diff options
| -rw-r--r-- | Documentation/kbuild/makefiles.txt | 14 | ||||
| -rw-r--r-- | scripts/Kbuild.include | 8 |
2 files changed, 21 insertions, 1 deletions
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index 7847fce13bd..71c602d6168 100644 --- a/Documentation/kbuild/makefiles.txt +++ b/Documentation/kbuild/makefiles.txt @@ -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 diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 94a4f682f38..b3452601b0b 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -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)) + ###### ### |