xref: /netbsd-src/usr.bin/xlint/lint1/decl.c (revision 10ad5ffa714ce1a679dcc9dd8159648df2d67b5a)
1 /* $NetBSD: decl.c,v 1.46 2009/04/15 01:20:57 christos 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) && !defined(lint)
41 __RCSID("$NetBSD: decl.c,v 1.46 2009/04/15 01:20:57 christos 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 arithmtic types and void */
54 static	type_t	*typetab;
55 
56 /* value of next enumerator during declaration of enum types */
57 int	enumval;
58 
59 /*
60  * pointer to top element of a stack which contains informations local
61  * to nested declarations
62  */
63 dinfo_t	*dcs;
64 
65 static	type_t	*tdeferr(type_t *, tspec_t);
66 static	void	settdsym(type_t *, sym_t *);
67 static	tspec_t	mrgtspec(tspec_t, tspec_t);
68 static	void	align(int, int);
69 static	sym_t	*newtag(sym_t *, scl_t, int, int);
70 static	int	eqargs(type_t *, type_t *, int *);
71 static	int	mnoarg(type_t *, int *);
72 static	int	chkosdef(sym_t *, sym_t *);
73 static	int	chkptdecl(sym_t *, sym_t *);
74 static	sym_t	*nsfunc(sym_t *, sym_t *);
75 static	void	osfunc(sym_t *, sym_t *);
76 static	void	ledecl(sym_t *);
77 static	int	chkinit(sym_t *);
78 static	void	chkausg(int, sym_t *);
79 static	void	chkvusg(int, sym_t *);
80 static	void	chklusg(sym_t *);
81 static	void	chktusg(sym_t *);
82 static	void	chkglvar(sym_t *);
83 static	void	glchksz(sym_t *);
84 
85 /*
86  * initializes all global vars used in declarations
87  */
88 void
89 initdecl(void)
90 {
91 	int i;
92 
93 	/* declaration stack */
94 	dcs = xcalloc(1, sizeof (dinfo_t));
95 	dcs->d_ctx = EXTERN;
96 	dcs->d_ldlsym = &dcs->d_dlsyms;
97 
98 	/* type information and classification */
99 	inittyp();
100 
101 	/* shared type structures */
102 	typetab = xcalloc(NTSPEC, sizeof (type_t));
103 	for (i = 0; i < NTSPEC; i++)
104 		typetab[i].t_tspec = NOTSPEC;
105 	typetab[BOOL].t_tspec = BOOL;
106 	typetab[CHAR].t_tspec = CHAR;
107 	typetab[SCHAR].t_tspec = SCHAR;
108 	typetab[UCHAR].t_tspec = UCHAR;
109 	typetab[SHORT].t_tspec = SHORT;
110 	typetab[USHORT].t_tspec = USHORT;
111 	typetab[INT].t_tspec = INT;
112 	typetab[UINT].t_tspec = UINT;
113 	typetab[LONG].t_tspec = LONG;
114 	typetab[ULONG].t_tspec = ULONG;
115 	typetab[QUAD].t_tspec = QUAD;
116 	typetab[UQUAD].t_tspec = UQUAD;
117 	typetab[FLOAT].t_tspec = FLOAT;
118 	typetab[DOUBLE].t_tspec = DOUBLE;
119 	typetab[LDOUBLE].t_tspec = LDOUBLE;
120 	typetab[FCOMPLEX].t_tspec = FCOMPLEX;
121 	typetab[DCOMPLEX].t_tspec = DCOMPLEX;
122 	typetab[LCOMPLEX].t_tspec = LCOMPLEX;
123 	typetab[COMPLEX].t_tspec = COMPLEX;
124 	typetab[VOID].t_tspec = VOID;
125 	/*
126 	 * Next two are not real types. They are only used by the parser
127 	 * to return keywords "signed" and "unsigned"
128 	 */
129 	typetab[SIGNED].t_tspec = SIGNED;
130 	typetab[UNSIGN].t_tspec = UNSIGN;
131 }
132 
133 /*
134  * Returns a shared type structure vor arithmetic types and void.
135  *
136  * It's important do duplicate this structure (using duptyp() or tdupdyp())
137  * if it is to be modified (adding qualifiers or anything else).
138  */
139 type_t *
140 gettyp(tspec_t t)
141 {
142 
143 	return (&typetab[t]);
144 }
145 
146 type_t *
147 duptyp(const type_t *tp)
148 {
149 	type_t	*ntp;
150 
151 	ntp = getblk(sizeof (type_t));
152 	STRUCT_ASSIGN(*ntp, *tp);
153 	return (ntp);
154 }
155 
156 /*
157  * Use tduptyp() instead of duptyp() inside expressions (if the
158  * allocated memory should be freed after the expr).
159  */
160 type_t *
161 tduptyp(const type_t *tp)
162 {
163 	type_t	*ntp;
164 
165 	ntp = tgetblk(sizeof (type_t));
166 	STRUCT_ASSIGN(*ntp, *tp);
167 	return (ntp);
168 }
169 
170 /*
171  * Returns 1 if the argument is void or an incomplete array,
172  * struct, union or enum type.
173  */
174 int
175 incompl(type_t *tp)
176 {
177 	tspec_t	t;
178 
179 	if ((t = tp->t_tspec) == VOID) {
180 		return (1);
181 	} else if (t == ARRAY) {
182 		return (tp->t_aincompl);
183 	} else if (t == STRUCT || t == UNION) {
184 		return (tp->t_str->sincompl);
185 	} else if (t == ENUM) {
186 		return (tp->t_enum->eincompl);
187 	}
188 	return (0);
189 }
190 
191 /*
192  * Set the flag for (in)complete array, struct, union or enum
193  * types.
194  */
195 void
196 setcompl(type_t *tp, int ic)
197 {
198 	tspec_t	t;
199 
200 	if ((t = tp->t_tspec) == ARRAY) {
201 		tp->t_aincompl = ic;
202 	} else if (t == STRUCT || t == UNION) {
203 		tp->t_str->sincompl = ic;
204 	} else {
205 		if (t != ENUM)
206 			LERROR("setcompl()");
207 		tp->t_enum->eincompl = ic;
208 	}
209 }
210 
211 /*
212  * Remember the storage class of the current declaration in dcs->d_scl
213  * (the top element of the declaration stack) and detect multiple
214  * storage classes.
215  */
216 void
217 addscl(scl_t sc)
218 {
219 
220 	if (sc == INLINE) {
221 		if (dcs->d_inline)
222 			/* duplicate '%s' */
223 			warning(10, "inline");
224 		dcs->d_inline = 1;
225 		return;
226 	}
227 	if (dcs->d_type != NULL || dcs->d_atyp != NOTSPEC ||
228 	    dcs->d_smod != NOTSPEC || dcs->d_lmod != NOTSPEC) {
229 		/* storage class after type is obsolescent */
230 		warning(83);
231 	}
232 	if (dcs->d_scl == NOSCL) {
233 		dcs->d_scl = sc;
234 	} else {
235 		/*
236 		 * multiple storage classes. An error will be reported in
237 		 * deftyp().
238 		 */
239 		dcs->d_mscl = 1;
240 	}
241 }
242 
243 /*
244  * Remember the type, modifier or typedef name returned by the parser
245  * in *dcs (top element of decl stack). This information is used in
246  * deftyp() to build the type used for all declarators in this
247  * declaration.
248  *
249  * Is tp->t_typedef 1, the type comes from a previously defined typename.
250  * Otherwise it comes from a type specifier (int, long, ...) or a
251  * struct/union/enum tag.
252  */
253 void
254 addtype(type_t *tp)
255 {
256 	tspec_t	t;
257 //	char buf[1024];
258 // printf("addtype %s\n", tyname(buf, sizeof(buf), tp));
259 	if (tp->t_typedef) {
260 		if (dcs->d_type != NULL || dcs->d_atyp != NOTSPEC ||
261 		    dcs->d_lmod != NOTSPEC || dcs->d_smod != NOTSPEC) {
262 			/*
263 			 * something like "typedef int a; int a b;"
264 			 * This should not happen with current grammar.
265 			 */
266 			LERROR("addtype()");
267 		}
268 		dcs->d_type = tp;
269 		return;
270 	}
271 
272 	t = tp->t_tspec;
273 
274 	if (t == STRUCT || t == UNION || t == ENUM) {
275 		/*
276 		 * something like "int struct a ..."
277 		 * struct/union/enum with anything else is not allowed
278 		 */
279 		if (dcs->d_type != NULL || dcs->d_atyp != NOTSPEC ||
280 		    dcs->d_lmod != NOTSPEC || dcs->d_smod != NOTSPEC) {
281 			/*
282 			 * remember that an error must be reported in
283 			 * deftyp().
284 			 */
285 			dcs->d_terr = 1;
286 			dcs->d_atyp = dcs->d_lmod = dcs->d_smod = NOTSPEC;
287 		}
288 		dcs->d_type = tp;
289 		return;
290 	}
291 
292 	if (dcs->d_type != NULL && !dcs->d_type->t_typedef) {
293 		/*
294 		 * something like "struct a int"
295 		 * struct/union/enum with anything else is not allowed
296 		 */
297 		dcs->d_terr = 1;
298 		return;
299 	}
300 
301 	if (t == COMPLEX) {
302 		if (dcs->d_cmod == FLOAT)
303 			t = FCOMPLEX;
304 		else if (dcs->d_cmod == DOUBLE) {
305 			t = DCOMPLEX;
306 		} else
307 			error(308, basictyname(dcs->d_cmod));
308 		dcs->d_cmod = NOTSPEC;
309 	}
310 
311 	if (t == LONG && dcs->d_lmod == LONG) {
312 		/* "long long" or "long ... long" */
313 		t = QUAD;
314 		dcs->d_lmod = NOTSPEC;
315 		if (!quadflg)
316 			/* %s C does not support 'long long' */
317 			(void)c99ism(265, tflag ? "traditional" : "c89");
318 	}
319 
320 	if (dcs->d_type != NULL && dcs->d_type->t_typedef) {
321 		/* something like "typedef int a; a long ..." */
322 		dcs->d_type = tdeferr(dcs->d_type, t);
323 		return;
324 	}
325 
326 	/* now it can be only a combination of arithmetic types and void */
327 	if (t == SIGNED || t == UNSIGN) {
328 		/* remember specifiers "signed" & "unsigned" in dcs->d_smod */
329 		if (dcs->d_smod != NOTSPEC)
330 			/*
331 			 * more than one "signed" and/or "unsigned"; print
332 			 * an error in deftyp()
333 			 */
334 			dcs->d_terr = 1;
335 		dcs->d_smod = t;
336 	} else if (t == SHORT || t == LONG || t == QUAD) {
337 		/*
338 		 * remember specifiers "short", "long" and "long long" in
339 		 * dcs->d_lmod
340 		 */
341 		if (dcs->d_lmod != NOTSPEC)
342 			/* more than one, print error in deftyp() */
343 			dcs->d_terr = 1;
344 		dcs->d_lmod = t;
345 	} else if (t == FLOAT || t == DOUBLE) {
346 		if (dcs->d_lmod == NOTSPEC || dcs->d_lmod == LONG) {
347 			if (dcs->d_cmod != NOTSPEC
348 			    || (t == FLOAT && dcs->d_lmod == LONG))
349 				dcs->d_terr = 1;
350 			dcs->d_cmod = t;
351 		} else {
352 			if (dcs->d_atyp != NOTSPEC)
353 				dcs->d_terr = 1;
354 			dcs->d_atyp = t;
355 		}
356 	} else {
357 		/*
358 		 * remember specifiers "void", "char", "int",
359 		 * or "_Complex" int dcs->d_atyp
360 		 */
361 		if (dcs->d_atyp != NOTSPEC)
362 			/* more than one, print error in deftyp() */
363 			dcs->d_terr = 1;
364 		dcs->d_atyp = t;
365 	}
366 }
367 
368 /*
369  * called if a list of declaration specifiers contains a typedef name
370  * and other specifiers (except struct, union, enum, typedef name)
371  */
372 static type_t *
373 tdeferr(type_t *td, tspec_t t)
374 {
375 	tspec_t	t2;
376 
377 	t2 = td->t_tspec;
378 
379 	switch (t) {
380 	case SIGNED:
381 	case UNSIGN:
382 		if (t2 == CHAR || t2 == SHORT || t2 == INT || t2 == LONG ||
383 		    t2 == QUAD) {
384 			if (!tflag)
385 				/* modifying typedef with ... */
386 				warning(5, ttab[t].tt_name);
387 			td = duptyp(gettyp(mrgtspec(t2, t)));
388 			td->t_typedef = 1;
389 			return (td);
390 		}
391 		break;
392 	case SHORT:
393 		if (t2 == INT || t2 == UINT) {
394 			/* modifying typedef with ... */
395 			warning(5, "short");
396 			td = duptyp(gettyp(t2 == INT ? SHORT : USHORT));
397 			td->t_typedef = 1;
398 			return (td);
399 		}
400 		break;
401 	case LONG:
402 		if (t2 == INT || t2 == UINT || t2 == LONG || t2 == ULONG ||
403 		    t2 == FLOAT || t2 == DOUBLE || t2 == DCOMPLEX) {
404 			/* modifying typedef with ... */
405 			warning(5, "long");
406 			if (t2 == INT) {
407 				td = gettyp(LONG);
408 			} else if (t2 == UINT) {
409 				td = gettyp(ULONG);
410 			} else if (t2 == LONG) {
411 				td = gettyp(QUAD);
412 			} else if (t2 == ULONG) {
413 				td = gettyp(UQUAD);
414 			} else if (t2 == FLOAT) {
415 				td = gettyp(DOUBLE);
416 			} else if (t2 == DOUBLE) {
417 				td = gettyp(LDOUBLE);
418 			} else if (t2 == DCOMPLEX) {
419 				td = gettyp(LCOMPLEX);
420 			}
421 			td = duptyp(td);
422 			td->t_typedef = 1;
423 			return (td);
424 		}
425 		break;
426 		/* LINTED (enumeration values not handled in switch) */
427 	case NOTSPEC:
428 	case USHORT:
429 	case UCHAR:
430 	case SCHAR:
431 	case CHAR:
432 	case BOOL:
433 	case FUNC:
434 	case ARRAY:
435 	case PTR:
436 	case ENUM:
437 	case UNION:
438 	case STRUCT:
439 	case VOID:
440 	case LDOUBLE:
441 	case FLOAT:
442 	case DOUBLE:
443 	case UQUAD:
444 	case QUAD:
445 	case ULONG:
446 	case UINT:
447 	case INT:
448 	case FCOMPLEX:
449 	case DCOMPLEX:
450 	case LCOMPLEX:
451 	case COMPLEX:
452 		break;
453 
454 	case NTSPEC:	/* this value unused */
455 		break;
456 	}
457 
458 	/* Anything other is not accepted. */
459 
460 	dcs->d_terr = 1;
461 	return (td);
462 }
463 
464 /*
465  * Remember the symbol of a typedef name (2nd arg) in a struct, union
466  * or enum tag if the typedef name is the first defined for this tag.
