memalloc.c revision 250527
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 250527 2013-05-11 20:51:00Z jilles $"); 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; 127111422Smarcelchar *stacknxt; 128111422Smarcelint stacknleft; 129216743Sjilleschar *sstrend; 1301556Srgrimes 1311556Srgrimes 132213811Sobrienstatic void 133111422Smarcelstnewblock(int nbytes) 134111422Smarcel{ 135111422Smarcel struct stack_block *sp; 136111422Smarcel int allocsize; 1371556Srgrimes 138111422Smarcel if (nbytes < MINSIZE) 139111422Smarcel nbytes = MINSIZE; 140111422Smarcel 141111422Smarcel allocsize = ALIGN(sizeof(struct stack_block)) + ALIGN(nbytes); 142111422Smarcel 143111422Smarcel INTOFF; 144111422Smarcel sp = ckmalloc(allocsize); 145111422Smarcel sp->prev = stackp; 146111422Smarcel stacknxt = SPACE(sp); 147111422Smarcel stacknleft = allocsize - (stacknxt - (char*)sp); 148216743Sjilles sstrend = stacknxt + stacknleft; 149111422Smarcel stackp = sp; 150111422Smarcel INTON; 151111422Smarcel} 152111422Smarcel 153111422Smarcel 1541556Srgrimespointer 15590111Simpstalloc(int nbytes) 15617987Speter{ 15725222Ssteve char *p; 1581556Srgrimes 1591556Srgrimes nbytes = ALIGN(nbytes); 160111422Smarcel if (nbytes > stacknleft) 161111422Smarcel stnewblock(nbytes); 1621556Srgrimes p = stacknxt; 1631556Srgrimes stacknxt += nbytes; 1641556Srgrimes stacknleft -= nbytes; 1651556Srgrimes return p; 1661556Srgrimes} 1671556Srgrimes 1681556Srgrimes 1691556Srgrimesvoid 17090111Simpstunalloc(pointer p) 17145618Scracauer{ 1721556Srgrimes if (p == NULL) { /*DEBUG */ 17380381Ssheldonh write(STDERR_FILENO, "stunalloc\n", 10); 1741556Srgrimes abort(); 1751556Srgrimes } 1761556Srgrimes stacknleft += stacknxt - (char *)p; 1771556Srgrimes stacknxt = p; 1781556Srgrimes} 1791556Srgrimes 1801556Srgrimes 1811556Srgrimes 1821556Srgrimesvoid 18390111Simpsetstackmark(struct stackmark *mark) 18445618Scracauer{ 1851556Srgrimes mark->stackp = stackp; 1861556Srgrimes mark->stacknxt = stacknxt; 1871556Srgrimes mark->stacknleft = stacknleft; 188250527Sjilles /* Ensure this block stays in place. */ 189250527Sjilles if (stackp != NULL && stacknxt == SPACE(stackp)) 190250527Sjilles stalloc(1); 1911556Srgrimes} 1921556Srgrimes 1931556Srgrimes 1941556Srgrimesvoid 19590111Simppopstackmark(struct stackmark *mark) 19645618Scracauer{ 1971556Srgrimes struct stack_block *sp; 1981556Srgrimes 1991556Srgrimes INTOFF; 2001556Srgrimes while (stackp != mark->stackp) { 2011556Srgrimes sp = stackp; 2021556Srgrimes stackp = sp->prev; 2031556Srgrimes ckfree(sp); 2041556Srgrimes } 2051556Srgrimes stacknxt = mark->stacknxt; 2061556Srgrimes stacknleft = mark->stacknleft; 207216743Sjilles sstrend = stacknxt + 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 222216706Sjillesstatic void 223216706Sjillesgrowstackblock(int min) 22445618Scracauer{ 2251556Srgrimes char *p; 22645618Scracauer int newlen; 22745618Scracauer char *oldspace; 22845618Scracauer int oldlen; 2291556Srgrimes struct stack_block *sp; 23064702Scracauer struct stack_block *oldstackp; 2311556Srgrimes 232216706Sjilles if (min < stacknleft) 233216706Sjilles min = stacknleft; 234248980Sjilles if ((unsigned int)min >= 235248980Sjilles INT_MAX / 2 - ALIGN(sizeof(struct stack_block))) 236216706Sjilles error("Out of space"); 237216706Sjilles min += stacknleft; 238216706Sjilles min += ALIGN(sizeof(struct stack_block)); 239216706Sjilles newlen = 512; 240216706Sjilles while (newlen < min) 241216706Sjilles newlen <<= 1; 24245618Scracauer oldspace = stacknxt; 24345618Scracauer oldlen = stacknleft; 24445618Scracauer 245111422Smarcel if (stackp != NULL && stacknxt == SPACE(stackp)) { 2461556Srgrimes INTOFF; 24764702Scracauer oldstackp = stackp; 248111422Smarcel stackp = oldstackp->prev; 249111422Smarcel sp = ckrealloc((pointer)oldstackp, newlen); 2501556Srgrimes sp->prev = stackp; 2511556Srgrimes stackp = sp; 252111422Smarcel stacknxt = SPACE(sp); 253111422Smarcel stacknleft = newlen - (stacknxt - (char*)sp); 254216743Sjilles sstrend = stacknxt + stacknleft; 2551556Srgrimes INTON; 2561556Srgrimes } else { 257216706Sjilles newlen -= ALIGN(sizeof(struct stack_block)); 2581556Srgrimes p = stalloc(newlen); 259111422Smarcel if (oldlen != 0) 260111422Smarcel memcpy(p, oldspace, oldlen); 261111422Smarcel stunalloc(p); 2621556Srgrimes } 2631556Srgrimes} 2641556Srgrimes 2651556Srgrimes 2661556Srgrimes 2671556Srgrimes/* 2681556Srgrimes * The following routines are somewhat easier to use that the above. 2691556Srgrimes * The user declares a variable of type STACKSTR, which may be declared 2701556Srgrimes * to be a register. The macro STARTSTACKSTR initializes things. Then 2711556Srgrimes * the user uses the macro STPUTC to add characters to the string. In 2721556Srgrimes * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is 2731556Srgrimes * grown as necessary. When the user is done, she can just leave the 2741556Srgrimes * string there and refer to it using stackblock(). Or she can allocate 2751556Srgrimes * the space for it using grabstackstr(). If it is necessary to allow 2761556Srgrimes * someone else to use the stack temporarily and then continue to grow 2771556Srgrimes * the string, the user should use grabstack to allocate the space, and 2781556Srgrimes * then call ungrabstr(p) to return to the previous mode of operation. 2791556Srgrimes * 2801556Srgrimes * USTPUTC is like STPUTC except that it doesn't check for overflow. 2811556Srgrimes * CHECKSTACKSPACE can be called before USTPUTC to ensure that there 2821556Srgrimes * is space for at least one character. 2831556Srgrimes */ 2841556Srgrimes 285213814Sobrienstatic char * 286216706Sjillesgrowstrstackblock(int n, int min) 287213814Sobrien{ 288216706Sjilles growstackblock(min); 289213814Sobrien return stackblock() + n; 290213814Sobrien} 2911556Srgrimes 2921556Srgrimeschar * 29390111Simpgrowstackstr(void) 29445618Scracauer{ 29545618Scracauer int len; 29645618Scracauer 29745618Scracauer len = stackblocksize(); 298216706Sjilles return (growstrstackblock(len, 0)); 2991556Srgrimes} 3001556Srgrimes 3011556Srgrimes 3021556Srgrimes/* 3031556Srgrimes * Called from CHECKSTRSPACE. 3041556Srgrimes */ 3051556Srgrimes 3061556Srgrimeschar * 307216743Sjillesmakestrspace(int min, char *p) 30845618Scracauer{ 30945618Scracauer int len; 31045618Scracauer 311216743Sjilles len = p - stackblock(); 312216706Sjilles return (growstrstackblock(len, min)); 3131556Srgrimes} 3141556Srgrimes 3151556Srgrimes 316215783Sjilleschar * 317248980Sjillesstputbin(const char *data, size_t len, char *p) 318215783Sjilles{ 319216706Sjilles CHECKSTRSPACE(len, p); 320216706Sjilles memcpy(p, data, len); 321216706Sjilles return (p + len); 322215783Sjilles} 323215783Sjilles 324215783Sjilleschar * 325215783Sjillesstputs(const char *data, char *p) 326215783Sjilles{ 327215783Sjilles return (stputbin(data, strlen(data), p)); 328215783Sjilles} 329