1 /* $OpenBSD: syn.c,v 1.30 2015/09/01 13:12:31 tedu Exp $ */
2
3 /*-
4 * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009,
5 * 2011, 2012, 2013, 2014, 2015, 2016, 2017,
6 * 2018
7 * mirabilos <m@mirbsd.org>
8 *
9 * Provided that these terms and disclaimer and all copyright notices
10 * are retained or reproduced in an accompanying document, permission
11 * is granted to deal in this work without restriction, including un-
12 * limited rights to use, publicly perform, distribute, sell, modify,
13 * merge, give away, or sublicence.
14 *
15 * This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
16 * the utmost extent permitted by applicable law, neither express nor
17 * implied; without malicious intent or gross negligence. In no event
18 * may a licensor, author or contributor be held liable for indirect,
19 * direct, other damage, loss, or other issues arising in any way out
20 * of dealing in the work, even if advised of the possibility of such
21 * damage or existence of a defect, except proven that it results out
22 * of said person's immediate fault when using the work as intended.
23 */
24
25 #include "sh.h"
26
27 __RCSID("$MirOS: src/bin/mksh/syn.c,v 1.127 2018/01/14 00:22:30 tg Exp $");
28
29 struct nesting_state {
30 int start_token; /* token than began nesting (eg, FOR) */
31 int start_line; /* line nesting began on */
32 };
33
34 struct yyrecursive_state {
35 struct ioword *old_heres[HERES];
36 struct yyrecursive_state *next;
37 struct ioword **old_herep;
38 int old_symbol;
39 unsigned int old_nesting_type;
40 bool old_reject;
41 };
42
43 static void yyparse(bool);
44 static struct op *pipeline(int, int);
45 static struct op *andor(int);
46 static struct op *c_list(int, bool);
47 static struct ioword *synio(int);
48 static struct op *nested(int, int, int, int);
49 static struct op *get_command(int, int);
50 static struct op *dogroup(int);
51 static struct op *thenpart(int);
52 static struct op *elsepart(int);
53 static struct op *caselist(int);
54 static struct op *casepart(int, int);
55 static struct op *function_body(char *, int, bool);
56 static char **wordlist(int);
57 static struct op *block(int, struct op *, struct op *);
58 static struct op *newtp(int);
59 static void syntaxerr(const char *) MKSH_A_NORETURN;
60 static void nesting_push(struct nesting_state *, int);
61 static void nesting_pop(struct nesting_state *);
62 static int inalias(struct source *) MKSH_A_PURE;
63 static Test_op dbtestp_isa(Test_env *, Test_meta);
64 static const char *dbtestp_getopnd(Test_env *, Test_op, bool);
65 static int dbtestp_eval(Test_env *, Test_op, const char *,
66 const char *, bool);
67 static void dbtestp_error(Test_env *, int, const char *) MKSH_A_NORETURN;
68
69 static struct op *outtree; /* yyparse output */
70 static struct nesting_state nesting; /* \n changed to ; */
71
72 static bool reject; /* token(cf) gets symbol again */
73 static int symbol; /* yylex value */
74
75 #define REJECT (reject = true)
76 #define ACCEPT (reject = false)
77 #define token(cf) ((reject) ? (ACCEPT, symbol) : (symbol = yylex(cf)))
78 #define tpeek(cf) ((reject) ? (symbol) : (REJECT, symbol = yylex(cf)))
79 #define musthave(c,cf) do { \
80 if ((unsigned int)token(cf) != (unsigned int)(c)) \
81 syntaxerr(NULL); \
82 } while (/* CONSTCOND */ 0)
83
84 static const char Tcbrace[] = "}";
85 static const char Tesac[] = "esac";
86
87 static void
yyparse(bool doalias)88 yyparse(bool doalias)
89 {
90 int c;
91
92 ACCEPT;
93
94 outtree = c_list(doalias ? ALIAS : 0, source->type == SSTRING);
95 c = tpeek(0);
96 if (c == 0 && !outtree)
97 outtree = newtp(TEOF);
