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1 | /* obstack.c - subroutines used implicitly by object stack macros |
2 | Copyright (C) 1988 Free Software Foundation, Inc. |
3 | |
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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 1, 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. |
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17 | |
18 | |
19 | In other words, you are welcome to use, share and improve this program. |
20 | You are forbidden to forbid anyone else to use, share and improve |
21 | what you give them. Help stamp out software-hoarding! */ |
22 | |
23 | |
24 | #include "obstack.h" |
25 | |
26 | #ifdef __STDC__ |
27 | #define POINTER void * |
28 | #else |
29 | #define POINTER char * |
30 | #endif |
31 | |
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32 | /* Determine default alignment. */ |
33 | struct fooalign {char x; double d;}; |
34 | #define DEFAULT_ALIGNMENT ((char *)&((struct fooalign *) 0)->d - (char *)0) |
35 | /* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT. |
36 | But in fact it might be less smart and round addresses to as much as |
37 | DEFAULT_ROUNDING. So we prepare for it to do that. */ |
38 | union fooround {long x; double d;}; |
39 | #define DEFAULT_ROUNDING (sizeof (union fooround)) |
40 | |
41 | /* When we copy a long block of data, this is the unit to do it with. |
42 | On some machines, copying successive ints does not work; |
43 | in such a case, redefine COPYING_UNIT to `long' (if that works) |
44 | or `char' as a last resort. */ |
45 | #ifndef COPYING_UNIT |
46 | #define COPYING_UNIT int |
47 | #endif |
48 | |
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49 | /* The non-GNU-C macros copy the obstack into this global variable |
50 | to avoid multiple evaluation. */ |
51 | |
52 | struct obstack *_obstack; |
53 | \f |
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54 | /* Initialize an obstack H for use. Specify chunk size SIZE (0 means default). |
55 | Objects start on multiples of ALIGNMENT (0 means use default). |
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56 | CHUNKFUN is the function to use to allocate chunks, |
57 | and FREEFUN the function to free them. */ |
58 | |
59 | void |
60 | _obstack_begin (h, size, alignment, chunkfun, freefun) |
61 | struct obstack *h; |
62 | int size; |
63 | int alignment; |
64 | POINTER (*chunkfun) (); |
65 | void (*freefun) (); |
66 | { |
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67 | register struct _obstack_chunk* chunk; /* points to new chunk */ |
68 | |
69 | if (alignment == 0) |
70 | alignment = DEFAULT_ALIGNMENT; |
71 | if (size == 0) |
72 | /* Default size is what GNU malloc can fit in a 4096-byte block. |
73 | Pick a number small enough that when rounded up to DEFAULT_ROUNDING |
74 | it is still smaller than 4096 - 4. */ |
75 | { |
76 | int extra = 4; |
77 | if (extra < DEFAULT_ROUNDING) |
78 | extra = DEFAULT_ROUNDING; |
79 | size = 4096 - extra; |
80 | } |
81 | |
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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 | } |
93 | |
94 | /* Allocate a new current chunk for the obstack *H |
95 | on the assumption that LENGTH bytes need to be added |
96 | to the current object, or a new object of length LENGTH allocated. |
97 | Copies any partial object from the end of the old chunk |
98 | to the beginning of the new one. */ |
99 | |
100 | void |
101 | _obstack_newchunk (h, length) |
102 | struct obstack *h; |
103 | int length; |
104 | { |
105 | register struct _obstack_chunk* old_chunk = h->chunk; |
106 | register struct _obstack_chunk* new_chunk; |
107 | register long new_size; |
108 | register int obj_size = h->next_free - h->object_base; |
109 | register int i; |
110 | |
111 | /* Compute size for new chunk. */ |
112 | new_size = (obj_size + length) << 1; |
113 | if (new_size < h->chunk_size) |
114 | new_size = h->chunk_size; |
115 | |
116 | /* Allocate and initialize the new chunk. */ |
117 | new_chunk = h->chunk = (*h->chunkfun) (new_size); |
118 | new_chunk->prev = old_chunk; |
119 | new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size; |
120 | |
121 | /* Move the existing object to the new chunk. |
122 | Word at a time is fast and is safe because these |
123 | structures are aligned at least that much. */ |
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124 | for (i = (obj_size + sizeof (COPYING_UNIT) - 1) / sizeof (COPYING_UNIT) - 1; |
125 | i >= 0; i--) |
126 | ((COPYING_UNIT *)new_chunk->contents)[i] |
127 | = ((COPYING_UNIT *)h->object_base)[i]; |
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128 | |
129 | h->object_base = new_chunk->contents; |
130 | h->next_free = h->object_base + obj_size; |
131 | } |
132 | |
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133 | /* Return nonzero if object OBJ has been allocated from obstack H. |
134 | This is here for debugging. |
135 | If you use it in a program, you are probably losing. */ |
136 | |
137 | int |
138 | _obstack_allocated_p (h, obj) |
139 | struct obstack *h; |
140 | POINTER obj; |
141 | { |
142 | register struct _obstack_chunk* lp; /* below addr of any objects in this chunk */ |
143 | register struct _obstack_chunk* plp; /* point to previous chunk if any */ |
144 | |
