kbuild: cherry-pick kbuild changes from Linux

b42841b7bb62 kbuild: Get rid of KBUILD_STR
2aedcd098a94 kbuild: suppress annoying "... is up to date." message
9c8fa9bc08f6 kbuild: fix if_change and friends to consider argument order
ebf003f0cfb3 kbuild: Consolidate header generation from ASM offset information
2982c953570b kbuild: remove redundant $(wildcard ...) for cmd_files calculation
8a78756eb545 kbuild: create object directories simpler and faster
4d4b5c2e3b6e treewide: remove explicit rules for *offsets.s
01d509a48b46 kbuild: remove unimportant comments from ./Kbuild

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
diff --git a/Kbuild b/Kbuild
index e2e3b29..6014f7c 100644
--- a/Kbuild
+++ b/Kbuild
@@ -1,54 +1,20 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Kbuild for top-level directory of U-Boot
-# This file takes care of the following:
-# 1) Generate generic-asm-offsets.h
-# 2) Generate asm-offsets.h
-
-# Default sed regexp - multiline due to syntax constraints
-define sed-y
-	"s:[[:space:]]*\.ascii[[:space:]]*\"\(.*\)\":\1:; \
-	/^->/{s:->#\(.*\):/* \1 */:; \
-	s:^->\([^ ]*\) [\$$#]*\([-0-9]*\) \(.*\):#define \1 \2 /* \3 */:; \
-	s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
-	s:->::; p;}"
-endef
-
-# Use filechk to avoid rebuilds when a header changes, but the resulting file
-# does not
-define filechk_offsets
-	(set -e; \
-	 echo "#ifndef $2"; \
-	 echo "#define $2"; \
-	 echo "/*"; \
-	 echo " * DO NOT MODIFY."; \
-	 echo " *"; \
-	 echo " * This file was generated by Kbuild"; \
-	 echo " */"; \
-	 echo ""; \
-	 sed -ne $(sed-y); \
-	 echo ""; \
-	 echo "#endif" )
-endef
 
 #####
-# 1) Generate generic-asm-offsets.h
+# Generate generic-asm-offsets.h
 
 generic-offsets-file := include/generated/generic-asm-offsets.h
 
 always  := $(generic-offsets-file)
 targets := lib/asm-offsets.s
 
-# We use internal kbuild rules to avoid the "is up to date" message from make
-lib/asm-offsets.s: lib/asm-offsets.c FORCE
-	$(Q)mkdir -p $(dir $@)
-	$(call if_changed_dep,cc_s_c)
-
 $(obj)/$(generic-offsets-file): lib/asm-offsets.s FORCE
 	$(call filechk,offsets,__GENERIC_ASM_OFFSETS_H__)
 
 #####
-# 2) Generate asm-offsets.h
-#
+# Generate asm-offsets.h
 
 ifneq ($(wildcard $(srctree)/arch/$(ARCH)/lib/asm-offsets.c),)
 offsets-file := include/generated/asm-offsets.h
@@ -59,10 +25,5 @@
 
 CFLAGS_asm-offsets.o := -DDO_DEPS_ONLY
 
-# We use internal kbuild rules to avoid the "is up to date" message from make
-arch/$(ARCH)/lib/asm-offsets.s: arch/$(ARCH)/lib/asm-offsets.c FORCE
-	$(Q)mkdir -p $(dir $@)
-	$(call if_changed_dep,cc_s_c)
-
 $(obj)/$(offsets-file): arch/$(ARCH)/lib/asm-offsets.s FORCE
 	$(call filechk,offsets,__ASM_OFFSETS_H__)
diff --git a/Makefile b/Makefile
index b7fa6d8..b8a4b50 100644
--- a/Makefile
+++ b/Makefile
@@ -2241,8 +2241,7 @@
 
 # read all saved command lines
 
-targets := $(wildcard $(sort $(targets)))
-cmd_files := $(wildcard .*.cmd $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
+cmd_files := $(wildcard .*.cmd $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd))
 
 ifneq ($(cmd_files),)
   $(cmd_files): ;	# Do not try to update included dependency files
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index cad3b6e..dfb6722 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -7,6 +7,7 @@
 squote  := '
 empty   :=
 space   := $(empty) $(empty)
+space_escape := _-_SPACE_-_
 pound := \#
 
