1 /* $OpenBSD: lex.c,v 1.49 2013/12/17 16:37:06 deraadt Exp $ */
2
3 /*-
4 * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
5 * 2011, 2012, 2013, 2014
6 * Thorsten Glaser <tg@mirbsd.org>
7 *
8 * Provided that these terms and disclaimer and all copyright notices
9 * are retained or reproduced in an accompanying document, permission
10 * is granted to deal in this work without restriction, including un-
11 * limited rights to use, publicly perform, distribute, sell, modify,
12 * merge, give away, or sublicence.
13 *
14 * This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
15 * the utmost extent permitted by applicable law, neither express nor
16 * implied; without malicious intent or gross negligence. In no event
17 * may a licensor, author or contributor be held liable for indirect,
18 * direct, other damage, loss, or other issues arising in any way out
19 * of dealing in the work, even if advised of the possibility of such
20 * damage or existence of a defect, except proven that it results out
21 * of said person's immediate fault when using the work as intended.
22 */
23
24 #include "sh.h"
25
26 __RCSID("$MirOS: src/bin/mksh/lex.c,v 1.193 2014/06/29 11:28:28 tg Exp $");
27
28 /*
29 * states while lexing word
30 */
31 #define SBASE 0 /* outside any lexical constructs */
32 #define SWORD 1 /* implicit quoting for substitute() */
33 #define SLETPAREN 2 /* inside (( )), implicit quoting */
34 #define SSQUOTE 3 /* inside '' */
35 #define SDQUOTE 4 /* inside "" */
36 #define SEQUOTE 5 /* inside $'' */
37 #define SBRACE 6 /* inside ${} */
38 #define SQBRACE 7 /* inside "${}" */
39 #define SBQUOTE 8 /* inside `` */
40 #define SASPAREN 9 /* inside $(( )) */
41 #define SHEREDELIM 10 /* parsing <<,<<-,<<< delimiter */
42 #define SHEREDQUOTE 11 /* parsing " in <<,<<-,<<< delimiter */
43 #define SPATTERN 12 /* parsing *(...|...) pattern (*+?@!) */
44 #define SADELIM 13 /* like SBASE, looking for delimiter */
45 #define STBRACEKORN 14 /* parsing ${...[#%]...} !FSH */
46 #define STBRACEBOURNE 15 /* parsing ${...[#%]...} FSH */
47 #define SINVALID 255 /* invalid state */
48
49 struct sretrace_info {
50 struct sretrace_info *next;
51 XString xs;
52 char *xp;
53 };
54
55 /*
56 * Structure to keep track of the lexing state and the various pieces of info
57 * needed for each particular state.
58 */
59 typedef struct lex_state {
60 union {
61 /* point to the next state block */
62 struct lex_state *base;
63 /* marks start of state output in output string */
64 int start;
65 /* SBQUOTE: true if in double quotes: "`...`" */
66 /* SEQUOTE: got NUL, ignore rest of string */
67 bool abool;
68 /* SADELIM information */
69 struct {
70 /* character to search for */
71 unsigned char delimiter;
72 /* max. number of delimiters */
73 unsigned char num;
74 } adelim;
75 } u;
76 /* count open parentheses */
77 short nparen;
78 /* type of this state */
79 uint8_t type;
80 } Lex_state;
81 #define ls_base u.base
82 #define ls_start u.start
83 #define ls_bool u.abool
84 #define ls_adelim u.adelim
85
86 typedef struct {
87 Lex_state *base;
88 Lex_state *end;
89 } State_info;
90
91 static void readhere(struct ioword *);
92 static void ungetsc(int);
93 static void ungetsc_i(int);
94 static int getsc_uu(void);
95 static void getsc_line(Source *);
96 static int getsc_bn(void);
97 static int s_get(void);
98 static void s_put(int);
99 static char *get_brace_var(XString *, char *);
100 static bool arraysub(char **);
101 static void gethere(bool);
102 static Lex_state *push_state_i(State_info *, Lex_state *);
103 static Lex_state *pop_state_i(State_info *, Lex_state *);
104
105 static int backslash_skip;
106 static int ignore_backslash_newline;
107
108 /* optimised getsc_bn() */
109 #define o_getsc() (*source->str != '\0' && *source->str != '\\' && \
110 !backslash_skip ? *source->str++ : getsc_bn())
111 /* optimised getsc_uu() */
112 #define o_getsc_u() ((*source->str != '\0') ? *source->str++ : getsc_uu())
113
114 /* retrace helper */
115 #define o_getsc_r(carg) { \
116 int cev = (carg); \
117 struct sretrace_info *rp = retrace_info; \
118 \
119 while (rp) { \
120 Xcheck(rp->xs, rp->xp); \
121 *rp->xp++ = cev; \
122 rp = rp->next; \
123 } \
124 \
125 return (cev); \
126 }
127
128 #if defined(MKSH_SMALL) && !defined(MKSH_SMALL_BUT_FAST)
129 static int getsc(void);
130
131 static int
getsc(void)132 getsc(void)
133 {
134 o_getsc_r(o_getsc());
135 }
136 #else
137 static int getsc_r(int);
138
139 static int
getsc_r(int c)140 getsc_r(int c)
141 {
142 o_getsc_r(c);
143 }
144
145 #define getsc() getsc_r(o_getsc())
146 #endif
147
148 #define STATE_BSIZE 8
149
150 #define PUSH_STATE(s) do { \
151 if (++statep == state_info.end) \
152 statep = push_state_i(&state_info, statep); \
153 state = statep->type = (s); \
154 } while (/* CONSTCOND */ 0)
155
156 #define POP_STATE() do { \
157 if (--statep == state_info.base) \
158 statep = pop_state_i(&state_info, statep); \
159 state = statep->type; \
160 } while (/* CONSTCOND */ 0)
161
162 #define PUSH_SRETRACE(s) do { \
163 struct sretrace_info *ri; \
164 \
165 PUSH_STATE(s); \
166 statep->ls_start = Xsavepos(ws, wp); \
167 ri = alloc(sizeof(struct sretrace_info), ATEMP); \
168 Xinit(ri->xs, ri->xp, 64, ATEMP); \
169 ri->next = retrace_info; \
170 retrace_info = ri; \
171 } while (/* CONSTCOND */ 0)
172
173 #define POP_SRETRACE() do { \
174 wp = Xrestpos(ws, wp, statep->ls_start); \
175 *retrace_info->xp = '\0'; \
176 sp = Xstring(retrace_info->xs, retrace_info->xp); \
177 dp = (void *)retrace_info; \
178 retrace_info = retrace_info->next; \
179 afree(dp, ATEMP); \
180 POP_STATE(); \
181 } while (/* CONSTCOND */ 0)
182
183 /**
184 * Lexical analyser
185 *
186 * tokens are not regular expressions, they are LL(1).
187 * for example, "${var:-${PWD}}", and "$(size $(whence ksh))".
188 * hence the state stack. Note "$(...)" are now parsed recursively.
