scripts/kallsyms.c

   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, _sextratext, _eextratext;
  71 static int all_symbols = 0;
  72 static char symbol_prefix_char = '\0';
  73
  74 struct token {
  75         unsigned char data[MAX_TOK_SIZE];
  76         unsigned char len;
  77         /* profit: the number of bytes that could be saved by inserting this
  78          * token into the table */
  79         int profit;
  80         struct token *next;     /* next token on the hash list */
  81         struct token *right;    /* next token on the good/bad list */
  82         struct token *left;    /* previous token on the good/bad list */
  83         struct token *smaller; /* token that is less one letter than this one */
  84         };
  85
  86 struct token bad_head, good_head;
  87 struct token *hash_table[HASH_TABLE_SIZE];
  88
  89 /* the table that holds the result of the compression */
  90 unsigned char best_table[256][MAX_TOK_SIZE+1];
  91 unsigned char best_table_len[256];
  92
  93
  94 static void
  95 usage(void)
  96 {
  97         fprintf(stderr, "Usage: kallsyms [--all-symbols] [--symbol-prefix=<prefix char>] < in.map > out.S\n");
  98         exit(1);
  99 }
 100
 101 /*
 102  * This ignores the intensely annoying "mapping symbols" found
 103  * in ARM ELF files: $a, $t and $d.
 104  */
 105 static inline int
 106 is_arm_mapping_symbol(const char *str)
 107 {
 108         return str[0] == '$' && strchr("atd", str[1])
 109                && (str[2] == '\0' || str[2] == '.');
 110 }
 111
 112 static int
 113 read_symbol(FILE *in, struct sym_entry *s)
 114 {
 115         char str[500];
 116         char *sym;
 117         int rc;
 118
 119         rc = fscanf(in, "%llx %c %499s\n", &s->addr, &s->type, str);
 120         if (rc != 3) {
 121                 if (rc != EOF) {
 122                         /* skip line */
 123                         fgets(str, 500, in);
 124                 }
 125                 return -1;
 126         }
 127
 128         sym = str;
 129         /* skip prefix char */
 130         if (symbol_prefix_char && str[0] == symbol_prefix_char)
 131                 sym++;
 132
 133         /* Ignore most absolute/undefined (?) symbols. */
 134         if (strcmp(sym, "_stext") == 0)
 135                 _stext = s->addr;
 136         else if (strcmp(sym, "_etext") == 0)
 137                 _etext = s->addr;
 138         else if (strcmp(sym, "_sinittext") == 0)
 139                 _sinittext = s->addr;
 140         else if (strcmp(sym, "_einittext") == 0)
 141                 _einittext = s->addr;
 142         else if (strcmp(sym, "_sextratext") == 0)
 143                 _sextratext = s->addr;
 144         else if (strcmp(sym, "_eextratext") == 0)
 145                 _eextratext = s->addr;
 146         else if (toupper(s->type) == 'A')
 147         {
 148                 /* Keep these useful absolute symbols */
 149                 if (strcmp(sym, "__kernel_syscall_via_break") &&
 150                     strcmp(sym, "__kernel_syscall_via_epc") &&
 151                     strcmp(sym, "__kernel_sigtramp") &&
 152                     strcmp(sym, "__gp"))
 153                         return -1;
 154
 155         }
 156         else if (toupper(s->type) == 'U' ||
 157                  is_arm_mapping_symbol(sym))
 158                 return -1;
 159
 160         /* include the type field in the symbol name, so that it gets
 161          * compressed together */
 162         s->len = strlen(str) + 1;
 163         s->sym = (char *) malloc(s->len + 1);
 164         strcpy(s->sym + 1, str);
 165         s->sym[0] = s->type;
 166
 167         return 0;
 168 }
 169
 170 static int
 171 symbol_valid(struct sym_entry *s)
 172 {
 173         /* Symbols which vary between passes.  Passes 1 and 2 must have
 174          * identical symbol lists.  The kallsyms_* symbols below are only added
 175          * after pass 1, they would be included in pass 2 when --all-symbols is
 176          * specified so exclude them to get a stable symbol list.
