Integrate Starlark-based configuration runner

If RBC_PRODUCT_CONFIG variable is set, obtain product configuration
variables by converting product configuration makefiles to Starlark
files and then executing them.
Also, introduce RBC_NO_PRODUCT_GRAPH variable to suppress product graph
generation. We cannot generate product graph with Starlark, so this
option allows to verify that the rest of the contents of the generated
Ninja files remains the same when Starlark-based converter is used.
This allows to perform the regression testing, i.e. running
`RBC_NO_PRODUCT_GRAPH=t DISABLE_ARTIFACT_PATH_REQUIREMENTS=t m nothing`
and
`RBC_PRODUCT_CONFIG=t m nothing`
should generate identical *.ninja files.

Bug: 181797530
Test: Manual
Change-Id: Ic6173a9640f32766b71c02a2b1833ce7a278e4cc
diff --git a/core/main.mk b/core/main.mk
index 8b75931..e0fb58d 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -1242,14 +1242,43 @@
 # Name resolution for LOCAL_REQUIRED_MODULES:
 #   See the select-bitness-of-required-modules definition.
 # $(1): product makefile
+
+# TODO(asmundak):
+# `product-installed-files` and `host-installed-files` macros below used to
+# call `get-product-var` directly to obtain per-file configuration variable
+# values (the value of variable FOO is fetched from PRODUCT.<product-makefile>.FOO).
+# Starlark-based configuration does not maintain per-file variable variable
+# values. To work around this problem, we utilize the fact that
+# `product-installed-files` and `host-installed-files` are called only in
+# two places:
+# 1. For the top-level product makefile (in this file). In this case
+#    $(call get-product-var <product>, FOO) is the same as $(FOO) as the
+#    product configuration has been run already. Therefore we define
+#    _product-var macro to pick the values directly from product config
+#    variables when using Starlark-based configuration.
+# 2. To check the path requirements (in artifact_path_requirements.mk).
+#    Starlark-based configuration does not perform this check at the moment.
+# In the longer run most of the logic of this file will be moved to the
+# Starlark.
+
+ifndef RBC_PRODUCT_CONFIG
+define _product-var
+  $(call get-product-var,$(1),$(2))
+endef
+else
+define _product-var
+  $(call $(2))
+endef
+endif
+
 define product-installed-files
   $(eval _pif_modules := \
-    $(call get-product-var,$(1),PRODUCT_PACKAGES) \
-    $(if $(filter eng,$(tags_to_install)),$(call get-product-var,$(1),PRODUCT_PACKAGES_ENG)) \
-    $(if $(filter debug,$(tags_to_install)),$(call get-product-var,$(1),PRODUCT_PACKAGES_DEBUG)) \
-    $(if $(filter tests,$(tags_to_install)),$(call get-product-var,$(1),PRODUCT_PACKAGES_TESTS)) \
-    $(if $(filter asan,$(tags_to_install)),$(call get-product-var,$(1),PRODUCT_PACKAGES_DEBUG_ASAN)) \
-    $(if $(filter java_coverage,$(tags_to_install)),$(call get-product-var,$(1),PRODUCT_PACKAGES_DEBUG_JAVA_COVERAGE)) \
+    $(call _product-var,$(1),PRODUCT_PACKAGES) \
+    $(if $(filter eng,$(tags_to_install)),$(call _product-var,$(1),PRODUCT_PACKAGES_ENG)) \
+    $(if $(filter debug,$(tags_to_install)),$(call _product-var,$(1),PRODUCT_PACKAGES_DEBUG)) \
+    $(if $(filter tests,$(tags_to_install)),$(call _product-var,$(1),PRODUCT_PACKAGES_TESTS)) \
+    $(if $(filter asan,$(tags_to_install)),$(call _product-var,$(1),PRODUCT_PACKAGES_DEBUG_ASAN)) \
+    $(if $(filter java_coverage,$(tags_to_install)),$(call _product-var,$(1),PRODUCT_PACKAGES_DEBUG_JAVA_COVERAGE)) \
     $(call auto-included-modules) \
   ) \
   $(eval ### Filter out the overridden packages and executables before doing expansion) \
@@ -1260,13 +1289,13 @@
   $(call expand-required-modules,_pif_modules,$(_pif_modules),$(_pif_overrides)) \
   $(filter-out $(HOST_OUT_ROOT)/%,$(call module-installed-files, $(_pif_modules))) \
   $(call resolve-product-relative-paths,\
-    $(foreach cf,$(call get-product-var,$(1),PRODUCT_COPY_FILES),$(call word-colon,2,$(cf))))
+    $(foreach cf,$(call _product-var,$(1),PRODUCT_COPY_FILES),$(call word-colon,2,$(cf))))
 endef
 
