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2 7u83 1 
/*
7 7u83 2 
 * Copyright (c) 2002-2006 The TenDRA Project <http://www.tendra.org/>.
3 
 * All rights reserved.
4 
 *
5 
 * Redistribution and use in source and binary forms, with or without
6 
 * modification, are permitted provided that the following conditions are met:
7 
 *
8 
 * 1. Redistributions of source code must retain the above copyright notice,
9 
 *    this list of conditions and the following disclaimer.
10 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 
 *    this list of conditions and the following disclaimer in the documentation
12 
 *    and/or other materials provided with the distribution.
13 
 * 3. Neither the name of The TenDRA Project nor the names of its contributors
14 
 *    may be used to endorse or promote products derived from this software
15 
 *    without specific, prior written permission.
16 
 *
17 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
18 
 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
19 
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20 
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
21 
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22 
 * EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23 
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24 
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25 
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
26 
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
27 
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 
 *
29 
 * $Id$
30 
 */
31 
/*
2 7u83 32 
    		 Crown Copyright (c) 1997
7 7u83 33 
 
2 7u83 34 
    This TenDRA(r) Computer Program is subject to Copyright
35 
    owned by the United Kingdom Secretary of State for Defence
36 
    acting through the Defence Evaluation and Research Agency
37 
    (DERA).  It is made available to Recipients with a
38 
    royalty-free licence for its use, reproduction, transfer
39 
    to other parties and amendment for any purpose not excluding
40 
    product development provided that any such use et cetera
41 
    shall be deemed to be acceptance of the following conditions:-
7 7u83 42 
 
2 7u83 43 
        (1) Its Recipients shall ensure that this Notice is
44 
        reproduced upon any copies or amended versions of it;
7 7u83 45 
 
2 7u83 46 
        (2) Any amended version of it shall be clearly marked to
47 
        show both the nature of and the organisation responsible
48 
        for the relevant amendment or amendments;
7 7u83 49 
 
2 7u83 50 
        (3) Its onward transfer from a recipient to another
51 
        party shall be deemed to be that party's acceptance of
52 
        these conditions;
7 7u83 53 
 
2 7u83 54 
        (4) DERA gives no warranty or assurance as to its
55 
        quality or suitability for any purpose and DERA accepts
56 
        no liability whatsoever in relation to any use to which
57 
        it may be put.
58 
*/
59 
 
60 
 
61 
#include "config.h"
62 
#include "c_types.h"
63 
#include "ctype_ops.h"
64 
#include "etype_ops.h"
65 
#include "exp_ops.h"
66 
#include "graph_ops.h"
67 
#include "hashid_ops.h"
68 
#include "id_ops.h"
69 
#include "itype_ops.h"
70 
#include "member_ops.h"
71 
#include "nspace_ops.h"
72 
#include "tok_ops.h"
73 
#include "type_ops.h"
74 
#include "error.h"
75 
#include "catalog.h"
76 
#include "assign.h"
77 
#include "basetype.h"
78 
#include "cast.h"
79 
#include "chktype.h"
80 
#include "class.h"
81 
#include "construct.h"
82 
#include "convert.h"
83 
#include "copy.h"
84 
#include "declare.h"
85 
#include "derive.h"
86 
#include "destroy.h"
87 
#include "dump.h"
88 
#include "exception.h"
89 
#include "expression.h"
90 
#include "function.h"
91 
#include "hash.h"
92 
#include "identifier.h"
93 
#include "initialise.h"
94 
#include "instance.h"
95 
#include "namespace.h"
96 
#include "operator.h"
97 
#include "option.h"
98 
#include "overload.h"
99 
#include "predict.h"
100 
#include "syntax.h"
101 
#include "template.h"
102 
#include "tokdef.h"
103 
#include "token.h"
104 
#include "ustring.h"
105 
#include "xalloc.h"
106 
 
107 
 
108 
/*
109 
    CANDIDATE LIST
110 
 
111 
    This variable gives the main candidate list used in overload resolution.
112 
*/
113 
 
7 7u83 114 
CANDIDATE_LIST candidates = { NULL, 0, 0, NULL, 0 };
2 7u83 115 
 
116 
 
117 
/*
118 
    ADD A CANDIDATE TO A LIST
119 
 
120 
    This routine adds the candidate given by id, bid and kind to the
121 
    candidate list p.
122 
*/
123 
 
7 7u83 124 
static void
125 
add_candidate(CANDIDATE_LIST *p, IDENTIFIER id, IDENTIFIER bid, int kind)
2 7u83 126 
{
7 7u83 127 
	CANDIDATE *q = p->elem;
128 
	unsigned n = p->size;
129 
	unsigned m = p->max_size;
130 
	if (n >= m) {
131 
		/* Increase size if necessary */
132 
		m += 200;
133 
		q = xrealloc_nof(q, CANDIDATE, m);
134 
		p->elem = q;
135 
		p->max_size = m;
136 
	}
137 
	q[n].func = id;
138 
	q[n].base = bid;
139 
	q[n].kind = kind;
140 
	q[n].rank = RANK_NONE;
141 
	q[n].convs = NULL;
142 
	q[n].cond = NULL_exp;
143 
	p->size = n + 1;
144 
	return;
2 7u83 145 
}
146 
 
147 
 
148 
/*
149 
    ADD AN IDENTIFIER TO A CANDIDATE LIST
150 
 
151 
    This routine adds the overloaded function identifier id to the candidate
152 
    list given by p.  The kind argument is stored in the kind field of each
153 
    candidate.  The table of candidate functions may need extending.  Note
154 
    that the candidates are added in the reverse order in which they were
155 
    declared.
156 
*/
157 
 
7 7u83 158 
void
159 
add_candidates(CANDIDATE_LIST *p, IDENTIFIER id, int over, int kind)
2 7u83 160 
{
7 7u83 161 
	unsigned tag = TAG_id(id);
162 
	switch (tag) {
163 
	case id_function_tag:
164 
	case id_mem_func_tag:
165 
	case id_stat_mem_func_tag:
166 
		/* Functions */
167 
		while (!IS_NULL_id(id)) {
168 
			IDENTIFIER bid = DEREF_id(id_alias(id));
169 
			add_candidate(p, id, bid, kind);
170 
			if (!over) {
171 
				break;
172 
			}
173 
			id = DEREF_id(id_function_etc_over(id));
174 
		}
175 
		break;
176 
	case id_builtin_tag:
177 
		/* Built-in operators */
178 
		add_candidate(p, id, id, kind);
179 
		break;
180 
	case id_ambig_tag: {
181 
		/* Ambiguous functions */
182 
		LIST(IDENTIFIER) r = DEREF_list(id_ambig_ids(id));
183 
		if (over) {
184 
			over = DEREF_int(id_ambig_over(id));
185 
		}
186 
		while (!IS_NULL_list(r)) {
187 
			IDENTIFIER rid = DEREF_id(HEAD_list(r));
188 
			add_candidates(p, rid, over, kind);
189 
			r = TAIL_list(r);
190 
		}
191 
		break;
2 7u83 192 
	}
193 
	}
7 7u83 194 
	return;
2 7u83 195 
}
196 
 
197 
 
198 
/*
199 
    LOOK UP A FUNCTION IN AN ARGUMENT NAMESPACE
200 
 
201 
    This routine looks up the function id in the namespace containing the
202 
    type name cid.  Any functions found are added to the candidate list p.
203 
*/
204 
 
7 7u83 205 
static IDENTIFIER
206 
koenig_id(CANDIDATE_LIST *p, IDENTIFIER id, IDENTIFIER cid, int kind)
2 7u83 207 
{
7 7u83 208 
	if (!IS_NULL_id(cid)) {
209 
		NAMESPACE cns = DEREF_nspace(id_parent(cid));
210 
		if (!IS_NULL_nspace(cns)) {
211 
			switch (TAG_nspace(cns)) {
212 
			case nspace_named_tag:
213 
			case nspace_unnamed_tag:
214 
			case nspace_global_tag: {
215 
				/* Look up identifier in parent class */
216 
				HASHID nm = DEREF_hashid(id_name(id));
217 
				MEMBER mem = search_member(cns, nm, 0);
218 
				if (!IS_NULL_member(mem)) {
219 
					IDENTIFIER fid =
220 
					    DEREF_id(member_id(mem));
221 
					if (!IS_NULL_id(fid) &&
222 
					    !EQ_id(fid, id)) {
223 
						add_candidates(p, fid, 1, kind);
224 
						id = fid;
225 
					}
226 
				}
227 
				break;
2 7u83 228 
			}
7 7u83 229 
			case nspace_ctype_tag: {
230 
				/* Allow for nested classes */
231 
				IDENTIFIER pid = DEREF_id(nspace_name(cns));
232 
				id = koenig_id(p, id, pid, kind);
233 
				break;
234 
			}
235 
			}
2 7u83 236 
		}
237 
	}
7 7u83 238 
	return (id);
2 7u83 239 
}
240 
 
241 
 
242 
/*
243 
    PERFORM ARGUMENT DEPENDENT NAME LOOK-UP FOR A CLASS
244 
 
245 
    This routine performs argument dependent name look-up for the function
246 
    id and the argument class type ct.
247 
*/
248 
 
7 7u83 249 
static IDENTIFIER
250 
koenig_class(CANDIDATE_LIST *p, IDENTIFIER id, CLASS_TYPE ct, int kind)
2 7u83 251 
{
7 7u83 252 
	TYPE form = DEREF_type(ctype_form(ct));
253 
	if (IS_NULL_type(form)) {
254 
		IDENTIFIER cid = DEREF_id(ctype_name(ct));
255 
		GRAPH gr = DEREF_graph(ctype_base(ct));
256 
		LIST(GRAPH) br = DEREF_list(graph_tails(gr));
257 
		id = koenig_id(p, id, cid, kind);
258 
		while (!IS_NULL_list(br)) {
259 
			GRAPH gs = DEREF_graph(HEAD_list(br));
260 
			CLASS_TYPE cs = DEREF_ctype(graph_head(gs));
261 
			id = koenig_class(p, id, cs, kind);
262 
			br = TAIL_list(br);
263 
		}
264 
	} else {
265 
		id = koenig_candidates(p, id, form, kind);
2 7u83 266 
	}
7 7u83 267 
	return (id);
2 7u83 268 
}
269 
 
270 
 
271 
/*
272 
    PERFORM ARGUMENT DEPENDENT NAME LOOK-UP FOR A TOKEN ARGUMENT
273 
 
274 
    This routine performs argument dependent name look-up for the function
275 
    id and the token argument tok.
276 
*/
277 
 
7 7u83 278 
static IDENTIFIER
279 
koenig_token(CANDIDATE_LIST *p, IDENTIFIER id, TOKEN tok, int kind)
2 7u83 280 
{
7 7u83 281 
	if (!IS_NULL_tok(tok)) {
282 
		ASSERT(ORDER_tok == 10);
283 
		switch (TAG_tok(tok)) {
284 
		case tok_type_tag: {
285 
			TYPE t = DEREF_type(tok_type_value(tok));
286 
			id = koenig_candidates(p, id, t, kind);
287 
			break;
288 
		}
289 
		case tok_class_tag: {
290 
			IDENTIFIER tid = DEREF_id(tok_class_value(tok));
291 
			id = koenig_id(p, id, tid, kind);
292 
			break;
293 
		}
294 
		}
2 7u83 295 
	}
7 7u83 296 
	return (id);
2 7u83 297 
}
298 
 
