usr/src/cmd/awk_xpg4/awk3.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * awk -- executor
  23  *
  24  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  25  * Use is subject to license terms.
  26  *
  27  * Copyright 1985, 1994 by Mortice Kern Systems Inc.  All rights reserved.
  28  *
  29  * Based on MKS awk(1) ported to be /usr/xpg4/bin/awk with POSIX/XCU4 changes
  30  */
  31
  32 #include "awk.h"
  33 #include "y.tab.h"
  34
  35 static int      dohash(wchar_t *name);
  36 static NODE     *arithmetic(NODE *np);
  37 static NODE     *comparison(NODE *np);
  38 static int      type_of(NODE *np);
  39 static NODE     *lfield(INT fieldno, NODE *value);
  40 static NODE     *rfield(INT fieldno);
  41 static NODE     *userfunc(NODE *np);
  42 static wchar_t  *lltoa(long long l);
  43 static NODE     *exprconcat(NODE *np, int len);
  44 static int      s_if(NODE *np);
  45 static int      s_while(NODE *np);
  46 static int      s_for(NODE *np);
  47 static int      s_forin(NODE *np);
  48 static void     setrefield(NODE *value);
  49 static void     freetemps(void);
  50 static int      action(NODE *np);
  51 static wchar_t  *makeindex(NODE *np, wchar_t *array, int tag);
  52 static int      exprtest(NODE *np);
  53
  54 #define regmatch(rp, s) REGWEXEC(rp, s, 0, (REGWMATCH_T*)NULL, 0)
  55
  56 /*
  57  * This code allows for integers to be stored in longs (type INT) and
  58  * only promoted to double precision floating point numbers (type REAL)
  59  * when overflow occurs during +, -, or * operations.  This is very
  60  * non-portable if you desire such a speed optimisation.  You may wish
  61  * to put something here for your system.  This "something" would likely
  62  * include either an assembler "jump on overflow" instruction or a
  63  * method to get traps on overflows from the hardware.
  64  *
  65  * This portable method works for ones and twos complement integer
  66  * representations (which is, realistically) almost all machines.
  67  */
  68 #if     __TURBOC__
  69 #define addoverflow()   asm     jo      overflow
  70 #define suboverflow()   asm     jo      overflow
  71 #else
  72 /*
  73  * These are portable to two's complement integer machines
  74  */
  75 #define addoverflow()   if ((i1^i2) >= 0 && (iresult^i1) < 0) goto overflow
  76 #define suboverflow()   if ((i1^i2) < 0 && (iresult^i2) >= 0) goto overflow
  77 #endif
  78 #define muloverflow()   if (((short)i1 != i1 || (short)i2 != i2) &&     \
  79                             ((i2 != 0 && iresult/i2 != i1) ||           \
  80                             (i1 == LONG_MIN && i2 == -1)))        goto overflow
  81
  82 static char     notarray[] = "scalar \"%s\" cannot be used as array";
  83 static char     badarray[] = "array \"%s\" cannot be used as a scalar";
  84 static char     varnotfunc[] = "variable \"%s\" cannot be used as a function";
  85 static char     tmfld[] = "Too many fields (LIMIT: %d)";
  86 static char     toolong[] = "Record too long (LIMIT: %d bytes)";
  87 static char     divzero[] =  "division (/ or %%) by zero";
  88 static char     toodeep[] = "too deeply nested for in loop (LIMIT: %d)";
  89
  90 static wchar_t  numbuf[NUMSIZE];        /* Used to convert INTs to strings */
  91 static wchar_t  *fields[NFIELD];        /* Cache of pointers into fieldbuf */
  92 static wchar_t  *fieldbuf;              /* '\0' separated copy of linebuf */
  93 static NODE     nodes[NSNODE];          /* Cache of quick access nodes */
  94 static NODE     *fnodep = &nodes[0];
  95 #define NINDEXBUF       50
  96 static wchar_t  indexbuf[NINDEXBUF];    /* Used for simple array indices */
  97 static int      concflag;               /* In CONCAT operation (no frees) */
  98 static NODE     *retval;                /* Last return value of a function */
  99
 100 /*
 101  * The following stack is used to store the next pointers for all nested
 102  * for-in loops. This needs to be global so that delete can check to see
 103  * if it is deleting the next node to be used by a loop.
 104  */
 105 #define NFORINLOOP      10
 106 static NODE*    forindex[NFORINLOOP];
 107 static NODE**   next_forin = forindex;
 108
 109 /*
 110  * Assign a string directly to a NODE without creating an intermediate
 111  * NODE.  This can handle either FALLOC, FSTATIC, FNOALLOC or FSENSE for
 112  * "flags" argument.  Also the NODE "np" must be reduced to an lvalue
 113  * (PARM nodes are not acceptable).
 114  */
 115 void
 116 strassign(NODE *np, STRING string, int flags, size_t length)
 117 {
 118         if (np->n_type == FUNC)
 119                 awkerr(gettext("attempt to redefine builtin function"));
 120         else if (np->n_type == GETLINE || np->n_type == KEYWORD)
 121                 awkerr(gettext("inadmissible use of reserved keyword"));
 122         if (np->n_flags & FSPECIAL) {
 123                 (void) nassign(np, stringnode(string, flags, length));
 124                 return;
 125         }
 126         if (isastring(np->n_flags))
 127                 free((wchar_t *)np->n_string);
 128         np->n_strlen = length++;
 129         if (flags & FALLOC) {
 130                 length *= sizeof (wchar_t);
 131                 np->n_string = (STRING) emalloc(length);
 132                 (void) memcpy((void *)np->n_string, string, length);
 133         } else {
 134                 np->n_string = string;
 135                 if (flags & FNOALLOC) {
 136                         flags &= ~FNOALLOC;
 137                         flags |= FALLOC;
 138                 }
 139         }
 140         np->n_flags &= FSAVE;
 141         if (flags & FSENSE) {
 142                 flags &= ~FSENSE;
 143                 flags |= type_of(np);
 144         } else
 145                 flags |= FSTRING;
 146         np->n_flags |= flags;
 147 }
 148
 149 /*
 150  * Assign to a variable node.
 151  * LHS must be a VAR type and RHS must be reduced by now.
 152  * To speed certain operations up, check for
 153  * certain things here and do special assignments.
 154  */
 155 NODE *
 156 nassign(NODE *np, NODE *value)
 157 {
 158         register wchar_t *cp;
 159         register int len;
 160
 161         /* short circuit assignment of a node to itself */
 162         if (np == value)
 163                 return (np);
 164         if (np->n_flags & FSPECIAL) {
 165                 if (np == varRS || np == varFS) {
 166                         if (isastring(np->n_flags))
 167                                 free((void *)np->n_string);
 168                         len = sizeof (wchar_t) * ((np->n_strlen =
 169                                 wcslen(cp = exprstring(value)))+1);
 170                         np->n_string = emalloc(len);
 171                         (void) memcpy((wchar_t *)np->n_string, cp, len);
 172                         np->n_flags = FALLOC|FSTRING|FSPECIAL;
 173                         if (np == varRS) {
 174                                 if (np->n_string[0] == '\n')
 175                                         awkrecord = defrecord;
 176                                 else if (np->n_string[0] == '\0')
 177                                         awkrecord = multirecord;
 178                                 else
 179                                         awkrecord = charrecord;
 180                         } else if (np == varFS) {
 181                                 if (resep != (REGEXP)NULL) {
 182                                         REGWFREE(resep);
 183                                         resep = (REGEXP)NULL;
 184                                 }
 185                                 if (wcslen((wchar_t *)np->n_string) > 1)
 186                                         setrefield(np);
 187                                 else if (np->n_string[0] == ' ')
 188                                         awkfield = whitefield;
 189                                 else
 190                                         awkfield = blackfield;
 191                         }
 192                         return (np);
 193                 }
 194         }
 195         if (isastring(np->n_flags))
 196                 free((wchar_t *)np->n_string);
 197         if (isstring(value->n_flags)) {
 198                 np->n_strlen = value->n_strlen;
 199                 if (value->n_flags&FALLOC || value->n_string != _null) {
 200                         len = (np->n_strlen+1) * sizeof (wchar_t);
 201                         np->n_string = emalloc(len);
 202                         (void) memcpy(np->n_string, value->n_string, len);
 203                         np->n_flags &= FSAVE;
 204                         np->n_flags |= value->n_flags & ~FSAVE;
 205                         np->n_flags |= FALLOC;
 206                         return (np);
 207                 } else
 208                         np->n_string = value->n_string;
 209         } else if (value->n_flags & FINT)
 210                 np->n_int = value->n_int;
 211         else
 212                 np->n_real = value->n_real;
 213         np->n_flags &= FSAVE;
 214         np->n_flags |= value->n_flags & ~FSAVE;
 215         return (np);
 216 }
 217
 218 /*
 219  * Set regular expression FS value.
