Menuconfig: Don't ask to save configuration when nothing has changed

Closes https://github.com/espressif/esp-idf/issues/4303

Kconfig

@@ -20,7 +20,7 @@ mainmenu "Espressif IoT Development Framework Configuration"
         # the build system is responsible for detecting the mismatch between
         # CONFIG_IDF_TARGET and $IDF_TARGET.
         string
-        default "$(IDF_TARGET)"
+        default "$IDF_TARGET"
 
     config IDF_TARGET_ESP32
         bool

make/project_config.mk

@@ -34,7 +34,7 @@ SDKCONFIG_DEFAULTS ?= $(PROJECT_PATH)/sdkconfig.defaults
 $(KCONFIG_TOOL_DIR)/mconf-idf: $(KCONFIG_TOOL_DIR)/conf-idf
 
 # reset MAKEFLAGS as the menuconfig makefile uses implicit compile rules
-$(KCONFIG_TOOL_DIR)/mconf-idf $(KCONFIG_TOOL_DIR)/conf-idf: $(wildcard $(KCONFIG_TOOL_DIR)/*.c)
+$(KCONFIG_TOOL_DIR)/mconf-idf $(KCONFIG_TOOL_DIR)/conf-idf: $(wildcard $(KCONFIG_TOOL_DIR)/*.c) $(wildcard $(KCONFIG_TOOL_DIR)/*.y)
 ifeq ($(OS),Windows_NT)
 	# mconf-idf is used only in MSYS
 	MAKEFLAGS="" CC=$(HOSTCC) LD=$(HOSTLD) \
@@ -66,7 +66,8 @@ SDKCONFIG_DEFAULTS_FILES := $(foreach f,$(SDKCONFIG_DEFAULTS),$(wildcard $(f)))
 SDKCONFIG_DEFAULTS_FILES += $(foreach f,$(SDKCONFIG_DEFAULTS_FILES),$(wildcard $(f).$(IDF_TARGET)))
 
 ifeq ($(OS),Windows_NT)
-SDKCONFIG_DEFAULTS_FILES := $(shell cygpath -m $(SDKCONFIG_DEFAULTS_FILES))
+# -i is for ignore missing arguments in case SDKCONFIG_DEFAULTS_FILES is empty
+SDKCONFIG_DEFAULTS_FILES := $(shell cygpath -i -m $(SDKCONFIG_DEFAULTS_FILES))
 endif
 DEFAULTS_ARG := $(foreach f,$(SDKCONFIG_DEFAULTS_FILES),--defaults $(f))
 
@@ -94,7 +95,8 @@ define RunConfGen
 		$(DEFAULTS_ARG) \
 		--output config ${SDKCONFIG} \
 		--output makefile $(SDKCONFIG_MAKEFILE) \
-		--output header $(BUILD_DIR_BASE)/include/sdkconfig.h
+		--output header $(BUILD_DIR_BASE)/include/sdkconfig.h \
+		$1
 endef
 
 ifeq ($(OS),Windows_NT)
@@ -135,23 +137,23 @@ ifdef BATCH_BUILD
 	@echo "See esp-idf documentation for more details."
 	@exit 1
 else
-	$(call RunConfGen)
+	$(call RunConfGen,--dont-write-deprecated)
 	# RunConfGen before menuconfig ensures that deprecated options won't be ignored (they've got renamed)
 	$(call RunMenuConf)
 	# RunConfGen after menuconfig ensures that deprecated options are appended to $(SDKCONFIG) for backward compatibility
-	$(call RunConfGen)
+	$(call RunConfGen,)
 endif
 
 # defconfig creates a default config, based on SDKCONFIG_DEFAULTS if present
 defconfig: | check_python_dependencies prepare_kconfig_files
 	$(summary) DEFCONFIG
-	$(call RunConfGen)
+	$(call RunConfGen,)
 
 # if neither defconfig or menuconfig are requested, use the GENCONFIG rule to
 # ensure generated config files are up to date
 $(SDKCONFIG_MAKEFILE) $(BUILD_DIR_BASE)/include/sdkconfig.h: $(SDKCONFIG) $(COMPONENT_KCONFIGS) $(COMPONENT_KCONFIGS_PROJBUILD) | check_python_dependencies prepare_kconfig_files $(call prereq_if_explicit,defconfig) $(call prereq_if_explicit,menuconfig)
 	$(summary) GENCONFIG
-	$(call RunConfGen)
+	$(call RunConfGen,)
 	touch $(SDKCONFIG_MAKEFILE) $(BUILD_DIR_BASE)/include/sdkconfig.h  # ensure newer than sdkconfig
 
