mark platform un-availability

A module is marked unavailable for platform when 1) it does not have
"//apex_available:platform" in its apex_available property, or 2)
it depends on another module that is unavailable for platform.

In that case, LOCAL_NOT_AVAILABLE_FOR_PLATFORM is set to true for the
module in the Make world. Later, that flag is used to ensure that there
is no module with the flag is installed to the device.

The reason why this isn't entirely done in Soong is because Soong
doesn't know if a module will be installed to the device or not. To
explain this, let's have an example.

cc_test { name: "mytest", static_libs: ["libfoo"]}
cc_library_static { name: "libfoo", static_libs: ["libbar"]}
cc_library { name: "libbar", apex_available: ["com.android.xxx"]}

Here, libbar is not available for platform, but is used by libfoo which
is available for platform (apex_available defaults to
"//apex_available:platform"). libfoo is again depended on by mytest
which again is available for platform. The use of libbar should be
allowed in the context of test; we don't want to make libbar available
to platform just for the dependency from test because it will allow
non-test uses of the library as well.

Soong by itself can't tell whether libfoo and libbar are used only in the
context of a test. There could be another module depending them, e.g.,

cc_library_shared { name: "mylib", static_libs: ["libfoo"] }

can exist and it might be installed to the device, in which case
we really should trigger an error.

Since Make has the knowledge of what's installed and what's not,
the check should be done there.

Bug: 153073816
Test: m

Change-Id: I14ddf0e5700d0a7bf60e4e41536efbd26ab5ed3d

core/base_rules.mk

@@ -805,6 +805,16 @@ ifdef LOCAL_PICKUP_FILES
 ALL_MODULES.$(my_register_name).PICKUP_FILES := \
     $(ALL_MODULES.$(my_register_name).PICKUP_FILES) $(LOCAL_PICKUP_FILES)
 endif
+# Record the platform availability of this module. Note that the availability is not
+# meaningful for non-installable modules (e.g., static libs) or host modules.
+# We only care about modules that are installable to the device.
+ifeq (true,$(LOCAL_NOT_AVAILABLE_FOR_PLATFORM))
+  ifneq (true,$(LOCAL_UNINSTALLABLE_MODULE))
+    ifndef LOCAL_IS_HOST_MODULE
+      ALL_MODULES.$(my_register_name).NOT_AVAILABLE_FOR_PLATFORM := true
+    endif
+  endif
+endif
 
 my_required_modules := $(LOCAL_REQUIRED_MODULES) \
     $(LOCAL_REQUIRED_MODULES_$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH))

core/clear_vars.mk

@@ -192,6 +192,7 @@ LOCAL_NO_PIC:=
 LOCAL_NOSANITIZE:=
 LOCAL_NO_STANDARD_LIBRARIES:=
 LOCAL_NO_STATIC_ANALYZER:=
+LOCAL_NOT_AVAILABLE_FOR_PLATFORM:=
 LOCAL_NOTICE_FILE:=
 LOCAL_ODM_MODULE:=
 LOCAL_OEM_MODULE:=

core/tasks/platform_availability_check.mk

@@ -0,0 +1,36 @@
+#
+# Copyright (C) 2020 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.
+#
+
+# Check whether there is any module that isn't available for platform
+# is installed to the platform.
+
+# Filter FAKE and NON_INSTALLABLE modules out and then collect those are not
+# available for platform
+_modules_not_available_for_platform := \
+$(strip $(foreach m,$(product_MODULES),\
+  $(if $(filter-out FAKE,$(ALL_MODULES.$(m).CLASS)),\
+    $(if $(ALL_MODULES.$(m).INSTALLED),\
+      $(if $(filter true,$(ALL_MODULES.$(m).NOT_AVAILABLE_FOR_PLATFORM)),\
+        $(m))))))
+
+_violators_with_path := $(foreach m,$(sort $(_modules_not_available_for_platform)),\
+    $(m):$(word 1,$(ALL_MODULES.$(m).PATH))\
+)
+
+$(call maybe-print-list-and-error,$(_violators_with_path),\
+Following modules are requested to be installed. But are not available \
+for platform because they do not have "//apex_available:platform" or \
+they depend on other modules that are not available for platform)