kbuild: Bump the build system to 6.1

Our last sync with the kernel was 5.1.

We are so out of sync now, that tracking the patches and backporting
them one by one makes little sense and it's going to take ages.

This is an attempt to sync up Makefiles to 6.1.
Unfortunately due to sheer amount of patches this is not easy to review,
but that's what we decided during a community call for the bump to 5.1,
so we are following the same guidelines here.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>a #rebased on -next

1 files changed, 52 insertions, 182 deletions

diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index fd7a744478f..ece44b73506 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 ####
 # kbuild: Generic definitions
 
@@ -15,7 +16,11 @@ pound := \#
 dot-target = $(dir $@).$(notdir $@)
 
 ###
-# The temporary file to save gcc -MD generated dependencies must not
+# Name of target with a '.tmp_' as filename prefix. foo/bar.o => foo/.tmp_bar.o
+tmp-target = $(dir $@).tmp_$(notdir $@)
+
+###
+# The temporary file to save gcc -MMD generated dependencies must not
 # contain a comma
 depfile = $(subst $(comma),_,$(dot-target).d)
 
@@ -24,10 +29,6 @@ depfile = $(subst $(comma),_,$(dot-target).d)
 basetarget = $(basename $(notdir $@))
 
 ###
-# filename of first prerequisite with directory and extension stripped
-baseprereq = $(basename $(notdir $<))
-
-###
 # real prerequisites without phony targets
 real-prereqs = $(filter-out $(PHONY), $^)
 
@@ -36,8 +37,8 @@ real-prereqs = $(filter-out $(PHONY), $^)
 escsq = $(subst $(squote),'\$(squote)',$1)
 
 ###
-# real prerequisites without phony targets
-real-prereqs = $(filter-out $(PHONY), $^)
+# Quote a string to pass it to C files. foo => '"foo"'
+stringify = $(squote)$(quote)$1$(quote)$(squote)
 
 ###
 # Easy method for doing a status message
@@ -49,6 +50,7 @@ kecho := $($(quiet)kecho)
 ###
 # filechk is used to check if the content of a generated file is updated.
 # Sample usage:
+#
 # filechk_sample = echo $(KERNELRELEASE)
 # version.h: FORCE
 #	$(call filechk,sample)
@@ -58,129 +60,18 @@ kecho := $($(quiet)kecho)
 # - If no file exist it is created
 # - If the content differ the new file is used
 # - If they are equal no change, and no timestamp update
-# - stdin is piped in from the first prerequisite ($<) so one has
-#   to specify a valid file as first prerequisite (often the kbuild file)
 define filechk
-	$(Q)set -e;				\
-	mkdir -p $(dir $@);			\
-	$(filechk_$(1)) < $< > $@.tmp;		\
-	if [ -r $@ ] && cmp -s $@ $@.tmp; then	\
-		rm -f $@.tmp;			\
-	else					\
-		$(kecho) '  UPD     $@';	\
-		mv -f $@.tmp $@;		\
+	$(check-FORCE)
+	$(Q)set -e;						\
+	mkdir -p $(dir $@);					\
+	trap "rm -f $(dot-target).tmp" EXIT;			\
+	{ $(filechk_$(1)); } > $(dot-target).tmp;		\
+	if [ ! -r $@ ] || ! cmp -s $@ $(dot-target).tmp; then	\
+		$(kecho) '  UPD     $@';			\
+		mv -f $(dot-target).tmp $@;			\
 	fi
 endef
 
