lexi.c revision 1.65 1 /* $NetBSD: lexi.c,v 1.65 2021/10/03 20:35:59 rillig Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-4-Clause
5 *
6 * Copyright (c) 1985 Sun Microsystems, Inc.
7 * Copyright (c) 1980, 1993
8 * The Regents of the University of California. All rights reserved.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the University of
22 * California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 */
39
40 #if 0
41 static char sccsid[] = "@(#)lexi.c 8.1 (Berkeley) 6/6/93";
42 #endif
43
44 #include <sys/cdefs.h>
45 #if defined(__NetBSD__)
46 __RCSID("$NetBSD: lexi.c,v 1.65 2021/10/03 20:35:59 rillig Exp $");
47 #elif defined(__FreeBSD__)
48 __FBSDID("$FreeBSD: head/usr.bin/indent/lexi.c 337862 2018-08-15 18:19:45Z pstef $");
49 #endif
50
51 #include <assert.h>
52 #include <stdio.h>
53 #include <ctype.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <sys/param.h>
57
58 #include "indent.h"
59
60 /* must be sorted alphabetically, is used in binary search */
61 static const struct keyword {
62 const char *name;
63 enum keyword_kind kind;
64 } keywords[] = {
65 {"_Bool", kw_type},
66 {"_Complex", kw_type},
67 {"_Imaginary", kw_type},
68 {"auto", kw_storage_class},
69 {"bool", kw_type},
70 {"break", kw_jump},
71 {"case", kw_case_or_default},
72 {"char", kw_type},
73 {"complex", kw_type},
74 {"const", kw_type},
75 {"continue", kw_jump},
76 {"default", kw_case_or_default},
77 {"do", kw_do_or_else},
78 {"double", kw_type},
79 {"else", kw_do_or_else},
80 {"enum", kw_struct_or_union_or_enum},
81 {"extern", kw_storage_class},
82 {"float", kw_type},
83 {"for", kw_for_or_if_or_while},
84 {"global", kw_type},
85 {"goto", kw_jump},
86 {"if", kw_for_or_if_or_while},
87 {"imaginary", kw_type},
88 {"inline", kw_inline_or_restrict},
89 {"int", kw_type},
90 {"long", kw_type},
91 {"offsetof", kw_offsetof},
92 {"register", kw_storage_class},
93 {"restrict", kw_inline_or_restrict},
94 {"return", kw_jump},
95 {"short", kw_type},
96 {"signed", kw_type},
97 {"sizeof", kw_sizeof},
98 {"static", kw_storage_class},
99 {"struct", kw_struct_or_union_or_enum},
100 {"switch", kw_switch},
101 {"typedef", kw_typedef},
102 {"union", kw_struct_or_union_or_enum},
103 {"unsigned", kw_type},
104 {"void", kw_type},
105 {"volatile", kw_type},
106 {"while", kw_for_or_if_or_while}
107 };
108
109 struct {
110 const char **items;
111 unsigned int len;
112 unsigned int cap;
113 } typenames;
114
115 /*
116 * The transition table below was rewritten by hand from lx's output, given
117 * the following definitions. lx is Katherine Flavel's lexer generator.
118 *
119 * O = /[0-7]/; D = /[0-9]/; NZ = /[1-9]/;
120 * H = /[a-f0-9]/i; B = /[0-1]/; HP = /0x/i;
121 * BP = /0b/i; E = /e[+\-]?/i D+; P = /p[+\-]?/i D+;
122 * FS = /[fl]/i; IS = /u/i /(l|L|ll|LL)/? | /(l|L|ll|LL)/ /u/i?;
123 *
124 * D+ E FS? -> $float;
125 * D* "." D+ E? FS? -> $float;
126 * D+ "." E? FS? -> $float; HP H+ IS? -> $int;
127 * HP H+ P FS? -> $float; NZ D* IS? -> $int;
128 * HP H* "." H+ P FS? -> $float; "0" O* IS? -> $int;
129 * HP H+ "." P FS -> $float; BP B+ IS? -> $int;
130 */
131 static const char num_lex_state[][26] = {
132 /* examples:
133 00
134 s 0xx
135 t 00xaa
136 a 11 101100xxa..
