cpp.c

   1 #include <ctype.h>
   2 #include <fcntl.h>
   3 #include <stdarg.h>
   4 #include <stddef.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <unistd.h>
   9 #include <sys/types.h>
  10 #include <sys/stat.h>
  11 #include "mem.h"
  12 #include "ncc.h"
  13 #include "tab.h"
  14 #include "tok.h"
  15
  16 static char *buf;
  17 static int len;
  18 static int cur;
  19
  20 static struct macro {
  21         char name[NAMELEN];
  22         char def[MDEFLEN];
  23         char args[NARGS][NAMELEN];
  24         int nargs;
  25         int isfunc;
  26 } macros[NDEFS];
  27 static int nmacros;
  28 /* macro hash table */
  29 static struct tab mtab;
  30
  31 #define BUF_FILE                0
  32 #define BUF_MACRO               1
  33 #define BUF_ARG                 2
  34 #define BUF_EVAL                3
  35 #define BUF_TEMP                4
  36
  37 static struct buf {
  38         char *buf;
  39         int len;
  40         int cur;
  41         int type;
  42         /* for BUF_FILE */
  43         char path[NAMELEN];
  44         /* for BUF_MACRO */
  45         struct macro *macro;
  46         char args[NARGS][MARGLEN];      /* arguments passed to a macro */
  47         /* for BUF_ARG */
  48         int arg_buf;                    /* the bufs index of the owning macro */
  49 } bufs[NBUFS];
  50 static int nbufs;
  51 static int bufs_limit = 1;              /* cpp_read() limit; useful in cpp_eval() */
  52
  53 void die(char *fmt, ...)
  54 {
  55         va_list ap;
  56         char msg[512];
  57         va_start(ap, fmt);
  58         vsprintf(msg, fmt, ap);
  59         va_end(ap);
  60         write(2, msg, strlen(msg));
  61         exit(1);
  62 }
  63
  64 static void buf_new(int type, char *dat, int dlen)
  65 {
  66         if (nbufs) {
  67                 bufs[nbufs - 1].buf = buf;
  68                 bufs[nbufs - 1].cur = cur;
  69                 bufs[nbufs - 1].len = len;
  70         }
  71         if (nbufs >= NBUFS)
  72                 die("nomem: NBUFS reached!\n");
  73         nbufs++;
  74         cur = 0;
  75         buf = dat;
  76         len = dlen;
  77         bufs[nbufs - 1].type = type;
  78 }
  79
  80 static void buf_file(char *path, char *dat, int dlen)
  81 {
  82         buf_new(BUF_FILE, dat, dlen);
  83         strcpy(bufs[nbufs - 1].path, path ? path : "");
  84 }
  85
  86 static void buf_macro(struct macro *m)
  87 {
  88         buf_new(BUF_MACRO, m->def, strlen(m->def));
  89         bufs[nbufs - 1].macro = m;
  90 }
  91
  92 static void buf_arg(char *arg, int mbuf)
  93 {
  94         buf_new(BUF_ARG, arg, strlen(arg));
  95         bufs[nbufs - 1].arg_buf = mbuf;
  96 }
  97
  98 static void buf_pop(void)
  99 {
 100         nbufs--;
 101         if (nbufs) {
 102                 cur = bufs[nbufs - 1].cur;
 103                 len = bufs[nbufs - 1].len;
 104                 buf = bufs[nbufs - 1].buf;
 105         }
 106 }
 107
 108 static int buf_iseval(void)
 109 {
 110         int i;
 111         for (i = nbufs - 1; i >= 0; i--)
 112                 if (bufs[i].type == BUF_EVAL)
 113                         return 1;
 114         return 0;
 115 }
 116
 117 static size_t file_size(int fd)
 118 {
 119         struct stat st;
 120         if (!fstat(fd, &st))
 121                 return st.st_size;
 122         return 0;
 123 }
 124
 125 static int include_file(char *path)
 126 {
 127         int fd = open(path, O_RDONLY);
 128         int n = 0, nr = 0;
 129         char *dat;
 130         int size;
 131         if (fd == -1)
 132                 return -1;
 133         size = file_size(fd) + 1;
 134         dat = malloc(size);
 135         while ((n = read(fd, dat + nr, size - nr)) > 0)
 136                 nr += n;
 137         close(fd);
 138         dat[nr] = '\0';
 139         buf_file(path, dat, nr);
 140         return 0;
 141 }
