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1da177e4 LT |
1 | /* Generate assembler source containing symbol information |
2 | * | |
3 | * Copyright 2002 by Kai Germaschewski | |
4 | * | |
5 | * This software may be used and distributed according to the terms | |
6 | * of the GNU General Public License, incorporated herein by reference. | |
7 | * | |
8 | * Usage: nm -n vmlinux | scripts/kallsyms [--all-symbols] > symbols.S | |
9 | * | |
10 | * ChangeLog: | |
11 | * | |
12 | * (25/Aug/2004) Paulo Marques <pmarques@grupopie.com> | |
13 | * Changed the compression method from stem compression to "table lookup" | |
14 | * compression | |
15 | * | |
16 | * Table compression uses all the unused char codes on the symbols and | |
17 | * maps these to the most used substrings (tokens). For instance, it might | |
18 | * map char code 0xF7 to represent "write_" and then in every symbol where | |
19 | * "write_" appears it can be replaced by 0xF7, saving 5 bytes. | |
20 | * The used codes themselves are also placed in the table so that the | |
21 | * decompresion can work without "special cases". | |
22 | * Applied to kernel symbols, this usually produces a compression ratio | |
23 | * of about 50%. | |
24 | * | |
25 | */ | |
26 | ||
27 | #include <stdio.h> | |
28 | #include <stdlib.h> | |
29 | #include <string.h> | |
30 | #include <ctype.h> | |
31 | ||
32 | /* maximum token length used. It doesn't pay to increase it a lot, because | |
33 | * very long substrings probably don't repeat themselves too often. */ | |
34 | #define MAX_TOK_SIZE 11 | |
35 | #define KSYM_NAME_LEN 127 | |
36 | ||
37 | /* we use only a subset of the complete symbol table to gather the token count, | |
38 | * to speed up compression, at the expense of a little compression ratio */ | |
39 | #define WORKING_SET 1024 | |
40 | ||
41 | /* first find the best token only on the list of tokens that would profit more | |
42 | * than GOOD_BAD_THRESHOLD. Only if this list is empty go to the "bad" list. | |
43 | * Increasing this value will put less tokens on the "good" list, so the search | |
44 | * is faster. However, if the good list runs out of tokens, we must painfully | |
45 | * search the bad list. */ | |
46 | #define GOOD_BAD_THRESHOLD 10 | |
47 | ||
48 | /* token hash parameters */ | |
49 | #define HASH_BITS 18 | |
50 | #define HASH_TABLE_SIZE (1 << HASH_BITS) | |
51 | #define HASH_MASK (HASH_TABLE_SIZE - 1) | |
52 | #define HASH_BASE_OFFSET 2166136261U | |
53 | #define HASH_FOLD(a) ((a)&(HASH_MASK)) | |
54 | ||
55 | /* flags to mark symbols */ | |
56 | #define SYM_FLAG_VALID 1 | |
57 | #define SYM_FLAG_SAMPLED 2 | |
58 | ||
59 | struct sym_entry { | |
60 | unsigned long long addr; | |
61 | char type; | |
62 | unsigned char flags; | |
63 | unsigned char len; | |
64 | unsigned char *sym; | |
65 | }; | |
66 | ||
67 | ||
68 | static struct sym_entry *table; | |
69 | static int size, cnt; | |
70 | static unsigned long long _stext, _etext, _sinittext, _einittext; | |
71 | static int all_symbols = 0; | |
72 | ||
73 | struct token { | |
74 | unsigned char data[MAX_TOK_SIZE]; | |
75 | unsigned char len; | |
76 | /* profit: the number of bytes that could be saved by inserting this | |
