/*

 * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>

 * Released under the terms of the GNU GPL v2.0.

 */

#include <ctype.h>

#include <stdlib.h>

#include <string.h>

#include <regex.h>

#include <sys/utsname.h>

#define LKC_DIRECT_LINK

#include "lkc.h"

struct symbol symbol_yes = {

	.name = "y",

	.curr = { "y", yes },

	.flags = SYMBOL_CONST|SYMBOL_VALID,

}, symbol_mod = {

	.name = "m",

	.curr = { "m", mod },

	.flags = SYMBOL_CONST|SYMBOL_VALID,

}, symbol_no = {

	.name = "n",

	.curr = { "n", no },

	.flags = SYMBOL_CONST|SYMBOL_VALID,

}, symbol_empty = {

	.name = "",

	.curr = { "", no },

	.flags = SYMBOL_VALID,

};

struct symbol *sym_defconfig_list;

struct symbol *modules_sym;

tristate modules_val;

struct expr *sym_env_list;

void sym_add_default(struct symbol *sym, const char *def)

{

	struct property *prop = prop_alloc(P_DEFAULT, sym);

	prop->expr = expr_alloc_symbol(sym_lookup(def, SYMBOL_CONST));

}

void sym_init(void)

{

	struct symbol *sym;

	struct utsname uts;

	static bool inited = false;

	char* p;

	if (inited)

		return;

	inited = true;

	uname(&uts);

	sym = sym_lookup("UNAME_RELEASE", 0);

	sym->type = S_STRING;

	sym->flags |= SYMBOL_AUTO;

	sym_add_default(sym, uts.release);

	sym = sym_lookup("PROJECTVERSION", 0);

	sym->type = S_STRING;

	sym->flags |= SYMBOL_AUTO;

	p = getenv("PROJECTVERSION");

	if (p)

		sym_add_default(sym, p);

}

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 "boolean";

	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";

	case S_OTHER:

		break;

	}

	return "???";

}

struct property *sym_get_choice_prop(struct symbol *sym)

{

	struct property *prop;

	for_all_choices(sym, prop)

		return prop;

	return NULL;

}

struct property *sym_get_env_prop(struct symbol *sym)

{

	struct property *prop;

	for_all_properties(sym, prop, P_ENV)

		return prop;

	return NULL;

}

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 int 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 strtol(sym->curr.val, NULL, base);

}

static void sym_validate_range(struct symbol *sym)

{

	struct property *prop;

	int base, val, val2;

	char str[64];

	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 = strtol(sym->curr.val, NULL, base);

	val2 = sym_get_range_val(prop->expr->left.sym, base);

	if (val >= val2) {

		val2 = sym_get_range_val(prop->expr->right.sym, base);

		if (val <= val2)

			return;

	}

	if (sym->type == S_INT)

		sprintf(str, "%d", val2);

	else

		sprintf(str, "0x%x", val2);

	sym->curr.val = strdup(str);

}

static void sym_calc_visibility(struct symbol *sym)

{

	struct property *prop;

	tristate tri;

	/* any prompt visible? */

	tri = no;

	for_all_prompts(sym, prop) {

		prop->visible.tri = expr_calc_value(prop->visible.expr);

		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;

	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);

	}

}

static struct symbol *sym_calc_choice(struct symbol *sym)

{

	struct symbol *def_sym;

	struct property *prop;

	struct expr *e;

	/* is the user choice visible? */

	def_sym = sym->def[S_DEF_USER].val;

	if (def_sym) {

		sym_calc_visibility(def_sym);

		if (def_sym->visible != no)

			return def_sym;

	}

	/* 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);

		sym_calc_visibility(def_sym);

		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) {

		sym_calc_visibility(def_sym);

		if (def_sym->visible != no)

			return def_sym;

	}

	/* no choice? reset tristate value */

	sym->curr.tri = no;

	return NULL;

}

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;

	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;

	}

	if (!sym_is_choice_value(sym))

		sym->flags &= ~SYMBOL_WRITE;

	sym_calc_visibility(sym);

	/* 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

				 */

				sym->flags |= SYMBOL_WRITE;

				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) {

					sym->flags |= SYMBOL_WRITE;

					newval.tri = EXPR_AND(expr_calc_value(prop->expr),

							      prop->visible.tri);

				}

			}

		calc_newval:

			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->flags |= SYMBOL_WRITE;

			if (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;

		int flags = sym->flags & (SYMBOL_CHANGED | SYMBOL_WRITE);

		prop = sym_get_choice_prop(sym);

		expr_list_for_each_sym(prop->expr, e, choice_sym) {

			choice_sym->flags |= flags;

			if (flags & SYMBOL_CHANGED)

				sym_set_changed(choice_sym);

		}

	}

	if (sym->flags & SYMBOL_AUTO)

		sym->flags &= ~SYMBOL_WRITE;

}

void sym_clear_all_valid(void)

{

	struct symbol *sym;

	int i;

	for_all_symbols(i, sym)

		sym->flags &= ~SYMBOL_VALID;

	sym_add_change_count(1);

	if (modules_sym)

		sym_calc_value(modules_sym);

}

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;

	}

}

void sym_set_all_changed(void)

{

	struct symbol *sym;

	int i;

	for_all_symbols(i, sym)

		sym_set_changed(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;

	int 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 = strtol(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 = strtol(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 = malloc(size);

		*val++ = '0';

		*val++ = 'x';

	} else if (!oldval || strcmp(oldval, newval))

		sym->def[S_DEF_USER].val = val = malloc(size);

	else

		return true;

	strcpy(val, newval);

	free((void *)oldval);

	sym_clear_all_valid();

	return true;

}

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:

			return "m";

		case yes:

			return "y";

		}

		break;

	default:

		;

	}

	return (const char *)sym->curr.val;

}

bool sym_is_changable(struct symbol *sym)

{

	return sym->visible > sym->rev_dep.tri;

}

struct symbol *sym_lookup(const char *name, int flags)

{

	struct symbol *symbol;

	const char *ptr;

	char *new_name;

	int hash = 0;

	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;

			}

		}

		for (ptr = name; *ptr; ptr++)

			hash += *ptr;

		hash &= 0xff;

		for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {

			if (!strcmp(symbol->name, name) &&

			    (flags ? symbol->flags & flags

				   : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))

				return symbol;

		}

		new_name = strdup(name);

	} else {

		new_name = NULL;

		hash = 256;

	}

	symbol = malloc(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;

	const char *ptr;

	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;

		}

	}

	for (ptr = name; *ptr; ptr++)

		hash += *ptr;

	hash &= 0xff;

	for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {

		if (!strcmp(symbol->name, name) &&

		    !(symbol->flags & SYMBOL_CONST))

				break;

	}

	return symbol;

}

struct symbol **sym_re_search(const char *pattern)

{

	struct symbol *sym, **sym_arr = NULL;

	int i, cnt, size;

	regex_t re;

	cnt = size = 0;

	/* Skip if empty */

	if (strlen(pattern) == 0)

		return NULL;

	if (regcomp(&re, pattern, REG_EXTENDED|REG_NOSUB|REG_ICASE))

		return NULL;

	for_all_symbols(i, sym) {

		if (sym->flags & SYMBOL_CONST || !sym->name)

			continue;

		if (regexec(&re, sym->name, 0, NULL, 0))

			continue;

		if (cnt + 1 >= size) {

			void *tmp = sym_arr;

			size += 16;

			sym_arr = realloc(sym_arr, size * sizeof(struct symbol *));

			if (!sym_arr) {

				free(tmp);

				return NULL;

			}

		}

		sym_arr[cnt++] = sym;

	}

	if (sym_arr)

		sym_arr[cnt] = NULL;

	regfree(&re);

	return sym_arr;

}

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_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;

	}

	printf("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;

	sym2 = sym_check_expr_deps(sym->rev_dep.expr);

	if (sym2)

		return sym2;

	for (prop = sym->prop; prop; prop = prop->next) {

		if (prop->type == P_CHOICE || prop->type == P_SELECT)

			continue;

		sym2 = sym_check_expr_deps(prop->visible.expr);

		if (sym2)

			break;

		if (prop->type != P_DEFAULT || sym_is_choice(sym))

			continue;

		sym2 = sym_check_expr_deps(prop->expr);

		if (sym2)

			break;

	}

	return sym2;

}

static struct symbol *sym_check_choice_deps(struct symbol *choice)

{

	struct symbol *sym, *sym2;

	struct property *prop;

	struct expr *e;

	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) {

			fprintf(stderr, " -> %s", sym->name);

			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;

	return sym2;

}

struct symbol *sym_check_deps(struct symbol *sym)

{

	struct symbol *sym2;

	struct property *prop;

	if (sym->flags & SYMBOL_CHECK) {

		fprintf(stderr, "%s:%d:error: found recursive dependency: %s",

		        sym->prop->file->name, sym->prop->lineno,

			sym->name ? sym->name : "<choice>");

		return sym;

	}

	if (sym->flags & SYMBOL_CHECKED)

		return NULL;

	if (sym_is_choice_value(sym)) {

		/* for choice groups start the check with main choice symbol */

		prop = sym_get_choice_prop(sym);

		sym2 = sym_check_deps(prop_get_symbol(prop));

	} 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;

	}

	if (sym2) {

		fprintf(stderr, " -> %s", sym->name ? sym->name : "<choice>");

		if (sym2 == sym) {

			fprintf(stderr, "\n");

			zconfnerrs++;

			sym2 = NULL;

		}

	}

	return sym2;

}

struct property *prop_alloc(enum prop_type type, struct symbol *sym)

{

	struct property *prop;

	struct property **propp;

	prop = malloc(sizeof(*prop));

	memset(prop, 0, sizeof(*prop));

	prop->type = type;

	prop->sym = sym;

	prop->file = current_file;

	prop->lineno = zconf_lineno();

	/* append property to the prop list of symbol */

	if (sym) {

		for (propp = &sym->prop; *propp; propp = &(*propp)->next)

			;

		*propp = prop;

	}

	return prop;

}

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_ENV:

		return "env";

	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_RANGE:

		return "range";

	case P_UNKNOWN:

		break;

	}

	return "unknown";

}

void prop_add_env(const char *env)

{

	struct symbol *sym, *sym2;

	struct property *prop;

	char *p;

	sym = current_entry->sym;

	sym->flags |= SYMBOL_AUTO;

	for_all_properties(sym, prop, P_ENV) {

		sym2 = prop_get_symbol(prop);

		if (strcmp(sym2->name, env))

			menu_warn(current_entry, "redefining environment symbol from %s",

				  sym2->name);

		return;

	}

	prop = prop_alloc(P_ENV, sym);

	prop->expr = expr_alloc_symbol(sym_lookup(env, SYMBOL_CONST));

	sym_env_list = expr_alloc_one(E_LIST, sym_env_list);

	sym_env_list->right.sym = sym;

	p = getenv(env);

	if (p)

		sym_add_default(sym, p);

	else

		menu_warn(current_entry, "environment variable %s undefined", env);

}