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   1/*
   2 * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
   3 * Released under the terms of the GNU GPL v2.0.
   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}, symbol_mod = {
  19	.name = "m",
  20	.curr = { "m", mod },
  21	.flags = SYMBOL_CONST|SYMBOL_VALID,
  22}, symbol_no = {
  23	.name = "n",
  24	.curr = { "n", no },
  25	.flags = SYMBOL_CONST|SYMBOL_VALID,
  26}, symbol_empty = {
  27	.name = "",
  28	.curr = { "", no },
  29	.flags = SYMBOL_VALID,
  30};
  31
  32struct symbol *sym_defconfig_list;
  33struct symbol *modules_sym;
  34tristate modules_val;
  35
  36struct expr *sym_env_list;
  37
  38static void sym_add_default(struct symbol *sym, const char *def)
  39{
  40	struct property *prop = prop_alloc(P_DEFAULT, sym);
  41
  42	prop->expr = expr_alloc_symbol(sym_lookup(def, SYMBOL_CONST));
  43}
  44
  45void sym_init(void)
  46{
  47	struct symbol *sym;
  48	struct utsname uts;
  49	static bool inited = false;
  50
  51	if (inited)
  52		return;
  53	inited = true;
  54
  55	uname(&uts);
  56
  57	sym = sym_lookup("UNAME_RELEASE", 0);
  58	sym->type = S_STRING;
  59	sym->flags |= SYMBOL_AUTO;
  60	sym_add_default(sym, uts.release);
  61}
  62
  63enum symbol_type sym_get_type(struct symbol *sym)
  64{
  65	enum symbol_type type = sym->type;
  66
  67	if (type == S_TRISTATE) {
  68		if (sym_is_choice_value(sym) && sym->visible == yes)
  69			type = S_BOOLEAN;
  70		else if (modules_val == no)
  71			type = S_BOOLEAN;
  72	}
  73	return type;
  74}
  75
  76const char *sym_type_name(enum symbol_type type)
  77{
  78	switch (type) {
  79	case S_BOOLEAN:
  80		return "boolean";
  81	case S_TRISTATE:
  82		return "tristate";
  83	case S_INT:
  84		return "integer";
  85	case S_HEX:
  86		return "hex";
  87	case S_STRING:
  88		return "string";
  89	case S_UNKNOWN:
  90		return "unknown";
  91	case S_OTHER:
  92		break;
  93	}
  94	return "???";
  95}
  96
  97struct property *sym_get_choice_prop(struct symbol *sym)
  98{
  99	struct property *prop;
 100
 101	for_all_choices(sym, prop)
 102		return prop;
 103	return NULL;
 104}
 105
 106struct property *sym_get_env_prop(struct symbol *sym)
 107{
 108	struct property *prop;
 109
 110	for_all_properties(sym, prop, P_ENV)
 111		return prop;
 112	return NULL;
 113}
 114
 115struct property *sym_get_default_prop(struct symbol *sym)
 116{
 117	struct property *prop;
 118
 119	for_all_defaults(sym, prop) {
 120		prop->visible.tri = expr_calc_value(prop->visible.expr);
 121		if (prop->visible.tri != no)
 122			return prop;
 123	}
 124	return NULL;
 125}
 126
 127static struct property *sym_get_range_prop(struct symbol *sym)
 128{
 129	struct property *prop;
 130
 131	for_all_properties(sym, prop, P_RANGE) {
 132		prop->visible.tri = expr_calc_value(prop->visible.expr);
 133		if (prop->visible.tri != no)
 134			return prop;
 135	}
 136	return NULL;
 137}
 138
 139static int sym_get_range_val(struct symbol *sym, int base)
 140{
 141	sym_calc_value(sym);
 142	switch (sym->type) {
 143	case S_INT:
 144		base = 10;
 145		break;
 146	case S_HEX:
 147		base = 16;
 148		break;
 149	default:
 150		break;
 151	}
 152	return strtol(sym->curr.val, NULL, base);
 153}
 154
 155static void sym_validate_range(struct symbol *sym)
 156{
 157	struct property *prop;
 158	int base, val, val2;
 159	char str[64];
 160
 161	switch (sym->type) {
 162	case S_INT:
 163		base = 10;
 164		break;
 165	case S_HEX:
 166		base = 16;
 167		break;
 168	default:
 169		return;
 170	}
 171	prop = sym_get_range_prop(sym);
 172	if (!prop)
 173		return;
 174	val = strtol(sym->curr.val, NULL, base);
 175	val2 = sym_get_range_val(prop->expr->left.sym, base);
 176	if (val >= val2) {
 177		val2 = sym_get_range_val(prop->expr->right.sym, base);
 178		if (val <= val2)
 179			return;
 180	}
 181	if (sym->type == S_INT)
 182		sprintf(str, "%d", val2);
 183	else
 184		sprintf(str, "0x%x", val2);
 185	sym->curr.val = strdup(str);
 186}
 187
 188static void sym_calc_visibility(struct symbol *sym)
 189{
 190	struct property *prop;
 191	tristate tri;
 192
 193	/* any prompt visible? */
 194	tri = no;
 195	for_all_prompts(sym, prop) {
 196		prop->visible.tri = expr_calc_value(prop->visible.expr);
 197		tri = EXPR_OR(tri, prop->visible.tri);
 198	}
 199	if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
 200		tri = yes;
 201	if (sym->visible != tri) {
 202		sym->visible = tri;
 203		sym_set_changed(sym);
 204	}
 205	if (sym_is_choice_value(sym))
 206		return;
 207	/* defaulting to "yes" if no explicit "depends on" are given */
 208	tri = yes;
 209	if (sym->dir_dep.expr)
 210		tri = expr_calc_value(sym->dir_dep.expr);
 211	if (tri == mod)
 212		tri = yes;
 213	if (sym->dir_dep.tri != tri) {
 214		sym->dir_dep.tri = tri;
 215		sym_set_changed(sym);
 216	}
 217	tri = no;
 218	if (sym->rev_dep.expr)
 219		tri = expr_calc_value(sym->rev_dep.expr);
 220	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 221		tri = yes;
 222	if (sym->rev_dep.tri != tri) {
 223		sym->rev_dep.tri = tri;
 224		sym_set_changed(sym);
 225	}
 226}
 227
 228/*
 229 * Find the default symbol for a choice.
