Support Linux PowerPC64 LE platform

.travis.yml

@@ -1,19 +1,21 @@
-dist: xenial
+dist: bionic
 compiler: clang
 language: ruby
 rvm:
-  - 2.7
   - 2.6
-  - 2.5
 matrix:
   include:
+    - rvm: 2.6
+      arch: ppc64le
     - os: osx
       osx_image: xcode11.6
 addons:
   apt:
     packages:
       - clang
       - pkg-config
+      - python3.8
+      - python2.7
 bundler_args: --jobs=4 --retry=3
 before_install:
   - if [ "$TRAVIS_OS_NAME" == "linux" ]; then gem update bundler; fi

ext/libv8/arch.rb

@@ -6,6 +6,7 @@ module Arch
 
     def libv8_arch
       case Gem::Platform.local.cpu
+      when /^powerpc64/        then 'ppc64'
       when /^arm(v6.*|v7.*)*$/ then 'arm'
       when /^a(rm|arch)64$/    then 'arm64'
       when /^x86$/             then 'ia32'

ext/libv8/builder.rb

@@ -1,6 +1,7 @@
 unless $:.include? File.expand_path("../../../lib", __FILE__)
   $:.unshift File.expand_path("../../../lib", __FILE__)
 end
+require 'fileutils'
 require 'mkmf'
 require 'rbconfig'
 require 'shellwords'
@@ -36,8 +37,11 @@ def debug_build?
     end
 
     def build_libv8!
+      setup_depot_tools!
       setup_python!
       setup_build_deps!
+      setup_ninja!
+      setup_gn!
       Dir.chdir(File.expand_path('../../../vendor/v8', __FILE__)) do
         puts 'Beginning compilation. This will take some time.'
         generate_gn_args
@@ -47,6 +51,10 @@ def build_libv8!
       return $?.exitstatus
     end
 
+    def setup_depot_tools!
+      ENV['PATH'] = "#{File.expand_path('../../../vendor/depot_tools', __FILE__)}:#{ENV['PATH']}"
+    end
+
     def setup_python!
       # If python v2 cannot be found in PATH,
       # create a symbolic link to python2 the current directory and put it
@@ -59,6 +67,19 @@ def setup_python!
         `ln -fs #{`which python2`.chomp} python`
         ENV['PATH'] = "#{File.expand_path '.'}:#{ENV['PATH']}"
       end
+
+      if arch_ppc64?
+        unless system 'which python3 2>&1 > /dev/null'
+          fail "libv8 requires python 3 to be installed in order to build"
+        end
+
+        # Because infra/3pp/tools/cpython3/linux-ppc64le@version:3.8.0.chromium.8 CIPD is not yet available
+        # fallback to host's python3
+        ENV['VPYTHON_BYPASS'] = 'manually managed python not supported by chrome operations'
+
+        # stub the CIPD cpython3 with host's python3
+        FileUtils.symlink(`which python3`.chomp, File.expand_path("../../../vendor/depot_tools/python3", __FILE__), force: true)
+      end
     end
 
     ##
@@ -73,11 +94,7 @@ def source_version
     # Checkout all of the V8 source and its dependencies using the
     # chromium depot tools.
     #
-    # https://chromium.googlesource.com/v8/v8.git#Getting-the-Code
-    #
     def setup_build_deps!
-      ENV['PATH'] = "#{File.expand_path('../../../vendor/depot_tools', __FILE__)}:#{ENV['PATH']}"
-
       Dir.chdir(File.expand_path('../../../vendor', __FILE__)) do
         unless Dir.exists?('v8') || File.exists?('.gclient')
           system "fetch v8" or fail "unable to fetch v8 source"
@@ -93,8 +110,63 @@ def setup_build_deps!
       end
     end
 
+    ##
+    # Build ninja for linux ppc64le
+    #
+    def setup_ninja!
+      return unless arch_ppc64?
+
+      ninja_filepath = File.expand_path("../../../vendor/depot_tools/ninja-linux-ppc64le", __FILE__)
+      return if File.exists?(ninja_filepath)
+
+      Dir.chdir("/tmp") do
+        FileUtils.rm_rf("ninja")
+        system "git clone https://github.com/ninja-build/ninja.git -b v1.8.2" or fail "unable to git clone ninja repository"
+      end
+
+      Dir.chdir("/tmp/ninja") do
+        system "python2 ./configure.py --bootstrap" or fail "unable to build ninja"
+        FileUtils.mv(File.expand_path("#{Dir.pwd}/ninja"), ninja_filepath)
+      end
+
+      patch_filepath = File.expand_path("../../../vendor/patches/0001-support-ninja-ppc64le.patch", __FILE__)
+      Dir.chdir(File.expand_path('../../../vendor/depot_tools', __FILE__)) do
+        system "patch -p1 < #{patch_filepath}" or fail "unable to patch depot_tools/ninja"
+      end
+    end
+
+    ##
+    # Build gn for linux ppc64le
+    # Upstream issue: https://bugs.chromium.org/p/chromium/issues/detail?id=1076455
+    # TODO: Remove once upstream has supported ppc64le
+    #
+    def setup_gn!
+      return unless arch_ppc64?
+
+      gn_filepath = File.expand_path("../../../vendor/depot_tools/gn-linux-ppc64le", __FILE__)
+      return if File.exists?(gn_filepath)
+
+      Dir.chdir("/tmp") do
+        FileUtils.rm_rf("gn")
+        system "git clone https://gn.googlesource.com/gn" or fail "unable to git clone gn repository"
+      end
+
+      Dir.chdir("/tmp/gn") do
+        system "python2 build/gen.py"
+        fail "unable to prepare gn for compilation" unless File.exists?(File.expand_path("#{Dir.pwd}/out/build.ninja"))
+        system "ninja -C out" or fail "unable to build gn"
+        FileUtils.mv(File.expand_path("#{Dir.pwd}/out/gn"), gn_filepath)
+        FileUtils.rm_f(File.expand_path("../../../vendor/depot_tools/gn", __FILE__))
+        FileUtils.symlink(gn_filepath, File.expand_path("../../../vendor/depot_tools/gn", __FILE__), force: true)
+      end
+    end
+
     private
 
+    def arch_ppc64?
+      libv8_arch == "ppc64"
+    end
+
     def python_version
       if system 'which python 2>&1 > /dev/null'
         `python -c 'import platform; print(platform.python_version())'`.chomp

vendor/patches/0001-support-ninja-ppc64le.patch

@@ -0,0 +1,24 @@
+From 88070442df48a857460a68d065957d0f7efc5468 Mon Sep 17 00:00:00 2001
+From: Trung LE <[email protected]>
+Date: Sun, 8 Mar 2020 07:46:10 +0000
+Subject: [PATCH] Support ninja ppc64le
+
+---
+ ninja | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/ninja b/ninja
+index 1a650b54..eb146a4b 100755
+--- a/ninja
++++ b/ninja
+@@ -28,6 +28,8 @@ case "$OS" in
+         # bittage of the userspace install (e.g. when running 32-bit userspace
+         # on x86_64 kernel)
+         exec "${THIS_DIR}/ninja-linux${LONG_BIT}" "$@";;
++      ppc64le)
++	 exec "${THIS_DIR}/ninja-linux-ppc64le" "$@";;
+       *)
+         echo Unknown architecture \($MACHINE\) -- unable to run ninja.
+         print_help
+--
+2.17.1