 142
 143 int cpp_init(char *path)
 144 {
 145         return include_file(path);
 146 }
 147
 148 static int jumpws(void)
 149 {
 150         int old = cur;
 151         while (cur < len && isspace(buf[cur]))
 152                 cur++;
 153         return cur == old;
 154 }
 155
 156 static void read_word(char *dst)
 157 {
 158         jumpws();
 159         while (cur < len && (isalnum(buf[cur]) || buf[cur] == '_'))
 160                 *dst++ = buf[cur++];
 161         *dst = '\0';
 162 }
 163
 164 static int jumpcomment(void)
 165 {
 166         if (buf[cur] == '/' && buf[cur + 1] == '*') {
 167                 while (++cur < len) {
 168                         if (buf[cur] == '*' && buf[cur + 1] == '/') {
 169                                 cur += 2;
 170                                 return 0;
 171                         }
 172                 }
 173         }
 174         if (buf[cur] == '/' && buf[cur + 1] == '/') {
 175                 while (++cur < len)
 176                         if (buf[cur] == '\n')
 177                                 break;
 178                 return 0;
 179         }
 180         return 1;
 181 }
 182
 183 static int jumpstr(void)
 184 {
 185         if (buf[cur] == '\'') {
 186                 while (cur < len && buf[++cur] != '\'')
 187                         if (buf[cur] == '\\')
 188                                 cur++;
 189                 cur++;
 190                 return 0;
 191         }
 192         if (buf[cur] == '"') {
 193                 while (cur < len && buf[++cur] != '"')
 194                         if (buf[cur] == '\\')
 195                                 cur++;
 196                 cur++;
 197                 return 0;
 198         }
 199         return 1;
 200 }
 201
 202 static void read_tilleol(char *dst)
 203 {
 204         while (cur < len && isspace(buf[cur]) && buf[cur] != '\n')
 205                 cur++;
 206         while (cur < len && buf[cur] != '\n') {
 207                 int last = cur;
 208                 if (buf[cur] == '\\' && buf[cur + 1] == '\n') {
 209                         cur += 2;
 210                         continue;
 211                 }
 212                 if (!jumpstr()) {
 213                         memcpy(dst, buf + last, cur - last);
 214                         dst += cur - last;
 215                         continue;
 216                 }
 217                 if (!jumpcomment())
 218                         continue;
 219                 *dst++ = buf[cur++];
 220         }
 221         *dst = '\0';
 222 }
 223
 224 static char *locs[NLOCS] = {};
 225 static int nlocs = 0;
 226
 227 void cpp_addpath(char *s)
 228 {
 229         locs[nlocs++] = s;
 230 }
 231
 232 static int include_find(char *name, int std)
 233 {
 234         int i;
 235         for (i = std ? nlocs - 1 : nlocs; i >= 0; i--) {
 236                 char path[1 << 10];
 237                 if (locs[i])
 238                         sprintf(path, "%s/%s", locs[i], name);
 239                 else
 240                         strcpy(path, name);
 241                 if (!include_file(path))
 242                         return 0;
 243         }
 244         return -1;
 245 }
 246
 247 static void readarg(char *s)
 248 {
 249         int depth = 0;
 250         int beg = cur;
 251         while (cur < len && (depth || (buf[cur] != ',' && buf[cur] != ')'))) {
 252                 if (!jumpstr() || !jumpcomment())
 253                         continue;
 254                 switch (buf[cur++]) {
 255                 case '(':
 256                 case '[':
 257                 case '{':
 258                         depth++;
 259                         break;
 260                 case ')':
 261                 case ']':
 262                 case '}':
 263                         depth--;
 264                         break;
 265                 }
