Add compiler flags for specific files in Xcode project with Ruby

add_compiler_flags_under_specific_condition_in_xcode_project_with_ruby.rb

#!/usr/bin/env ruby
# -*- coding: utf-8 -*-

require 'xcodeproj'

# Add compiler flags to "Build Phases > Compile Sources"
def add_compiler_flags(xcproj, flags)
  xcproj.targets.each do |target|
    target.source_build_phase.files_references.each do |fileref|
      # You can check fileref with fileref.path or fileref.parent
      # fileref.parent is PBXGroup or PBXProject

      # In this sample, we check if any parent group has "WinObjC/Frameworks" path
      add_flags = false
      r = fileref
      loop {
          if r.kind_of?(Xcodeproj::Project::Object::PBXProject) || r.source_tree != '<group>'
              break
          elsif r.path == 'WinObjC/Frameworks'
              add_flags = true
              break
          end
          r = r.parent
      }
      next unless add_flags
      fileref.build_files.each do |bf|
        # TODO: merge settings with original COMPILER_FLAGS
        bf.settings = {'COMPILER_FLAGS' => flags}
      end
    end
  end
end

def main
  xcproj_path = ARGV.shift
  flags = ARGV.shift

  xcproj = Xcodeproj::Project.new(xcproj_path)
  xcproj.initialize_from_file

  add_compiler_flags(xcproj, flags)

  xcproj.save
end

main