From 19aae949c608c8e78475988a8c7b453b8187d865 Mon Sep 17 00:00:00 2001
From: Eneas U de Queiroz <cotequeiroz@gmail.com>
Date: Fri, 22 Oct 2021 16:12:10 -0300
Subject: [PATCH] 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@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 192f0726d20..77e603e4208 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 19f09c2311d..bd50edb75f7 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 be080859b79..d33b947fdf8 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),@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),,
-- 
2.30.2