src/parser.c

   1 /*-
   2  * Copyright (c) 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  * Copyright (c) 1997-2005
   5  *      Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Kenneth Almquist.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #if HAVE_ALLOCA_H
  36 #include <alloca.h>
  37 #endif
  38
  39 #include <stdlib.h>
  40
  41 #include "shell.h"
  42 #include "parser.h"
  43 #include "nodes.h"
  44 #include "expand.h"     /* defines rmescapes() */
  45 #include "exec.h"       /* defines find_builtin() */
  46 #include "syntax.h"
  47 #include "options.h"
  48 #include "input.h"
  49 #include "output.h"
  50 #include "var.h"
  51 #include "error.h"
  52 #include "memalloc.h"
  53 #include "mystring.h"
  54 #include "alias.h"
  55 #include "show.h"
  56 #include "builtins.h"
  57 #include "system.h"
  58 #ifndef SMALL
  59 #include "myhistedit.h"
  60 #endif
  61
  62 /*
  63  * Shell command parser.
  64  */
  65
  66 /* values returned by readtoken */
  67 #include "token_vars.h"
  68
  69
  70
  71 /* Used by expandstr to get here-doc like behaviour. */
  72 #define FAKEEOFMARK (char *)1
  73
  74
  75
  76 struct heredoc {
  77         struct heredoc *next;   /* next here document in list */
  78         union node *here;               /* redirection node */
  79         char *eofmark;          /* string indicating end of input */
  80         int striptabs;          /* if set, strip leading tabs */
  81 };
  82
  83 struct synstack {
  84         const char *syntax;
  85         struct synstack *prev;
  86         struct synstack *next;
  87         int innerdq;
  88         int varpushed;
  89         int dblquote;
  90         int varnest;            /* levels of variables expansion */
  91         int parenlevel;         /* levels of parens in arithmetic */
  92         int dqvarnest;          /* levels of variables expansion within double quotes */
  93 };
  94
  95
  96
  97 struct heredoc *heredoclist;    /* list of here documents to read */
  98 int doprompt;                   /* if set, prompt the user */
  99 int needprompt;                 /* true if interactive and at start of line */
 100 int lasttoken;                  /* last token read */
 101 int tokpushback;                /* last token pushed back */
 102 char *wordtext;                 /* text of last word returned by readtoken */
 103 int checkkwd;
 104 struct nodelist *backquotelist;
 105 union node *redirnode;
 106 struct heredoc *heredoc;
 107 int quoteflag;                  /* set if (part of) last token was quoted */
 108
 109
 110 STATIC union node *list(int);
 111 STATIC union node *andor(void);
 112 STATIC union node *pipeline(void);
 113 STATIC union node *command(void);
 114 STATIC union node *simplecmd(void);
 115 STATIC union node *makename(void);
 116 STATIC void parsefname(void);
 117 STATIC void parseheredoc(void);
 118 STATIC int readtoken(void);
 119 STATIC int xxreadtoken(void);
 120 STATIC int pgetc_eatbnl();
 121 STATIC int readtoken1(int, char const *, char *, int);
 122 STATIC void synexpect(int) __attribute__((__noreturn__));
 123 STATIC void synerror(const char *) __attribute__((__noreturn__));
 124 STATIC void setprompt(int);
 125
 126
 127 int isassignment(const char *p)
 128 {
 129         const char *q = endofname(p);
 130         if (p == q)
 131                 return 0;
 132         return *q == '=';
 133 }
 134
 135 static inline int realeofmark(const char *eofmark)
 136 {
 137         return eofmark && eofmark != FAKEEOFMARK;
 138 }
 139
 140
 141 /*
 142  * Read and parse a command.  Returns NEOF on end of file.  (NULL is a
 143  * valid parse tree indicating a blank line.)
 144  */
 145
 146 union node *
 147 parsecmd(int interact)
 148 {
 149         tokpushback = 0;
 150         checkkwd = 0;
 151         heredoclist = 0;
 152         doprompt = interact;
 153         if (doprompt)
 154                 setprompt(doprompt);
 155         needprompt = 0;
 156         return list(1);
 157 }
 158
 159
 160 STATIC union node *
 161 list(int nlflag)
 162 {
 163         int chknl = nlflag & 1 ? 0 : CHKNL;
 164         union node *n1, *n2, *n3;
 165         int tok;
 166
 167         n1 = NULL;
 168         for (;;) {
 169                 checkkwd = chknl | CHKKWD | CHKALIAS;
 170                 tok = readtoken();
 171                 switch (tok) {
 172                 case TNL:
 173                         parseheredoc();
 174                         return n1;
 175
 176                 case TEOF:
 177                         if (!n1 && !chknl)
 178                                 n1 = NEOF;
 179 out_eof:
 180                         parseheredoc();
 181                         tokpushback++;
 182                         lasttoken = TEOF;
 183                         return n1;
 184                 }
 185
 186                 tokpushback++;
 187                 if (nlflag == 2 && tokendlist[tok])
 188                         return n1;
 189                 nlflag |= 2;
 190
 191                 n2 = andor();
 192                 tok = readtoken();
 193                 if (tok == TBACKGND) {
 194                         if (n2->type == NPIPE) {
 195                                 n2->npipe.backgnd = 1;
 196                         } else {
 197                                 if (n2->type != NREDIR) {
 198                                         n3 = stalloc(sizeof(struct nredir));
 199                                         n3->nredir.n = n2;
 200                                         n3->nredir.redirect = NULL;
 201                                         n2 = n3;
 202                                 }
 203                                 n2->type = NBACKGND;
 204                         }
 205                 }
 206                 if (n1 == NULL) {
 207                         n1 = n2;
 208                 }
 209                 else {
 210                         n3 = (union node *)stalloc(sizeof (struct nbinary));
 211                         n3->type = NSEMI;
 212                         n3->nbinary.ch1 = n1;
 213                         n3->nbinary.ch2 = n2;
 214                         n1 = n3;
 215                 }
 216                 switch (tok) {
 217                 case TEOF:
 218                         goto out_eof;
 219                 case TNL:
 220                         tokpushback++;
 221                         /* fall through */
 222                 case TBACKGND:
 223                 case TSEMI:
 224                         break;
 225                 default:
 226                         if (!chknl)