189 */
190
191 int
yylex(int cf)192 yylex(int cf)
193 {
194 Lex_state states[STATE_BSIZE], *statep, *s2, *base;
195 State_info state_info;
196 int c, c2, state;
197 size_t cz;
198 XString ws; /* expandable output word */
199 char *wp; /* output word pointer */
200 char *sp, *dp;
201
202 Again:
203 states[0].type = SINVALID;
204 states[0].ls_base = NULL;
205 statep = &states[1];
206 state_info.base = states;
207 state_info.end = &state_info.base[STATE_BSIZE];
208
209 Xinit(ws, wp, 64, ATEMP);
210
211 backslash_skip = 0;
212 ignore_backslash_newline = 0;
213
214 if (cf & ONEWORD)
215 state = SWORD;
216 else if (cf & LETEXPR) {
217 /* enclose arguments in (double) quotes */
218 *wp++ = OQUOTE;
219 state = SLETPAREN;
220 statep->nparen = 0;
221 } else {
222 /* normal lexing */
223 state = (cf & HEREDELIM) ? SHEREDELIM : SBASE;
224 while ((c = getsc()) == ' ' || c == '\t')
225 ;
226 if (c == '#') {
227 ignore_backslash_newline++;
228 while ((c = getsc()) != '\0' && c != '\n')
229 ;
230 ignore_backslash_newline--;
231 }
232 ungetsc(c);
233 }
234 if (source->flags & SF_ALIAS) {
235 /* trailing ' ' in alias definition */
236 source->flags &= ~SF_ALIAS;
237 cf |= ALIAS;
238 }
239
240 /* Initial state: one of SWORD SLETPAREN SHEREDELIM SBASE */
241 statep->type = state;
242
243 /* check for here string */
244 if (state == SHEREDELIM) {
245 c = getsc();
246 if (c == '<') {
247 state = SHEREDELIM;
248 while ((c = getsc()) == ' ' || c == '\t')
249 ;
250 ungetsc(c);
251 c = '<';
252 goto accept_nonword;
253 }
254 ungetsc(c);
255 }
256
257 /* collect non-special or quoted characters to form word */
258 while (!((c = getsc()) == 0 ||
259 ((state == SBASE || state == SHEREDELIM) && ctype(c, C_LEX1)))) {
260 if (state == SBASE &&
261 subshell_nesting_type == /*{*/ '}' &&
262 c == /*{*/ '}')
263 /* possibly end ${ :;} */
264 break;
265 accept_nonword:
266 Xcheck(ws, wp);
267 switch (state) {
268 case SADELIM:
269 if (c == '(')
270 statep->nparen++;
271 else if (c == ')')
272 statep->nparen--;
273 else if (statep->nparen == 0 && (c == /*{*/ '}' ||
274 c == (int)statep->ls_adelim.delimiter)) {
275 *wp++ = ADELIM;
276 *wp++ = c;
277 if (c == /*{*/ '}' || --statep->ls_adelim.num == 0)
278 POP_STATE();
279 if (c == /*{*/ '}')
280 POP_STATE();
281 break;
282 }
283 /* FALLTHROUGH */
284 case SBASE:
285 if (c == '[' && (cf & (VARASN|ARRAYVAR))) {
286 /* temporary */
287 *wp = EOS;
288 if (is_wdvarname(Xstring(ws, wp), false)) {
289 char *p, *tmp;
290
291 if (arraysub(&tmp)) {
292 *wp++ = CHAR;
293 *wp++ = c;
294 for (p = tmp; *p; ) {
295 Xcheck(ws, wp);
296 *wp++ = CHAR;
297 *wp++ = *p++;
298 }
299 afree(tmp, ATEMP);
300 break;
301 } else {
302 Source *s;
303
304 s = pushs(SREREAD,
305 source->areap);
306 s->start = s->str =
307 s->u.freeme = tmp;
308 s->next = source;
309 source = s;
310 }
311 }
312 *wp++ = CHAR;
313 *wp++ = c;
314 break;
315 }
316 /* FALLTHROUGH */
317 Sbase1: /* includes *(...|...) pattern (*+?@!) */
318 if (c == '*' || c == '@' || c == '+' || c == '?' ||
319 c == '!') {
320 c2 = getsc();
321 if (c2 == '(' /*)*/ ) {
322 *wp++ = OPAT;
323 *wp++ = c;
324 PUSH_STATE(SPATTERN);
325 break;
326 }
327 ungetsc(c2);
328 }
329 /* FALLTHROUGH */
330 Sbase2: /* doesn't include *(...|...) pattern (*+?@!) */
331 switch (c) {
332 case '\\':
333 getsc_qchar:
334 if ((c = getsc())) {
335 /* trailing \ is lost */
336 *wp++ = QCHAR;
337 *wp++ = c;
338 }
339 break;
340 case '\'':
341 open_ssquote_unless_heredoc:
342 if ((cf & HEREDOC))
343 goto store_char;
344 *wp++ = OQUOTE;
345 ignore_backslash_newline++;
346 PUSH_STATE(SSQUOTE);
347 break;
348 case '"':
349 open_sdquote:
350 *wp++ = OQUOTE;
351 PUSH_STATE(SDQUOTE);
352 break;
353 case '$':
354 /*
355 * processing of dollar sign belongs into
356 * Subst, except for those which can open
357 * a string: $'…' and $"…"
358 */
359 subst_dollar_ex:
360 c = getsc();
361 switch (c) {
362 case '"':
363 goto open_sdquote;
364 case '\'':
365 goto open_sequote;
366 default:
367 goto SubstS;
368 }
369 default:
370 goto Subst;
371 }
372 break;
373
374 Subst:
375 switch (c) {
376 case '\\':
377 c = getsc();
378 switch (c) {
379 case '"':
380 if ((cf & HEREDOC))
381 goto heredocquote;
382 /* FALLTHROUGH */
383 case '\\':
384 case '$': case '`':
385 store_qchar:
386 *wp++ = QCHAR;
387 *wp++ = c;
388 break;
389 default:
390 heredocquote:
391 Xcheck(ws, wp);
392 if (c) {
393 /* trailing \ is lost */
394 *wp++ = CHAR;
395 *wp++ = '\\';
396 *wp++ = CHAR;
397 *wp++ = c;
398 }
399 break;
400 }
401 break;
402 case '$':
403 c = getsc();
404 SubstS:
405 if (c == '(') /*)*/ {
406 c = getsc();
407 if (c == '(') /*)*/ {
408 *wp++ = EXPRSUB;
409 PUSH_SRETRACE(SASPAREN);
410 statep->nparen = 2;
411 *retrace_info->xp++ = '(';
412 } else {
413 ungetsc(c);
414 subst_command:
415 c = COMSUB;
416 subst_command2:
417 sp = yyrecursive(c);
418 cz = strlen(sp) + 1;
419 XcheckN(ws, wp, cz);
420 *wp++ = c;
421 memcpy(wp, sp, cz);
422 wp += cz;
423 }
424 } else if (c == '{') /*}*/ {
425 if ((c = getsc()) == '|') {
426 /*
427 * non-subenvironment
428 * value substitution
429 */
430 c = VALSUB;
431 goto subst_command2;
432 } else if (ctype(c, C_IFSWS)) {
433 /*
434 * non-subenvironment
435 * "command" substitution
436 */
437 c = FUNSUB;
438 goto subst_command2;
439 }
440 ungetsc(c);
441 *wp++ = OSUBST;
442 *wp++ = '{'; /*}*/
443 wp = get_brace_var(&ws, wp);
444 c = getsc();
445 /* allow :# and :% (ksh88 compat) */
446 if (c == ':') {
447 *wp++ = CHAR;
448 *wp++ = c;
449 c = getsc();
450 if (c == ':') {
451 *wp++ = CHAR;
452 *wp++ = '0';
453 *wp++ = ADELIM;
454 *wp++ = ':';
455 PUSH_STATE(SBRACE);
456 PUSH_STATE(SADELIM);
457 statep->ls_adelim.delimiter = ':';
458 statep->ls_adelim.num = 1;
459 statep->nparen = 0;
460 break;
461 } else if (ksh_isdigit(c) ||
462 c == '('/*)*/ || c == ' ' ||
463 /*XXX what else? */
464 c == '$') {
465 /* substring subst. */
466 if (c != ' ') {
467 *wp++ = CHAR;
468 *wp++ = ' ';
469 }
470 ungetsc(c);
471 PUSH_STATE(SBRACE);
472 PUSH_STATE(SADELIM);
473 statep->ls_adelim.delimiter = ':';
474 statep->ls_adelim.num = 2;
475 statep->nparen = 0;
476 break;
477 }
478 } else if (c == '/') {
479 *wp++ = CHAR;
480 *wp++ = c;
481 if ((c = getsc()) == '/') {
482 *wp++ = ADELIM;
483 *wp++ = c;
484 } else
485 ungetsc(c);
486 PUSH_STATE(SBRACE);
487 PUSH_STATE(SADELIM);
488 statep->ls_adelim.delimiter = '/';
489 statep->ls_adelim.num = 1;
490 statep->nparen = 0;
491 break;
492 }
493 /*
494 * If this is a trim operation,
495 * treat (,|,) specially in STBRACE.
496 */
497 if (ctype(c, C_SUBOP2)) {
498 ungetsc(c);
499 if (Flag(FSH))
500 PUSH_STATE(STBRACEBOURNE);
501 else
502 PUSH_STATE(STBRACEKORN);
503 } else {
504 ungetsc(c);
505 if (state == SDQUOTE ||
506 state == SQBRACE)
507 PUSH_STATE(SQBRACE);
508 else
509 PUSH_STATE(SBRACE);
510 }
511 } else if (ksh_isalphx(c)) {
512 *wp++ = OSUBST;
513 *wp++ = 'X';
514 do {
515 Xcheck(ws, wp);
516 *wp++ = c;
517 c = getsc();
518 } while (ksh_isalnux(c));
519 *wp++ = '\0';
520 *wp++ = CSUBST;
521 *wp++ = 'X';
522 ungetsc(c);
523 } else if (ctype(c, C_VAR1 | C_DIGIT)) {
524 Xcheck(ws, wp);
525 *wp++ = OSUBST;
526 *wp++ = 'X';
527 *wp++ = c;
528 *wp++ = '\0';
529 *wp++ = CSUBST;
530 *wp++ = 'X';
531 } else {
532 *wp++ = CHAR;
533 *wp++ = '$';
534 ungetsc(c);
535 }
536 break;
537 case '`':
538 subst_gravis:
539 PUSH_STATE(SBQUOTE);
540 *wp++ = COMSUB;
541 /*
542 * Need to know if we are inside double quotes
543 * since sh/AT&T-ksh translate the \" to " in
544 * "`...\"...`".
545 * This is not done in POSIX mode (section
546 * 3.2.3, Double Quotes: "The backquote shall
547 * retain its special meaning introducing the
548 * other form of command substitution (see
549 * 3.6.3). The portion of the quoted string
550 * from the initial backquote and the
551 * characters up to the next backquote that
552 * is not preceded by a backslash (having
553 * escape characters removed) defines that
554 * command whose output replaces `...` when
555 * the word is expanded."
556 * Section 3.6.3, Command Substitution:
557 * "Within the backquoted style of command
558 * substitution, backslash shall retain its
559 * literal meaning, except when followed by
560 * $ ` \.").
561 */
562 statep->ls_bool = false;
563 s2 = statep;
564 base = state_info.base;
565 while (/* CONSTCOND */ 1) {
566 for (; s2 != base; s2--) {
567 if (s2->type == SDQUOTE) {
568 statep->ls_bool = true;
569 break;
570 }
571 }
572 if (s2 != base)
573 break;
574 if (!(s2 = s2->ls_base))
575 break;
576 base = s2-- - STATE_BSIZE;
577 }
578 break;
579 case QCHAR:
580 if (cf & LQCHAR) {
581 *wp++ = QCHAR;
582 *wp++ = getsc();
583 break;
584 }
585 /* FALLTHROUGH */
586 default:
587 store_char:
588 *wp++ = CHAR;
589 *wp++ = c;
590 }
591 break;
592
593 case SEQUOTE:
594 if (c == '\'') {
595 POP_STATE();
596 *wp++ = CQUOTE;
597 ignore_backslash_newline--;
598 } else if (c == '\\') {
599 if ((c2 = unbksl(true, s_get, s_put)) == -1)
600 c2 = s_get();
601 if (c2 == 0)
602 statep->ls_bool = true;
603 if (!statep->ls_bool) {
604 char ts[4];
605
606 if ((unsigned int)c2 < 0x100) {
607 *wp++ = QCHAR;
608 *wp++ = c2;
609 } else {
610 cz = utf_wctomb(ts, c2 - 0x100);
611 ts[cz] = 0;
612 for (cz = 0; ts[cz]; ++cz) {
613 *wp++ = QCHAR;
614 *wp++ = ts[cz];
615 }
616 }
617 }
618 } else if (!statep->ls_bool) {
619 *wp++ = QCHAR;
620 *wp++ = c;
621 }
622 break;
623
624 case SSQUOTE:
625 if (c == '\'') {
626 POP_STATE();
627 if ((cf & HEREDOC) || state == SQBRACE)
628 goto store_char;
629 *wp++ = CQUOTE;
630 ignore_backslash_newline--;
631 } else {
632 *wp++ = QCHAR;
633 *wp++ = c;
634 }
635 break;
636
637 case SDQUOTE:
638 if (c == '"') {
639 POP_STATE();
640 *wp++ = CQUOTE;
641 } else
642 goto Subst;
643 break;
644
645 /* $(( ... )) */
646 case SASPAREN:
647 if (c == '(')
648 statep->nparen++;
649 else if (c == ')') {
650 statep->nparen--;
651 if (statep->nparen == 1) {
652 /* end of EXPRSUB */
653 POP_SRETRACE();
654
655 if ((c2 = getsc()) == /*(*/ ')') {
656 cz = strlen(sp) - 2;
657 XcheckN(ws, wp, cz);
658 memcpy(wp, sp + 1, cz);
659 wp += cz;
660 afree(sp, ATEMP);
661 *wp++ = '\0';
662 break;
663 } else {
664 Source *s;
665
666 ungetsc(c2);
667 /*
668 * mismatched parenthesis -
669 * assume we were really
670 * parsing a $(...) expression
671 */
672 --wp;
673 s = pushs(SREREAD,
674 source->areap);
675 s->start = s->str =
676 s->u.freeme = sp;
677 s->next = source;
678 source = s;
679 goto subst_command;
680 }
681 }
682 }
683 /* reuse existing state machine */
684 goto Sbase2;
685
686 case SQBRACE:
687 if (c == '\\') {
688 /*
689 * perform POSIX "quote removal" if the back-
690 * slash is "special", i.e. same cases as the
691 * {case '\\':} in Subst: plus closing brace;
692 * in mksh code "quote removal" on '\c' means
693 * write QCHAR+c, otherwise CHAR+\+CHAR+c are
694 * emitted (in heredocquote:)
695 */
696 if ((c = getsc()) == '"' || c == '\\' ||
697 c == '$' || c == '`' || c == /*{*/'}')
698 goto store_qchar;
699 goto heredocquote;
700 }
701 goto common_SQBRACE;
702
703 case SBRACE:
704 if (c == '\'')
705 goto open_ssquote_unless_heredoc;
706 else if (c == '\\')
707 goto getsc_qchar;
708 common_SQBRACE:
709 if (c == '"')
710 goto open_sdquote;
711 else if (c == '$')
712 goto subst_dollar_ex;
713 else if (c == '`')
