makefiles: add FEATURES_OPTIONAL_ANY

dist/tools/buildsystem_sanity_check/check.sh

@@ -63,7 +63,9 @@ check_not_parsing_features() {
 
     patterns+=(-e 'if.*filter.*FEATURES_PROVIDED')
     patterns+=(-e 'if.*filter.*FEATURES_REQUIRED')
+    patterns+=(-e 'if.*filter.*FEATURES_REQUIRED_ANY')
     patterns+=(-e 'if.*filter.*FEATURES_OPTIONAL')
+    patterns+=(-e 'if.*filter.*FEATURES_OPTIONAL_ANY')
 
     # Pathspec with exclude should start by an inclusive pathspec in git 2.7.4
     pathspec+=('*')

doc/doxygen/src/build-system-basics.md

@@ -55,6 +55,11 @@ For a `FEATURE` to be provided by a `board` it must meet 2 criteria, and for
 - `FEATURES_OPTIONAL` are "nice to have" `FEATURES`, not needed but useful. If
   available they are always included.
 
+- `FEATURES_OPTIONAL_ANY` are nice to have `FEATURES` that fullfil a similar
+  function. Alternatives are separated by a pipe (`|`) in order of preference,
+  e.g.: `FEATURES_OPTIONAL_ANY += puf_sram|periph_hwrng` if both are provided
+  then only `puf_sram` will be used.
+
 - `FEATURES_REQUIRED_ANY` are `FEATURES` of which (at least) one of
   is needed by a `MODULE` or `APPLICATION`. Alternatives are separated by
   a pipe (`|`) in order of preference, e.g.:

makefiles/dependencies_debug.inc.mk

@@ -54,6 +54,7 @@ _DEPS_DEBUG_VARS += BOARD CPU CPU_MODEL CPU_FAM CPU_CORE CPU_ARCH
 _DEPS_DEBUG_VARS += FEATURES_PROVIDED _FEATURES_PROVIDED_SORTED
 _DEPS_DEBUG_VARS += FEATURES_REQUIRED _FEATURES_REQUIRED_SORTED
 _DEPS_DEBUG_VARS += FEATURES_REQUIRED_ANY _FEATURES_REQUIRED_ANY_SORTED
+_DEPS_DEBUG_VARS += FEATURES_OPTIONAL_ANY _FEATURES_OPTIONAL_ANY_SORTED
 _DEPS_DEBUG_VARS += FEATURES_OPTIONAL FEATURES_USED FEATURES_MISSING
 _DEPS_DEBUG_VARS += FEATURES_CONFLICT FEATURES_CONFLICTING
 _DEPS_DEBUG_VARS += USEMODULE DEFAULT_MODULE DISABLE_MODULE
@@ -62,6 +63,7 @@ DEPS_DEBUG_VARS ?= $(_DEPS_DEBUG_VARS)
 _FEATURES_PROVIDED_SORTED = $(sort $(FEATURES_PROVIDED))
 _FEATURES_REQUIRED_SORTED = $(sort $(FEATURES_REQUIRED))
 _FEATURES_REQUIRED_ANY_SORTED = $(sort $(FEATURES_REQUIRED_ANY))
+_FEATURES_OPTIONAL_ANY_SORTED = $(sort $(FEATURES_OPTIONAL_ANY))
 
 file_save_dependencies_variables = $(call file_save_variable,$(DEPENDENCY_DEBUG_OUTPUT_DIR)/$1_$(BOARD),$(DEPS_DEBUG_VARS))
 # Remove file before to be sure appending is started with an empty file

