Add a "direct" mode to "blaze run" that makes the process being run a direct

child of the process where the Blaze client itself was run.

Limitations:

- Untested on Windows; it should work because ExecuteProgram() is implemented there, too, but since Windows doesn't support exec(), there is at least one process in between

Progress towards #2815.

RELNOTES[NEW]: The new "--direct_run" flag on "blaze run" lets one run interactive binaries.

PiperOrigin-RevId: 184528845

27 files changed, 346 insertions, 179 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/bazel/commands/FetchCommand.java b/src/main/java/com/google/devtools/build/lib/bazel/commands/FetchCommand.java
index 7581de0eb0..202a29b45c 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/commands/FetchCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/commands/FetchCommand.java
@@ -28,6 +28,7 @@ import com.google.devtools.build.lib.query2.engine.QueryException;
 import com.google.devtools.build.lib.query2.engine.QueryExpression;
 import com.google.devtools.build.lib.query2.engine.ThreadSafeOutputFormatterCallback;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.BlazeRuntime;
 import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
@@ -60,29 +61,29 @@ public final class FetchCommand implements BlazeCommand {
   public void editOptions(OptionsParser optionsParser) { }
 
   @Override
-  public ExitCode exec(CommandEnvironment env, OptionsProvider options) {
+  public BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options) {
     BlazeRuntime runtime = env.getRuntime();
     if (options.getResidue().isEmpty()) {
       env.getReporter().handle(Event.error(String.format(
           "missing fetch expression. Type '%s help fetch' for syntax and help",
           env.getRuntime().getProductName())));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
 
     try {
       env.setupPackageCache(options, runtime.getDefaultsPackageContent());
     } catch (InterruptedException e) {
       env.getReporter().handle(Event.error("fetch interrupted"));
-      return ExitCode.INTERRUPTED;
+      return BlazeCommandResult.exitCode(ExitCode.INTERRUPTED);
     } catch (AbruptExitException e) {
       env.getReporter().handle(Event.error(null, "Unknown error: " + e.getMessage()));
-      return e.getExitCode();
+      return BlazeCommandResult.exitCode(e.getExitCode());
     }
 
     PackageCacheOptions pkgOptions = options.getOptions(PackageCacheOptions.class);
     if (!pkgOptions.fetch) {
       env.getReporter().handle(Event.error(null, "You cannot run fetch with --fetch=false"));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
 
     // Querying for all of the dependencies of the targets has the side-effect of populating the
@@ -110,7 +111,7 @@ public final class FetchCommand implements BlazeCommand {
     } catch (QueryException e) {
       env.getReporter().handle(Event.error(
           null, "Error while parsing '" + query + "': " + e.getMessage()));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
 
     env.getReporter()
@@ -139,7 +140,7 @@ public final class FetchCommand implements BlazeCommand {
           .post(
               new NoBuildRequestFinishedEvent(
                   ExitCode.COMMAND_LINE_ERROR, env.getRuntime().getClock().currentTimeMillis()));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     } catch (QueryException e) {
       // Keep consistent with reportBuildFileError()
       env.getReporter().handle(Event.error(e.getMessage()));
@@ -147,7 +148,7 @@ public final class FetchCommand implements BlazeCommand {
           .post(
               new NoBuildRequestFinishedEvent(
                   ExitCode.COMMAND_LINE_ERROR, env.getRuntime().getClock().currentTimeMillis()));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     } catch (IOException e) {
       // Should be impossible since our OutputFormatterCallback doesn't throw IOException.
       throw new IllegalStateException(e);
@@ -162,6 +163,6 @@ public final class FetchCommand implements BlazeCommand {
         .post(
             new NoBuildRequestFinishedEvent(
                 exitCode, env.getRuntime().getClock().currentTimeMillis()));
-    return exitCode;
+    return BlazeCommandResult.exitCode(exitCode);
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommand.java
index b5759edf77..22c1e636f5 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommand.java
@@ -13,7 +13,6 @@
 // limitations under the License.
 package com.google.devtools.build.lib.runtime;
 
-import com.google.devtools.build.lib.util.ExitCode;
 import com.google.devtools.common.options.OptionsParser;
 import com.google.devtools.common.options.OptionsProvider;
 
@@ -41,7 +40,7 @@ public interface BlazeCommand {
    * @throws BlazeCommandDispatcher.ShutdownBlazeServerException Indicates that the command wants to
    *     shutdown the Blaze server.
    */
-  ExitCode exec(CommandEnvironment env, OptionsProvider options)
+  BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options)
       throws BlazeCommandDispatcher.ShutdownBlazeServerException;
 
   /**
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java b/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java
index b664561d0d..e58d670e1b 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java
@@ -80,19 +80,19 @@ public class BlazeCommandDispatcher {
    * the Blaze server process.
    */
   public static class ShutdownBlazeServerException extends Exception {
-    private final int exitStatus;
+    private final ExitCode exitCode;
 
-    public ShutdownBlazeServerException(int exitStatus, Throwable cause) {
+    public ShutdownBlazeServerException(ExitCode exitCode, Throwable cause) {
       super(cause);
-      this.exitStatus = exitStatus;
+      this.exitCode = exitCode;
     }
 
-    public ShutdownBlazeServerException(int exitStatus) {
-      this.exitStatus = exitStatus;
+    public ShutdownBlazeServerException(ExitCode exitCode) {
+      this.exitCode = exitCode;
     }
 
-    public int getExitStatus() {
-      return exitStatus;
+    public ExitCode getExitCode() {
+      return exitCode;
     }
   }
 
@@ -138,7 +138,7 @@ public class BlazeCommandDispatcher {
    * {@link ShutdownBlazeServerException} to indicate that a command wants to shutdown the Blaze
    * server.
    */
-  int exec(
+  BlazeCommandResult exec(
       InvocationPolicy invocationPolicy,
       List<String> args,
       OutErr outErr,
@@ -165,7 +165,7 @@ public class BlazeCommandDispatcher {
     if (command == null) {
       outErr.printErrLn(String.format(
           "Command '%s' not found. Try '%s help'.", commandName, runtime.getProductName()));
-      return ExitCode.COMMAND_LINE_ERROR.getNumericExitCode();
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
 
     // Take the exclusive server lock.  If we fail, we busy-wait until the lock becomes available.
@@ -193,7 +193,7 @@ public class BlazeCommandDispatcher {
           case ERROR_OUT:
             outErr.printErrLn(String.format("Another command (" + currentClientDescription + ") is "
                 + "running. Exiting immediately."));
-            return ExitCode.COMMAND_LINE_ERROR.getNumericExitCode();
+            return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
 
           default:
             throw new IllegalStateException();
@@ -213,7 +213,7 @@ public class BlazeCommandDispatcher {
     try {
       if (shutdownReason != null) {
         outErr.printErrLn("Server shut down " + shutdownReason);
-        return ExitCode.LOCAL_ENVIRONMENTAL_ERROR.getNumericExitCode();
+        return BlazeCommandResult.exitCode(ExitCode.LOCAL_ENVIRONMENTAL_ERROR);
       }
       return execExclusively(
           originalCommandLine,
@@ -236,7 +236,7 @@ public class BlazeCommandDispatcher {
     }
   }
 
-  private int execExclusively(
+  private BlazeCommandResult execExclusively(
       OriginalUnstructuredCommandLineEvent unstructuredServerCommandLineEvent,
       InvocationPolicy invocationPolicy,
       List<String> args,
@@ -325,7 +325,7 @@ public class BlazeCommandDispatcher {
         env.getEventBus().post(post);
       }
       // TODO(ulfjack): We're not calling BlazeModule.afterCommand here, even though we should.
-      return earlyExitCode.getNumericExitCode();
+      return BlazeCommandResult.exitCode(earlyExitCode);
     }
 
     // Setup log filtering
@@ -360,7 +360,7 @@ public class BlazeCommandDispatcher {
     // Do this before an actual crash so we don't have to worry about
     // allocating memory post-crash.
     String[] crashData = env.getCrashData();
-    int numericExitCode = ExitCode.BLAZE_INTERNAL_ERROR.getNumericExitCode();
+    BlazeCommandResult result = BlazeCommandResult.exitCode(ExitCode.BLAZE_INTERNAL_ERROR);
     PrintStream savedOut = System.out;
     PrintStream savedErr = System.err;
 
@@ -379,14 +379,14 @@ public class BlazeCommandDispatcher {
     }
     if (oomMoreEagerlyThreshold < 0 || oomMoreEagerlyThreshold > 100) {
       reporter.handle(Event.error("--oom_more_eagerly_threshold must be non-negative percent"));
-      return ExitCode.COMMAND_LINE_ERROR.getNumericExitCode();
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
     if (oomMoreEagerlyThreshold != 100) {
       try {
         RetainedHeapLimiter.maybeInstallRetainedHeapLimiter(oomMoreEagerlyThreshold);
       } catch (OptionsParsingException e) {
         reporter.handle(Event.error(e.getMessage()));
-        return ExitCode.COMMAND_LINE_ERROR.getNumericExitCode();
+        return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
       }
     }
 
