kbuild: sync if_changed and friends with Linux 5.7-rc2

Resync cmd, if_change, if_changed_dep, and if_changed_rule.

Clean up the users of if_changed_rule.

I deleted the modversions rule. It is dead code because barebox
does not define CONFIG_MODVERSIONS. It does not work without
scripts/genksyms/ anyway.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 23 insertions, 24 deletions

diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 983329e40d..074d2db045 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -165,7 +165,7 @@ echo-cmd = $(if $($(quiet)cmd_$(1)),\
 	echo '  $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
 
 # printing commands
-cmd = @$(echo-cmd) $(cmd_$(1))
+cmd = @set -e; $(echo-cmd) $(cmd_$(1))
 
 # Add $(obj)/ for paths that are not absolute
 objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
@@ -176,15 +176,15 @@ 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 Documentation/kbuild/makefiles.txt 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 >$$< to preserve $ when reloading the .cmd file
@@ -195,34 +195,33 @@ endif
 # (needed for the shell)
 make-cmd = $(call escsq,$(subst $(pound),$$(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 $(PHONY),$?)
 
 # 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 $(newer-prereqs)$(cmd-check),                              \
+	$(cmd);                                                              \
+	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
 
 # Execute the command and also postprocess generated .d dependencies file.
-if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ),                  \
-	@set -e;                                                             \
-	$(echo-cmd) $(cmd_$(1));                                             \
-	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
-	rm -f $(depfile);                                                    \
-	mv -f $(dot-target).tmp $(dot-target).cmd)
+if_changed_dep = $(if $(newer-prereqs)$(cmd-check),$(cmd_and_fixdep),@:)
+
+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) ),                 \
-	@set -e;                                                             \
-	$(rule_$(1)))
+if_changed_rule = $(if $(newer-prereqs)$(cmd-check),$(rule_$(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
@@ -244,8 +243,8 @@ 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,                      \