Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1268 insertions, 0 deletions

diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
new file mode 100644
index 000000000..a76925b46
--- /dev/null
+++ b/scripts/kconfig/symbol.c
@@ -0,0 +1,1268 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
+ */
+
+#include <sys/types.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+#include <regex.h>
+
+#include "lkc.h"
+
+struct symbol symbol_yes = {
+	.name = "y",
+	.curr = { "y", yes },
+	.flags = SYMBOL_CONST|SYMBOL_VALID,
+};
+
+struct symbol symbol_mod = {
+	.name = "m",
+	.curr = { "m", mod },
+	.flags = SYMBOL_CONST|SYMBOL_VALID,
+};
+
+struct symbol symbol_no = {
+	.name = "n",
+	.curr = { "n", no },
+	.flags = SYMBOL_CONST|SYMBOL_VALID,
+};
+
+static struct symbol symbol_empty = {
+	.name = "",
+	.curr = { "", no },
+	.flags = SYMBOL_VALID,
+};
+
+struct symbol *modules_sym;
+static tristate modules_val;
+
+enum symbol_type sym_get_type(struct symbol *sym)
+{
+	enum symbol_type type = sym->type;
+
+	if (type == S_TRISTATE) {
+		if (sym_is_choice_value(sym) && sym->visible == yes)
+			type = S_BOOLEAN;
+		else if (modules_val == no)
+			type = S_BOOLEAN;
+	}
+	return type;
+}
+
+const char *sym_type_name(enum symbol_type type)
+{
+	switch (type) {
+	case S_BOOLEAN:
+		return "bool";
+	case S_TRISTATE:
+		return "tristate";
+	case S_INT:
+		return "integer";
+	case S_HEX:
+		return "hex";
+	case S_STRING:
+		return "string";
+	case S_UNKNOWN:
+		return "unknown";
+	}
+	return "???";
+}
+
+struct property *sym_get_choice_prop(struct symbol *sym)
+{
+	struct property *prop;
+
+	for_all_choices(sym, prop)
+		return prop;
+	return NULL;
+}
+
+static struct property *sym_get_default_prop(struct symbol *sym)
+{
+	struct property *prop;
+
+	for_all_defaults(sym, prop) {
+		prop->visible.tri = expr_calc_value(prop->visible.expr);
+		if (prop->visible.tri != no)
+			return prop;
+	}
+	return NULL;
+}
+
+struct property *sym_get_range_prop(struct symbol *sym)
+{
+	struct property *prop;
+
+	for_all_properties(sym, prop, P_RANGE) {
+		prop->visible.tri = expr_calc_value(prop->visible.expr);
+		if (prop->visible.tri != no)
+			return prop;
+	}
+	return NULL;
+}
+
+static long long sym_get_range_val(struct symbol *sym, int base)
+{
+	sym_calc_value(sym);
+	switch (sym->type) {
+	case S_INT:
+		base = 10;
+		break;
+	case S_HEX:
+		base = 16;
+		break;
+	default:
+		break;
+	}
+	return strtoll(sym->curr.val, NULL, base);
+}
+
+static void sym_validate_range(struct symbol *sym)
+{
+	struct property *prop;
+	struct symbol *range_sym;
+	int base;
+	long long val, val2;
+
+	switch (sym->type) {
+	case S_INT:
+		base = 10;
+		break;
+	case S_HEX:
+		base = 16;
+		break;
+	default:
+		return;
+	}
+	prop = sym_get_range_prop(sym);
+	if (!prop)
+		return;
+	val = strtoll(sym->curr.val, NULL, base);
+	range_sym = prop->expr->left.sym;
+	val2 = sym_get_range_val(range_sym, base);
+	if (val >= val2) {
+		range_sym = prop->expr->right.sym;
+		val2 = sym_get_range_val(range_sym, base);
+		if (val <= val2)
+			return;
+	}
+	sym->curr.val = range_sym->curr.val;
+}
+
+static void sym_set_changed(struct symbol *sym)
+{
+	struct property *prop;
+
+	sym->flags |= SYMBOL_CHANGED;
+	for (prop = sym->prop; prop; prop = prop->next) {
+		if (prop->menu)
+			prop->menu->flags |= MENU_CHANGED;
+	}
+}
+
+static void sym_set_all_changed(void)
+{
+	struct symbol *sym;
+	int i;
+
+	for_all_symbols(i, sym)
+		sym_set_changed(sym);
+}
+
+static void sym_calc_visibility(struct symbol *sym)
+{
+	struct property *prop;
+	struct symbol *choice_sym = NULL;
+	tristate tri;
+
+	/* any prompt visible? */
+	tri = no;
+
+	if (sym_is_choice_value(sym))
+		choice_sym = prop_get_symbol(sym_get_choice_prop(sym));
+
+	for_all_prompts(sym, prop) {
+		prop->visible.tri = expr_calc_value(prop->visible.expr);
+		/*
+		 * Tristate choice_values with visibility 'mod' are
+		 * not visible if the corresponding choice's value is
+		 * 'yes'.