77 | * token into the table */ | |
78 | int profit; | |
79 | struct token *next; /* next token on the hash list */ | |
80 | struct token *right; /* next token on the good/bad list */ | |
81 | struct token *left; /* previous token on the good/bad list */ | |
82 | struct token *smaller; /* token that is less one letter than this one */ | |
83 | }; | |
84 | ||
85 | struct token bad_head, good_head; | |
86 | struct token *hash_table[HASH_TABLE_SIZE]; | |
87 | ||
88 | /* the table that holds the result of the compression */ | |
89 | unsigned char best_table[256][MAX_TOK_SIZE+1]; | |
90 | unsigned char best_table_len[256]; | |
91 | ||
92 | ||
93 | static void | |
94 | usage(void) | |
95 | { | |
96 | fprintf(stderr, "Usage: kallsyms [--all-symbols] < in.map > out.S\n"); | |
97 | exit(1); | |
98 | } | |
99 | ||
100 | /* | |
101 | * This ignores the intensely annoying "mapping symbols" found | |
102 | * in ARM ELF files: $a, $t and $d. | |
103 | */ | |
104 | static inline int | |
105 | is_arm_mapping_symbol(const char *str) | |
106 | { | |
107 | return str[0] == '$' && strchr("atd", str[1]) | |
108 | && (str[2] == '\0' || str[2] == '.'); | |
109 | } | |
110 | ||
111 | static int | |
112 | read_symbol(FILE *in, struct sym_entry *s) | |
113 | { | |
114 | char str[500]; | |
115 | int rc; | |
116 | ||
117 | rc = fscanf(in, "%llx %c %499s\n", &s->addr, &s->type, str); | |
118 | if (rc != 3) { | |
119 | if (rc != EOF) { | |
120 | /* skip line */ | |
121 | fgets(str, 500, in); | |
122 | } | |
123 | return -1; | |
124 | } | |
125 | ||
126 | /* Ignore most absolute/undefined (?) symbols. */ | |
127 | if (strcmp(str, "_stext") == 0) | |
128 | _stext = s->addr; | |
129 | else if (strcmp(str, "_etext") == 0) | |
130 | _etext = s->addr; | |
131 | else if (strcmp(str, "_sinittext") == 0) | |
132 | _sinittext = s->addr; | |
133 | else if (strcmp(str, "_einittext") == 0) | |
134 | _einittext = s->addr; | |
135 | else if (toupper(s->type) == 'A') | |
136 | { | |
137 | /* Keep these useful absolute symbols */ | |
138 | if (strcmp(str, "__kernel_syscall_via_break") && | |
139 | strcmp(str, "__kernel_syscall_via_epc") && | |
140 | strcmp(str, "__kernel_sigtramp") && | |
141 | strcmp(str, "__gp")) | |
142 | return -1; | |
143 | ||
144 | } | |
145 | else if (toupper(s->type) == 'U' || | |
146 | is_arm_mapping_symbol(str)) | |
147 | return -1; | |
148 | ||
149 | /* include the type field in the symbol name, so that it gets | |
150 | * compressed together */ | |
151 | s->len = strlen(str) + 1; | |
152 | s->sym = (char *) malloc(s->len + 1); | |
153 | strcpy(s->sym + 1, str); | |
154 | s->sym[0] = s->type; | |
155 | ||
156 | return 0; | |
157 | } | |
158 | ||
159 | static int | |
160 | symbol_valid(struct sym_entry *s) | |
161 | { | |
162 | /* Symbols which vary between passes. Passes 1 and 2 must have | |
163 | * identical symbol lists. The kallsyms_* symbols below are only added | |
164 | * after pass 1, they would be included in pass 2 when --all-symbols is | |
165 | * specified so exclude them to get a stable symbol list. | |
166 | */ | |
167 | static char *special_symbols[] = { | |
168 | "kallsyms_addresses", | |
169 | "kallsyms_num_syms", | |
170 | "kallsyms_names", | |
171 | "kallsyms_markers", | |
