memalloc.c revision 262951
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: stable/10/bin/sh/memalloc.c 262951 2014-03-09 17:04:31Z jmmv $"); 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; 101262951Sjmmv size_t len; 1021556Srgrimes 103262951Sjmmv len = strlen(s); 104262951Sjmmv p = ckmalloc(len + 1); 105262951Sjmmv memcpy(p, s, len + 1); 1061556Srgrimes return p; 1071556Srgrimes} 1081556Srgrimes 1091556Srgrimes 1101556Srgrimes/* 1111556Srgrimes * Parse trees for commands are allocated in lifo order, so we use a stack 1121556Srgrimes * to make this more efficient, and also to avoid all sorts of exception 1131556Srgrimes * handling code to handle interrupts in the middle of a parse. 1141556Srgrimes * 115111422Smarcel * The size 496 was chosen because with 16-byte alignment the total size 116111422Smarcel * for the allocated block is 512. 1171556Srgrimes */ 1181556Srgrimes 119111422Smarcel#define MINSIZE 496 /* minimum size of a block. */ 1201556Srgrimes 1211556Srgrimes 1221556Srgrimesstruct stack_block { 1231556Srgrimes struct stack_block *prev; 124111422Smarcel /* Data follows */ 1251556Srgrimes}; 126111422Smarcel#define SPACE(sp) ((char*)(sp) + ALIGN(sizeof(struct stack_block))) 1271556Srgrimes 128213760Sobrienstatic struct stack_block *stackp; 129111422Smarcelchar *stacknxt; 130111422Smarcelint stacknleft; 131216743Sjilleschar *sstrend; 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); 150216743Sjilles sstrend = stacknxt + stacknleft; 151111422Smarcel stackp = sp; 152111422Smarcel INTON; 153111422Smarcel} 154111422Smarcel 155111422Smarcel 1561556Srgrimespointer 15790111Simpstalloc(int nbytes) 15817987Speter{ 15925222Ssteve char *p; 1601556Srgrimes 1611556Srgrimes nbytes = ALIGN(nbytes); 162111422Smarcel if (nbytes > stacknleft) 163111422Smarcel stnewblock(nbytes); 1641556Srgrimes p = stacknxt; 1651556Srgrimes stacknxt += nbytes; 1661556Srgrimes stacknleft -= nbytes; 1671556Srgrimes return p; 1681556Srgrimes} 1691556Srgrimes 1701556Srgrimes 1711556Srgrimesvoid 17290111Simpstunalloc(pointer p) 17345618Scracauer{ 1741556Srgrimes if (p == NULL) { /*DEBUG */ 17580381Ssheldonh write(STDERR_FILENO, "stunalloc\n", 10); 1761556Srgrimes abort(); 1771556Srgrimes } 1781556Srgrimes stacknleft += stacknxt - (char *)p; 1791556Srgrimes stacknxt = p; 1801556Srgrimes} 1811556Srgrimes 1821556Srgrimes 1831556Srgrimes 1841556Srgrimesvoid 18590111Simpsetstackmark(struct stackmark *mark) 18645618Scracauer{ 1871556Srgrimes mark->stackp = stackp; 1881556Srgrimes mark->stacknxt = stacknxt; 1891556Srgrimes mark->stacknleft = stacknleft; 190250527Sjilles /* Ensure this block stays in place. */ 191250527Sjilles if (stackp != NULL && stacknxt == SPACE(stackp)) 192250527Sjilles stalloc(1); 1931556Srgrimes} 1941556Srgrimes 1951556Srgrimes 1961556Srgrimesvoid 19790111Simppopstackmark(struct stackmark *mark) 19845618Scracauer{ 1991556Srgrimes struct stack_block *sp; 2001556Srgrimes 2011556Srgrimes INTOFF; 2021556Srgrimes while (stackp != mark->stackp) { 2031556Srgrimes sp = stackp; 2041556Srgrimes stackp = sp->prev; 2051556Srgrimes ckfree(sp); 2061556Srgrimes } 2071556Srgrimes stacknxt = mark->stacknxt; 2081556Srgrimes stacknleft = mark->stacknleft; 209216743Sjilles sstrend = stacknxt + stacknleft; 2101556Srgrimes INTON; 2111556Srgrimes} 2121556Srgrimes 2131556Srgrimes 2141556Srgrimes/* 2151556Srgrimes * When the parser reads in a string, it wants to stick the string on the 2161556Srgrimes * stack and only adjust the stack pointer when it knows how big the 2171556Srgrimes * string is. Stackblock (defined in stack.h) returns a pointer to a block 2181556Srgrimes * of space on top of the stack and stackblocklen returns the length of 2191556Srgrimes * this block. Growstackblock will grow this space by at least one byte, 2201556Srgrimes * possibly moving it (like realloc). Grabstackblock actually allocates the 2211556Srgrimes * part of the block that has been used. 2221556Srgrimes */ 2231556Srgrimes 224216706Sjillesstatic void 225216706Sjillesgrowstackblock(int min) 22645618Scracauer{ 