 220  */
 221 static void
 222 setrefield(NODE *np)
 223 {
 224         static REGEXP re;
 225         int n;
 226
 227         if ((n = REGWCOMP(&re, np->n_string)) != REG_OK) {
 228                 REGWERROR(n, &re, (char *)linebuf, sizeof (linebuf));
 229                 awkerr(gettext("syntax error \"%s\" in /%s/\n"),
 230                         (char *)linebuf, np->n_string);
 231         }
 232         resep = re;
 233         awkfield = refield;
 234 }
 235
 236 /*
 237  * Assign to an l-value node.
 238  */
 239 NODE *
 240 assign(NODE *left, NODE *right)
 241 {
 242         if (isleaf(right->n_flags)) {
 243                 if (right->n_type == PARM)
 244                         right = right->n_next;
 245         } else
 246                 right = exprreduce(right);
 247 top:
 248         switch (left->n_type) {
 249         case INDEX:
 250                 left = exprreduce(left);
 251                 /* FALLTHROUGH */
 252         case VAR:
 253                 return (nassign(left, right));
 254
 255         case PARM:
 256                 /*
 257                  * If it's a parameter then link to the actual value node and
 258                  * do the checks again.
 259                  */
 260                 left = left->n_next;
 261                 goto top;
 262
 263         case FIELD:
 264                 return (lfield(exprint(left->n_left), right));
 265
 266         case CALLUFUNC:
 267         case UFUNC:
 268                 awkerr(gettext("cannot assign to function \"%s\""),
 269                     left->n_name);
 270
 271         default:
 272                 awkerr(gettext("lvalue required in assignment"));
 273         }
 274         /* NOTREACHED */
 275         return (0);
 276 }
 277
 278 /*
 279  * Compiled tree non-terminal node.
 280  */
 281 NODE *
 282 node(int type, NODE *left, NODE *right)
 283 {
 284         register NODE *np;
 285
 286         np = emptynode(type, 0);
 287         np->n_left = left;
 288         np->n_right = right;
 289         np->n_lineno = lineno;
 290         return (np);
 291 }
 292
 293 /*
 294  * Create an integer node.
 295  */
 296 NODE *
 297 intnode(INT i)
 298 {
 299         register NODE *np;
 300
 301         np = emptynode(CONSTANT, 0);
 302         np->n_flags = FINT|FVINT;
 303         np->n_int = i;
 304         return (np);
 305 }
 306
 307 /*
 308  * Create a real number node.
 309  */
 310 NODE *
 311 realnode(REAL real)
 312 {
 313         register NODE *np;
 314
 315         np = emptynode(CONSTANT, 0);
 316         np->n_flags = FREAL|FVREAL;
 317         np->n_real = real;
 318         return (np);
 319 }
 320
 321 /*
 322  * Make a node for a string.
 323  */
 324 NODE *
 325 stringnode(STRING s, int how, size_t length)
 326 {
 327         register NODE *np;
 328
 329         np = emptynode(CONSTANT, 0);
 330         np->n_strlen = length;
 331         if (how & FALLOC) {
 332                 np->n_string = emalloc(length = (length+1) * sizeof (wchar_t));
 333                 (void) memcpy(np->n_string, s, length);
 334         } else {
 335                 np->n_string = s;
 336                 if (how & FNOALLOC) {
 337                         how &= ~FNOALLOC;
 338                         how |= FALLOC;
 339                 }
 340         }
 341         if (how & FSENSE) {
 342                 np->n_flags = type_of(np);
 343                 how &= ~FSENSE;
 344         } else
 345                 np->n_flags = FSTRING;
 346         np->n_flags |= how;
 347         return (np);
 348 }
 349
 350 /*
 351  * Save a copy of a string.
 352  */
 353 STRING
 354 strsave(wchar_t *old)
 355 {
 356         STRING new;
 357         register size_t len;
 358
 359         new = (STRING)emalloc(len = (wcslen(old)+1) * sizeof (wchar_t));
 360         (void) memcpy(new, old, len);
 361         return (new);
 362 }
 363
 364 /*
 365  * Allocate an empty node of given type.
 366  * String space for the node is given by `length'.
 367  */
 368 NODE *
 369 emptynode(int type, size_t length)
 370 {
 371         register NODE *np;
 372
 373         if (length == 0 && running && fnodep < &nodes[NSNODE]) {
 374                 np = fnodep++;
 375         } else {
 376                 np = (NODE *)emalloc(sizeof (NODE) +
 377                     (length * sizeof (wchar_t)));
 378                 if (running && type != VAR && type != ARRAY) {
 379                         np->n_next = freelist;
 380                         freelist = np;
 381                 }
 382         }
 383         np->n_flags = FNONTOK;
 384         np->n_type = type;
 385         np->n_alink = NNULL;
 386
 387         return (np);
 388 }
 389
 390 /*
 391  * Free a node.
 392  */
 393 void
 394 freenode(NODE *np)
 395 {
 396         if (isastring(np->n_flags))
 397                 free((wchar_t *)np->n_string);
 398         else if (np->n_type == RE) {
 399                 REGWFREE(np->n_regexp);
 400         }
 401         free((wchar_t *)np);
 402 }
 403
 404 /*
 405  * Install a keyword of given `type'.
 406  */
 407 void
 408 kinstall(LOCCHARP name, int type)
 409 {
 410         register NODE *np;
 411         register size_t l;
 412
 413         l = wcslen(name);
 414         np = emptynode(KEYWORD, l);
 415         np->n_keywtype = type;
 416         (void) memcpy(np->n_name, name, (l+1) * sizeof (wchar_t));
 417         addsymtab(np);
 418 }
 419
 420 /*
 421  * Install built-in function.
 422  */
 423 NODE *
 424 finstall(LOCCHARP name, FUNCTION func, int type)
 425 {
 426         register NODE *np;
 427         register size_t l;
 428
 429         l = wcslen(name);
 430         np = emptynode(type, l);
 431         np->n_function = func;
 432         (void) memcpy(np->n_name, name, (l+1) * sizeof (wchar_t));
 433         addsymtab(np);
 434         return (np);
 435 }
 436
 437 /*
 438  * Lookup an identifier.
 439  * nocreate contains the following flag values:
 440  *      1 if no creation of a new NODE,
 441  *      0 if ok to create new NODE
 442  */
 443 NODE *
 444 vlookup(wchar_t *name, int nocreate)
 445 {
 446         register ushort_t hash;
 447         register NODE *np;
 448
 449         np = symtab[hashbuck(hash = dohash((wchar_t *)name))];
 450         while (np != NNULL) {
 451                 if (np->n_hash == hash && wcscmp(name, np->n_name) == 0)
 452                         return (np);
 453                 np = np->n_next;
 454         }
 455         if (nocreate) {
 456                 np = NNULL;
 457         } else {
 458                 np = emptynode(VAR, hash = wcslen(name));
 459                 np->n_flags = FSTRING|FVINT;
 460                 np->n_strlen = 0;
 461                 np->n_string = _null;
 462                 (void) memcpy(np->n_name, name,
 463                         (hash+1) * sizeof (wchar_t));
 464                 addsymtab(np);
 465         }
 466         return (np);
 467 }
 468
 469 /*
 470  * Add a symbol to the table.
 471  */
 472 void
 473 addsymtab(NODE *np)
 474 {
 475         register NODE **spp;
 476
 477         np->n_hash = dohash((wchar_t *)np->n_name);
 478         spp = &symtab[hashbuck(np->n_hash)];
 479         np->n_next = *spp;
 480         *spp = np;
 481 }
 482
 483 /*
 484  * Delete the given node from the symbol table.
 485  * If fflag is non-zero, also free the node space.
 486  * This routine must also check the stack of forin loop pointers. If
 487  * we are deleting the next item to be used, then the pointer must be
 488  * advanced.
 489  */
 490 void
 491 delsymtab(NODE *np, int fflag)
 492 {
 493         register NODE *rnp;
 494         register NODE *prevp;
 495         register NODE **sptr;
 496         register ushort_t h;
 497
 498
 499
 500
 501
 502         h = hashbuck(np->n_hash);
 503         prevp = NNULL;
 504         for (rnp = symtab[h]; rnp != NNULL; rnp = rnp->n_next) {
 505                 if (rnp == np) {
 506                         /*
 507                          * check all of the for-in loop pointers
 508                          * to see if any need to be advanced because
 509                          * this element is being deleted.
 510                          */
 511                         if (next_forin != forindex) {
 512                                 sptr = next_forin;
 513                                 do {
 514                                         if (*--sptr == rnp) {
 515                                                 *sptr = rnp->n_next;
 516                                                 break;
 517                                         }
 518                                 } while (sptr != forindex);
 519                         }
 520                         if (prevp == NNULL)
 521                                 symtab[h] = rnp->n_next; else
 522                                 prevp->n_next = rnp->n_next;
 523                         if (fflag)
 524                                 freenode(rnp);
 525                         break;
 526                 }
 527                 prevp = rnp;
 528         }
 529 }
 530
 531 /*
 532  * Hashing function.