 177          */
 178         static char *special_symbols[] = {
 179                 "kallsyms_addresses",
 180                 "kallsyms_num_syms",
 181                 "kallsyms_names",
 182                 "kallsyms_markers",
 183                 "kallsyms_token_table",
 184                 "kallsyms_token_index",
 185
 186         /* Exclude linker generated symbols which vary between passes */
 187                 "_SDA_BASE_",           /* ppc */
 188                 "_SDA2_BASE_",          /* ppc */
 189                 NULL };
 190         int i;
 191         int offset = 1;
 192
 193         /* skip prefix char */
 194         if (symbol_prefix_char && *(s->sym + 1) == symbol_prefix_char)
 195                 offset++;
 196
 197         /* if --all-symbols is not specified, then symbols outside the text
 198          * and inittext sections are discarded */
 199         if (!all_symbols) {
 200                 if ((s->addr < _stext || s->addr > _etext)
 201                     && (s->addr < _sinittext || s->addr > _einittext)
 202                     && (s->addr < _sextratext || s->addr > _eextratext))
 203                         return 0;
 204                 /* Corner case.  Discard any symbols with the same value as
 205                  * _etext _einittext or _eextratext; they can move between pass
 206                  * 1 and 2 when the kallsyms data are added.  If these symbols
 207                  * move then they may get dropped in pass 2, which breaks the
 208                  * kallsyms rules.
 209                  */
 210                 if ((s->addr == _etext && strcmp(s->sym + offset, "_etext")) ||
 211                     (s->addr == _einittext && strcmp(s->sym + offset, "_einittext")) ||
 212                     (s->addr == _eextratext && strcmp(s->sym + offset, "_eextratext")))
 213                         return 0;
 214         }
 215
 216         /* Exclude symbols which vary between passes. */
 217         if (strstr(s->sym + offset, "_compiled."))
 218                 return 0;
 219
 220         for (i = 0; special_symbols[i]; i++)
 221                 if( strcmp(s->sym + offset, special_symbols[i]) == 0 )
 222                         return 0;
 223
 224         return 1;
 225 }
 226
 227 static void
 228 read_map(FILE *in)
 229 {
 230         while (!feof(in)) {
 231                 if (cnt >= size) {
 232                         size += 10000;
 233                         table = realloc(table, sizeof(*table) * size);
 234                         if (!table) {
 235                                 fprintf(stderr, "out of memory\n");
 236                                 exit (1);
 237                         }
 238                 }
 239                 if (read_symbol(in, &table[cnt]) == 0)
 240                         cnt++;
 241         }
 242 }
 243
 244 static void output_label(char *label)
 245 {
 246         if (symbol_prefix_char)
 247                 printf(".globl %c%s\n", symbol_prefix_char, label);
 248         else
 249                 printf(".globl %s\n", label);
 250         printf("\tALGN\n");
 251         if (symbol_prefix_char)
 252                 printf("%c%s:\n", symbol_prefix_char, label);
 253         else
 254                 printf("%s:\n", label);
 255 }
 256
 257 /* uncompress a compressed symbol. When this function is called, the best table
 258  * might still be compressed itself, so the function needs to be recursive */
 259 static int expand_symbol(unsigned char *data, int len, char *result)
 260 {
 261         int c, rlen, total=0;
 262
 263         while (len) {
 264                 c = *data;
 265                 /* if the table holds a single char that is the same as the one
 266                  * we are looking for, then end the search */
 267                 if (best_table[c][0]==c && best_table_len[c]==1) {
 268                         *result++ = c;
 269                         total++;
 270                 } else {
 271                         /* if not, recurse and expand */
 272                         rlen = expand_symbol(best_table[c], best_table_len[c], result);
 273                         total += rlen;
 274                         result += rlen;
 275                 }
 276                 data++;
 277                 len--;
 278         }
 279         *result=0;
 280
 281         return total;
 282 }
 283
 284 static void
 285 write_src(void)
 286 {
 287         int i, k, off, valid;
 288         unsigned int best_idx[256];
 289         unsigned int *markers;
 290         char buf[KSYM_NAME_LEN+1];
 291
 292         printf("#include <asm/types.h>\n");
 293         printf("#if BITS_PER_LONG == 64\n");
 294         printf("#define PTR .quad\n");
 295         printf("#define ALGN .align 8\n");
 296         printf("#else\n");
 297         printf("#define PTR .long\n");
 298         printf("#define ALGN .align 4\n");
 299         printf("#endif\n");
 300
 301         printf(".data\n");
 302
 303         output_label("kallsyms_addresses");
 304         valid = 0;
 305         for (i = 0; i < cnt; i++) {
 306                 if (table[i].flags & SYM_FLAG_VALID) {
 307                         printf("\tPTR\t%#llx\n", table[i].addr);
 308                         valid++;
 309                 }
 310         }
 311         printf("\n");
 312
 313         output_label("kallsyms_num_syms");
 314         printf("\tPTR\t%d\n", valid);
 315         printf("\n");
 316
 317         /* table of offset markers, that give the offset in the compressed stream
 318          * every 256 symbols */
 319         markers = (unsigned int *) malloc(sizeof(unsigned int)*((valid + 255) / 256));
 320
 321         output_label("kallsyms_names");
 322         valid = 0;
 323         off = 0;
 324         for (i = 0; i < cnt; i++) {
 325
 326                 if (!table[i].flags & SYM_FLAG_VALID)
 327                         continue;
 328
 329                 if ((valid & 0xFF) == 0)
 330                         markers[valid >> 8] = off;
 331
 332                 printf("\t.byte 0x%02x", table[i].len);
 333                 for (k = 0; k < table[i].len; k++)
 334                         printf(", 0x%02x", table[i].sym[k]);
 335                 printf("\n");
 336
 337                 off += table[i].len + 1;
 338                 valid++;
 339         }
 340         printf("\n");
 341
 342         output_label("kallsyms_markers");
 343         for (i = 0; i < ((valid + 255) >> 8); i++)
 344                 printf("\tPTR\t%d\n", markers[i]);
 345         printf("\n");
 346
 347         free(markers);
 348
 349         output_label("kallsyms_token_table");
 350         off = 0;
 351         for (i = 0; i < 256; i++) {
 352                 best_idx[i] = off;
 353                 expand_symbol(best_table[i],best_table_len[i],buf);
 354                 printf("\t.asciz\t\"%s\"\n", buf);
 355                 off += strlen(buf) + 1;
 356         }
 357         printf("\n");
 358
 359         output_label("kallsyms_token_index");
 360         for (i = 0; i < 256; i++)
 361                 printf("\t.short\t%d\n", best_idx[i]);
 362         printf("\n");
 363 }
 364
 365
 366 /* table lookup compression functions */
 367
 368 static inline unsigned int rehash_token(unsigned int hash, unsigned char data)
 369 {
 370         return ((hash * 16777619) ^ data);
 371 }
 372
 373 static unsigned int hash_token(unsigned char *data, int len)
 374 {
 375         unsigned int hash=HASH_BASE_OFFSET;
 376         int i;
 377
 378         for (i = 0; i < len; i++)
 379                 hash = rehash_token(hash, data[i]);
 380
 381         return HASH_FOLD(hash);
 382 }
 383
