Mermaid: Make mermaid aware of cowns

src/rt/core.h

@@ -198,12 +198,8 @@ namespace rt::core
       //
       // FIXME: Also check that the region has a LRC == 1, with 1
       // being the reference passed into this constructor
-      this->set("region", region);
-    }
-
-    bool is_aquired()
-    {
-      return aquired;
+      auto old = this->set("region", region);
+      assert(old == nullptr);
     }
 
     std::string get_name()
@@ -220,6 +216,11 @@ namespace rt::core
     {
       return true;
     }
+
+    bool is_cown_aquired() override
+    {
+      return aquired;
+    }
   };
 
   inline std::set<objects::DynObject*>* globals()

src/rt/objects/dyn_object.h

@@ -261,6 +261,14 @@ namespace rt::objects
     {
       return false;
     }
+    virtual bool is_cown_aquired()
+    {
+      assert(false && "should only be called on cowns");
+    }
+    bool is_opaque()
+    {
+      return this->is_cown() && !this->is_cown_aquired();
+    }
 
     [[nodiscard]] DynObject* get(std::string name)
     {

src/rt/rt.cc

@@ -56,14 +56,9 @@ namespace rt
 
   objects::DynObject* get(objects::DynObject* obj, std::string key)
   {
-    if (obj->get_prototype() == core::cownPrototypeObject())
+    if (obj->is_opaque())
     {
-      core::CownObject* cown = reinterpret_cast<core::CownObject*>(obj);
-      if (!cown->is_aquired())
-      {
-        ui::error(
-          "the cown needs to be aquired, before its data can be accessed");
-      }
+      ui::error("opaque objects can't be accessed");
     }
     return obj->get(key);
   }
@@ -88,15 +83,11 @@ namespace rt
   objects::DynObject*
   set(objects::DynObject* obj, std::string key, objects::DynObject* value)
   {
-    if (obj->get_prototype() == core::cownPrototypeObject())
+    if (obj->is_opaque())
     {
-      core::CownObject* cown = reinterpret_cast<core::CownObject*>(obj);
-      if (!cown->is_aquired())
-      {
-        // Overwriting data can change the RC and then call destructors of the
-        // type this action therefore requires the cown to be aquired
-        ui::error("the cown needs to be aquired, before its data can modified");
-      }
+      // Overwriting data can change the RC and then call destructors of the
+      // type this action therefore requires the cown to be aquired
+      ui::error("opaque objects can't be modified");
     }
 
     return obj->set(key, value);

src/rt/ui/mermaid.cc

@@ -10,6 +10,15 @@
 namespace rt::ui
 {
 
+  struct MermaidDecoration
+  {
+    const char* start;
+    const char* end;
+    const char* out;
+  };
+  const inline auto NORMAL = MermaidDecoration{"[", "]", "-->"};
+  const inline auto COWN = MermaidDecoration{"[[", "]]", "-.->"};
+
   void replace(std::string& text, std::string from, std::string replace)
   {
     size_t pos = 0;
@@ -64,9 +73,13 @@ namespace rt::ui
       {
         return false;
       }
+      auto src_deco = ((src && src->is_cown()) ? &COWN : &NORMAL);
+      auto dst_deco = ((dst && dst->is_cown()) ? &COWN : &NORMAL);
+
       if (src != nullptr)
       {
-        out << "  id" << visited[src] << " -->|" << escape(key) << "| ";
+        out << "  id" << visited[src] << " " << src_deco->out << "|"
+            << escape(key) << "| ";
       }
       if (visited.find(dst) != visited.end())
       {
@@ -75,11 +88,12 @@ namespace rt::ui
       }
       auto curr_id = id++;
       visited[dst] = curr_id;
-      out << "id" << curr_id << "[ ";
+      out << "id" << curr_id << dst_deco->start << " ";
       out << escape(dst->get_name());
       out << "<br/>rc=" << dst->rc;
 
-      out << " ]" << (unreachable ? ":::unreachable" : "") << std::endl;
+      out << " " << dst_deco->end << (unreachable ? ":::unreachable" : "")
+          << std::endl;
 
       auto region = objects::DynObject::get_region(dst);
       if (region != nullptr)
@@ -169,7 +183,7 @@ namespace rt::ui
         out << "class id" << visited[dst] << " tainted;" << std::endl;
         tainted.insert(dst);
 
-        return true;
+        return dst->is_opaque();
       };
 
       for (auto root : *taint)