714 goto subst_gravis;
715 else if (c != /*{*/ '}')
716 goto store_char;
717 POP_STATE();
718 *wp++ = CSUBST;
719 *wp++ = /*{*/ '}';
720 break;
721
722 /* Same as SBASE, except (,|,) treated specially */
723 case STBRACEKORN:
724 if (c == '|')
725 *wp++ = SPAT;
726 else if (c == '(') {
727 *wp++ = OPAT;
728 /* simile for @ */
729 *wp++ = ' ';
730 PUSH_STATE(SPATTERN);
731 } else /* FALLTHROUGH */
732 case STBRACEBOURNE:
733 if (c == /*{*/ '}') {
734 POP_STATE();
735 *wp++ = CSUBST;
736 *wp++ = /*{*/ '}';
737 } else
738 goto Sbase1;
739 break;
740
741 case SBQUOTE:
742 if (c == '`') {
743 *wp++ = 0;
744 POP_STATE();
745 } else if (c == '\\') {
746 switch (c = getsc()) {
747 case 0:
748 /* trailing \ is lost */
749 break;
750 case '\\':
751 case '$': case '`':
752 *wp++ = c;
753 break;
754 case '"':
755 if (statep->ls_bool) {
756 *wp++ = c;
757 break;
758 }
759 /* FALLTHROUGH */
760 default:
761 *wp++ = '\\';
762 *wp++ = c;
763 break;
764 }
765 } else
766 *wp++ = c;
767 break;
768
769 /* ONEWORD */
770 case SWORD:
771 goto Subst;
772
773 /* LETEXPR: (( ... )) */
774 case SLETPAREN:
775 if (c == /*(*/ ')') {
776 if (statep->nparen > 0)
777 --statep->nparen;
778 else if ((c2 = getsc()) == /*(*/ ')') {
779 c = 0;
780 *wp++ = CQUOTE;
781 goto Done;
782 } else {
783 Source *s;
784
785 ungetsc(c2);
786 /*
787 * mismatched parenthesis -
788 * assume we were really
789 * parsing a (...) expression
790 */
791 *wp = EOS;
792 sp = Xstring(ws, wp);
793 dp = wdstrip(sp, WDS_KEEPQ);
794 s = pushs(SREREAD, source->areap);
795 s->start = s->str = s->u.freeme = dp;
796 s->next = source;
797 source = s;
798 return ('('/*)*/);
799 }
800 } else if (c == '(')
801 /*
802 * parentheses inside quotes and
803 * backslashes are lost, but AT&T ksh
804 * doesn't count them either
805 */
806 ++statep->nparen;
807 goto Sbase2;
808
809 /* <<, <<-, <<< delimiter */
810 case SHEREDELIM:
811 /*
812 * here delimiters need a special case since
813 * $ and `...` are not to be treated specially
814 */
815 switch (c) {
816 case '\\':
817 if ((c = getsc())) {
818 /* trailing \ is lost */
819 *wp++ = QCHAR;
820 *wp++ = c;
821 }
822 break;
823 case '\'':
824 goto open_ssquote_unless_heredoc;
825 case '$':
826 if ((c2 = getsc()) == '\'') {
827 open_sequote:
828 *wp++ = OQUOTE;
829 ignore_backslash_newline++;
830 PUSH_STATE(SEQUOTE);
831 statep->ls_bool = false;
832 break;
833 } else if (c2 == '"') {
834 /* FALLTHROUGH */
835 case '"':
836 PUSH_SRETRACE(SHEREDQUOTE);
837 break;
838 }
839 ungetsc(c2);
840 /* FALLTHROUGH */
841 default:
842 *wp++ = CHAR;
843 *wp++ = c;
844 }
845 break;
846
847 /* " in <<, <<-, <<< delimiter */
848 case SHEREDQUOTE:
849 if (c != '"')
850 goto Subst;
851 POP_SRETRACE();
852 dp = strnul(sp) - 1;
853 /* remove the trailing double quote */
854 *dp = '\0';
855 /* store the quoted string */
856 *wp++ = OQUOTE;
857 XcheckN(ws, wp, (dp - sp));
858 dp = sp;
859 while ((c = *dp++)) {
860 if (c == '\\') {
861 switch ((c = *dp++)) {
862 case '\\':
863 case '"':
864 case '$':
865 case '`':
866 break;
867 default:
868 *wp++ = CHAR;
869 *wp++ = '\\';
870 break;
871 }
872 }
873 *wp++ = CHAR;
874 *wp++ = c;
875 }
876 afree(sp, ATEMP);
877 *wp++ = CQUOTE;
878 state = statep->type = SHEREDELIM;
879 break;
880
881 /* in *(...|...) pattern (*+?@!) */
882 case SPATTERN:
883 if (c == /*(*/ ')') {
884 *wp++ = CPAT;
885 POP_STATE();
886 } else if (c == '|') {
887 *wp++ = SPAT;
888 } else if (c == '(') {
889 *wp++ = OPAT;
890 /* simile for @ */
891 *wp++ = ' ';
892 PUSH_STATE(SPATTERN);
893 } else
894 goto Sbase1;
895 break;
896 }
897 }
898 Done:
899 Xcheck(ws, wp);
900 if (statep != &states[1])
901 /* XXX figure out what is missing */
902 yyerror("no closing quote\n");
903
904 /* This done to avoid tests for SHEREDELIM wherever SBASE tested */
905 if (state == SHEREDELIM)
906 state = SBASE;
907
908 dp = Xstring(ws, wp);
909 if (state == SBASE && (
910 #ifndef MKSH_LEGACY_MODE
911 (c == '&' && !Flag(FSH) && !Flag(FPOSIX)) ||
912 #endif
913 c == '<' || c == '>')) {
914 struct ioword *iop = alloc(sizeof(struct ioword), ATEMP);
915
916 if (Xlength(ws, wp) == 0)
917 iop->unit = c == '<' ? 0 : 1;
918 else for (iop->unit = 0, c2 = 0; c2 < Xlength(ws, wp); c2 += 2) {
919 if (dp[c2] != CHAR)
920 goto no_iop;
921 if (!ksh_isdigit(dp[c2 + 1]))
922 goto no_iop;
923 iop->unit = (iop->unit * 10) + dp[c2 + 1] - '0';
924 }
925
926 if (iop->unit >= FDBASE)
927 goto no_iop;
928
929 if (c == '&') {
930 if ((c2 = getsc()) != '>') {
931 ungetsc(c2);
932 goto no_iop;
933 }
934 c = c2;
935 iop->flag = IOBASH;
936 } else
937 iop->flag = 0;
938
939 c2 = getsc();
940 /* <<, >>, <> are ok, >< is not */
941 if (c == c2 || (c == '<' && c2 == '>')) {
942 iop->flag |= c == c2 ?
