1 files changed, 45 insertions, 0 deletions
diff --git a/tools/asciidoctor-includetracker.rb b/tools/asciidoctor-includetracker.rb
new file mode 100644
index 0000000..bcf9ce0
--- /dev/null
+++ b/tools/asciidoctor-includetracker.rb
@@ -0,0 +1,45 @@
+# Copyright (C) 2023 Thomas Weißschuh <thomas@t-8ch.de>
+# Extensions for asciidoctor to write dependency files for include directives.
+
+require 'asciidoctor/extensions'
+
+module IncludeTracker
+
+  class Preprocessor < Asciidoctor::Extensions::Preprocessor
+    def process document, reader
+      document.attributes["include_dependencies"] = []
+      reader
+    end
+  end
+
+  class IncludeProcessor < Asciidoctor::Extensions::IncludeProcessor
+    def process doc, reader, target, attributes
+      docdir = doc.attributes["docdir"]
+      path = target
+      file = File.expand_path path, docdir
+      data = File.read file
+      reader.push_include data, file, path, 1, attributes
+      doc.attributes["include_dependencies"] << file
+      reader
+    end
+  end
+
+  class Postprocessor < Asciidoctor::Extensions::Postprocessor
+    def process document, output
+      outfile = document.attributes["outfile"]
+      fail if !outfile
+      File.open outfile + '.deps', 'w' do |f|
+        f.write outfile + ": " +
+          document.attributes["include_dependencies"].join(' ')
+      end
+      output
+    end
+  end
+
+  Asciidoctor::Extensions.register do
+    preprocessor Preprocessor
+    include_processor IncludeProcessor
+    postprocessor Postprocessor
+  end
+
+end