+		 */
+		if (choice_sym && sym->type == S_TRISTATE &&
+		    prop->visible.tri == mod && choice_sym->curr.tri == yes)
+			prop->visible.tri = no;
+
+		tri = EXPR_OR(tri, prop->visible.tri);
+	}
+	if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
+		tri = yes;
+	if (sym->visible != tri) {
+		sym->visible = tri;
+		sym_set_changed(sym);
+	}
+	if (sym_is_choice_value(sym))
+		return;
+	/* defaulting to "yes" if no explicit "depends on" are given */
+	tri = yes;
+	if (sym->dir_dep.expr)
+		tri = expr_calc_value(sym->dir_dep.expr);
+	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
+		tri = yes;
+	if (sym->dir_dep.tri != tri) {
+		sym->dir_dep.tri = tri;
+		sym_set_changed(sym);
+	}
+	tri = no;
+	if (sym->rev_dep.expr)
+		tri = expr_calc_value(sym->rev_dep.expr);
+	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
+		tri = yes;
+	if (sym->rev_dep.tri != tri) {
+		sym->rev_dep.tri = tri;
+		sym_set_changed(sym);
+	}
+	tri = no;
+	if (sym->implied.expr)
+		tri = expr_calc_value(sym->implied.expr);
+	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
+		tri = yes;
+	if (sym->implied.tri != tri) {
+		sym->implied.tri = tri;
+		sym_set_changed(sym);
+	}
+}
+
+/*
+ * Find the default symbol for a choice.
+ * First try the default values for the choice symbol
+ * Next locate the first visible choice value
+ * Return NULL if none was found
+ */
+struct symbol *sym_choice_default(struct symbol *sym)
+{
+	struct symbol *def_sym;
+	struct property *prop;
+	struct expr *e;
+
+	/* any of the defaults visible? */
+	for_all_defaults(sym, prop) {
+		prop->visible.tri = expr_calc_value(prop->visible.expr);
+		if (prop->visible.tri == no)
+			continue;
+		def_sym = prop_get_symbol(prop);
+		if (def_sym->visible != no)
+			return def_sym;
+	}
+
+	/* just get the first visible value */
+	prop = sym_get_choice_prop(sym);
+	expr_list_for_each_sym(prop->expr, e, def_sym)
+		if (def_sym->visible != no)
+			return def_sym;
+
+	/* failed to locate any defaults */
+	return NULL;
+}
+
+static struct symbol *sym_calc_choice(struct symbol *sym)
+{
+	struct symbol *def_sym;
+	struct property *prop;
+	struct expr *e;
+	int flags;
+
+	/* first calculate all choice values' visibilities */
+	flags = sym->flags;
+	prop = sym_get_choice_prop(sym);
+	expr_list_for_each_sym(prop->expr, e, def_sym) {
+		sym_calc_visibility(def_sym);
+		if (def_sym->visible != no)
+			flags &= def_sym->flags;
+	}
+
+	sym->flags &= flags | ~SYMBOL_DEF_USER;
+
+	/* is the user choice visible? */
+	def_sym = sym->def[S_DEF_USER].val;
+	if (def_sym && def_sym->visible != no)
+		return def_sym;
+
+	def_sym = sym_choice_default(sym);
+
+	if (def_sym == NULL)
+		/* no choice? reset tristate value */
+		sym->curr.tri = no;
+
+	return def_sym;
+}
+
+static void sym_warn_unmet_dep(struct symbol *sym)
+{
+	struct gstr gs = str_new();
+
+	str_printf(&gs,
+		   "\nWARNING: unmet direct dependencies detected for %s\n",
+		   sym->name);
+	str_printf(&gs,
+		   "  Depends on [%c]: ",
+		   sym->dir_dep.tri == mod ? 'm' : 'n');
+	expr_gstr_print(sym->dir_dep.expr, &gs);
+	str_printf(&gs, "\n");
+
+	expr_gstr_print_revdep(sym->rev_dep.expr, &gs, yes,
+			       "  Selected by [y]:\n");
+	expr_gstr_print_revdep(sym->rev_dep.expr, &gs, mod,
+			       "  Selected by [m]:\n");
+
+	fputs(str_get(&gs), stderr);
+}
+
+void sym_calc_value(struct symbol *sym)
+{
+	struct symbol_value newval, oldval;
+	struct property *prop;
+	struct expr *e;
+
+	if (!sym)
+		return;
+
+	if (sym->flags & SYMBOL_VALID)
+		return;
+
+	if (sym_is_choice_value(sym) &&
+	    sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
+		sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
+		prop = sym_get_choice_prop(sym);
+		sym_calc_value(prop_get_symbol(prop));
+	}
+
+	sym->flags |= SYMBOL_VALID;
+
+	oldval = sym->curr;
+
+	switch (sym->type) {
+	case S_INT:
+	case S_HEX:
+	case S_STRING:
+		newval = symbol_empty.curr;
+		break;
+	case S_BOOLEAN:
+	case S_TRISTATE:
+		newval = symbol_no.curr;
+		break;
+	default:
+		sym->curr.val = sym->name;
+		sym->curr.tri = no;
+		return;
+	}
+	sym->flags &= ~SYMBOL_WRITE;
+
+	sym_calc_visibility(sym);
+
+	if (sym->visible != no)
+		sym->flags |= SYMBOL_WRITE;
+
+	/* set default if recursively called */
+	sym->curr = newval;
+
+	switch (sym_get_type(sym)) {
+	case S_BOOLEAN:
+	case S_TRISTATE:
+		if (sym_is_choice_value(sym) && sym->visible == yes) {
+			prop = sym_get_choice_prop(sym);
+			newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
+		} else {
+			if (sym->visible != no) {
+				/* if the symbol is visible use the user value
+				 * if available, otherwise try the default value
+				 */
+				if (sym_has_value(sym)) {
+					newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
+							      sym->visible);
+					goto calc_newval;
+				}
+			}
+			if (sym->rev_dep.tri != no)
+				sym->flags |= SYMBOL_WRITE;
+			if (!sym_is_choice(sym)) {
+				prop = sym_get_default_prop(sym);
+				if (prop) {
+					newval.tri = EXPR_AND(expr_calc_value(prop->expr),
+							      prop->visible.tri);
+					if (newval.tri != no)
+						sym->flags |= SYMBOL_WRITE;
+				}
+				if (sym->implied.tri != no) {
+					sym->flags |= SYMBOL_WRITE;
+					newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
+					newval.tri = EXPR_AND(newval.tri,
+							      sym->dir_dep.tri);
+				}
+			}
+		calc_newval:
+			if (sym->dir_dep.tri < sym->rev_dep.tri)
+				sym_warn_unmet_dep(sym);
+			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
+		}
+		if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
+			newval.tri = yes;
+		break;
+	case S_STRING:
+	case S_HEX:
+	case S_INT:
+		if (sym->visible != no && sym_has_value(sym)) {
+			newval.val = sym->def[S_DEF_USER].val;
+			break;
+		}
+		prop = sym_get_default_prop(sym);
+		if (prop) {
+			struct symbol *ds = prop_get_symbol(prop);
+			if (ds) {
+				sym->flags |= SYMBOL_WRITE;
+				sym_calc_value(ds);
+				newval.val = ds->curr.val;
+			}
+		}
+		break;
+	default:
+		;
+	}
+
+	sym->curr = newval;
+	if (sym_is_choice(sym) && newval.tri == yes)
+		sym->curr.val = sym_calc_choice(sym);
+	sym_validate_range(sym);
+
+	if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
+		sym_set_changed(sym);
+		if (modules_sym == sym) {
+			sym_set_all_changed();
+			modules_val = modules_sym->curr.tri;
+		}
+	}
+
+	if (sym_is_choice(sym)) {
+		struct symbol *choice_sym;
+
+		prop = sym_get_choice_prop(sym);
+		expr_list_for_each_sym(prop->expr, e, choice_sym) {
+			if ((sym->flags & SYMBOL_WRITE) &&
+			    choice_sym->visible != no)
+				choice_sym->flags |= SYMBOL_WRITE;
+			if (sym->flags & SYMBOL_CHANGED)
+				sym_set_changed(choice_sym);
+		}
+	}
+
+	if (sym->flags & SYMBOL_NO_WRITE)
+		sym->flags &= ~SYMBOL_WRITE;
+
+	if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
+		set_all_choice_values(sym);
+}
+
+void sym_clear_all_valid(void)
+{
+	struct symbol *sym;
+	int i;
+
+	for_all_symbols(i, sym)
+		sym->flags &= ~SYMBOL_VALID;
+	conf_set_changed(true);
+	sym_calc_value(modules_sym);
+}
+
+bool sym_tristate_within_range(struct symbol *sym, tristate val)
+{
+	int type = sym_get_type(sym);
+
+	if (sym->visible == no)
+		return false;
+
+	if (type != S_BOOLEAN && type != S_TRISTATE)
+		return false;
+
+	if (type == S_BOOLEAN && val == mod)
+		return false;
+	if (sym->visible <= sym->rev_dep.tri)
+		return false;
+	if (sym_is_choice_value(sym) && sym->visible == yes)
+		return val == yes;
+	return val >= sym->rev_dep.tri && val <= sym->visible;
+}
+
+bool sym_set_tristate_value(struct symbol *sym, tristate val)
+{
+	tristate oldval = sym_get_tristate_value(sym);
+
+	if (oldval != val && !sym_tristate_within_range(sym, val))
+		return false;
+
+	if (!(sym->flags & SYMBOL_DEF_USER)) {
+		sym->flags |= SYMBOL_DEF_USER;
+		sym_set_changed(sym);
+	}
+	/*
+	 * setting a choice value also resets the new flag of the choice
+	 * symbol and all other choice values.