172 | "kallsyms_token_table", | |
173 | "kallsyms_token_index", | |
174 | ||
175 | /* Exclude linker generated symbols which vary between passes */ | |
176 | "_SDA_BASE_", /* ppc */ | |
177 | "_SDA2_BASE_", /* ppc */ | |
178 | NULL }; | |
179 | int i; | |
180 | ||
181 | /* if --all-symbols is not specified, then symbols outside the text | |
182 | * and inittext sections are discarded */ | |
183 | if (!all_symbols) { | |
184 | if ((s->addr < _stext || s->addr > _etext) | |
185 | && (s->addr < _sinittext || s->addr > _einittext)) | |
186 | return 0; | |
187 | /* Corner case. Discard any symbols with the same value as | |
188 | * _etext or _einittext, they can move between pass 1 and 2 | |
189 | * when the kallsyms data is added. If these symbols move then | |
190 | * they may get dropped in pass 2, which breaks the kallsyms | |
191 | * rules. | |
192 | */ | |
193 | if ((s->addr == _etext && strcmp(s->sym + 1, "_etext")) || | |
194 | (s->addr == _einittext && strcmp(s->sym + 1, "_einittext"))) | |
195 | return 0; | |
196 | } | |
197 | ||
198 | /* Exclude symbols which vary between passes. */ | |
199 | if (strstr(s->sym + 1, "_compiled.")) | |
200 | return 0; | |
201 | ||
202 | for (i = 0; special_symbols[i]; i++) | |
203 | if( strcmp(s->sym + 1, special_symbols[i]) == 0 ) | |
204 | return 0; | |
205 | ||
206 | return 1; | |
207 | } | |
208 | ||
209 | static void | |
210 | read_map(FILE *in) | |
211 | { | |
212 | while (!feof(in)) { | |
213 | if (cnt >= size) { | |
214 | size += 10000; | |
215 | table = realloc(table, sizeof(*table) * size); | |
216 | if (!table) { | |
217 | fprintf(stderr, "out of memory\n"); | |
218 | exit (1); | |
219 | } | |
220 | } | |
221 | if (read_symbol(in, &table[cnt]) == 0) | |
222 | cnt++; | |
223 | } | |
224 | } | |
225 | ||
226 | static void output_label(char *label) | |
227 | { | |
228 | printf(".globl %s\n",label); | |
229 | printf("\tALGN\n"); | |
230 | printf("%s:\n",label); | |
231 | } | |
232 | ||
233 | /* uncompress a compressed symbol. When this function is called, the best table | |
234 | * might still be compressed itself, so the function needs to be recursive */ | |
235 | static int expand_symbol(unsigned char *data, int len, char *result) | |
236 | { | |
237 | int c, rlen, total=0; | |
238 | ||
239 | while (len) { | |
240 | c = *data; | |
241 | /* if the table holds a single char that is the same as the one | |
242 | * we are looking for, then end the search */ | |
243 | if (best_table[c][0]==c && best_table_len[c]==1) { | |
244 | *result++ = c; | |
245 | total++; | |
246 | } else { | |
247 | /* if not, recurse and expand */ | |
248 | rlen = expand_symbol(best_table[c], best_table_len[c], result); | |
249 | total += rlen; | |
250 | result += rlen; | |
251 | } | |
252 | data++; | |
253 | len--; | |
254 | } | |
255 | *result=0; | |
256 | ||
257 | return total; | |
258 | } | |
259 | ||
260 | static void | |
261 | write_src(void) | |
262 | { | |
263 | int i, k, off, valid; | |
264 | unsigned int best_idx[256]; | |
265 | unsigned int *markers; | |
266 | char buf[KSYM_NAME_LEN+1]; | |
267 | ||
268 | printf("#include <asm/types.h>\n"); | |
269 | printf("#if BITS_PER_LONG == 64\n"); | |
270 | printf("#define PTR .quad\n"); | |
