From 893098b06c8755f9239d55efddb651a08b2b21ad Mon Sep 17 00:00:00 2001
From: Simran Basi <sbasi@google.com>
Date: Thu, 1 Feb 2018 19:48:59 -0800
Subject: [PATCH] LOCAL_HOST_REQUIRED_MODULES support

Allows target modules to directly request host modules they
require to be built and installed as well.

Bug: 72761631
Test: Added LOCAL_HOST_REQUIRED_MODULES to a target apk test and
      the host module was built.

Change-Id: I5aca11b3ba8b54676f068d337f1c9ba0e0b01997
---
 core/base_rules.mk |  3 +++
 core/clear_vars.mk |  1 +
 core/main.mk       | 25 +++++++++++++++++++++++++
 3 files changed, 29 insertions(+)

diff --git a/core/base_rules.mk b/core/base_rules.mk
index 3ff3bd3f2..bbcf20214 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -654,6 +654,9 @@ ALL_MODULES.$(my_register_name).EXPLICITLY_REQUIRED := \
 ALL_MODULES.$(my_register_name).TARGET_REQUIRED := \
     $(strip $(ALL_MODULES.$(my_register_name).TARGET_REQUIRED)\
         $(LOCAL_TARGET_REQUIRED_MODULES))
+ALL_MODULES.$(my_register_name).HOST_REQUIRED := \
+    $(strip $(ALL_MODULES.$(my_register_name).HOST_REQUIRED)\
+        $(LOCAL_HOST_REQUIRED_MODULES))
 ALL_MODULES.$(my_register_name).EVENT_LOG_TAGS := \
     $(ALL_MODULES.$(my_register_name).EVENT_LOG_TAGS) $(event_log_tags)
 ALL_MODULES.$(my_register_name).MAKEFILE := \
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index 7d3fa75d8..05e0d8e8e 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -98,6 +98,7 @@ LOCAL_GROUP_STATIC_LIBRARIES:=
 LOCAL_GTEST:=true
 LOCAL_HAL_STATIC_LIBRARIES:=
 LOCAL_HEADER_LIBRARIES:=
+LOCAL_HOST_REQUIRED_MODULES:=
 LOCAL_INIT_RC:=
 LOCAL_INSTALLED_MODULE:=
 LOCAL_INSTALLED_MODULE_STEM:=
diff --git a/core/main.mk b/core/main.mk
index 38e9bd1fd..4d4329583 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -610,6 +610,31 @@ $(foreach m,$(ALL_MODULES), \
 endef
 $(call add-all-host-to-target-required-modules-deps)
 
+# Sets up dependencies such that whenever a target module is installed,
+# any host modules listed in $(ALL_MODULES.$(m).HOST_REQUIRED) will also be installed
+define add-all-target-to-host-required-modules-deps
+$(foreach m,$(ALL_MODULES), \
+  $(eval req_mods := $(ALL_MODULES.$(m).HOST_REQUIRED))\
+  $(if $(req_mods), \
+    $(eval req_files := )\
+    $(foreach req_mod,$(req_mods), \
+      $(eval req_file := $(filter $(HOST_OUT)/%, $(call module-installed-files,$(req_mod)))) \
+      $(if $(strip $(req_file)),\
+        ,\
+        $(error $(m).LOCAL_HOST_REQUIRED_MODULES : illegal value $(req_mod) : not a host module. If you want to specify target modules to be required to be installed along with your target module, add those module names to LOCAL_REQUIRED_MODULES instead)\
+      )\
+      $(eval req_files := $(req_files)$(space)$(req_file))\
+    )\
+    $(eval req_files := $(strip $(req_files)))\
+    $(eval mod_files := $(filter $(TARGET_OUT_ROOT)/%, $(call module-installed-files,$(m))))\
+    $(eval mod_files := $(filter-out $(req_files),$(mod_files)))\
+    $(if $(mod_files),\
+      $(eval $(call add-required-deps, $(mod_files),$(req_files))) \
+    )\
+  )\
+)
+endef
+$(call add-all-target-to-host-required-modules-deps)
 
 t_m :=
 h_m :=