@@ -472,7 +472,7 @@ public class BlazeCommandDispatcher {
             invocationPolicy);
       } catch (AbruptExitException e) {
         reporter.handle(Event.error(e.getMessage()));
-        return e.getExitCode().getNumericExitCode();
+        return BlazeCommandResult.exitCode(e.getExitCode());
       }
 
       // Log the command line now that the modules have all had a change to register their listeners
@@ -486,21 +486,29 @@ public class BlazeCommandDispatcher {
         env.getSkyframeExecutor().injectExtraPrecomputedValues(module.getPrecomputedValues());
       }
 
-      ExitCode outcome = command.exec(env, options);
-      outcome = env.precompleteCommand(outcome);
-      numericExitCode = outcome.getNumericExitCode();
-      return numericExitCode;
+      result = command.exec(env, options);
+      ExitCode moduleExitCode = env.precompleteCommand(result.getExitCode());
+      // If Blaze did not suffer an infrastructure failure, check for errors in modules.
+      if (result.getExitCode() != null
+          && !result.getExitCode().isInfrastructureFailure()
+          && moduleExitCode != null) {
+        result = BlazeCommandResult.exitCode(moduleExitCode);
+      }
+      return result;
     } catch (ShutdownBlazeServerException e) {
-      numericExitCode = e.getExitStatus();
+      // result is read in the finally block
+      result = BlazeCommandResult.exitCode(e.getExitCode());
       throw e;
     } catch (Throwable e) {
       e.printStackTrace();
       BugReport.printBug(outErr, e);
       BugReport.sendBugReport(e, args, crashData);
-      numericExitCode = BugReport.getExitCodeForThrowable(e);
-      throw new ShutdownBlazeServerException(numericExitCode, e);
+      throw new ShutdownBlazeServerException(BugReport.getExitCodeForThrowable(e), e);
     } finally {
       env.getEventBus().post(new AfterCommandEvent());
+      int numericExitCode = result.getExitCode() == null
+          ? 0
+          : result.getExitCode().getNumericExitCode();
       runtime.afterCommand(env, numericExitCode);
       // Swallow IOException, as we are already in a finally clause
       Flushables.flushQuietly(outErr.getOutputStream());
@@ -533,7 +541,7 @@ public class BlazeCommandDispatcher {
         LockingMode.ERROR_OUT,
         clientDescription,
         runtime.getClock().currentTimeMillis(),
-        Optional.empty() /* startupOptionBundles */);
+        Optional.empty() /* startupOptionBundles */).getExitCode().getNumericExitCode();
   }
 
 
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandResult.java b/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandResult.java
new file mode 100644
index 0000000000..c1701c6ece
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandResult.java
@@ -0,0 +1,53 @@
+// Copyright 2018 The Bazel Authors. 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 com.google.devtools.build.lib.runtime;
+
+import com.google.common.base.Preconditions;
+import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
+import com.google.devtools.build.lib.server.CommandProtos.ExecRequest;
+import com.google.devtools.build.lib.util.ExitCode;
+import javax.annotation.Nullable;
+
+/**
+ * The result of a Blaze command. It is usually an exit code, but can be an instruction to the
+ * client to execute a particular binary for "blaze run".
+ */
+@Immutable
+public final class BlazeCommandResult {
+  private final ExitCode exitCode;
+  @Nullable
+  private final ExecRequest execDescription;
+
+  private BlazeCommandResult(ExitCode exitCode, ExecRequest execDescription) {
+    this.exitCode = Preconditions.checkNotNull(exitCode);
+    this.execDescription = execDescription;
+  }
+
+  public ExitCode getExitCode() {
+    return exitCode;
+  }
+
+  @Nullable public ExecRequest getExecRequest() {
+    return execDescription;
+  }
+
+  public static BlazeCommandResult exitCode(ExitCode exitCode) {
+    return new BlazeCommandResult(exitCode, null);
+  }
+
+  public static BlazeCommandResult execute(ExecRequest execDescription) {
+    return new BlazeCommandResult(ExitCode.SUCCESS, Preconditions.checkNotNull(execDescription));
+  }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java b/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
index 7789605f1d..7319206e80 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
@@ -54,6 +54,8 @@ import com.google.devtools.build.lib.query2.output.OutputFormatter;
 import com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.LockingMode;
 import com.google.devtools.build.lib.runtime.commands.InfoItem;
 import com.google.devtools.build.lib.runtime.proto.InvocationPolicyOuterClass.InvocationPolicy;
+import com.google.devtools.build.lib.server.CommandProtos.EnvironmentVariable;
+import com.google.devtools.build.lib.server.CommandProtos.ExecRequest;
 import com.google.devtools.build.lib.server.RPCServer;
 import com.google.devtools.build.lib.server.signal.InterruptSignalHandler;
 import com.google.devtools.build.lib.shell.JavaSubprocessFactory;
@@ -86,9 +88,11 @@ import com.google.devtools.common.options.OptionsParsingException;
 import com.google.devtools.common.options.OptionsProvider;
 import com.google.devtools.common.options.TriState;
 import java.io.BufferedOutputStream;
+import java.io.File;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.lang.reflect.Type;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Date;
@@ -702,7 +706,7 @@ public final class BlazeRuntime {
     return new CommandLineOptions(startupArgs, otherArgs);
   }
 
-  private static void captureSigint() {
+  private static InterruptSignalHandler captureSigint() {
     final Thread mainThread = Thread.currentThread();
     final AtomicInteger numInterrupts = new AtomicInteger();
 
@@ -718,7 +722,7 @@ public final class BlazeRuntime {
           }
         };
 
-    new InterruptSignalHandler() {
+    return new InterruptSignalHandler() {
       @Override
       public void run() {
         logger.info("User interrupt");
@@ -743,7 +747,7 @@ public final class BlazeRuntime {
    * exit status of the program.
    */
   private static int batchMain(Iterable<BlazeModule> modules, String[] args) {
-    captureSigint();
+    InterruptSignalHandler signalHandler = captureSigint();
     CommandLineOptions commandLineOptions = splitStartupOptions(modules, args);
     logger.info(
         "Running Blaze in batch mode with "
@@ -773,10 +777,11 @@ public final class BlazeRuntime {
     }
 
     BlazeCommandDispatcher dispatcher = new BlazeCommandDispatcher(runtime);
+    boolean shutdownDone = false;
 
     try {
       logger.info(getRequestLogString(commandLineOptions.getOtherArgs()));
-      return dispatcher.exec(
+      BlazeCommandResult result = dispatcher.exec(
           policy,
           commandLineOptions.getOtherArgs(),
           OutErr.SYSTEM_OUT_ERR,
@@ -784,14 +789,57 @@ public final class BlazeRuntime {
           "batch client",
           runtime.getClock().currentTimeMillis(),
           Optional.of(startupOptionsFromCommandLine.build()));
+      if (result.getExecRequest() == null) {
+        // Simple case: we are given an exit code
+        return result.getExitCode().getNumericExitCode();
+      }
+
+      // Not so simple case: we need to execute a binary on shutdown. exec() is not accessible from
+      // Java and is impossible on Windows in any case, so we just execute the binary after getting
+      // out of the way as completely as possible and forward its exit code.
+      // When this code is executed, no locks are held: the client lock is released by the client
+      // before it executes any command and the server lock is handled by BlazeCommandDispatcher,
+      // whose job is done by the time we get here.
+      runtime.shutdown();
+      dispatcher.shutdown();
+      shutdownDone = true;
+      signalHandler.uninstall();
+      ExecRequest request = result.getExecRequest();
+      String[] argv = new String[request.getArgvCount()];
+      for (int i = 0; i < argv.length; i++) {
+        argv[i] = request.getArgv(i).toString(StandardCharsets.ISO_8859_1);
+      }
+
+      String workingDirectory = request.getWorkingDirectory().toString(StandardCharsets.ISO_8859_1);
+      try {
+        ProcessBuilder process = new ProcessBuilder()
+            .command(argv)
+            .directory(new File(workingDirectory))
+            .inheritIO();
+
+        for (int i = 0;  i < request.getEnvironmentVariableCount(); i++) {
+          EnvironmentVariable variable = request.getEnvironmentVariable(i);
+          process.environment().put(variable.getName().toString(StandardCharsets.ISO_8859_1),
+              variable.getValue().toString(StandardCharsets.ISO_8859_1));
+        }
+
+        return process.start().waitFor();
+      } catch (IOException e) {
+        // We are in batch mode, thus, stdout/stderr are the same as that of the client.
+        System.err.println("Cannot execute process for 'run' command: " + e.getMessage());
+        logger.log(Level.SEVERE, "Exception while executing binary from 'run' command", e);
+        return ExitCode.LOCAL_ENVIRONMENTAL_ERROR.getNumericExitCode();
+      }
     } catch (BlazeCommandDispatcher.ShutdownBlazeServerException e) {
-      return e.getExitStatus();
+      return e.getExitCode().getNumericExitCode();
     } catch (InterruptedException e) {
       // This is almost main(), so it's okay to just swallow it. We are exiting soon.
       return ExitCode.INTERRUPTED.getNumericExitCode();
     } finally {
-      runtime.shutdown();
-      dispatcher.shutdown();
+      if (!shutdownDone) {
+        runtime.shutdown();
+        dispatcher.shutdown();
+      }
     }
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BugReport.java b/src/main/java/com/google/devtools/build/lib/runtime/BugReport.java
index 1d8c0d874a..af1d263e08 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BugReport.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BugReport.java
@@ -87,7 +87,7 @@ public abstract class BugReport {
    * halts the runtime in that case.
    */
   public static void handleCrash(Throwable throwable, String... args) {
-    int exitCode = getExitCodeForThrowable(throwable);
+    int exitCode = getExitCodeForThrowable(throwable).getNumericExitCode();
     try {
       if (alreadyHandlingCrash.compareAndSet(false, true)) {
         try {
@@ -131,10 +131,10 @@ public abstract class BugReport {
   }
 
