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v5.9
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
   4 */
   5
 
   6#include <ctype.h>
   7#include <stdlib.h>
   8#include <string.h>
   9#include <regex.h>
  10#include <sys/utsname.h>
  11
  12#include "lkc.h"
  13
  14struct symbol symbol_yes = {
  15	.name = "y",
  16	.curr = { "y", yes },
  17	.flags = SYMBOL_CONST|SYMBOL_VALID,
  18};
  19
  20struct symbol symbol_mod = {
  21	.name = "m",
  22	.curr = { "m", mod },
  23	.flags = SYMBOL_CONST|SYMBOL_VALID,
  24};
  25
  26struct symbol symbol_no = {
  27	.name = "n",
  28	.curr = { "n", no },
  29	.flags = SYMBOL_CONST|SYMBOL_VALID,
  30};
  31
  32static struct symbol symbol_empty = {
  33	.name = "",
  34	.curr = { "", no },
  35	.flags = SYMBOL_VALID,
  36};
  37
  38struct symbol *sym_defconfig_list;
  39struct symbol *modules_sym;
  40static tristate modules_val;
  41
  42enum symbol_type sym_get_type(struct symbol *sym)
  43{
  44	enum symbol_type type = sym->type;
  45
  46	if (type == S_TRISTATE) {
  47		if (sym_is_choice_value(sym) && sym->visible == yes)
  48			type = S_BOOLEAN;
  49		else if (modules_val == no)
  50			type = S_BOOLEAN;
  51	}
  52	return type;
  53}
  54
  55const char *sym_type_name(enum symbol_type type)
  56{
  57	switch (type) {
  58	case S_BOOLEAN:
  59		return "bool";
  60	case S_TRISTATE:
  61		return "tristate";
  62	case S_INT:
  63		return "integer";
  64	case S_HEX:
  65		return "hex";
  66	case S_STRING:
  67		return "string";
  68	case S_UNKNOWN:
  69		return "unknown";
  70	}
  71	return "???";
  72}
  73
  74struct property *sym_get_choice_prop(struct symbol *sym)
  75{
  76	struct property *prop;
  77
  78	for_all_choices(sym, prop)
  79		return prop;
  80	return NULL;
  81}
  82
  83static struct property *sym_get_default_prop(struct symbol *sym)
  84{
  85	struct property *prop;
  86
  87	for_all_defaults(sym, prop) {
  88		prop->visible.tri = expr_calc_value(prop->visible.expr);
  89		if (prop->visible.tri != no)
  90			return prop;
  91	}
  92	return NULL;
  93}
  94
  95struct property *sym_get_range_prop(struct symbol *sym)
  96{
  97	struct property *prop;
  98
  99	for_all_properties(sym, prop, P_RANGE) {
 100		prop->visible.tri = expr_calc_value(prop->visible.expr);
 101		if (prop->visible.tri != no)
 102			return prop;
 103	}
 104	return NULL;
 105}
 106
 107static long long sym_get_range_val(struct symbol *sym, int base)
 108{
 109	sym_calc_value(sym);
 110	switch (sym->type) {
 111	case S_INT:
 112		base = 10;
 113		break;
 114	case S_HEX:
 115		base = 16;
 116		break;
 117	default:
 118		break;
 119	}
 120	return strtoll(sym->curr.val, NULL, base);
 121}
 122
 123static void sym_validate_range(struct symbol *sym)
 124{
 125	struct property *prop;
 126	int base;
 127	long long val, val2;
 128	char str[64];
 129
 130	switch (sym->type) {
 131	case S_INT:
 132		base = 10;
 133		break;
 134	case S_HEX:
 135		base = 16;
 136		break;
 137	default:
 138		return;
 139	}
 140	prop = sym_get_range_prop(sym);
 141	if (!prop)
 142		return;
 143	val = strtoll(sym->curr.val, NULL, base);
 144	val2 = sym_get_range_val(prop->expr->left.sym, base);
 145	if (val >= val2) {
 146		val2 = sym_get_range_val(prop->expr->right.sym, base);
 147		if (val <= val2)
 148			return;
 149	}
 150	if (sym->type == S_INT)
 151		sprintf(str, "%lld", val2);
 152	else
 153		sprintf(str, "0x%llx", val2);
 154	sym->curr.val = xstrdup(str);
 155}
 156
 157static void sym_set_changed(struct symbol *sym)
 158{
 159	struct property *prop;
 160
 161	sym->flags |= SYMBOL_CHANGED;
 162	for (prop = sym->prop; prop; prop = prop->next) {
 163		if (prop->menu)
 164			prop->menu->flags |= MENU_CHANGED;
 165	}
 166}
 167
 168static void sym_set_all_changed(void)
 169{
 170	struct symbol *sym;
 171	int i;
 172
 173	for_all_symbols(i, sym)
 174		sym_set_changed(sym);
 175}
 176
 177static void sym_calc_visibility(struct symbol *sym)
 178{
 179	struct property *prop;
 180	struct symbol *choice_sym = NULL;
 181	tristate tri;
 182
 183	/* any prompt visible? */
 184	tri = no;
 185
 186	if (sym_is_choice_value(sym))
 187		choice_sym = prop_get_symbol(sym_get_choice_prop(sym));
 188
 189	for_all_prompts(sym, prop) {
 190		prop->visible.tri = expr_calc_value(prop->visible.expr);
 191		/*
 192		 * Tristate choice_values with visibility 'mod' are
 193		 * not visible if the corresponding choice's value is
 194		 * 'yes'.
 195		 */
 196		if (choice_sym && sym->type == S_TRISTATE &&
 197		    prop->visible.tri == mod && choice_sym->curr.tri == yes)
 198			prop->visible.tri = no;
 199
 200		tri = EXPR_OR(tri, prop->visible.tri);
 201	}
 202	if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
 203		tri = yes;
 204	if (sym->visible != tri) {
 205		sym->visible = tri;
 206		sym_set_changed(sym);
 207	}
 208	if (sym_is_choice_value(sym))
 209		return;
 210	/* defaulting to "yes" if no explicit "depends on" are given */
 211	tri = yes;
 212	if (sym->dir_dep.expr)
 213		tri = expr_calc_value(sym->dir_dep.expr);
 214	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 215		tri = yes;
 216	if (sym->dir_dep.tri != tri) {
 217		sym->dir_dep.tri = tri;
 218		sym_set_changed(sym);
 219	}
 220	tri = no;
 221	if (sym->rev_dep.expr)
 222		tri = expr_calc_value(sym->rev_dep.expr);
 223	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 224		tri = yes;
 225	if (sym->rev_dep.tri != tri) {
 226		sym->rev_dep.tri = tri;
 227		sym_set_changed(sym);
 228	}
 229	tri = no;
 230	if (sym->implied.expr)
 231		tri = expr_calc_value(sym->implied.expr);
 232	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 233		tri = yes;
 234	if (sym->implied.tri != tri) {
 235		sym->implied.tri = tri;
 236		sym_set_changed(sym);
 237	}
 238}
 239
 240/*
 241 * Find the default symbol for a choice.
 242 * First try the default values for the choice symbol
 243 * Next locate the first visible choice value
 244 * Return NULL if none was found
 245 */
 246struct symbol *sym_choice_default(struct symbol *sym)
 247{
 248	struct symbol *def_sym;
 249	struct property *prop;
 250	struct expr *e;
 251
 252	/* any of the defaults visible? */
 253	for_all_defaults(sym, prop) {
 254		prop->visible.tri = expr_calc_value(prop->visible.expr);
 255		if (prop->visible.tri == no)
 256			continue;
 257		def_sym = prop_get_symbol(prop);
 258		if (def_sym->visible != no)
 259			return def_sym;
 260	}
 261
 262	/* just get the first visible value */
 263	prop = sym_get_choice_prop(sym);
 264	expr_list_for_each_sym(prop->expr, e, def_sym)
 265		if (def_sym->visible != no)
 266			return def_sym;
 267
 268	/* failed to locate any defaults */
 269	return NULL;
 270}
 271
 272static struct symbol *sym_calc_choice(struct symbol *sym)
 273{
 274	struct symbol *def_sym;
 275	struct property *prop;
 276	struct expr *e;
 277	int flags;
 278
 279	/* first calculate all choice values' visibilities */
 280	flags = sym->flags;
 281	prop = sym_get_choice_prop(sym);
 282	expr_list_for_each_sym(prop->expr, e, def_sym) {
 283		sym_calc_visibility(def_sym);
 284		if (def_sym->visible != no)
 285			flags &= def_sym->flags;
 286	}
 287
 288	sym->flags &= flags | ~SYMBOL_DEF_USER;
 289
 290	/* is the user choice visible? */
 291	def_sym = sym->def[S_DEF_USER].val;
 292	if (def_sym && def_sym->visible != no)
 293		return def_sym;
 294
 295	def_sym = sym_choice_default(sym);
 296
 297	if (def_sym == NULL)
 298		/* no choice? reset tristate value */
 299		sym->curr.tri = no;
 300
 301	return def_sym;
 302}
 303
 304static void sym_warn_unmet_dep(struct symbol *sym)
 305{
 306	struct gstr gs = str_new();
 307
 308	str_printf(&gs,
 309		   "\nWARNING: unmet direct dependencies detected for %s\n",
 310		   sym->name);
 311	str_printf(&gs,
 312		   "  Depends on [%c]: ",
 313		   sym->dir_dep.tri == mod ? 'm' : 'n');
 314	expr_gstr_print(sym->dir_dep.expr, &gs);
 315	str_printf(&gs, "\n");
 316
 317	expr_gstr_print_revdep(sym->rev_dep.expr, &gs, yes,
 318			       "  Selected by [y]:\n");
 319	expr_gstr_print_revdep(sym->rev_dep.expr, &gs, mod,
 320			       "  Selected by [m]:\n");
 321
 322	fputs(str_get(&gs), stderr);
 323}
 324
 325void sym_calc_value(struct symbol *sym)
 326{
 327	struct symbol_value newval, oldval;
 328	struct property *prop;
 329	struct expr *e;
 330
 331	if (!sym)
 332		return;
 333
 334	if (sym->flags & SYMBOL_VALID)
 335		return;
 336
 337	if (sym_is_choice_value(sym) &&
 338	    sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
 339		sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
 340		prop = sym_get_choice_prop(sym);
 341		sym_calc_value(prop_get_symbol(prop));
 342	}
 343
 344	sym->flags |= SYMBOL_VALID;
 345
 346	oldval = sym->curr;
 347
 348	switch (sym->type) {
 349	case S_INT:
 350	case S_HEX:
 351	case S_STRING:
 352		newval = symbol_empty.curr;
 353		break;
 354	case S_BOOLEAN:
 355	case S_TRISTATE:
