 90111
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[] = 4250471Speter "$FreeBSD: head/bin/sh/memalloc.c 90111 2002-02-02 06:50:57Z imp $"; 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" 5139049Scracauer#include "expand.h" 5217987Speter#include <stdlib.h> 5317987Speter#include <unistd.h> 541556Srgrimes 551556Srgrimes/* 561556Srgrimes * Like malloc, but returns an error when out of space. 571556Srgrimes */ 581556Srgrimes 591556Srgrimespointer 6090111Simpckmalloc(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 7590111Simpckrealloc(pointer p, int nbytes) 7617987Speter{ 771556Srgrimes if ((p = realloc(p, nbytes)) == NULL) 781556Srgrimes error("Out of space"); 791556Srgrimes return p; 801556Srgrimes} 811556Srgrimes 821556Srgrimes 831556Srgrimes/* 841556Srgrimes * Make a copy of a string in safe storage. 851556Srgrimes */ 861556Srgrimes 871556Srgrimeschar * 8890111Simpsavestr(char *s) 8945618Scracauer{ 9025222Ssteve char *p; 911556Srgrimes 921556Srgrimes p = ckmalloc(strlen(s) + 1); 931556Srgrimes scopy(s, p); 941556Srgrimes return p; 951556Srgrimes} 961556Srgrimes 971556Srgrimes 981556Srgrimes/* 991556Srgrimes * Parse trees for commands are allocated in lifo order, so we use a stack 1001556Srgrimes * to make this more efficient, and also to avoid all sorts of exception 1011556Srgrimes * handling code to handle interrupts in the middle of a parse. 1021556Srgrimes * 1031556Srgrimes * The size 504 was chosen because the Ultrix malloc handles that size 1041556Srgrimes * well. 1051556Srgrimes */ 1061556Srgrimes 1071556Srgrimes#define MINSIZE 504 /* minimum size of a block */ 1081556Srgrimes 1091556Srgrimes 1101556Srgrimesstruct stack_block { 1111556Srgrimes struct stack_block *prev; 1121556Srgrimes char space[MINSIZE]; 1131556Srgrimes}; 1141556Srgrimes 1151556Srgrimesstruct stack_block stackbase; 1161556Srgrimesstruct stack_block *stackp = &stackbase; 11764702Scracauerstruct stackmark *markp; 1181556Srgrimeschar *stacknxt = stackbase.space; 1191556Srgrimesint stacknleft = MINSIZE; 1201556Srgrimesint sstrnleft; 1211556Srgrimesint herefd = -1; 1221556Srgrimes 1231556Srgrimes 1241556Srgrimes 1251556Srgrimespointer 12690111Simpstalloc(int nbytes) 12717987Speter{ 12825222Ssteve char *p; 1291556Srgrimes 1301556Srgrimes nbytes = ALIGN(nbytes); 1311556Srgrimes if (nbytes > stacknleft) { 1321556Srgrimes int blocksize; 1331556Srgrimes struct stack_block *sp; 1341556Srgrimes 1351556Srgrimes blocksize = nbytes; 1361556Srgrimes if (blocksize < MINSIZE) 1371556Srgrimes blocksize = MINSIZE; 1381556Srgrimes INTOFF; 13945618Scracauer sp = ckmalloc(sizeof(struct stack_block) - MINSIZE + 14045618Scracauer blocksize); 1411556Srgrimes sp->prev = stackp; 1421556Srgrimes stacknxt = sp->space; 1431556Srgrimes stacknleft = blocksize; 1441556Srgrimes stackp = sp; 1451556Srgrimes INTON; 1461556Srgrimes } 1471556Srgrimes p = stacknxt; 1481556Srgrimes stacknxt += nbytes; 1491556Srgrimes stacknleft -= nbytes; 1501556Srgrimes return p; 1511556Srgrimes} 1521556Srgrimes 1531556Srgrimes 1541556Srgrimesvoid 15590111Simpstunalloc(pointer p) 15645618Scracauer{ 1571556Srgrimes if (p == NULL) { /*DEBUG */ 15880381Ssheldonh write(STDERR_FILENO, "stunalloc\n", 10); 1591556Srgrimes abort(); 1601556Srgrimes } 1611556Srgrimes stacknleft += stacknxt - (char *)p; 1621556Srgrimes stacknxt = p; 1631556Srgrimes} 1641556Srgrimes 1651556Srgrimes 1661556Srgrimes 1671556Srgrimesvoid 16890111Simpsetstackmark(struct stackmark *mark) 16945618Scracauer{ 1701556Srgrimes mark->stackp = stackp; 1711556Srgrimes mark->stacknxt = stacknxt; 1721556Srgrimes mark->stacknleft = stacknleft; 17364702Scracauer mark->marknext = markp; 17464702Scracauer markp = mark; 1751556Srgrimes} 1761556Srgrimes 1771556Srgrimes 1781556Srgrimesvoid 17990111Simppopstackmark(struct stackmark *mark) 18045618Scracauer{ 1811556Srgrimes struct stack_block *sp; 1821556Srgrimes 1831556Srgrimes INTOFF; 18464702Scracauer markp = mark->marknext; 1851556Srgrimes while (stackp != mark->stackp) { 1861556Srgrimes sp = stackp; 1871556Srgrimes stackp = sp->prev; 1881556Srgrimes ckfree(sp); 1891556Srgrimes } 1901556Srgrimes stacknxt = mark->stacknxt; 1911556Srgrimes stacknleft = mark->stacknleft; 1921556Srgrimes INTON; 1931556Srgrimes} 1941556Srgrimes 1951556Srgrimes 1961556Srgrimes/* 1971556Srgrimes * When the parser reads in a string, it wants to stick the string on the 1981556Srgrimes * stack and only adjust the stack pointer when it knows how big the 1991556Srgrimes * string is. Stackblock (defined in stack.h) returns a pointer to a block 2001556Srgrimes * of space on top of the stack and stackblocklen returns the length of 2011556Srgrimes * this block. Growstackblock will grow this space by at least one byte, 2021556Srgrimes * possibly moving it (like realloc). Grabstackblock actually allocates the 2031556Srgrimes * part of the block that has been used. 2041556Srgrimes */ 2051556Srgrimes 2061556Srgrimesvoid 20790111Simpgrowstackblock(void) 20845618Scracauer{ 2091556Srgrimes char *p; 21045618Scracauer int newlen; 21145618Scracauer char *oldspace; 21245618Scracauer int oldlen; 2131556Srgrimes struct stack_block *sp; 21464702Scracauer struct stack_block *oldstackp; 2151556Srgrimes 21645618Scracauer newlen = ALIGN(stacknleft * 2 + 100); 21745618Scracauer oldspace = stacknxt; 21845618Scracauer oldlen = stacknleft; 21945618Scracauer 2201556Srgrimes if (stacknxt == stackp->space && stackp != &stackbase) { 2211556Srgrimes INTOFF; 22264702Scracauer oldstackp = stackp; 2231556Srgrimes sp = stackp; 2241556Srgrimes stackp = sp->prev; 22545618Scracauer sp = ckrealloc((pointer)sp, sizeof(struct stack_block) - 22645618Scracauer MINSIZE + newlen); 2271556Srgrimes sp->prev = stackp; 2281556Srgrimes stackp = sp; 2291556Srgrimes stacknxt = sp->space; 2301556Srgrimes stacknleft = newlen; 23164702Scracauer { 23264702Scracauer /* Stack marks pointing to the start of the old block 23364702Scracauer * must be relocated to point to the new block 23464702Scracauer */ 23564702Scracauer struct stackmark *xmark; 23664702Scracauer xmark = markp; 23764702Scracauer while (xmark != NULL && xmark->stackp == oldstackp) { 23864702Scracauer xmark->stackp = stackp; 23964702Scracauer xmark->stacknxt = stacknxt; 24064702Scracauer xmark->stacknleft = stacknleft; 24164702Scracauer xmark = xmark->marknext; 24264702Scracauer } 24364702Scracauer } 2441556Srgrimes INTON; 2451556Srgrimes } else { 2461556Srgrimes p = stalloc(newlen); 24717987Speter memcpy(p, oldspace, oldlen); 2481556Srgrimes stacknxt = p; /* free the space */ 24918018Speter stacknleft += newlen; /* we just allocated */ 2501556Srgrimes } 2511556Srgrimes} 2521556Srgrimes 2531556Srgrimes 2541556Srgrimes 2551556Srgrimesvoid 25690111Simpgrabstackblock(int len) 25717987Speter{ 2581556Srgrimes len = ALIGN(len); 2591556Srgrimes stacknxt += len; 2601556Srgrimes stacknleft -= len; 2611556Srgrimes} 2621556Srgrimes 2631556Srgrimes 2641556Srgrimes 2651556Srgrimes/* 2661556Srgrimes * The following routines are somewhat easier to use that the above. 2671556Srgrimes * The user declares a variable of type STACKSTR, which may be declared 2681556Srgrimes * to be a register. The macro STARTSTACKSTR initializes things. Then 2691556Srgrimes * the user uses the macro STPUTC to add characters to the string. In 2701556Srgrimes * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is 2711556Srgrimes * grown as necessary. When the user is done, she can just leave the 2721556Srgrimes * string there and refer to it using stackblock(). Or she can allocate 2731556Srgrimes * the space for it using grabstackstr(). If it is necessary to allow 2741556Srgrimes * someone else to use the stack temporarily and then continue to grow 2751556Srgrimes * the string, the user should use grabstack to allocate the space, and 2761556Srgrimes * then call ungrabstr(p) to return to the previous mode of operation. 2771556Srgrimes * 2781556Srgrimes * USTPUTC is like STPUTC except that it doesn't check for overflow. 2791556Srgrimes * CHECKSTACKSPACE can be called before USTPUTC to ensure that there 2801556Srgrimes * is space for at least one character. 2811556Srgrimes */ 2821556Srgrimes 2831556Srgrimes 2841556Srgrimeschar * 28590111Simpgrowstackstr(void) 28645618Scracauer{ 28745618Scracauer int len; 28845618Scracauer 28945618Scracauer len = stackblocksize(); 2901556Srgrimes if (herefd >= 0 && len >= 1024) { 29139137Stegge xwrite(herefd, stackblock(), len); 2921556Srgrimes sstrnleft = len - 1; 2931556Srgrimes return stackblock(); 2941556Srgrimes } 2951556Srgrimes growstackblock(); 2961556Srgrimes sstrnleft = stackblocksize() - len - 1; 2971556Srgrimes return stackblock() + len; 2981556Srgrimes} 2991556Srgrimes 3001556Srgrimes 3011556Srgrimes/* 3021556Srgrimes * Called from CHECKSTRSPACE. 3031556Srgrimes */ 3041556Srgrimes 3051556Srgrimeschar * 30690111Simpmakestrspace(void) 30745618Scracauer{ 30845618Scracauer int len; 30945618Scracauer 31045618Scracauer len = stackblocksize() - sstrnleft; 3111556Srgrimes growstackblock(); 3121556Srgrimes sstrnleft = stackblocksize() - len; 3131556Srgrimes return stackblock() + len; 3141556Srgrimes} 3151556Srgrimes 3161556Srgrimes 3171556Srgrimes 3181556Srgrimesvoid 31990111Simpungrabstackstr(char *s, char *p) 32045618Scracauer{ 3211556Srgrimes stacknleft += stacknxt - s; 3221556Srgrimes stacknxt = s; 3231556Srgrimes sstrnleft = stacknleft - (p - s); 3241556Srgrimes} 325