 230 * First try the default values for the choice symbol
 231 * Next locate the first visible choice value
 232 * Return NULL if none was found
 233 */
 234struct symbol *sym_choice_default(struct symbol *sym)
 235{
 236	struct symbol *def_sym;
 237	struct property *prop;
 238	struct expr *e;
 239
 240	/* any of the defaults visible? */
 241	for_all_defaults(sym, prop) {
 242		prop->visible.tri = expr_calc_value(prop->visible.expr);
 243		if (prop->visible.tri == no)
 244			continue;
 245		def_sym = prop_get_symbol(prop);
 246		if (def_sym->visible != no)
 247			return def_sym;
 248	}
 249
 250	/* just get the first visible value */
 251	prop = sym_get_choice_prop(sym);
 252	expr_list_for_each_sym(prop->expr, e, def_sym)
 253		if (def_sym->visible != no)
 254			return def_sym;
 255
 256	/* failed to locate any defaults */
 257	return NULL;
 258}
 259
 260static struct symbol *sym_calc_choice(struct symbol *sym)
 261{
 262	struct symbol *def_sym;
 263	struct property *prop;
 264	struct expr *e;
 265	int flags;
 266
 267	/* first calculate all choice values' visibilities */
 268	flags = sym->flags;
 269	prop = sym_get_choice_prop(sym);
 270	expr_list_for_each_sym(prop->expr, e, def_sym) {
 271		sym_calc_visibility(def_sym);
 272		if (def_sym->visible != no)
 273			flags &= def_sym->flags;
 274	}
 275
 276	sym->flags &= flags | ~SYMBOL_DEF_USER;
 277
 278	/* is the user choice visible? */
 279	def_sym = sym->def[S_DEF_USER].val;
 280	if (def_sym && def_sym->visible != no)
 281		return def_sym;
 282
 283	def_sym = sym_choice_default(sym);
 284
 285	if (def_sym == NULL)
 286		/* no choice? reset tristate value */
 287		sym->curr.tri = no;
 288
 289	return def_sym;
 290}
 291
 292void sym_calc_value(struct symbol *sym)
 293{
 294	struct symbol_value newval, oldval;
 295	struct property *prop;
 296	struct expr *e;
 297
 298	if (!sym)
 299		return;
 300
 301	if (sym->flags & SYMBOL_VALID)
 302		return;
 303	sym->flags |= SYMBOL_VALID;
 304
 305	oldval = sym->curr;
 306
 307	switch (sym->type) {
 308	case S_INT:
 309	case S_HEX:
 310	case S_STRING:
 311		newval = symbol_empty.curr;
 312		break;
 313	case S_BOOLEAN:
 314	case S_TRISTATE:
 315		newval = symbol_no.curr;
 316		break;
 317	default:
 318		sym->curr.val = sym->name;
 319		sym->curr.tri = no;
 320		return;
 321	}
 322	if (!sym_is_choice_value(sym))
 323		sym->flags &= ~SYMBOL_WRITE;
 324
 325	sym_calc_visibility(sym);
 326
 327	/* set default if recursively called */
 328	sym->curr = newval;
 329
 330	switch (sym_get_type(sym)) {
 331	case S_BOOLEAN:
 332	case S_TRISTATE:
 333		if (sym_is_choice_value(sym) && sym->visible == yes) {
 334			prop = sym_get_choice_prop(sym);
 335			newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
 336		} else {
 337			if (sym->visible != no) {
 338				/* if the symbol is visible use the user value
 339				 * if available, otherwise try the default value
 340				 */
 341				sym->flags |= SYMBOL_WRITE;
 342				if (sym_has_value(sym)) {
 343					newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
 344							      sym->visible);
 345					goto calc_newval;
 346				}
 347			}
 348			if (sym->rev_dep.tri != no)
 349				sym->flags |= SYMBOL_WRITE;
 350			if (!sym_is_choice(sym)) {
 351				prop = sym_get_default_prop(sym);
 352				if (prop) {
 353					sym->flags |= SYMBOL_WRITE;
 354					newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 355							      prop->visible.tri);
 356				}
 357			}
 358		calc_newval:
 359			if (sym->dir_dep.tri == no && sym->rev_dep.tri != no) {
