1 files changed, 65 insertions, 0 deletions
diff --git a/tool/mjit_without_tabs.rb b/tool/mjit_without_tabs.rb
new file mode 100644
index 0000000000..bc2ca773d5
--- /dev/null
+++ b/tool/mjit_without_tabs.rb
@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+# This is a script to run a command in ARGV, expanding tabs in some files
+# included by vm.c to normalize indentation of MJIT header. You can disable
+# this feature by setting MJIT_WITHOUT_TABS=false make variable.
+#
+# Note that preprocessor of GCC converts a hard tab to one spaces, where
+# we expect it to be shown as 8 spaces. To obviate this script, we need
+# to convert all tabs to spaces in these files.
+
+require 'fileutils'
+
+EXPAND_TARGETS = %w[
+  vm*.*
+  include/ruby/ruby.h
+]
+
+# These files have no hard tab indentations. Skip normalizing these files from the glob result.
+SKIPPED_FILES = %w[
+  vm_callinfo.h
+  vm_debug.h
+  vm_exec.h
+  vm_opts.h
+]
+
+srcdir = File.expand_path('..', __dir__)
+targets = EXPAND_TARGETS.flat_map { |t| Dir.glob(File.join(srcdir, t)) } - SKIPPED_FILES.map { |f| File.join(srcdir, f) }
+sources = {}
+mtimes = {}
+
+flag, *command = ARGV
+
+targets.each do |target|
+  next if flag != 'true'
+  unless File.writable?(target)
+    puts "tool/mjit_without_tabs.rb: Skipping #{target.dump} as it's not writable."
+    next
+  end
+  source = File.read(target)
+  begin
+    expanded = source.gsub(/^\t+/) { |tab| ' ' * 8 * tab.length }
+  rescue ArgumentError # invalid byte sequence in UTF-8 (Travis, RubyCI)
+    puts "tool/mjit_without_tabs.rb: Skipping #{target.dump} as the encoding is #{source.encoding}."
+    next
+  end
+
+  sources[target] = source
+  mtimes[target] = File.mtime(target)
+
+  if sources[target] == expanded
+    puts "#{target.dump} has no hard tab indentation. This should be ignored in tool/mjit_without_tabs.rb."
+  end
+  File.write(target, expanded)
+  FileUtils.touch(target, mtime: mtimes[target])
+end
+
+result = system(*command)
+
+targets.each do |target|
+  if sources.key?(target)
+    File.write(target, sources[target])
+    FileUtils.touch(target, mtime: mtimes.fetch(target))
+  end
+end
+
+exit result