build: avoid rebuilds of unset VARIANT packages

If a Makefile defines some packages with VARIANT set, and others without
it, the latter will be built once for every different VARIANT set, each
build trumping the previous one.

Avoid rebuilds by only building unnamed variant packages when the first
variant is built.

Signed-off-by: Eneas U de Queiroz <[email protected]>

include/package-bin.mk

@@ -4,7 +4,8 @@
 
 ifeq ($(DUMP),)
   define BuildTarget/bin
-    ifeq ($(if $(VARIANT),$(BUILD_VARIANT)),$(VARIANT))
+    TARGET_VARIANT=$(if $(ALL_VARIANTS),$(if $(VARIANT),$(VARIANT),$(firstword $(ALL_VARIANTS))))
+    ifeq ($(if $(TARGET_VARIANT),$(BUILD_VARIANT)),$(TARGET_VARIANT))
     ifdef Package/$(1)/install
       ifneq ($(CONFIG_PACKAGE_$(1))$(DEVELOPER),)
         $(_pkg_target)compile: $(PKG_BUILD_DIR)/.pkgdir/$(1).installed

include/package-ipkg.mk

@@ -105,7 +105,8 @@ ifeq ($(DUMP),)
     IDIR_$(1):=$(PKG_BUILD_DIR)/ipkg-$(PKGARCH)/$(1)
     KEEP_$(1):=$(strip $(call Package/$(1)/conffiles))
 
-    ifeq ($(BUILD_VARIANT),$$(if $$(VARIANT),$$(VARIANT),$(BUILD_VARIANT)))
+    TARGET_VARIANT:=$$(if $(ALL_VARIANTS),$$(if $$(VARIANT),$$(VARIANT),$(firstword $(ALL_VARIANTS))))
+    ifeq ($(BUILD_VARIANT),$$(if $$(TARGET_VARIANT),$$(TARGET_VARIANT),$(BUILD_VARIANT)))
     do_install=
     ifdef Package/$(1)/install
       do_install=yes

include/subdir.mk

@@ -29,12 +29,14 @@ diralias=$(if $(findstring $(1),$(call lastdir,$(1))),,$(call lastdir,$(1)))
 subdir_make_opts = \
 	-r -C $(1) \
 		BUILD_SUBDIR="$(1)" \
-		BUILD_VARIANT="$(4)"
+		BUILD_VARIANT="$(4)" \
+		ALL_VARIANTS="$(5)"
 
 # 1: subdir
 # 2: target
 # 3: build type
 # 4: build variant
+# 5: all variants
 log_make = \
 	 $(if $(call debug,$(1),v),,@)+ \
 	 $(if $(BUILD_LOG), \
@@ -62,15 +64,15 @@ define subdir
     $(foreach target,$(SUBTARGETS) $($(1)/subtargets),
       $(foreach btype,$(buildtypes-$(bd)),
         $(call warn_eval,$(1)/$(bd),t,T,$(1)/$(bd)/$(btype)/$(target): $(if $(NO_DEPS)$(QUILT),,$($(1)/$(bd)/$(btype)/$(target)) $(call $(1)//$(btype)/$(target),$(1)/$(bd)/$(btype))))
-		  $(call log_make,$(1)/$(bd),$(target),$(btype),$(filter-out __default,$(variant))) \
+		  $(call log_make,$(1)/$(bd),$(target),$(btype),$(filter-out __default,$(variant)),$($(1)/$(bd)/variants)) \
 			|| $(call ERROR,$(2),   ERROR: $(1)/$(bd) [$(btype)] failed to build.,$(findstring $(bd),$($(1)/builddirs-ignore-$(btype)-$(target))))
         $(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 $(NO_DEPS)$(QUILT),,$($(1)/$(bd)/$(target)) $(call $(1)//$(target),$(1)/$(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),@mkdir -p $(BUILD_LOG_DIR)/$(1)/$(bd)/$(filter-out __default,$(variant)))
-			$(if $($(1)/autoremove),$(call rebuild_check,$(1)/$(bd),$(target),,$(filter-out __default,$(variant))))
-			$(call log_make,$(1)/$(bd),$(target),,$(filter-out __default,$(variant))) \
+			$(if $($(1)/autoremove),$(call rebuild_check,$(1)/$(bd),$(target),,$(filter-out __default,$(variant)),$($(1)/$(bd)/variants)))
+			$(call log_make,$(1)/$(bd),$(target),,$(filter-out __default,$(variant)),$($(1)/$(bd)/variants)) \
 				|| $(call ERROR,$(1),   ERROR: $(1)/$(bd) failed to build$(if $(filter-out __default,$(variant)), (build variant: $(variant))).,$(findstring $(bd),$($(1)/builddirs-ignore-$(target)))) 
         )
       $(if $(PREREQ_ONLY)$(DUMP_TARGET_DB),,