1 /* -*- buffer-read-only: t -*- vi: set ro: */ 2 /* DO NOT EDIT! GENERATED AUTOMATICALLY! */ 3 /* obstack.h - object stack macros 4 Copyright (C) 1988-1994,1996-1999,2003,2004,2005,2006 5 Free Software Foundation, Inc. 6 This file is part of the GNU C Library. 7 8 This program is free software: you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 3 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 20 21 /* Summary: 22 23 All the apparent functions defined here are macros. The idea 24 is that you would use these pre-tested macros to solve a 25 very specific set of problems, and they would run fast. 26 Caution: no side-effects in arguments please!! They may be 27 evaluated MANY times!! 28 29 These macros operate a stack of objects. Each object starts life 30 small, and may grow to maturity. (Consider building a word syllable 31 by syllable.) An object can move while it is growing. Once it has 32 been "finished" it never changes address again. So the "top of the 33 stack" is typically an immature growing object, while the rest of the 34 stack is of mature, fixed size and fixed address objects. 35 36 These routines grab large chunks of memory, using a function you 37 supply, called `obstack_chunk_alloc'. On occasion, they free chunks, 38 by calling `obstack_chunk_free'. You must define them and declare 39 them before using any obstack macros. 40 41 Each independent stack is represented by a `struct obstack'. 42 Each of the obstack macros expects a pointer to such a structure 43 as the first argument. 44 45 One motivation for this package is the problem of growing char strings 46 in symbol tables. Unless you are "fascist pig with a read-only mind" 47 --Gosper's immortal quote from HAKMEM item 154, out of context--you 48 would not like to put any arbitrary upper limit on the length of your 49 symbols. 50 51 In practice this often means you will build many short symbols and a 52 few long symbols. At the time you are reading a symbol you don't know 53 how long it is. One traditional method is to read a symbol into a 54 buffer, realloc()ating the buffer every time you try to read a symbol 55 that is longer than the buffer. This is beaut, but you still will 56 want to copy the symbol from the buffer to a more permanent 57 symbol-table entry say about half the time. 58 59 With obstacks, you can work differently. Use one obstack for all symbol 60 names. As you read a symbol, grow the name in the obstack gradually. 61 When the name is complete, finalize it. Then, if the symbol exists already, 62 free the newly read name. 63 64 The way we do this is to take a large chunk, allocating memory from 65 low addresses. When you want to build a symbol in the chunk you just 66 add chars above the current "high water mark" in the chunk. When you 67 have finished adding chars, because you got to the end of the symbol, 68 you know how long the chars are, and you can create a new object. 69 Mostly the chars will not burst over the highest address of the chunk, 70 because you would typically expect a chunk to be (say) 100 times as 71 long as an average object. 72 73 In case that isn't clear, when we have enough chars to make up 74 the object, THEY ARE ALREADY CONTIGUOUS IN THE CHUNK (guaranteed) 75 so we just point to it where it lies. No moving of chars is 76 needed and this is the second win: potentially long strings need 77 never be explicitly shuffled. Once an object is formed, it does not 78 change its address during its lifetime. 