Use EmptyActionInput instead of null in SpawnInputExpander

This simplifies some spawn runners, which no longer have to specially handle
null; unfortunately, the sandbox runners do not support VirtualActionInput,
so they still have to special-case it.

PiperOrigin-RevId: 181175408

1 files changed, 1 insertions, 2 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/remote/RemoteSpawnRunner.java b/src/main/java/com/google/devtools/build/lib/remote/RemoteSpawnRunner.java
index 87a3058f1a..b8a1080c7b 100644
--- a/src/main/java/com/google/devtools/build/lib/remote/RemoteSpawnRunner.java
+++ b/src/main/java/com/google/devtools/build/lib/remote/RemoteSpawnRunner.java
@@ -30,7 +30,6 @@ import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.events.Reporter;
 import com.google.devtools.build.lib.exec.SpawnExecException;
-import com.google.devtools.build.lib.exec.SpawnInputExpander;
 import com.google.devtools.build.lib.exec.SpawnRunner;
 import com.google.devtools.build.lib.remote.DigestUtil.ActionKey;
 import com.google.devtools.build.lib.remote.Retrier.RetryException;
@@ -310,7 +309,7 @@ class RemoteSpawnRunner implements SpawnRunner {
     HashMap<Path, Long>  ctimes = new HashMap<>();
     for (Map.Entry<PathFragment, ActionInput> e : inputMap.entrySet()) {
       ActionInput input = e.getValue();
-      if (input == SpawnInputExpander.EMPTY_FILE || input instanceof VirtualActionInput) {
+      if (input instanceof VirtualActionInput) {
         continue;
       }
       Path path = execRoot.getRelative(input.getExecPathString());