   /** Get exit code corresponding to throwable. */
-  public static int getExitCodeForThrowable(Throwable throwable) {
+  public static ExitCode getExitCodeForThrowable(Throwable throwable) {
     return (Throwables.getRootCause(throwable) instanceof OutOfMemoryError)
-        ? ExitCode.OOM_ERROR.getNumericExitCode()
-        : ExitCode.BLAZE_INTERNAL_ERROR.getNumericExitCode();
+        ? ExitCode.OOM_ERROR
+        : ExitCode.BLAZE_INTERNAL_ERROR;
   }
 
   private static void printThrowableTo(OutErr outErr, Throwable e) {
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/CommandEnvironment.java b/src/main/java/com/google/devtools/build/lib/runtime/CommandEnvironment.java
index 34a2ebfcdd..f75f06a0b4 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/CommandEnvironment.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/CommandEnvironment.java
@@ -481,13 +481,7 @@ public final class CommandEnvironment {
    */
   ExitCode precompleteCommand(ExitCode originalExit) {
     eventBus.post(new CommandPrecompleteEvent(originalExit));
-    // If Blaze did not suffer an infrastructure failure, check for errors in modules.
-    ExitCode exitCode = originalExit;
-    ExitCode newExitCode = finalizeExitCode();
-    if (!originalExit.isInfrastructureFailure() && newExitCode != null) {
-      exitCode = newExitCode;
-    }
-    return exitCode;
+    return finalizeExitCode();
   }
 
   /**
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/CommandExecutor.java b/src/main/java/com/google/devtools/build/lib/runtime/CommandExecutor.java
index f57c8ca04a..89c3a57911 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/CommandExecutor.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/CommandExecutor.java
@@ -43,7 +43,7 @@ public class CommandExecutor implements ServerCommand {
   }
 
   @Override
-  public int exec(
+  public BlazeCommandResult exec(
       InvocationPolicy invocationPolicy,
       List<String> args,
       OutErr outErr,
@@ -75,7 +75,7 @@ public class CommandExecutor implements ServerCommand {
       shutdown = true;
       runtime.shutdown();
       dispatcher.shutdown();
-      return e.getExitStatus();
+      return BlazeCommandResult.exitCode(e.getExitCode());
     }
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/BuildCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/BuildCommand.java
index a02c991839..4803aaf115 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/BuildCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/BuildCommand.java
@@ -22,6 +22,7 @@ import com.google.devtools.build.lib.exec.local.LocalExecutionOptions;
 import com.google.devtools.build.lib.pkgcache.LoadingOptions;
 import com.google.devtools.build.lib.pkgcache.PackageCacheOptions;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.BlazeRuntime;
 import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
@@ -62,7 +63,7 @@ public final class BuildCommand implements BlazeCommand {
   }
 
   @Override
-  public ExitCode exec(CommandEnvironment env, OptionsProvider options) {
+  public BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options) {
     BlazeRuntime runtime = env.getRuntime();
     List<String> targets = ProjectFileSupport.getTargets(runtime.getProjectFileProvider(), options);
 
@@ -71,6 +72,7 @@ public final class BuildCommand implements BlazeCommand {
         runtime.getStartupOptionsProvider(),
         targets,
         env.getReporter().getOutErr(), env.getCommandId(), env.getCommandStartTime());
-    return new BuildTool(env).processRequest(request, null).getExitCondition();
+    ExitCode exitCode = new BuildTool(env).processRequest(request, null).getExitCondition();
+    return BlazeCommandResult.exitCode(exitCode);
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/CanonicalizeCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/CanonicalizeCommand.java
index c2951f1d28..d17b281fbb 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/CanonicalizeCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/CanonicalizeCommand.java
@@ -17,6 +17,7 @@ import com.google.common.base.Joiner;
 import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.BlazeCommandUtils;
 import com.google.devtools.build.lib.runtime.BlazeRuntime;
 import com.google.devtools.build.lib.runtime.Command;
@@ -127,7 +128,7 @@ public final class CanonicalizeCommand implements BlazeCommand {
   }
 
   @Override
-  public ExitCode exec(CommandEnvironment env, OptionsProvider options) {
+  public BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options) {
     BlazeRuntime runtime = env.getRuntime();
     Options canonicalizeOptions = options.getOptions(Options.class);
     String commandName = canonicalizeOptions.forCommand;
@@ -135,7 +136,7 @@ public final class CanonicalizeCommand implements BlazeCommand {
     if (command == null) {
       env.getReporter().handle(Event.error("Not a valid command: '" + commandName
           + "' (should be one of " + Joiner.on(", ").join(runtime.getCommandMap().keySet()) + ")"));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
     Collection<Class<? extends OptionsBase>> optionsClasses =
         ImmutableList.<Class<? extends OptionsBase>>builder()
@@ -175,9 +176,9 @@ public final class CanonicalizeCommand implements BlazeCommand {
       }
     } catch (OptionsParsingException e) {
       env.getReporter().handle(Event.error(e.getMessage()));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
-    return ExitCode.SUCCESS;
+    return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
   }
 
   @Override
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/CleanCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/CleanCommand.java
index 721a0644fc..bf88f451a0 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/CleanCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/CleanCommand.java
@@ -21,6 +21,7 @@ import com.google.devtools.build.lib.buildtool.OutputDirectoryLinksUtils;
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
 import com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.ShutdownBlazeServerException;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
 import com.google.devtools.build.lib.shell.CommandException;
@@ -127,7 +128,7 @@ public final class CleanCommand implements BlazeCommand {
   private static final Logger logger = Logger.getLogger(CleanCommand.class.getName());
 
   @Override
-  public ExitCode exec(CommandEnvironment env, OptionsProvider options)
+  public BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options)
       throws ShutdownBlazeServerException {
     Options cleanOptions = options.getOptions(Options.class);
     boolean async = cleanOptions.async;
@@ -165,16 +166,16 @@ public final class CleanCommand implements BlazeCommand {
               .getOptions(BuildRequestOptions.class)
               .getSymlinkPrefix(env.getRuntime().getProductName());
       actuallyClean(env, env.getOutputBase(), cleanOptions.expunge, async, symlinkPrefix);
-      return ExitCode.SUCCESS;
+      return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
     } catch (IOException e) {
       env.getReporter().handle(Event.error(e.getMessage()));
-      return ExitCode.LOCAL_ENVIRONMENTAL_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.LOCAL_ENVIRONMENTAL_ERROR);
     } catch (CommandException | ExecException e) {
       env.getReporter().handle(Event.error(e.getMessage()));
-      return ExitCode.RUN_FAILURE;
+      return BlazeCommandResult.exitCode(ExitCode.RUN_FAILURE);
     } catch (InterruptedException e) {
       env.getReporter().handle(Event.error("clean interrupted"));
-      return ExitCode.INTERRUPTED;
+      return BlazeCommandResult.exitCode(ExitCode.INTERRUPTED);
     }
   }
 
@@ -265,7 +266,7 @@ public final class CleanCommand implements BlazeCommand {
 
     // shutdown on expunge cleans
     if (expunge) {
-      throw new ShutdownBlazeServerException(0);
+      throw new ShutdownBlazeServerException(ExitCode.SUCCESS);
     }
     System.gc();
   }
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/CqueryCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/CqueryCommand.java
index b99002ad9c..1aa6c8dc4e 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/CqueryCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/CqueryCommand.java
@@ -25,6 +25,7 @@ import com.google.devtools.build.lib.query2.engine.QueryException;
 import com.google.devtools.build.lib.query2.engine.QueryExpression;
 import com.google.devtools.build.lib.query2.engine.QueryParser;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.BlazeRuntime;
 import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
@@ -66,13 +67,13 @@ public final class CqueryCommand implements BlazeCommand {
   }
 