79 80 When the chars burst over a chunk boundary, we allocate a larger 81 chunk, and then copy the partly formed object from the end of the old 82 chunk to the beginning of the new larger chunk. We then carry on 83 accreting characters to the end of the object as we normally would. 84 85 A special macro is provided to add a single char at a time to a 86 growing object. This allows the use of register variables, which 87 break the ordinary 'growth' macro. 88 89 Summary: 90 We allocate large chunks. 91 We carve out one object at a time from the current chunk. 92 Once carved, an object never moves. 93 We are free to append data of any size to the currently 94 growing object. 95 Exactly one object is growing in an obstack at any one time. 96 You can run one obstack per control block. 97 You may have as many control blocks as you dare. 98 Because of the way we do it, you can `unwind' an obstack 99 back to a previous state. (You may remove objects much 100 as you would with a stack.) 101 */ 102 103 104 /* Don't do the contents of this file more than once. */ 105 106 #ifndef _OBSTACK_H 107 #define _OBSTACK_H 1 108 109 #ifdef __cplusplus 110 extern "C" { 111 #endif 112 113 /* We need the type of a pointer subtraction. If __PTRDIFF_TYPE__ is 114 defined, as with GNU C, use that; that way we don't pollute the 115 namespace with <stddef.h>'s symbols. Otherwise, include <stddef.h> 116 and use ptrdiff_t. */ 117 118 #ifdef __PTRDIFF_TYPE__ 119 # define PTR_INT_TYPE __PTRDIFF_TYPE__ 120 #else 121 # include <stddef.h> 122 # define PTR_INT_TYPE ptrdiff_t 123 #endif 124 125 /* If B is the base of an object addressed by P, return the result of 126 aligning P to the next multiple of A + 1. B and P must be of type 127 char *. A + 1 must be a power of 2. */ 128 129 #define __BPTR_ALIGN(B, P, A) ((B) + (((P) - (B) + (A)) & ~(A))) 130 131 /* Similiar to _BPTR_ALIGN (B, P, A), except optimize the common case 132 where pointers can be converted to integers, aligned as integers, 133 and converted back again. If PTR_INT_TYPE is narrower than a 134 pointer (e.g., the AS/400), play it safe and compute the alignment 135 relative to B. Otherwise, use the faster strategy of computing the 136 alignment relative to 0. */ 137 138 #define __PTR_ALIGN(B, P, A) \ 139 __BPTR_ALIGN (sizeof (PTR_INT_TYPE) < sizeof (void *) ? (B) : (char *) 0, \ 140 P, A) 141 142 #include <string.h> 143 144 struct _obstack_chunk /* Lives at front of each chunk. */ 145 { 146 char *limit; /* 1 past end of this chunk */ 147 struct _obstack_chunk *prev; /* address of prior chunk or NULL */ 148 char contents[4]; /* objects begin here */ 149 }; 150 151 struct obstack /* control current object in current chunk */ 152 { 153 long chunk_size; /* preferred size to allocate chunks in */ 154 struct _obstack_chunk *chunk; /* address of current struct obstack_chunk */ 155 char *object_base; /* address of object we are building */ 156 char *next_free; /* where to add next char to current object */ 157 char *chunk_limit; /* address of char after current chunk */ 158 union 159 { 160 PTR_INT_TYPE tempint; 161 void *tempptr; 162 } temp; /* Temporary for some