 else  # "$(MAKE_RESTARTS)" != ""

tools/cmake/kconfig.cmake

@@ -263,12 +263,14 @@ function(__kconfig_generate_config sdkconfig sdkconfig_defaults)
         ${menuconfig_depends}
         # create any missing config file, with defaults if necessary
         COMMAND ${prepare_kconfig_files_command}
-        COMMAND ${confgen_basecommand} --env "IDF_TARGET=${idf_target}" --output config ${sdkconfig}
+        COMMAND ${confgen_basecommand}
+        --env "IDF_TARGET=${idf_target}"
+        --dont-write-deprecated
+        --output config ${sdkconfig}
         COMMAND ${CMAKE_COMMAND} -E env
         "COMPONENT_KCONFIGS_SOURCE_FILE=${kconfigs_path}"
         "COMPONENT_KCONFIGS_PROJBUILD_SOURCE_FILE=${kconfigs_projbuild_path}"
         "IDF_CMAKE=y"
-        "IDF_TARGET=${IDF_TARGET}"
         "KCONFIG_CONFIG=${sdkconfig}"
         "IDF_TARGET=${idf_target}"
         ${MENUCONFIG_CMD} ${root_kconfig}

tools/kconfig/Makefile

@@ -311,7 +311,7 @@ ifeq ($(MAKECMDGOALS),gconfig)
 	fi
 endif
 
-zconf.tab.o: zconf.lex.c zconf.hash.c
+zconf.tab.o: zconf.lex.c zconf.hash.c zconf.tab.c
 
 qconf.o: qconf.moc
 

tools/kconfig/mconf.c

@@ -1042,6 +1042,8 @@ int main(int ac, char **av)
 		return 1;
 	}
 
+	sym_set_change_count(0);
+
 	set_config_filename(conf_get_configname());
 	conf_set_message_callback(conf_message_callback);
 	do {

tools/kconfig/zconf.y

@@ -12,6 +12,7 @@
 #include <stdbool.h>
 
 #include "lkc.h"
+#include "expand_env.h"
 
 #define printd(mask, fmt...) if (cdebug & (mask)) printf(fmt)
 
@@ -202,6 +203,14 @@ config_option: T_PROMPT prompt if_expr T_EOL
 
 config_option: T_DEFAULT expr if_expr T_EOL
 {
+	if ($2 && $2->type == E_SYMBOL) {
+		char *str = expand_environment($2->left.sym->name, zconf_curname(), zconf_lineno());
+		if (strcmp($2->left.sym->name, str) != 0) {
+			$2->left.sym->name = realloc($2->left.sym->name, strlen(str) + 1);
+			strncpy($2->left.sym->name, str, strlen(str) + 1);
+		}
+		free_expanded(str);
+	}
 	menu_add_expr(P_DEFAULT, $2, $3);
 	if ($1->stype != S_UNKNOWN)
 		menu_set_type($1->stype);

tools/kconfig_new/confgen.py

@@ -213,6 +213,10 @@ def main():
                         help='File with deprecated Kconfig options',
                         required=False)
 
+    parser.add_argument('--dont-write-deprecated',
+                        help='Do not write compatibility statements for deprecated values',
+                        action='store_true')
+
     parser.add_argument('--output', nargs=2, action='append',
                         help='Write output file (format and output filename)',
                         metavar=('FORMAT', 'FILENAME'),
@@ -253,10 +257,6 @@ def main():
     sdkconfig_renames += os.environ.get("COMPONENT_SDKCONFIG_RENAMES", "").split()
     deprecated_options = DeprecatedOptions(config.config_prefix, path_rename_files=sdkconfig_renames)
 
-    sdkconfig_renames = [args.sdkconfig_rename] if args.sdkconfig_rename else []
-    sdkconfig_renames += os.environ.get("COMPONENT_SDKCONFIG_RENAMES", "").split()
-    deprecated_options = DeprecatedOptions(config.config_prefix, path_rename_files=sdkconfig_renames)
-
     if len(args.defaults) > 0:
         def _replace_empty_assignments(path_in, path_out):
             with open(path_in, 'r') as f_in, open(path_out, 'w') as f_out:
@@ -304,6 +304,11 @@ def main():
             except OSError:
                 pass
 
+    if args.dont_write_deprecated:
+        # The deprecated object was useful until now for replacements. Now it will be redefined with no configurations
+        # and as the consequence, it won't generate output with deprecated statements.
+        deprecated_options = DeprecatedOptions('', path_rename_files=[])
+
     # Output the files specified in the arguments
     for output_type, filename in args.output:
         with tempfile.NamedTemporaryFile(prefix="confgen_tmp", delete=False) as f: