kbuild: split cc-option and friends to scripts/Makefile.compiler

scripts/Kbuild.include is included everywhere, but macros such as
cc-option are needed by build targets only.

For example, when 'make clean' traverses the tree, it does not need
to evaluate $(call cc-option,).

Split cc-option, ld-option, etc. to scripts/Makefile.compiler, which
is only included from the top Makefile and scripts/Makefile.build.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Makefile

@@ -584,6 +584,10 @@ KBUILD_AFLAGS	+= $(CLANG_FLAGS)
 export CLANG_FLAGS
 endif
 
+# Include this also for config targets because some architectures need
+# cc-cross-prefix to determine CROSS_COMPILE.
+include $(srctree)/scripts/Makefile.compiler
+
 ifdef config-build
 # ===========================================================================
 # *config targets only - make sure prerequisites are updated, and descend

scripts/Kbuild.include

@@ -67,86 +67,6 @@ define filechk
 	fi
 endef
 
-######
-# gcc support functions
-# See documentation in Documentation/kbuild/makefiles.rst
-
-# cc-cross-prefix
-# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
-# Return first <prefix> where a <prefix>gcc is found in PATH.
-# If no gcc found in PATH with listed prefixes return nothing
-#
-# Note: '2>/dev/null' is here to force Make to invoke a shell. Otherwise, it
-# would try to directly execute the shell builtin 'command'. This workaround
-# should be kept for a long time since this issue was fixed only after the
-# GNU Make 4.2.1 release.
-cc-cross-prefix = $(firstword $(foreach c, $(1), \
-			$(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c))))
-
-# output directory for tests below
-TMPOUT = $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_$$$$
-
-# try-run
-# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
-# Exit code chooses option. "$$TMP" serves as a temporary file and is
-# automatically cleaned up.
-try-run = $(shell set -e;		\
-	TMP=$(TMPOUT)/tmp;		\
-	TMPO=$(TMPOUT)/tmp.o;		\
-	mkdir -p $(TMPOUT);		\
-	trap "rm -rf $(TMPOUT)" EXIT;	\
-	if ($(1)) >/dev/null 2>&1;	\
-	then echo "$(2)";		\
-	else echo "$(3)";		\
-	fi)
-
-# as-option
-# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
-
-as-option = $(call try-run,\
-	$(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
-
-# as-instr
-# Usage: cflags-y += $(call as-instr,instr,option1,option2)
-
-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 __cc-option, $(CC),\
-	$(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS),$(1),$(2))
-
-# cc-option-yn
-# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
-cc-option-yn = $(call try-run,\
-	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
-
-# cc-disable-warning
-# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
-cc-disable-warning = $(call try-run,\
-	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
-
-# cc-ifversion
-# Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
-cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4))
-
-# ld-option
-# Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
-ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
-
-# ld-ifversion
-# Usage:  $(call ld-ifversion, -ge, 22252, y)
-ld-ifversion = $(shell [ $(CONFIG_LD_VERSION)0 $(1) $(2)0 ] && echo $(3) || echo $(4))
-
-######
-
 ###
 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
 # Usage:

scripts/Makefile.build

@@ -36,6 +36,7 @@ subdir-ccflags-y :=
 -include include/config/auto.conf
 
 include $(srctree)/scripts/Kbuild.include
+include $(srctree)/scripts/Makefile.compiler
 
 # The filename Kbuild has precedence over Makefile
 kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))

scripts/Makefile.compiler

+# SPDX-License-Identifier: GPL-2.0-only
+
+# cc-cross-prefix
+# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
+# Return first <prefix> where a <prefix>gcc is found in PATH.
+# If no gcc found in PATH with listed prefixes return nothing
+#
+# Note: '2>/dev/null' is here to force Make to invoke a shell. Otherwise, it
+# would try to directly execute the shell builtin 'command'. This workaround
+# should be kept for a long time since this issue was fixed only after the
+# GNU Make 4.2.1 release.
+cc-cross-prefix = $(firstword $(foreach c, $(1), \
+			$(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c))))
+
+# output directory for tests below
+TMPOUT = $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_$$$$
+
+# try-run
+# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
+# Exit code chooses option. "$$TMP" serves as a temporary file and is
+# automatically cleaned up.
+try-run = $(shell set -e;		\
+	TMP=$(TMPOUT)/tmp;		\
+	TMPO=$(TMPOUT)/tmp.o;		\
+	mkdir -p $(TMPOUT);		\
+	trap "rm -rf $(TMPOUT)" EXIT;	\
+	if ($(1)) >/dev/null 2>&1;	\
+	then echo "$(2)";		\
+	else echo "$(3)";		\
+	fi)
+
+# as-option
+# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
+
+as-option = $(call try-run,\
+	$(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
+
+# as-instr
+# Usage: cflags-y += $(call as-instr,instr,option1,option2)
+
+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 __cc-option, $(CC),\
+	$(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS),$(1),$(2))
+
+# cc-option-yn
+# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
+cc-option-yn = $(call try-run,\
+	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
+
+# cc-disable-warning
+# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
+cc-disable-warning = $(call try-run,\
+	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
+
+# cc-ifversion
+# Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
+cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4))
+
+# ld-option
+# Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
+ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
+
+# ld-ifversion
+# Usage:  $(call ld-ifversion, -ge, 22252, y)
+ld-ifversion = $(shell [ $(CONFIG_LD_VERSION)0 $(1) $(2)0 ] && echo $(3) || echo $(4))