 533  */
 534 static int
 535 dohash(wchar_t *name)
 536 {
 537         register int hash = 0;
 538
 539         while (*name != '\0')
 540                 hash += *name++;
 541         return (hash);
 542 }
 543
 544 /*
 545  * Top level executor for an awk programme.
 546  * This will be passed: pattern, action or a list of these.
 547  * The former function to evaluate a pattern has been
 548  * subsumed into this function for speed.
 549  * Patterns are:
 550  *      BEGIN,
 551  *      END,
 552  *      other expressions (including regular expressions)
 553  */
 554 void
 555 execute(NODE *wp)
 556 {
 557         register NODE *np;
 558         register int type;
 559         register NODE *tnp;
 560
 561         curnode = wp;
 562         if (phase != 0) {
 563                 linebuf[0] = '\0';
 564                 lbuflen = 0;
 565         }
 566         while (wp != NNULL) {
 567                 if (wp->n_type == COMMA) {
 568                         np = wp->n_left;
 569                         wp = wp->n_right;
 570                 } else {
 571                         np = wp;
 572                         wp = NNULL;
 573                 }
 574                 if (np->n_type != PACT)
 575                         awkerr(interr, "PACT");
 576                 /*
 577                  * Save the parent node and evaluate the pattern.
 578                  * If it evaluates to false (0) just continue
 579                  * to the next pattern/action (PACT) pair.
 580                  */
 581                 tnp = np;
 582                 np = np->n_left;
 583                 if (np == NNULL) {
 584                         if (phase != 0)
 585                                 continue;
 586                 } else if (phase != 0) {
 587                         if (np->n_type != phase)
 588                                 continue;
 589                 } else if ((type = np->n_type) == BEGIN || type == END) {
 590                         continue;
 591                 } else if (type == COMMA) {
 592                         /*
 593                          * The grammar only allows expressions
 594                          * to be separated by the ',' operator
 595                          * for range patterns.
 596                          */
 597                         if (np->n_flags & FMATCH) {
 598                                 if (exprint(np->n_right) != 0)
 599                                         np->n_flags &= ~FMATCH;
 600                         } else if (exprint(np->n_left) != 0) {
 601                                 if (exprint(np->n_right) == 0)
 602                                         np->n_flags |= FMATCH;
 603                         } else
 604                                 continue;
 605                 } else if (exprint(np) == 0)
 606                         continue;
 607                 np = tnp;
 608                 if (action(np->n_right)) {
 609                         loopexit = 0;
 610                         break;
 611                 }
 612         }
 613         if (freelist != NNULL)
 614                 freetemps();
 615 }
 616
 617 /*
 618  * Free all temporary nodes.
 619  */
 620 static void
 621 freetemps()
 622 {
 623         register NODE *np, *nnp;
 624
 625         if (concflag)
 626                 return;
 627         for (np = &nodes[0]; np < fnodep; np++) {
 628                 if (isastring(np->n_flags)) {
 629                         free((wchar_t *)np->n_string);
 630                 } else if (np->n_type == RE) {
 631                         REGWFREE(np->n_regexp);
 632                 }
 633         }
 634         fnodep = &nodes[0];
 635         for (np = freelist; np != NNULL; np = nnp) {
 636                 nnp = np->n_next;
 637                 freenode(np);
 638         }
 639         freelist = NNULL;
 640 }
 641
 642 /*
 643  * Do the given action.
 644  * Actions are statements or expressions.
 645  */
 646 static int
 647 action(NODE *wp)
 648 {
 649         register NODE *np;
 650         register int act = 0;
 651         register NODE *l;
 652
 653         while (wp != NNULL) {
 654                 if (wp->n_type == COMMA) {
 655                         np = wp->n_left;
 656                         wp = wp->n_right;
 657                 } else {
 658                         np = wp;
 659                         wp = NNULL;
 660                 }
 661                 if (freelist != NNULL)
 662                         freetemps();
 663                 curnode = np;
 664                 /*
 665                  * Don't change order of these cases without
 666                  * changing order in awk.y declarations.
 667                  * The order is optimised.
 668                  */
 669                 switch (np->n_type) {
 670                 case ASG:
 671                         (void) assign(np->n_left, np->n_right);
 672                         continue;
 673
 674                 case PRINT:
 675                         s_print(np);
 676                         continue;
 677
 678                 case PRINTF:
 679                         s_prf(np);
 680                         continue;
 681
 682                 case EXIT:
 683                         if (np->n_left != NNULL)
 684                                 act = (int)exprint(np->n_left); else
 685                                 act = 0;
 686                         doend(act);
 687                         /* NOTREACHED */
 688
 689                 case RETURN:
 690                         if (slevel == 0)
 691                                 awkerr(gettext("return outside of a function"));
 692                         np = np->n_left != NNULL
 693                             ? exprreduce(np->n_left)
 694                             : const0;
 695                         retval = emptynode(CONSTANT, 0);
 696                         retval->n_flags = FINT;
 697                         (void) nassign(retval, np);
 698                         return (RETURN);
 699
 700                 case NEXT:
 701                         loopexit = NEXT;
 702                 /* FALLTHROUGH */
 703                 case BREAK:
 704                 case CONTINUE:
 705                         return (np->n_type);
 706
 707                 case DELETE:
 708                         if ((l = np->n_left)->n_type == PARM) {
 709                                 l = l->n_next;
 710                                 if (!(l->n_flags & FLARRAY))
 711                                         l = l->n_alink;
 712                         }
 713                         switch (l->n_type) {
 714                         case ARRAY:
 715                                 delarray(l);
 716                                 break;
 717
 718                         case INDEX:
 719                                 if ((np = l->n_left)->n_type == PARM) {
 720                                         np = np->n_next;
 721                                         if (!(np->n_flags & FLARRAY))
 722                                                 np = np->n_alink;
 723                                 }
 724                                 /*
 725                                  * get pointer to the node for this array
 726                                  * element using the hash key.
 727                                  */
 728                                 l = exprreduce(l);
 729                                 /*
 730                                  * now search linearly from the beginning of
 731                                  * the list to find the element before the
 732                                  * one being deleted. This must be done
 733                                  * because arrays are singley-linked.
 734                                  */
 735                                 while (np != NNULL) {
 736                                         if (np->n_alink == l) {
 737                                                 np->n_alink = l->n_alink;
 738                                                 break;
 739                                         }
 740                                         np = np->n_alink;
 741                                 }
 742                                 delsymtab(l, 1);
 743                                 break;
 744
 745                         case VAR:
 746                                 if (isstring(l->n_flags) &&
 747                                     l->n_string == _null)
 748                                         break;
 749                                 /* FALLTHROUGH */
 750                         default:
 751                                 awkerr(gettext(
 752                                     "may delete only array element or array"));
 753                                 break;
 754                         }
 755                         continue;
 756
 757                 case WHILE:
 758                 case DO:
 759                         if ((act = s_while(np)) != 0)
 760                                 break;
 761                         continue;
 762
 763                 case FOR:
 764                         if ((act = s_for(np)) != 0)
 765                                 break;
 766                         continue;
 767
 768                 case FORIN:
 769                         if ((act = s_forin(np)) != 0)
 770                                 break;
 771                         continue;
 772
 773                 case IF:
 774                         if ((act = s_if(np)) != 0)
 775                                 break;
 776                         continue;
 777
 778                 default:
 779                         (void) exprreduce(np);
 780                         if (loopexit != 0) {
 781                                 act = loopexit;
 782                                 break;
 783                         }
 784                         continue;
 785                 }
 786                 return (act);
 787         }
 788         return (0);
 789 }
 790
 791 /*
 792  * Delete an entire array
 793  */
 794 void
 795 delarray(NODE *np)
 796 {
 797         register NODE *nnp;
 798
 799         nnp = np->n_alink;
 800         np->n_alink = NNULL;
 801         while (nnp != NNULL) {
 802                 np = nnp->n_alink;
 803                 delsymtab(nnp, 1);
 804                 nnp = np;
 805         }
 806 }
 807
 808 /*
 809  * Return the INT value of an expression.
 810  */
 811 INT
 812 exprint(NODE *np)
 813 {
 814         if (isleaf(np->n_flags)) {
 815                 if (np->n_type == PARM)
 816                         np = np->n_next;
 817                 goto leaf;
 818         }
 819         np = exprreduce(np);
 820         switch (np->n_type) {
 821         case CONSTANT:
 822         case VAR:
 823         leaf:
 824                 if (np->n_flags & FINT)
 825                         return (np->n_int);
 826                 if (np->n_flags & FREAL)
 827                         return ((INT)np->n_real);
 828                 return ((INT)wcstoll(np->n_string, NULL, 10));
 829
 830         default:
 831                 awkerr(interr, "exprint");
 832         }
 833         /* NOTREACHED */
 834         return (0);
 835 }
 836
 837 /*
 838  * Return a real number from an expression tree.
