I am uploading an update to my existing app in the app store. I have used Xcode 6,4, now in latest Xcode (7.2), multi tasking support in iPad is a new addition and also bit code support. The archive file is double the previous build and also Launch file warnings are displayed when building. Can I use Xcode 6.4 itself or the new Xcode 7.2.
Apple states that you should use the validate feature on the archive to check if it can be published on the App Store. Quoting:
For compatibility reasons, the App Store will often accept apps that are built with some older versions of Xcode or Base SDK. To determine if an older Xcode configuration is currently accepted by the App Store, you can choose "Archive" under the "Product" menu to make an archived build, then use the Validate feature, to test if that build meets minimum requirements for submission to the App Store.
Source: What version of Xcode and SDK should I be using when building for the App Store?
As of today - May '16, the link
use the Validate feature
in that page is broken, the validate feature is located on the right hand side of the Organizer, under the big blue button "Upload to App Store..."
来源：https://stackoverflow.com/questions/35285502/minimum-xcode-version-to-upload-to-app-store-as-on-february-2016