# The following definitions are the defaults used by all toolchains. # This is included in setup-toolchain.mk just before the inclusion # of the toolchain's specific setup.mk file which can then override # these definitions. # # These flags are used to ensure that a binary doesn't reference undefined # flags. TARGET_NO_UNDEFINED_LDFLAGS := -Wl,--no-undefined # Return the list of object, static libraries and shared libraries as they # must appear on the final static linker command (order is important). # # This can be over-ridden by a specific toolchain. Note that by default # we always put libgcc _after_ all static libraries and _before_ shared # libraries. This ensures that any libgcc function used by the final # executable will be copied into it. Otherwise, it could contain # symbol references to the same symbols as exported by shared libraries # and this causes binary compatibility problems when they come from # system libraries (e.g. libc.so and others). # # IMPORTANT: The result must use the host path convention. # # $1: object files # $2: static libraries # $3: whole static libraries # $4: shared libraries # TARGET-get-linker-objects-and-libraries = \ $(call host-path, $1) \ $(call link-whole-archives,$3) \ $(call host-path, $2 $(PRIVATE_LIBGCC) $4) \ # These flags are used to enforce the NX (no execute) security feature in the # generated machine code. This adds a special section to the generated shared # libraries that instruct the Linux kernel to disable code execution from # the stack and the heap. TARGET_NO_EXECUTE_CFLAGS := -Wa,--noexecstack TARGET_NO_EXECUTE_LDFLAGS := -Wl,-z,noexecstack # These flags disable the above security feature TARGET_DISABLE_NO_EXECUTE_CFLAGS := -Wa,--execstack TARGET_DISABLE_NO_EXECUTE_LDFLAGS := -Wl,-z,execstack # These flags are used to mark certain regions of the resulting # executable or shared library as being read-only after the dynamic # linker has run. This makes GOT overwrite security attacks harder to # exploit. TARGET_RELRO_LDFLAGS := -Wl,-z,relro -Wl,-z,now # These flags disable the above security feature TARGET_DISABLE_RELRO_LDFLAGS := -Wl,-z,norelro -Wl,-z,lazy # This flag are used to provide compiler protection against format # string vulnerabilities. TARGET_FORMAT_STRING_CFLAGS := -Wformat -Werror=format-security # This flag disables the above security checks TARGET_DISABLE_FORMAT_STRING_CFLAGS := -Wno-error=format-security # NOTE: Ensure that TARGET_LIBGCC is placed after all private objects # and static libraries, but before any other library in the link # command line when generating shared libraries and executables. # # This ensures that all libgcc.a functions required by the target # will be included into it, instead of relying on what's available # on other libraries like libc.so, which may change between system # releases due to toolchain or library changes. # define cmd-build-shared-library $(PRIVATE_CXX) \ -Wl,-soname,$(notdir $(LOCAL_BUILT_MODULE)) \ -shared \ --sysroot=$(call host-path,$(PRIVATE_SYSROOT_LINK)) \ $(PRIVATE_LINKER_OBJECTS_AND_LIBRARIES) \ $(PRIVATE_LDFLAGS) \ $(PRIVATE_LDLIBS) \ -o $(call host-path,$(LOCAL_BUILT_MODULE)) endef define cmd-build-executable $(PRIVATE_CXX) \ -Wl,--gc-sections \ -Wl,-z,nocopyreloc \ --sysroot=$(call host-path,$(PRIVATE_SYSROOT_LINK)) \ $(PRIVATE_LINKER_OBJECTS_AND_LIBRARIES) \ $(PRIVATE_LDFLAGS) \ $(PRIVATE_LDLIBS) \ -o $(call host-path,$(LOCAL_BUILT_MODULE)) endef define cmd-build-static-library $(PRIVATE_AR) $(call host-path,$(LOCAL_BUILT_MODULE)) $(PRIVATE_AR_OBJECTS) endef # The strip command is only used for shared libraries and executables. # It is thus safe to use --strip-unneeded, which is only dangerous # when applied to static libraries or object files. cmd-strip = $(PRIVATE_STRIP) --strip-unneeded $(call host-path,$1) TARGET_LIBGCC = -lgcc TARGET_LDLIBS := -lc -lm # # IMPORTANT: The following definitions must use lazy assignment because # the value of TOOLCHAIN_PREFIX or TARGET_CFLAGS can be changed later by # the toolchain's setup.mk script. # ifneq ($(findstring ccc-analyzer,$(CC)),) TARGET_CC = $(CC) else TARGET_CC = $(TOOLCHAIN_PREFIX)gcc endif TARGET_CFLAGS = TARGET_CONLYFLAGS = ifneq ($(findstring c++-analyzer,$(CXX)),) TARGET_CXX = $(CXX) else TARGET_CXX = $(TOOLCHAIN_PREFIX)g++ endif TARGET_CXXFLAGS = $(TARGET_CFLAGS) -fno-exceptions -fno-rtti TARGET_RS_CC = $(RENDERSCRIPT_TOOLCHAIN_PREFIX)llvm-rs-cc TARGET_RS_BCC = $(RENDERSCRIPT_TOOLCHAIN_PREFIX)bcc_compat TARGET_RS_FLAGS = -Wall -Werror TARGET_LD = $(TOOLCHAIN_PREFIX)ld TARGET_LDFLAGS := TARGET_AR = $(TOOLCHAIN_PREFIX)ar TARGET_ARFLAGS := crsD TARGET_STRIP = $(TOOLCHAIN_PREFIX)strip TARGET_OBJ_EXTENSION := .o TARGET_LIB_EXTENSION := .a TARGET_SONAME_EXTENSION := .so