Only copy headers to release dir if contents changed

makefile

@@ -1053,7 +1053,8 @@ $(CORE.incdirs): _release_c_h
 
 define .release.dd
 $3: $2
-$2: $1 ; $(value mkdir)$(value cpy)
+$2: $1 ; $(value mkdir)
+	@if [ ! -f $2 ] || ! cmp -s $1 $2; then $(value cpy); fi
 	$(if $(filter %library_version_info.h,$2),+$(daalmake) -f makefile update_headers_version)
 	$(if $(USECPUS.out.defs.filter),$(if $(filter %daal_kernel_defines.h,$2),$(USECPUS.out.defs.filter) $2; rm -rf $(subst .h,.h.bak,$2)))
 endef

makefile.ver

@@ -59,11 +59,20 @@ $(VERSION_DATA_FILE): | $(WORKDIR)/.
 	@bash -c 'echo "$$DAAL_VERSION_DATA"' > $@
 
 # update public headers in release directory with actual version data
+# copy file only if the result is different from the previous run
+# to avoid interference with incremental builds
 update_headers_version:
-	@file=$(RELEASEDIR.include)/services/library_version_info.h && mark="#define __INTEL_DAAL" && \
-	sed $(sed.-b) $(sed.-i) -e "s/_DAAL_BUILD_DATE.*/_DAAL_BUILD_DATE $(BUILD)$(sed.eol)/" \
-		-e "s/\($${mark}__\).*/\1 $(MAJOR)$(sed.eol)/;s/\($${mark}_MINOR__\).*/\1 $(MINOR)$(sed.eol)/" \
-		-e "s/\($${mark}_MAJOR_BINARY__\).*/\1 $(MAJORBINARY)$(sed.eol)/;s/\($${mark}_MINOR_BINARY__\).*/\1 $(MINORBINARY)$(sed.eol)/" \
-		-e "s/\($${mark}_UPDATE__\).*/\1 $(UPDATE)$(sed.eol)/" \
-		-e "s/\($${mark}_STATUS__\).*/\1 \"$(STATUS)\"$(sed.eol)/" $$file && \
-        rm -f $$file.bak
+    @file=$(RELEASEDIR.include)/services/library_version_info.h && \
+    tempfile=$${file}.tmp && \
+    mark="#define __INTEL_DAAL" && \
+    sed $(sed.-b) $(sed.-i) -e "s/_DAAL_BUILD_DATE.*/_DAAL_BUILD_DATE $(BUILD)$(sed.eol)/" \
+        -e "s/\($${mark}__\).*/\1 $(MAJOR)$(sed.eol)/;s/\($${mark}_MINOR__\).*/\1 $(MINOR)$(sed.eol)/" \
+        -e "s/\($${mark}_MAJOR_BINARY__\).*/\1 $(MAJORBINARY)$(sed.eol)/;s/\($${mark}_MINOR_BINARY__\).*/\1 $(MINORBINARY)$(sed.eol)/" \
+        -e "s/\($${mark}_UPDATE__\).*/\1 $(UPDATE)$(sed.eol)/" \
+        -e "s/\($${mark}_STATUS__\).*/\1 \"$(STATUS)\"$(sed.eol)/" $$file > $$tempfile && \
+    if [ ! -f $$file ] || ! cmp -s $$tempfile $$file; then \
+        # echo "Updating $$file with new version data."; \
+        mv $$tempfile $$file; \
+    else \
+        rm $$tempfile; \
+    fi