 360				struct expr *e;
 361				e = expr_simplify_unmet_dep(sym->rev_dep.expr,
 362				    sym->dir_dep.expr);
 363				fprintf(stderr, "warning: (");
 364				expr_fprint(e, stderr);
 365				fprintf(stderr, ") selects %s which has unmet direct dependencies (",
 366					sym->name);
 367				expr_fprint(sym->dir_dep.expr, stderr);
 368				fprintf(stderr, ")\n");
 369				expr_free(e);
 370			}
 371			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 372		}
 373		if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
 374			newval.tri = yes;
 375		break;
 376	case S_STRING:
 377	case S_HEX:
 378	case S_INT:
 379		if (sym->visible != no) {
 380			sym->flags |= SYMBOL_WRITE;
 381			if (sym_has_value(sym)) {
 382				newval.val = sym->def[S_DEF_USER].val;
 383				break;
 384			}
 385		}
 386		prop = sym_get_default_prop(sym);
 387		if (prop) {
 388			struct symbol *ds = prop_get_symbol(prop);
 389			if (ds) {
 390				sym->flags |= SYMBOL_WRITE;
 391				sym_calc_value(ds);
 392				newval.val = ds->curr.val;
 393			}
 394		}
 395		break;
 396	default:
 397		;
 398	}
 399
 400	sym->curr = newval;
 401	if (sym_is_choice(sym) && newval.tri == yes)
 402		sym->curr.val = sym_calc_choice(sym);
 403	sym_validate_range(sym);
 404
 405	if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
 406		sym_set_changed(sym);
 407		if (modules_sym == sym) {
 408			sym_set_all_changed();
 409			modules_val = modules_sym->curr.tri;
 410		}
 411	}
 412
 413	if (sym_is_choice(sym)) {
 414		struct symbol *choice_sym;
 415
 416		prop = sym_get_choice_prop(sym);
 417		expr_list_for_each_sym(prop->expr, e, choice_sym) {
 418			if ((sym->flags & SYMBOL_WRITE) &&
 419			    choice_sym->visible != no)
 420				choice_sym->flags |= SYMBOL_WRITE;
 421			if (sym->flags & SYMBOL_CHANGED)
 422				sym_set_changed(choice_sym);
 423		}
 424	}
 425
 426	if (sym->flags & SYMBOL_AUTO)
 427		sym->flags &= ~SYMBOL_WRITE;
 428}
 429
 430void sym_clear_all_valid(void)
 431{
 432	struct symbol *sym;
 433	int i;
 434
 435	for_all_symbols(i, sym)
 436		sym->flags &= ~SYMBOL_VALID;
 437	sym_add_change_count(1);
 438	if (modules_sym)
 439		sym_calc_value(modules_sym);
 440}
 441
 442void sym_set_changed(struct symbol *sym)
 443{
 444	struct property *prop;
 445
 446	sym->flags |= SYMBOL_CHANGED;
 447	for (prop = sym->prop; prop; prop = prop->next) {
 448		if (prop->menu)
 449			prop->menu->flags |= MENU_CHANGED;
 450	}
 451}
 452
 453void sym_set_all_changed(void)
 454{
 455	struct symbol *sym;
 456	int i;
 457
 458	for_all_symbols(i, sym)
 459		sym_set_changed(sym);
 460}
 461
 462bool sym_tristate_within_range(struct symbol *sym, tristate val)
 463{
 464	int type = sym_get_type(sym);
 465
 466	if (sym->visible == no)
 467		return false;
 468
 469	if (type != S_BOOLEAN && type != S_TRISTATE)
 470		return false;
 471
 472	if (type == S_BOOLEAN && val == mod)
 473		return false;
 474	if (sym->visible <= sym->rev_dep.tri)
 475		return false;
 476	if (sym_is_choice_value(sym) && sym->visible == yes)
 477		return val == yes;
 478	return val >= sym->rev_dep.tri && val <= sym->visible;
 479}
 480
 481bool sym_set_tristate_value(struct symbol *sym, tristate val)
 482{
 483	tristate oldval = sym_get_tristate_value(sym);
 484
 485	if (oldval != val && !sym_tristate_within_range(sym, val))
 486		return false;
 487
 488	if (!(sym->flags & SYMBOL_DEF_USER)) {
 489		sym->flags |= SYMBOL_DEF_USER;
 490		sym_set_changed(sym);
 491	}
 492	/*
 493	 * setting a choice value also resets the new flag of the choice
 494	 * symbol and all other choice values.
