Lazily construct NoSuchVariableException message

Code typically doesn't use the message, so avoid creating it if we don't need to.

--
MOS_MIGRATED_REVID=128837352

1 files changed, 8 insertions, 3 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Environment.java b/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
index c8c89219af..a2db357ef6 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
@@ -30,7 +30,6 @@ import com.google.devtools.build.lib.syntax.Mutability.MutabilityException;
 import com.google.devtools.build.lib.util.Fingerprint;
 import com.google.devtools.build.lib.util.Pair;
 import com.google.devtools.build.lib.util.Preconditions;
-
 import java.io.Serializable;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -38,7 +37,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.TreeSet;
-
 import javax.annotation.Nullable;
 
 /**
@@ -818,8 +816,15 @@ public final class Environment implements Freezable {
    * variable in the Environment.
    */
   public static class NoSuchVariableException extends Exception {
+    private final String variable;
     NoSuchVariableException(String variable) {
-      super("no such variable: " + variable, null, false, false /* don't fillInStackTrace() */);
+      super(null, null, false, false /* don't fillInStackTrace() */);
+      this.variable = variable;
+    }
+
+    @Override
+    public String getMessage() {
+      return "no such variable: " + variable;
     }
   }