Converts relative C/C++ imports that reference parent folders to absolute imports

absolute-importer.rb

#!/usr/bin/env ruby

require "pathname"

$cwd = Pathname::new(".").expand_path

ARGV.each do |fname|
	begin
		path = Pathname::new(fname).expand_path
		parent = path.parent
		content = File.read(path, :encoding => "iso-8859-1")
		newcontent = content.gsub(/#include "([^"]+)"/) do |full_include|
			inc = Pathname::new($1).expand_path(parent)
			if !inc.exist? then
				next full_include
			end

			relative = inc.relative_path_from(parent)
			absolute = inc.relative_path_from($cwd)
			if absolute.to_s.start_with? ".." then
				STDERR.puts "Warning: #{fname} import of #{$1} reaches outside of absolute base directory!"
				next full_include
			elsif relative.to_s.start_with? ".." then
				choice = absolute
			else
				choice = relative
			end

			next "\#include \"#{choice}\""
		end

		if content != newcontent then
			File.write(path, newcontent, :encoding => "iso-8859-1")
		end
	rescue => err
		STDERR.puts "Failed to update #{fname}: #{err}"
	end
end