[openwrt/openwrt] build: avoid rebuilds of unset VARIANT packages

[LEDE Commits]

nbd pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/19aae949c608c8e78475988a8c7b453b8187d865

commit 19aae949c608c8e78475988a8c7b453b8187d865
Author: Eneas U de Queiroz <cotequeiroz at gmail.com>
AuthorDate: Fri Oct 22 16:12:10 2021 -0300

    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 <cotequeiroz at gmail.com>
---
 include/package-bin.mk  |  3 ++-
 include/package-ipkg.mk |  3 ++-
 include/subdir.mk       | 10 ++++++----
 3 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/include/package-bin.mk b/include/package-bin.mk
index 192f0726d2..77e603e420 100644
--- a/include/package-bin.mk
+++ b/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
diff --git a/include/package-ipkg.mk b/include/package-ipkg.mk
index 19f09c2311..bd50edb75f 100644
--- a/include/package-ipkg.mk
+++ b/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
diff --git a/include/subdir.mk b/include/subdir.mk
index be080859b7..d33b947fdf 100644
--- a/include/subdir.mk
+++ b/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), at 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),,