 227                                 synexpect(-1);
 228                         tokpushback++;
 229                         return n1;
 230                 }
 231         }
 232 }
 233
 234
 235
 236 STATIC union node *
 237 andor(void)
 238 {
 239         union node *n1, *n2, *n3;
 240         int t;
 241
 242         n1 = pipeline();
 243         for (;;) {
 244                 if ((t = readtoken()) == TAND) {
 245                         t = NAND;
 246                 } else if (t == TOR) {
 247                         t = NOR;
 248                 } else {
 249                         tokpushback++;
 250                         return n1;
 251                 }
 252                 checkkwd = CHKNL | CHKKWD | CHKALIAS;
 253                 n2 = pipeline();
 254                 n3 = (union node *)stalloc(sizeof (struct nbinary));
 255                 n3->type = t;
 256                 n3->nbinary.ch1 = n1;
 257                 n3->nbinary.ch2 = n2;
 258                 n1 = n3;
 259         }
 260 }
 261
 262
 263
 264 STATIC union node *
 265 pipeline(void)
 266 {
 267         union node *n1, *n2, *pipenode;
 268         struct nodelist *lp, *prev;
 269         int negate;
 270
 271         negate = 0;
 272         TRACE(("pipeline: entered\n"));
 273         if (readtoken() == TNOT) {
 274                 negate = !negate;
 275                 checkkwd = CHKKWD | CHKALIAS;
 276         } else
 277                 tokpushback++;
 278         n1 = command();
 279         if (readtoken() == TPIPE) {
 280                 pipenode = (union node *)stalloc(sizeof (struct npipe));
 281                 pipenode->type = NPIPE;
 282                 pipenode->npipe.backgnd = 0;
 283                 lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
 284                 pipenode->npipe.cmdlist = lp;
 285                 lp->n = n1;
 286                 do {
 287                         prev = lp;
 288                         lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
 289                         checkkwd = CHKNL | CHKKWD | CHKALIAS;
 290                         lp->n = command();
 291                         prev->next = lp;
 292                 } while (readtoken() == TPIPE);
 293                 lp->next = NULL;
 294                 n1 = pipenode;
 295         }
 296         tokpushback++;
 297         if (negate) {
 298                 n2 = (union node *)stalloc(sizeof (struct nnot));
 299                 n2->type = NNOT;
 300                 n2->nnot.com = n1;
 301                 return n2;
 302         } else
 303                 return n1;
 304 }
 305
 306
 307
 308 STATIC union node *
 309 command(void)
 310 {
 311         union node *n1, *n2;
 312         union node *ap, **app;
 313         union node *cp, **cpp;
 314         union node *redir, **rpp;
 315         union node **rpp2;
 316         int t;
 317         int savelinno;
 318
 319         redir = NULL;
 320         rpp2 = &redir;
 321
 322         savelinno = plinno;
 323
 324         switch (readtoken()) {
 325         default:
 326                 synexpect(-1);
 327                 /* NOTREACHED */
 328         case TIF:
 329                 n1 = (union node *)stalloc(sizeof (struct nif));
 330                 n1->type = NIF;
 331                 n1->nif.test = list(0);
 332                 if (readtoken() != TTHEN)
 333                         synexpect(TTHEN);
 334                 n1->nif.ifpart = list(0);
 335                 n2 = n1;
 336                 while (readtoken() == TELIF) {
 337                         n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif));
 338                         n2 = n2->nif.elsepart;
 339                         n2->type = NIF;
 340                         n2->nif.test = list(0);
 341                         if (readtoken() != TTHEN)
 342                                 synexpect(TTHEN);
 343                         n2->nif.ifpart = list(0);
 344                 }
 345                 if (lasttoken == TELSE)
 346                         n2->nif.elsepart = list(0);
 347                 else {
 348                         n2->nif.elsepart = NULL;
 349                         tokpushback++;
 350                 }
 351                 t = TFI;
 352                 break;
 353         case TWHILE:
 354         case TUNTIL: {
 355                 int got;
 356                 n1 = (union node *)stalloc(sizeof (struct nbinary));
 357                 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL;
 358                 n1->nbinary.ch1 = list(0);
 359                 if ((got=readtoken()) != TDO) {
 360 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : ""));
 361                         synexpect(TDO);
 362                 }
 363                 n1->nbinary.ch2 = list(0);
 364                 t = TDONE;
 365                 break;
 366         }
 367         case TFOR:
 368                 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext))
 369                         synerror("Bad for loop variable");
 370                 n1 = (union node *)stalloc(sizeof (struct nfor));
 371                 n1->type = NFOR;
 372                 n1->nfor.linno = savelinno;
 373                 n1->nfor.var = wordtext;
 374                 checkkwd = CHKNL | CHKKWD | CHKALIAS;
 375                 if (readtoken() == TIN) {
 376                         app = &ap;
 377                         while (readtoken() == TWORD) {
 378                                 n2 = (union node *)stalloc(sizeof (struct narg));
 379                                 n2->type = NARG;
 380                                 n2->narg.text = wordtext;
 381                                 n2->narg.backquote = backquotelist;
 382                                 *app = n2;
 383                                 app = &n2->narg.next;
 384                         }
 385                         *app = NULL;
 386                         n1->nfor.args = ap;
 387                         if (lasttoken != TNL && lasttoken != TSEMI)
 388                                 synexpect(-1);
 389                 } else {
 390                         n2 = (union node *)stalloc(sizeof (struct narg));
 391                         n2->type = NARG;
 392                         n2->narg.text = (char *)dolatstr;
 393                         n2->narg.backquote = NULL;
 394                         n2->narg.next = NULL;
 395                         n1->nfor.args = n2;
 396                         /*
 397                          * Newline or semicolon here is optional (but note
 398                          * that the original Bourne shell only allowed NL).
