Make export_includes a restat rule
There is currently an intentional incremental rebuild issue with
import_includes. export_includes might get updated with an identical
version, but we don't want to force everything downstream of it to
rebuild.
When BUILDING_WITH_NINJA==true, only update export_includes if it
changes, and use .KATI_RESTAT to only run downstream rules if it
changes. import_includes will only be updated if one of the
export_includes files is updated, so object files can have a normal
dependency on import_includes instead of an order-only dependency.
All downstream object files will now be recompiled if their imported
include paths change.
Bug: 25910568
Change-Id: I626f3b24ac02ac1309049cf1ce66cfe8ec816513
diff --git a/core/binary.mk b/core/binary.mk
index 028950a..a62423c 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -1134,7 +1134,11 @@
# that custom build rules which generate .o files don't consume other generated
# sources as input (or if they do they take care of that dependency themselves).
$(normal_objects) : | $(my_generated_sources)
+ifeq ($(BUILDING_WITH_NINJA),true)
+$(all_objects) : $(import_includes)
+else
$(all_objects) : | $(import_includes)
+endif
ALL_C_CPP_ETC_OBJECTS += $(all_objects)
@@ -1307,14 +1311,26 @@
# generated after the headers, so this is a convenient way to ensure the headers exist.
$(export_includes) : $(LOCAL_MODULE_MAKEFILE_DEP) $(proto_generated_headers) $(dbus_generated_headers) $(aidl_gen_cpp)
@echo Export includes file: $< -- $@
- $(hide) mkdir -p $(dir $@) && rm -f $@
+ $(hide) mkdir -p $(dir $@) && rm -f $@.tmp
ifdef my_export_c_include_dirs
$(hide) for d in $(PRIVATE_EXPORT_C_INCLUDE_DIRS); do \
- echo "-I $$d" >> $@; \
+ echo "-I $$d" >> $@.tmp; \
done
else
- $(hide) touch $@
+ $(hide) touch $@.tmp
endif
+ifeq ($(BUILDING_WITH_NINJA),true)
+ $(hide) if cmp -s $@.tmp $@ ; then \
+ rm $@.tmp ; \
+ else \
+ mv $@.tmp $@ ; \
+ fi
+else
+ mv $@.tmp $@ ;
+endif
+
+# Kati adds restat=1 to ninja. GNU make does nothing for this.
+.KATI_RESTAT: $(export_includes)
# Make sure export_includes gets generated when you are running mm/mmm
$(LOCAL_BUILT_MODULE) : | $(export_includes)
