cc-option

# cc-option
# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)

cc-option = $(call try-run,\
    $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",$(1),$(2))

# try-run
# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
# Exit code chooses option. "$$TMP" is can be used as temporary file and
# 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" "$$TMPO")


cc-option 检查选项是否支持