 356		newval = symbol_no.curr;
 357		break;
 358	default:
 359		sym->curr.val = sym->name;
 360		sym->curr.tri = no;
 361		return;
 362	}
 363	sym->flags &= ~SYMBOL_WRITE;
 364
 365	sym_calc_visibility(sym);
 366
 367	if (sym->visible != no)
 368		sym->flags |= SYMBOL_WRITE;
 369
 370	/* set default if recursively called */
 371	sym->curr = newval;
 372
 373	switch (sym_get_type(sym)) {
 374	case S_BOOLEAN:
 375	case S_TRISTATE:
 376		if (sym_is_choice_value(sym) && sym->visible == yes) {
 377			prop = sym_get_choice_prop(sym);
 378			newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
 379		} else {
 380			if (sym->visible != no) {
 381				/* if the symbol is visible use the user value
 382				 * if available, otherwise try the default value
 383				 */
 384				if (sym_has_value(sym)) {
 385					newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
 386							      sym->visible);
 387					goto calc_newval;
 388				}
 389			}
 390			if (sym->rev_dep.tri != no)
 391				sym->flags |= SYMBOL_WRITE;
 392			if (!sym_is_choice(sym)) {
 393				prop = sym_get_default_prop(sym);
 394				if (prop) {
 395					newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 396							      prop->visible.tri);
 397					if (newval.tri != no)
 398						sym->flags |= SYMBOL_WRITE;
 399				}
 400				if (sym->implied.tri != no) {
 401					sym->flags |= SYMBOL_WRITE;
 402					newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
 403					newval.tri = EXPR_AND(newval.tri,
 404							      sym->dir_dep.tri);
 405				}
 406			}
 407		calc_newval:
 408			if (sym->dir_dep.tri < sym->rev_dep.tri)
 409				sym_warn_unmet_dep(sym);
 410			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 411		}
 412		if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
 413			newval.tri = yes;
 414		break;
 415	case S_STRING:
 416	case S_HEX:
 417	case S_INT:
 418		if (sym->visible != no && sym_has_value(sym)) {
 419			newval.val = sym->def[S_DEF_USER].val;
 420			break;
 421		}
 422		prop = sym_get_default_prop(sym);
 423		if (prop) {
 424			struct symbol *ds = prop_get_symbol(prop);
 425			if (ds) {
 426				sym->flags |= SYMBOL_WRITE;
 427				sym_calc_value(ds);
 428				newval.val = ds->curr.val;
 429			}
 430		}
 431		break;
 432	default:
 433		;
 434	}
 435
 436	sym->curr = newval;
 437	if (sym_is_choice(sym) && newval.tri == yes)
 438		sym->curr.val = sym_calc_choice(sym);
 439	sym_validate_range(sym);
 440
 441	if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
 442		sym_set_changed(sym);
 443		if (modules_sym == sym) {
 444			sym_set_all_changed();
 445			modules_val = modules_sym->curr.tri;
 446		}
 447	}
 448
 449	if (sym_is_choice(sym)) {
 450		struct symbol *choice_sym;
 451
 452		prop = sym_get_choice_prop(sym);
 453		expr_list_for_each_sym(prop->expr, e, choice_sym) {
 454			if ((sym->flags & SYMBOL_WRITE) &&
 455			    choice_sym->visible != no)
 456				choice_sym->flags |= SYMBOL_WRITE;
 457			if (sym->flags & SYMBOL_CHANGED)
 458				sym_set_changed(choice_sym);
 459		}
 460	}
 461
 462	if (sym->flags & SYMBOL_NO_WRITE)
 463		sym->flags &= ~SYMBOL_WRITE;
 464
 465	if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
 466		set_all_choice_values(sym);
 467}
 468
 469void sym_clear_all_valid(void)
 470{
 471	struct symbol *sym;
 472	int i;
 473
 474	for_all_symbols(i, sym)
 475		sym->flags &= ~SYMBOL_VALID;
 476	sym_add_change_count(1);
 477	sym_calc_value(modules_sym);
 478}
 479
 480bool sym_tristate_within_range(struct symbol *sym, tristate val)
 481{
 482	int type = sym_get_type(sym);
 483
 484	if (sym->visible == no)
 485		return false;
 486
 487	if (type != S_BOOLEAN && type != S_TRISTATE)
 488		return false;
 489
 490	if (type == S_BOOLEAN && val == mod)
 491		return false;
 492	if (sym->visible <= sym->rev_dep.tri)
 493		return false;
 494	if (sym_is_choice_value(sym) && sym->visible == yes)
 495		return val == yes;
 496	return val >= sym->rev_dep.tri && val <= sym->visible;
 497}
 498
 499bool sym_set_tristate_value(struct symbol *sym, tristate val)
 500{
 501	tristate oldval = sym_get_tristate_value(sym);
 502
 503	if (oldval != val && !sym_tristate_within_range(sym, val))
 504		return false;
 505
 506	if (!(sym->flags & SYMBOL_DEF_USER)) {
 507		sym->flags |= SYMBOL_DEF_USER;
 508		sym_set_changed(sym);
 509	}
 510	/*
 511	 * setting a choice value also resets the new flag of the choice
 512	 * symbol and all other choice values.
 513	 */
 514	if (sym_is_choice_value(sym) && val == yes) {
 515		struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 516		struct property *prop;
 517		struct expr *e;
 518
 519		cs->def[S_DEF_USER].val = sym;
 520		cs->flags |= SYMBOL_DEF_USER;
 521		prop = sym_get_choice_prop(cs);
 522		for (e = prop->expr; e; e = e->left.expr) {
 523			if (e->right.sym->visible != no)
 524				e->right.sym->flags |= SYMBOL_DEF_USER;
 525		}
 526	}
 527
 528	sym->def[S_DEF_USER].tri = val;
 529	if (oldval != val)
 530		sym_clear_all_valid();
 531
 532	return true;
 533}
 534
 535tristate sym_toggle_tristate_value(struct symbol *sym)
 536{
 537	tristate oldval, newval;
 538
 539	oldval = newval = sym_get_tristate_value(sym);
 540	do {
 541		switch (newval) {
 542		case no:
 543			newval = mod;
 544			break;
 545		case mod:
 546			newval = yes;
 547			break;
 548		case yes:
 549			newval = no;
 550			break;
 551		}
 552		if (sym_set_tristate_value(sym, newval))
 553			break;
 554	} while (oldval != newval);
 555	return newval;
 556}
 557
 558bool sym_string_valid(struct symbol *sym, const char *str)
 559{
 560	signed char ch;
 561
 562	switch (sym->type) {
 563	case S_STRING:
 564		return true;
 565	case S_INT:
 566		ch = *str++;
 567		if (ch == '-')
 568			ch = *str++;
 569		if (!isdigit(ch))
 570			return false;
 571		if (ch == '0' && *str != 0)
 572			return false;
 573		while ((ch = *str++)) {
 574			if (!isdigit(ch))
 575				return false;
 576		}
 577		return true;
 578	case S_HEX:
 579		if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
 580			str += 2;
 581		ch = *str++;
 582		do {
 583			if (!isxdigit(ch))
 584				return false;
 585		} while ((ch = *str++));
 586		return true;
 587	case S_BOOLEAN:
 588	case S_TRISTATE:
 589		switch (str[0]) {
 590		case 'y': case 'Y':
 591		case 'm': case 'M':
 592		case 'n': case 'N':
 593			return true;
 594		}
 595		return false;
 596	default:
 597		return false;
 598	}
 599}
 600
 601bool sym_string_within_range(struct symbol *sym, const char *str)
 602{
 603	struct property *prop;
 604	long long val;
 605
 606	switch (sym->type) {
 607	case S_STRING:
 608		return sym_string_valid(sym, str);
 609	case S_INT:
 610		if (!sym_string_valid(sym, str))
 611			return false;
 612		prop = sym_get_range_prop(sym);
 613		if (!prop)
 614			return true;
 615		val = strtoll(str, NULL, 10);
 616		return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
 617		       val <= sym_get_range_val(prop->expr->right.sym, 10);
 618	case S_HEX:
 619		if (!sym_string_valid(sym, str))
 620			return false;
 621		prop = sym_get_range_prop(sym);
 622		if (!prop)
 623			return true;
 624		val = strtoll(str, NULL, 16);
 625		return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
 626		       val <= sym_get_range_val(prop->expr->right.sym, 16);
 627	case S_BOOLEAN:
 628	case S_TRISTATE:
 629		switch (str[0]) {
 630		case 'y': case 'Y':
 631			return sym_tristate_within_range(sym, yes);
 632		case 'm': case 'M':
 633			return sym_tristate_within_range(sym, mod);
 634		case 'n': case 'N':
 635			return sym_tristate_within_range(sym, no);
 636		}
 637		return false;
 638	default:
 639		return false;
 640	}
 641}
 642
 643bool sym_set_string_value(struct symbol *sym, const char *newval)
 644{
 645	const char *oldval;
 646	char *val;
 647	int size;
 648
 649	switch (sym->type) {
 650	case S_BOOLEAN:
 651	case S_TRISTATE:
 652		switch (newval[0]) {
 653		case 'y': case 'Y':
 654			return sym_set_tristate_value(sym, yes);
 655		case 'm': case 'M':
 656			return sym_set_tristate_value(sym, mod);
 657		case 'n': case 'N':
 658			return sym_set_tristate_value(sym, no);
 659		}
 660		return false;
 661	default:
 662		;
 663	}
 664
 665	if (!sym_string_within_range(sym, newval))
 666		return false;
 667
 668	if (!(sym->flags & SYMBOL_DEF_USER)) {
 669		sym->flags |= SYMBOL_DEF_USER;
 670		sym_set_changed(sym);
 671	}
 672
 673	oldval = sym->def[S_DEF_USER].val;
 674	size = strlen(newval) + 1;
 675	if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
 676		size += 2;
 677		sym->def[S_DEF_USER].val = val = xmalloc(size);
 678		*val++ = '0';
 679		*val++ = 'x';
 680	} else if (!oldval || strcmp(oldval, newval))
 681		sym->def[S_DEF_USER].val = val = xmalloc(size);
 682	else
 683		return true;
 684
 685	strcpy(val, newval);
 686	free((void *)oldval);
 687	sym_clear_all_valid();
 688
 689	return true;
 690}
 691
 692/*
 693 * Find the default value associated to a symbol.
