treewide: add support for "gc-sections" in PKG_BUILD_FLAGS

This reduces open coding and allows to easily add a knob to
enable it treewide, where chosen packages can still opt-out via
"no-gc-sections".

Note: libnl, mbedtls and opkg only used the CFLAGS part without the
LDFLAGS counterpart. That doesn't help at all if the goal is to produce
smaller binaries. I consider that an accident, and this fixes it.

Note: there are also packages using only the LDFLAGS part. I didn't
touch those, as gc might have been disabled via CFLAGS intentionally.

Signed-off-by: Andre Heider <a.heider@gmail.com>

10 files changed, 27 insertions, 27 deletions

diff --git a/package/network/config/firewall/Makefile b/package/network/config/firewall/Makefile
index e4a3ad97f7..95e2ae4b67 100644
--- a/package/network/config/firewall/Makefile
+++ b/package/network/config/firewall/Makefile
@@ -21,6 +21,8 @@ PKG_LICENSE:=ISC
 
 PKG_CONFIG_DEPENDS := CONFIG_IPV6
 
+PKG_BUILD_FLAGS:=gc-sections
+
 include $(INCLUDE_DIR)/package.mk
 include $(INCLUDE_DIR)/cmake.mk
 
@@ -42,8 +44,8 @@ define Package/firewall/conffiles
 /etc/firewall.user
 endef
 
-TARGET_CFLAGS += -ffunction-sections -fdata-sections -flto
-TARGET_LDFLAGS += -Wl,--gc-sections -flto
+TARGET_CFLAGS += -flto
+TARGET_LDFLAGS += -flto
 CMAKE_OPTIONS += $(if $(CONFIG_IPV6),,-DDISABLE_IPV6=1)
 
 define Package/firewall/install
diff --git a/package/network/services/dropbear/Makefile b/package/network/services/dropbear/Makefile
index ddd19bfa55..1b3fdad067 100644
--- a/package/network/services/dropbear/Makefile
+++ b/package/network/services/dropbear/Makefile
@@ -23,7 +23,7 @@ PKG_CPE_ID:=cpe:/a:matt_johnston:dropbear_ssh_server
 
 PKG_BUILD_PARALLEL:=1
 PKG_ASLR_PIE_REGULAR:=1
-PKG_BUILD_FLAGS:=no-mips16
+PKG_BUILD_FLAGS:=no-mips16 gc-sections
 PKG_FIXUP:=autoreconf
 PKG_FLAGS:=nonshared
 
@@ -142,8 +142,8 @@ DB_OPT_CONFIG = \
 	DROPBEAR_SVR_AGENTFWD|CONFIG_DROPBEAR_AGENTFORWARD|1|0 \
 
 
-TARGET_CFLAGS += -DARGTYPE=3 -ffunction-sections -fdata-sections -flto
-TARGET_LDFLAGS += -Wl,--gc-sections -flto=jobserver
+TARGET_CFLAGS += -DARGTYPE=3 -flto
+TARGET_LDFLAGS += -flto=jobserver
 
 db_opt_add     =echo '\#define $(1) $(2)' >> $(PKG_BUILD_DIR)/localoptions.h
 db_opt_replace =$(ESED) 's,^(\#define $(1)) .*$$$$,\1 $(2),g' $(PKG_BUILD_DIR)/sysoptions.h
diff --git a/package/network/services/hostapd/Makefile b/package/network/services/hostapd/Makefile
index 889f145504..1b077530e1 100644
--- a/package/network/services/hostapd/Makefile
+++ b/package/network/services/hostapd/Makefile
@@ -32,6 +32,8 @@ PKG_CONFIG_DEPENDS:= \
 	CONFIG_DRIVER_11AX_SUPPORT \
 	CONFIG_WPA_ENABLE_WEP
 
+PKG_BUILD_FLAGS:=gc-sections
+
 EAPOL_TEST_PROVIDERS:=eapol-test eapol-test-openssl eapol-test-wolfssl
 
 SUPPLICANT_PROVIDERS:=
@@ -585,8 +587,8 @@ TARGET_CPPFLAGS := \
 	-D_GNU_SOURCE \
 	$(if $(CONFIG_WPA_MSG_MIN_PRIORITY),-DCONFIG_MSG_MIN_PRIORITY=$(CONFIG_WPA_MSG_MIN_PRIORITY))
 
