decl.c revision 1.306 1 /* $NetBSD: decl.c,v 1.306 2023/03/28 14:44:35 rillig Exp $ */
2
3 /*
4 * Copyright (c) 1996 Christopher G. Demetriou. All Rights Reserved.
5 * Copyright (c) 1994, 1995 Jochen Pohl
6 * All Rights Reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by Jochen Pohl for
19 * The NetBSD Project.
20 * 4. The name of the author may not be used to endorse or promote products
21 * derived from this software without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35 #if HAVE_NBTOOL_CONFIG_H
36 #include "nbtool_config.h"
37 #endif
38
39 #include <sys/cdefs.h>
40 #if defined(__RCSID)
41 __RCSID("$NetBSD: decl.c,v 1.306 2023/03/28 14:44:35 rillig Exp $");
42 #endif
43
44 #include <sys/param.h>
45 #include <limits.h>
46 #include <stdlib.h>
47 #include <string.h>
48
49 #include "lint1.h"
50
51 const char unnamed[] = "<unnamed>";
52
53 /* shared type structures for arithmetic types and void */
54 static type_t typetab[NTSPEC];
55
56 /* value of next enumerator during declaration of enum types */
57 int enumval;
58
59 /*
60 * pointer to innermost element of a stack which contains information local
61 * to nested declarations
62 */
63 dinfo_t *dcs;
64
65 static type_t *typedef_error(type_t *, tspec_t);
66 static void set_first_typedef(type_t *, sym_t *);
67 static void dcs_align(unsigned int, unsigned int);
68 static sym_t *new_tag(sym_t *, scl_t, bool, bool);
69 static bool prototypes_compatible(const type_t *, const type_t *, bool *);
70 static bool matches_no_arg_function(const type_t *, bool *);
71 static bool check_old_style_definition(sym_t *, sym_t *);
72 static bool check_prototype_declaration(sym_t *, sym_t *);
73 static sym_t *new_style_function(sym_t *);
74 static void old_style_function(sym_t *, sym_t *);
75 static void declare_external_in_block(sym_t *);
76 static bool check_init(sym_t *);
77 static void check_argument_usage(bool, sym_t *);
78 static void check_variable_usage(bool, sym_t *);
79 static void check_label_usage(sym_t *);
80 static void check_tag_usage(sym_t *);
81 static void check_global_variable(const sym_t *);
82 static void check_global_variable_size(const sym_t *);
83
84 /*
85 * initializes all global vars used in declarations
86 */
87 void
88 #ifdef __sh3__
89 /* XXX port-sh3/56311 */
90 __attribute__((optimize("O0")))
91 #endif
92 initdecl(void)
93 {
94
95 /* declaration stack */
96 dcs = xcalloc(1, sizeof(*dcs));
97 dcs->d_kind = DK_EXTERN;
98 dcs->d_ldlsym = &dcs->d_dlsyms;
99
100 /* type information and classification */
101 inittyp();
102
103 /*
104 * The following two are not really types. They are only used by the
105 * parser to handle the keywords "signed" and "unsigned".
106 */
107 typetab[SIGNED].t_tspec = SIGNED;
108 typetab[UNSIGN].t_tspec = UNSIGN;
109
110 typetab[BOOL].t_tspec = BOOL;
111 typetab[CHAR].t_tspec = CHAR;
112 typetab[SCHAR].t_tspec = SCHAR;
113 typetab[UCHAR].t_tspec = UCHAR;
114 typetab[SHORT].t_tspec = SHORT;
115 typetab[USHORT].t_tspec = USHORT;
116 typetab[INT].t_tspec = INT;
117 typetab[UINT].t_tspec = UINT;
118 typetab[LONG].t_tspec = LONG;
119 typetab[ULONG].t_tspec = ULONG;
120 typetab[QUAD].t_tspec = QUAD;
121 typetab[UQUAD].t_tspec = UQUAD;
122 #ifdef INT128_SIZE
123 typetab[INT128].t_tspec = INT128;
124 typetab[UINT128].t_tspec = UINT128;
125 #endif
126 typetab[FLOAT].t_tspec = FLOAT;
127 typetab[DOUBLE].t_tspec = DOUBLE;
128 typetab[LDOUBLE].t_tspec = LDOUBLE;
129 typetab[VOID].t_tspec = VOID;
130 /* struct, union, enum, ptr, array and func are not shared. */
131 typetab[COMPLEX].t_tspec = COMPLEX;
132 typetab[FCOMPLEX].t_tspec = FCOMPLEX;
133 typetab[DCOMPLEX].t_tspec = DCOMPLEX;
134 typetab[LCOMPLEX].t_tspec = LCOMPLEX;
135 }
136
137 /*
138 * Returns a shared type structure for arithmetic types and void.
139 *
140 * It's important to duplicate this structure using block_dup_type or
141 * expr_dup_type if it is to be modified (adding qualifiers or anything
142 * else).
143 */
144 type_t *
145 gettyp(tspec_t t)
146 {
147
148 /* TODO: make the return type 'const' */
149 return &typetab[t];
150 }
151
152 type_t *
153 block_dup_type(const type_t *tp)
154 {
155 type_t *ntp;
156
157 ntp = block_zero_alloc(sizeof(*ntp));
158 *ntp = *tp;
159 return ntp;
160 }
161
162 /* Duplicate a type, free the allocated memory after the expression. */
163 type_t *
164 expr_dup_type(const type_t *tp)
165 {
166 type_t *ntp;
167
168 ntp = expr_zero_alloc(sizeof(*ntp));
169 *ntp = *tp;
170 return ntp;
171 }
172
173 /*
174 * Return the unqualified version of the type. The returned type is freed at
175 * the end of the current expression.
176 *
177 * See C99 6.2.5p25.
178 */
179 type_t *
180 expr_unqualified_type(const type_t *tp)
181 {
182 type_t *ntp;
183
184 ntp = expr_zero_alloc(sizeof(*ntp));
185 *ntp = *tp;
186 ntp->t_const = false;
187 ntp->t_volatile = false;
188
189 /*
190 * In case of a struct or union type, the members should lose their
191 * qualifiers as well, but that would require a deep copy of the
192 * struct or union type. This in turn would defeat the type
193 * comparison in types_compatible, which simply tests whether
194 * tp1->t_str == tp2->t_str.
195 */
196
197 return ntp;
198 }
199
200 /*
201 * Returns whether the argument is void or an incomplete array,
202 * struct, union or enum type.
203 */
204 bool
205 is_incomplete(const type_t *tp)
206 {
207 tspec_t t;
208
209 if ((t = tp->t_tspec) == VOID)
210 return true;
211 if (t == ARRAY)
212 return tp->t_incomplete_array;
213 if (is_struct_or_union(t))
214 return tp->t_str->sou_incomplete;
215 if (t == ENUM)
216 return tp->t_enum->en_incomplete;
217
218 return false;
219 }
220
221 /*
222 * Remember the storage class of the current declaration and detect multiple
223 * storage classes.
224 */
225 void
226 dcs_add_storage_class(scl_t sc)
227 {
228
229 if (sc == INLINE) {
230 if (dcs->d_inline)
231 /* duplicate '%s' */
232 warning(10, "inline");
233 dcs->d_inline = true;
234 return;
235 }
236
237 if (dcs->d_type != NULL || dcs->d_abstract_type != NOTSPEC ||
238 dcs->d_sign_mod != NOTSPEC || dcs->d_rank_mod != NOTSPEC) {
239 /* storage class after type is obsolescent */
240 warning(83);
241 }
242
243 if (dcs->d_scl == NOSCL)
244 dcs->d_scl = sc;
245 else
246 dcs->d_multiple_storage_classes = true;
247 }
248
249 /*
250 * Remember the type, modifier or typedef name returned by the parser
251 * in *dcs (top element of decl stack). This information is used in
252 * dcs_end_type to build the type used for all declarators in this
253 * declaration.
254 *
255 * If tp->t_typedef is true, the type comes from a previously defined
256 * typename. Otherwise, it comes from a type specifier (int, long, ...) or a
257 * struct/union/enum tag.
258 */
259 void
260 dcs_add_type(type_t *tp)
261 {
262 tspec_t t;
263
264 debug_step("%s: %s", __func__, type_name(tp));
265 if (tp->t_typedef) {
266 /*
267 * something like "typedef int a; int a b;"
268 * This should not happen with current grammar.
269 */
270 lint_assert(dcs->d_type == NULL);
271 lint_assert(dcs->d_abstract_type == NOTSPEC);
272 lint_assert(dcs->d_sign_mod == NOTSPEC);
273 lint_assert(dcs->d_rank_mod == NOTSPEC);
274
275 dcs->d_type = tp;
276 return;
277 }
278
279 t = tp->t_tspec;
280
281 if (is_struct_or_union(t) || t == ENUM) {
282 /*
283 * something like "int struct a ..."
284 * struct/union/enum with anything else is not allowed
285 */
286 if (dcs->d_type != NULL || dcs->d_abstract_type != NOTSPEC ||
287 dcs->d_rank_mod != NOTSPEC || dcs->d_sign_mod != NOTSPEC) {
288 dcs->d_invalid_type_combination = true;
289 dcs->d_abstract_type = NOTSPEC;
290 dcs->d_sign_mod = NOTSPEC;
291 dcs->d_rank_mod = NOTSPEC;
292 }
293 dcs->d_type = tp;
294 return;
295 }
296
297 if (dcs->d_type != NULL && !dcs->d_type->t_typedef) {
298 /*
299 * something like "struct a int"
300 * struct/union/enum with anything else is not allowed
301 */
302 dcs->d_invalid_type_combination = true;
303 return;
304 }
305
306 if (t == COMPLEX) {
307 if (dcs->d_complex_mod == FLOAT)
308 t = FCOMPLEX;
309 else if (dcs->d_complex_mod == DOUBLE)
310 t = DCOMPLEX;
311 else {
312 /* invalid type for _Complex */
313 error(308);
314 t = DCOMPLEX; /* just as a fallback */
315 }
316 dcs->d_complex_mod = NOTSPEC;
317 }
318
319 if (t == LONG && dcs->d_rank_mod == LONG) {
320 /* "long long" or "long ... long" */
321 t = QUAD;
322 dcs->d_rank_mod = NOTSPEC;
323 if (!quadflg)
324 /* %s does not support 'long long' */
325 c99ism(265, allow_c90 ? "C90" : "traditional C");
326 }
327
328 if (dcs->d_type != NULL && dcs->d_type->t_typedef) {
329 /* something like "typedef int a; a long ..." */
330 dcs->d_type = typedef_error(dcs->d_type, t);
331 return;
332 }
333
334 /* now it can be only a combination of arithmetic types and void */
335 if (t == SIGNED || t == UNSIGN) {
336 /*
337 * remember specifiers "signed" & "unsigned" in
338 * dcs->d_sign_mod
339 */
340 if (dcs->d_sign_mod != NOTSPEC)
341 /* more than one "signed" and/or "unsigned" */
342 dcs->d_invalid_type_combination = true;
343 dcs->d_sign_mod = t;
344 } else if (t == SHORT || t == LONG || t == QUAD) {
345 /*
346 * remember specifiers "short", "long" and "long long" in
347 * dcs->d_rank_mod
348 */
349 if (dcs->d_rank_mod != NOTSPEC)
350 dcs->d_invalid_type_combination = true;
351 dcs->d_rank_mod = t;
352 } else if (t == FLOAT || t == DOUBLE) {
353 if (dcs->d_rank_mod == NOTSPEC || dcs->d_rank_mod == LONG) {
354 if (dcs->d_complex_mod != NOTSPEC
355 || (t == FLOAT && dcs->d_rank_mod == LONG))
356 dcs->d_invalid_type_combination = true;
357 dcs->d_complex_mod = t;
358 } else {
359 if (dcs->d_abstract_type != NOTSPEC)
360 dcs->d_invalid_type_combination = true;
361 dcs->d_abstract_type = t;
362 }
363 } else if (t == PTR) {
364 dcs->d_type = tp;
365 } else {
366 /*
367 * remember specifiers "void", "char", "int",
368 * or "_Complex" in dcs->d_abstract_type
369 */
370 if (dcs->d_abstract_type != NOTSPEC)
371 dcs->d_invalid_type_combination = true;
372 dcs->d_abstract_type = t;
373 }
374 }
375
376 /* Merge the signedness into the abstract type. */
377 static tspec_t
378 merge_signedness(tspec_t t, tspec_t s)
379 {
380
381 if (s == SIGNED)
382 return t == CHAR ? SCHAR : t;
383 if (s != UNSIGN)
384 return t;
385 return t == CHAR ? UCHAR
386 : t == SHORT ? USHORT
387 : t == INT ? UINT
388 : t == LONG ? ULONG
389 : t == QUAD ? UQUAD
390 : t;
391 }
392
393 /*
394 * called if a list of declaration specifiers contains a typedef name
395 * and other specifiers (except struct, union, enum, typedef name)
396 */
397 static type_t *
398 typedef_error(type_t *td, tspec_t t)
399 {
400 tspec_t t2;
401
402 t2 = td->t_tspec;
403
404 if ((t == SIGNED || t == UNSIGN) &&
405 (t2 == CHAR || t2 == SHORT || t2 == INT ||
406 t2 == LONG || t2 == QUAD)) {
407 if (allow_c90)
408 /* modifying typedef with '%s'; only qualifiers... */
409 warning(5, tspec_name(t));
410 td = block_dup_type(gettyp(merge_signedness(t2, t)));
411 td->t_typedef = true;
412 return td;
413 }
414
415 if (t == SHORT && (t2 == INT || t2 == UINT)) {
416 /* modifying typedef with '%s'; only qualifiers allowed */
417 warning(5, "short");
418 td = block_dup_type(gettyp(t2 == INT ? SHORT : USHORT));
419 td->t_typedef = true;
420 return td;
421 }
422
423 if (t != LONG)
424 goto invalid;
425
426 if (t2 == INT)
427 td = gettyp(LONG);
428 else if (t2 == UINT)
429 td = gettyp(ULONG);
430 else if (t2 == LONG)
431 td = gettyp(QUAD);
432 else if (t2 == ULONG)
433 td = gettyp(UQUAD);
434 else if (t2 == FLOAT)
435 td = gettyp(DOUBLE);
436 else if (t2 == DOUBLE)
437 td = gettyp(LDOUBLE);
438 else if (t2 == DCOMPLEX)
439 td = gettyp(LCOMPLEX);
440 else
441 goto invalid;
442
443 /* modifying typedef with '%s'; only qualifiers allowed */
444 warning(5, "long");
445 td = block_dup_type(td);
446 td->t_typedef = true;
447 return td;
448
449 invalid:
450 /* Anything else is not accepted. */
451 dcs->d_invalid_type_combination = true;
452 return td;
453 }
454
455 /*
456 * Remember the symbol of a typedef name (2nd arg) in a struct, union
457 * or enum tag if the typedef name is the first defined for this tag.
