hostapd: build with LTO enabled (using jobserver for parallel build)

Signed-off-by: Felix Fietkau <nbd@nbd.name>

package/network/services/hostapd/Makefile

@@ -457,8 +457,8 @@ 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
-TARGET_LDFLAGS += -Wl,--gc-sections
+TARGET_CFLAGS += -ffunction-sections -fdata-sections -flto
+TARGET_LDFLAGS += -Wl,--gc-sections -flto=jobserver -fuse-linker-plugin
 ifeq ($(findstring supplicant,$(BUILD_VARIANT)),)
   TARGET_LDFLAGS += -lubox -lubus
 endif
@@ -474,6 +474,7 @@ define Build/RunMake
 		$(DRIVER_MAKEOPTS) \
 		LIBS="$(TARGET_LDFLAGS)" \
 		LIBS_c="$(TARGET_LDFLAGS_C)" \
+		AR="$(TARGET_CROSS)gcc-ar" \
 		BCHECK= \
 		$(2)
 endef
@@ -495,7 +496,7 @@ define Build/Compile/wpad
 		MULTICALL=1 \
 		wpa_cli wpa_supplicant_multi.a \
 	)
-	$(TARGET_CC) -o $(PKG_BUILD_DIR)/wpad \
+	+export MAKEFLAGS="$(MAKE_JOBSERVER)"; $(TARGET_CC) -o $(PKG_BUILD_DIR)/wpad \
 		$(TARGET_CFLAGS) \
 		./files/multicall.c \
 		$(PKG_BUILD_DIR)/hostapd/hostapd_multi.a \

package/network/services/hostapd/patches/500-lto-jobserver-support.patch

@@ -0,0 +1,50 @@
+--- a/hostapd/Makefile
++++ b/hostapd/Makefile
+@@ -1290,14 +1290,14 @@ hostapd_multi.a: $(BCHECK) $(OBJS)
+ 	@$(AR) cr $@ hostapd_multi.o $(OBJS)
+ 
+ hostapd: $(BCHECK) $(OBJS)
+-	$(Q)$(CC) $(LDFLAGS) -o hostapd $(OBJS) $(LIBS)
++	+$(Q)$(CC) $(LDFLAGS) -o hostapd $(OBJS) $(LIBS)
+ 	@$(E) "  LD " $@
+ 
+ ifdef CONFIG_WPA_TRACE
+ OBJS_c += ../src/utils/trace.o
+ endif
+ hostapd_cli: $(OBJS_c)
+-	$(Q)$(CC) $(LDFLAGS) -o hostapd_cli $(OBJS_c) $(LIBS_c)
++	+$(Q)$(CC) $(LDFLAGS) -o hostapd_cli $(OBJS_c) $(LIBS_c)
+ 	@$(E) "  LD " $@
+ 
+ NOBJS = nt_password_hash.o ../src/crypto/ms_funcs.o $(SHA1OBJS)
+--- a/wpa_supplicant/Makefile
++++ b/wpa_supplicant/Makefile
+@@ -1921,23 +1921,23 @@ wpa_supplicant_multi.a: .config $(BCHECK
+ 	@$(AR) cr $@ wpa_supplicant_multi.o $(OBJS)
+ 
+ wpa_supplicant: $(BCHECK) $(OBJS) $(EXTRA_progs)
+-	$(Q)$(LDO) $(LDFLAGS) -o wpa_supplicant $(OBJS) $(LIBS) $(EXTRALIBS)
++	+$(Q)$(LDO) $(LDFLAGS) -o wpa_supplicant $(OBJS) $(LIBS) $(EXTRALIBS)
+ 	@$(E) "  LD " $@
+ 
+ eapol_test: $(OBJS_t)
+-	$(Q)$(LDO) $(LDFLAGS) -o eapol_test $(OBJS_t) $(LIBS)
++	+$(Q)$(LDO) $(LDFLAGS) -o eapol_test $(OBJS_t) $(LIBS)
+ 	@$(E) "  LD " $@
+ 
+ preauth_test: $(OBJS_t2)
+-	$(Q)$(LDO) $(LDFLAGS) -o preauth_test $(OBJS_t2) $(LIBS)
++	+$(Q)$(LDO) $(LDFLAGS) -o preauth_test $(OBJS_t2) $(LIBS)
+ 	@$(E) "  LD " $@
+ 
+ wpa_passphrase: $(OBJS_p)
+-	$(Q)$(LDO) $(LDFLAGS) -o wpa_passphrase $(OBJS_p) $(LIBS_p) $(LIBS)
++	+$(Q)$(LDO) $(LDFLAGS) -o wpa_passphrase $(OBJS_p) $(LIBS_p) $(LIBS)
+ 	@$(E) "  LD " $@
+ 
+ wpa_cli: $(OBJS_c)
+-	$(Q)$(LDO) $(LDFLAGS) -o wpa_cli $(OBJS_c) $(LIBS_c)
++	+$(Q)$(LDO) $(LDFLAGS) -o wpa_cli $(OBJS_c) $(LIBS_c)
+ 	@$(E) "  LD " $@
+ 
+ LIBCTRL += ../src/common/wpa_ctrl.o