Add support for LOCAL_MODULE_SYMLINKS

Specifying LOCAL_MODULE_SYMLINKS will create symlinks to the installed
module in the same directory.

Change-Id: Idecb2b75f0c9999eb000eed9a79a989244ccf6c2

core/base_rules.mk

@@ -323,6 +323,9 @@ $(foreach c, $(my_path_components),\
 ## Module installation rule
 ###########################################################
 
+my_init_rc_installed :=
+my_init_rc_pairs :=
+my_installed_symlinks :=
 ifndef LOCAL_UNINSTALLABLE_MODULE
 $(LOCAL_INSTALLED_MODULE): PRIVATE_POST_INSTALL_CMD := $(LOCAL_POST_INSTALL_CMD)
 $(LOCAL_INSTALLED_MODULE): $(LOCAL_BUILT_MODULE)
@@ -331,8 +334,6 @@ $(LOCAL_INSTALLED_MODULE): $(LOCAL_BUILT_MODULE)
 	$(PRIVATE_POST_INSTALL_CMD)
 
 # Rule to install the module's companion init.rc.
-my_init_rc_installed :=
-my_init_rc_pairs :=
 my_init_rc := $(LOCAL_INIT_RC_$(my_32_64_bit_suffix))
 ifneq ($(my_init_rc),)
 my_init_rc_pairs += $(LOCAL_PATH)/$(my_init_rc):$(TARGET_OUT$(partition_tag)_ETC)/init/$(notdir $(my_init_rc))
@@ -347,6 +348,12 @@ my_init_rc_installed := $(call copy-many-files,$(my_init_rc_pairs))
 
 $(my_register_name) : $(my_init_rc_installed)
 endif # my_init_rc_pairs
+
+# Rule to install the module's companion symlinks
+my_installed_symlinks := $(addprefix $(my_module_path)/,$(LOCAL_MODULE_SYMLINKS) $(LOCAL_MODULE_SYMLINKS_$(my_32_64_bit_suffix)))
+$(foreach symlink,$(my_installed_symlinks),\
+    $(call symlink-file,$(LOCAL_INSTALLED_MODULE),$(my_installed_module_stem),$(symlink)))
+
 endif # !LOCAL_UNINSTALLABLE_MODULE
 
 ###########################################################
@@ -395,7 +402,7 @@ ALL_MODULES.$(my_register_name).BUILT := \
 ifneq (true,$(LOCAL_UNINSTALLABLE_MODULE))
 ALL_MODULES.$(my_register_name).INSTALLED := \
     $(strip $(ALL_MODULES.$(my_register_name).INSTALLED) \
-    $(LOCAL_INSTALLED_MODULE) $(my_init_rc_installed))
+    $(LOCAL_INSTALLED_MODULE) $(my_init_rc_installed) $(my_installed_symlinks))
 ALL_MODULES.$(my_register_name).BUILT_INSTALLED := \
     $(strip $(ALL_MODULES.$(my_register_name).BUILT_INSTALLED) \
     $(LOCAL_BUILT_MODULE):$(LOCAL_INSTALLED_MODULE) \

core/clear_vars.mk

@@ -192,6 +192,7 @@ LOCAL_SANITIZE_RECOVER:=
 LOCAL_NOSANITIZE:=
 LOCAL_DBUS_PROXY_PREFIX:=
 LOCAL_INIT_RC:=
+LOCAL_MODULE_SYMLINKS:=
 LOCAL_MODULE_HOST_OS:=
 LOCAL_NOTICE_FILE:=
 # Used to replace the installed file of a presigned prebuilt apk in PDK fusion build,
@@ -355,6 +356,8 @@ LOCAL_CLANG_32:=
 LOCAL_CLANG_64:=
 LOCAL_INIT_RC_32:=
 LOCAL_INIT_RC_64:=
+LOCAL_MODULE_SYMLINKS_32:=
+LOCAL_MODULE_SYMLINKS_64:=
 LOCAL_JAVA_LANGUAGE_VERSION:=
 LOCAL_CTS_GTEST_LIST_EXECUTABLE:=
 

core/definitions.mk

@@ -2605,6 +2605,24 @@ $(foreach t,$(1),\
   $(hide) mkdir -p $(dir $(3)/$(s)); cp -Rf $(t) $(3)/$(s)$(newline))
 endef
 