 694 * For tristate symbol handle the modules=n case
 695 * in which case "m" becomes "y".
 696 * If the symbol does not have any default then fallback
 697 * to the fixed default values.
 698 */
 699const char *sym_get_string_default(struct symbol *sym)
 700{
 701	struct property *prop;
 702	struct symbol *ds;
 703	const char *str;
 704	tristate val;
 705
 706	sym_calc_visibility(sym);
 707	sym_calc_value(modules_sym);
 708	val = symbol_no.curr.tri;
 709	str = symbol_empty.curr.val;
 710
 711	/* If symbol has a default value look it up */
 712	prop = sym_get_default_prop(sym);
 713	if (prop != NULL) {
 714		switch (sym->type) {
 715		case S_BOOLEAN:
 716		case S_TRISTATE:
 717			/* The visibility may limit the value from yes => mod */
 718			val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
 719			break;
 720		default:
 721			/*
 722			 * The following fails to handle the situation
 723			 * where a default value is further limited by
 724			 * the valid range.
 725			 */
 726			ds = prop_get_symbol(prop);
 727			if (ds != NULL) {
 728				sym_calc_value(ds);
 729				str = (const char *)ds->curr.val;
 730			}
 731		}
 732	}
 733
 734	/* Handle select statements */
 735	val = EXPR_OR(val, sym->rev_dep.tri);
 736
 737	/* transpose mod to yes if modules are not enabled */
 738	if (val == mod)
 739		if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
 740			val = yes;
 741
 742	/* transpose mod to yes if type is bool */
 743	if (sym->type == S_BOOLEAN && val == mod)
 744		val = yes;
 745
 746	/* adjust the default value if this symbol is implied by another */
 747	if (val < sym->implied.tri)
 748		val = sym->implied.tri;
 749
 750	switch (sym->type) {
 751	case S_BOOLEAN:
 752	case S_TRISTATE:
 753		switch (val) {
 754		case no: return "n";
 755		case mod: return "m";
 756		case yes: return "y";
 757		}
 758	case S_INT:
 759	case S_HEX:
 760		return str;
 761	case S_STRING:
 762		return str;
 763	case S_UNKNOWN:
 764		break;
 765	}
 766	return "";
 767}
 768
 769const char *sym_get_string_value(struct symbol *sym)
 770{
 771	tristate val;
 772
 773	switch (sym->type) {
 774	case S_BOOLEAN:
 775	case S_TRISTATE:
 776		val = sym_get_tristate_value(sym);
 777		switch (val) {
 778		case no:
 779			return "n";
 780		case mod:
 781			sym_calc_value(modules_sym);
 782			return (modules_sym->curr.tri == no) ? "n" : "m";
 783		case yes:
 784			return "y";
 785		}
 786		break;
 787	default:
 788		;
 789	}
 790	return (const char *)sym->curr.val;
 791}
 792
 793bool sym_is_changeable(struct symbol *sym)
 794{
 795	return sym->visible > sym->rev_dep.tri;
 796}
 797
 798static unsigned strhash(const char *s)
 799{
 800	/* fnv32 hash */
 801	unsigned hash = 2166136261U;
 802	for (; *s; s++)
 803		hash = (hash ^ *s) * 0x01000193;
 804	return hash;
 805}
 806
 807struct symbol *sym_lookup(const char *name, int flags)
 808{
 809	struct symbol *symbol;
 810	char *new_name;
 811	int hash;
 812
 813	if (name) {
 814		if (name[0] && !name[1]) {
 815			switch (name[0]) {
 816			case 'y': return &symbol_yes;
 817			case 'm': return &symbol_mod;
 818			case 'n': return &symbol_no;
 819			}
 820		}
 821		hash = strhash(name) % SYMBOL_HASHSIZE;
 822
 823		for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 824			if (symbol->name &&
 825			    !strcmp(symbol->name, name) &&
 826			    (flags ? symbol->flags & flags
 827				   : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
 828				return symbol;
 829		}
 830		new_name = xstrdup(name);
 831	} else {
 832		new_name = NULL;
 833		hash = 0;
 834	}
 835
 836	symbol = xmalloc(sizeof(*symbol));
 837	memset(symbol, 0, sizeof(*symbol));
 838	symbol->name = new_name;
 839	symbol->type = S_UNKNOWN;
 840	symbol->flags = flags;
 841
 842	symbol->next = symbol_hash[hash];
 843	symbol_hash[hash] = symbol;
 844
 845	return symbol;
 846}
 847
 848struct symbol *sym_find(const char *name)
 849{
 850	struct symbol *symbol = NULL;
 851	int hash = 0;
 852
 853	if (!name)
 854		return NULL;
 855
 856	if (name[0] && !name[1]) {
 857		switch (name[0]) {
 858		case 'y': return &symbol_yes;
 859		case 'm': return &symbol_mod;
 860		case 'n': return &symbol_no;
 861		}
 862	}
 863	hash = strhash(name) % SYMBOL_HASHSIZE;
 864
 865	for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 866		if (symbol->name &&
 867		    !strcmp(symbol->name, name) &&
 868		    !(symbol->flags & SYMBOL_CONST))
 869				break;
 870	}
 871
 872	return symbol;
 873}
 874
 875const char *sym_escape_string_value(const char *in)
 876{
 877	const char *p;
 878	size_t reslen;
 879	char *res;
 880	size_t l;
 881
 882	reslen = strlen(in) + strlen("\"\"") + 1;
 883
 884	p = in;
 885	for (;;) {
 886		l = strcspn(p, "\"\\");
 887		p += l;
 888
 889		if (p[0] == '\0')
 890			break;
 891
 892		reslen++;
 893		p++;
 894	}
 895
 896	res = xmalloc(reslen);
 897	res[0] = '\0';
 898
 899	strcat(res, "\"");
 900
 901	p = in;
 902	for (;;) {
 903		l = strcspn(p, "\"\\");
 904		strncat(res, p, l);
 905		p += l;
 906
 907		if (p[0] == '\0')
 908			break;
 909
 910		strcat(res, "\\");
 911		strncat(res, p++, 1);
 912	}
 913
 914	strcat(res, "\"");
 915	return res;
 916}
 917
 918struct sym_match {
 919	struct symbol	*sym;
 920	off_t		so, eo;
 921};
 922
 923/* Compare matched symbols as thus:
 924 * - first, symbols that match exactly
 925 * - then, alphabetical sort
 926 */
 927static int sym_rel_comp(const void *sym1, const void *sym2)
 928{
 929	const struct sym_match *s1 = sym1;
 930	const struct sym_match *s2 = sym2;
 931	int exact1, exact2;
 932
 933	/* Exact match:
 934	 * - if matched length on symbol s1 is the length of that symbol,
 935	 *   then this symbol should come first;
 936	 * - if matched length on symbol s2 is the length of that symbol,
 937	 *   then this symbol should come first.
 938	 * Note: since the search can be a regexp, both symbols may match
 939	 * exactly; if this is the case, we can't decide which comes first,
 940	 * and we fallback to sorting alphabetically.
 941	 */
 942	exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
 943	exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
 944	if (exact1 && !exact2)
 945		return -1;
 946	if (!exact1 && exact2)
 947		return 1;
 948
 949	/* As a fallback, sort symbols alphabetically */
 950	return strcmp(s1->sym->name, s2->sym->name);
 951}
 952
 953struct symbol **sym_re_search(const char *pattern)
 954{
 955	struct symbol *sym, **sym_arr = NULL;
 956	struct sym_match *sym_match_arr = NULL;
 957	int i, cnt, size;
 958	regex_t re;
 959	regmatch_t match[1];
 960
 961	cnt = size = 0;
 962	/* Skip if empty */
 963	if (strlen(pattern) == 0)
 964		return NULL;
 965	if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
 966		return NULL;
 967
 968	for_all_symbols(i, sym) {
 969		if (sym->flags & SYMBOL_CONST || !sym->name)
 970			continue;
 971		if (regexec(&re, sym->name, 1, match, 0))
 972			continue;
 973		if (cnt >= size) {
 974			void *tmp;
 975			size += 16;
 976			tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
 977			if (!tmp)
 978				goto sym_re_search_free;
 979			sym_match_arr = tmp;
 980		}
 981		sym_calc_value(sym);
 982		/* As regexec returned 0, we know we have a match, so
 983		 * we can use match[0].rm_[se]o without further checks
 984		 */
 985		sym_match_arr[cnt].so = match[0].rm_so;
 986		sym_match_arr[cnt].eo = match[0].rm_eo;
 987		sym_match_arr[cnt++].sym = sym;
 988	}
 989	if (sym_match_arr) {
 990		qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
 991		sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
 992		if (!sym_arr)
 993			goto sym_re_search_free;
 994		for (i = 0; i < cnt; i++)
 995			sym_arr[i] = sym_match_arr[i].sym;
 996		sym_arr[cnt] = NULL;
 997	}
 998sym_re_search_free:
 999	/* sym_match_arr can be NULL if no match, but free(NULL) is OK */
1000	free(sym_match_arr);
1001	regfree(&re);
1002
1003	return sym_arr;
1004}
1005
1006/*
1007 * When we check for recursive dependencies we use a stack to save
1008 * current state so we can print out relevant info to user.
