From e3ecce67c14e0edda22938648cb3a797ca2409ef Mon Sep 17 00:00:00 2001
From: Paul Duffin <paulduffin@google.com>
Date: Thu, 29 Apr 2021 10:34:11 +0100
Subject: [PATCH] Make platform_bootclasspath a singleton module

This is needed in order to allow it to implement MakeVars so it can
create make variables just like the dexpreopt_bootjars and hiddenapi
singletons currently do.

Bug: 177892522
Bug: 179354495
Test: m nothing
Change-Id: Ida5bf8abeecde531e1f6430151650065445804ac
---
 java/platform_bootclasspath.go | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/java/platform_bootclasspath.go b/java/platform_bootclasspath.go
index 6bf9ea0b8..d341591d3 100644
--- a/java/platform_bootclasspath.go
+++ b/java/platform_bootclasspath.go
@@ -26,7 +26,7 @@ func init() {
 }
 
 func registerPlatformBootclasspathBuildComponents(ctx android.RegistrationContext) {
-	ctx.RegisterModuleType("platform_bootclasspath", platformBootclasspathFactory)
+	ctx.RegisterSingletonModuleType("platform_bootclasspath", platformBootclasspathFactory)
 }
 
 // The tags used for the dependencies between the platform bootclasspath and any configured boot
@@ -38,7 +38,7 @@ var (
 )
 
 type platformBootclasspathModule struct {
-	android.ModuleBase
+	android.SingletonModuleBase
 	ClasspathFragmentBase
 
 	properties platformBootclasspathProperties
@@ -69,7 +69,7 @@ type platformBootclasspathProperties struct {
 	Hidden_api HiddenAPIFlagFileProperties
 }
 
-func platformBootclasspathFactory() android.Module {
+func platformBootclasspathFactory() android.SingletonModule {
 	m := &platformBootclasspathModule{}
 	m.AddProperties(&m.properties)
 	// TODO(satayev): split systemserver and apex jars into separate configs.
@@ -154,6 +154,18 @@ func addDependenciesOntoBootImageModules(ctx android.BottomUpMutatorContext, mod
 	}
 }
 
+// GenerateSingletonBuildActions does nothing and must never do anything.
+//
+// This module only implements android.SingletonModule so that it can implement
+// android.SingletonMakeVarsProvider.
+func (b *platformBootclasspathModule) GenerateSingletonBuildActions(android.SingletonContext) {
+	// Keep empty
+}
+
+func (d *platformBootclasspathModule) MakeVars(ctx android.MakeVarsContext) {
+	// Placeholder for now.
+}
+
 func (b *platformBootclasspathModule) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	b.classpathFragmentBase().generateAndroidBuildActions(ctx)