From bdd5e8e7fe6afb14c9b3028fdaa094008ada309c Mon Sep 17 00:00:00 2001
From: Adam Powell <adamp@google.com>
Date: Thu, 21 May 2015 13:49:05 -0700
Subject: [PATCH] Initialize ro.build.version.preview_sdk

Set the initial (version 1!) value for the preview SDK version
readable by apps. If we're on a release version, force it to be 0.

Change-Id: Ib3e6cad1f59cea8e4a781827d4a35dd3620b90f1
---
 core/Makefile            |  1 +
 core/version_defaults.mk | 17 +++++++++++++++++
 tools/buildinfo.sh       |  1 +
 3 files changed, 19 insertions(+)

diff --git a/core/Makefile b/core/Makefile
index b5cb727151..0528b44082 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -205,6 +205,7 @@ endif
 			BUILD_NUMBER="$(BUILD_NUMBER)" \
 			PLATFORM_VERSION="$(PLATFORM_VERSION)" \
 			PLATFORM_SDK_VERSION="$(PLATFORM_SDK_VERSION)" \
+			PLATFORM_PREVIEW_SDK_VERSION="$(PLATFORM_PREVIEW_SDK_VERSION)" \
 			PLATFORM_VERSION_CODENAME="$(PLATFORM_VERSION_CODENAME)" \
 			PLATFORM_VERSION_ALL_CODENAMES="$(PLATFORM_VERSION_ALL_CODENAMES)" \
 			BUILD_VERSION_TAGS="$(BUILD_VERSION_TAGS)" \
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index d325fd3279..6cbe81c5ad 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -67,6 +67,23 @@ ifeq "" "$(PLATFORM_VERSION_CODENAME)"
   PLATFORM_VERSION_ALL_CODENAMES := $(PLATFORM_VERSION_CODENAME)
 endif
 
+ifeq "REL" "$(PLATFORM_VERSION_CODENAME)"
+  PLATFORM_PREVIEW_SDK_VERSION := 0
+else
+  ifeq "" "$(PLATFORM_PREVIEW_SDK_VERSION)"
+    # This is the definition of a preview SDK version over and above the current
+    # platform SDK version. Unlike the platform SDK version, a higher value
+    # for preview SDK version does NOT mean that all prior preview APIs are
+    # included. Packages reading this value to determine compatibility with
+    # known APIs should check that this value is precisely equal to the preview
+    # SDK version the package was built for, otherwise it should fall back to
+    # assuming the device can only support APIs as of the previous official
+    # public release.
+    # This value will always be 0 for release builds.
+    PLATFORM_PREVIEW_SDK_VERSION := 1
+  endif
+endif
+
 ifeq "" "$(DEFAULT_APP_TARGET_SDK)"
   # This is the default minSdkVersion and targetSdkVersion to use for
   # all .apks created by the build system.  It can be overridden by explicitly
diff --git a/tools/buildinfo.sh b/tools/buildinfo.sh
index dcd9ab5dd5..6cd94998ba 100755
--- a/tools/buildinfo.sh
+++ b/tools/buildinfo.sh
@@ -7,6 +7,7 @@ echo "ro.build.id=$BUILD_ID"
 echo "ro.build.display.id=$BUILD_DISPLAY_ID"
 echo "ro.build.version.incremental=$BUILD_NUMBER"
 echo "ro.build.version.sdk=$PLATFORM_SDK_VERSION"
+echo "ro.build.version.preview_sdk=$PLATFORM_PREVIEW_SDK_VERSION"
 echo "ro.build.version.codename=$PLATFORM_VERSION_CODENAME"
 echo "ro.build.version.all_codenames=$PLATFORM_VERSION_ALL_CODENAMES"
 echo "ro.build.version.release=$PLATFORM_VERSION"