From d5f55334f15a4202aaff19f52bb588e9511f3951 Mon Sep 17 00:00:00 2001
From: Mike McQuaid <mike@mikemcquaid.com>
Date: Sat, 7 Mar 2015 11:55:14 +0000
Subject: [PATCH] cmd/readall: add --syntax to check for valid Ruby.

---
 Library/Homebrew/cmd/readall.rb | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/Library/Homebrew/cmd/readall.rb b/Library/Homebrew/cmd/readall.rb
index f43b30bfd7..7bb921b885 100644
--- a/Library/Homebrew/cmd/readall.rb
+++ b/Library/Homebrew/cmd/readall.rb
@@ -5,9 +5,31 @@
 
 require 'formula'
 require 'cmd/tap'
+require 'thread'
 
 module Homebrew
   def readall
+    if ARGV.delete("--syntax")
+      ruby_files = Queue.new
+      Dir.glob("#{HOMEBREW_LIBRARY}/Homebrew/**/*.rb").each do |rb|
+        ruby_files << rb
+      end
+
+      failed = false
+      workers = (0...Hardware::CPU.cores).map do
+        Thread.new do
+          begin
+            while rb = ruby_files.pop(true)
+              nostdout { failed = true unless system "ruby", "-c", "-w", rb }
+            end
+          rescue ThreadError, IOError # ignore empty queue error
+          end
+        end
+      end
+      workers.map(&:join)
+      Homebrew.failed = failed
+    end
+
     formulae = []
     if ARGV.empty?
       formulae = Formula.names