 495	 */
 496	if (sym_is_choice_value(sym) && val == yes) {
 497		struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 498		struct property *prop;
 499		struct expr *e;
 500
 501		cs->def[S_DEF_USER].val = sym;
 502		cs->flags |= SYMBOL_DEF_USER;
 503		prop = sym_get_choice_prop(cs);
 504		for (e = prop->expr; e; e = e->left.expr) {
 505			if (e->right.sym->visible != no)
 506				e->right.sym->flags |= SYMBOL_DEF_USER;
 507		}
 508	}
 509
 510	sym->def[S_DEF_USER].tri = val;
 511	if (oldval != val)
 512		sym_clear_all_valid();
 513
 514	return true;
 515}
 516
 517tristate sym_toggle_tristate_value(struct symbol *sym)
 518{
 519	tristate oldval, newval;
 520
 521	oldval = newval = sym_get_tristate_value(sym);
 522	do {
 523		switch (newval) {
 524		case no:
 525			newval = mod;
 526			break;
 527		case mod:
 528			newval = yes;
 529			break;
 530		case yes:
 531			newval = no;
 532			break;
 533		}
 534		if (sym_set_tristate_value(sym, newval))
 535			break;
 536	} while (oldval != newval);
 537	return newval;
 538}
 539
 540bool sym_string_valid(struct symbol *sym, const char *str)
 541{
 542	signed char ch;
 543
 544	switch (sym->type) {
 545	case S_STRING:
 546		return true;
 547	case S_INT:
 548		ch = *str++;
 549		if (ch == '-')
 550			ch = *str++;
 551		if (!isdigit(ch))
 552			return false;
 553		if (ch == '0' && *str != 0)
 554			return false;
 555		while ((ch = *str++)) {
 556			if (!isdigit(ch))
 557				return false;
 558		}
 559		return true;
 560	case S_HEX:
 561		if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
 562			str += 2;
 563		ch = *str++;
 564		do {
 565			if (!isxdigit(ch))
 566				return false;
 567		} while ((ch = *str++));
 568		return true;
 569	case S_BOOLEAN:
 570	case S_TRISTATE:
 571		switch (str[0]) {
 572		case 'y': case 'Y':
 573		case 'm': case 'M':
 574		case 'n': case 'N':
 575			return true;
 576		}
 577		return false;
 578	default:
 579		return false;
 580	}
 581}
 582
 583bool sym_string_within_range(struct symbol *sym, const char *str)
 584{
 585	struct property *prop;
 586	int val;
 587
 588	switch (sym->type) {
 589	case S_STRING:
 590		return sym_string_valid(sym, str);
 591	case S_INT:
 592		if (!sym_string_valid(sym, str))
 593			return false;
 594		prop = sym_get_range_prop(sym);
 595		if (!prop)
 596			return true;
 597		val = strtol(str, NULL, 10);
 598		return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
 599		       val <= sym_get_range_val(prop->expr->right.sym, 10);
 600	case S_HEX:
 601		if (!sym_string_valid(sym, str))
 602			return false;
 603		prop = sym_get_range_prop(sym);
 604		if (!prop)
 605			return true;
 606		val = strtol(str, NULL, 16);
 607		return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
 608		       val <= sym_get_range_val(prop->expr->right.sym, 16);
 609	case S_BOOLEAN:
 610	case S_TRISTATE:
 611		switch (str[0]) {
 612		case 'y': case 'Y':
 613			return sym_tristate_within_range(sym, yes);
 614		case 'm': case 'M':
 615			return sym_tristate_within_range(sym, mod);
 616		case 'n': case 'N':
 617			return sym_tristate_within_range(sym, no);
 618		}
 619		return false;
 620	default:
 621		return false;
 622	}
 623}
 624
 625bool sym_set_string_value(struct symbol *sym, const char *newval)
 626{
 627	const char *oldval;
 628	char *val;
 629	int size;
 630
 631	switch (sym->type) {
 632	case S_BOOLEAN:
 633	case S_TRISTATE:
 634		switch (newval[0]) {
 635		case 'y': case 'Y':
 636			return sym_set_tristate_value(sym, yes);
 637		case 'm': case 'M':
 638			return sym_set_tristate_value(sym, mod);
 639		case 'n': case 'N':
 640			return sym_set_tristate_value(sym, no);
 641		}
 642		return false;
 643	default:
 644		;
 645	}
 646
 647	if (!sym_string_within_range(sym, newval))
 648		return false;
 649
 650	if (!(sym->flags & SYMBOL_DEF_USER)) {
 651		sym->flags |= SYMBOL_DEF_USER;
 652		sym_set_changed(sym);
 653	}
 654
 655	oldval = sym->def[S_DEF_USER].val;
 656	size = strlen(newval) + 1;
 657	if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
 658		size += 2;
 659		sym->def[S_DEF_USER].val = val = malloc(size);
 660		*val++ = '0';
 661		*val++ = 'x';
 662	} else if (!oldval || strcmp(oldval, newval))
 663		sym->def[S_DEF_USER].val = val = malloc(size);
 664	else
 665		return true;
 666
 667	strcpy(val, newval);
 668	free((void *)oldval);
 669	sym_clear_all_valid();
 670
 671	return true;
 672}
 673
 674/*
 675 * Find the default value associated to a symbol.