271 | printf("#define ALGN .align 8\n"); | |
272 | printf("#else\n"); | |
273 | printf("#define PTR .long\n"); | |
274 | printf("#define ALGN .align 4\n"); | |
275 | printf("#endif\n"); | |
276 | ||
277 | printf(".data\n"); | |
278 | ||
279 | output_label("kallsyms_addresses"); | |
280 | valid = 0; | |
281 | for (i = 0; i < cnt; i++) { | |
282 | if (table[i].flags & SYM_FLAG_VALID) { | |
283 | printf("\tPTR\t%#llx\n", table[i].addr); | |
284 | valid++; | |
285 | } | |
286 | } | |
287 | printf("\n"); | |
288 | ||
289 | output_label("kallsyms_num_syms"); | |
290 | printf("\tPTR\t%d\n", valid); | |
291 | printf("\n"); | |
292 | ||
293 | /* table of offset markers, that give the offset in the compressed stream | |
294 | * every 256 symbols */ | |
295 | markers = (unsigned int *) malloc(sizeof(unsigned int)*((valid + 255) / 256)); | |
296 | ||
297 | output_label("kallsyms_names"); | |
298 | valid = 0; | |
299 | off = 0; | |
300 | for (i = 0; i < cnt; i++) { | |
301 | ||
302 | if (!table[i].flags & SYM_FLAG_VALID) | |
303 | continue; | |
304 | ||
305 | if ((valid & 0xFF) == 0) | |
306 | markers[valid >> 8] = off; | |
307 | ||
308 | printf("\t.byte 0x%02x", table[i].len); | |
309 | for (k = 0; k < table[i].len; k++) | |
310 | printf(", 0x%02x", table[i].sym[k]); | |
311 | printf("\n"); | |
312 | ||
313 | off += table[i].len + 1; | |
314 | valid++; | |
315 | } | |
316 | printf("\n"); | |
317 | ||
318 | output_label("kallsyms_markers"); | |
319 | for (i = 0; i < ((valid + 255) >> 8); i++) | |
320 | printf("\tPTR\t%d\n", markers[i]); | |
321 | printf("\n"); | |
322 | ||
323 | free(markers); | |
324 | ||
325 | output_label("kallsyms_token_table"); | |
326 | off = 0; | |
327 | for (i = 0; i < 256; i++) { | |
328 | best_idx[i] = off; | |
329 | expand_symbol(best_table[i],best_table_len[i],buf); | |
330 | printf("\t.asciz\t\"%s\"\n", buf); | |
331 | off += strlen(buf) + 1; | |
332 | } | |
333 | printf("\n"); | |
334 | ||
335 | output_label("kallsyms_token_index"); | |
336 | for (i = 0; i < 256; i++) | |
337 | printf("\t.short\t%d\n", best_idx[i]); | |
338 | printf("\n"); | |
339 | } | |
340 | ||
341 | ||
342 | /* table lookup compression functions */ | |
343 | ||
344 | static inline unsigned int rehash_token(unsigned int hash, unsigned char data) | |
345 | { | |
346 | return ((hash * 16777619) ^ data); | |
347 | } | |
348 | ||
349 | static unsigned int hash_token(unsigned char *data, int len) | |
350 | { | |
351 | unsigned int hash=HASH_BASE_OFFSET; | |
352 | int i; | |
353 | ||
354 | for (i = 0; i < len; i++) | |
355 | hash = rehash_token(hash, data[i]); | |
356 | ||
357 | return HASH_FOLD(hash); | |
358 | } | |
359 | ||
360 | /* find a token given its data and hash value */ | |
361 | static struct token *find_token_hash(unsigned char *data, int len, unsigned int hash) | |
362 | { | |
363 | struct token *ptr; | |
364 | ||
365 | ptr = hash_table[hash]; | |
366 | ||
367 | while (ptr) { | |
368 | if ((ptr->len == len) && (memcmp(ptr->data, data, len) == 0)) | |
369 | return ptr; | |
370 | ptr=ptr->next; | |
371 | } | |
372 | ||
373 | return NULL; | |
374 | } | |
375 | ||
376 | static inline void insert_token_in_group(struct token *head, struct token *ptr) | |
377 | { | |
