build: use a conditional @ sign before silenced targets instead of .SILENT - makes prereq checks more than twice as fast

SVN-Revision: 26435

include/subdir.mk

@@ -29,16 +29,14 @@ define subdir
     $(foreach target,$(SUBTARGETS),
       $(foreach btype,$(buildtypes-$(bd)),
         $(call warn_eval,$(1)/$(bd),t,T,$(1)/$(bd)/$(btype)/$(target): $(if $(QUILT),,$($(1)/$(bd)/$(btype)/$(target)) $(call $(1)//$(btype)/$(target),$(1)/$(bd)/$(btype))))
-		  +$$(SUBMAKE) -C $(1)/$(bd) $(btype)-$(target) $(if $(findstring $(bd),$($(1)/builddirs-ignore-$(btype)-$(target))), || $(call MESSAGE,   ERROR: $(1)/$(bd) [$(btype)] failed to build.))
-        $$(if $(call debug,$(1)/$(bd),v),,.SILENT: $(1)/$(bd)/$(btype)/$(target))
+		  $(if $(call debug,$(1)/$(bd),v),,@)+$$(SUBMAKE) -C $(1)/$(bd) $(btype)-$(target) $(if $(findstring $(bd),$($(1)/builddirs-ignore-$(btype)-$(target))), || $(call MESSAGE,   ERROR: $(1)/$(bd) [$(btype)] failed to build.))
         $(if $(call diralias,$(bd)),$(call warn_eval,$(1)/$(bd),l,T,$(1)/$(call diralias,$(bd))/$(btype)/$(target): $(1)/$(bd)/$(btype)/$(target)))
       )
       $(call warn_eval,$(1)/$(bd),t,T,$(1)/$(bd)/$(target): $(if $(QUILT),,$($(1)/$(bd)/$(target)) $(call $(1)//$(target),$(1)/$(bd))))
 	  	$(if $(BUILD_LOG),@mkdir -p $(BUILD_LOG_DIR)/$(1)/$(bd))
         $(foreach variant,$(if $(BUILD_VARIANT),$(BUILD_VARIANT),$(if $(strip $($(1)/$(bd)/variants)),$($(1)/$(bd)/variants),$(if $($(1)/$(bd)/default-variant),$($(1)/$(bd)/default-variant),__default))),
-			+$(if $(BUILD_LOG),set -o pipefail;) $$(SUBMAKE) -C $(1)/$(bd) $(target) BUILD_VARIANT="$(filter-out __default,$(variant))" $(if $(BUILD_LOG),SILENT= 2>&1 | tee $(BUILD_LOG_DIR)/$(1)/$(bd)/$(target).txt) $(if $(findstring $(bd),$($(1)/builddirs-ignore-$(target))), || $(call MESSAGE,   ERROR: $(1)/$(bd) failed to build$(if $(filter-out __default,$(variant)), (build variant: $(variant))).))
+			$(if $(call debug,$(1)/$(bd),v),,@)+$(if $(BUILD_LOG),set -o pipefail;) $$(SUBMAKE) -C $(1)/$(bd) $(target) BUILD_VARIANT="$(filter-out __default,$(variant))" $(if $(BUILD_LOG),SILENT= 2>&1 | tee $(BUILD_LOG_DIR)/$(1)/$(bd)/$(target).txt) $(if $(findstring $(bd),$($(1)/builddirs-ignore-$(target))), || $(call MESSAGE,   ERROR: $(1)/$(bd) failed to build$(if $(filter-out __default,$(variant)), (build variant: $(variant))).))
         )
-        $$(if $(call debug,$(1)/$(bd),v),,.SILENT: $(1)/$(bd)/$(target))
       $(if $(DUMP_TARGET_DB),,
         # legacy targets
         $(call warn_eval,$(1)/$(bd),l,T,$(1)/$(bd)-$(target): $(1)/$(bd)/$(target))