299 
 
300 
/*
301 
    PERFORM ARGUMENT DEPENDENT NAME LOOK-UP
302 
 
303 
    This routine performs argument dependent name look-up for the function
304 
    id and the argument type t, adding any candidates found to the list p.
305 
*/
306 
 
7 7u83 307 
IDENTIFIER
308 
koenig_candidates(CANDIDATE_LIST *p, IDENTIFIER id, TYPE t, int kind)
2 7u83 309 
{
7 7u83 310 
	if (!IS_NULL_type(t)) {
311 
		ASSERT(ORDER_type == 18);
312 
		switch (TAG_type(t)) {
313 
		case type_ptr_tag:
314 
		case type_ref_tag: {
315 
			TYPE s = DEREF_type(type_ptr_etc_sub(t));
316 
			id = koenig_candidates(p, id, s, kind);
317 
			break;
2 7u83 318 
		}
7 7u83 319 
		case type_ptr_mem_tag: {
320 
			CLASS_TYPE cs = DEREF_ctype(type_ptr_mem_of(t));
321 
			TYPE s = DEREF_type(type_ptr_mem_sub(t));
322 
			id = koenig_class(p, id, cs, kind);
323 
			id = koenig_candidates(p, id, s, kind);
324 
			break;
2 7u83 325 
		}
7 7u83 326 
		case type_func_tag: {
327 
			TYPE r = DEREF_type(type_func_ret(t));
328 
			LIST(TYPE) q = DEREF_list(type_func_ptypes(t));
329 
			id = koenig_candidates(p, id, r, kind);
330 
			while (!IS_NULL_list(q)) {
331 
				TYPE s = DEREF_type(HEAD_list(q));
332 
				id = koenig_candidates(p, id, s, kind);
333 
				q = TAIL_list(q);
334 
			}
335 
			break;
2 7u83 336 
		}
7 7u83 337 
		case type_array_tag: {
338 
			TYPE s = DEREF_type(type_array_sub(t));
339 
			id = koenig_candidates(p, id, s, kind);
340 
			break;
341 
		}
342 
		case type_compound_tag: {
343 
			CLASS_TYPE ct = DEREF_ctype(type_compound_defn(t));
344 
			id = koenig_class(p, id, ct, kind);
345 
			break;
346 
		}
347 
		case type_enumerate_tag: {
348 
			ENUM_TYPE et = DEREF_etype(type_enumerate_defn(t));
349 
			IDENTIFIER eid = DEREF_id(etype_name(et));
350 
			id = koenig_id(p, id, eid, kind);
351 
			break;
352 
		}
353 
		case type_token_tag: {
354 
			IDENTIFIER tid = DEREF_id(type_token_tok(t));
355 
			LIST(TOKEN) args = DEREF_list(type_token_args(t));
356 
			if (IS_id_token(tid)) {
357 
				tid = DEREF_id(id_token_alt(tid));
358 
			}
359 
			id = koenig_id(p, id, tid, kind);
360 
			while (!IS_NULL_list(args)) {
361 
				TOKEN arg = DEREF_tok(HEAD_list(args));
362 
				id = koenig_token(p, id, arg, kind);
363 
				args = TAIL_list(args);
364 
			}
365 
			break;
366 
		}
367 
		case type_templ_tag: {
368 
			TYPE s = DEREF_type(type_templ_defn(t));
369 
			id = koenig_candidates(p, id, s, kind);
370 
			break;
371 
		}
372 
		}
2 7u83 373 
	}
7 7u83 374 
	return (id);
2 7u83 375 
}
376 
 
377 
 
378 
/*
379 
    FREE A LIST OF CANDIDATES
380 
 
381 
    This routine frees the elements of the candidate list p.
382 
*/
383 
 
7 7u83 384 
void
385 
free_candidates(CANDIDATE_LIST *p)
2 7u83 386 
{
7 7u83 387 
	xfree_nof(p->elem);
388 
	xfree_nof(p->convs);
389 
	p->elem = NULL;
390 
	p->size = 0;
391 
	p->max_size = 0;
392 
	p->convs = NULL;
393 
	p->nconvs = 0;
394 
	return;
2 7u83 395 
}
396 
 
397 
 
398 
/*
399 
    SWAP PARAMETER TYPE FIELDS FOR A FUNCTION
400 
 
401 
    Overload resolution is based on the mtypes field of the function type.
402 
    This routine can be used to force resolution on the ptypes field by
403 
    swapping the two fields for the overloaded function identifier id.
404 
    Note that after overload resolution the fields should be swapped back.
405 
*/
406 
 
7 7u83 407 
void
408 
swap_ptypes(IDENTIFIER id)
2 7u83 409 
{
7 7u83 410 
	LIST(TYPE) ptypes;
411 
	LIST(TYPE) mtypes;
412 
	TYPE fn = DEREF_type(id_function_etc_type(id));
413 
	while (IS_type_templ(fn)) {
414 
		/* Allow for template functions */
415 
		fn = DEREF_type(type_templ_defn(fn));
416 
	}
417 
	ptypes = DEREF_list(type_func_ptypes(fn));
418 
	mtypes = DEREF_list(type_func_mtypes(fn));
419 
	if (!EQ_list(ptypes, mtypes)) {
420 
		COPY_list(type_func_ptypes(fn), mtypes);
421 
		COPY_list(type_func_mtypes(fn), ptypes);
422 
	}
423 
	return;
2 7u83 424 
}
425 
 
426 
 
427 
/*
428 
    SWAP PARAMETER TYPE FIELDS FOR CANDIDATES FUNCTIONS
429 
 
430 
    This routine swaps the parameter type fields for all the constructor
431 
    candidates in p, starting with the nth entry.
432 
*/
433 
 
7 7u83 434 
void
435 
swap_candidates(CANDIDATE_LIST *p, unsigned n)
2 7u83 436 
{
7 7u83 437 
	unsigned i, m = p->size;
438 
	for (i = n; i < m; i++) {
439 
		CANDIDATE *r = p->elem + i;
440 
		if (r->kind == KIND_CONSTR) {
441 
			swap_ptypes(r->base);
442 
		}
2 7u83 443 
	}
7 7u83 444 
	return;
2 7u83 445 
}
446 
 
447 
 
448 
/*
449 
    LIST CANDIDATES FOR ERROR REPORTING
450 
 
451 
    This routine appends messages listing all the candidates from the list
452 
    p of rank at least rank to the end of the error message err.  No action
453 
    is taken if err is the null error.
454 
*/
455 
 
7 7u83 456 
ERROR
457 
list_candidates(ERROR err, CANDIDATE_LIST *p, unsigned rank)
2 7u83 458 
{
7 7u83 459 
	if (!IS_NULL_err(err)) {
460 
		ERROR err2 = ERR_over_match_viable_list();
461 
		if (!IS_NULL_err(err2)) {
462 
			unsigned m = 0;
463 
			CANDIDATE *q = p->elem;
464 
			unsigned n = p->size;
465 
			err = concat_error(err, err2);
466 
			while (n) {
467 
				CANDIDATE *r = q + (--n);
468 
				if (r->rank >= rank) {
469 
					/* List viable candidates */
470 
					IDENTIFIER bid = r->base;
471 
					DECL_SPEC ds =
472 
					    DEREF_dspec(id_storage(bid));
473 
					if (!(ds & dspec_register)) {
474 
						IDENTIFIER id = r->func;
475 
						if (IS_id_builtin(id)) {
476 
							/* Dump dummy built-in
477 
							 * operators */
478 
							if (do_dump) {
479 
								dump_builtin(id);
480 
							}
481 
						}
482 
						m++;
483 
						err2 = ERR_fail_list_item(m, id, id_loc(id));
484 
						err = concat_error(err, err2);
485 
						ds |= dspec_register;
486 
						COPY_dspec(id_storage(bid), ds);
487 
					}
488 
				}
2 7u83 489 
			}
7 7u83 490 
			if (m) {
491 
				n = p->size;
492 
				while (n) {
493 
					/* Clear marks */
494 
					CANDIDATE *r = q + (--n);
495 
					IDENTIFIER bid = r->base;
496 
					DECL_SPEC ds =
497 
					    DEREF_dspec(id_storage(bid));
498 
					if (ds & dspec_register) {
499 
						ds &= ~dspec_register;
500 
						COPY_dspec(id_storage(bid), ds);
501 
					}
502 
				}
503 
			}
504 
			err = concat_error(err, ERR_fail_list_end(m));
2 7u83 505 
		}
506 
	}
7 7u83 507 
	return (err);
2 7u83 508 
}
509 
 
510 
 
511 
/*
512 
    OVERLOAD MATCHING INFORMATION
513 
 
514 
    These variables are used to store information gained during overload
515 
    resolution.  If match_no_args is nonzero it gives the number of
516 
    candidates which take the right number of arguments, otherwise if it
517 
    is zero it indicates that either there are no such functions or there
518 
    is only one candidate.  Similarly match_no_viable gives the number of
519 
    viable candidates (counting viable templates twice).
520 
*/
521 
 
7 7u83 522 
unsigned match_no_args = 0;
523 
unsigned match_no_viable = 0;
524 
static unsigned viable_templates = 0;
525 
int resolved_kind = KIND_FUNC;
2 7u83 526 
 
527 
 
528 
/*
529 
    IS A CANDIDATE FUNCTION PLAUSIBLE?
530 
 
531 
    A candidate function is plausible for a list of arguments if it accepts
532 
    that number of arguments.  This routine tests whether the candidate r
533 
    is plausible.  It returns the absolute difference between the number
534 
    of arguments and the number of parameters (i.e. zero for a plausible
535 
    candidate).
536 
*/
537 
 
7 7u83 538 
static unsigned
539 
plausible_candidate(CANDIDATE *r, unsigned nargs)
2 7u83 540 
{
7 7u83 541 
	IDENTIFIER id = r->base;
542 
	if (IS_id_builtin(id)) {
543 
		/* Built-in candidates */
544 
		LIST(TYPE) mtypes = DEREF_list(id_builtin_ptypes(id));
545 
		unsigned npars = LENGTH_list(mtypes);
546 
		if (nargs == npars) {
547 
			/* Equal numbers of arguments and parameters */
548 
			return (0);
549 
		} else if (nargs > npars) {
550 
			/* More arguments than parameters */
551 
			return (nargs - npars);
552 
		} else {
553 
			/* Less arguments than parameters */
554 
			return (npars - nargs);
555 
		}
2 7u83 556 
	} else {
7 7u83 557 
		/* Function candidates */
558 
		unsigned npars;
559 
		LIST(TYPE) mtypes;
560 
		TYPE fn = DEREF_type(id_function_etc_type(id));
561 
		while (IS_type_templ(fn)) {
562 
			/* Allow for template functions */
563 
			fn = DEREF_type(type_templ_defn(fn));
564 
		}
565 
		mtypes = DEREF_list(type_func_mtypes(fn));
566 
		npars = LENGTH_list(mtypes);
567 
		if (nargs == npars) {
568 
			/* Equal numbers of arguments and parameters */
569 
			return (0);
570 
		} else if (nargs > npars) {
571 
			/* More arguments than parameters */
572 
			int ell = DEREF_int(type_func_ellipsis(fn));
573 
			if (ell) {
574 
				/* Match with ellipsis */
575 
				return (0);
576 
			}
577 
			return (nargs - npars);
578 
		} else {
579 
			/* Less arguments than parameters */
580 
			unsigned margs = min_no_args(fn);
581 
			if (nargs >= margs) {
582 
				/* Match with default arguments */
583 
				return (0);
584 
			}
585 
			return (margs - nargs);
586 
		}
2 7u83 587 
	}
7 7u83 588 
	/* NOTREACHED */
2 7u83 589 
}
590 
 