378 | ptr->right = head->right; | |
379 | ptr->right->left = ptr; | |
380 | head->right = ptr; | |
381 | ptr->left = head; | |
382 | } | |
383 | ||
384 | static inline void remove_token_from_group(struct token *ptr) | |
385 | { | |
386 | ptr->left->right = ptr->right; | |
387 | ptr->right->left = ptr->left; | |
388 | } | |
389 | ||
390 | ||
391 | /* build the counts for all the tokens that start with "data", and have lenghts | |
392 | * from 2 to "len" */ | |
393 | static void learn_token(unsigned char *data, int len) | |
394 | { | |
395 | struct token *ptr,*last_ptr; | |
396 | int i, newprofit; | |
397 | unsigned int hash = HASH_BASE_OFFSET; | |
398 | unsigned int hashes[MAX_TOK_SIZE + 1]; | |
399 | ||
400 | if (len > MAX_TOK_SIZE) | |
401 | len = MAX_TOK_SIZE; | |
402 | ||
403 | /* calculate and store the hash values for all the sub-tokens */ | |
404 | hash = rehash_token(hash, data[0]); | |
405 | for (i = 2; i <= len; i++) { | |
406 | hash = rehash_token(hash, data[i-1]); | |
407 | hashes[i] = HASH_FOLD(hash); | |
408 | } | |
409 | ||
410 | last_ptr = NULL; | |
411 | ptr = NULL; | |
412 | ||
413 | for (i = len; i >= 2; i--) { | |
414 | hash = hashes[i]; | |
415 | ||
416 | if (!ptr) ptr = find_token_hash(data, i, hash); | |
417 | ||
418 | if (!ptr) { | |
419 | /* create a new token entry */ | |
420 | ptr = (struct token *) malloc(sizeof(*ptr)); | |
421 | ||
422 | memcpy(ptr->data, data, i); | |
423 | ptr->len = i; | |
424 | ||
425 | /* when we create an entry, it's profit is 0 because | |
426 | * we also take into account the size of the token on | |
427 | * the compressed table. We then subtract GOOD_BAD_THRESHOLD | |
428 | * so that the test to see if this token belongs to | |
429 | * the good or bad list, is a comparison to zero */ | |
430 | ptr->profit = -GOOD_BAD_THRESHOLD; | |
431 | ||
432 | ptr->next = hash_table[hash]; | |
433 | hash_table[hash] = ptr; | |
434 | ||
435 | insert_token_in_group(&bad_head, ptr); | |
436 | ||
437 | ptr->smaller = NULL; | |
438 | } else { | |
439 | newprofit = ptr->profit + (ptr->len - 1); | |
440 | /* check to see if this token needs to be moved to a | |
441 | * different list */ | |
442 | if((ptr->profit < 0) && (newprofit >= 0)) { | |
443 | remove_token_from_group(ptr); | |
444 | insert_token_in_group(&good_head,ptr); | |
445 | } | |
446 | ptr->profit = newprofit; | |
447 | } | |
448 | ||
449 | if (last_ptr) last_ptr->smaller = ptr; | |
450 | last_ptr = ptr; | |
451 | ||
452 | ptr = ptr->smaller; | |
453 | } | |
454 | } | |
455 | ||
456 | /* decrease the counts for all the tokens that start with "data", and have lenghts | |
457 | * from 2 to "len". This function is much simpler than learn_token because we have | |
458 | * more guarantees (tho tokens exist, the ->smaller pointer is set, etc.) | |
459 | * The two separate functions exist only because of compression performance */ | |
460 | static void forget_token(unsigned char *data, int len) | |
461 | { | |
462 | struct token *ptr; | |
463 | int i, newprofit; | |
464 | unsigned int hash=0; | |
465 | ||
466 | if (len > MAX_TOK_SIZE) len = MAX_TOK_SIZE; | |
467 | ||
468 | hash = hash_token(data, len); | |
469 | ptr = find_token_hash(data, len, hash); | |
470 | ||
