X-Git-Url: https://jxself.org/git/?p=carl9170fw.git;a=blobdiff_plain;f=config%2Fsymbol.c;h=c9123ed2b791ad2de18450485f11ed15984cf448;hp=556aeda1416a7d19f6b9877e74a9a791a868e457;hb=2f1132cbcec40e431991cda7ff3744455b46c3df;hpb=e72388a0aa23da8bc8e24a0cbe9d523c5a9ce294

diff --git a/config/symbol.c b/config/symbol.c
index 556aeda..c9123ed 100644
--- a/config/symbol.c
+++ b/config/symbol.c
@@ -9,7 +9,6 @@
 #include <regex.h>
 #include <sys/utsname.h>
 
-#define LKC_DIRECT_LINK
 #include "lkc.h"
 
 struct symbol symbol_yes = {
@@ -47,7 +46,7 @@ void sym_init(void)
 {
 	struct symbol *sym;
 	struct utsname uts;
-	static bool inited;
+	static bool inited = false;
 
 	if (inited)
 		return;
@@ -78,7 +77,7 @@ const char *sym_type_name(enum symbol_type type)
 {
 	switch (type) {
 	case S_BOOLEAN:
-		return "boolean";
+		return "bool";
 	case S_TRISTATE:
 		return "tristate";
 	case S_INT:
@@ -113,7 +112,7 @@ struct property *sym_get_env_prop(struct symbol *sym)
 	return NULL;
 }
 
-struct property *sym_get_default_prop(struct symbol *sym)
+static struct property *sym_get_default_prop(struct symbol *sym)
 {
 	struct property *prop;
 
@@ -137,7 +136,7 @@ static struct property *sym_get_range_prop(struct symbol *sym)
 	return NULL;
 }
 
-static int sym_get_range_val(struct symbol *sym, int base)
+static long long sym_get_range_val(struct symbol *sym, int base)
 {
 	sym_calc_value(sym);
 	switch (sym->type) {
@@ -150,13 +149,14 @@ static int sym_get_range_val(struct symbol *sym, int base)
 	default:
 		break;
 	}
-	return strtol(sym->curr.val, NULL, base);
+	return strtoll(sym->curr.val, NULL, base);
 }
 
 static void sym_validate_range(struct symbol *sym)
 {
 	struct property *prop;
-	int base, val, val2;
+	int base;
+	long long val, val2;
 	char str[64];
 
 	switch (sym->type) {
@@ -172,7 +172,7 @@ static void sym_validate_range(struct symbol *sym)
 	prop = sym_get_range_prop(sym);
 	if (!prop)
 		return;
-	val = strtol(sym->curr.val, NULL, base);
+	val = strtoll(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);
@@ -180,21 +180,55 @@ static void sym_validate_range(struct symbol *sym)
 			return;
 	}
 	if (sym->type == S_INT)
-		sprintf(str, "%d", val2);
+		sprintf(str, "%lld", val2);
 	else
-		sprintf(str, "0x%x", val2);
+		sprintf(str, "0x%llx", val2);
 	sym->curr.val = strdup(str);
 }
 
+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))
@@ -205,6 +239,16 @@ static void sym_calc_visibility(struct symbol *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)
+		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);
@@ -214,44 +258,79 @@ static void sym_calc_visibility(struct symbol *sym)
 		sym->rev_dep.tri = tri;
 		sym_set_changed(sym);
 	}
+	tri = no;
+	if (sym->implied.expr && sym->dir_dep.tri != no)
+		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);
+	}
 }
 
-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->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)
+		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)
-			return def_sym;
+			flags &= def_sym->flags;
 	}
 
-	/* no choice? reset tristate value */
-	sym->curr.tri = no;
-	return NULL;
+	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;
 }
 
 void sym_calc_value(struct symbol *sym)
@@ -265,6 +344,14 @@ void sym_calc_value(struct symbol *sym)
 
 	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;
@@ -319,11 +406,28 @@ void sym_calc_value(struct symbol *sym)
 					newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 							      prop->visible.tri);
 				}
+				if (sym->implied.tri != no) {
+					sym->flags |= SYMBOL_WRITE;
+					newval.tri = EXPR_OR(newval.tri, sym->implied.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);
 			}
-calc_newval:
 			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 		}
-		if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
+		if (newval.tri == mod &&
+		    (sym_get_type(sym) == S_BOOLEAN || sym->implied.tri == yes))
 			newval.tri = yes;
 		break;
 	case S_STRING:
@@ -365,18 +469,22 @@ calc_newval:
 
 	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)
+			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_AUTO)
 		sym->flags &= ~SYMBOL_WRITE;
+
+	if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
+		set_all_choice_values(sym);
 }
 
 void sym_clear_all_valid(void)
@@ -387,28 +495,7 @@ void sym_clear_all_valid(void)
 	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);
+	sym_calc_value(modules_sym);
 }
 
 bool sym_tristate_within_range(struct symbol *sym, tristate val)
@@ -425,6 +512,8 @@ bool sym_tristate_within_range(struct symbol *sym, tristate val)
 		return false;
 	if (sym->visible <= sym->rev_dep.tri)
 		return false;
+	if (sym->implied.tri == yes && val == mod)
+		return false;
 	if (sym_is_choice_value(sym) && sym->visible == yes)
 		return val == yes;
 	return val >= sym->rev_dep.tri && val <= sym->visible;
@@ -535,7 +624,7 @@ bool sym_string_valid(struct symbol *sym, const char *str)
 bool sym_string_within_range(struct symbol *sym, const char *str)
 {
 	struct property *prop;
-	int val;
+	long long val;
 
