kbuild: introduce ld-option (691ef3e7) · Commits · 戴 / test

Documentation/kbuild/makefiles.txt

+14 −0

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@ This document describes the Linux kernel Makefiles.
		--- 3.9 Dependency tracking
		--- 3.10 Special Rules
		--- 3.11 $(CC) support functions
		--- 3.12 $(LD) support functions

		=== 4 Host Program support
		--- 4.1 Simple Host Program
		@@ -570,6 +571,19 @@ more details, with real examples.
		endif
		endif

		--- 3.12 $(LD) support functions

		ld-option
		ld-option is used to check if $(LD) supports the supplied option.
		ld-option takes two options as arguments.
		The second argument is an optional option that can be used if the
		first option is not supported by $(LD).

		Example:
		#Makefile
		LDFLAGS_vmlinux += $(call really-ld-option, -X)


		=== 4 Host Program support

		Kbuild supports building executables on the host for use during the

+7 −1

Original line number	Diff line number	Diff line
		@@ -83,11 +83,12 @@ TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
		# is automatically cleaned up.
		try-run = $(shell set -e; \
		TMP="$(TMPOUT).$$$$.tmp"; \
		TMPO="$(TMPOUT).$$$$.o"; \
		if ($(1)) >/dev/null 2>&1; \
		then echo "$(2)"; \
		else echo "$(3)"; \
		fi; \
		rm -f "$$TMP")
		rm -f "$$TMP" "$$TMPO")

		# as-option
		# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
		@@ -135,6 +136,11 @@ cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3))
		cc-ldoption = $(call try-run,\
		$(CC) $(1) -nostdlib -xc /dev/null -o "$$TMP",$(1),$(2))

		# ld-option
		# Usage: LDFLAGS += $(call ld-option, -X)
		ld-option = $(call try-run,\
		$(CC) /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))

		######

		###