137 r 11ee0001101lbuuxx.a.pp
138 t.01.e+008bLuxll0Ll.aa.p+0
139 states: ABCDEFGHIJKLMNOPQRSTUVWXYZ */
140 [0] = "uuiifuufiuuiiuiiiiiuiuuuuu",
141 [1] = "CEIDEHHHIJQ U Q VUVVZZZ",
142 [2] = "DEIDEHHHIJQ U Q VUVVZZZ",
143 [3] = "DEIDEHHHIJ U VUVVZZZ",
144 [4] = "DEJDEHHHJJ U VUVVZZZ",
145 [5] = " U VUVV ",
146 [6] = " K U VUVV ",
147 [7] = " FFF FF U VUVV ",
148 [8] = " f f U VUVV f",
149 [9] = " LLf fL PR Li L f",
150 [10] = " OOf fO S P O i O f",
151 [11] = " FFX ",
152 [12] = " MM M i iiM M ",
153 [13] = " N ",
154 [14] = " G Y ",
155 [15] = "B EE EE T W ",
156 /* ABCDEFGHIJKLMNOPQRSTUVWXYZ */
157 };
158
159 static const uint8_t num_lex_row[] = {
160 ['0'] = 1,
161 ['1'] = 2,
162 ['2'] = 3, ['3'] = 3, ['4'] = 3, ['5'] = 3, ['6'] = 3, ['7'] = 3,
163 ['8'] = 4, ['9'] = 4,
164 ['A'] = 5, ['a'] = 5, ['C'] = 5, ['c'] = 5, ['D'] = 5, ['d'] = 5,
165 ['B'] = 6, ['b'] = 6,
166 ['E'] = 7, ['e'] = 7,
167 ['F'] = 8, ['f'] = 8,
168 ['L'] = 9,
169 ['l'] = 10,
170 ['P'] = 11, ['p'] = 11,
171 ['U'] = 12, ['u'] = 12,
172 ['X'] = 13, ['x'] = 13,
173 ['+'] = 14, ['-'] = 14,
174 ['.'] = 15,
175 };
176
177 static char
178 inbuf_peek(void)
179 {
180 return *buf_ptr;
181 }
182
183 static void
184 inbuf_skip(void)
185 {
186 buf_ptr++;
187 if (buf_ptr >= buf_end)
188 fill_buffer();
189 }
190
191 static char
192 inbuf_next(void)
193 {
194 char ch = inbuf_peek();
195 inbuf_skip();
196 return ch;
197 }
198
199 static void
200 check_size_token(size_t desired_size)
201 {
202 if (token.e + desired_size >= token.l)
203 buf_expand(&token, desired_size);
204 }
205
206 static int
207 cmp_keyword_by_name(const void *key, const void *elem)
208 {
209 return strcmp(key, ((const struct keyword *)elem)->name);
210 }
211
212 static int
213 cmp_type_by_name(const void *key, const void *elem)
214 {
215 return strcmp(key, *((const char *const *)elem));
216 }
217
218 #ifdef debug
219 const char *
220 token_type_name(token_type ttype)
221 {
222 static const char *const name[] = {
223 "end_of_file", "newline", "lparen", "rparen", "unary_op",
224 "binary_op", "postfix_op", "question", "case_label", "colon",
225 "semicolon", "lbrace", "rbrace", "ident", "comma",
226 "comment", "switch_expr", "preprocessing", "form_feed", "decl",
227 "keyword_for_if_while", "keyword_do_else",
228 "if_expr", "while_expr", "for_exprs",
229 "stmt", "stmt_list", "keyword_else", "keyword_do", "do_stmt",
230 "if_expr_stmt", "if_expr_stmt_else", "period", "string_prefix",
231 "storage_class", "funcname", "type_def", "keyword_struct_union_enum"
232 };
233
234 assert(0 <= ttype && ttype < nitems(name));
235
236 return name[ttype];
237 }
238
239 static void
240 print_buf(const char *name, const char *s, const char *e)
241 {
242 if (s < e) {
243 debug_printf(" %s ", name);
244 debug_vis_range("\"", s, e, "\"");
245 }
246 }
247
248 static token_type
249 lexi_end(token_type ttype)
250 {
251 debug_printf("in line %d, lexi returns '%s'",
252 line_no, token_type_name(ttype));
253 print_buf("token", token.s, token.e);
254 print_buf("label", lab.s, lab.e);
255 print_buf("code", code.s, code.e);
256 print_buf("comment", com.s, com.e);
257 debug_printf("\n");
258
259 return ttype;
260 }
261 #else
262 # define lexi_end(tk) (tk)
263 #endif
264
265 static void
266 lex_number(void)
267 {
268 for (uint8_t s = 'A'; s != 'f' && s != 'i' && s != 'u'; ) {
269 uint8_t ch = (uint8_t)*buf_ptr;
270 if (ch >= nitems(num_lex_row) || num_lex_row[ch] == 0)
271 break;
272 uint8_t row = num_lex_row[ch];
273 if (num_lex_state[row][s - 'A'] == ' ') {
274 /*
275 * num_lex_state[0][s - 'A'] now indicates the type:
276 * f = floating, ch = integer, u = unknown
277 */
278 break;
279 }