2271556Srgrimes char *p; 22845618Scracauer int newlen; 22945618Scracauer char *oldspace; 23045618Scracauer int oldlen; 2311556Srgrimes struct stack_block *sp; 23264702Scracauer struct stack_block *oldstackp; 2331556Srgrimes 234216706Sjilles if (min < stacknleft) 235216706Sjilles min = stacknleft; 236248980Sjilles if ((unsigned int)min >= 237248980Sjilles INT_MAX / 2 - ALIGN(sizeof(struct stack_block))) 238216706Sjilles error("Out of space"); 239216706Sjilles min += stacknleft; 240216706Sjilles min += ALIGN(sizeof(struct stack_block)); 241216706Sjilles newlen = 512; 242216706Sjilles while (newlen < min) 243216706Sjilles newlen <<= 1; 24445618Scracauer oldspace = stacknxt; 24545618Scracauer oldlen = stacknleft; 24645618Scracauer 247111422Smarcel if (stackp != NULL && stacknxt == SPACE(stackp)) { 2481556Srgrimes INTOFF; 24964702Scracauer oldstackp = stackp; 250111422Smarcel stackp = oldstackp->prev; 251111422Smarcel sp = ckrealloc((pointer)oldstackp, newlen); 2521556Srgrimes sp->prev = stackp; 2531556Srgrimes stackp = sp; 254111422Smarcel stacknxt = SPACE(sp); 255111422Smarcel stacknleft = newlen - (stacknxt - (char*)sp); 256216743Sjilles sstrend = stacknxt + stacknleft; 2571556Srgrimes INTON; 2581556Srgrimes } else { 259216706Sjilles newlen -= ALIGN(sizeof(struct stack_block)); 2601556Srgrimes p = stalloc(newlen); 261111422Smarcel if (oldlen != 0) 262111422Smarcel memcpy(p, oldspace, oldlen); 263111422Smarcel stunalloc(p); 2641556Srgrimes } 2651556Srgrimes} 2661556Srgrimes 2671556Srgrimes 2681556Srgrimes 2691556Srgrimes/* 2701556Srgrimes * The following routines are somewhat easier to use that the above. 2711556Srgrimes * The user declares a variable of type STACKSTR, which may be declared 2721556Srgrimes * to be a register. The macro STARTSTACKSTR initializes things. Then 2731556Srgrimes * the user uses the macro STPUTC to add characters to the string. In 2741556Srgrimes * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is 2751556Srgrimes * grown as necessary. When the user is done, she can just leave the 2761556Srgrimes * string there and refer to it using stackblock(). Or she can allocate 2771556Srgrimes * the space for it using grabstackstr(). If it is necessary to allow 2781556Srgrimes * someone else to use the stack temporarily and then continue to grow 2791556Srgrimes * the string, the user should use grabstack to allocate the space, and 2801556Srgrimes * then call ungrabstr(p) to return to the previous mode of operation. 2811556Srgrimes * 2821556Srgrimes * USTPUTC is like STPUTC except that it doesn't check for overflow. 2831556Srgrimes * CHECKSTACKSPACE can be called before USTPUTC to ensure that there 2841556Srgrimes * is space for at least one character. 2851556Srgrimes */ 2861556Srgrimes 287213814Sobrienstatic char * 288216706Sjillesgrowstrstackblock(int n, int min) 289213814Sobrien{ 290216706Sjilles growstackblock(min); 291213814Sobrien return stackblock() + n; 292213814Sobrien} 2931556Srgrimes 2941556Srgrimeschar * 29590111Simpgrowstackstr(void) 29645618Scracauer{ 29745618Scracauer int len; 29845618Scracauer 29945618Scracauer len = stackblocksize(); 300216706Sjilles return (growstrstackblock(len, 0)); 3011556Srgrimes} 3021556Srgrimes 3031556Srgrimes 3041556Srgrimes/* 3051556Srgrimes * Called from CHECKSTRSPACE. 3061556Srgrimes */ 3071556Srgrimes 3081556Srgrimeschar * 309216743Sjillesmakestrspace(int min, char *p) 31045618Scracauer{ 31145618Scracauer int len; 31245618Scracauer 313216743Sjilles len = p - stackblock(); 314216706Sjilles return (growstrstackblock(len, min)); 3151556Srgrimes} 3161556Srgrimes 3171556Srgrimes 318215783Sjilleschar * 319248980Sjillesstputbin(const char *data, size_t len, char *p) 320215783Sjilles{ 321216706Sjilles CHECKSTRSPACE(len, p); 322216706Sjilles memcpy(p, data, len); 323216706Sjilles return (p + len); 324215783Sjilles} 325215783Sjilles 326215783Sjilleschar * 327215783Sjillesstputs(const char *data, char *p) 328215783Sjilles{ 329215783Sjilles return (stputbin(data, strlen(data), p)); 330215783Sjilles} 331