Do not generate targets for Pods without sources

If a PodTarget should not be build:
- Do not install a target
- Skip the non-existing native targets in Installer
- Do not add linker flags to XCConfig

lib/cocoapods/generator/xcconfig/aggregate_xcconfig.rb

@@ -73,6 +73,7 @@ module Pod
             # Add pod static lib to list of libraries that are to be linked with
             # the user’s project.
 
+            next unless pod_target.should_build
             @xcconfig.merge!('OTHER_LDFLAGS' => %(-l "#{pod_target.name}"))
           end
 

lib/cocoapods/installer.rb

@@ -435,16 +435,19 @@ module Pod
         pod_targets.sort_by(&:name).each do |pod_target|
           pod_target.file_accessors.each do |file_accessor|
             file_accessor.spec_consumer.frameworks.each do |framework|
+              if pod_target.should_build
                 pod_target.native_target.add_system_framework(framework)
               end
             end
           end
         end
       end
+    end
 
     def set_target_dependencies
       aggregate_targets.each do |aggregate_target|
         aggregate_target.pod_targets.each do |pod_target|
+          next unless pod_target.should_build
           aggregate_target.native_target.add_dependency(pod_target.native_target)
           pod_target.dependencies.each do |dep|
 

lib/cocoapods/installer/target_installer/pod_target_installer.rb

@@ -9,6 +9,8 @@ module Pod
       # @return [void]
       #
       def install!
+        return unless target.should_build
+
         UI.message "- Installing target `#{target.name}` #{target.platform}" do
           add_target
           create_support_files_dir

lib/cocoapods/target/pod_target.rb

@@ -34,6 +34,16 @@ module Pod
     #
     attr_accessor :file_accessors
 
+    # @return [Bool] Whether or not this target should be build.
+    #
+    # A target should not be build if it has no source files.
+    #
+    def should_build
+      file_accessors.map do |fa|
+        fa.source_files.count
+      end.inject(0, :+) > 0
+    end
+
     # @return [Array<Specification::Consumer>] the specification consumers for
     #         the target.
     #

spec/unit/generator/xcconfig/aggregate_xcconfig_spec.rb

@@ -17,6 +17,8 @@ module Pod
           @pod_target = PodTarget.new([@spec], target_definition, config.sandbox)
           @pod_target.stubs(:platform).returns(:ios)
           @pod_target.stubs(:spec_consumers).returns([@consumer])
+          file_accessor = fixture_file_accessor('banana-lib/BananaLib.podspec')
+          @pod_target.stubs(:file_accessors).returns([file_accessor])
           @target.pod_targets = [@pod_target]
           @generator = AggregateXCConfig.new(@target, 'Release')
         end
@@ -79,6 +81,12 @@ module Pod
           @xcconfig.to_hash['OTHER_LDFLAGS'].should.include '-l"Pods-BananaLib"'
         end
 
+        it 'does not link with the aggregate integration library target if it does not contain source files' do
+          @pod_target.file_accessors.first.stubs(:source_files).returns([])
+          @xcconfig = @generator.generate
+          @xcconfig.to_hash['OTHER_LDFLAGS'].should.not.include '-l"Pods-BananaLib"'
+        end
+
         it 'does not links the pod targets with the aggregate integration library target for non-whitelisted configuration' do
           @generator = AggregateXCConfig.new(@target, 'Debug')
           @xcconfig = @generator.generate

spec/unit/installer/target_installer/pod_target_installer_spec.rb

@@ -151,6 +151,14 @@ module Pod
         dummy.read.should.include?('@interface PodsDummy_Pods')
       end
 
+      #--------------------------------------------------------------------------------#
+
+      it 'does not create a target if the specification does not define source files' do
+        @pod_target.file_accessors.first.stubs(:source_files).returns([])
+        @installer.install!
+        @project.targets.should == []
+      end
+
       #--------------------------------------------------------------------------------#
       describe 'concerning compiler flags' do
         before do