280 s = num_lex_state[row][s - 'A'];
281 check_size_token(1);
282 *token.e++ = inbuf_next();
283 }
284 }
285
286 static void
287 lex_word(void)
288 {
289 while (isalnum((unsigned char)*buf_ptr) ||
290 *buf_ptr == '\\' ||
291 *buf_ptr == '_' || *buf_ptr == '$') {
292 /* fill_buffer() terminates buffer with newline */
293 if (*buf_ptr == '\\') {
294 if (buf_ptr[1] == '\n') {
295 buf_ptr += 2;
296 if (buf_ptr >= buf_end)
297 fill_buffer();
298 } else
299 break;
300 }
301 check_size_token(1);
302 *token.e++ = inbuf_next();
303 }
304 }
305
306 static void
307 lex_char_or_string(void)
308 {
309 for (char delim = *token.s;;) {
310 if (*buf_ptr == '\n') {
311 diag(1, "Unterminated literal");
312 return;
313 }
314 check_size_token(2);
315 *token.e++ = inbuf_next();
316 if (token.e[-1] == delim)
317 return;
318 if (token.e[-1] == '\\') {
319 if (*buf_ptr == '\n')
320 ++line_no;
321 *token.e++ = inbuf_next();
322 }
323 }
324 }
325
326 /*
327 * This hack attempts to guess whether the current token is in fact a
328 * declaration keyword -- one that has been defined by typedef.
329 */
330 static bool
331 probably_typedef(const struct parser_state *state)
332 {
333 return state->p_l_follow == 0 && !state->block_init && !state->in_stmt &&
334 ((*buf_ptr == '*' && buf_ptr[1] != '=') ||
335 isalpha((unsigned char)*buf_ptr)) &&
336 (state->last_token == semicolon || state->last_token == lbrace ||
337 state->last_token == rbrace);
338 }
339
340 static bool
341 is_typename(void)
342 {
343 if (opt.auto_typedefs) {
344 const char *u;
345 if ((u = strrchr(token.s, '_')) != NULL && strcmp(u, "_t") == 0)
346 return true;
347 }
348
349 if (typenames.len == 0)
350 return false;
351 return bsearch(token.s, typenames.items, (size_t)typenames.len,
352 sizeof(typenames.items[0]), cmp_type_by_name) != NULL;
353 }
354
355 /* Reads the next token, placing it in the global variable "token". */
356 token_type
357 lexi(struct parser_state *state)
358 {
359 bool unary_delim; /* whether the current token forces a
360 * following operator to be unary */
361 token_type ttype;
362
363 token.e = token.s; /* point to start of place to save token */
364 unary_delim = false;
365 state->col_1 = state->last_nl; /* tell world that this token started
366 * in column 1 iff the last thing
367 * scanned was a newline */
368 state->last_nl = false;
369
370 while (*buf_ptr == ' ' || *buf_ptr == '\t') { /* get rid of blanks */
371 state->col_1 = false; /* leading blanks imply token is not in column
372 * 1 */
373 inbuf_skip();
374 }
375
376 /* Scan an alphanumeric token */
377 if (isalnum((unsigned char)*buf_ptr) ||
378 *buf_ptr == '_' || *buf_ptr == '$' ||
379 (buf_ptr[0] == '.' && isdigit((unsigned char)buf_ptr[1]))) {
380 struct keyword *kw;
381
382 if (isdigit((unsigned char)*buf_ptr) ||
383 (buf_ptr[0] == '.' && isdigit((unsigned char)buf_ptr[1]))) {
384 lex_number();
385 } else {
386 lex_word();
387 }
388 *token.e = '\0';
389
390 if (token.s[0] == 'L' && token.s[1] == '\0' &&
391 (*buf_ptr == '"' || *buf_ptr == '\''))
392 return lexi_end(string_prefix);
393
394 while (*buf_ptr == ' ' || *buf_ptr == '\t') /* get rid of blanks */
395 inbuf_next();
396 state->keyword = kw_0;
397
398 if (state->last_token == keyword_struct_union_enum &&
399 state->p_l_follow == 0) {
400 state->last_u_d = true;
401 return lexi_end(decl);
402 }
403 /*
404 * Operator after identifier is binary unless last token was 'struct'
405 */
406 state->last_u_d = (state->last_token == keyword_struct_union_enum);
407
408 kw = bsearch(token.s, keywords, nitems(keywords),
409 sizeof(keywords[0]), cmp_keyword_by_name);
410 if (kw == NULL) {
411 if (is_typename()) {
412 state->keyword = kw_type;
413 state->last_u_d = true;
414 goto found_typename;
415 }
416 } else { /* we have a keyword */
417 state->keyword = kw->kind;
418 state->last_u_d = true;
419 switch (kw->kind) {
420 case kw_switch:
421 return lexi_end(switch_expr);
422 case kw_case_or_default:
423 return lexi_end(case_label);
424 case kw_struct_or_union_or_enum:
425 case kw_type:
426 found_typename:
427 if (state->p_l_follow != 0) {
428 /* inside parens: cast, param list, offsetof or sizeof */
429 state->cast_mask |= (1 << state->p_l_follow) & ~state->not_cast_mask;
430 }
431 if (state->last_token == period || state->last_token == unary_op) {
432 state->keyword = kw_0;
433 break;
434 }
435 if (kw != NULL && kw->kind == kw_struct_or_union_or_enum)
436 return lexi_end(keyword_struct_union_enum);
437 if (state->p_l_follow != 0)
438 break;
439 return lexi_end(decl);
440
441 case kw_for_or_if_or_while:
442 return lexi_end(keyword_for_if_while);
443
444 case kw_do_or_else:
445 return lexi_end(keyword_do_else);
446
447 case kw_storage_class:
448 return lexi_end(storage_class);
449
450 case kw_typedef:
451 return lexi_end(type_def);
452
453 default: /* all others are treated like any other
454 * identifier */
455 return lexi_end(ident);
456 } /* end of switch */
457 } /* end of if (found_it) */
458 if (*buf_ptr == '(' && state->tos <= 1 && state->ind_level == 0 &&
459 !state->in_parameter_declaration && !state->block_init) {
460 char *tp = buf_ptr;
461 while (tp < buf_end)
462 if (*tp++ == ')' && (*tp == ';' || *tp == ','))
463 goto not_proc;
464 strncpy(state->procname, token.s, sizeof state->procname - 1);
465 if (state->in_decl)
466 state->in_parameter_declaration = true;
467 return lexi_end(funcname);
468 not_proc:;
469 } else if (probably_typedef(state)) {
470 state->keyword = kw_type;
471 state->last_u_d = true;
472 return lexi_end(decl);
473 }
474 if (state->last_token == decl) /* if this is a declared variable,
475 * then following sign is unary */
476 state->last_u_d = true; /* will make "int a -1" work */
477 return lexi_end(ident); /* the ident is not in the list */
478 } /* end of procesing for alpanum character */
479
480 /* Scan a non-alphanumeric token */
481
482 check_size_token(3); /* things like "<<=" */
483 *token.e++ = inbuf_next(); /* if it is only a one-character token, it is
484 * moved here */
485 *token.e = '\0';
486
487 switch (*token.s) {
488 case '\n':
489 unary_delim = state->last_u_d;
490 state->last_nl = true; /* remember that we just had a newline */
491 /* if data has been exhausted, the newline is a dummy. */
492 ttype = had_eof ? end_of_file : newline;
493 break;
494
495 case '\'':
496 case '"':
497 lex_char_or_string();
498 ttype = ident;
499 break;
500
501 case '(':
502 case '[':
503 unary_delim = true;
504 ttype = lparen;
505 break;
506
507 case ')':
508 case ']':
509 ttype = rparen;
510 break;
511
512 case '#':
513 unary_delim = state->last_u_d;
514 ttype = preprocessing;
515 break;
516
517 case '?':
518 unary_delim = true;
519 ttype = question;
520 break;
521
522 case ':':
523 ttype = colon;
524 unary_delim = true;
525 break;
526
527 case ';':
528 unary_delim = true;
529 ttype = semicolon;
530 break;
531
532 case '{':
533 unary_delim = true;
534 ttype = lbrace;
535 break;
536
537 case '}':
538 unary_delim = true;
539 ttype = rbrace;
540 break;
541
542 case 014: /* a form feed */
543 unary_delim = state->last_u_d;
544 state->last_nl = true; /* remember this so we can set 'state->col_1'
545 * right */
546 ttype = form_feed;
547 break;
548
549 case ',':
550 unary_delim = true;
551 ttype = comma;
552 break;
553
554 case '.':
555 unary_delim = false;
556 ttype = period;
557 break;
558
