build: add new menuconfig code based on linux 3.9

SVN-Revision: 36361

1 files changed, 553 insertions, 142 deletions

diff --git a/scripts/config/symbol.c b/scripts/config/symbol.c
index 49bb254558..ecc5aa5f86 100644
--- a/scripts/config/symbol.c
+++ b/scripts/config/symbol.c
@@ -9,43 +9,43 @@
 #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_YES|SYMBOL_VALID,
+	.flags = SYMBOL_CONST|SYMBOL_VALID,
 }, symbol_mod = {
 	.name = "m",
 	.curr = { "m", mod },
-	.flags = SYMBOL_MOD|SYMBOL_VALID,
+	.flags = SYMBOL_CONST|SYMBOL_VALID,
 }, symbol_no = {
 	.name = "n",
 	.curr = { "n", no },
-	.flags = SYMBOL_NO|SYMBOL_VALID,
+	.flags = SYMBOL_CONST|SYMBOL_VALID,
 }, symbol_empty = {
 	.name = "",
 	.curr = { "", no },
 	.flags = SYMBOL_VALID,
 };
 
-int sym_change_count;
+struct symbol *sym_defconfig_list;
 struct symbol *modules_sym;
 tristate modules_val;
 
-void sym_add_default(struct symbol *sym, const char *def)
+struct expr *sym_env_list;
+
+static 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, 1));
+	prop->expr = expr_alloc_symbol(sym_lookup(def, SYMBOL_CONST));
 }
 
 void sym_init(void)
 {
 	struct symbol *sym;
 	struct utsname uts;
-	char *p;
 	static bool inited = false;
 
 	if (inited)
@@ -54,19 +54,6 @@ void sym_init(void)
 
 	uname(&uts);
 
-	sym = sym_lookup("ARCH", 0);
-	sym->type = S_STRING;
-	p = getenv("ARCH");
-	if (p)
-		sym_add_default(sym, p);
-
-	sym = sym_lookup("OPENWRTVERSION", 0);
-	sym->type = S_STRING;
-	sym->flags |= SYMBOL_AUTO;
-	p = getenv("OPENWRTVERSION");
-	if (p)
-		sym_add_default(sym, p);
-
 	sym = sym_lookup("UNAME_RELEASE", 0);
 	sym->type = S_STRING;
 	sym->flags |= SYMBOL_AUTO;
@@ -80,11 +67,8 @@ enum symbol_type sym_get_type(struct symbol *sym)
 	if (type == S_TRISTATE) {
 		if (sym_is_choice_value(sym) && sym->visible == yes)
 			type = S_BOOLEAN;
-/* tristate always enabled */
-#if 0
 		else if (modules_val == no)
 			type = S_BOOLEAN;
-#endif
 	}
 	return type;
 }
@@ -119,6 +103,15 @@ struct property *sym_get_choice_prop(struct symbol *sym)
 	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;
@@ -131,7 +124,7 @@ struct property *sym_get_default_prop(struct symbol *sym)
 	return NULL;
 }
 
-struct property *sym_get_range_prop(struct symbol *sym)
+static struct property *sym_get_range_prop(struct symbol *sym)
 {
 	struct property *prop;
 
@@ -196,26 +189,31 @@ static void sym_calc_visibility(struct symbol *sym)
 {
 	struct property *prop;
 	tristate tri;
-	int deselected = 0;
 
 	/* any prompt visible? */
 	tri = no;
 	for_all_prompts(sym, prop) {
 		prop->visible.tri = expr_calc_value(prop->visible.expr);
-		tri = E_OR(tri, prop->visible.tri);
+		tri = EXPR_OR(tri, prop->visible.tri);
 	}
-	if (tri == mod && (sym->type != S_TRISTATE))
+	if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
 		tri = yes;
-	if (sym->rev_dep_inv.expr && (expr_calc_value(sym->rev_dep_inv.expr) == yes)) {
-		tri = no;
-		deselected = 1;
-	}
 	if (sym->visible != tri) {
 		sym->visible = tri;
 		sym_set_changed(sym);
 	}
-	if (sym_is_choice_value(sym) || deselected)
+	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)
+		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);
@@ -227,63 +225,68 @@ static void sym_calc_visibility(struct symbol *sym)
 	}
 }
 