 266         }
 267         if (s) {
 268                 memcpy(s, buf + beg, cur - beg);
 269                 s[cur - beg] = '\0';
 270         }
 271 }
 272
 273 static int macro_find(char *name)
 274 {
 275         char *n = tab_get(&mtab, name);
 276         if (!n)
 277                 return -1;
 278         return container(n, struct macro, name) - macros;
 279 }
 280
 281 static void macro_undef(char *name)
 282 {
 283         int i = macro_find(name);
 284         if (i >= 0)
 285                 tab_del(&mtab, macros[i].name);
 286 }
 287
 288 static int macro_new(char *name)
 289 {
 290         int i = macro_find(name);
 291         if (i >= 0)
 292                 return i;
 293         if (nmacros >= NDEFS)
 294                 die("nomem: NDEFS reached!\n");
 295         i = nmacros++;
 296         strcpy(macros[i].name, name);
 297         tab_add(&mtab, macros[i].name);
 298         return i;
 299 }
 300
 301 static void macro_define(void)
 302 {
 303         char name[NAMELEN];
 304         struct macro *d;
 305         read_word(name);
 306         d = &macros[macro_new(name)];
 307         d->isfunc = 0;
 308         d->nargs = 0;
 309         if (buf[cur] == '(') {
 310                 cur++;
 311                 jumpws();
 312                 while (cur < len && buf[cur] != ')') {
 313                         readarg(d->args[d->nargs++]);
 314                         jumpws();
 315                         if (buf[cur] != ',')
 316                                 break;
 317                         cur++;
 318                         jumpws();
 319                 }
 320                 cur++;
 321                 d->isfunc = 1;
 322         }
 323         read_tilleol(d->def);
 324 }
 325
 326 static char ebuf[MARGLEN];
 327 static int elen;
 328 static int ecur;
 329
 330 static long evalexpr(void);
 331
 332 static int cpp_eval(void)
 333 {
 334         char evalbuf[MARGLEN];
 335         int old_limit;
 336         int ret, clen;
 337         char *cbuf;
 338         read_tilleol(evalbuf);
 339         buf_new(BUF_EVAL, evalbuf, strlen(evalbuf));
 340         elen = 0;
 341         ecur = 0;
 342         old_limit = bufs_limit;
 343         bufs_limit = nbufs;
 344         while (!cpp_read(&cbuf, &clen)) {
 345                 memcpy(ebuf + elen, cbuf, clen);
 346                 elen += clen;
 347         }
 348         bufs_limit = old_limit;
 349         ret = evalexpr();
 350         buf_pop();
 351         return ret;
 352 }
 353
 354 static void jumpifs(int jumpelse)
 355 {
 356         int depth = 0;
 357         while (cur < len) {
 358                 if (buf[cur] == '#') {
 359                         char cmd[NAMELEN];
 360                         cur++;
 361                         read_word(cmd);
 362                         if (!strcmp("else", cmd))
 363                                 if (!depth && !jumpelse)
 364                                         break;
 365                         if (!strcmp("elif", cmd))
 366                                 if (!depth && !jumpelse && cpp_eval())
 367                                         break;
 368                         if (!strcmp("endif", cmd)) {
 369                                 if (!depth)
 370                                         break;
 371                                 else
 372                                         depth--;
 373                         }
 374                         if (!strcmp("ifdef", cmd) || !strcmp("ifndef", cmd) ||
 375                                         !strcmp("if", cmd))
 376                                 depth++;
 377                         continue;
 378                 }
 379                 if (!jumpcomment())
 380                         continue;
 381                 if (!jumpstr())
 382                         continue;
 383                 cur++;
 384         }
 385 }