 676 * For tristate symbol handle the modules=n case
 677 * in which case "m" becomes "y".
 678 * If the symbol does not have any default then fallback
 679 * to the fixed default values.
 680 */
 681const char *sym_get_string_default(struct symbol *sym)
 682{
 683	struct property *prop;
 684	struct symbol *ds;
 685	const char *str;
 686	tristate val;
 687
 688	sym_calc_visibility(sym);
 689	sym_calc_value(modules_sym);
 690	val = symbol_no.curr.tri;
 691	str = symbol_empty.curr.val;
 692
 693	/* If symbol has a default value look it up */
 694	prop = sym_get_default_prop(sym);
 695	if (prop != NULL) {
 696		switch (sym->type) {
 697		case S_BOOLEAN:
 698		case S_TRISTATE:
 699			/* The visibility may limit the value from yes => mod */
 700			val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
 701			break;
 702		default:
 703			/*
 704			 * The following fails to handle the situation
 705			 * where a default value is further limited by
 706			 * the valid range.
 707			 */
 708			ds = prop_get_symbol(prop);
 709			if (ds != NULL) {
 710				sym_calc_value(ds);
 711				str = (const char *)ds->curr.val;
 712			}
 713		}
 714	}
 715
 716	/* Handle select statements */
 717	val = EXPR_OR(val, sym->rev_dep.tri);
 718
 719	/* transpose mod to yes if modules are not enabled */
 720	if (val == mod)
 721		if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
 722			val = yes;
 723
 724	/* transpose mod to yes if type is bool */
 725	if (sym->type == S_BOOLEAN && val == mod)
 726		val = yes;
 727
 728	switch (sym->type) {
 729	case S_BOOLEAN:
 730	case S_TRISTATE:
 731		switch (val) {
 732		case no: return "n";
 733		case mod: return "m";
 734		case yes: return "y";
 735		}
 736	case S_INT:
 737	case S_HEX:
 738		return str;
 739	case S_STRING:
 740		return str;
 741	case S_OTHER:
 742	case S_UNKNOWN:
 743		break;
 744	}
 745	return "";
 746}
 747
 748const char *sym_get_string_value(struct symbol *sym)
 749{
 750	tristate val;
 751
 752	switch (sym->type) {
 753	case S_BOOLEAN:
 754	case S_TRISTATE:
 755		val = sym_get_tristate_value(sym);
 756		switch (val) {
 757		case no:
 758			return "n";
 759		case mod:
 760			sym_calc_value(modules_sym);
 761			return (modules_sym->curr.tri == no) ? "n" : "m";
 762		case yes:
 763			return "y";
 764		}
 765		break;
 766	default:
 767		;
 768	}
 769	return (const char *)sym->curr.val;
 770}
 771
 772bool sym_is_changable(struct symbol *sym)
 773{
 774	return sym->visible > sym->rev_dep.tri;
 775}
 776
 777static unsigned strhash(const char *s)
 778{
 779	/* fnv32 hash */
 780	unsigned hash = 2166136261U;
 781	for (; *s; s++)
 782		hash = (hash ^ *s) * 0x01000193;
 783	return hash;
 784}
 785
 786struct symbol *sym_lookup(const char *name, int flags)
 787{
 788	struct symbol *symbol;
 789	char *new_name;
 790	int hash;
 791
 792	if (name) {
 793		if (name[0] && !name[1]) {
 794			switch (name[0]) {
 795			case 'y': return &symbol_yes;
 796			case 'm': return &symbol_mod;
 797			case 'n': return &symbol_no;
 798			}
 799		}
 800		hash = strhash(name) % SYMBOL_HASHSIZE;
 801
 802		for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 803			if (symbol->name &&
 804			    !strcmp(symbol->name, name) &&
 805			    (flags ? symbol->flags & flags
 806				   : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
 807				return symbol;
 808		}
 809		new_name = strdup(name);
 810	} else {
 811		new_name = NULL;
 812		hash = 0;
 813	}
 814
 815	symbol = malloc(sizeof(*symbol));
 816	memset(symbol, 0, sizeof(*symbol));
 817	symbol->name = new_name;
 818	symbol->type = S_UNKNOWN;
 819	symbol->flags |= flags;
 820
 821	symbol->next = symbol_hash[hash];
 822	symbol_hash[hash] = symbol;
 823
 824	return symbol;
 825}
 826
 827struct symbol *sym_find(const char *name)
 828{
 829	struct symbol *symbol = NULL;
 830	int hash = 0;
 831
 832	if (!name)
 833		return NULL;
 834
 835	if (name[0] && !name[1]) {
 836		switch (name[0]) {
 837		case 'y': return &symbol_yes;
 838		case 'm': return &symbol_mod;
 839		case 'n': return &symbol_no;
 840		}
 841	}
 842	hash = strhash(name) % SYMBOL_HASHSIZE;
 843
 844	for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 845		if (symbol->name &&
 846		    !strcmp(symbol->name, name) &&
 847		    !(symbol->flags & SYMBOL_CONST))
 848				break;
 849	}
 850
 851	return symbol;
 852}
 853
 854/*
 855 * Expand symbol's names embedded in the string given in argument. Symbols'
 856 * name to be expanded shall be prefixed by a '$'. Unknown symbol expands to
 857 * the empty string.
