[openwrt/openwrt] build: filter out more autogenerated kernel config options

[LEDE Commits]

nbd pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/a8fb12a7d62c94fd1bbda332752e0f8c794f3702

commit a8fb12a7d62c94fd1bbda332752e0f8c794f3702
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Tue Oct 20 21:36:52 2020 +0200

    build: filter out more autogenerated kernel config options
    
    Define wildcard patterns for filtering in target/linux/generic/config-filter
    Preparation for supporting newer kernels
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 include/kernel-build.mk            | 4 +---
 include/target.mk                  | 8 ++++----
 target/linux/generic/config-filter | 7 +++++++
 3 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/include/kernel-build.mk b/include/kernel-build.mk
index 600cf1d771..a698deec3c 100644
--- a/include/kernel-build.mk
+++ b/include/kernel-build.mk
@@ -170,9 +170,7 @@ define BuildKernel
 		) \
 		YACC=$(STAGING_DIR_HOST)/bin/bison \
 		$$@
-	$(LINUX_RECONF_DIFF) $(LINUX_DIR)/.config | \
-		grep -vE '(CONFIG_CC_(HAS_ASM_GOTO|IS_GCC|IS_CLANG)|GCC_VERSION)=' \
-		> $(LINUX_RECONFIG_TARGET)
+	$(call LINUX_RECONF_DIFF,$(LINUX_DIR)/.config) > $(LINUX_RECONFIG_TARGET)
 
   install: $(LINUX_DIR)/.image
 	+$(MAKE) -C image compile install TARGET_BUILD=
diff --git a/include/target.mk b/include/target.mk
index a2e76f8149..edc6a146de 100644
--- a/include/target.mk
+++ b/include/target.mk
@@ -185,11 +185,11 @@ ifeq ($(CONFIG_TARGET),env)
   LINUX_RECONFIG_TARGET = $(TOPDIR)/env/kernel-config
 endif
 
-__linux_confcmd = $(SCRIPT_DIR)/kconfig.pl $(2) $(patsubst %,+,$(wordlist 2,9999,$(1))) $(1)
+__linux_confcmd = $(2) $(patsubst %,+,$(wordlist 2,9999,$(1))) $(1)
 
-LINUX_CONF_CMD = $(call __linux_confcmd,$(LINUX_KCONFIG_LIST),)
-LINUX_RECONF_CMD = $(call __linux_confcmd,$(LINUX_RECONFIG_LIST),)
-LINUX_RECONF_DIFF = $(call __linux_confcmd,$(filter-out $(LINUX_RECONFIG_TARGET),$(LINUX_RECONFIG_LIST)),'>')
+LINUX_CONF_CMD = $(SCRIPT_DIR)/kconfig.pl $(call __linux_confcmd,$(LINUX_KCONFIG_LIST))
+LINUX_RECONF_CMD = $(SCRIPT_DIR)/kconfig.pl $(call __linux_confcmd,$(LINUX_RECONFIG_LIST))
+LINUX_RECONF_DIFF = $(SCRIPT_DIR)/kconfig.pl - '>' $(call __linux_confcmd,$(filter-out $(LINUX_RECONFIG_TARGET),$(LINUX_RECONFIG_LIST))) $(1) $(GENERIC_PLATFORM_DIR)/config-filter
 
 ifeq ($(DUMP),1)
   BuildTarget=$(BuildTargets/DumpCurrent)
diff --git a/target/linux/generic/config-filter b/target/linux/generic/config-filter
new file mode 100644
index 0000000000..0d53ed9c3c
--- /dev/null
+++ b/target/linux/generic/config-filter
@@ -0,0 +1,7 @@
+# CONFIG_ARCH_(ENABLE|HAS|HAVE|INLINE|SUPPORTS|USE|WANT)_.* is not set
+# CONFIG_AS_.* is not set
+# CONFIG_CC_(CAN|HAS|IS|VERSION)_.* is not set
+# CONFIG_LD_.* is not set
+# CONFIG_GCC_VERSION is not set
+# CONFIG_INLINE_.* is not set
+# CONFIG_HAVE_(?!(ARCH_TIMER|TCM|SMP)).* is not set