-static struct symbol *sym_calc_choice(struct symbol *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;
 
-	/* is the user choice visible? */
-	def_sym = sym->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);
-	for (e = prop->expr; e; e = e->left.expr) {
-		def_sym = e->right.sym;
-		sym_calc_visibility(def_sym);
+	expr_list_for_each_sym(prop->expr, e, def_sym)
 		if (def_sym->visible != no)
 			return def_sym;
-	}
 
-	/* no choice? reset tristate value */
-	sym->curr.tri = no;
+	/* failed to locate any defaults */
 	return NULL;
 }
 
-void sym_set_changed(struct symbol *sym)
+static struct symbol *sym_calc_choice(struct symbol *sym)
 {
+	struct symbol *def_sym;
 	struct property *prop;
+	struct expr *e;
+	int flags;
 
-	sym->flags |= SYMBOL_CHANGED;
-	for (prop = sym->prop; prop; prop = prop->next) {
-		if (prop->menu)
-			prop->menu->flags |= MENU_CHANGED;
+	/* 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;
 	}
-}
 
-void sym_set_all_changed(void)
-{
-	struct symbol *sym;
-	int i;
+	sym->flags &= flags | ~SYMBOL_DEF_USER;
 
-	for_all_symbols(i, sym)
-		sym_set_changed(sym);
+	/* 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;
 }
 
 void sym_calc_value(struct symbol *sym)
@@ -330,24 +333,42 @@ void sym_calc_value(struct symbol *sym)
 		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->rev_dep_inv.expr && (expr_calc_value(sym->rev_dep_inv.expr) == yes)) {
-			newval.tri = no;
-		} else if (E_OR(sym->visible, sym->rev_dep.tri) != no) {
-			sym->flags |= SYMBOL_WRITE;
-			if (sym_has_value(sym))
-				newval.tri = sym->user.tri;
-			else if (!sym_is_choice(sym)) {
-				prop = sym_get_default_prop(sym);
-				if (prop)
-					newval.tri = expr_calc_value(prop->expr);
+		} 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;
+				}
 			}
-			newval.tri = E_OR(E_AND(newval.tri, sym->visible), sym->rev_dep.tri);
-		} else if (!sym_is_choice(sym)) {
-			prop = sym_get_default_prop(sym);
-			if (prop) {
+			if (sym->rev_dep.tri != no)
 				sym->flags |= SYMBOL_WRITE;
-				newval.tri = expr_calc_value(prop->expr);
+			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:
+			if (sym->dir_dep.tri == no && sym->rev_dep.tri != no) {
+				struct expr *e;
+				e = expr_simplify_unmet_dep(sym->rev_dep.expr,
+				    sym->dir_dep.expr);
+				fprintf(stderr, "warning: (");
+				expr_fprint(e, stderr);
+				fprintf(stderr, ") selects %s which has unmet direct dependencies (",
+					sym->name);
+				expr_fprint(sym->dir_dep.expr, stderr);
+				fprintf(stderr, ")\n");
+				expr_free(e);
 			}
+			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 		}
 		if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
 			newval.tri = yes;
@@ -358,7 +379,7 @@ void sym_calc_value(struct symbol *sym)
 		if (sym->visible != no) {
 			sym->flags |= SYMBOL_WRITE;
 			if (sym_has_value(sym)) {
-				newval.val = sym->user.val;
+				newval.val = sym->def[S_DEF_USER].val;
 				break;
 			}
 		}
@@ -382,7 +403,6 @@ void sym_calc_value(struct symbol *sym)
 	sym_validate_range(sym);
 
