memalloc.c revision 213814
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 * 4. Neither the name of the University nor the names of its contributors 171556Srgrimes * may be used to endorse or promote products derived from this software 181556Srgrimes * without specific prior written permission. 191556Srgrimes * 201556Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 211556Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 221556Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 231556Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 241556Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 251556Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 261556Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 271556Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 281556Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 291556Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 301556Srgrimes * SUCH DAMAGE. 311556Srgrimes */ 321556Srgrimes 331556Srgrimes#ifndef lint 3436150Scharnier#if 0 3536150Scharnierstatic char sccsid[] = "@(#)memalloc.c 8.3 (Berkeley) 5/4/95"; 3636150Scharnier#endif 371556Srgrimes#endif /* not lint */ 3899110Sobrien#include <sys/cdefs.h> 3999110Sobrien__FBSDID("$FreeBSD: head/bin/sh/memalloc.c 213814 2010-10-13 23:29:09Z obrien $"); 401556Srgrimes 41111422Smarcel#include <sys/param.h> 421556Srgrimes#include "shell.h" 431556Srgrimes#include "output.h" 441556Srgrimes#include "memalloc.h" 451556Srgrimes#include "error.h" 461556Srgrimes#include "mystring.h" 4739049Scracauer#include "expand.h" 4817987Speter#include <stdlib.h> 4917987Speter#include <unistd.h> 501556Srgrimes 511556Srgrimes/* 521556Srgrimes * Like malloc, but returns an error when out of space. 531556Srgrimes */ 541556Srgrimes 551556Srgrimespointer 56193221Srseckmalloc(size_t nbytes) 5717987Speter{ 5825222Ssteve pointer p; 591556Srgrimes 60151795Sstefanf INTOFF; 61151795Sstefanf p = malloc(nbytes); 62151795Sstefanf INTON; 63151795Sstefanf if (p == NULL) 641556Srgrimes error("Out of space"); 651556Srgrimes return p; 661556Srgrimes} 671556Srgrimes 681556Srgrimes 691556Srgrimes/* 701556Srgrimes * Same for realloc. 711556Srgrimes */ 721556Srgrimes 731556Srgrimespointer 7490111Simpckrealloc(pointer p, int nbytes) 7517987Speter{ 76151795Sstefanf INTOFF; 77151795Sstefanf p = realloc(p, nbytes); 78151795Sstefanf INTON; 79151795Sstefanf if (p == NULL) 801556Srgrimes error("Out of space"); 811556Srgrimes return p; 821556Srgrimes} 831556Srgrimes 84151795Sstefanfvoid 85151795Sstefanfckfree(pointer p) 86151795Sstefanf{ 87151795Sstefanf INTOFF; 88151795Sstefanf free(p); 89151795Sstefanf INTON; 90151795Sstefanf} 911556Srgrimes 92151795Sstefanf 931556Srgrimes/* 941556Srgrimes * Make a copy of a string in safe storage. 951556Srgrimes */ 961556Srgrimes 971556Srgrimeschar * 98200956Sjillessavestr(const char *s) 9945618Scracauer{ 10025222Ssteve char *p; 1011556Srgrimes 1021556Srgrimes p = ckmalloc(strlen(s) + 1); 1031556Srgrimes scopy(s, p); 1041556Srgrimes return p; 1051556Srgrimes} 1061556Srgrimes 1071556Srgrimes 1081556Srgrimes/* 1091556Srgrimes * Parse trees for commands are allocated in lifo order, so we use a stack 1101556Srgrimes * to make this more efficient, and also to avoid all sorts of exception 1111556Srgrimes * handling code to handle interrupts in the middle of a parse. 1121556Srgrimes * 113111422Smarcel * The size 496 was chosen because with 16-byte alignment the total size 114111422Smarcel * for the allocated block is 512. 