macros. */ 163 int alignment_mask; /* Mask of alignment for each object. */ 164 /* These prototypes vary based on `use_extra_arg', and we use 165 casts to the prototypeless function type in all assignments, 166 but having prototypes here quiets -Wstrict-prototypes. */ 167 struct _obstack_chunk *(*chunkfun) (void *, long); 168 void (*freefun) (void *, struct _obstack_chunk *); 169 void *extra_arg; /* first arg for chunk alloc/dealloc funcs */ 170 unsigned use_extra_arg:1; /* chunk alloc/dealloc funcs take extra arg */ 171 unsigned maybe_empty_object:1;/* There is a possibility that the current 172 chunk contains a zero-length object. This 173 prevents freeing the chunk if we allocate 174 a bigger chunk to replace it. */ 175 unsigned alloc_failed:1; /* No longer used, as we now call the failed 176 handler on error, but retained for binary 177 compatibility. */ 178 }; 179 180 /* Declare the external functions we use; they are in obstack.c. */ 181 182 extern void _obstack_newchunk (struct obstack *, int); 183 extern int _obstack_begin (struct obstack *, int, int, 184 void *(*) (long), void (*) (void *)); 185 extern int _obstack_begin_1 (struct obstack *, int, int, 186 void *(*) (void *, long), 187 void (*) (void *, void *), void *); 188 extern int _obstack_memory_used (struct obstack *); 189 190 /* The default name of the function for freeing a chunk is 'obstack_free', 191 but gnulib users can override this by defining '__obstack_free'. */ 192 #ifndef __obstack_free 193 # define __obstack_free obstack_free 194 #endif 195 extern void __obstack_free (struct obstack *obstack, void *block); 196 197 198 /* Error handler called when `obstack_chunk_alloc' failed to allocate 199 more memory. This can be set to a user defined function which 200 should either abort gracefully or use longjump - but shouldn't 201 return. The default action is to print a message and abort. */ 202 extern void (*obstack_alloc_failed_handler) (void); 203 204 /* Exit value used when `print_and_abort' is used. */ 205 extern int obstack_exit_failure; 206 207 /* Pointer to beginning of object being allocated or to be allocated next. 208 Note that this might not be the final address of the object 209 because a new chunk might be needed to hold the final size. */ 210 211 #define obstack_base(h) ((void *) (h)->object_base) 212 213 /* Size for allocating ordinary chunks. */ 214 215 #define obstack_chunk_size(h) ((h)->chunk_size) 216 217 /* Pointer to next byte not yet allocated in current chunk. */ 218 219 #define obstack_next_free(h) ((h)->next_free) 220 221 /* Mask specifying low bits that should be clear in address of an object. */ 222 223 #define obstack_alignment_mask(h) ((h)->alignment_mask) 224 225 /* To prevent prototype warnings provide complete argument list. */ 226 #define obstack_init(h) \ 227 _obstack_begin ((h), 0, 0, \ 228 (void *(*) (long)) obstack_chunk_alloc, \ 229 (void (*) (void *)) obstack_chunk_free) 230 231 #define obstack_begin(h, size) \ 232 _obstack_begin ((h), (size), 0, \ 233 (void *(*) (long)) obstack_chunk_alloc, \ 234 (void (*) (void *)) obstack_chunk_free) 235 236 #define obstack_specify_allocation(h, size, alignment, chunkfun, freefun) \ 237 _obstack_begin ((h), (size), (alignment), \ 238 (void *(*) (long)) (chunkfun), \ 239 (void (*) (void *)) (freefun)) 240 241 #define obstack_specify_allocation_with_arg(h, size, alignment, chunkfun, freefun, arg) \ 242 _obstack_begin_1 ((h), (size), (alignment), \ 243 (void *(*) (void *, long)) (chunkfun), \ 244 (void (*) (void *, void *)) (freefun), (arg)) 245 246 #define obstack_chunkfun(h, newchunkfun) \ 247 ((h) -> chunkfun = (struct _obstack_chunk *(*)(void *, long)) (newchunkfun)) 248 249 #define obstack_freefun(h, newfreefun) \ 250 ((h) -> freefun = (void (*)(void *, struct _obstack_chunk *)) (newfreefun)) 251 252 #define obstack_1grow_fast(h,achar) (*((h)->next_free)++ = (achar)) 253 254 #define obstack_blank_fast(h,n) ((h)->next_free += (n)) 255 256 #define obstack_memory_used(h) _obstack_memory_used (h) 257 258 #if defined __GNUC__ && defined __STDC__ && __STDC__ 259 /* NextStep 2.0 cc is really gcc 1.93 but it defines __GNUC__ = 2 and 260 does not implement __extension__. But that compiler doesn't define 261 __GNUC_MINOR__. */ 262 # if __GNUC__ < 2 || (__NeXT__ && !__GNUC_MINOR__) 263 # define __extension__ 264 # endif 265 266 /* For GNU C, if not -traditional, 267 we can define these macros to compute all args only once 268 without using a global variable. 269 Also, we can avoid using the `temp' slot, to make faster code. */ 270 271 # define obstack_object_size(OBSTACK) \ 272 __extension__ \ 273 ({ struct obstack const *__o = (OBSTACK); \ 274 (unsigned) (__o->next_free - __o->object_base); }) 275 276 # define obstack_room(OBSTACK) \ 277 __extension__ \ 278 ({ struct obstack const *__o = (OBSTACK); \ 279 (unsigned) (__o->chunk_limit - __o->next_free); }) 280 281 # define obstack_make_room(OBSTACK,length) \ 282 __extension__ \ 283 ({ struct obstack *__o = (OBSTACK); \ 284 int __len = (length); \ 285 if (__o->chunk_limit - __o->next_free < __len) \ 286 _obstack_newchunk (__o, __len); \ 287 (void) 0; }) 288 289 # define obstack_empty_p(OBSTACK) \ 290 __extension__ \ 291 ({ struct obstack const *__o = (OBSTACK); \ 292 (__o->chunk->prev == 0 \ 293 && __o->next_free == __PTR_ALIGN ((char *) __o->chunk, \ 294 __o->chunk->contents, \ 295 __o->alignment_mask)); }) 296 297 # define obstack_grow(OBSTACK,where,length) \ 298 __extension__ \ 299 ({ struct obstack *__o = (OBSTACK); \ 300 int __len = (length); \ 301 if (__o->next_free + __len > __o->chunk_limit) \ 302 _obstack_newchunk (__o, __len); \ 303 memcpy (__o->next_free, where, __len); \ 304 __o->next_free += __len; \ 305 (void) 0; }) 306 307 # define obstack_grow0(OBSTACK,where,length) \ 308 __extension__ \ 309 ({ struct obstack *__o = (OBSTACK); \ 310 int __len = (length); \ 311 if (__o->next_free + __len + 1 > __o->chunk_limit) \ 312 _obstack_newchunk (__o, __len + 1); \ 313 memcpy (__o->next_free, where, __len); \ 314 __o->next_free += __len; \ 315 *(__o->next_free)++ = 0; \ 316 (void) 0; }) 317 318 # define obstack_1grow(OBSTACK,datum) \ 319 __extension__ \ 320 ({ struct obstack *__o = (OBSTACK); \ 321 if (__o->next_free + 1 > __o->chunk_limit) \ 322 _obstack_newchunk (__o, 1); \ 323 obstack_1grow_fast (__o, datum); \ 324 (void) 0; }) 325 326 /* These assume that the obstack alignment is good enough for pointers 327 or ints, and that the data added so far to the current object 328 shares that much alignment. */ 329 330 # define obstack_ptr_grow(OBSTACK,datum) \ 331 __extension__ \ 332 ({ struct obstack *__o = (OBSTACK); \ 