 399                          */
 400                         if (lasttoken != TSEMI)
 401                                 tokpushback++;
 402                 }
 403                 checkkwd = CHKNL | CHKKWD | CHKALIAS;
 404                 if (readtoken() != TDO)
 405                         synexpect(TDO);
 406                 n1->nfor.body = list(0);
 407                 t = TDONE;
 408                 break;
 409         case TCASE:
 410                 n1 = (union node *)stalloc(sizeof (struct ncase));
 411                 n1->type = NCASE;
 412                 n1->ncase.linno = savelinno;
 413                 if (readtoken() != TWORD)
 414                         synexpect(TWORD);
 415                 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg));
 416                 n2->type = NARG;
 417                 n2->narg.text = wordtext;
 418                 n2->narg.backquote = backquotelist;
 419                 n2->narg.next = NULL;
 420                 checkkwd = CHKNL | CHKKWD | CHKALIAS;
 421                 if (readtoken() != TIN)
 422                         synexpect(TIN);
 423                 cpp = &n1->ncase.cases;
 424 next_case:
 425                 checkkwd = CHKNL | CHKKWD;
 426                 t = readtoken();
 427                 while(t != TESAC) {
 428                         if (lasttoken == TLP)
 429                                 readtoken();
 430                         *cpp = cp = (union node *)stalloc(sizeof (struct nclist));
 431                         cp->type = NCLIST;
 432                         app = &cp->nclist.pattern;
 433                         for (;;) {
 434                                 *app = ap = (union node *)stalloc(sizeof (struct narg));
 435                                 ap->type = NARG;
 436                                 ap->narg.text = wordtext;
 437                                 ap->narg.backquote = backquotelist;
 438                                 if (readtoken() != TPIPE)
 439                                         break;
 440                                 app = &ap->narg.next;
 441                                 readtoken();
 442                         }
 443                         ap->narg.next = NULL;
 444                         if (lasttoken != TRP)
 445                                 synexpect(TRP);
 446                         cp->nclist.body = list(2);
 447
 448                         cpp = &cp->nclist.next;
 449
 450                         checkkwd = CHKNL | CHKKWD;
 451                         if ((t = readtoken()) != TESAC) {
 452                                 if (t != TENDCASE)
 453                                         synexpect(TENDCASE);
 454                                 else
 455                                         goto next_case;
 456                         }
 457                 }
 458                 *cpp = NULL;
 459                 goto redir;
 460         case TLP:
 461                 n1 = (union node *)stalloc(sizeof (struct nredir));
 462                 n1->type = NSUBSHELL;
 463                 n1->nredir.linno = savelinno;
 464                 n1->nredir.n = list(0);
 465                 n1->nredir.redirect = NULL;
 466                 t = TRP;
 467                 break;
 468         case TBEGIN:
 469                 n1 = list(0);
 470                 t = TEND;
 471                 break;
 472         case TWORD:
 473         case TREDIR:
 474                 tokpushback++;
 475                 return simplecmd();
 476         }
 477
 478         if (readtoken() != t)
 479                 synexpect(t);
 480
 481 redir:
 482         /* Now check for redirection which may follow command */
 483         checkkwd = CHKKWD | CHKALIAS;
 484         rpp = rpp2;
 485         while (readtoken() == TREDIR) {
 486                 *rpp = n2 = redirnode;
 487                 rpp = &n2->nfile.next;
 488                 parsefname();
 489         }
 490         tokpushback++;
 491         *rpp = NULL;
 492         if (redir) {
 493                 if (n1->type != NSUBSHELL) {
 494                         n2 = (union node *)stalloc(sizeof (struct nredir));
 495                         n2->type = NREDIR;
 496                         n2->nredir.linno = savelinno;
 497                         n2->nredir.n = n1;
 498                         n1 = n2;
 499                 }
 500                 n1->nredir.redirect = redir;
 501         }
 502
 503         return n1;
 504 }
 505
 506
 507 STATIC union node *
 508 simplecmd(void) {
 509         union node *args, **app;
 510         union node *n = NULL;
 511         union node *vars, **vpp;
 512         union node **rpp, *redir;
 513         int savecheckkwd;
 514         int savelinno;
 515
 516         args = NULL;
 517         app = &args;
 518         vars = NULL;
 519         vpp = &vars;
 520         redir = NULL;
 521         rpp = &redir;
 522
 523         savecheckkwd = CHKALIAS;
 524         savelinno = plinno;
 525         for (;;) {
 526                 checkkwd = savecheckkwd;
 527                 switch (readtoken()) {
 528                 case TWORD:
 529                         n = (union node *)stalloc(sizeof (struct narg));
 530                         n->type = NARG;
 531                         n->narg.text = wordtext;
 532                         n->narg.backquote = backquotelist;
 533                         if (savecheckkwd && isassignment(wordtext)) {
 534                                 *vpp = n;
 535                                 vpp = &n->narg.next;
 536                         } else {
 537                                 *app = n;
 538                                 app = &n->narg.next;
 539                                 savecheckkwd = 0;
 540                         }
 541                         break;
 542                 case TREDIR:
 543                         *rpp = n = redirnode;
 544                         rpp = &n->nfile.next;
 545                         parsefname();   /* read name of redirection file */
 546                         break;
 547                 case TLP:
 548                         if (
 549                                 args && app == &args->narg.next &&
 550                                 !vars && !redir
 551                         ) {
 552                                 struct builtincmd *bcmd;
 553                                 const char *name;
 554
 555                                 /* We have a function */
 556                                 if (readtoken() != TRP)
 557                                         synexpect(TRP);
 558                                 name = n->narg.text;
 559                                 if (
 560                                         !goodname(name) || (
 561                                                 (bcmd = find_builtin(name)) &&
 562                                                 bcmd->flags & BUILTIN_SPECIAL
 563                                         )
 564                                 )
 565                                         synerror("Bad function name");
 566                                 n->type = NDEFUN;
 567                                 checkkwd = CHKNL | CHKKWD | CHKALIAS;
 568                                 n->ndefun.text = n->narg.text;
 569                                 n->ndefun.linno = plinno;
 570                                 n->ndefun.body = command();
 571                                 return n;
 572                         }
 573                         /* fall through */
 574                 default:
 575                         tokpushback++;
 576                         goto out;
 577                 }
 578         }
 579 out:
 580         *app = NULL;
 581         *vpp = NULL;
 582         *rpp = NULL;
 583         n = (union node *)stalloc(sizeof (struct ncmd));
 584         n->type = NCMD;
 585         n->ncmd.linno = savelinno;
 586         n->ncmd.args = args;
 587         n->ncmd.assign = vars;
 588         n->ncmd.redirect = redir;
 589         return n;
 590 }
 591
 592 STATIC union node *
 593 makename(void)
 594 {
 595         union node *n;
 596
 597         n = (union node *)stalloc(sizeof (struct narg));
 598         n->type = NARG;
 599         n->narg.next = NULL;
 600         n->narg.text = wordtext;
 601         n->narg.backquote = backquotelist;
 602         return n;
 603 }
 604
 605 void fixredir(union node *n, const char *text, int err)
 606         {
 607         TRACE(("Fix redir %s %d\n", text, err));
 608         if (!err)
 609                 n->ndup.vname = NULL;
 610
 611         if (is_digit(text[0]) && text[1] == '\0')
 612                 n->ndup.dupfd = digit_val(text[0]);
 613         else if (text[0] == '-' && text[1] == '\0')
 614                 n->ndup.dupfd = -1;
 615         else {
 616
 617                 if (err)
 618                         synerror("Bad fd number");
 619                 else
 620                         n->ndup.vname = makename();
 621         }
 622 }
 623
 624
 625 STATIC void
 626 parsefname(void)
 627 {
 628         union node *n = redirnode;
 629
 630         if (n->type == NHERE)
 631                 checkkwd = CHKEOFMARK;
 632         if (readtoken() != TWORD)
 633                 synexpect(-1);
 634         if (n->type == NHERE) {
 635                 struct heredoc *here = heredoc;
 636                 struct heredoc *p;
 637
 638                 if (quoteflag == 0)
 639                         n->type = NXHERE;
 640                 TRACE(("Here document %d\n", n->type));
 641                 rmescapes(wordtext);
 642                 here->eofmark = wordtext;
 643                 here->next = NULL;
 644                 if (heredoclist == NULL)
 645                         heredoclist = here;
 646                 else {
 647                         for (p = heredoclist ; p->next ; p = p->next);
 648                         p->next = here;
 649                 }
 650         } else if (n->type == NTOFD || n->type == NFROMFD) {
 651                 fixredir(n, wordtext, 0);
 652         } else {
 653                 n->nfile.fname = makename();
 654         }
 655 }
 656
 657
 658 /*
 659  * Input any here documents.
