Add task to print transitive dependencies and their license files.

Print modules and their transitive dependencies with license files.
To invoke, run
"make deps-license PROJ_PATH=<proj-path-patterns> DEP_PATH=<dep-path-patterns>".
PROJ_PATH restricts the paths of the source modules;
DEP_PATH restricts the paths of the dependency modules.
Both can be makefile patterns supported by makefile function $(filter).
Example:
  $ make deps-license packages/app/% external/%
  prints all modules in packages/app/ with their dpendencies in external/.
The printout lines look like "<module_name> :: <module_paths> :: <license_files>".

Bug: 20823995
Change-Id: I06b66e85ff56c8628bffa3d948085ed45870100f
(cherry-pick from 39b9b690a824c82465fe0ac9b44a0c1f5e6ae13a)
diff --git a/core/base_rules.mk b/core/base_rules.mk
index 8c25897..afaf934 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -87,6 +87,7 @@
 # file, tag the module as "gnu".  Search for "*_GPL*", "*_LGPL*" and "*_MPL*"
 # so that we can also find files like MODULE_LICENSE_GPL_AND_AFL
 #
+license_files := $(call find-parent-file,$(LOCAL_PATH),MODULE_LICENSE*)
 gpl_license_file := $(call find-parent-file,$(LOCAL_PATH),MODULE_LICENSE*_GPL* MODULE_LICENSE*_MPL* MODULE_LICENSE*_LGPL*)
 ifneq ($(gpl_license_file),)
   my_module_tags += gnu
@@ -638,6 +639,21 @@
 
 INSTALLABLE_FILES.$(LOCAL_INSTALLED_MODULE).MODULE := $(my_register_name)
 
+##########################################################
+# Track module-level dependencies.
+# Use $(LOCAL_MODULE) instead of $(my_register_name) to ignore module's bitness.
+ALL_DEPS.MODULES := $(sort $(ALL_DEPS.MODULES) $(LOCAL_MODULE))
+ALL_DEPS.$(LOCAL_MODULE).ALL_DEPS := $(sort \
+  $(ALL_MODULES.$(LOCAL_MODULE).ALL_DEPS) \
+  $(LOCAL_STATIC_LIBRARIES) \
+  $(LOCAL_WHOLE_STATIC_LIBRARIES) \
+  $(LOCAL_SHARED_LIBRARIES) \
+  $(LOCAL_STATIC_JAVA_LIBRARIES) \
+  $(LOCAL_JAVA_LIBRARIES)\
+  $(LOCAL_JNI_SHARED_LIBRARIES))
+
+ALL_DEPS.$(LOCAL_MODULE).LICENSE := $(sort $(ALL_DEPS.$(LOCAL_MODULE).LICENSE) $(license_files))
+
 ###########################################################
 ## Take care of my_module_tags
 ###########################################################
diff --git a/core/tasks/deps_licenses.mk b/core/tasks/deps_licenses.mk
new file mode 100644
index 0000000..bb20fa0
--- /dev/null
+++ b/core/tasks/deps_licenses.mk
@@ -0,0 +1,59 @@
+#
+# 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.
+#
+
+# Print modules and their transitive dependencies with license files.
+# To invoke, run "make deps-license PROJ_PATH=<proj-path-patterns> DEP_PATH=<dep-path-patterns>".
+# PROJ_PATH restricts the paths of the source modules; DEP_PATH restricts the paths of the dependency modules.
+# Both can be makefile patterns supported by makefile function $(filter).
+# Example: "make deps-license packages/app/% external/%" prints all modules in packages/app/ with their dpendencies in external/.
+# The printout lines look like "<module_name> :: <module_paths> :: <license_files>".
+
+ifneq (,$(filter deps-license,$(MAKECMDGOALS)))
+ifndef PROJ_PATH
+$(error To "make deps-license" you must specify PROJ_PATH and DEP_PATH.)
+endif
+ifndef DEP_PATH
+$(error To "make deps-license" you must specify PROJ_PATH and DEP_PATH.)
+endif
+
+# Expand a module's dependencies transitively.
+# $(1): the variable name to hold the result.
+# $(2): the initial module name.
+define get-module-all-dependencies
+$(eval _gmad_new := $(sort $(filter-out $($(1)),\
+  $(foreach m,$(2),$(ALL_DEPS.$(m).ALL_DEPS)))))\
+$(if $(_gmad_new),$(eval $(1) += $(_gmad_new))\
+  $(call get-module-all-dependencies,$(1),$(_gmad_new)))
+endef
+
+define print-deps-license
+$(foreach m, $(ALL_DEPS.MODULES),\
+  $(eval m_p := $(sort $(ALL_MODULES.$(m).PATH) $(ALL_MODULES.$(m)$(TARGET_2ND_ARCH_MODULE_SUFFIX).PATH)))\
+  $(if $(filter $(PROJ_PATH),$(m_p)),\
+    $(eval deps :=)\
+    $(eval $(call get-module-all-dependencies,deps,$(m)))\
+    $(info $(m) :: $(m_p) :: $(ALL_DEPS.$(m).LICENSE))\
+    $(foreach d,$(deps),\
+      $(eval d_p := $(sort $(ALL_MODULES.$(d).PATH) $(ALL_MODULES.$(d)$(TARGET_2ND_ARCH_MODULE_SUFFIX).PATH)))\
+      $(if $(filter $(DEP_PATH),$(d_p)),\
+        $(info $(space)$(space)$(space)$(space)$(d) :: $(d_p) :: $(ALL_DEPS.$(d).LICENSE))))))
+endef
+
+.PHONY: deps-license
+deps-license:
+	@$(call print-deps-license)
+
+endif