467  *
468  * If the tag is unnamed, the typdef name is used for identification
469  * of this tag in lint2. Although its possible that more than one typedef
470  * name is defined for one tag, the first name defined should be unique
471  * if the tag is unnamed.
472  */
473 static void
474 settdsym(type_t *tp, sym_t *sym)
475 {
476 	tspec_t	t;
477 
478 	if ((t = tp->t_tspec) == STRUCT || t == UNION) {
479 		if (tp->t_str->stdef == NULL)
480 			tp->t_str->stdef = sym;
481 	} else if (t == ENUM) {
482 		if (tp->t_enum->etdef == NULL)
483 			tp->t_enum->etdef = sym;
484 	}
485 }
486 
487 /*
488  * Remember a qualifier which is part of the declaration specifiers
489  * (and not the declarator) in the top element of the declaration stack.
490  * Also detect multiple qualifiers of the same kind.
491 
492  * The remembered qualifier is used by deftyp() to construct the type
493  * for all declarators.
494  */
495 void
496 addqual(tqual_t q)
497 {
498 
499 	if (q == CONST) {
500 		if (dcs->d_const) {
501 			/* duplicate "%s" */
502 			warning(10, "const");
503 		}
504 		dcs->d_const = 1;
505 	} else {
506 		if (q != VOLATILE)
507 			LERROR("addqual()");
508 		if (dcs->d_volatile) {
509 			/* duplicate "%s" */
510 			warning(10, "volatile");
511 		}
512 		dcs->d_volatile = 1;
513 	}
514 }
515 
516 /*
517  * Go to the next declaration level (structs, nested structs, blocks,
518  * argument declaration lists ...)
519  */
520 void
521 pushdecl(scl_t sc)
522 {
523 	dinfo_t	*di;
524 
525 	if (dflag)
526 		(void)printf("pushdecl(%d)\n", (int)sc);
527 
528 	/* put a new element on the declaration stack */
529 	di = xcalloc(1, sizeof (dinfo_t));
530 	di->d_nxt = dcs;
531 	dcs = di;
532 	di->d_ctx = sc;
533 	di->d_ldlsym = &di->d_dlsyms;
534 }
535 
536 /*
537  * Go back to previous declaration level
538  */
539 void
540 popdecl(void)
541 {
542 	dinfo_t	*di;
543 
544 	if (dflag)
545 		(void)printf("popdecl(%d)\n", (int)dcs->d_ctx);
546 
547 	if (dcs->d_nxt == NULL)
548 		LERROR("popdecl()");
549 	di = dcs;
550 	dcs = di->d_nxt;
551 	switch (di->d_ctx) {
552 	case EXTERN:
553 		/* there is nothing after external declarations */
554 		LERROR("popdecl()");
555 		/* NOTREACHED */
556 	case MOS:
557 	case MOU:
558 	case ENUMCON:
559 		/*
560 		 * Symbols declared in (nested) structs or enums are
561 		 * part of the next level (they are removed from the
562 		 * symbol table if the symbols of the outher level are
563 		 * removed)
564 		 */
565 		if ((*dcs->d_ldlsym = di->d_dlsyms) != NULL)
566 			dcs->d_ldlsym = di->d_ldlsym;
567 		break;
568 	case ARG:
569 		/*
570 		 * All symbols in dcs->d_dlsyms are introduced in old style
571 		 * argument declarations (it's not clean, but possible).
572 		 * They are appended to the list of symbols declared in
573 		 * an old style argument identifier list or a new style
574 		 * parameter type list.
575 		 */
576 		if (di->d_dlsyms != NULL) {
577 			*di->d_ldlsym = dcs->d_fpsyms;
578 			dcs->d_fpsyms = di->d_dlsyms;
579 		}
580 		break;
581 	case ABSTRACT:
582 		/*
583 		 * casts and sizeof
584 		 * Append all symbols declared in the abstract declaration
585 		 * to the list of symbols declared in the surounding decl.
586 		 * or block.
587 		 * XXX I'm not sure whether they should be removed from the
588 		 * symbol table now or later.
589 		 */
590 		if ((*dcs->d_ldlsym = di->d_dlsyms) != NULL)
591 			dcs->d_ldlsym = di->d_ldlsym;
592 		break;
593 	case AUTO:
594 		/* check usage of local vars */
595 		chkusage(di);
596 		/* FALLTHROUGH */
597 	case PARG:
598 		/* usage of arguments will be checked by funcend() */
599 		rmsyms(di->d_dlsyms);
600 		break;
601 	default:
602 		LERROR("popdecl()");
603 	}
604 	free(di);
605 }
606 
607 /*
608  * Set flag d_asm in all declaration stack elements up to the
609  * outermost one.
610  *
611  * This is used to mark compound statements which have, possibly in
612  * nested compound statements, asm statements. For these compound
613  * statements no warnings about unused or unitialized variables are
614  * printed.
615  *
616  * There is no need to clear d_asm in dinfo structs with context AUTO,
617  * because these structs are freed at the end of the compound statement.
618  * But it must be cleard in the outermost dinfo struct, which has
619  * context EXTERN. This could be done in clrtyp() and would work for
620  * C, but not for C++ (due to mixed statements and declarations). Thus
621  * we clear it in glclup(), which is used to do some cleanup after
622  * global declarations/definitions.
623  */
624 void
625 setasm(void)
626 {
627 	dinfo_t	*di;
628 
629 	for (di = dcs; di != NULL; di = di->d_nxt)
630 		di->d_asm = 1;
631 }
632 
633 /*
634  * Clean all elements of the top element of declaration stack which
635  * will be used by the next declaration
636  */
637 void
638 clrtyp(void)
639 {
640 
641 	dcs->d_atyp = dcs->d_cmod = dcs->d_smod = dcs->d_lmod = NOTSPEC;
642 	dcs->d_scl = NOSCL;
643 	dcs->d_type = NULL;
644 	dcs->d_const = dcs->d_volatile = 0;
645 	dcs->d_inline = 0;
646 	dcs->d_mscl = dcs->d_terr = 0;
647 	dcs->d_nedecl = 0;
648 	dcs->d_notyp = 0;
649 }
650 
651 /*
652  * Create a type structure from the informations gathered in
653  * the declaration stack.
654  * Complain about storage classes which are not possible in current
655  * context.
656  */
657 void
658 deftyp(void)
659 {
660 	tspec_t	t, s, l, c;
661 	type_t	*tp;
662 	scl_t	scl;
663 
664 	t = dcs->d_atyp;	/* BOOL, CHAR, INT, COMPLEX, VOID */
665 	s = dcs->d_smod;	/* SIGNED, UNSIGNED */
666 	l = dcs->d_lmod;	/* SHORT, LONG, QUAD */
667 	c = dcs->d_cmod;	/* FLOAT, DOUBLE */
668 	tp = dcs->d_type;
669 	scl = dcs->d_scl;
670 
671 	if (t == NOTSPEC && s == NOTSPEC && l == NOTSPEC && c == NOTSPEC &&
672 	    tp == NULL)
673 		dcs->d_notyp = 1;
674 	if (t == NOTSPEC && s == NOTSPEC && (l == NOTSPEC || l == LONG) &&
675 	    tp == NULL)
676 		t = c;
677 
678 	if (tp != NULL && (t != NOTSPEC || s != NOTSPEC || l != NOTSPEC)) {
679 		/* should never happen */
680 		LERROR("deftyp()");
681 	}
682 
683 	if (tp == NULL) {
684 		switch (t) {
685 		case BOOL:
686 			break;
687 		case NOTSPEC:
688 			t = INT;
689 			/* FALLTHROUGH */
690 		case INT:
691 			if (s == NOTSPEC)
692 				s = SIGNED;
693 			break;
694 		case CHAR:
695 			if (l != NOTSPEC) {
696 				dcs->d_terr = 1;
697 				l = NOTSPEC;
698 			}
699 			break;
700 		case FLOAT:
701 			if (l == LONG) {
702 				l = NOTSPEC;
703 				t = DOUBLE;
704 				if (!tflag)
705 					/* use 'double' instead of ...  */
706 					warning(6);
707 			}
708 			break;
709 		case DOUBLE:
710 			if (l == LONG) {
711 				l = NOTSPEC;
712 				t = LDOUBLE;
713 				if (tflag)
714 					/* 'long double' is illegal in ... */
715 					warning(266);
716 			}
717 			break;
718 		case DCOMPLEX:
719 			if (l == LONG) {
720 				l = NOTSPEC;
721 				t = LCOMPLEX;
722 				if (tflag)
723 					/* 'long double' is illegal in ... */
724 					warning(266);
725 			}
726 			break;
727 		case VOID:
728 		case FCOMPLEX:
729 		case LCOMPLEX:
730 			break;
731 		default:
732 			LERROR("deftyp()");
733 		}
734 		if (t != INT && t != CHAR && (s != NOTSPEC || l != NOTSPEC)) {
735 			dcs->d_terr = 1;
736 			l = s = NOTSPEC;
737 		}
738 		if (l != NOTSPEC)
739 			t = l;
740 		dcs->d_type = gettyp(mrgtspec(t, s));
741 	}
742 
743 	if (dcs->d_mscl) {
744 		/* only one storage class allowed */
745 		error(7);
746 	}
747 	if (dcs->d_terr) {
748 		/* illegal type combination */
749 		error(4);
750 	}
751 
752 	if (dcs->d_ctx == EXTERN) {
753 		if (scl == REG || scl == AUTO) {
754 			/* illegal storage class */
755 			error(8);
756 			scl = NOSCL;
757 		}
758 	} else if (dcs->d_ctx == ARG || dcs->d_ctx == PARG) {
759 		if (scl != NOSCL && scl != REG) {
760 			/* only "register" valid ... */
761 			error(9);
762 			scl = NOSCL;
763 		}
764 	}
765 
766 	dcs->d_scl = scl;
767 
768 	if (dcs->d_const && dcs->d_type->t_const) {
769 		if (!dcs->d_type->t_typedef)
770 			LERROR("deftyp()");
771 		/* typedef already qualified with "%s" */
772 		warning(68, "const");
773 	}
774 	if (dcs->d_volatile && dcs->d_type->t_volatile) {
775 		if (!dcs->d_type->t_typedef)
776 			LERROR("deftyp()");
777 		/* typedef already qualified with "%s" */
778 		warning(68, "volatile");
779 	}
780 
781 	if (dcs->d_const || dcs->d_volatile) {
782 		dcs->d_type = duptyp(dcs->d_type);
783 		dcs->d_type->t_const |= dcs->d_const;
784 		dcs->d_type->t_volatile |= dcs->d_volatile;
785 	}
786 }
787 
788 /*
789  * Merge type specifiers (char, ..., long long, signed, unsigned).
790  */
791 static tspec_t
792 mrgtspec(tspec_t t, tspec_t s)
793 {
794 
795 	if (s == SIGNED || s == UNSIGN) {
796 		if (t == CHAR) {
797 			t = s == SIGNED ? SCHAR : UCHAR;
798 		} else if (t == SHORT) {
799 			t = s == SIGNED ? SHORT : USHORT;
800 		} else if (t == INT) {
801 			t = s == SIGNED ? INT : UINT;
802 		} else if (t == LONG) {
803 			t = s == SIGNED ? LONG : ULONG;
804 		} else if (t == QUAD) {
805 			t = s == SIGNED ? QUAD : UQUAD;
806 		}
807 	}
808 
809 	return (t);
810 }
811 
812 /*
813  * Return the length of a type in bit.
814  *
815  * Printing a message if the outhermost dimension of an array is 0 must
816  * be done by the caller. All other problems are reported by length()
817  * if name is not NULL.