-######
-# gcc support functions
-# See documentation in Documentation/kbuild/makefiles.txt
-
-# cc-cross-prefix
-# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
-# Return first prefix where a prefix$(CC) is found in PATH.
-# If no $(CC) found in PATH with listed prefixes return nothing
-cc-cross-prefix =  \
-	$(word 1, $(foreach c,$(1),                                   \
-		$(shell set -e;                                       \
-		if (which $(strip $(c))$(CC)) > /dev/null 2>&1 ; then \
-			echo $(c);                                    \
-		fi)))
-
-# output directory for tests below
-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.
-# modifed for U-Boot: prevent cc-option from leaving .*.su files
-try-run = $(shell set -e;		\
-	TMP="$(TMPOUT).$$$$.tmp";	\
-	TMPO="$(TMPOUT).$$$$.o";	\
-	TMPSU="$(TMPOUT).$$$$.su";	\
-	if ($(1)) >/dev/null 2>&1;	\
-	then echo "$(2)";		\
-	else echo "$(3)";		\
-	fi;				\
-	rm -f "$$TMP" "$$TMPO" "$$TMPSU")
-
-# 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 "$$TMP",$(3),$(4))
-
-# cc-option
-# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
-cc-option = $(call __cc-option, $(CC),\
-	$(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS),$(1),$(2))
-
-# hostcc-option
-# Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586)
-hostcc-option = $(call __cc-option, $(HOSTCC),\
-	$(HOSTCFLAGS) $(HOST_EXTRACFLAGS),$(1),$(2))
-
-# cc-option-yn
-# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
-cc-option-yn = $(call try-run,\
-	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$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 "$$TMP",-Wno-$(strip $(1)))
-
-# cc-name
-# Expands to either gcc or clang
-cc-name = $(shell $(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc)
-
-# cc-version
-cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
-
-# cc-ifversion
-# Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
-cc-ifversion = $(shell [ $(cc-version) $(1) $(2) ] && echo $(3) || echo $(4))
-
-# added for U-Boot
-binutils-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/binutils-version.sh $(AS))
-dtc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/dtc-version.sh $(DTC))
-
-# cc-ldoption
-# Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
-cc-ldoption = $(call try-run,\
-	$(CC) $(1) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
-
-# ld-option
-# Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
-ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
-
-# ar-option
-# Usage: KBUILD_ARFLAGS := $(call ar-option,D)
-# Important: no spaces around options
-ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
-
-# ld-version
-# Note this is mainly for HJ Lu's 3 number binutil versions
-ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
-
-# ld-ifversion
-# Usage:  $(call ld-ifversion, -ge, 22252, y)
-ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
-
-######
-
 ###
 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
 # Usage:
@@ -188,12 +79,6 @@ ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
 build := -f $(srctree)/scripts/Makefile.build obj
 
 ###
-# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj=
-# Usage:
-# $(Q)$(MAKE) $(modbuiltin)=dir
-modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
-
-###
 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
 # Usage:
 # $(Q)$(MAKE) $(dtbinst)=dir
@@ -205,30 +90,18 @@ dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj
 # $(Q)$(MAKE) $(clean)=dir
 clean := -f $(srctree)/scripts/Makefile.clean obj
 
-###
-# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.headersinst obj=
-# Usage:
-# $(Q)$(MAKE) $(hdr-inst)=dir
-hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
-
-# Prefix -I with $(srctree) if it is not an absolute path.
-# skip if -I has no parameter
-addtree = $(if $(patsubst -I%,%,$(1)), \
-$(if $(filter-out -I/% -I./% -I../%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1)),$(1)),$(1))
-
-# Find all -I options and call addtree
-flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
-
 # echo command.
 # Short version is used, if $(quiet) equals `quiet_', otherwise full one.
 echo-cmd = $(if $($(quiet)cmd_$(1)),\
 	echo '  $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
 
-# printing commands
-cmd = @set -e; $(echo-cmd) $(cmd_$(1))
+# sink stdout for 'make -s'
+       redirect :=
+ quiet_redirect :=
+silent_redirect := exec >/dev/null;
 
-# Add $(obj)/ for paths that are not absolute
-objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
+# printing commands
+cmd = @set -e; $(echo-cmd) $($(quiet)redirect) $(cmd_$(1))
 
 ###
 # if_changed      - execute command if any prerequisite is newer than
@@ -236,15 +109,15 @@ objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
 # if_changed_dep  - as if_changed, but uses fixdep to reveal dependencies
 #                   including used config symbols
 # if_changed_rule - as if_changed but execute rule instead
-# See doc/develop/makefiles.rst for more info
+# See Documentation/kbuild/makefiles.rst for more info
 
 ifneq ($(KBUILD_NOCMDDEP),1)
-# Check if both arguments are the same including their order. Result is empty
+# Check if both commands are the same including their order. Result is empty
 # string if equal. User may override this check using make KBUILD_NOCMDDEP=1
-arg-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
+cmd-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
                          $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
 else
-arg-check = $(if $(strip $(cmd_$@)),,1)
+cmd-check = $(if $(strip $(cmd_$@)),,1)
 endif
 
