From 9ddf9aabfc1e756cbc9ce3433f4d35b41591a846 Mon Sep 17 00:00:00 2001
From: Logan Smyth <loganfsmyth@gmail.com>
Date: Sun, 17 Apr 2016 15:13:34 -0700
Subject: [PATCH] Don't track position when sourcemaps are off.

---
 packages/babel-generator/src/buffer.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/packages/babel-generator/src/buffer.js b/packages/babel-generator/src/buffer.js
index 6a27cf66d0..3158a7c3e4 100644
--- a/packages/babel-generator/src/buffer.js
+++ b/packages/babel-generator/src/buffer.js
@@ -249,6 +249,8 @@ export default class Buffer {
    */
 
   withSource(prop: string, loc: Location, cb: () => void) {
+    if (!this.opts.sourceMaps) return cb();
+
     // Use the call stack to manage a stack of "source location" data.
     let originalLine = this._sourcePosition.line;
     let originalColumn = this._sourcePosition.column;
@@ -310,7 +312,7 @@ export default class Buffer {
     }
 
     // If there the line is ending, adding a new mapping marker is redundant
-    if (str[0] !== "\n") this.map.mark(this._sourcePosition);
+    if (this.opts.sourceMaps && str[0] !== "\n") this.map.mark(this._sourcePosition);
 
     //
     this.position.push(str);