 ###
@@ -234,10 +235,10 @@
 # See Documentation/kbuild/makefiles.txt for more info
 
 ifneq ($(KBUILD_NOCMDDEP),1)
-# Check if both arguments has same arguments. Result is empty string if equal.
-# User may override this check using make KBUILD_NOCMDDEP=1
-arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
-                    $(filter-out $(cmd_$@),   $(cmd_$(1))) )
+# Check if both arguments 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 $(cmd_$@))), \
+                         $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
 else
 arg-check = $(if $(strip $(cmd_$@)),,1)
 endif
@@ -259,7 +260,7 @@
 if_changed = $(if $(strip $(any-prereq) $(arg-check)),                       \
 	@set -e;                                                             \
 	$(echo-cmd) $(cmd_$(1));                                             \
-	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
+	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
 
 # Execute the command and also postprocess generated .d dependencies file.
 if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ),                  \
@@ -267,14 +268,14 @@
 	$(echo-cmd) $(cmd_$(1));                                             \
 	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
 	rm -f $(depfile);                                                    \
-	mv -f $(dot-target).tmp $(dot-target).cmd)
+	mv -f $(dot-target).tmp $(dot-target).cmd, @:)
 
 # 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) ),                 \
 	@set -e;                                                             \
-	$(rule_$(1)))
+	$(rule_$(1)), @:)
 
 ###
 # why - tell why a a target got build
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 5e5f168..705a886 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -75,17 +75,6 @@
 include scripts/Makefile.host
 endif
 
-# Uncommented for U-Boot
-#  We need to create output dicrectory for SPL and TPL even for in-tree build
-#ifneq ($(KBUILD_SRC),)
-# Create output directory if not already present
-_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
-
-# Create directories for object files if directory does not exist
-# Needed when obj-y := dir/file.o syntax is used
-_dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
-#endif
-
 ifndef obj
 $(warning kbuild: Makefile.build is included improperly)
 endif
@@ -441,11 +430,14 @@
 # optimization, we don't need to read them if the target does not
 # exist, we will rebuild anyway in that case.
 
-targets := $(wildcard $(sort $(targets)))
-cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
+cmd_files := $(wildcard $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd))
 
 ifneq ($(cmd_files),)
   include $(cmd_files)
 endif
 
+# Create directories for object files if they do not exist
+obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets))))
+$(shell mkdir -p $(obj-dirs))
+
 .PHONY: $(PHONY)
diff --git a/scripts/Makefile.host b/scripts/Makefile.host
index da2f4d5..69983a1 100644
--- a/scripts/Makefile.host
+++ b/scripts/Makefile.host
@@ -53,15 +53,6 @@
 host-cshobjs	:= $(sort $(foreach m,$(host-cshlib),$($(m:.so=-objs))))
 host-cxxshobjs	:= $(sort $(foreach m,$(host-cxxshlib),$($(m:.so=-objs))))
 
-# output directory for programs/.o files
-# hostprogs-y := tools/build may have been specified.
-# Retrieve also directory of .o files from prog-objs or prog-cxxobjs notation
-host-objdirs := $(dir $(__hostprogs) $(host-cobjs) $(host-cxxobjs))
-
-host-objdirs := $(strip $(sort $(filter-out ./,$(host-objdirs))))
-
-
-__hostprogs     := $(addprefix $(obj)/,$(__hostprogs))
 host-csingle	:= $(addprefix $(obj)/,$(host-csingle))
 host-cmulti	:= $(addprefix $(obj)/,$(host-cmulti))
 host-cobjs	:= $(addprefix $(obj)/,$(host-cobjs))
@@ -72,9 +63,6 @@
 host-cshobjs	:= $(addprefix $(obj)/,$(host-cshobjs))
 host-cxxshobjs	:= $(addprefix $(obj)/,$(host-cxxshobjs))
 host-shared	:= $(addprefix $(obj)/,$(host-shared))
-host-objdirs    := $(addprefix $(obj)/,$(host-objdirs))
-
-obj-dirs += $(host-objdirs)
 
