Fix RuleBuilder remoteable actions running in the local pool.

This CL fixes a bug with RuleBuilder's handling of remoteable actions.
It adds a new type of pool to identify remoteable rules by the android
module context. The pool is then set to nil to actually run actions at
NINJA_REMOTE_NUM_JOBS parallelism.

Test: built aosp crosshatch userdebug
Change-Id: I29452f6fc7a161b94189731e3e3cc1f34907b80c
diff --git a/android/defs.go b/android/defs.go
index 5c815e6..4552224 100644
--- a/android/defs.go
+++ b/android/defs.go
@@ -100,6 +100,9 @@
 	// Used only when USE_GOMA=true is set, to restrict non-goma jobs to the local parallelism value
 	localPool = blueprint.NewBuiltinPool("local_pool")
 
+	// Used only by RuleBuilder to identify remoteable rules. Does not actually get created in ninja.
+	remotePool = blueprint.NewBuiltinPool("remote_pool")
+
 	// Used for processes that need significant RAM to ensure there are not too many running in parallel.
 	highmemPool = blueprint.NewBuiltinPool("highmem_pool")
 )
diff --git a/android/module.go b/android/module.go
index d57abd1..80f477b 100644
--- a/android/module.go
+++ b/android/module.go
@@ -908,7 +908,7 @@
 		// partition at "system/vendor/odm".
 		if config.OdmPath() == "odm" {
 			partition = "odm"
-		} else if strings.HasPrefix(config.OdmPath (), "vendor/") {
+		} else if strings.HasPrefix(config.OdmPath(), "vendor/") {
 			partition = "vendor"
 		}
 	} else if m.ProductSpecific() {
@@ -1506,10 +1506,17 @@
 func (m *moduleContext) Rule(pctx PackageContext, name string, params blueprint.RuleParams,
 	argNames ...string) blueprint.Rule {
 
-	if m.config.UseRemoteBuild() && params.Pool == nil {
-		// When USE_GOMA=true or USE_RBE=true are set and the rule is not supported by goma/RBE, restrict
-		// jobs to the local parallelism value
-		params.Pool = localPool
+	if m.config.UseRemoteBuild() {
+		if params.Pool == nil {
+			// When USE_GOMA=true or USE_RBE=true are set and the rule is not supported by goma/RBE, restrict
+			// jobs to the local parallelism value
+			params.Pool = localPool
+		} else if params.Pool == remotePool {
+			// remotePool is a fake pool used to identify rule that are supported for remoting. If the rule's
+			// pool is the remotePool, replace with nil so that ninja runs it at NINJA_REMOTE_NUM_JOBS
+			// parallelism.
+			params.Pool = nil
+		}
 	}
 
 	rule := m.bp.Rule(pctx.PackageContext, name, params, argNames...)
diff --git a/android/rule_builder.go b/android/rule_builder.go
index 9005f07..6226548 100644
--- a/android/rule_builder.go
+++ b/android/rule_builder.go
@@ -446,7 +446,8 @@
 	if ctx.Config().UseGoma() && r.remoteable.Goma {
 		// When USE_GOMA=true is set and the rule is supported by goma, allow jobs to run outside the local pool.
 	} else if ctx.Config().UseRBE() && r.remoteable.RBE {
-		// When USE_RBE=true is set and the rule is supported by RBE, allow jobs to run outside the local pool.
+		// When USE_RBE=true is set and the rule is supported by RBE, use the remotePool.
+		pool = remotePool
 	} else if r.highmem {
 		pool = highmemPool
 	} else if ctx.Config().UseRemoteBuild() {
diff --git a/android/singleton.go b/android/singleton.go
index 45a9b82..568398c 100644
--- a/android/singleton.go
+++ b/android/singleton.go
@@ -128,10 +128,17 @@
 }
 
 func (s *singletonContextAdaptor) Rule(pctx PackageContext, name string, params blueprint.RuleParams, argNames ...string) blueprint.Rule {
-	if s.Config().UseRemoteBuild() && params.Pool == nil {
-		// When USE_GOMA=true or USE_RBE=true are set and the rule is not supported by goma/RBE, restrict
-		// jobs to the local parallelism value
-		params.Pool = localPool
+	if s.Config().UseRemoteBuild() {
+		if params.Pool == nil {
+			// When USE_GOMA=true or USE_RBE=true are set and the rule is not supported by goma/RBE, restrict
+			// jobs to the local parallelism value
+			params.Pool = localPool
+		} else if params.Pool == remotePool {
+			// remotePool is a fake pool used to identify rule that are supported for remoting. If the rule's
+			// pool is the remotePool, replace with nil so that ninja runs it at NINJA_REMOTE_NUM_JOBS
+			// parallelism.
+			params.Pool = nil
+		}
 	}
 	rule := s.SingletonContext.Rule(pctx.PackageContext, name, params, argNames...)
 	if s.Config().captureBuild {