 384 /* find a token given its data and hash value */
 385 static struct token *find_token_hash(unsigned char *data, int len, unsigned int hash)
 386 {
 387         struct token *ptr;
 388
 389         ptr = hash_table[hash];
 390
 391         while (ptr) {
 392                 if ((ptr->len == len) && (memcmp(ptr->data, data, len) == 0))
 393                         return ptr;
 394                 ptr=ptr->next;
 395         }
 396
 397         return NULL;
 398 }
 399
 400 static inline void insert_token_in_group(struct token *head, struct token *ptr)
 401 {
 402         ptr->right = head->right;
 403         ptr->right->left = ptr;
 404         head->right = ptr;
 405         ptr->left = head;
 406 }
 407
 408 static inline void remove_token_from_group(struct token *ptr)
 409 {
 410         ptr->left->right = ptr->right;
 411         ptr->right->left = ptr->left;
 412 }
 413
 414
 415 /* build the counts for all the tokens that start with "data", and have lenghts
 416  * from 2 to "len" */
 417 static void learn_token(unsigned char *data, int len)
 418 {
 419         struct token *ptr,*last_ptr;
 420         int i, newprofit;
 421         unsigned int hash = HASH_BASE_OFFSET;
 422         unsigned int hashes[MAX_TOK_SIZE + 1];
 423
 424         if (len > MAX_TOK_SIZE)
 425                 len = MAX_TOK_SIZE;
 426
 427         /* calculate and store the hash values for all the sub-tokens */
 428         hash = rehash_token(hash, data[0]);
 429         for (i = 2; i <= len; i++) {
 430                 hash = rehash_token(hash, data[i-1]);
 431                 hashes[i] = HASH_FOLD(hash);
 432         }
 433
 434         last_ptr = NULL;
 435         ptr = NULL;
 436
 437         for (i = len; i >= 2; i--) {
 438                 hash = hashes[i];
 439
 440                 if (!ptr) ptr = find_token_hash(data, i, hash);
 441
 442                 if (!ptr) {
 443                         /* create a new token entry */
 444                         ptr = (struct token *) malloc(sizeof(*ptr));
 445
 446                         memcpy(ptr->data, data, i);
 447                         ptr->len = i;
 448
 449                         /* when we create an entry, it's profit is 0 because
 450                          * we also take into account the size of the token on
 451                          * the compressed table. We then subtract GOOD_BAD_THRESHOLD
 452                          * so that the test to see if this token belongs to
 453                          * the good or bad list, is a comparison to zero */
 454                         ptr->profit = -GOOD_BAD_THRESHOLD;
 455
 456                         ptr->next = hash_table[hash];
 457                         hash_table[hash] = ptr;
 458
 459                         insert_token_in_group(&bad_head, ptr);
 460
 461                         ptr->smaller = NULL;
 462                 } else {
 463                         newprofit = ptr->profit + (ptr->len - 1);
 464                         /* check to see if this token needs to be moved to a
 465                          * different list */
 466                         if((ptr->profit < 0) && (newprofit >= 0)) {
 467                                 remove_token_from_group(ptr);
 468                                 insert_token_in_group(&good_head,ptr);
 469                         }
 470                         ptr->profit = newprofit;
 471                 }
 472
 473                 if (last_ptr) last_ptr->smaller = ptr;
 474                 last_ptr = ptr;
 475
 476                 ptr = ptr->smaller;
 477         }
 478 }
 479
 480 /* decrease the counts for all the tokens that start with "data", and have lenghts
 481  * from 2 to "len". This function is much simpler than learn_token because we have
 482  * more guarantees (tho tokens exist, the ->smaller pointer is set, etc.)