 386
 387 static int cpp_cmd(void)
 388 {
 389         char cmd[NAMELEN];
 390         cur++;
 391         read_word(cmd);
 392         if (!strcmp("define", cmd)) {
 393                 macro_define();
 394                 return 0;
 395         }
 396         if (!strcmp("undef", cmd)) {
 397                 char name[NAMELEN];
 398                 read_word(name);
 399                 macro_undef(name);
 400                 return 0;
 401         }
 402         if (!strcmp("ifdef", cmd) || !strcmp("ifndef", cmd) ||
 403                                                 !strcmp("if", cmd)) {
 404                 char name[NAMELEN];
 405                 int matched = 0;
 406                 if (cmd[2]) {
 407                         int not = cmd[2] == 'n';
 408                         read_word(name);
 409                         matched = not ? macro_find(name) < 0 :
 410                                         macro_find(name) >= 0;
 411                 } else {
 412                         matched = cpp_eval();
 413                 }
 414                 if (!matched)
 415                         jumpifs(0);
 416                 return 0;
 417         }
 418         if (!strcmp("else", cmd) || !strcmp("elif", cmd)) {
 419                 jumpifs(1);
 420                 return 0;
 421         }
 422         if (!strcmp("endif", cmd))
 423                 return 0;
 424         if (!strcmp("include", cmd)) {
 425                 char file[NAMELEN];
 426                 char *s, *e;
 427                 jumpws();
 428                 s = buf + cur + 1;
 429                 e = strchr(buf + cur + 1, buf[cur] == '"' ? '"' : '>');
 430                 memcpy(file, s, e - s);
 431                 file[e - s] = '\0';
 432                 cur += e - s + 2;
 433                 if (include_find(file, *e == '>') == -1)
 434                         err("cannot include <%s>\n", file);
 435                 return 0;
 436         }
 437         return 1;
 438 }
 439
 440 static int macro_arg(struct macro *m, char *arg)
 441 {
 442         int i;
 443         for (i = 0; i < m->nargs; i++)
 444                 if (!strcmp(arg, m->args[i]))
 445                         return i;
 446         return -1;
 447 }
 448
 449 static int buf_arg_find(char *name)
 450 {
 451         int i;
 452         for (i = nbufs - 1; i >= 0; i--) {
 453                 struct buf *mbuf = &bufs[i];
 454                 struct macro *m = mbuf->macro;
 455                 if (mbuf->type == BUF_MACRO && macro_arg(m, name) >= 0)
 456                         return i;
 457                 if (mbuf->type == BUF_ARG)
 458                         i = mbuf->arg_buf;
 459         }
 460         return -1;
 461 }
 462
 463 static void macro_expand(char *name)
 464 {
 465         struct macro *m;
 466         int mbuf;
 467         if ((mbuf = buf_arg_find(name)) >= 0) {
 468                 int arg = macro_arg(bufs[mbuf].macro, name);
 469                 char *dat = bufs[mbuf].args[arg];
 470                 buf_arg(dat, mbuf);
 471                 return;
 472         }
 473         m = &macros[macro_find(name)];
 474         if (!m->isfunc) {
 475                 buf_macro(m);
 476                 return;
 477         }
 478         jumpws();
 479         if (buf[cur] == '(') {
 480                 int i = 0;
 481                 struct buf *mbuf = &bufs[nbufs];
 482                 cur++;
 483                 jumpws();
 484                 while (cur < len && buf[cur] != ')') {
 485                         readarg(mbuf->args[i++]);
 486                         jumpws();
 487                         if (buf[cur] != ',')
 488                                 break;
 489                         cur++;
 490                         jumpws();
 491                 }
 492                 while (i < m->nargs)
 493                         mbuf->args[i++][0] = '\0';
