Add deprecated_option to software_spec.

Allows remapping one option name to another and updates build options
and flags accordingly.

Library/Homebrew/options.rb

@@ -47,6 +47,11 @@ class DeprecatedOption
   def current_flag
     "--#{current}"
   end
+
+  def ==(other)
+    instance_of?(other.class) && old == other.old && current == other.current
+  end
+  alias_method :eql?, :==
 end
 
 class Options

Library/Homebrew/software_spec.rb

@@ -20,6 +20,7 @@ class SoftwareSpec
 
   attr_reader :name, :owner
   attr_reader :build, :resources, :patches, :options
+  attr_reader :deprecated_flags, :deprecated_options
   attr_reader :dependency_collector
   attr_reader :bottle_specification
   attr_reader :compiler_failures
@@ -36,7 +37,10 @@ class SoftwareSpec
     @bottle_specification = BottleSpecification.new
     @patches = []
     @options = Options.new
-    @build = BuildOptions.new(Options.create(ARGV.flags_only), options)
+    @flags = ARGV.flags_only
+    @deprecated_flags = []
+    @deprecated_options = []
+    @build = BuildOptions.new(Options.create(@flags), options)
     @compiler_failures = []
   end
 
@@ -99,6 +103,26 @@ class SoftwareSpec
     options << opt
   end
 
+  def deprecated_option hash
+    raise ArgumentError, "deprecated_option hash must not be empty" if hash.empty?
+    hash.each do |old_options, new_options|
+      Array(old_options).each do |old_option|
+        Array(new_options).each do |new_option|
+          deprecated_option = DeprecatedOption.new(old_option, new_option)
+          deprecated_options << deprecated_option
+
+          old_flag = deprecated_option.old_flag
+          new_flag = deprecated_option.current_flag
+          next unless @flags.include? old_flag
+          @flags -= [old_flag]
+          @flags |= [new_flag]
+          @deprecated_flags << deprecated_option
+        end
+      end
+    end
+    @build = BuildOptions.new(Options.create(@flags), options)
+  end
+
   def depends_on spec
     dep = dependency_collector.add(spec)
     add_dep_option(dep) if dep

Library/Homebrew/test/test_options.rb

@@ -37,6 +37,23 @@ class DeprecatedOptionTests < Homebrew::TestCase
   def test_current
     assert_equal "bar", @deprecated_option.current
   end
+
+  def test_old
+    assert_equal "--foo", @deprecated_option.old_flag
+  end
+
+  def test_current
+    assert_equal "--bar", @deprecated_option.current_flag
+  end
+
+  def test_equality
+    foobar = DeprecatedOption.new("foo", "bar")
+    boofar = DeprecatedOption.new("boo", "far")
+    assert_equal foobar, @deprecated_option
+    refute_equal boofar, @deprecated_option
+    assert_eql @deprecated_option, foobar
+    refute_eql @deprecated_option, boofar
+  end
 end
 
 class OptionsTests < Homebrew::TestCase

Library/Homebrew/test/test_software_spec.rb

@@ -72,6 +72,30 @@ class SoftwareSpecTests < Homebrew::TestCase
     assert_equal "", @spec.options.first.description
   end
 
+  def test_deprecated_option
+    @spec.deprecated_option('foo' => 'bar')
+    assert @spec.deprecated_options.any?
+    assert_equal "foo", @spec.deprecated_options.first.old
+    assert_equal "bar", @spec.deprecated_options.first.current
+  end
+
+  def test_deprecated_options
+    @spec.deprecated_option(['foo1', 'foo2'] => 'bar1', 'foo3' => ['bar2', 'bar3'])
+    refute_empty @spec.deprecated_options
+    assert_equal "foo1", @spec.deprecated_options.first.old
+    assert_equal "bar1", @spec.deprecated_options.first.current
+    assert_equal "foo2", @spec.deprecated_options[1].old
+    assert_equal "bar1", @spec.deprecated_options[1].current
+    assert_equal "foo3", @spec.deprecated_options[2].old
+    assert_equal "bar2", @spec.deprecated_options[2].current
+    assert_equal "foo3", @spec.deprecated_options.last.old
+    assert_equal "bar3", @spec.deprecated_options.last.current
+  end
+
+  def test_deprecated_option_raises_when_empty
+    assert_raises(ArgumentError) { @spec.deprecated_option({}) }
+  end
+
   def test_depends_on
     @spec.depends_on('foo')
     assert_equal 'foo', @spec.deps.first.name