Refactoring Android NDK toolchain

tasks/toolchains/androidndk.rake

+
+class MRuby::Toolchain::AndroidNDK
+  DEFAULT_ARCH = 'armeabi'
+  DEFAULT_PLATFORM = 'android-14'
+  DEFAULT_TOOLCHAIN = :gcc
+  KNOWN_NDK_HOMES = %w{
+    /usr/local/opt/android-ndk
+  }
+  ARCHITECTURES = %w{
+    armeabi armeabi-v7a arm64-v8a
+    mips mips64
+    x86 x86_64
+  }
+
+  class AndroidNDKHomeNotFound < StandardError
+    def message
+        <<-EOM
+Couldn't find Android NDK Home.
+Set ANDROID_NDK_HOME environment variable or set :ndk_home parameter
+        EOM
+    end
+  end
+
+  attr_reader :params
+
+  def initialize(params)
+    @params = params
+  end
+
+  def home_path
+    @home_path ||= Pathname(
+      params[:ndk_home] ||
+        ENV['ANDROID_NDK_HOME'] ||
+        KNOWN_NDK_HOMES.find{ |path| File.directory?(path) } ||
+        raise(AndroidNDKHomeNotFound)
+    )
+  end
+
+  def arch
+    params.fetch(:arch){ DEFAULT_ARCH }
+  end
+
+  def platform
+    params.fetch(:platform){ DEFAULT_PLATFORM }
+  end
+
+  def toolchain
+    params.fetch(:toolchain){ DEFAULT_TOOLCHAIN }
+  end
+
+  def toolchain_version
+    params.fetch(:toolchain_version) do
+      test = case toolchain
+      when :gcc
+        'arm-linux-androideabi-*'
+      when :clang
+        'llvm-*'
+      end
+
+      Dir[home_path.join('toolchains',test)].map{|t| t.match(/-(\d+\.\d+)$/); $1.to_f }.max
+    end
+  end
+
+  def toolchain_path
+    prefix = case toolchain
+             when :clang then 'llvm-'
+             when :gcc
+               case arch
+               when /arm/  then 'arm-linux-androideabi-'
+               when /x86/  then 'x86-'
+               when /mips/ then 'mipsel-linux-android-'
+               end
+             end
+    home_path.join('toolchains', prefix + toolchain_version.to_s, 'prebuilt', host_platform)
+  end
+
+  def sysroot
+    path = case arch
+           when /arm/  then 'arch-arm'
+           when /x86/  then 'arch-x86'
+           when /mips/ then 'arch-mips'
+           end
+
+    home_path.join('platforms', platform, path).to_s
+  end
+
+  def bin(command)
+    command = command.to_s
+
+    if toolchain == :gcc
+      command = case arch
+                when /arm/  then 'arm-linux-androideabi-'
+                when /x86/  then 'i686-linux-android-'
+                when /mips/ then 'mipsel-linux-android-'
+                end + command
+    end
+
+    toolchain_path.join('bin',command).to_s
+  end
+
+  def cc
+    case toolchain
+    when :gcc   then bin(:gcc)
+    when :clang then bin(:clang)
+    end
+  end
+
+  def cflags
+    flags = []
+
+    case toolchain
+    when :gcc
+      flags += %W(-ffunction-sections -funwind-tables -fstack-protector)
+      flags += %W(-D__android__ -mandroid --sysroot="#{sysroot}")
+      case arch
+      when 'armeabi-v7a'
+        flags += %W(-march=armv7-a -mfloat-abi=softfp -mfpu=vfpv3-d16)
+      when /arm/
+        flags += %W(-march=armv5te -mtune=xscale -msoft-float)
+      when /mips/
+        flags += %W(-fpic -fno-strict-aliasing -finline-functions -fmessage-length=0 -fno-inline-functions-called-once -fgcse-after-reload -frerun-cse-after-loop -frename-registers)
+      end
+    when :clang
+    end
+
+    flags
+  end
+
+  def ld
+    cc
+  end
+
+  def ldflags
+    %W(-D__android__ -mandroid --sysroot="#{sysroot}")
+  end
+
+  def ar
+    case toolchain
+    when :gcc   then bin(:ar)
+    when :clang then bin('llvm-ar')
+    end
+  end
+
+  def host_platform
+    case RUBY_PLATFORM
+    when /cygwin|mswin|mingw|bccwin|wince|emx/i
+      'windows'
+    when /x86_64-darwin/i
+      'darwin-x86_64'
+    when /darwin/i
+      'darwin-x86'
+    when /x86_64-linux/i
+      'linux-x86_64'
+    when /linux/i
+      'linux-x86'
+    else
+      raise NotImplementedError, "Unknown host platform (#{RUBY_PLATFORM})"
+    end
+  end
+end
+
+MRuby::Toolchain.new(:androidndk) do |conf, params|
+  ndk = MRuby::Toolchain::AndroidNDK.new(params)
+
+  toolchain ndk.toolchain
+
+  [conf.cc, conf.cxx, conf.objc, conf.asm].each do |cc|
+    cc.command = ndk.cc
+    cc.flags = ndk.cflags
+  end
+  conf.linker.command = ndk.ld
+  conf.linker.flags = ndk.ldflags
+  conf.archiver.command = ndk.ar
+end
+