| 1 | /* obstack.c - subroutines used implicitly by object stack macros |
| 2 | Copyright (C) 1988 Free Software Foundation, Inc. |
| 3 | |
| 4 | This program is free software; you can redistribute it and/or modify it |
| 5 | under the terms of the GNU General Public License as published by the |
| 6 | Free Software Foundation; either version 2, or (at your option) any |
| 7 | later version. |
| 8 | |
| 9 | This program is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | GNU General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU General Public License |
| 15 | along with this program; if not, write to the Free Software |
| 16 | Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 17 | |
| 18 | #include "obstack.h" |
| 19 | |
| 20 | #ifdef __STDC__ |
| 21 | #define POINTER void * |
| 22 | #else |
| 23 | #define POINTER char * |
| 24 | #endif |
| 25 | |
| 26 | /* Determine default alignment. */ |
| 27 | struct fooalign {char x; double d;}; |
| 28 | #define DEFAULT_ALIGNMENT ((char *)&((struct fooalign *) 0)->d - (char *)0) |
| 29 | /* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT. |
| 30 | But in fact it might be less smart and round addresses to as much as |
| 31 | DEFAULT_ROUNDING. So we prepare for it to do that. */ |
| 32 | union fooround {long x; double d;}; |
| 33 | #define DEFAULT_ROUNDING (sizeof (union fooround)) |
| 34 | |
| 35 | /* When we copy a long block of data, this is the unit to do it with. |
| 36 | On some machines, copying successive ints does not work; |
| 37 | in such a case, redefine COPYING_UNIT to `long' (if that works) |
| 38 | or `char' as a last resort. */ |
| 39 | #ifndef COPYING_UNIT |
| 40 | #define COPYING_UNIT int |
| 41 | #endif |
| 42 | |
| 43 | /* The non-GNU-C macros copy the obstack into this global variable |
| 44 | to avoid multiple evaluation. */ |
| 45 | |
| 46 | struct obstack *_obstack; |
| 47 | \f |
| 48 | /* Initialize an obstack H for use. Specify chunk size SIZE (0 means default). |
| 49 | Objects start on multiples of ALIGNMENT (0 means use default). |
| 50 | CHUNKFUN is the function to use to allocate chunks, |
| 51 | and FREEFUN the function to free them. */ |
| 52 | |
| 53 | void |
| 54 | _obstack_begin (h, size, alignment, chunkfun, freefun) |
| 55 | struct obstack *h; |
| 56 | int size; |
| 57 | int alignment; |
| 58 | POINTER (*chunkfun) (); |
| 59 | void (*freefun) (); |
| 60 | { |
| 61 | register struct _obstack_chunk* chunk; /* points to new chunk */ |
| 62 | |
| 63 | if (alignment == 0) |
| 64 | alignment = DEFAULT_ALIGNMENT; |
| 65 | if (size == 0) |
| 66 | /* Default size is what GNU malloc can fit in a 4096-byte block. */ |
| 67 | { |
| 68 | /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc. |
| 69 | Use the values for range checking, because if range checking is off, |
| 70 | the extra bytes won't be missed terribly, but if range checking is on |
| 71 | and we used a larger request, a whole extra 4096 bytes would be |
| 72 | allocated. |
| 73 | |
| 74 | These number are irrelevant to the new GNU malloc. I suspect it is |
| 75 | less sensitive to the size of the request. */ |
| 76 | int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1)) |
| 77 | + 4 + DEFAULT_ROUNDING - 1) |
| 78 | & ~(DEFAULT_ROUNDING - 1)); |
| 79 | size = 4096 - extra; |
| 80 | } |
| 81 | |
| 82 | h->chunkfun = (struct _obstack_chunk * (*)()) chunkfun; |