 839  */
 840 REAL
 841 exprreal(NODE *np)
 842 {
 843         if (loopexit)
 844                 return ((REAL)loopexit);
 845         if (isleaf(np->n_flags)) {
 846                 if (np->n_type == PARM)
 847                         np = np->n_next;
 848                 goto leaf;
 849         }
 850         np = exprreduce(np);
 851         switch (np->n_type) {
 852         case CONSTANT:
 853         case VAR:
 854         leaf:
 855                 if (np->n_flags & FREAL)
 856                         return (np->n_real);
 857                 if (np->n_flags & FINT)
 858                         return ((REAL)np->n_int);
 859                 return ((REAL)wcstod((wchar_t *)np->n_string, (wchar_t **)0));
 860
 861         default:
 862                 awkerr(interr, "exprreal");
 863         }
 864         /* NOTREACHED */
 865         return ((REAL)0);
 866 }
 867
 868 /*
 869  * Return a string from an expression tree.
 870  */
 871 STRING
 872 exprstring(NODE *np)
 873 {
 874         if (isleaf(np->n_flags)) {
 875                 if (np->n_type == PARM)
 876                         np = np->n_next;
 877                 goto leaf;
 878         }
 879         np = exprreduce(np);
 880         switch (np->n_type) {
 881         case CONSTANT:
 882         case VAR:
 883         leaf:
 884                 if (isstring(np->n_flags))
 885                         return (np->n_string);
 886                 if (np->n_flags & FINT)
 887                         return (STRING)lltoa((long long)np->n_int);
 888                 {
 889                         char *tmp;
 890                         (void) wsprintf(numbuf,
 891                 (const char *) (tmp = wcstombsdup(exprstring(varCONVFMT))),
 892                                 (double)np->n_real);
 893                         if (tmp != NULL)
 894                                 free(tmp);
 895                 }
 896                 return ((STRING)numbuf);
 897
 898         default:
 899                 awkerr(interr, "exprstring");
 900         }
 901         /* NOTREACHED */
 902         return (0);
 903 }
 904
 905 /*
 906  * Convert number to string.
 907  */
 908 static wchar_t *
 909 lltoa(long long l)
 910 {
 911         register wchar_t *p = &numbuf[NUMSIZE];
 912         register int s;
 913         register int neg;
 914         static wchar_t zero[] = M_MB_L("0");
 915
 916         if (l == 0)
 917                 return (zero);
 918         *--p = '\0';
 919         if (l < 0)
 920                 neg = 1, l = -l; else
 921                 neg = 0;
 922         if ((s = (short)l) == l) {
 923                 while (s != 0) {
 924                         *--p = s%10 + '0';
 925                         s /= 10;
 926                 }
 927         } else {
 928                 while (l != 0) {
 929                         *--p = l%10 + '0';
 930                         l /= 10;
 931                 }
 932         }
 933         if (neg)
 934                 *--p = '-';
 935         return (wcscpy(numbuf, p));
 936 }
 937
 938 /*
 939  * Return pointer to node with concatenation of operands of CONCAT node.
 940  * In the interest of speed, a left recursive tree of CONCAT nodes
 941  * is handled with a single malloc.  The accumulated lengths of the
 942  * right operands are passed down recursive invocations of this
 943  * routine, which allocates a large enough string when the left
 944  * operand is not a CONCAT node.
 945  */
 946 static NODE *
 947 exprconcat(NODE *np, int len)
 948 {
 949         /* we KNOW (np->n_type==CONCAT) */
 950         register NODE *lnp = np->n_left;
 951         register NODE *rnp = np->n_right;
 952         register STRING rsp;
 953         int rlen;
 954         size_t llen;
 955         wchar_t *cp;
 956         wchar_t rnumbuf[NUMSIZE];
 957
 958         if (isleaf(rnp->n_flags) && rnp->n_type == PARM)
 959                 rnp = rnp->n_next;
 960         if (isstring(rnp->n_flags)) {
 961                 rsp = rnp->n_string;
 962                 rlen = rnp->n_strlen;
 963         } else
 964                 rlen = wcslen((wchar_t *)(rsp = exprstring(rnp)));
 965         if (rsp == numbuf) {    /* static, so save a copy */
 966                 (void) memcpy(rnumbuf, (wchar_t *)rsp,
 967                         (rlen+1) * sizeof (wchar_t));
 968                 rsp = rnumbuf;
 969         }
 970         len += rlen;
 971         if (lnp->n_type == CONCAT) {
 972                 lnp = exprconcat(lnp, len);
 973                 cp = lnp->n_string;
 974                 llen = lnp->n_strlen;
 975         } else {
 976                 register STRING lsp;
 977
 978                 if (isleaf(lnp->n_flags) && lnp->n_type == PARM)
 979                         lnp = lnp->n_next;
 980                 if (isstring(lnp->n_flags)) {
 981                         lsp = lnp->n_string;
 982                         llen = lnp->n_strlen;
 983                 } else
 984                         llen = wcslen((wchar_t *)(lsp = exprstring(lnp)));
 985                 cp = emalloc((llen+len+1) * sizeof (wchar_t));
 986                 (void) memcpy(cp, (wchar_t *)lsp, llen * sizeof (wchar_t));
 987                 lnp = stringnode(cp, FNOALLOC, llen);
 988         }
 989         (void) memcpy(cp+llen, (wchar_t *)rsp, (rlen+1) * sizeof (wchar_t));
 990         lnp->n_strlen += rlen;
 991         return (lnp);
 992 }
 993
 994 /*
 995  * Reduce an expression to a terminal node.
 996  */
 997 NODE *
 998 exprreduce(NODE *np)
 999 {
1000         register wchar_t *cp;
1001         NODE *tnp;
1002         register int temp;
1003         register int t;
1004         register int  tag;
1005         register wchar_t *fname;
1006         register wchar_t *aname;
1007
1008         /*
1009          * a var or constant is a leaf-node (no further reduction required)
1010          * so return immediately.
1011          */
1012         if ((t = np->n_type) == VAR || t == CONSTANT)
1013                 return (np);
1014         /*
1015          * If it's a parameter then it is probably a leaf node but it
1016          * might be an array so we check.. If it is an array, then signal
1017          * an error as an array by itself cannot be used in this context.
1018          */
1019         if (t == PARM)
1020                 if ((np = np->n_next)->n_type == ARRAY)
1021                         awkerr(badarray, np->n_name);
1022                 else
1023                         return (np);
1024         /*
1025          * All the rest are non-leaf nodes.
1026          */
1027         curnode = np;
1028         switch (t) {
1029         case CALLUFUNC:
1030                 return (userfunc(np));
1031
1032         case FIELD:
1033                 return (rfield(exprint(np->n_left)));
1034
1035         case IN:
1036         case INDEX:
1037                 tag = 0;
1038                 temp = np->n_type;
1039                 tnp = np->n_left;
1040                 np = np->n_right;
1041                 /* initially formal var name and array key name are the same */
1042                 fname = aname = tnp->n_name;
1043                 if (tnp->n_type == PARM) {
1044                         tnp = tnp->n_next;
1045                         tag = tnp->n_scope;
1046                         if (!(tnp->n_flags & FLARRAY)) {
1047                                 tnp = tnp->n_alink;
1048                         }
1049                         aname = tnp->n_name;
1050                 }
1051                 if (tnp->n_type != ARRAY) {
1052                         if (!isstring(tnp->n_flags) || tnp->n_string != _null)
1053                                 awkerr(notarray, fname);
1054                         else {
1055                                 /* promotion to array */
1056                                 promote(tnp);
1057                                 if (tnp->n_alink != NNULL) {
1058                                         tag = tnp->n_scope;
1059                                         if (!(tnp->n_flags & FLARRAY))
1060                                                 tnp = tnp->n_alink;
1061                                         aname = tnp->n_name;
1062                                 } else {
1063                                         tag = 0;
1064                                         if (tnp->n_flags & FLARRAY)
1065                                                 tag = tnp->n_scope;
1066                                 }
1067                         }
1068                 }
1069                 if (tnp == varSYMTAB) {
1070                         if (np == NNULL || np->n_type == COMMA)
1071                                 awkerr(gettext(
1072                                     "SYMTAB must have exactly one index"));
1073                         np = vlook(exprstring(np));
1074                         return (np);
1075                 }
1076                 cp = makeindex(np, aname, tag);
1077                 if (temp == INDEX) {
1078                         np = vlook(cp);
1079                         if (!(np->n_flags & FINARRAY)) {
1080                                 np->n_alink = tnp->n_alink;
1081                                 tnp->n_alink = np;
1082                                 np->n_flags |= FINARRAY;
1083                         }
1084                 } else
1085                         np = vlookup(cp, 1) == NNULL ? const0 : const1;
1086                 if (cp != indexbuf)
1087                         free(cp);
1088                 return (np);
1089
1090         case CONCAT:
1091                 ++concflag;
1092                 np = exprconcat(np, 0);
1093                 --concflag;
1094                 return (np);
1095
1096         case NOT:
1097                 return (intnode(exprtest(np->n_left) == 0 ? (INT)1 : (INT)0));
1098
1099         case AND:
1100                 return ((exprtest(np->n_left) != 0 &&
1101                     exprtest(np->n_right) != 0) ? const1 : const0);
1102
1103         case OR:
1104                 return ((exprtest(np->n_left) != 0 ||
1105                     exprtest(np->n_right) != 0) ? const1 : const0);
1106
1107         case EXP:
1108                 {
1109                         double f1, f2;
1110
1111                         /*
1112                          * evaluate expressions in proper order before
1113                          * calling pow().
