Embed ruby minor version as build tag

Author: sue445

_tools/ruby_h_to_go/lib/ruby_h_to_go/go_util.rb

@@ -16,12 +16,16 @@ def self.snake_to_camel(str)
     def self.generate_initial_go_file(go_file_path)
       return if File.exist?(go_file_path)
 
+      ruby_build_tag = ruby_minor_version_build_tag(RUBY_VERSION)
+
       File.binwrite(go_file_path, <<~GO)
         // THE AUTOGENERATED LICENSE. ALL THE RIGHTS ARE RESERVED BY ROBOTS.
 
         // WARNING: This file has automatically been generated
         // Code generated by ruby_h_to_go. DO NOT EDIT.
 
+        //go:build #{ruby_build_tag}
+
         package ruby
 
         /*
@@ -36,6 +40,12 @@ def self.generate_initial_go_file(go_file_path)
       GO
     end
 
+    # @param ruby_version [String]
+    # @return [String]
+    def self.ruby_minor_version_build_tag(ruby_version = RUBY_VERSION)
+      "ruby_#{ruby_version.to_f.to_s.gsub(".", "_")}"
+    end
+
     C_TYPE_TO_GO_TYPE = {
       "RUBY_DATA_FUNC"     => "unsafe.Pointer",
       "long long"          => "Longlong",

_tools/ruby_h_to_go/spec/ruby_h_to_go/go_util_spec.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+RSpec.describe RubyHToGo::GoUtil do
+  describe ".ruby_minor_version_build_tag" do
+    subject { RubyHToGo::GoUtil.ruby_minor_version_build_tag(ruby_version) }
+
+    let(:ruby_version) { "3.4.1" }
+
+    it { should eq "ruby_3_4" }
+  end
+end