Revamp patching functionality and add clang patches

This commit fixes #94 and closes #105

ext/libv8/builder.rb

@@ -3,12 +3,14 @@ require File.expand_path '../compiler', __FILE__
 require File.expand_path '../arch', __FILE__
 require File.expand_path '../make', __FILE__
 require File.expand_path '../checkout', __FILE__
+require File.expand_path '../patcher', __FILE__
 
 module Libv8
   class Builder
     include Libv8::Arch
     include Libv8::Make
     include Libv8::Checkout
+    include Libv8::Patcher
 
     def initialize
       @compiler = choose_compiler
@@ -45,7 +47,7 @@ module Libv8
         checkout!
         setup_python!
         setup_build_deps!
-        apply_patches!
+        patch! *patch_directories_for(@compiler)
         print_build_info
         puts `env CXX=#{@compiler} LINK=#{@compiler} #{make} #{make_flags}`
       end
@@ -73,18 +75,6 @@ module Libv8
       `ln -fs #{GYP_Source} build/gyp`
     end
 
-    def apply_patches!
-      File.open(".applied_patches", File::RDWR|File::CREAT) do |f|
-        available_patches = Dir.glob(File.expand_path '../../../patches/*.patch', __FILE__).sort
-        applied_patches = f.readlines.map(&:chomp)
-
-        (available_patches - applied_patches).each do |patch|
-          `patch -p1 -N < #{patch}`
-          f.puts patch
-        end
-      end
-    end
-
     private
 
     def choose_compiler

ext/libv8/compiler/clang.rb

@@ -8,7 +8,7 @@ module Libv8
       end
 
       def compatible?
-        version > '3.1'
+        version >= '3.1'
       end
     end
   end

ext/libv8/compiler/gcc.rb

@@ -8,7 +8,7 @@ module Libv8
       end
 
       def compatible?
-        version > '4.2' and version < '4.9'
+        version > '4.3' and version < '4.9'
       end
     end
   end

ext/libv8/patcher.rb

@@ -0,0 +1,54 @@
+module Libv8
+  module Patcher
+    PATCH_DIRECTORY = File.expand_path '../../../patches', __FILE__
+
+    module_function
+
+    def patch_directories_for(compiler)
+      patch_directories = []
+
+      case
+      when compiler.target =~ /arm/
+        patch_directories += 'arm'
+      end
+
+      case compiler
+      when Compiler::GCC
+        patch_directories << 'gcc48' if compiler.version >= '4.8'
+      when Compiler::Clang
+        patch_directories << 'clang'
+        patch_directories << 'clang33' if compiler.version >= '3.3'
+      end
+
+      patch_directories
+    end
+
+    def patch_directories(*additional_directories)
+      absolute_paths = [PATCH_DIRECTORY]
+
+      additional_directories.each do |directory|
+        absolute_paths << File.join(PATCH_DIRECTORY, directory)
+      end
+
+      absolute_paths.uniq
+    end
+
+    def patches(*additional_directories)
+      patch_directories(*additional_directories).map do |directory|
+        Dir.glob(File.join directory, '*.patch')
+      end.flatten.sort
+    end
+
+    def patch!(*additional_directories)
+      File.open(".applied_patches", File::RDWR|File::CREAT) do |f|
+        available_patches = patches *additional_directories
+        applied_patches = f.readlines.map(&:chomp)
+
+        (available_patches - applied_patches).each do |patch|
+          `patch -p1 -N < #{patch}`
+          f.puts patch
+        end
+      end
+    end
+  end
+end

patches/clang/no-unused-private-field.patch

@@ -0,0 +1,28 @@
+diff --git a/build/common.gypi b/build/common.gypi
+index 3a59639..14bf0f9 100644
+--- a/build/common.gypi
++++ b/build/common.gypi
+@@ -376,7 +376,8 @@
+           }],
+           ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="netbsd"', {
+             'cflags': [ '-Wall', '<(werror)', '-W', '-Wno-unused-parameter',
+-                        '-Wnon-virtual-dtor', '-Woverloaded-virtual' ],
++                        '-Wnon-virtual-dtor', '-Woverloaded-virtual',
++                        '-Wno-unused-private-field' ],
+           }],
+           ['OS=="linux" and v8_enable_backtrace==1', {
+             # Support for backtrace_symbols.
+diff --git a/build/standalone.gypi b/build/standalone.gypi
+index 125c5bf..c8d9b4f 100644
+--- a/build/standalone.gypi
++++ b/build/standalone.gypi
+@@ -98,7 +98,8 @@
+       'target_defaults': {
+         'cflags': [ '-Wall', '<(werror)', '-W', '-Wno-unused-parameter',
+                     '-Wnon-virtual-dtor', '-pthread', '-fno-rtti',
+-                    '-fno-exceptions', '-pedantic' ],
++                    '-fno-exceptions', '-pedantic',
++                    '-Wno-unused-private-field' ],
+         'ldflags': [ '-pthread', ],
+         'conditions': [
+           [ 'OS=="linux"', {

patches/clang33/silence-nested-anon-types-and-unused-function-warnings.patch

@@ -0,0 +1,28 @@
+diff --git a/build/common.gypi b/build/common.gypi
+index 14bf0f9..301109a 100644
+--- a/build/common.gypi
++++ b/build/common.gypi
+@@ -377,7 +377,8 @@
+           ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="netbsd"', {
+             'cflags': [ '-Wall', '<(werror)', '-W', '-Wno-unused-parameter',
+                         '-Wnon-virtual-dtor', '-Woverloaded-virtual',
+-                        '-Wno-unused-private-field' ],
++                        '-Wno-unused-private-field', '-Wno-nested-anon-types',
++                        '-Wno-unused-function' ],
+           }],
+           ['OS=="linux" and v8_enable_backtrace==1', {
+             # Support for backtrace_symbols.
+diff --git a/build/standalone.gypi b/build/standalone.gypi
+index c8d9b4f..ddd1693 100644
+--- a/build/standalone.gypi
++++ b/build/standalone.gypi
+@@ -99,7 +99,8 @@
+         'cflags': [ '-Wall', '<(werror)', '-W', '-Wno-unused-parameter',
+                     '-Wnon-virtual-dtor', '-pthread', '-fno-rtti',
+                     '-fno-exceptions', '-pedantic',
+-                    '-Wno-unused-private-field' ],
++                    '-Wno-unused-private-field', '-Wno-nested-anon-types',
++                    '-Wno-unused-function' ],
+         'ldflags': [ '-pthread', ],
+         'conditions': [
+           [ 'OS=="linux"', {