cpp.c

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