 660  */
 661
 662 STATIC void
 663 parseheredoc(void)
 664 {
 665         struct heredoc *here;
 666         union node *n;
 667
 668         here = heredoclist;
 669         heredoclist = 0;
 670
 671         while (here) {
 672                 if (needprompt) {
 673                         setprompt(2);
 674                 }
 675                 if (here->here->type == NHERE)
 676                         readtoken1(pgetc(), SQSYNTAX, here->eofmark, here->striptabs);
 677                 else
 678                         readtoken1(pgetc_eatbnl(), DQSYNTAX, here->eofmark, here->striptabs);
 679                 n = (union node *)stalloc(sizeof (struct narg));
 680                 n->narg.type = NARG;
 681                 n->narg.next = NULL;
 682                 n->narg.text = wordtext;
 683                 n->narg.backquote = backquotelist;
 684                 here->here->nhere.doc = n;
 685                 here = here->next;
 686         }
 687 }
 688
 689 STATIC int
 690 readtoken(void)
 691 {
 692         int t;
 693         int kwd = checkkwd;
 694 #ifdef DEBUG
 695         int alreadyseen = tokpushback;
 696 #endif
 697
 698 top:
 699         t = xxreadtoken();
 700
 701         /*
 702          * eat newlines
 703          */
 704         if (kwd & CHKNL) {
 705                 while (t == TNL) {
 706                         parseheredoc();
 707                         checkkwd = 0;
 708                         t = xxreadtoken();
 709                 }
 710         }
 711
 712         kwd |= checkkwd;
 713         checkkwd = 0;
 714
 715         if (t != TWORD || quoteflag) {
 716                 goto out;
 717         }
 718
 719         /*
 720          * check for keywords
 721          */
 722         if (kwd & CHKKWD) {
 723                 const char *const *pp;
 724
 725                 if ((pp = findkwd(wordtext))) {
 726                         lasttoken = t = pp - parsekwd + KWDOFFSET;
 727                         TRACE(("keyword %s recognized\n", tokname[t]));
 728                         goto out;
 729                 }
 730         }
 731
 732         if (kwd & CHKALIAS) {
 733                 struct alias *ap;
 734                 if ((ap = lookupalias(wordtext, 1)) != NULL) {
 735                         if (*ap->val) {
 736                                 pushstring(ap->val, ap);
 737                         }
 738                         goto top;
 739                 }
 740         }
 741 out:
 742 #ifdef DEBUG
 743         if (!alreadyseen)
 744             TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
 745         else
 746             TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
 747 #endif
 748         return (t);
 749 }
 750
 751 static void nlprompt(void)
 752 {
 753         plinno++;
 754         if (doprompt)
 755                 setprompt(2);
 756 }
 757
 758 static void nlnoprompt(void)
 759 {
 760         plinno++;
 761         needprompt = doprompt;
 762 }
 763
 764
 765 /*
 766  * Read the next input token.
 767  * If the token is a word, we set backquotelist to the list of cmds in
 768  *      backquotes.  We set quoteflag to true if any part of the word was
 769  *      quoted.
 770  * If the token is TREDIR, then we set redirnode to a structure containing
 771  *      the redirection.
 772  *
 773  * [Change comment:  here documents and internal procedures]
 774  * [Readtoken shouldn't have any arguments.  Perhaps we should make the
 775  *  word parsing code into a separate routine.  In this case, readtoken
 776  *  doesn't need to have any internal procedures, but parseword does.
 777  *  We could also make parseoperator in essence the main routine, and
 778  *  have parseword (readtoken1?) handle both words and redirection.]
 779  */
 780
 781 #define RETURN(token)   return lasttoken = token
 782
 783 STATIC int
 784 xxreadtoken(void)
 785 {
 786         int c;
 787
 788         if (tokpushback) {
 789                 tokpushback = 0;
 790                 return lasttoken;
 791         }
 792         if (needprompt) {
 793                 setprompt(2);
 794         }
 795         for (;;) {      /* until token or start of word found */
 796                 c = pgetc_eatbnl();
 797                 switch (c) {
 798                 case ' ': case '\t':
 799                         continue;
 800                 case '#':
 801                         while ((c = pgetc()) != '\n' && c != PEOF);
 802                         pungetc();
 803                         continue;
 804                 case '\n':
 805                         nlnoprompt();
 806                         RETURN(TNL);
 807                 case PEOF:
 808                         RETURN(TEOF);
 809                 case '&':
 810                         if (pgetc_eatbnl() == '&')
 811                                 RETURN(TAND);
 812                         pungetc();
 813                         RETURN(TBACKGND);
 814                 case '|':
 815                         if (pgetc_eatbnl() == '|')
 816                                 RETURN(TOR);
 817                         pungetc();
 818                         RETURN(TPIPE);
 819                 case ';':
 820                         if (pgetc_eatbnl() == ';')
 821                                 RETURN(TENDCASE);
 822                         pungetc();
 823                         RETURN(TSEMI);
 824                 case '(':
 825                         RETURN(TLP);
 826                 case ')':
 827                         RETURN(TRP);
 828                 }
 829                 break;
 830         }
 831         return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
 832 #undef RETURN
 833 }
 834
 835 static int pgetc_eatbnl(void)
 836 {
 837         int c;
 838
 839         while ((c = pgetc()) == '\\') {
 840                 if (pgetc() != '\n') {
 841                         pungetc();
 842                         break;
 843                 }
 844
 845                 nlprompt();
 846         }
 847
 848         return c;
 849 }
 850
 851 static int pgetc_top(struct synstack *stack)
 852 {
 853         return stack->syntax == SQSYNTAX ? pgetc() : pgetc_eatbnl();
 854 }
 855
 856 static void synstack_push(struct synstack **stack, struct synstack *next,
 857                           const char *syntax)
 858 {
 859         memset(next, 0, sizeof(*next));
 860         next->syntax = syntax;
 861         next->next = *stack;
 862         (*stack)->prev = next;
 863         *stack = next;
 864 }
 865
 866 static void synstack_pop(struct synstack **stack)
 867 {
 868         *stack = (*stack)->next;
 869 }
 870
 871
 872
 873 /*
 874  * If eofmark is NULL, read a word or a redirection symbol.  If eofmark
 875  * is not NULL, read a here document.  In the latter case, eofmark is the
 876  * word which marks the end of the document and striptabs is true if
 877  * leading tabs should be stripped from the document.  The argument firstc
 878  * is the first character of the input token or document.
 879  *
 880  * Because C does not have internal subroutines, I have simulated them
 881  * using goto's to implement the subroutine linkage.  The following macros
 882  * will run code that appears at the end of readtoken1.
 883  */
 884
 885 #define CHECKEND()      {goto checkend; checkend_return:;}
 886 #define PARSEREDIR()    {goto parseredir; parseredir_return:;}
 887 #define PARSESUB()      {goto parsesub; parsesub_return:;}
 888 #define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;}
 889 #define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;}
 890 #define PARSEARITH()    {goto parsearith; parsearith_return:;}
 891
 892 STATIC int
 893 readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs)
 894 {
 895         int c = firstc;
 896         char *out;
 897         size_t len;
 898         struct nodelist *bqlist;
 899         int quotef;
 900         int oldstyle;
 901         /* syntax stack */
 902         struct synstack synbase = { .syntax = syntax };
 903         struct synstack *synstack = &synbase;
 904
 905         if (syntax == DQSYNTAX)
 906                 synstack->dblquote = 1;
 907         quotef = 0;
 908         bqlist = NULL;
 909
 910         STARTSTACKSTR(out);
 911         loop: { /* for each line, until end of word */
 912 #if ATTY
 913                 if (c == '\034' && doprompt
 914                  && attyset() && ! equal(termval(), "emacs")) {
 915                         attyline();
 916                         if (synstack->syntax == BASESYNTAX)
 917                                 return readtoken();
 918                         c = pgetc_top(synstack);
 919                         goto loop;
 920                 }
 921 #endif
 922                 CHECKEND();     /* set c to PEOF if at end of here document */
 923                 for (;;) {      /* until end of line or end of word */
 924                         CHECKSTRSPACE(4, out);  /* permit 4 calls to USTPUTC */
 925                         switch(synstack->syntax[c]) {
 926                         case CNL:       /* '\n' */
 927                                 if (synstack->syntax == BASESYNTAX &&
 928                                     !synstack->varnest)
 929                                         goto endword;   /* exit outer loop */
 930                                 USTPUTC(c, out);
 931                                 nlprompt();
 932                                 c = pgetc_top(synstack);
 933                                 goto loop;              /* continue outer loop */
 934                         case CWORD:
 935                                 USTPUTC(c, out);
 936                                 break;
 937                         case CCTL:
 938                                 if ((!eofmark) | synstack->dblquote |
 939                                     synstack->varnest)
 940                                         USTPUTC(CTLESC, out);
 941                                 USTPUTC(c, out);
 942                                 break;
 943                         /* backslash */
 944                         case CBACK:
 945                                 c = pgetc();
 946                                 if (c == PEOF) {
 947                                         USTPUTC(CTLESC, out);
 948                                         USTPUTC('\\', out);
 949                                         pungetc();
 950                                 } else {
 951                                         if (
 952                                                 synstack->dblquote &&
 953                                                 c != '\\' && c != '`' &&
 954                                                 c != '$' && (
 955                                                         c != '"' ||
 956                                                         (eofmark != NULL &&
 957                                                          !synstack->varnest)
 958                                                 ) && (
 959                                                         c != '}' ||
 960                                                         !synstack->varnest
 961                                                 )
 962                                         ) {
 963                                                 USTPUTC(CTLESC, out);
 964                                                 USTPUTC('\\', out);
 965                                         }
 966                                         USTPUTC(CTLESC, out);
 967                                         USTPUTC(c, out);
 968                                         quotef++;
 969                                 }
 970                                 break;
 971                         case CSQUOTE:
 972                                 synstack->syntax = SQSYNTAX;
 973 quotemark:
 974                                 if (eofmark == NULL) {
 975                                         USTPUTC(CTLQUOTEMARK, out);
 976                                 }
 977                                 break;
 978                         case CDQUOTE:
 979                                 synstack->syntax = DQSYNTAX;
 980                                 synstack->dblquote = 1;
 981 toggledq:
 982                                 if (synstack->varnest)
 983                                         synstack->innerdq ^= 1;
 984                                 goto quotemark;
 985                         case CENDQUOTE:
 986                                 if (eofmark && !synstack->varnest) {
 987                                         USTPUTC(c, out);
 988                                         break;
 989                                 }
 990
 991                                 if (synstack->dqvarnest == 0) {
 992                                         synstack->syntax = BASESYNTAX;