1114                          * Can't guarantee that compiler will do this
1115                          * correctly for us if we put them inline.
1116                          */
1117                         f1 = (double)exprreal(np->n_left);
1118                         f2 = (double)exprreal(np->n_right);
1119                         return (realnode((REAL)pow(f1, f2)));
1120                 }
1121
1122         case QUEST:
1123                 if (np->n_right->n_type != COLON)
1124                         awkerr(interr, "?:");
1125                 if (exprtest(np->n_left))
1126                         np = np->n_right->n_left; else
1127                         np = np->n_right->n_right;
1128                 return (exprreduce(np));
1129
1130         case EQ:
1131         case NE:
1132         case GE:
1133         case LE:
1134         case GT:
1135         case LT:
1136                 return (comparison(np));
1137
1138         case ADD:
1139         case SUB:
1140         case MUL:
1141         case DIV:
1142         case REM:
1143                 return (arithmetic(np));
1144
1145         case DEC:
1146                 inc_oper->n_type = SUB;
1147                 goto do_inc_op;
1148         case INC:
1149                 inc_oper->n_type = ADD;
1150 do_inc_op:
1151                 if ((np = np->n_left)->n_type == INDEX)
1152                         np = exprreduce(np);
1153                 if (np->n_flags & FREAL)
1154                         tnp = realnode(np->n_real);
1155                 else
1156                         tnp = intnode(exprint(np));
1157                 inc_oper->n_left = np;
1158                 (void) assign(np, inc_oper);
1159                 return (tnp);
1160
1161         case PRE_DEC:
1162                 inc_oper->n_type = SUB;
1163                 goto do_pinc_op;
1164         case PRE_INC:
1165                 inc_oper->n_type = ADD;
1166 do_pinc_op:
1167                 if ((np = np->n_left)->n_type == INDEX)
1168                         np = exprreduce(np);
1169                 inc_oper->n_left = np;
1170                 return (assign(np, inc_oper));
1171
1172         case AADD:
1173                 asn_oper->n_type = ADD;
1174                 goto do_asn_op;
1175         case ASUB:
1176                 asn_oper->n_type = SUB;
1177                 goto do_asn_op;
1178         case AMUL:
1179                 asn_oper->n_type = MUL;
1180                 goto do_asn_op;
1181         case ADIV:
1182                 asn_oper->n_type = DIV;
1183                 goto do_asn_op;
1184         case AREM:
1185                 asn_oper->n_type = REM;
1186                 goto do_asn_op;
1187         case AEXP:
1188                 asn_oper->n_type = EXP;
1189 do_asn_op:
1190                 asn_oper->n_right = np->n_right;
1191                 if ((np = np->n_left)->n_type == INDEX)
1192                         np = exprreduce(np);
1193                 asn_oper->n_left = np;
1194                 return (assign(np, asn_oper));
1195
1196
1197         case GETLINE:
1198                 return (f_getline(np));
1199
1200         case CALLFUNC:
1201                 return ((*np->n_left->n_function)(np->n_right));
1202
1203         case RE:
1204                 if (regmatch(np->n_regexp, linebuf) == REG_OK)
1205                         return (const1);
1206                 return (const0);
1207
1208         case TILDE:
1209                 cp = exprstring(np->n_left);
1210                 if (regmatch(getregexp(np->n_right), cp) == REG_OK)
1211                         return (const1);
1212                 return (const0);
1213
1214         case NRE:
1215                 cp = exprstring(np->n_left);
1216                 if (regmatch(getregexp(np->n_right), cp) != REG_OK)
1217                         return (const1);
1218                 return (const0);
1219
1220         case ASG:
1221                 return (assign(np->n_left, np->n_right));
1222
1223         case ARRAY:
1224                 awkerr(badarray, np->n_name);
1225
1226         case UFUNC:
1227                 awkerr(varnotfunc, np->n_name);
1228
1229         default:
1230                 awkerr(gettext("panic: exprreduce(%d)"), t);
1231                 /* NOTREACHED */
1232         }
1233         return (0);
1234 }
1235
1236 /*
1237  * Do arithmetic operators.
1238  */
1239 static NODE *
1240 arithmetic(NODE *np)
1241 {
1242         register NODE *left, *right;
1243         int type;
1244         register INT i1, i2;
1245         register INT iresult;
1246         register REAL r1, r2;
1247
1248         left = exprreduce(np->n_left);
1249         if (isreal(left->n_flags) ||
1250             (isstring(left->n_flags) && (type_of(left)&FVREAL))) {
1251                 type = FREAL;
1252                 r1 = exprreal(left);
1253                 r2 = exprreal(np->n_right);
1254         } else {
1255                 i1 = exprint(left);
1256                 right = exprreduce(np->n_right);
1257                 if (isreal(right->n_flags) ||
1258                     (isstring(right->n_flags) && (type_of(right)&FVREAL))) {
1259
1260                         type = FREAL;
1261                         r1 = i1;
1262                         r2 = exprreal(right);
1263                 } else {
1264                         type = FINT;
1265                         i2 = exprint(right);
1266                 }
1267         }
1268 reswitch:
1269         switch (np->n_type) {
1270         case ADD:
1271                 if (type == FINT) {
1272                         iresult = i1 + i2;
1273                         addoverflow();
1274                 } else
1275                         r1 += r2;
1276                 break;
1277
1278         /*
1279          * Strategically placed between ADD and SUB
1280          * so "jo" branches will reach on 80*86
1281          */
1282         overflow:
1283                 r1 = i1;
1284                 r2 = i2;
1285                 type = FREAL;
1286                 goto reswitch;
1287
1288         case SUB:
1289                 if (type == FINT) {
1290                         iresult = i1 - i2;
1291                         suboverflow();
1292                 } else
1293                         r1 -= r2;
1294                 break;
1295
1296         case MUL:
1297                 if (type == FINT) {
1298                         iresult = i1 * i2;
1299                         muloverflow();
1300                 } else
1301                         r1 *= r2;
1302                 break;
1303
1304         case DIV:
1305                 if (type == FINT) {
1306                         r1 = i1;
1307                         r2 = i2;
1308                         type = FREAL;
1309                 }
1310                 if (r2 == 0.0)
1311                         awkerr(divzero);
1312                 r1 /= r2;
1313                 break;
1314
1315         case REM:
1316                 if (type == FINT) {
1317                         if (i2 == 0)
1318                                 awkerr(divzero);
1319                         iresult = i1 % i2;
1320                 } else {
1321                         double fmod(double x, double y);
1322
1323                         errno = 0;
1324                         r1 = fmod(r1, r2);
1325                         if (errno == EDOM)
1326                                 awkerr(divzero);
1327                 }
1328                 break;
1329         }
1330         return (type == FINT ? intnode(iresult) : realnode(r1));
1331 }
1332
1333 /*
1334  * Do comparison operators.
1335  */
1336 static NODE *
1337 comparison(NODE *np)
1338 {
1339         register NODE *left, *right;
1340         register int cmp;
1341         int tl, tr;
1342         register REAL r1, r2;
1343         register INT i1, i2;
1344
1345         left = np->n_left;
1346         if (isleaf(left->n_flags)) {
1347                 if (left->n_type == PARM)
1348                         left = left->n_next;
1349         } else
1350                 left = exprreduce(left);
1351         tl = left->n_flags;
1352         right = np->n_right;
1353         if (isleaf(right->n_flags)) {
1354                 if (right->n_type == PARM)
1355                         right = right->n_next;
1356         } else {
1357                 ++concflag;
1358                 right = exprreduce(right);
1359                 --concflag;
1360         }
1361         tr = right->n_flags;
1362         /*
1363          * Posix mandates semantics for the comparison operators that
1364          * are incompatible with traditional AWK behaviour. If the following
1365          * define is true then awk will use the traditional behaviour.
1366          * if it's false, then AWK will use the POSIX-mandated behaviour.