943 (c == '>' ? IOCAT : IOHERE) : IORDWR;
944 if (iop->flag == IOHERE) {
945 if ((c2 = getsc()) == '-') {
946 iop->flag |= IOSKIP;
947 c2 = getsc();
948 } else if (c2 == '<')
949 iop->flag |= IOHERESTR;
950 ungetsc(c2);
951 if (c2 == '\n')
952 iop->flag |= IONDELIM;
953 }
954 } else if (c2 == '&')
955 iop->flag |= IODUP | (c == '<' ? IORDUP : 0);
956 else {
957 iop->flag |= c == '>' ? IOWRITE : IOREAD;
958 if (c == '>' && c2 == '|')
959 iop->flag |= IOCLOB;
960 else
961 ungetsc(c2);
962 }
963
964 iop->name = NULL;
965 iop->delim = NULL;
966 iop->heredoc = NULL;
967 /* free word */
968 Xfree(ws, wp);
969 yylval.iop = iop;
970 return (REDIR);
971 no_iop:
972 afree(iop, ATEMP);
973 }
974
975 if (wp == dp && state == SBASE) {
976 /* free word */
977 Xfree(ws, wp);
978 /* no word, process LEX1 character */
979 if ((c == '|') || (c == '&') || (c == ';') || (c == '('/*)*/)) {
980 if ((c2 = getsc()) == c)
981 c = (c == ';') ? BREAK :
982 (c == '|') ? LOGOR :
983 (c == '&') ? LOGAND :
984 /* c == '(' ) */ MDPAREN;
985 else if (c == '|' && c2 == '&')
986 c = COPROC;
987 else if (c == ';' && c2 == '|')
988 c = BRKEV;
989 else if (c == ';' && c2 == '&')
990 c = BRKFT;
991 else
992 ungetsc(c2);
993 #ifndef MKSH_SMALL
994 if (c == BREAK) {
995 if ((c2 = getsc()) == '&')
996 c = BRKEV;
997 else
998 ungetsc(c2);
999 }
1000 #endif
1001 } else if (c == '\n') {
1002 gethere(false);
1003 if (cf & CONTIN)
1004 goto Again;
1005 } else if (c == '\0')
1006 /* need here strings at EOF */
1007 gethere(true);
1008 return (c);
1009 }
1010
1011 /* terminate word */
1012 *wp++ = EOS;
1013 yylval.cp = Xclose(ws, wp);
1014 if (state == SWORD || state == SLETPAREN
1015 /* XXX ONEWORD? */)
1016 return (LWORD);
1017
1018 /* unget terminator */
1019 ungetsc(c);
1020
1021 /*
1022 * note: the alias-vs-function code below depends on several
1023 * interna: starting from here, source->str is not modified;
1024 * the way getsc() and ungetsc() operate; etc.
1025 */
1026
1027 /* copy word to unprefixed string ident */
1028 sp = yylval.cp;
1029 dp = ident;
1030 if ((cf & HEREDELIM) && (sp[1] == '<'))
1031 while ((dp - ident) < IDENT) {
1032 if ((c = *sp++) == CHAR)
1033 *dp++ = *sp++;
1034 else if ((c != OQUOTE) && (c != CQUOTE))
1035 break;
1036 }
1037 else
1038 while ((dp - ident) < IDENT && (c = *sp++) == CHAR)
1039 *dp++ = *sp++;
1040 /* Make sure the ident array stays '\0' padded */
1041 memset(dp, 0, (ident + IDENT) - dp + 1);
1042 if (c != EOS)
1043 /* word is not unquoted */
1044 *ident = '\0';
1045
1046 if (*ident != '\0' && (cf & (KEYWORD | ALIAS))) {
1047 struct tbl *p;
1048 uint32_t h = hash(ident);
1049
1050 if ((cf & KEYWORD) && (p = ktsearch(&keywords, ident, h)) &&
1051 (!(cf & ESACONLY) || p->val.i == ESAC ||
1052 p->val.i == /*{*/ '}')) {
1053 afree(yylval.cp, ATEMP);
1054 return (p->val.i);
1055 }
1056 if ((cf & ALIAS) && (p = ktsearch(&aliases, ident, h)) &&
1057 (p->flag & ISSET)) {
1058 /*
1059 * this still points to the same character as the
1060 * ungetsc'd terminator from above
1061 */
1062 const char *cp = source->str;
1063
1064 /* prefer POSIX but not Korn functions over aliases */
1065 while (*cp == ' ' || *cp == '\t')
1066 /*
1067 * this is like getsc() without skipping
1068 * over Source boundaries (including not
1069 * parsing ungetsc'd characters that got
1070 * pushed into an SREREAD) which is what
1071 * we want here anyway: find out whether
1072 * the alias name is followed by a POSIX
1073 * function definition (only the opening
1074 * parenthesis is checked though)
1075 */
1076 ++cp;
1077 /* prefer functions over aliases */
1078 if (cp[0] != '(' || cp[1] != ')') {
1079 Source *s = source;
1080
1081 while (s && (s->flags & SF_HASALIAS))
1082 if (s->u.tblp == p)
1083 return (LWORD);
1084 else
1085 s = s->next;
1086 /* push alias expansion */
1087 s = pushs(SALIAS, source->areap);
1088 s->start = s->str = p->val.s;
1089 s->u.tblp = p;
1090 s->flags |= SF_HASALIAS;
1091 s->next = source;
1092 if (source->type == SEOF) {
1093 /* prevent infinite recursion at EOS */
1094 source->u.tblp = p;
1095 source->flags |= SF_HASALIAS;
1096 }
1097 source = s;
1098 afree(yylval.cp, ATEMP);
1099 goto Again;
1100 }
1101 }
1102 }
1103
1104 return (LWORD);
1105 }
1106
1107 static void
gethere(bool iseof)1108 gethere(bool iseof)
1109 {
1110 struct ioword **p;
1111
1112 for (p = heres; p < herep; p++)
1113 if (iseof && !((*p)->flag & IOHERESTR))
1114 /* only here strings at EOF */
1115 return;
1116 else
1117 readhere(*p);
1118 herep = heres;
1119 }
1120
1121 /*
1122 * read "<<word" text into temp file
1123 */
1124
1125 static void
readhere(struct ioword * iop)1126 readhere(struct ioword *iop)
1127 {
1128 int c;
1129 const char *eof, *eofp;
1130 XString xs;
1131 char *xp;
1132 int xpos;
1133
1134 if (iop->flag & IOHERESTR) {
1135 /* process the here string */
1136 iop->heredoc = xp = evalstr(iop->delim, DOBLANK);
1137 xpos = strlen(xp) - 1;
1138 memmove(xp, xp + 1, xpos);
1139 xp[xpos] = '\n';
1140 return;
1141 }
1142
1143 eof = iop->flag & IONDELIM ? "<<" : evalstr(iop->delim, 0);
1144
1145 if (!(iop->flag & IOEVAL))
1146 ignore_backslash_newline++;
1147
1148 Xinit(xs, xp, 256, ATEMP);
1149
1150 heredoc_read_line:
1151 /* beginning of line */
1152 eofp = eof;
1153 xpos = Xsavepos(xs, xp);
1154 if (iop->flag & IOSKIP) {
1155 /* skip over leading tabs */
1156 while ((c = getsc()) == '\t')
1157 /* nothing */;
1158 goto heredoc_parse_char;
1159 }
1160 heredoc_read_char:
1161 c = getsc();
1162 heredoc_parse_char:
1163 /* compare with here document marker */
1164 if (!*eofp) {
1165 /* end of here document marker, what to do? */
1166 switch (c) {
1167 case /*(*/ ')':
1168 if (!subshell_nesting_type)
1169 /*-
1170 * not allowed outside $(...) or (...)