+	 */
+	if (sym_is_choice_value(sym) && val == yes) {
+		struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
+		struct property *prop;
+		struct expr *e;
+
+		cs->def[S_DEF_USER].val = sym;
+		cs->flags |= SYMBOL_DEF_USER;
+		prop = sym_get_choice_prop(cs);
+		for (e = prop->expr; e; e = e->left.expr) {
+			if (e->right.sym->visible != no)
+				e->right.sym->flags |= SYMBOL_DEF_USER;
+		}
+	}
+
+	sym->def[S_DEF_USER].tri = val;
+	if (oldval != val)
+		sym_clear_all_valid();
+
+	return true;
+}
+
+tristate sym_toggle_tristate_value(struct symbol *sym)
+{
+	tristate oldval, newval;
+
+	oldval = newval = sym_get_tristate_value(sym);
+	do {
+		switch (newval) {
+		case no:
+			newval = mod;
+			break;
+		case mod:
+			newval = yes;
+			break;
+		case yes:
+			newval = no;
+			break;
+		}
+		if (sym_set_tristate_value(sym, newval))
+			break;
+	} while (oldval != newval);
+	return newval;
+}
+
+bool sym_string_valid(struct symbol *sym, const char *str)
+{
+	signed char ch;
+
+	switch (sym->type) {
+	case S_STRING:
+		return true;
+	case S_INT:
+		ch = *str++;
+		if (ch == '-')
+			ch = *str++;
+		if (!isdigit(ch))
+			return false;
+		if (ch == '0' && *str != 0)
+			return false;
+		while ((ch = *str++)) {
+			if (!isdigit(ch))
+				return false;
+		}
+		return true;
+	case S_HEX:
+		if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
+			str += 2;
+		ch = *str++;
+		do {
+			if (!isxdigit(ch))
+				return false;
+		} while ((ch = *str++));
+		return true;
+	case S_BOOLEAN:
+	case S_TRISTATE:
+		switch (str[0]) {
+		case 'y': case 'Y':
+		case 'm': case 'M':
+		case 'n': case 'N':
+			return true;
+		}
+		return false;
+	default:
+		return false;
+	}
+}
+
+bool sym_string_within_range(struct symbol *sym, const char *str)
+{
+	struct property *prop;
+	long long val;
+
+	switch (sym->type) {
+	case S_STRING:
+		return sym_string_valid(sym, str);
+	case S_INT:
+		if (!sym_string_valid(sym, str))
+			return false;
+		prop = sym_get_range_prop(sym);
+		if (!prop)
+			return true;
+		val = strtoll(str, NULL, 10);
+		return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
+		       val <= sym_get_range_val(prop->expr->right.sym, 10);
+	case S_HEX:
+		if (!sym_string_valid(sym, str))
+			return false;
+		prop = sym_get_range_prop(sym);
+		if (!prop)
+			return true;
+		val = strtoll(str, NULL, 16);
+		return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
+		       val <= sym_get_range_val(prop->expr->right.sym, 16);
+	case S_BOOLEAN:
+	case S_TRISTATE:
+		switch (str[0]) {
+		case 'y': case 'Y':
+			return sym_tristate_within_range(sym, yes);
+		case 'm': case 'M':
+			return sym_tristate_within_range(sym, mod);
+		case 'n': case 'N':
+			return sym_tristate_within_range(sym, no);
+		}
+		return false;
+	default:
+		return false;
+	}
+}
+
+bool sym_set_string_value(struct symbol *sym, const char *newval)
+{
+	const char *oldval;
+	char *val;
+	int size;
+
+	switch (sym->type) {
+	case S_BOOLEAN:
+	case S_TRISTATE:
+		switch (newval[0]) {
+		case 'y': case 'Y':
+			return sym_set_tristate_value(sym, yes);
+		case 'm': case 'M':
+			return sym_set_tristate_value(sym, mod);
+		case 'n': case 'N':
+			return sym_set_tristate_value(sym, no);
+		}
+		return false;
+	default:
+		;
+	}
+
+	if (!sym_string_within_range(sym, newval))
+		return false;
+
+	if (!(sym->flags & SYMBOL_DEF_USER)) {
+		sym->flags |= SYMBOL_DEF_USER;
+		sym_set_changed(sym);
+	}
+
+	oldval = sym->def[S_DEF_USER].val;
+	size = strlen(newval) + 1;
+	if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
+		size += 2;
+		sym->def[S_DEF_USER].val = val = xmalloc(size);
+		*val++ = '0';
+		*val++ = 'x';
+	} else if (!oldval || strcmp(oldval, newval))
+		sym->def[S_DEF_USER].val = val = xmalloc(size);
+	else
+		return true;
+
+	strcpy(val, newval);
+	free((void *)oldval);
+	sym_clear_all_valid();
+
+	return true;
+}
+
+/*
+ * Find the default value associated to a symbol.
