Add Swift specific settings to the generated xcconfig files if required

lib/cocoapods/generator/xcconfig/aggregate_xcconfig.rb

@@ -57,6 +57,8 @@ module Pod
                                               'OTHER_CFLAGS' => '$(inherited) ' + XCConfigHelper.quote(header_search_path_flags, '-isystem')
                                             )
 
+          XCConfigHelper.add_language_specific_settings(target, @xcconfig)
+
           target.pod_targets.each do |pod_target|
             next unless pod_target.include_in_build_config?(@configuration_name)
 

lib/cocoapods/generator/xcconfig/private_pod_xcconfig.rb

@@ -59,6 +59,7 @@ module Pod
 
           xcconfig_hash = add_xcconfig_namespaced_keys(public_xcconfig.to_hash, config, target.xcconfig_prefix)
           @xcconfig = Xcodeproj::Config.new(xcconfig_hash)
+          XCConfigHelper.add_language_specific_settings(target, @xcconfig)
           @xcconfig.includes = [target.name]
           @xcconfig
         end

lib/cocoapods/generator/xcconfig/xcconfig_helper.rb

@@ -88,6 +88,24 @@ module Pod
           xcconfig.merge!(build_settings)
         end
 
+        # Checks if the given target requires language specific settings and
+        # configures the given Xcconfig.
+        #
+        # @param  [Target] target
+        #         The target.
+        #
+        # @param  [Xcodeproj::Config] xcconfig
+        #         The xcconfig to edit.
+        #
+        def self.add_language_specific_settings(target, xcconfig)
+          if target.uses_swift?
+            build_settings = {
+              'OTHER_SWIFT_FLAGS' => quote(['-D COCOAPODS']),
+            }
+            xcconfig.merge!(build_settings)
+          end
+        end
+
         # Adds the search paths of the developer frameworks to the specification
         # if needed. This is done because the `SenTestingKit` requires them and
         # adding them to each specification which requires it is repetitive and