98 else if (!cinttype(c, C_LF | C_NUL))
99 syntaxerr(NULL);
100 }
101
102 static struct op *
pipeline(int cf,int sALIAS)103 pipeline(int cf, int sALIAS)
104 {
105 struct op *t, *p, *tl = NULL;
106
107 t = get_command(cf, sALIAS);
108 if (t != NULL) {
109 while (token(0) == '|') {
110 if ((p = get_command(CONTIN, sALIAS)) == NULL)
111 syntaxerr(NULL);
112 if (tl == NULL)
113 t = tl = block(TPIPE, t, p);
114 else
115 tl = tl->right = block(TPIPE, tl->right, p);
116 }
117 REJECT;
118 }
119 return (t);
120 }
121
122 static struct op *
andor(int sALIAS)123 andor(int sALIAS)
124 {
125 struct op *t, *p;
126 int c;
127
128 t = pipeline(0, sALIAS);
129 if (t != NULL) {
130 while ((c = token(0)) == LOGAND || c == LOGOR) {
131 if ((p = pipeline(CONTIN, sALIAS)) == NULL)
132 syntaxerr(NULL);
133 t = block(c == LOGAND? TAND: TOR, t, p);
134 }
135 REJECT;
136 }
137 return (t);
138 }
139
140 static struct op *
c_list(int sALIAS,bool multi)141 c_list(int sALIAS, bool multi)
142 {
143 struct op *t = NULL, *p, *tl = NULL;
144 int c;
145 bool have_sep;
146
147 while (/* CONSTCOND */ 1) {
148 p = andor(sALIAS);
149 /*
150 * Token has always been read/rejected at this point, so
151 * we don't worry about what flags to pass token()
152 */
153 c = token(0);
154 have_sep = true;
155 if (c == '\n' && (multi || inalias(source))) {
156 if (!p)
157 /* ignore blank lines */
158 continue;
159 } else if (!p)
160 break;
161 else if (c == '&' || c == COPROC)
162 p = block(c == '&' ? TASYNC : TCOPROC, p, NULL);
163 else if (c != ';')
164 have_sep = false;
165 if (!t)
166 t = p;
167 else if (!tl)
168 t = tl = block(TLIST, t, p);
169 else
170 tl = tl->right = block(TLIST, tl->right, p);
171 if (!have_sep)
172 break;
173 }
174 REJECT;
175 return (t);
176 }
177
178 static const char IONDELIM_delim[] = { CHAR, '<', CHAR, '<', EOS };
179
180 static struct ioword *
synio(int cf)181 synio(int cf)
182 {
183 struct ioword *iop;
184 static struct ioword *nextiop;
185 bool ishere;
186
187 if (nextiop != NULL) {
188 iop = nextiop;
189 nextiop = NULL;
190 return (iop);
191 }
192
193 if (tpeek(cf) != REDIR)
194 return (NULL);
195 ACCEPT;
196 iop = yylval.iop;
197 ishere = (iop->ioflag & IOTYPE) == IOHERE;
198 if (iop->ioflag & IOHERESTR) {
199 musthave(LWORD, 0);
200 } else if (ishere && tpeek(HEREDELIM) == '\n') {
201 ACCEPT;
202 yylval.cp = wdcopy(IONDELIM_delim, ATEMP);
203 iop->ioflag |= IOEVAL | IONDELIM;
204 } else
205 musthave(LWORD, ishere ? HEREDELIM : 0);
206 if (ishere) {
207 iop->delim = yylval.cp;
208 if (*ident != 0 && !(iop->ioflag & IOHERESTR)) {
209 /* unquoted */
210 iop->ioflag |= IOEVAL;
211 }
212 if (herep > &heres[HERES - 1])
213 yyerror(Tf_toomany, "<<");
214 *herep++ = iop;
215 } else
216 iop->ioname = yylval.cp;
217
218 if (iop->ioflag & IOBASH) {
219 char *cp;
220
221 nextiop = alloc(sizeof(*iop), ATEMP);
222 nextiop->ioname = cp = alloc(3, ATEMP);
223 *cp++ = CHAR;
224 *cp++ = digits_lc[iop->unit % 10];
225 *cp = EOS;
226
227 iop->ioflag &= ~IOBASH;
228 nextiop->unit = 2;
229 nextiop->ioflag = IODUP;
230 nextiop->delim = NULL;
231 nextiop->heredoc = NULL;
232 }
233 return (iop);
234 }
235
236 static struct op *
nested(int type,int smark,int emark,int sALIAS)237 nested(int type, int smark, int emark, int sALIAS)
238 {
239 struct op *t;
240 struct nesting_state old_nesting;
241
242 nesting_push(&old_nesting, smark);
243 t = c_list(sALIAS, true);
244 musthave(emark, KEYWORD|sALIAS);
245 nesting_pop(&old_nesting);
246 return (block(type, t, NULL));
247 }
248
249 static const char builtin_cmd[] = {
250 QCHAR, '\\', CHAR, 'b', CHAR, 'u', CHAR, 'i',
251 CHAR, 'l', CHAR, 't', CHAR, 'i', CHAR, 'n', EOS