818  */
819 int
820 length(type_t *tp, const char *name)
821 {
822 	int	elem, elsz;
823 
824 	elem = 1;
825 	while (tp && tp->t_tspec == ARRAY) {
826 		elem *= tp->t_dim;
827 		tp = tp->t_subt;
828 	}
829 	if (tp == NULL)
830 		return -1;
831 
832 	switch (tp->t_tspec) {
833 	case FUNC:
834 		/* compiler takes size of function */
835 		LERROR(msgs[12]);
836 		/* NOTREACHED */
837 	case STRUCT:
838 	case UNION:
839 		if (incompl(tp) && name != NULL) {
840 			/* incomplete structure or union %s: %s */
841 			error(31, tp->t_str->stag->s_name, name);
842 		}
843 		elsz = tp->t_str->size;
844 		break;
845 	case ENUM:
846 		if (incompl(tp) && name != NULL) {
847 			/* incomplete enum type: %s */
848 			warning(13, name);
849 		}
850 		/* FALLTHROUGH */
851 	default:
852 		elsz = size(tp->t_tspec);
853 		if (elsz <= 0)
854 			LERROR("length()");
855 		break;
856 	}
857 	return (elem * elsz);
858 }
859 
860 /*
861  * Get the alignment of the given Type in bits.
862  */
863 int
864 getbound(type_t *tp)
865 {
866 	size_t	a;
867 	tspec_t	t;
868 
869 	while (tp && tp->t_tspec == ARRAY)
870 		tp = tp->t_subt;
871 
872 	if (tp == NULL)
873 		return -1;
874 
875 	if ((t = tp->t_tspec) == STRUCT || t == UNION) {
876 		a = tp->t_str->align;
877 	} else if (t == FUNC) {
878 		/* compiler takes alignment of function */
879 		error(14);
880 		a = ALIGN(1) * CHAR_BIT;
881 	} else {
882 		if ((a = size(t)) == 0) {
883 			a = CHAR_BIT;
884 		} else if (a > ALIGN(1) * CHAR_BIT) {
885 			a = ALIGN(1) * CHAR_BIT;
886 		}
887 	}
888 	if (a < CHAR_BIT || a > ALIGN(1) * CHAR_BIT)
889 		LERROR("getbound()");
890 	return (a);
891 }
892 
893 /*
894  * Concatenate two lists of symbols by s_nxt. Used by declarations of
895  * struct/union/enum elements and parameters.
896  */
897 sym_t *
898 lnklst(sym_t *l1, sym_t *l2)
899 {
900 	sym_t	*l;
901 
902 	if ((l = l1) == NULL)
903 		return (l2);
904 	while (l1->s_nxt != NULL)
905 		l1 = l1->s_nxt;
906 	l1->s_nxt = l2;
907 	return (l);
908 }
909 
910 /*
911  * Check if the type of the given symbol is valid and print an error
912  * message if it is not.
913  *
914  * Invalid types are:
915  * - arrays of incomlete types or functions
916  * - functions returning arrays or functions
917  * - void types other than type of function or pointer
918  */
919 void
920 chktyp(sym_t *sym)
921 {
922 	tspec_t	to, t;
923 	type_t	**tpp, *tp;
924 
925 	tpp = &sym->s_type;
926 	to = NOTSPEC;
927 	while ((tp = *tpp) != NULL) {
928 		t = tp->t_tspec;
929 		/*
930 		 * If this is the type of an old style function definition,
931 		 * a better warning is printed in funcdef().
932 		 */
933 		if (t == FUNC && !tp->t_proto &&
934 		    !(to == NOTSPEC && sym->s_osdef)) {
935 			if (sflag && hflag)
936 				/* function declaration is not a prototype */
937 				warning(287);
938 		}
939 		if (to == FUNC) {
940 			if (t == FUNC || t == ARRAY) {
941 				/* function returns illegal type */
942 				error(15);
943 				if (t == FUNC) {
944 					*tpp = incref(*tpp, PTR);
945 				} else {
946 					*tpp = incref((*tpp)->t_subt, PTR);
947 				}
948 				return;
949 			} else if (tp->t_const || tp->t_volatile) {
950 				if (sflag) {	/* XXX oder better !tflag ? */
951 					/* function cannot return const... */
952 					warning(228);
953 				}
954 			}
955 		} if (to == ARRAY) {
956 			if (t == FUNC) {
957 				/* array of function is illegal */
958 				error(16);
959 				*tpp = gettyp(INT);
960 				return;
961 			} else if (t == ARRAY && tp->t_dim == 0) {
962 				/* null dimension */
963 				error(17);
964 				return;
965 			} else if (t == VOID) {
966 				/* illegal use of void */
967 				error(18);
968 				*tpp = gettyp(INT);
969 #if 0	/* errors are produced by length() */
970 			} else if (incompl(tp)) {
971 				/* array of incomplete type */
972 				if (sflag) {
973 					error(301);
974 				} else {
975 					warning(301);
976 				}
977 #endif
978 			}
979 		} else if (to == NOTSPEC && t == VOID) {
980 			if (dcs->d_ctx == PARG) {
981 				if (sym->s_scl != ABSTRACT) {
982 					if (sym->s_name == unnamed)
983 						LERROR("chktyp()");
984 					/* void param cannot have name: %s */
985 					error(61, sym->s_name);
986 					*tpp = gettyp(INT);
987 				}
988 			} else if (dcs->d_ctx == ABSTRACT) {
989 				/* ok */
990 			} else if (sym->s_scl != TYPEDEF) {
991 				/* void type for %s */
992 				error(19, sym->s_name);
993 				*tpp = gettyp(INT);
994 			}
995 		}
996 		if (t == VOID && to != PTR) {
997 			if (tp->t_const || tp->t_volatile) {
998 				/* inappropriate qualifiers with "void" */
999 				warning(69);
1000 				tp->t_const = tp->t_volatile = 0;
1001 			}
1002 		}
1003 		tpp = &tp->t_subt;
1004 		to = t;
1005 	}
1006 }
1007 
1008 /*
1009  * Process the declarator of a struct/union element.
1010  */
1011 sym_t *
1012 decl1str(sym_t *dsym)
1013 {
1014 	type_t	*tp;
1015 	tspec_t	t;
1016 	int	sz, len;
1017 	int	o = 0;	/* Appease gcc */
1018 	scl_t	sc;
1019 
1020 	if ((sc = dsym->s_scl) != MOS && sc != MOU)
1021 		LERROR("decl1str()");
1022 
1023 	if (dcs->d_rdcsym != NULL) {
1024 		if ((sc = dcs->d_rdcsym->s_scl) != MOS && sc != MOU)
1025 			/* should be ensured by storesym() */
1026 			LERROR("decl1str()");
1027 		if (dsym->s_styp == dcs->d_rdcsym->s_styp) {
1028 			/* duplicate member name: %s */
1029 			error(33, dsym->s_name);
1030 			rmsym(dcs->d_rdcsym);
1031 		}
1032 	}
1033 
1034 	chktyp(dsym);
1035 
1036 	t = (tp = dsym->s_type)->t_tspec;
1037 
1038 	if (dsym->s_field) {
1039 		/*
1040 		 * bit field
1041 		 *
1042 		 * only unsigned und signed int are protable bit-field types
1043 		 *(at least in ANSI C, in traditional C only unsigned int)
1044 		 */
1045 		if (t == CHAR || t == UCHAR || t == SCHAR ||
1046 		    t == SHORT || t == USHORT || t == ENUM) {
1047 			if (bitfieldtype_ok == 0) {
1048 				if (sflag) {
1049 					char buf[64];
1050 					/*
1051 					 * bit-field type '%s' invalid in
1052 					 * ANSI C
1053 					 */
1054 					warning(273,
1055 					    tyname(buf, sizeof(buf), tp));
1056 				} else if (pflag) {
1057 					/* nonportable bit-field type */
1058 					warning(34);
1059 				}
1060 			}
1061 		} else if (t == INT && dcs->d_smod == NOTSPEC) {
1062 			if (pflag && bitfieldtype_ok == 0) {
1063 				/* nonportable bit-field type */
1064 				warning(34);
1065 			}
1066 		} else if (t != INT && t != UINT) {
1067 			/*
1068 			 * Non-integer types are always illegal for
1069 			 * bitfields, regardless of BITFIELDTYPE.
1070 			 * Integer types not dealt with above are
1071 			 * okay only if BITFIELDTYPE is in effect.
1072 			 */
1073 			if (bitfieldtype_ok == 0 || isityp(t) == 0) {
1074 				/* illegal bit-field type */
1075 				error(35);
1076 				sz = tp->t_flen;
1077 				dsym->s_type = tp = duptyp(gettyp(t = INT));
1078 				if ((tp->t_flen = sz) > size(t))
1079 					tp->t_flen = size(t);
1080 			}
1081 		}
1082 		if ((len = tp->t_flen) < 0 || len > (ssize_t)size(t)) {
1083 			/* illegal bit-field size */
1084 			error(36);
1085 			tp->t_flen = size(t);
1086 		} else if (len == 0 && dsym->s_name != unnamed) {
1087 			/* zero size bit-field */
1088 			error(37);
1089 			tp->t_flen = size(t);
1090 		}
1091 		if (dsym->s_scl == MOU) {
1092 			/* illegal use of bit-field */
1093 			error(41);
1094 			dsym->s_type->t_isfield = 0;
1095 			dsym->s_field = 0;
1096 		}
1097 	} else if (t == FUNC) {
1098 		/* function illegal in structure or union */
1099 		error(38);
1100 		dsym->s_type = tp = incref(tp, t = PTR);
1101 	}
1102 
1103 	/*
1104 	 * bit-fields of length 0 are not warned about because length()
1105 	 * does not return the length of the bit-field but the length
1106 	 * of the type the bit-field is packed in (its ok)
1107 	 */
1108 	if ((sz = length(dsym->s_type, dsym->s_name)) == 0) {
1109 		if (t == ARRAY && dsym->s_type->t_dim == 0) {
1110 			/* illegal zero sized structure member: %s */
1111 			c99ism(39, dsym->s_name);
1112 		}
1113 	}
1114 
1115 	if (dcs->d_ctx == MOU) {
1116 		o = dcs->d_offset;
1117 		dcs->d_offset = 0;
1118 	}
1119 	if (dsym->s_field) {
1120 		align(getbound(tp), tp->t_flen);
1121 		dsym->s_value.v_quad = (dcs->d_offset / size(t)) * size(t);
1122 		tp->t_foffs = dcs->d_offset - (int)dsym->s_value.v_quad;
1123 		dcs->d_offset += tp->t_flen;
1124 	} else {
1125 		align(getbound(tp), 0);
1126 		dsym->s_value.v_quad = dcs->d_offset;
1127 		dcs->d_offset += sz;
1128 	}
1129 	if (dcs->d_ctx == MOU) {
1130 		if (o > dcs->d_offset)
1131 			dcs->d_offset = o;
1132 	}
1133 
1134 	chkfdef(dsym, 0);
1135 
1136 	/*
1137 	 * Clear the BITFIELDTYPE indicator after processing each
1138 	 * structure element.
1139 	 */
1140 	bitfieldtype_ok = 0;
1141 
1142 	return (dsym);
1143 }
1144 
1145 /*
1146  * Aligns next structure element as required.
1147  *
1148  * al contains the required alignment, len the length of a bit-field.
1149  */
1150 static void
1151 align(int al, int len)
1152 {
1153 	int	no;
1154 
1155 	/*
1156 	 * The alignment of the current element becomes the alignment of
1157 	 * the struct/union if it is larger than the current alignment
1158 	 * of the struct/union.
1159 	 */
1160 	if (al > dcs->d_stralign)
1161 		dcs->d_stralign = al;
1162 
1163 	no = (dcs->d_offset + (al - 1)) & ~(al - 1);
1164 	if (len == 0 || dcs->d_offset + len > no)
1165 		dcs->d_offset = no;
1166 }
1167 
1168 /*
1169  * Remember the width of the field in its type structure.
1170  */
1171 sym_t *
1172 bitfield(sym_t *dsym, int len)
1173 {
1174 
1175 	if (dsym == NULL) {
1176 		dsym = getblk(sizeof (sym_t));
1177 		dsym->s_name = unnamed;
1178 		dsym->s_kind = FMOS;
1179 		dsym->s_scl = MOS;
1180 		dsym->s_type = gettyp(UINT);
1181 		dsym->s_blklev = -1;
1182 	}
1183 	dsym->s_type = duptyp(dsym->s_type);
1184 	dsym->s_type->t_isfield = 1;
1185 	dsym->s_type->t_flen = len;
1186 	dsym->s_field = 1;
1187 	return (dsym);
1188 }
1189 
1190 /*
1191  * Collect informations about a sequence of asterisks and qualifiers
1192  * in a list of type pqinf_t.
1193  * Qualifiers refer always to the left asterisk. The rightmost asterisk
1194  * will be at the top of the list.
1195  */
1196 pqinf_t *
1197 mergepq(pqinf_t *p1, pqinf_t *p2)
1198 {
1199 	pqinf_t	*p;
1200 
1201 	if (p2->p_pcnt != 0) {
1202 		/* left '*' at the end of the list */
1203 		for (p = p2; p->p_nxt != NULL; p = p->p_nxt)
1204 			continue;
1205 		p->p_nxt = p1;
1206 		return (p2);
1207 	} else {
1208 		if (p2->p_const) {
1209 			if (p1->p_const) {
1210 				/* duplicate %s */
1211 				warning(10, "const");
1212 			}
1213 			p1->p_const = 1;
1214 		}
1215 		if (p2->p_volatile) {
1216 			if (p1->p_volatile) {
1217 				/* duplicate %s */
1218 				warning(10, "volatile");
1219 			}
1220 			p1->p_volatile = 1;
1221 		}
1222 		free(p2);
1223 		return (p1);
1224 	}
1225 }
1226 
1227 /*
1228  * Followint 3 functions extend the type of a declarator with
1229  * pointer, function and array types.