145 | lp = (h)->chunk; |
146 | while (lp != 0 && ((POINTER)lp > obj || (POINTER)(lp)->limit < obj)) |
147 | { |
148 | plp = lp -> prev; |
149 | lp = plp; |
150 | } |
151 | return lp != 0; |
152 | } |
153 | |
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154 | /* Free objects in obstack H, including OBJ and everything allocate |
155 | more recently than OBJ. If OBJ is zero, free everything in H. */ |
156 | |
157 | void |
158 | #ifdef __STDC__ |
159 | #undef obstack_free |
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160 | obstack_free (struct obstack *h, POINTER obj) |
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161 | #else |
162 | _obstack_free (h, obj) |
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163 | struct obstack *h; |
164 | POINTER obj; |
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165 | #endif |
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166 | { |
167 | register struct _obstack_chunk* lp; /* below addr of any objects in this chunk */ |
168 | register struct _obstack_chunk* plp; /* point to previous chunk if any */ |
169 | |
170 | lp = (h)->chunk; |
171 | while (lp != 0 && ((POINTER)lp > obj || (POINTER)(lp)->limit < obj)) |
172 | { |
173 | plp = lp -> prev; |
174 | (*h->freefun) (lp); |
175 | lp = plp; |
176 | } |
177 | if (lp) |
178 | { |
179 | (h)->object_base = (h)->next_free = (char *)(obj); |
180 | (h)->chunk_limit = lp->limit; |
181 | (h)->chunk = lp; |
182 | } |
183 | else if (obj != 0) |
184 | /* obj is not in any of the chunks! */ |
185 | abort (); |
186 | } |
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187 | |
188 | /* Let same .o link with output of gcc and other compilers. */ |
189 | |
190 | #ifdef __STDC__ |
191 | void |
192 | _obstack_free (h, obj) |
193 | struct obstack *h; |
194 | POINTER obj; |
195 | { |
196 | obstack_free (h, obj); |
197 | } |
198 | #endif |
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199 | \f |
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200 | #if 0 |
201 | /* These are now turned off because the applications do not use it |
202 | and it uses bcopy via obstack_grow, which causes trouble on sysV. */ |
203 | |
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204 | /* Now define the functional versions of the obstack macros. |
205 | Define them to simply use the corresponding macros to do the job. */ |
206 | |
207 | #ifdef __STDC__ |
208 | /* These function definitions do not work with non-ANSI preprocessors; |
209 | they won't pass through the macro names in parentheses. */ |
210 | |
211 | /* The function names appear in parentheses in order to prevent |
212 | the macro-definitions of the names from being expanded there. */ |
213 | |
214 | POINTER (obstack_base) (obstack) |
215 | struct obstack *obstack; |
216 | { |
217 | return obstack_base (obstack); |
218 | } |
219 | |
220 | POINTER (obstack_next_free) (obstack) |
221 | struct obstack *obstack; |
222 | { |
223 | return obstack_next_free (obstack); |
224 | } |
225 | |
226 | int (obstack_object_size) (obstack) |
227 | struct obstack *obstack; |
228 | { |
229 | return obstack_object_size (obstack); |
230 | } |
231 | |
232 | int (obstack_room) (obstack) |
233 | struct obstack *obstack; |
234 | { |
235 | return obstack_room (obstack); |
236 | } |
237 | |
238 | void (obstack_grow) (obstack, pointer, length) |
239 | struct obstack *obstack; |
240 | POINTER pointer; |
241 | int length; |
242 | { |
243 | obstack_grow (obstack, pointer, length); |
244 | } |
245 | |
246 | void (obstack_grow0) (obstack, pointer, length) |
247 | struct obstack *obstack; |
248 | POINTER pointer; |
249 | int length; |
250 | { |
251 | obstack_grow0 (obstack, pointer, length); |
252 | } |
253 | |
254 | void (obstack_1grow) (obstack, character) |
255 | struct obstack *obstack; |
256 | int character; |
257 | { |
258 | obstack_1grow (obstack, character); |
259 | } |
260 | |
261 | void (obstack_blank) (obstack, length) |
262 | struct obstack *obstack; |
263 | int length; |
264 | { |
265 | obstack_blank (obstack, length); |
266 | } |
267 | |
268 | void (obstack_1grow_fast) (obstack, character) |
269 | struct obstack *obstack; |
270 | int character; |
271 | { |
272 | obstack_1grow_fast (obstack, character); |
273 | } |
274 | |
275 | void (obstack_blank_fast) (obstack, length) |
276 | struct obstack *obstack; |
277 | int length; |
278 | { |
279 | obstack_blank_fast (obstack, length); |
280 | } |
281 | |
282 | POINTER (obstack_finish) (obstack) |
283 | struct obstack *obstack; |
284 | { |
285 | return obstack_finish (obstack); |
286 | } |
287 | |
288 | POINTER (obstack_alloc) (obstack, length) |
289 | struct obstack *obstack; |
290 | int length; |
291 | { |
292 | return obstack_alloc (obstack, length); |
293 | } |
294 | |
295 | POINTER (obstack_copy) (obstack, pointer, length) |
296 | struct obstack *obstack; |
297 | POINTER pointer; |
298 | int length; |
299 | { |
300 | return obstack_copy (obstack, pointer, length); |
301 | } |
302 | |
303 | POINTER (obstack_copy0) (obstack, pointer, length) |
304 | struct obstack *obstack; |
305 | POINTER pointer; |
306 | int length; |
307 | { |
308 | return obstack_copy0 (obstack, pointer, length); |
309 | } |
310 | |
311 | #endif /* __STDC__ */ |
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312 | |
313 | #endif /* 0 */ |