Add doxygen and graphviz support

docs/conf.py

@@ -1,3 +1,9 @@
+import os
+import subprocess
+
+from sphinx.application import Sphinx
+from pathlib import Path
+
 project = 'Catch2'
 copyright = '2023, Martin Hořeňovský'
 author = 'Martin Hořeňovský'
@@ -19,11 +25,28 @@ exclude_patterns = [
 ]
 source_suffix = [".md"]
 
-
 html_theme = 'furo'
-#html_static_path = ['_static']
+# html_static_path = ['_static']
 
 myst_enable_extensions = [
     "tasklist",
     "colon_fence",
 ]
+
+breathe_projects = {
+    "Catch2": "build/doxygen/xml",
+}
+breathe_default_project = "Catch2"
+
+
+def generate_doxygen_xml(app: Sphinx):
+    """
+    Run the doxygen commands
+    """
+    os.chdir(Path(app.confdir).parent)
+    subprocess.run(["doxygen"])
+
+
+def setup(app: Sphinx):
+    # Add hook for building doxygen xml when needed
+    app.connect("builder-inited", generate_doxygen_xml)