kbuild: make V=2 tell why a target is rebuild (45d506bd) · Commits · 戴 / test

Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -1101,6 +1101,7 @@ help:
		echo '')

		@echo ' make V=0\|1 [targets] 0 => quiet build (default), 1 => verbose build'
		@echo ' make V=2 [targets] 2 => give reason for rebuild of target'
		@echo ' make O=dir [targets] Locate all output files in "dir", including .config'
		@echo ' make C=1 [targets] Check all c source with $$CHECK (sparse by default)'
		@echo ' make C=2 [targets] Force check of all c source with $$CHECK'

scripts/Kbuild.include

+40 −1

Original line number	Diff line number	Diff line
		@@ -129,7 +129,7 @@ endif

		# echo command. Short version is $(quiet) equals quiet, otherwise full command
		echo-cmd = $(if $($(quiet)cmd_$(1)), \
		echo ' $(call escsq,$($(quiet)cmd_$(1)))';)
		echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)

		# >'< substitution is for echo to work,
		# >$< substitution to preserve $ when reloading .cmd file
		@@ -164,3 +164,42 @@ if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \
		@set -e; \
		$(rule_$(1)))

		###
		# why - tell why a a target got build
		# enabled by make V=2
		# Output (listed in the order they are checked):
		# (1) - due to target is PHONY
		# (2) - due to target missing
		# (3) - due to: file1.h file2.h
		# (4) - due to command line change
		# (5) - due to missing .cmd file
		# (6) - due to target not in $(targets)
		# (1) PHONY targets are always build
		# (2) No target, so we better build it
		# (3) Prerequisite is newer than target
		# (4) The command line stored in the file named dir/.target.cmd
		# differed from actual command line. This happens when compiler
		# options changes
		# (5) No dir/.target.cmd file (used to store command line)
		# (6) No dir/.target.cmd file and target not listed in $(targets)
		# This is a good hint that there is a bug in the kbuild file
		ifeq ($(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 $(cmd_$@),- due to command line change, \
		$(if $(filter $@, $(targets)), \
		- due to missing .cmd file, \
		- due to $(notdir $@) not in $$(targets) \
		) \
		) \
		) \
		), \
		- due to target missing \
		) \
		)

		echo-why = $(call escsq, $(strip $(why)))
		endif

Admin message