 #####
 # Handle options to gcc. Support building with separate output directory
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 1c8cb74..63fbadd 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -57,15 +57,11 @@
 # objects depend on those (obviously)
 multi-objs-y := $(foreach m, $(multi-used-y), $($(m:.o=-objs)) $($(m:.o=-y)))
 multi-objs-m := $(foreach m, $(multi-used-m), $($(m:.o=-objs)) $($(m:.o=-y)))
-multi-objs   := $(multi-objs-y) $(multi-objs-m)
 
 # $(subdir-obj-y) is the list of objects in $(obj-y) which uses dir/ to
 # tell kbuild to descend
 subdir-obj-y := $(filter %/built-in.o, $(obj-y))
 
-# $(obj-dirs) is a list of directories that contain object files
-obj-dirs := $(dir $(multi-objs) $(obj-y))
-
 # Replace multi-part objects by their individual parts, look at local dir only
 real-objs-y := $(foreach m, $(filter-out $(subdir-obj-y), $(obj-y)), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m))) $(extra-y)
 real-objs-m := $(foreach m, $(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m)))
@@ -88,7 +84,6 @@
 multi-objs-y	:= $(addprefix $(obj)/,$(multi-objs-y))
 multi-objs-m	:= $(addprefix $(obj)/,$(multi-objs-m))
 subdir-ym	:= $(addprefix $(obj)/,$(subdir-ym))
-obj-dirs	:= $(addprefix $(obj)/,$(obj-dirs))
 
 # These flags are needed for modversions and compiling, so we define them here
 # already
@@ -97,10 +92,10 @@
 # Note: Files that end up in two or more modules are compiled without the
 #       KBUILD_MODNAME definition. The reason is that any made-up name would
 #       differ in different configs.
-name-fix = $(subst $(comma),_,$(subst -,_,$1))
-basename_flags = -D"KBUILD_BASENAME=KBUILD_STR($(call name-fix,$(basetarget)))"
+name-fix = $(squote)$(quote)$(subst $(comma),_,$(subst -,_,$1))$(quote)$(squote)
+basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
 modname_flags  = $(if $(filter 1,$(words $(modname))),\
-                 -D"KBUILD_MODNAME=KBUILD_STR($(call name-fix,$(modname)))")
+                 -DKBUILD_MODNAME=$(call name-fix,$(modname)))
 
 orig_c_flags   = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(KBUILD_SUBDIR_CCFLAGS) \
                  $(ccflags-y) $(CFLAGS_$(basetarget).o)
@@ -153,7 +148,7 @@
 # Modified for U-Boot: LINUXINCLUDE -> UBOOTINCLUDE
 c_flags        = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(UBOOTINCLUDE)     \
 		 $(__c_flags) $(modkern_cflags)                           \
-		 -D"KBUILD_STR(s)=\#s" $(basename_flags) $(modname_flags)
+		 $(basename_flags) $(modname_flags)
 
 a_flags        = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(UBOOTINCLUDE)     \
 		 $(__a_flags) $(modkern_aflags)
@@ -576,3 +571,32 @@
 quiet_cmd_fdt_rm_props = FDTGREP $@
 	cmd_fdt_rm_props = cat $< | $(objtree)/tools/fdtgrep -r -O dtb - -o $@ \
 			$(addprefix -P ,$(subst $\",,$(CONFIG_OF_REMOVE_PROPS)))
+
+# ASM offsets
+# ---------------------------------------------------------------------------
+
+# Default sed regexp - multiline due to syntax constraints
+define sed-offsets
+	"s:[[:space:]]*\.ascii[[:space:]]*\"\(.*\)\":\1:; \
+	/^->/{s:->#\(.*\):/* \1 */:; \
+	s:^->\([^ ]*\) [\$$#]*\([-0-9]*\) \(.*\):#define \1 \2 /* \3 */:; \
+	s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
+	s:->::; p;}"
+endef
+
+# Use filechk to avoid rebuilds when a header changes, but the resulting file
+# does not
+define filechk_offsets
+	(set -e; \
+	 echo "#ifndef $2"; \
+	 echo "#define $2"; \
+	 echo "/*"; \
+	 echo " * DO NOT MODIFY."; \
+	 echo " *"; \
+	 echo " * This file was generated by Kbuild"; \
+	 echo " */"; \
+	 echo ""; \
+	 sed -ne $(sed-offsets); \
+	 echo ""; \
+	 echo "#endif" )
+endef