 993                                         synstack->dblquote = 0;
 994                                 }
 995
 996                                 quotef++;
 997
 998                                 if (c == '"')
 999                                         goto toggledq;
1000
1001                                 goto quotemark;
1002                         case CVAR:      /* '$' */
1003                                 PARSESUB();             /* parse substitution */
1004                                 break;
1005                         case CENDVAR:   /* '}' */
1006                                 if (!synstack->innerdq &&
1007                                     synstack->varnest > 0) {
1008                                         if (!--synstack->varnest &&
1009                                             synstack->varpushed)
1010                                                 synstack_pop(&synstack);
1011                                         else if (synstack->dqvarnest > 0)
1012                                                 synstack->dqvarnest--;
1013                                         USTPUTC(CTLENDVAR, out);
1014                                 } else {
1015                                         USTPUTC(c, out);
1016                                 }
1017                                 break;
1018                         case CLP:       /* '(' in arithmetic */
1019                                 synstack->parenlevel++;
1020                                 USTPUTC(c, out);
1021                                 break;
1022                         case CRP:       /* ')' in arithmetic */
1023                                 if (synstack->parenlevel > 0) {
1024                                         USTPUTC(c, out);
1025                                         --synstack->parenlevel;
1026                                 } else {
1027                                         if (pgetc_eatbnl() == ')') {
1028                                                 USTPUTC(CTLENDARI, out);
1029                                                 synstack_pop(&synstack);
1030                                         } else {
1031                                                 /*
1032                                                  * unbalanced parens
1033                                                  *  (don't 2nd guess - no error)
1034                                                  */
1035                                                 pungetc();
1036                                                 USTPUTC(')', out);
1037                                         }
1038                                 }
1039                                 break;
1040                         case CBQUOTE:   /* '`' */
1041                                 if (checkkwd & CHKEOFMARK) {
1042                                         USTPUTC('`', out);
1043                                         break;
1044                                 }
1045
1046                                 PARSEBACKQOLD();
1047                                 break;
1048                         case CEOF:
1049                                 goto endword;           /* exit outer loop */
1050                         default:
1051                                 if (synstack->varnest == 0)
1052                                         goto endword;   /* exit outer loop */
1053                                 USTPUTC(c, out);
1054                         }
1055                         c = pgetc_top(synstack);
1056                 }
1057         }
1058 endword:
1059         if (synstack->syntax == ARISYNTAX)
1060                 synerror("Missing '))'");
1061         if (synstack->syntax != BASESYNTAX && eofmark == NULL)
1062                 synerror("Unterminated quoted string");
1063         if (synstack->varnest != 0) {
1064                 /* { */
1065                 synerror("Missing '}'");
1066         }
1067         USTPUTC('\0', out);
1068         len = out - (char *)stackblock();
1069         out = stackblock();
1070         if (eofmark == NULL) {
1071                 if ((c == '>' || c == '<')
1072                  && quotef == 0
1073                  && len <= 2
1074                  && (*out == '\0' || is_digit(*out))) {
1075                         PARSEREDIR();
1076                         return lasttoken = TREDIR;
1077                 } else {
1078                         pungetc();
1079                 }
1080         }
1081         quoteflag = quotef;
1082         backquotelist = bqlist;
1083         grabstackblock(len);
1084         wordtext = out;
1085         return lasttoken = TWORD;
1086 /* end of readtoken routine */
1087
1088
1089
1090 /*
1091  * Check to see whether we are at the end of the here document.  When this
1092  * is called, c is set to the first character of the next input line.  If
1093  * we are at the end of the here document, this routine sets the c to PEOF.
1094  */
1095
1096 checkend: {
1097         if (realeofmark(eofmark)) {
1098                 int markloc;
1099                 char *p;
1100
1101                 if (striptabs) {
1102                         while (c == '\t')
1103                                 c = pgetc();
1104                 }
1105
1106                 markloc = out - (char *)stackblock();
1107                 for (p = eofmark; STPUTC(c, out), *p; p++) {
1108                         if (c != *p)
1109                                 goto more_heredoc;
1110
1111                         c = pgetc();
1112                 }
1113
1114                 if (c == '\n' || c == PEOF) {
1115                         c = PEOF;
1116                         nlnoprompt();
1117                 } else {
1118                         int len;
1119
1120 more_heredoc:
1121                         p = (char *)stackblock() + markloc + 1;
1122                         len = out - p;
1123
1124                         if (len) {
1125                                 len -= c < 0;
1126                                 c = p[-1];
1127
1128                                 if (len) {
1129                                         char *str;
1130
1131                                         str = alloca(len + 1);
1132                                         *(char *)mempcpy(str, p, len) = 0;
1133
1134                                         pushstring(str, NULL);
1135                                 }
1136                         }
1137                 }
1138
1139                 STADJUST((char *)stackblock() + markloc - out, out);
1140         }
1141         goto checkend_return;
1142 }
1143
1144
1145 /*
1146  * Parse a redirection operator.  The variable "out" points to a string
1147  * specifying the fd to be redirected.  The variable "c" contains the
1148  * first character of the redirection operator.
1149  */
1150
1151 parseredir: {
1152         char fd = *out;
1153         union node *np;
1154
1155         np = (union node *)stalloc(sizeof (struct nfile));
1156         if (c == '>') {
1157                 np->nfile.fd = 1;
1158                 c = pgetc_eatbnl();
1159                 if (c == '>')
1160                         np->type = NAPPEND;
1161                 else if (c == '|')
1162                         np->type = NCLOBBER;
1163                 else if (c == '&')
1164                         np->type = NTOFD;
1165                 else {
1166                         np->type = NTO;
1167                         pungetc();
1168                 }
1169         } else {        /* c == '<' */
1170                 np->nfile.fd = 0;
1171                 switch (c = pgetc_eatbnl()) {
1172                 case '<':
1173                         if (sizeof (struct nfile) != sizeof (struct nhere)) {
1174                                 np = (union node *)stalloc(sizeof (struct nhere));
1175                                 np->nfile.fd = 0;
1176                         }
1177                         np->type = NHERE;
1178                         heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc));
1179                         heredoc->here = np;
1180                         if ((c = pgetc_eatbnl()) == '-') {
1181                                 heredoc->striptabs = 1;
1182                         } else {
1183                                 heredoc->striptabs = 0;
1184                                 pungetc();
1185                         }
1186                         break;
1187
1188                 case '&':
1189                         np->type = NFROMFD;
1190                         break;
1191
1192                 case '>':
1193                         np->type = NFROMTO;
1194                         break;
1195
1196                 default:
1197                         np->type = NFROM;
1198                         pungetc();
1199                         break;
1200                 }
1201         }
1202         if (fd != '\0')
1203                 np->nfile.fd = digit_val(fd);
1204         redirnode = np;
1205         goto parseredir_return;
1206 }
1207
1208
1209 /*
1210  * Parse a substitution.  At this point, we have read the dollar sign
1211  * and nothing else.