252 };
253 static const char let_cmd[] = {
254 CHAR, 'l', CHAR, 'e', CHAR, 't', EOS
255 };
256 static const char setA_cmd0[] = {
257 CHAR, 's', CHAR, 'e', CHAR, 't', EOS
258 };
259 static const char setA_cmd1[] = {
260 CHAR, '-', CHAR, 'A', EOS
261 };
262 static const char setA_cmd2[] = {
263 CHAR, '-', CHAR, '-', EOS
264 };
265
266 static struct op *
get_command(int cf,int sALIAS)267 get_command(int cf, int sALIAS)
268 {
269 struct op *t;
270 int c, iopn = 0, syniocf, lno;
271 struct ioword *iop, **iops;
272 XPtrV args, vars;
273 struct nesting_state old_nesting;
274
275 /* NUFILE is small enough to leave this addition unchecked */
276 iops = alloc2((NUFILE + 1), sizeof(struct ioword *), ATEMP);
277 XPinit(args, 16);
278 XPinit(vars, 16);
279
280 syniocf = KEYWORD|sALIAS;
281 switch (c = token(cf|KEYWORD|sALIAS|CMDASN)) {
282 default:
283 REJECT;
284 afree(iops, ATEMP);
285 XPfree(args);
286 XPfree(vars);
287 /* empty line */
288 return (NULL);
289
290 case LWORD:
291 case REDIR:
292 REJECT;
293 syniocf &= ~(KEYWORD|sALIAS);
294 t = newtp(TCOM);
295 t->lineno = source->line;
296 goto get_command_start;
297 while (/* CONSTCOND */ 1) {
298 bool check_decl_utility;
299
300 if (XPsize(args) == 0) {
301 get_command_start:
302 check_decl_utility = true;
303 cf = sALIAS | CMDASN;
304 } else if (t->u.evalflags)
305 cf = CMDWORD | CMDASN;
306 else
307 cf = CMDWORD;
308 switch (tpeek(cf)) {
309 case REDIR:
310 while ((iop = synio(cf)) != NULL) {
311 if (iopn >= NUFILE)
312 yyerror(Tf_toomany,
313 Tredirection);
314 iops[iopn++] = iop;
315 }
316 break;
317
318 case LWORD:
319 ACCEPT;
320 if (check_decl_utility) {
321 struct tbl *tt = get_builtin(ident);
322 uint32_t flag;
323
324 flag = tt ? tt->flag : 0;
325 if (flag & DECL_UTIL)
326 t->u.evalflags = DOVACHECK;
327 if (!(flag & DECL_FWDR))
328 check_decl_utility = false;
329 }
330 if ((XPsize(args) == 0 || Flag(FKEYWORD)) &&
331 is_wdvarassign(yylval.cp))
332 XPput(vars, yylval.cp);
333 else
334 XPput(args, yylval.cp);
335 break;
336
337 case ORD('(' /*)*/):
338 if (XPsize(args) == 0 && XPsize(vars) == 1 &&
339 is_wdvarassign(yylval.cp)) {
340 char *tcp;
341
342 /* wdarrassign: foo=(bar) */
343 ACCEPT;
344
345 /* manipulate the vars string */
346 tcp = XPptrv(vars)[(vars.len = 0)];
347 /* 'varname=' -> 'varname' */
348 tcp[wdscan(tcp, EOS) - tcp - 3] = EOS;
349
350 /* construct new args strings */
351 XPput(args, wdcopy(builtin_cmd, ATEMP));
352 XPput(args, wdcopy(setA_cmd0, ATEMP));
353 XPput(args, wdcopy(setA_cmd1, ATEMP));
354 XPput(args, tcp);
355 XPput(args, wdcopy(setA_cmd2, ATEMP));
356
357 /* slurp in words till closing paren */
358 while (token(CONTIN) == LWORD)
359 XPput(args, yylval.cp);
360 if (symbol != /*(*/ ')')
361 syntaxerr(NULL);
362 } else {
363 /*
364 * Check for "> foo (echo hi)"
365 * which AT&T ksh allows (not
366 * POSIX, but not disallowed)
367 */
368 afree(t, ATEMP);
369 if (XPsize(args) == 0 &&
370 XPsize(vars) == 0) {
371 ACCEPT;
372 goto Subshell;
373 }
374
375 /* must be a function */
376 if (iopn != 0 || XPsize(args) != 1 ||
377 XPsize(vars) != 0)
378 syntaxerr(NULL);
379 ACCEPT;
380 musthave(/*(*/ ')', 0);
381 t = function_body(XPptrv(args)[0],
382 sALIAS, false);
383 }
384 goto Leave;
385
386 default:
387 goto Leave;
388 }
389 }
390 Leave:
391 break;
392
393 case ORD('(' /*)*/): {
394 unsigned int subshell_nesting_type_saved;
395 Subshell:
396 subshell_nesting_type_saved = subshell_nesting_type;
397 subshell_nesting_type = ORD(')');
398 t = nested(TPAREN, ORD('('), ORD(')'), sALIAS);
399 subshell_nesting_type = subshell_nesting_type_saved;
400 break;
401 }
