This Ruby script extracts dependency data from CMake project (supports nested CMake files) in graphviz's dot format

gistfile1.rb

#!/usr/bin/env ruby

# usage:
# ruby depscanner.rb [path_to_project_dir]
# brew install graphviz / apt-get install graphviz (if graphviz is not installed yet)
# dot -Tpng dependencies.dot -o dependencies.png

$binaries = {}
$dependencies = {}

def args_to_array(args_str)
  args_str.gsub("\n", '').gsub(/\s+/, ' ').strip().split(' ')
end

def scan_cmake_file_in(dir)
  file = "#{dir}/CMakeLists.txt"
  return unless File.exist?(file)
  puts "scanning #{file}"
  File.open(file, 'r') do |f|
    content = ''
    f.each do |l|
      next if l =~ /^\s*#/
      content << l
      scan_cmake_file_in("#{dir}/#{$1}") if l =~ /add_subdirectory\(\s*([\w\/]+)\s*\)/
    end
    content.scan(/add_library\(([^\)]+)\)/m).each do |m|
      args = args_to_array(m[0])
      $binaries[args[0]] = :library
    end
    content.scan(/add_executable\(([^\)]+)\)/m).each do |m|
      args = args_to_array(m[0])
      $binaries[args[0]] = :executable
    end
    content.scan(/target_link_libraries\(([^\)]+)\)/m).each do |m|
      args = args_to_array(m[0])
      $dependencies[args.shift] = args
    end
  end
end

project_dir = ARGV[0] || '.'
scan_cmake_file_in(project_dir.chomp('/'))
#$binaries.delete_if { |key, value| key.match(/dns/) }
$binaries.delete_if { |key, value| key.match(/test/) }

deps_graph = "digraph {\n"
deps_graph << "  rankdir = LR;\n"
$binaries.each do |b,type|
  if type == :library
    deps_graph << "  #{b} [shape = circle, fillcolor = yellow, style = filled];\n"
  else
    deps_graph << "  #{b} [shape = circle, fillcolor = green, style = filled];\n"
  end
end
$dependencies.each do |b, deps|
  next unless $binaries[b]
  deps.each do |d|
    next unless $binaries[d]
    deps_graph << "  #{b} -> #{d};\n"
  end
end
deps_graph << "}\n"

File.open('dependencies.dot','w') do |f|
  f.write(deps_graph)
end