[DO NOT MERGE] Add USE_RBE support to soong.

Test: Built aosp_arm-user with and without USE_RBE. USE_RBE uses
a proxy script in place of rewrapper.

Bug: b/166182389
Change-Id: I5bf008a940513872d70b5b215bd6209f759826ae
Merged-In: I5bf008a940513872d70b5b215bd6209f759826ae

android/config.go

@@ -714,6 +714,10 @@ func (c *config) UseGoma() bool {
 	return Bool(c.productVariables.UseGoma)
 }
 
+func (c *config) UseRBE() bool {
+	return Bool(c.productVariables.UseRBE)
+}
+
 func (c *config) RunErrorProne() bool {
 	return c.IsEnvTrue("RUN_ERROR_PRONE")
 }

android/variable.go

@@ -192,6 +192,7 @@ type productVariables struct {
 	HostStaticBinaries               *bool `json:",omitempty"`
 	Binder32bit                      *bool `json:",omitempty"`
 	UseGoma                          *bool `json:",omitempty"`
+	UseRBE                           *bool `json:",omitempty"`
 	Debuggable                       *bool `json:",omitempty"`
 	Eng                              *bool `json:",omitempty"`
 	Treble_linker_namespaces         *bool `json:",omitempty"`

ui/build/Android.bp

@@ -52,6 +52,7 @@ bootstrap_go_package {
         "ninja.go",
         "path.go",
         "proc_sync.go",
+        "rbe.go",
         "signal.go",
         "soong.go",
         "test_build.go",

ui/build/build.go

@@ -161,6 +161,11 @@ func Build(ctx Context, config Config, what int) {
 		startGoma(ctx, config)
 	}
 
+	if config.StartRBE() {
+		// Ensure RBE proxy is started
+		startRBE(ctx, config)
+	}
+
 	if what&BuildProductConfig != 0 {
 		// Run make for product config
 		runMakeProductConfig(ctx, config)

ui/build/config.go

@@ -493,6 +493,30 @@ func (c *configImpl) StartGoma() bool {
 	return true
 }
 
+func (c *configImpl) UseRBE() bool {
+	if v, ok := c.environ.Get("USE_RBE"); ok {
+		v = strings.TrimSpace(v)
+		if v != "" && v != "false" {
+			return true
+		}
+	}
+	return false
+}
+
+func (c *configImpl) StartRBE() bool {
+	if !c.UseRBE() {
+		return false
+	}
+
+	if v, ok := c.environ.Get("NOSTART_RBE"); ok {
+		v = strings.TrimSpace(v)
+		if v != "" && v != "false" {
+			return false
+		}
+	}
+	return true
+}
+
 // RemoteParallel controls how many remote jobs (i.e., commands which contain
 // gomacc) are run in parallel.  Note the parallelism of all other jobs is
 // still limited by Parallel()

ui/build/ninja.go

@@ -43,7 +43,7 @@ func runNinja(ctx Context, config Config) {
 	args = append(args, config.NinjaArgs()...)
 
 	var parallel int
-	if config.UseGoma() {
+	if config.UseGoma() || config.UseRBE() {
 		parallel = config.RemoteParallel()
 	} else {
 		parallel = config.Parallel()

ui/build/rbe.go

@@ -0,0 +1,52 @@
+// Copyright 2019 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package build
+
+import (
+	"path/filepath"
+
+	"android/soong/ui/metrics"
+)
+
+const bootstrapCmd = "bootstrap"
+const rbeLeastNProcs = 2500
+const rbeLeastNFiles = 16000
+
+func startRBE(ctx Context, config Config) {
+	ctx.BeginTrace(metrics.RunSetupTool, "rbe_bootstrap")
+	defer ctx.EndTrace()
+
+	if u := ulimitOrFatal(ctx, config, "-u"); u < rbeLeastNProcs {
+		ctx.Fatalf("max user processes is insufficient: %d; want >= %d.\n", u, rbeLeastNProcs)
+	}
+	if n := ulimitOrFatal(ctx, config, "-n"); n < rbeLeastNFiles {
+		ctx.Fatalf("max open files is insufficient: %d; want >= %d.\n", n, rbeLeastNFiles)
+	}
+
+	var rbeBootstrap string
+	if rbeDir, ok := config.Environment().Get("RBE_DIR"); ok {
+		rbeBootstrap = filepath.Join(rbeDir, bootstrapCmd)
+	} else if home, ok := config.Environment().Get("HOME"); ok {
+		rbeBootstrap = filepath.Join(home, "rbe", bootstrapCmd)
+	} else {
+		ctx.Fatalln("rbe bootstrap not found")
+	}
+
+	cmd := Command(ctx, config, "bootstrap", rbeBootstrap)
+
+	if output, err := cmd.CombinedOutput(); err != nil {
+		ctx.Fatalf("rbe bootstrap failed with: %v\n%s\n", err, output)
+	}
+}