+ * For tristate symbol handle the modules=n case
+ * in which case "m" becomes "y".
+ * If the symbol does not have any default then fallback
+ * to the fixed default values.
+ */
+const char *sym_get_string_default(struct symbol *sym)
+{
+	struct property *prop;
+	struct symbol *ds;
+	const char *str;
+	tristate val;
+
+	sym_calc_visibility(sym);
+	sym_calc_value(modules_sym);
+	val = symbol_no.curr.tri;
+	str = symbol_empty.curr.val;
+
+	/* If symbol has a default value look it up */
+	prop = sym_get_default_prop(sym);
+	if (prop != NULL) {
+		switch (sym->type) {
+		case S_BOOLEAN:
+		case S_TRISTATE:
+			/* The visibility may limit the value from yes => mod */
+			val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
+			break;
+		default:
+			/*
+			 * The following fails to handle the situation
+			 * where a default value is further limited by
+			 * the valid range.
+			 */
+			ds = prop_get_symbol(prop);
+			if (ds != NULL) {
+				sym_calc_value(ds);
+				str = (const char *)ds->curr.val;
+			}
+		}
+	}
+
+	/* Handle select statements */
+	val = EXPR_OR(val, sym->rev_dep.tri);
+
+	/* transpose mod to yes if modules are not enabled */
+	if (val == mod)
+		if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
+			val = yes;
+
+	/* transpose mod to yes if type is bool */
+	if (sym->type == S_BOOLEAN && val == mod)
+		val = yes;
+
+	/* adjust the default value if this symbol is implied by another */
+	if (val < sym->implied.tri)
+		val = sym->implied.tri;
+
+	switch (sym->type) {
+	case S_BOOLEAN:
+	case S_TRISTATE:
+		switch (val) {
+		case no: return "n";
+		case mod: return "m";
+		case yes: return "y";
+		}
+	case S_INT:
+	case S_HEX:
+		return str;
+	case S_STRING:
+		return str;
+	case S_UNKNOWN:
+		break;
+	}
+	return "";
+}
+
+const char *sym_get_string_value(struct symbol *sym)
+{
+	tristate val;
+
+	switch (sym->type) {
+	case S_BOOLEAN:
+	case S_TRISTATE:
+		val = sym_get_tristate_value(sym);
+		switch (val) {
+		case no:
+			return "n";
+		case mod:
+			sym_calc_value(modules_sym);
+			return (modules_sym->curr.tri == no) ? "n" : "m";
+		case yes:
+			return "y";
+		}
+		break;
+	default:
+		;
+	}
+	return (const char *)sym->curr.val;
+}
+
+bool sym_is_changeable(struct symbol *sym)
+{
+	return sym->visible > sym->rev_dep.tri;
+}
+
+static unsigned strhash(const char *s)
+{
+	/* fnv32 hash */
+	unsigned hash = 2166136261U;
+	for (; *s; s++)
+		hash = (hash ^ *s) * 0x01000193;
+	return hash;
+}
+
+struct symbol *sym_lookup(const char *name, int flags)
+{
+	struct symbol *symbol;
+	char *new_name;
+	int hash;
+
+	if (name) {
+		if (name[0] && !name[1]) {
+			switch (name[0]) {
+			case 'y': return &symbol_yes;
+			case 'm': return &symbol_mod;
+			case 'n': return &symbol_no;
+			}
+		}
+		hash = strhash(name) % SYMBOL_HASHSIZE;
+
+		for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
+			if (symbol->name &&
+			    !strcmp(symbol->name, name) &&
+			    (flags ? symbol->flags & flags
+				   : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
+				return symbol;
+		}
+		new_name = xstrdup(name);
+	} else {
+		new_name = NULL;
+		hash = 0;
+	}
+
+	symbol = xmalloc(sizeof(*symbol));
+	memset(symbol, 0, sizeof(*symbol));
+	symbol->name = new_name;
+	symbol->type = S_UNKNOWN;
+	symbol->flags = flags;
+
+	symbol->next = symbol_hash[hash];