1009 * The entries are located on the call stack so no need to free memory.
1010 * Note insert() remove() must always match to properly clear the stack.
1011 */
1012static struct dep_stack {
1013	struct dep_stack *prev, *next;
1014	struct symbol *sym;
1015	struct property *prop;
1016	struct expr **expr;
1017} *check_top;
1018
1019static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
1020{
1021	memset(stack, 0, sizeof(*stack));
1022	if (check_top)
1023		check_top->next = stack;
1024	stack->prev = check_top;
1025	stack->sym = sym;
1026	check_top = stack;
1027}
1028
1029static void dep_stack_remove(void)
1030{
1031	check_top = check_top->prev;
1032	if (check_top)
1033		check_top->next = NULL;
1034}
1035
1036/*
1037 * Called when we have detected a recursive dependency.
1038 * check_top point to the top of the stact so we use
1039 * the ->prev pointer to locate the bottom of the stack.
1040 */
1041static void sym_check_print_recursive(struct symbol *last_sym)
1042{
1043	struct dep_stack *stack;
1044	struct symbol *sym, *next_sym;
1045	struct menu *menu = NULL;
1046	struct property *prop;
1047	struct dep_stack cv_stack;
1048
1049	if (sym_is_choice_value(last_sym)) {
1050		dep_stack_insert(&cv_stack, last_sym);
1051		last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1052	}
1053
1054	for (stack = check_top; stack != NULL; stack = stack->prev)
1055		if (stack->sym == last_sym)
1056			break;
1057	if (!stack) {
1058		fprintf(stderr, "unexpected recursive dependency error\n");
1059		return;
1060	}
1061
1062	for (; stack; stack = stack->next) {
1063		sym = stack->sym;
1064		next_sym = stack->next ? stack->next->sym : last_sym;
1065		prop = stack->prop;
1066		if (prop == NULL)
1067			prop = stack->sym->prop;
1068
1069		/* for choice values find the menu entry (used below) */
1070		if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1071			for (prop = sym->prop; prop; prop = prop->next) {
1072				menu = prop->menu;
1073				if (prop->menu)
1074					break;
1075			}
1076		}
1077		if (stack->sym == last_sym)
1078			fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1079				prop->file->name, prop->lineno);
1080
1081		if (sym_is_choice(sym)) {
1082			fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1083				menu->file->name, menu->lineno,
1084				sym->name ? sym->name : "<choice>",
1085				next_sym->name ? next_sym->name : "<choice>");
1086		} else if (sym_is_choice_value(sym)) {
1087			fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1088				menu->file->name, menu->lineno,
1089				sym->name ? sym->name : "<choice>",
1090				next_sym->name ? next_sym->name : "<choice>");
1091		} else if (stack->expr == &sym->dir_dep.expr) {
1092			fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1093				prop->file->name, prop->lineno,
1094				sym->name ? sym->name : "<choice>",
1095				next_sym->name ? next_sym->name : "<choice>");
1096		} else if (stack->expr == &sym->rev_dep.expr) {
1097			fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1098				prop->file->name, prop->lineno,
1099				sym->name ? sym->name : "<choice>",
1100				next_sym->name ? next_sym->name : "<choice>");
1101		} else if (stack->expr == &sym->implied.expr) {
1102			fprintf(stderr, "%s:%d:\tsymbol %s is implied by %s\n",
1103				prop->file->name, prop->lineno,
1104				sym->name ? sym->name : "<choice>",
1105				next_sym->name ? next_sym->name : "<choice>");
1106		} else if (stack->expr) {
1107			fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1108				prop->file->name, prop->lineno,
1109				sym->name ? sym->name : "<choice>",
1110				prop_get_type_name(prop->type),
1111				next_sym->name ? next_sym->name : "<choice>");
1112		} else {
1113			fprintf(stderr, "%s:%d:\tsymbol %s %s is visible depending on %s\n",
1114				prop->file->name, prop->lineno,
1115				sym->name ? sym->name : "<choice>",
1116				prop_get_type_name(prop->type),
1117				next_sym->name ? next_sym->name : "<choice>");
1118		}
1119	}
1120
1121	fprintf(stderr,
1122		"For a resolution refer to Documentation/kbuild/kconfig-language.rst\n"
1123		"subsection \"Kconfig recursive dependency limitations\"\n"
1124		"\n");
1125
1126	if (check_top == &cv_stack)
1127		dep_stack_remove();
1128}
1129
1130static struct symbol *sym_check_expr_deps(struct expr *e)
1131{
1132	struct symbol *sym;
1133
1134	if (!e)
1135		return NULL;
1136	switch (e->type) {
1137	case E_OR:
1138	case E_AND:
1139		sym = sym_check_expr_deps(e->left.expr);
1140		if (sym)
1141			return sym;
1142		return sym_check_expr_deps(e->right.expr);
1143	case E_NOT:
1144		return sym_check_expr_deps(e->left.expr);
1145	case E_EQUAL:
1146	case E_GEQ:
1147	case E_GTH:
1148	case E_LEQ:
1149	case E_LTH:
1150	case E_UNEQUAL:
1151		sym = sym_check_deps(e->left.sym);
1152		if (sym)
1153			return sym;
1154		return sym_check_deps(e->right.sym);
1155	case E_SYMBOL:
1156		return sym_check_deps(e->left.sym);
1157	default:
1158		break;
1159	}
1160	fprintf(stderr, "Oops! How to check %d?\n", e->type);
1161	return NULL;
1162}
1163
1164/* return NULL when dependencies are OK */
1165static struct symbol *sym_check_sym_deps(struct symbol *sym)
1166{
1167	struct symbol *sym2;
1168	struct property *prop;
1169	struct dep_stack stack;
1170
1171	dep_stack_insert(&stack, sym);
1172
1173	stack.expr = &sym->dir_dep.expr;
1174	sym2 = sym_check_expr_deps(sym->dir_dep.expr);
1175	if (sym2)
1176		goto out;
1177
1178	stack.expr = &sym->rev_dep.expr;
1179	sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1180	if (sym2)
1181		goto out;
1182
1183	stack.expr = &sym->implied.expr;
1184	sym2 = sym_check_expr_deps(sym->implied.expr);
1185	if (sym2)
1186		goto out;
1187
1188	stack.expr = NULL;
1189
1190	for (prop = sym->prop; prop; prop = prop->next) {
1191		if (prop->type == P_CHOICE || prop->type == P_SELECT ||
1192		    prop->type == P_IMPLY)
1193			continue;
1194		stack.prop = prop;
1195		sym2 = sym_check_expr_deps(prop->visible.expr);
1196		if (sym2)
1197			break;
1198		if (prop->type != P_DEFAULT || sym_is_choice(sym))
1199			continue;
1200		stack.expr = &prop->expr;
1201		sym2 = sym_check_expr_deps(prop->expr);
1202		if (sym2)
1203			break;
1204		stack.expr = NULL;
1205	}
1206
1207out:
1208	dep_stack_remove();
1209
1210	return sym2;
1211}
1212
1213static struct symbol *sym_check_choice_deps(struct symbol *choice)
1214{
1215	struct symbol *sym, *sym2;
1216	struct property *prop;
1217	struct expr *e;
1218	struct dep_stack stack;
1219
1220	dep_stack_insert(&stack, choice);
1221
1222	prop = sym_get_choice_prop(choice);
1223	expr_list_for_each_sym(prop->expr, e, sym)
1224		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1225
1226	choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1227	sym2 = sym_check_sym_deps(choice);
1228	choice->flags &= ~SYMBOL_CHECK;
1229	if (sym2)
1230		goto out;
1231
1232	expr_list_for_each_sym(prop->expr, e, sym) {
1233		sym2 = sym_check_sym_deps(sym);
1234		if (sym2)
1235			break;
1236	}
1237out:
1238	expr_list_for_each_sym(prop->expr, e, sym)
1239		sym->flags &= ~SYMBOL_CHECK;
1240
1241	if (sym2 && sym_is_choice_value(sym2) &&
1242	    prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1243		sym2 = choice;
1244
1245	dep_stack_remove();
1246
1247	return sym2;
1248}
1249
1250struct symbol *sym_check_deps(struct symbol *sym)
1251{
1252	struct symbol *sym2;
1253	struct property *prop;
1254
1255	if (sym->flags & SYMBOL_CHECK) {
1256		sym_check_print_recursive(sym);
1257		return sym;
1258	}
1259	if (sym->flags & SYMBOL_CHECKED)
1260		return NULL;
1261
1262	if (sym_is_choice_value(sym)) {
1263		struct dep_stack stack;
1264
1265		/* for choice groups start the check with main choice symbol */
1266		dep_stack_insert(&stack, sym);
1267		prop = sym_get_choice_prop(sym);
1268		sym2 = sym_check_deps(prop_get_symbol(prop));
1269		dep_stack_remove();
1270	} else if (sym_is_choice(sym)) {
1271		sym2 = sym_check_choice_deps(sym);
1272	} else {
1273		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1274		sym2 = sym_check_sym_deps(sym);
1275		sym->flags &= ~SYMBOL_CHECK;
1276	}
1277
1278	return sym2;
1279}
1280
1281struct symbol *prop_get_symbol(struct property *prop)
1282{
1283	if (prop->expr && (prop->expr->type == E_SYMBOL ||
1284			   prop->expr->type == E_LIST))
1285		return prop->expr->left.sym;
1286	return NULL;
1287}
1288
1289const char *prop_get_type_name(enum prop_type type)
1290{
1291	switch (type) {
1292	case P_PROMPT:
1293		return "prompt";
1294	case P_COMMENT:
1295		return "comment";
1296	case P_MENU:
1297		return "menu";
1298	case P_DEFAULT:
1299		return "default";
1300	case P_CHOICE:
1301		return "choice";
1302	case P_SELECT:
1303		return "select";
1304	case P_IMPLY:
1305		return "imply";
1306	case P_RANGE:
1307		return "range";
1308	case P_SYMBOL:
1309		return "symbol";
1310	case P_UNKNOWN:
1311		break;
1312	}
1313	return "unknown";
1314}