   @Override
-  public ExitCode exec(CommandEnvironment env, OptionsProvider options) {
+  public BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options) {
     if (options.getResidue().isEmpty()) {
       env.getReporter()
           .handle(
               Event.error(
                   "Missing query expression. Use the 'help cquery' command for syntax and help."));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
     String query = Joiner.on(' ').join(options.getResidue());
     HashMap<String, QueryFunction> functions = new HashMap<>();
@@ -85,7 +86,7 @@ public final class CqueryCommand implements BlazeCommand {
     } catch (QueryException e) {
       env.getReporter()
           .handle(Event.error("Error while parsing '" + query + "': " + e.getMessage()));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
 
     List<String> topLevelTargets = options.getOptions(CommonQueryOptions.class).universeScope;
@@ -104,6 +105,7 @@ public final class CqueryCommand implements BlazeCommand {
             env.getReporter().getOutErr(),
             env.getCommandId(),
             env.getCommandStartTime());
-    return new BuildTool(env).processRequest(request, null, expr).getExitCondition();
+    ExitCode exitCode = new BuildTool(env).processRequest(request, null, expr).getExitCondition();
+    return BlazeCommandResult.exitCode(exitCode);
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/DumpCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/DumpCommand.java
index 96b3149463..6f92ae0a06 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/DumpCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/DumpCommand.java
@@ -23,6 +23,7 @@ import com.google.devtools.build.lib.packages.RuleClass;
 import com.google.devtools.build.lib.profiler.memory.AllocationTracker;
 import com.google.devtools.build.lib.profiler.memory.AllocationTracker.RuleBytes;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.BlazeCommandUtils;
 import com.google.devtools.build.lib.runtime.BlazeRuntime;
 import com.google.devtools.build.lib.runtime.BlazeWorkspace;
@@ -166,7 +167,7 @@ public class DumpCommand implements BlazeCommand {
   public void editOptions(OptionsParser optionsParser) {}
 
   @Override
-  public ExitCode exec(CommandEnvironment env, OptionsProvider options) {
+  public BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options) {
     BlazeRuntime runtime = env.getRuntime();
     DumpOptions dumpOptions = options.getOptions(DumpOptions.class);
 
@@ -190,7 +191,7 @@ public class DumpCommand implements BlazeCommand {
           getClass(),
           optionList, categories, OptionsParser.HelpVerbosity.LONG,
           runtime.getProductName()));
-      return ExitCode.ANALYSIS_FAILURE;
+      return BlazeCommandResult.exitCode(ExitCode.ANALYSIS_FAILURE);
     }
     PrintStream out = new PrintStream(env.getReporter().getOutErr().getOutputStream());
     try {
@@ -241,7 +242,7 @@ public class DumpCommand implements BlazeCommand {
         out.println();
       }
 
-      return success ? ExitCode.SUCCESS : ExitCode.ANALYSIS_FAILURE;
+      return BlazeCommandResult.exitCode(success ? ExitCode.SUCCESS : ExitCode.ANALYSIS_FAILURE);
 
     } finally {
       out.flush();
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/HelpCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/HelpCommand.java
index 1e163e295e..6f47e3d1fb 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/HelpCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/HelpCommand.java
@@ -29,6 +29,7 @@ import com.google.devtools.build.lib.analysis.NoBuildEvent;
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.packages.RuleClass;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.BlazeCommandUtils;
 import com.google.devtools.build.lib.runtime.BlazeModule;
 import com.google.devtools.build.lib.runtime.BlazeRuntime;
@@ -176,7 +177,7 @@ public final class HelpCommand implements BlazeCommand {
   public void editOptions(OptionsParser optionsParser) {}
 
   @Override
-  public ExitCode exec(CommandEnvironment env, OptionsProvider options) {
+  public BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options) {
     env.getEventBus().post(new NoBuildEvent());
 
     BlazeRuntime runtime = env.getRuntime();
@@ -185,11 +186,11 @@ public final class HelpCommand implements BlazeCommand {
     if (options.getResidue().isEmpty()) {
       emitBlazeVersionInfo(outErr, runtime.getProductName());
       emitGenericHelp(outErr, runtime);
-      return ExitCode.SUCCESS;
+      return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
     }
     if (options.getResidue().size() != 1) {
       env.getReporter().handle(Event.error("You must specify exactly one command"));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
     String helpSubject = options.getResidue().get(0);
     String productName = runtime.getProductName();
@@ -203,7 +204,7 @@ public final class HelpCommand implements BlazeCommand {
             runtime,
             getDeprecatedOptionCategoriesDescriptions(productName),
             helpOptions.useNewCategoryEnum);
-        return ExitCode.SUCCESS;
+        return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
       case "target-syntax":
         emitBlazeVersionInfo(outErr, runtime.getProductName());
         emitTargetSyntaxHelp(
@@ -212,19 +213,19 @@ public final class HelpCommand implements BlazeCommand {
             productName,
             helpOptions.useNewCategoryEnum);
 
-        return ExitCode.SUCCESS;
+        return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
       case "info-keys":
         emitInfoKeysHelp(env, outErr);
-        return ExitCode.SUCCESS;
+        return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
       case "completion":
         emitCompletionHelp(runtime, outErr);
-        return ExitCode.SUCCESS;
+        return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
       case "flags-as-proto":
         emitFlagsAsProtoHelp(runtime, outErr);
-        return ExitCode.SUCCESS;
+        return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
       case "everything-as-html":
         new HtmlEmitter(runtime, helpOptions.useNewCategoryEnum).emit(outErr);
-        return ExitCode.SUCCESS;
+        return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
       default: // fall out
     }
 
@@ -236,11 +237,11 @@ public final class HelpCommand implements BlazeCommand {
         // There is a rule with a corresponding name
         outErr.printOut(
             BlazeRuleHelpPrinter.getRuleDoc(helpSubject, runtime.getProductName(), provider));
-        return ExitCode.SUCCESS;
+        return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
       } else {
         env.getReporter().handle(Event.error(
             null, "'" + helpSubject + "' is neither a command nor a build rule"));
-        return ExitCode.COMMAND_LINE_ERROR;
+        return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
       }
     }
     emitBlazeVersionInfo(outErr, productName);
@@ -254,7 +255,7 @@ public final class HelpCommand implements BlazeCommand {
             productName,
             helpOptions.useNewCategoryEnum));
 
-    return ExitCode.SUCCESS;
+    return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
   }
 
   private void emitBlazeVersionInfo(OutErr outErr, String productName) {
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/InfoCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/InfoCommand.java
index ca32232cc0..e10e5735e1 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/InfoCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/InfoCommand.java
@@ -22,6 +22,7 @@ import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
 import com.google.devtools.build.lib.analysis.config.InvalidConfigurationException;
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.BlazeRuntime;
 import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
@@ -101,7 +102,8 @@ public class InfoCommand implements BlazeCommand {
   public void editOptions(OptionsParser optionsParser) { }
 
   @Override
-  public ExitCode exec(final CommandEnvironment env, final OptionsProvider optionsProvider) {
+  public BlazeCommandResult exec(
+      final CommandEnvironment env, final OptionsProvider optionsProvider) {
     final BlazeRuntime runtime = env.getRuntime();
     env.getReporter().switchToAnsiAllowingHandler();
     Options infoOptions = optionsProvider.getOptions(Options.class);
@@ -152,7 +154,7 @@ public class InfoCommand implements BlazeCommand {
       List<String> residue = optionsProvider.getResidue();
       if (residue.size() > 1) {
         env.getReporter().handle(Event.error("at most one key may be specified"));
-        return ExitCode.COMMAND_LINE_ERROR;
+        return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
       }
 
       String key = residue.size() == 1 ? residue.get(0) : null;
@@ -163,14 +165,14 @@ public class InfoCommand implements BlazeCommand {
           value = items.get(key).get(configurationSupplier, env);
         } else {
           env.getReporter().handle(Event.error("unknown key: '" + key + "'"));
-          return ExitCode.COMMAND_LINE_ERROR;
+          return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
         }
         try {
           outErr.getOutputStream().write(value);
           outErr.getOutputStream().flush();
         } catch (IOException e) {
           env.getReporter().handle(Event.error("Cannot write info block: " + e.getMessage()));
-          return ExitCode.ANALYSIS_FAILURE;
+          return BlazeCommandResult.exitCode(ExitCode.ANALYSIS_FAILURE);
         }
       } else { // print them all
         configurationSupplier.get();  // We'll need this later anyway
@@ -184,15 +186,15 @@ public class InfoCommand implements BlazeCommand {
         }
       }
     } catch (AbruptExitException e) {
-      return e.getExitCode();
+      return BlazeCommandResult.exitCode(e.getExitCode());
     } catch (ExitCausingRuntimeException e) {
-      return e.getExitCode();
+      return BlazeCommandResult.exitCode(e.getExitCode());
     } catch (IOException e) {
-      return ExitCode.LOCAL_ENVIRONMENTAL_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.LOCAL_ENVIRONMENTAL_ERROR);
     } catch (InterruptedException e) {
-      return ExitCode.INTERRUPTED;
+      return BlazeCommandResult.exitCode(ExitCode.INTERRUPTED);
     }
-    return ExitCode.SUCCESS;
+    return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
   }
 
   static Map<String, InfoItem> getHardwiredInfoItemMap(OptionsProvider commandOptions,
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/LicenseCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/LicenseCommand.java
index b735107e79..7ad512acb6 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/LicenseCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/LicenseCommand.java
@@ -16,6 +16,7 @@ package com.google.devtools.build.lib.runtime.commands;
 import com.google.common.io.Files;
 import com.google.devtools.build.lib.analysis.NoBuildEvent;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
 import com.google.devtools.build.lib.util.ExitCode;
@@ -52,7 +53,7 @@ public class LicenseCommand implements BlazeCommand {
   }
 
   @Override
-  public ExitCode exec(CommandEnvironment env, OptionsProvider options) {
+  public BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options) {
     env.getEventBus().post(new NoBuildEvent());
     OutErr outErr = env.getReporter().getOutErr();
 
@@ -81,7 +82,7 @@ public class LicenseCommand implements BlazeCommand {
       printJavaLicenseFiles(outErr, bundledJre);
     }
 
-    return ExitCode.SUCCESS;
+    return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
   }
 
   private static void printJavaLicenseFiles(OutErr outErr, Path bundledJdkOrJre) {
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/PrintActionCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/PrintActionCommand.java
index 930575f674..6b4b266076 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/PrintActionCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/PrintActionCommand.java
@@ -44,6 +44,7 @@ import com.google.devtools.build.lib.packages.Rule;
 import com.google.devtools.build.lib.packages.Target;
 import com.google.devtools.build.lib.pkgcache.LoadingOptions;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.BlazeRuntime;
 import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
@@ -99,7 +100,7 @@ public final class PrintActionCommand implements BlazeCommand {
   }
 
   @Override
-  public ExitCode exec(CommandEnvironment env, OptionsProvider options) {
+  public BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options) {
     LoadingOptions loadingOptions =
         options.getOptions(LoadingOptions.class);
 
@@ -107,7 +108,7 @@ public final class PrintActionCommand implements BlazeCommand {
     PrintActionRunner runner = new PrintActionRunner(loadingOptions.compileOneDependency, options,
         env.getReporter().getOutErr(),
         options.getResidue(), Sets.newHashSet(printActionOptions.printActionMnemonics));
-    return runner.printActionsForTargets(env);
+    return BlazeCommandResult.exitCode(runner.printActionsForTargets(env));
   }
 
   /**
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/ProfileCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/ProfileCommand.java
index 951e5c490b..f39f0054b3 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/ProfileCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/ProfileCommand.java
@@ -30,6 +30,7 @@ import com.google.devtools.build.lib.profiler.statistics.MultiProfileStatistics;
 import com.google.devtools.build.lib.profiler.statistics.PhaseStatistics;
 import com.google.devtools.build.lib.profiler.statistics.PhaseSummaryStatistics;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
 import com.google.devtools.build.lib.util.ExitCode;
@@ -212,7 +213,7 @@ public final class ProfileCommand implements BlazeCommand {
   public void editOptions(OptionsParser optionsParser) {}
 
   @Override
-  public ExitCode exec(final CommandEnvironment env, OptionsProvider options) {
+  public BlazeCommandResult exec(final CommandEnvironment env, OptionsProvider options) {
     ProfileOptions opts =
         options.getOptions(ProfileOptions.class);
 
@@ -325,7 +326,7 @@ public final class ProfileCommand implements BlazeCommand {
         }
       }
     }
-    return ExitCode.SUCCESS;
+    return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
   }
 
   /**
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java
index d34ae7b4a5..75b20fea68 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java
@@ -36,6 +36,7 @@ import com.google.devtools.build.lib.query2.output.OutputFormatter.StreamedForma
 import com.google.devtools.build.lib.query2.output.QueryOptions;
 import com.google.devtools.build.lib.query2.output.QueryOutputUtils;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.BlazeRuntime;
 import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
@@ -85,7 +86,7 @@ public final class QueryCommand implements BlazeCommand {
    *        (only when --keep_going is in effect.)
    */
   @Override
-  public ExitCode exec(CommandEnvironment env, OptionsProvider options) {
+  public BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options) {
     BlazeRuntime runtime = env.getRuntime();
     QueryOptions queryOptions = options.getOptions(QueryOptions.class);
 
@@ -93,10 +94,10 @@ public final class QueryCommand implements BlazeCommand {
       env.setupPackageCache(options, runtime.getDefaultsPackageContent());
     } catch (InterruptedException e) {
       env.getReporter().handle(Event.error("query interrupted"));
-      return ExitCode.INTERRUPTED;
+      return BlazeCommandResult.exitCode(ExitCode.INTERRUPTED);
     } catch (AbruptExitException e) {
       env.getReporter().handle(Event.error(null, "Unknown error: " + e.getMessage()));
-      return e.getExitCode();
+      return BlazeCommandResult.exitCode(e.getExitCode());
     }
 
     String query;
@@ -104,7 +105,7 @@ public final class QueryCommand implements BlazeCommand {
       if (!queryOptions.queryFile.isEmpty()) {
         env.getReporter()
             .handle(Event.error("Command-line query and --query_file cannot both be specified"));
-        return ExitCode.COMMAND_LINE_ERROR;
+        return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
       }
       query = Joiner.on(' ').join(options.getResidue());
     } else if (!queryOptions.queryFile.isEmpty()) {
@@ -115,13 +116,13 @@ public final class QueryCommand implements BlazeCommand {
       } catch (IOException e) {
         env.getReporter()
             .handle(Event.error("I/O error reading from " + residuePath.getPathString()));
-        return ExitCode.COMMAND_LINE_ERROR;
+        return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
       }
     } else {
       env.getReporter().handle(Event.error(String.format(
           "missing query expression. Type '%s help query' for syntax and help",
           runtime.getProductName())));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
 
     Iterable<OutputFormatter> formatters = runtime.getQueryOutputFormatters();
@@ -131,7 +132,7 @@ public final class QueryCommand implements BlazeCommand {
       env.getReporter().handle(Event.error(
           String.format("Invalid output format '%s'. Valid values are: %s",
               queryOptions.outputFormat, OutputFormatter.formatterNames(formatters))));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
 
     Set<Setting> settings = queryOptions.toSettings();
@@ -151,14 +152,14 @@ public final class QueryCommand implements BlazeCommand {
     } catch (QueryException e) {
       env.getReporter()
           .handle(Event.error(null, "Error while parsing '" + query + "': " + e.getMessage()));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
 
     try {
       formatter.verifyCompatible(queryEnv, expr);
     } catch (QueryException e) {
       env.getReporter().handle(Event.error(e.getMessage()));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
 