1212  */
1213
1214 parsesub: {
1215         int subtype;
1216         int typeloc;
1217         char *p;
1218         static const char types[] = "}-+?=";
1219
1220         c = pgetc_eatbnl();
1221         if (
1222                 (checkkwd & CHKEOFMARK) ||
1223                 (c != '(' && c != '{' && !is_name(c) && !is_special(c))
1224         ) {
1225                 USTPUTC('$', out);
1226                 pungetc();
1227         } else if (c == '(') {  /* $(command) or $((arith)) */
1228                 if (pgetc_eatbnl() == '(') {
1229                         PARSEARITH();
1230                 } else {
1231                         pungetc();
1232                         PARSEBACKQNEW();
1233                 }
1234         } else {
1235                 const char *newsyn = synstack->syntax;
1236
1237                 USTPUTC(CTLVAR, out);
1238                 typeloc = out - (char *)stackblock();
1239                 STADJUST(1, out);
1240                 subtype = VSNORMAL;
1241                 if (likely(c == '{')) {
1242                         c = pgetc_eatbnl();
1243                         subtype = 0;
1244                 }
1245 varname:
1246                 if (is_name(c)) {
1247                         do {
1248                                 STPUTC(c, out);
1249                                 c = pgetc_eatbnl();
1250                         } while (is_in_name(c));
1251                 } else if (is_digit(c)) {
1252                         do {
1253                                 STPUTC(c, out);
1254                                 c = pgetc_eatbnl();
1255                         } while ((subtype <= 0 || subtype >= VSLENGTH) &&
1256                                  is_digit(c));
1257                 } else if (c != '}') {
1258                         int cc = c;
1259
1260                         c = pgetc_eatbnl();
1261
1262                         if (!subtype && cc == '#') {
1263                                 subtype = VSLENGTH;
1264
1265                                 if (c == '_' || isalnum(c))
1266                                         goto varname;
1267
1268                                 cc = c;
1269                                 c = pgetc_eatbnl();
1270                                 if (cc == '}' || c != '}') {
1271                                         pungetc();
1272                                         subtype = 0;
1273                                         c = cc;
1274                                         cc = '#';
1275                                 }
1276                         }
1277
1278                         if (!is_special(cc)) {
1279                                 if (subtype == VSLENGTH)
1280                                         subtype = 0;
1281                                 goto badsub;
1282                         }
1283
1284                         USTPUTC(cc, out);
1285                 } else
1286                         goto badsub;
1287
1288                 if (subtype == 0) {
1289                         int cc = c;
1290
1291                         switch (c) {
1292                         case ':':
1293                                 subtype = VSNUL;
1294                                 c = pgetc_eatbnl();
1295                                 /*FALLTHROUGH*/
1296                         default:
1297                                 p = strchr(types, c);
1298                                 if (p == NULL)
1299                                         break;
1300                                 subtype |= p - types + VSNORMAL;
1301                                 break;
1302                         case '%':
1303                         case '#':
1304                                 subtype = c == '#' ? VSTRIMLEFT :
1305                                                      VSTRIMRIGHT;
1306                                 c = pgetc_eatbnl();
1307                                 if (c == cc)
1308                                         subtype++;
1309                                 else
1310                                         pungetc();
1311
1312                                 newsyn = BASESYNTAX;
1313                                 break;
1314                         }
1315                 } else {
1316                         if (subtype == VSLENGTH && c != '}')
1317                                 subtype = 0;
1318 badsub:
1319                         pungetc();
1320                 }
1321
1322                 if (newsyn == ARISYNTAX)
1323                         newsyn = DQSYNTAX;
1324
1325                 if ((newsyn != synstack->syntax || synstack->innerdq) &&
1326                     subtype != VSNORMAL) {
1327                         synstack_push(&synstack,
1328                                       synstack->prev ?:
1329                                       alloca(sizeof(*synstack)),
1330                                       newsyn);
1331
1332                         synstack->varpushed++;
1333                         synstack->dblquote = newsyn != BASESYNTAX;
1334                 }
1335
1336                 *((char *)stackblock() + typeloc) = subtype | VSBIT;
1337                 if (subtype != VSNORMAL) {
1338                         synstack->varnest++;
1339                         if (synstack->dblquote)
1340                                 synstack->dqvarnest++;
1341                 }
1342                 STPUTC('=', out);
1343         }
1344         goto parsesub_return;
1345 }
1346
1347
1348 /*
1349  * Called to parse command substitutions.  Newstyle is set if the command
1350  * is enclosed inside $(...); nlpp is a pointer to the head of the linked
1351  * list of commands (passed by reference), and savelen is the number of
1352  * characters on the top of the stack which must be preserved.
1353  */
1354
1355 parsebackq: {
1356         struct nodelist **nlpp;
1357         union node *n;
1358         char *str;
1359         size_t savelen;
1360         struct heredoc *saveheredoclist;
1361         int uninitialized_var(saveprompt);
1362
1363         str = NULL;
1364         savelen = out - (char *)stackblock();
1365         if (savelen > 0) {
1366                 str = alloca(savelen);
1367                 memcpy(str, stackblock(), savelen);
1368         }
1369         if (oldstyle) {
1370                 /* We must read until the closing backquote, giving special
1371                    treatment to some slashes, and then push the string and
1372                    reread it as input, interpreting it normally.  */
1373                 char *pout;
1374                 int pc;
1375                 size_t psavelen;
1376                 char *pstr;
1377
1378
1379                 STARTSTACKSTR(pout);
1380                 for (;;) {
1381                         if (needprompt) {
1382                                 setprompt(2);
1383                         }
1384                         switch (pc = pgetc_eatbnl()) {
1385                         case '`':
1386                                 goto done;
1387
1388                         case '\\':
1389                                 pc = pgetc();
1390                                 if (pc != '\\' && pc != '`' && pc != '$'
1391                                     && (!synstack->dblquote || pc != '"'))
1392                                         STPUTC('\\', pout);
1393                                 break;
1394
1395                         case PEOF:
1396                                 synerror("EOF in backquote substitution");
1397
1398                         case '\n':
1399                                 nlnoprompt();
1400                                 break;
1401
1402                         default:
1403                                 break;
1404                         }
1405                         STPUTC(pc, pout);
1406                 }
1407 done:
1408                 STPUTC('\0', pout);
1409                 psavelen = pout - (char *)stackblock();
1410                 if (psavelen > 0) {
1411                         pstr = grabstackstr(pout);
1412                         setinputstring(pstr);
1413                 }
1414         }
1415         nlpp = &bqlist;
1416         while (*nlpp)
1417                 nlpp = &(*nlpp)->next;
1418         *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist));
1419         (*nlpp)->next = NULL;
1420
1421         saveheredoclist = heredoclist;
1422         heredoclist = NULL;
1423
1424         if (oldstyle) {
1425                 saveprompt = doprompt;
1426                 doprompt = 0;
1427         }
1428
1429         n = list(2);
1430
1431         if (oldstyle)
1432                 doprompt = saveprompt;
1433         else {
1434                 if (readtoken() != TRP)
1435                         synexpect(TRP);
1436                 setinputstring(nullstr);
1437         }
1438
1439         parseheredoc();
1440         heredoclist = saveheredoclist;
1441
1442         (*nlpp)->n = n;
1443         /* Start reading from old file again. */
1444         popfile();
1445         /* Ignore any pushed back tokens left from the backquote parsing. */
1446         if (oldstyle)
1447                 tokpushback = 0;
1448         out = growstackto(savelen + 1);
1449         if (str) {
1450                 memcpy(out, str, savelen);
1451                 STADJUST(savelen, out);
1452         }
1453         USTPUTC(CTLBACKQ, out);
1454         if (oldstyle)
1455                 goto parsebackq_oldreturn;
1456         else
1457                 goto parsebackq_newreturn;
1458 }
1459
1460 /*
1461  * Parse an arithmetic expansion (indicate start of one and set state)
1462  */
1463 parsearith: {
1464
1465         synstack_push(&synstack,
1466                       synstack->prev ?: alloca(sizeof(*synstack)),
1467                       ARISYNTAX);
1468         synstack->dblquote = 1;
1469         USTPUTC(CTLARI, out);
1470         goto parsearith_return;
1471 }
1472
1473 } /* end of readtoken */
1474
1475
1476
1477 #ifdef mkinit
1478 INCLUDE "parser.h"
1479 #endif
1480
1481
1482 /*
1483  * Return of a legal variable name (a letter or underscore followed by zero or
1484  * more letters, underscores, and digits).
1485  */
1486
1487 char *
1488 endofname(const char *name)
1489         {
1490         char *p;
1491
1492         p = (char *) name;
1493         if (! is_name(*p))
1494                 return p;
1495         while (*++p) {
1496                 if (! is_in_name(*p))
1497                         break;
1498         }
1499         return p;
1500 }
1501
1502
1503 /*
1504  * Called when an unexpected token is read during the parse.  The argument
1505  * is the token that is expected, or -1 if more than one type of token can
1506  * occur at this point.
1507  */
1508
1509 STATIC void
1510 synexpect(int token)
1511 {
1512         char msg[64];
1513
1514         if (token >= 0) {
1515                 fmtstr(msg, 64, "%s unexpected (expecting %s)",
1516                         tokname[lasttoken], tokname[token]);
1517         } else {
1518                 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]);
1519         }
1520         synerror(msg);
1521         /* NOTREACHED */
1522 }
1523
1524
1525 STATIC void
1526 synerror(const char *msg)
1527 {
1528         errlinno = plinno;
1529         sh_error("Syntax error: %s", msg);
1530         /* NOTREACHED */
1531 }
1532
1533 STATIC void
1534 setprompt(int which)
1535 {
1536         struct stackmark smark;
1537         int show;
1538
1539         needprompt = 0;
1540         whichprompt = which;
1541
1542 #ifdef SMALL
1543         show = 1;
1544 #else
1545         show = !el;
1546 #endif
1547         if (show) {
1548                 pushstackmark(&smark, stackblocksize());
1549                 out2str(getprompt(NULL));
1550                 popstackmark(&smark);
1551         }
1552 }
1553
1554 const char *
1555 expandstr(const char *ps)
1556 {
1557         struct parsefile *file_stop;
1558         struct jmploc *volatile savehandler;
1559         struct heredoc *saveheredoclist;
1560         const char *result;
1561         int saveprompt;
1562         struct jmploc jmploc;
1563         union node n;
1564         int err;
1565
1566         file_stop = parsefile;
1567
1568         /* XXX Fix (char *) cast. */
1569         setinputstring((char *)ps);
1570
1571         saveheredoclist = heredoclist;
1572         heredoclist = NULL;
1573         saveprompt = doprompt;
1574         doprompt = 0;
1575         result = ps;
1576         savehandler = handler;
1577         if (unlikely(err = setjmp(jmploc.loc)))
1578                 goto out;
1579         handler = &jmploc;
1580
1581         readtoken1(pgetc_eatbnl(), DQSYNTAX, FAKEEOFMARK, 0);
1582
1583         n.narg.type = NARG;
1584         n.narg.next = NULL;
1585         n.narg.text = wordtext;
1586         n.narg.backquote = backquotelist;
1587
1588         expandarg(&n, NULL, EXP_QUOTED);
1589         result = stackblock();
1590
1591 out:
1592         restore_handler_expandarg(savehandler, err);
1593
1594         doprompt = saveprompt;
1595         unwindfiles(file_stop);
1596         heredoclist = saveheredoclist;
1597
1598         return result;
1599 }
1600
1601 /*
1602  * called by editline -- any expansions to the prompt
1603  *    should be added here.
1604  */
1605 const char *
1606 getprompt(void *unused)
1607 {
1608         const char *prompt;
1609
1610         switch (whichprompt) {
1611         default:
1612 #ifdef DEBUG
1613                 return "<internal prompt error>";
1614 #endif
1615         case 0:
1616                 return nullstr;
1617         case 1:
1618                 prompt = ps1val();
1619                 break;
1620         case 2:
1621                 prompt = ps2val();
1622                 break;
1623         }
1624
1625         return expandstr(prompt);
1626 }
1627
1628 const char *const *
1629 findkwd(const char *s)
1630 {
1631         return findstring(
1632                 s, parsekwd, sizeof(parsekwd) / sizeof(const char *)
1633         );
1634 }