1367          */
1368 #define TRADITIONAL 0
1369 #if TRADITIONAL
1370         if (!isnumber(tl) || !isnumber(tr)) {
1371                 cmp = wcscoll((wchar_t *)exprstring(left),
1372                     (wchar_t *)exprstring(right));
1373         } else if (isreal(tl) || isreal(tr)) {
1374                 r1 = exprreal(left);
1375                 r2 = exprreal(right);
1376                 if (r1 < r2)
1377                         cmp = -1;
1378                 else if (r1 > r2)
1379                         cmp = 1;
1380                 else
1381                         cmp = 0;
1382         } else {
1383                 i1 = exprint(left);
1384                 i2 = exprint(right);
1385                 if (i1 < i2)
1386                         cmp = -1;
1387                 else if (i1 > i2)
1388                         cmp = 1;
1389                 else
1390                         cmp = 0;
1391         }
1392 #else
1393         if (!isnumber(tl) && !isnumber(tr)) {
1394 do_strcmp:
1395                 cmp = wcscoll((wchar_t *)exprstring(left),
1396                     (wchar_t *)exprstring(right));
1397         } else {
1398                 if (isstring(tl))
1399                         tl = type_of(left);
1400                 if (isstring(tr))
1401                         tr = type_of(right);
1402                 if (!isnumber(tl) || !isnumber(tr))
1403                         goto do_strcmp;
1404                 if (isreal(tl) || isreal(tr)) {
1405                         r1 = exprreal(left);
1406                         r2 = exprreal(right);
1407                         if (r1 < r2)
1408                                 cmp = -1;
1409                         else if (r1 > r2)
1410                                 cmp = 1;
1411                         else
1412                                 cmp = 0;
1413                 } else {
1414                         i1 = exprint(left);
1415                         i2 = exprint(right);
1416                         if (i1 < i2)
1417                                 cmp = -1;
1418                         else if (i1 > i2)
1419                                 cmp = 1;
1420                         else
1421                                 cmp = 0;
1422                 }
1423         }
1424 #endif
1425         switch (np->n_type) {
1426         case EQ:
1427                 return (cmp == 0 ? const1 : const0);
1428
1429         case  NE:
1430                 return (cmp != 0 ? const1 : const0);
1431
1432         case GE:
1433                 return (cmp >= 0 ? const1 : const0);
1434
1435         case LE:
1436                 return (cmp <= 0 ? const1 : const0);
1437
1438         case GT:
1439                 return (cmp > 0 ? const1 : const0);
1440
1441         case LT:
1442                 return (cmp < 0 ? const1 : const0);
1443
1444         default:
1445                 awkerr(interr, "comparison");
1446         }
1447         /* NOTREACHED */
1448         return (0);
1449 }
1450
1451 /*
1452  * Return the type of a constant that is a string.
1453  * The node must be a FSTRING type and the return value
1454  * will possibly have FVINT or FVREAL or'ed in.
1455  */
1456 static int
1457 type_of(NODE *np)
1458 {
1459         wchar_t *cp;
1460         int somedigits = 0;
1461         int seene = 0;
1462         int seenradix = 0;
1463         int seensign = 0;
1464         int digitsaftere = 0;
1465
1466         cp = (wchar_t *)np->n_string;
1467         if (*cp == '\0')
1468                 return (FSTRING|FVINT);
1469         while (iswspace(*cp))
1470                 cp++;
1471         if (*cp == '-' || *cp == '+')
1472                 cp++;
1473         while (*cp != '\0') {
1474                 switch (*cp) {
1475                 case '0':
1476                 case '1':
1477                 case '2':
1478                 case '3':
1479                 case '4':
1480                 case '5':
1481                 case '6':
1482                 case '7':
1483                 case '8':
1484                 case '9':
1485                         if (seene)
1486                                 digitsaftere = 1;
1487                         somedigits++;
1488                         break;
1489
1490                 case 'E':
1491                 case 'e':
1492                         if (seene || !somedigits)
1493                                 return (FSTRING);
1494                         seene = 1;
1495                         break;
1496
1497                 case '+':
1498                 case '-':
1499                         if (seensign || !seene || digitsaftere)
1500                                 return (FSTRING);
1501                         seensign = 1;
1502                         break;
1503
1504                 default:
1505                         if (*cp == radixpoint) {
1506                                 if (seenradix || seene || (!somedigits &&
1507                                     !iswdigit(*++cp)))
1508                                         return (FSTRING);
1509                         } else
1510                                 return (FSTRING);
1511                         seenradix = 1;
1512                 }
1513                 cp++;
1514         }
1515         if (somedigits == 0)
1516                 return (FSTRING);
1517         if (somedigits >= MAXDIGINT || seenradix || seene) {
1518                 if (seensign && !digitsaftere)
1519                         return (FSTRING);
1520                 else
1521                         return (FSTRING|FVREAL);
1522         } else
1523                 return (FSTRING|FVINT);
1524 }
1525
1526 /*
1527  * Return a field rvalue.
1528  */
1529 static NODE *
1530 rfield(INT fieldno)
1531 {
1532         register wchar_t *cp;
1533
1534         if (fieldno == 0)
1535                 return (stringnode(linebuf, FSTATIC|FSENSE, lbuflen));
1536         if (!splitdone)
1537                 fieldsplit();
1538         if (fieldno > nfield || fieldno < 0)
1539                 return (stringnode(_null, FSTATIC, 0));
1540         cp = fields[fieldno-1];
1541         return (stringnode(cp, FSTATIC|FSENSE, wcslen(cp)));
1542 }
1543
1544 /*
1545  * Split linebuf into fields.  Done only once
1546  * per input record (maximum).
1547  */
1548 void
1549 fieldsplit()
1550 {
1551         register wchar_t *ip, *op;
1552         register int n;
1553         wchar_t *ep;
1554
1555         if (fieldbuf == NULL)
1556                 fieldbuf = emalloc(NLINE * sizeof (wchar_t));
1557         fcount = 0;
1558         ep = linebuf;
1559         op = fieldbuf;
1560         while ((ip = (*awkfield)(&ep)) != NULL) {
1561                 fields[fcount++] = op;
1562                 if (fcount > NFIELD)
1563                         awkerr(tmfld, NFIELD);
1564                 n = ep-ip;
1565                 (void) memcpy(op, ip, n * sizeof (wchar_t));
1566                 op += n;
1567                 *op++ = '\0';
1568         }
1569         if (varNF->n_flags & FINT)
1570                 varNF->n_int = fcount;
1571         else {
1572                 constant->n_int = fcount;
1573                 (void) nassign(varNF, constant);
1574         }
1575         nfield = fcount;
1576         splitdone++;
1577 }
1578
1579 /*
1580  * Assign to a field as an lvalue.
1581  * Return the unevaluated node as one doesn't always need it
1582  * evaluated in an assignment.
1583  */
1584 static NODE *
1585 lfield(INT fieldno, NODE *np)
1586 {
1587         register wchar_t *cp;
1588         register wchar_t *op;
1589         register wchar_t *sep;
1590         register int i;
1591         register wchar_t *newval;
1592         register int seplen;
1593         register int newlen;
1594
1595         newlen = wcslen(newval = (wchar_t *)exprstring(np));
1596         if (fieldno == 0) {
1597                 splitdone = 0;
1598                 (void) memcpy(linebuf, newval, (newlen+1) * sizeof (wchar_t));
1599                 lbuflen = newlen;
1600                 fieldsplit();
1601         } else {
1602                 seplen = wcslen(sep = (wchar_t *)exprstring(varOFS));
1603                 if (!splitdone)
1604                         fieldsplit();
1605                 if (--fieldno < nfield &&
1606                     (newlen <= wcslen(fields[fieldno]))) {
1607                         (void) memcpy(fields[fieldno], newval,
1608                                 (newlen+1) * sizeof (wchar_t));
1609                 } else {
1610                         register wchar_t *buf;
1611
1612                         buf = fieldbuf;
1613                         fieldbuf = emalloc(NLINE * sizeof (wchar_t));
1614                         if (fieldno >= nfield) {
1615                                 if (fieldno >= NFIELD)
1616                                         awkerr(tmfld, NFIELD);
1617                                 while (nfield < fieldno)
1618                                         fields[nfield++] = _null;
1619                                 ++nfield;
1620                         }
1621                         fields[fieldno] = newval;
1622                         op = fieldbuf;
1623                         for (i = 0; i < nfield; i++) {
1624                                 newlen = wcslen(cp = fields[i])+1;
1625                                 fields[i] = op;
1626                                 if (op+newlen >= fieldbuf+NLINE)
1627                                         awkerr(toolong, NLINE);
1628                                 (void) memcpy(op, cp,
1629                                     newlen * sizeof (wchar_t));
1630                                 op += newlen;
1631                         }
1632                         free(buf);
1633                 }
1634                 /*
1635                  * Reconstruct $0
1636                  */
1637                 op = linebuf;
1638                 i = 0;
1639                 while (i < nfield) {
1640                         newlen = wcslen(cp = fields[i++]);
1641                         (void) memcpy(op, cp, newlen * sizeof (wchar_t));
1642                         op += newlen;
1643                         if (i < nfield) {
1644                                 (void) memcpy(op, sep,
1645                                         seplen * sizeof (wchar_t));
1646                                 op += seplen;
1647                         }
1648                         if (op >= &linebuf[NLINE])
1649                                 awkerr(toolong, NLINE);
1650                 }
1651                 *op = '\0';
1652                 lbuflen = op-linebuf;
1653                 if (varNF->n_flags & FINT)
1654                         varNF->n_int = nfield;
1655                 else {
1656                         constant->n_int = nfield;
1657                         (void) nassign(varNF, constant);
1658                 }
1659         }
1660         return (np);
1661 }
1662
1663 /*
1664  * Do a user function.