 	if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
-		sym->flags &= ~SYMBOL_VALID;
 		sym_set_changed(sym);
 		if (modules_sym == sym) {
 			sym_set_all_changed();
@@ -391,12 +411,15 @@ void sym_calc_value(struct symbol *sym)
 	}
 
 	if (sym_is_choice(sym)) {
-		int flags = sym->flags & (SYMBOL_CHANGED | SYMBOL_WRITE);
+		struct symbol *choice_sym;
+
 		prop = sym_get_choice_prop(sym);
-		for (e = prop->expr; e; e = e->left.expr) {
-			e->right.sym->flags |= flags;
-			if (flags & SYMBOL_CHANGED)
-				sym_set_changed(e->right.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);
 		}
 	}
 
@@ -411,11 +434,31 @@ void sym_clear_all_valid(void)
 
 	for_all_symbols(i, sym)
 		sym->flags &= ~SYMBOL_VALID;
-	sym_change_count++;
+	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);
@@ -442,8 +485,8 @@ bool sym_set_tristate_value(struct symbol *sym, tristate val)
 	if (oldval != val && !sym_tristate_within_range(sym, val))
 		return false;
 
-	if (sym->flags & SYMBOL_NEW) {
-		sym->flags &= ~SYMBOL_NEW;
+	if (!(sym->flags & SYMBOL_DEF_USER)) {
+		sym->flags |= SYMBOL_DEF_USER;
 		sym_set_changed(sym);
 	}
 	/*
@@ -455,19 +498,18 @@ bool sym_set_tristate_value(struct symbol *sym, tristate val)
 		struct property *prop;
 		struct expr *e;
 
-		cs->user.val = sym;
-		cs->flags &= ~SYMBOL_NEW;
+		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_NEW;
+				e->right.sym->flags |= SYMBOL_DEF_USER;
 		}
 	}
 
-	sym->user.tri = val;
-	if (oldval != val) {
+	sym->def[S_DEF_USER].tri = val;
+	if (oldval != val)
 		sym_clear_all_valid();
-	}
 
 	return true;
 }
@@ -605,20 +647,20 @@ bool sym_set_string_value(struct symbol *sym, const char *newval)
 	if (!sym_string_within_range(sym, newval))
 		return false;
 
-	if (sym->flags & SYMBOL_NEW) {
-		sym->flags &= ~SYMBOL_NEW;
+	if (!(sym->flags & SYMBOL_DEF_USER)) {
+		sym->flags |= SYMBOL_DEF_USER;
 		sym_set_changed(sym);
 	}
 
-	oldval = sym->user.val;
+	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->user.val = val = malloc(size);
+		sym->def[S_DEF_USER].val = val = xmalloc(size);
 		*val++ = '0';
 		*val++ = 'x';
 	} else if (!oldval || strcmp(oldval, newval))
-		sym->user.val = val = malloc(size);
+		sym->def[S_DEF_USER].val = val = xmalloc(size);
 	else
 		return true;
 
@@ -629,6 +671,80 @@ bool sym_set_string_value(struct symbol *sym, const char *newval)
 	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;
+
+	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_OTHER:
+	case S_UNKNOWN:
+		break;
+	}
+	return "";
+}
+
 const char *sym_get_string_value(struct symbol *sym)
 {
 	tristate val;
@@ -641,7 +757,8 @@ const char *sym_get_string_value(struct symbol *sym)
 		case no:
 			return "n";
 		case mod:
-			return "m";
+			sym_calc_value(modules_sym);
+			return (modules_sym->curr.tri == no) ? "n" : "m";
 		case yes:
 			return "y";
 		}
@@ -657,12 +774,20 @@ bool sym_is_changable(struct symbol *sym)
 	return sym->visible > sym->rev_dep.tri;
 }
 
-struct symbol *sym_lookup(const char *name, int isconst)
+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;
-	const char *ptr;
 	char *new_name;
-	int hash = 0;
+	int hash;
 
 	if (name) {
 		if (name[0] && !name[1]) {
@@ -672,30 +797,26 @@ struct symbol *sym_lookup(const char *name, int isconst)
 			case 'n': return &symbol_no;
 			}
 		}
-		for (ptr = name; *ptr; ptr++)
-			hash += *ptr;
-		hash &= 0xff;
+		hash = strhash(name) % SYMBOL_HASHSIZE;
 
 		for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
-			if (!strcmp(symbol->name, name)) {
-				if ((isconst && symbol->flags & SYMBOL_CONST) ||
-				    (!isconst && !(symbol->flags & SYMBOL_CONST)))
-					return symbol;
-			}
+			if (symbol->name &&
+			    !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;
+		hash = 0;
 	}
 
-	symbol = malloc(sizeof(*symbol));
+	symbol = xmalloc(sizeof(*symbol));
 	memset(symbol, 0, sizeof(*symbol));
 	symbol->name = new_name;
 	symbol->type = S_UNKNOWN;
-	symbol->flags = SYMBOL_NEW;
-	if (isconst)
-		symbol->flags |= SYMBOL_CONST;
+	symbol->flags |= flags;
 
 	symbol->next = symbol_hash[hash];
 	symbol_hash[hash] = symbol;
@@ -706,7 +827,6 @@ struct symbol *sym_lookup(const char *name, int isconst)
 struct symbol *sym_find(const char *name)
 {
 	struct symbol *symbol = NULL;
-	const char *ptr;
 	int hash = 0;
 
 	if (!name)
@@ -719,12 +839,11 @@ struct symbol *sym_find(const char *name)
 		case 'n': return &symbol_no;
 		}
 	}
-	for (ptr = name; *ptr; ptr++)
-		hash += *ptr;
-	hash &= 0xff;
+	hash = strhash(name) % SYMBOL_HASHSIZE;
 
 	for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
-		if (!strcmp(symbol->name, name) &&
+		if (symbol->name &&
+		    !strcmp(symbol->name, name) &&
 		    !(symbol->flags & SYMBOL_CONST))
 				break;
 	}
@@ -732,6 +851,98 @@ struct symbol *sym_find(const char *name)
 	return symbol;
 }
 
+/*
+ * Expand symbol's names embedded in the string given in argument. Symbols'
+ * name to be expanded shall be prefixed by a '$'. Unknown symbol expands to
+ * the empty string.
+ */
+const char *sym_expand_string_value(const char *in)
+{
+	const char *src;
+	char *res;
+	size_t reslen;
+
+	reslen = strlen(in) + 1;
+	res = xmalloc(reslen);
+	res[0] = '\0';
+
+	while ((src = strchr(in, '$'))) {
+		char *p, name[SYMBOL_MAXLENGTH];
+		const char *symval = "";
+		struct symbol *sym;
+		size_t newlen;
+
+		strncat(res, in, src - in);
+		src++;
+
+		p = name;
+		while (isalnum(*src) || *src == '_')
+			*p++ = *src++;
+		*p = '\0';
+
+		sym = sym_find(name);
+		if (sym != NULL) {
+			sym_calc_value(sym);
+			symval = sym_get_string_value(sym);
+		}
+
+		newlen = strlen(res) + strlen(symval) + strlen(src) + 1;
+		if (newlen > reslen) {
+			reslen = newlen;
+			res = realloc(res, reslen);
+		}
+
+		strcat(res, symval);
+		in = src;
+	}
+	strcat(res, in);
+
+	return res;
+}
+
+const char *sym_escape_string_value(const char *in)
+{
+	const char *p;
+	size_t reslen;
+	char *res;
+	size_t l;
+
+	reslen = strlen(in) + strlen("\"\"") + 1;
+
+	p = in;
+	for (;;) {
+		l = strcspn(p, "\"\\");
+		p += l;
+
+		if (p[0] == '\0')
+			break;
+
+		reslen++;
+		p++;
+	}
+
+	res = xmalloc(reslen);
+	res[0] = '\0';
+
+	strcat(res, "\"");
+
+	p = in;
+	for (;;) {
+		l = strcspn(p, "\"\\");
+		strncat(res, p, l);
+		p += l;
+
+		if (p[0] == '\0')
+			break;
+
+		strcat(res, "\\");
+		strncat(res, p++, 1);
+	}
+
+	strcat(res, "\"");
+	return res;
+}
+
 struct symbol **sym_re_search(const char *pattern)
 {
 	struct symbol *sym, **sym_arr = NULL;
@@ -769,8 +980,112 @@ struct symbol **sym_re_search(const char *pattern)
 	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 inser() 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));
+	}
 