 483  * The two separate functions exist only because of compression performance */
 484 static void forget_token(unsigned char *data, int len)
 485 {
 486         struct token *ptr;
 487         int i, newprofit;
 488         unsigned int hash=0;
 489
 490         if (len > MAX_TOK_SIZE) len = MAX_TOK_SIZE;
 491
 492         hash = hash_token(data, len);
 493         ptr = find_token_hash(data, len, hash);
 494
 495         for (i = len; i >= 2; i--) {
 496
 497                 newprofit = ptr->profit - (ptr->len - 1);
 498                 if ((ptr->profit >= 0) && (newprofit < 0)) {
 499                         remove_token_from_group(ptr);
 500                         insert_token_in_group(&bad_head, ptr);
 501                 }
 502                 ptr->profit=newprofit;
 503
 504                 ptr=ptr->smaller;
 505         }
 506 }
 507
 508 /* count all the possible tokens in a symbol */
 509 static void learn_symbol(unsigned char *symbol, int len)
 510 {
 511         int i;
 512
 513         for (i = 0; i < len - 1; i++)
 514                 learn_token(symbol + i, len - i);
 515 }
 516
 517 /* decrease the count for all the possible tokens in a symbol */
 518 static void forget_symbol(unsigned char *symbol, int len)
 519 {
 520         int i;
 521
 522         for (i = 0; i < len - 1; i++)
 523                 forget_token(symbol + i, len - i);
 524 }
 525
 526 /* set all the symbol flags and do the initial token count */
 527 static void build_initial_tok_table(void)
 528 {
 529         int i, use_it, valid;
 530
 531         valid = 0;
 532         for (i = 0; i < cnt; i++) {
 533                 table[i].flags = 0;
 534                 if ( symbol_valid(&table[i]) ) {
 535                         table[i].flags |= SYM_FLAG_VALID;
 536                         valid++;
 537                 }
 538         }
 539
 540         use_it = 0;
 541         for (i = 0; i < cnt; i++) {
 542
 543                 /* subsample the available symbols. This method is almost like
 544                  * a Bresenham's algorithm to get uniformly distributed samples
 545                  * across the symbol table */
 546                 if (table[i].flags & SYM_FLAG_VALID) {
 547
 548                         use_it += WORKING_SET;
 549
 550                         if (use_it >= valid) {
 551                                 table[i].flags |= SYM_FLAG_SAMPLED;
 552                                 use_it -= valid;
 553                         }
 554                 }
 555                 if (table[i].flags & SYM_FLAG_SAMPLED)
 556                         learn_symbol(table[i].sym, table[i].len);
 557         }
 558 }
 559
 560 /* replace a given token in all the valid symbols. Use the sampled symbols
 561  * to update the counts */
 562 static void compress_symbols(unsigned char *str, int tlen, int idx)
 563 {
 564         int i, len, learn, size;
 565         unsigned char *p;
 566
 567         for (i = 0; i < cnt; i++) {
 568
 569                 if (!(table[i].flags & SYM_FLAG_VALID)) continue;
 570
 571                 len = table[i].len;
 572                 learn = 0;
 573                 p = table[i].sym;
 574
 575                 do {
 576                         /* find the token on the symbol */
 577                         p = (unsigned char *) strstr((char *) p, (char *) str);
 578                         if (!p) break;
 579
 580                         if (!learn) {
 581                                 /* if this symbol was used to count, decrease it */
 582                                 if (table[i].flags & SYM_FLAG_SAMPLED)
 583                                         forget_symbol(table[i].sym, len);
 584                                 learn = 1;
 585                         }
 586
 587                         *p = idx;
 588                         size = (len - (p - table[i].sym)) - tlen + 1;
 589                         memmove(p + 1, p + tlen, size);
 590                         p++;
 591                         len -= tlen - 1;
 592
 593                 } while (size >= tlen);
 594
 595                 if(learn) {
 596                         table[i].len = len;
 597                         /* if this symbol was used to count, learn it again */
 598                         if(table[i].flags & SYM_FLAG_SAMPLED)
 599                                 learn_symbol(table[i].sym, len);
 600                 }
 601         }
 602 }
 603
 604 /* search the token with the maximum profit */