1665  * Each formal parameter must:
1666  *      have the actual parameter assigned to it (call by value),
1667  *      have a pointer to an array put into it (call by reference),
1668  *      and be made undefined (extra formal parameters)
1669  */
1670 static NODE *
1671 userfunc(NODE *np)
1672 {
1673         register NODE *temp;
1674         NODE *fnp;
1675
1676         if ((fnp = np->n_left) == NNULL)
1677                 awkerr(gettext("impossible function call"));
1678         if (fnp->n_type != UFUNC)
1679                 awkerr(varnotfunc, fnp->n_name);
1680
1681 #ifndef M_STKCHK
1682         if (slevel >= NRECUR)
1683                 awkerr(gettext("function \"%S\" nesting level > %u"),
1684                     fnp->n_name, NRECUR);
1685 #else
1686         if (!M_STKCHK)
1687                 awkerr(gettext("function \"%s\" nesting level too deep"),
1688                     fnp->n_name);
1689 #endif
1690
1691         fnp = fnp->n_ufunc;
1692         {
1693                 register NODE *formal;
1694                 register NODE *actual;
1695                 NODE *formlist, *actlist, *templist, *temptail;
1696
1697                 templist = temptail = NNULL;
1698                 actlist = np->n_right;
1699                 formlist = fnp->n_left;
1700                 /*
1701                  * pass through formal list, setting up a list
1702                  * (on templist) containing temps for the values
1703                  * of the actuals.
1704                  * If the actual list runs out before the formal
1705                  * list, assign 'constundef' as the value
1706                  */
1707                 while ((formal = getlist(&formlist)) != NNULL) {
1708                         register NODE *array;
1709                         register int t;
1710                         register size_t len;
1711                         register int scope_tag;
1712
1713                         actual = getlist(&actlist);
1714                         if (actual == NNULL) {
1715                                 actual = constundef;
1716                                 scope_tag = slevel+1;
1717                         } else
1718                                 scope_tag = 0;
1719                         array = actual;
1720                         switch (actual->n_type) {
1721                         case ARRAY:
1722                                 t = ARRAY;
1723                                 scope_tag = 0;
1724                                 break;
1725
1726                         case PARM:
1727                                 array = actual = actual->n_next;
1728                                 t = actual->n_type;
1729                                 scope_tag = actual->n_scope;
1730                                 if (!(actual->n_flags & FLARRAY))
1731                                         array = actual->n_alink;
1732                                 break;
1733
1734                         default:
1735                                 t = VAR;
1736                                 break;
1737                         }
1738                         temp = emptynode(t, len = wcslen(formal->n_name));
1739                         (void) memcpy(temp->n_name, formal->n_name,
1740                             (len+1) * sizeof (wchar_t));
1741                         temp->n_flags = FSTRING|FVINT;
1742                         temp->n_string = _null;
1743                         temp->n_strlen = 0;
1744                         if (t == VAR)
1745                                 (void) assign(temp, actual);
1746                         if (t != ARRAY)
1747                                 temp->n_flags |= FLARRAY;
1748                         temp->n_scope = scope_tag;
1749                         /*
1750                          * link to actual parameter in case of promotion to
1751                          * array
1752                          */
1753                         if (actual != constundef)
1754                                 temp->n_alink = actual;
1755                         /*
1756                          * Build the templist
1757                          */
1758                         if (templist != NNULL) {
1759                                 temptail->n_next = temp;
1760                                 temptail = temp;
1761                         } else
1762                                 templist = temptail = temp;
1763                         temp->n_next = NNULL;
1764                         if (actual->n_type == CONSTANT)
1765                                 temp->n_alink = temp;
1766                         else
1767                                 temp->n_alink = array;
1768                 }
1769                 /*
1770                  * Bind results of the evaluation of actuals to formals.
1771                  */
1772                 formlist = fnp->n_left;
1773                 while (templist != NNULL) {
1774                         temp = templist;
1775                         templist = temp->n_next;
1776                         formal = getlist(&formlist);
1777                         temp->n_next = formal->n_next;
1778                         formal->n_next = temp;
1779
1780
1781
1782
1783
1784
1785
1786
1787                 }
1788         }
1789         {
1790                 register NODE *savenode = curnode;
1791
1792                 ++slevel;
1793                 if (action(fnp->n_right) == RETURN)
1794                         np = retval; else
1795                         np = const0;
1796                 curnode = savenode;
1797         }
1798         {
1799                 register NODE *formal;
1800                 NODE *formlist;
1801
1802                 formlist = fnp->n_left;
1803                 while ((formal = getlist(&formlist)) != NNULL) {
1804                         temp = formal->n_next;
1805                         formal->n_next = temp->n_next;
1806                         /* if node is a local array, free the elements */
1807                         if (temp->n_type == ARRAY && (temp->n_scope == slevel))
1808                                 delarray(temp);
1809                         freenode(temp);
1810                 }
1811         }
1812         --slevel;
1813         return (np);
1814 }
1815
1816 /*
1817  * Get the regular expression from an expression tree.
1818  */
1819 REGEXP
1820 getregexp(NODE *np)
1821 {
1822         if (np->n_type == RE)
1823                 return (np->n_regexp);
1824         np = renode((wchar_t *)exprstring(np));
1825         return (np->n_regexp);
1826 }
1827
1828 /*
1829  * Get the next element from a list.
1830  */
1831 NODE *
1832 getlist(NODE **npp)
1833 {
1834         register NODE *np;
1835
1836         if ((np = *npp) == NNULL)
1837                 return (np);
1838         if (np->n_type == COMMA) {
1839                 *npp = np->n_right;
1840                 return (np->n_left);
1841         } else {
1842                 *npp = NNULL;
1843                 return (np);
1844         }
1845 }
1846
1847 /*
1848  * if statement.
1849  */
1850 static int
1851 s_if(NODE *np)
1852 {
1853         register NODE *xp;
1854         register int test;
1855
1856         test = exprtest(np->n_left);
1857         xp = np->n_right;
1858         if (xp->n_type != ELSE)
1859                 awkerr(interr, "if/else");
1860         if (test)
1861                 xp = xp->n_left;
1862         else
1863                 xp = xp->n_right;
1864         return (action(xp));
1865 }
1866
1867 /*
1868  * while and do{}while statements.
1869  */
1870 static int
1871 s_while(NODE *np)
1872 {
1873         register int act = 0;
1874
1875         if (np->n_type == DO)
1876                 goto dowhile;
1877         for (;;) {
1878                 if (exprtest(np->n_left) == 0)
1879                         break;
1880         dowhile:
1881                 if ((act = action(np->n_right)) != 0) {
1882                         switch (act) {
1883                         case BREAK:
1884                                 act = 0;
1885                                 break;
1886
1887                         case CONTINUE:
1888                                 act = 0;
1889                                 continue;
1890                         }
1891                         break;
1892                 }
1893         }
1894         return (act);
1895 }
1896
1897 /*
1898  * for statement.
1899  */
1900 static int
1901 s_for(NODE *np)
1902 {
1903         register NODE *testnp, *incnp, *initnp;
1904         register int act = 0;
1905         NODE *listp;
1906
1907         listp = np->n_left;
1908         initnp = getlist(&listp);
1909         testnp = getlist(&listp);
1910         incnp = getlist(&listp);
1911         if (initnp != NNULL)
1912                 (void) exprreduce(initnp);
1913         for (;;) {
1914                 if (exprtest(testnp) == 0)
1915                         break;
1916                 if ((act = action(np->n_right)) != 0) {
1917                         switch (act) {
1918                         case BREAK:
1919                                 act = 0;
1920                                 break;
1921
1922                         case CONTINUE:
1923                                 act = 0;
1924                                 goto clabel;
1925                         }
1926                         break;
1927                 }
1928         clabel:
1929                 if (incnp != NNULL)
1930                         (void) exprreduce(incnp);
1931         }
1932         return (act);
1933 }
1934
1935 /*
1936  * for variable in array statement.
1937  */
1938 static int
1939 s_forin(NODE *np)
1940 {
1941         register NODE *left;
1942         register int act = 0;
1943         register NODE *var;
1944         register NODE **nnp;
1945         register NODE *statement;
1946         register int issymtab = 0;
1947         wchar_t *index;
1948         register int alen;
1949         int nbuck;
1950
1951         left = np->n_left;
1952         statement = np->n_right;
1953         if (left->n_type != IN)
1954                 awkerr(interr, "for (var in array)");
1955         if ((var = left->n_left)->n_type == PARM)
1956                 var = var->n_next;
1957         np = left->n_right;
1958         if (np->n_type == PARM) {
1959                 np = np->n_next;
1960                 if (!(np->n_flags & FLARRAY))
1961                         np = np->n_alink;
1962         }
1963         if (np == varSYMTAB) {
1964                 issymtab++;
1965                 np = NNULL;
1966                 nbuck = 0;
1967         } else {
1968                 /*
1969                  * At this point if the node is not actually an array
1970                  * check to see if it has already been established as
1971                  * a scalar. If it is a scalar then flag an error. If
1972                  * not then promote the object to an array type.