559 case '-':
560 case '+': /* check for -, +, --, ++ */
561 ttype = state->last_u_d ? unary_op : binary_op;
562 unary_delim = true;
563
564 if (*buf_ptr == token.s[0]) {
565 /* check for doubled character */
566 *token.e++ = *buf_ptr++;
567 /* buffer overflow will be checked at end of loop */
568 if (state->last_token == ident || state->last_token == rparen) {
569 ttype = state->last_u_d ? unary_op : postfix_op;
570 /* check for following ++ or -- */
571 unary_delim = false;
572 }
573 } else if (*buf_ptr == '=')
574 /* check for operator += */
575 *token.e++ = *buf_ptr++;
576 else if (*buf_ptr == '>') {
577 /* check for operator -> */
578 *token.e++ = *buf_ptr++;
579 unary_delim = false;
580 ttype = unary_op;
581 state->want_blank = false;
582 }
583 break; /* buffer overflow will be checked at end of
584 * switch */
585
586 case '=':
587 if (state->in_or_st)
588 state->block_init = true;
589 if (*buf_ptr == '=') { /* == */
590 *token.e++ = '='; /* Flip =+ to += */
591 buf_ptr++;
592 *token.e = 0;
593 }
594 ttype = binary_op;
595 unary_delim = true;
596 break;
597 /* can drop thru!!! */
598
599 case '>':
600 case '<':
601 case '!': /* ops like <, <<, <=, !=, etc */
602 if (*buf_ptr == '>' || *buf_ptr == '<' || *buf_ptr == '=')
603 *token.e++ = inbuf_next();
604 if (*buf_ptr == '=')
605 *token.e++ = *buf_ptr++;
606 ttype = state->last_u_d ? unary_op : binary_op;
607 unary_delim = true;
608 break;
609
610 case '*':
611 unary_delim = true;
612 if (!state->last_u_d) {
613 if (*buf_ptr == '=')
614 *token.e++ = *buf_ptr++;
615 ttype = binary_op;
616 break;
617 }
618 while (*buf_ptr == '*' || isspace((unsigned char)*buf_ptr)) {
619 if (*buf_ptr == '*') {
620 check_size_token(1);
621 *token.e++ = *buf_ptr;
622 }
623 inbuf_skip();
624 }
625 if (ps.in_decl) {
626 char *tp = buf_ptr;
627
628 while (isalpha((unsigned char)*tp) ||
629 isspace((unsigned char)*tp)) {
630 if (++tp >= buf_end)
631 fill_buffer();
632 }
633 if (*tp == '(')
634 ps.procname[0] = ' ';
635 }
636 ttype = unary_op;
637 break;
638
639 default:
640 if (token.s[0] == '/' && (*buf_ptr == '*' || *buf_ptr == '/')) {
641 /* it is start of comment */
642 *token.e++ = inbuf_next();
643
644 ttype = comment;
645 unary_delim = state->last_u_d;
646 break;
647 }
648 while (token.e[-1] == *buf_ptr || *buf_ptr == '=') {
649 /*
650 * handle ||, &&, etc, and also things as in int *****i
651 */
652 check_size_token(1);
653 *token.e++ = inbuf_next();
654 }
655 ttype = state->last_u_d ? unary_op : binary_op;
656 unary_delim = true;
657 }
658
659 if (buf_ptr >= buf_end) /* check for input buffer empty */
660 fill_buffer();
661 state->last_u_d = unary_delim;
662 check_size_token(1);
663 *token.e = '\0';
664 return lexi_end(ttype);
665 }
666
667 static int
668 insert_pos(const char *key, const char **arr, unsigned int len) {
669 int lo = 0;
670 int hi = (int)len - 1;
671
672 while (lo <= hi) {
673 int mid = (int)((unsigned)(lo + hi) >> 1);
674 int cmp = strcmp(arr[mid], key);
675 if (cmp < 0)
676 lo = mid + 1;
677 else if (cmp > 0)
678 hi = mid - 1;
679 else
680 return mid;
681 }
682 return -(lo + 1);
683 }
684
685 void
686 add_typename(const char *name)
687 {
688 if (typenames.len >= typenames.cap) {
689 typenames.cap = 16 + 2 * typenames.cap;
690 typenames.items = xrealloc(typenames.items,
691 sizeof(typenames.items[0]) * typenames.cap);
692 }
693
694 int pos = insert_pos(name, typenames.items, typenames.len);
695 if (pos >= 0)
696 return; /* already in the list */
697 pos = -(pos + 1);
698 memmove(typenames.items + pos + 1, typenames.items + pos,
699 sizeof(typenames.items[0]) * (typenames.len++ - pos));
700 typenames.items[pos] = xstrdup(name);
701 }
702