     expr = queryEnv.transformParsedQuery(expr);
@@ -194,21 +195,21 @@ public final class QueryCommand implements BlazeCommand {
           // TODO(bazel-team): this is a kludge to fix a bug observed in the wild. We should make
           // sure no null error messages ever get in.
           .handle(Event.error(e.getMessage() == null ? e.toString() : e.getMessage()));
-      return ExitCode.ANALYSIS_FAILURE;
+      return BlazeCommandResult.exitCode(ExitCode.ANALYSIS_FAILURE);
     } catch (InterruptedException e) {
       catastrophe = false;
       IOException ioException = callback.getIoException();
       if (ioException == null || ioException instanceof ClosedByInterruptException) {
         env.getReporter().handle(Event.error("query interrupted"));
-        return ExitCode.INTERRUPTED;
+        return BlazeCommandResult.exitCode(ExitCode.INTERRUPTED);
       } else {
         env.getReporter().handle(Event.error("I/O error: " + e.getMessage()));
-        return ExitCode.LOCAL_ENVIRONMENTAL_ERROR;
+        return BlazeCommandResult.exitCode(ExitCode.LOCAL_ENVIRONMENTAL_ERROR);
       }
     } catch (IOException e) {
       catastrophe = false;
       env.getReporter().handle(Event.error("I/O error: " + e.getMessage()));
-      return ExitCode.LOCAL_ENVIRONMENTAL_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.LOCAL_ENVIRONMENTAL_ERROR);
     } finally {
       if (!catastrophe) {
         try {
@@ -216,7 +217,7 @@ public final class QueryCommand implements BlazeCommand {
         } catch (IOException e) {
           env.getReporter().handle(
               Event.error("Failed to flush query results: " + e.getMessage()));
-          return ExitCode.LOCAL_ENVIRONMENTAL_ERROR;
+          return BlazeCommandResult.exitCode(ExitCode.LOCAL_ENVIRONMENTAL_ERROR);
         }
       }
     }
@@ -236,17 +237,17 @@ public final class QueryCommand implements BlazeCommand {
             queryOptions.aspectDeps.createResolver(env.getPackageManager(), env.getReporter()));
       } catch (ClosedByInterruptException | InterruptedException e) {
         env.getReporter().handle(Event.error("query interrupted"));
-        return ExitCode.INTERRUPTED;
+        return BlazeCommandResult.exitCode(ExitCode.INTERRUPTED);
       } catch (IOException e) {
         env.getReporter().handle(Event.error("I/O error: " + e.getMessage()));
-        return ExitCode.LOCAL_ENVIRONMENTAL_ERROR;
+        return BlazeCommandResult.exitCode(ExitCode.LOCAL_ENVIRONMENTAL_ERROR);
       } finally {
         try {
           out.flush();
         } catch (IOException e) {
           env.getReporter().handle(
               Event.error("Failed to flush query results: " + e.getMessage()));
-          return ExitCode.LOCAL_ENVIRONMENTAL_ERROR;
+          return BlazeCommandResult.exitCode(ExitCode.LOCAL_ENVIRONMENTAL_ERROR);
         }
       }
     }
@@ -258,7 +259,7 @@ public final class QueryCommand implements BlazeCommand {
     ExitCode exitCode = result.getSuccess() ? ExitCode.SUCCESS : ExitCode.PARTIAL_ANALYSIS_FAILURE;
     env.getEventBus()
         .post(new NoBuildRequestFinishedEvent(exitCode, runtime.getClock().currentTimeMillis()));
-    return exitCode;
+    return BlazeCommandResult.exitCode(exitCode);
   }
 
   /**
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/RunCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/RunCommand.java
index 921fd7dda0..8535616a4b 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/RunCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/RunCommand.java
@@ -46,9 +46,12 @@ import com.google.devtools.build.lib.packages.Target;
 import com.google.devtools.build.lib.packages.TargetUtils;
 import com.google.devtools.build.lib.pkgcache.LoadingFailedException;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
 import com.google.devtools.build.lib.runtime.ProcessWrapperUtil;
+import com.google.devtools.build.lib.server.CommandProtos.EnvironmentVariable;
+import com.google.devtools.build.lib.server.CommandProtos.ExecRequest;
 import com.google.devtools.build.lib.shell.AbnormalTerminationException;
 import com.google.devtools.build.lib.shell.BadExitStatusException;
 import com.google.devtools.build.lib.shell.CommandException;
@@ -71,11 +74,13 @@ import com.google.devtools.common.options.OptionEffectTag;
 import com.google.devtools.common.options.OptionsBase;
 import com.google.devtools.common.options.OptionsParser;
 import com.google.devtools.common.options.OptionsProvider;
+import com.google.protobuf.ByteString;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.Map;
 
 /**
  * Builds and run a target with the given command line arguments.
@@ -92,9 +97,21 @@ import java.util.List;
          completion = "label-bin",
          binaryStdErr = true)
 public class RunCommand implements BlazeCommand  {
-
   public static class RunOptions extends OptionsBase {
     @Option(
+      name = "direct_run",
+      category = "run",
+      defaultValue = "false",
+      documentationCategory =  OptionDocumentationCategory.OUTPUT_PARAMETERS,
+      effectTags = {OptionEffectTag.EXECUTION},
+      help = "If set, the 'run' command will execute the binary to be executed in the terminal "
+          + "where the command was called. Otherwise, it'll be executed as a child of the server "
+          + "process. If set, the binary will have access to direct terminal I/O and the command "
+          + "lock will not be held during its execution. This makes it possible to run other "
+          + "commands in parallel.")
+    public boolean direct;
+
+    @Option(
       name = "script_path",
       category = "run",
       defaultValue = "null",
@@ -139,7 +156,7 @@ public class RunCommand implements BlazeCommand  {
   public void editOptions(OptionsParser optionsParser) { }
 
   @Override
-  public ExitCode exec(CommandEnvironment env, OptionsProvider options) {
+  public BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options) {
     RunOptions runOptions = options.getOptions(RunOptions.class);
     // This list should look like: ["//executable:target", "arg1", "arg2"]
     List<String> targetAndArgs = options.getResidue();
@@ -147,7 +164,7 @@ public class RunCommand implements BlazeCommand  {
     // The user must at the least specify an executable target.
     if (targetAndArgs.isEmpty()) {
       env.getReporter().handle(Event.error("Must specify a target to run"));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
     String targetString = targetAndArgs.get(0);
     List<String> runTargetArgs = targetAndArgs.subList(1, targetAndArgs.size());
@@ -172,7 +189,7 @@ public class RunCommand implements BlazeCommand  {
 
     if (!result.getSuccess()) {
       env.getReporter().handle(Event.error("Build failed. Not running target"));
-      return result.getExitCondition();
+      return BlazeCommandResult.exitCode(result.getExitCondition());
     }
 
     // Make sure that we have exactly 1 built target (excluding --run_under),
@@ -187,25 +204,25 @@ public class RunCommand implements BlazeCommand  {
       int maxTargets = runUnder != null && runUnder.getLabel() != null ? 2 : 1;
       if (targetsBuilt.size() > maxTargets) {
         env.getReporter().handle(Event.error(SINGLE_TARGET_MESSAGE));
-        return ExitCode.COMMAND_LINE_ERROR;
+        return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
       }
       for (ConfiguredTarget target : targetsBuilt) {
         ExitCode targetValidation = fullyValidateTarget(env, target);
         if (!targetValidation.equals(ExitCode.SUCCESS)) {
-          return targetValidation;
+          return BlazeCommandResult.exitCode(targetValidation);
         }
         if (runUnder != null && target.getLabel().equals(runUnder.getLabel())) {
           if (runUnderTarget != null) {
             env.getReporter().handle(Event.error(
                 null, "Can't identify the run_under target from multiple options?"));
-            return ExitCode.COMMAND_LINE_ERROR;
+            return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
           }
           runUnderTarget = target;
         } else if (targetToRun == null) {
           targetToRun = target;
         } else {
           env.getReporter().handle(Event.error(SINGLE_TARGET_MESSAGE));
-          return ExitCode.COMMAND_LINE_ERROR;
+          return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
         }
       }
     }
@@ -215,7 +232,7 @@ public class RunCommand implements BlazeCommand  {
     }
     if (targetToRun == null) {
       env.getReporter().handle(Event.error(NO_TARGET_MESSAGE));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
 
     Path executablePath = Preconditions.checkNotNull(
@@ -231,13 +248,13 @@ public class RunCommand implements BlazeCommand  {
       env.getReporter()
           .handle(
               Event.error("--nobuild_runfile_manifests is incompatible with the \"run\" command"));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
     try {
       workingDir = ensureRunfilesBuilt(env, targetToRun);
     } catch (CommandException e) {
       env.getReporter().handle(Event.error("Error creating runfiles: " + e.getMessage()));
-      return ExitCode.LOCAL_ENVIRONMENTAL_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.LOCAL_ENVIRONMENTAL_ERROR);
     }
 
     List<String> args = Lists.newArrayList();
@@ -250,7 +267,7 @@ public class RunCommand implements BlazeCommand  {
         Iterables.addAll(args, targetArgs.arguments());
       } catch (CommandLineExpansionException e) {
         env.getReporter().handle(Event.error("Could not expand target command line: " + e));
-        return ExitCode.ANALYSIS_FAILURE;
+        return BlazeCommandResult.exitCode(ExitCode.ANALYSIS_FAILURE);
       }
     }
     args.addAll(runTargetArgs);
@@ -271,7 +288,8 @@ public class RunCommand implements BlazeCommand  {
     // process-wrapper does not work on Windows (nor is it necessary), so don't use it
     // on that platform. Also we skip it when writing the command-line to a file instead
     // of executing it directly.
-    if (OS.getCurrent() != OS.WINDOWS && runOptions.scriptPath == null) {
+    if (OS.getCurrent() != OS.WINDOWS && runOptions.scriptPath == null
+        && !runOptions.direct) {
       Preconditions.checkState(ProcessWrapperUtil.isSupported(env),
           "process-wraper not found in embedded tools");
       cmdLine.add(ProcessWrapperUtil.getProcessWrapper(env).getPathString());
@@ -317,19 +335,38 @@ public class RunCommand implements BlazeCommand  {
           CommandDescriptionForm.COMPLETE_UNISOLATED,
           cmdLine, null, workingDir.getPathString());
       if (writeScript(env, runOptions.scriptPath, unisolatedCommand)) {
-        return ExitCode.SUCCESS;
+        return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
       } else {
-        return ExitCode.RUN_FAILURE;
+        return BlazeCommandResult.exitCode(ExitCode.RUN_FAILURE);
       }
     }
 
     env.getReporter().handle(Event.info(
         null, "Running command line: " + ShellEscaper.escapeJoinAll(prettyCmdLine)));
 