-struct symbol *sym_check_deps(struct symbol *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 (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 if (stack->prop) {
+			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 (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 {
+			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>");
+		}
+	}
+
+	if (check_top == &cv_stack)
+		dep_stack_remove();
+}
 
 static struct symbol *sym_check_expr_deps(struct expr *e)
 {
@@ -802,44 +1117,109 @@ static struct symbol *sym_check_expr_deps(struct expr *e)
 	return NULL;
 }
 
-struct symbol *sym_check_deps(struct symbol *sym)
+/* 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;
 
-	if (sym->flags & SYMBOL_CHECK) {
-		printf("Warning! Found recursive dependency: %s", sym->name);
-		return sym;
-	}
-	if (sym->flags & SYMBOL_CHECKED)
-		return NULL;
+	dep_stack_insert(&stack, sym);
 
-	sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
 	sym2 = sym_check_expr_deps(sym->rev_dep.expr);
 	if (sym2)
 		goto out;
 
 	for (prop = sym->prop; prop; prop = prop->next) {
-		if (prop->type == P_CHOICE || prop->type == P_SELECT || prop->type == P_DESELECT)
+		if (prop->type == P_CHOICE || prop->type == P_SELECT)
 			continue;
+		stack.prop = prop;
 		sym2 = sym_check_expr_deps(prop->visible.expr);
 		if (sym2)
-			goto out;
+			break;
 		if (prop->type != P_DEFAULT || sym_is_choice(sym))
 			continue;
+		stack.expr = prop->expr;
 		sym2 = sym_check_expr_deps(prop->expr);
 		if (sym2)
-			goto out;
+			break;
+		stack.expr = NULL;
 	}
+
 out:
-	if (sym2) {
-		printf(" %s", sym->name);
-		if (sym2 == sym) {
-			printf("\n");
-			sym2 = NULL;
-		}
+	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;
 	}
-	sym->flags &= ~SYMBOL_CHECK;
+	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;
+	}
+
+	if (sym2 && sym2 == sym)
+		sym2 = NULL;
+
 	return sym2;
 }
 
@@ -848,7 +1228,7 @@ struct property *prop_alloc(enum prop_type type, struct symbol *sym)
 	struct property *prop;
 	struct property **propp;
 
-	prop = malloc(sizeof(*prop));
+	prop = xmalloc(sizeof(*prop));
 	memset(prop, 0, sizeof(*prop));
 	prop->type = type;
 	prop->sym = sym;
@@ -868,7 +1248,7 @@ struct property *prop_alloc(enum prop_type type, struct symbol *sym)
 struct symbol *prop_get_symbol(struct property *prop)
 {
 	if (prop->expr && (prop->expr->type == E_SYMBOL ||
-			   prop->expr->type == E_CHOICE))
+			   prop->expr->type == E_LIST))
 		return prop->expr->left.sym;
 	return NULL;
 }
@@ -878,6 +1258,8 @@ 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:
@@ -888,12 +1270,41 @@ const char *prop_get_type_name(enum prop_type type)
 		return "choice";
 	case P_SELECT:
 		return "select";
-	case P_DESELECT:
-		return "deselect";
 	case P_RANGE:
 		return "range";
+	case P_SYMBOL:
+		return "symbol";
 	case P_UNKNOWN:
 		break;
 	}
 	return "unknown";
 }
+
+static 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);
+}