 858 */
 859const char *sym_expand_string_value(const char *in)
 860{
 861	const char *src;
 862	char *res;
 863	size_t reslen;
 864
 865	reslen = strlen(in) + 1;
 866	res = malloc(reslen);
 867	res[0] = '\0';
 868
 869	while ((src = strchr(in, '$'))) {
 870		char *p, name[SYMBOL_MAXLENGTH];
 871		const char *symval = "";
 872		struct symbol *sym;
 873		size_t newlen;
 874
 875		strncat(res, in, src - in);
 876		src++;
 877
 878		p = name;
 879		while (isalnum(*src) || *src == '_')
 880			*p++ = *src++;
 881		*p = '\0';
 882
 883		sym = sym_find(name);
 884		if (sym != NULL) {
 885			sym_calc_value(sym);
 886			symval = sym_get_string_value(sym);
 887		}
 888
 889		newlen = strlen(res) + strlen(symval) + strlen(src) + 1;
 890		if (newlen > reslen) {
 891			reslen = newlen;
 892			res = realloc(res, reslen);
 893		}
 894
 895		strcat(res, symval);
 896		in = src;
 897	}
 898	strcat(res, in);
 899
 900	return res;
 901}
 902
 903const char *sym_escape_string_value(const char *in)
 904{
 905	const char *p;
 906	size_t reslen;
 907	char *res;
 908	size_t l;
 909
 910	reslen = strlen(in) + strlen("\"\"") + 1;
 911
 912	p = in;
 913	for (;;) {
 914		l = strcspn(p, "\"\\");
 915		p += l;
 916
 917		if (p[0] == '\0')
 918			break;
 919
 920		reslen++;
 921		p++;
 922	}
 923
 924	res = malloc(reslen);
 925	res[0] = '\0';
 926
 927	strcat(res, "\"");
 928
 929	p = in;
 930	for (;;) {
 931		l = strcspn(p, "\"\\");
 932		strncat(res, p, l);
 933		p += l;
 934
 935		if (p[0] == '\0')
 936			break;
 937
 938		strcat(res, "\\");
 939		strncat(res, p++, 1);
 940	}
 941
 942	strcat(res, "\"");
 943	return res;
 944}
 945
 946struct symbol **sym_re_search(const char *pattern)
 947{
 948	struct symbol *sym, **sym_arr = NULL;
 949	int i, cnt, size;
 950	regex_t re;
 951
 952	cnt = size = 0;
 953	/* Skip if empty */
 954	if (strlen(pattern) == 0)
 955		return NULL;
 956	if (regcomp(&re, pattern, REG_EXTENDED|REG_NOSUB|REG_ICASE))
 957		return NULL;
 958
 959	for_all_symbols(i, sym) {
 960		if (sym->flags & SYMBOL_CONST || !sym->name)
 961			continue;
 962		if (regexec(&re, sym->name, 0, NULL, 0))
 963			continue;
 964		if (cnt + 1 >= size) {
 965			void *tmp = sym_arr;
 966			size += 16;
 967			sym_arr = realloc(sym_arr, size * sizeof(struct symbol *));
 968			if (!sym_arr) {
 969				free(tmp);
 970				return NULL;
 971			}
 972		}
 973		sym_calc_value(sym);
 974		sym_arr[cnt++] = sym;
 975	}
 976	if (sym_arr)
 977		sym_arr[cnt] = NULL;
 978	regfree(&re);
 979
 980	return sym_arr;
 981}
 982
 983/*
 984 * When we check for recursive dependencies we use a stack to save
 985 * current state so we can print out relevant info to user.
 986 * The entries are located on the call stack so no need to free memory.
 987 * Note inser() remove() must always match to properly clear the stack.
 988 */
 989static struct dep_stack {
 990	struct dep_stack *prev, *next;
 991	struct symbol *sym;
 992	struct property *prop;
 993	struct expr *expr;
 994} *check_top;
 995
 996static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
 997{
 998	memset(stack, 0, sizeof(*stack));
 999	if (check_top)
1000		check_top->next = stack;
1001	stack->prev = check_top;
1002	stack->sym = sym;
1003	check_top = stack;
1004}
1005
1006static void dep_stack_remove(void)
1007{
1008	check_top = check_top->prev;
1009	if (check_top)
1010		check_top->next = NULL;
1011}
1012
1013/*
1014 * Called when we have detected a recursive dependency.
