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| author | Masahiro Yamada <masahiroy@kernel.org> | 2021-08-13 15:30:05 +0900 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2021-09-03 08:17:19 +0900 |
| commit | e1f86d7b4b2a5213b012c2b4fe3e5b6ad537686e (patch) | |
| tree | 8d727e69ee73d264c626599c794718d47b228599 | |
| parent | 6796e80409b9031458e33dc39a3ac8aa3b93855b (diff) | |
| download | lwn-e1f86d7b4b2a5213b012c2b4fe3e5b6ad537686e.tar.gz lwn-e1f86d7b4b2a5213b012c2b4fe3e5b6ad537686e.zip | |
kbuild: warn if FORCE is missing for if_changed(_dep,_rule) and filechk
if_changed, if_changed_dep, and if_changed_rule must have FORCE as a
prerequisite so the command line change is detected.
Documentation/kbuild/makefiles.rst clearly explains it:
Note: It is a typical mistake to forget the FORCE prerequisite.
However, not all people follow the document.
This mistake occurred again and again, so a compelling force is needed.
Show a warning if FORCE is missing in the prerequisite of if_changed
and friends. Same for filechk.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nicolas Schier <n.schier@avm.de>
| -rw-r--r-- | scripts/Kbuild.include | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index c3c975a92318..cdec22088423 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -57,6 +57,7 @@ kecho := $($(quiet)kecho) # - If the content differ the new file is used # - If they are equal no change, and no timestamp update define filechk + $(check-FORCE) $(Q)set -e; \ mkdir -p $(dir $@); \ trap "rm -f $(dot-target).tmp" EXIT; \ @@ -130,7 +131,11 @@ make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))) # PHONY targets skipped in both cases. newer-prereqs = $(filter-out $(PHONY),$?) -if-changed-cond = $(newer-prereqs)$(cmd-check) +# 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 $(if-changed-cond), \ |