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 char *stacknxt = stackbase.space; 122 int stacknleft = MINSIZE; 123 int sstrnleft; 124 int herefd = -1; 125 126 127 128 pointer 129 stalloc(nbytes) 130 int nbytes; 131 { 132 char *p; 133 134 nbytes = ALIGN(nbytes); 135 if (nbytes > stacknleft) { 136 int blocksize; 137 struct stack_block *sp; 138 139 blocksize = nbytes; 140 if (blocksize < MINSIZE) 141 blocksize = MINSIZE; 142 INTOFF; 143 sp = ckmalloc(sizeof(struct stack_block) - MINSIZE + 144 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 { 213 char *p; 214 int newlen; 215 char *oldspace; 216 int oldlen; 217 struct stack_block *sp; 218 219 newlen = ALIGN(stacknleft * 2 + 100); 220 oldspace = stacknxt; 221 oldlen = stacknleft; 222 223 if (stacknxt == stackp->space && stackp != &stackbase) { 224 INTOFF; 225 sp = stackp; 226 stackp = sp->prev; 227 sp = ckrealloc((pointer)sp, sizeof(struct stack_block) - 228 MINSIZE + newlen); 229 sp->prev = stackp; 230 stackp = sp; 231 stacknxt = sp->space; 232 stacknleft = newlen; 233 INTON; 234 } else { 235 p = stalloc(newlen); 236 memcpy(p, oldspace, oldlen); 237 stacknxt = p; /* free the space */ 238 stacknleft += newlen; /* we just allocated */ 239 } 240 } 241 242 243 244 void 245 grabstackblock(len) 246 int len; 247 { 248 len = ALIGN(len); 249 stacknxt += len; 250 stacknleft -= len; 251 } 252 253 254 255 /* 256 * The following routines are somewhat easier to use that the above. 257 * The user declares a variable of type STACKSTR, which may be declared 258 * to be a register. The macro STARTSTACKSTR initializes things. Then 259 * the user uses the macro STPUTC to add characters to the string. In 260 * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is 261 * grown as necessary. When the user is done, she can just leave the 262 * string there and refer to it using stackblock(). Or she can allocate 263 * the space for it using grabstackstr(). If it is necessary to allow 264 * someone else to use the stack temporarily and then continue to grow 265 * the string, the user should use grabstack to allocate the space, and 266 * then call ungrabstr(p) to return to the previous mode of operation. 267 * 268 * USTPUTC is like STPUTC except that it doesn't check for overflow. 269 * CHECKSTACKSPACE can be called before USTPUTC to ensure that there 270 * is space for at least one character. 271 */ 272 273 274 char * 275 growstackstr() 276 { 277 int len; 278 279 len = stackblocksize(); 280 if (herefd >= 0 && len >= 1024) { 281 xwrite(herefd, stackblock(), len); 282 sstrnleft = len - 1; 283 return stackblock(); 284 } 285 growstackblock(); 286 sstrnleft = stackblocksize() - len - 1; 287 return stackblock() + len; 288 } 289 290 291 /* 292 * Called from CHECKSTRSPACE. 293 */ 294 295 char * 296 makestrspace() 297 { 298 int len; 299 300 len = stackblocksize() - sstrnleft; 301 growstackblock(); 302 sstrnleft = stackblocksize() - len; 303 return stackblock() + len; 304 } 305 306 307 308 void 309 ungrabstackstr(s, p) 310 char *s; 311 char *p; 312 { 313 stacknleft += stacknxt - s; 314 stacknxt = s; 315 sstrnleft = stacknleft - (p - s); 316 } 317