 # Similar to product-installed-files above, but handles PRODUCT_HOST_PACKAGES instead
 # This does support the :32 / :64 syntax, but does not support module overrides.
 define host-installed-files
-  $(eval _hif_modules := $(call get-product-var,$(1),PRODUCT_HOST_PACKAGES)) \
+  $(eval _hif_modules := $(call _product-var,$(1),PRODUCT_HOST_PACKAGES)) \
   $(eval ### Split host vs host cross modules) \
   $(eval _hcif_modules := $(filter host_cross_%,$(_hif_modules))) \
   $(eval _hif_modules := $(filter-out host_cross_%,$(_hif_modules))) \
@@ -1351,7 +1380,7 @@
 
   # Verify the artifact path requirements made by included products.
   is_asan := $(if $(filter address,$(SANITIZE_TARGET)),true)
-  ifneq (true,$(or $(is_asan),$(DISABLE_ARTIFACT_PATH_REQUIREMENTS)))
+  ifeq (,$(or $(is_asan),$(DISABLE_ARTIFACT_PATH_REQUIREMENTS),$(RBC_PRODUCT_CONFIG)))
     include $(BUILD_SYSTEM)/artifact_path_requirements.mk
   endif
 else
diff --git a/core/product-graph.mk b/core/product-graph.mk
index 968d01b..de4e581 100644
--- a/core/product-graph.mk
+++ b/core/product-graph.mk
@@ -81,6 +81,7 @@
 $(products_graph): PRIVATE_PRODUCTS_FILTER := $(products_list)
 
 $(products_graph): $(this_makefile)
+ifeq (,$(RBC_PRODUCT_CONFIG)$(RBC_NO_PRODUCT_GRAPH))
 	@echo Product graph DOT: $@ for $(PRIVATE_PRODUCTS_FILTER)
 	$(hide) echo 'digraph {' > $@.in
 	$(hide) echo 'graph [ ratio=.5 ];' >> $@.in
@@ -89,6 +90,10 @@
 	$(foreach p,$(PRIVATE_PRODUCTS),$(call emit-product-node-props,$(p),$@.in))
 	$(hide) echo '}' >> $@.in
 	$(hide) build/make/tools/filter-product-graph.py $(PRIVATE_PRODUCTS_FILTER) < $@.in > $@
+else
+	@echo RBC_PRODUCT_CONFIG and RBC_NO_PRODUCT_GRAPH should be unset to generate product graph
+	false
+endif
 
 # Evaluates to the name of the product file
 # $(1) product file
@@ -143,6 +148,7 @@
 	$(hide) cat $$< | build/make/tools/product_debug.py > $$@
 endef
 
+ifeq (,$(RBC_PRODUCT_CONFIG)$(RBC_NO_PRODUCT_GRAPH))
 product_debug_files:=
 $(foreach p,$(all_products), \
 			$(eval $(call transform-product-debug, $(p))) \
@@ -154,3 +160,8 @@
 	@echo Product graph .dot file: $(products_graph)
 	@echo Command to convert to pdf: dot -Tpdf -Nshape=box -o $(OUT_DIR)/products.pdf $(products_graph)
 	@echo Command to convert to svg: dot -Tsvg -Nshape=box -o $(OUT_DIR)/products.svg $(products_graph)
+else
+.PHONY: product-graph
+	@echo RBC_PRODUCT_CONFIG and RBC_NO_PRODUCT_GRAPH should be unset to generate product graph
+	false
+endif
\ No newline at end of file
diff --git a/core/product_config.mk b/core/product_config.mk
index 99ff8aa..403c6be 100644
--- a/core/product_config.mk
+++ b/core/product_config.mk
@@ -172,11 +172,24 @@
 ifneq (1,$(words $(current_product_makefile)))
 $(error Product "$(TARGET_PRODUCT)" ambiguous: matches $(current_product_makefile))
 endif
+
+ifndef RBC_PRODUCT_CONFIG
 $(call import-products, $(current_product_makefile))
+else
+  rbcscript=build/soong/scripts/rbc-run
+  rc := $(shell $(rbcscript) $(TARGET_PRODUCT)-$(TARGET_BUILD_VARIANT) >$(OUT_DIR)/rbctemp.mk || echo $$?)
+  ifneq (,$(rc))
+    $(error product configuration converter failed: $(rc))
+  endif
+  include $(OUT_DIR)/rbctemp.mk
+  PRODUCTS += $(current_product_makefile)
+endif
 endif  # Import all or just the current product makefile
 
+ifndef RBC_PRODUCT_CONFIG
 # Quick check
 $(check-all-products)
+endif
 
 ifeq ($(SKIP_ARTIFACT_PATH_REQUIREMENT_PRODUCTS_CHECK),)
 # Import all the products that have made artifact path requirements, so that we can verify
@@ -196,6 +209,7 @@
 $(dump-products)
 endif
 
+ifndef RBC_PRODUCT_CONFIG
 # Convert a short name like "sooner" into the path to the product
 # file defining that product.
 #
@@ -208,6 +222,9 @@
 ############################################################################
 # Strip and assign the PRODUCT_ variables.
 $(call strip-product-vars)
+else
+INTERNAL_PRODUCT := $(current_product_makefile)
+endif
 
 current_product_makefile :=
 all_product_makefiles :=