| 83 | h->freefun = freefun; |
| 84 | h->chunk_size = size; |
| 85 | h->alignment_mask = alignment - 1; |
| 86 | |
| 87 | chunk = h->chunk = (*h->chunkfun) (h->chunk_size); |
| 88 | h->next_free = h->object_base = chunk->contents; |
| 89 | h->chunk_limit = chunk->limit |
| 90 | = (char *) chunk + h->chunk_size; |
| 91 | chunk->prev = 0; |
| 92 | /* The initial chunk now contains no empty object. */ |
| 93 | h->maybe_empty_object = 0; |
| 94 | } |
| 95 | |
| 96 | /* Allocate a new current chunk for the obstack *H |
| 97 | on the assumption that LENGTH bytes need to be added |
| 98 | to the current object, or a new object of length LENGTH allocated. |
| 99 | Copies any partial object from the end of the old chunk |
| 100 | to the beginning of the new one. */ |
| 101 | |
| 102 | void |
| 103 | _obstack_newchunk (h, length) |
| 104 | struct obstack *h; |
| 105 | int length; |
| 106 | { |
| 107 | register struct _obstack_chunk* old_chunk = h->chunk; |
| 108 | register struct _obstack_chunk* new_chunk; |
| 109 | register long new_size; |
| 110 | register int obj_size = h->next_free - h->object_base; |
| 111 | register int i; |
| 112 | int already; |
| 113 | |
| 114 | /* Compute size for new chunk. */ |
| 115 | new_size = (obj_size + length) + (obj_size >> 3) + 100; |
| 116 | if (new_size < h->chunk_size) |
| 117 | new_size = h->chunk_size; |
| 118 | |
| 119 | /* Allocate and initialize the new chunk. */ |
| 120 | new_chunk = h->chunk = (*h->chunkfun) (new_size); |
| 121 | new_chunk->prev = old_chunk; |
| 122 | new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size; |
| 123 | |
| 124 | /* Move the existing object to the new chunk. |
| 125 | Word at a time is fast and is safe if the object |
| 126 | is sufficiently aligned. */ |
| 127 | if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT) |
| 128 | { |
| 129 | for (i = obj_size / sizeof (COPYING_UNIT) - 1; |
| 130 | i >= 0; i--) |
| 131 | ((COPYING_UNIT *)new_chunk->contents)[i] |
| 132 | = ((COPYING_UNIT *)h->object_base)[i]; |
| 133 | /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT, |
| 134 | but that can cross a page boundary on a machine |
| 135 | which does not do strict alignment for COPYING_UNITS. */ |
| 136 | already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT); |
| 137 | } |
| 138 | else |
| 139 | already = 0; |
| 140 | /* Copy remaining bytes one by one. */ |
| 141 | for (i = already; i < obj_size; i++) |
| 142 | new_chunk->contents[i] = h->object_base[i]; |
| 143 | |
| 144 | /* If the object just copied was the only data in OLD_CHUNK, |
| 145 | free that chunk and remove it from the chain. |
| 146 | But not if that chunk might contain an empty object. */ |
| 147 | if (h->object_base == old_chunk->contents && ! h->maybe_empty_object) |
| 148 | { |
| 149 | new_chunk->prev = old_chunk->prev; |
| 150 | (*h->freefun) (old_chunk); |
| 151 | } |
| 152 | |
| 153 | h->object_base = new_chunk->contents; |
| 154 | h->next_free = h->object_base + obj_size; |
| 155 | /* The new chunk certainly contains no empty object yet. */ |
| 156 | h->maybe_empty_object = 0; |
| 157 | } |
| 158 | |
| 159 | /* Return nonzero if object OBJ has been allocated from obstack H. |
| 160 | This is here for debugging. |
| 161 | If you use it in a program, you are probably losing. */ |
| 162 | |
| 163 | int |
| 164 | _obstack_allocated_p (h, obj) |
| 165 | struct obstack *h; |
