Build apps/* only once

Replicating the behavior for deps/*.

With refactoring from Loïc.

core/core.mk

@@ -12,7 +12,7 @@
 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 # OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
-.PHONY: all app deps search rel docs install-docs check tests clean distclean help erlang-mk
+.PHONY: all app apps deps search rel docs install-docs check tests clean distclean help erlang-mk
 
 ERLANG_MK_FILENAME := $(realpath $(lastword $(MAKEFILE_LIST)))
 

core/deps.mk

@@ -48,19 +48,35 @@ dep_verbose = $(dep_verbose_$(V))
 
 # Core targets.
 
-ifneq ($(SKIP_DEPS),)
-deps::
+ifdef IS_APP
+apps::
 else
-deps:: $(ALL_DEPS_DIRS)
-ifndef IS_APP
+apps:: $(ALL_APPS_DIRS)
+ifeq ($(IS_APP)$(IS_DEP),)
+	$(verbose) rm -f $(ERLANG_MK_TMP)/apps.log
+endif
+	$(verbose) mkdir -p $(ERLANG_MK_TMP)
+# Create ebin directory for all apps to make sure Erlang recognizes them
+# as proper OTP applications when using -include_lib. This is a temporary
+# fix, a proper fix would be to compile apps/* in the right order.
 	$(verbose) for dep in $(ALL_APPS_DIRS) ; do \
-		mkdir -p $$dep/ebin; \
+		mkdir -p $$dep/ebin || exit $$?; \
 	done
 	$(verbose) for dep in $(ALL_APPS_DIRS) ; do \
-		$(MAKE) -C $$dep IS_APP=1 || exit $$?; \
+		if grep -qs ^$$dep$$ $(ERLANG_MK_TMP)/apps.log; then \
+			:; \
+		else \
+			echo $$dep >> $(ERLANG_MK_TMP)/apps.log; \
+			$(MAKE) -C $$dep IS_APP=1 || exit $$?; \
+		fi \
 	done
 endif
-ifneq ($(IS_DEP),1)
+
+ifneq ($(SKIP_DEPS),)
+deps::
+else
+deps:: $(ALL_DEPS_DIRS) apps
+ifeq ($(IS_APP)$(IS_DEP),)
 	$(verbose) rm -f $(ERLANG_MK_TMP)/deps.log
 endif
 	$(verbose) mkdir -p $(ERLANG_MK_TMP)

test/core_deps.mk

@@ -1,6 +1,6 @@
 # Core: Packages and dependencies.
 
-CORE_DEPS_CASES = apps apps-conflict apps-deep-conflict apps-dir apps-dir-include-lib apps-new-app apps-new-lib apps-new-tpl apps-only autopatch-rebar build-c-8cc build-c-imagejs build-erl build-js dep-commit dir doc fetch-cp fetch-custom fetch-fail-bad fetch-fail-unknown fetch-git fetch-git-submodule fetch-hex fetch-hg fetch-legacy fetch-svn ignore mv mv-rebar no-autopatch no-autopatch-erlang-mk no-autopatch-rebar order-first order-top otp pkg rel search shell skip test
+CORE_DEPS_CASES = apps apps-build-count apps-conflict apps-deep-conflict apps-dir apps-dir-include-lib apps-new-app apps-new-lib apps-new-tpl apps-only autopatch-rebar build-c-8cc build-c-imagejs build-erl build-js dep-commit dir doc fetch-cp fetch-custom fetch-fail-bad fetch-fail-unknown fetch-git fetch-git-submodule fetch-hex fetch-hg fetch-legacy fetch-svn ignore mv mv-rebar no-autopatch no-autopatch-erlang-mk no-autopatch-rebar order-first order-top otp pkg rel search shell skip test
 CORE_DEPS_TARGETS = $(addprefix core-deps-,$(CORE_DEPS_CASES))
 
 .PHONY: core-deps $(CORE_DEPS_TARGETS)
@@ -101,6 +101,42 @@ endif
 		[{module, M} = code:load_file(M) || M <- Mods], \
 		halt()"
 
+core-deps-apps-build-count: build clean
+
+	$i "Bootstrap a new OTP library named $(APP)"
+	$t mkdir $(APP)/
+	$t cp ../erlang.mk $(APP)/
+	$t $(MAKE) -C $(APP) -f erlang.mk bootstrap-lib $v
+
+	$t mkdir -p "$(APP)/priv/dep"
+	$t echo "PROJECT = fake_dep" > $(APP)/priv/dep/Makefile
+	$t echo "include ../../erlang.mk" >> $(APP)/priv/dep/Makefile
+
+	$i "Bootstrap a repository-local application my_app"
+	$t echo "DEPS = dep1 dep2 dep3 dep4" > $(APP)/Makefile
+	$t echo "dep_dep1 = cp ./priv/dep" >> $(APP)/Makefile
+	$t echo "dep_dep2 = cp ./priv/dep" >> $(APP)/Makefile
+	$t echo "dep_dep3 = cp ./priv/dep" >> $(APP)/Makefile
+	$t echo "dep_dep4 = cp ./priv/dep" >> $(APP)/Makefile
+	$t echo "include erlang.mk" >> $(APP)/Makefile
+
+	$i "Create a new application app_one"
+	$t $(MAKE) -C $(APP) new-app in=app_one $v
+	$t echo "all::" >> $(APP)/apps/app_one/Makefile
+	$t echo "	@echo -n '#' >> count" >> $(APP)/apps/app_one/Makefile
+
+	$i "Create a new application app_two"
+	$t $(MAKE) -C $(APP) new-app in=app_two $v
+	$t echo "all::" >> $(APP)/apps/app_two/Makefile
+	$t echo "	@echo -n '#' >> count" >> $(APP)/apps/app_two/Makefile
+
+	$i "Build the application"
+	$t $(MAKE) -C $(APP) $v
+
+	$i "Check the number of times each app was compiled"
+	$t test "`wc -c $(APP)/apps/app_one/count | awk '{printf $$1}'`" -eq 1
+	$t test "`wc -c $(APP)/apps/app_two/count | awk '{printf $$1}'`" -eq 1
+
 core-deps-apps-conflict: build clean
 
 	$i "Bootstrap a new OTP library named $(APP)"