402
403 case ORD('{' /*}*/):
404 t = nested(TBRACE, ORD('{'), ORD('}'), sALIAS);
405 break;
406
407 case MDPAREN:
408 /* leave KEYWORD in syniocf (allow if (( 1 )) then ...) */
409 lno = source->line;
410 ACCEPT;
411 switch (token(LETEXPR)) {
412 case LWORD:
413 break;
414 case ORD('(' /*)*/):
415 c = ORD('(');
416 goto Subshell;
417 default:
418 syntaxerr(NULL);
419 }
420 t = newtp(TCOM);
421 t->lineno = lno;
422 XPput(args, wdcopy(builtin_cmd, ATEMP));
423 XPput(args, wdcopy(let_cmd, ATEMP));
424 XPput(args, yylval.cp);
425 break;
426
427 case DBRACKET: /* [[ .. ]] */
428 /* leave KEYWORD in syniocf (allow if [[ -n 1 ]] then ...) */
429 t = newtp(TDBRACKET);
430 ACCEPT;
431 {
432 Test_env te;
433
434 te.flags = TEF_DBRACKET;
435 te.pos.av = &args;
436 te.isa = dbtestp_isa;
437 te.getopnd = dbtestp_getopnd;
438 te.eval = dbtestp_eval;
439 te.error = dbtestp_error;
440
441 test_parse(&te);
442 }
443 break;
444
445 case FOR:
446 case SELECT:
447 t = newtp((c == FOR) ? TFOR : TSELECT);
448 musthave(LWORD, CMDASN);
449 if (!is_wdvarname(yylval.cp, true))
450 yyerror("%s: bad identifier",
451 c == FOR ? "for" : Tselect);
452 strdupx(t->str, ident, ATEMP);
453 nesting_push(&old_nesting, c);
454 t->vars = wordlist(sALIAS);
455 t->left = dogroup(sALIAS);
456 nesting_pop(&old_nesting);
457 break;
458
459 case WHILE:
460 case UNTIL:
461 nesting_push(&old_nesting, c);
462 t = newtp((c == WHILE) ? TWHILE : TUNTIL);
463 t->left = c_list(sALIAS, true);
464 t->right = dogroup(sALIAS);
465 nesting_pop(&old_nesting);
466 break;
467
468 case CASE:
469 t = newtp(TCASE);
470 musthave(LWORD, 0);
471 t->str = yylval.cp;
472 nesting_push(&old_nesting, c);
473 t->left = caselist(sALIAS);
474 nesting_pop(&old_nesting);
475 break;
476
477 case IF:
478 nesting_push(&old_nesting, c);
479 t = newtp(TIF);
480 t->left = c_list(sALIAS, true);
481 t->right = thenpart(sALIAS);
482 musthave(FI, KEYWORD|sALIAS);
483 nesting_pop(&old_nesting);
484 break;
485
486 case BANG:
487 syniocf &= ~(KEYWORD|sALIAS);
488 t = pipeline(0, sALIAS);
489 if (t == NULL)
490 syntaxerr(NULL);
491 t = block(TBANG, NULL, t);
492 break;
493
494 case TIME:
495 syniocf &= ~(KEYWORD|sALIAS);
496 t = pipeline(0, sALIAS);
497 if (t && t->type == TCOM) {
498 t->str = alloc(2, ATEMP);
499 /* TF_* flags */
500 t->str[0] = '\0';
501 t->str[1] = '\0';
502 }
503 t = block(TTIME, t, NULL);
504 break;
505
506 case FUNCTION:
507 musthave(LWORD, 0);
508 t = function_body(yylval.cp, sALIAS, true);
509 break;
510 }
511
512 while ((iop = synio(syniocf)) != NULL) {
513 if (iopn >= NUFILE)
514 yyerror(Tf_toomany, Tredirection);
515 iops[iopn++] = iop;
516 }
517
518 if (iopn == 0) {
519 afree(iops, ATEMP);
520 t->ioact = NULL;
521 } else {
522 iops[iopn++] = NULL;
523 iops = aresize2(iops, iopn, sizeof(struct ioword *), ATEMP);
524 t->ioact = iops;
525 }
526
527 if (t->type == TCOM || t->type == TDBRACKET) {
528 XPput(args, NULL);
529 t->args = (const char **)XPclose(args);
530 XPput(vars, NULL);
531 t->vars = (char **)XPclose(vars);
532 } else {
533 XPfree(args);
534 XPfree(vars);
535 }
536
537 if (c == MDPAREN) {
538 t = block(TBRACE, t, NULL);
539 t->ioact = t->left->ioact;
540 t->left->ioact = NULL;
541 }
542
543 return (t);
544 }
545
546 static struct op *
dogroup(int sALIAS)547 dogroup(int sALIAS)
548 {
549 int c;
550 struct op *list;
551
552 c = token(CONTIN|KEYWORD|sALIAS);
553 /*
554 * A {...} can be used instead of do...done for for/select loops
555 * but not for while/until loops - we don't need to check if it
556 * is a while loop because it would have been parsed as part of
557 * the conditional command list...