 605 static struct token *find_best_token(void)
 606 {
 607         struct token *ptr,*best,*head;
 608         int bestprofit;
 609
 610         bestprofit=-10000;
 611
 612         /* failsafe: if the "good" list is empty search from the "bad" list */
 613         if(good_head.right == &good_head) head = &bad_head;
 614         else head = &good_head;
 615
 616         ptr = head->right;
 617         best = NULL;
 618         while (ptr != head) {
 619                 if (ptr->profit > bestprofit) {
 620                         bestprofit = ptr->profit;
 621                         best = ptr;
 622                 }
 623                 ptr = ptr->right;
 624         }
 625
 626         return best;
 627 }
 628
 629 /* this is the core of the algorithm: calculate the "best" table */
 630 static void optimize_result(void)
 631 {
 632         struct token *best;
 633         int i;
 634
 635         /* using the '\0' symbol last allows compress_symbols to use standard
 636          * fast string functions */
 637         for (i = 255; i >= 0; i--) {
 638
 639                 /* if this table slot is empty (it is not used by an actual
 640                  * original char code */
 641                 if (!best_table_len[i]) {
 642
 643                         /* find the token with the breates profit value */
 644                         best = find_best_token();
 645
 646                         /* place it in the "best" table */
 647                         best_table_len[i] = best->len;
 648                         memcpy(best_table[i], best->data, best_table_len[i]);
 649                         /* zero terminate the token so that we can use strstr
 650                            in compress_symbols */
 651                         best_table[i][best_table_len[i]]='\0';
 652
 653                         /* replace this token in all the valid symbols */
 654                         compress_symbols(best_table[i], best_table_len[i], i);
 655                 }
 656         }
 657 }
 658
 659 /* start by placing the symbols that are actually used on the table */
 660 static void insert_real_symbols_in_table(void)
 661 {
 662         int i, j, c;
 663
 664         memset(best_table, 0, sizeof(best_table));
 665         memset(best_table_len, 0, sizeof(best_table_len));
 666
 667         for (i = 0; i < cnt; i++) {
 668                 if (table[i].flags & SYM_FLAG_VALID) {
 669                         for (j = 0; j < table[i].len; j++) {
 670                                 c = table[i].sym[j];
 671                                 best_table[c][0]=c;
 672                                 best_table_len[c]=1;
 673                         }
 674                 }
 675         }
 676 }
 677
 678 static void optimize_token_table(void)
 679 {
 680         memset(hash_table, 0, sizeof(hash_table));
 681
 682         good_head.left = &good_head;
 683         good_head.right = &good_head;
 684
 685         bad_head.left = &bad_head;
 686         bad_head.right = &bad_head;
 687
 688         build_initial_tok_table();
 689
 690         insert_real_symbols_in_table();
 691
 692         /* When valid symbol is not registered, exit to error */
 693         if (good_head.left == good_head.right &&
 694             bad_head.left == bad_head.right) {
 695                 fprintf(stderr, "No valid symbol.\n");
 696                 exit(1);
 697         }
 698
 699         optimize_result();
 700 }
 701
 702
 703 int
 704 main(int argc, char **argv)
 705 {
 706         if (argc >= 2) {
 707                 int i;
 708                 for (i = 1; i < argc; i++) {
 709                         if(strcmp(argv[i], "--all-symbols") == 0)
 710                                 all_symbols = 1;
 711                         else if (strncmp(argv[i], "--symbol-prefix=", 16) == 0) {
 712                                 char *p = &argv[i][16];
 713                                 /* skip quote */
 714                                 if ((*p == '"' && *(p+2) == '"') || (*p == '\'' && *(p+2) == '\''))
 715                                         p++;
 716                                 symbol_prefix_char = *p;
 717                         } else
 718                                 usage();
 719                 }
 720         } else if (argc != 1)
 721                 usage();
 722
 723         read_map(stdin);
 724         optimize_token_table();
 725         write_src();
 726
 727         return 0;
 728 }