In Xcode, how to suppress all warnings in specific source files?

In my application I use 3rd party code that triggers some warnings. I reviewed them and they can be safely ignored.

Now I want to "mark" a file somehow, so Xcode won't show any warnings for the code in that file.

How should I do that?

Select your target and show Build Phases. Then enter the name of the file in the search box, and you should see it listed in the Compile Sources phase. Double-click in the Compiler Flags column for that file and enter -w to turn off all warnings for that file.

Select Project in left navigator and select target go to build phase and Put -w in Build Phase of target file. It will hide all compiler warnings

This works for Xcode 10.2+ and Swift 5

Manual fix:

Add -w -Xanalyzer -analyzer-disable-all-checks to the problematic file from Xcode > Project > Targets > Compile Sources > Double click the file where you want to turn off warnings.

Cocoapods Fix:

If you're trying to suppress warnings from a problematic pod, you can automatically suppress all warnings from the dependency with the inhibit_warnings flag in your podfile:

pod 'Kingfisher', '~> 4.6', :inhibit_warnings => true