makefiles/features_check.inc.mk

@@ -1,40 +1,79 @@
 # Check if all required FEATURES are provided
 
-FEATURES_OPTIONAL_ONLY := $(sort $(filter-out $(FEATURES_REQUIRED),$(FEATURES_OPTIONAL)))
-FEATURES_OPTIONAL_USED := $(sort $(filter $(FEATURES_PROVIDED),$(FEATURES_OPTIONAL_ONLY)))
+# Receives a list of list of '|' separated features and resturns for each
+# item in list, the first match that is present in the whitelist.
+#
+# _features_one_out_of <features-list> <whitelist>
+#
+# Parameters
+#   features-list: list of list of '|' separated features
+#     e.g.: "periph_spi|periph_i2c puf_sram|periph_hwrng"
+#   whitelist: possible features to select one out of
+#     e.g.: "$(FEATURES_PROVIDED)"
+#
+# One out of Algorithm:
+#  - For each list in features-list as "item":
+#     - Store the intersection of features-whitelist and the features in
+#       "item" in "tmp"
+#     - Append "item" to "tmp" (with pipes between features, e.g.
+#       "periph_spi|periph_i2c")
+#     - Appends the first's element of "tmp" to the caller
+#   ==> If one (or more) features in whitelist is listed in item, the first
+#       one will be taken.
+#   ==> At the end of the list item itself (with pipes between features) is the
+#       last item in "tmp". If no feature in the feature-list is in whitelist
+#       this will be the only item in "tmp" and be picked
+_features_one_out_of = $(foreach item, $1, $(firstword \
+                          $(filter $2, $(subst |, ,$(item))) $(item)))
+
+# Features that are provided and not blacklisted
+FEATURES_USABLE := $(filter-out $(FEATURES_BLACKLIST),$(FEATURES_PROVIDED))
+
+# FEATURES_OPTIONAL that have not been required
+FEATURES_OPTIONAL_ONLY_SO_FAR := $(sort $(filter-out $(FEATURES_REQUIRED),\
+                                    $(FEATURES_OPTIONAL)))
+
+# Only add FEATURES that are usable
+FEATURES_OPTIONAL_USED_SO_FAR := $(sort $(filter $(FEATURES_USABLE),\
+                                    $(FEATURES_OPTIONAL_ONLY_SO_FAR)))
+
+# Additionally optional features due to the "one out of" dependencies,
+#   For each features list in $(FEATURES_OPTIONAL_ANY):
+#     ==> If one (or more) features is already added to OPTIONAL_USED
+#          then the firs of the used ones is returned
+#     ==> If one (or more) features is usable select the first one in list
+#     ==> If no feature is usable return the list
+FEATURES_OPTIONAL_ONE_OUT_OF := $(call _features_one_out_of,\
+                                  $(FEATURES_OPTIONAL_ANY),\
+                                    $(FEATURES_OPTIONAL_USED_SO_FAR) \
+                                    $(FEATURES_USABLE))
+
+# FEATURES_OPTIONAL that have not been required
+FEATURES_OPTIONAL_ONLY := $(sort $(filter-out $(FEATURES_REQUIRED),\
+                            $(FEATURES_OPTIONAL_ONE_OUT_OF) \
+                            $(FEATURES_OPTIONAL)))
+
+# Only add FEATURES that are usable
+FEATURES_OPTIONAL_USED := $(sort $(filter $(FEATURES_USABLE),\
+                                    $(FEATURES_OPTIONAL_ONLY)))
+
 # Optional features that will not be used because they are not provided
-FEATURES_OPTIONAL_MISSING := $(sort $(filter-out $(FEATURES_PROVIDED),$(FEATURES_OPTIONAL_ONLY)))
+FEATURES_OPTIONAL_MISSING := $(sort $(filter-out $(FEATURES_PROVIDED),\
+                              $(FEATURES_OPTIONAL_ONLY)))
 
 # Features that are used without taking "one out of" dependencies into account
 FEATURES_USED_SO_FAR := $(sort $(FEATURES_REQUIRED) $(FEATURES_OPTIONAL_USED))
 
-# Features that are provided and not blacklisted
-FEATURES_USABLE := $(filter-out $(FEATURES_BLACKLIST),$(FEATURES_PROVIDED))
-
 # Additionally required features due to the "one out of" dependencies
-# Algorithm:
-#  - For each list in FEATURES_REQUIRED_ANY as "item":
-#     - Store the intersection of FEATURES_USED_SO_FAR and the features in
-#       "item" in "tmp"
-#     - Append the intersection of FEATURES_USABLE and the features in "item"
-#       to "tmp"
-#     - Append "item" to "tmp" (with pipes between features, e.g.
-#       "periph_spi|periph_i2c")
-#     - Append the first element of "tmp" to FEATURES_REQUIRED_ONE_OUT_OF
-#   ==> If one (or more) already used features is listed in item, this (or
-#       one of these) will be in the front of "tmp" and be taken
-#   ==> If one (or more) usable features is listed in item, this will come
-#       afterwards. If no no feature in item is used so for, one of the
-#       features supported and listed in item will be picked
-#   ==> At the end of the list item itself (with pipes between features) is the
-#       last item in "tmp". If no feature is item is supported or used, this
-#       will be the only item in "tmp" and be picked
-FEATURES_REQUIRED_ONE_OUT_OF := $(foreach item,\
+#   For each features list in $(FEATURES_REQUIRED_ANY):
+#     ==> If one (or more) features is already used then the first one
+#         will be taken
+#     ==> If one (or more) features is usable select the first one in list
+#     ==> If no feature is usable return the list
+FEATURES_REQUIRED_ONE_OUT_OF := $(call _features_one_out_of,\
                                   $(FEATURES_REQUIRED_ANY),\
-                                  $(word 1,\
-                                    $(filter $(FEATURES_USED_SO_FAR) $(FEATURES_USABLE),\
-                                             $(subst |, ,$(item)))\
-                                    $(item)))
+                                  $(FEATURES_USED_SO_FAR) \
+                                    $(FEATURES_USABLE))
 
 # Features that are required by the application but not provided by the BSP
 # Having features missing may case the build to fail.

makefiles/info.inc.mk

@@ -60,6 +60,8 @@ info-build:
 	@echo '         $(or $(sort $(FEATURES_REQUIRED_ANY)), -none-)'
 	@echo 'FEATURES_OPTIONAL_ONLY (optional that are not required, strictly "nice to have"):'
 	@echo '         $(or $(FEATURES_OPTIONAL_ONLY), -none-)'
+	@echo 'FEATURES_OPTIONAL_ANY:'
+	@echo '         $(or $(sort $(FEATURES_OPTIONAL_ANY)), -none-)'
 	@echo 'FEATURES_OPTIONAL_MISSING (missing optional features):'
 	@echo '         $(or $(FEATURES_OPTIONAL_MISSING), -none-)'
 	@echo 'FEATURES_PROVIDED (by the board or USEMODULE'"'"'d drivers):'