Merge "cfgtree.mk: file-based configuration" into mnc-brillo-devbrillo-m7-releasebrillo-m7-dev

2 files changed, 80 insertions, 0 deletions

diff --git a/brillo_base.mk b/brillo_base.mk
index e7e27bf..3101c59 100644
--- a/brillo_base.mk
+++ b/brillo_base.mk
@@ -34,6 +34,9 @@ OSRELEASED_DIRECTORY := os-release.d
 PRODUCT_COPY_FILES += \
   tools/bdk/VERSION:system/etc/$(OSRELEASED_DIRECTORY)/bdk_version
 
+# Include the cfgtree helpers for loading config values from disk.
+include device/generic/brillo/cfgtree.mk
+
 # Skip API checks.
 WITHOUT_CHECK_API := true
 # Don't try to build and run all tests by default. Several tests have
@@ -318,10 +321,16 @@ define generate-initrc-file
 endef
 
 # Called from the product makefile, it sets any derived defaults.
+# DEPRECATED
 define set-product-defaults
   $(eval PRODUCT_NAME := $$(basename $$(notdir \
     $$(filter $$(LOCAL_PATH)/%.mk,$$(MAKEFILE_LIST)))))
 endef
+# Returns the product name as guessed from the calling file.
+define get_product_name_from_file
+$(firstword $(basename $(notdir \
+  $(filter $(LOCAL_PATH)/%.mk,$(MAKEFILE_LIST)))))
+endef
 
 HARDWARE_BSP_PREFIX := hardware/bsp
 HARDWARE_BSP_PREBUILTS_PREFIX := vendor/bsp
diff --git a/cfgtree.mk b/cfgtree.mk
new file mode 100644
index 0000000..dea3943
--- /dev/null
+++ b/cfgtree.mk
@@ -0,0 +1,71 @@
+#
+# Copyright (C) 2015 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# This file provides a helper which loads the contents of a given file
+# relative to a common root path.  The helper ensures there is consistent
+# path resolution for loading and error messaging for missing or empty
+# files that are required.
+#
+# The primary usage of this file is for loading product-level configuration
+# from plaintext files. An example usage in a makefile is:
+#    BRILLO_CRASH_SERVER := $(call cfgtree_get,brillo/crash_server,required)
+#
+# Note the use of an immediate assignment. If any other variable assignment is
+# used, be sure to test that it resolves as and when expected.
+#
+# Populating the file is as simple as:
+#    cd $PRODUCT_DIR
+#    mkdir -p config/brillo
+#    echo https://some.server/handle/crash.cgi > config/brillo/crash_server
+#
+# Any lines beginning with '#' will be ignored, but if a '#' is required, it
+# can be inserted by simply starting the line with a space which will be
+# stripped off during the loading process.
+#
+# Note, there is no central mapping of variables to files. If any files will
+# be used from different contexts, be sure to keep all users in sync.
+#
+# For any PRODUCT_* variable set using this mechanism, it is possible to
+# verify a correct assignment by calling:
+#
+#   m dump-products
+#
+
+# Path to load from
+CFGTREE_ROOT ?= $(LOCAL_PATH)
+CFGTREE_PREFIX ?= config
+CFGTREE_PATH := $(CFGTREE_ROOT)/$(CFGTREE_PREFIX)
+
+# Command to run to dump the file content.
+CFGTREE_CMD ?= grep -v -e '^$(shell printf '\043')'
+
+# $(1) is the file to load from cfgtree
+#
+# Returns the output of $(CFGTREE_CMD) $(1)/$(2) if the file exists.
+# Normally, this is all the text excluding lines starting with '#'.
+#
+define cfgtree-get
+$(strip \
+  $(if $(filter 0,$(words $(call cfgtree-get-if-exists,$(1)))),\
+    $(error Required configuration file \
+            $(CFGTREE_PREFIX)/$(1) is empty or missing.),\
+    $(call cfgtree-get-if-exists,$(1)))\
+)
+endef
+
+define cfgtree-get-if-exists
+$(strip $(shell $(CFGTREE_CMD) $(CFGTREE_PATH)/$(1) 2>/dev/null))
+endef