1171 * => mismatch
1172 */
1173 break;
1174 /* allow $(...) or (...) to close here */
1175 ungetsc(/*(*/ ')');
1176 /* FALLTHROUGH */
1177 case 0:
1178 /*
1179 * Allow EOF here to commands without trailing
1180 * newlines (mksh -c '...') will work as well.
1181 */
1182 case '\n':
1183 /* Newline terminates here document marker */
1184 goto heredoc_found_terminator;
1185 }
1186 } else if (c == *eofp++)
1187 /* store; then read and compare next character */
1188 goto heredoc_store_and_loop;
1189 /* nope, mismatch; read until end of line */
1190 while (c != '\n') {
1191 if (!c)
1192 /* oops, reached EOF */
1193 yyerror("%s '%s' unclosed\n", "here document", eof);
1194 /* store character */
1195 Xcheck(xs, xp);
1196 Xput(xs, xp, c);
1197 /* read next character */
1198 c = getsc();
1199 }
1200 /* we read a newline as last character */
1201 heredoc_store_and_loop:
1202 /* store character */
1203 Xcheck(xs, xp);
1204 Xput(xs, xp, c);
1205 if (c == '\n')
1206 goto heredoc_read_line;
1207 goto heredoc_read_char;
1208
1209 heredoc_found_terminator:
1210 /* jump back to saved beginning of line */
1211 xp = Xrestpos(xs, xp, xpos);
1212 /* terminate, close and store */
1213 Xput(xs, xp, '\0');
1214 iop->heredoc = Xclose(xs, xp);
1215
1216 if (!(iop->flag & IOEVAL))
1217 ignore_backslash_newline--;
1218 }
1219
1220 void
yyerror(const char * fmt,...)1221 yyerror(const char *fmt, ...)
1222 {
1223 va_list va;
1224
1225 /* pop aliases and re-reads */
1226 while (source->type == SALIAS || source->type == SREREAD)
1227 source = source->next;
1228 /* zap pending input */
1229 source->str = null;
1230
1231 error_prefix(true);
1232 va_start(va, fmt);
1233 shf_vfprintf(shl_out, fmt, va);
1234 va_end(va);
1235 errorfz();
1236 }
1237
1238 /*
1239 * input for yylex with alias expansion
1240 */
1241
1242 Source *
pushs(int type,Area * areap)1243 pushs(int type, Area *areap)
1244 {
1245 Source *s;
1246
1247 s = alloc(sizeof(Source), areap);
1248 memset(s, 0, sizeof(Source));
1249 s->type = type;
1250 s->str = null;
1251 s->areap = areap;
1252 if (type == SFILE || type == SSTDIN)
1253 XinitN(s->xs, 256, s->areap);
1254 return (s);
1255 }
1256
1257 static int
getsc_uu(void)1258 getsc_uu(void)
1259 {
1260 Source *s = source;
1261 int c;
1262
1263 while ((c = *s->str++) == 0) {
1264 /* return 0 for EOF by default */
1265 s->str = NULL;
1266 switch (s->type) {
1267 case SEOF:
1268 s->str = null;
1269 return (0);
1270
1271 case SSTDIN:
1272 case SFILE:
1273 getsc_line(s);
1274 break;
1275
1276 case SWSTR:
1277 break;
1278
1279 case SSTRING:
1280 case SSTRINGCMDLINE:
1281 break;
1282
1283 case SWORDS:
1284 s->start = s->str = *s->u.strv++;
1285 s->type = SWORDSEP;
1286 break;
1287
1288 case SWORDSEP:
1289 if (*s->u.strv == NULL) {
1290 s->start = s->str = "\n";
1291 s->type = SEOF;
1292 } else {
1293 s->start = s->str = " ";
1294 s->type = SWORDS;
1295 }
1296 break;
1297
1298 case SALIAS:
1299 if (s->flags & SF_ALIASEND) {
1300 /* pass on an unused SF_ALIAS flag */
1301 source = s->next;
1302 source->flags |= s->flags & SF_ALIAS;
1303 s = source;
1304 } else if (*s->u.tblp->val.s &&
1305 (c = strnul(s->u.tblp->val.s)[-1], ksh_isspace(c))) {
1306 /* pop source stack */
1307 source = s = s->next;
1308 /*
1309 * Note that this alias ended with a
1310 * space, enabling alias expansion on
1311 * the following word.
1312 */
1313 s->flags |= SF_ALIAS;
1314 } else {
1315 /*
1316 * At this point, we need to keep the current
1317 * alias in the source list so recursive
1318 * aliases can be detected and we also need to
1319 * return the next character. Do this by
1320 * temporarily popping the alias to get the
1321 * next character and then put it back in the
1322 * source list with the SF_ALIASEND flag set.
