4 files changed, 80 insertions, 31 deletions

diff --git a/scripts/kconfig/conf.c b/scripts/kconfig/conf.c
index 4178065ca27f..33d19e419908 100644
--- a/scripts/kconfig/conf.c
+++ b/scripts/kconfig/conf.c
@@ -551,7 +551,7 @@ static int conf_choice(struct menu *menu)
 			print_help(child);
 			continue;
 		}
-		sym_set_choice_value(sym, child->sym);
+		sym_set_tristate_value(child->sym, yes);
 		for (child = child->list; child; child = child->next) {
 			indent += 2;
 			conf(child);
diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index c4340c90e172..b7c9f1dd5e42 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -216,6 +216,13 @@ static const char *conf_get_autoheader_name(void)
 	return name ? name : "include/generated/autoconf.h";
 }
 
+static const char *conf_get_rustccfg_name(void)
+{
+	char *name = getenv("KCONFIG_RUSTCCFG");
+
+	return name ? name : "include/generated/rustc_cfg";
+}
+
 static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
 {
 	char *p2;
@@ -605,6 +612,9 @@ static const struct comment_style comment_style_c = {
 
 static void conf_write_heading(FILE *fp, const struct comment_style *cs)
 {
+	if (!cs)
+		return;
+
 	fprintf(fp, "%s\n", cs->prefix);
 
 	fprintf(fp, "%s Automatically generated file; DO NOT EDIT.\n",
@@ -745,6 +755,65 @@ static void print_symbol_for_c(FILE *fp, struct symbol *sym)
 	free(escaped);
 }
 
+static void print_symbol_for_rustccfg(FILE *fp, struct symbol *sym)
+{
+	const char *val;
+	const char *val_prefix = "";
+	char *val_prefixed = NULL;
+	size_t val_prefixed_len;
+	char *escaped = NULL;
+
+	if (sym->type == S_UNKNOWN)
+		return;
+
+	val = sym_get_string_value(sym);
+
+	switch (sym->type) {
+	case S_BOOLEAN:
+	case S_TRISTATE:
+		/*
+		 * We do not care about disabled ones, i.e. no need for
+		 * what otherwise are "comments" in other printers.
+		 */
+		if (*val == 'n')
+			return;
+
+		/*
+		 * To have similar functionality to the C macro `IS_ENABLED()`
+		 * we provide an empty `--cfg CONFIG_X` here in both `y`
+		 * and `m` cases.
+		 *
+		 * Then, the common `fprintf()` below will also give us
+		 * a `--cfg CONFIG_X="y"` or `--cfg CONFIG_X="m"`, which can
+		 * be used as the equivalent of `IS_BUILTIN()`/`IS_MODULE()`.
+		 */
+		fprintf(fp, "--cfg=%s%s\n", CONFIG_, sym->name);
+		break;
+	case S_HEX:
+		if (val[0] != '0' || (val[1] != 'x' && val[1] != 'X'))
+			val_prefix = "0x";
+		break;
+	default:
+		break;
+	}
+
+	if (strlen(val_prefix) > 0) {
+		val_prefixed_len = strlen(val) + strlen(val_prefix) + 1;
+		val_prefixed = xmalloc(val_prefixed_len);
+		snprintf(val_prefixed, val_prefixed_len, "%s%s", val_prefix, val);
+		val = val_prefixed;
+	}
+
+	/* All values get escaped: the `--cfg` option only takes strings */
+	escaped = escape_string_value(val);
+	val = escaped;
+
+	fprintf(fp, "--cfg=%s%s=%s\n", CONFIG_, sym->name, val);
+
+	free(escaped);
+	free(val_prefixed);
+}
+
 /*
  * Write out a minimal config.
  * All values that has default values are skipped as this is redundant.
@@ -1132,6 +1201,12 @@ int conf_write_autoconf(int overwrite)
 	if (ret)
 		return ret;
 
