Fixed include diagram visitor

src/include_diagram/visitor/translation_unit_visitor.cc

@@ -69,9 +69,15 @@ void translation_unit_visitor::include_visitor::InclusionDirective(
     include_path = include_path / file->getName().str();
     include_path = include_path.lexically_normal();
 
-    LOG_DBG("Processing include file {} in file {}", include_path.string(),
+    if (!diagram().should_include(source_file{include_path}) ||
+        visited_.find(include_path.string()) != visited_.end())
+        return;
+
+    LOG_INFO("Processing include file {} in file {}", include_path.string(),
         current_file.string());
 
+    visited_.emplace(include_path.string());
+
     auto relative_include_path = include_path;
     if (config().relative_to) {
         const std::filesystem::path relative_to{config().relative_to()};

src/include_diagram/visitor/translation_unit_visitor.h

@@ -29,6 +29,7 @@
 #include <functional>
 #include <map>
 #include <memory>
+#include <set>
 #include <string>
 
 namespace clanguml::include_diagram::visitor {
@@ -80,6 +81,9 @@ public:
 
         // Reference to class diagram config
         const clanguml::config::include_diagram &config_;
+
+        // Keep track of already visited headers and source files
+        std::set<std::string> visited_;
     };
 
     translation_unit_visitor(clang::SourceManager &sm,