kconfig / kbuild: Re-sync with Linux 4.19

Align Kconfig and Kbuild logic to Linux 4.19 release with minimal impact
on files outside of this scope.

Our previous Kconfig sync was done by commit 5972ff077e0f ("kconfig /
kbuild: re-sync with Linux 4.18").

In this particular re-sync in order to keep clang support working a
number of related changes needed to be pulled in that had been missed
previously.  Not all of these changes we easily traceable and so have
been omitted from the list below.

The imported Linux commits are:
[From prior to v4.18]
9f3f1fd29976 kbuild: Add __cc-option macro
d7f14c66c273 kbuild: Enable Large File Support for hostprogs
6d79a7b424a5 kbuild: suppress warnings from 'getconf LFS_*'
24403874316a Shared library support
86a9df597cdd kbuild: fix linker feature test macros when cross compiling with Clang
0294e6f4a000 kbuild: simplify ld-option implementation

[From v4.18 to v4.19]
96f14fe738b6 kbuild: Rename HOSTCFLAGS to KBUILD_HOSTCFLAGS
10844aebf448 kbuild: Rename HOSTCXXFLAGS to KBUILD_HOSTCXXFLAGS
b90a368000ab kbuild: Rename HOSTLDFLAGS to KBUILD_HOSTLDFLAGS
8377bd2b9ee1 kbuild: Rename HOST_LOADLIBES to KBUILD_HOSTLDLIBS
f92d19e0ef9b kbuild: Use HOST*FLAGS options from the command line
4ab3b80159d4 kconfig: check for pkg-config on make {menu,n,g,x}config
693359f7ac90 kconfig: rename SYMBOL_AUTO to SYMBOL_NO_WRITE
f60b992e30ff kbuild: replace $(LDFLAGS) $(ldflags-y) with $(ld_flags)
2fb9279f2c3e kbuild: change ld_flags to contain LDFLAGS_$(@F)
c931d34ea085 arm64: build with baremetal linker target instead of Linux when available
5accd7f3360e kconfig: handle format string before calling conf_message_callback()
a2ff4040151a kconfig: rename file_write_dep and move it to confdata.c
0608182ad542 kconfig: split out useful helpers in confdata.c
adc18acf42a1 kconfig: remove unneeded directory generation from local*config
79123b1389cc kconfig: create directories needed for syncconfig by itself
16952b77d8b5 kconfig: make syncconfig update .config regardless of sym_change_count
d6c6ab93e17f kbuild: remove deprecated host-progs variable
56869d45e364 kconfig: fix the rule of mainmenu_stmt symbol
c151272d1687 kconfig: remove unused sym_get_env_prop() function
1880861226c1 kconfig: remove P_ENV property type
e3fd9b5384f3 scripts/dtc: consolidate include path options in Makefile
4bf6a9af0e91 kconfig: add build-only configurator targets
f1575595d156 kconfig: error out when seeing recursive dependency
5e8c5299d315 kconfig: report recursive dependency involving 'imply'
f498926c47aa kconfig: improve the recursive dependency report
98a4afbfafd2 kconfig: fix "Can't open ..." in parallel build
9a9ddcf47831 kconfig: suppress "configuration written to .config" for syncconfig
87a32e624037 kbuild: pass LDFLAGS to recordmcount.pl
d503ac531a52 kbuild: rename LDFLAGS to KBUILD_LDFLAGS
217c3e019675 disable stringop truncation warnings for now
bc8d2e20a3eb kconfig: remove a spurious self-assignment
fd65465b7016 kconfig: do not require pkg-config on make {menu,n}config
5a4630aadb9a ftrace: Build with CPPFLAGS to get -Qunused-arguments

Note that this adds new cleanup work to do in that we should adapt the
shared library support we have to what is now upstream.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>

23 files changed, 299 insertions, 191 deletions

diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile
index 30b90cfde23..559bb88264c 100644
--- a/scripts/kconfig/Makefile
+++ b/scripts/kconfig/Makefile
@@ -3,8 +3,8 @@
 # Kernel configuration targets
 # These targets are used from top-level makefile
 
-PHONY += xconfig gconfig menuconfig config syncconfig \
-	localmodconfig localyesconfig
+PHONY += xconfig gconfig menuconfig config localmodconfig localyesconfig \
+	build_menuconfig build_nconfig build_gconfig build_xconfig
 
 # Added for U-Boot
 #  Linux has defconfig files in arch/$(SRCARCH)/configs/,
@@ -40,14 +40,15 @@ config: $(obj)/conf
 nconfig: $(obj)/nconf
 	$< $(silent) $(Kconfig)
 
-# This has become an internal implementation detail and is now deprecated
-# for external use.
-syncconfig: $(obj)/conf
-	$(Q)mkdir -p include/config include/generated
-	$< $(silent) --$@ $(Kconfig)
+build_menuconfig: $(obj)/mconf
+
+build_nconfig: $(obj)/nconf
+
+build_gconfig: $(obj)/gconf
+
+build_xconfig: $(obj)/qconf
 
 localyesconfig localmodconfig: $(obj)/conf
-	$(Q)mkdir -p include/config include/generated
 	$(Q)perl $(srctree)/$(src)/streamline_config.pl --$@ $(srctree) $(Kconfig) > .tmp.config
 	$(Q)if [ -f .config ]; then 					\
 			cmp -s .tmp.config .config ||			\
@@ -62,8 +63,12 @@ localyesconfig localmodconfig: $(obj)/conf
 	$(Q)rm -f .tmp.config
 