| 166 | POINTER obj; |
| 167 | { |
| 168 | register struct _obstack_chunk* lp; /* below addr of any objects in this chunk */ |
| 169 | register struct _obstack_chunk* plp; /* point to previous chunk if any */ |
| 170 | |
| 171 | lp = (h)->chunk; |
| 172 | /* We use >= rather than > since the object cannot be exactly at |
| 173 | the beginning of the chunk but might be an empty object exactly |
| 174 | at the end of an adjacent chunk. */ |
| 175 | while (lp != 0 && ((POINTER)lp >= obj || (POINTER)(lp)->limit < obj)) |
| 176 | { |
| 177 | plp = lp->prev; |
| 178 | lp = plp; |
| 179 | } |
| 180 | return lp != 0; |
| 181 | } |
| 182 | \f |
| 183 | /* Free objects in obstack H, including OBJ and everything allocate |
| 184 | more recently than OBJ. If OBJ is zero, free everything in H. */ |
| 185 | |
| 186 | #undef obstack_free |
| 187 | |
| 188 | /* This function has two names with identical definitions. |
| 189 | This is the first one, called from non-ANSI code. */ |
| 190 | |
| 191 | void |
| 192 | _obstack_free (h, obj) |
| 193 | struct obstack *h; |
| 194 | POINTER obj; |
| 195 | { |
| 196 | register struct _obstack_chunk* lp; /* below addr of any objects in this chunk */ |
| 197 | register struct _obstack_chunk* plp; /* point to previous chunk if any */ |
| 198 | |
| 199 | lp = h->chunk; |
| 200 | /* We use >= because there cannot be an object at the beginning of a chunk. |
| 201 | But there can be an empty object at that address |
| 202 | at the end of another chunk. */ |
| 203 | while (lp != 0 && ((POINTER)lp >= obj || (POINTER)(lp)->limit < obj)) |
| 204 | { |
| 205 | plp = lp->prev; |
| 206 | (*h->freefun) (lp); |
| 207 | lp = plp; |
| 208 | /* If we switch chunks, we can't tell whether the new current |
| 209 | chunk contains an empty object, so assume that it may. */ |
| 210 | h->maybe_empty_object = 1; |
| 211 | } |
| 212 | if (lp) |
| 213 | { |
| 214 | h->object_base = h->next_free = (char *)(obj); |
| 215 | h->chunk_limit = lp->limit; |
| 216 | h->chunk = lp; |
| 217 | } |
| 218 | else if (obj != 0) |
| 219 | /* obj is not in any of the chunks! */ |
| 220 | abort (); |
| 221 | } |
| 222 | |
| 223 | /* This function is used from ANSI code. */ |
| 224 | |
| 225 | void |
| 226 | obstack_free (h, obj) |
| 227 | struct obstack *h; |
| 228 | POINTER obj; |
| 229 | { |
| 230 | register struct _obstack_chunk* lp; /* below addr of any objects in this chunk */ |
| 231 | register struct _obstack_chunk* plp; /* point to previous chunk if any */ |
| 232 | |
| 233 | lp = h->chunk; |
| 234 | /* We use >= because there cannot be an object at the beginning of a chunk. |
| 235 | But there can be an empty object at that address |
| 236 | at the end of another chunk. */ |
| 237 | while (lp != 0 && ((POINTER)lp >= obj || (POINTER)(lp)->limit < obj)) |
| 238 | { |
| 239 | plp = lp->prev; |
| 240 | (*h->freefun) (lp); |
| 241 | lp = plp; |
| 242 | /* If we switch chunks, we can't tell whether the new current |
| 243 | chunk contains an empty object, so assume that it may. */ |
| 244 | h->maybe_empty_object = 1; |
| 245 | } |
| 246 | if (lp) |
| 247 | { |
| 248 | h->object_base = h->next_free = (char *)(obj); |
| 249 | h->chunk_limit = lp->limit; |
| 250 | h->chunk = lp; |
| 251 | } |
| 252 | else if (obj != 0) |
| 253 | /* obj is not in any of the chunks! */ |
| 254 | abort (); |
| 255 | } |
| 256 | \f |
| 257 | #if 0 |
