[PATCH 4.4 32/70] kbuild: Add __cc-option macro

Greg Kroah-Hartman
2018-11-26T10:54:47Z

From: Matthias Kaehlcke <mka@chromium.org>

commit 9f3f1fd299768782465cb32cdf0dd4528d11f26b upstream.

cc-option uses KBUILD_CFLAGS and KBUILD_CPPFLAGS when it determines
whether an option is supported or not. This is fine for options used to
build the kernel itself, however some components like the x86 boot code
use a different set of flags.

Add the new macro __cc-option which is a more generic version of
cc-option with additional parameters. One parameter is the compiler
with which the check should be performed, the other the compiler options
to be used instead KBUILD_C*FLAGS.

Refactor cc-option and hostcc-option to use __cc-option and move
hostcc-option to scripts/Kbuild.include.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
[nc: Fix conflicts due to lack of CC_OPTION_CFLAGS and hostcc-option
wasn't added until v4.8 so no point including it in this tree]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
Makefile | 2 +-
scripts/Kbuild.include | 9 +++++++--
2 files changed, 8 insertions(+), 3 deletions(-)

--- a/Makefile
+++ b/Makefile
@@ -303,7 +303,7 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH"

HOSTCC = gcc
HOSTCXX = g++
-HOSTCFLAGS = -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer -std=gnu89
+HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer -std=gnu89
HOSTCXXFLAGS = -O2

# Decide whether to build built-in, modular, or both.
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -108,11 +108,16 @@ as-option = $(call try-run,\
as-instr = $(call try-run,\
printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))

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

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

# cc-option-yn
# Usage: flag := $(call cc-option-yn,-march=winchip-c6)