1230  *
1231  * The current type is the Type built by deftyp() (dcs->d_type) and
1232  * pointer, function and array types already added for this
1233  * declarator. The new type extension is inserted between both.
1234  */
1235 sym_t *
1236 addptr(sym_t *decl, pqinf_t *pi)
1237 {
1238 	type_t	**tpp, *tp;
1239 	pqinf_t	*npi;
1240 
1241 	tpp = &decl->s_type;
1242 	while (*tpp && *tpp != dcs->d_type)
1243 		tpp = &(*tpp)->t_subt;
1244 	if (*tpp == NULL)
1245 		return decl;
1246 
1247 	while (pi != NULL) {
1248 		*tpp = tp = getblk(sizeof (type_t));
1249 		tp->t_tspec = PTR;
1250 		tp->t_const = pi->p_const;
1251 		tp->t_volatile = pi->p_volatile;
1252 		*(tpp = &tp->t_subt) = dcs->d_type;
1253 		npi = pi->p_nxt;
1254 		free(pi);
1255 		pi = npi;
1256 	}
1257 	return (decl);
1258 }
1259 
1260 /*
1261  * If a dimension was specified, dim is 1, otherwise 0
1262  * n is the specified dimension
1263  */
1264 sym_t *
1265 addarray(sym_t *decl, int dim, int n)
1266 {
1267 	type_t	**tpp, *tp;
1268 
1269 	tpp = &decl->s_type;
1270 	while (*tpp && *tpp != dcs->d_type)
1271 		tpp = &(*tpp)->t_subt;
1272 	if (*tpp == NULL)
1273 	    return decl;
1274 
1275 	*tpp = tp = getblk(sizeof (type_t));
1276 	tp->t_tspec = ARRAY;
1277 	tp->t_subt = dcs->d_type;
1278 	tp->t_dim = n;
1279 
1280 	if (n < 0) {
1281 		/* negative array dimension */
1282 		error(20, n);
1283 		n = 0;
1284 	} else if (n == 0 && dim) {
1285 		/* zero array dimension */
1286 		c99ism(322, dim);
1287 	} else if (n == 0 && !dim) {
1288 		/* is incomplete type */
1289 		setcompl(tp, 1);
1290 	}
1291 
1292 	return (decl);
1293 }
1294 
1295 sym_t *
1296 addfunc(sym_t *decl, sym_t *args)
1297 {
1298 	type_t	**tpp, *tp;
1299 
1300 	if (dcs->d_proto) {
1301 		if (tflag)
1302 			/* function prototypes are illegal in traditional C */
1303 			warning(270);
1304 		args = nsfunc(decl, args);
1305 	} else {
1306 		osfunc(decl, args);
1307 	}
1308 
1309 	/*
1310 	 * The symbols are removed from the symbol table by popdecl() after
1311 	 * addfunc(). To be able to restore them if this is a function
1312 	 * definition, a pointer to the list of all symbols is stored in
1313 	 * dcs->d_nxt->d_fpsyms. Also a list of the arguments (concatenated
1314 	 * by s_nxt) is stored in dcs->d_nxt->d_fargs.
1315 	 * (dcs->d_nxt must be used because *dcs is the declaration stack
1316 	 * element created for the list of params and is removed after
1317 	 * addfunc())
1318 	 */
1319 	if (dcs->d_nxt->d_ctx == EXTERN &&
1320 	    decl->s_type == dcs->d_nxt->d_type) {
1321 		dcs->d_nxt->d_fpsyms = dcs->d_dlsyms;
1322 		dcs->d_nxt->d_fargs = args;
1323 	}
1324 
1325 	tpp = &decl->s_type;
1326 	while (*tpp && *tpp != dcs->d_nxt->d_type)
1327 		tpp = &(*tpp)->t_subt;
1328 	if (*tpp == NULL)
1329 	    return decl;
1330 
1331 	*tpp = tp = getblk(sizeof (type_t));
1332 	tp->t_tspec = FUNC;
1333 	tp->t_subt = dcs->d_nxt->d_type;
1334 	if ((tp->t_proto = dcs->d_proto) != 0)
1335 		tp->t_args = args;
1336 	tp->t_vararg = dcs->d_vararg;
1337 
1338 	return (decl);
1339 }
1340 
1341 /*
1342  * Called for new style function declarations.
1343  */
1344 /* ARGSUSED */
1345 static sym_t *
1346 nsfunc(sym_t *decl, sym_t *args)
1347 {
1348 	sym_t	*arg, *sym;
1349 	scl_t	sc;
1350 	int	n;
1351 
1352 	/*
1353 	 * Declarations of structs/unions/enums in param lists are legal,
1354 	 * but senseless.
1355 	 */
1356 	for (sym = dcs->d_dlsyms; sym != NULL; sym = sym->s_dlnxt) {
1357 		sc = sym->s_scl;
1358 		if (sc == STRTAG || sc == UNIONTAG || sc == ENUMTAG) {
1359 			/* dubious tag declaration: %s %s */
1360 			warning(85, scltoa(sc), sym->s_name);
1361 		}
1362 	}
1363 
1364 	n = 1;
1365 	for (arg = args; arg != NULL; arg = arg->s_nxt) {
1366 		if (arg->s_type->t_tspec == VOID) {
1367 			if (n > 1 || arg->s_nxt != NULL) {
1368 				/* "void" must be sole parameter */
1369 				error(60);
1370 				arg->s_type = gettyp(INT);
1371 			}
1372 		}
1373 		n++;
1374 	}
1375 
1376 	/* return NULL if first param is VOID */
1377 	return (args != NULL && args->s_type->t_tspec != VOID ? args : NULL);
1378 }
1379 
1380 /*
1381  * Called for old style function declarations.
1382  */
1383 static void
1384 osfunc(sym_t *decl, sym_t *args)
1385 {
1386 
1387 	/*
1388 	 * Remember list of params only if this is really seams to be
1389 	 * a function definition.
1390 	 */
1391 	if (dcs->d_nxt->d_ctx == EXTERN &&
1392 	    decl->s_type == dcs->d_nxt->d_type) {
1393 		/*
1394 		 * We assume that this becomes a function definition. If
1395 		 * we are wrong, its corrected in chkfdef().
1396 		 */
1397 		if (args != NULL) {
1398 			decl->s_osdef = 1;
1399 			decl->s_args = args;
1400 		}
1401 	} else {
1402 		if (args != NULL)
1403 			/* function prototype parameters must have types */
1404 			warning(62);
1405 	}
1406 }
1407 
1408 /*
1409  * Lists of Identifiers in functions declarations are allowed only if
1410  * its also a function definition. If this is not the case, print a
1411  * error message.
1412  */
1413 void
1414 chkfdef(sym_t *sym, int msg)
1415 {
1416 
1417 	if (sym->s_osdef) {
1418 		if (msg) {
1419 			/* incomplete or misplaced function definition */
1420 			error(22);
1421 		}
1422 		sym->s_osdef = 0;
1423 		sym->s_args = NULL;
1424 	}
1425 }
1426 
1427 /*
1428  * Process the name in a declarator.
1429  * If the symbol does already exists, a new one is created.
1430  * The symbol becomes one of the storage classes EXTERN, STATIC, AUTO or
1431  * TYPEDEF.
1432  * s_def and s_reg are valid after dname().
1433  */
1434 sym_t *
1435 dname(sym_t *sym)
1436 {
1437 	scl_t	sc = NOSCL;
1438 
1439 	if (sym->s_scl == NOSCL) {
1440 		dcs->d_rdcsym = NULL;
1441 	} else if (sym->s_defarg) {
1442 		sym->s_defarg = 0;
1443 		dcs->d_rdcsym = NULL;
1444 	} else {
1445 		dcs->d_rdcsym = sym;
1446 		sym = pushdown(sym);
1447 	}
1448 
1449 	switch (dcs->d_ctx) {
1450 	case MOS:
1451 	case MOU:
1452 		/* Parent setzen */
1453 		sym->s_styp = dcs->d_tagtyp->t_str;
1454 		sym->s_def = DEF;
1455 		sym->s_value.v_tspec = INT;
1456 		sc = dcs->d_ctx;
1457 		break;
1458 	case EXTERN:
1459 		/*
1460 		 * static and external symbols without "extern" are
1461 		 * considered to be tentative defined, external
1462 		 * symbols with "extern" are declared, and typedef names
1463 		 * are defined. Tentative defined and declared symbols
1464 		 * may become defined if an initializer is present or
1465 		 * this is a function definition.
1466 		 */
1467 		if ((sc = dcs->d_scl) == NOSCL) {
1468 			sc = EXTERN;
1469 			sym->s_def = TDEF;
1470 		} else if (sc == STATIC) {
1471 			sym->s_def = TDEF;
1472 		} else if (sc == TYPEDEF) {
1473 			sym->s_def = DEF;
1474 		} else if (sc == EXTERN) {
1475 			sym->s_def = DECL;
1476 		} else {
1477 			LERROR("dname()");
1478 		}
1479 		break;
1480 	case PARG:
1481 		sym->s_arg = 1;
1482 		/* FALLTHROUGH */
1483 	case ARG:
1484 		if ((sc = dcs->d_scl) == NOSCL) {
1485 			sc = AUTO;
1486 		} else if (sc == REG) {
1487 			sym->s_reg = 1;
1488 			sc = AUTO;
1489 		} else {
1490 			LERROR("dname()");
1491 		}
1492 		sym->s_def = DEF;
1493 		break;
1494 	case AUTO:
1495 		if ((sc = dcs->d_scl) == NOSCL) {
1496 			/*
1497 			 * XXX somewhat ugly because we dont know whether
1498 			 * this is AUTO or EXTERN (functions). If we are
1499 			 * wrong it must be corrected in decl1loc(), where
1500 			 * we have the necessary type information.
1501 			 */
1502 			sc = AUTO;
1503 			sym->s_def = DEF;
1504 		} else if (sc == AUTO || sc == STATIC || sc == TYPEDEF) {
1505 			sym->s_def = DEF;
1506 		} else if (sc == REG) {
1507 			sym->s_reg = 1;
1508 			sc = AUTO;
1509 			sym->s_def = DEF;
1510 		} else if (sc == EXTERN) {
1511 			sym->s_def = DECL;
1512 		} else {
1513 			LERROR("dname()");
1514 		}
1515 		break;
1516 	default:
1517 		LERROR("dname()");
1518 	}
1519 	sym->s_scl = sc;
1520 
1521 	sym->s_type = dcs->d_type;
1522 
1523 	dcs->d_fpsyms = NULL;
1524 
1525 	return (sym);
1526 }
1527 
1528 /*
1529  * Process a name in the list of formal params in an old style function
1530  * definition.
1531  */
1532 sym_t *
1533 iname(sym_t *sym)
1534 {
1535 
1536 	if (sym->s_scl != NOSCL) {
1537 		if (blklev == sym->s_blklev) {
1538 			/* redeclaration of formal parameter %s */
1539 			error(21, sym->s_name);
1540 			if (!sym->s_defarg)
1541 				LERROR("iname()");
1542 		}
1543 		sym = pushdown(sym);
1544 	}
1545 	sym->s_type = gettyp(INT);
1546 	sym->s_scl = AUTO;
1547 	sym->s_def = DEF;
1548 	sym->s_defarg = sym->s_arg = 1;
1549 	return (sym);
1550 }
1551 
1552 /*
1553  * Create the type of a tag.
1554  *
1555  * tag points to the symbol table entry of the tag
1556  * kind is the kind of the tag (STRUCT/UNION/ENUM)
1557  * decl is 1 if the type of the tag will be completed in this declaration
1558  * (the following token is T_LBRACE)
1559  * semi is 1 if the following token is T_SEMI
1560  */
1561 type_t *
1562 mktag(sym_t *tag, tspec_t kind, int decl, int semi)
1563 {
1564 	scl_t	scl = NOSCL;
1565 	type_t	*tp;
1566 
1567 	if (kind == STRUCT) {
1568 		scl = STRTAG;
1569 	} else if (kind == UNION) {
1570 		scl = UNIONTAG;
1571 	} else if (kind == ENUM) {
1572 		scl = ENUMTAG;
1573 	} else {
1574 		LERROR("mktag()");
1575 	}
1576 
1577 	if (tag != NULL) {
1578 		if (tag->s_scl != NOSCL) {
1579 			tag = newtag(tag, scl, decl, semi);
1580 		} else {
1581 			/* a new tag, no empty declaration */
1582 			dcs->d_nxt->d_nedecl = 1;
1583 			if (scl == ENUMTAG && !decl) {
1584 				if (!tflag && (sflag || pflag))
1585 					/* forward reference to enum type */
1586 					warning(42);
1587 			}
1588 		}
1589 		if (tag->s_scl == NOSCL) {
1590 			tag->s_scl = scl;
1591 			tag->s_type = tp = getblk(sizeof (type_t));
1592 		} else {
1593 			tp = tag->s_type;
1594 		}
1595 	} else {
1596 		tag = getblk(sizeof (sym_t));
1597 		tag->s_name = unnamed;
1598 		UNIQUE_CURR_POS(tag->s_dpos);
1599 		tag->s_kind = FTAG;
1600 		tag->s_scl = scl;
1601 		tag->s_blklev = -1;
1602 		tag->s_type = tp = getblk(sizeof (type_t));
1603 		dcs->d_nxt->d_nedecl = 1;
1604 	}
1605 
1606 	if (tp->t_tspec == NOTSPEC) {
1607 		tp->t_tspec = kind;
1608 		if (kind != ENUM) {
1609 			tp->t_str = getblk(sizeof (str_t));
1610 			tp->t_str->align = CHAR_BIT;
1611 			tp->t_str->stag = tag;
1612 		} else {
1613 			tp->t_isenum = 1;
1614 			tp->t_enum = getblk(sizeof (enum_t));
1615 			tp->t_enum->etag = tag;
1616 		}
1617 		/* ist unvollstaendiger Typ */
1618 		setcompl(tp, 1);
1619 	}
1620 
1621 	return (tp);
1622 }
1623 
1624 /*
1625  * Checks all possible cases of tag redeclarations.
