kbuild: do not quote string values in include/config/auto.conf

The previous commit fixed up all shell scripts to not include
include/config/auto.conf.

Now that include/config/auto.conf is only included by Makefiles,
we can change it into a more Make-friendly form.

Previously, Kconfig output string values enclosed with double-quotes
(both in the .config and include/config/auto.conf):

    CONFIG_X="foo bar"

Unlike shell, Make handles double-quotes (and single-quotes as well)
verbatim. We must rip them off when used.

There are some patterns:

  [1] $(patsubst "%",%,$(CONFIG_X))
  [2] $(CONFIG_X:"%"=%)
  [3] $(subst ",,$(CONFIG_X))
  [4] $(shell echo $(CONFIG_X))

These are not only ugly, but also fragile.

[1] and [2] do not work if the value contains spaces, like
   CONFIG_X=" foo bar "

[3] does not work correctly if the value contains double-quotes like
   CONFIG_X="foo\"bar"

[4] seems to work better, but has a cost of forking a process.

Anyway, quoted strings were always PITA for our Makefiles.

This commit changes Kconfig to stop quoting in include/config/auto.conf.

These are the string type symbols referenced in Makefiles or scripts:

    ACPI_CUSTOM_DSDT_FILE
    ARC_BUILTIN_DTB_NAME
    ARC_TUNE_MCPU
    BUILTIN_DTB_SOURCE
    CC_IMPLICIT_FALLTHROUGH
    CC_VERSION_TEXT
    CFG80211_EXTRA_REGDB_KEYDIR
    EXTRA_FIRMWARE
    EXTRA_FIRMWARE_DIR
    EXTRA_TARGETS
    H8300_BUILTIN_DTB
    INITRAMFS_SOURCE
    LOCALVERSION
    MODULE_SIG_HASH
    MODULE_SIG_KEY
    NDS32_BUILTIN_DTB
    NIOS2_DTB_SOURCE
    OPENRISC_BUILTIN_DTB
    SOC_CANAAN_K210_DTB_SOURCE
    SYSTEM_BLACKLIST_HASH_LIST
    SYSTEM_REVOCATION_KEYS
    SYSTEM_TRUSTED_KEYS
    TARGET_CPU
    UNUSED_KSYMS_WHITELIST
    XILINX_MICROBLAZE0_FAMILY
    XILINX_MICROBLAZE0_HW_VER
    XTENSA_VARIANT_NAME

I checked them one by one, and fixed up the code where necessary.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/arc/Makefile b/arch/arc/Makefile
index f252e7b924e9..efc54f3e35e0 100644
--- a/arch/arc/Makefile
+++ b/arch/arc/Makefile
@@ -14,10 +14,10 @@ cflags-y	+= -fno-common -pipe -fno-builtin -mmedium-calls -D__linux__
 tune-mcpu-def-$(CONFIG_ISA_ARCOMPACT)	:= -mcpu=arc700
 tune-mcpu-def-$(CONFIG_ISA_ARCV2)	:= -mcpu=hs38
 
-ifeq ($(CONFIG_ARC_TUNE_MCPU),"")
+ifeq ($(CONFIG_ARC_TUNE_MCPU),)
 cflags-y				+= $(tune-mcpu-def-y)
 else
-tune-mcpu				:= $(shell echo $(CONFIG_ARC_TUNE_MCPU))
+tune-mcpu				:= $(CONFIG_ARC_TUNE_MCPU)
 ifneq ($(call cc-option,$(tune-mcpu)),)
 cflags-y				+= $(tune-mcpu)
 else