During parallel build, the top Makefile spawns multiple sub-makes for targets in cpu/$(CPU) and $(dir $(LDSCRIPT)). If the .depend files are not present in these directories, the sub-makes may end up generating these files simultaneously which leads to corrupted content.
A typical error message is:
.depend:39: *** multiple target patterns. Stop.
This patch serializes the creation of .depend in cpu/$(CPU) and $(dir $(LDSCRIPT)) by adding these directories to the depend target in the top Makefile.
Other directories in $(LIBS) are not affected since they contain only one Make target and thus only one sub-make is spawned per directory.
Signed-off-by: Daniel Hobi daniel.hobi@schmid-telecom.ch --- v3: - Add a comment why make _depend is required for these two subdirs v2: - Also build target depend in $(dir $(LDSCRIPT)) (suggested by Mike) - Break overlong line
Makefile | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-)
diff --git a/Makefile b/Makefile index 793fcec..1ab197b 100644 --- a/Makefile +++ b/Makefile @@ -398,8 +398,11 @@ updater: env: $(MAKE) -C tools/env all MTD_VERSION=${MTD_VERSION} || exit 1
+# Explicitly make _depend in subdirs containing multiple targets to prevent +# parallel sub-makes creating .depend files simultaneously. depend dep: $(TIMESTAMP_FILE) $(VERSION_FILE) $(obj)include/autoconf.mk - for dir in $(SUBDIRS) ; do $(MAKE) -C $$dir _depend ; done + for dir in $(SUBDIRS) cpu/$(CPU) $(dir $(LDSCRIPT)) ; do \ + $(MAKE) -C $$dir _depend ; done
TAG_SUBDIRS = $(SUBDIRS) TAG_SUBDIRS += $(dir $(__LIBS))