458 *
459 * If the tag is unnamed, the typedef name is used for identification
460 * of this tag in lint2. Although it's possible that more than one typedef
461 * name is defined for one tag, the first name defined should be unique
462 * if the tag is unnamed.
463 */
464 static void
465 set_first_typedef(type_t *tp, sym_t *sym)
466 {
467 tspec_t t;
468
469 if (is_struct_or_union(t = tp->t_tspec)) {
470 if (tp->t_str->sou_first_typedef == NULL)
471 tp->t_str->sou_first_typedef = sym;
472 } else if (t == ENUM) {
473 if (tp->t_enum->en_first_typedef == NULL)
474 tp->t_enum->en_first_typedef = sym;
475 }
476 }
477
478 static unsigned int
479 bit_field_size(sym_t **mem)
480 {
481 unsigned int len = (*mem)->s_type->t_flen;
482 while (*mem != NULL && (*mem)->s_type->t_bitfield) {
483 len += (*mem)->s_type->t_flen;
484 *mem = (*mem)->s_next;
485 }
486 return len - len % INT_SIZE;
487 }
488
489 static void
490 set_packed_size(type_t *tp)
491 {
492 struct_or_union *sp;
493 sym_t *mem;
494
495 switch (tp->t_tspec) {
496 case STRUCT:
497 case UNION:
498 sp = tp->t_str;
499 sp->sou_size_in_bits = 0;
500 for (mem = sp->sou_first_member;
501 mem != NULL; mem = mem->s_next) {
502 unsigned int x;
503
504 if (mem->s_type->t_bitfield) {
505 sp->sou_size_in_bits += bit_field_size(&mem);
506 if (mem == NULL)
507 break;
508 }
509 x = type_size_in_bits(mem->s_type);
510 if (tp->t_tspec == STRUCT)
511 sp->sou_size_in_bits += x;
512 else if (x > sp->sou_size_in_bits)
513 sp->sou_size_in_bits = x;
514 }
515 break;
516 default:
517 /* attribute '%s' ignored for '%s' */
518 warning(326, "packed", type_name(tp));
519 break;
520 }
521 }
522
523 void
524 dcs_add_packed(void)
525 {
526 if (dcs->d_type == NULL)
527 dcs->d_packed = true;
528 else
529 set_packed_size(dcs->d_type);
530 }
531
532 void
533 dcs_set_used(void)
534 {
535 dcs->d_used = true;
536 }
537
538 /*
539 * Remember a qualifier which is part of the declaration specifiers
540 * (and not the declarator).
541 * Also detect multiple qualifiers of the same kind.
542
543 * The remembered qualifier is used by dcs_end_type to construct the type
544 * for all declarators.
545 */
546 void
547 dcs_add_qualifier(tqual_t q)
548 {
549
550 if (q == CONST) {
551 if (dcs->d_const) {
552 /* duplicate '%s' */
553 warning(10, "const");
554 }
555 dcs->d_const = true;
556 } else if (q == VOLATILE) {
557 if (dcs->d_volatile) {
558 /* duplicate '%s' */
559 warning(10, "volatile");
560 }
561 dcs->d_volatile = true;
562 } else {
563 lint_assert(q == RESTRICT || q == THREAD || q == ATOMIC);
564 /* Silently ignore these qualifiers. */
565 }
566 }
567
568 /*
569 * Go to the next declaration level (structs, nested structs, blocks,
570 * argument declaration lists ...)
571 */
572 void
573 begin_declaration_level(declaration_kind dk)
574 {
575 dinfo_t *di;
576
577 /* put a new element on the declaration stack */
578 di = xcalloc(1, sizeof(*di));
579 di->d_enclosing = dcs;
580 dcs = di;
581 di->d_kind = dk;
582 di->d_ldlsym = &di->d_dlsyms;
583 debug_step("%s(%s)", __func__, declaration_kind_name(dk));
584 }
585
586 /*
587 * Go back to previous declaration level
588 */
589 void
590 end_declaration_level(void)
591 {
592 dinfo_t *di;
593
594 debug_step("%s(%s)", __func__, declaration_kind_name(dcs->d_kind));
595
596 lint_assert(dcs->d_enclosing != NULL);
597 di = dcs;
598 dcs = di->d_enclosing;
599
600 switch (di->d_kind) {
601 case DK_STRUCT_MEMBER:
602 case DK_UNION_MEMBER:
603 case DK_ENUM_CONSTANT:
604 /*
605 * Symbols declared in (nested) structs or enums are
606 * part of the next level (they are removed from the
607 * symbol table if the symbols of the outer level are
608 * removed).
609 */
610 if ((*dcs->d_ldlsym = di->d_dlsyms) != NULL)
611 dcs->d_ldlsym = di->d_ldlsym;
612 break;
613 case DK_OLD_STYLE_ARG:
614 /*
615 * All symbols in dcs->d_dlsyms are introduced in old-style
616 * argument declarations (it's not clean, but possible).
617 * They are appended to the list of symbols declared in
618 * an old-style argument identifier list or a new style
619 * parameter type list.
620 */
621 if (di->d_dlsyms != NULL) {
622 *di->d_ldlsym = dcs->d_func_proto_syms;
623 dcs->d_func_proto_syms = di->d_dlsyms;
624 }
625 break;
626 case DK_ABSTRACT: /* casts and sizeof */
627 /*
628 * Append all symbols declared in the abstract declaration
629 * to the list of symbols declared in the surrounding
630 * declaration or block.
631 * XXX I'm not sure whether they should be removed from the
632 * symbol table now or later.
633 */
634 if ((*dcs->d_ldlsym = di->d_dlsyms) != NULL)
635 dcs->d_ldlsym = di->d_ldlsym;
636 break;
637 case DK_AUTO:
638 /* check usage of local vars */
639 check_usage(di);
640 /* FALLTHROUGH */
641 case DK_PROTO_ARG:
642 /* usage of arguments will be checked by end_function() */
643 rmsyms(di->d_dlsyms);
644 break;
645 case DK_EXTERN:
646 /* there is nothing around an external declarations */
647 /* FALLTHROUGH */
648 default:
649 lint_assert(/*CONSTCOND*/false);
650 }
651 free(di);
652 }
653
654 /*
655 * Set flag d_asm in all declaration stack elements up to the
656 * outermost one.
657 *
658 * This is used to mark compound statements which have, possibly in
659 * nested compound statements, asm statements. For these compound
660 * statements no warnings about unused or uninitialized variables are
661 * printed.
662 *
663 * There is no need to clear d_asm in dinfo structs with context AUTO,
664 * because these structs are freed at the end of the compound statement.
665 * But it must be cleared in the outermost dinfo struct, which has
666 * context EXTERN. This could be done in dcs_begin_type and would work for
667 * C90, but not for C99 or C++ (due to mixed statements and declarations).
668 * Thus we clear it in global_clean_up_decl(), which is used to do some
669 * cleanup after global declarations/definitions.
670 */
671 void
672 dcs_set_asm(void)
673 {
674
675 for (dinfo_t *di = dcs; di != NULL; di = di->d_enclosing)
676 di->d_asm = true;
677 }
678
679 /*
680 * Clean all elements of the top element of declaration stack which
681 * will be used by the next declaration
682 */
683 void
684 dcs_begin_type(void)
685 {
686
687 dcs->d_abstract_type = NOTSPEC;
688 dcs->d_complex_mod = NOTSPEC;
689 dcs->d_sign_mod = NOTSPEC;
690 dcs->d_rank_mod = NOTSPEC;
691 dcs->d_scl = NOSCL;
692 dcs->d_type = NULL;
693 dcs->d_const = false;
694 dcs->d_volatile = false;
695 dcs->d_inline = false;
696 dcs->d_multiple_storage_classes = false;
697 dcs->d_invalid_type_combination = false;
698 dcs->d_nonempty_decl = false;
699 dcs->d_notyp = false;
700 }
701
702 static void
703 dcs_adjust_storage_class(void)
704 {
705 if (dcs->d_kind == DK_EXTERN) {
706 if (dcs->d_scl == REG || dcs->d_scl == AUTO) {
707 /* illegal storage class */
708 error(8);
709 dcs->d_scl = NOSCL;
710 }
711 } else if (dcs->d_kind == DK_OLD_STYLE_ARG ||
712 dcs->d_kind == DK_PROTO_ARG) {
713 if (dcs->d_scl != NOSCL && dcs->d_scl != REG) {
714 /* only register valid as formal parameter storage... */
715 error(9);
716 dcs->d_scl = NOSCL;
717 }
718 }
719 }
720
721 /*
722 * Merge the declaration specifiers from dcs into dcs->d_type.
723 *
724 * See C99 6.7.2 "Type specifiers".
725 */
726 static void
727 dcs_merge_declaration_specifiers(void)
728 {
729 tspec_t t, s, l, c;
730 type_t *tp;
731
732 t = dcs->d_abstract_type; /* VOID, BOOL, CHAR, INT or COMPLEX */
733 c = dcs->d_complex_mod; /* FLOAT or DOUBLE */
734 s = dcs->d_sign_mod; /* SIGNED or UNSIGN */
735 l = dcs->d_rank_mod; /* SHORT, LONG or QUAD */
736 tp = dcs->d_type;
737
738 debug_step("%s: %s", __func__, type_name(tp));
739 if (t == NOTSPEC && s == NOTSPEC && l == NOTSPEC && c == NOTSPEC &&
740 tp == NULL)
741 dcs->d_notyp = true;
742 if (t == NOTSPEC && s == NOTSPEC && (l == NOTSPEC || l == LONG) &&
743 tp == NULL)
744 t = c;
745
746 if (tp != NULL) {
747 lint_assert(t == NOTSPEC);
748 lint_assert(s == NOTSPEC);
749 lint_assert(l == NOTSPEC);
750 return;
751 }
752
753 if (t == NOTSPEC)
754 t = INT;
755 if (s == NOTSPEC && t == INT)
756 s = SIGNED;
757 if (l != NOTSPEC && t == CHAR) {
758 dcs->d_invalid_type_combination = true;
759 l = NOTSPEC;
760 }
761 if (l == LONG && t == FLOAT) {
762 l = NOTSPEC;
763 t = DOUBLE;
764 if (allow_c90)
765 /* use 'double' instead of 'long float' */
766 warning(6);
767 }
768 if ((l == LONG && t == DOUBLE) || t == LDOUBLE) {
769 l = NOTSPEC;
770 t = LDOUBLE;
771 }
772 if (t == LDOUBLE && !allow_c90) {
773 /* 'long double' is illegal in traditional C */
774 warning(266);
775 }
776 if (l == LONG && t == DCOMPLEX) {
777 l = NOTSPEC;
778 t = LCOMPLEX;
779 }
780
781 if (t != INT && t != CHAR && (s != NOTSPEC || l != NOTSPEC)) {
782 dcs->d_invalid_type_combination = true;
783 l = s = NOTSPEC;
784 }
785 if (l != NOTSPEC)
786 t = l;
787 dcs->d_type = gettyp(merge_signedness(t, s));
788 }
789
790 /*
791 * Create a type structure from the information gathered in the declaration
792 * stack.
793 * Complain about storage classes which are not possible in current context.
794 */
795 void
796 dcs_end_type(void)
797 {
798
799 dcs_merge_declaration_specifiers();
800
801 if (dcs->d_multiple_storage_classes) {
802 /* only one storage class allowed */
803 error(7);
804 }
805 if (dcs->d_invalid_type_combination) {
806 /* illegal type combination */
807 error(4);
808 }
809
810 dcs_adjust_storage_class();
811
812 if (dcs->d_const && dcs->d_type->t_const && !dcs->d_type->t_typeof) {
813 lint_assert(dcs->d_type->t_typedef);
814 /* typedef already qualified with '%s' */
815 warning(68, "const");
816 }
817 if (dcs->d_volatile && dcs->d_type->t_volatile &&
818 !dcs->d_type->t_typeof) {
819 lint_assert(dcs->d_type->t_typedef);
820 /* typedef already qualified with '%s' */
821 warning(68, "volatile");
822 }
823
824 if (dcs->d_const || dcs->d_volatile) {
825 dcs->d_type = block_dup_type(dcs->d_type);
826 dcs->d_type->t_const |= dcs->d_const;
827 dcs->d_type->t_volatile |= dcs->d_volatile;
828 }
829 }
830
831 /*
832 * Return the length of a type in bits.
833 *
834 * Printing a message if the outermost dimension of an array is 0 must
835 * be done by the caller. All other problems are reported by this function
836 * if name is not NULL.
837 */
838 int
839 length_in_bits(const type_t *tp, const char *name)
840 {
841 unsigned int elem, elsz;
842
843 elem = 1;
844 while (tp != NULL && tp->t_tspec == ARRAY) {
845 elem *= tp->t_dim;
846 tp = tp->t_subt;
847 }
848 if (tp == NULL)
849 return -1;
850
851 switch (tp->t_tspec) {
852 case FUNC:
853 lint_assert(/*CONSTCOND*/ false);
854 break; /* GCC 10 thinks this were reachable */
855 /* NOTREACHED */
856 case STRUCT:
857 case UNION:
858 if (is_incomplete(tp) && name != NULL) {
859 /* '%s' has incomplete type '%s' */
860 error(31, name, type_name(tp));
861 }
862 elsz = tp->t_str->sou_size_in_bits;
863 break;
864 case ENUM:
865 if (is_incomplete(tp) && name != NULL) {
866 /* incomplete enum type '%s' */
867 warning(13, name);
868 }
869 /* FALLTHROUGH */
870 default:
871 elsz = size_in_bits(tp->t_tspec);
872 /*
873 * Workaround until the type parser (see add_function,
874 * add_array, add_pointer) does not construct the invalid
875 * intermediate declaration 'void b[4]' for the legitimate
876 * declaration 'void *b[4]'.
