diff --git a/scripts/config/expr.h b/scripts/config/expr.h
new file mode 100644
index 0000000..005e27f
--- /dev/null
+++ b/scripts/config/expr.h
@@ -0,0 +1,326 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
+ */
+
+#ifndef EXPR_H
+#define EXPR_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <assert.h>
+#include <stdio.h>
+#include "list.h"
+#ifndef __cplusplus
+#include <stdbool.h>
+#endif
+
+struct file {
+	struct file *next;
+	struct file *parent;
+	const char *name;
+	int lineno;
+};
+
+typedef enum tristate {
+	no, mod, yes
+} tristate;
+
+enum expr_type {
+	E_NONE, E_OR, E_AND, E_NOT,
+	E_EQUAL, E_UNEQUAL, E_LTH, E_LEQ, E_GTH, E_GEQ,
+	E_LIST, E_SYMBOL, E_RANGE
+};
+
+union expr_data {
+	struct expr *expr;
+	struct symbol *sym;
+};
+
+struct expr {
+	enum expr_type type;
+	union expr_data left, right;
+};
+
+#define EXPR_OR(dep1, dep2)	(((dep1)>(dep2))?(dep1):(dep2))
+#define EXPR_AND(dep1, dep2)	(((dep1)<(dep2))?(dep1):(dep2))
+#define EXPR_NOT(dep)		(2-(dep))
+
+#define expr_list_for_each_sym(l, e, s) \
+	for (e = (l); e && (s = e->right.sym); e = e->left.expr)
+
+struct expr_value {
+	struct expr *expr;
+	tristate tri;
+};
+
+struct symbol_value {
+	void *val;
+	tristate tri;
+};
+
+enum symbol_type {
+	S_UNKNOWN, S_BOOLEAN, S_TRISTATE, S_INT, S_HEX, S_STRING
+};
+
+/* enum values are used as index to symbol.def[] */
+enum {
+	S_DEF_USER,		/* main user value */
+	S_DEF_AUTO,		/* values read from auto.conf */
+	S_DEF_DEF3,		/* Reserved for UI usage */
+	S_DEF_DEF4,		/* Reserved for UI usage */
+	S_DEF_COUNT
+};
+
+/*
+ * Represents a configuration symbol.
+ *
+ * Choices are represented as a special kind of symbol and have the
+ * SYMBOL_CHOICE bit set in 'flags'.
+ */
+struct symbol {
+	/* The next symbol in the same bucket in the symbol hash table */
+	struct symbol *next;
+
+	/* The name of the symbol, e.g. "FOO" for 'config FOO' */
+	char *name;
+
+	/* S_BOOLEAN, S_TRISTATE, ... */
+	enum symbol_type type;
+
+	/*
+	 * The calculated value of the symbol. The SYMBOL_VALID bit is set in
+	 * 'flags' when this is up to date. Note that this value might differ
+	 * from the user value set in e.g. a .config file, due to visibility.
+	 */
+	struct symbol_value curr;
+
+	/*
+	 * Values for the symbol provided from outside. def[S_DEF_USER] holds
+	 * the .config value.
+	 */
+	struct symbol_value def[S_DEF_COUNT];
+
+	/*
+	 * An upper bound on the tristate value the user can set for the symbol
+	 * if it is a boolean or tristate. Calculated from prompt dependencies,
+	 * which also inherit dependencies from enclosing menus, choices, and
+	 * ifs. If 'n', the user value will be ignored.
+	 *
+	 * Symbols lacking prompts always have visibility 'n'.