 # These targets map 1:1 to the commandline options of 'conf'
+#
+# Note:
+#  syncconfig has become an internal implementation detail and is now
+#  deprecated for external use
 simple-targets := oldconfig allnoconfig allyesconfig allmodconfig \
-	alldefconfig randconfig listnewconfig olddefconfig
+	alldefconfig randconfig listnewconfig olddefconfig syncconfig
 PHONY += $(simple-targets)
 
 $(simple-targets): $(obj)/conf
@@ -179,29 +184,30 @@ HOSTCFLAGS_zconf.tab.o	:= -I$(src)
 hostprogs-y	+= nconf
 nconf-objs	:= nconf.o zconf.tab.o nconf.gui.o
 
-HOSTLOADLIBES_nconf	= $(shell . $(obj)/.nconf-cfg && echo $$libs)
+HOSTLDLIBS_nconf	= $(shell . $(obj)/.nconf-cfg && echo $$libs)
 HOSTCFLAGS_nconf.o	= $(shell . $(obj)/.nconf-cfg && echo $$cflags)
 HOSTCFLAGS_nconf.gui.o	= $(shell . $(obj)/.nconf-cfg && echo $$cflags)
 
-$(obj)/nconf.o: $(obj)/.nconf-cfg
+$(obj)/nconf.o $(obj)/nconf.gui.o: $(obj)/.nconf-cfg
 
 # mconf: Used for the menuconfig target based on lxdialog
 hostprogs-y	+= mconf
 lxdialog	:= checklist.o inputbox.o menubox.o textbox.o util.o yesno.o
 mconf-objs	:= mconf.o zconf.tab.o $(addprefix lxdialog/, $(lxdialog))
 
-HOSTLOADLIBES_mconf = $(shell . $(obj)/.mconf-cfg && echo $$libs)
+HOSTLDLIBS_mconf = $(shell . $(obj)/.mconf-cfg && echo $$libs)
 $(foreach f, mconf.o $(lxdialog), \
   $(eval HOSTCFLAGS_$f = $$(shell . $(obj)/.mconf-cfg && echo $$$$cflags)))
 
-$(addprefix $(obj)/, mconf.o $(lxdialog)): $(obj)/.mconf-cfg
+$(obj)/mconf.o: $(obj)/.mconf-cfg
+$(addprefix $(obj)/lxdialog/, $(lxdialog)): $(obj)/.mconf-cfg
 
 # qconf: Used for the xconfig target based on Qt
 hostprogs-y	+= qconf
 qconf-cxxobjs	:= qconf.o
 qconf-objs	:= zconf.tab.o
 
-HOSTLOADLIBES_qconf	= $(shell . $(obj)/.qconf-cfg && echo $$libs)
+HOSTLDLIBS_qconf	= $(shell . $(obj)/.qconf-cfg && echo $$libs)
 HOSTCXXFLAGS_qconf.o	= $(shell . $(obj)/.qconf-cfg && echo $$cflags)
 
 $(obj)/qconf.o: $(obj)/.qconf-cfg $(obj)/qconf.moc
@@ -216,7 +222,7 @@ $(obj)/%.moc: $(src)/%.h $(obj)/.qconf-cfg
 hostprogs-y	+= gconf
 gconf-objs	:= gconf.o zconf.tab.o
 
-HOSTLOADLIBES_gconf = $(shell . $(obj)/.gconf-cfg && echo $$libs)
+HOSTLDLIBS_gconf = $(shell . $(obj)/.gconf-cfg && echo $$libs)
 HOSTCFLAGS_gconf.o  = $(shell . $(obj)/.gconf-cfg && echo $$cflags)
 
 $(obj)/gconf.o: $(obj)/.gconf-cfg
diff --git a/scripts/kconfig/conf.c b/scripts/kconfig/conf.c
index 671ff536449..c54ff0453c3 100644
--- a/scripts/kconfig/conf.c
+++ b/scripts/kconfig/conf.c
@@ -496,6 +496,7 @@ int main(int ac, char **av)
 	int opt;
 	const char *name, *defconfig_file = NULL /* gcc uninit */;
 	struct stat tmpstat;
+	int no_conf_write = 0;
 
 	tty_stdio = isatty(0) && isatty(1);
 
@@ -507,6 +508,11 @@ int main(int ac, char **av)
 		input_mode = (enum input_mode)opt;
 		switch (opt) {
 		case syncconfig:
+			/*
+			 * syncconfig is invoked during the build stage.
+			 * Suppress distracting "configuration written to ..."
+			 */
+			conf_set_message_callback(NULL);
 			sync_kconfig = 1;
 			break;
 		case defconfig:
@@ -633,13 +639,14 @@ int main(int ac, char **av)
 	}
 
 	if (sync_kconfig) {
-		if (conf_get_changed()) {
-			name = getenv("KCONFIG_NOSILENTUPDATE");
-			if (name && *name) {
+		name = getenv("KCONFIG_NOSILENTUPDATE");
+		if (name && *name) {
+			if (conf_get_changed()) {
 				fprintf(stderr,
 					"\n*** The configuration requires explicit update.\n\n");
 				return 1;
 			}
+			no_conf_write = 1;
 		}
 	}
 
