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 static char sccsid[] = "@(#)memalloc.c 8.1 (Berkeley) 5/31/93"; 39 #endif /* not lint */ 40 41 #include "shell.h" 42 #include "output.h" 43 #include "memalloc.h" 44 #include "error.h" 45 #include "machdep.h" 46 #include "mystring.h" 47 48 /* 49 * Like malloc, but returns an error when out of space. 50 */ 51 52 pointer 53 ckmalloc(nbytes) { 54 register pointer p; 55 pointer malloc(); 56 57 if ((p = malloc(nbytes)) == NULL) 58 error("Out of space"); 59 return p; 60 } 61 62 63 /* 64 * Same for realloc. 65 */ 66 67 pointer 68 ckrealloc(p, nbytes) 69 register pointer p; 70 { 71 pointer realloc(); 72 73 if ((p = realloc(p, nbytes)) == NULL) 74 error("Out of space"); 75 return p; 76 } 77 78 79 /* 80 * Make a copy of a string in safe storage. 81 */ 82 83 char * 84 savestr(s) 85 char *s; 86 { 87 register char *p; 88 89 p = ckmalloc(strlen(s) + 1); 90 scopy(s, p); 91 return p; 92 } 93 94 95 /* 96 * Parse trees for commands are allocated in lifo order, so we use a stack 97 * to make this more efficient, and also to avoid all sorts of exception 98 * handling code to handle interrupts in the middle of a parse. 99 * 100 * The size 504 was chosen because the Ultrix malloc handles that size 101 * well. 102 */ 103 104 #define MINSIZE 504 /* minimum size of a block */ 105 106 107 struct stack_block { 108 struct stack_block *prev; 109 char space[MINSIZE]; 110 }; 111 112 struct stack_block stackbase; 113 struct stack_block *stackp = &stackbase; 114 char *stacknxt = stackbase.space; 115 int stacknleft = MINSIZE; 116 int sstrnleft; 117 int herefd = -1; 118 119 120 121 pointer 122 stalloc(nbytes) { 123 register char *p; 124 125 nbytes = ALIGN(nbytes); 126 if (nbytes > stacknleft) { 127 int blocksize; 128 struct stack_block *sp; 129 130 blocksize = nbytes; 131 if (blocksize < MINSIZE) 132 blocksize = MINSIZE; 133 INTOFF; 134 sp = ckmalloc(sizeof(struct stack_block) - MINSIZE + blocksize); 135 sp->prev = stackp; 136 stacknxt = sp->space; 137 stacknleft = blocksize; 138 stackp = sp; 139 INTON; 140 } 141 p = stacknxt; 142 stacknxt += nbytes; 143 stacknleft -= nbytes; 144 return p; 145 } 146 147 148 void 149 stunalloc(p) 150 pointer p; 151 { 152 if (p == NULL) { /*DEBUG */ 153 write(2, "stunalloc\n", 10); 154 abort(); 155 } 156 stacknleft += stacknxt - (char *)p; 157 stacknxt = p; 158 } 159 160 161 162 void 163 setstackmark(mark) 164 struct stackmark *mark; 165 { 166 mark->stackp = stackp; 167 mark->stacknxt = stacknxt; 168 mark->stacknleft = stacknleft; 169 } 170 171 172 void 173 popstackmark(mark) 174 struct stackmark *mark; 175 { 176 struct stack_block *sp; 177 178 INTOFF; 179 while (stackp != mark->stackp) { 180 sp = stackp; 181 stackp = sp->prev; 182 ckfree(sp); 183 } 184 stacknxt = mark->stacknxt; 185 stacknleft = mark->stacknleft; 186 INTON; 187 } 188 189 190 /* 191 * When the parser reads in a string, it wants to stick the string on the 192 * stack and only adjust the stack pointer when it knows how big the 193 * string is. Stackblock (defined in stack.h) returns a pointer to a block 194 * of space on top of the stack and stackblocklen returns the length of 195 * this block. Growstackblock will grow this space by at least one byte, 196 * possibly moving it (like realloc). Grabstackblock actually allocates the 197 * part of the block that has been used. 198 */ 199 200 void 201 growstackblock() { 202 char *p; 203 int newlen = stacknleft * 2 + 100; 204 char *oldspace = stacknxt; 205 int oldlen = stacknleft; 206 struct stack_block *sp; 207 208 if (stacknxt == stackp->space && stackp != &stackbase) { 209 INTOFF; 210 sp = stackp; 211 stackp = sp->prev; 212 sp = ckrealloc((pointer)sp, sizeof(struct stack_block) - MINSIZE + newlen); 213 sp->prev = stackp; 214 stackp = sp; 215 stacknxt = sp->space; 216 stacknleft = newlen; 217 INTON; 218 } else { 219 p = stalloc(newlen); 220 bcopy(oldspace, p, oldlen); 221 stacknxt = p; /* free the space */ 222 stacknleft += newlen; /* we just allocated */ 223 } 224 } 225 226 227 228 void 229 grabstackblock(len) { 230 len = ALIGN(len); 231 stacknxt += len; 232 stacknleft -= len; 233 } 234 235 236 237 /* 238 * The following routines are somewhat easier to use that the above. 239 * The user declares a variable of type STACKSTR, which may be declared 240 * to be a register. The macro STARTSTACKSTR initializes things. Then 241 * the user uses the macro STPUTC to add characters to the string. In 242 * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is 243 * grown as necessary. When the user is done, she can just leave the 244 * string there and refer to it using stackblock(). Or she can allocate 245 * the space for it using grabstackstr(). If it is necessary to allow 246 * someone else to use the stack temporarily and then continue to grow 247 * the string, the user should use grabstack to allocate the space, and 248 * then call ungrabstr(p) to return to the previous mode of operation. 249 * 250 * USTPUTC is like STPUTC except that it doesn't check for overflow. 251 * CHECKSTACKSPACE can be called before USTPUTC to ensure that there 252 * is space for at least one character. 253 */ 254 255 256 char * 257 growstackstr() { 258 int len = stackblocksize(); 259 if (herefd >= 0 && len >= 1024) { 260 xwrite(herefd, stackblock(), len); 261 sstrnleft = len - 1; 262 return stackblock(); 263 } 264 growstackblock(); 265 sstrnleft = stackblocksize() - len - 1; 266 return stackblock() + len; 267 } 268 269 270 /* 271 * Called from CHECKSTRSPACE. 272 */ 273 274 char * 275 makestrspace() { 276 int len = stackblocksize() - sstrnleft; 277 growstackblock(); 278 sstrnleft = stackblocksize() - len; 279 return stackblock() + len; 280 } 281 282 283 284 void 285 ungrabstackstr(s, p) 286 char *s; 287 char *p; 288 { 289 stacknleft += stacknxt - s; 290 stacknxt = s; 291 sstrnleft = stacknleft - (p - s); 292 } 293