333 if (__o->next_free + sizeof (void *) > __o->chunk_limit) \ 334 _obstack_newchunk (__o, sizeof (void *)); \ 335 obstack_ptr_grow_fast (__o, datum); }) \ 336 337 # define obstack_int_grow(OBSTACK,datum) \ 338 __extension__ \ 339 ({ struct obstack *__o = (OBSTACK); \ 340 if (__o->next_free + sizeof (int) > __o->chunk_limit) \ 341 _obstack_newchunk (__o, sizeof (int)); \ 342 obstack_int_grow_fast (__o, datum); }) 343 344 # define obstack_ptr_grow_fast(OBSTACK,aptr) \ 345 __extension__ \ 346 ({ struct obstack *__o1 = (OBSTACK); \ 347 *(const void **) __o1->next_free = (aptr); \ 348 __o1->next_free += sizeof (const void *); \ 349 (void) 0; }) 350 351 # define obstack_int_grow_fast(OBSTACK,aint) \ 352 __extension__ \ 353 ({ struct obstack *__o1 = (OBSTACK); \ 354 *(int *) __o1->next_free = (aint); \ 355 __o1->next_free += sizeof (int); \ 356 (void) 0; }) 357 358 # define obstack_blank(OBSTACK,length) \ 359 __extension__ \ 360 ({ struct obstack *__o = (OBSTACK); \ 361 int __len = (length); \ 362 if (__o->chunk_limit - __o->next_free < __len) \ 363 _obstack_newchunk (__o, __len); \ 364 obstack_blank_fast (__o, __len); \ 365 (void) 0; }) 366 367 # define obstack_alloc(OBSTACK,length) \ 368 __extension__ \ 369 ({ struct obstack *__h = (OBSTACK); \ 370 obstack_blank (__h, (length)); \ 371 obstack_finish (__h); }) 372 373 # define obstack_copy(OBSTACK,where,length) \ 374 __extension__ \ 375 ({ struct obstack *__h = (OBSTACK); \ 376 obstack_grow (__h, (where), (length)); \ 377 obstack_finish (__h); }) 378 379 # define obstack_copy0(OBSTACK,where,length) \ 380 __extension__ \ 381 ({ struct obstack *__h = (OBSTACK); \ 382 obstack_grow0 (__h, (where), (length)); \ 383 obstack_finish (__h); }) 384 385 /* The local variable is named __o1 to avoid a name conflict 386 when obstack_blank is called. */ 387 # define obstack_finish(OBSTACK) \ 388 __extension__ \ 389 ({ struct obstack *__o1 = (OBSTACK); \ 390 void *__value = (void *) __o1->object_base; \ 391 if (__o1->next_free == __value) \ 392 __o1->maybe_empty_object = 1; \ 393 __o1->next_free \ 394 = __PTR_ALIGN (__o1->object_base, __o1->next_free, \ 395 __o1->alignment_mask); \ 396 if (__o1->next_free - (char *)__o1->chunk \ 397 > __o1->chunk_limit - (char *)__o1->chunk) \ 398 __o1->next_free = __o1->chunk_limit; \ 399 __o1->object_base = __o1->next_free; \ 400 __value; }) 401 402 # define obstack_free(OBSTACK, OBJ) \ 403 __extension__ \ 404 ({ struct obstack *__o = (OBSTACK); \ 405 void *__obj = (OBJ); \ 406 if (__obj > (void *)__o->chunk && __obj < (void *)__o->chunk_limit) \ 407 __o->next_free = __o->object_base = (char *)__obj; \ 408 else (__obstack_free) (__o, __obj); }) 409 410 #else /* not __GNUC__ or not __STDC__ */ 411 412 # define obstack_object_size(h) \ 413 (unsigned) ((h)->next_free - (h)->object_base) 414 415 # define obstack_room(h) \ 416 (unsigned) ((h)->chunk_limit - (h)->next_free) 417 418 # define obstack_empty_p(h) \ 419 ((h)->chunk->prev == 0 \ 420 && (h)->next_free == __PTR_ALIGN ((char *) (h)->chunk, \ 421 (h)->chunk->contents, \ 422 (h)->alignment_mask)) 423 424 /* Note that the call to _obstack_newchunk is enclosed in (..., 0) 425 so that we can avoid having void expressions 426 in the arms of the conditional expression. 