877 */
878 if (sytxerr > 0 && elsz == 0)
879 elsz = CHAR_SIZE;
880 lint_assert(elsz > 0);
881 break;
882 }
883 return (int)(elem * elsz);
884 }
885
886 unsigned int
887 alignment_in_bits(const type_t *tp)
888 {
889 unsigned int a;
890 tspec_t t;
891
892 /* Super conservative so that it works for most systems. */
893 unsigned int worst_align_in_bits = 2 * LONG_SIZE;
894
895 while (tp->t_tspec == ARRAY)
896 tp = tp->t_subt;
897
898 if (is_struct_or_union(t = tp->t_tspec))
899 a = tp->t_str->sou_align_in_bits;
900 else {
901 lint_assert(t != FUNC);
902 if ((a = size_in_bits(t)) == 0)
903 a = CHAR_SIZE;
904 else if (a > worst_align_in_bits)
905 a = worst_align_in_bits;
906
907 }
908 lint_assert(a >= CHAR_SIZE);
909 lint_assert(a <= worst_align_in_bits);
910 return a;
911 }
912
913 /*
914 * Concatenate two lists of symbols by s_next. Used by declarations of
915 * struct/union/enum elements and parameters.
916 */
917 sym_t *
918 concat_lists(sym_t *l1, sym_t *l2)
919 {
920 sym_t *l;
921
922 if ((l = l1) == NULL)
923 return l2;
924 while (l1->s_next != NULL)
925 l1 = l1->s_next;
926 l1->s_next = l2;
927 return l;
928 }
929
930 /*
931 * Check if the type of the given symbol is valid and print an error
932 * message if it is not.
933 *
934 * Invalid types are:
935 * - arrays of incomplete types or functions
936 * - functions returning arrays or functions
937 * - void types other than type of function or pointer
938 */
939 void
940 check_type(sym_t *sym)
941 {
942 tspec_t to, t;
943 type_t **tpp, *tp;
944
945 tpp = &sym->s_type;
946 to = NOTSPEC;
947 while ((tp = *tpp) != NULL) {
948 t = tp->t_tspec;
949 /*
950 * If this is the type of an old-style function definition,
951 * a better warning is printed in begin_function().
952 */
953 if (t == FUNC && !tp->t_proto &&
954 !(to == NOTSPEC && sym->s_osdef)) {
955 /* TODO: Make this an error in C99 mode as well. */
956 if ((!allow_trad && !allow_c99) && hflag)
957 /* function declaration is not a prototype */
958 warning(287);
959 }
960 if (to == FUNC) {
961 if (t == FUNC || t == ARRAY) {
962 /* function returns illegal type '%s' */
963 error(15, type_name(tp));
964 *tpp = block_derive_type(
965 t == FUNC ? *tpp : (*tpp)->t_subt, PTR);
966 return;
967 }
968 if (tp->t_const || tp->t_volatile) {
969 /* TODO: Make this a warning in C99 mode as well. */
970 if (!allow_trad && !allow_c99) { /* XXX or better allow_c90? */
971 /* function cannot return const... */
972 warning(228);
973 }
974 }
975 } else if (to == ARRAY) {
976 if (t == FUNC) {
977 /* array of function is illegal */
978 error(16);
979 *tpp = gettyp(INT);
980 return;
981 }
982 if (t == ARRAY && tp->t_dim == 0) {
983 /* null dimension */
984 error(17);
985 return;
986 }
987 if (t == VOID) {
988 /* illegal use of 'void' */
989 error(18);
990 *tpp = gettyp(INT);
991 }
992 /*
993 * No need to check for incomplete types here as
994 * length_in_bits already does this.
995 */
996 } else if (to == NOTSPEC && t == VOID) {
997 if (dcs->d_kind == DK_PROTO_ARG) {
998 if (sym->s_scl != ABSTRACT) {
999 lint_assert(sym->s_name != unnamed);
1000 /* void parameter '%s' cannot ... */
1001 error(61, sym->s_name);
1002 *tpp = gettyp(INT);
1003 }
1004 } else if (dcs->d_kind == DK_ABSTRACT) {
1005 /* ok */
1006 } else if (sym->s_scl != TYPEDEF) {
1007 /* void type for '%s' */
1008 error(19, sym->s_name);
1009 *tpp = gettyp(INT);
1010 }
1011 }
1012 if (t == VOID && to != PTR) {
1013 if (tp->t_const || tp->t_volatile) {
1014 /* inappropriate qualifiers with 'void' */
1015 warning(69);
1016 tp->t_const = tp->t_volatile = false;
1017 }
1018 }
1019 tpp = &tp->t_subt;
1020 to = t;
1021 }
1022 }
1023
1024 /*
1025 * In traditional C, the only portable type for bit-fields is unsigned int.
1026 *
1027 * In C90, the only allowed types for bit-fields are int, signed int and
1028 * unsigned int (3.5.2.1). There is no mention of implementation-defined
1029 * types.
1030 *
1031 * In C99, the only portable types for bit-fields are _Bool, signed int and
1032 * unsigned int (6.7.2.1p4). In addition, C99 allows "or some other
1033 * implementation-defined type".
1034 */
1035 static void
1036 check_bit_field_type(sym_t *dsym, type_t **const inout_tp, tspec_t *inout_t)
1037 {
1038 type_t *tp = *inout_tp;
1039 tspec_t t = *inout_t;
1040
1041 if (t == CHAR || t == UCHAR || t == SCHAR ||
1042 t == SHORT || t == USHORT || t == ENUM) {
1043 if (!bitfieldtype_ok) {
1044 /* TODO: Make this an error in C99 mode as well. */
1045 if (!allow_trad && !allow_c99) {
1046 type_t *btp = block_dup_type(tp);
1047 btp->t_bitfield = false;
1048 /* bit-field type '%s' invalid in ANSI C */
1049 warning(273, type_name(btp));
1050 } else if (pflag) {
1051 type_t *btp = block_dup_type(tp);
1052 btp->t_bitfield = false;
1053 /* nonportable bit-field type '%s' */
1054 warning(34, type_name(btp));
1055 }
1056 }
1057 } else if (t == INT && dcs->d_sign_mod == NOTSPEC) {
1058 if (pflag && !bitfieldtype_ok) {
1059 /* bit-field of type plain 'int' has ... */
1060 warning(344);
1061 }
1062 } else if (!(t == INT || t == UINT || t == BOOL ||
1063 (is_integer(t) && (bitfieldtype_ok || allow_gcc)))) {
1064
1065 type_t *btp = block_dup_type(tp);
1066 btp->t_bitfield = false;
1067 /* illegal bit-field type '%s' */
1068 warning(35, type_name(btp));
1069
1070 unsigned int sz = tp->t_flen;
1071 dsym->s_type = tp = block_dup_type(gettyp(t = INT));
1072 if ((tp->t_flen = sz) > size_in_bits(t))
1073 tp->t_flen = size_in_bits(t);
1074 *inout_t = t;
1075 *inout_tp = tp;
1076 }
1077 }
1078
1079 static void
1080 declare_bit_field(sym_t *dsym, tspec_t *inout_t, type_t **const inout_tp)
1081 {
1082 type_t *tp;
1083 tspec_t t;
1084
1085 check_bit_field_type(dsym, inout_tp, inout_t);
1086
1087 tp = *inout_tp;
1088 t = *inout_t;
1089 if (tp->t_flen > size_in_bits(t)) {
1090 /* illegal bit-field size: %d */
1091 error(36, tp->t_flen);
1092 tp->t_flen = size_in_bits(t);
1093 } else if (tp->t_flen == 0 && dsym->s_name != unnamed) {
1094 /* zero size bit-field */
1095 error(37);
1096 tp->t_flen = size_in_bits(t);
1097 }
1098 if (dsym->s_scl == UNION_MEMBER) {
1099 /* bit-field in union is very unusual */
1100 warning(41);
1101 dsym->s_type->t_bitfield = false;
1102 dsym->s_bitfield = false;
1103 }
1104 }
1105
1106 /*
1107 * Process the declarator of a struct/union element.
1108 */
1109 sym_t *
1110 declarator_1_struct_union(sym_t *dsym)
1111 {
1112 type_t *tp;
1113 tspec_t t;
1114 int sz;
1115 unsigned int o = 0; /* Appease GCC */
1116
1117 lint_assert(is_member(dsym));
1118
1119 if (dcs->d_redeclared_symbol != NULL) {
1120 lint_assert(is_member(dcs->d_redeclared_symbol));
1121
1122 if (dsym->u.s_member.sm_sou_type ==
1123 dcs->d_redeclared_symbol->u.s_member.sm_sou_type) {
1124 /* duplicate member name '%s' */
1125 error(33, dsym->s_name);
1126 rmsym(dcs->d_redeclared_symbol);
1127 }
1128 }
1129
1130 check_type(dsym);
1131
1132 t = (tp = dsym->s_type)->t_tspec;
1133
1134 if (dsym->s_bitfield)
1135 declare_bit_field(dsym, &t, &tp);
1136 else if (t == FUNC) {
1137 /* function illegal in structure or union */
1138 error(38);
1139 dsym->s_type = tp = block_derive_type(tp, t = PTR);
1140 }
1141
1142 /*
1143 * bit-fields of length 0 are not warned about because length_in_bits
1144 * does not return the length of the bit-field but the length
1145 * of the type the bit-field is packed in (it's ok)
1146 */
1147 if ((sz = length_in_bits(dsym->s_type, dsym->s_name)) == 0) {
1148 if (t == ARRAY && dsym->s_type->t_dim == 0) {
1149 /* zero-sized array '%s' in struct is a C99 extension */
1150 c99ism(39, dsym->s_name);
1151 }
1152 }
1153
1154 if (dcs->d_kind == DK_UNION_MEMBER) {
1155 o = dcs->d_offset_in_bits;
1156 dcs->d_offset_in_bits = 0;
1157 }
1158 if (dsym->s_bitfield) {
1159 dcs_align(alignment_in_bits(tp), tp->t_flen);
1160 dsym->u.s_member.sm_offset_in_bits = dcs->d_offset_in_bits -
1161 dcs->d_offset_in_bits % size_in_bits(t);
1162 tp->t_foffs = dcs->d_offset_in_bits -
1163 dsym->u.s_member.sm_offset_in_bits;
1164 dcs->d_offset_in_bits += tp->t_flen;
1165 } else {
1166 dcs_align(alignment_in_bits(tp), 0);
1167 dsym->u.s_member.sm_offset_in_bits = dcs->d_offset_in_bits;
1168 dcs->d_offset_in_bits += sz;
1169 }
1170 if (dcs->d_kind == DK_UNION_MEMBER && o > dcs->d_offset_in_bits)
1171 dcs->d_offset_in_bits = o;
1172
1173 check_function_definition(dsym, false);
1174
1175 /*
1176 * Clear the BITFIELDTYPE indicator after processing each
1177 * structure element.
1178 */
1179 bitfieldtype_ok = false;
1180
1181 return dsym;
1182 }
1183
1184 /*
1185 * Aligns next structure element as required.
1186 *
1187 * al contains the required alignment, len the length of a bit-field.
1188 */
1189 static void
1190 dcs_align(unsigned int al, unsigned int len)
1191 {
1192 unsigned int no;
1193
1194 /*
1195 * The alignment of the current element becomes the alignment of
1196 * the struct/union if it is larger than the current alignment
1197 * of the struct/union.
1198 */
1199 if (al > dcs->d_sou_align_in_bits)
1200 dcs->d_sou_align_in_bits = al;
1201
1202 no = (dcs->d_offset_in_bits + (al - 1)) & ~(al - 1);
1203 if (len == 0 || dcs->d_offset_in_bits + len > no)
1204 dcs->d_offset_in_bits = no;
1205 }
1206
1207 /*
1208 * Remember the width of the field in its type structure.
1209 */
1210 sym_t *
1211 set_bit_field_width(sym_t *dsym, int len)
1212 {
1213
1214 if (dsym == NULL) {
1215 dsym = block_zero_alloc(sizeof(*dsym));
1216 dsym->s_name = unnamed;
1217 dsym->s_kind = FMEMBER;
1218 dsym->s_scl = STRUCT_MEMBER;
1219 dsym->s_type = gettyp(UINT);
1220 dsym->s_block_level = -1;
1221 }
1222 dsym->s_type = block_dup_type(dsym->s_type);
1223 dsym->s_type->t_bitfield = true;
1224 dsym->s_type->t_flen = len;
1225 dsym->s_bitfield = true;
1226 return dsym;
1227 }
1228
1229 /*
1230 * A sequence of asterisks and qualifiers, from right to left. For example,
1231 * 'const ***volatile **const volatile' results in [cvp, p, vp, p, p]. The
1232 * leftmost 'const' is not included in this list, it is stored in dcs->d_const
1233 * instead.
1234 */
1235 qual_ptr *
1236 merge_qualified_pointer(qual_ptr *p1, qual_ptr *p2)
1237 {
1238 qual_ptr *tail;
1239
1240 if (p2 == NULL)
1241 return p1; /* for optional qualifiers */
1242
1243 if (p2->p_pointer) {
1244 /* append p1 to p2, keeping p2 */
1245 for (tail = p2; tail->p_next != NULL; tail = tail->p_next)
1246 continue;
1247 tail->p_next = p1;
1248 return p2;
1249 }
1250
1251 /* merge p2 into p1, keeping p1 */
1252 if (p2->p_const) {
1253 if (p1->p_const) {
1254 /* duplicate '%s' */
1255 warning(10, "const");
1256 }
1257 p1->p_const = true;
1258 }
1259 if (p2->p_volatile) {
1260 if (p1->p_volatile) {
1261 /* duplicate '%s' */
1262 warning(10, "volatile");
1263 }
1264 p1->p_volatile = true;
1265 }
1266 free(p2);
1267 return p1;
1268 }
1269
1270 static type_t *
1271 block_derive_pointer(type_t *stp, bool is_const, bool is_volatile)
1272 {
1273 type_t *tp;
1274
1275 tp = block_derive_type(stp, PTR);
1276 tp->t_const = is_const;
1277 tp->t_volatile = is_volatile;
1278 return tp;
1279 }
1280
1281 /*
1282 * The following 3 functions extend the type of a declarator with
1283 * pointer, function and array types.
