Add genrule for the current sdk proto

This is intended to be added to all apexes exposing SDK apis. The
version can then be bumped by changing the value in a single place.
The current version is 0.

Also build this into the sdkext module.

Bug: 137191822
Test: m com.android.sdkext
Change-Id: Ic2cd92ad1d184c8a01f0bc3d4fc21deb588cb7e8

2 files changed, 48 insertions, 1 deletions

diff --git a/apex/sdkext/Android.bp b/apex/sdkext/Android.bp
index 12d6b8687eb1..b132f7e3ff4c 100644
--- a/apex/sdkext/Android.bp
+++ b/apex/sdkext/Android.bp
@@ -17,7 +17,10 @@ apex {
     manifest: "manifest.json",
     binaries: [ "derive_sdk" ],
     java_libs: [ "framework-sdkext" ],
-    prebuilts: [ "com.android.sdkext.ldconfig" ],
+    prebuilts: [
+      "com.android.sdkext.ldconfig",
+      "cur_sdkinfo",
+    ],
     key: "com.android.sdkext.key",
     certificate: ":com.android.sdkext.certificate",
 }
@@ -39,3 +42,28 @@ prebuilt_etc {
     filename: "ld.config.txt",
     installable: false,
 }
+
+python_binary_host {
+    name: "gen_sdkinfo",
+    srcs: [
+        "derive_sdk/sdk.proto",
+        "gen_sdkinfo.py",
+    ],
+    proto: {
+        canonical_path_from_root: false,
+    },
+}
+
+gensrcs {
+    name: "cur_sdkinfo_src",
+    srcs: [""],
+    tools: [ "gen_sdkinfo" ],
+    cmd: "$(location) -v 0 -o $(out)",
+}
+
+prebuilt_etc {
+    name: "cur_sdkinfo",
+    src: ":cur_sdkinfo_src",
+    filename: "sdkinfo.binarypb",
+    installable: false,
+}
diff --git a/apex/sdkext/gen_sdkinfo.py b/apex/sdkext/gen_sdkinfo.py
new file mode 100644
index 000000000000..5af478ba7fe6
--- /dev/null
+++ b/apex/sdkext/gen_sdkinfo.py
@@ -0,0 +1,19 @@
+import sdk_pb2
+import sys
+
+if __name__ == '__main__':
+  argv = sys.argv[1:]
+  if not len(argv) == 4 or sorted([argv[0], argv[2]]) != ['-o', '-v']:
+    print('usage: gen_sdkinfo -v <version> -o <output-file>')
+    sys.exit(1)
+
+  for i in range(len(argv)):
+    if sys.argv[i] == '-o':
+      filename = sys.argv[i+1]
+    if sys.argv[i] == '-v':
+      version = int(sys.argv[i+1])
+
+  proto = sdk_pb2.SdkVersion()
+  proto.version = version
+  with open(filename, 'wb') as f:
+    f.write(proto.SerializeToString())