@@ -688,7 +695,7 @@ int main(int ac, char **av)
 		/* syncconfig is used during the build so we shall update autoconf.
 		 * All other commands are only used to generate a config.
 		 */
-		if (conf_get_changed() && conf_write(NULL)) {
+		if (!no_conf_write && conf_write(NULL)) {
 			fprintf(stderr, "\n*** Error during writing of the configuration.\n\n");
 			exit(1);
 		}
diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index 1abf849bf54..d587b10d7f8 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -16,6 +16,64 @@
 
 #include "lkc.h"
 
+/* return true if 'path' exists, false otherwise */
+static bool is_present(const char *path)
+{
+	struct stat st;
+
+	return !stat(path, &st);
+}
+
+/* return true if 'path' exists and it is a directory, false otherwise */
+static bool is_dir(const char *path)
+{
+	struct stat st;
+
+	if (stat(path, &st))
+		return 0;
+
+	return S_ISDIR(st.st_mode);
+}
+
+/*
+ * Create the parent directory of the given path.
+ *
+ * For example, if 'include/config/auto.conf' is given, create 'include/config'.
+ */
+static int make_parent_dir(const char *path)
+{
+	char tmp[PATH_MAX + 1];
+	char *p;
+
+	strncpy(tmp, path, sizeof(tmp));
+	tmp[sizeof(tmp) - 1] = 0;
+
+	/* Remove the base name. Just return if nothing is left */
+	p = strrchr(tmp, '/');
+	if (!p)
+		return 0;
+	*(p + 1) = 0;
+
+	/* Just in case it is an absolute path */
+	p = tmp;
+	while (*p == '/')
+		p++;
+
+	while ((p = strchr(p, '/'))) {
+		*p = 0;
+
+		/* skip if the directory exists */
+		if (!is_dir(tmp) && mkdir(tmp, 0755))
+			return -1;
+
+		*p = '/';
+		while (*p == '/')
+			p++;
+	}
+
+	return 0;
+}
+
 struct conf_printer {
 	void (*print_symbol)(FILE *, struct symbol *, const char *, void *);
 	void (*print_comment)(FILE *, const char *, void *);
@@ -43,16 +101,16 @@ static void conf_warning(const char *fmt, ...)
 	conf_warnings++;
 }
 
-static void conf_default_message_callback(const char *fmt, va_list ap)
+static void conf_default_message_callback(const char *s)
 {
 	printf("#\n# ");
-	vprintf(fmt, ap);
+	printf("%s", s);
 	printf("\n#\n");
 }
 
-static void (*conf_message_callback) (const char *fmt, va_list ap) =
+static void (*conf_message_callback)(const char *s) =
 	conf_default_message_callback;
-void conf_set_message_callback(void (*fn) (const char *fmt, va_list ap))
+void conf_set_message_callback(void (*fn)(const char *s))
 {
 	conf_message_callback = fn;
 }
@@ -60,10 +118,15 @@ void conf_set_message_callback(void (*fn) (const char *fmt, va_list ap))
 static void conf_message(const char *fmt, ...)
 {
 	va_list ap;
+	char buf[4096];
+
+	if (!conf_message_callback)
+		return;
 
 	va_start(ap, fmt);
-	if (conf_message_callback)
-		conf_message_callback(fmt, ap);
+
+	vsnprintf(buf, sizeof(buf), fmt, ap);
+	conf_message_callback(buf);
 	va_end(ap);
 }
 
@@ -83,7 +146,6 @@ const char *conf_get_autoconfig_name(void)
 
 char *conf_get_default_confname(void)
 {
-	struct stat buf;
 	static char fullname[PATH_MAX+1];
 	char *env, *name;
 
@@ -91,7 +153,7 @@ char *conf_get_default_confname(void)
 	env = getenv(SRCTREE);
 	if (env) {
 		sprintf(fullname, "%s/%s", env, name);
-		if (!stat(fullname, &buf))
+		if (is_present(fullname))
 			return fullname;
 	}
 	return name;
@@ -393,7 +455,7 @@ int conf_read(const char *name)
 
 	for_all_symbols(i, sym) {
 		sym_calc_value(sym);
-		if (sym_is_choice(sym) || (sym->flags & SYMBOL_AUTO))
+		if (sym_is_choice(sym) || (sym->flags & SYMBOL_NO_WRITE))
 			continue;
 		if (sym_has_value(sym) && (sym->flags & SYMBOL_WRITE)) {
 			/* check that calculated value agrees with saved value */
@@ -723,10 +785,9 @@ int conf_write(const char *name)
 
 	dirname[0] = 0;
 	if (name && name[0]) {
-		struct stat st;
 		char *slash;
 
-		if (!stat(name, &st) && S_ISDIR(st.st_mode)) {
+		if (is_dir(name)) {
 			strcpy(dirname, name);
 			strcat(dirname, "/");
 			basename = conf_get_configname();
@@ -811,26 +872,59 @@ next:
 	return 0;
 }
 