 # Replace >$< with >$$< to preserve $ when reloading the .cmd file
@@ -255,32 +128,41 @@ endif
 # (needed for the shell)
 make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
 
-# Find any prerequisites that is newer than target or that does not exist.
+# Find any prerequisites that are newer than target or that do not exist.
+# (This is not true for now; $? should contain any non-existent prerequisites,
+# but it does not work as expected when .SECONDARY is present. This seems a bug
+# of GNU Make.)
 # PHONY targets skipped in both cases.
-any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
+newer-prereqs = $(filter-out $(PHONY),$?)
+
+# It is a typical mistake to forget the FORCE prerequisite. Check it here so
+# no more breakage will slip in.
+check-FORCE = $(if $(filter FORCE, $^),,$(warning FORCE prerequisite is missing))
+
+if-changed-cond = $(newer-prereqs)$(cmd-check)$(check-FORCE)
 
 # Execute command if command has changed or prerequisite(s) are updated.
-#
-if_changed = $(if $(strip $(any-prereq) $(arg-check)),                       \
-	@set -e;                                                             \
-	$(echo-cmd) $(cmd_$(1));                                             \
-	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
+if_changed = $(if $(if-changed-cond),$(cmd_and_savecmd),@:)
+
+cmd_and_savecmd =                                                            \
+	$(cmd);                                                              \
+	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd
 
 # Execute the command and also postprocess generated .d dependencies file.
-if_changed_dep = $(if $(strip $(any-prereq) $(arg-check)),$(cmd_and_fixdep),@:)
+if_changed_dep = $(if $(if-changed-cond),$(cmd_and_fixdep),@:)
 
-cmd_and_fixdep =						             \
-	$(cmd);							             \
+cmd_and_fixdep =                                                             \
+	$(cmd);                                                              \
 	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).cmd;\
 	rm -f $(depfile)
 
 # Usage: $(call if_changed_rule,foo)
 # Will check if $(cmd_foo) or any of the prerequisites changed,
 # and if so will execute $(rule_foo).
-if_changed_rule = $(if $(strip $(any-prereq) $(arg-check)),$(rule_$(1)),@:)
+if_changed_rule = $(if $(if-changed-cond),$(rule_$(1)),@:)
 
 ###
-# why - tell why a a target got build
+# why - tell why a target got built
 #       enabled by make V=2
 #       Output (listed in the order they are checked):
 #          (1) - due to target is PHONY
@@ -302,8 +184,8 @@ ifeq ($(KBUILD_VERBOSE),2)
 why =                                                                        \
     $(if $(filter $@, $(PHONY)),- due to target is PHONY,                    \
         $(if $(wildcard $@),                                                 \
-            $(if $(strip $(any-prereq)),- due to: $(any-prereq),             \
-                $(if $(arg-check),                                           \
+            $(if $(newer-prereqs),- due to: $(newer-prereqs),                \
+                $(if $(cmd-check),                                           \
                     $(if $(cmd_$@),- due to command line change,             \
                         $(if $(filter $@, $(targets)),                       \
                             - due to missing .cmd file,                      \
@@ -319,22 +201,10 @@ why =                                                                        \
 echo-why = $(call escsq, $(strip $(why)))
 endif
 
+###############################################################################
+
 # delete partially updated (i.e. corrupted) files on error
 .DELETE_ON_ERROR:
 
 # do not delete intermediate files automatically
 .SECONDARY:
-
-ifeq ($(CONFIG_SPL_BUILD),y)
-PHASE_ := SPL_
-else
-ifeq ($(CONFIG_VPL_BUILD),y)
-PHASE_ := VPL_
-else
-ifeq ($(CONFIG_TPL_BUILD),y)
-PHASE_ := TPL_
-else
-PHASE_ :=
-endif
-endif
-endif