From 62dfb591b172a3f6dabd6809ecd97a672c9a57a2 Mon Sep 17 00:00:00 2001
From: Dan Willemsen <dwillemsen@google.com>
Date: Fri, 8 Jul 2016 21:33:05 -0700
Subject: [PATCH] Extend SDK link check to java libraries

Java code using the SDK should not link to java code built with the
platform APIs or the system SDK. Java code using the system SDK should
not link to the platform APIs either, but it can link to java code using
another SDK.

Change-Id: Iaae0a7e01993cfa1e023649fbd8a7974b5eca709
---
 core/java_common.mk       | 39 +++++++++++++++++++++++++++++++++++++++
 core/prebuilt_internal.mk | 14 ++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/core/java_common.mk b/core/java_common.mk
index 1b12ea23b..5eac1f229 100644
--- a/core/java_common.mk
+++ b/core/java_common.mk
@@ -369,3 +369,42 @@ $(LOCAL_INTERMEDIATE_TARGETS) : PRIVATE_JACK_SHARED_LIBRARIES:= $(full_shared_ja
 $(LOCAL_INTERMEDIATE_TARGETS) : PRIVATE_JARJAR_RULES := $(LOCAL_JARJAR_RULES)
 
 endif  # need_compile_java
+
+
+###########################################################
+# Verify that all libraries are safe to use
+###########################################################
+ifndef LOCAL_IS_HOST_MODULE
+my_link_type := $(intermediates.COMMON)/link_type
+my_link_type_deps := $(strip \
+  $(foreach lib,$(LOCAL_STATIC_JAVA_LIBRARIES),\
+    $(call intermediates-dir-for, \
+      JAVA_LIBRARIES,$(lib),,COMMON)/link_type) \
+  $(foreach lib,$(apk_libraries), \
+    $(call intermediates-dir-for, \
+      APPS,$(lib),,COMMON)/link_type))
+ifeq ($(LOCAL_SDK_VERSION),system_current)
+$(my_link_type): PRIVATE_LINK_TYPE := system
+$(my_link_type): PRIVATE_ALLOWED_TYPES := (sdk|system)
+else ifneq ($(LOCAL_SDK_VERSION),)
+$(my_link_type): PRIVATE_LINK_TYPE := sdk
+$(my_link_type): PRIVATE_ALLOWED_TYPES := sdk
+else
+$(my_link_type): PRIVATE_LINK_TYPE := platform
+$(my_link_type): PRIVATE_ALLOWED_TYPES := (sdk|system|platform)
+endif
+$(my_link_type): PRIVATE_DEPS := $(my_link_type_deps)
+$(my_link_type): PRIVATE_MODULE := $(LOCAL_MODULE)
+$(my_link_type): PRIVATE_MAKEFILE := $(LOCAL_MODULE_MAKEFILE)
+$(my_link_type): $(my_link_type_deps)
+	@echo Check Java library module types: $@
+	$(hide) mkdir -p $(dir $@)
+	$(hide) rm -f $@
+	$(hide) for f in $(PRIVATE_DEPS); do \
+	  grep -qE '^$(PRIVATE_ALLOWED_TYPES)$$' $$f || \
+	    $(call echo-warning,"$(PRIVATE_MAKEFILE): $(PRIVATE_MODULE) ($(PRIVATE_LINK_TYPE)) should not link to $$(basename $${f%_intermediates/link_type}) ($$(cat $$f))"); \
+	done
+	$(hide) echo $(PRIVATE_LINK_TYPE) >$@
+
+$(LOCAL_BUILT_MODULE): $(my_link_type)
+endif  # !LOCAL_IS_HOST_MODULE
diff --git a/core/prebuilt_internal.mk b/core/prebuilt_internal.mk
index efdfe1942..7b4f7fb21 100644
--- a/core/prebuilt_internal.mk
+++ b/core/prebuilt_internal.mk
@@ -368,6 +368,20 @@ common_javalib_jar := $(intermediates.COMMON)/javalib.jar
 
 $(common_classes_jar) $(common_javalib_jar): PRIVATE_MODULE := $(LOCAL_MODULE)
 
+my_link_type := $(intermediates.COMMON)/link_type
+ifeq ($(LOCAL_SDK_VERSION),system_current)
+$(my_link_type): PRIVATE_LINK_TYPE := system
+else ifneq ($(LOCAL_SDK_VERSION),)
+$(my_link_type): PRIVATE_LINK_TYPE := sdk
+else
+$(my_link_type): PRIVATE_LINK_TYPE := platform
+endif
+$(my_link_type):
+	@echo Check module type: $@
+	$(hide) mkdir -p $(dir $@) && rm -f $@
+	$(hide) echo $(PRIVATE_LINK_TYPE) >$@
+$(LOCAL_BUILT_MODULE): $(my_link_type)
+
 ifeq ($(prebuilt_module_is_dex_javalib),true)
 # For prebuilt shared Java library we don't have classes.jar.
 $(common_javalib_jar) : $(my_src_jar) | $(ACP)