+	 */
+	tristate visible;
+
+	/* SYMBOL_* flags */
+	int flags;
+
+	/* List of properties. See prop_type. */
+	struct property *prop;
+
+	/* Dependencies from enclosing menus, choices, and ifs */
+	struct expr_value dir_dep;
+
+	/* Reverse dependencies through being selected by other symbols */
+	struct expr_value rev_dep;
+
+	/*
+	 * "Weak" reverse dependencies through being implied by other symbols
+	 */
+	struct expr_value implied;
+};
+
+#define for_all_symbols(i, sym) for (i = 0; i < SYMBOL_HASHSIZE; i++) for (sym = symbol_hash[i]; sym; sym = sym->next)
+
+#define SYMBOL_CONST      0x0001  /* symbol is const */
+#define SYMBOL_CHECK      0x0008  /* used during dependency checking */
+#define SYMBOL_CHOICE     0x0010  /* start of a choice block (null name) */
+#define SYMBOL_CHOICEVAL  0x0020  /* used as a value in a choice block */
+#define SYMBOL_VALID      0x0080  /* set when symbol.curr is calculated */
+#define SYMBOL_OPTIONAL   0x0100  /* choice is optional - values can be 'n' */
+#define SYMBOL_WRITE      0x0200  /* write symbol to file (KCONFIG_CONFIG) */
+#define SYMBOL_CHANGED    0x0400  /* ? */
+#define SYMBOL_WRITTEN    0x0800  /* track info to avoid double-write to .config */
+#define SYMBOL_NO_WRITE   0x1000  /* Symbol for internal use only; it will not be written */
+#define SYMBOL_CHECKED    0x2000  /* used during dependency checking */
+#define SYMBOL_WARNED     0x8000  /* warning has been issued */
+
+/* Set when symbol.def[] is used */
+#define SYMBOL_DEF        0x10000  /* First bit of SYMBOL_DEF */
+#define SYMBOL_DEF_USER   0x10000  /* symbol.def[S_DEF_USER] is valid */
+#define SYMBOL_DEF_AUTO   0x20000  /* symbol.def[S_DEF_AUTO] is valid */
+#define SYMBOL_DEF3       0x40000  /* symbol.def[S_DEF_3] is valid */
+#define SYMBOL_DEF4       0x80000  /* symbol.def[S_DEF_4] is valid */
+
+/* choice values need to be set before calculating this symbol value */
+#define SYMBOL_NEED_SET_CHOICE_VALUES  0x100000
+
+#define SYMBOL_MAXLENGTH	256
+#define SYMBOL_HASHSIZE		9973
+
+/* A property represent the config options that can be associated
+ * with a config "symbol".
+ * Sample:
+ * config FOO
+ *         default y
+ *         prompt "foo prompt"
+ *         select BAR
+ * config BAZ
+ *         int "BAZ Value"
+ *         range 1..255
+ *
+ * Please, also check parser.y:print_symbol() when modifying the
+ * list of property types!
+ */
+enum prop_type {
+	P_UNKNOWN,
+	P_PROMPT,   /* prompt "foo prompt" or "BAZ Value" */
+	P_COMMENT,  /* text associated with a comment */
+	P_MENU,     /* prompt associated with a menu or menuconfig symbol */
+	P_DEFAULT,  /* default y */
+	P_CHOICE,   /* choice value */
+	P_SELECT,   /* select BAR */
+	P_IMPLY,    /* imply BAR */
+	P_RANGE,    /* range 7..100 (for a symbol) */
+	P_SYMBOL,   /* where a symbol is defined */
+	P_RESET,	/* reset to defaults condition */
+};
+
+struct property {
+	struct property *next;     /* next property - null if last */
+	enum prop_type type;       /* type of property */
+	const char *text;          /* the prompt value - P_PROMPT, P_MENU, P_COMMENT */
+	struct expr_value visible;
+	struct expr *expr;         /* the optional conditional part of the property */
+	struct menu *menu;         /* the menu the property are associated with
+	                            * valid for: P_SELECT, P_RANGE, P_CHOICE,
+	                            * P_PROMPT, P_DEFAULT, P_MENU, P_COMMENT */
+	struct file *file;         /* what file was this property defined */
+	int lineno;                /* what lineno was this property defined */
+};
+
+#define for_all_properties(sym, st, tok) \
+	for (st = sym->prop; st; st = st->next) \
+		if (st->type == (tok))
+#define for_all_defaults(sym, st) for_all_properties(sym, st, P_DEFAULT)
+#define for_all_choices(sym, st) for_all_properties(sym, st, P_CHOICE)
+#define for_all_prompts(sym, st) \
+	for (st = sym->prop; st; st = st->next) \
+		if (st->text)
+
+/*
+ * Represents a node in the menu tree, as seen in e.g. menuconfig (though used
+ * for all front ends). Each symbol, menu, etc. defined in the Kconfig files
+ * gets a node. A symbol defined in multiple locations gets one node at each
+ * location.