-    com.google.devtools.build.lib.shell.Command command = new CommandBuilder()
-        .addArgs(cmdLine).setEnv(env.getClientEnv()).setWorkingDir(workingDir).build();
+    if (runOptions.direct) {
+      ExecRequest.Builder execDescription = ExecRequest.newBuilder()
+          .setWorkingDirectory(
+              ByteString.copyFrom(workingDir.getPathString(), StandardCharsets.ISO_8859_1));
+
+      for (String arg : cmdLine) {
+        execDescription.addArgv(ByteString.copyFrom(arg, StandardCharsets.ISO_8859_1));
+      }
+
+      for (Map.Entry<String, String> variable : env.getClientEnv().entrySet()) {
+        execDescription.addEnvironmentVariable(EnvironmentVariable.newBuilder()
+            .setName(ByteString.copyFrom(variable.getKey(), StandardCharsets.ISO_8859_1))
+            .setValue(ByteString.copyFrom(variable.getValue(), StandardCharsets.ISO_8859_1))
+            .build());
+      }
+
+      return BlazeCommandResult.execute(execDescription.build());
+    }
 
     try {
+      com.google.devtools.build.lib.shell.Command command = new CommandBuilder()
+          .addArgs(cmdLine).setEnv(env.getClientEnv()).setWorkingDir(workingDir).build();
+
       // Restore a raw EventHandler if it is registered. This allows for blaze run to produce the
       // actual output of the command being run even if --color=no is specified.
       env.getReporter().switchToAnsiAllowingHandler();
@@ -341,19 +378,19 @@ public class RunCommand implements BlazeCommand  {
           .execute(outErr.getOutputStream(), outErr.getErrorStream())
           .getTerminationStatus()
           .getExitCode();
-      return ExitCode.SUCCESS;
+      return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
     } catch (BadExitStatusException e) {
       String message = "Non-zero return code '"
                        + e.getResult().getTerminationStatus().getExitCode()
                        + "' from command: " + e.getMessage();
       env.getReporter().handle(Event.error(message));
-      return ExitCode.RUN_FAILURE;
+      return BlazeCommandResult.exitCode(ExitCode.RUN_FAILURE);
     } catch (AbnormalTerminationException e) {
       // The process was likely terminated by a signal in this case.
-      return ExitCode.INTERRUPTED;
+      return BlazeCommandResult.exitCode(ExitCode.INTERRUPTED);
     } catch (CommandException e) {
       env.getReporter().handle(Event.error("Error running program: " + e.getMessage()));
-      return ExitCode.RUN_FAILURE;
+      return BlazeCommandResult.exitCode(ExitCode.RUN_FAILURE);
     }
   }
 
@@ -480,7 +517,8 @@ public class RunCommand implements BlazeCommand  {
    * Performs all available validation checks on an individual target.
    *
    * @param configuredTarget ConfiguredTarget to validate
-   * @return ExitCode.SUCCESS if all checks succeeded, otherwise a different error code.
+   * @return BlazeCommandResult.exitCode(ExitCode.SUCCESS) if all checks succeeded, otherwise a
+   *     different error code.
    * @throws IllegalStateException if unable to find a target from the package manager.
    */
   private ExitCode fullyValidateTarget(CommandEnvironment env, ConfiguredTarget configuredTarget) {
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/ShutdownCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/ShutdownCommand.java
index 09423c0b56..f242c9d7ce 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/ShutdownCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/ShutdownCommand.java
@@ -15,6 +15,7 @@ package com.google.devtools.build.lib.runtime.commands;
 
 import com.google.devtools.build.lib.runtime.BlazeCommand;
 import com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.ShutdownBlazeServerException;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
 import com.google.devtools.build.lib.util.ExitCode;
@@ -56,7 +57,7 @@ public final class ShutdownCommand implements BlazeCommand {
   public void editOptions(OptionsParser optionsParser) {}
 
   @Override
-  public ExitCode exec(CommandEnvironment env, OptionsProvider options)
+  public BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options)
       throws ShutdownBlazeServerException {
     int limit = options.getOptions(Options.class).heapSizeLimit;
 
@@ -69,9 +70,9 @@ public final class ShutdownCommand implements BlazeCommand {
 
     if (limit == 0 ||
         Runtime.getRuntime().totalMemory() > limit * 1000L * 1000) {
-      throw new ShutdownBlazeServerException(0);
+      throw new ShutdownBlazeServerException(ExitCode.SUCCESS);
     }
-    return ExitCode.SUCCESS;
+    return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
   }
 
 }
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/TestCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/TestCommand.java
index 1e3f61a97a..5887aa59da 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/TestCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/TestCommand.java
@@ -29,6 +29,7 @@ import com.google.devtools.build.lib.exec.TestStrategy.TestOutputFormat;
 import com.google.devtools.build.lib.runtime.AggregatingTestListener;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
 import com.google.devtools.build.lib.runtime.BlazeCommandEventHandler;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.BlazeRuntime;
 import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
@@ -81,7 +82,7 @@ public class TestCommand implements BlazeCommand {
   }
 
   @Override
-  public ExitCode exec(CommandEnvironment env, OptionsProvider options) {
+  public BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options) {
     TestOutputFormat testOutput = options.getOptions(ExecutionOptions.class).testOutput;
     if (testOutput == TestStrategy.TestOutputFormat.STREAMED) {
       env.getReporter().handle(Event.warn(
@@ -105,7 +106,7 @@ public class TestCommand implements BlazeCommand {
     return doTest(env, options, testListener);
   }
 
-  private ExitCode doTest(CommandEnvironment env,
+  private BlazeCommandResult doTest(CommandEnvironment env,
       OptionsProvider options,
       AggregatingTestListener testListener) {
     BlazeRuntime runtime = env.getRuntime();
@@ -134,7 +135,7 @@ public class TestCommand implements BlazeCommand {
       ExitCode exitCode =
           buildResult.getSuccess() ? ExitCode.PARSING_FAILURE : buildResult.getExitCondition();
       env.getEventBus().post(new TestingCompleteEvent(exitCode, buildResult.getStopTime()));
-      return exitCode;
+      return BlazeCommandResult.exitCode(exitCode);
     }
     // TODO(bazel-team): the check above shadows NO_TESTS_FOUND, but switching the conditions breaks
     // more tests
@@ -146,7 +147,7 @@ public class TestCommand implements BlazeCommand {
           buildResult.getSuccess() ? ExitCode.NO_TESTS_FOUND : buildResult.getExitCondition();
       env.getEventBus()
           .post(new NoTestsFound(exitCode, env.getRuntime().getClock().currentTimeMillis()));
-      return exitCode;
+      return BlazeCommandResult.exitCode(exitCode);
     }
 
     boolean buildSuccess = buildResult.getSuccess();
@@ -165,7 +166,7 @@ public class TestCommand implements BlazeCommand {
         ? (testSuccess ? ExitCode.SUCCESS : ExitCode.TESTS_FAILED)
         : buildResult.getExitCondition();
     env.getEventBus().post(new TestingCompleteEvent(exitCode, buildResult.getStopTime()));
-    return exitCode;
+    return BlazeCommandResult.exitCode(exitCode);
   }
 
   /**
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/VersionCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/VersionCommand.java
index eff8700248..729c3b7c25 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/VersionCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/VersionCommand.java
@@ -17,6 +17,7 @@ import com.google.devtools.build.lib.analysis.BlazeVersionInfo;
 import com.google.devtools.build.lib.analysis.NoBuildEvent;
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
 import com.google.devtools.build.lib.util.ExitCode;
@@ -38,14 +39,14 @@ public final class VersionCommand implements BlazeCommand {
   public void editOptions(OptionsParser optionsParser) {}
 
   @Override
-  public ExitCode exec(CommandEnvironment env, OptionsProvider options) {
+  public BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options) {
     BlazeVersionInfo info = BlazeVersionInfo.instance();
     if (info.getSummary() == null) {
       env.getReporter().handle(Event.error("Version information not available"));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
     env.getEventBus().post(new NoBuildEvent());
     env.getReporter().getOutErr().printOutLn(info.getSummary());
-    return ExitCode.SUCCESS;
+    return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/mobileinstall/MobileInstallCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/mobileinstall/MobileInstallCommand.java
index acdd49784d..d382daf5c4 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/mobileinstall/MobileInstallCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/mobileinstall/MobileInstallCommand.java
@@ -28,6 +28,7 @@ import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.rules.android.WriteAdbArgsAction;
 import com.google.devtools.build.lib.rules.android.WriteAdbArgsAction.StartType;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
 import com.google.devtools.build.lib.runtime.CommonCommandOptions;
@@ -167,7 +168,7 @@ public class MobileInstallCommand implements BlazeCommand {
   private static final String NO_TARGET_MESSAGE = "No targets found to run";
 
