use shorter file path in debug trace

Author: yyx990803

lib/loader.js

@@ -63,6 +63,7 @@ module.exports = function (content) {
 
   var context = (this._compiler && this._compiler.context) || this.options.context || process.cwd()
   var moduleId = 'data-v-' + genId(filePath, context, options.hashKey)
+  var shortFilePath = path.relative(context, filePath).replace(/^(\.\.\/)+/, '')
 
   var cssLoaderOptions = ''
   if (!isProduction && this.sourceMap && options.cssSourceMap !== false) {
@@ -470,7 +471,7 @@ module.exports = function (content) {
   // development-only code
   if (!isProduction) {
     // add filename in dev
-    output += 'Component.options.__file = ' + JSON.stringify(filePath) + '\n'
+    output += 'Component.options.__file = ' + JSON.stringify(shortFilePath) + '\n'
     // check named exports
     output +=
       'if (Component.esModule && Object.keys(Component.esModule).some(function (key) {' +