+ */
+struct menu {
+	/* The next menu node at the same level */
+	struct menu *next;
+
+	/* The parent menu node, corresponding to e.g. a menu or choice */
+	struct menu *parent;
+
+	/* The first child menu node, for e.g. menus and choices */
+	struct menu *list;
+
+	/*
+	 * The symbol associated with the menu node. Choices are implemented as
+	 * a special kind of symbol. NULL for menus, comments, and ifs.
+	 */
+	struct symbol *sym;
+
+	/*
+	 * The prompt associated with the node. This holds the prompt for a
+	 * symbol as well as the text for a menu or comment, along with the
+	 * type (P_PROMPT, P_MENU, etc.)
+	 */
+	struct property *prompt;
+
+	/*
+	 * 'visible if' dependencies. If more than one is given, they will be
+	 * ANDed together.
+	 */
+	struct expr *visibility;
+
+	/*
+	 * Ordinary dependencies from e.g. 'depends on' and 'if', ANDed
+	 * together
+	 */
+	struct expr *dep;
+
+	/* MENU_* flags */
+	unsigned int flags;
+
+	/* Any help text associated with the node */
+	char *help;
+
+	/* The location where the menu node appears in the Kconfig files */
+	struct file *file;
+	int lineno;
+
+	/* For use by front ends that need to store auxiliary data */
+	void *data;
+};
+
+/*
+ * Set on a menu node when the corresponding symbol changes state in some way.
+ * Can be checked by front ends.
+ */
+#define MENU_CHANGED		0x0001
+
+#define MENU_ROOT		0x0002
+
+struct jump_key {
+	struct list_head entries;
+	size_t offset;
+	struct menu *target;
+};
+
+extern struct file *file_list;
+extern struct file *current_file;
+struct file *lookup_file(const char *name);
+
+extern struct symbol symbol_yes, symbol_no, symbol_mod;
+extern struct symbol *modules_sym;
+extern int cdebug;
+struct expr *expr_alloc_symbol(struct symbol *sym);
+struct expr *expr_alloc_one(enum expr_type type, struct expr *ce);
+struct expr *expr_alloc_two(enum expr_type type, struct expr *e1, struct expr *e2);
+struct expr *expr_alloc_comp(enum expr_type type, struct symbol *s1, struct symbol *s2);
+struct expr *expr_alloc_and(struct expr *e1, struct expr *e2);
+struct expr *expr_alloc_or(struct expr *e1, struct expr *e2);
+struct expr *expr_copy(const struct expr *org);
+void expr_free(struct expr *e);
+void expr_eliminate_eq(struct expr **ep1, struct expr **ep2);
+int expr_eq(struct expr *e1, struct expr *e2);
+tristate expr_calc_value(struct expr *e);
+struct expr *expr_trans_bool(struct expr *e);
+struct expr *expr_eliminate_dups(struct expr *e);
+struct expr *expr_transform(struct expr *e);
+int expr_contains_symbol(struct expr *dep, struct symbol *sym);
+bool expr_depends_symbol(struct expr *dep, struct symbol *sym);
+struct expr *expr_trans_compare(struct expr *e, enum expr_type type, struct symbol *sym);
+
+void expr_fprint(struct expr *e, FILE *out);
+struct gstr; /* forward */
+void expr_gstr_print(struct expr *e, struct gstr *gs);
+void expr_gstr_print_revdep(struct expr *e, struct gstr *gs,
+			    tristate pr_type, const char *title);
+
+static inline int expr_is_yes(struct expr *e)
+{
+	return !e || (e->type == E_SYMBOL && e->left.sym == &symbol_yes);
+}
+
+static inline int expr_is_no(struct expr *e)
+{
+	return e && (e->type == E_SYMBOL && e->left.sym == &symbol_no);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* EXPR_H */