+/* write a dependency file as used by kbuild to track dependencies */
+static int conf_write_dep(const char *name)
+{
+	struct file *file;
+	FILE *out;
+
+	if (!name)
+		name = ".kconfig.d";
+	out = fopen("..config.tmp", "w");
+	if (!out)
+		return 1;
+	fprintf(out, "deps_config := \\\n");
+	for (file = file_list; file; file = file->next) {
+		if (file->next)
+			fprintf(out, "\t%s \\\n", file->name);
+		else
+			fprintf(out, "\t%s\n", file->name);
+	}
+	fprintf(out, "\n%s: \\\n"
+		     "\t$(deps_config)\n\n", conf_get_autoconfig_name());
+
+	env_write_dep(out, conf_get_autoconfig_name());
+
+	fprintf(out, "\n$(deps_config): ;\n");
+	fclose(out);
+
+	if (make_parent_dir(name))
+		return 1;
+	rename("..config.tmp", name);
+	return 0;
+}
+
 static int conf_split_config(void)
 {
 	const char *name;
 	char path[PATH_MAX+1];
 	char *s, *d, c;
 	struct symbol *sym;
-	struct stat sb;
 	int res, i, fd;
 
 	name = conf_get_autoconfig_name();
 	conf_read_simple(name, S_DEF_AUTO);
 	sym_calc_value(modules_sym);
 
+	if (make_parent_dir("include/config/foo.h"))
+		return 1;
 	if (chdir("include/config"))
 		return 1;
 
 	res = 0;
 	for_all_symbols(i, sym) {
 		sym_calc_value(sym);
-		if ((sym->flags & SYMBOL_AUTO) || !sym->name)
+		if ((sym->flags & SYMBOL_NO_WRITE) || !sym->name)
 			continue;
 		if (sym->flags & SYMBOL_WRITE) {
 			if (sym->flags & SYMBOL_DEF_AUTO) {
@@ -895,19 +989,12 @@ static int conf_split_config(void)
 				res = 1;
 				break;
 			}
-			/*
-			 * Create directory components,
-			 * unless they exist already.
-			 */
-			d = path;
-			while ((d = strchr(d, '/'))) {
-				*d = 0;
-				if (stat(path, &sb) && mkdir(path, 0755)) {
-					res = 1;
-					goto out;
-				}
-				*d++ = '/';
+
+			if (make_parent_dir(path)) {
+				res = 1;
+				goto out;
 			}
+
 			/* Try it again. */
 			fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 			if (fd == -1) {
@@ -933,7 +1020,7 @@ int conf_write_autoconf(void)
 
 	sym_clear_all_valid();
 
-	file_write_dep("include/config/auto.conf.cmd");
+	conf_write_dep("include/config/auto.conf.cmd");
 
 	if (conf_split_config())
 		return 1;
@@ -980,14 +1067,22 @@ int conf_write_autoconf(void)
 	name = getenv("KCONFIG_AUTOHEADER");
 	if (!name)
 		name = "include/generated/autoconf.h";
+	if (make_parent_dir(name))
+		return 1;
 	if (rename(".tmpconfig.h", name))
 		return 1;
+
 	name = getenv("KCONFIG_TRISTATE");
 	if (!name)
 		name = "include/config/tristate.conf";
+	if (make_parent_dir(name))
+		return 1;
 	if (rename(".tmpconfig_tristate", name))
 		return 1;
+
 	name = conf_get_autoconfig_name();
+	if (make_parent_dir(name))
+		return 1;
 	/*
 	 * This must be the last step, kbuild has a dependency on auto.conf
 	 * and this marks the successful completion of the previous steps.
diff --git a/scripts/kconfig/expr.h b/scripts/kconfig/expr.h
index f63b41b0dd4..7c329e17900 100644
--- a/scripts/kconfig/expr.h
+++ b/scripts/kconfig/expr.h
@@ -141,7 +141,7 @@ struct symbol {
 #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_AUTO       0x1000  /* value from environment variable */
+#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 */
 
@@ -185,7 +185,6 @@ enum prop_type {
 	P_SELECT,   /* select BAR */
 	P_IMPLY,    /* imply BAR */
 	P_RANGE,    /* range 7..100 (for a symbol) */
-	P_ENV,      /* value from environment variable */
 	P_SYMBOL,   /* where a symbol is defined */
 };
 
diff --git a/scripts/kconfig/gconf-cfg.sh b/scripts/kconfig/gconf-cfg.sh
index 533b3d8f8f0..480ecd8b9f4 100755
--- a/scripts/kconfig/gconf-cfg.sh
+++ b/scripts/kconfig/gconf-cfg.sh
@@ -3,6 +3,13 @@
 
 PKG="gtk+-2.0 gmodule-2.0 libglade-2.0"
 
+if [ -z "$(command -v pkg-config)" ]; then
+	echo >&2 "*"
+	echo >&2 "* 'make gconfig' requires 'pkg-config'. Please install it."
+	echo >&2 "*"
+	exit 1
+fi
+
 if ! pkg-config --exists $PKG; then
 	echo >&2 "*"
 	echo >&2 "* Unable to find the GTK+ installation. Please make sure that"
diff --git a/scripts/kconfig/gconf.c b/scripts/kconfig/gconf.c
index 610c4ab54d7..a9e48cc7b50 100644
--- a/scripts/kconfig/gconf.c
+++ b/scripts/kconfig/gconf.c
@@ -101,8 +101,8 @@ const char *dbg_sym_flags(int val)
 		strcat(buf, "write/");
 	if (val & SYMBOL_CHANGED)
 		strcat(buf, "changed/");
-	if (val & SYMBOL_AUTO)
-		strcat(buf, "auto/");
+	if (val & SYMBOL_NO_WRITE)
+		strcat(buf, "no_write/");
 
 	buf[strlen(buf) - 1] = '\0';
 
diff --git a/scripts/kconfig/lkc.h b/scripts/kconfig/lkc.h
index ed3ff88e60b..9eb7c837cd8 100644
--- a/scripts/kconfig/lkc.h
+++ b/scripts/kconfig/lkc.h
@@ -97,7 +97,6 @@ void menu_set_type(int type);
 
