handle compile warnings

Author: yyx990803

lib/template-compiler.js

@@ -58,9 +58,18 @@ module.exports = function (html) {
       options.transformToRequire
     )
   }
+
   var compiled = compiler.compile(html, Object.assign({
     preserveWhitespace: options.preserveWhitespace
   }, defaultCompileOptions))
+
+  // tips
+  if (compiled.tips && compiled.tips.length) {
+    compiled.tips.forEach(tip => {
+      this.emitWarning(tip)
+    })
+  }
+
   var code
   if (compiled.errors && compiled.errors.length) {
     this.emitError(