1284 *
1285 * The current type is the type built by dcs_end_type (dcs->d_type) and
1286 * pointer, function and array types already added for this
1287 * declarator. The new type extension is inserted between both.
1288 */
1289 sym_t *
1290 add_pointer(sym_t *decl, qual_ptr *p)
1291 {
1292
1293 debug_dinfo(dcs);
1294
1295 type_t **tpp = &decl->s_type;
1296 while (*tpp != NULL && *tpp != dcs->d_type)
1297 tpp = &(*tpp)->t_subt;
1298 if (*tpp == NULL) {
1299 debug_step("add_pointer: unchanged '%s'",
1300 type_name(decl->s_type));
1301 return decl;
1302 }
1303
1304 while (p != NULL) {
1305 *tpp = block_derive_pointer(dcs->d_type,
1306 p->p_const, p->p_volatile);
1307
1308 tpp = &(*tpp)->t_subt;
1309
1310 qual_ptr *next = p->p_next;
1311 free(p);
1312 p = next;
1313 }
1314 debug_step("add_pointer: '%s'", type_name(decl->s_type));
1315 return decl;
1316 }
1317
1318 static type_t *
1319 block_derive_array(type_t *stp, bool dim, int len)
1320 {
1321
1322 type_t *tp = block_derive_type(stp, ARRAY);
1323 tp->t_dim = len;
1324
1325 #if 0
1326 /*
1327 * As of 2022-04-03, the implementation of the type parser (see
1328 * add_function, add_array, add_pointer) is strange. When it sees
1329 * the type 'void *b[4]', it first creates 'void b[4]' and only later
1330 * inserts the '*' in the middle of the type. Late modifications like
1331 * these should not be done at all, instead the parser should be fixed
1332 * to process the type names in the proper syntactical order.
1333 *
1334 * Since the intermediate type would be an array of void, but the
1335 * final type is valid, this check cannot be enabled yet.
1336 */
1337 if (stp->t_tspec == VOID) {
1338 /* array of incomplete type */
1339 error(301);
1340 tp->t_subt = gettyp(CHAR);
1341 }
1342 #endif
1343 if (len < 0) {
1344 /* negative array dimension (%d) */
1345 error(20, len);
1346 } else if (len == 0 && dim) {
1347 /* zero sized array is a C99 extension */
1348 c99ism(322);
1349 } else if (len == 0 && !dim)
1350 tp->t_incomplete_array = true;
1351
1352 return tp;
1353 }
1354
1355 /*
1356 * If a dimension was specified, dim is true, otherwise false
1357 * n is the specified dimension
1358 */
1359 sym_t *
1360 add_array(sym_t *decl, bool dim, int n)
1361 {
1362
1363 debug_dinfo(dcs);
1364
1365 type_t **tpp = &decl->s_type;
1366 while (*tpp != NULL && *tpp != dcs->d_type)
1367 tpp = &(*tpp)->t_subt;
1368 if (*tpp == NULL) {
1369 debug_step("add_array: unchanged '%s'",
1370 type_name(decl->s_type));
1371 return decl;
1372 }
1373
1374 *tpp = block_derive_array(dcs->d_type, dim, n);
1375
1376 debug_step("add_array: '%s'", type_name(decl->s_type));
1377 return decl;
1378 }
1379
1380 static type_t *
1381 block_derive_function(type_t *ret, bool proto, sym_t *args, bool vararg)
1382 {
1383
1384 type_t *tp = block_derive_type(ret, FUNC);
1385 tp->t_proto = proto;
1386 if (proto)
1387 tp->t_args = args;
1388 tp->t_vararg = vararg;
1389 return tp;
1390 }
1391
1392 sym_t *
1393 add_function(sym_t *decl, sym_t *args)
1394 {
1395
1396 debug_enter();
1397 debug_dinfo(dcs);
1398 debug_sym("decl: ", decl, "\n");
1399 #ifdef DEBUG
1400 for (const sym_t *arg = args; arg != NULL; arg = arg->s_next)
1401 debug_sym("arg: ", arg, "\n");
1402 #endif
1403
1404 if (dcs->d_proto) {
1405 if (!allow_c90)
1406 /* function prototypes are illegal in traditional C */
1407 warning(270);
1408 args = new_style_function(args);
1409 } else {
1410 old_style_function(decl, args);
1411 }
1412
1413 /*
1414 * The symbols are removed from the symbol table by
1415 * end_declaration_level after add_function. To be able to restore
1416 * them if this is a function definition, a pointer to the list of
1417 * all symbols is stored in dcs->d_enclosing->d_func_proto_syms. Also
1418 * a list of the arguments (concatenated by s_next) is stored in
1419 * dcs->d_enclosing->d_func_args. (dcs->d_enclosing must be used
1420 * because *dcs is the declaration stack element created for the list
1421 * of params and is removed after add_function.)
1422 */
1423 if (dcs->d_enclosing->d_kind == DK_EXTERN &&
1424 decl->s_type == dcs->d_enclosing->d_type) {
1425 dcs->d_enclosing->d_func_proto_syms = dcs->d_dlsyms;
1426 dcs->d_enclosing->d_func_args = args;
1427 }
1428
1429 /*
1430 * XXX: What is this code doing on a semantic level, and why?
1431 * Returning decl leads to the wrong function types in msg_347.
1432 */
1433 type_t **tpp = &decl->s_type;
1434 if (*tpp == NULL)
1435 decl->s_type = dcs->d_enclosing->d_type;
1436 while (*tpp != NULL && *tpp != dcs->d_enclosing->d_type)
1437 /*
1438 * XXX: accessing INT->t_subt feels strange, even though it
1439 * may even be guaranteed to be NULL.
1440 */
1441 tpp = &(*tpp)->t_subt;
1442 if (*tpp == NULL) {
1443 debug_step("add_function: unchanged '%s'",
1444 type_name(decl->s_type));
1445 debug_leave();
1446 return decl; /* see msg_347 */
1447 }
1448
1449 *tpp = block_derive_function(dcs->d_enclosing->d_type,
1450 dcs->d_proto, args, dcs->d_vararg);
1451
1452 debug_step("add_function: '%s'", type_name(decl->s_type));
1453 debug_leave();
1454 return decl;
1455 }
1456
1457 static sym_t *
1458 new_style_function(sym_t *args)
1459 {
1460 sym_t *arg, *sym;
1461 scl_t sc;
1462
1463 /*
1464 * Declarations of structs/unions/enums in param lists are legal,
1465 * but senseless.
1466 */
1467 for (sym = dcs->d_dlsyms; sym != NULL; sym = sym->s_level_next) {
1468 sc = sym->s_scl;
1469 if (sc == STRUCT_TAG || sc == UNION_TAG || sc == ENUM_TAG) {
1470 /* dubious tag declaration '%s %s' */
1471 warning(85, storage_class_name(sc), sym->s_name);
1472 }
1473 }
1474
1475 for (arg = args; arg != NULL; arg = arg->s_next) {
1476 if (arg->s_type->t_tspec == VOID &&
1477 !(arg == args && arg->s_next == NULL)) {
1478 /* void must be sole parameter */
1479 error(60);
1480 arg->s_type = gettyp(INT);
1481 }
1482 }
1483
1484 if (args == NULL || args->s_type->t_tspec == VOID)
1485 return NULL;
1486 return args;
1487 }
1488
1489 /*
1490 * Called for old-style function declarations.
1491 */
1492 static void
1493 old_style_function(sym_t *decl, sym_t *args)
1494 {
1495
1496 /*
1497 * Remember list of parameters only if this really seems to be a
1498 * function definition.
1499 */
1500 if (dcs->d_enclosing->d_kind == DK_EXTERN &&
1501 decl->s_type == dcs->d_enclosing->d_type) {
1502 /*
1503 * We assume that this becomes a function definition. If
1504 * we are wrong, it's corrected in check_function_definition.
1505 */
1506 if (args != NULL) {
1507 decl->s_osdef = true;
1508 decl->u.s_old_style_args = args;
1509 }
1510 } else {
1511 if (args != NULL)
1512 /* function prototype parameters must have types */
1513 warning(62);
1514 }
1515 }
1516
1517 /*
1518 * In a function declaration, a list of identifiers (as opposed to a list of
1519 * types) is allowed only if it's also a function definition.
1520 */
1521 void
1522 check_function_definition(sym_t *sym, bool msg)
1523 {
1524
1525 if (sym->s_osdef) {
1526 if (msg) {
1527 /* incomplete or misplaced function definition */
1528 error(22);
1529 }
1530 sym->s_osdef = false;
1531 sym->u.s_old_style_args = NULL;
1532 }
1533 }
1534
1535 /*
1536 * Process the name in a declarator.
1537 * The symbol gets one of the storage classes EXTERN, STATIC, AUTO or
1538 * TYPEDEF.
1539 * s_def and s_register are valid after declarator_name().
1540 */
1541 sym_t *
1542 declarator_name(sym_t *sym)
1543 {
1544 scl_t sc = NOSCL;
1545
1546 if (sym->s_scl == NOSCL)
1547 dcs->d_redeclared_symbol = NULL;
1548 else if (sym->s_defarg) {
1549 sym->s_defarg = false;
1550 dcs->d_redeclared_symbol = NULL;
1551 } else {
1552 dcs->d_redeclared_symbol = sym;
1553 sym = pushdown(sym);
1554 }
1555
1556 switch (dcs->d_kind) {
1557 case DK_STRUCT_MEMBER:
1558 case DK_UNION_MEMBER:
1559 /* Set parent */
1560 sym->u.s_member.sm_sou_type = dcs->d_tagtyp->t_str;
1561 sym->s_def = DEF;
1562 /* XXX: Where is sym->u.s_member.sm_offset_in_bits set? */
1563 sc = dcs->d_kind == DK_STRUCT_MEMBER
1564 ? STRUCT_MEMBER
1565 : UNION_MEMBER;
1566 break;
1567 case DK_EXTERN:
1568 /*
1569 * static and external symbols without "extern" are
1570 * considered to be tentatively defined, external
1571 * symbols with "extern" are declared, and typedef names
1572 * are defined. Tentatively defined and declared symbols
1573 * may become defined if an initializer is present or
1574 * this is a function definition.
1575 */
1576 if ((sc = dcs->d_scl) == NOSCL) {
1577 sc = EXTERN;
1578 sym->s_def = TDEF;
1579 } else if (sc == STATIC)
1580 sym->s_def = TDEF;
1581 else if (sc == TYPEDEF)
1582 sym->s_def = DEF;
1583 else {
1584 lint_assert(sc == EXTERN);
1585 sym->s_def = DECL;
1586 }
1587 break;
1588 case DK_PROTO_ARG:
1589 sym->s_arg = true;
1590 /* FALLTHROUGH */
1591 case DK_OLD_STYLE_ARG:
1592 if ((sc = dcs->d_scl) == NOSCL)
1593 sc = AUTO;
1594 else {
1595 lint_assert(sc == REG);
1596 sym->s_register = true;
1597 sc = AUTO;
1598 }
1599 sym->s_def = DEF;
1600 break;
1601 case DK_AUTO:
1602 if ((sc = dcs->d_scl) == NOSCL) {
1603 /*
1604 * XXX somewhat ugly because we dont know whether
1605 * this is AUTO or EXTERN (functions). If we are
1606 * wrong it must be corrected in declare_local(),
1607 * where we have the necessary type information.
1608 */
1609 sc = AUTO;
1610 sym->s_def = DEF;
1611 } else if (sc == AUTO || sc == STATIC || sc == TYPEDEF)
1612 sym->s_def = DEF;
1613 else if (sc == REG) {
1614 sym->s_register = true;
1615 sc = AUTO;
1616 sym->s_def = DEF;
1617 } else {
1618 lint_assert(sc == EXTERN);
1619 sym->s_def = DECL;
1620 }
1621 break;
1622 case DK_ABSTRACT: /* try to continue after syntax errors */
1623 sc = NOSCL;
1624 break;
1625 default:
1626 lint_assert(/*CONSTCOND*/false);
1627 }
1628 sym->s_scl = sc;
1629
1630 sym->s_type = dcs->d_type;
1631
1632 dcs->d_func_proto_syms = NULL;
1633
1634 return sym;
1635 }
1636
1637 /*
1638 * Process a name in the list of formal parameters in an old-style function
1639 * definition.
1640 */
1641 sym_t *
1642 old_style_function_name(sym_t *sym)
1643 {
1644
1645 if (sym->s_scl != NOSCL) {
1646 if (block_level == sym->s_block_level) {
1647 /* redeclaration of formal parameter '%s' */
1648 error(21, sym->s_name);
1649 lint_assert(sym->s_defarg);
1650 }
1651 sym = pushdown(sym);
1652 }
1653 sym->s_type = gettyp(INT);
1654 sym->s_scl = AUTO;
1655 sym->s_def = DEF;
1656 sym->s_defarg = sym->s_arg = true;
1657 return sym;
1658 }
1659
1660 /*
1661 * Create the type of a tag.