1151556Srgrimes */ 1161556Srgrimes 117111422Smarcel#define MINSIZE 496 /* minimum size of a block. */ 1181556Srgrimes 1191556Srgrimes 1201556Srgrimesstruct stack_block { 1211556Srgrimes struct stack_block *prev; 122111422Smarcel /* Data follows */ 1231556Srgrimes}; 124111422Smarcel#define SPACE(sp) ((char*)(sp) + ALIGN(sizeof(struct stack_block))) 1251556Srgrimes 126213760Sobrienstatic struct stack_block *stackp; 127213760Sobrienstatic struct stackmark *markp; 128111422Smarcelchar *stacknxt; 129111422Smarcelint stacknleft; 1301556Srgrimesint sstrnleft; 1311556Srgrimesint herefd = -1; 1321556Srgrimes 1331556Srgrimes 134213811Sobrienstatic void 135111422Smarcelstnewblock(int nbytes) 136111422Smarcel{ 137111422Smarcel struct stack_block *sp; 138111422Smarcel int allocsize; 1391556Srgrimes 140111422Smarcel if (nbytes < MINSIZE) 141111422Smarcel nbytes = MINSIZE; 142111422Smarcel 143111422Smarcel allocsize = ALIGN(sizeof(struct stack_block)) + ALIGN(nbytes); 144111422Smarcel 145111422Smarcel INTOFF; 146111422Smarcel sp = ckmalloc(allocsize); 147111422Smarcel sp->prev = stackp; 148111422Smarcel stacknxt = SPACE(sp); 149111422Smarcel stacknleft = allocsize - (stacknxt - (char*)sp); 150111422Smarcel stackp = sp; 151111422Smarcel INTON; 152111422Smarcel} 153111422Smarcel 154111422Smarcel 1551556Srgrimespointer 15690111Simpstalloc(int nbytes) 15717987Speter{ 15825222Ssteve char *p; 1591556Srgrimes 1601556Srgrimes nbytes = ALIGN(nbytes); 161111422Smarcel if (nbytes > stacknleft) 162111422Smarcel stnewblock(nbytes); 1631556Srgrimes p = stacknxt; 1641556Srgrimes stacknxt += nbytes; 1651556Srgrimes stacknleft -= nbytes; 1661556Srgrimes return p; 1671556Srgrimes} 1681556Srgrimes 1691556Srgrimes 1701556Srgrimesvoid 17190111Simpstunalloc(pointer p) 17245618Scracauer{ 1731556Srgrimes if (p == NULL) { /*DEBUG */ 17480381Ssheldonh write(STDERR_FILENO, "stunalloc\n", 10); 1751556Srgrimes abort(); 1761556Srgrimes } 1771556Srgrimes stacknleft += stacknxt - (char *)p; 1781556Srgrimes stacknxt = p; 1791556Srgrimes} 1801556Srgrimes 1811556Srgrimes 1821556Srgrimes 1831556Srgrimesvoid 18490111Simpsetstackmark(struct stackmark *mark) 18545618Scracauer{ 1861556Srgrimes mark->stackp = stackp; 1871556Srgrimes mark->stacknxt = stacknxt; 1881556Srgrimes mark->stacknleft = stacknleft; 18964702Scracauer mark->marknext = markp; 19064702Scracauer markp = mark; 1911556Srgrimes} 1921556Srgrimes 1931556Srgrimes 1941556Srgrimesvoid 19590111Simppopstackmark(struct stackmark *mark) 19645618Scracauer{ 1971556Srgrimes struct stack_block *sp; 1981556Srgrimes 1991556Srgrimes INTOFF; 20064702Scracauer markp = mark->marknext; 2011556Srgrimes while (stackp != mark->stackp) { 2021556Srgrimes sp = stackp; 2031556Srgrimes stackp = sp->prev; 2041556Srgrimes ckfree(sp); 2051556Srgrimes } 2061556Srgrimes stacknxt = mark->stacknxt; 2071556Srgrimes stacknleft = mark->stacknleft; 2081556Srgrimes INTON; 2091556Srgrimes} 2101556Srgrimes 2111556Srgrimes 2121556Srgrimes/* 2131556Srgrimes * When the parser reads in a string, it wants to stick the string on the 2141556Srgrimes * stack and only adjust the stack pointer when it knows how big the 2151556Srgrimes * string is. Stackblock (defined in stack.h) returns a pointer to a block 2161556Srgrimes * of space on top of the stack and stackblocklen returns the length of 2171556Srgrimes * this block. Growstackblock will grow this space by at least one byte, 2181556Srgrimes * possibly moving it (like realloc). Grabstackblock actually allocates the 2191556Srgrimes * part of the block that has been used. 2201556Srgrimes */ 2211556Srgrimes 2221556Srgrimesvoid 22390111Simpgrowstackblock(void) 22445618Scracauer{ 2251556Srgrimes char *p; 22645618Scracauer int newlen; 22745618Scracauer char *oldspace; 22845618Scracauer int oldlen; 2291556Srgrimes struct stack_block *sp; 23064702Scracauer struct stack_block *oldstackp; 231111422Smarcel struct stackmark *xmark; 2321556Srgrimes 233111422Smarcel newlen = (stacknleft == 0) ? MINSIZE : stacknleft * 2 + 100; 234111422Smarcel newlen = ALIGN(newlen); 23545618Scracauer oldspace = stacknxt; 23645618Scracauer oldlen = stacknleft; 23745618Scracauer 238111422Smarcel if (stackp != NULL && stacknxt == SPACE(stackp)) { 2391556Srgrimes