 494                 cur++;
 495                 buf_macro(m);
 496         }
 497 }
 498
 499 static int buf_expanding(char *macro)
 500 {
 501         int i;
 502         for (i = nbufs - 1; i >= 0; i--) {
 503                 if (bufs[i].type == BUF_ARG)
 504                         return 0;
 505                 if (bufs[i].type == BUF_MACRO &&
 506                                 !strcmp(macro, bufs[i].macro->name))
 507                         return 1;
 508         }
 509         return 0;
 510 }
 511
 512 /* return 1 for plain macros and arguments and 2 for function macros */
 513 static int expandable(char *word)
 514 {
 515         int i;
 516         if (buf_arg_find(word) >= 0)
 517                 return 1;
 518         if (buf_expanding(word))
 519                 return 0;
 520         i = macro_find(word);
 521         return i >= 0 ? macros[i].isfunc + 1 : 0;
 522 }
 523
 524 void cpp_define(char *name, char *def)
 525 {
 526         char tmp_buf[MDEFLEN];
 527         sprintf(tmp_buf, "%s\t%s", name, def);
 528         buf_new(BUF_TEMP, tmp_buf, strlen(tmp_buf));
 529         macro_define();
 530         buf_pop();
 531 }
 532
 533 static int seen_macro;          /* seen a macro; 2 if a function macro */
 534 static char seen_name[NAMELEN]; /* the name of the last macro */
 535
 536 static int hunk_off;
 537 static int hunk_len;
 538
 539 int cpp_read(char **obuf, int *olen)
 540 {
 541         int old, end;
 542         int jump_name = 0;
 543         *olen = 0;
 544         *obuf = "";
 545         if (seen_macro == 1) {
 546                 macro_expand(seen_name);
 547                 seen_macro = 0;
 548         }
 549         if (cur == len) {
 550                 struct buf *cbuf = &bufs[nbufs - 1];
 551                 if (nbufs < bufs_limit + 1)
 552                         return -1;
 553                 if (cbuf->type == BUF_FILE)
 554                         free(buf);
 555                 buf_pop();
 556         }
 557         old = cur;
 558         if (buf[cur] == '#')
 559                 if (!cpp_cmd())
 560                         return 0;
 561         while (cur < len) {
 562                 if (!jumpws())
 563                         continue;
 564                 if (buf[cur] == '#')
 565                         break;
 566                 if (!jumpcomment())
 567                         continue;
 568                 if (seen_macro == 2) {
 569                         if (buf[cur] == '(')
 570                                 macro_expand(seen_name);
 571                         seen_macro = 0;
 572                         old = cur;
 573                         continue;
 574                 }
 575                 if (!jumpstr())
 576                         continue;
 577                 if (isalnum(buf[cur]) || buf[cur] == '_') {
 578                         char word[NAMELEN];
 579                         read_word(word);
 580                         seen_macro = expandable(word);
 581                         if (seen_macro) {
 582                                 strcpy(seen_name, word);
 583                                 jump_name = 1;
 584                                 break;
 585                         }
 586                         if (buf_iseval() && !strcmp("defined", word)) {
 587                                 int parens = 0;
 588                                 jumpws();
 589                                 if (buf[cur] == '(') {
 590                                         parens = 1;
 591                                         cur++;
 592                                 }
 593                                 read_word(word);
 594                                 if (parens) {
 595                                         jumpws();
 596                                         cur++;
 597                                 }
 598                         }