1323 */
1324 /* pop source stack */
1325 source = s->next;
1326 source->flags |= s->flags & SF_ALIAS;
1327 c = getsc_uu();
1328 if (c) {
1329 s->flags |= SF_ALIASEND;
1330 s->ugbuf[0] = c; s->ugbuf[1] = '\0';
1331 s->start = s->str = s->ugbuf;
1332 s->next = source;
1333 source = s;
1334 } else {
1335 s = source;
1336 /* avoid reading EOF twice */
1337 s->str = NULL;
1338 break;
1339 }
1340 }
1341 continue;
1342
1343 case SREREAD:
1344 if (s->start != s->ugbuf)
1345 /* yuck */
1346 afree(s->u.freeme, ATEMP);
1347 source = s = s->next;
1348 continue;
1349 }
1350 if (s->str == NULL) {
1351 s->type = SEOF;
1352 s->start = s->str = null;
1353 return ('\0');
1354 }
1355 if (s->flags & SF_ECHO) {
1356 shf_puts(s->str, shl_out);
1357 shf_flush(shl_out);
1358 }
1359 }
1360 return (c);
1361 }
1362
1363 static void
getsc_line(Source * s)1364 getsc_line(Source *s)
1365 {
1366 char *xp = Xstring(s->xs, xp), *cp;
1367 bool interactive = Flag(FTALKING) && s->type == SSTDIN;
1368 bool have_tty = tobool(interactive && (s->flags & SF_TTY));
1369
1370 /* Done here to ensure nothing odd happens when a timeout occurs */
1371 XcheckN(s->xs, xp, LINE);
1372 *xp = '\0';
1373 s->start = s->str = xp;
1374
1375 if (have_tty && ksh_tmout) {
1376 ksh_tmout_state = TMOUT_READING;
1377 alarm(ksh_tmout);
1378 }
1379 if (interactive)
1380 change_winsz();
1381 #ifndef MKSH_NO_CMDLINE_EDITING
1382 if (have_tty && (
1383 #if !MKSH_S_NOVI
1384 Flag(FVI) ||
1385 #endif
1386 Flag(FEMACS) || Flag(FGMACS))) {
1387 int nread;
1388
1389 nread = x_read(xp);
1390 if (nread < 0)
1391 /* read error */
1392 nread = 0;
1393 xp[nread] = '\0';
1394 xp += nread;
1395 } else
1396 #endif
1397 {
1398 if (interactive)
1399 pprompt(prompt, 0);
1400 else
1401 s->line++;
1402
1403 while (/* CONSTCOND */ 1) {
1404 char *p = shf_getse(xp, Xnleft(s->xs, xp), s->u.shf);
1405
1406 if (!p && shf_error(s->u.shf) &&
1407 shf_errno(s->u.shf) == EINTR) {
1408 shf_clearerr(s->u.shf);
1409 if (trap)
1410 runtraps(0);
1411 continue;
1412 }
1413 if (!p || (xp = p, xp[-1] == '\n'))
1414 break;
1415 /* double buffer size */
1416 /* move past NUL so doubling works... */
1417 xp++;
1418 XcheckN(s->xs, xp, Xlength(s->xs, xp));
1419 /* ...and move back again */
1420 xp--;
1421 }
1422 /*
1423 * flush any unwanted input so other programs/builtins
1424 * can read it. Not very optimal, but less error prone
1425 * than flushing else where, dealing with redirections,
1426 * etc.
1427 * TODO: reduce size of shf buffer (~128?) if SSTDIN
1428 */
1429 if (s->type == SSTDIN)
1430 shf_flush(s->u.shf);
1431 }
1432 /*
1433 * XXX: temporary kludge to restore source after a
1434 * trap may have been executed.
1435 */
1436 source = s;
1437 if (have_tty && ksh_tmout) {
1438 ksh_tmout_state = TMOUT_EXECUTING;
1439 alarm(0);
1440 }
1441 cp = Xstring(s->xs, xp);
1442 rndpush(cp);
1443 s->start = s->str = cp;
1444 strip_nuls(Xstring(s->xs, xp), Xlength(s->xs, xp));
1445 /* Note: if input is all nulls, this is not eof */
1446 if (Xlength(s->xs, xp) == 0) {
1447 /* EOF */
1448 if (s->type == SFILE)
1449 shf_fdclose(s->u.shf);
1450 s->str = NULL;
1451 } else if (interactive && *s->str &&
1452 (cur_prompt != PS1 || !ctype(*s->str, C_IFS | C_IFSWS))) {
1453 histsave(&s->line, s->str, true, true);
1454 #if !defined(MKSH_SMALL) && HAVE_PERSISTENT_HISTORY
1455 } else if (interactive && cur_prompt == PS1) {
1456 cp = Xstring(s->xs, xp);
1457 while (*cp && ctype(*cp, C_IFSWS))
1458 ++cp;
1459 if (!*cp)
1460 histsync();
1461 #endif
1462 }
1463 if (interactive)
1464 set_prompt(PS2, NULL);
1465 }
1466
1467 void
set_prompt(int to,Source * s)1468 set_prompt(int to, Source *s)
1469 {
1470 cur_prompt = to;
1471
1472 switch (to) {
1473 /* command */
1474 case PS1:
1475 /*
1476 * Substitute ! and !! here, before substitutions are done
1477 * so ! in expanded variables are not expanded.
1478 * NOTE: this is not what AT&T ksh does (it does it after
1479 * substitutions, POSIX doesn't say which is to be done.
1480 */
1481 {
1482 struct shf *shf;
1483 char * volatile ps1;
1484 Area *saved_atemp;
1485
1486 ps1 = str_val(global("PS1"));
1487 shf = shf_sopen(NULL, strlen(ps1) * 2,
1488 SHF_WR | SHF_DYNAMIC, NULL);
1489 while (*ps1)
1490 if (*ps1 != '!' || *++ps1 == '!')
1491 shf_putchar(*ps1++, shf);
1492 else
1493 shf_fprintf(shf, "%d",
1494 s ? s->line + 1 : 0);
1495 ps1 = shf_sclose(shf);
1496 saved_atemp = ATEMP;
1497 newenv(E_ERRH);
1498 if (kshsetjmp(e->jbuf)) {
1499 prompt = safe_prompt;
1500 /*
1501 * Don't print an error - assume it has already
1502 * been printed. Reason is we may have forked
1503 * to run a command and the child may be
1504 * unwinding its stack through this code as it
1505 * exits.
1506 */
1507 } else {
1508 char *cp = substitute(ps1, 0);
1509 strdupx(prompt, cp, saved_atemp);
1510 }
1511 quitenv(NULL);
1512 }
1513 break;
1514 /* command continuation */
1515 case PS2:
1516 prompt = str_val(global("PS2"));
1517 break;
1518 }
1519 }
1520
1521 int
pprompt(const char * cp,int ntruncate)1522 pprompt(const char *cp, int ntruncate)
1523 {
1524 char delimiter = 0;
1525 bool doprint = (ntruncate != -1);
1526 bool indelimit = false;
1527 int columns = 0, lines = 0;
1528
1529 /*
1530 * Undocumented AT&T ksh feature:
1531 * If the second char in the prompt string is \r then the first
1532 * char is taken to be a non-printing delimiter and any chars
1533 * between two instances of the delimiter are not considered to
1534 * be part of the prompt length
1535 */
1536 if (*cp && cp[1] == '\r') {
1537 delimiter = *cp;
1538 cp += 2;
1539 }
1540 for (; *cp; cp++) {
1541 if (indelimit && *cp != delimiter)
1542 ;
1543 else if (*cp == '\n' || *cp == '\r') {
1544 lines += columns / x_cols + ((*cp == '\n') ? 1 : 0);
1545 columns = 0;
1546 } else if (*cp == '\t') {
1547 columns = (columns | 7) + 1;
1548 } else if (*cp == '\b') {
1549 if (columns > 0)
1550 columns--;
1551 } else if (*cp == delimiter)
1552 indelimit = !indelimit;
1553 else if (UTFMODE && ((unsigned char)*cp > 0x7F)) {
1554 const char *cp2;
1555 columns += utf_widthadj(cp, &cp2);
1556 if (doprint && (indelimit ||
1557 (ntruncate < (x_cols * lines + columns))))
1558 shf_write(cp, cp2 - cp, shl_out);
1559 cp = cp2 - /* loop increment */ 1;
1560 continue;
1561 } else
1562 columns++;
1563 if (doprint && (*cp != delimiter) &&
1564 (indelimit || (ntruncate < (x_cols * lines + columns))))
1565 shf_putc(*cp, shl_out);
1566 }
1567 if (doprint)
1568 shf_flush(shl_out);
1569 return (x_cols * lines + columns);
1570 }
1571
1572 /*
1573 * Read the variable part of a ${...} expression (i.e. up to but not
1574 * including the :[-+?=#%] or close-brace).