+	symbol_hash[hash] = symbol;
+
+	return symbol;
+}
+
+struct symbol *sym_find(const char *name)
+{
+	struct symbol *symbol = NULL;
+	int hash = 0;
+
+	if (!name)
+		return NULL;
+
+	if (name[0] && !name[1]) {
+		switch (name[0]) {
+		case 'y': return &symbol_yes;
+		case 'm': return &symbol_mod;
+		case 'n': return &symbol_no;
+		}
+	}
+	hash = strhash(name) % SYMBOL_HASHSIZE;
+
+	for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
+		if (symbol->name &&
+		    !strcmp(symbol->name, name) &&
+		    !(symbol->flags & SYMBOL_CONST))
+				break;
+	}
+
+	return symbol;
+}
+
+struct sym_match {
+	struct symbol	*sym;
+	off_t		so, eo;
+};
+
+/* Compare matched symbols as thus:
+ * - first, symbols that match exactly
+ * - then, alphabetical sort
+ */
+static int sym_rel_comp(const void *sym1, const void *sym2)
+{
+	const struct sym_match *s1 = sym1;
+	const struct sym_match *s2 = sym2;
+	int exact1, exact2;
+
+	/* Exact match:
+	 * - if matched length on symbol s1 is the length of that symbol,
+	 *   then this symbol should come first;
+	 * - if matched length on symbol s2 is the length of that symbol,
+	 *   then this symbol should come first.
+	 * Note: since the search can be a regexp, both symbols may match
+	 * exactly; if this is the case, we can't decide which comes first,
+	 * and we fallback to sorting alphabetically.
+	 */
+	exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
+	exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
+	if (exact1 && !exact2)
+		return -1;
+	if (!exact1 && exact2)
+		return 1;
+
+	/* As a fallback, sort symbols alphabetically */
+	return strcmp(s1->sym->name, s2->sym->name);
+}
+
+struct symbol **sym_re_search(const char *pattern)
+{
+	struct symbol *sym, **sym_arr = NULL;
+	struct sym_match *sym_match_arr = NULL;
+	int i, cnt, size;
+	regex_t re;
+	regmatch_t match[1];
+
+	cnt = size = 0;
+	/* Skip if empty */
+	if (strlen(pattern) == 0)
+		return NULL;
+	if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
+		return NULL;
+
+	for_all_symbols(i, sym) {
+		if (sym->flags & SYMBOL_CONST || !sym->name)
+			continue;
+		if (regexec(&re, sym->name, 1, match, 0))
+			continue;
+		if (cnt >= size) {
+			void *tmp;
+			size += 16;
+			tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
+			if (!tmp)
+				goto sym_re_search_free;
+			sym_match_arr = tmp;
+		}
+		sym_calc_value(sym);
+		/* As regexec returned 0, we know we have a match, so
+		 * we can use match[0].rm_[se]o without further checks
+		 */
+		sym_match_arr[cnt].so = match[0].rm_so;
+		sym_match_arr[cnt].eo = match[0].rm_eo;
+		sym_match_arr[cnt++].sym = sym;
+	}
+	if (sym_match_arr) {
+		qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
+		sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
+		if (!sym_arr)
+			goto sym_re_search_free;
+		for (i = 0; i < cnt; i++)
+			sym_arr[i] = sym_match_arr[i].sym;
+		sym_arr[cnt] = NULL;
+	}
+sym_re_search_free:
+	/* sym_match_arr can be NULL if no match, but free(NULL) is OK */
+	free(sym_match_arr);
+	regfree(&re);
+
+	return sym_arr;
+}
+
+/*
+ * When we check for recursive dependencies we use a stack to save
+ * current state so we can print out relevant info to user.
+ * The entries are located on the call stack so no need to free memory.
+ * Note insert() remove() must always match to properly clear the stack.
