From 97acbe8f66648ca5939c92e61c90ab21ee4c8cb2 Mon Sep 17 00:00:00 2001
From: Max Howell <mxcl@me.com>
Date: Mon, 6 Aug 2012 13:46:02 -0400
Subject: [PATCH] Actually cache Xcode.version

The short-circuit returns would cause the caching ||= syntax to be skipped. For me on my CLT-less install, this was noticeably slowing down brew for some operations due to the frequent calls to xcodebuild.
---
 Library/Homebrew/macos/xcode.rb | 111 +++++++++++++++++---------------
 1 file changed, 58 insertions(+), 53 deletions(-)

diff --git a/Library/Homebrew/macos/xcode.rb b/Library/Homebrew/macos/xcode.rb
index 0c8139c623..844926ede2 100644
--- a/Library/Homebrew/macos/xcode.rb
+++ b/Library/Homebrew/macos/xcode.rb
@@ -56,65 +56,70 @@ module MacOS::Xcode extend self
     # may return a version string
     # that is guessed based on the compiler, so do not
     # use it in order to check if Xcode is installed.
-    @version ||= begin
-      return "0" unless MACOS
+    @version ||= uncached_version
+  end
 
-      # this shortcut makes version work for people who don't realise you
-      # need to install the CLI tools
-      xcode43build = V4_BUNDLE_PATH/'Contents/Developer/usr/bin/xcodebuild'
-      if xcode43build.file?
-        `#{xcode43build} -version 2>/dev/null` =~ /Xcode (\d(\.\d)*)/
-        return $1 if $1
-      end
+  def uncached_version
+    # This is a separate function as you can't cache the value out of a block
+    # if return is used in the middle, which we do many times in here.
 
-      # Xcode 4.3 xc* tools hang indefinately if xcode-select path is set thus
-      raise if bad_xcode_select_path?
+    return "0" unless MACOS
 
-      raise unless which "xcodebuild"
-      `xcodebuild -version 2>/dev/null` =~ /Xcode (\d(\.\d)*)/
-      raise if $1.nil? or not $?.success?
-      $1
-    rescue
-      # For people who's xcode-select is unset, or who have installed
-      # xcode-gcc-installer or whatever other combinations we can try and
-      # supprt. See https://github.com/mxcl/homebrew/wiki/Xcode
-      case MacOS.llvm_build_version.to_i
-      when 1..2063 then "3.1.0"
-      when 2064..2065 then "3.1.4"
-      when 2366..2325
-        # we have no data for this range so we are guessing
-        "3.2.0"
-      when 2326
-        # also applies to "3.2.3"
+    # this shortcut makes version work for people who don't realise you
+    # need to install the CLI tools
+    xcode43build = V4_BUNDLE_PATH/'Contents/Developer/usr/bin/xcodebuild'
+    if xcode43build.file?
+      `#{xcode43build} -version 2>/dev/null` =~ /Xcode (\d(\.\d)*)/
+      $1 if $1
+    end
+
+    # Xcode 4.3 xc* tools hang indefinately if xcode-select path is set thus
+    raise if bad_xcode_select_path?
+
+    raise unless which "xcodebuild"
+    `xcodebuild -version 2>/dev/null` =~ /Xcode (\d(\.\d)*)/
+    raise if $1.nil? or not $?.success?
+    $1
+  rescue
+    # For people who's xcode-select is unset, or who have installed
+    # xcode-gcc-installer or whatever other combinations we can try and
+    # supprt. See https://github.com/mxcl/homebrew/wiki/Xcode
+    case MacOS.llvm_build_version.to_i
+    when 1..2063 then "3.1.0"
+    when 2064..2065 then "3.1.4"
+    when 2366..2325
+      # we have no data for this range so we are guessing
+      "3.2.0"
+    when 2326
+      # also applies to "3.2.3"
+      "3.2.4"
+    when 2327..2333 then "3.2.5"
+    when 2335
+      # this build number applies to 3.2.6, 4.0 and 4.1
+      # https://github.com/mxcl/homebrew/wiki/Xcode
+      "4.0"
+    else
+      case (MacOS.clang_version.to_f * 10).to_i
+      when 0
+        "dunno"
+      when 1..14
+        "3.2.2"
+      when 15
         "3.2.4"
-      when 2327..2333 then "3.2.5"
-      when 2335
-        # this build number applies to 3.2.6, 4.0 and 4.1
-        # https://github.com/mxcl/homebrew/wiki/Xcode
+      when 16
+        "3.2.5"
+      when 17..20
         "4.0"
+      when 21
+        "4.1"
+      when 22..30
+        "4.2"
+      when 31
+        "4.3"
+      when 40
+        "4.4"
       else
-        case (MacOS.clang_version.to_f * 10).to_i
-        when 0
-          "dunno"
-        when 1..14
-          "3.2.2"
-        when 15
-          "3.2.4"
-        when 16
-          "3.2.5"
-        when 17..20
-          "4.0"
-        when 21
-          "4.1"
-        when 22..30
-          "4.2"
-        when 31
-          "4.3"
-        when 40
-          "4.4"
-        else
-          "4.4"
-        end
+        "4.4"
       end
     end
   end