558 */
559 if (c == DO)
560 c = DONE;
561 else if ((unsigned int)c == ORD('{'))
562 c = ORD('}');
563 else
564 syntaxerr(NULL);
565 list = c_list(sALIAS, true);
566 musthave(c, KEYWORD|sALIAS);
567 return (list);
568 }
569
570 static struct op *
thenpart(int sALIAS)571 thenpart(int sALIAS)
572 {
573 struct op *t;
574
575 musthave(THEN, KEYWORD|sALIAS);
576 t = newtp(0);
577 t->left = c_list(sALIAS, true);
578 if (t->left == NULL)
579 syntaxerr(NULL);
580 t->right = elsepart(sALIAS);
581 return (t);
582 }
583
584 static struct op *
elsepart(int sALIAS)585 elsepart(int sALIAS)
586 {
587 struct op *t;
588
589 switch (token(KEYWORD|sALIAS|CMDASN)) {
590 case ELSE:
591 if ((t = c_list(sALIAS, true)) == NULL)
592 syntaxerr(NULL);
593 return (t);
594
595 case ELIF:
596 t = newtp(TELIF);
597 t->left = c_list(sALIAS, true);
598 t->right = thenpart(sALIAS);
599 return (t);
600
601 default:
602 REJECT;
603 }
604 return (NULL);
605 }
606
607 static struct op *
caselist(int sALIAS)608 caselist(int sALIAS)
609 {
610 struct op *t, *tl;
611 int c;
612
613 c = token(CONTIN|KEYWORD|sALIAS);
614 /* A {...} can be used instead of in...esac for case statements */
615 if (c == IN)
616 c = ESAC;
617 else if ((unsigned int)c == ORD('{'))
618 c = ORD('}');
619 else
620 syntaxerr(NULL);
621 t = tl = NULL;
622 /* no ALIAS here */
623 while ((tpeek(CONTIN|KEYWORD|ESACONLY)) != c) {
624 struct op *tc = casepart(c, sALIAS);
625 if (tl == NULL)
626 t = tl = tc, tl->right = NULL;
627 else
628 tl->right = tc, tl = tc;
629 }
630 musthave(c, KEYWORD|sALIAS);
631 return (t);
632 }
633
634 static struct op *
casepart(int endtok,int sALIAS)635 casepart(int endtok, int sALIAS)
636 {
637 struct op *t;
638 XPtrV ptns;
639
640 XPinit(ptns, 16);
641 t = newtp(TPAT);
642 /* no ALIAS here */
643 if ((unsigned int)token(CONTIN | KEYWORD) != ORD('('))
644 REJECT;
645 do {
646 switch (token(0)) {
647 case LWORD:
648 break;
649 case ORD('}'):
650 case ESAC:
651 if (symbol != endtok) {
652 strdupx(yylval.cp, (unsigned int)symbol ==
653 ORD('}') ? Tcbrace : Tesac, ATEMP);
654 break;
655 }
656 /* FALLTHROUGH */
657 default:
658 syntaxerr(NULL);
659 }
660 XPput(ptns, yylval.cp);
661 } while (token(0) == '|');
662 REJECT;
663 XPput(ptns, NULL);
664 t->vars = (char **)XPclose(ptns);
665 musthave(ORD(')'), 0);
666
667 t->left = c_list(sALIAS, true);
668
669 /* initialise to default for ;; or omitted */
670 t->u.charflag = ORD(';');
671 /* SUSv4 requires the ;; except in the last casepart */
672 if ((tpeek(CONTIN|KEYWORD|sALIAS)) != endtok)
673 switch (symbol) {
674 default:
675 syntaxerr(NULL);
676 case BRKEV:
677 t->u.charflag = ORD('|');
678 if (0)
679 /* FALLTHROUGH */
680 case BRKFT:
681 t->u.charflag = ORD('&');
682 /* FALLTHROUGH */
683 case BREAK:
684 /* initialised above, but we need to eat the token */
685 ACCEPT;
686 }
687 return (t);
688 }
689
690 static struct op *
function_body(char * name,int sALIAS,bool ksh_func)691 function_body(char *name, int sALIAS,
692 /* function foo { ... } vs foo() { .. } */
693 bool ksh_func)
694 {
695 char *sname, *p;
696 struct op *t;
697
698 sname = wdstrip(name, 0);
699 /*-
700 * Check for valid characters in name. POSIX and AT&T ksh93 say
701 * only allow [a-zA-Z_0-9] but this allows more as old pdkshs
702 * have allowed more; the following were never allowed:
703 * NUL TAB NL SP " $ & ' ( ) ; < = > \ ` |
704 * C_QUOTE|C_SPC covers all but adds # * ? [ ]
705 */
706 for (p = sname; *p; p++)
707 if (ctype(*p, C_QUOTE | C_SPC))
708 yyerror(Tinvname, sname, Tfunction);
709
710 /*
711 * Note that POSIX allows only compound statements after foo(),
712 * sh and AT&T ksh allow any command, go with the later since it
713 * shouldn't break anything. However, for function foo, AT&T ksh
714 * only accepts an open-brace.
715 */
716 if (ksh_func) {
717 if ((unsigned int)tpeek(CONTIN|KEYWORD|sALIAS) == ORD('(' /*)*/)) {
718 /* function foo () { //}*/
719 ACCEPT;
720 musthave(ORD(/*(*/ ')'), 0);
721 /* degrade to POSIX function */
722 ksh_func = false;
723 }
724 musthave(ORD('{' /*}*/), CONTIN|KEYWORD|sALIAS);
725 REJECT;
726 }
727
728 t = newtp(TFUNCT);
729 t->str = sname;
730 t->u.ksh_func = tobool(ksh_func);
731 t->lineno = source->line;
732
733 if ((t->left = get_command(CONTIN, sALIAS)) == NULL) {
734 char *tv;
735 /*
736 * Probably something like foo() followed by EOF or ';'.
737 * This is accepted by sh and ksh88.
738 * To make "typeset -f foo" work reliably (so its output can
739 * be used as input), we pretend there is a colon here.