471 | for (i = len; i >= 2; i--) { | |
472 | ||
473 | newprofit = ptr->profit - (ptr->len - 1); | |
474 | if ((ptr->profit >= 0) && (newprofit < 0)) { | |
475 | remove_token_from_group(ptr); | |
476 | insert_token_in_group(&bad_head, ptr); | |
477 | } | |
478 | ptr->profit=newprofit; | |
479 | ||
480 | ptr=ptr->smaller; | |
481 | } | |
482 | } | |
483 | ||
484 | /* count all the possible tokens in a symbol */ | |
485 | static void learn_symbol(unsigned char *symbol, int len) | |
486 | { | |
487 | int i; | |
488 | ||
489 | for (i = 0; i < len - 1; i++) | |
490 | learn_token(symbol + i, len - i); | |
491 | } | |
492 | ||
493 | /* decrease the count for all the possible tokens in a symbol */ | |
494 | static void forget_symbol(unsigned char *symbol, int len) | |
495 | { | |
496 | int i; | |
497 | ||
498 | for (i = 0; i < len - 1; i++) | |
499 | forget_token(symbol + i, len - i); | |
500 | } | |
501 | ||
502 | /* set all the symbol flags and do the initial token count */ | |
503 | static void build_initial_tok_table(void) | |
504 | { | |
505 | int i, use_it, valid; | |
506 | ||
507 | valid = 0; | |
508 | for (i = 0; i < cnt; i++) { | |
509 | table[i].flags = 0; | |
510 | if ( symbol_valid(&table[i]) ) { | |
511 | table[i].flags |= SYM_FLAG_VALID; | |
512 | valid++; | |
513 | } | |
514 | } | |
515 | ||
516 | use_it = 0; | |
517 | for (i = 0; i < cnt; i++) { | |
518 | ||
519 | /* subsample the available symbols. This method is almost like | |
520 | * a Bresenham's algorithm to get uniformly distributed samples | |
521 | * across the symbol table */ | |
522 | if (table[i].flags & SYM_FLAG_VALID) { | |
523 | ||
524 | use_it += WORKING_SET; | |
525 | ||
526 | if (use_it >= valid) { | |
527 | table[i].flags |= SYM_FLAG_SAMPLED; | |
528 | use_it -= valid; | |
529 | } | |
530 | } | |
531 | if (table[i].flags & SYM_FLAG_SAMPLED) | |
532 | learn_symbol(table[i].sym, table[i].len); | |
533 | } | |
534 | } | |
535 | ||
536 | /* replace a given token in all the valid symbols. Use the sampled symbols | |
537 | * to update the counts */ | |
538 | static void compress_symbols(unsigned char *str, int tlen, int idx) | |
539 | { | |
540 | int i, len, learn, size; | |
541 | unsigned char *p; | |
542 | ||
543 | for (i = 0; i < cnt; i++) { | |
544 | ||
545 | if (!(table[i].flags & SYM_FLAG_VALID)) continue; | |
546 | ||
547 | len = table[i].len; | |
548 | learn = 0; | |
549 | p = table[i].sym; | |
550 | ||
551 | do { | |
552 | /* find the token on the symbol */ | |
553 | p = (unsigned char *) strstr((char *) p, (char *) str); | |
554 | if (!p) break; | |
555 | ||
556 | if (!learn) { | |
557 | /* if this symbol was used to count, decrease it */ | |
558 | if (table[i].flags & SYM_FLAG_SAMPLED) | |
559 | forget_symbol(table[i].sym, len); | |
560 | learn = 1; | |
561 | } | |
562 | ||
563 | *p = idx; | |
564 | size = (len - (p - table[i].sym)) - tlen + 1; | |
565 | memmove(p + 1, p + tlen, size); | |
566 | p++; | |
567 | len -= tlen - 1; | |
568 | ||
569 | } while (size >= tlen); | |
570 | ||
571 | if(learn) { | |
572 | table[i].len = len; | |
573 | /* if this symbol was used to count, learn it again */ | |
574 | if(table[i].flags & SYM_FLAG_SAMPLED) | |
575 | learn_symbol(table[i].sym, len); | |
576 | } | |
