--- a/.lldbinit
+++ b/.lldbinit
@@ -15,8 +15,11 @@ settings set target.prefer-dynamic-value
 # the top level source directory.
 script sys.path.append('python/lldbutils'); import lldbutils; lldbutils.init()
 
 # Show the string value in atoms.
 type summary add nsIAtom --summary-string "${var.mString}"
 
 # Show the value of text nodes.
 type summary add nsTextNode --summary-string "${var.mText}"
+
+# Dump the current JS stack.
+command alias js expr DumpJSStack()