1662 *
1663 * tag points to the symbol table entry of the tag
1664 * kind is the kind of the tag (STRUCT/UNION/ENUM)
1665 * decl is true if the type of the tag will be completed in this declaration
1666 * (the following token is T_LBRACE)
1667 * semi is true if the following token is T_SEMI
1668 */
1669 type_t *
1670 make_tag_type(sym_t *tag, tspec_t kind, bool decl, bool semi)
1671 {
1672 scl_t scl;
1673 type_t *tp;
1674
1675 if (kind == STRUCT)
1676 scl = STRUCT_TAG;
1677 else if (kind == UNION)
1678 scl = UNION_TAG;
1679 else {
1680 lint_assert(kind == ENUM);
1681 scl = ENUM_TAG;
1682 }
1683
1684 if (tag != NULL) {
1685 if (tag->s_scl != NOSCL)
1686 tag = new_tag(tag, scl, decl, semi);
1687 else {
1688 /* a new tag, no empty declaration */
1689 dcs->d_enclosing->d_nonempty_decl = true;
1690 if (scl == ENUM_TAG && !decl) {
1691 /* TODO: Make this an error in C99 mode as well. */
1692 if (allow_c90 &&
1693 ((!allow_trad && !allow_c99) || pflag))
1694 /* forward reference to enum type */
1695 warning(42);
1696 }
1697 }
1698 if (tag->s_scl == NOSCL) {
1699 tag->s_scl = scl;
1700 tag->s_type = tp = block_zero_alloc(sizeof(*tp));
1701 tp->t_packed = dcs->d_packed;
1702 } else
1703 tp = tag->s_type;
1704
1705 } else {
1706 tag = block_zero_alloc(sizeof(*tag));
1707 tag->s_name = unnamed;
1708 UNIQUE_CURR_POS(tag->s_def_pos);
1709 tag->s_kind = FTAG;
1710 tag->s_scl = scl;
1711 tag->s_block_level = -1;
1712 tag->s_type = tp = block_zero_alloc(sizeof(*tp));
1713 tp->t_packed = dcs->d_packed;
1714 dcs->d_enclosing->d_nonempty_decl = true;
1715 }
1716
1717 if (tp->t_tspec == NOTSPEC) {
1718 tp->t_tspec = kind;
1719 if (kind != ENUM) {
1720 tp->t_str = block_zero_alloc(sizeof(*tp->t_str));
1721 tp->t_str->sou_align_in_bits = CHAR_SIZE;
1722 tp->t_str->sou_tag = tag;
1723 tp->t_str->sou_incomplete = true;
1724 } else {
1725 tp->t_is_enum = true;
1726 tp->t_enum = block_zero_alloc(sizeof(*tp->t_enum));
1727 tp->t_enum->en_tag = tag;
1728 tp->t_enum->en_incomplete = true;
1729 }
1730 }
1731 return tp;
1732 }
1733
1734 /*
1735 * Checks all possible cases of tag redeclarations.
1736 * decl is true if T_LBRACE follows
1737 * semi is true if T_SEMI follows
1738 */
1739 static sym_t *
1740 new_tag(sym_t *tag, scl_t scl, bool decl, bool semi)
1741 {
1742
1743 if (tag->s_block_level < block_level) {
1744 if (semi) {
1745 /* "struct a;" */
1746 if (allow_c90) {
1747 /* XXX: Why is this warning suppressed in C90 mode? */
1748 if (allow_trad || allow_c99)
1749 /* declaration of '%s %s' intro... */
1750 warning(44, storage_class_name(scl),
1751 tag->s_name);
1752 tag = pushdown(tag);
1753 } else if (tag->s_scl != scl) {
1754 /* base type is really '%s %s' */
1755 warning(45, storage_class_name(tag->s_scl),
1756 tag->s_name);
1757 }
1758 dcs->d_enclosing->d_nonempty_decl = true;
1759 } else if (decl) {
1760 /* "struct a { ... } " */
1761 if (hflag)
1762 /* redefinition of '%s' hides earlier one */
1763 warning(43, tag->s_name);
1764 tag = pushdown(tag);
1765 dcs->d_enclosing->d_nonempty_decl = true;
1766 } else if (tag->s_scl != scl) {
1767 /* base type is really '%s %s' */
1768 warning(45, storage_class_name(tag->s_scl),
1769 tag->s_name);
1770 /* XXX: Why is this warning suppressed in C90 mode? */
1771 if (allow_trad || allow_c99) {
1772 /* declaration of '%s %s' introduces ... */
1773 warning(44, storage_class_name(scl),
1774 tag->s_name);
1775 }
1776 tag = pushdown(tag);
1777 dcs->d_enclosing->d_nonempty_decl = true;
1778 }
1779 } else {
1780 if (tag->s_scl != scl ||
1781 (decl && !is_incomplete(tag->s_type))) {
1782 /* %s tag '%s' redeclared as %s */
1783 error(46, storage_class_name(tag->s_scl),
1784 tag->s_name, storage_class_name(scl));
1785 print_previous_declaration(tag);
1786 tag = pushdown(tag);
1787 dcs->d_enclosing->d_nonempty_decl = true;
1788 } else if (semi || decl)
1789 dcs->d_enclosing->d_nonempty_decl = true;
1790 }
1791 return tag;
1792 }
1793
1794 const char *
1795 storage_class_name(scl_t sc)
1796 {
1797 switch (sc) {
1798 case EXTERN: return "extern";
1799 case STATIC: return "static";
1800 case AUTO: return "auto";
1801 case REG: return "register";
1802 case TYPEDEF: return "typedef";
1803 case STRUCT_TAG:return "struct";
1804 case UNION_TAG: return "union";
1805 case ENUM_TAG: return "enum";
1806 default: lint_assert(/*CONSTCOND*/false);
1807 }
1808 /* NOTREACHED */
1809 }
1810
1811 /*
1812 * tp points to the type of the tag, fmem to the list of members.
1813 */
1814 type_t *
1815 complete_tag_struct_or_union(type_t *tp, sym_t *fmem)
1816 {
1817
1818 if (tp == NULL) /* in case of syntax errors */
1819 return gettyp(INT);
1820
1821 if (tp->t_tspec == ENUM)
1822 tp->t_enum->en_incomplete = false;
1823 else
1824 tp->t_str->sou_incomplete = false;
1825
1826 tspec_t t = tp->t_tspec;
1827 dcs_align((u_int)dcs->d_sou_align_in_bits, 0);
1828
1829 struct_or_union *sp = tp->t_str;
1830 sp->sou_align_in_bits = dcs->d_sou_align_in_bits;
1831 sp->sou_first_member = fmem;
1832 if (tp->t_packed)
1833 set_packed_size(tp);
1834 else
1835 sp->sou_size_in_bits = dcs->d_offset_in_bits;
1836
1837 if (sp->sou_size_in_bits == 0) {
1838 /* zero sized %s is a C99 feature */
1839 c99ism(47, ttab[t].tt_name);
1840 }
1841
1842 int n = 0;
1843 for (sym_t *mem = fmem; mem != NULL; mem = mem->s_next) {
1844 /* bind anonymous members to the structure */
1845 if (mem->u.s_member.sm_sou_type == NULL) {
1846 mem->u.s_member.sm_sou_type = sp;
1847 if (mem->s_type->t_bitfield) {
1848 sp->sou_size_in_bits += bit_field_size(&mem);
1849 if (mem == NULL)
1850 break;
1851 }
1852 sp->sou_size_in_bits +=
1853 type_size_in_bits(mem->s_type);
1854 }
1855 if (mem->s_name != unnamed)
1856 n++;
1857 }
1858
1859 if (n == 0 && sp->sou_size_in_bits != 0) {
1860 /* '%s' has no named members */
1861 warning(65, type_name(tp));
1862 }
1863 return tp;
1864 }
1865
1866 type_t *
1867 complete_tag_enum(type_t *tp, sym_t *first_enumerator)
1868 {
1869
1870 tp->t_enum->en_incomplete = false;
1871 tp->t_enum->en_first_enumerator = first_enumerator;
1872 return tp;
1873 }
1874
1875 /*
1876 * Processes the name of an enumerator in an enum declaration.
1877 *
1878 * sym points to the enumerator
1879 * val is the value of the enumerator
1880 * impl is true if the value of the enumerator was not explicitly specified.
1881 */
1882 sym_t *
1883 enumeration_constant(sym_t *sym, int val, bool impl)
1884 {
1885
1886 if (sym->s_scl != NOSCL) {
1887 if (sym->s_block_level == block_level) {
1888 /* no hflag, because this is illegal */
1889 if (sym->s_arg) {
1890 /* enumeration constant '%s' hides parameter */
1891 warning(57, sym->s_name);
1892 } else {
1893 /* redeclaration of '%s' */
1894 error(27, sym->s_name);
1895 /*
1896 * inside blocks it should not be too
1897 * complicated to find the position of the
1898 * previous declaration
1899 */
1900 if (block_level == 0)
1901 print_previous_declaration(sym);
1902 }
1903 } else {
1904 if (hflag)
1905 /* redefinition of '%s' hides earlier one */
1906 warning(43, sym->s_name);
1907 }
1908 sym = pushdown(sym);
1909 }
1910
1911 sym->s_scl = ENUM_CONST;
1912 sym->s_type = dcs->d_tagtyp;
1913 sym->u.s_enum_constant = val;
1914
1915 if (impl && val == TARG_INT_MIN) {
1916 /* enumeration value '%s' overflows */
1917 warning(48, sym->s_name);
1918 }
1919
1920 enumval = val == TARG_INT_MAX ? TARG_INT_MIN : val + 1;
1921 return sym;
1922 }
1923
1924 static bool
1925 ends_with(const char *s, const char *suffix)
1926 {
1927 size_t s_len = strlen(s);
1928 size_t suffix_len = strlen(suffix);
1929 return s_len >= suffix_len &&
1930 memcmp(s + s_len - suffix_len, suffix, suffix_len) == 0;
1931 }
1932
1933 static void
1934 check_extern_declaration(const sym_t *sym)
1935 {
1936
1937 if (sym->s_scl == EXTERN &&
1938 dcs->d_redeclared_symbol == NULL &&
1939 ends_with(curr_pos.p_file, ".c")) {
1940 /* 'extern' declaration of '%s' outside a header */
1941 warning(351, sym->s_name);
1942 }
1943 }
1944
1945 /* Process a single external or 'static' declarator. */
1946 static void
1947 declare_extern(sym_t *dsym, bool initflg, sbuf_t *renaming)
1948 {
1949
1950 if (renaming != NULL) {
1951 lint_assert(dsym->s_rename == NULL);
1952
1953 char *s = level_zero_alloc(1, renaming->sb_len + 1);
1954 (void)memcpy(s, renaming->sb_name, renaming->sb_len + 1);
1955 dsym->s_rename = s;
1956 }
1957
1958 check_extern_declaration(dsym);
1959
1960 check_function_definition(dsym, true);
1961
1962 check_type(dsym);
1963
1964 if (initflg && !check_init(dsym))
1965 dsym->s_def = DEF;
1966
1967 /*
1968 * Declarations of functions are marked as "tentative" in
1969 * declarator_name(). This is wrong because there are no
1970 * tentative function definitions.
1971 */
1972 if (dsym->s_type->t_tspec == FUNC && dsym->s_def == TDEF)
1973 dsym->s_def = DECL;
1974
1975 if (dcs->d_inline) {
1976 if (dsym->s_type->t_tspec == FUNC) {
1977 dsym->s_inline = true;
1978 } else {
1979 /* variable '%s' declared inline */
1980 warning(268, dsym->s_name);
1981 }
1982 }
1983
1984 /* Write the declaration into the output file */
1985 if (plibflg && llibflg &&
1986 dsym->s_type->t_tspec == FUNC && dsym->s_type->t_proto) {
1987 /*
1988 * With both LINTLIBRARY and PROTOLIB the prototype is
1989 * written as a function definition to the output file.
1990 */
1991 bool rval = dsym->s_type->t_subt->t_tspec != VOID;
1992 outfdef(dsym, &dsym->s_def_pos, rval, false, NULL);
1993 } else if (!is_compiler_builtin(dsym->s_name)) {
1994 outsym(dsym, dsym->s_scl, dsym->s_def);
1995 }
1996
1997 sym_t *rdsym;
1998 if ((rdsym = dcs->d_redeclared_symbol) != NULL) {
1999
2000 /*
2001 * If the old symbol stems from an old-style function
2002 * definition, we have remembered the params in
2003 * rdsym->s_old_style_args and compare them with the params
2004 * of the prototype.
2005 */
2006 bool redec = rdsym->s_osdef && dsym->s_type->t_proto &&
2007 check_old_style_definition(rdsym, dsym);
2008
2009 bool dowarn = false;
2010 if (!redec && !check_redeclaration(dsym, &dowarn)) {
2011 if (dowarn) {
2012 /* TODO: Make this an error in C99 mode as well. */
2013 if (!allow_trad && !allow_c99)
2014 /* redeclaration of '%s' */
2015 error(27, dsym->s_name);
2016 else
2017 /* redeclaration of '%s' */
2018 warning(27, dsym->s_name);
2019 print_previous_declaration(rdsym);
2020 }
2021
2022 /*
2023 * Take over the remembered params if the new symbol
2024 * is not a prototype.
2025 */
2026 if (rdsym->s_osdef && !dsym->s_type->t_proto) {
2027 dsym->s_osdef = rdsym->s_osdef;
2028 dsym->u.s_old_style_args =
2029 rdsym->u.s_old_style_args;
2030 dsym->s_def_pos = rdsym->s_def_pos;
2031 }
2032
2033 if (rdsym->s_type->t_proto && !dsym->s_type->t_proto)
2034 dsym->s_def_pos = rdsym->s_def_pos;
2035 else if (rdsym->s_def == DEF && dsym->s_def != DEF)
2036 dsym->s_def_pos = rdsym->s_def_pos;
2037
2038 copy_usage_info(dsym, rdsym);
2039
2040 /* Once a name is defined, it remains defined. */
2041 if (rdsym->s_def == DEF)
2042 dsym->s_def = DEF;
2043
2044 /* once a function is inline, it remains inline */
2045 if (rdsym->s_inline)
2046 dsym->s_inline = true;
2047
2048 complete_type(dsym, rdsym);
2049 }
2050
2051 rmsym(rdsym);
2052 }
2053
2054 if (dsym->s_scl == TYPEDEF) {
2055 dsym->s_type = block_dup_type(dsym->s_type);
2056 dsym->s_type->t_typedef = true;
2057 set_first_typedef(dsym->s_type, dsym);
2058 }
2059 }
2060
2061 void
2062 declare(sym_t *decl, bool initflg, sbuf_t *renaming)
2063 {
2064
2065 if (dcs->d_kind == DK_EXTERN)
2066 declare_extern(decl, initflg, renaming);
2067 else if (dcs->d_kind == DK_OLD_STYLE_ARG ||
2068 dcs->d_kind == DK_PROTO_ARG) {
2069 if (renaming != NULL) {
2070 /* symbol renaming can't be used on function arguments */
2071 error(310);
2072 } else
2073 (void)declare_argument(decl, initflg);
2074 } else {
2075 lint_assert(dcs->d_kind == DK_AUTO);
2076 if (renaming != NULL) {
2077 /* symbol renaming can't be used on automatic variables */
2078 error(311);
2079 } else
2080 declare_local(decl, initflg);
2081 }
2082 }
2083
2084 /*
2085 * Copies information about usage into a new symbol table entry of
2086 * the same symbol.