577 | } | |
578 | } | |
579 | ||
580 | /* search the token with the maximum profit */ | |
581 | static struct token *find_best_token(void) | |
582 | { | |
583 | struct token *ptr,*best,*head; | |
584 | int bestprofit; | |
585 | ||
586 | bestprofit=-10000; | |
587 | ||
588 | /* failsafe: if the "good" list is empty search from the "bad" list */ | |
589 | if(good_head.right == &good_head) head = &bad_head; | |
590 | else head = &good_head; | |
591 | ||
592 | ptr = head->right; | |
593 | best = NULL; | |
594 | while (ptr != head) { | |
595 | if (ptr->profit > bestprofit) { | |
596 | bestprofit = ptr->profit; | |
597 | best = ptr; | |
598 | } | |
599 | ptr = ptr->right; | |
600 | } | |
601 | ||
602 | return best; | |
603 | } | |
604 | ||
605 | /* this is the core of the algorithm: calculate the "best" table */ | |
606 | static void optimize_result(void) | |
607 | { | |
608 | struct token *best; | |
609 | int i; | |
610 | ||
611 | /* using the '\0' symbol last allows compress_symbols to use standard | |
612 | * fast string functions */ | |
613 | for (i = 255; i >= 0; i--) { | |
614 | ||
615 | /* if this table slot is empty (it is not used by an actual | |
616 | * original char code */ | |
617 | if (!best_table_len[i]) { | |
618 | ||
619 | /* find the token with the breates profit value */ | |
620 | best = find_best_token(); | |
621 | ||
622 | /* place it in the "best" table */ | |
623 | best_table_len[i] = best->len; | |
624 | memcpy(best_table[i], best->data, best_table_len[i]); | |
625 | /* zero terminate the token so that we can use strstr | |
626 | in compress_symbols */ | |
627 | best_table[i][best_table_len[i]]='\0'; | |
628 | ||
629 | /* replace this token in all the valid symbols */ | |
630 | compress_symbols(best_table[i], best_table_len[i], i); | |
631 | } | |
632 | } | |
633 | } | |
634 | ||
635 | /* start by placing the symbols that are actually used on the table */ | |
636 | static void insert_real_symbols_in_table(void) | |
637 | { | |
638 | int i, j, c; | |
639 | ||
640 | memset(best_table, 0, sizeof(best_table)); | |
641 | memset(best_table_len, 0, sizeof(best_table_len)); | |
642 | ||
643 | for (i = 0; i < cnt; i++) { | |
644 | if (table[i].flags & SYM_FLAG_VALID) { | |
645 | for (j = 0; j < table[i].len; j++) { | |
646 | c = table[i].sym[j]; | |
647 | best_table[c][0]=c; | |
648 | best_table_len[c]=1; | |
649 | } | |
650 | } | |
651 | } | |
652 | } | |
653 | ||
654 | static void optimize_token_table(void) | |
655 | { | |
656 | memset(hash_table, 0, sizeof(hash_table)); | |
657 | ||
658 | good_head.left = &good_head; | |
659 | good_head.right = &good_head; | |
660 | ||
661 | bad_head.left = &bad_head; | |
662 | bad_head.right = &bad_head; | |
663 | ||
664 | build_initial_tok_table(); | |
665 | ||
666 | insert_real_symbols_in_table(); | |
667 | ||
668 | optimize_result(); | |
669 | } | |
670 | ||
671 | ||
672 | int | |
673 | main(int argc, char **argv) | |
674 | { | |
675 | if (argc == 2 && strcmp(argv[1], "--all-symbols") == 0) | |
676 | all_symbols = 1; | |
677 | else if (argc != 1) | |
678 | usage(); | |
679 | ||
680 | read_map(stdin); | |
681 | optimize_token_table(); | |
682 | write_src(); | |
683 | ||
684 | return 0; | |
685 | } | |
686 |