1015 * check_top point to the top of the stact so we use
1016 * the ->prev pointer to locate the bottom of the stack.
1017 */
1018static void sym_check_print_recursive(struct symbol *last_sym)
1019{
1020	struct dep_stack *stack;
1021	struct symbol *sym, *next_sym;
1022	struct menu *menu = NULL;
1023	struct property *prop;
1024	struct dep_stack cv_stack;
1025
1026	if (sym_is_choice_value(last_sym)) {
1027		dep_stack_insert(&cv_stack, last_sym);
1028		last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1029	}
1030
1031	for (stack = check_top; stack != NULL; stack = stack->prev)
1032		if (stack->sym == last_sym)
1033			break;
1034	if (!stack) {
1035		fprintf(stderr, "unexpected recursive dependency error\n");
1036		return;
1037	}
1038
1039	for (; stack; stack = stack->next) {
1040		sym = stack->sym;
1041		next_sym = stack->next ? stack->next->sym : last_sym;
1042		prop = stack->prop;
1043		if (prop == NULL)
1044			prop = stack->sym->prop;
1045
1046		/* for choice values find the menu entry (used below) */
1047		if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1048			for (prop = sym->prop; prop; prop = prop->next) {
1049				menu = prop->menu;
1050				if (prop->menu)
1051					break;
1052			}
1053		}
1054		if (stack->sym == last_sym)
1055			fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1056				prop->file->name, prop->lineno);
1057		if (stack->expr) {
1058			fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1059				prop->file->name, prop->lineno,
1060				sym->name ? sym->name : "<choice>",
1061				prop_get_type_name(prop->type),
1062				next_sym->name ? next_sym->name : "<choice>");
1063		} else if (stack->prop) {
1064			fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1065				prop->file->name, prop->lineno,
1066				sym->name ? sym->name : "<choice>",
1067				next_sym->name ? next_sym->name : "<choice>");
1068		} else if (sym_is_choice(sym)) {
1069			fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1070				menu->file->name, menu->lineno,
1071				sym->name ? sym->name : "<choice>",
1072				next_sym->name ? next_sym->name : "<choice>");
1073		} else if (sym_is_choice_value(sym)) {
1074			fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1075				menu->file->name, menu->lineno,
1076				sym->name ? sym->name : "<choice>",
1077				next_sym->name ? next_sym->name : "<choice>");
1078		} else {
1079			fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1080				prop->file->name, prop->lineno,
1081				sym->name ? sym->name : "<choice>",
1082				next_sym->name ? next_sym->name : "<choice>");
1083		}
1084	}
1085
1086	if (check_top == &cv_stack)
1087		dep_stack_remove();
1088}
1089
1090static struct symbol *sym_check_expr_deps(struct expr *e)
1091{
1092	struct symbol *sym;
1093
1094	if (!e)
1095		return NULL;
1096	switch (e->type) {
1097	case E_OR:
1098	case E_AND:
1099		sym = sym_check_expr_deps(e->left.expr);
1100		if (sym)
1101			return sym;
1102		return sym_check_expr_deps(e->right.expr);
1103	case E_NOT:
1104		return sym_check_expr_deps(e->left.expr);
1105	case E_EQUAL:
1106	case E_UNEQUAL:
1107		sym = sym_check_deps(e->left.sym);
1108		if (sym)
1109			return sym;
1110		return sym_check_deps(e->right.sym);
1111	case E_SYMBOL:
1112		return sym_check_deps(e->left.sym);
1113	default:
1114		break;
1115	}
1116	printf("Oops! How to check %d?\n", e->type);
1117	return NULL;
1118}
1119
1120/* return NULL when dependencies are OK */
1121static struct symbol *sym_check_sym_deps(struct symbol *sym)
1122{
1123	struct symbol *sym2;
1124	struct property *prop;
1125	struct dep_stack stack;
1126
1127	dep_stack_insert(&stack, sym);
1128
1129	sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1130	if (sym2)
1131		goto out;
1132
1133	for (prop = sym->prop; prop; prop = prop->next) {
1134		if (prop->type == P_CHOICE || prop->type == P_SELECT)
1135			continue;
1136		stack.prop = prop;
1137		sym2 = sym_check_expr_deps(prop->visible.expr);
1138		if (sym2)
1139			break;
1140		if (prop->type != P_DEFAULT || sym_is_choice(sym))
1141			continue;
1142		stack.expr = prop->expr;
1143		sym2 = sym_check_expr_deps(prop->expr);