740 */
741 t->left = newtp(TCOM);
742 /* (2 * sizeof(char *)) is small enough */
743 t->left->args = alloc(2 * sizeof(char *), ATEMP);
744 t->left->args[0] = tv = alloc(3, ATEMP);
745 tv[0] = QCHAR;
746 tv[1] = ':';
747 tv[2] = EOS;
748 t->left->args[1] = NULL;
749 t->left->vars = alloc(sizeof(char *), ATEMP);
750 t->left->vars[0] = NULL;
751 t->left->lineno = 1;
752 }
753
754 return (t);
755 }
756
757 static char **
wordlist(int sALIAS)758 wordlist(int sALIAS)
759 {
760 int c;
761 XPtrV args;
762
763 XPinit(args, 16);
764 /* POSIX does not do alias expansion here... */
765 if ((c = token(CONTIN|KEYWORD|sALIAS)) != IN) {
766 if (c != ';')
767 /* non-POSIX, but AT&T ksh accepts a ; here */
768 REJECT;
769 return (NULL);
770 }
771 while ((c = token(0)) == LWORD)
772 XPput(args, yylval.cp);
773 if (c != '\n' && c != ';')
774 syntaxerr(NULL);
775 XPput(args, NULL);
776 return ((char **)XPclose(args));
777 }
778
779 /*
780 * supporting functions
781 */
782
783 static struct op *
block(int type,struct op * t1,struct op * t2)784 block(int type, struct op *t1, struct op *t2)
785 {
786 struct op *t;
787
788 t = newtp(type);
789 t->left = t1;
790 t->right = t2;
791 return (t);
792 }
793
794 static const struct tokeninfo {
795 const char *name;
796 short val;
797 short reserved;
798 } tokentab[] = {
799 /* Reserved words */
800 { "if", IF, true },
801 { "then", THEN, true },
802 { "else", ELSE, true },
803 { "elif", ELIF, true },
804 { "fi", FI, true },
805 { "case", CASE, true },
806 { Tesac, ESAC, true },
807 { "for", FOR, true },
808 { Tselect, SELECT, true },
809 { "while", WHILE, true },
810 { "until", UNTIL, true },
811 { "do", DO, true },
812 { "done", DONE, true },
813 { "in", IN, true },
814 { Tfunction, FUNCTION, true },
815 { Ttime, TIME, true },
816 { "{", ORD('{'), true },
817 { Tcbrace, ORD('}'), true },
818 { "!", BANG, true },
819 { "[[", DBRACKET, true },
820 /* Lexical tokens (0[EOF], LWORD and REDIR handled specially) */
821 { "&&", LOGAND, false },
822 { "||", LOGOR, false },
823 { ";;", BREAK, false },
824 { ";|", BRKEV, false },
825 { ";&", BRKFT, false },
826 { "((", MDPAREN, false },
827 { "|&", COPROC, false },
828 /* and some special cases... */
829 { "newline", ORD('\n'), false },
830 { NULL, 0, false }
831 };
832
833 void
initkeywords(void)834 initkeywords(void)
835 {
836 struct tokeninfo const *tt;
837 struct tbl *p;
838
839 ktinit(APERM, &keywords,
840 /* currently 28 keywords: 75% of 64 = 2^6 */
841 6);
842 for (tt = tokentab; tt->name; tt++) {
843 if (tt->reserved) {
844 p = ktenter(&keywords, tt->name, hash(tt->name));
845 p->flag |= DEFINED|ISSET;
846 p->type = CKEYWD;
847 p->val.i = tt->val;
848 }
849 }
850 }
851
852 static void
syntaxerr(const char * what)853 syntaxerr(const char *what)
854 {
855 /* 23<<- is the longest redirection, I think */
856 char redir[8];
857 const char *s;
858 struct tokeninfo const *tt;
859 int c;
860
861 if (!what)
862 what = Tunexpected;
863 REJECT;
864 c = token(0);
865 Again:
866 switch (c) {
867 case 0:
868 if (nesting.start_token) {
869 c = nesting.start_token;
870 source->errline = nesting.start_line;
871 what = "unmatched";
872 goto Again;
873 }
874 /* don't quote the EOF */
875 yyerror("%s: unexpected EOF", Tsynerr);
876 /* NOTREACHED */
877
878 case LWORD:
879 s = snptreef(NULL, 32, Tf_S, yylval.cp);
880 break;
881
882 case REDIR:
883 s = snptreef(redir, sizeof(redir), Tft_R, yylval.iop);
884 break;
885
886 default:
887 for (tt = tokentab; tt->name; tt++)
888 if (tt->val == c)
889 break;
890 if (tt->name)
891 s = tt->name;
892 else {
893 if (c > 0 && c < 256) {
894 redir[0] = c;
895 redir[1] = '\0';
896 } else
897 shf_snprintf(redir, sizeof(redir),
898 "?%d", c);
899 s = redir;
900 }
901 }
902 yyerror(Tf_sD_s_qs, Tsynerr, what, s);
903 }
904
905 static void
nesting_push(struct nesting_state * save,int tok)906 nesting_push(struct nesting_state *save, int tok)
907 {
908 *save = nesting;
909 nesting.start_token = tok;
910 nesting.start_line = source->line;
911 }
912
913 static void
nesting_pop(struct nesting_state * saved)914 nesting_pop(struct nesting_state *saved)
915 {
916 nesting = *saved;
917 }
918
919 static struct op *
newtp(int type)920 newtp(int type)
921 {
922 struct op *t;
923
924 t = alloc(sizeof(struct op), ATEMP);
925 t->type = type;
926 t->u.evalflags = 0;
927 t->args = NULL;
928 t->vars = NULL;
929 t->ioact = NULL;
930 t->left = t->right = NULL;
931 t->str = NULL;
932 return (t);
933 }
934
935 struct op *
compile(Source * s,bool skiputf8bom,bool doalias)936 compile(Source *s, bool skiputf8bom, bool doalias)
937 {
938 nesting.start_token = 0;
939 nesting.start_line = 0;
940 herep = heres;
941 source = s;
942 if (skiputf8bom)
943 yyskiputf8bom();
944 yyparse(doalias);
945 return (outtree);
946 }
947
948 /* Check if we are in the middle of reading an alias */
949 static int
inalias(struct source * s)950 inalias(struct source *s)
951 {
952 while (s && s->type == SALIAS) {
953 if (!(s->flags & SF_ALIASEND))
954 return (1);
955 s = s->next;
956 }
957 return (0);
958 }
959
960
961 /*
962 * Order important - indexed by Test_meta values
963 * Note that ||, &&, ( and ) can't appear in as unquoted strings
964 * in normal shell input, so these can be interpreted unambiguously
965 * in the evaluation pass.