-TARGET_CFLAGS += -ffunction-sections -fdata-sections -flto
-TARGET_LDFLAGS += -Wl,--gc-sections -flto=jobserver -fuse-linker-plugin -lubox -lubus
+TARGET_CFLAGS += -flto
+TARGET_LDFLAGS += -flto=jobserver -fuse-linker-plugin -lubox -lubus
 
 ifdef CONFIG_PACKAGE_kmod-cfg80211
   TARGET_LDFLAGS += -lm -lnl-tiny
diff --git a/package/network/services/ppp/Makefile b/package/network/services/ppp/Makefile
index 8476204e14..48f2091a1f 100644
--- a/package/network/services/ppp/Makefile
+++ b/package/network/services/ppp/Makefile
@@ -26,6 +26,7 @@ PKG_VERSION:=$(PKG_RELEASE_VERSION).git-$(PKG_SOURCE_DATE)
 PKG_BUILD_DEPENDS:=libpcap
 
 PKG_ASLR_PIE_REGULAR:=1
+PKG_BUILD_FLAGS:=gc-sections
 PKG_BUILD_PARALLEL:=1
 PKG_INSTALL:=1
 
@@ -192,8 +193,8 @@ $(call Build/Configure/Default,, \
 		$(PKG_BUILD_DIR)/pppd/plugins/pppoatm/linux/
 endef
 
-TARGET_CFLAGS += -ffunction-sections -fdata-sections -flto
-TARGET_LDFLAGS += -Wl,--gc-sections -flto -fuse-linker-plugin
+TARGET_CFLAGS += -flto
+TARGET_LDFLAGS += -flto -fuse-linker-plugin
 
 MAKE_FLAGS += COPTS="$(TARGET_CFLAGS)" \
 		PRECOMPILED_FILTER=1 \
diff --git a/package/network/utils/iproute2/Makefile b/package/network/utils/iproute2/Makefile
index 302d57bf8b..b3a809e0b5 100644
--- a/package/network/utils/iproute2/Makefile
+++ b/package/network/utils/iproute2/Makefile
@@ -19,6 +19,8 @@ PKG_BUILD_DEPENDS:=iptables
 PKG_LICENSE:=GPL-2.0
 PKG_CPE_ID:=cpe:/a:iproute2_project:iproute2
 
+PKG_BUILD_FLAGS:=gc-sections
+
 include $(INCLUDE_DIR)/kernel.mk
 include $(INCLUDE_DIR)/package.mk
 include $(INCLUDE_DIR)/nls.mk
@@ -171,8 +173,8 @@ define Build/Configure
 		> $(PKG_BUILD_DIR)/include/SNAPSHOT.h
 endef
 
-TARGET_CFLAGS += -ffunction-sections -fdata-sections -flto
-TARGET_LDFLAGS += -Wl,--gc-sections -Wl,--as-needed
+TARGET_CFLAGS += -flto
+TARGET_LDFLAGS += -Wl,--as-needed
 TARGET_CPPFLAGS += -I$(STAGING_DIR)/usr/include/libnl-tiny
 
 MAKE_FLAGS += \
diff --git a/package/network/utils/iptables/Makefile b/package/network/utils/iptables/Makefile
index e96cfa0b16..0d6d76fc08 100644
--- a/package/network/utils/iptables/Makefile
+++ b/package/network/utils/iptables/Makefile
@@ -20,6 +20,7 @@ PKG_FIXUP:=autoreconf
 PKG_FLAGS:=nonshared
 
 PKG_INSTALL:=1
+PKG_BUILD_FLAGS:=gc-sections
 PKG_BUILD_PARALLEL:=1
 PKG_LICENSE:=GPL-2.0
 PKG_CPE_ID:=cpe:/a:netfilter_core_team:iptables
@@ -591,12 +592,8 @@ TARGET_CPPFLAGS := \
 TARGET_CFLAGS += \
 	-I$(PKG_BUILD_DIR)/include \
 	-I$(LINUX_DIR)/user_headers/include \
-	-ffunction-sections -fdata-sections \
 	-DNO_LEGACY
 
-TARGET_LDFLAGS += \
-	-Wl,--gc-sections
-
 CONFIGURE_ARGS += \
 	--enable-shared \
 	--enable-static \
diff --git a/package/network/utils/iw/Makefile b/package/network/utils/iw/Makefile
index eb3a9ba091..1eb3cd721a 100644
--- a/package/network/utils/iw/Makefile
+++ b/package/network/utils/iw/Makefile
@@ -18,6 +18,8 @@ PKG_HASH:=f167bbe947dd53bb9ebc0c1dcef5db6ad73ac1d6084f2c6f9376c5c360cc4d4e
 PKG_MAINTAINER:=Felix Fietkau <nbd@nbd.name>
 PKG_LICENSE:=GPL-2.0
 