   @Override
-  public ExitCode exec(CommandEnvironment env, OptionsProvider options) {
+  public BlazeCommandResult exec(CommandEnvironment env, OptionsProvider options) {
     Options mobileInstallOptions = options.getOptions(Options.class);
     WriteAdbArgsAction.Options adbOptions = options.getOptions(WriteAdbArgsAction.Options.class);
 
@@ -193,7 +194,8 @@ public class MobileInstallCommand implements BlazeCommand {
               env.getReporter().getOutErr(),
               env.getCommandId(),
               env.getCommandStartTime());
-      return new BuildTool(env).processRequest(request, null).getExitCondition();
+      ExitCode exitCode = new BuildTool(env).processRequest(request, null).getExitCondition();
+      return BlazeCommandResult.exitCode(exitCode);
     }
 
     // This list should look like: ["//executable:target", "arg1", "arg2"]
@@ -202,7 +204,7 @@ public class MobileInstallCommand implements BlazeCommand {
     // The user must at least specify an executable target.
     if (targetAndArgs.isEmpty()) {
       env.getReporter().handle(Event.error("Must specify a target to run"));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
 
     List<String> targets = ImmutableList.of(targetAndArgs.get(0));
@@ -222,17 +224,17 @@ public class MobileInstallCommand implements BlazeCommand {
 
     if (!result.getSuccess()) {
       env.getReporter().handle(Event.error("Build failed. Not running target"));
-      return result.getExitCondition();
+      return BlazeCommandResult.exitCode(result.getExitCondition());
     }
 
     Collection<ConfiguredTarget> targetsBuilt = result.getSuccessfulTargets();
     if (targetsBuilt == null) {
       env.getReporter().handle(Event.error(NO_TARGET_MESSAGE));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
     if (targetsBuilt.size() != 1) {
       env.getReporter().handle(Event.error(SINGLE_TARGET_MESSAGE));
-      return ExitCode.COMMAND_LINE_ERROR;
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
     }
     ConfiguredTarget targetToRun = Iterables.getOnlyElement(targetsBuilt);
 
@@ -299,7 +301,7 @@ public class MobileInstallCommand implements BlazeCommand {
           .execute(outErr.getOutputStream(), outErr.getErrorStream())
           .getTerminationStatus()
           .getExitCode();
-      return ExitCode.SUCCESS;
+      return BlazeCommandResult.exitCode(ExitCode.SUCCESS);
     } catch (BadExitStatusException e) {
       String message =
           "Non-zero return code '"
@@ -307,13 +309,13 @@ public class MobileInstallCommand implements BlazeCommand {
               + "' from command: "
               + e.getMessage();
       env.getReporter().handle(Event.error(message));
-      return ExitCode.RUN_FAILURE;
+      return BlazeCommandResult.exitCode(ExitCode.RUN_FAILURE);
     } catch (AbnormalTerminationException e) {
       // The process was likely terminated by a signal in this case.
-      return ExitCode.INTERRUPTED;
+      return BlazeCommandResult.exitCode(ExitCode.INTERRUPTED);
     } catch (CommandException e) {
       env.getReporter().handle(Event.error("Error running program: " + e.getMessage()));
-      return ExitCode.RUN_FAILURE;
+      return BlazeCommandResult.exitCode(ExitCode.RUN_FAILURE);
     }
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/server/GrpcServerImpl.java b/src/main/java/com/google/devtools/build/lib/server/GrpcServerImpl.java
index c412131ead..aa575da2b5 100644
--- a/src/main/java/com/google/devtools/build/lib/server/GrpcServerImpl.java
+++ b/src/main/java/com/google/devtools/build/lib/server/GrpcServerImpl.java
@@ -26,6 +26,7 @@ import com.google.devtools.build.lib.clock.BlazeClock;
 import com.google.devtools.build.lib.clock.Clock;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.LockingMode;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.CommandExecutor;
 import com.google.devtools.build.lib.runtime.proto.InvocationPolicyOuterClass.InvocationPolicy;
 import com.google.devtools.build.lib.server.CommandProtos.CancelRequest;
@@ -814,7 +815,7 @@ public class GrpcServerImpl implements RPCServer {
     }
 
     String commandId;
-    int exitCode;
+    BlazeCommandResult result;
 
     // TODO(b/63925394): This information needs to be passed to the GotOptionsEvent, which does not
     // currently have the explicit startup options. See Improved Command Line Reporting design doc
@@ -847,7 +848,7 @@ public class GrpcServerImpl implements RPCServer {
 
       try {
         InvocationPolicy policy = InvocationPolicyParser.parsePolicy(request.getInvocationPolicy());
-        exitCode =
+        result =
             commandExecutor.exec(
                 policy,
                 args.build(),
@@ -858,10 +859,10 @@ public class GrpcServerImpl implements RPCServer {
                 Optional.of(startupOptions.build()));
       } catch (OptionsParsingException e) {
         rpcOutErr.printErrLn(e.getMessage());
-        exitCode = ExitCode.COMMAND_LINE_ERROR.getNumericExitCode();
+        result = BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
       }
     } catch (InterruptedException e) {
-      exitCode = ExitCode.INTERRUPTED.getNumericExitCode();
+      result = BlazeCommandResult.exitCode(ExitCode.INTERRUPTED);
       commandId = ""; // The default value, the client will ignore it
     }
 
@@ -883,17 +884,22 @@ public class GrpcServerImpl implements RPCServer {
     if (shutdown) {
       server.shutdown();
     }
-    RunResponse response =
-        RunResponse.newBuilder()
-            .setCookie(responseCookie)
-            .setCommandId(commandId)
-            .setFinished(true)
-            .setExitCode(exitCode)
-            .setTerminationExpected(shutdown)
-            .build();
+
+    RunResponse.Builder response = RunResponse.newBuilder()
+        .setCookie(responseCookie)
+        .setCommandId(commandId)
+        .setFinished(true)
+        .setTerminationExpected(shutdown);
+
+    if (result.getExecRequest() != null) {
+      response.setExitCode(0);
+      response.setExecRequest(result.getExecRequest());
+    } else {
+      response.setExitCode(result.getExitCode().getNumericExitCode());
+    }
 
     try {
-      observer.onNext(response);
+      observer.onNext(response.build());
       observer.onCompleted();
     } catch (StatusRuntimeException e) {
       // The client cancelled the call. Log an error and go on.
diff --git a/src/main/java/com/google/devtools/build/lib/server/ServerCommand.java b/src/main/java/com/google/devtools/build/lib/server/ServerCommand.java
index f0574cdbaa..aed9d73b98 100644
--- a/src/main/java/com/google/devtools/build/lib/server/ServerCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/server/ServerCommand.java
@@ -14,6 +14,7 @@
 package com.google.devtools.build.lib.server;
 
 import com.google.devtools.build.lib.runtime.BlazeCommandDispatcher;
+import com.google.devtools.build.lib.runtime.BlazeCommandResult;
 import com.google.devtools.build.lib.runtime.proto.InvocationPolicyOuterClass.InvocationPolicy;
 import com.google.devtools.build.lib.util.Pair;
 import com.google.devtools.build.lib.util.io.OutErr;
@@ -35,7 +36,7 @@ public interface ServerCommand {
    *     --[no]flag or --flag=value form. If we don't have access to this information (--batch),
    *     leave this parameter as Optional.empty().
    */
-  int exec(
+  BlazeCommandResult exec(
       InvocationPolicy policy,
       List<String> args,
       OutErr outErr,
diff --git a/src/main/java/com/google/devtools/build/lib/shell/Command.java b/src/main/java/com/google/devtools/build/lib/shell/Command.java
index 0e8c5a0247..1584275184 100644
--- a/src/main/java/com/google/devtools/build/lib/shell/Command.java
+++ b/src/main/java/com/google/devtools/build/lib/shell/Command.java
@@ -46,7 +46,7 @@ import javax.annotation.Nullable;
  * <p>The most basic use-case for this class is as follows:
  * <pre>
  *   String[] args = { "/bin/du", "-s", directory };
- *   CommandResult result = new Command(args).execute();
+ *   BlazeCommandResult result = new Command(args).execute();
  *   String output = new String(result.getStdout());
  * </pre>
  * which writes the output of the {@code du(1)} command into {@code output}. More complex cases
@@ -78,7 +78,7 @@ import javax.annotation.Nullable;
  * <p>To execute a shell command directly, use the following pattern:
  * <pre>
  *   String[] args = { "/bin/sh", "-c", shellCommand };
- *   CommandResult result = new Command(args).execute();
+ *   BlazeCommandResult result = new Command(args).execute();
  * </pre>
  * {@code shellCommand} is a complete Bourne shell program, possibly containing all kinds of
  * unescaped metacharacters.  For example, here's a shell command that enumerates the working