966 */
967 static const char dbtest_or[] = { CHAR, '|', CHAR, '|', EOS };
968 static const char dbtest_and[] = { CHAR, '&', CHAR, '&', EOS };
969 static const char dbtest_not[] = { CHAR, '!', EOS };
970 static const char dbtest_oparen[] = { CHAR, '(', EOS };
971 static const char dbtest_cparen[] = { CHAR, ')', EOS };
972 const char * const dbtest_tokens[] = {
973 dbtest_or, dbtest_and, dbtest_not,
974 dbtest_oparen, dbtest_cparen
975 };
976 static const char db_close[] = { CHAR, ']', CHAR, ']', EOS };
977 static const char db_lthan[] = { CHAR, '<', EOS };
978 static const char db_gthan[] = { CHAR, '>', EOS };
979
980 /*
981 * Test if the current token is a whatever. Accepts the current token if
982 * it is. Returns 0 if it is not, non-zero if it is (in the case of
983 * TM_UNOP and TM_BINOP, the returned value is a Test_op).
984 */
985 static Test_op
dbtestp_isa(Test_env * te,Test_meta meta)986 dbtestp_isa(Test_env *te, Test_meta meta)
987 {
988 int c = tpeek(CMDASN | (meta == TM_BINOP ? 0 : CONTIN));
989 bool uqword;
990 char *save = NULL;
991 Test_op ret = TO_NONOP;
992
993 /* unquoted word? */
994 uqword = c == LWORD && *ident;
995
996 if (meta == TM_OR)
997 ret = c == LOGOR ? TO_NONNULL : TO_NONOP;
998 else if (meta == TM_AND)
999 ret = c == LOGAND ? TO_NONNULL : TO_NONOP;
1000 else if (meta == TM_NOT)
1001 ret = (uqword && !strcmp(yylval.cp,
1002 dbtest_tokens[(int)TM_NOT])) ? TO_NONNULL : TO_NONOP;
1003 else if (meta == TM_OPAREN)
1004 ret = (unsigned int)c == ORD('(') /*)*/ ? TO_NONNULL : TO_NONOP;
1005 else if (meta == TM_CPAREN)
1006 ret = (unsigned int)c == /*(*/ ORD(')') ? TO_NONNULL : TO_NONOP;
1007 else if (meta == TM_UNOP || meta == TM_BINOP) {
1008 if (meta == TM_BINOP && c == REDIR &&
1009 (yylval.iop->ioflag == IOREAD ||
1010 yylval.iop->ioflag == IOWRITE)) {
1011 ret = TO_NONNULL;
1012 save = wdcopy(yylval.iop->ioflag == IOREAD ?