+PKG_BUILD_FLAGS:=gc-sections
+
 include $(INCLUDE_DIR)/package.mk
 
 define Package/iw
@@ -55,8 +57,8 @@ ifeq ($(BUILD_VARIANT),full)
 endif
 
 MAKE_FLAGS += \
-	CFLAGS="$(TARGET_CPPFLAGS) $(TARGET_CFLAGS) -ffunction-sections -fdata-sections" \
-	LDFLAGS="$(TARGET_LDFLAGS) -Wl,--gc-sections -flto" \
+	CFLAGS="$(TARGET_CPPFLAGS) $(TARGET_CFLAGS)" \
+	LDFLAGS="$(TARGET_LDFLAGS) -flto" \
 	NL1FOUND="" NL2FOUND=Y \
 	NLLIBNAME="libnl-tiny" \
 	LIBS="-lm -lnl-tiny" \
diff --git a/package/network/utils/tcpdump/Makefile b/package/network/utils/tcpdump/Makefile
index 827a66e860..e07e9feb6d 100644
--- a/package/network/utils/tcpdump/Makefile
+++ b/package/network/utils/tcpdump/Makefile
@@ -20,6 +20,7 @@ PKG_LICENSE:=BSD-3-Clause
 PKG_CPE_ID:=cpe:/a:tcpdump:tcpdump
 
 PKG_INSTALL:=1
+PKG_BUILD_FLAGS:=gc-sections
 PKG_BUILD_PARALLEL:=1
 
 include $(INCLUDE_DIR)/package.mk
@@ -48,9 +49,6 @@ CONFIGURE_ARGS += \
 	--without-crypto \
 	$(call autoconf_bool,CONFIG_IPV6,ipv6)
 
-TARGET_CFLAGS += -ffunction-sections -fdata-sections
-TARGET_LDFLAGS += -Wl,--gc-sections
-
 ifeq ($(BUILD_VARIANT),mini)
   TARGET_CFLAGS += -DTCPDUMP_MINI
   CONFIGURE_ARGS += --disable-smb
diff --git a/package/network/utils/umbim/Makefile b/package/network/utils/umbim/Makefile
index 3563949c67..1a09984a43 100644
--- a/package/network/utils/umbim/Makefile
+++ b/package/network/utils/umbim/Makefile
@@ -14,6 +14,7 @@ PKG_LICENSE:=GPL-2.0
 PKG_LICENSE_FILES:=
 
 PKG_FLAGS:=nonshared
+PKG_BUILD_FLAGS:=gc-sections
 
 include $(INCLUDE_DIR)/package.mk
 include $(INCLUDE_DIR)/cmake.mk
@@ -32,9 +33,7 @@ define Package/umbim/description
 endef
 
 TARGET_CFLAGS += \
-	-I$(STAGING_DIR)/usr/include -ffunction-sections -fdata-sections
-
-TARGET_LDFLAGS += -Wl,--gc-sections
+	-I$(STAGING_DIR)/usr/include
 
 define Package/umbim/install
 	$(INSTALL_DIR) $(1)/sbin
diff --git a/package/network/utils/uqmi/Makefile b/package/network/utils/uqmi/Makefile
index 02265d400c..989e7c11b6 100644
--- a/package/network/utils/uqmi/Makefile
+++ b/package/network/utils/uqmi/Makefile
@@ -14,6 +14,7 @@ PKG_LICENSE:=GPL-2.0
 PKG_LICENSE_FILES:=
 
 PKG_FLAGS:=nonshared
+PKG_BUILD_FLAGS:=gc-sections
 
 include $(INCLUDE_DIR)/package.mk
 include $(INCLUDE_DIR)/cmake.mk
@@ -33,13 +34,9 @@ endef
 
 TARGET_CFLAGS += \
 	-I$(STAGING_DIR)/usr/include \
-	-ffunction-sections \
-	-fdata-sections \
 	-Wno-error=dangling-pointer \
 	-Wno-error=maybe-uninitialized
 
-TARGET_LDFLAGS += -Wl,--gc-sections
-
 CMAKE_OPTIONS += \
 	-DDEBUG=1