v5.14.15
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
   4 */
   5
   6#include <sys/types.h>
   7#include <ctype.h>
   8#include <stdlib.h>
   9#include <string.h>
  10#include <regex.h>
 
  11
  12#include "lkc.h"
  13
  14struct symbol symbol_yes = {
  15	.name = "y",
  16	.curr = { "y", yes },
  17	.flags = SYMBOL_CONST|SYMBOL_VALID,
  18};
  19
  20struct symbol symbol_mod = {
  21	.name = "m",
  22	.curr = { "m", mod },
  23	.flags = SYMBOL_CONST|SYMBOL_VALID,
  24};
  25
  26struct symbol symbol_no = {
  27	.name = "n",
  28	.curr = { "n", no },
  29	.flags = SYMBOL_CONST|SYMBOL_VALID,
  30};
  31
  32static struct symbol symbol_empty = {
  33	.name = "",
  34	.curr = { "", no },
  35	.flags = SYMBOL_VALID,
  36};
  37
 
  38struct symbol *modules_sym;
  39static tristate modules_val;
  40
  41enum symbol_type sym_get_type(struct symbol *sym)
  42{
  43	enum symbol_type type = sym->type;
  44
  45	if (type == S_TRISTATE) {
  46		if (sym_is_choice_value(sym) && sym->visible == yes)
  47			type = S_BOOLEAN;
  48		else if (modules_val == no)
  49			type = S_BOOLEAN;
  50	}
  51	return type;
  52}
  53
  54const char *sym_type_name(enum symbol_type type)
  55{
  56	switch (type) {
  57	case S_BOOLEAN:
  58		return "bool";
  59	case S_TRISTATE:
  60		return "tristate";
  61	case S_INT:
  62		return "integer";
  63	case S_HEX:
  64		return "hex";
  65	case S_STRING:
  66		return "string";
  67	case S_UNKNOWN:
  68		return "unknown";
  69	}
  70	return "???";
  71}
  72
  73struct property *sym_get_choice_prop(struct symbol *sym)
  74{
  75	struct property *prop;
  76
  77	for_all_choices(sym, prop)
  78		return prop;
  79	return NULL;
  80}
  81
  82static struct property *sym_get_default_prop(struct symbol *sym)
  83{
  84	struct property *prop;
  85
  86	for_all_defaults(sym, prop) {
  87		prop->visible.tri = expr_calc_value(prop->visible.expr);
  88		if (prop->visible.tri != no)
  89			return prop;
  90	}
  91	return NULL;
  92}
  93
  94struct property *sym_get_range_prop(struct symbol *sym)
  95{
  96	struct property *prop;
  97
  98	for_all_properties(sym, prop, P_RANGE) {
  99		prop->visible.tri = expr_calc_value(prop->visible.expr);
 100		if (prop->visible.tri != no)
 101			return prop;
 102	}
 103	return NULL;
 104}
 105
 106static long long sym_get_range_val(struct symbol *sym, int base)
 107{
 108	sym_calc_value(sym);
 109	switch (sym->type) {
 110	case S_INT:
 111		base = 10;
 112		break;
 113	case S_HEX:
 114		base = 16;
 115		break;
 116	default:
 117		break;
 118	}
 119	return strtoll(sym->curr.val, NULL, base);
 120}
 121
 122static void sym_validate_range(struct symbol *sym)
 123{
 124	struct property *prop;
 125	int base;
 126	long long val, val2;
 127	char str[64];
 128
 129	switch (sym->type) {
 130	case S_INT:
 131		base = 10;
 132		break;
 133	case S_HEX:
 134		base = 16;
 135		break;
 136	default:
 137		return;
 138	}
 139	prop = sym_get_range_prop(sym);
 140	if (!prop)
 141		return;
 142	val = strtoll(sym->curr.val, NULL, base);
 143	val2 = sym_get_range_val(prop->expr->left.sym, base);
 144	if (val >= val2) {
 145		val2 = sym_get_range_val(prop->expr->right.sym, base);
 146		if (val <= val2)
 147			return;
 148	}
 149	if (sym->type == S_INT)
 150		sprintf(str, "%lld", val2);
 151	else
 152		sprintf(str, "0x%llx", val2);
 153	sym->curr.val = xstrdup(str);
 154}
 155
 156static void sym_set_changed(struct symbol *sym)
 157{
 158	struct property *prop;
 159
 160	sym->flags |= SYMBOL_CHANGED;
 161	for (prop = sym->prop; prop; prop = prop->next) {
 162		if (prop->menu)
 163			prop->menu->flags |= MENU_CHANGED;
 164	}
 165}
 166
 167static void sym_set_all_changed(void)
 168{
 169	struct symbol *sym;
 170	int i;
 171
 172	for_all_symbols(i, sym)
 173		sym_set_changed(sym);
 174}
 175
 176static void sym_calc_visibility(struct symbol *sym)
 177{
 178	struct property *prop;
 179	struct symbol *choice_sym = NULL;
 180	tristate tri;
 181
 182	/* any prompt visible? */
 183	tri = no;
 184
 185	if (sym_is_choice_value(sym))
 186		choice_sym = prop_get_symbol(sym_get_choice_prop(sym));
 187
 188	for_all_prompts(sym, prop) {
 189		prop->visible.tri = expr_calc_value(prop->visible.expr);
 190		/*
 191		 * Tristate choice_values with visibility 'mod' are
 192		 * not visible if the corresponding choice's value is
 193		 * 'yes'.
 194		 */
 195		if (choice_sym && sym->type == S_TRISTATE &&
 196		    prop->visible.tri == mod && choice_sym->curr.tri == yes)
 197			prop->visible.tri = no;
 198
 199		tri = EXPR_OR(tri, prop->visible.tri);
 200	}
 201	if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
 202		tri = yes;
 203	if (sym->visible != tri) {
 204		sym->visible = tri;
 205		sym_set_changed(sym);
 206	}
 207	if (sym_is_choice_value(sym))
 208		return;
 209	/* defaulting to "yes" if no explicit "depends on" are given */
 210	tri = yes;
 211	if (sym->dir_dep.expr)
 212		tri = expr_calc_value(sym->dir_dep.expr);
 213	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 214		tri = yes;
 215	if (sym->dir_dep.tri != tri) {
 216		sym->dir_dep.tri = tri;
 217		sym_set_changed(sym);
 218	}
 219	tri = no;
 220	if (sym->rev_dep.expr)
 221		tri = expr_calc_value(sym->rev_dep.expr);
 222	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 223		tri = yes;
 224	if (sym->rev_dep.tri != tri) {
 225		sym->rev_dep.tri = tri;
 226		sym_set_changed(sym);
 227	}
 228	tri = no;
 229	if (sym->implied.expr)
 230		tri = expr_calc_value(sym->implied.expr);
 231	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 232		tri = yes;
 233	if (sym->implied.tri != tri) {
 234		sym->implied.tri = tri;
 235		sym_set_changed(sym);
 236	}
 237}
 238
 239/*
 240 * Find the default symbol for a choice.
 241 * First try the default values for the choice symbol
 242 * Next locate the first visible choice value
 243 * Return NULL if none was found
 244 */
 245struct symbol *sym_choice_default(struct symbol *sym)
 246{
 247	struct symbol *def_sym;
 248	struct property *prop;
 249	struct expr *e;
 250
 251	/* any of the defaults visible? */
 252	for_all_defaults(sym, prop) {
 253		prop->visible.tri = expr_calc_value(prop->visible.expr);
 254		if (prop->visible.tri == no)
 255			continue;
 256		def_sym = prop_get_symbol(prop);
 257		if (def_sym->visible != no)
 258			return def_sym;
 259	}
 260
 261	/* just get the first visible value */
 262	prop = sym_get_choice_prop(sym);
 263	expr_list_for_each_sym(prop->expr, e, def_sym)
 264		if (def_sym->visible != no)
 265			return def_sym;
 266
 267	/* failed to locate any defaults */
 268	return NULL;
 269}
 270
 271static struct symbol *sym_calc_choice(struct symbol *sym)
 272{
 273	struct symbol *def_sym;
 274	struct property *prop;
 275	struct expr *e;
 276	int flags;
 277
 278	/* first calculate all choice values' visibilities */
 279	flags = sym->flags;
 280	prop = sym_get_choice_prop(sym);
 281	expr_list_for_each_sym(prop->expr, e, def_sym) {
 282		sym_calc_visibility(def_sym);
 283		if (def_sym->visible != no)
 284			flags &= def_sym->flags;
 285	}
 286
 287	sym->flags &= flags | ~SYMBOL_DEF_USER;
 288
 289	/* is the user choice visible? */
 290	def_sym = sym->def[S_DEF_USER].val;
 291	if (def_sym && def_sym->visible != no)
 292		return def_sym;
 293
 294	def_sym = sym_choice_default(sym);
 295
 296	if (def_sym == NULL)
 297		/* no choice? reset tristate value */
 298		sym->curr.tri = no;
 299
 300	return def_sym;
 301}
 302
 303static void sym_warn_unmet_dep(struct symbol *sym)
 304{
 305	struct gstr gs = str_new();
 306
 307	str_printf(&gs,
 308		   "\nWARNING: unmet direct dependencies detected for %s\n",
 309		   sym->name);
 310	str_printf(&gs,
 311		   "  Depends on [%c]: ",
 312		   sym->dir_dep.tri == mod ? 'm' : 'n');
 313	expr_gstr_print(sym->dir_dep.expr, &gs);
 314	str_printf(&gs, "\n");
 315
 316	expr_gstr_print_revdep(sym->rev_dep.expr, &gs, yes,
 317			       "  Selected by [y]:\n");
 318	expr_gstr_print_revdep(sym->rev_dep.expr, &gs, mod,
 319			       "  Selected by [m]:\n");
 320
 321	fputs(str_get(&gs), stderr);
 322}
 323
 324void sym_calc_value(struct symbol *sym)
 325{
 326	struct symbol_value newval, oldval;
 327	struct property *prop;
 328	struct expr *e;
 329
 330	if (!sym)
 331		return;
 332
 333	if (sym->flags & SYMBOL_VALID)
 334		return;
 335
 336	if (sym_is_choice_value(sym) &&
 337	    sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
 338		sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
 339		prop = sym_get_choice_prop(sym);
 340		sym_calc_value(prop_get_symbol(prop));
 341	}
 342
 343	sym->flags |= SYMBOL_VALID;
 344
 345	oldval = sym->curr;
 346
 347	switch (sym->type) {
 348	case S_INT:
 349	case S_HEX:
 350	case S_STRING:
 351		newval = symbol_empty.curr;
 352		break;
 353	case S_BOOLEAN:
 354	case S_TRISTATE:
 355		newval = symbol_no.curr;
 356		break;
 357	default:
 358		sym->curr.val = sym->name;
 359		sym->curr.tri = no;
 360		return;
 361	}
 362	sym->flags &= ~SYMBOL_WRITE;
 363
 364	sym_calc_visibility(sym);
 365
 366	if (sym->visible != no)
 367		sym->flags |= SYMBOL_WRITE;
 368
 369	/* set default if recursively called */
 370	sym->curr = newval;
 371
 372	switch (sym_get_type(sym)) {
 373	case S_BOOLEAN:
 374	case S_TRISTATE:
 375		if (sym_is_choice_value(sym) && sym->visible == yes) {
 376			prop = sym_get_choice_prop(sym);
 377			newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
 378		} else {
 379			if (sym->visible != no) {
 380				/* if the symbol is visible use the user value
 381				 * if available, otherwise try the default value
 382				 */
 383				if (sym_has_value(sym)) {
 384					newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
 385							      sym->visible);
 386					goto calc_newval;
 387				}
 388			}
 389			if (sym->rev_dep.tri != no)
 390				sym->flags |= SYMBOL_WRITE;
 391			if (!sym_is_choice(sym)) {
 392				prop = sym_get_default_prop(sym);
 393				if (prop) {
 394					newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 395							      prop->visible.tri);
 396					if (newval.tri != no)
 397						sym->flags |= SYMBOL_WRITE;
 398				}
 399				if (sym->implied.tri != no) {
 400					sym->flags |= SYMBOL_WRITE;
 401					newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
 402					newval.tri = EXPR_AND(newval.tri,
 403							      sym->dir_dep.tri);
 404				}
 405			}
 406		calc_newval:
 407			if (sym->dir_dep.tri < sym->rev_dep.tri)
 408				sym_warn_unmet_dep(sym);
 409			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 410		}
 411		if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
 412			newval.tri = yes;
 413		break;
 414	case S_STRING:
 415	case S_HEX:
 416	case S_INT:
 417		if (sym->visible != no && sym_has_value(sym)) {
 418			newval.val = sym->def[S_DEF_USER].val;
 419			break;
 420		}
 421		prop = sym_get_default_prop(sym);
 422		if (prop) {
 423			struct symbol *ds = prop_get_symbol(prop);
 424			if (ds) {
 425				sym->flags |= SYMBOL_WRITE;
 426				sym_calc_value(ds);
 427				newval.val = ds->curr.val;
 428			}
 429		}
 430		break;
 431	default:
 432		;
 433	}
 434
 435	sym->curr = newval;
 436	if (sym_is_choice(sym) && newval.tri == yes)
 437		sym->curr.val = sym_calc_choice(sym);
 438	sym_validate_range(sym);
 439
 440	if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
 441		sym_set_changed(sym);
 442		if (modules_sym == sym) {
 443			sym_set_all_changed();
 444			modules_val = modules_sym->curr.tri;
 445		}
 446	}
 447
 448	if (sym_is_choice(sym)) {
 449		struct symbol *choice_sym;
 450
 451		prop = sym_get_choice_prop(sym);
 452		expr_list_for_each_sym(prop->expr, e, choice_sym) {
 453			if ((sym->flags & SYMBOL_WRITE) &&
 454			    choice_sym->visible != no)
 455				choice_sym->flags |= SYMBOL_WRITE;
 456			if (sym->flags & SYMBOL_CHANGED)
 457				sym_set_changed(choice_sym);
 458		}
 459	}
 460
 461	if (sym->flags & SYMBOL_NO_WRITE)
 462		sym->flags &= ~SYMBOL_WRITE;
 463
 464	if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
 465		set_all_choice_values(sym);
 466}
 467
 468void sym_clear_all_valid(void)
 469{
 470	struct symbol *sym;
 471	int i;
 472
 473	for_all_symbols(i, sym)
 474		sym->flags &= ~SYMBOL_VALID;
 475	conf_set_changed(true);
 476	sym_calc_value(modules_sym);
 477}
 478
 479bool sym_tristate_within_range(struct symbol *sym, tristate val)
 480{
 481	int type = sym_get_type(sym);
 482
 483	if (sym->visible == no)
 484		return false;
 485
 486	if (type != S_BOOLEAN && type != S_TRISTATE)
 487		return false;
 488
 489	if (type == S_BOOLEAN && val == mod)
 490		return false;
 491	if (sym->visible <= sym->rev_dep.tri)
 492		return false;
 493	if (sym_is_choice_value(sym) && sym->visible == yes)
 494		return val == yes;
 495	return val >= sym->rev_dep.tri && val <= sym->visible;
 496}
 497
 498bool sym_set_tristate_value(struct symbol *sym, tristate val)
 499{
 500	tristate oldval = sym_get_tristate_value(sym);
 501
 502	if (oldval != val && !sym_tristate_within_range(sym, val))
 503		return false;
 504
 505	if (!(sym->flags & SYMBOL_DEF_USER)) {
 506		sym->flags |= SYMBOL_DEF_USER;
 507		sym_set_changed(sym);
 508	}
 509	/*
 510	 * setting a choice value also resets the new flag of the choice
 511	 * symbol and all other choice values.
 512	 */
 513	if (sym_is_choice_value(sym) && val == yes) {
 514		struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 515		struct property *prop;
 516		struct expr *e;
 517
 518		cs->def[S_DEF_USER].val = sym;
 519		cs->flags |= SYMBOL_DEF_USER;
 520		prop = sym_get_choice_prop(cs);
 521		for (e = prop->expr; e; e = e->left.expr) {
 522			if (e->right.sym->visible != no)
 523				e->right.sym->flags |= SYMBOL_DEF_USER;
 524		}
 525	}
 526
 527	sym->def[S_DEF_USER].tri = val;
 528	if (oldval != val)
 529		sym_clear_all_valid();
 530
 531	return true;
 532}
 533
 534tristate sym_toggle_tristate_value(struct symbol *sym)
 535{
 536	tristate oldval, newval;
 537
 538	oldval = newval = sym_get_tristate_value(sym);
 539	do {
 540		switch (newval) {
 541		case no:
 542			newval = mod;
 543			break;
 544		case mod:
 545			newval = yes;
 546			break;
 547		case yes:
 548			newval = no;
 549			break;
 550		}
 551		if (sym_set_tristate_value(sym, newval))
 552			break;
 553	} while (oldval != newval);
 554	return newval;
 555}
 556
 557bool sym_string_valid(struct symbol *sym, const char *str)
 558{
 559	signed char ch;
 560
 561	switch (sym->type) {
 562	case S_STRING:
 563		return true;
 564	case S_INT:
 565		ch = *str++;
 566		if (ch == '-')
 567			ch = *str++;
 568		if (!isdigit(ch))
 569			return false;
 570		if (ch == '0' && *str != 0)
 571			return false;
 572		while ((ch = *str++)) {
 573			if (!isdigit(ch))
 574				return false;
 575		}
 576		return true;
 577	case S_HEX:
 578		if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
 579			str += 2;
 580		ch = *str++;
 581		do {
 582			if (!isxdigit(ch))
 583				return false;
 584		} while ((ch = *str++));
 585		return true;
 586	case S_BOOLEAN:
 587	case S_TRISTATE:
 588		switch (str[0]) {
 589		case 'y': case 'Y':
 590		case 'm': case 'M':
 591		case 'n': case 'N':
 592			return true;
 593		}
 594		return false;
 595	default:
 596		return false;
 597	}
 598}
 599
 600bool sym_string_within_range(struct symbol *sym, const char *str)
 601{
 602	struct property *prop;
 603	long long val;
 604
 605	switch (sym->type) {
 606	case S_STRING:
 607		return sym_string_valid(sym, str);
 608	case S_INT:
 609		if (!sym_string_valid(sym, str))
 610			return false;
 611		prop = sym_get_range_prop(sym);
 612		if (!prop)
 613			return true;
 614		val = strtoll(str, NULL, 10);
 615		return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
 616		       val <= sym_get_range_val(prop->expr->right.sym, 10);
 617	case S_HEX:
 618		if (!sym_string_valid(sym, str))
 619			return false;
 620		prop = sym_get_range_prop(sym);
 621		if (!prop)
 622			return true;
 623		val = strtoll(str, NULL, 16);
 624		return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
 625		       val <= sym_get_range_val(prop->expr->right.sym, 16);
 626	case S_BOOLEAN:
 627	case S_TRISTATE:
 628		switch (str[0]) {
 629		case 'y': case 'Y':
 630			return sym_tristate_within_range(sym, yes);
 631		case 'm': case 'M':
 632			return sym_tristate_within_range(sym, mod);
 633		case 'n': case 'N':
 634			return sym_tristate_within_range(sym, no);
 635		}
 636		return false;
 637	default:
 638		return false;
 639	}
 640}
 641
 642bool sym_set_string_value(struct symbol *sym, const char *newval)
 643{
 644	const char *oldval;
 645	char *val;
 646	int size;
 647
 648	switch (sym->type) {
 649	case S_BOOLEAN:
 650	case S_TRISTATE:
 651		switch (newval[0]) {
 652		case 'y': case 'Y':
 653			return sym_set_tristate_value(sym, yes);
 654		case 'm': case 'M':
 655			return sym_set_tristate_value(sym, mod);
 656		case 'n': case 'N':
 657			return sym_set_tristate_value(sym, no);
 658		}
 659		return false;
 660	default:
 661		;
 662	}
 663
 664	if (!sym_string_within_range(sym, newval))
 665		return false;
 666
 667	if (!(sym->flags & SYMBOL_DEF_USER)) {
 668		sym->flags |= SYMBOL_DEF_USER;
 669		sym_set_changed(sym);
 670	}
 671
 672	oldval = sym->def[S_DEF_USER].val;
 673	size = strlen(newval) + 1;
 674	if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
 675		size += 2;
 676		sym->def[S_DEF_USER].val = val = xmalloc(size);
 677		*val++ = '0';
 678		*val++ = 'x';
 679	} else if (!oldval || strcmp(oldval, newval))
 680		sym->def[S_DEF_USER].val = val = xmalloc(size);
 681	else
 682		return true;
 683
 684	strcpy(val, newval);
 685	free((void *)oldval);
 686	sym_clear_all_valid();
 687
 688	return true;
 689}
 690
 691/*
 692 * Find the default value associated to a symbol.