+ */
+static struct dep_stack {
+	struct dep_stack *prev, *next;
+	struct symbol *sym;
+	struct property *prop;
+	struct expr **expr;
+} *check_top;
+
+static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
+{
+	memset(stack, 0, sizeof(*stack));
+	if (check_top)
+		check_top->next = stack;
+	stack->prev = check_top;
+	stack->sym = sym;
+	check_top = stack;
+}
+
+static void dep_stack_remove(void)
+{
+	check_top = check_top->prev;
+	if (check_top)
+		check_top->next = NULL;
+}
+
+/*
+ * Called when we have detected a recursive dependency.
+ * check_top point to the top of the stact so we use
+ * the ->prev pointer to locate the bottom of the stack.
+ */
+static void sym_check_print_recursive(struct symbol *last_sym)
+{
+	struct dep_stack *stack;
+	struct symbol *sym, *next_sym;
+	struct menu *menu = NULL;
+	struct property *prop;
+	struct dep_stack cv_stack;
+
+	if (sym_is_choice_value(last_sym)) {
+		dep_stack_insert(&cv_stack, last_sym);
+		last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
+	}
+
+	for (stack = check_top; stack != NULL; stack = stack->prev)
+		if (stack->sym == last_sym)
+			break;
+	if (!stack) {
+		fprintf(stderr, "unexpected recursive dependency error\n");
+		return;
+	}
+
+	for (; stack; stack = stack->next) {
+		sym = stack->sym;
+		next_sym = stack->next ? stack->next->sym : last_sym;
+		prop = stack->prop;
+		if (prop == NULL)
+			prop = stack->sym->prop;
+
+		/* for choice values find the menu entry (used below) */
+		if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
+			for (prop = sym->prop; prop; prop = prop->next) {
+				menu = prop->menu;
+				if (prop->menu)
+					break;
+			}
+		}
+		if (stack->sym == last_sym)
+			fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
+				prop->file->name, prop->lineno);
+
+		if (sym_is_choice(sym)) {
+			fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
+				menu->file->name, menu->lineno,
+				sym->name ? sym->name : "<choice>",
+				next_sym->name ? next_sym->name : "<choice>");
+		} else if (sym_is_choice_value(sym)) {
+			fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
+				menu->file->name, menu->lineno,
+				sym->name ? sym->name : "<choice>",
+				next_sym->name ? next_sym->name : "<choice>");
+		} else if (stack->expr == &sym->dir_dep.expr) {
+			fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
+				prop->file->name, prop->lineno,
+				sym->name ? sym->name : "<choice>",
+				next_sym->name ? next_sym->name : "<choice>");
+		} else if (stack->expr == &sym->rev_dep.expr) {
+			fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
+				prop->file->name, prop->lineno,
+				sym->name ? sym->name : "<choice>",
+				next_sym->name ? next_sym->name : "<choice>");
+		} else if (stack->expr == &sym->implied.expr) {
+			fprintf(stderr, "%s:%d:\tsymbol %s is implied by %s\n",
+				prop->file->name, prop->lineno,
+				sym->name ? sym->name : "<choice>",
+				next_sym->name ? next_sym->name : "<choice>");
+		} else if (stack->expr) {
+			fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
+				prop->file->name, prop->lineno,
+				sym->name ? sym->name : "<choice>",
+				prop_get_type_name(prop->type),
+				next_sym->name ? next_sym->name : "<choice>");
+		} else {
+			fprintf(stderr, "%s:%d:\tsymbol %s %s is visible depending on %s\n",
+				prop->file->name, prop->lineno,
+				sym->name ? sym->name : "<choice>",
+				prop_get_type_name(prop->type),
+				next_sym->name ? next_sym->name : "<choice>");
+		}
+	}
+
+	fprintf(stderr,
+		"For a resolution refer to Documentation/kbuild/kconfig-language.rst\n"
+		"subsection \"Kconfig recursive dependency limitations\"\n"
+		"\n");
+
+	if (check_top == &cv_stack)
+		dep_stack_remove();
+}
+
+static struct symbol *sym_check_expr_deps(struct expr *e)
+{
+	struct symbol *sym;
+
+	if (!e)
+		return NULL;
+	switch (e->type) {
+	case E_OR:
+	case E_AND:
