Merge pull request #1411 from xu-cheng/homebrew-formula

Let homebrew handle external resources download

neovim.rb

@@ -9,9 +9,34 @@ class Neovim < Formula
   depends_on "automake" => :build
   depends_on "autoconf" => :build
 
+  resource "libuv" do
+    url "https://github.com/joyent/libuv/archive/v0.11.28.tar.gz"
+    sha1 "3b70b65467ee693228b8b8385665a52690d74092"
+  end
+
+  resource "msgpack" do
+    url "https://github.com/msgpack/msgpack-c/archive/ecf4b09acd29746829b6a02939db91dfdec635b4.tar.gz"
+    sha1 "c160ff99f20d9d0a25bea0a57f4452f1c9bde370"
+  end
+
+  resource "luajit" do
+    url "http://luajit.org/download/LuaJIT-2.0.3.tar.gz"
+    sha1 "2db39e7d1264918c2266b0436c313fbd12da4ceb"
+  end
+
+  resource "luarocks" do
+    url "https://github.com/keplerproject/luarocks/archive/0587afbb5fe8ceb2f2eea16f486bd6183bf02f29.tar.gz"
+    sha1 "61a894fd5d61987bf7e7f9c3e0c5de16ba4b68c4"
+  end
+
   def install
     ENV["GIT_DIR"] = cached_download/".git" if build.head?
     ENV.deparallelize
+
+    resources.each do |r|
+      r.stage(target=buildpath/".deps/build/src/#{r.name}")
+    end
+
     system "make", "CMAKE_BUILD_TYPE=RelWithDebInfo", "CMAKE_EXTRA_FLAGS=\"-DCMAKE_INSTALL_PREFIX:PATH=#{prefix}\"", "install"
   end
 end

third-party/cmake/DownloadAndExtractFile.cmake

@@ -18,6 +18,15 @@ if(NOT DEFINED TARGET)
   message(FATAL_ERROR "TARGET must be defined.")
 endif()
 
+set(SRC_DIR ${PREFIX}/src/${TARGET})
+
+# Check whether the source has been downloaded. If true, skip it.
+# Useful for external downloads like homebrew.
+if(EXISTS "${SRC_DIR}" AND IS_DIRECTORY "${SRC_DIR}")
+  message(STATUS "${SRC_DIR} is found, skipping download and extraction. ")
+  return()
+endif()
+
 # Taken from ExternalProject_Add.  Let's hope we can drop this one day when
 # ExternalProject_Add allows you to disable SHOW_PROGRESS on the file download.
 if(TIMEOUT)
@@ -71,8 +80,6 @@ endif()
 
 message(STATUS "downloading... done")
 
-set(SRC_DIR ${PREFIX}/src/${TARGET})
-
 # Slurped from a generated extract-TARGET.cmake file.
 message(STATUS "extracting...
      src='${file}'