Use CustomCommandLine.Builder in SpawnAction always.

This takes advantage of CustomCommandLine's ability to defer argument expansion. I can't think of any situation where this would be inferior, at it also cleans up the code a little.

After the execution phase when Artifact strings will have been prodded and interned, I expect the memory difference to be less pronounced.

PiperOrigin-RevId: 164996323

1 files changed, 10 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/actions/CustomCommandLine.java b/src/main/java/com/google/devtools/build/lib/analysis/actions/CustomCommandLine.java
index 83adf2e6ac..9ef6545700 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/actions/CustomCommandLine.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/actions/CustomCommandLine.java
@@ -605,12 +605,22 @@ public final class CustomCommandLine extends CommandLine {
     public CustomCommandLine build() {
       return new CustomCommandLine(arguments);
     }
+
+    public boolean isEmpty() {
+      return arguments.isEmpty();
+    }
   }
 
   public static Builder builder() {
     return new Builder();
   }
 
+  public static Builder builder(Builder other) {
+    Builder builder = new Builder();
+    builder.arguments.addAll(other.arguments);
+    return builder;
+  }
+
   private final ImmutableList<Object> arguments;
 
   /**