 599                         continue;
 600                 }
 601                 cur++;
 602         }
 603         /* macros are expanded later; ignoring their names */
 604         end = jump_name ? cur - strlen(seen_name) : cur;
 605         if (!buf_iseval()) {
 606                 hunk_off += hunk_len;
 607                 hunk_len = end - old;
 608         }
 609         *obuf = buf + old;
 610         *olen = end - old;
 611         return 0;
 612 }
 613
 614 /* preprocessor constant expression evaluation */
 615
 616 static char etok[NAMELEN];
 617 static int enext;
 618
 619 static char *tok2[] = {
 620         "<<", ">>", "&&", "||", "==", "!=", "<=", ">="
 621 };
 622
 623 static int eval_tok(void)
 624 {
 625         char *s = etok;
 626         int i;
 627         while (ecur < elen) {
 628                 while (ecur < elen && isspace(ebuf[ecur]))
 629                         ecur++;
 630                 if (ebuf[ecur] == '/' && ebuf[ecur + 1] == '*') {
 631                         while (ecur < elen && (ebuf[ecur - 2] != '*' ||
 632                                                 ebuf[ecur - 1] != '/'))
 633                                 ecur++;
 634                         continue;
 635                 }
 636                 break;
 637         }
 638         if (ecur >= elen)
 639                 return TOK_EOF;
 640         if (isalpha(ebuf[ecur]) || ebuf[ecur] == '_') {
 641                 while (isalnum(ebuf[ecur]) || ebuf[ecur] == '_')
 642                         *s++ = ebuf[ecur++];
 643                 *s = '\0';
 644                 return TOK_NAME;
 645         }
 646         if (isdigit(ebuf[ecur])) {
 647                 while (isdigit(ebuf[ecur]))
 648                         *s++ = ebuf[ecur++];
 649                 while (tolower(ebuf[ecur]) == 'u' || tolower(ebuf[ecur]) == 'l')
 650                         ecur++;
 651                 *s = '\0';
 652                 return TOK_NUM;
 653         }
 654         for (i = 0; i < LEN(tok2); i++)
 655                 if (TOK2(tok2[i]) == TOK2(ebuf + ecur)) {
 656                         int ret = TOK2(tok2[i]);
 657                         ecur += 2;
 658                         return ret;
 659                 }
 660         return ebuf[ecur++];
 661 }
 662
 663 static int eval_see(void)
 664 {
 665         if (enext == -1)
 666                 enext = eval_tok();
 667         return enext;
 668 }
 669
 670 static int eval_get(void)
 671 {
 672         if (enext != -1) {
 673                 int ret = enext;
 674                 enext = -1;
 675                 return ret;
 676         }
 677         return eval_tok();
 678 }
 679
 680 static long eval_num(void)
 681 {
 682         return atol(etok);
 683 }
 684
 685 static int eval_jmp(int tok)
 686 {
 687         if (eval_see() == tok) {
 688                 eval_get();
 689                 return 0;
 690         }
 691         return 1;
 692 }
 693
 694 static void eval_expect(int tok)
 695 {
 696         eval_jmp(tok);
 697 }
 698
 699 static char *eval_id(void)
 700 {
 701         return etok;
 702 }
 703
 704 static long evalcexpr(void);
 705
 706 static long evalatom(void)
 707 {
 708         if (!eval_jmp(TOK_NUM))
 709                 return eval_num();
 710         if (!eval_jmp(TOK_NAME)) {
 711                 int parens = !eval_jmp('(');
 712                 long ret;
 713                 eval_expect(TOK_NAME);
 714                 ret = macro_find(eval_id()) >= 0;
 715                 if (parens)
 716                         eval_expect(')');
 717                 return ret;
 718         }
 719         if (!eval_jmp('(')) {
 720                 long ret = evalcexpr();
 721                 eval_expect(')');
 722                 return ret;
 723         }
 724         return -1;
 725 }
 726
 727 static long evalpre(void)
 728 {
 729         if (!eval_jmp('!'))
