Decouple addition of new sdk member types from sdk code

Previously, adding a new SdkMemberType would require adding a new
sdkMemberListProperty instance to the sdkMemberListProperties as well
as adding a new property into the sdkProperties struct. They are
potential sources of conflict and couple the sdk code with all the
packages that add members to it. This change switched to a
registration model that allows each package to register its sdk
member types decoupling them from the sdk code.

Adds an SdkPropertyName() method to SdkMemberType that specifies the
name of the property to use in the sdk/sdk_snapshot. Also provides
an SdkMemberTypeBase struct to be used by providers of SdkMemberType
implementations.

SdkMemberType instances are registered using the
RegisterSdkMemberType() func which sorts the registered instances
by their SdkPropertyName() to ensure the behavior is consistent and
not affected by order of registration.

When creating a new sdk module a dynamicSdkMemberTypes instance is
created that contains the following:

* A properties struct is created dynamically that contains a field for
  each registered SdkMemberType, corresponding to that type's
  SdkPropertyName().

* A list of sdkMemberListProperty instances is also created, one for
  each registered SdkMemberType.

The dynamicSdkMemberTypes instance is cached using a key that uniquely
identifies the set of registered types just in case new types are
registered after one has been created, e.g. by tests.

Bug: 142918168
Test: m checkbuild
Change-Id: I4bf2bf56a2a49025aa41454048bc1e8ccc6baca2

1 files changed, 18 insertions, 4 deletions

diff --git a/java/java.go b/java/java.go
index f58e5ba24..d8db5f8a4 100644
--- a/java/java.go
+++ b/java/java.go
@@ -52,6 +52,23 @@ func init() {
 
 	android.RegisterSingletonType("logtags", LogtagsSingleton)
 	android.RegisterSingletonType("kythe_java_extract", kytheExtractJavaFactory)
+
+	// Register sdk member types.
+	android.RegisterSdkMemberType(&headerLibrarySdkMemberType{
+		librarySdkMemberType{
+			android.SdkMemberTypeBase{
+				PropertyName: "java_header_libs",
+			},
+		},
+	})
+
+	android.RegisterSdkMemberType(&implLibrarySdkMemberType{
+		librarySdkMemberType{
+			android.SdkMemberTypeBase{
+				PropertyName: "java_libs",
+			},
+		},
+	})
 }
 
 func (j *Module) checkSdkVersion(ctx android.ModuleContext) {
@@ -1721,6 +1738,7 @@ func (j *Library) sdkSnapshotFilePathForJar() string {
 }
 
 type librarySdkMemberType struct {
+	android.SdkMemberTypeBase
 }
 
 func (mt *librarySdkMemberType) AddDependencies(mctx android.BottomUpMutatorContext, dependencyTag blueprint.DependencyTag, names []string) {
@@ -1764,8 +1782,6 @@ func (mt *librarySdkMemberType) buildSnapshot(
 	module.AddProperty("jars", []string{snapshotRelativeJavaLibPath})
 }
 
-var HeaderLibrarySdkMemberType = &headerLibrarySdkMemberType{}
-
 type headerLibrarySdkMemberType struct {
 	librarySdkMemberType
 }
@@ -1781,8 +1797,6 @@ func (mt *headerLibrarySdkMemberType) BuildSnapshot(sdkModuleContext android.Mod
 	})
 }
 
-var ImplLibrarySdkMemberType = &implLibrarySdkMemberType{}
-
 type implLibrarySdkMemberType struct {
 	librarySdkMemberType
 }