1 files changed, 39 insertions, 0 deletions
diff --git a/Library/Homebrew/requirements/xcode_requirement.rb b/Library/Homebrew/requirements/xcode_requirement.rb
new file mode 100644
index 000000000..ff167c6fd
--- /dev/null
+++ b/Library/Homebrew/requirements/xcode_requirement.rb
@@ -0,0 +1,39 @@
+require "requirement"
+
+class XcodeRequirement < Requirement
+  fatal true
+
+  satisfy(build_env: false) { xcode_installed_version }
+
+  def initialize(tags)
+    @version = tags.find { |tag| tags.delete(tag) if tag =~ /(\d\.)+\d/ }
+    super
+  end
+
+  def xcode_installed_version
+    return false unless MacOS::Xcode.installed?
+    return true unless @version
+    MacOS::Xcode.version >= @version
+  end
+
+  def message
+    version = " #{@version}" if @version
+    message = <<~EOS
+      A full installation of Xcode.app#{version} is required to compile this software.
+      Installing just the Command Line Tools is not sufficient.
+    EOS
+    if MacOS.version >= :lion
+      message + <<~EOS
+        Xcode can be installed from the App Store.
+      EOS
+    else
+      message + <<~EOS
+        Xcode can be installed from #{Formatter.url("https://developer.apple.com/download/more/")}.
+      EOS
+    end
+  end
+
+  def inspect
+    "#<#{self.class.name}: #{name.inspect} #{tags.inspect} version=#{@version.inspect}>"
+  end
+end