 693 * For tristate symbol handle the modules=n case
 694 * in which case "m" becomes "y".
 695 * If the symbol does not have any default then fallback
 696 * to the fixed default values.
 697 */
 698const char *sym_get_string_default(struct symbol *sym)
 699{
 700	struct property *prop;
 701	struct symbol *ds;
 702	const char *str;
 703	tristate val;
 704
 705	sym_calc_visibility(sym);
 706	sym_calc_value(modules_sym);
 707	val = symbol_no.curr.tri;
 708	str = symbol_empty.curr.val;
 709
 710	/* If symbol has a default value look it up */
 711	prop = sym_get_default_prop(sym);
 712	if (prop != NULL) {
 713		switch (sym->type) {
 714		case S_BOOLEAN:
 715		case S_TRISTATE:
 716			/* The visibility may limit the value from yes => mod */
 717			val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
 718			break;
 719		default:
 720			/*
 721			 * The following fails to handle the situation
 722			 * where a default value is further limited by
 723			 * the valid range.
 724			 */
 725			ds = prop_get_symbol(prop);
 726			if (ds != NULL) {
 727				sym_calc_value(ds);
 728				str = (const char *)ds->curr.val;
 729			}
 730		}
 731	}
 732
 733	/* Handle select statements */
 734	val = EXPR_OR(val, sym->rev_dep.tri);
 735
 736	/* transpose mod to yes if modules are not enabled */
 737	if (val == mod)
 738		if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
 739			val = yes;
 740
 741	/* transpose mod to yes if type is bool */
 742	if (sym->type == S_BOOLEAN && val == mod)
 743		val = yes;
 744
 745	/* adjust the default value if this symbol is implied by another */
 746	if (val < sym->implied.tri)
 747		val = sym->implied.tri;
 748
 749	switch (sym->type) {
 750	case S_BOOLEAN:
 751	case S_TRISTATE:
 752		switch (val) {
 753		case no: return "n";
 754		case mod: return "m";
 755		case yes: return "y";
 756		}
 757	case S_INT:
 758	case S_HEX:
 759		return str;
 760	case S_STRING:
 761		return str;
 762	case S_UNKNOWN:
 763		break;
 764	}
 765	return "";
 766}
 767
 768const char *sym_get_string_value(struct symbol *sym)
 769{
 770	tristate val;
 771
 772	switch (sym->type) {
 773	case S_BOOLEAN:
 774	case S_TRISTATE:
 775		val = sym_get_tristate_value(sym);
 776		switch (val) {
 777		case no:
 778			return "n";
 779		case mod:
 780			sym_calc_value(modules_sym);
 781			return (modules_sym->curr.tri == no) ? "n" : "m";
 782		case yes:
 783			return "y";
 784		}
 785		break;
 786	default:
 787		;
 788	}
 789	return (const char *)sym->curr.val;
 790}
 791
 792bool sym_is_changeable(struct symbol *sym)
 793{
 794	return sym->visible > sym->rev_dep.tri;
 795}
 796
 797static unsigned strhash(const char *s)
 798{
 799	/* fnv32 hash */
 800	unsigned hash = 2166136261U;
 801	for (; *s; s++)
 802		hash = (hash ^ *s) * 0x01000193;
 803	return hash;
 804}
 805
 806struct symbol *sym_lookup(const char *name, int flags)
 807{
 808	struct symbol *symbol;
 809	char *new_name;
 810	int hash;
 811
 812	if (name) {
 813		if (name[0] && !name[1]) {
 814			switch (name[0]) {
 815			case 'y': return &symbol_yes;
 816			case 'm': return &symbol_mod;
 817			case 'n': return &symbol_no;
 818			}
 819		}
 820		hash = strhash(name) % SYMBOL_HASHSIZE;
 821
 822		for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 823			if (symbol->name &&
 824			    !strcmp(symbol->name, name) &&
 825			    (flags ? symbol->flags & flags
 826				   : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
 827				return symbol;
 828		}
 829		new_name = xstrdup(name);
 830	} else {
 831		new_name = NULL;
 832		hash = 0;
 833	}
 834
 835	symbol = xmalloc(sizeof(*symbol));
 836	memset(symbol, 0, sizeof(*symbol));
 837	symbol->name = new_name;
 838	symbol->type = S_UNKNOWN;
 839	symbol->flags = flags;
 840
 841	symbol->next = symbol_hash[hash];
 842	symbol_hash[hash] = symbol;
 843
 844	return symbol;
 845}
 846
 847struct symbol *sym_find(const char *name)
 848{
 849	struct symbol *symbol = NULL;
 850	int hash = 0;
 851
 852	if (!name)
 853		return NULL;
 854
 855	if (name[0] && !name[1]) {
 856		switch (name[0]) {
 857		case 'y': return &symbol_yes;
 858		case 'm': return &symbol_mod;
 859		case 'n': return &symbol_no;
 860		}
 861	}
 862	hash = strhash(name) % SYMBOL_HASHSIZE;
 863
 864	for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 865		if (symbol->name &&
 866		    !strcmp(symbol->name, name) &&
 867		    !(symbol->flags & SYMBOL_CONST))
 868				break;
 869	}
 870
 871	return symbol;
 872}
 873
 874const char *sym_escape_string_value(const char *in)
 875{
 876	const char *p;
 877	size_t reslen;
 878	char *res;
 879	size_t l;
 880
 881	reslen = strlen(in) + strlen("\"\"") + 1;
 882
 883	p = in;
 884	for (;;) {
 885		l = strcspn(p, "\"\\");
 886		p += l;
 887
 888		if (p[0] == '\0')
 889			break;
 890
 891		reslen++;
 892		p++;
 893	}
 894
 895	res = xmalloc(reslen);
 896	res[0] = '\0';
 897
 898	strcat(res, "\"");
 899
 900	p = in;
 901	for (;;) {
 902		l = strcspn(p, "\"\\");
 903		strncat(res, p, l);
 904		p += l;
 905
 906		if (p[0] == '\0')
 907			break;
 908
 909		strcat(res, "\\");
 910		strncat(res, p++, 1);
 911	}
 912
 913	strcat(res, "\"");
 914	return res;
 915}
 916
 917struct sym_match {
 918	struct symbol	*sym;
 919	off_t		so, eo;
 920};
 921
 922/* Compare matched symbols as thus:
 923 * - first, symbols that match exactly
 924 * - then, alphabetical sort
 925 */
 926static int sym_rel_comp(const void *sym1, const void *sym2)
 927{
 928	const struct sym_match *s1 = sym1;
 929	const struct sym_match *s2 = sym2;
 930	int exact1, exact2;
 931
 932	/* Exact match:
 933	 * - if matched length on symbol s1 is the length of that symbol,
 934	 *   then this symbol should come first;
 935	 * - if matched length on symbol s2 is the length of that symbol,
 936	 *   then this symbol should come first.
 937	 * Note: since the search can be a regexp, both symbols may match
 938	 * exactly; if this is the case, we can't decide which comes first,
 939	 * and we fallback to sorting alphabetically.
 940	 */
 941	exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
 942	exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
 943	if (exact1 && !exact2)
 944		return -1;
 945	if (!exact1 && exact2)
 946		return 1;
 947
 948	/* As a fallback, sort symbols alphabetically */
 949	return strcmp(s1->sym->name, s2->sym->name);
 950}
 951
 952struct symbol **sym_re_search(const char *pattern)
 953{
 954	struct symbol *sym, **sym_arr = NULL;
 955	struct sym_match *sym_match_arr = NULL;
 956	int i, cnt, size;
 957	regex_t re;
 958	regmatch_t match[1];
 959
 960	cnt = size = 0;
 961	/* Skip if empty */
 962	if (strlen(pattern) == 0)
 963		return NULL;
 964	if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
 965		return NULL;
 966
 967	for_all_symbols(i, sym) {
 968		if (sym->flags & SYMBOL_CONST || !sym->name)
 969			continue;
 970		if (regexec(&re, sym->name, 1, match, 0))
 971			continue;
 972		if (cnt >= size) {
 973			void *tmp;
 974			size += 16;
 975			tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
 976			if (!tmp)
 977				goto sym_re_search_free;
 978			sym_match_arr = tmp;
 979		}
 980		sym_calc_value(sym);
 981		/* As regexec returned 0, we know we have a match, so
 982		 * we can use match[0].rm_[se]o without further checks
 983		 */
 984		sym_match_arr[cnt].so = match[0].rm_so;
 985		sym_match_arr[cnt].eo = match[0].rm_eo;
 986		sym_match_arr[cnt++].sym = sym;
 987	}
 988	if (sym_match_arr) {
 989		qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
 990		sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
 991		if (!sym_arr)
 992			goto sym_re_search_free;
 993		for (i = 0; i < cnt; i++)
 994			sym_arr[i] = sym_match_arr[i].sym;
 995		sym_arr[cnt] = NULL;
 996	}
 997sym_re_search_free:
 998	/* sym_match_arr can be NULL if no match, but free(NULL) is OK */
 999	free(sym_match_arr);
1000	regfree(&re);
1001
1002	return sym_arr;
1003}
1004
1005/*
1006 * When we check for recursive dependencies we use a stack to save
1007 * current state so we can print out relevant info to user.
1008 * The entries are located on the call stack so no need to free memory.
1009 * Note insert() remove() must always match to properly clear the stack.
1010 */
1011static struct dep_stack {
1012	struct dep_stack *prev, *next;
1013	struct symbol *sym;
1014	struct property *prop;
1015	struct expr **expr;
1016} *check_top;
1017
1018static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
1019{
1020	memset(stack, 0, sizeof(*stack));
1021	if (check_top)
1022		check_top->next = stack;
1023	stack->prev = check_top;
1024	stack->sym = sym;
1025	check_top = stack;
1026}
1027
1028static void dep_stack_remove(void)
1029{
1030	check_top = check_top->prev;
1031	if (check_top)
1032		check_top->next = NULL;
1033}
1034
1035/*
1036 * Called when we have detected a recursive dependency.
1037 * check_top point to the top of the stact so we use
1038 * the ->prev pointer to locate the bottom of the stack.
1039 */
1040static void sym_check_print_recursive(struct symbol *last_sym)
1041{
1042	struct dep_stack *stack;
1043	struct symbol *sym, *next_sym;
1044	struct menu *menu = NULL;
1045	struct property *prop;
1046	struct dep_stack cv_stack;
1047
1048	if (sym_is_choice_value(last_sym)) {
1049		dep_stack_insert(&cv_stack, last_sym);
1050		last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1051	}
1052
1053	for (stack = check_top; stack != NULL; stack = stack->prev)
1054		if (stack->sym == last_sym)
1055			break;
1056	if (!stack) {
1057		fprintf(stderr, "unexpected recursive dependency error\n");
1058		return;
1059	}
1060
1061	for (; stack; stack = stack->next) {
1062		sym = stack->sym;
1063		next_sym = stack->next ? stack->next->sym : last_sym;
1064		prop = stack->prop;
1065		if (prop == NULL)
1066			prop = stack->sym->prop;
1067
1068		/* for choice values find the menu entry (used below) */
1069		if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1070			for (prop = sym->prop; prop; prop = prop->next) {
1071				menu = prop->menu;
1072				if (prop->menu)
1073					break;
1074			}
1075		}
1076		if (stack->sym == last_sym)
1077			fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1078				prop->file->name, prop->lineno);
1079
1080		if (sym_is_choice(sym)) {
1081			fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1082				menu->file->name, menu->lineno,
1083				sym->name ? sym->name : "<choice>",
1084				next_sym->name ? next_sym->name : "<choice>");
1085		} else if (sym_is_choice_value(sym)) {
1086			fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1087				menu->file->name, menu->lineno,
1088				sym->name ? sym->name : "<choice>",
1089				next_sym->name ? next_sym->name : "<choice>");
1090		} else if (stack->expr == &sym->dir_dep.expr) {
1091			fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1092				prop->file->name, prop->lineno,
1093				sym->name ? sym->name : "<choice>",
1094				next_sym->name ? next_sym->name : "<choice>");
1095		} else if (stack->expr == &sym->rev_dep.expr) {
1096			fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1097				prop->file->name, prop->lineno,
1098				sym->name ? sym->name : "<choice>",
1099				next_sym->name ? next_sym->name : "<choice>");
1100		} else if (stack->expr == &sym->implied.expr) {
1101			fprintf(stderr, "%s:%d:\tsymbol %s is implied by %s\n",
1102				prop->file->name, prop->lineno,
1103				sym->name ? sym->name : "<choice>",
1104				next_sym->name ? next_sym->name : "<choice>");
1105		} else if (stack->expr) {
1106			fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1107				prop->file->name, prop->lineno,
1108				sym->name ? sym->name : "<choice>",
1109				prop_get_type_name(prop->type),
1110				next_sym->name ? next_sym->name : "<choice>");
1111		} else {
1112			fprintf(stderr, "%s:%d:\tsymbol %s %s is visible depending on %s\n",
1113				prop->file->name, prop->lineno,
1114				sym->name ? sym->name : "<choice>",
1115				prop_get_type_name(prop->type),
1116				next_sym->name ? next_sym->name : "<choice>");
1117		}
1118	}
1119
1120	fprintf(stderr,
1121		"For a resolution refer to Documentation/kbuild/kconfig-language.rst\n"
1122		"subsection \"Kconfig recursive dependency limitations\"\n"
1123		"\n");
1124
1125	if (check_top == &cv_stack)
1126		dep_stack_remove();
1127}
1128
1129static struct symbol *sym_check_expr_deps(struct expr *e)
1130{
1131	struct symbol *sym;
1132
1133	if (!e)
1134		return NULL;
1135	switch (e->type) {
1136	case E_OR:
1137	case E_AND:
1138		sym = sym_check_expr_deps(e->left.expr);
1139		if (sym)
1140			return sym;
1141		return sym_check_expr_deps(e->right.expr);
1142	case E_NOT:
1143		return sym_check_expr_deps(e->left.expr);
1144	case E_EQUAL:
1145	case E_GEQ:
1146	case E_GTH:
1147	case E_LEQ:
1148	case E_LTH:
1149	case E_UNEQUAL:
1150		sym = sym_check_deps(e->left.sym);
1151		if (sym)
1152			return sym;
1153		return sym_check_deps(e->right.sym);
1154	case E_SYMBOL:
1155		return sym_check_deps(e->left.sym);
1156	default:
1157		break;
1158	}
1159	fprintf(stderr, "Oops! How to check %d?\n", e->type);
1160	return NULL;
1161}
1162
1163/* return NULL when dependencies are OK */
1164static struct symbol *sym_check_sym_deps(struct symbol *sym)
1165{
1166	struct symbol *sym2;
1167	struct property *prop;
1168	struct dep_stack stack;
1169
1170	dep_stack_insert(&stack, sym);
1171
1172	stack.expr = &sym->dir_dep.expr;
1173	sym2 = sym_check_expr_deps(sym->dir_dep.expr);
1174	if (sym2)
1175		goto out;
1176
1177	stack.expr = &sym->rev_dep.expr;
1178	sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1179	if (sym2)
1180		goto out;
1181
1182	stack.expr = &sym->implied.expr;
1183	sym2 = sym_check_expr_deps(sym->implied.expr);
1184	if (sym2)
1185		goto out;
1186
1187	stack.expr = NULL;
1188
1189	for (prop = sym->prop; prop; prop = prop->next) {
1190		if (prop->type == P_CHOICE || prop->type == P_SELECT ||
1191		    prop->type == P_IMPLY)
1192			continue;
1193		stack.prop = prop;
1194		sym2 = sym_check_expr_deps(prop->visible.expr);
1195		if (sym2)
1196			break;
1197		if (prop->type != P_DEFAULT || sym_is_choice(sym))
1198			continue;
1199		stack.expr = &prop->expr;
1200		sym2 = sym_check_expr_deps(prop->expr);
1201		if (sym2)
1202			break;
1203		stack.expr = NULL;
1204	}
1205
1206out:
1207	dep_stack_remove();
1208
1209	return sym2;
1210}
1211
1212static struct symbol *sym_check_choice_deps(struct symbol *choice)
1213{
1214	struct symbol *sym, *sym2;
1215	struct property *prop;
1216	struct expr *e;
1217	struct dep_stack stack;
1218
1219	dep_stack_insert(&stack, choice);
1220
1221	prop = sym_get_choice_prop(choice);
1222	expr_list_for_each_sym(prop->expr, e, sym)
1223		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1224
1225	choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1226	sym2 = sym_check_sym_deps(choice);
1227	choice->flags &= ~SYMBOL_CHECK;
1228	if (sym2)
1229		goto out;
1230
1231	expr_list_for_each_sym(prop->expr, e, sym) {
1232		sym2 = sym_check_sym_deps(sym);
1233		if (sym2)
1234			break;
1235	}
1236out:
1237	expr_list_for_each_sym(prop->expr, e, sym)
1238		sym->flags &= ~SYMBOL_CHECK;
1239
1240	if (sym2 && sym_is_choice_value(sym2) &&
1241	    prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1242		sym2 = choice;
1243
1244	dep_stack_remove();
1245
1246	return sym2;
1247}
1248
1249struct symbol *sym_check_deps(struct symbol *sym)
1250{
1251	struct symbol *sym2;
1252	struct property *prop;
1253
1254	if (sym->flags & SYMBOL_CHECK) {
1255		sym_check_print_recursive(sym);
1256		return sym;
1257	}
1258	if (sym->flags & SYMBOL_CHECKED)
1259		return NULL;
1260
1261	if (sym_is_choice_value(sym)) {
1262		struct dep_stack stack;
1263
1264		/* for choice groups start the check with main choice symbol */
1265		dep_stack_insert(&stack, sym);
1266		prop = sym_get_choice_prop(sym);
1267		sym2 = sym_check_deps(prop_get_symbol(prop));
1268		dep_stack_remove();
1269	} else if (sym_is_choice(sym)) {
1270		sym2 = sym_check_choice_deps(sym);
1271	} else {
1272		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1273		sym2 = sym_check_sym_deps(sym);
1274		sym->flags &= ~SYMBOL_CHECK;
1275	}
1276
1277	return sym2;
1278}
1279
1280struct symbol *prop_get_symbol(struct property *prop)
1281{
1282	if (prop->expr && (prop->expr->type == E_SYMBOL ||
1283			   prop->expr->type == E_LIST))
1284		return prop->expr->left.sym;
1285	return NULL;
1286}
1287
1288const char *prop_get_type_name(enum prop_type type)
1289{
1290	switch (type) {
1291	case P_PROMPT:
1292		return "prompt";
1293	case P_COMMENT:
1294		return "comment";
1295	case P_MENU:
1296		return "menu";
1297	case P_DEFAULT:
1298		return "default";
1299	case P_CHOICE:
1300		return "choice";
1301	case P_SELECT:
1302		return "select";
1303	case P_IMPLY:
1304		return "imply";
1305	case P_RANGE:
1306		return "range";
1307	case P_SYMBOL:
1308		return "symbol";
1309	case P_UNKNOWN:
1310		break;
1311	}
1312	return "unknown";
1313}