591 
 
592 
/*
593 
    INHERITANCE MATCHING FLAG
594 
 
595 
    This flag may be set to true to make the match for the implicit
596 
    this parameter for an inherited function as good as a match for
597 
    a non-inherited function from the point of view of function
598 
    overloading.
599 
*/
600 
 
7 7u83 601 
int match_this = 0;
2 7u83 602 
 
603 
 
604 
/*
605 
    IS A PLAUSIBLE CANDIDATE FUNCTION VIABLE?
606 
 
607 
    A plausible candidate function is viable for a list of arguments if
608 
    there is an implicit conversion sequence for each argument to the
609 
    corresponding parameter type.  This routine tests whether the plausible
610 
    candidate r is viable, building up the corresponding list of conversions.
611 
    It returns the number of arguments for which a sequence exists, plus
612 
    one.
613 
*/
614 
 
7 7u83 615 
static unsigned
616 
viable_candidate(CANDIDATE *r, LIST(EXP) args, TYPE ret)
2 7u83 617 
{
7 7u83 618 
	TYPE rtype;
619 
	int bind = 0;
620 
	unsigned conv;
621 
	unsigned match = 1;
622 
	LIST(TYPE) mtypes;
623 
	IDENTIFIER id = r->base;
624 
	CONVERSION *convs = r->convs;
625 
	HASHID nm = DEREF_hashid(id_name(id));
2 7u83 626 
 
7 7u83 627 
	/* Extract type information */
628 
	if (IS_id_builtin(id)) {
629 
		if (IS_hashid_op(nm)) {
630 
			int op = DEREF_int(hashid_op_lex(nm));
631 
			if (op == lex_assign) {
632 
				bind = 1;
633 
			}
2 7u83 634 
		}
7 7u83 635 
		mtypes = DEREF_list(id_builtin_ptypes(id));
636 
		rtype = DEREF_type(id_builtin_ret(id));
2 7u83 637 
	} else {
7 7u83 638 
		LIST(TYPE) ptypes;
639 
		TYPE fn = DEREF_type(id_function_etc_type(id));
640 
		if (IS_type_templ(fn)) {
641 
			/* Allow for template functions */
642 
			ERROR err = NULL_err;
643 
			if (r->kind == KIND_CONSTR) {
644 
				/* Deal with swapped candidates */
645 
				IDENTIFIER tid;
646 
				EXP a = NULL_exp;
647 
				LIST(EXP) dargs;
648 
				swap_ptypes(id);
649 
				CONS_exp(a, args, dargs);
650 
				tid = deduce_args(id, dargs, 2, 0, 1, &err);
651 
				DESTROY_CONS_exp(destroy, a, args, dargs);
652 
				UNUSED(a);
653 
				if (IS_NULL_id(tid)) {
654 
					swap_ptypes(id);
655 
					return (0);
656 
				}
657 
				swap_ptypes(tid);
658 
				id = tid;
659 
			} else {
660 
				/* Deal with normal candidates */
661 
				id = deduce_args(id, args, 2, 0, 1, &err);
662 
				if (IS_NULL_id(id)) {
663 
					return (0);
664 
				}
665 
			}
666 
			fn = DEREF_type(id_function_etc_type(id));
667 
			if (!IS_type_func(fn)) {
668 
				return (0);
669 
			}
670 
			viable_templates++;
671 
			r->func = id;
672 
			r->base = id;
673 
		}
674 
		mtypes = DEREF_list(type_func_mtypes(fn));
675 
		ptypes = DEREF_list(type_func_ptypes(fn));
676 
		if (IS_hashid_constr(nm)) {
677 
			rtype = DEREF_type(hashid_constr_type(nm));
2 7u83 678 
		} else {
7 7u83 679 
			rtype = DEREF_type(type_func_ret(fn));
2 7u83 680 
		}
7 7u83 681 
		if (!EQ_list(mtypes, ptypes)) {
682 
			/* Member function */
683 
			if (!IS_NULL_list(ptypes)) {
684 
				ptypes = TAIL_list(ptypes);
685 
			}
686 
			if (EQ_list(mtypes, ptypes)) {
687 
				/* Parameter types have been swapped */
688 
				/* EMPTY */
689 
			} else {
690 
				/* Matching implicit this parameter */
691 
				if (match_this) {
692 
					/* Force exact match */
693 
					bind = 2;
694 
				} else {
695 
					IDENTIFIER fid = r->func;
696 
					DECL_SPEC ds =
697 
					    DEREF_dspec(id_storage(fid));
698 
					if ((ds & dspec_inherit) &&
699 
					    !(ds & dspec_alias)) {
700 
						/* Inherited member function */
701 
						bind = 3;
702 
					} else {
703 
						bind = 2;
704 
					}
705 
				}
706 
			}
707 
		}
2 7u83 708 
	}
709 
 
7 7u83 710 
	/* Check for implicit conversion sequences */
711 
	while (!IS_NULL_list(mtypes) && !IS_NULL_list(args)) {
712 
		conv = convs->rank;
713 
		if (conv == CONV_NONE) {
714 
			/* Recalculate if necessary */
715 
			EXP a = DEREF_exp(HEAD_list(args));
716 
			TYPE t = DEREF_type(HEAD_list(mtypes));
717 
			convs->to = t;
718 
			if (IS_NULL_exp(a)) {
719 
				/* A null expression counts as an exact match */
720 
				convs->from = t;
721 
				conv = CONV_EXACT;
722 
			} else {
723 
				/* Calculate conversion sequence */
724 
				TYPE s = DEREF_type(exp_type(a));
725 
				convs->from = s;
726 
				if (IS_NULL_type(ret)) {
727 
					conv = convert_seq(convs, a, bind, 0);
728 
				} else {
729 
					conv =
730 
					    std_convert_seq(convs, a, bind, 0);
731 
				}
732 
				convs->from = s;
733 
				convs->to = t;
734 
			}
2 7u83 735 
		}
7 7u83 736 
		if (conv != CONV_NONE) {
737 
			match++;
738 
		}
739 
		convs->rank = conv;
740 
		convs++;
741 
		args = TAIL_list(args);
742 
		mtypes = TAIL_list(mtypes);
743 
		bind = 0;
2 7u83 744 
	}
745 
 
7 7u83 746 
	/* Remaining arguments match with ellipsis */
747 
	while (!IS_NULL_list(args)) {
748 
		convs->rank = CONV_ELLIPSIS;
749 
		convs++;
750 
		match++;
751 
		args = TAIL_list(args);
752 
	}
2 7u83 753 
 
7 7u83 754 
	/* Check for return conversion sequences */
755 
	if (!IS_NULL_type(ret)) {
756 
		conv = convs->rank;
757 
		if (conv == CONV_NONE) {
758 
			convs->to = ret;
759 
			convs->from = rtype;
760 
			conv = std_convert_seq(convs, NULL_exp, 0, 0);
761 
			convs->from = rtype;
762 
			convs->to = ret;
763 
		}
764 
	} else {
765 
		conv = CONV_ELLIPSIS;
2 7u83 766 
	}
7 7u83 767 
	convs->rank = conv;
768 
	return (match);
2 7u83 769 
}
770 
 
771 
 
772 
/*
773 
    COMPARE TWO FUNCTIONS
774 
 
775 
    This routine compares the candidate functions rid and sid to determine
776 
    which is better under the template specialisation rules.  It returns
777 
    1 if rid is better than sid, 2 if sid is better than rid, and 0 otherwise.
778 
*/
779 
 
7 7u83 780 
static int
781 
compare_funcs(IDENTIFIER rid, IDENTIFIER sid)
2 7u83 782 
{
7 7u83 783 
	int res = 0;
784 
	if (EQ_id(rid, sid)) {
785 
		/* Select first if equal */
786 
		res = 1;
2 7u83 787 
	} else {
7 7u83 788 
		if (IS_NULL_id(rid)) {
789 
			res = 2;
790 
		} else if (IS_NULL_id(sid)) {
791 
			res = 1;
2 7u83 792 
		} else {
7 7u83 793 
			rid = find_template(rid, 0);
794 
			sid = find_template(sid, 0);
795 
			if (!IS_NULL_id(rid)) {
796 
				if (!IS_NULL_id(sid)) {
797 
					/* Both template functions */
798 
					res = compare_specs(rid, sid);
799 
				} else {
800 
					/* rid is a template function */
801 
					res = 2;
802 
				}
803 
			} else if (!IS_NULL_id(sid)) {
804 
				/* sid is a template function */
805 
				res = 1;
806 
			}
2 7u83 807 
		}
808 
	}
7 7u83 809 
	return (res);
2 7u83 810 
}
811 
 
812 
 
813 
/*
814 
    COMPARE TWO CANDIDATE FUNCTIONS
815 
 
816 
    This routine compares the candidate functions r and s for the argument
817 
    list args and return type ret.  It returns 1 if r is better than s, 2 if
818 
    s is better than r, and some other value otherwise.  Better in this
819 
    sense means at least as good for all arguments, plus strictly better
820 
    in at least one argument or the return type.
821 
*/
822 
 
7 7u83 823 
static int
824 
compare_candidates(CANDIDATE *r, CANDIDATE *s, LIST(EXP) args, TYPE ret)
2 7u83 825 
{
7 7u83 826 
	int res = 0;
827 
	CONVERSION *cr = r->convs;
828 
	CONVERSION *cs = s->convs;
2 7u83 829 
 
7 7u83 830 
	/* Compare each argument in turn */
831 
	while (!IS_NULL_list(args)) {
832 
		int cmp = compare_seq(cr, cs);
833 
		if (cmp == 1) {
834 
			/* r better in this argument */
835 
			if (res == 2) {
836 
				return (0);
837 
			}
838 
			res = 1;
839 
		} else if (cmp == 2) {
840 
			/* s better in this argument */
841 
			if (res == 1) {
842 
				return (0);
843 
			}
844 
			res = 2;
845 
		}
846 
		cr++;
847 
		cs++;
848 
		args = TAIL_list(args);
2 7u83 849 
	}
850 
 
7 7u83 851 
	/* Tie breakers */
852 
	if (res == 0) {
853 
		res = compare_funcs(r->base, s->base);
854 
		if (res == 0 && !IS_NULL_type(ret)) {
855 
			/* Resolve on return type */
856 
			res = compare_seq(cr, cs);
857 
		}
2 7u83 858 
	}
7 7u83 859 
	return (res);
2 7u83 860 
}
861 
 
862 
 
863 
/*
864 
    OVERLOADED FUNCTION RESOLUTION
865 
 
866 
    This routine selects the best match from the list of overloaded function
867 
    given by p based on the argument list args and the return type ret (which
868 
    may be the null type).  The list of candidate functions will not be empty.
869 
    If replay is true then the conversion sequences have already been
870 
    calculated and only the final tournament to select the best viable
871 
    candidate is necessary.
872 
*/
873 
 
7 7u83 874 
CANDIDATE *
875 
resolve_overload(CANDIDATE_LIST *p, LIST(EXP) args, TYPE ret, int replay)
2 7u83 876 
{
7 7u83 877 
	unsigned round;
878 
	unsigned match = 0;
879 
	CANDIDATE *q = p->elem;
880 
	CANDIDATE *best = q;
881 
	CANDIDATE *beat = NULL;
882 
	unsigned i, n = p->size;
2 7u83 883 
 
7 7u83 884 
	if (!replay) {
885 
		/* Eliminate all non-viable candidates */
886 
		unsigned nargs;
887 
		unsigned margs;
888 
		unsigned mconvs;
889 
		unsigned best_margs;
890 
		unsigned nconvs = p->nconvs;
891 
		CONVERSION *convs = p->convs;
2 7u83 892 
 
7 7u83 893 
		/* Check for plausible candidates */
894 
		nargs = LENGTH_list(args);
895 
		best_margs = nargs + 1;
896 
		for (i = 0; i < n; i++) {
897 
			CANDIDATE *r = q + i;
898 
			if (r->rank != RANK_IGNORE) {
899 
				margs = plausible_candidate(r, nargs);
900 
				if (margs == 0) {
901 
					/* Plausible candidate */
902 
					r->rank = RANK_ARGS;
903 
					best = r;
904 
					match++;
905 
				} else if (match == 0 && margs <= best_margs) {
906 
					/* Most nearly plausible candidate so
907 
					 * far */
908 
					best_margs = margs;
909 
					best = r;
910 
				}
911 
			}
2 7u83 912 
		}
7 7u83 913 
		match_no_args = match;
914 
		if (match == 0) {
915 
			/* No plausible candidates - return most nearly
916 
			 * plausible */
917 
			match_no_viable = 0;
918 
			return (best);
919 
		}
2 7u83 920 
 
7 7u83 921 
		/* Allocate room for conversion ranks */
922 
		nargs++;
923 
		mconvs = match * nargs;
924 
		if (mconvs >= nconvs) {
925 
			nconvs = mconvs + 200;
926 
			convs = xrealloc_nof(convs, CONVERSION, nconvs);
927 
			p->nconvs = nconvs;
928 
			p->convs = convs;
929 
		}
2 7u83 930 
 
7 7u83 931 
		/* Check for viable candidates */
932 
		match = 0;
933 
		best_margs = 0;
934 
		viable_templates = 0;
935 
		for (i = 0; i < n; i++) {
936 
			CANDIDATE *r = q + i;
937 
			if (r->rank == RANK_ARGS) {
938 
				/* Only check plausible candidates */
939 
				unsigned m;
940 
				r->convs = convs;
941 
				for (m = 0; m < nargs; m++) {
942 
					convs->rank = CONV_NONE;
943 
					convs++;
944 
				}
945 
				margs = viable_candidate(r, args, ret);
946 
				if (margs == nargs) {
947 
					/* Viable candidate */
948 
					r->rank = RANK_VIABLE;
949 
					best = r;
950 
					match++;
951 
				} else if (match == 0 && margs >= best_margs) {
952 
					/* Most nearly viable candidate so
953 
					 * far */
954 
					best_margs = margs;
955 
					best = r;
956 
				}
957 
			}
2 7u83 958 
		}
7 7u83 959 
		match_no_viable = match + viable_templates;
960 
		if (match == 0) {
961 
			/* No viable candidates - return most nearly viable */
962 
			return (best);
2 7u83 963 
		}
7 7u83 964 
		if (match == 1) {
965 
			/* Exactly one viable candidate - must be the winner */
966 
			best->rank = RANK_BEST;
967 
			return (best);
968 
		}
969 
	} else {
970 
		/* Replay - pick a viable candidate */
971 
		for (i = 0; i < n; i++) {
972 
			CANDIDATE *r = q + i;
973 
			if (r->rank >= RANK_VIABLE) {
974 
				r->rank = RANK_VIABLE;
975 
				best = r;
976 
				match++;
977 
			}
978 
		}
2 7u83 979 
	}
980 
 
7 7u83 981 
	/* Play tournament among viable candidates */
982 
	round = RANK_VIABLE;
983 
	while (match > 1) {
984 
		CANDIDATE *s = NULL;
985 
		match = 0;
986 
		for (i = 0; i < n; i++) {
987 
			CANDIDATE *r = q + i;
988 
			if (r->rank == round) {
989 
				/* Only check those through to this round */
990 
				if (s == NULL) {
991 
					/* r is first candidate in contest */
992 
					s = r;
993 
				} else {
994 
					/* r is second candidate in contest */
995 
					int cmp =
996 
					    compare_candidates(s, r, args, ret);
997 
					if (cmp == 1) {
998 
						/* s wins */
999 
						s->rank = round + 1;
1000 
						r->rank = RANK_VIABLE;
1001 
						best = s;
1002 
						beat = r;
1003 
						match++;
1004 
					} else if (cmp == 2) {
1005 
						/* r wins */
1006 
						r->rank = round + 1;
1007 
						s->rank = RANK_VIABLE;
1008 
						best = r;
1009 
						beat = s;
1010 
						match++;
1011 
					} else {
1012 
						/* Draw - both eliminated */
1013 
						s->rank = RANK_VIABLE;
1014 
						r->rank = RANK_VIABLE;
1015 
					}
1016 
					s = NULL;
1017 
				}
1018 
			}
2 7u83 1019 
		}
7 7u83 1020 
		if (s != NULL) {
1021 
			/* Bye - s goes through */
1022 
			s->rank = round + 1;
1023 
			best = s;
1024 
			match++;
1025 
		}
1026 
		round++;
2 7u83 1027 
	}
1028 
 
7 7u83 1029 
	/* Examine the tournament winner */
1030 
	if (match == 1) {
1031 
		/* Tournament winner must now beat all the others */
1032 
		best->rank = RANK_BEST;
1033 
		for (i = 0; i < n; i++) {
1034 
			CANDIDATE *r = q + i;
1035 
			if (r->rank >= RANK_VIABLE) {
1036 
				if (r == best) {
1037 
					/* Don't compare against self */
1038 
					/* EMPTY */
1039 
				} else if (r == beat) {
1040 
					/* This has already been beaten */
1041 
					/* EMPTY */
1042 
				} else {
1043 
					int cmp =
1044 
					    compare_candidates(best, r, args,
1045 
							       ret);
1046 
					if (cmp != 1) {
1047 
						/* r is at least as good as
1048 
						 * best */
1049 
						best->rank = RANK_VIABLE;
1050 
						break;
1051 
					}
1052 
				}
1053 
			}
2 7u83 1054 
		}
7 7u83 1055 
	} else {
1056 
		/* No clear tournament winner */
1057 
		if (best->rank >= RANK_VIABLE) {
1058 
			best->rank = RANK_VIABLE;
1059 
		}
2 7u83 1060 
	}
7 7u83 1061 
	return (best);
2 7u83 1062 
}
1063 
 
1064 
 
1065 
/*
1066 
    FIND A LIST OF POSSIBLE TYPE VALUES
1067 
 
1068 
    This routine constructs a list of the possible resolutions for the
1069 
    target dependent type t or its promotion.  In the latter case prom
1070 
    is set to true.  If neither t or its promotion is target dependent
1071 
    then the empty list is returned.
1072 
*/
1073 
 
7 7u83 1074 
static LIST(TYPE)
1075 
possible_types(TYPE t, int *prom)
2 7u83 1076 
{
7 7u83 1077 
	LIST(TYPE) r = NULL_list(TYPE);
1078 
	switch (TAG_type(t)) {
1079 
	case type_integer_tag: {
1080 
		/* Integral type */
1081 
		INT_TYPE it = DEREF_itype(type_integer_rep(t));
1082 
		r = DEREF_list(itype_cases(it));
1083 
		if (LENGTH_list(r) == 1) {
1084 
			/* Type is not target dependent */
1085 
			t = DEREF_type(itype_prom(it));
1086 
			it = DEREF_itype(type_integer_rep(t));
1087 
			r = DEREF_list(itype_cases(it));
1088 
			if (LENGTH_list(r) == 1) {
1089 
				/* Promoted type is not target dependent */
1090 
				r = NULL_list(TYPE);
1091 
			} else {
1092 
				*prom = 1;
1093 
			}
2 7u83 1094 
		}
7 7u83 1095 
		break;
2 7u83 1096 
	}
7 7u83 1097 
	case type_bitfield_tag:
1098 
	case type_enumerate_tag:
1099 
		/* Enumeration and bitfield types */
1100 
		t = promote_type(t);
1101 
		r = possible_types(t, prom);
1102 
		*prom = 1;
1103 
		break;
2 7u83 1104 
	}
7 7u83 1105 
	return (r);
2 7u83 1106 
}
1107 
 
1108 
 
1109 
/*
1110 
    CHECK FOR TARGET DEPENDENT OVERLOADED FUNCTION RESOLUTIONS
1111 
 
1112 
    This routine is called when an ambiguous overload resolution is
1113 
    detected to determine which of the viable candidates to proceed with.
1114 
    The parameters are as in resolve_overload.
1115 
*/
1116 
 
7 7u83 1117 
CANDIDATE *
1118 
resolve_ambiguous(CANDIDATE_LIST *p, LIST(EXP) args, TYPE ret, int depth)
2 7u83 1119 
{
7 7u83 1120 
    CANDIDATE *q = p->elem;
1121 
    CANDIDATE *best = q;
1122 
    unsigned i, n = p->size;
1123 
    unsigned overall_rank = RANK_VIABLE;
2 7u83 1124 
 
1125 
    /* Check for arguments of error type */
7 7u83 1126 
    if (depth == 0) {
1127 
	LIST(EXP) a = args;
1128 
	while (!IS_NULL_list(a)) {
1129 
	    EXP e = DEREF_exp(HEAD_list(a));
1130 
	    if (!IS_NULL_exp(e)) {
1131 
		TYPE t = DEREF_type(exp_type(e));
1132 
		if (IS_type_error(t)) {
2 7u83 1133 
		    /* Error types are ignored */
7 7u83 1134 
		    overall_rank = RANK_BEST;
1135 
		    break;
2 7u83 1136 
		}
1137 
	    }
7 7u83 1138 
	    a = TAIL_list(a);
2 7u83 1139 
	}
1140 
    }
1141 
 
1142 
    /* Check for target dependent resolutions */
7 7u83 1143 
    if (overall_rank != RANK_BEST) {
1144 
	unsigned na = 0;
1145 
	LIST(EXP) a = args;
1146 
	EXP saved[100];
1147 
	EXP *save = saved;
1148 
	if (n >= 100) {
1149 
		save = xmalloc_nof(EXP, n);
1150 
	}
1151 
	for (i = 0; i < n; i++)save[i] = NULL_exp;
1152 
	while (!IS_NULL_list(a)) {
1153 
	    EXP e = DEREF_exp(HEAD_list(a));
1154 
	    if (!IS_NULL_exp(e)) {
1155 
		int prom = 0;
1156 
		int have_match = 0;
1157 
		TYPE t = DEREF_type(exp_type(e));
1158 
		LIST(TYPE) pt = possible_types(t, &prom);
1159 
		if (!IS_NULL_list(pt)) {
1160 
		    CANDIDATE *r;
1161 
		    LIST(TYPE) ps = pt;
1162 
		    unsigned new_rank = RANK_TARGET;
1163 
		    if (prom) {
2 7u83 1164 
			/* Only use promoted types if no exact match */
7 7u83 1165 
			for (i = 0; i < n; i++) {
1166 
			    r = q + i;
1167 
			    if (r->rank >= RANK_VIABLE) {
1168 
				if (r->convs[na].rank == CONV_EXACT) {
1169 
				    ps = NULL_list(TYPE);
1170 
				    new_rank = overall_rank;
1171 
				    break;
2 7u83 1172 
				}
1173 
			    }
1174 
			}
1175 
		    }
7 7u83 1176 
		    overall_rank = new_rank;
1177 
		    while (!IS_NULL_list(ps)) {
1178 
			TYPE u = t;
1179 
			TYPE s = DEREF_type(HEAD_list(ps));
1180 
			COPY_type(exp_type(e), s);
1181 
			for (i = 0; i < n; i++) {
1182 
			    r = q + i;
1183 
			    if (r->rank >= RANK_VIABLE) {
2 7u83 1184 
				/* Recalculate conversions */
7 7u83 1185 
				r->convs[na].rank = CONV_NONE;
1186 
				IGNORE viable_candidate(r, args, ret);
1187 
				r->rank = RANK_VIABLE;
2 7u83 1188 
			    }
1189 
			}
7 7u83 1190 
			r = resolve_overload(p, args, ret, 1);
1191 
			if (r->rank == RANK_VIABLE) {
2 7u83 1192 
			    /* Check further arguments */
7 7u83 1193 
			    for (i = 0; i < n; i++) {
2 7u83 1194 
				/* Save conditions */
7 7u83 1195 
				save[i] = q[i].cond;
1196 
				q[i].cond = NULL_exp;
2 7u83 1197 
			    }
7 7u83 1198 
			    r = resolve_ambiguous(p, args, ret, 1);
1199 
			    for (i = 0; i < n; i++) {
2 7u83 1200 
				/* Restore conditions */
7 7u83 1201 
				EXP c = q[i].cond;
1202 
				q[i].cond = save[i];
1203 
				save[i] = c;
2 7u83 1204 
			    }
1205 
			}
7 7u83 1206 
			COPY_type(exp_type(e), t);
1207 
			if (r->rank >= RANK_TARGET) {
2 7u83 1208 
			    /* Create condition for resolution */
7 7u83 1209 
			    if (prom) {
1210 
				    u = promote_type(u);
1211 
			    }
1212 
			    for (i = 0; i < n; i++) {
1213 
				r = q + i;
1214 
				if (r->rank >= RANK_TARGET) {
1215 
				    EXP c1, c2;
1216 
				    TYPE ti = type_sint;
1217 
				    TYPE tb = type_bool;
1218 
				    NTEST nt = ntest_eq;
1219 
				    MAKE_exp_rtti_no(ti, u, c1);
1220 
				    MAKE_exp_rtti_no(ti, s, c2);
1221 
				    MAKE_exp_compare(tb, nt, c1, c2, c1);
1222 
				    c2 = save[i];
1223 
				    if (!IS_NULL_exp(c2)) {
1224 
					MAKE_exp_log_and(tb, c1, c2, c1);
2 7u83 1225 
				    }
7 7u83 1226 
				    c2 = r->cond;
1227 
				    if (!IS_NULL_exp(c2)) {
1228 
					MAKE_exp_log_or(tb, c1, c2, c1);
2 7u83 1229 
				    }
7 7u83 1230 
				    r->cond = c1;
1231 
				    have_match = 1;
2 7u83 1232 
				}
7 7u83 1233 
				save[i] = NULL_exp;
2 7u83 1234 
			    }
7 7u83 1235 
			} else if (option(OPT_overload_strict)) {
2 7u83 1236 
			    /* Don't have match in all cases */
7 7u83 1237 
			    have_match = 0;
1238 
			    break;
2 7u83 1239 
			}
7 7u83 1240 
			ps = TAIL_list(ps);
2 7u83 1241 
		    }
7 7u83 1242 
		    if (!have_match) {
1243 
			overall_rank = RANK_VIABLE;
1244 
			break;
2 7u83 1245 
		    }
1246 
		}
1247 
	    }
7 7u83 1248 
	    a = TAIL_list(a);
1249 
	    na++;
2 7u83 1250 
	}
7 7u83 1251 
	if (save != saved) {
1252 
		xfree_nof(save);
1253 
	}
2 7u83 1254 
    }
1255 
 
1256 
    /* Select last viable candidate */
7 7u83 1257 
    for (i = 0; i < n; i++) {
1258 
	CANDIDATE *r = q + i;
1259 
	if (r->rank >= RANK_VIABLE) {
1260 
	    if (overall_rank == RANK_TARGET) {
1261 
		if (IS_NULL_exp(r->cond)) {
1262 
		    if (depth == 0)r->rank = RANK_ARGS;
2 7u83 1263 
		} else {
7 7u83 1264 
		    r->rank = overall_rank;
1265 
		    best = r;
2 7u83 1266 
		}
1267 
	    } else {
7 7u83 1268 
		r->rank = overall_rank;
1269 
		best = r;
2 7u83 1270 
	    }
1271 
	}
1272 
    }
7 7u83 1273 
    return (best);
2 7u83 1274 
}
1275 
 
1276 
 
1277 
/*
1278 
    LIST OF ALL AMBIGUOUS OVERLOADED FUNCTIONS
1279 
 
1280 
    This list is used to hold all the dummy tokenised functions constructed
1281 
    to represent target dependent overload resolutions.  The functions are
1282 
    determined by the list of candidates, the list of argument types and
1283 
    the qualifier used.
1284 
*/
1285 
 
1286 
typedef struct ambig_func_tag {
7 7u83 1287 
	IDENTIFIER id;
1288 
	LIST(IDENTIFIER) funcs;
1289 
	LIST(TYPE) types;
1290 
	QUALIFIER qual;
1291 
	struct ambig_func_tag *next;
1292 
} AMBIG_FUNCTION;
2 7u83 1293 
 
7 7u83 1294 
static AMBIG_FUNCTION *all_ambig_funcs = NULL;
2 7u83 1295 
 
1296 
 
1297 
/*
1298 
    FIND A PREVIOUS AMBIGUOUS OVERLOADED FUNCTION
1299 
 
1300 
    This routine searches the list of all ambiguous overloaded functions
1301 
    for one which candidate functions p, argument types q and qualifier
1302 
    qual.
1303 
*/
1304 
 
7 7u83 1305 
static IDENTIFIER
1306 
previous_ambig_func(LIST(IDENTIFIER) p, LIST(TYPE) q, QUALIFIER qual)
2 7u83 1307 
{
7 7u83 1308 
	AMBIG_FUNCTION *f = all_ambig_funcs;
1309 
	if (f) {
1310 
		unsigned np = LENGTH_list(p);
1311 
		unsigned nq = LENGTH_list(q);
1312 
		while (f != NULL) {
1313 
			if (f->qual == qual) {
1314 
				int ok = 1;
1315 
				LIST(IDENTIFIER) pf = f->funcs;
1316 
				LIST(TYPE) qf = f->types;
1317 
				if (LENGTH_list(pf) == np) {
1318 
					LIST(IDENTIFIER) pg = p;
1319 
					while (!IS_NULL_list(pg)) {
1320 
						IDENTIFIER nf =
1321 
						    DEREF_id(HEAD_list(pf));
1322 
						IDENTIFIER ng =
1323 
						    DEREF_id(HEAD_list(pg));
1324 
						if (!EQ_id(nf, ng)) {
1325 
							ok = 0;
1326 
							break;
1327 
						}
1328 
						pf = TAIL_list(pf);
1329 
						pg = TAIL_list(pg);
1330 
					}
1331 
				}
1332 
				if (ok && LENGTH_list(qf) == nq) {
1333 
					LIST(TYPE) qg = q;
1334 
					while (!IS_NULL_list(qg)) {
1335 
						TYPE tf =
1336 
						    DEREF_type(HEAD_list(qf));
1337 
						TYPE tg =
1338 
						    DEREF_type(HEAD_list(qg));
1339 
						if (!eq_type(tf, tg)) {
1340 
							ok = 0;
1341 
							break;
1342 
						}
1343 
						qf = TAIL_list(qf);
1344 
						qg = TAIL_list(qg);
1345 
					}
1346 
				}
1347 
				if (ok) {
1348 
					return (f->id);
1349 
				}
2 7u83 1350 
			}
7 7u83 1351 
			f = f->next;
2 7u83 1352 
		}
1353 
	}
7 7u83 1354 
	return (NULL_id);
2 7u83 1355 
}
1356 
 
1357 
 
1358 
/*
1359 
    CONSTRUCT AN AMBIGUOUS OVERLOADED FUNCTION
1360 
 
1361 
    This routine constructs a dummy tokenised function to represent the
1362 
    target dependent overload resolution given by the candidates p for
1363 
    the function call 'id ( args )' detected by the previous call to
1364 
    resolve_ambiguous.  Any errors arising are added to err.
1365 
*/
1366 
 
7 7u83 1367 
IDENTIFIER
1368 
make_ambig_func(CANDIDATE_LIST *p, IDENTIFIER id, LIST(EXP) args,
1369 
		QUALIFIER qual, ERROR *err)
2 7u83 1370 
{
7 7u83 1371 
	EXP res;
1372 
	TYPE fn;
1373 
	TOKEN tok;
1374 
	TYPE form;
1375 
	MEMBER mem;
1376 
	DECL_SPEC ds;
1377 
	IDENTIFIER tid;
1378 
	LIST(TYPE) mt;
1379 
	AMBIG_FUNCTION *all;
1380 
	TYPE ret = NULL_type;
1381 
	TYPE et = type_error;
1382 
	CANDIDATE *q = p->elem;
1383 
	unsigned i, n = p->size;
1384 
	NAMESPACE ns = crt_namespace;
1385 
	QUALIFIER cq = crt_id_qualifier;
1386 
	int tq = crt_templ_qualifier;
1387 
	int td = have_type_declaration;
1388 
	unsigned tag = id_function_tag;
1389 
	HASHID nm = DEREF_hashid(id_name(id));
2 7u83 1390 
 
7 7u83 1391 
	/* List of viable candidates */
1392 
	LIST(EXP) conds = NULL_list(EXP);
1393 
	LIST(TYPE) types = NULL_list(TYPE);
1394 
	LIST(IDENTIFIER) funcs = NULL_list(IDENTIFIER);
2 7u83 1395 
 
7 7u83 1396 
	/* Check function return types */
1397 
	for (i = 0; i < n; i++) {
1398 
		CANDIDATE *r = q + i;
1399 
		if (r->rank >= RANK_VIABLE) {
1400 
			int suspect = 0;
1401 
			TYPE ta = NULL_type;
1402 
			IDENTIFIER fid = r->base;
1403 
			switch (TAG_id(fid)) {
1404 
			case id_builtin_tag: {
1405 
				ta = DEREF_type(id_builtin_ret(fid));
1406 
				break;
2 7u83 1407 
			}
7 7u83 1408 
			case id_function_tag: {
1409 
				TYPE fa = DEREF_type(id_function_type(fid));
1410 
				if (IS_type_func(fa)) {
1411 
					ta = DEREF_type(type_func_ret(fa));
1412 
				}
1413 
				break;
2 7u83 1414 
			}
7 7u83 1415 
			case id_mem_func_tag: {
1416 
				TYPE fa = DEREF_type(id_mem_func_type(fid));
1417 
				if (IS_type_func(fa)) {
1418 
					HASHID fnm = DEREF_hashid(id_name(fid));
1419 
					mt = DEREF_list(type_func_mtypes(fa));
1420 
					et = DEREF_type(HEAD_list(mt));
1421 
					if (IS_hashid_constr(fnm)) {
1422 
						ta = DEREF_type(hashid_constr_type(fnm));
1423 
					} else {
1424 
						ta = DEREF_type(type_func_ret(fa));
1425 
						tag = id_mem_func_tag;
1426 
					}
1427 
				}
1428 
				break;
1429 
			}
1430 
			case id_stat_mem_func_tag: {
1431 
				TYPE fa =
1432 
				    DEREF_type(id_stat_mem_func_type(fid));
1433 
				if (IS_type_func(fa)) {
1434 
					mt = DEREF_list(type_func_mtypes(fa));
1435 
					et = DEREF_type(HEAD_list(mt));
1436 
					ta = DEREF_type(type_func_ret(fa));
1437 
					if (tag != id_mem_func_tag) {
1438 
						tag = id_stat_mem_func_tag;
1439 
					}
1440 
				}
1441 
				break;
1442 
			}
1443 
			}
1444 
			ret = common_type(ret, ta, &suspect);
1445 
			if (suspect) {
1446 
				ret = NULL_type;
1447 
			}
1448 
			CONS_exp(r->cond, conds, conds);
1449 
			CONS_id(fid, funcs, funcs);
2 7u83 1450 
		}
1451 
	}
7 7u83 1452 
	if (IS_NULL_type(ret)) {
1453 
		/* Couldn't bring return types to common type */
1454 
		ERROR err2 = ERR_over_match_best_common();
1455 
		add_error(err, err2);
1456 
		ret = type_error;
1457 
	}
1458 
	if (err != KILL_err) {
1459 
		*err = list_candidates(*err, p, RANK_VIABLE);
1460 
	}
2 7u83 1461 
 
7 7u83 1462 
	/* Create list of argument types */
1463 
	while (!IS_NULL_list(args)) {
1464 
		TYPE t;
1465 
		EXP e = DEREF_exp(HEAD_list(args));
1466 
		if (IS_NULL_exp(e)) {
1467 
			t = et;
1468 
			et = type_error;
1469 
		} else {
1470 
			t = DEREF_type(exp_type(e));
1471 
			if (IS_type_bitfield(t)) {
1472 
				t = promote_type(t);
1473 
			} else {
1474 
				CV_SPEC cv = DEREF_cv(type_qual(t));
1475 
				if (cv & cv_lvalue) {
1476 
					MAKE_type_ref(cv_none, t, t);
1477 
				}
1478 
			}
2 7u83 1479 
		}
7 7u83 1480 
		CONS_type(t, types, types);
1481 
		args = TAIL_list(args);
2 7u83 1482 
	}
7 7u83 1483 
	types = REVERSE_list(types);
2 7u83 1484 
 
7 7u83 1485 
	/* Check for previous instance */
1486 
	tid = previous_ambig_func(funcs, types, qual);
1487 
	if (!IS_NULL_id(tid)) {
1488 
		DESTROY_list(funcs, SIZE_id);
1489 
		DESTROY_list(types, SIZE_type);
1490 
		free_exp_list(conds, 1);
1491 
		return (tid);
1492 
	}
2 7u83 1493 
 
7 7u83 1494 
	/* Create new instance */
1495 
	all = xmalloc_one(AMBIG_FUNCTION);
1496 
	all->id = NULL_id;
1497 
	all->funcs = funcs;
1498 
	all->types = types;
1499 
	all->qual = qual;
1500 
	all->next = all_ambig_funcs;
1501 
	all_ambig_funcs = all;
2 7u83 1502 
 
7 7u83 1503 
	/* Scan through argument types */
1504 
	crt_id_qualifier = qual_none;
1505 
	crt_templ_qualifier = 0;
1506 
	have_type_declaration = TYPE_DECL_NONE;
1507 
	decl_loc = crt_loc;
1508 
	begin_param(id);
1509 
	mt = types;
1510 
	while (!IS_NULL_list(mt)) {
1511 
		HASHID pnm = lookup_anon();
1512 
		IDENTIFIER pid = DEREF_id(hashid_id(pnm));
1513 
		TYPE t = DEREF_type(HEAD_list(mt));
1514 
		pid = make_param_decl(dspec_none, t, pid, CONTEXT_PARAMETER);
1515 
		init_param(pid, NULL_exp);
1516 
		mt = TAIL_list(mt);
1517 
	}
1518 
	fn = make_func_type(ret, FUNC_NONE, cv_none, empty_type_set);
1519 
	if (tag != id_function_tag) {
1520 
		mt = DEREF_list(type_func_ptypes(fn));
1521 
		mt = TAIL_list(mt);
1522 
		COPY_list(type_func_ptypes(fn), mt);
1523 
	}
1524 
	end_param();
2 7u83 1525 
 
7 7u83 1526 
	/* Create a function identifier */
1527 
	ds = (dspec_static | dspec_token | dspec_reserve);
1528 
	MAKE_id_function_etc(tag, nm, ds, ns, crt_loc, fn, NULL_id, id);
2 7u83 1529 
 
7 7u83 1530 
	/* Create token identifier */
1531 
	ns = token_namespace;
1532 
	nm = lookup_anon();
1533 
	mem = search_member(ns, nm, 1);
1534 
	MAKE_tok_func(fn, tok);
1535 
	MAKE_id_token(nm, ds, ns, crt_loc, tok, id, tid);
1536 
	MAKE_type_token(cv_none, tid, NULL_list(TOKEN), form);
1537 
	COPY_type(id_function_etc_form(id), form);
1538 
	set_member(mem, tid);
1539 
	tok = func_proc_token(tok);
2 7u83 1540 
 
7 7u83 1541 
	/* Define token */
1542 
	res = install_error(&crt_loc, ERR_over_match_best_install());
1543 
	while (!IS_NULL_list(funcs)) {
1544 
		EXP c, f;
1545 
		LIST(EXP) fargs = NULL_list(EXP);
1546 
		LIST(IDENTIFIER) pids = DEREF_list(tok_proc_bids(tok));
1547 
		IDENTIFIER fid = DEREF_id(HEAD_list(funcs));
1548 
		DESTROY_CONS_exp(destroy, c, conds, conds);
1549 
		while (!IS_NULL_list(pids)) {
1550 
			/* Build up argument list */
1551 
			TYPE t;
1552 
			int prom = 0;
1553 
			LIST(TYPE) pt;
1554 
			IDENTIFIER pid = DEREF_id(HEAD_list(pids));
1555 
			EXP e = apply_exp_token(pid, NULL_list(TOKEN), 0);
1556 
			e = convert_reference(e, REF_NORMAL);
1557 
			t = DEREF_type(exp_type(e));
1558 
			pt = possible_types(t, &prom);
1559 
			if (!IS_NULL_list(pt)) {
1560 
				/* Mark target dependent arguments */
1561 
				MAKE_exp_paren(t, e, e);
1562 
			}
1563 
			CONS_exp(e, fargs, fargs);
1564 
			pids = TAIL_list(pids);
1565 
		}
1566 
		fargs = REVERSE_list(fargs);
1567 
		if (IS_id_builtin(fid)) {
1568 
			f = apply_builtin(fid, fargs);
1569 
		} else {
1570 
			HASHID fnm = DEREF_hashid(id_name(fid));
1571 
			use_func_id(fid, 1, 0);
1572 
			if (IS_hashid_constr(fnm)) {
1573 
				f = apply_constr(fid, fargs);
1574 
			} else {
1575 
				f = apply_func_id(fid, qual, NULL_graph, fargs);
1576 
			}
1577 
		}
1578 
		if (!IS_type_top_etc(ret)) {
1579 
			/* Convert to common return type */
1580 
			ERROR err2 = NULL_err;
1581 
			f = convert_reference(f, REF_ASSIGN);
1582 
			f = cast_exp(ret, f, &err2, CAST_IMPLICIT);
1583 
			if (!IS_NULL_err(err2)) {
1584 
				report(crt_loc, err2);
1585 
			}
1586 
		}
1587 
		if (IS_NULL_exp(res)) {
1588 
			free_exp(c, 1);
1589 
			res = f;
1590 
		} else {
1591 
			MAKE_exp_hash_if (ret, c, f, res, res);
1592 
		}
1593 
		funcs = TAIL_list(funcs);
2 7u83 1594 
	}
7 7u83 1595 
	IGNORE define_exp_token(tid, res, 1);
2 7u83 1596 
 
7 7u83 1597 
	/* Restore previous state */
1598 
	have_type_declaration = td;
1599 
	crt_templ_qualifier = tq;
1600 
	crt_id_qualifier = cq;
1601 
	all->id = id;
1602 
	return (id);
2 7u83 1603 
}
1604 
 
1605 
 
1606 
/*
1607 
    IS AN IDENTIFIER A FUNCTION TEMPLATE?
1608 
 
1609 
    This routine returns true if id is a function template.  In this case
1610 
    overload resolution is always done even if id is not overloaded.
1611 
*/
1612 
 
7 7u83 1613 
static int
1614 
is_template_func(IDENTIFIER id)
2 7u83 1615 
{
7 7u83 1616 
	if (IS_id_function_etc(id)) {
1617 
		TYPE fn = DEREF_type(id_function_etc_type(id));
1618 
		if (IS_type_templ(fn)) {
1619 
			return (1);
1620 
		}
1621 
	}
1622 
	return (0);
2 7u83 1623 
}
1624 
 
1625 
 
1626 
/*
1627 
    RESOLVE AN OVERLOADED FUNCTION CALL
1628 
 
1629 
    This routine resolves the overloaded function call 'id ( args )' where
1630 
    id is an identifier expression.  dep is true when id is a simple
1631 
    unqualified function name.  It returns the identifier for id which
1632 
    provides the best match for the given arguments.  For ambiguities the
1633 
    identifier returned is the first of the viable functions to be declared
1634 
    (this is a side effect of the algorithm in resolve_overload and the
1635 
    way in which overloaded functions are represented).
1636 
*/
1637 
 
7 7u83 1638 
IDENTIFIER
1639 
resolve_call(IDENTIFIER id, LIST(EXP) args, QUALIFIER qual, int dep)
2 7u83 1640 
{
7 7u83 1641 
	/* Build up candidate list */
1642 
	unsigned sz;
1643 
	IDENTIFIER fid = id;
1644 
	CANDIDATE_LIST *p = &candidates;
1645 
	p->size = 0;
1646 
	if (dep) {
1647 
		/* Allow for argument dependent look-up */
1648 
		LIST(EXP) q = args;
1649 
		while (!IS_NULL_list(q)) {
1650 
			EXP a = DEREF_exp(HEAD_list(q));
1651 
			if (!IS_NULL_exp(a)) {
1652 
				TYPE t = DEREF_type(exp_type(a));
1653 
				IGNORE koenig_candidates(p, fid, t, KIND_FUNC);
1654 
			}
1655 
			q = TAIL_list(q);
1656 
		}
2 7u83 1657 
	}
7 7u83 1658 
	add_candidates(p, fid, 1, KIND_FUNC);
1659 
	sz = p->size;
1660 
	if (sz == 0) {
1661 
		/* No candidates */
1662 
		EXP a;
1663 
		int fn = 2;
1664 
		QUALIFIER cq = crt_id_qualifier;
1665 
		crt_id_qualifier = (qual & qual_explicit);
1666 
		if (qual & qual_mark) {
1667 
			fn = 1;
1668 
		}
1669 
		a = implicit_id_exp(fid, fn);
1670 
		if (IS_exp_identifier_etc(a)) {
1671 
			fid = DEREF_id(exp_identifier_etc_id(a));
1672 
			add_candidates(p, fid, 1, KIND_FUNC);
1673 
			sz = p->size;
1674 
			if (sz != 0) {
1675 
				fid = p->elem[0].func;
1676 
			}
1677 
		}
1678 
		crt_id_qualifier = cq;
1679 
	} else {
1680 
		fid = p->elem[0].func;
2 7u83 1681 
	}
1682 
 
7 7u83 1683 
	/* Resolve overloaded functions */
1684 
	if (sz > 1) {
1685 
		CANDIDATE *q = resolve_overload(p, args, NULL_type, 0);
1686 
		IDENTIFIER qid = q->func;
1687 
		unsigned rank = q->rank;
1688 
		int kind = q->kind;
1689 
		if (rank == RANK_BEST) {
1690 
			/* Unambiguous resolution */
1691 
			if (match_no_viable > 1) {
1692 
				ERROR err = ERR_over_match_call_ok(qid);
1693 
				if (!IS_NULL_err(err)) {
1694 
					report(crt_loc, err);
1695 
				}
1696 
			}
1697 
		} else if (rank == RANK_VIABLE) {
1698 
			/* Ambiguous resolution */
1699 
			q = resolve_ambiguous(p, args, NULL_type, 0);
1700 
			qid = q->func;
1701 
			rank = q->rank;
1702 
			if (rank == RANK_TARGET) {
1703 
				ERROR err = ERR_over_match_call_target(id);
1704 
				qid = make_ambig_func(p, qid, args, qual, &err);
1705 
				kind = KIND_FUNC;
1706 
				report(crt_loc, err);
1707 
			} else if (rank == RANK_VIABLE) {
1708 
				ERROR err = ERR_over_match_call_ambig(id);
1709 
				err = list_candidates(err, p, RANK_VIABLE);
1710 
				report(crt_loc, err);
1711 
			}
1712 
		} else {
1713 
			/* Unviable resolution */
1714 
			report(crt_loc, ERR_over_match_viable_none(id));
1715 
		}
1716 
		resolved_kind = kind;
1717 
		return (qid);
2 7u83 1718 
	}
1719 
 
7 7u83 1720 
	/* Check template functions */
1721 
	if (is_template_func(fid)) {
1722 
		ERROR err = NULL_err;
1723 
		IDENTIFIER qid = deduce_args(fid, args, 2, 0, 1, &err);
1724 
		if (IS_NULL_id(qid)) {
1725 
			/* No viable resolution */
1726 
			err = concat_error(err, ERR_over_match_viable_none(id));
1727 
			qid = fid;
1728 
		}
1729 
		if (!IS_NULL_err(err)) {
1730 
			/* Report any argument deduction errors */
1731 
			err = concat_error(err, ERR_temp_deduct_fail(id));
1732 
			report(crt_loc, err);
1733 
		} else {
1734 
			/* Successful argument deduction */
1735 
			report(crt_loc, ERR_over_match_call_ok(qid));
1736 
		}
1737 
		fid = qid;
2 7u83 1738 
	}
1739 
 
7 7u83 1740 
	/* Don't check non-overloaded functions */
1741 
	match_no_args = 0;
1742 
	match_no_viable = 0;
1743 
	resolved_kind = KIND_FUNC;
1744 
	return (fid);
2 7u83 1745 
}
1746 
 
1747 
 
1748 
/*
1749 
    RESOLVE AN AMBIGUOUS FUNCTION ADDRESS
1750 
 
1751 
    This routine resolves the list of functions ids to see which is the
1752 
    best under the template specialisation rules.  If no one best candidate
1753 
    is found the null identifier is returned.  This rule is not actually
1754 
    in ISO C++, but it could have been.
1755 
*/
1756 
 
7 7u83 1757 
static IDENTIFIER
1758 
resolve_ambig_func(LIST(IDENTIFIER) ids, int depth)
2 7u83 1759 
{
7 7u83 1760 
	if (!IS_NULL_list(ids)) {
1761 
		int cmp;
1762 
		IDENTIFIER rid, sid;
1763 
		LIST(IDENTIFIER) pids = ids;
2 7u83 1764 
 
7 7u83 1765 
		/* Find the first two functions */
1766 
		rid = DEREF_id(HEAD_list(pids));
1767 
		pids = TAIL_list(pids);
1768 
		if (IS_NULL_list(pids)) {
1769 
			return (rid);
1770 
		}
1771 
		sid = DEREF_id(HEAD_list(pids));
1772 
		pids = TAIL_list(pids);
2 7u83 1773 
 
7 7u83 1774 
		/* Compare them */
1775 
		cmp = compare_funcs(rid, sid);
1776 
		if (cmp == 2) {
1777 
			rid = sid;
1778 
		} else if (cmp != 1) {
1779 
			rid = NULL_id;
1780 
		}
2 7u83 1781 
 
7 7u83 1782 
		/* Compare the winner against the best of the rest */
1783 
		sid = resolve_ambig_func(pids, depth + 1);
1784 
		cmp = compare_funcs(rid, sid);
1785 
		if (cmp == 2) {
1786 
			rid = sid;
1787 
		} else if (cmp != 1) {
1788 
			rid = NULL_id;
1789 
		}
2 7u83 1790 
 
7 7u83 1791 
		/* Check overall winner */
1792 
		if (depth == 0 && !IS_NULL_id(rid)) {
1793 
			pids = ids;
1794 
			while (!IS_NULL_list(pids)) {
1795 
				sid = DEREF_id(HEAD_list(pids));
1796 
				if (!EQ_id(rid, sid)) {
1797 
					cmp = compare_funcs(rid, sid);
1798 
					if (cmp != 1) {
1799 
						return (NULL_id);
1800 
					}
1801 
				}
1802 
				pids = TAIL_list(pids);
1803 
			}
2 7u83 1804 
		}
7 7u83 1805 
		return (rid);
2 7u83 1806 
	}
7 7u83 1807 
	return (NULL_id);
2 7u83 1808 
}
1809 
 
1810 
 
1811 
/*
1812 
    FIND AN OVERLOADED FUNCTION OF A GIVEN TYPE
1813 
 
1814 
    This routine returns whichever of the set of overloaded or ambiguous
1815 
    functions id has type t.  Type deduction is allowed for the template
1816 
    parameters pids if templ is true. The null identifier is returned if
1817 
    none has the correct type, an ambiguous identifier is returned if
1818 
    more than one has the correct type (although overload resolution
1819 
    occurs if res is true).  If there is a match ignoring linkage
1820 
    specifiers then this is returned, the value of eq_func_type for the
1821 
    result is assigned to peq.
1822 
*/
1823 
 
7 7u83 1824 
IDENTIFIER
1825 
resolve_func(IDENTIFIER id, TYPE t, int templ, int res, LIST(IDENTIFIER) pids,
1826 
	     int *peq)
2 7u83 1827 
{
7 7u83 1828 
	int best = 2;
1829 
	IDENTIFIER rid = NULL_id;
1830 
	switch (TAG_id(id)) {
1831 
	case id_function_tag:
1832 
	case id_mem_func_tag:
1833 
	case id_stat_mem_func_tag: {
1834 
		/* Check overloaded functions */
1835 
		IDENTIFIER fid = id;
1836 
		int have_templates = 0;
1837 
		LIST(IDENTIFIER) rids = NULL_list(IDENTIFIER);
1838 
		while (!IS_NULL_id(fid)) {
1839 
			TYPE s;
1840 
			int d = 0;
1841 
			int eq = 0;
1842 
			IDENTIFIER tid = fid;
1843 
			if (!IS_NULL_list(pids)) {
1844 
				/* Save template parameter values */
1845 
				d = save_token_args(pids, NULL_list(TOKEN));
1846 
			}
1847 
			s = DEREF_type(id_function_etc_type(fid));
1848 
			if (IS_type_templ(s) && templ) {
1849 
				/* Template functions */
1850 
				tid = deduce_func(tid, t, &eq);
1851 
				if (!IS_NULL_id(tid)) {
1852 
					have_templates = 1;
1853 
				}
1854 
			} else {
1855 
				/* Simple functions */
2 7u83 1856 
#if LANGUAGE_CPP
7 7u83 1857 
				eq = eq_func_type(s, t, 1, 0);
2 7u83 1858 
#else
7 7u83 1859 
				TYPE r = type_composite(s, t, 1, 0, KILL_err,
1860 
							0);
1861 
				if (!IS_NULL_type(r)) {
1862 
					eq = 3;
1863 
				}
2 7u83 1864 
#endif
7 7u83 1865 
			}
1866 
			if (eq >= best) {
1867 
				if (eq > best) {
1868 
					/* Better match than previous */
1869 
					if (!IS_NULL_list(rids)) {
1870 
						DESTROY_list(rids, SIZE_id);
1871 
						rids = NULL_list(IDENTIFIER);
1872 
					}
1873 
					rid = NULL_id;
1874 
					best = eq;
1875 
				}
1876 
				if (!IS_NULL_id(rid)) {
1877 
					CONS_id(rid, rids, rids);
1878 
				}
1879 
				rid = tid;
1880 
			}
1881 
			if (!IS_NULL_list(pids)) {
1882 
				/* Restore template parameters */
1883 
				restore_token_args(pids, d);
1884 
			}
1885 
			fid = DEREF_id(id_function_etc_over(fid));
2 7u83 1886 
		}
7 7u83 1887 
		if (!IS_NULL_list(rids)) {
1888 
			/* Construct ambiguous result */
1889 
			HASHID nm;
1890 
			NAMESPACE ns;
1891 
			DECL_SPEC ds;
1892 
			CONS_id(rid, rids, rids);
1893 
			if (have_templates && res) {
1894 
				/* Perform overload resolution */
1895 
				rid = resolve_ambig_func(rids, 0);
1896 
				if (!IS_NULL_id(rid)) {
1897 
					DESTROY_list(rids, SIZE_id);
1898 
					break;
1899 
				}
2 7u83 1900 
			}
7 7u83 1901 
			nm = DEREF_hashid(id_name(id));
1902 
			ns = DEREF_nspace(id_parent(id));
1903 
			ds = find_ambig_dspec(rids);
1904 
			MAKE_id_ambig(nm, ds, ns, crt_loc, rids, 0, rid);
2 7u83 1905 
		}
7 7u83 1906 
		break;
2 7u83 1907 
	}
1908 
 
7 7u83 1909 
	case id_ambig_tag: {
1910 
		/* Check ambiguous functions */
1911 
		LIST(IDENTIFIER) rids = NULL_list(IDENTIFIER);
1912 
		LIST(IDENTIFIER) p = DEREF_list(id_ambig_ids(id));
1913 
		while (!IS_NULL_list(p)) {
1914 
			int eq = 0;
1915 
			IDENTIFIER pid = DEREF_id(HEAD_list(p));
1916 
			pid = resolve_func(pid, t, templ, 0, pids, &eq);
1917 
			if (!IS_NULL_id(pid) && eq >= best) {
1918 
				if (eq > best) {
1919 
					/* Better match than previous */
1920 
					if (!IS_NULL_list(rids)) {
1921 
						DESTROY_list(rids, SIZE_id);
1922 
						rids = NULL_list(IDENTIFIER);
1923 
					}
1924 
					rid = NULL_id;
1925 
					best = eq;
1926 
				}
1927 
				if (IS_id_ambig(pid)) {
1928 
					LIST(IDENTIFIER) q;
1929 
					q = DEREF_list(id_ambig_ids(pid));
1930 
					while (!IS_NULL_list(q)) {
1931 
						pid = DEREF_id(HEAD_list(q));
1932 
						if (!IS_NULL_id(rid)) {
1933 
							CONS_id(rid, rids, rids);
1934 
						}
1935 
						rid = pid;
1936 
						q = TAIL_list(q);
1937 
					}
1938 
				} else {
1939 
					if (!IS_NULL_id(rid)) {
1940 
						CONS_id(rid, rids, rids);
1941 
					}
1942 
					rid = pid;
1943 
				}
2 7u83 1944 
			}
7 7u83 1945 
			p = TAIL_list(p);
1946 
		}
1947 
		if (!IS_NULL_list(rids)) {
1948 
			HASHID nm;
1949 
			NAMESPACE ns;
1950 
			DECL_SPEC ds;
1951 
			CONS_id(rid, rids, rids);
1952 
			if (res) {
1953 
				/* Perform overload resolution */
1954 
				rid = resolve_ambig_func(rids, 0);
1955 
				if (!IS_NULL_id(rid)) {
1956 
					DESTROY_list(rids, SIZE_id);
1957 
					break;
1958 
				}
2 7u83 1959 
			}
7 7u83 1960 
			nm = DEREF_hashid(id_name(id));
1961 
			ns = DEREF_nspace(id_parent(id));
1962 
			ds = find_ambig_dspec(rids);
1963 
			MAKE_id_ambig(nm, ds, ns, crt_loc, rids, 0, rid);
2 7u83 1964 
		}
7 7u83 1965 
		break;
2 7u83 1966 
	}
7 7u83 1967 
	}
1968 
	if (IS_NULL_id(rid)) {
1969 
		best = 0;
1970 
	}
1971 
	*peq = best;
1972 
	return (rid);
2 7u83 1973 
}
1974 
 
1975 
 
1976 
/*
1977 
    CREATE A RESOLVED OVERLOADED FUNCTION EXPRESSION
1978 
 
1979 
    This routine creates a resolved overloaded function expression for
1980 
    the function id.
1981 
*/
1982 
 
7 7u83 1983 
static EXP
1984 
make_resolved_exp(IDENTIFIER id, QUALIFIER q, EXP b, int addr, int paren)
2 7u83 1985 
{
7 7u83 1986 
	EXP e;
1987 
	TYPE fn = DEREF_type(id_function_etc_type(id));
1988 
	if (IS_id_mem_func(id)) {
1989 
		if (!IS_NULL_exp(b)) {
1990 
			report(crt_loc, ERR_expr_ref_call());
1991 
			q = qual_nested;
1992 
		}
1993 
		MAKE_exp_member(fn, id, q, e);
1994 
	} else {
1995 
		MAKE_exp_identifier(fn, id, q, e);
1996 
		if (!IS_NULL_exp(b)) {
1997 
			e = join_exp(b, e);
1998 
		}
2 7u83 1999 
	}
7 7u83 2000 
	if (addr) {
2001 
		if (paren) {
2002 
			e = make_paren_exp(e);
2003 
		}
2004 
		e = make_ref_exp(e, 1);
2005 
	}
2006 
	return (e);
2 7u83 2007 
}
2008 
 
2009 
 
2010 
/*
2011 
    RESOLVE THE ADDRESS OF AN OVERLOADED FUNCTION
2012 
 
2013 
    This routine checks the conversion of the expression e to type t.  If
2014 
    e is an overloaded function identifier expression and t is a function
2015 
    type, or pointer to function type, or pointer to member function type,
2016 
    then the various versions of e are checked for the one which matches
2017 
    the function type underlying t in the context of the template
2018 
    parameters pids.  An error is added to err if this does not exist.
2019 
    The result is the appropriate version of e.  Note that member
2020 
    expressions which resolve to static function members are replaced
2021 
    by identifier expressions at this stage (see make_id_exp).
2022 
*/
2023 
 
7 7u83 2024 
EXP
2025 
resolve_cast(TYPE t, EXP e, ERROR *err, int use, int rescan,
2026 
	     LIST(IDENTIFIER) pids)
2 7u83 2027 
{
7 7u83 2028 
	/* Check for identifier expressions */
2029 
	EXP a = e;
2030 
	QUALIFIER q;
2031 
	int addr = 0;
2032 
	int paren = 0;
2033 
	IDENTIFIER id;
2034 
	EXP b = NULL_exp;
2035 
	unsigned tag = TAG_exp(a);
2036 
	while (tag == exp_paren_tag) {
2037 
		a = DEREF_exp(exp_paren_arg(a));
2038 
		tag = TAG_exp(a);
2 7u83 2039 
	}
7 7u83 2040 
	if (tag == exp_address_tag) {
2041 
		/* Address expression */
2042 
		a = DEREF_exp(exp_address_arg(a));
2043 
		tag = TAG_exp(a);
2044 
		addr = 1;
2045 
	} else if (tag == exp_address_mem_tag) {
2046 
		/* Address of member expression */
2047 
		paren = DEREF_int(exp_address_mem_paren(a));
2048 
		a = DEREF_exp(exp_address_mem_arg(a));
2049 
		tag = TAG_exp(a);
2050 
		addr = 1;
2051 
	} else if (tag == exp_op_tag) {
2052 
		/* Check for undetermined address expressions */
2053 
		int op = DEREF_int(exp_op_lex(a));
2054 
		EXP c = DEREF_exp(exp_op_arg2(a));
2055 
		if (op == lex_and_H1 && IS_NULL_exp(c)) {
2056 
			a = DEREF_exp(exp_op_arg1(a));
2057 
			tag = TAG_exp(a);
2058 
			addr = 1;
2 7u83 2059 
		}
2060 
	}
7 7u83 2061 
	while (tag == exp_paren_tag) {
2062 
		a = DEREF_exp(exp_paren_arg(a));
2063 
		paren = 1;
2064 
		tag = TAG_exp(a);
2065 
	}
2066 
	if (tag == exp_call_tag) {
2067 
		/* Member reference expression */
2068 
		b = DEREF_exp(exp_call_arg(a));
2069 
		a = DEREF_exp(exp_call_ptr(a));
2070 
	}
2071 
	if (!IS_exp_identifier_etc(a)) {
2072 
		/* Not an identifier expression */
2073 
		return (e);
2074 
	}
2 7u83 2075 
 
7 7u83 2076 
	/* Mark identifiers as resolved */
2077 
	id = DEREF_id(exp_identifier_etc_id(a));
2078 
	q = DEREF_qual(exp_identifier_etc_qual(a));
2079 
	if (q & qual_mark) {
2080 
		return (e);
2 7u83 2081 
	}
7 7u83 2082 
	if (rescan) {
2083 
		/* Rescan function name if necessary */
2084 
		id = rescan_func_id(id, q);
2085 
	}
2086 
	q |= qual_mark;
2 7u83 2087 
 
7 7u83 2088 
	/* Check for overloaded functions */
2089 
	tag = TAG_id(id);
2090 
	switch (tag) {
2091 
	case id_function_tag:
2092 
	case id_mem_func_tag:
2093 
	case id_stat_mem_func_tag:
2094 
function_lab: {
2095 
		       /* Check functions for overloading */
2096 
		       TYPE s;
2097 
		       IDENTIFIER over;
2098 
		       if (rescan) {
2099 
			       goto overload_lab;
2100 
		       }
2101 
		       if (dependent_cast(id, t)) {
2102 
			       /* Allow for template parameters */
2103 
			       if (!IS_type_func(t)) {
2104 
				       t = rvalue_type(t);
2105 
			       }
2106 
			       MAKE_exp_op(t, lex_function, e, NULL_exp, e);
2107 
			       return (e);
2108 
		       }
2109 
		       over = DEREF_id(id_function_etc_over(id));
2110 
		       if (!IS_NULL_id(over)) {
2111 
			       goto overload_lab;
2112 
		       }
2113 
		       s = DEREF_type(id_function_etc_type(id));
2114 
		       if (IS_type_templ(s)) {
2115 
			       goto overload_lab;
2116 
		       }
2117 
		       if (tag == id_mem_func_tag) {
2118 
			       if (!IS_NULL_exp(b) || addr) {
2119 
				       /* Force error in this case */
2120 
				       e = make_resolved_exp(id, q, b, addr,
2121 
							     paren);
2122 
			       }
2123 
		       }
2124 
		       if (use) {
2125 
			       COPY_qual(exp_identifier_etc_qual(a), q);
2126 
			       use_id(id, suppress_usage);
2127 
		       }
2128 
		       break;
2129 
	       }
2130 
 
2131 
	case id_ambig_tag:
2132 
	case id_undef_tag:
2133 
overload_lab: {
2134 
		      /* Overloaded and ambiguous functions */
2135 
		      TYPE fn = find_func_type(t);
2136 
		      if (!IS_NULL_type(fn)) {
2137 
			      /* Overload resolution */
2138 
			      int eq = 0;
2139 
			      IDENTIFIER rid;
2140 
			      if (dependent_cast(id, t)) {
2141 
				      /* Allow for template parameters */
2142 
				      if (!IS_type_func(t)) {
2143 
					      t = rvalue_type(t);
2144 
				      }
2145 
				      MAKE_exp_op(t, lex_function, e, NULL_exp,
2146 
						  e);
2147 
				      return (e);
2148 
			      }
2149 
			      if (tag == id_undef_tag) {
2150 
				      goto default_lab;
2151 
			      }
2152 
			      rid = resolve_func(id, fn, 1, 0, pids, &eq);
2153 
			      if (!IS_NULL_id(rid)) {
2154 
				      if (IS_id_ambig(rid)) {
2155 
					      /* Ambiguous resolution */
2156 
					      if (use) {
2157 
						      /* Select one function */
2158 
						      LIST(IDENTIFIER) ids;
2159 
						      IGNORE report_ambiguous(rid, 0, 0, 0);
2160 
						      ids = DEREF_list(id_ambig_ids(rid));
2161 
						      rid = resolve_ambig_func(ids, 0);
2162 
						      if (IS_NULL_id(rid)) {
2163 
							      rid = DEREF_id(HEAD_list(ids));
2164 
						      }
2165 
					      } else {
2166 
						      e = NULL_exp;
2167 
						      rid = NULL_id;
2168 
					      }
2169 
				      }
2170 
				      if (!IS_NULL_id(rid)) {
2171 
					      /* Unique resolution */
2172 
					      report(crt_loc, ERR_over_over_ok(rid));
2173 
					      e = make_resolved_exp(rid, q, b, addr, paren);
2174 
					      if (use) {
2175 
						      use_id(rid, suppress_usage);
2176 
					      }
2177 
				      }
2178 
			      } else {
2179 
				      /* Unsuccessful resolution */
2180 
				      if (use) {
2181 
					      add_error(err, ERR_over_over_none(id, fn));
2182 
					      e = make_error_exp(0);
2183 
				      } else {
2184 
					      e = NULL_exp;
2185 
				      }
2186 
			      }
2187 
		      } else {
2188 
			      /* No context for resolution */
2189 
			      if (tag == id_undef_tag) {
2190 
				      goto default_lab;
2191 
			      }
2192 
			      if (use) {
2193 
				      add_error(err, ERR_over_over_context(id));
2194 
				      e = make_error_exp(0);
2195 
			      } else {
2196 
				      e = NULL_exp;
2197 
			      }
2198 
		      }
2199 
		      break;
2200 
	      }
2201 
 
2202 
	default:
2203 
default_lab:
2204 
	      /* Other identifiers */
2205 
	      if (rescan) {
2206 
		      if (use) {
2207 
			      EXP c = implicit_id_exp(id, 1);
2208 
			      if (IS_exp_identifier_etc(c)) {
2209 
				      id = DEREF_id(exp_identifier_etc_id(a));
2210 
				      if (IS_id_function_etc(id)) {
2211 
					      goto function_lab;
2212 
				      }
2213 
			      }
2214 
		      } else {
2215 
			      e = NULL_exp;
2216 
		      }
2217 
	      }
2218 
	      break;
2 7u83 2219 
	}
7 7u83 2220 
	return (e);
2 7u83 2221 
}