 /* util.c */
 struct file *file_lookup(const char *name);
-int file_write_dep(const char *name);
 void *xmalloc(size_t size);
 void *xcalloc(size_t nmemb, size_t size);
 void *xrealloc(void *p, size_t size);
@@ -126,7 +125,6 @@ const char *sym_get_string_default(struct symbol *sym);
 struct symbol *sym_check_deps(struct symbol *sym);
 struct property *prop_alloc(enum prop_type type, struct symbol *sym);
 struct symbol *prop_get_symbol(struct property *prop);
-struct property *sym_get_env_prop(struct symbol *sym);
 
 static inline tristate sym_get_tristate_value(struct symbol *sym)
 {
diff --git a/scripts/kconfig/lkc_proto.h b/scripts/kconfig/lkc_proto.h
index a8b7a330587..cf4510a2bdc 100644
--- a/scripts/kconfig/lkc_proto.h
+++ b/scripts/kconfig/lkc_proto.h
@@ -10,7 +10,7 @@ int conf_write(const char *name);
 int conf_write_autoconf(void);
 bool conf_get_changed(void);
 void conf_set_changed_callback(void (*fn)(void));
-void conf_set_message_callback(void (*fn)(const char *fmt, va_list ap));
+void conf_set_message_callback(void (*fn)(const char *s));
 
 /* menu.c */
 extern struct menu rootmenu;
diff --git a/scripts/kconfig/mconf-cfg.sh b/scripts/kconfig/mconf-cfg.sh
index e6f9facd007..c812872d7f9 100755
--- a/scripts/kconfig/mconf-cfg.sh
+++ b/scripts/kconfig/mconf-cfg.sh
@@ -4,20 +4,23 @@
 PKG="ncursesw"
 PKG2="ncurses"
 
-if pkg-config --exists $PKG; then
-	echo cflags=\"$(pkg-config --cflags $PKG)\"
-	echo libs=\"$(pkg-config --libs $PKG)\"
-	exit 0
-fi
+if [ -n "$(command -v pkg-config)" ]; then
+	if pkg-config --exists $PKG; then
+		echo cflags=\"$(pkg-config --cflags $PKG)\"
+		echo libs=\"$(pkg-config --libs $PKG)\"
+		exit 0
+	fi
 
-if pkg-config --exists $PKG2; then
-	echo cflags=\"$(pkg-config --cflags $PKG2)\"
-	echo libs=\"$(pkg-config --libs $PKG2)\"
-	exit 0
+	if pkg-config --exists $PKG2; then
+		echo cflags=\"$(pkg-config --cflags $PKG2)\"
+		echo libs=\"$(pkg-config --libs $PKG2)\"
+		exit 0
+	fi
 fi
 
-# Unfortunately, some distributions (e.g. openSUSE) cannot find ncurses
-# by pkg-config.
+# Check the default paths in case pkg-config is not installed.
+# (Even if it is installed, some distributions such as openSUSE cannot
+# find ncurses by pkg-config.)
 if [ -f /usr/include/ncursesw/ncurses.h ]; then
 	echo cflags=\"-D_GNU_SOURCE -I/usr/include/ncursesw\"
 	echo libs=\"-lncursesw\"
diff --git a/scripts/kconfig/mconf.c b/scripts/kconfig/mconf.c
index 5294ed159b9..c1b38747c14 100644
--- a/scripts/kconfig/mconf.c
+++ b/scripts/kconfig/mconf.c
@@ -490,7 +490,6 @@ static void build_conf(struct menu *menu)
 			switch (prop->type) {
 			case P_MENU:
 				child_count++;
-				prompt = prompt;
 				if (single_menu_mode) {
 					item_make("%s%*c%s",
 						  menu->data ? "-->" : "++>",
@@ -772,16 +771,13 @@ static void show_helptext(const char *title, const char *text)
 	show_textbox(title, text, 0, 0);
 }
 
-static void conf_message_callback(const char *fmt, va_list ap)
+static void conf_message_callback(const char *s)
 {
-	char buf[PATH_MAX+1];
-
-	vsnprintf(buf, sizeof(buf), fmt, ap);
 	if (save_and_exit) {
 		if (!silent)
-			printf("%s", buf);
+			printf("%s", s);
 	} else {
-		show_textbox(NULL, buf, 6, 60);
+		show_textbox(NULL, s, 6, 60);
 	}
 }
 
diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
index 379a119dcd1..4cf15d449c0 100644
--- a/scripts/kconfig/menu.c
+++ b/scripts/kconfig/menu.c
@@ -212,7 +212,7 @@ void menu_add_option(int token, char *arg)
 			sym_defconfig_list = current_entry->sym;
 		else if (sym_defconfig_list != current_entry->sym)
 			zconf_error("trying to redefine defconfig symbol");
-		sym_defconfig_list->flags |= SYMBOL_AUTO;
+		sym_defconfig_list->flags |= SYMBOL_NO_WRITE;
 		break;
 	case T_OPT_ALLNOCONFIG_Y:
 		current_entry->sym->flags |= SYMBOL_ALLNOCONFIG_Y;
diff --git a/scripts/kconfig/nconf-cfg.sh b/scripts/kconfig/nconf-cfg.sh
index 42f5ac73548..001559ef0a6 100644
--- a/scripts/kconfig/nconf-cfg.sh
+++ b/scripts/kconfig/nconf-cfg.sh
@@ -4,20 +4,23 @@
 PKG="ncursesw menuw panelw"
 PKG2="ncurses menu panel"
 
