subclass struct_identity for unions

library/DataDefs.cpp

@@ -224,6 +224,13 @@ std::string df::buffer_container_identity::getFullName(type_identity *item)
            (size > 0 ? stl_sprintf("[%d]", size) : std::string("[]"));
 }
 
+union_identity::union_identity(size_t size, TAllocateFn alloc,
+        compound_identity *scope_parent, const char *dfhack_name,
+        struct_identity *parent, const struct_field_info *fields)
+    : struct_identity(size, alloc, scope_parent, dfhack_name, parent, fields)
+{
+}
+
 virtual_identity::virtual_identity(size_t size, TAllocateFn alloc,
                                    const char *dfhack_name, const char *original_name,
                                    virtual_identity *parent, const struct_field_info *fields,

library/LuaTypes.cpp

@@ -1179,7 +1179,7 @@ static void IndexFields(lua_State *state, int base, struct_identity *pstruct, bo
 
         case struct_field_info::POINTER:
             // Skip class-typed pointers within unions and other bad pointers
-            if ((fields[i].count & 2) != 0 && fields[i].type)
+            if ((pstruct->type() == IDTYPE_UNION || (fields[i].count & 2) != 0) && fields[i].type)
                 add_to_enum = false;
             break;
 

library/LuaWrapper.cpp

@@ -296,6 +296,7 @@ bool LuaWrapper::is_type_compatible(lua_State *state, type_identity *type1, int
     }
 
     case IDTYPE_STRUCT:
+    case IDTYPE_UNION:
     case IDTYPE_CLASS:
     {
         auto b1 = (struct_identity*)type1;
@@ -1618,6 +1619,7 @@ static void RenderType(lua_State *state, compound_identity *node)
     switch (node->type())
     {
     case IDTYPE_STRUCT:
+    case IDTYPE_UNION: // TODO: change this to union-type? what relies on this?
         lua_pushstring(state, "struct-type");
         lua_setfield(state, ftable, "_kind");
         IndexStatics(state, ix_meta, ftable, (struct_identity*)node);

library/include/DataDefs.h

@@ -64,7 +64,13 @@ namespace DFHack
         IDTYPE_CLASS,
         IDTYPE_BUFFER,
         IDTYPE_STL_PTR_VECTOR,
-        IDTYPE_OPAQUE
+        IDTYPE_OPAQUE,
+        IDTYPE_UNION
+    };
+
+    enum pointer_identity_flags {
+        PTRFLAG_IS_ARRAY = 1,
+        PTRFLAG_HAS_BAD_POINTERS = 2,
     };
 
     typedef void *(*TAllocateFn)(void*,const void*);
@@ -305,6 +311,15 @@ namespace DFHack
         virtual void build_metatable(lua_State *state);
     };
 
+    class DFHACK_EXPORT global_identity : public union_identity {
+    public:
+        union_identity(size_t size, TAllocateFn alloc,
+                compound_identity *scope_parent, const char *dfhack_name,
+                struct_identity *parent, const struct_field_info *fields);
+
+        virtual identity_type type() { return IDTYPE_UNION; }
+    };
+
 #ifdef _MSC_VER
     typedef void *virtual_ptr;
 #else

library/xml

@@ -1 +1 @@
-Subproject commit 3486919f01b86d558558ecd36c815d0a527459c2
+Subproject commit 17b1c45fff78d0c49aa8b4dc4824dc36ae7eae08

plugins/devel/check-structures-sanity.cpp

@@ -448,6 +448,7 @@ void Checker::queue_field(ToCheck && item, const struct_field_info *field)
             // TODO: check static strings?
             break;
         case struct_field_info::POINTER:
+            // TODO: flags inside field->count
             item.temp_identity = std::unique_ptr<df::pointer_identity>(new df::pointer_identity(field->type));
             item.identity = item.temp_identity.get();
             queue.push_back(std::move(item));
@@ -554,12 +555,12 @@ bool Checker::maybe_queue_tagged_union(const ToCheck & item, const struct_field_
 
     auto tag_identity = static_cast<enum_identity *>(tag_field->type);
 
-    if (!field->type || field->type->type() != IDTYPE_STRUCT)
+    if (!field->type || field->type->type() != IDTYPE_UNION)
     {
         return false;
     }
 
-    auto union_identity = static_cast<struct_identity *>(field->type);
+    auto union_identity = static_cast<union_identity *>(field->type);
 
     if (!union_identity->getFields() || union_identity->getFields()->mode != struct_field_info::POINTER)
     {
@@ -699,6 +700,7 @@ void Checker::check_dispatch(const ToCheck & item)
             check_enum(item);
             break;
         case IDTYPE_STRUCT:
+        case IDTYPE_UNION:
             check_struct(item);
             break;
         case IDTYPE_CLASS: