From b6c89a84152dc6accca9c8943be13c4997f36516 Mon Sep 17 00:00:00 2001
From: =?utf-8?q?Fran=C3=A7ois=20Beausoleil?= <francois@teksol.info>
Date: Wed, 2 Apr 2008 13:54:02 -0400
Subject: [PATCH] New build:checkdeps task to tell the developer which dependencies are missing before attempting build.

---
 Rakefile |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/Rakefile b/Rakefile
index bdf4b4b..7288b2b 100644
--- a/Rakefile
+++ b/Rakefile
@@ -82,6 +82,7 @@ AllPreCompiled << "runtime/loader.rbc"
 namespace :build do
 
   task :all => %w[
+    build:checkdeps
     build:shotgun
     build:platform
     build:rbc
@@ -125,6 +126,23 @@ namespace :build do
     sh make('vm')
   end
 
+  desc "Checks that you have all required dependencies"
+  task :checkdeps do
+    puts "Checking build dependencies..."
+    missing_dependencies = []
+    %w(bison git ruby gem pkg-config make).each do |dependency|
+      sh dependency + " --version >/dev/null" rescue nil
+      missing_dependencies << dependency if $?.exitstatus == 127
+    end
+
+    unless missing_dependencies.empty? then
+      puts "\nYou are missing these required dependencies (which might have dependencies of their own):"
+      puts missing_dependencies.map {|dep| "  * #{dep}"}.join("\n")
+      puts
+      exit 1
+    end
+  end
+
   desc "Compiles shotgun (the C-code VM)"
   task :shotgun => %w[configure shotgun/rubinius.bin shotgun/rubinius.local.bin]
 
-- 
1.5.3.6