| 258 | /* These are now turned off because the applications do not use it |
| 259 | and it uses bcopy via obstack_grow, which causes trouble on sysV. */ |
| 260 | |
| 261 | /* Now define the functional versions of the obstack macros. |
| 262 | Define them to simply use the corresponding macros to do the job. */ |
| 263 | |
| 264 | #ifdef __STDC__ |
| 265 | /* These function definitions do not work with non-ANSI preprocessors; |
| 266 | they won't pass through the macro names in parentheses. */ |
| 267 | |
| 268 | /* The function names appear in parentheses in order to prevent |
| 269 | the macro-definitions of the names from being expanded there. */ |
| 270 | |
| 271 | POINTER (obstack_base) (obstack) |
| 272 | struct obstack *obstack; |
| 273 | { |
| 274 | return obstack_base (obstack); |
| 275 | } |
| 276 | |
| 277 | POINTER (obstack_next_free) (obstack) |
| 278 | struct obstack *obstack; |
| 279 | { |
| 280 | return obstack_next_free (obstack); |
| 281 | } |
| 282 | |
| 283 | int (obstack_object_size) (obstack) |
| 284 | struct obstack *obstack; |
| 285 | { |
| 286 | return obstack_object_size (obstack); |
| 287 | } |
| 288 | |
| 289 | int (obstack_room) (obstack) |
| 290 | struct obstack *obstack; |
| 291 | { |
| 292 | return obstack_room (obstack); |
| 293 | } |
| 294 | |
| 295 | void (obstack_grow) (obstack, pointer, length) |
| 296 | struct obstack *obstack; |
| 297 | POINTER pointer; |
| 298 | int length; |
| 299 | { |
| 300 | obstack_grow (obstack, pointer, length); |
| 301 | } |
| 302 | |
| 303 | void (obstack_grow0) (obstack, pointer, length) |
| 304 | struct obstack *obstack; |
| 305 | POINTER pointer; |
| 306 | int length; |
| 307 | { |
| 308 | obstack_grow0 (obstack, pointer, length); |
| 309 | } |
| 310 | |
| 311 | void (obstack_1grow) (obstack, character) |
| 312 | struct obstack *obstack; |
| 313 | int character; |
| 314 | { |
| 315 | obstack_1grow (obstack, character); |
| 316 | } |
| 317 | |
| 318 | void (obstack_blank) (obstack, length) |
| 319 | struct obstack *obstack; |
| 320 | int length; |
| 321 | { |
| 322 | obstack_blank (obstack, length); |
| 323 | } |
| 324 | |
| 325 | void (obstack_1grow_fast) (obstack, character) |
| 326 | struct obstack *obstack; |
| 327 | int character; |
| 328 | { |
| 329 | obstack_1grow_fast (obstack, character); |
| 330 | } |
| 331 | |
| 332 | void (obstack_blank_fast) (obstack, length) |
| 333 | struct obstack *obstack; |
| 334 | int length; |
| 335 | { |
| 336 | obstack_blank_fast (obstack, length); |
| 337 | } |
| 338 | |
| 339 | POINTER (obstack_finish) (obstack) |
| 340 | struct obstack *obstack; |
| 341 | { |
| 342 | return obstack_finish (obstack); |
| 343 | } |
| 344 | |
| 345 | POINTER (obstack_alloc) (obstack, length) |
| 346 | struct obstack *obstack; |
| 347 | int length; |
| 348 | { |
| 349 | return obstack_alloc (obstack, length); |
| 350 | } |
| 351 | |
| 352 | POINTER (obstack_copy) (obstack, pointer, length) |
| 353 | struct obstack *obstack; |
| 354 | POINTER pointer; |
| 355 | int length; |
| 356 | { |
| 357 | return obstack_copy (obstack, pointer, length); |
| 358 | } |
| 359 | |
| 360 | POINTER (obstack_copy0) (obstack, pointer, length) |
| 361 | struct obstack *obstack; |
| 362 | POINTER pointer; |
| 363 | int length; |
| 364 | { |
| 365 | return obstack_copy0 (obstack, pointer, length); |
| 366 | } |
| 367 | |
| 368 | #endif /* __STDC__ */ |
| 369 | |
| 370 | #endif /* 0 */ |