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 "$FreeBSD$"; 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 if ((p = realloc(p, nbytes)) == NULL) 81 error("Out of space"); 82 return p; 83 } 84 85 86 /* 87 * Make a copy of a string in safe storage. 88 */ 89 90 char * 91 savestr(s) 92 char *s; 93 { 94 char *p; 95 96 p = ckmalloc(strlen(s) + 1); 97 scopy(s, p); 98 return p; 99 } 100 101 102 /* 103 * Parse trees for commands are allocated in lifo order, so we use a stack 104 * to make this more efficient, and also to avoid all sorts of exception 105 * handling code to handle interrupts in the middle of a parse. 106 * 107 * The size 504 was chosen because the Ultrix malloc handles that size 108 * well. 109 */ 110 111 #define MINSIZE 504 /* minimum size of a block */ 112 113 114 struct stack_block { 115 struct stack_block *prev; 116 char space[MINSIZE]; 117 }; 118 119 struct stack_block stackbase; 120 struct stack_block *stackp = &stackbase; 121 struct stackmark *markp; 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 + 145 blocksize); 146 sp->prev = stackp; 147 stacknxt = sp->space; 148 stacknleft = blocksize; 149 stackp = sp; 150 INTON; 151 } 152 p = stacknxt; 153 stacknxt += nbytes; 154 stacknleft -= nbytes; 155 return p; 156 } 157 158 159 void 160 stunalloc(p) 161 pointer p; 162 { 163 if (p == NULL) { /*DEBUG */ 164 write(STDERR_FILENO, "stunalloc\n", 10); 165 abort(); 166 } 167 stacknleft += stacknxt - (char *)p; 168 stacknxt = p; 169 } 170 171 172 173 void 174 setstackmark(mark) 175 struct stackmark *mark; 176 { 177 mark->stackp = stackp; 178 mark->stacknxt = stacknxt; 179 mark->stacknleft = stacknleft; 180 mark->marknext = markp; 181 markp = mark; 182 } 183 184 185 void 186 popstackmark(mark) 187 struct stackmark *mark; 188 { 189 struct stack_block *sp; 190 191 INTOFF; 192 markp = mark->marknext; 193 while (stackp != mark->stackp) { 194 sp = stackp; 195 stackp = sp->prev; 196 ckfree(sp); 197 } 198 stacknxt = mark->stacknxt; 199 stacknleft = mark->stacknleft; 200 INTON; 201 } 202 203 204 /* 205 * When the parser reads in a string, it wants to stick the string on the 206 * stack and only adjust the stack pointer when it knows how big the 207 * string is. Stackblock (defined in stack.h) returns a pointer to a block 208 * of space on top of the stack and stackblocklen returns the length of 209 * this block. Growstackblock will grow this space by at least one byte, 210 * possibly moving it (like realloc). Grabstackblock actually allocates the 211 * part of the block that has been used. 212 */ 213 214 void 215 growstackblock() 216 { 217 char *p; 218 int newlen; 219 char *oldspace; 220 int oldlen; 221 struct stack_block *sp; 222 struct stack_block *oldstackp; 223 224 newlen = ALIGN(stacknleft * 2 + 100); 225 oldspace = stacknxt; 226 oldlen = stacknleft; 227 228 if (stacknxt == stackp->space && stackp != &stackbase) { 229 INTOFF; 230 oldstackp = stackp; 231 sp = stackp; 232 stackp = sp->prev; 233 sp = ckrealloc((pointer)sp, sizeof(struct stack_block) - 234 MINSIZE + newlen); 235 sp->prev = stackp; 236 stackp = sp; 237 stacknxt = sp->space; 238 stacknleft = newlen; 239 { 240 /* Stack marks pointing to the start of the old block 241 * must be relocated to point to the new block 242 */ 243 struct stackmark *xmark; 244 xmark = markp; 245 while (xmark != NULL && xmark->stackp == oldstackp) { 246 xmark->stackp = stackp; 247 xmark->stacknxt = stacknxt; 248 xmark->stacknleft = stacknleft; 249 xmark = xmark->marknext; 250 } 251 } 252 INTON; 253 } else { 254 p = stalloc(newlen); 255 memcpy(p, oldspace, oldlen); 256 stacknxt = p; /* free the space */ 257 stacknleft += newlen; /* we just allocated */ 258 } 259 } 260 261 262 263 void 264 grabstackblock(len) 265 int len; 266 { 267 len = ALIGN(len); 268 stacknxt += len; 269 stacknleft -= len; 270 } 271 272 273 274 /* 275 * The following routines are somewhat easier to use that the above. 276 * The user declares a variable of type STACKSTR, which may be declared 277 * to be a register. The macro STARTSTACKSTR initializes things. Then 278 * the user uses the macro STPUTC to add characters to the string. In 279 * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is 280 * grown as necessary. When the user is done, she can just leave the 281 * string there and refer to it using stackblock(). Or she can allocate 282 * the space for it using grabstackstr(). If it is necessary to allow 283 * someone else to use the stack temporarily and then continue to grow 284 * the string, the user should use grabstack to allocate the space, and 285 * then call ungrabstr(p) to return to the previous mode of operation. 286 * 287 * USTPUTC is like STPUTC except that it doesn't check for overflow. 288 * CHECKSTACKSPACE can be called before USTPUTC to ensure that there 289 * is space for at least one character. 290 */ 291 292 293 char * 294 growstackstr() 295 { 296 int len; 297 298 len = stackblocksize(); 299 if (herefd >= 0 && len >= 1024) { 300 xwrite(herefd, stackblock(), len); 301 sstrnleft = len - 1; 302 return stackblock(); 303 } 304 growstackblock(); 305 sstrnleft = stackblocksize() - len - 1; 306 return stackblock() + len; 307 } 308 309 310 /* 311 * Called from CHECKSTRSPACE. 312 */ 313 314 char * 315 makestrspace() 316 { 317 int len; 318 319 len = stackblocksize() - sstrnleft; 320 growstackblock(); 321 sstrnleft = stackblocksize() - len; 322 return stackblock() + len; 323 } 324 325 326 327 void 328 ungrabstackstr(s, p) 329 char *s; 330 char *p; 331 { 332 stacknleft += stacknxt - s; 333 stacknxt = s; 334 sstrnleft = stacknleft - (p - s); 335 } 336