-if pkg-config --exists $PKG; then
-	echo cflags=\"$(pkg-config --cflags $PKG)\"
-	echo libs=\"$(pkg-config --libs $PKG)\"
-	exit 0
-fi
+if [ -n "$(command -v pkg-config)" ]; then
+	if pkg-config --exists $PKG; then
+		echo cflags=\"$(pkg-config --cflags $PKG)\"
+		echo libs=\"$(pkg-config --libs $PKG)\"
+		exit 0
+	fi
 
-if pkg-config --exists $PKG2; then
-	echo cflags=\"$(pkg-config --cflags $PKG2)\"
-	echo libs=\"$(pkg-config --libs $PKG2)\"
-	exit 0
+	if pkg-config --exists $PKG2; then
+		echo cflags=\"$(pkg-config --cflags $PKG2)\"
+		echo libs=\"$(pkg-config --libs $PKG2)\"
+		exit 0
+	fi
 fi
 
-# Unfortunately, some distributions (e.g. openSUSE) cannot find ncurses
-# by pkg-config.
+# Check the default paths in case pkg-config is not installed.
+# (Even if it is installed, some distributions such as openSUSE cannot
+# find ncurses by pkg-config.)
 if [ -f /usr/include/ncursesw/ncurses.h ]; then
 	echo cflags=\"-D_GNU_SOURCE -I/usr/include/ncursesw\"
 	echo libs=\"-lncursesw -lmenuw -lpanelw\"
diff --git a/scripts/kconfig/nconf.c b/scripts/kconfig/nconf.c
index 97b78445584..5cbdb92e11b 100644
--- a/scripts/kconfig/nconf.c
+++ b/scripts/kconfig/nconf.c
@@ -1210,12 +1210,9 @@ static void conf(struct menu *menu)
 	}
 }
 
-static void conf_message_callback(const char *fmt, va_list ap)
+static void conf_message_callback(const char *s)
 {
-	char buf[1024];
-
-	vsnprintf(buf, sizeof(buf), fmt, ap);
-	btn_dialog(main_window, buf, 1, "<OK>");
+	btn_dialog(main_window, s, 1, "<OK>");
 }
 
 static void show_help(struct menu *menu)
diff --git a/scripts/kconfig/qconf-cfg.sh b/scripts/kconfig/qconf-cfg.sh
index 0862e156253..02ccc0ae103 100755
--- a/scripts/kconfig/qconf-cfg.sh
+++ b/scripts/kconfig/qconf-cfg.sh
@@ -4,6 +4,13 @@
 PKG="Qt5Core Qt5Gui Qt5Widgets"
 PKG2="QtCore QtGui"
 
+if [ -z "$(command -v pkg-config)" ]; then
+	echo >&2 "*"
+	echo >&2 "* 'make xconfig' requires 'pkg-config'. Please install it."
+	echo >&2 "*"
+	exit 1
+fi
+
 if pkg-config --exists $PKG; then
 	echo cflags=\"-std=c++11 -fPIC $(pkg-config --cflags Qt5Core Qt5Gui Qt5Widgets)\"
 	echo libs=\"$(pkg-config --libs $PKG)\"
diff --git a/scripts/kconfig/qconf.cc b/scripts/kconfig/qconf.cc
index ad9c22dd04f..0c3fa940568 100644
--- a/scripts/kconfig/qconf.cc
+++ b/scripts/kconfig/qconf.cc
@@ -1149,7 +1149,6 @@ QString ConfigInfoView::debug_info(struct symbol *sym)
 		case P_DEFAULT:
 		case P_SELECT:
 		case P_RANGE:
-		case P_ENV:
 			debug += prop_get_type_name(prop->type);
 			debug += ": ";
 			expr_print(prop->expr, expr_print_help, &debug, E_NONE);
diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
index 7c9a88e91cf..703b9b899ee 100644
--- a/scripts/kconfig/symbol.c
+++ b/scripts/kconfig/symbol.c
@@ -76,15 +76,6 @@ 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;
-}
-
 static struct property *sym_get_default_prop(struct symbol *sym)
 {
 	struct property *prop;
@@ -463,7 +454,7 @@ void sym_calc_value(struct symbol *sym)
 		}
 	}
 
-	if (sym->flags & SYMBOL_AUTO)
+	if (sym->flags & SYMBOL_NO_WRITE)
 		sym->flags &= ~SYMBOL_WRITE;
 
 	if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
@@ -1020,7 +1011,7 @@ static struct dep_stack {
 	struct dep_stack *prev, *next;
 	struct symbol *sym;
 	struct property *prop;
-	struct expr *expr;
+	struct expr **expr;
 } *check_top;
 
 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
@@ -1085,31 +1076,42 @@ static void sym_check_print_recursive(struct symbol *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,
+		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>",
-				prop_get_type_name(prop->type),
 				next_sym->name ? next_sym->name : "<choice>");
-		} else if (stack->prop) {
+		} else if (stack->expr == &sym->dir_dep.expr) {
 			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,
+		} else if (stack->expr == &sym->rev_dep.expr) {
+			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>");
-		} else if (sym_is_choice_value(sym)) {
-			fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
-				menu->file->name, menu->lineno,
+		} else if (stack->expr == &sym->implied.expr) {
+			fprintf(stderr, "%s:%d:\tsymbol %s is implied by %s\n",
+				prop->file->name, prop->lineno,
 				sym->name ? sym->name : "<choice>",
 				next_sym->name ? next_sym->name : "<choice>");
+		} else 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 {
-			fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
+			fprintf(stderr, "%s:%d:\tsymbol %s %s is visible depending on %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>");
 		}
 	}
@@ -1166,12 +1168,26 @@ static struct symbol *sym_check_sym_deps(struct symbol *sym)
 
 	dep_stack_insert(&stack, sym);
 
+	stack.expr = &sym->dir_dep.expr;
+	sym2 = sym_check_expr_deps(sym->dir_dep.expr);
+	if (sym2)
+		goto out;
+
+	stack.expr = &sym->rev_dep.expr;
 	sym2 = sym_check_expr_deps(sym->rev_dep.expr);
 	if (sym2)
 		goto out;
 
+	stack.expr = &sym->implied.expr;
+	sym2 = sym_check_expr_deps(sym->implied.expr);
+	if (sym2)
+		goto out;
+
+	stack.expr = NULL;
+
 	for (prop = sym->prop; prop; prop = prop->next) {
-		if (prop->type == P_CHOICE || prop->type == P_SELECT)
+		if (prop->type == P_CHOICE || prop->type == P_SELECT ||
+		    prop->type == P_IMPLY)
 			continue;
 		stack.prop = prop;
 		sym2 = sym_check_expr_deps(prop->visible.expr);
@@ -1179,7 +1195,7 @@ static struct symbol *sym_check_sym_deps(struct symbol *sym)
 			break;
 		if (prop->type != P_DEFAULT || sym_is_choice(sym))
 			continue;
-		stack.expr = prop->expr;
+		stack.expr = &prop->expr;
 		sym2 = sym_check_expr_deps(prop->expr);
 		if (sym2)
 			break;
@@ -1257,9 +1273,6 @@ struct symbol *sym_check_deps(struct symbol *sym)
 		sym->flags &= ~SYMBOL_CHECK;
 	}
 
-	if (sym2 && sym2 == sym)
-		sym2 = NULL;
-
 	return sym2;
 }
 
@@ -1298,8 +1311,6 @@ 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:
diff --git a/scripts/kconfig/tests/warn_recursive_dep/Kconfig b/scripts/kconfig/tests/err_recursive_dep/Kconfig
index a65bfcb7137..ebdb3ffd871 100644
--- a/scripts/kconfig/tests/warn_recursive_dep/Kconfig
+++ b/scripts/kconfig/tests/err_recursive_dep/Kconfig
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+
 # depends on itself
 
 config A
@@ -31,7 +33,6 @@ config D2
 	bool
 
 # depends on and imply
-# This is not recursive dependency
 
 config E1
 	bool "E1"
diff --git a/scripts/kconfig/tests/err_recursive_dep/__init__.py b/scripts/kconfig/tests/err_recursive_dep/__init__.py
new file mode 100644
index 00000000000..5f3821b43ce
--- /dev/null
+++ b/scripts/kconfig/tests/err_recursive_dep/__init__.py
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0
+"""
+Detect recursive dependency error.
+
+Recursive dependency should be treated as an error.
+"""
+
+def test(conf):
+    assert conf.oldaskconfig() == 1
+    assert conf.stderr_contains('expected_stderr')
diff --git a/scripts/kconfig/tests/err_recursive_dep/expected_stderr b/scripts/kconfig/tests/err_recursive_dep/expected_stderr
new file mode 100644
index 00000000000..84679b10465
--- /dev/null
+++ b/scripts/kconfig/tests/err_recursive_dep/expected_stderr
@@ -0,0 +1,38 @@
+Kconfig:11:error: recursive dependency detected!
+Kconfig:11:	symbol B is selected by B
+For a resolution refer to Documentation/kbuild/kconfig-language.txt
+subsection "Kconfig recursive dependency limitations"
+
+Kconfig:5:error: recursive dependency detected!
+Kconfig:5:	symbol A depends on A
+For a resolution refer to Documentation/kbuild/kconfig-language.txt
+subsection "Kconfig recursive dependency limitations"
+
+Kconfig:17:error: recursive dependency detected!
+Kconfig:17:	symbol C1 depends on C2
+Kconfig:21:	symbol C2 depends on C1
+For a resolution refer to Documentation/kbuild/kconfig-language.txt
+subsection "Kconfig recursive dependency limitations"
+
+Kconfig:32:error: recursive dependency detected!
+Kconfig:32:	symbol D2 is selected by D1
+Kconfig:27:	symbol D1 depends on D2
+For a resolution refer to Documentation/kbuild/kconfig-language.txt
+subsection "Kconfig recursive dependency limitations"
+
+Kconfig:37:error: recursive dependency detected!
+Kconfig:37:	symbol E1 depends on E2
+Kconfig:42:	symbol E2 is implied by E1
+For a resolution refer to Documentation/kbuild/kconfig-language.txt
+subsection "Kconfig recursive dependency limitations"
+
+Kconfig:60:error: recursive dependency detected!
+Kconfig:60:	symbol G depends on G
+For a resolution refer to Documentation/kbuild/kconfig-language.txt
+subsection "Kconfig recursive dependency limitations"
+
+Kconfig:51:error: recursive dependency detected!
+Kconfig:51:	symbol F2 depends on F1
+Kconfig:49:	symbol F1 default value contains F2
+For a resolution refer to Documentation/kbuild/kconfig-language.txt
+subsection "Kconfig recursive dependency limitations"
diff --git a/scripts/kconfig/tests/warn_recursive_dep/__init__.py b/scripts/kconfig/tests/warn_recursive_dep/__init__.py
deleted file mode 100644
index adb21951ba4..00000000000
--- a/scripts/kconfig/tests/warn_recursive_dep/__init__.py
+++ /dev/null
@@ -1,9 +0,0 @@
-"""
-Warn recursive inclusion.
-
-Recursive dependency should be warned.
-"""
-
-def test(conf):
-    assert conf.oldaskconfig() == 0
-    assert conf.stderr_contains('expected_stderr')
diff --git a/scripts/kconfig/tests/warn_recursive_dep/expected_stderr b/scripts/kconfig/tests/warn_recursive_dep/expected_stderr
deleted file mode 100644
index 3de807dd9cb..00000000000
--- a/scripts/kconfig/tests/warn_recursive_dep/expected_stderr
+++ /dev/null
@@ -1,30 +0,0 @@
-Kconfig:9:error: recursive dependency detected!
-Kconfig:9:	symbol B is selected by B
-For a resolution refer to Documentation/kbuild/kconfig-language.txt
-subsection "Kconfig recursive dependency limitations"
-
-Kconfig:3:error: recursive dependency detected!
-Kconfig:3:	symbol A depends on A
-For a resolution refer to Documentation/kbuild/kconfig-language.txt
-subsection "Kconfig recursive dependency limitations"
-
-Kconfig:15:error: recursive dependency detected!
-Kconfig:15:	symbol C1 depends on C2
-Kconfig:19:	symbol C2 depends on C1
-For a resolution refer to Documentation/kbuild/kconfig-language.txt
-subsection "Kconfig recursive dependency limitations"
-
-Kconfig:30:error: recursive dependency detected!
-Kconfig:30:	symbol D2 is selected by D1
-Kconfig:25:	symbol D1 depends on D2
-For a resolution refer to Documentation/kbuild/kconfig-language.txt
-subsection "Kconfig recursive dependency limitations"
-
-Kconfig:59:error: recursive dependency detected!
-Kconfig:59:	symbol G depends on G
-For a resolution refer to Documentation/kbuild/kconfig-language.txt
-subsection "Kconfig recursive dependency limitations"
-
-Kconfig:50:error: recursive dependency detected!
-Kconfig:50:	symbol F2 depends on F1
-Kconfig:48:	symbol F1 default value contains F2
diff --git a/scripts/kconfig/util.c b/scripts/kconfig/util.c
index a365594770d..d999683bb2a 100644
--- a/scripts/kconfig/util.c
+++ b/scripts/kconfig/util.c
@@ -29,36 +29,6 @@ struct file *file_lookup(const char *name)
 	return file;
 }
 
-/* write a dependency file as used by kbuild to track dependencies */
-int file_write_dep(const char *name)
-{
-	struct file *file;
-	FILE *out;
-
-	if (!name)
-		name = ".kconfig.d";
-	out = fopen("..config.tmp", "w");
-	if (!out)
-		return 1;
-	fprintf(out, "deps_config := \\\n");
-	for (file = file_list; file; file = file->next) {
-		if (file->next)
-			fprintf(out, "\t%s \\\n", file->name);
-		else
-			fprintf(out, "\t%s\n", file->name);
-	}
-	fprintf(out, "\n%s: \\\n"
-		     "\t$(deps_config)\n\n", conf_get_autoconfig_name());
-
-	env_write_dep(out, conf_get_autoconfig_name());
-
-	fprintf(out, "\n$(deps_config): ;\n");
-	fclose(out);
-	rename("..config.tmp", name);
-	return 0;
-}
-
-
 /* Allocate initial growable string */
 struct gstr str_new(void)
 {
diff --git a/scripts/kconfig/zconf.y b/scripts/kconfig/zconf.y
index 4b68272ebdb..22fceb264cf 100644
--- a/scripts/kconfig/zconf.y
+++ b/scripts/kconfig/zconf.y
@@ -31,7 +31,7 @@ struct symbol *symbol_hash[SYMBOL_HASHSIZE];
 static struct menu *current_menu, *current_entry;
 
 %}
-%expect 31
+%expect 30
 
 %union
 {
@@ -117,7 +117,7 @@ start: mainmenu_stmt stmt_list | stmt_list;
 
 /* mainmenu entry */
 
-mainmenu_stmt: T_MAINMENU prompt nl
+mainmenu_stmt: T_MAINMENU prompt T_EOL
 {
 	menu_add_prompt(P_MENU, $2, NULL);
 };
@@ -265,7 +265,7 @@ symbol_option_arg:
 choice: T_CHOICE word_opt T_EOL
 {
 	struct symbol *sym = sym_lookup($2, SYMBOL_CHOICE);
-	sym->flags |= SYMBOL_AUTO;
+	sym->flags |= SYMBOL_NO_WRITE;
 	menu_add_entry(sym);
 	menu_add_expr(P_CHOICE, NULL, NULL);
 	free($2);