 730                 return !evalpre();
 731         if (!eval_jmp('-'))
 732                 return -evalpre();
 733         if (!eval_jmp('~'))
 734                 return ~evalpre();
 735         return evalatom();
 736 }
 737
 738 static long evalmul(void)
 739 {
 740         long ret = evalpre();
 741         while (1) {
 742                 if (!eval_jmp('*')) {
 743                         ret *= evalpre();
 744                         continue;
 745                 }
 746                 if (!eval_jmp('/')) {
 747                         ret /= evalpre();
 748                         continue;
 749                 }
 750                 if (!eval_jmp('%')) {
 751                         ret %= evalpre();
 752                         continue;
 753                 }
 754                 break;
 755         }
 756         return ret;
 757 }
 758
 759 static long evaladd(void)
 760 {
 761         long ret = evalmul();
 762         while (1) {
 763                 if (!eval_jmp('+')) {
 764                         ret += evalmul();
 765                         continue;
 766                 }
 767                 if (!eval_jmp('-')) {
 768                         ret -= evalmul();
 769                         continue;
 770                 }
 771                 break;
 772         }
 773         return ret;
 774 }
 775
 776 static long evalshift(void)
 777 {
 778         long ret = evaladd();
 779         while (1) {
 780                 if (!eval_jmp(TOK2("<<"))) {
 781                         ret <<= evaladd();
 782                         continue;
 783                 }
 784                 if (!eval_jmp(TOK2(">>"))) {
 785                         ret >>= evaladd();
 786                         continue;
 787                 }
 788                 break;
 789         }
 790         return ret;
 791 }
 792
 793 static long evalcmp(void)
 794 {
 795         long ret = evalshift();
 796         while (1) {
 797                 if (!eval_jmp('<')) {
 798                         ret = ret < evalshift();
 799                         continue;
 800                 }
 801                 if (!eval_jmp('>')) {
 802                         ret = ret > evalshift();
 803                         continue;
 804                 }
 805                 if (!eval_jmp(TOK2("<="))) {
 806                         ret = ret <= evalshift();
 807                         continue;
 808                 }
 809                 if (!eval_jmp(TOK2(">="))) {
 810                         ret = ret >= evalshift();
 811                         continue;
 812                 }
 813                 break;
 814         }
 815         return ret;
 816 }
 817
 818 static long evaleq(void)
 819 {
 820         long ret = evalcmp();
 821         while (1) {
 822                 if (!eval_jmp(TOK2("=="))) {
 823                         ret = ret == evalcmp();
 824                         continue;
 825                 }
 826                 if (!eval_jmp(TOK2("!="))) {
 827                         ret = ret != evalcmp();
 828                         continue;
 829                 }
 830                 break;
 831         }
 832         return ret;
 833 }
 834
 835 static long evalbitand(void)
 836 {
 837         long ret = evaleq();
 838         while (!eval_jmp('&'))
 839                 ret &= evaleq();
 840         return ret;
 841 }
 842
 843 static long evalxor(void)
 844 {
 845         long ret = evalbitand();
 846         while (!eval_jmp('^'))
 847                 ret ^= evalbitand();
 848         return ret;
 849 }
 850
 851 static long evalbitor(void)
 852 {
 853         long ret = evalxor();
 854         while (!eval_jmp('|'))
 855                 ret |= evalxor();
 856         return ret;
 857 }
 858
 859 static long evaland(void)
 860 {
 861         long ret = evalbitor();
 862         while (!eval_jmp(TOK2("&&")))
 863                 ret = ret && evalbitor();
 864         return ret;
 865 }
 866
 867 static long evalor(void)
 868 {
 869         long ret = evaland();
 870         while (!eval_jmp(TOK2("||")))
 871                 ret = ret || evaland();
 872         return ret;
 873 }
 874
 875 static long evalcexpr(void)
 876 {
 877         long ret = evalor();
 878         if (eval_jmp('?'))
 879                 return ret;
 880         if (ret)
 881                 return evalor();
 882         while (eval_get() != ':')
 883                 ;
 884         return evalor();
 885 }
 886
 887 static long evalexpr(void)
 888 {
 889         enext = -1;
 890         return evalcexpr();
 891 }
 892
 893 static int buf_loc(char *s, int off)
 894 {
 895         char *e = s + off;
 896         int n = 1;
 897         while ((s = strchr(s, '\n')) && s < e) {
 898                 n++;
 899                 s++;
 900         }
 901         return n;
 902 }
 903
 904 char *cpp_loc(long addr)
 905 {
 906         static char loc[256];
 907         int line = -1;
 908         int i;
 909         for (i = nbufs - 1; i > 0; i--)
 910                 if (bufs[i].type == BUF_FILE)
 911                         break;
 912         if (addr >= hunk_off && i == nbufs - 1)
 913                 line = buf_loc(buf, (cur - hunk_len) + (addr - hunk_off));
 914         else
 915                 line = buf_loc(bufs[i].buf, bufs[i].cur);
 916         sprintf(loc, "%s:%d", bufs[i].path, line);
 917         return loc;
 918 }