The macro cc-option receives two parameters (the second may be empty). It returns the first parameter if it is a valid compiler option, otherwise the second one. It is not evaluated if the second parameter is a valid compiler option. This seems to be fine in virtually all cases, however there are scenarios where the second parameter needs to be evaluated too, and an empty value (or a third option) should be returned if it is not valid. The new macro try-run-opt receives a 'base command' and two options as parameters. It runs 'base command' + option 1 and returns option 1 upon success. In case of failure 'base command' + option 2 is executed, in case of success option 2 is returned, otherwise an empty string. Rework [__]cc-option, ld-option, and cc-ldoption to use try-run-opt instead of try-run to make sure the alternative option is evaluated. Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx> --- Changes in v2: - add try-run-opt instead of cc-option-3 - use try-run-opt for [__]cc-option, ld-option and ccld-option - updated subject (was 'kbuild: Add macros cc-option-3 and __cc-option-3') and commit message scripts/Kbuild.include | 33 +++++++++++++++++++++++++-------- 1 file changed, 25 insertions(+), 8 deletions(-) diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index dd8e2dde0b34..48a6d0e9b073 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -85,8 +85,8 @@ TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) # 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. +# Runs the command $1, exit code chooses option. "$$TMP" is used as temporary +# file and is automatically cleaned up. try-run = $(shell set -e; \ TMP="$(TMPOUT).$$$$.tmp"; \ TMPO="$(TMPOUT).$$$$.o"; \ @@ -96,6 +96,23 @@ try-run = $(shell set -e; \ fi; \ rm -f "$$TMP" "$$TMPO") +# try-run-opt +# Usage: option = $(call try-run-opt, $(CC)...-o "$$TMP",option-ok,otherwise) +# Runs the command '$1 $2' and outputs $2 if the execution was successful. +# Otherwise runs '$1 $3' (if $3 is not empty) and outputs $3 upon success. No +# output if both commands fail. "$$TMP" is used as temporary file and is +# automatically cleaned up. +try-run-opt = $(shell set -e; \ + TMP="$(TMPOUT).$$$$.tmp"; \ + TMPO="$(TMPOUT).$$$$.o"; \ + if ($(1) $(2)) >/dev/null 2>&1; \ + then echo "$(2)"; \ + elif [ -n "$(3)" ] && ($(1) $(3)) >/dev/null 2>&1; \ + then echo "$(3)"; \ + else echo ""; \ + fi; \ + rm -f "$$TMP" "$$TMPO") + # as-option # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) @@ -110,8 +127,8 @@ as-instr = $(call try-run,\ # __cc-option # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586) -__cc-option = $(call try-run,\ - $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4)) +__cc-option = $(call try-run-opt,\ + $(1) -Werror $(2) -c -x c /dev/null -o "$$TMP",$(3),$(4)) # Do not attempt to build with gcc plugins during cc-option tests. # (And this uses delayed resolution so the flags will be up to date.) @@ -159,13 +176,13 @@ cc-if-fullversion = $(shell [ $(cc-fullversion) $(1) $(2) ] && echo $(3) || echo # cc-ldoption # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both) -cc-ldoption = $(call try-run,\ - $(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2)) +cc-ldoption = $(call try-run-opt,\ + $(CC) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2)) # ld-option # Usage: LDFLAGS += $(call ld-option, -X) -ld-option = $(call try-run,\ - $(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2)) +ld-option = $(call try-run-opt,\ + $(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) "$$TMPO" -o "$$TMP",$(1),$(2)) # ar-option # Usage: KBUILD_ARFLAGS := $(call ar-option,D) -- 2.14.0.434.g98096fd7a8-goog -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
