build: add a config knob to enable LTO for all packages

[openwrt/staging/stintel.git] / include / package.mk

diff --git a/include/package.mk b/include/package.mk
index a1717a603d500a67fda46df79c88a01f9da88977..d80f3bce49f4c946f9d6c814c976e9f31f6cdb0b 100644 (file)
--- a/include/package.mk
+++ b/include/package.mk
@@ -30,7 +30,7 @@ ifneq ($(strip $(PKG_USE_MIPS16)),1)
   PKG_BUILD_FLAGS+=no-mips16
 endif
 
-__unknown_flags=$(filter-out no-iremap no-mips16,$(PKG_BUILD_FLAGS))
+__unknown_flags=$(filter-out no-iremap no-mips16 gc-sections no-gc-sections lto no-lto,$(PKG_BUILD_FLAGS))
 ifneq ($(__unknown_flags),)
   $(error unknown PKG_BUILD_FLAGS: $(__unknown_flags))
 endif
@@ -51,6 +51,16 @@ ifdef CONFIG_USE_MIPS16
     TARGET_CXXFLAGS += -mips16 -minterlink-mips16
   endif
 endif
+ifeq ($(call pkg_build_flag,gc-sections,$(if $(CONFIG_USE_GC_SECTIONS),1,0)),1)
+  TARGET_CFLAGS+= -ffunction-sections -fdata-sections
+  TARGET_CXXFLAGS+= -ffunction-sections -fdata-sections
+  TARGET_LDFLAGS+= -Wl,--gc-sections
+endif
+ifeq ($(call pkg_build_flag,lto,$(if $(CONFIG_USE_LTO),1,0)),1)
+  TARGET_CFLAGS+= -flto=auto -fno-fat-lto-objects
+  TARGET_CXXFLAGS+= -flto=auto -fno-fat-lto-objects
+  TARGET_LDFLAGS+= -flto=auto -fuse-linker-plugin
+endif
 
 include $(INCLUDE_DIR)/hardening.mk
 include $(INCLUDE_DIR)/prereq.mk