 	switch (sym->type) {
 	case S_STRING:
@@ -546,7 +635,7 @@ bool sym_string_within_range(struct symbol *sym, const char *str)
 		prop = sym_get_range_prop(sym);
 		if (!prop)
 			return true;
-		val = strtol(str, NULL, 10);
+		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:
@@ -555,7 +644,7 @@ bool sym_string_within_range(struct symbol *sym, const char *str)
 		prop = sym_get_range_prop(sym);
 		if (!prop)
 			return true;
-		val = strtol(str, NULL, 16);
+		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:
@@ -608,11 +697,11 @@ bool sym_set_string_value(struct symbol *sym, const char *newval)
 	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);
+		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 = malloc(size);
+		sym->def[S_DEF_USER].val = val = xmalloc(size);
 	else
 		return true;
 
@@ -623,6 +712,84 @@ 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;
+
+	/* 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_OTHER:
+	case S_UNKNOWN:
+		break;
+	}
+	return "";
+}
+
 const char *sym_get_string_value(struct symbol *sym)
 {
 	tristate val;
@@ -635,7 +802,8 @@ 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";
 		}
@@ -651,12 +819,20 @@ bool sym_is_changable(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;
-	const char *ptr;
 	char *new_name;
-	int hash = 0;
+	int hash;
 
 	if (name) {
 		if (name[0] && !name[1]) {
@@ -666,12 +842,11 @@ struct symbol *sym_lookup(const char *name, int flags)
 			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) &&
 			    (flags ? symbol->flags & flags
 				   : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
 				return symbol;
@@ -679,10 +854,10 @@ struct symbol *sym_lookup(const char *name, int flags)
 		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;
@@ -697,7 +872,6 @@ struct symbol *sym_lookup(const char *name, int flags)
 struct symbol *sym_find(const char *name)
 {
 	struct symbol *symbol = NULL;
-	const char *ptr;
 	int hash = 0;
 
 	if (!name)
@@ -710,12 +884,11 @@ 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;
 	}
@@ -723,42 +896,302 @@ 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 '$'. Unknown symbol expands to
+ * the empty string.
+ */
+const char *sym_expand_string_value(const char *in)
+{
+	const char *src;
+	char *res;
+	size_t reslen;
+
+	/*
+	 * Note: 'in' might come from a token that's about to be
+	 * freed, so make sure to always allocate a new string
+	 */
+	reslen = strlen(in) + 1;
+	res = xmalloc(reslen);
+	res[0] = '\0';
+
+	while ((src = strchr(in, '$'))) {
+		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 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_NOSUB|REG_ICASE))
+	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, 0, NULL, 0))
+		if (regexec(&re, sym->name, 1, match, 0))
 			continue;
-		if (cnt + 1 >= size) {
-			void *tmp = sym_arr;
+		if (cnt >= size) {
+			void *tmp;
 			size += 16;
-			sym_arr = realloc(sym_arr, size * sizeof(struct symbol *));
-			if (!sym_arr) {
-				free(tmp);
-				return NULL;
-			}
+			tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
+			if (!tmp)
+				goto sym_re_search_free;
+			sym_match_arr = tmp;
 		}
-		sym_arr[cnt++] = sym;
+		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_arr)
+	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 (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>");
+		}
+	}
+
+	fprintf(stderr,
+		"For a resolution refer to Documentation/kbuild/kconfig-language.txt\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)
 {
@@ -776,6 +1209,10 @@ static struct symbol *sym_check_expr_deps(struct expr *e)
 	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)
@@ -795,24 +1232,33 @@ 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);
 
 	sym2 = sym_check_expr_deps(sym->rev_dep.expr);
 	if (sym2)
-		return sym2;
+		goto out;
 
 	for (prop = sym->prop; prop; prop = prop->next) {
 		if (prop->type == P_CHOICE || prop->type == P_SELECT)
 			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;
 }
 
@@ -821,6 +1267,9 @@ 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)
@@ -834,10 +1283,8 @@ static struct symbol *sym_check_choice_deps(struct symbol *choice)
 
 	expr_list_for_each_sym(prop->expr, e, sym) {
 		sym2 = sym_check_sym_deps(sym);
-		if (sym2) {
-			fprintf(stderr, " -> %s", sym->name);
+		if (sym2)
 			break;
-		}
 	}
 out:
 	expr_list_for_each_sym(prop->expr, e, sym)
@@ -847,6 +1294,8 @@ out:
 	    prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
 		sym2 = choice;
 
+	dep_stack_remove();
+
 	return sym2;
 }
 
@@ -856,18 +1305,20 @@ struct symbol *sym_check_deps(struct symbol *sym)
 	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>");
+		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 {
@@ -876,14 +1327,8 @@ struct symbol *sym_check_deps(struct symbol *sym)
 		sym->flags &= ~SYMBOL_CHECK;
 	}
 
-	if (sym2) {
-		fprintf(stderr, " -> %s", sym->name ? sym->name : "<choice>");
-		if (sym2 == sym) {
-			fprintf(stderr, "\n");
-			zconfnerrs++;
-			sym2 = NULL;
-		}
-	}
+	if (sym2 && sym2 == sym)
+		sym2 = NULL;
 
 	return sym2;
 }
@@ -893,7 +1338,7 @@ 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;
@@ -935,8 +1380,12 @@ const char *prop_get_type_name(enum prop_type type)
 		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;
 	}