427 Casting the third operand to void was tried before, 428 but some compilers won't accept it. */ 429 430 # define obstack_make_room(h,length) \ 431 ( (h)->temp.tempint = (length), \ 432 (((h)->next_free + (h)->temp.tempint > (h)->chunk_limit) \ 433 ? (_obstack_newchunk ((h), (h)->temp.tempint), 0) : 0)) 434 435 # define obstack_grow(h,where,length) \ 436 ( (h)->temp.tempint = (length), \ 437 (((h)->next_free + (h)->temp.tempint > (h)->chunk_limit) \ 438 ? (_obstack_newchunk ((h), (h)->temp.tempint), 0) : 0), \ 439 memcpy ((h)->next_free, where, (h)->temp.tempint), \ 440 (h)->next_free += (h)->temp.tempint) 441 442 # define obstack_grow0(h,where,length) \ 443 ( (h)->temp.tempint = (length), \ 444 (((h)->next_free + (h)->temp.tempint + 1 > (h)->chunk_limit) \ 445 ? (_obstack_newchunk ((h), (h)->temp.tempint + 1), 0) : 0), \ 446 memcpy ((h)->next_free, where, (h)->temp.tempint), \ 447 (h)->next_free += (h)->temp.tempint, \ 448 *((h)->next_free)++ = 0) 449 450 # define obstack_1grow(h,datum) \ 451 ( (((h)->next_free + 1 > (h)->chunk_limit) \ 452 ? (_obstack_newchunk ((h), 1), 0) : 0), \ 453 obstack_1grow_fast (h, datum)) 454 455 # define obstack_ptr_grow(h,datum) \ 456 ( (((h)->next_free + sizeof (char *) > (h)->chunk_limit) \ 457 ? (_obstack_newchunk ((h), sizeof (char *)), 0) : 0), \ 458 obstack_ptr_grow_fast (h, datum)) 459 460 # define obstack_int_grow(h,datum) \ 461 ( (((h)->next_free + sizeof (int) > (h)->chunk_limit) \ 462 ? (_obstack_newchunk ((h), sizeof (int)), 0) : 0), \ 463 obstack_int_grow_fast (h, datum)) 464 465 # define obstack_ptr_grow_fast(h,aptr) \ 466 (((const void **) ((h)->next_free += sizeof (void *)))[-1] = (aptr)) 467 468 # define obstack_int_grow_fast(h,aint) \ 469 (((int *) ((h)->next_free += sizeof (int)))[-1] = (aint)) 470 471 # define obstack_blank(h,length) \ 472 ( (h)->temp.tempint = (length), \ 473 (((h)->chunk_limit - (h)->next_free < (h)->temp.tempint) \ 474 ? (_obstack_newchunk ((h), (h)->temp.tempint), 0) : 0), \ 475 obstack_blank_fast (h, (h)->temp.tempint)) 476 477 # define obstack_alloc(h,length) \ 478 (obstack_blank ((h), (length)), obstack_finish ((h))) 479 480 # define obstack_copy(h,where,length) \ 481 (obstack_grow ((h), (where), (length)), obstack_finish ((h))) 482 483 # define obstack_copy0(h,where,length) \ 484 (obstack_grow0 ((h), (where), (length)), obstack_finish ((h))) 485 486 # define obstack_finish(h) \ 487 ( ((h)->next_free == (h)->object_base \ 488 ? (((h)->maybe_empty_object = 1), 0) \ 489 : 0), \ 490 (h)->temp.tempptr = (h)->object_base, \ 491 (h)->next_free \ 492 = __PTR_ALIGN ((h)->object_base, (h)->next_free, \ 493 (h)->alignment_mask), \ 494 (((h)->next_free - (char *) (h)->chunk \ 495 > (h)->chunk_limit - (char *) (h)->chunk) \ 496 ? ((h)->next_free = (h)->chunk_limit) : 0), \ 497 (h)->object_base = (h)->next_free, \ 498 (h)->temp.tempptr) 499 500 # define obstack_free(h,obj) \ 501 ( (h)->temp.tempint = (char *) (obj) - (char *) (h)->chunk, \ 502 ((((h)->temp.tempint > 0 \ 503 && (h)->temp.tempint < (h)->chunk_limit - (char *) (h)->chunk)) \ 504 ? (int) ((h)->next_free = (h)->object_base \ 505 = (h)->temp.tempint + (char *) (h)->chunk) \ 506 : (((__obstack_free) ((h), (h)->temp.tempint + (char *) (h)->chunk), 0), 0))) 507 508 #endif /* not __GNUC__ or not __STDC__ */ 509 510 #ifdef __cplusplus 511 } /* C++ */ 512 #endif 513 514 #endif /* obstack.h */ 515