2087 */
2088 void
2089 copy_usage_info(sym_t *sym, sym_t *rdsym)
2090 {
2091
2092 sym->s_set_pos = rdsym->s_set_pos;
2093 sym->s_use_pos = rdsym->s_use_pos;
2094 sym->s_set = rdsym->s_set;
2095 sym->s_used = rdsym->s_used;
2096 }
2097
2098 /*
2099 * Prints an error and returns true if a symbol is redeclared/redefined.
2100 * Otherwise, returns false and, in some cases of minor problems, prints
2101 * a warning.
2102 */
2103 bool
2104 check_redeclaration(sym_t *dsym, bool *dowarn)
2105 {
2106
2107 sym_t *rsym = dcs->d_redeclared_symbol;
2108 if (rsym->s_scl == ENUM_CONST) {
2109 /* redeclaration of '%s' */
2110 error(27, dsym->s_name);
2111 print_previous_declaration(rsym);
2112 return true;
2113 }
2114 if (rsym->s_scl == TYPEDEF) {
2115 /* typedef '%s' redeclared */
2116 error(89, dsym->s_name);
2117 print_previous_declaration(rsym);
2118 return true;
2119 }
2120 if (dsym->s_scl == TYPEDEF) {
2121 /* redeclaration of '%s' */
2122 error(27, dsym->s_name);
2123 print_previous_declaration(rsym);
2124 return true;
2125 }
2126 if (rsym->s_def == DEF && dsym->s_def == DEF) {
2127 /* redefinition of '%s' */
2128 error(28, dsym->s_name);
2129 print_previous_declaration(rsym);
2130 return true;
2131 }
2132 if (!types_compatible(rsym->s_type, dsym->s_type, false, false, dowarn)) {
2133 /* redeclaration of '%s' with type '%s', expected '%s' */
2134 error(347, dsym->s_name,
2135 type_name(dsym->s_type), type_name(rsym->s_type));
2136 print_previous_declaration(rsym);
2137 return true;
2138 }
2139 if (rsym->s_scl == EXTERN && dsym->s_scl == EXTERN)
2140 return false;
2141 if (rsym->s_scl == STATIC && dsym->s_scl == STATIC)
2142 return false;
2143 if (rsym->s_scl == STATIC && dsym->s_def == DECL)
2144 return false;
2145 if (rsym->s_scl == EXTERN && rsym->s_def == DEF) {
2146 /*
2147 * All cases except "int a = 1; static int a;" are caught
2148 * above with or without a warning
2149 */
2150 /* redeclaration of '%s' */
2151 error(27, dsym->s_name);
2152 print_previous_declaration(rsym);
2153 return true;
2154 }
2155 if (rsym->s_scl == EXTERN) {
2156 /* '%s' was previously declared extern, becomes static */
2157 warning(29, dsym->s_name);
2158 print_previous_declaration(rsym);
2159 return false;
2160 }
2161 /*
2162 * Now it's one of:
2163 * "static a; int a;", "static a; int a = 1;", "static a = 1; int a;"
2164 */
2165 /* TODO: Make this an error in C99 mode as well. */
2166 if (!allow_trad && !allow_c99) {
2167 /* redeclaration of '%s'; ANSI C requires static */
2168 warning(30, dsym->s_name);
2169 print_previous_declaration(rsym);
2170 }
2171 dsym->s_scl = STATIC;
2172 return false;
2173 }
2174
2175 static bool
2176 qualifiers_correspond(const type_t *tp1, const type_t *tp2, bool ignqual)
2177 {
2178
2179 if (tp1->t_const != tp2->t_const && !ignqual && allow_c90)
2180 return false;
2181 if (tp1->t_volatile != tp2->t_volatile && !ignqual && allow_c90)
2182 return false;
2183 return true;
2184 }
2185
2186 bool
2187 pointer_types_are_compatible(const type_t *tp1, const type_t *tp2, bool ignqual)
2188 {
2189
2190 return tp1->t_tspec == VOID || tp2->t_tspec == VOID ||
2191 qualifiers_correspond(tp1, tp2, ignqual);
2192 }
2193
2194 /*
2195 * ignqual ignore qualifiers of type; used for function parameters
2196 * promot promote the left type; used for comparison of parameters of
2197 * old-style function definitions with parameters of prototypes.
2198 * *dowarn is set to true if an old-style function declaration is not
2199 * compatible with a prototype
2200 */
2201 bool
2202 types_compatible(const type_t *tp1, const type_t *tp2,
2203 bool ignqual, bool promot, bool *dowarn)
2204 {
2205
2206 while (tp1 != NULL && tp2 != NULL) {
2207 tspec_t t = tp1->t_tspec;
2208 if (promot) {
2209 if (t == FLOAT)
2210 t = DOUBLE;
2211 else if (t == CHAR || t == SCHAR)
2212 t = INT;
2213 else if (t == UCHAR)
2214 t = allow_c90 ? INT : UINT;
2215 else if (t == SHORT)
2216 t = INT;
2217 else if (t == USHORT) {
2218 /* CONSTCOND */
2219 t = TARG_INT_MAX < TARG_USHRT_MAX || !allow_c90
2220 ? UINT : INT;
2221 }
2222 }
2223
2224 if (t != tp2->t_tspec)
2225 return false;
2226
2227 if (!qualifiers_correspond(tp1, tp2, ignqual))
2228 return false;
2229
2230 if (is_struct_or_union(t))
2231 return tp1->t_str == tp2->t_str;
2232
2233 if (t == ENUM && eflag)
2234 return tp1->t_enum == tp2->t_enum;
2235
2236 if (t == ARRAY && tp1->t_dim != tp2->t_dim) {
2237 if (tp1->t_dim != 0 && tp2->t_dim != 0)
2238 return false;
2239 }
2240
2241 /* don't check prototypes for traditional */
2242 if (t == FUNC && allow_c90) {
2243 if (tp1->t_proto && tp2->t_proto) {
2244 if (!prototypes_compatible(tp1, tp2, dowarn))
2245 return false;
2246 } else if (tp1->t_proto) {
2247 if (!matches_no_arg_function(tp1, dowarn))
2248 return false;
2249 } else if (tp2->t_proto) {
2250 if (!matches_no_arg_function(tp2, dowarn))
2251 return false;
2252 }
2253 }
2254
2255 tp1 = tp1->t_subt;
2256 tp2 = tp2->t_subt;
2257 ignqual = promot = false;
2258 }
2259
2260 return tp1 == tp2;
2261 }
2262
2263 static bool
2264 prototypes_compatible(const type_t *tp1, const type_t *tp2, bool *dowarn)
2265 {
2266
2267 if (tp1->t_vararg != tp2->t_vararg)
2268 return false;
2269
2270 sym_t *a1 = tp1->t_args;
2271 sym_t *a2 = tp2->t_args;
2272
2273 for (; a1 != NULL && a2 != NULL; a1 = a1->s_next, a2 = a2->s_next) {
2274 if (!types_compatible(a1->s_type, a2->s_type,
2275 true, false, dowarn))
2276 return false;
2277 }
2278 return a1 == a2;
2279 }
2280
2281 /*
2282 * Returns whether all parameters of a prototype are compatible with an
2283 * old-style function declaration.
2284 *
2285 * This is the case if the following conditions are met:
2286 * 1. the prototype has a fixed number of parameters
2287 * 2. no parameter is of type float
2288 * 3. no parameter is converted to another type if integer promotion
2289 * is applied on it
2290 */
2291 static bool
2292 matches_no_arg_function(const type_t *tp, bool *dowarn)
2293 {
2294 sym_t *arg;
2295 tspec_t t;
2296
2297 if (tp->t_vararg && dowarn != NULL)
2298 *dowarn = true;
2299 for (arg = tp->t_args; arg != NULL; arg = arg->s_next) {
2300 if ((t = arg->s_type->t_tspec) == FLOAT ||
2301 t == CHAR || t == SCHAR || t == UCHAR ||
2302 t == SHORT || t == USHORT) {
2303 if (dowarn != NULL)
2304 *dowarn = true;
2305 }
2306 }
2307 /* FIXME: Always returning true cannot be correct. */
2308 return true;
2309 }
2310
2311 /*
2312 * Compares a prototype declaration with the remembered arguments of
2313 * a previous old-style function definition.
2314 */
2315 static bool
2316 check_old_style_definition(sym_t *rdsym, sym_t *dsym)
2317 {
2318 sym_t *args, *pargs, *arg, *parg;
2319 int narg, nparg, n;
2320 bool dowarn, msg;
2321
2322 args = rdsym->u.s_old_style_args;
2323 pargs = dsym->s_type->t_args;
2324
2325 msg = false;
2326
2327 narg = nparg = 0;
2328 for (arg = args; arg != NULL; arg = arg->s_next)
2329 narg++;
2330 for (parg = pargs; parg != NULL; parg = parg->s_next)
2331 nparg++;
2332 if (narg != nparg) {
2333 /* prototype does not match old-style definition */
2334 error(63);
2335 msg = true;
2336 goto end;
2337 }
2338
2339 arg = args;
2340 parg = pargs;
2341 n = 1;
2342 while (narg-- > 0) {
2343 dowarn = false;
2344 /*
2345 * If it does not match due to promotion and lint runs in
2346 * "traditional to C90" migration mode, print only a warning.
2347 *
2348 * XXX: Where is this "only a warning"?
2349 */
2350 if (!types_compatible(arg->s_type, parg->s_type,
2351 true, true, &dowarn) ||
2352 dowarn) {
2353 /* prototype does not match old-style ... */
2354 error(299, n);
2355 msg = true;
2356 }
2357 arg = arg->s_next;
2358 parg = parg->s_next;
2359 n++;
2360 }
2361
2362 end:
2363 if (msg && rflag) {
2364 /* old-style definition */
2365 message_at(300, &rdsym->s_def_pos);
2366 }
2367
2368 return msg;
2369 }
2370
2371 /*
2372 * Completes a type by copying the dimension and prototype information
2373 * from a second compatible type.
2374 *
2375 * Following lines are legal:
2376 * "typedef a[]; a b; a b[10]; a c; a c[20];"
2377 * "typedef ft(); ft f; f(int); ft g; g(long);"
2378 * This means that, if a type is completed, the type structure must
2379 * be duplicated.
2380 */
2381 void
2382 complete_type(sym_t *dsym, sym_t *ssym)
2383 {
2384 type_t **dstp, *src;
2385 type_t *dst;
2386
2387 dstp = &dsym->s_type;
2388 src = ssym->s_type;
2389
2390 while ((dst = *dstp) != NULL) {
2391 lint_assert(src != NULL);
2392 lint_assert(dst->t_tspec == src->t_tspec);
2393 if (dst->t_tspec == ARRAY) {
2394 if (dst->t_dim == 0 && src->t_dim != 0) {
2395 *dstp = dst = block_dup_type(dst);
2396 dst->t_dim = src->t_dim;
2397 dst->t_incomplete_array = false;
2398 }
2399 } else if (dst->t_tspec == FUNC) {
2400 if (!dst->t_proto && src->t_proto) {
2401 *dstp = dst = block_dup_type(dst);
2402 dst->t_proto = true;
2403 dst->t_args = src->t_args;
2404 }
2405 }
2406 dstp = &dst->t_subt;
2407 src = src->t_subt;
2408 }
2409 }
2410
2411 /*
2412 * Completes the declaration of a single argument.
2413 */
2414 sym_t *
2415 declare_argument(sym_t *sym, bool initflg)
2416 {
2417 tspec_t t;
2418
2419 check_function_definition(sym, true);
2420
2421 check_type(sym);
2422
2423 if (dcs->d_redeclared_symbol != NULL &&
2424 dcs->d_redeclared_symbol->s_block_level == block_level) {
2425 /* redeclaration of formal parameter '%s' */
2426 error(237, sym->s_name);
2427 rmsym(dcs->d_redeclared_symbol);
2428 sym->s_arg = true;
2429 }
2430
2431 if (!sym->s_arg) {
2432 /* declared argument '%s' is missing */
2433 error(53, sym->s_name);
2434 sym->s_arg = true;
2435 }
2436
2437 if (initflg) {
2438 /* cannot initialize parameter '%s' */
2439 error(52, sym->s_name);
2440 }
2441
2442 if (sym->s_type == NULL) /* for c(void()) */
2443 sym->s_type = gettyp(VOID);
2444
2445 if ((t = sym->s_type->t_tspec) == ARRAY)
2446 sym->s_type = block_derive_type(sym->s_type->t_subt, PTR);
2447 else if (t == FUNC) {
2448 if (!allow_c90)
2449 /* argument '%s' has function type, should be ... */
2450 warning(50, sym->s_name);
2451 sym->s_type = block_derive_type(sym->s_type, PTR);
2452 } else if (t == FLOAT) {
2453 if (!allow_c90)
2454 sym->s_type = gettyp(DOUBLE);
2455 }
2456
2457 if (dcs->d_inline)
2458 /* argument '%s' declared inline */
2459 warning(269, sym->s_name);
2460
2461 /*
2462 * Arguments must have complete types. length_in_bits prints the
2463 * needed error messages (null dimension is impossible because arrays
2464 * are converted to pointers).
2465 */
2466 if (sym->s_type->t_tspec != VOID)
2467 (void)length_in_bits(sym->s_type, sym->s_name);
2468
2469 sym->s_used = dcs->d_used;
2470 mark_as_set(sym);
2471
2472 return sym;
2473 }
2474
2475 static bool
2476 is_character_pointer(const type_t *tp)
2477 {
2478 tspec_t st;
2479
2480 return tp->t_tspec == PTR &&
2481 (st = tp->t_subt->t_tspec,
2482 st == CHAR || st == SCHAR || st == UCHAR);
2483 }
2484
2485 void
2486 check_func_lint_directives(void)
2487 {
2488
2489 /* check for illegal combinations of lint directives */
2490 if (printflike_argnum != -1 && scanflike_argnum != -1) {
2491 /* can't be used together: ** PRINTFLIKE ** ** SCANFLIKE ** */
2492 warning(289);
2493 printflike_argnum = scanflike_argnum = -1;
2494 }
2495 if (nvararg != -1 &&
2496 (printflike_argnum != -1 || scanflike_argnum != -1)) {
2497 /* dubious use of ** VARARGS ** with ** %s ** */
2498 warning(288,
2499 printflike_argnum != -1 ? "PRINTFLIKE" : "SCANFLIKE");
2500 nvararg = -1;
2501 }
2502
2503 /*
2504 * check if the argument of a lint directive is compatible with the
2505 * number of arguments.