1144		if (sym2)
1145			break;
1146		stack.expr = NULL;
1147	}
1148
1149out:
1150	dep_stack_remove();
1151
1152	return sym2;
1153}
1154
1155static struct symbol *sym_check_choice_deps(struct symbol *choice)
1156{
1157	struct symbol *sym, *sym2;
1158	struct property *prop;
1159	struct expr *e;
1160	struct dep_stack stack;
1161
1162	dep_stack_insert(&stack, choice);
1163
1164	prop = sym_get_choice_prop(choice);
1165	expr_list_for_each_sym(prop->expr, e, sym)
1166		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1167
1168	choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1169	sym2 = sym_check_sym_deps(choice);
1170	choice->flags &= ~SYMBOL_CHECK;
1171	if (sym2)
1172		goto out;
1173
1174	expr_list_for_each_sym(prop->expr, e, sym) {
1175		sym2 = sym_check_sym_deps(sym);
1176		if (sym2)
1177			break;
1178	}
1179out:
1180	expr_list_for_each_sym(prop->expr, e, sym)
1181		sym->flags &= ~SYMBOL_CHECK;
1182
1183	if (sym2 && sym_is_choice_value(sym2) &&
1184	    prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1185		sym2 = choice;
1186
1187	dep_stack_remove();
1188
1189	return sym2;
1190}
1191
1192struct symbol *sym_check_deps(struct symbol *sym)
1193{
1194	struct symbol *sym2;
1195	struct property *prop;
1196
1197	if (sym->flags & SYMBOL_CHECK) {
1198		sym_check_print_recursive(sym);
1199		return sym;
1200	}
1201	if (sym->flags & SYMBOL_CHECKED)
1202		return NULL;
1203
1204	if (sym_is_choice_value(sym)) {
1205		struct dep_stack stack;
1206
1207		/* for choice groups start the check with main choice symbol */
1208		dep_stack_insert(&stack, sym);
1209		prop = sym_get_choice_prop(sym);
1210		sym2 = sym_check_deps(prop_get_symbol(prop));
1211		dep_stack_remove();
1212	} else if (sym_is_choice(sym)) {
1213		sym2 = sym_check_choice_deps(sym);
1214	} else {
1215		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1216		sym2 = sym_check_sym_deps(sym);
1217		sym->flags &= ~SYMBOL_CHECK;
1218	}
1219
1220	if (sym2 && sym2 == sym)
1221		sym2 = NULL;
1222
1223	return sym2;
1224}
1225
1226struct property *prop_alloc(enum prop_type type, struct symbol *sym)
1227{
1228	struct property *prop;
1229	struct property **propp;
1230
1231	prop = malloc(sizeof(*prop));
1232	memset(prop, 0, sizeof(*prop));
1233	prop->type = type;
1234	prop->sym = sym;
1235	prop->file = current_file;
1236	prop->lineno = zconf_lineno();
1237
1238	/* append property to the prop list of symbol */
1239	if (sym) {
1240		for (propp = &sym->prop; *propp; propp = &(*propp)->next)
1241			;
1242		*propp = prop;
1243	}
1244
1245	return prop;
1246}
1247
1248struct symbol *prop_get_symbol(struct property *prop)
1249{
1250	if (prop->expr && (prop->expr->type == E_SYMBOL ||
1251			   prop->expr->type == E_LIST))
1252		return prop->expr->left.sym;
1253	return NULL;
1254}
1255
1256const char *prop_get_type_name(enum prop_type type)
1257{
1258	switch (type) {
1259	case P_PROMPT:
1260		return "prompt";
1261	case P_ENV:
1262		return "env";
1263	case P_COMMENT:
1264		return "comment";
1265	case P_MENU:
1266		return "menu";
1267	case P_DEFAULT:
1268		return "default";
1269	case P_CHOICE:
1270		return "choice";
1271	case P_SELECT:
1272		return "select";
1273	case P_RANGE:
1274		return "range";
1275	case P_SYMBOL:
1276		return "symbol";
1277	case P_UNKNOWN:
1278		break;
1279	}
1280	return "unknown";
1281}
1282
1283static void prop_add_env(const char *env)
1284{
1285	struct symbol *sym, *sym2;
1286	struct property *prop;
1287	char *p;
1288
1289	sym = current_entry->sym;
1290	sym->flags |= SYMBOL_AUTO;
1291	for_all_properties(sym, prop, P_ENV) {
1292		sym2 = prop_get_symbol(prop);
1293		if (strcmp(sym2->name, env))
1294			menu_warn(current_entry, "redefining environment symbol from %s",
1295				  sym2->name);
1296		return;
1297	}
1298
1299	prop = prop_alloc(P_ENV, sym);
1300	prop->expr = expr_alloc_symbol(sym_lookup(env, SYMBOL_CONST));
1301
1302	sym_env_list = expr_alloc_one(E_LIST, sym_env_list);
1303	sym_env_list->right.sym = sym;
1304
1305	p = getenv(env);
1306	if (p)
1307		sym_add_default(sym, p);
1308	else
1309		menu_warn(current_entry, "environment variable %s undefined", env);
1310}