+# Define a rule to create a symlink to a file.
+# $(1): full path to source
+# $(2): source (may be relative)
+# $(3): full path to destination
+define symlink-file
+$(eval $(_symlink-file))
+endef
+
+# Order-only dependency because make/ninja will follow the link when checking
+# the timestamp, so the file must exist
+define _symlink-file
+$(3): | $(1)
+	@echo "Symlink: $$@ -> $(2)"
+	@mkdir -p $(dir $$@)
+	@rm -rf $$@
+	$(hide) ln -sf $(2) $$@
+endef
+
 ###########################################################
 ## Commands to call Proguard
 ###########################################################

core/executable_prefer_symlink.mk

@@ -10,43 +10,37 @@
 # et al. since those variables make no sense in that context.
 ifneq ($(LOCAL_IS_HOST_MODULE),true)
   my_symlink := $(addprefix $(TARGET_OUT)/bin/, $(LOCAL_MODULE))
+  my_src_binary_name :=
   ifeq ($(TARGET_IS_64_BIT),true)
     ifeq ($(TARGET_SUPPORTS_64_BIT_APPS)|$(TARGET_SUPPORTS_32_BIT_APPS),true|true)
       # We support both 32 and 64 bit apps, so we will have to
       # base our decision on whether the target prefers one or the
       # other.
       ifeq ($(TARGET_PREFER_32_BIT_APPS),true)
-        $(my_symlink): PRIVATE_SRC_BINARY_NAME := $(LOCAL_MODULE_STEM_32)
+        my_src_binary_name := $(LOCAL_MODULE_STEM_32)
       else
-        $(my_symlink): PRIVATE_SRC_BINARY_NAME := $(LOCAL_MODULE_STEM_64)
+        my_src_binary_name := $(LOCAL_MODULE_STEM_64)
       endif
     else ifeq ($(TARGET_SUPPORTS_64_BIT_APPS),true)
       # We support only 64 bit apps.
-      $(my_symlink): PRIVATE_SRC_BINARY_NAME := $(LOCAL_MODULE_STEM_64)
+      my_src_binary_name := $(LOCAL_MODULE_STEM_64)
     else
       # We support only 32 bit apps.
-      $(my_symlink): PRIVATE_SRC_BINARY_NAME := $(LOCAL_MODULE_STEM_32)
+      my_src_binary_name := $(LOCAL_MODULE_STEM_32)
     endif
   else
-    $(my_symlink): PRIVATE_SRC_BINARY_NAME := $(LOCAL_MODULE_STEM_32)
+    my_src_binary_name := $(LOCAL_MODULE_STEM_32)
   endif
 else
   my_symlink := $(addprefix $(HOST_OUT)/bin/, $(LOCAL_MODULE))
   ifneq ($(HOST_PREFER_32_BIT),true)
-$(my_symlink): PRIVATE_SRC_BINARY_NAME := $(LOCAL_MODULE_STEM_64)
+    my_src_binary_name := $(LOCAL_MODULE_STEM_64)
   else
-$(my_symlink): PRIVATE_SRC_BINARY_NAME := $(LOCAL_MODULE_STEM_32)
+    my_src_binary_name := $(LOCAL_MODULE_STEM_32)
   endif
 endif
 
-# $(my_symlink) doesn't need to depend on $(PRIVATE_SRC_BINARY_NAME): we can generate symlink to nonexistent file.
-# If you add the dependency, make would compare the timestamp of a file against that of its symlink:
-# they are always equal, because make follows symlink.
-$(my_symlink):
-	@echo "Symlink: $@ -> $(PRIVATE_SRC_BINARY_NAME)"
-	@mkdir -p $(dir $@)
-	@rm -rf $@
-	$(hide) ln -sf $(PRIVATE_SRC_BINARY_NAME) $@
+$(call symlink-file,$(my_module_path)/$(my_src_binary_name),$(my_src_binary_name),$(my_symlink))
 
 # We need this so that the installed files could be picked up based on the
 # local module name