From 8bbd873f54366792c23c652d794151def65ce3d8 Mon Sep 17 00:00:00 2001
From: =?utf-8?q?Fran=C3=A7ois=20Beausoleil?= <francois@teksol.info>
Date: Thu, 3 Apr 2008 09:39:24 -0400
Subject: [PATCH] New build:checkdeps task to tell the developer which dependencies are missing before attempting the build.

Refactored the dependency code checking to be done once whenever any #make
invocation is attempted.  This allows us to dynamically select the proper
make, and ensures all build and installation dependencies are managed.
---
 Rakefile            |    8 +++++++-
 rakelib/rubinius.rb |   48 +++++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/Rakefile b/Rakefile
index bdf4b4b..faabc11 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 +126,11 @@ namespace :build do
     sh make('vm')
   end
 
+  desc "Checks that you have all required dependencies"
+  task :checkdeps do
+    check_dependencies
+  end
+
   desc "Compiles shotgun (the C-code VM)"
   task :shotgun => %w[configure shotgun/rubinius.bin shotgun/rubinius.local.bin]
 
@@ -167,7 +173,7 @@ end
 # INSTALL TASKS
 
 desc "Install rubinius as rbx"
-task :install => :config_env do
+task :install => %w[build:checkdeps config_env] do
   sh "cd shotgun; #{make "install"}"
 
   mkdir_p RBAPATH, :verbose => true
diff --git a/rakelib/rubinius.rb b/rakelib/rubinius.rb
index fbe9bdd..4bbd6b9 100644
--- a/rakelib/rubinius.rb
+++ b/rakelib/rubinius.rb
@@ -25,13 +25,51 @@ def clear_compiler
   ENV.delete 'RBX_PLATFORM'
 end
 
-def make(args = nil)
-  if RUBY_PLATFORM =~ /bsd/
-    gmake = 'gmake'
+def check_dependencies
+  if ENV["MAKE"] then
+    `#{ENV['MAKE']} --version` rescue nil
+    if $?.success? then
+      Object.const_set("MAKE", ENV["MAKE"])
+    else
+      abort "You specified #{ENV['MAKE']} as your make, but I could not run it.  Aborting..."
+    end
   else
-    gmake = 'make'
+    # We need GNU Make, so try gmake then make
+    ouptut = `gmake --version` rescue nil
+    if $?.success? then
+      Object.const_set("MAKE", "gmake")
+    else
+      output = `make --version` rescue nil
+      if $?.success? then
+        Object.const_set("MAKE", "make")
+      else
+        abort "We need either gmake or make, but none found.  If you have a compatible GNU make, you can set MAKE to point to it.  Aborting..."
+      end
+    end
+
+    unless output =~ /GNU Make/
+      abort "We need GNU Make, but we found #{output.inspect}.  If you know your make is compatible, you can set MAKE to point to it.  Aborting..."
+    end
+  end
+
+  puts "Checking build dependencies..."
+  missing_dependencies = []
+  %w(bison git ruby gem pkg-config libtool).each do |dependency|
+    `#{dependency} --version >/dev/null`
+    missing_dependencies << dependency unless $?.success?
+  end
+
+  unless missing_dependencies.empty? then
+    puts "\nYou are missing one or more required dependencies (which might have dependencies of their own):"
+    puts missing_dependencies.map {|dep| "  * #{dep}"}.join("\n")
+    puts
+    exit 1
   end
-  "#{ENV['MAKE'] || gmake} #{args}"
+end
+
+def make(args = nil)
+  checkdeps unless const_defined?(:MAKE)
+  "#{MAKE} #{args}"
 end
 
 def rbx(*args)
-- 
1.5.3.6