1626  * decl is 1 if T_LBRACE follows
1627  * semi is 1 if T_SEMI follows
1628  */
1629 static sym_t *
1630 newtag(sym_t *tag, scl_t scl, int decl, int semi)
1631 {
1632 
1633 	if (tag->s_blklev < blklev) {
1634 		if (semi) {
1635 			/* "struct a;" */
1636 			if (!tflag) {
1637 				if (!sflag)
1638 					/* decl. introduces new type ... */
1639 					warning(44, scltoa(scl), tag->s_name);
1640 				tag = pushdown(tag);
1641 			} else if (tag->s_scl != scl) {
1642 				/* base type is really "%s %s" */
1643 				warning(45, scltoa(tag->s_scl), tag->s_name);
1644 			}
1645 			dcs->d_nxt->d_nedecl = 1;
1646 		} else if (decl) {
1647 			/* "struct a { ... } " */
1648 			if (hflag)
1649 				/* redefinition hides earlier one: %s */
1650 				warning(43, tag->s_name);
1651 			tag = pushdown(tag);
1652 			dcs->d_nxt->d_nedecl = 1;
1653 		} else if (tag->s_scl != scl) {
1654 			/* base type is really "%s %s" */
1655 			warning(45, scltoa(tag->s_scl), tag->s_name);
1656 			/* declaration introduces new type in ANSI C: %s %s */
1657 			if (!sflag)
1658 				warning(44, scltoa(scl), tag->s_name);
1659 			tag = pushdown(tag);
1660 			dcs->d_nxt->d_nedecl = 1;
1661 		}
1662 	} else {
1663 		if (tag->s_scl != scl) {
1664 			/* (%s) tag redeclared */
1665 			error(46, scltoa(tag->s_scl));
1666 			prevdecl(-1, tag);
1667 			tag = pushdown(tag);
1668 			dcs->d_nxt->d_nedecl = 1;
1669 		} else if (decl && !incompl(tag->s_type)) {
1670 			/* (%s) tag redeclared */
1671 			error(46, scltoa(tag->s_scl));
1672 			prevdecl(-1, tag);
1673 			tag = pushdown(tag);
1674 			dcs->d_nxt->d_nedecl = 1;
1675 		} else if (semi || decl) {
1676 			dcs->d_nxt->d_nedecl = 1;
1677 		}
1678 	}
1679 	return (tag);
1680 }
1681 
1682 const char *
1683 scltoa(scl_t sc)
1684 {
1685 	const	char *s;
1686 
1687 	switch (sc) {
1688 	case EXTERN:	s = "extern";	break;
1689 	case STATIC:	s = "static";	break;
1690 	case AUTO:	s = "auto";	break;
1691 	case REG:	s = "register";	break;
1692 	case TYPEDEF:	s = "typedef";	break;
1693 	case STRTAG:	s = "struct";	break;
1694 	case UNIONTAG:	s = "union";	break;
1695 	case ENUMTAG:	s = "enum";	break;
1696 	default:	LERROR("tagttoa()");
1697 	}
1698 	return (s);
1699 }
1700 
1701 /*
1702  * Completes the type of a tag in a struct/union/enum declaration.
1703  * tp points to the type of the, tag, fmem to the list of members/enums.
1704  */
1705 type_t *
1706 compltag(type_t *tp, sym_t *fmem)
1707 {
1708 	tspec_t	t;
1709 	str_t	*sp;
1710 	int	n;
1711 	sym_t	*mem;
1712 
1713 	/* from now a complete type */
1714 	setcompl(tp, 0);
1715 
1716 	if ((t = tp->t_tspec) != ENUM) {
1717 		align(dcs->d_stralign, 0);
1718 		sp = tp->t_str;
1719 		sp->align = dcs->d_stralign;
1720 		sp->size = dcs->d_offset;
1721 		sp->memb = fmem;
1722 		if (sp->size == 0) {
1723 			/* zero sized %s */
1724 			(void)c99ism(47, ttab[t].tt_name);
1725 		} else {
1726 			n = 0;
1727 			for (mem = fmem; mem != NULL; mem = mem->s_nxt) {
1728 				if (mem->s_name != unnamed)
1729 					n++;
1730 			}
1731 			if (n == 0) {
1732 				/* %s has no named members */
1733 				warning(65,
1734 					t == STRUCT ? "structure" : "union");
1735 			}
1736 		}
1737 	} else {
1738 		tp->t_enum->elem = fmem;
1739 	}
1740 	return (tp);
1741 }
1742 
1743 /*
1744  * Processes the name of an enumerator in en enum declaration.
1745  *
1746  * sym points to the enumerator
1747  * val is the value of the enumerator
1748  * impl is 1 if the value of the enumerator was not explicit specified.
1749  */
1750 sym_t *
1751 ename(sym_t *sym, int val, int impl)
1752 {
1753 
1754 	if (sym->s_scl) {
1755 		if (sym->s_blklev == blklev) {
1756 			/* no hflag, because this is illegal!!! */
1757 			if (sym->s_arg) {
1758 				/* enumeration constant hides parameter: %s */
1759 				warning(57, sym->s_name);
1760 			} else {
1761 				/* redeclaration of %s */
1762 				error(27, sym->s_name);
1763 				/*
1764 				 * inside blocks it should not too complicated
1765 				 * to find the position of the previous
1766 				 * declaration
1767 				 */
1768 				if (blklev == 0)
1769 					prevdecl(-1, sym);
1770 			}
1771 		} else {
1772 			if (hflag)
1773 				/* redefinition hides earlier one: %s */
1774 				warning(43, sym->s_name);
1775 		}
1776 		sym = pushdown(sym);
1777 	}
1778 	sym->s_scl = ENUMCON;
1779 	sym->s_type = dcs->d_tagtyp;
1780 	sym->s_value.v_tspec = INT;
1781 	sym->s_value.v_quad = val;
1782 	if (impl && val - 1 == INT_MAX) {
1783 		/* overflow in enumeration values: %s */
1784 		warning(48, sym->s_name);
1785 	}
1786 	enumval = val + 1;
1787 	return (sym);
1788 }
1789 
1790 /*
1791  * Process a single external declarator.
1792  */
1793 void
1794 decl1ext(sym_t *dsym, int initflg)
1795 {
1796 	int	dowarn, rval, redec;
1797 	sym_t	*rdsym;
1798 
1799 	chkfdef(dsym, 1);
1800 
1801 	chktyp(dsym);
1802 
1803 	if (initflg && !(initerr = chkinit(dsym)))
1804 		dsym->s_def = DEF;
1805 
1806 	/*
1807 	 * Declarations of functions are marked as "tentative" in dname().
1808 	 * This is wrong because there are no tentative function
1809 	 * definitions.
1810 	 */
1811 	if (dsym->s_type->t_tspec == FUNC && dsym->s_def == TDEF)
1812 		dsym->s_def = DECL;
1813 
1814 	if (dcs->d_inline) {
1815 		if (dsym->s_type->t_tspec == FUNC) {
1816 			dsym->s_inline = 1;
1817 		} else {
1818 			/* variable declared inline: %s */
1819 			warning(268, dsym->s_name);
1820 		}
1821 	}
1822 
1823 	/* Write the declaration into the output file */
1824 	if (plibflg && llibflg &&
1825 	    dsym->s_type->t_tspec == FUNC && dsym->s_type->t_proto) {
1826 		/*
1827 		 * With both LINTLIBRARY and PROTOLIB the prototyp is
1828 		 * written as a function definition to the output file.
1829 		 */
1830 		rval = dsym->s_type->t_subt->t_tspec != VOID;
1831 		outfdef(dsym, &dsym->s_dpos, rval, 0, NULL);
1832 	} else {
1833 		outsym(dsym, dsym->s_scl, dsym->s_def);
1834 	}
1835 
1836 	if ((rdsym = dcs->d_rdcsym) != NULL) {
1837 
1838 		/*
1839 		 * If the old symbol stems from a old style function definition
1840 		 * we have remembered the params in rdsmy->s_args and compare
1841 		 * them with the params of the prototype.
1842 		 */
1843 		if (rdsym->s_osdef && dsym->s_type->t_proto) {
1844 			redec = chkosdef(rdsym, dsym);
1845 		} else {
1846 			redec = 0;
1847 		}
1848 
1849 		if (!redec && !isredec(dsym, (dowarn = 0, &dowarn))) {
1850 
1851 			if (dowarn) {
1852 				/* redeclaration of %s */
1853 				(*(sflag ? error : warning))(27, dsym->s_name);
1854 				prevdecl(-1, rdsym);
1855 			}
1856 
1857 			/*
1858 			 * Overtake the rememberd params if the new symbol
1859 			 * is not a prototype.
1860 			 */
1861 			if (rdsym->s_osdef && !dsym->s_type->t_proto) {
1862 				dsym->s_osdef = rdsym->s_osdef;
1863 				dsym->s_args = rdsym->s_args;
1864 				STRUCT_ASSIGN(dsym->s_dpos, rdsym->s_dpos);
1865 			}
1866 
1867 			/*
1868 			 * Remember the position of the declaration if the
1869 			 * old symbol was a prototype and the new is not.
1870 			 * Also remember the position if the old symbol
1871 			 * was defined and the new is not.
1872 			 */
1873 			if (rdsym->s_type->t_proto && !dsym->s_type->t_proto) {
1874 				STRUCT_ASSIGN(dsym->s_dpos, rdsym->s_dpos);
1875 			} else if (rdsym->s_def == DEF && dsym->s_def != DEF) {
1876 				STRUCT_ASSIGN(dsym->s_dpos, rdsym->s_dpos);
1877 			}
1878 
1879 			/*
1880 			 * Copy informations about usage of the name into
1881 			 * the new symbol.
1882 			 */
1883 			cpuinfo(dsym, rdsym);
1884 
1885 			/* Once a name is defined, it remains defined. */
1886 			if (rdsym->s_def == DEF)
1887 				dsym->s_def = DEF;
1888 
1889 			/* once a function is inline, it remains inline */
1890 			if (rdsym->s_inline)
1891 				dsym->s_inline = 1;
1892 
1893 			compltyp(dsym, rdsym);
1894 
1895 		}
1896 
1897 		rmsym(rdsym);
1898 	}
1899 
1900 	if (dsym->s_scl == TYPEDEF) {
1901 		dsym->s_type = duptyp(dsym->s_type);
1902 		dsym->s_type->t_typedef = 1;
1903 		settdsym(dsym->s_type, dsym);
1904 	}
1905 
1906 }
1907 
1908 /*
1909  * Copies informations about usage into a new symbol table entry of
1910  * the same symbol.
1911  */
1912 void
1913 cpuinfo(sym_t *sym, sym_t *rdsym)
1914 {
1915 
1916 	sym->s_spos = rdsym->s_spos;
1917 	sym->s_upos = rdsym->s_upos;
1918 	sym->s_set = rdsym->s_set;
1919 	sym->s_used = rdsym->s_used;
1920 }
1921 
1922 /*
1923  * Prints an error and returns 1 if a symbol is redeclared/redefined.
1924  * Otherwise returns 0 and, in some cases of minor problems, prints
1925  * a warning.
1926  */
1927 int
1928 isredec(sym_t *dsym, int *dowarn)
1929 {
1930 	sym_t	*rsym;
1931 
1932 	if ((rsym = dcs->d_rdcsym)->s_scl == ENUMCON) {
1933 		/* redeclaration of %s */
1934 		error(27, dsym->s_name);
1935 		prevdecl(-1, rsym);
1936 		return (1);
1937 	}
1938 	if (rsym->s_scl == TYPEDEF) {
1939 		/* typedef redeclared: %s */
1940 		error(89, dsym->s_name);
1941 		prevdecl(-1, rsym);
1942 		return (1);
1943 	}
1944 	if (dsym->s_scl == TYPEDEF) {
1945 		/* redeclaration of %s */
1946 		error(27, dsym->s_name);
1947 		prevdecl(-1, rsym);
1948 		return (1);
1949 	}
1950 	if (rsym->s_def == DEF && dsym->s_def == DEF) {
1951 		/* redefinition of %s */
1952 		error(28, dsym->s_name);
1953 		prevdecl(-1, rsym);
1954 		return(1);
1955 	}
1956 	if (!eqtype(rsym->s_type, dsym->s_type, 0, 0, dowarn)) {
1957 		/* redeclaration of %s */
1958 		error(27, dsym->s_name);
1959 		prevdecl(-1, rsym);
1960 		return(1);
1961 	}
1962 	if (rsym->s_scl == EXTERN && dsym->s_scl == EXTERN)
1963 		return(0);
1964 	if (rsym->s_scl == STATIC && dsym->s_scl == STATIC)
1965 		return(0);
1966 	if (rsym->s_scl == STATIC && dsym->s_def == DECL)
1967 		return(0);
1968 	if (rsym->s_scl == EXTERN && rsym->s_def == DEF) {
1969 		/*
1970 		 * All cases except "int a = 1; static int a;" are catched
1971 		 * above with or without a warning
1972 		 */
1973 		/* redeclaration of %s */
1974 		error(27, dsym->s_name);
1975 		prevdecl(-1, rsym);
1976 		return(1);
1977 	}
1978 	if (rsym->s_scl == EXTERN) {
1979 		/* previously declared extern, becomes static: %s */
1980 		warning(29, dsym->s_name);
1981 		prevdecl(-1, rsym);
1982 		return(0);
1983 	}
1984 	/*
1985 	 * Now its on of:
1986 	 * "static a; int a;", "static a; int a = 1;", "static a = 1; int a;"
1987 	 */
1988 	/* redeclaration of %s; ANSI C requires "static" */
1989 	if (sflag) {
1990 		warning(30, dsym->s_name);
1991 		prevdecl(-1, rsym);
1992 	}
1993 	dsym->s_scl = STATIC;
1994 	return (0);
1995 }
1996 
1997 static int
1998 chkqual(type_t *tp1, type_t *tp2, int ignqual)
1999 {
2000 	if (tp1->t_const != tp2->t_const && !ignqual && !tflag)
2001 		return 0;
2002 
2003 	if (tp1->t_volatile != tp2->t_volatile && !ignqual && !tflag)
2004 		return 0;
2005 
2006 	return 1;
2007 }
2008 
2009 int
2010 eqptrtype(type_t *tp1, type_t *tp2, int ignqual)
2011 {
2012 	if (tp1->t_tspec != VOID && tp2->t_tspec != VOID)
2013 		return 0;
2014 
2015 	if (!chkqual(tp1, tp2, ignqual))
2016 		return 0;
2017 
2018 	return 1;
2019 }
2020 
2021 
2022 /*
2023  * Checks if two types are compatible. Returns 0 if not, otherwise 1.
2024  *
2025  * ignqual	ignore qualifiers of type; used for function params
2026  * promot	promote left type; used for comparison of params of
2027  *		old style function definitions with params of prototypes.
2028  * *dowarn	set to 1 if an old style function declaration is not
2029  *		compatible with a prototype
2030  */
2031 int
2032 eqtype(type_t *tp1, type_t *tp2, int ignqual, int promot, int *dowarn)
2033 {
2034 	tspec_t	t;
2035 
2036 	while (tp1 != NULL && tp2 != NULL) {
2037 
2038 		t = tp1->t_tspec;
2039 		if (promot) {
2040 			if (t == FLOAT) {
2041 				t = DOUBLE;
2042 			} else if (t == CHAR || t == SCHAR) {
2043 				t = INT;
2044 			} else if (t == UCHAR) {
2045 				t = tflag ? UINT : INT;
2046 			} else if (t == SHORT) {
2047 				t = INT;
2048 			} else if (t == USHORT) {
2049 				/* CONSTCOND */
2050 				t = INT_MAX < USHRT_MAX || tflag ? UINT : INT;
2051 			}
2052 		}
2053 
2054 		if (t != tp2->t_tspec)
2055 			return (0);
2056 
2057 		if (!chkqual(tp1, tp2, ignqual))
2058 			return 0;
2059 
2060 		if (t == STRUCT || t == UNION)
2061 			return (tp1->t_str == tp2->t_str);
2062 
2063 		if (t == ARRAY && tp1->t_dim != tp2->t_dim) {
2064 			if (tp1->t_dim != 0 && tp2->t_dim != 0)
2065 				return (0);
2066 		}
2067 
2068 		/* dont check prototypes for traditional */
2069 		if (t == FUNC && !tflag) {
2070 			if (tp1->t_proto && tp2->t_proto) {
2071 				if (!eqargs(tp1, tp2, dowarn))
2072 					return (0);
2073 			} else if (tp1->t_proto) {
2074 				if (!mnoarg(tp1, dowarn))
2075 					return (0);
2076 			} else if (tp2->t_proto) {
2077 				if (!mnoarg(tp2, dowarn))
2078 					return (0);
2079 			}
2080 		}
2081 
2082 		tp1 = tp1->t_subt;
2083 		tp2 = tp2->t_subt;
2084 		ignqual = promot = 0;
2085 
2086 	}
2087 
2088 	return (tp1 == tp2);
2089 }
2090 
2091 /*
2092  * Compares the parameter types of two prototypes.
2093  */
2094 static int
2095 eqargs(type_t *tp1, type_t *tp2, int *dowarn)
2096 {
2097 	sym_t	*a1, *a2;
2098 
2099 	if (tp1->t_vararg != tp2->t_vararg)
2100 		return (0);
2101 
2102 	a1 = tp1->t_args;
2103 	a2 = tp2->t_args;
2104 
2105 	while (a1 != NULL && a2 != NULL) {
2106 
2107 		if (eqtype(a1->s_type, a2->s_type, 1, 0, dowarn) == 0)
2108 			return (0);
2109 
2110 		a1 = a1->s_nxt;
2111 		a2 = a2->s_nxt;
2112 
2113 	}
2114 
2115 	return (a1 == a2);
2116 }
2117 
2118 /*
2119  * mnoarg() (matches functions with no argument type information)
2120  * returns 1 if all parameters of a prototype are compatible with
2121  * and old style function declaration.
2122  * This is the case if following conditions are met:
2123  *	1. the prototype must have a fixed number of parameters
2124  *	2. no parameter is of type float
2125  *	3. no parameter is converted to another type if integer promotion
2126  *	   is applied on it
2127  */
2128 static int
2129 mnoarg(type_t *tp, int *dowarn)
2130 {
2131 	sym_t	*arg;
2132 	tspec_t	t;
2133 
2134 	if (tp->t_vararg) {
2135 		if (dowarn != NULL)
2136 			*dowarn = 1;
2137 	}
2138 	for (arg = tp->t_args; arg != NULL; arg = arg->s_nxt) {
2139 		if ((t = arg->s_type->t_tspec) == FLOAT ||
2140 		    t == CHAR || t == SCHAR || t == UCHAR ||
2141 		    t == SHORT || t == USHORT) {
2142 			if (dowarn != NULL)
2143 				*dowarn = 1;
2144 		}
2145 	}
2146 	return (1);
2147 }
2148 
2149 /*
2150  * Compares a prototype declaration with the remembered arguments of
2151  * a previous old style function definition.
2152  */
2153 static int
2154 chkosdef(sym_t *rdsym, sym_t *dsym)
2155 {
2156 	sym_t	*args, *pargs, *arg, *parg;
2157 	int	narg, nparg, n;
2158 	int	dowarn, msg;
2159 
2160 	args = rdsym->s_args;
2161 	pargs = dsym->s_type->t_args;
2162 
2163 	msg = 0;
2164 
2165 	narg = nparg = 0;
2166 	for (arg = args; arg != NULL; arg = arg->s_nxt)
2167 		narg++;
2168 	for (parg = pargs; parg != NULL; parg = parg->s_nxt)
2169 		nparg++;
2170 	if (narg != nparg) {
2171 		/* prototype does not match old-style definition */
2172 		error(63);
2173 		msg = 1;
2174 		goto end;
2175 	}
2176 
2177 	arg = args;
2178 	parg = pargs;
2179 	n = 1;
2180 	while (narg--) {
2181 		dowarn = 0;
2182 		/*
2183 		 * If it does not match due to promotion and sflag is
2184 		 * not set we print only a warning.
2185 		 */
2186 		if (!eqtype(arg->s_type, parg->s_type, 1, 1, &dowarn) || dowarn) {
2187 			/* prototype does not match old-style def., arg #%d */
2188 			error(299, n);
2189 			msg = 1;
2190 		}
2191 		arg = arg->s_nxt;
2192 		parg = parg->s_nxt;
2193 		n++;
2194 	}
2195 
2196  end:
2197 	if (msg)
2198 		/* old style definition */
2199 		prevdecl(300, rdsym);
2200 
2201 	return (msg);
2202 }
2203 
2204 /*
2205  * Complets a type by copying the dimension and prototype information
2206  * from a second compatible type.
2207  *
2208  * Following lines are legal:
2209  *  "typedef a[]; a b; a b[10]; a c; a c[20];"
2210  *  "typedef ft(); ft f; f(int); ft g; g(long);"
2211  * This means that, if a type is completed, the type structure must
2212  * be duplicated.
2213  */
2214 void
2215 compltyp(sym_t *dsym, sym_t *ssym)
2216 {
2217 	type_t	**dstp, *src;
2218 	type_t	*dst;
2219 
2220 	dstp = &dsym->s_type;
2221 	src = ssym->s_type;
2222 
2223 	while ((dst = *dstp) != NULL) {
2224 		if (src == NULL || dst->t_tspec != src->t_tspec)
2225 			LERROR("compltyp()");
2226 		if (dst->t_tspec == ARRAY) {
2227 			if (dst->t_dim == 0 && src->t_dim != 0) {
2228 				*dstp = dst = duptyp(dst);
2229 				dst->t_dim = src->t_dim;
2230 				/* now a complete Typ */
2231 				setcompl(dst, 0);
2232 			}
2233 		} else if (dst->t_tspec == FUNC) {
2234 			if (!dst->t_proto && src->t_proto) {
2235 				*dstp = dst = duptyp(dst);
2236 				dst->t_proto = 1;
2237 				dst->t_args = src->t_args;
2238 			}
2239 		}
2240 		dstp = &dst->t_subt;
2241 		src = src->t_subt;
2242 	}
2243 }
2244 
2245 /*
2246  * Completes the declaration of a single argument.
2247  */
2248 sym_t *
2249 decl1arg(sym_t *sym, int initflg)
2250 {
2251 	tspec_t	t;
2252 
2253 	chkfdef(sym, 1);
2254 
2255 	chktyp(sym);
2256 
2257 	if (dcs->d_rdcsym != NULL && dcs->d_rdcsym->s_blklev == blklev) {
2258 		/* redeclaration of formal parameter %s */
2259 		error(237, sym->s_name);
2260 		rmsym(dcs->d_rdcsym);
2261 		sym->s_arg = 1;
2262 	}
2263 
2264 	if (!sym->s_arg) {
2265 		/* declared argument %s is missing */
2266 		error(53, sym->s_name);
2267 		sym->s_arg = 1;
2268 	}
2269 
2270 	if (initflg) {
2271 		/* cannot initialize parameter: %s */
2272 		error(52, sym->s_name);
2273 		initerr = 1;
2274 	}
2275 
2276 	if ((t = sym->s_type->t_tspec) == ARRAY) {
2277 		sym->s_type = incref(sym->s_type->t_subt, PTR);
2278 	} else if (t == FUNC) {
2279 		if (tflag)
2280 			/* a function is declared as an argument: %s */
2281 			warning(50, sym->s_name);
2282 		sym->s_type = incref(sym->s_type, PTR);
2283 	} else if (t == FLOAT) {
2284 		if (tflag)
2285 			sym->s_type = gettyp(DOUBLE);
2286 	}
2287 
2288 	if (dcs->d_inline)
2289 		/* argument declared inline: %s */
2290 		warning(269, sym->s_name);
2291 
2292 	/*
2293 	 * Arguments must have complete types. lengths() prints the needed
2294 	 * error messages (null dimension is impossible because arrays are
2295 	 * converted to pointers).
2296 	 */
2297 	if (sym->s_type->t_tspec != VOID)
2298 		(void)length(sym->s_type, sym->s_name);
2299 
2300 	setsflg(sym);
2301 
2302 	return (sym);
2303 }
2304 
2305 /*
2306  * Does some checks for lint directives which apply to functions.
2307  * Processes arguments in old style function definitions which default
2308  * to int.
2309  * Checks compatiblility of old style function definition with previous
2310  * prototype.
2311  */
2312 void
2313 cluparg(void)
2314 {
2315 	sym_t	*args, *arg, *pargs, *parg;
2316 	int	narg, nparg, n, msg;
2317 	tspec_t	t;
2318 
2319 	args = funcsym->s_args;
2320 	pargs = funcsym->s_type->t_args;
2321 
2322 	/* check for illegal combinations of lint directives */
2323 	if (prflstrg != -1 && scflstrg != -1) {
2324 		/* can't be used together: ** PRINTFLIKE ** ** SCANFLIKE ** */
2325 		warning(289);
2326 		prflstrg = scflstrg = -1;
2327 	}
2328 	if (nvararg != -1 && (prflstrg != -1 || scflstrg != -1)) {
2329 		/* dubious use of ** VARARGS ** with ** %s ** */
2330 		warning(288, prflstrg != -1 ? "PRINTFLIKE" : "SCANFLIKE");
2331 		nvararg = -1;
2332 	}
2333 
2334 	/*
2335 	 * check if the argument of a lint directive is compatible with the
2336 	 * number of arguments.
2337 	 */
2338 	narg = 0;
2339 	for (arg = dcs->d_fargs; arg != NULL; arg = arg->s_nxt)
2340 		narg++;
2341 	if (nargusg > narg) {
2342 		/* argument number mismatch with directive: ** %s ** */
2343 		warning(283, "ARGSUSED");
2344 		nargusg = 0;
2345 	}
2346 	if (nvararg > narg) {
2347 		/* argument number mismatch with directive: ** %s ** */
2348 		warning(283, "VARARGS");
2349 		nvararg = 0;
2350 	}
2351 	if (prflstrg > narg) {
2352 		/* argument number mismatch with directive: ** %s ** */
2353 		warning(283, "PRINTFLIKE");
2354 		prflstrg = -1;
2355 	} else if (prflstrg == 0) {
2356 		prflstrg = -1;
2357 	}
2358 	if (scflstrg > narg) {
2359 		/* argument number mismatch with directive: ** %s ** */
2360 		warning(283, "SCANFLIKE");
2361 		scflstrg = -1;
2362 	} else if (scflstrg == 0) {
2363 		scflstrg = -1;
2364 	}
2365 	if (prflstrg != -1 || scflstrg != -1) {
2366 		narg = prflstrg != -1 ? prflstrg : scflstrg;
2367 		arg = dcs->d_fargs;
2368 		for (n = 1; n < narg; n++)
2369 			arg = arg->s_nxt;
2370 		if (arg->s_type->t_tspec != PTR ||
2371 		    ((t = arg->s_type->t_subt->t_tspec) != CHAR &&
2372 		     t != UCHAR && t != SCHAR)) {
2373 			/* arg. %d must be 'char *' for PRINTFLIKE/SCANFLIKE */
2374 			warning(293, narg);
2375 			prflstrg = scflstrg = -1;
2376 		}
2377 	}
2378 
2379 	/*
2380 	 * print a warning for each argument off an old style function
2381 	 * definition which defaults to int
2382 	 */
2383 	for (arg = args; arg != NULL; arg = arg->s_nxt) {
2384 		if (arg->s_defarg) {
2385 			/* argument type defaults to int: %s */
2386 			warning(32, arg->s_name);
2387 			arg->s_defarg = 0;
2388 			setsflg(arg);
2389 		}
2390 	}
2391 
2392 	/*
2393 	 * If this is an old style function definition and a prototyp
2394 	 * exists, compare the types of arguments.
2395 	 */
2396 	if (funcsym->s_osdef && funcsym->s_type->t_proto) {
2397 		/*
2398 		 * If the number of arguments does not macht, we need not
2399 		 * continue.
2400 		 */
2401 		narg = nparg = 0;
2402 		msg = 0;
2403 		for (parg = pargs; parg != NULL; parg = parg->s_nxt)
2404 			nparg++;
2405 		for (arg = args; arg != NULL; arg = arg->s_nxt)
2406 			narg++;
2407 		if (narg != nparg) {
2408 			/* parameter mismatch: %d declared, %d defined */
2409 			error(51, nparg, narg);
2410 			msg = 1;
2411 		} else {
2412 			parg = pargs;
2413 			arg = args;
2414 			while (narg--) {
2415 				msg |= chkptdecl(arg, parg);
2416 				parg = parg->s_nxt;
2417 				arg = arg->s_nxt;
2418 			}
2419 		}
2420 		if (msg)
2421 			/* prototype declaration */
2422 			prevdecl(285, dcs->d_rdcsym);
2423 
2424 		/* from now the prototype is valid */
2425 		funcsym->s_osdef = 0;
2426 		funcsym->s_args = NULL;
2427 
2428 	}
2429 
2430 }
2431 
2432 /*
2433  * Checks compatibility of an old style function definition with a previous
2434  * prototype declaration.
2435  * Returns 1 if the position of the previous declaration should be reported.
2436  */
2437 static int
2438 chkptdecl(sym_t *arg, sym_t *parg)
2439 {
2440 	type_t	*tp, *ptp;
2441 	int	dowarn, msg;
2442 
2443 	tp = arg->s_type;
2444 	ptp = parg->s_type;
2445 
2446 	msg = 0;
2447 	dowarn = 0;
2448 
2449 	if (!eqtype(tp, ptp, 1, 1, &dowarn)) {
2450 		if (eqtype(tp, ptp, 1, 0, &dowarn)) {
2451 			/* type does not match prototype: %s */
2452 			msg = gnuism(58, arg->s_name);
2453 		} else {
2454 			/* type does not match prototype: %s */
2455 			error(58, arg->s_name);
2456 			msg = 1;
2457 		}
2458 	} else if (dowarn) {
2459 		/* type does not match prototype: %s */
2460 		(*(sflag ? error : warning))(58, arg->s_name);
2461 		msg = 1;
2462 	}
2463 
2464 	return (msg);
2465 }
2466 
2467 /*
2468  * Completes a single local declaration/definition.
2469  */
2470 void
2471 decl1loc(sym_t *dsym, int initflg)
2472 {
2473 
2474 	/* Correct a mistake done in dname(). */
2475 	if (dsym->s_type->t_tspec == FUNC) {
2476 		dsym->s_def = DECL;
2477 		if (dcs->d_scl == NOSCL)
2478 			dsym->s_scl = EXTERN;
2479 	}
2480 
2481 	if (dsym->s_type->t_tspec == FUNC) {
2482 		if (dsym->s_scl == STATIC) {
2483 			/* dubious static function at block level: %s */
2484 			warning(93, dsym->s_name);
2485 			dsym->s_scl = EXTERN;
2486 		} else if (dsym->s_scl != EXTERN && dsym->s_scl != TYPEDEF) {
2487 			/* function has illegal storage class: %s */
2488 			error(94, dsym->s_name);
2489 			dsym->s_scl = EXTERN;
2490 		}
2491 	}
2492 
2493 	/*
2494 	 * functions may be declared inline at local scope, although
2495 	 * this has no effect for a later definition of the same
2496 	 * function.
2497 	 * XXX it should have an effect if tflag is set. this would
2498 	 * also be the way gcc behaves.
2499 	 */
2500 	if (dcs->d_inline) {
2501 		if (dsym->s_type->t_tspec == FUNC) {
2502 			dsym->s_inline = 1;
2503 		} else {
2504 			/* variable declared inline: %s */
2505 			warning(268, dsym->s_name);
2506 		}
2507 	}
2508 
2509 	chkfdef(dsym, 1);
2510 
2511 	chktyp(dsym);
2512 
2513 	if (dcs->d_rdcsym != NULL && dsym->s_scl == EXTERN)
2514 		ledecl(dsym);
2515 
2516 	if (dsym->s_scl == EXTERN) {
2517 		/*
2518 		 * XXX wenn die statische Variable auf Ebene 0 erst
2519 		 * spaeter definiert wird, haben wir die Brille auf.
2520 		 */
2521 		if (dsym->s_xsym == NULL) {
2522 			outsym(dsym, EXTERN, dsym->s_def);
2523 		} else {
2524 			outsym(dsym, dsym->s_xsym->s_scl, dsym->s_def);
2525 		}
2526 	}
2527 
2528 	if (dcs->d_rdcsym != NULL) {
2529 
2530 		if (dcs->d_rdcsym->s_blklev == 0) {
2531 
2532 			switch (dsym->s_scl) {
2533 			case AUTO:
2534 				/* automatic hides external declaration: %s */
2535 				if (hflag)
2536 					warning(86, dsym->s_name);
2537 				break;
2538 			case STATIC:
2539 				/* static hides external declaration: %s */
2540 				if (hflag)
2541 					warning(87, dsym->s_name);
2542 				break;
2543 			case TYPEDEF:
2544 				/* typedef hides  external declaration: %s */
2545 				if (hflag)
2546 					warning(88, dsym->s_name);
2547 				break;
2548 			case EXTERN:
2549 				/*
2550 				 * Warnings and errors are printed in ledecl()
2551 				 */
2552 				break;
2553 			default:
2554 				LERROR("decl1loc()");
2555 			}
2556 
2557 		} else if (dcs->d_rdcsym->s_blklev == blklev) {
2558 
2559 			/* no hflag, because its illegal! */
2560 			if (dcs->d_rdcsym->s_arg) {
2561 				/*
2562 				 * if !tflag, a "redeclaration of %s" error
2563 				 * is produced below
2564 				 */
2565 				if (tflag) {
2566 					if (hflag)
2567 						/* decl. hides parameter: %s */
2568 						warning(91, dsym->s_name);
2569 					rmsym(dcs->d_rdcsym);
2570 				}
2571 			}
2572 
2573 		} else if (dcs->d_rdcsym->s_blklev < blklev) {
2574 
2575 			if (hflag)
2576 				/* declaration hides earlier one: %s */
2577 				warning(95, dsym->s_name);
2578 
2579 		}
2580 
2581 		if (dcs->d_rdcsym->s_blklev == blklev) {
2582 
2583 			/* redeclaration of %s */
2584 			error(27, dsym->s_name);
2585 			rmsym(dcs->d_rdcsym);
2586 
2587 		}
2588 
2589 	}
2590 
2591 	if (initflg && !(initerr = chkinit(dsym))) {
2592 		dsym->s_def = DEF;
2593 		setsflg(dsym);
2594 	}
2595 
2596 	if (dsym->s_scl == TYPEDEF) {
2597 		dsym->s_type = duptyp(dsym->s_type);
2598 		dsym->s_type->t_typedef = 1;
2599 		settdsym(dsym->s_type, dsym);
2600 	}
2601 
2602 	/*
2603 	 * Before we can check the size we must wait for a initialisation
2604 	 * which may follow.
2605 	 */
2606 }
2607 
2608 /*
2609  * Processes (re)declarations of external Symbols inside blocks.
2610  */
2611 static void
2612 ledecl(sym_t *dsym)
2613 {
2614 	int	eqt, dowarn;
2615 	sym_t	*esym;
2616 
2617 	/* look for a symbol with the same name */
2618 	esym = dcs->d_rdcsym;
2619 	while (esym != NULL && esym->s_blklev != 0) {
2620 		while ((esym = esym->s_link) != NULL) {
2621 			if (esym->s_kind != FVFT)
2622 				continue;
2623 			if (strcmp(dsym->s_name, esym->s_name) == 0)
2624 				break;
2625 		}
2626 	}
2627 	if (esym == NULL)
2628 		return;
2629 	if (esym->s_scl != EXTERN && esym->s_scl != STATIC) {
2630 		/* gcc accepts this without a warning, pcc prints an error. */
2631 		/* redeclaration of %s */
2632 		warning(27, dsym->s_name);
2633 		prevdecl(-1, esym);
2634 		return;
2635 	}
2636 
2637 	dowarn = 0;
2638 	eqt = eqtype(esym->s_type, dsym->s_type, 0, 0, &dowarn);
2639 
2640 	if (!eqt || dowarn) {
2641 		if (esym->s_scl == EXTERN) {
2642 			/* inconsistent redeclaration of extern: %s */
2643 			warning(90, dsym->s_name);
2644 			prevdecl(-1, esym);
2645 		} else {
2646 			/* inconsistent redeclaration of static: %s */
2647 			warning(92, dsym->s_name);
2648 			prevdecl(-1, esym);
2649 		}
2650 	}
2651 
2652 	if (eqt) {
2653 		/*
2654 		 * Remember the external symbol so we can update usage
2655 		 * information at the end of the block.
2656 		 */
2657 		dsym->s_xsym = esym;
2658 	}
2659 }
2660 
2661 /*
2662  * Print an error or a warning if the symbol cant be initialized due
2663  * to type/storage class. Returnvalue is 1 if an error has been
2664  * detected.
2665  */
2666 static int
2667 chkinit(sym_t *sym)
2668 {
2669 	int	erred;
2670 
2671 	erred = 0;
2672 
2673 	if (sym->s_type->t_tspec == FUNC) {
2674 		/* cannot initialize function: %s */
2675 		error(24, sym->s_name);
2676 		erred = 1;
2677 	} else if (sym->s_scl == TYPEDEF) {
2678 		/* cannot initialize typedef: %s */
2679 		error(25, sym->s_name);
2680 		erred = 1;
2681 	} else if (sym->s_scl == EXTERN && sym->s_def == DECL) {
2682 		/* cannot initialize "extern" declaration: %s */
2683 		if (dcs->d_ctx == EXTERN) {
2684 			warning(26, sym->s_name);
2685 		} else {
2686 			error(26, sym->s_name);
2687 			erred = 1;
2688 		}
2689 	}
2690 
2691 	return (erred);
2692 }
2693 
2694 /*
2695  * Create a symbole for an abstract declaration.
2696  */
2697 sym_t *
2698 aname(void)
2699 {
2700 	sym_t	*sym;
2701 
2702 	if (dcs->d_ctx != ABSTRACT && dcs->d_ctx != PARG)
2703 		LERROR("aname()");
2704 
2705 	sym = getblk(sizeof (sym_t));
2706 
2707 	sym->s_name = unnamed;
2708 	sym->s_def = DEF;
2709 	sym->s_scl = ABSTRACT;
2710 	sym->s_blklev = -1;
2711 
2712 	if (dcs->d_ctx == PARG)
2713 		sym->s_arg = 1;
2714 
2715 	sym->s_type = dcs->d_type;
2716 	dcs->d_rdcsym = NULL;
2717 	dcs->d_vararg = 0;
2718 
2719 	return (sym);
2720 }
2721 
2722 /*
2723  * Removes anything which has nothing to do on global level.
2724  */
2725 void
2726 globclup(void)
2727 {
2728 
2729 	while (dcs->d_nxt != NULL)
2730 		popdecl();
2731 
2732 	cleanup();
2733 	blklev = 0;
2734 	mblklev = 0;
2735 
2736 	/*
2737 	 * remove all informations about pending lint directives without
2738 	 * warnings.
2739 	 */
2740 	glclup(1);
2741 }
2742 
2743 /*
2744  * Process an abstract type declaration
2745  */
2746 sym_t *
2747 decl1abs(sym_t *sym)
2748 {
2749 
2750 	chkfdef(sym, 1);
2751 	chktyp(sym);
2752 	return (sym);
2753 }
2754 
2755 /*
2756  * Checks size after declarations of variables and their initialisation.
2757  */
2758 void
2759 chksz(sym_t *dsym)
2760 {
2761 
2762 	/*
2763 	 * check size only for symbols which are defined and no function and
2764 	 * not typedef name
2765 	 */
2766 	if (dsym->s_def != DEF)
2767 		return;
2768 	if (dsym->s_scl == TYPEDEF)
2769 		return;
2770 	if (dsym->s_type->t_tspec == FUNC)
2771 		return;
2772 
2773 	if (length(dsym->s_type, dsym->s_name) == 0 &&
2774 	    dsym->s_type->t_tspec == ARRAY && dsym->s_type->t_dim == 0) {
2775 		/* empty array declaration: %s */
2776 		if (tflag) {
2777 			warning(190, dsym->s_name);
2778 		} else {
2779 			error(190, dsym->s_name);
2780 		}
2781 	}
2782 }
2783 
2784 /*
2785  * Mark an object as set if it is not already
2786  */
2787 void
2788 setsflg(sym_t *sym)
2789 {
2790 
2791 	if (!sym->s_set) {
2792 		sym->s_set = 1;
2793 		UNIQUE_CURR_POS(sym->s_spos);
2794 	}
2795 }
2796 
2797 /*
2798  * Mark an object as used if it is not already
2799  */
2800 void
2801 setuflg(sym_t *sym, int fcall, int szof)
2802 {
2803 
2804 	if (!sym->s_used) {
2805 		sym->s_used = 1;
2806 		UNIQUE_CURR_POS(sym->s_upos);
2807 	}
2808 	/*
2809 	 * for function calls another record is written
2810 	 *
2811 	 * XXX Should symbols used in sizeof() treated as used or not?
2812 	 * Probably not, because there is no sense to declare an
2813 	 * external variable only to get their size.
2814 	 */
2815 	if (!fcall && !szof && sym->s_kind == FVFT && sym->s_scl == EXTERN)
2816 		outusg(sym);
2817 }
2818 
2819 /*
2820  * Prints warnings for a list of variables and labels (concatenated
2821  * with s_dlnxt) if these are not used or only set.
2822  */
2823 void
2824 chkusage(dinfo_t *di)
2825 {
2826 	sym_t	*sym;
2827 	int	mknowarn;
2828 
2829 	/* for this warnings LINTED has no effect */
2830 	mknowarn = nowarn;
2831 	nowarn = 0;
2832 
2833 #ifdef DEBUG
2834 	printf("%s, %d: >temp nowarn = 0\n", curr_pos.p_file, curr_pos.p_line);
2835 #endif
2836 	for (sym = di->d_dlsyms; sym != NULL; sym = sym->s_dlnxt)
2837 		chkusg1(di->d_asm, sym);
2838 	nowarn = mknowarn;
2839 #ifdef DEBUG
2840 	printf("%s, %d: <temp nowarn = %d\n", curr_pos.p_file, curr_pos.p_line,
2841 	    nowarn);
2842 #endif
2843 }
2844 
2845 /*
2846  * Prints a warning for a single variable or label if it is not used or
2847  * only set.
2848  */
2849 void
2850 chkusg1(int novar, sym_t *sym)
2851 {
2852 	pos_t	cpos;
2853 
2854 	if (sym->s_blklev == -1)
2855 		return;
2856 
2857 	STRUCT_ASSIGN(cpos, curr_pos);
2858 
2859 	if (sym->s_kind == FVFT) {
2860 		if (sym->s_arg) {
2861 			chkausg(novar, sym);
2862 		} else {
2863 			chkvusg(novar, sym);
2864 		}
2865 	} else if (sym->s_kind == FLAB) {
2866 		chklusg(sym);
2867 	} else if (sym->s_kind == FTAG) {
2868 		chktusg(sym);
2869 	}
2870 
2871 	STRUCT_ASSIGN(curr_pos, cpos);
2872 }
2873 
2874 static void
2875 chkausg(int novar, sym_t *arg)
2876 {
2877 
2878 	if (!arg->s_set)
2879 		LERROR("chkausg()");
2880 
2881 	if (novar)
2882 		return;
2883 
2884 	if (!arg->s_used && vflag) {
2885 		STRUCT_ASSIGN(curr_pos, arg->s_dpos);
2886 		/* argument %s unused in function %s */
2887 		warning(231, arg->s_name, funcsym->s_name);
2888 	}
2889 }
2890 
2891 static void
2892 chkvusg(int novar, sym_t *sym)
2893 {
2894 	scl_t	sc;
2895 	sym_t	*xsym;
2896 
2897 	if (blklev == 0 || sym->s_blklev == 0)
2898 		LERROR("chkvusg()");
2899 
2900 	/* errors in expressions easily cause lots of these warnings */
2901 	if (nerr != 0)
2902 		return;
2903 
2904 	/*
2905 	 * XXX Only variables are checkd, although types should
2906 	 * probably also be checked
2907 	 */
2908 	if ((sc = sym->s_scl) != EXTERN && sc != STATIC &&
2909 	    sc != AUTO && sc != REG) {
2910 		return;
2911 	}
2912 
2913 	if (novar)
2914 		return;
2915 
2916 	if (sc == EXTERN) {
2917 		if (!sym->s_used && !sym->s_set) {
2918 			STRUCT_ASSIGN(curr_pos, sym->s_dpos);
2919 			/* %s unused in function %s */
2920 			warning(192, sym->s_name, funcsym->s_name);
2921 		}
2922 	} else {
2923 		if (sym->s_set && !sym->s_used) {
2924 			STRUCT_ASSIGN(curr_pos, sym->s_spos);
2925 			/* %s set but not used in function %s */
2926 			warning(191, sym->s_name, funcsym->s_name);
2927 		} else if (!sym->s_used) {
2928 			STRUCT_ASSIGN(curr_pos, sym->s_dpos);
2929 			/* %s unused in function %s */
2930 			warning(192, sym->s_name, funcsym->s_name);
2931 		}
2932 	}
2933 
2934 	if (sc == EXTERN) {
2935 		/*
2936 		 * information about usage is taken over into the symbol
2937 		 * tabel entry at level 0 if the symbol was locally declared
2938 		 * as an external symbol.
2939 		 *
2940 		 * XXX This is wrong for symbols declared static at level 0
2941 		 * if the usage information stems from sizeof(). This is
2942 		 * because symbols at level 0 only used in sizeof() are
2943 		 * considered to not be used.
2944 		 */
2945 		if ((xsym = sym->s_xsym) != NULL) {
2946 			if (sym->s_used && !xsym->s_used) {
2947 				xsym->s_used = 1;
2948 				STRUCT_ASSIGN(xsym->s_upos, sym->s_upos);
2949 			}
2950 			if (sym->s_set && !xsym->s_set) {
2951 				xsym->s_set = 1;
2952 				STRUCT_ASSIGN(xsym->s_spos, sym->s_spos);
2953 			}
2954 		}
2955 	}
2956 }
2957 
2958 static void
2959 chklusg(sym_t *lab)
2960 {
2961 
2962 	if (blklev != 1 || lab->s_blklev != 1)
2963 		LERROR("chklusg()");
2964 
2965 	if (lab->s_set && !lab->s_used) {
2966 		STRUCT_ASSIGN(curr_pos, lab->s_spos);
2967 		/* label %s unused in function %s */
2968 		warning(192, lab->s_name, funcsym->s_name);
2969 	} else if (!lab->s_set) {
2970 		STRUCT_ASSIGN(curr_pos, lab->s_upos);
2971 		/* undefined label %s */
2972 		warning(23, lab->s_name);
2973 	}
2974 }
2975 
2976 static void
2977 chktusg(sym_t *sym)
2978 {
2979 
2980 	if (!incompl(sym->s_type))
2981 		return;
2982 
2983 	/* complain alwasy about incomplet tags declared inside blocks */
2984 	if (!zflag || dcs->d_ctx != EXTERN)
2985 		return;
2986 
2987 	STRUCT_ASSIGN(curr_pos, sym->s_dpos);
2988 	switch (sym->s_type->t_tspec) {
2989 	case STRUCT:
2990 		/* struct %s never defined */
2991 		warning(233, sym->s_name);
2992 		break;
2993 	case UNION:
2994 		/* union %s never defined */
2995 		warning(234, sym->s_name);
2996 		break;
2997 	case ENUM:
2998 		/* enum %s never defined */
2999 		warning(235, sym->s_name);
3000 		break;
3001 	default:
3002 		LERROR("chktusg()");
3003 	}
3004 }
3005 
3006 /*
3007  * Called after the entire translation unit has been parsed.
3008  * Changes tentative definitions in definitions.
3009  * Performs some tests on global Symbols. Detected Problems are:
3010  * - defined variables of incomplete type
3011  * - constant variables which are not initialized
3012  * - static symbols which are never used
3013  */
3014 void
3015 chkglsyms(void)
3016 {
3017 	sym_t	*sym;
3018 	pos_t	cpos;
3019 
3020 	if (blklev != 0 || dcs->d_nxt != NULL)
3021 		norecover();
3022 
3023 	STRUCT_ASSIGN(cpos, curr_pos);
3024 
3025 	for (sym = dcs->d_dlsyms; sym != NULL; sym = sym->s_dlnxt) {
3026 		if (sym->s_blklev == -1)
3027 			continue;
3028 		if (sym->s_kind == FVFT) {
3029 			chkglvar(sym);
3030 		} else if (sym->s_kind == FTAG) {
3031 			chktusg(sym);
3032 		} else {
3033 			if (sym->s_kind != FMOS)
3034 				LERROR("chkglsyms()");
3035 		}
3036 	}
3037 
3038 	STRUCT_ASSIGN(curr_pos, cpos);
3039 }
3040 
3041 static void
3042 chkglvar(sym_t *sym)
3043 {
3044 
3045 	if (sym->s_scl == TYPEDEF || sym->s_scl == ENUMCON)
3046 		return;
3047 
3048 	if (sym->s_scl != EXTERN && sym->s_scl != STATIC)
3049 		LERROR("chkglvar()");
3050 
3051 	glchksz(sym);
3052 
3053 	if (sym->s_scl == STATIC) {
3054 		if (sym->s_type->t_tspec == FUNC) {
3055 			if (sym->s_used && sym->s_def != DEF) {
3056 				STRUCT_ASSIGN(curr_pos, sym->s_upos);
3057 				/* static func. called but not def.. */
3058 				error(225, sym->s_name);
3059 			}
3060 		}
3061 		if (!sym->s_used) {
3062 			STRUCT_ASSIGN(curr_pos, sym->s_dpos);
3063 			if (sym->s_type->t_tspec == FUNC) {
3064 				if (sym->s_def == DEF) {
3065 					if (!sym->s_inline)
3066 						/* static function %s unused */
3067 						warning(236, sym->s_name);
3068 				} else {
3069 					/* static function %s decl. but ... */
3070 					warning(290, sym->s_name);
3071 				}
3072 			} else if (!sym->s_set) {
3073 				/* static variable %s unused */
3074 				warning(226, sym->s_name);
3075 			} else {
3076 				/* static variable %s set but not used */
3077 				warning(307, sym->s_name);
3078 			}
3079 		}
3080 		if (!tflag && sym->s_def == TDEF && sym->s_type->t_const) {
3081 			STRUCT_ASSIGN(curr_pos, sym->s_dpos);
3082 			/* const object %s should have initializer */
3083 			warning(227, sym->s_name);
3084 		}
3085 	}
3086 }
3087 
3088 static void
3089 glchksz(sym_t *sym)
3090 {
3091 
3092 	if (sym->s_def == TDEF) {
3093 		if (sym->s_type->t_tspec == FUNC)
3094 			/*
3095 			 * this can happen if an syntax error occurred
3096 			 * after a function declaration
3097 			 */
3098 			return;
3099 		STRUCT_ASSIGN(curr_pos, sym->s_dpos);
3100 		if (length(sym->s_type, sym->s_name) == 0 &&
3101 		    sym->s_type->t_tspec == ARRAY && sym->s_type->t_dim == 0) {
3102 			/* empty array declaration: %s */
3103 			if (tflag || (sym->s_scl == EXTERN && !sflag)) {
3104 				warning(190, sym->s_name);
3105 			} else {
3106 				error(190, sym->s_name);
3107 			}
3108 		}
3109 	}
3110 }
3111 
3112 /*
3113  * Prints information about location of previous definition/declaration.
3114  */
3115 void
3116 prevdecl(int msg, sym_t *psym)
3117 {
3118 	pos_t	cpos;
3119 
3120 	if (!rflag)
3121 		return;
3122 
3123 	STRUCT_ASSIGN(cpos, curr_pos);
3124 	STRUCT_ASSIGN(curr_pos, psym->s_dpos);
3125 	if (msg != -1) {
3126 		message(msg, psym->s_name);
3127 	} else if (psym->s_def == DEF || psym->s_def == TDEF) {
3128 		/* previous definition of %s */
3129 		message(261, psym->s_name);
3130 	} else {
3131 		/* previous declaration of %s */
3132 		message(260, psym->s_name);
3133 	}
3134 	STRUCT_ASSIGN(curr_pos, cpos);
3135 }
3136