+		sym = sym_check_expr_deps(e->left.expr);
+		if (sym)
+			return sym;
+		return sym_check_expr_deps(e->right.expr);
+	case E_NOT:
+		return sym_check_expr_deps(e->left.expr);
+	case E_EQUAL:
+	case E_GEQ:
+	case E_GTH:
+	case E_LEQ:
+	case E_LTH:
+	case E_UNEQUAL:
+		sym = sym_check_deps(e->left.sym);
+		if (sym)
+			return sym;
+		return sym_check_deps(e->right.sym);
+	case E_SYMBOL:
+		return sym_check_deps(e->left.sym);
+	default:
+		break;
+	}
+	fprintf(stderr, "Oops! How to check %d?\n", e->type);
+	return NULL;
+}
+
+/* return NULL when dependencies are OK */
+static struct symbol *sym_check_sym_deps(struct symbol *sym)
+{
+	struct symbol *sym2;
+	struct property *prop;
+	struct dep_stack stack;
+
+	dep_stack_insert(&stack, sym);
+
+	stack.expr = &sym->dir_dep.expr;
+	sym2 = sym_check_expr_deps(sym->dir_dep.expr);
+	if (sym2)
+		goto out;
+
+	stack.expr = &sym->rev_dep.expr;
+	sym2 = sym_check_expr_deps(sym->rev_dep.expr);
+	if (sym2)
+		goto out;
+
+	stack.expr = &sym->implied.expr;
+	sym2 = sym_check_expr_deps(sym->implied.expr);
+	if (sym2)
+		goto out;
+
+	stack.expr = NULL;
+
+	for (prop = sym->prop; prop; prop = prop->next) {
+		if (prop->type == P_CHOICE || prop->type == P_SELECT ||
+		    prop->type == P_IMPLY)
+			continue;
+		stack.prop = prop;
+		sym2 = sym_check_expr_deps(prop->visible.expr);
+		if (sym2)
+			break;
+		if (prop->type != P_DEFAULT || sym_is_choice(sym))
+			continue;
+		stack.expr = &prop->expr;
+		sym2 = sym_check_expr_deps(prop->expr);
+		if (sym2)
+			break;
+		stack.expr = NULL;
+	}
+
+out:
+	dep_stack_remove();
+
+	return sym2;
+}
+
+static struct symbol *sym_check_choice_deps(struct symbol *choice)
+{
+	struct symbol *sym, *sym2;
+	struct property *prop;
+	struct expr *e;
+	struct dep_stack stack;
+
+	dep_stack_insert(&stack, choice);
+
+	prop = sym_get_choice_prop(choice);
+	expr_list_for_each_sym(prop->expr, e, sym)
+		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
+
+	choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
+	sym2 = sym_check_sym_deps(choice);
+	choice->flags &= ~SYMBOL_CHECK;
+	if (sym2)
+		goto out;
+
+	expr_list_for_each_sym(prop->expr, e, sym) {
+		sym2 = sym_check_sym_deps(sym);
+		if (sym2)
+			break;
+	}
+out:
+	expr_list_for_each_sym(prop->expr, e, sym)
+		sym->flags &= ~SYMBOL_CHECK;
+
+	if (sym2 && sym_is_choice_value(sym2) &&
+	    prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
+		sym2 = choice;
+
+	dep_stack_remove();
+
+	return sym2;
+}
+
+struct symbol *sym_check_deps(struct symbol *sym)
+{
+	struct symbol *sym2;
+	struct property *prop;
+
+	if (sym->flags & SYMBOL_CHECK) {
+		sym_check_print_recursive(sym);
+		return sym;
+	}
+	if (sym->flags & SYMBOL_CHECKED)
+		return NULL;
+
+	if (sym_is_choice_value(sym)) {
+		struct dep_stack stack;
+
+		/* for choice groups start the check with main choice symbol */
+		dep_stack_insert(&stack, sym);
+		prop = sym_get_choice_prop(sym);
+		sym2 = sym_check_deps(prop_get_symbol(prop));
+		dep_stack_remove();
+	} else if (sym_is_choice(sym)) {
+		sym2 = sym_check_choice_deps(sym);
+	} else {
+		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
+		sym2 = sym_check_sym_deps(sym);
+		sym->flags &= ~SYMBOL_CHECK;
+	}
+
+	return sym2;
+}
+
+struct symbol *prop_get_symbol(struct property *prop)
+{
+	if (prop->expr && (prop->expr->type == E_SYMBOL ||
+			   prop->expr->type == E_LIST))
+		return prop->expr->left.sym;
+	return NULL;
+}
+
+const char *prop_get_type_name(enum prop_type type)
+{
+	switch (type) {
+	case P_PROMPT:
+		return "prompt";
+	case P_COMMENT:
+		return "comment";
+	case P_MENU:
+		return "menu";
+	case P_DEFAULT:
+		return "default";
+	case P_CHOICE:
+		return "choice";
+	case P_SELECT:
+		return "select";
+	case P_IMPLY:
+		return "imply";
+	case P_RANGE:
+		return "range";
+	case P_SYMBOL:
+		return "symbol";
+	case P_UNKNOWN:
+		break;
+	}
+	return "unknown";
+}