+	ret = __conf_write_autoconf(conf_get_rustccfg_name(),
+				    print_symbol_for_rustccfg,
+				    NULL);
+	if (ret)
+		return ret;
+
 	/*
 	 * Create include/config/auto.conf. This must be the last step because
 	 * Kbuild has a dependency on auto.conf and this marks the successful
diff --git a/scripts/kconfig/lkc.h b/scripts/kconfig/lkc.h
index fa8c010aa683..6ac2eabe109d 100644
--- a/scripts/kconfig/lkc.h
+++ b/scripts/kconfig/lkc.h
@@ -98,7 +98,6 @@ bool menu_is_empty(struct menu *menu);
 bool menu_is_visible(struct menu *menu);
 bool menu_has_prompt(struct menu *menu);
 const char *menu_get_prompt(struct menu *menu);
-struct menu *menu_get_root_menu(struct menu *menu);
 struct menu *menu_get_parent_menu(struct menu *menu);
 bool menu_has_help(struct menu *menu);
 const char *menu_get_help(struct menu *menu);
@@ -124,11 +123,6 @@ static inline struct symbol *sym_get_choice_value(struct symbol *sym)
 	return (struct symbol *)sym->curr.val;
 }
 
-static inline bool sym_set_choice_value(struct symbol *ch, struct symbol *chval)
-{
-	return sym_set_tristate_value(chval, yes);
-}
-
 static inline bool sym_is_choice(struct symbol *sym)
 {
 	return sym->flags & SYMBOL_CHOICE ? true : false;
diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
index 3d6f7cba8846..109325f31bef 100644
--- a/scripts/kconfig/menu.c
+++ b/scripts/kconfig/menu.c
@@ -661,11 +661,6 @@ const char *menu_get_prompt(struct menu *menu)
 	return NULL;
 }
 
-struct menu *menu_get_root_menu(struct menu *menu)
-{
-	return &rootmenu;
-}
-
 struct menu *menu_get_parent_menu(struct menu *menu)
 {
 	enum prop_type type;
@@ -727,8 +722,8 @@ static void get_prompt_str(struct gstr *r, struct property *prop,
 	if (!expr_eq(prop->menu->dep, prop->visible.expr))
 		get_dep_str(r, prop->visible.expr, "  Visible if: ");
 
-	menu = prop->menu->parent;
-	for (i = 0; menu && i < 8; menu = menu->parent) {
+	menu = prop->menu;
+	for (i = 0; menu != &rootmenu && i < 8; menu = menu->parent) {
 		bool accessible = menu_is_visible(menu);
 
 		submenu[i++] = menu;
@@ -738,16 +733,7 @@ static void get_prompt_str(struct gstr *r, struct property *prop,
 	if (head && location) {
 		jump = xmalloc(sizeof(struct jump_key));
 
-		if (menu_is_visible(prop->menu)) {
-			/*
-			 * There is not enough room to put the hint at the
-			 * beginning of the "Prompt" line. Put the hint on the
-			 * last "Location" line even when it would belong on
-			 * the former.
-			 */
-			jump->target = prop->menu;
-		} else
-			jump->target = location;
+		jump->target = location;
 
 		if (list_empty(head))
 			jump->index = 0;
@@ -763,13 +749,7 @@ static void get_prompt_str(struct gstr *r, struct property *prop,
 		menu = submenu[i];
 		if (jump && menu == location)
 			jump->offset = strlen(r->s);
-
-		if (menu == &rootmenu)
-			/* The real rootmenu prompt is ugly */
-			str_printf(r, "%*cMain menu", j, ' ');
-		else
-			str_printf(r, "%*c-> %s", j, ' ', menu_get_prompt(menu));
-
+		str_printf(r, "%*c-> %s", j, ' ', menu_get_prompt(menu));
 		if (menu->sym) {
 			str_printf(r, " (%s [=%s])", menu->sym->name ?
 				menu->sym->name : "<choice>",