Commit 48f1f0589dd09df6ea07d41c737db3218ad2cb79
Committed by
Sam Ravnborg
Sam Ravnborg
1 parent
d3660a8cbd
kbuild: consistently decide when to rebuild a target
Consistently decide when to rebuild a target across all of if_changed, if_changed_dep, if_changed_rule. PHONY targets are now treated alike (ignored) for all targets While add it make Kbuild.include almost readable by factoring out a few bits to some common variables and reuse this in Makefile.build. Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Showing 3 changed files with 35 additions and 24 deletions Side-by-side Diff
scripts/Kbuild.include
| ... | ... | @@ -8,9 +8,13 @@ |
| 8 | 8 | space := $(empty) $(empty) |
| 9 | 9 | |
| 10 | 10 | ### |
| 11 | +# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o | |
| 12 | +dot-target = $(dir $@).$(notdir $@) | |
| 13 | + | |
| 14 | +### | |
| 11 | 15 | # The temporary file to save gcc -MD generated dependencies must not |
| 12 | 16 | # contain a comma |
| 13 | -depfile = $(subst $(comma),_,$(@D)/.$(@F).d) | |
| 17 | +depfile = $(subst $(comma),_,$(dot-target).d) | |
| 14 | 18 | |
| 15 | 19 | ### |
| 16 | 20 | # filename of target with directory and extension stripped |
| 17 | 21 | |
| 18 | 22 | |
| 19 | 23 | |
| 20 | 24 | |
| 21 | 25 | |
| ... | ... | @@ -119,41 +123,44 @@ |
| 119 | 123 | ifneq ($(KBUILD_NOCMDDEP),1) |
| 120 | 124 | # Check if both arguments has same arguments. Result in empty string if equal |
| 121 | 125 | # User may override this check using make KBUILD_NOCMDDEP=1 |
| 122 | -arg-check = $(strip $(filter-out $(1), $(2)) $(filter-out $(2), $(1)) ) | |
| 126 | +arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \ | |
| 127 | + $(filter-out $(cmd_$@), $(cmd_$(1))) ) | |
| 123 | 128 | endif |
| 124 | 129 | |
| 125 | 130 | # echo command. Short version is $(quiet) equals quiet, otherwise full command |
| 126 | 131 | echo-cmd = $(if $($(quiet)cmd_$(1)), \ |
| 127 | 132 | echo ' $(call escsq,$($(quiet)cmd_$(1)))';) |
| 128 | 133 | |
| 134 | +# >'< substitution is for echo to work, | |
| 135 | +# >$< substitution to preserve $ when reloading .cmd file | |
| 136 | +# note: when using inline perl scripts [perl -e '...$$t=1;...'] | |
| 137 | +# in $(cmd_xxx) double $$ your perl vars | |
| 129 | 138 | make-cmd = $(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1))))) |
| 130 | 139 | |
| 131 | -# function to only execute the passed command if necessary | |
| 132 | -# >'< substitution is for echo to work, >$< substitution to preserve $ when reloading .cmd file | |
| 133 | -# note: when using inline perl scripts [perl -e '...$$t=1;...'] in $(cmd_xxx) double $$ your perl vars | |
| 140 | +# Find any prerequisites that is newer than target or that does not exist. | |
| 141 | +# PHONY targets skipped in both cases. | |
| 142 | +any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^) | |
| 143 | + | |
| 144 | +# Execute command if command has changed or prerequisitei(s) are updated | |
| 134 | 145 | # |
| 135 | -if_changed = $(if $(strip $(filter-out $(PHONY),$?) \ | |
| 136 | - $(call arg-check, $(cmd_$(1)), $(cmd_$@)) ), \ | |
| 137 | - @set -e; \ | |
| 138 | - $(echo-cmd) $(cmd_$(1)); \ | |
| 139 | - echo 'cmd_$@ := $(make-cmd)' > $(@D)/.$(@F).cmd) | |
| 146 | +if_changed = $(if $(strip $(any-prereq) $(arg-check)), \ | |
| 147 | + @set -e; \ | |
| 148 | + $(echo-cmd) $(cmd_$(1)); \ | |
| 149 | + echo 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd) | |
| 140 | 150 | |
| 141 | 151 | # execute the command and also postprocess generated .d dependencies |
| 142 | 152 | # file |
| 143 | -if_changed_dep = $(if $(strip $(filter-out $(PHONY),$?) \ | |
| 144 | - $(filter-out FORCE $(wildcard $^),$^) \ | |
| 145 | - $(call arg-check, $(cmd_$(1)), $(cmd_$@)) ), \ | |
| 146 | - @set -e; \ | |
| 147 | - $(echo-cmd) $(cmd_$(1)); \ | |
| 148 | - scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(@D)/.$(@F).tmp; \ | |
| 149 | - rm -f $(depfile); \ | |
| 150 | - mv -f $(@D)/.$(@F).tmp $(@D)/.$(@F).cmd) | |
| 153 | +if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ), \ | |
| 154 | + @set -e; \ | |
| 155 | + $(echo-cmd) $(cmd_$(1)); \ | |
| 156 | + scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\ | |
| 157 | + rm -f $(depfile); \ | |
| 158 | + mv -f $(dot-target).tmp $(dot-target).cmd) | |
| 151 | 159 | |
| 152 | 160 | # Usage: $(call if_changed_rule,foo) |
| 153 | 161 | # will check if $(cmd_foo) changed, or any of the prequisites changed, |
| 154 | 162 | # and if so will execute $(rule_foo) |
| 155 | -if_changed_rule = $(if $(strip $(filter-out $(PHONY),$?) \ | |
| 156 | - $(call arg-check, $(cmd_$(1)), $(cmd_$@)) ),\ | |
| 157 | - @set -e; \ | |
| 158 | - $(rule_$(1))) | |
| 163 | +if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), \ | |
| 164 | + @set -e; \ | |
| 165 | + $(rule_$(1))) |
scripts/Makefile.build
| ... | ... | @@ -191,9 +191,10 @@ |
| 191 | 191 | $(call echo-cmd,checksrc) $(cmd_checksrc) \ |
| 192 | 192 | $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \ |
| 193 | 193 | $(cmd_modversions) \ |
| 194 | - scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > $(@D)/.$(@F).tmp; \ | |
| 194 | + scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \ | |
| 195 | + $(dot-target).tmp; \ | |
| 195 | 196 | rm -f $(depfile); \ |
| 196 | - mv -f $(@D)/.$(@F).tmp $(@D)/.$(@F).cmd | |
| 197 | + mv -f $(dot-target).tmp $(dot-target).cmd | |
| 197 | 198 | endef |
| 198 | 199 | |
| 199 | 200 | # Built-in and composite module parts |