1973                  */
1974                 if (np->n_type != ARRAY) {
1975                         if (!isstring(np->n_flags) || np->n_string != _null)
1976                                 awkerr(notarray, np->n_name);
1977                         else {
1978                                 /* promotion to array */
1979                                 promote(np);
1980                                 if (np->n_alink != NNULL)
1981                                         if (!(np->n_flags & FLARRAY))
1982                                                 np = np->n_alink;
1983                         }
1984                 }
1985                 /*
1986                  * Set up a pointer to the first node in the array list.
1987                  * Save this pointer on the delete stack. This information
1988                  * is used by the delete function to advance any pointers
1989                  * that might be pointing at a node which has been deleted.
1990                  * See the delsymtab() function for more information. Note
1991                  * that if the a_link field is nil, then just return 0 since
1992                  * this array has no elements yet.
1993                  */
1994                 if ((*(nnp = next_forin) = np->n_alink) == 0)
1995                         return (0);
1996                 if (++next_forin > &forindex[NFORINLOOP])
1997                         awkerr(toodeep, NFORINLOOP);
1998                 /*
1999                  * array elements have names of the form
2000                  *      <name>]<index> (global arrays)
2001                  * or
2002                  *      <name>[<scope>]<index> (local arrays)
2003                  * We need to know the offset of the index portion of the
2004                  * name string in order to place it in the index variable so
2005                  * we look for the ']'. This is calculated here and then
2006                  * used below.
2007                  */
2008                 for (alen = 0; (*nnp)->n_name[alen++] != ']'; )
2009                         if ((*nnp)->n_name[alen] == '\0')
2010                                 awkerr(interr, "for: invalid array");
2011         }
2012         for (;;) {
2013                 if (issymtab) {
2014                         if ((left = symwalk(&nbuck, &np)) == NNULL)
2015                                 break;
2016                         index = left->n_name;
2017                 } else {
2018                         if ((np = *nnp) == NNULL)
2019                                 break;
2020                         index = np->n_name+alen;
2021                         *nnp = np->n_alink;
2022                 }
2023                 strassign(var, index, FSTATIC, wcslen(index));
2024                 if ((act = action(statement)) != 0) {
2025                         switch (act) {
2026                         case BREAK:
2027                                 act = 0;
2028                                 break;
2029
2030                         case CONTINUE:
2031                                 act = 0;
2032                                 continue;
2033                         }
2034                         break;
2035                 }
2036         }
2037         next_forin--;
2038         return (act);
2039 }
2040
2041 /*
2042  * Walk the symbol table using the same algorithm as arraynode.
2043  */
2044 NODE *
2045 symwalk(int *buckp, NODE **npp)
2046 {
2047         register NODE *np;
2048
2049         np = *npp;
2050         for (;;) {
2051                 while (np == NNULL) {
2052                         if (*buckp >= NBUCKET)
2053                                 return (*npp = NNULL);
2054                         np = symtab[(*buckp)++];
2055                 }
2056                 if (np->n_type == VAR &&
2057                     (!isstring(np->n_flags) || np->n_string != _null)) {
2058                         *npp = np->n_next;
2059                         return (np);
2060                 }
2061                 np = np->n_next;
2062         }
2063         /* NOTREACHED */
2064 }
2065
2066 /*
2067  * Test the result of an expression.
2068  */
2069 static int
2070 exprtest(NODE *np)
2071 {
2072         register int t;
2073
2074         if (np == NNULL)
2075                 return (1);
2076         if (freelist != NNULL)
2077                 freetemps();
2078         np = exprreduce(np);
2079         if (isint(t = np->n_flags)) {
2080                 if (isstring(t))
2081                         return (exprint(np) != 0);
2082                 return (np->n_int != 0);
2083         }
2084         if (isreal(t)) {
2085                 REAL rval;
2086
2087                 rval = isstring(t) ? exprreal(np) : np->n_real;
2088                 return (rval != 0.0);
2089         }
2090         return (*(wchar_t *)exprstring(np) != '\0');
2091 }
2092
2093 /*
2094  * Return malloc'ed space that holds the given name "[" scope "]" index ...
2095  * concatenated string.
2096  * The node (np) is the list of indices and 'array' is the array name.
2097  */
2098 static wchar_t *
2099 makeindex(NODE *np, wchar_t *array, int tag)
2100 {
2101         static wchar_t tags[sizeof (int)];
2102         static wchar_t tag_chars[] = M_MB_L("0123456789ABCDEF");
2103         register wchar_t *cp;
2104         register NODE *index;
2105         register uint_t n;
2106         register int len;
2107         register wchar_t *indstr;
2108         register wchar_t *sep;
2109         register int seplen;
2110         register int taglen;
2111
2112
2113         /*
2114          * calculate and create the tag string
2115          */
2116         for (taglen = 0; tag; tag >>= 4)
2117                 tags[taglen++] = tag_chars[tag & 0xf];
2118         /*
2119          * Special (normal) case: only one index.
2120          */
2121         if (np->n_type != COMMA) {
2122                 wchar_t *ocp;
2123                 size_t i;
2124
2125                 if (isleaf(np->n_flags) && np->n_type == PARM)
2126                         np = np->n_next;
2127                 if (isstring(np->n_flags)) {
2128                         indstr = np->n_string;
2129                         len = np->n_strlen;
2130                 } else {
2131                         indstr = exprstring(np);
2132                         len = wcslen(indstr);
2133                 }
2134                 i = (n = wcslen(array)) + len + 3 + taglen;
2135                 if (i < NINDEXBUF)
2136                         ocp = indexbuf;
2137                 else
2138                         ocp = emalloc(i * sizeof (wchar_t));
2139                 (void) memcpy(ocp, array, n * sizeof (wchar_t));
2140                 cp = ocp+n;
2141                 if (taglen) {
2142                         *cp++ = '[';
2143                         while (taglen)
2144                                 *cp++ = tags[--taglen];
2145                 }
2146                 *cp++ = ']';
2147                 (void) memcpy(cp, indstr, (len+1) * sizeof (wchar_t));
2148
2149                 return (ocp);
2150         }
2151         n = 0;
2152         seplen = wcslen(sep = (wchar_t *)exprstring(varSUBSEP));
2153         while ((index = getlist(&np)) != NNULL) {
2154                 indstr = exprstring(index);
2155                 len = wcslen(indstr);
2156                 if (n == 0) {
2157                         cp = emalloc(sizeof (wchar_t) * ((n = wcslen(array)) +
2158                                 len + 3 + taglen));
2159                         (void) memcpy(cp, array, n * sizeof (wchar_t));
2160                         if (taglen) {
2161                                 cp[n++] = '[';
2162                                 while (taglen)
2163                                         cp[n++] = tags[--taglen];
2164                         }
2165                         cp[n++] = ']';
2166                 } else {
2167                         cp = erealloc(cp, (n+len+seplen+1) * sizeof (wchar_t));
2168                         (void) memcpy(cp+n, sep, seplen * sizeof (wchar_t));
2169                         n += seplen;
2170                 }
2171                 (void) memcpy(cp+n, indstr, (len+1) * sizeof (wchar_t));
2172                 n += len;
2173         }
2174         return (cp);
2175 }
2176
2177
2178 /*
2179  * Promote a node to an array. In the simplest case, just set the
2180  * node type field to ARRAY. The more complicated case involves walking
2181  * a list of variables that haven't been determined yet as scalar or array.
2182  * This routine plays with the pointers to avoid recursion.
2183  */
2184 void
2185 promote(NODE *n)
2186 {
2187         register NODE *prev = NNULL;
2188         register NODE *next;
2189
2190         /*
2191          * walk down the variable chain, reversing the pointers and
2192          * setting each node to type array.
2193          */
2194         while ((n->n_flags & FLARRAY) && (n->n_alink != n)) {
2195                 n->n_type = ARRAY;
2196                 next = n->n_alink;
2197                 n->n_alink = prev;
2198                 prev = n;
2199                 n = next;
2200         }
2201
2202         /*
2203          * If the final entity on the chain is a local variable, then
2204          * reset it's alink field to NNULL - normally it points back
2205          * to itself - this is used in other parts of the code to
2206          * reduce the number of conditionals when handling locals.
2207          */
2208         n->n_type = ARRAY;
2209         if (n->n_flags & FLARRAY)
2210                 n->n_alink = NNULL;
2211
2212         /*
2213          * Now walk back up the list setting the alink to point to
2214          * the last entry in the chain and clear the 'local array'
2215          * flag.
2216          */
2217         while (prev != NNULL) {
2218                 prev->n_flags &= ~FLARRAY;
2219                 next = prev->n_alink;
2220                 prev->n_alink = n;
2221                 prev = next;
2222         }
2223 }