1013 db_lthan : db_gthan, ATEMP);
1014 } else if (uqword && (ret = test_isop(meta, ident)))
1015 save = yylval.cp;
1016 } else
1017 /* meta == TM_END */
1018 ret = (uqword && !strcmp(yylval.cp,
1019 db_close)) ? TO_NONNULL : TO_NONOP;
1020 if (ret != TO_NONOP) {
1021 ACCEPT;
1022 if ((unsigned int)meta < NELEM(dbtest_tokens))
1023 save = wdcopy(dbtest_tokens[(int)meta], ATEMP);
1024 if (save)
1025 XPput(*te->pos.av, save);
1026 }
1027 return (ret);
1028 }
1029
1030 static const char *
dbtestp_getopnd(Test_env * te,Test_op op MKSH_A_UNUSED,bool do_eval MKSH_A_UNUSED)1031 dbtestp_getopnd(Test_env *te, Test_op op MKSH_A_UNUSED,
1032 bool do_eval MKSH_A_UNUSED)
1033 {
1034 int c = tpeek(CMDASN);
1035
1036 if (c != LWORD)
1037 return (NULL);
1038
1039 ACCEPT;
1040 XPput(*te->pos.av, yylval.cp);
1041
1042 return (null);
1043 }
1044
1045 static int
dbtestp_eval(Test_env * te MKSH_A_UNUSED,Test_op op MKSH_A_UNUSED,const char * opnd1 MKSH_A_UNUSED,const char * opnd2 MKSH_A_UNUSED,bool do_eval MKSH_A_UNUSED)1046 dbtestp_eval(Test_env *te MKSH_A_UNUSED, Test_op op MKSH_A_UNUSED,
1047 const char *opnd1 MKSH_A_UNUSED, const char *opnd2 MKSH_A_UNUSED,
1048 bool do_eval MKSH_A_UNUSED)
1049 {
1050 return (1);
1051 }
1052
1053 static void
dbtestp_error(Test_env * te,int offset,const char * msg)1054 dbtestp_error(Test_env *te, int offset, const char *msg)
1055 {
1056 te->flags |= TEF_ERROR;
1057
1058 if (offset < 0) {
1059 REJECT;
1060 /* Kludgy to say the least... */
1061 symbol = LWORD;
1062 yylval.cp = *(XPptrv(*te->pos.av) + XPsize(*te->pos.av) +
1063 offset);
1064 }
1065 syntaxerr(msg);
1066 }
1067
1068 #if HAVE_SELECT
1069
1070 #ifndef EOVERFLOW
1071 #ifdef ERANGE
1072 #define EOVERFLOW ERANGE
1073 #else
1074 #define EOVERFLOW EINVAL
1075 #endif
1076 #endif
1077
1078 bool
parse_usec(const char * s,struct timeval * tv)1079 parse_usec(const char *s, struct timeval *tv)
1080 {
1081 struct timeval tt;
1082 int i;
1083
1084 tv->tv_sec = 0;
1085 /* parse integral part */
1086 while (ctype(*s, C_DIGIT)) {
1087 tt.tv_sec = tv->tv_sec * 10 + ksh_numdig(*s++);
1088 /*XXX this overflow check maybe UB */
1089 if (tt.tv_sec / 10 != tv->tv_sec) {
1090 errno = EOVERFLOW;
1091 return (true);
1092 }
1093 tv->tv_sec = tt.tv_sec;
1094 }
1095
1096 tv->tv_usec = 0;
1097 if (!*s)
1098 /* no decimal fraction */
1099 return (false);
1100 else if (*s++ != '.') {
1101 /* junk after integral part */
1102 errno = EINVAL;
1103 return (true);
1104 }
1105
1106 /* parse decimal fraction */
1107 i = 100000;
1108 while (ctype(*s, C_DIGIT)) {
1109 tv->tv_usec += i * ksh_numdig(*s++);
1110 if (i == 1)
1111 break;
1112 i /= 10;
1113 }
1114 /* check for junk after fractional part */
1115 while (ctype(*s, C_DIGIT))
1116 ++s;
1117 if (*s) {
1118 errno = EINVAL;
1119 return (true);
1120 }
1121
1122 /* end of input string reached, no errors */
1123 return (false);
1124 }
1125 #endif
1126
1127 /*
1128 * Helper function called from within lex.c:yylex() to parse
1129 * a COMSUB recursively using the main shell parser and lexer
1130 */
1131 char *
yyrecursive(int subtype)1132 yyrecursive(int subtype)
1133 {
1134 struct op *t;
1135 char *cp;
1136 struct yyrecursive_state *ys;
1137 unsigned int stok, etok;
1138
1139 if (subtype != COMSUB) {
1140 stok = ORD('{');
1141 etok = ORD('}');
1142 } else {
1143 stok = ORD('(');
1144 etok = ORD(')');
1145 }
1146
1147 ys = alloc(sizeof(struct yyrecursive_state), ATEMP);
1148
1149 /* tell the lexer to accept a closing parenthesis as EOD */
1150 ys->old_nesting_type = subshell_nesting_type;
1151 subshell_nesting_type = etok;
1152
1153 /* push reject state, parse recursively, pop reject state */
1154 ys->old_reject = reject;
1155 ys->old_symbol = symbol;
1156 ACCEPT;
1157 memcpy(ys->old_heres, heres, sizeof(heres));
1158 ys->old_herep = herep;
1159 herep = heres;
1160 ys->next = e->yyrecursive_statep;
1161 e->yyrecursive_statep = ys;
1162 /* we use TPAREN as a helper container here */
1163 t = nested(TPAREN, stok, etok, ALIAS);
1164 yyrecursive_pop(false);
1165
1166 /* t->left because nested(TPAREN, ...) hides our goodies there */
1167 cp = snptreef(NULL, 0, Tf_T, t->left);
1168 tfree(t, ATEMP);
1169
1170 return (cp);
1171 }
1172
1173 void
yyrecursive_pop(bool popall)1174 yyrecursive_pop(bool popall)
1175 {
1176 struct yyrecursive_state *ys;
1177
1178 popnext:
1179 if (!(ys = e->yyrecursive_statep))
1180 return;
1181 e->yyrecursive_statep = ys->next;
1182
1183 memcpy(heres, ys->old_heres, sizeof(heres));
1184 herep = ys->old_herep;
1185 reject = ys->old_reject;
1186 symbol = ys->old_symbol;
1187
1188 subshell_nesting_type = ys->old_nesting_type;
1189
1190 afree(ys, ATEMP);
1191 if (popall)
1192 goto popnext;
1193 }
1194