INTOFF; 24064702Scracauer oldstackp = stackp; 241111422Smarcel stackp = oldstackp->prev; 242111422Smarcel sp = ckrealloc((pointer)oldstackp, newlen); 2431556Srgrimes sp->prev = stackp; 2441556Srgrimes stackp = sp; 245111422Smarcel stacknxt = SPACE(sp); 246111422Smarcel stacknleft = newlen - (stacknxt - (char*)sp); 247111422Smarcel 248111422Smarcel /* 249111422Smarcel * Stack marks pointing to the start of the old block 250111422Smarcel * must be relocated to point to the new block 251111422Smarcel */ 252111422Smarcel xmark = markp; 253111422Smarcel while (xmark != NULL && xmark->stackp == oldstackp) { 254111422Smarcel xmark->stackp = stackp; 255111422Smarcel xmark->stacknxt = stacknxt; 256111422Smarcel xmark->stacknleft = stacknleft; 257111422Smarcel xmark = xmark->marknext; 25864702Scracauer } 2591556Srgrimes INTON; 2601556Srgrimes } else { 2611556Srgrimes p = stalloc(newlen); 262111422Smarcel if (oldlen != 0) 263111422Smarcel memcpy(p, oldspace, oldlen); 264111422Smarcel stunalloc(p); 2651556Srgrimes } 2661556Srgrimes} 2671556Srgrimes 2681556Srgrimes 2691556Srgrimes 2701556Srgrimesvoid 27190111Simpgrabstackblock(int len) 27217987Speter{ 2731556Srgrimes len = ALIGN(len); 2741556Srgrimes stacknxt += len; 2751556Srgrimes stacknleft -= len; 2761556Srgrimes} 2771556Srgrimes 2781556Srgrimes 2791556Srgrimes 2801556Srgrimes/* 2811556Srgrimes * The following routines are somewhat easier to use that the above. 2821556Srgrimes * The user declares a variable of type STACKSTR, which may be declared 2831556Srgrimes * to be a register. The macro STARTSTACKSTR initializes things. Then 2841556Srgrimes * the user uses the macro STPUTC to add characters to the string. In 2851556Srgrimes * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is 2861556Srgrimes * grown as necessary. When the user is done, she can just leave the 2871556Srgrimes * string there and refer to it using stackblock(). Or she can allocate 2881556Srgrimes * the space for it using grabstackstr(). If it is necessary to allow 2891556Srgrimes * someone else to use the stack temporarily and then continue to grow 2901556Srgrimes * the string, the user should use grabstack to allocate the space, and 2911556Srgrimes * then call ungrabstr(p) to return to the previous mode of operation. 2921556Srgrimes * 2931556Srgrimes * USTPUTC is like STPUTC except that it doesn't check for overflow. 2941556Srgrimes * CHECKSTACKSPACE can be called before USTPUTC to ensure that there 2951556Srgrimes * is space for at least one character. 2961556Srgrimes */ 2971556Srgrimes 298213814Sobrienstatic char * 299213814Sobriengrowstrstackblock(int n) 300213814Sobrien{ 301213814Sobrien growstackblock(); 302213814Sobrien sstrnleft = stackblocksize() - n; 303213814Sobrien return stackblock() + n; 304213814Sobrien} 3051556Srgrimes 3061556Srgrimeschar * 30790111Simpgrowstackstr(void) 30845618Scracauer{ 30945618Scracauer int len; 31045618Scracauer 31145618Scracauer len = stackblocksize(); 3121556Srgrimes if (herefd >= 0 && len >= 1024) { 31339137Stegge xwrite(herefd, stackblock(), len); 314213814Sobrien sstrnleft = len; 3151556Srgrimes return stackblock(); 3161556Srgrimes } 317213814Sobrien return growstrstackblock(len); 3181556Srgrimes} 3191556Srgrimes 3201556Srgrimes 3211556Srgrimes/* 3221556Srgrimes * Called from CHECKSTRSPACE. 3231556Srgrimes */ 3241556Srgrimes 3251556Srgrimeschar * 32690111Simpmakestrspace(void) 32745618Scracauer{ 32845618Scracauer int len; 32945618Scracauer 33045618Scracauer len = stackblocksize() - sstrnleft; 331213814Sobrien return growstrstackblock(len); 3321556Srgrimes} 3331556Srgrimes 3341556Srgrimes 3351556Srgrimes 3361556Srgrimesvoid 33790111Simpungrabstackstr(char *s, char *p) 33845618Scracauer{ 3391556Srgrimes stacknleft += stacknxt - s; 3401556Srgrimes stacknxt = s; 3411556Srgrimes sstrnleft = stacknleft - (p - s); 3421556Srgrimes} 343