2506 */
2507 int narg = 0;
2508 for (sym_t *arg = dcs->d_func_args; arg != NULL; arg = arg->s_next)
2509 narg++;
2510 if (nargusg > narg) {
2511 /* argument number mismatch with directive ** %s ** */
2512 warning(283, "ARGSUSED");
2513 nargusg = 0;
2514 }
2515 if (nvararg > narg) {
2516 /* argument number mismatch with directive ** %s ** */
2517 warning(283, "VARARGS");
2518 nvararg = 0;
2519 }
2520 if (printflike_argnum > narg) {
2521 /* argument number mismatch with directive ** %s ** */
2522 warning(283, "PRINTFLIKE");
2523 printflike_argnum = -1;
2524 } else if (printflike_argnum == 0) {
2525 printflike_argnum = -1;
2526 }
2527 if (scanflike_argnum > narg) {
2528 /* argument number mismatch with directive ** %s ** */
2529 warning(283, "SCANFLIKE");
2530 scanflike_argnum = -1;
2531 } else if (scanflike_argnum == 0) {
2532 scanflike_argnum = -1;
2533 }
2534 if (printflike_argnum != -1 || scanflike_argnum != -1) {
2535 narg = printflike_argnum != -1
2536 ? printflike_argnum : scanflike_argnum;
2537 sym_t *arg = dcs->d_func_args;
2538 for (int n = 1; n < narg; n++)
2539 arg = arg->s_next;
2540 if (!is_character_pointer(arg->s_type)) {
2541 /* argument %d must be 'char *' for PRINTFLIKE/... */
2542 warning(293, narg);
2543 printflike_argnum = scanflike_argnum = -1;
2544 }
2545 }
2546 }
2547
2548 /*
2549 * Warn about arguments in old-style function definitions that default to int.
2550 * Check that an old-style function definition is compatible to a previous
2551 * prototype.
2552 */
2553 void
2554 check_func_old_style_arguments(void)
2555 {
2556 sym_t *args, *arg, *pargs, *parg;
2557 int narg, nparg;
2558 bool msg;
2559
2560 args = funcsym->u.s_old_style_args;
2561 pargs = funcsym->s_type->t_args;
2562
2563 /*
2564 * print a warning for each argument of an old-style function
2565 * definition which defaults to int
2566 */
2567 for (arg = args; arg != NULL; arg = arg->s_next) {
2568 if (arg->s_defarg) {
2569 /* type of argument '%s' defaults to 'int' */
2570 warning(32, arg->s_name);
2571 arg->s_defarg = false;
2572 mark_as_set(arg);
2573 }
2574 }
2575
2576 /*
2577 * If this is an old-style function definition and a prototype
2578 * exists, compare the types of arguments.
2579 */
2580 if (funcsym->s_osdef && funcsym->s_type->t_proto) {
2581 /*
2582 * If the number of arguments does not match, we need not
2583 * continue.
2584 */
2585 narg = nparg = 0;
2586 msg = false;
2587 for (parg = pargs; parg != NULL; parg = parg->s_next)
2588 nparg++;
2589 for (arg = args; arg != NULL; arg = arg->s_next)
2590 narg++;
2591 if (narg != nparg) {
2592 /* parameter mismatch: %d declared, %d defined */
2593 error(51, nparg, narg);
2594 msg = true;
2595 } else {
2596 parg = pargs;
2597 arg = args;
2598 while (narg-- > 0) {
2599 msg |= check_prototype_declaration(arg, parg);
2600 parg = parg->s_next;
2601 arg = arg->s_next;
2602 }
2603 }
2604 if (msg && rflag) {
2605 /* prototype declaration */
2606 message_at(285, &dcs->d_redeclared_symbol->s_def_pos);
2607 }
2608
2609 /* from now on the prototype is valid */
2610 funcsym->s_osdef = false;
2611 funcsym->u.s_old_style_args = NULL;
2612 }
2613 }
2614
2615 /*
2616 * Checks compatibility of an old-style function definition with a previous
2617 * prototype declaration.
2618 * Returns true if the position of the previous declaration should be reported.
2619 */
2620 static bool
2621 check_prototype_declaration(sym_t *arg, sym_t *parg)
2622 {
2623 type_t *tp, *ptp;
2624 bool dowarn;
2625
2626 tp = arg->s_type;
2627 ptp = parg->s_type;
2628
2629 dowarn = false;
2630
2631 if (!types_compatible(tp, ptp, true, true, &dowarn)) {
2632 if (types_compatible(tp, ptp, true, false, &dowarn)) {
2633 /* type of '%s' does not match prototype */
2634 return gnuism(58, arg->s_name);
2635 } else {
2636 /* type of '%s' does not match prototype */
2637 error(58, arg->s_name);
2638 return true;
2639 }
2640 }
2641 if (dowarn) {
2642 /* TODO: Make this an error in C99 mode as well. */
2643 if (!allow_trad && !allow_c99)
2644 /* type of '%s' does not match prototype */
2645 error(58, arg->s_name);
2646 else
2647 /* type of '%s' does not match prototype */
2648 warning(58, arg->s_name);
2649 return true;
2650 }
2651
2652 return false;
2653 }
2654
2655 static void
2656 check_local_hiding(const sym_t *dsym)
2657 {
2658 switch (dsym->s_scl) {
2659 case AUTO:
2660 /* automatic '%s' hides external declaration */
2661 warning(86, dsym->s_name);
2662 break;
2663 case STATIC:
2664 /* static '%s' hides external declaration */
2665 warning(87, dsym->s_name);
2666 break;
2667 case TYPEDEF:
2668 /* typedef '%s' hides external declaration */
2669 warning(88, dsym->s_name);
2670 break;
2671 case EXTERN:
2672 /* Already checked in declare_external_in_block. */
2673 break;
2674 default:
2675 lint_assert(/*CONSTCOND*/false);
2676 }
2677 }
2678
2679 static void
2680 check_local_redeclaration(const sym_t *dsym, sym_t *rsym)
2681 {
2682 if (rsym->s_block_level == 0) {
2683 if (hflag)
2684 check_local_hiding(dsym);
2685
2686 } else if (rsym->s_block_level == block_level) {
2687
2688 /* no hflag, because it's illegal! */
2689 if (rsym->s_arg) {
2690 /*
2691 * if allow_c90, a "redeclaration of '%s'" error
2692 * is produced below
2693 */
2694 if (!allow_c90) {
2695 if (hflag) {
2696 /* declaration of '%s' hides ... */
2697 warning(91, dsym->s_name);
2698 }
2699 rmsym(rsym);
2700 }
2701 }
2702
2703 } else if (rsym->s_block_level < block_level) {
2704 if (hflag) {
2705 /* declaration of '%s' hides earlier one */
2706 warning(95, dsym->s_name);
2707 }
2708 }
2709
2710 if (rsym->s_block_level == block_level) {
2711 /* redeclaration of '%s' */
2712 error(27, dsym->s_name);
2713 rmsym(rsym);
2714 }
2715 }
2716
2717 /*
2718 * Completes a single local declaration/definition.
2719 */
2720 void
2721 declare_local(sym_t *dsym, bool initflg)
2722 {
2723
2724 /* Correct a mistake done in declarator_name(). */
2725 if (dsym->s_type->t_tspec == FUNC) {
2726 dsym->s_def = DECL;
2727 if (dcs->d_scl == NOSCL)
2728 dsym->s_scl = EXTERN;
2729 }
2730
2731 if (dsym->s_type->t_tspec == FUNC) {
2732 if (dsym->s_scl == STATIC) {
2733 /* dubious static function '%s' at block level */
2734 warning(93, dsym->s_name);
2735 dsym->s_scl = EXTERN;
2736 } else if (dsym->s_scl != EXTERN && dsym->s_scl != TYPEDEF) {
2737 /* function '%s' has illegal storage class */
2738 error(94, dsym->s_name);
2739 dsym->s_scl = EXTERN;
2740 }
2741 }
2742
2743 /*
2744 * functions may be declared inline at local scope, although
2745 * this has no effect for a later definition of the same
2746 * function.
2747 * XXX it should have an effect if !allow_c90 is set. this would
2748 * also be the way gcc behaves.
2749 */
2750 if (dcs->d_inline) {
2751 if (dsym->s_type->t_tspec == FUNC)
2752 dsym->s_inline = true;
2753 else {
2754 /* variable '%s' declared inline */
2755 warning(268, dsym->s_name);
2756 }
2757 }
2758
2759 check_function_definition(dsym, true);
2760
2761 check_type(dsym);
2762
2763 if (dcs->d_redeclared_symbol != NULL && dsym->s_scl == EXTERN)
2764 declare_external_in_block(dsym);
2765
2766 if (dsym->s_scl == EXTERN) {
2767 /*
2768 * XXX if the static variable at level 0 is only defined
2769 * later, checking will be possible.
2770 */
2771 if (dsym->s_ext_sym == NULL)
2772 outsym(dsym, EXTERN, dsym->s_def);
2773 else
2774 outsym(dsym, dsym->s_ext_sym->s_scl, dsym->s_def);
2775
2776 }
2777
2778 if (dcs->d_redeclared_symbol != NULL)
2779 check_local_redeclaration(dsym, dcs->d_redeclared_symbol);
2780
2781 if (initflg && !check_init(dsym)) {
2782 dsym->s_def = DEF;
2783 mark_as_set(dsym);
2784 }
2785
2786 if (dsym->s_scl == TYPEDEF) {
2787 dsym->s_type = block_dup_type(dsym->s_type);
2788 dsym->s_type->t_typedef = true;
2789 set_first_typedef(dsym->s_type, dsym);
2790 }
2791
2792 /*
2793 * Before we can check the size we must wait for an initialization
2794 * that may follow.
2795 */
2796 }
2797
2798 /* Processes (re)declarations of external symbols inside blocks. */
2799 static void
2800 declare_external_in_block(sym_t *dsym)
2801 {
2802
2803 /* look for a symbol with the same name */
2804 sym_t *esym = dcs->d_redeclared_symbol;
2805 while (esym != NULL && esym->s_block_level != 0) {
2806 while ((esym = esym->s_symtab_next) != NULL) {
2807 if (esym->s_kind != FVFT)
2808 continue;
2809 if (strcmp(dsym->s_name, esym->s_name) == 0)
2810 break;
2811 }
2812 }
2813 if (esym == NULL)
2814 return;
2815 if (esym->s_scl != EXTERN && esym->s_scl != STATIC) {
2816 /* gcc accepts this without a warning, pcc prints an error. */
2817 /* redeclaration of '%s' */
2818 warning(27, dsym->s_name);
2819 print_previous_declaration(esym);
2820 return;
2821 }
2822
2823 bool dowarn = false;
2824 bool compatible = types_compatible(esym->s_type, dsym->s_type,
2825 false, false, &dowarn);
2826
2827 if (!compatible || dowarn) {
2828 if (esym->s_scl == EXTERN) {
2829 /* inconsistent redeclaration of extern '%s' */
2830 warning(90, dsym->s_name);
2831 print_previous_declaration(esym);
2832 } else {
2833 /* inconsistent redeclaration of static '%s' */
2834 warning(92, dsym->s_name);
2835 print_previous_declaration(esym);
2836 }
2837 }
2838
2839 if (compatible) {
2840 /*
2841 * Remember the external symbol so we can update usage
2842 * information at the end of the block.
2843 */
2844 dsym->s_ext_sym = esym;
2845 }
2846 }
2847
2848 /*
2849 * Print an error or a warning if the symbol cannot be initialized due
2850 * to type/storage class. Return whether an error has been detected.
2851 */
2852 static bool
2853 check_init(sym_t *sym)
2854 {
2855 bool erred;
2856
2857 erred = false;
2858
2859 if (sym->s_type->t_tspec == FUNC) {
2860 /* cannot initialize function '%s' */
2861 error(24, sym->s_name);
2862 erred = true;
2863 } else if (sym->s_scl == TYPEDEF) {
2864 /* cannot initialize typedef '%s' */
2865 error(25, sym->s_name);
2866 erred = true;
2867 } else if (sym->s_scl == EXTERN && sym->s_def == DECL) {
2868 if (dcs->d_kind == DK_EXTERN) {
2869 /* cannot initialize extern declaration '%s' */
2870 warning(26, sym->s_name);
2871 } else {
2872 /* cannot initialize extern declaration '%s' */
2873 error(26, sym->s_name);
2874 erred = true;
2875 }
2876 }
2877
2878 return erred;
2879 }
2880
2881 /*
2882 * Create a symbol for an abstract declaration.
2883 */
2884 sym_t *
2885 abstract_name(void)
2886 {
2887 sym_t *sym;
2888
2889 lint_assert(dcs->d_kind == DK_ABSTRACT ||
2890 dcs->d_kind == DK_PROTO_ARG);
2891
2892 sym = block_zero_alloc(sizeof(*sym));
2893
2894 sym->s_name = unnamed;
2895 sym->s_def = DEF;
2896 sym->s_scl = ABSTRACT;
2897 sym->s_block_level = -1;
2898
2899 if (dcs->d_kind == DK_PROTO_ARG)
2900 sym->s_arg = true;
2901
2902 /*
2903 * At this point, dcs->d_type contains only the basic type. That
2904 * type will be updated later, adding pointers, arrays and functions
2905 * as necessary.
2906 */
2907 /*
2908 * XXX: This is not the correct type. For example in msg_347, it is
2909 * the type of the last prototype parameter, but it should rather be
2910 * the return type of the function.
2911 */
2912 sym->s_type = dcs->d_type;
2913 dcs->d_redeclared_symbol = NULL;
2914 dcs->d_vararg = false;
2915
2916 return sym;
2917 }
2918
2919 /*
2920 * Removes anything which has nothing to do on global level.
2921 */
2922 void
2923 global_clean_up(void)
2924 {
2925
2926 while (dcs->d_enclosing != NULL)
2927 end_declaration_level();
2928
2929 clean_up_after_error();
2930 block_level = 0;
2931 mem_block_level = 0;
2932
2933 /*
2934 * remove all information about pending lint directives without
2935 * warnings.
2936 */
2937 global_clean_up_decl(true);
2938 }
2939
2940 /*
2941 * Process an abstract type declaration
2942 */
2943 sym_t *
2944 declare_1_abstract(sym_t *sym)
2945 {
2946
2947 check_function_definition(sym, true);
2948 check_type(sym);
2949 return sym;
2950 }
2951
2952 /*
2953 * Checks size after declarations of variables and their initialization.
2954 */
2955 void
2956 check_size(sym_t *dsym)
2957 {
2958
2959 if (dsym->s_def == DEF &&
2960 dsym->s_scl != TYPEDEF &&
2961 dsym->s_type->t_tspec != FUNC &&
2962 length_in_bits(dsym->s_type, dsym->s_name) == 0 &&
2963 dsym->s_type->t_tspec == ARRAY &&
2964 dsym->s_type->t_dim == 0) {
2965 if (!allow_c90) {
2966 /* empty array declaration for '%s' */
2967 warning(190, dsym->s_name);
2968 } else {
2969 /* empty array declaration for '%s' */
2970 error(190, dsym->s_name);
2971 }
2972 }
2973 }
2974
2975 /*
2976 * Mark an object as set if it is not already
2977 */
2978 void
2979 mark_as_set(sym_t *sym)
2980 {
2981
2982 if (!sym->s_set) {
2983 sym->s_set = true;
2984 UNIQUE_CURR_POS(sym->s_set_pos);
2985 }
2986 }
2987
2988 /*
2989 * Mark an object as used if it is not already
2990 */
2991 void
2992 mark_as_used(sym_t *sym, bool fcall, bool szof)
2993 {
2994
2995 if (!sym->s_used) {
2996 sym->s_used = true;
2997 UNIQUE_CURR_POS(sym->s_use_pos);
2998 }
2999 /*
3000 * For function calls, another record is written.
3001 *
3002 * XXX: Should symbols used in sizeof() be treated as used or not?
3003 * Probably not, because there is no point in declaring an external
3004 * variable only to get its size.
3005 */
3006 if (!fcall && !szof && sym->s_kind == FVFT && sym->s_scl == EXTERN)
3007 outusg(sym);
3008 }
3009
3010 /*
3011 * Prints warnings for a list of variables and labels (concatenated
3012 * with s_level_next) if these are not used or only set.
3013 */
3014 void
3015 check_usage(dinfo_t *di)
3016 {
3017 /* for this warning LINTED has no effect */
3018 int saved_lwarn = lwarn;
3019 lwarn = LWARN_ALL;
3020
3021 debug_step("begin lwarn %d", lwarn);
3022 for (sym_t *sym = di->d_dlsyms; sym != NULL; sym = sym->s_level_next)
3023 check_usage_sym(di->d_asm, sym);
3024 lwarn = saved_lwarn;
3025 debug_step("end lwarn %d", lwarn);
3026 }
3027
3028 /*
3029 * Prints a warning for a single variable or label if it is not used or
3030 * only set.
3031 */
3032 void
3033 check_usage_sym(bool novar, sym_t *sym)
3034 {
3035
3036 if (sym->s_block_level == -1)
3037 return;
3038
3039 if (sym->s_kind == FVFT && sym->s_arg)
3040 check_argument_usage(novar, sym);
3041 else if (sym->s_kind == FVFT)
3042 check_variable_usage(novar, sym);
3043 else if (sym->s_kind == FLABEL)
3044 check_label_usage(sym);
3045 else if (sym->s_kind == FTAG)
3046 check_tag_usage(sym);
3047 }
3048
3049 static void
3050 check_argument_usage(bool novar, sym_t *arg)
3051 {
3052
3053 lint_assert(arg->s_set);
3054
3055 if (novar)
3056 return;
3057
3058 if (!arg->s_used && vflag) {
3059 /* argument '%s' unused in function '%s' */
3060 warning_at(231, &arg->s_def_pos, arg->s_name, funcsym->s_name);
3061 }
3062 }
3063
3064 static void
3065 check_variable_usage(bool novar, sym_t *sym)
3066 {
3067 scl_t sc;
3068 sym_t *xsym;
3069
3070 lint_assert(block_level != 0);
3071
3072 /* example at file scope: int c = ({ return 3; }); */
3073 if (sym->s_block_level == 0 && ch_isdigit(sym->s_name[0]))
3074 return;
3075
3076 /* errors in expressions easily cause lots of these warnings */
3077 if (nerr != 0)
3078 return;
3079
3080 /*
3081 * XXX Only variables are checked, although types should
3082 * probably also be checked
3083 */
3084 sc = sym->s_scl;
3085 if (sc != EXTERN && sc != STATIC && sc != AUTO && sc != REG)
3086 return;
3087
3088 if (novar)
3089 return;
3090
3091 if (sc == EXTERN) {
3092 if (!sym->s_used && !sym->s_set) {
3093 /* '%s' unused in function '%s' */
3094 warning_at(192, &sym->s_def_pos,
3095 sym->s_name, funcsym->s_name);
3096 }
3097 } else {
3098 if (sym->s_set && !sym->s_used) {
3099 /* '%s' set but not used in function '%s' */
3100 warning_at(191, &sym->s_set_pos,
3101 sym->s_name, funcsym->s_name);
3102 } else if (!sym->s_used) {
3103 /* '%s' unused in function '%s' */
3104 warning_at(192, &sym->s_def_pos,
3105 sym->s_name, funcsym->s_name);
3106 }
3107 }
3108
3109 if (sc == EXTERN) {
3110 /*
3111 * information about usage is taken over into the symbol
3112 * table entry at level 0 if the symbol was locally declared
3113 * as an external symbol.
3114 *
3115 * XXX This is wrong for symbols declared static at level 0
3116 * if the usage information stems from sizeof(). This is
3117 * because symbols at level 0 only used in sizeof() are
3118 * considered to not be used.
3119 */
3120 if ((xsym = sym->s_ext_sym) != NULL) {
3121 if (sym->s_used && !xsym->s_used) {
3122 xsym->s_used = true;
3123 xsym->s_use_pos = sym->s_use_pos;
3124 }
3125 if (sym->s_set && !xsym->s_set) {
3126 xsym->s_set = true;
3127 xsym->s_set_pos = sym->s_set_pos;
3128 }
3129 }
3130 }
3131 }
3132
3133 static void
3134 check_label_usage(sym_t *lab)
3135 {
3136
3137 lint_assert(block_level == 1);
3138 lint_assert(lab->s_block_level == 1);
3139
3140 if (funcsym == NULL) {
3141 /* syntax error '%s' */
3142 error(249, "labels are only valid inside a function");
3143 } else if (lab->s_set && !lab->s_used) {
3144 /* label '%s' unused in function '%s' */
3145 warning_at(232, &lab->s_set_pos, lab->s_name, funcsym->s_name);
3146 } else if (!lab->s_set) {
3147 /* undefined label '%s' */
3148 warning_at(23, &lab->s_use_pos, lab->s_name);
3149 }
3150 }
3151
3152 static void
3153 check_tag_usage(sym_t *sym)
3154 {
3155
3156 if (!is_incomplete(sym->s_type))
3157 return;
3158
3159 /* always complain about incomplete tags declared inside blocks */
3160 if (!zflag || dcs->d_kind != DK_EXTERN)
3161 return;
3162
3163 switch (sym->s_type->t_tspec) {
3164 case STRUCT:
3165 /* struct '%s' never defined */
3166 warning_at(233, &sym->s_def_pos, sym->s_name);
3167 break;
3168 case UNION:
3169 /* union '%s' never defined */
3170 warning_at(234, &sym->s_def_pos, sym->s_name);
3171 break;
3172 case ENUM:
3173 /* enum '%s' never defined */
3174 warning_at(235, &sym->s_def_pos, sym->s_name);
3175 break;
3176 default:
3177 lint_assert(/*CONSTCOND*/false);
3178 }
3179 }
3180
3181 /*
3182 * Called after the entire translation unit has been parsed.
3183 * Changes tentative definitions into definitions.
3184 * Performs some tests on global symbols. Detected problems are:
3185 * - defined variables of incomplete type
3186 * - constant variables which are not initialized
3187 * - static symbols which are never used
3188 */
3189 void
3190 check_global_symbols(void)
3191 {
3192 sym_t *sym;
3193
3194 if (block_level != 0 || dcs->d_enclosing != NULL)
3195 norecover();
3196
3197 for (sym = dcs->d_dlsyms; sym != NULL; sym = sym->s_level_next) {
3198 if (sym->s_block_level == -1)
3199 continue;
3200 if (sym->s_kind == FVFT)
3201 check_global_variable(sym);
3202 else if (sym->s_kind == FTAG)
3203 check_tag_usage(sym);
3204 else
3205 lint_assert(sym->s_kind == FMEMBER);
3206 }
3207 }
3208
3209 static void
3210 check_unused_static_global_variable(const sym_t *sym)
3211 {
3212 if (sym->s_type->t_tspec == FUNC) {
3213 if (sym->s_def == DEF) {
3214 if (!sym->s_inline)
3215 /* static function '%s' unused */
3216 warning_at(236, &sym->s_def_pos, sym->s_name);
3217 } else {
3218 /* static function '%s' declared but not defined */
3219 warning_at(290, &sym->s_def_pos, sym->s_name);
3220 }
3221 } else if (!sym->s_set) {
3222 /* static variable '%s' unused */
3223 warning_at(226, &sym->s_def_pos, sym->s_name);
3224 } else {
3225 /* static variable '%s' set but not used */
3226 warning_at(307, &sym->s_def_pos, sym->s_name);
3227 }
3228 }
3229
3230 static void
3231 check_static_global_variable(const sym_t *sym)
3232 {
3233 if (sym->s_type->t_tspec == FUNC && sym->s_used && sym->s_def != DEF) {
3234 /* static function '%s' called but not defined */
3235 error_at(225, &sym->s_use_pos, sym->s_name);
3236 }
3237
3238 if (!sym->s_used)
3239 check_unused_static_global_variable(sym);
3240
3241 if (allow_c90 && sym->s_def == TDEF && sym->s_type->t_const) {
3242 /* const object '%s' should have initializer */
3243 warning_at(227, &sym->s_def_pos, sym->s_name);
3244 }
3245 }
3246
3247 static void
3248 check_global_variable(const sym_t *sym)
3249 {
3250 scl_t scl = sym->s_scl;
3251
3252 if (scl == TYPEDEF || scl == BOOL_CONST || scl == ENUM_CONST)
3253 return;
3254
3255 if (scl == NOSCL)
3256 return; /* May be caused by a syntax error. */
3257
3258 lint_assert(scl == EXTERN || scl == STATIC);
3259
3260 check_global_variable_size(sym);
3261
3262 if (scl == STATIC)
3263 check_static_global_variable(sym);
3264 }
3265
3266 static void
3267 check_global_variable_size(const sym_t *sym)
3268 {
3269 pos_t cpos;
3270 int len_in_bits;
3271
3272 if (sym->s_def != TDEF)
3273 return;
3274 if (sym->s_type->t_tspec == FUNC) {
3275 /* Maybe a syntax error after a function declaration. */
3276 return;
3277 }
3278 if (sym->s_def == TDEF && sym->s_type->t_tspec == VOID) {
3279 /* Prevent an internal error in length_in_bits below. */
3280 return;
3281 }
3282
3283 cpos = curr_pos;
3284 curr_pos = sym->s_def_pos;
3285 len_in_bits = length_in_bits(sym->s_type, sym->s_name);
3286 curr_pos = cpos;
3287
3288 if (len_in_bits == 0 &&
3289 sym->s_type->t_tspec == ARRAY && sym->s_type->t_dim == 0) {
3290 /* TODO: C99 6.7.5.2p1 defines this as an error as well. */
3291 if (!allow_c90 ||
3292 (sym->s_scl == EXTERN && (allow_trad || allow_c99))) {
3293 /* empty array declaration for '%s' */
3294 warning_at(190, &sym->s_def_pos, sym->s_name);
3295 } else {
3296 /* empty array declaration for '%s' */
3297 error_at(190, &sym->s_def_pos, sym->s_name);
3298 }
3299 }
3300 }
3301
3302 /*
3303 * Prints information about location of previous definition/declaration.
3304 */
3305 void
3306 print_previous_declaration(const sym_t *psym)
3307 {
3308
3309 if (!rflag)
3310 return;
3311
3312 if (psym->s_def == DEF || psym->s_def == TDEF) {
3313 /* previous definition of '%s' */
3314 message_at(261, &psym->s_def_pos, psym->s_name);
3315 } else {
3316 /* previous declaration of '%s' */
3317 message_at(260, &psym->s_def_pos, psym->s_name);
3318 }
3319 }
3320
3321 /*
3322 * Gets a node for a constant and returns the value of this constant
3323 * as integer.
3324 *
3325 * If the node is not constant or too large for int or of type float,
3326 * a warning will be printed.
3327 *
3328 * to_int_constant() should be used only inside declarations. If it is used in
3329 * expressions, it frees the memory used for the expression.
3330 */
3331 int
3332 to_int_constant(tnode_t *tn, bool required)
3333 {
3334 int i;
3335 tspec_t t;
3336
3337 if (tn == NULL)
3338 return 1;
3339
3340 val_t *v = constant(tn, required);
3341
3342 /*
3343 * Abstract declarations are used inside expression. To free
3344 * the memory would be a fatal error.
3345 * We don't free blocks that are inside casts because these
3346 * will be used later to match types.
3347 */
3348 if (tn->tn_op != CON && dcs->d_kind != DK_ABSTRACT)
3349 expr_free_all();
3350
3351 if ((t = v->v_tspec) == FLOAT || t == DOUBLE || t == LDOUBLE) {
3352 i = (int)v->v_ldbl;
3353 /* integral constant expression expected */
3354 error(55);
3355 } else {
3356 i = (int)v->v_quad;
3357 if (is_uinteger(t)) {
3358 if ((uint64_t)v->v_quad > (uint64_t)TARG_INT_MAX) {
3359 /* integral constant too large */
3360 warning(56);
3361 }
3362 } else {
3363 if (v->v_quad > (int64_t)TARG_INT_MAX ||
3364 v->v_quad < (int64_t)TARG_INT_MIN) {
3365 /* integral constant too large */
3366 warning(56);
3367 }
3368 }
3369 }
3370
3371 free(v);
3372 return i;
3373 }
3374