From 01454188e8df2de190c94e9c58a8fccef87d802e Mon Sep 17 00:00:00 2001
From: Leandro Lanzieri <leandro.lanzieri@haw-hamburg.de>
Date: Mon, 27 Jul 2020 17:52:48 +0200
Subject: [PATCH] Makefile.include: introduce TEST_KCONFIG switch

This switch allows to test the module dependency modelling during the
Kconfig migration. When set, it will use the symbols prefixed with
CONFIG_MOD_ defined by Kconfig as the list of modules to compile.
---
 Makefile.include     | 20 ++++++++++++++++----
 makefiles/kconfig.mk |  9 ++++++++-
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/Makefile.include b/Makefile.include
index 20dca49fa1..7cd2c30512 100644
--- a/Makefile.include
+++ b/Makefile.include
@@ -212,6 +212,11 @@ include $(RIOTMAKE)/scan-build.inc.mk
 
 export RIOTBUILD_CONFIG_HEADER_C = $(BINDIR)/riotbuild/riotbuild.h
 
+# When testing Kconfig's module modelling we need to run Kconfig
+ifeq (1,$(TEST_KCONFIG))
+  SHOULD_RUN_KCONFIG = 1
+endif
+
 # Include Kconfig functionalities
 include $(RIOTMAKE)/kconfig.mk
 
@@ -361,11 +366,18 @@ include $(RIOTBASE)/Makefile.features
 include $(RIOTMAKE)/pseudomodules.inc.mk
 include $(RIOTMAKE)/defaultmodules.inc.mk
 
-# handle removal of default modules
-USEMODULE += $(filter-out $(DISABLE_MODULE), $(DEFAULT_MODULE))
+# For testing, use TEST_KCONFIG as a switch between Makefile.dep and Kconfig
+ifeq (1,$(TEST_KCONFIG))
+  $(info === [ATTENTION] Testing Kconfig dependency modelling ===)
+  KCONFIG_MODULES := $(call lowercase,$(patsubst CONFIG_MOD_%,%,$(filter CONFIG_MOD_%,$(.VARIABLES))))
+  USEMODULE := $(KCONFIG_MODULES)
+else
+  # handle removal of default modules
+  USEMODULE += $(filter-out $(DISABLE_MODULE), $(DEFAULT_MODULE))
 
-# process dependencies
-include $(RIOTMAKE)/dependency_resolution.inc.mk
+  # process dependencies
+  include $(RIOTMAKE)/dependency_resolution.inc.mk
+endif
 
 # Include Board and CPU configuration
 INCLUDES += $(addprefix -I,$(wildcard $(BOARDDIR)/include))
diff --git a/makefiles/kconfig.mk b/makefiles/kconfig.mk
index 341ec45a0d..4c9b1c89f4 100644
--- a/makefiles/kconfig.mk
+++ b/makefiles/kconfig.mk
@@ -98,6 +98,12 @@ menuconfig: $(MENUCONFIG) $(KCONFIG_OUT_CONFIG)
 	$(Q)KCONFIG_CONFIG=$(KCONFIG_OUT_CONFIG) $(MENUCONFIG) $(KCONFIG)
 	$(MAKE) $(KCONFIG_GENERATED_AUTOCONF_HEADER_C)
 
+# Variable used to conditionally depend on KCONFIG_GENERATED_DEPDENDENCIES
+# When testing Kconfig module modelling this file is not needed
+ifneq (1, $(TEST_KCONFIG))
+  GENERATED_DEPENDENCIES_DEP = $(KCONFIG_GENERATED_DEPENDENCIES)
+endif
+
 # These rules are not included when only calling `make clean` in
 # order to keep the $(BINDIR) directory clean.
 ifneq (clean, $(MAKECMDGOALS))
@@ -106,6 +112,7 @@ ifneq (clean, $(MAKECMDGOALS))
 # defining symbols like 'MODULE_<MODULE_NAME>' or PKG_<PACKAGE_NAME> which
 # default to 'y'. Then, every module and package Kconfig menu will depend on
 # that symbol being set to show its options.
+# Do nothing when testing Kconfig module dependency modelling.
 $(KCONFIG_GENERATED_DEPENDENCIES): FORCE | $(GENERATED_DIR)
 	$(Q)printf "%s " $(USEMODULE_W_PREFIX) $(USEPKG_W_PREFIX) \
 	  | awk 'BEGIN {RS=" "}{ gsub("-", "_", $$0); \
@@ -115,7 +122,7 @@ $(KCONFIG_GENERATED_DEPENDENCIES): FORCE | $(GENERATED_DIR)
 # Generates a .config file by merging multiple sources specified in
 # MERGE_SOURCES. This will also generate KCONFIG_OUT_DEP with the list of used
 # Kconfig files.
-$(KCONFIG_OUT_CONFIG): $(KCONFIG_GENERATED_DEPENDENCIES) $(GENCONFIG) $(MERGE_SOURCES) | $(GENERATED_DIR)
+$(KCONFIG_OUT_CONFIG): $(GENERATED_DEPENDENCIES_DEP) $(GENCONFIG) $(MERGE_SOURCES) | $(GENERATED_DIR)
 	$(Q) $(GENCONFIG) \
 	  --config-out=$(KCONFIG_OUT_CONFIG) \
 	  --file-list $(KCONFIG_OUT_DEP) \