1 files changed, 6 insertions, 37 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/actions/CommandLine.java b/src/main/java/com/google/devtools/build/lib/analysis/actions/CommandLine.java
index 7bc670569a..1d3e0bebb8 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/actions/CommandLine.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/actions/CommandLine.java
@@ -19,17 +19,10 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
 import com.google.devtools.build.lib.actions.Artifact.ArtifactExpander;
 import com.google.devtools.build.lib.collect.CollectionUtils;
+import com.google.devtools.build.lib.util.Preconditions;
 
 /** A representation of a list of arguments, often a command executed by {@link SpawnAction}. */
 public abstract class CommandLine {
-  public static final CommandLine EMPTY =
-      new CommandLine() {
-        @Override
-        public Iterable<String> arguments() {
-          return ImmutableList.of();
-        }
-      };
-
   /**
    * Returns the command line.
    */
@@ -62,42 +55,18 @@ public abstract class CommandLine {
    * Returns a {@link CommandLine} that is constructed by prepending the {@code executableArgs} to
    * {@code commandLine}.
    */
-  public static CommandLine concat(
-      final ImmutableList<String> executableArgs, final CommandLine commandLine) {
-    if (executableArgs.isEmpty()) {
-      return commandLine;
-    }
-    return new CommandLine() {
-      @Override
-      public Iterable<String> arguments() {
-        return Iterables.concat(executableArgs, commandLine.arguments());
-      }
-
-      @Override
-      public Iterable<String> arguments(ArtifactExpander artifactExpander) {
-        return Iterables.concat(executableArgs, commandLine.arguments(artifactExpander));
-      }
-    };
-  }
-
-  /**
-   * Returns a {@link CommandLine} that is constructed by appending the {@code args} to {@code
-   * commandLine}.
-   */
-  public static CommandLine concat(
-      final CommandLine commandLine, final ImmutableList<String> args) {
-    if (args.isEmpty()) {
-      return commandLine;
-    }
+  CommandLine prepend(final ImmutableList<String> executableArgs) {
+    final CommandLine self = this;
+    Preconditions.checkState(!executableArgs.isEmpty());
     return new CommandLine() {
       @Override
       public Iterable<String> arguments() {
-        return Iterables.concat(commandLine.arguments(), args);
+        return Iterables.concat(executableArgs, self.arguments());
       }
 
       @Override
       public Iterable<String> arguments(ArtifactExpander artifactExpander) {
-        return Iterables.concat(commandLine.arguments(artifactExpander), args);
+        return Iterables.concat(executableArgs, self.arguments(artifactExpander));
       }
     };
   }