1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #ifndef lint 38 #if 0 39 static char sccsid[] = "@(#)memalloc.c 8.3 (Berkeley) 5/4/95"; 40 #endif 41 static const char rcsid[] = 42 "$Id: memalloc.c,v 1.11 1998/09/10 14:51:06 cracauer Exp $"; 43 #endif /* not lint */ 44 45 #include "shell.h" 46 #include "output.h" 47 #include "memalloc.h" 48 #include "error.h" 49 #include "machdep.h" 50 #include "mystring.h" 51 #include "expand.h" 52 #include <stdlib.h> 53 #include <unistd.h> 54 55 /* 56 * Like malloc, but returns an error when out of space. 57 */ 58 59 pointer 60 ckmalloc(nbytes) 61 int nbytes; 62 { 63 pointer p; 64 65 if ((p = malloc(nbytes)) == NULL) 66 error("Out of space"); 67 return p; 68 } 69 70 71 /* 72 * Same for realloc. 73 */ 74 75 pointer 76 ckrealloc(p, nbytes) 77 pointer p; 78 int nbytes; 79 { 80 81 if ((p = realloc(p, nbytes)) == NULL) 82 error("Out of space"); 83 return p; 84 } 85 86 87 /* 88 * Make a copy of a string in safe storage. 89 */ 90 91 char * 92 savestr(s) 93 char *s; 94 { 95 char *p; 96 97 p = ckmalloc(strlen(s) + 1); 98 scopy(s, p); 99 return p; 100 } 101 102 103 /* 104 * Parse trees for commands are allocated in lifo order, so we use a stack 105 * to make this more efficient, and also to avoid all sorts of exception 106 * handling code to handle interrupts in the middle of a parse. 107 * 108 * The size 504 was chosen because the Ultrix malloc handles that size 109 * well. 110 */ 111 112 #define MINSIZE 504 /* minimum size of a block */ 113 114 115 struct stack_block { 116 struct stack_block *prev; 117 char space[MINSIZE]; 118 }; 119 120 struct stack_block stackbase; 121 struct stack_block *stackp = &stackbase; 122 char *stacknxt = stackbase.space; 123 int stacknleft = MINSIZE; 124 int sstrnleft; 125 int herefd = -1; 126 127 128 129 pointer 130 stalloc(nbytes) 131 int nbytes; 132 { 133 char *p; 134 135 nbytes = ALIGN(nbytes); 136 if (nbytes > stacknleft) { 137 int blocksize; 138 struct stack_block *sp; 139 140 blocksize = nbytes; 141 if (blocksize < MINSIZE) 142 blocksize = MINSIZE; 143 INTOFF; 144 sp = ckmalloc(sizeof(struct stack_block) - MINSIZE + blocksize); 145 sp->prev = stackp; 146 stacknxt = sp->space; 147 stacknleft = blocksize; 148 stackp = sp; 149 INTON; 150 } 151 p = stacknxt; 152 stacknxt += nbytes; 153 stacknleft -= nbytes; 154 return p; 155 } 156 157 158 void 159 stunalloc(p) 160 pointer p; 161 { 162 if (p == NULL) { /*DEBUG */ 163 write(2, "stunalloc\n", 10); 164 abort(); 165 } 166 stacknleft += stacknxt - (char *)p; 167 stacknxt = p; 168 } 169 170 171 172 void 173 setstackmark(mark) 174 struct stackmark *mark; 175 { 176 mark->stackp = stackp; 177 mark->stacknxt = stacknxt; 178 mark->stacknleft = stacknleft; 179 } 180 181 182 void 183 popstackmark(mark) 184 struct stackmark *mark; 185 { 186 struct stack_block *sp; 187 188 INTOFF; 189 while (stackp != mark->stackp) { 190 sp = stackp; 191 stackp = sp->prev; 192 ckfree(sp); 193 } 194 stacknxt = mark->stacknxt; 195 stacknleft = mark->stacknleft; 196 INTON; 197 } 198 199 200 /* 201 * When the parser reads in a string, it wants to stick the string on the 202 * stack and only adjust the stack pointer when it knows how big the 203 * string is. Stackblock (defined in stack.h) returns a pointer to a block 204 * of space on top of the stack and stackblocklen returns the length of 205 * this block. Growstackblock will grow this space by at least one byte, 206 * possibly moving it (like realloc). Grabstackblock actually allocates the 207 * part of the block that has been used. 208 */ 209 210 void 211 growstackblock() { 212 char *p; 213 int newlen = ALIGN(stacknleft * 2 + 100); 214 char *oldspace = stacknxt; 215 int oldlen = stacknleft; 216 struct stack_block *sp; 217 218 if (stacknxt == stackp->space && stackp != &stackbase) { 219 INTOFF; 220 sp = stackp; 221 stackp = sp->prev; 222 sp = ckrealloc((pointer)sp, sizeof(struct stack_block) - MINSIZE + newlen); 223 sp->prev = stackp; 224 stackp = sp; 225 stacknxt = sp->space; 226 stacknleft = newlen; 227 INTON; 228 } else { 229 p = stalloc(newlen); 230 memcpy(p, oldspace, oldlen); 231 stacknxt = p; /* free the space */ 232 stacknleft += newlen; /* we just allocated */ 233 } 234 } 235 236 237 238 void 239 grabstackblock(len) 240 int len; 241 { 242 len = ALIGN(len); 243 stacknxt += len; 244 stacknleft -= len; 245 } 246 247 248 249 /* 250 * The following routines are somewhat easier to use that the above. 251 * The user declares a variable of type STACKSTR, which may be declared 252 * to be a register. The macro STARTSTACKSTR initializes things. Then 253 * the user uses the macro STPUTC to add characters to the string. In 254 * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is 255 * grown as necessary. When the user is done, she can just leave the 256 * string there and refer to it using stackblock(). Or she can allocate 257 * the space for it using grabstackstr(). If it is necessary to allow 258 * someone else to use the stack temporarily and then continue to grow 259 * the string, the user should use grabstack to allocate the space, and 260 * then call ungrabstr(p) to return to the previous mode of operation. 261 * 262 * USTPUTC is like STPUTC except that it doesn't check for overflow. 263 * CHECKSTACKSPACE can be called before USTPUTC to ensure that there 264 * is space for at least one character. 265 */ 266 267 268 char * 269 growstackstr() { 270 int len = stackblocksize(); 271 if (herefd >= 0 && len >= 1024) { 272 xwrite(herefd, stackblock(), len); 273 sstrnleft = len - 1; 274 return stackblock(); 275 } 276 growstackblock(); 277 sstrnleft = stackblocksize() - len - 1; 278 return stackblock() + len; 279 } 280 281 282 /* 283 * Called from CHECKSTRSPACE. 284 */ 285 286 char * 287 makestrspace() { 288 int len = stackblocksize() - sstrnleft; 289 growstackblock(); 290 sstrnleft = stackblocksize() - len; 291 return stackblock() + len; 292 } 293 294 295 296 void 297 ungrabstackstr(s, p) 298 char *s; 299 char *p; 300 { 301 stacknleft += stacknxt - s; 302 stacknxt = s; 303 sstrnleft = stacknleft - (p - s); 304 } 305