1575 */
1576 static char *
get_brace_var(XString * wsp,char * wp)1577 get_brace_var(XString *wsp, char *wp)
1578 {
1579 char c;
1580 enum parse_state {
1581 PS_INITIAL, PS_SAW_HASH, PS_IDENT,
1582 PS_NUMBER, PS_VAR1
1583 } state = PS_INITIAL;
1584
1585 while (/* CONSTCOND */ 1) {
1586 c = getsc();
1587 /* State machine to figure out where the variable part ends. */
1588 switch (state) {
1589 case PS_INITIAL:
1590 if (c == '#' || c == '!' || c == '%') {
1591 state = PS_SAW_HASH;
1592 break;
1593 }
1594 /* FALLTHROUGH */
1595 case PS_SAW_HASH:
1596 if (ksh_isalphx(c))
1597 state = PS_IDENT;
1598 else if (ksh_isdigit(c))
1599 state = PS_NUMBER;
1600 else if (c == '#') {
1601 if (state == PS_SAW_HASH) {
1602 char c2;
1603
1604 c2 = getsc();
1605 ungetsc(c2);
1606 if (c2 != /*{*/ '}') {
1607 ungetsc(c);
1608 goto out;
1609 }
1610 }
1611 state = PS_VAR1;
1612 } else if (ctype(c, C_VAR1))
1613 state = PS_VAR1;
1614 else
1615 goto out;
1616 break;
1617 case PS_IDENT:
1618 if (!ksh_isalnux(c)) {
1619 if (c == '[') {
1620 char *tmp, *p;
1621
1622 if (!arraysub(&tmp))
1623 yyerror("missing ]\n");
1624 *wp++ = c;
1625 for (p = tmp; *p; ) {
1626 Xcheck(*wsp, wp);
1627 *wp++ = *p++;
1628 }
1629 afree(tmp, ATEMP);
1630 /* the ] */
1631 c = getsc();
1632 }
1633 goto out;
1634 }
1635 break;
1636 case PS_NUMBER:
1637 if (!ksh_isdigit(c))
1638 goto out;
1639 break;
1640 case PS_VAR1:
1641 goto out;
1642 }
1643 Xcheck(*wsp, wp);
1644 *wp++ = c;
1645 }
1646 out:
1647 /* end of variable part */
1648 *wp++ = '\0';
1649 ungetsc(c);
1650 return (wp);
1651 }
1652
1653 /*
1654 * Save an array subscript - returns true if matching bracket found, false
1655 * if eof or newline was found.
1656 * (Returned string double null terminated)
1657 */
1658 static bool
arraysub(char ** strp)1659 arraysub(char **strp)
1660 {
1661 XString ws;
1662 char *wp, c;
1663 /* we are just past the initial [ */
1664 unsigned int depth = 1;
1665
1666 Xinit(ws, wp, 32, ATEMP);
1667
1668 do {
1669 c = getsc();
1670 Xcheck(ws, wp);
1671 *wp++ = c;
1672 if (c == '[')
1673 depth++;
1674 else if (c == ']')
1675 depth--;
1676 } while (depth > 0 && c && c != '\n');
1677
1678 *wp++ = '\0';
1679 *strp = Xclose(ws, wp);
1680
1681 return (tobool(depth == 0));
1682 }
1683
1684 /* Unget a char: handles case when we are already at the start of the buffer */
1685 static void
ungetsc(int c)1686 ungetsc(int c)
1687 {
1688 struct sretrace_info *rp = retrace_info;
1689
1690 if (backslash_skip)
1691 backslash_skip--;
1692 /* Don't unget EOF... */
1693 if (source->str == null && c == '\0')
1694 return;
1695 while (rp) {
1696 if (Xlength(rp->xs, rp->xp))
1697 rp->xp--;
1698 rp = rp->next;
1699 }
1700 ungetsc_i(c);
1701 }
1702 static void
ungetsc_i(int c)1703 ungetsc_i(int c)
1704 {
1705 if (source->str > source->start)
1706 source->str--;
1707 else {
1708 Source *s;
1709
1710 s = pushs(SREREAD, source->areap);
1711 s->ugbuf[0] = c; s->ugbuf[1] = '\0';
1712 s->start = s->str = s->ugbuf;
1713 s->next = source;
1714 source = s;
1715 }
1716 }
1717
1718
1719 /* Called to get a char that isn't a \newline sequence. */
1720 static int
getsc_bn(void)1721 getsc_bn(void)
1722 {
1723 int c, c2;
1724
1725 if (ignore_backslash_newline)
1726 return (o_getsc_u());
1727
1728 if (backslash_skip == 1) {
1729 backslash_skip = 2;
1730 return (o_getsc_u());
1731 }
1732
1733 backslash_skip = 0;
1734
1735 while (/* CONSTCOND */ 1) {
1736 c = o_getsc_u();
1737 if (c == '\\') {
1738 if ((c2 = o_getsc_u()) == '\n')
1739 /* ignore the \newline; get the next char... */
1740 continue;
1741 ungetsc_i(c2);
1742 backslash_skip = 1;
1743 }
1744 return (c);
1745 }
1746 }
1747
1748 void
yyskiputf8bom(void)1749 yyskiputf8bom(void)
1750 {
1751 int c;
1752
1753 if ((unsigned char)(c = o_getsc_u()) != 0xEF) {
1754 ungetsc_i(c);
1755 return;
1756 }
1757 if ((unsigned char)(c = o_getsc_u()) != 0xBB) {
1758 ungetsc_i(c);
1759 ungetsc_i(0xEF);
1760 return;
1761 }
1762 if ((unsigned char)(c = o_getsc_u()) != 0xBF) {
1763 ungetsc_i(c);
1764 ungetsc_i(0xBB);
1765 ungetsc_i(0xEF);
1766 return;
1767 }
1768 UTFMODE |= 8;
1769 }
1770
1771 static Lex_state *
push_state_i(State_info * si,Lex_state * old_end)1772 push_state_i(State_info *si, Lex_state *old_end)
1773 {
1774 Lex_state *news = alloc2(STATE_BSIZE, sizeof(Lex_state), ATEMP);
1775
1776 news[0].ls_base = old_end;
1777 si->base = &news[0];
1778 si->end = &news[STATE_BSIZE];
1779 return (&news[1]);
1780 }
1781
1782 static Lex_state *
pop_state_i(State_info * si,Lex_state * old_end)1783 pop_state_i(State_info *si, Lex_state *old_end)
1784 {
1785 Lex_state *old_base = si->base;
1786
1787 si->base = old_end->ls_base - STATE_BSIZE;
1788 si->end = old_end->ls_base;
1789
1790 afree(old_base, ATEMP);
1791
1792 return (si->base + STATE_BSIZE - 1);
1793 }
1794
1795 static int
s_get(void)1796 s_get(void)
1797 {
1798 return (getsc());
1799 }
1800
1801 static void
s_put(int c)1802 s_put(int c)
1803 {
1804 ungetsc(c);
1805 }
1806