2 files changed, 20 insertions, 3 deletions
diff --git a/src/tools/fuzzing/fuzzing.cpp b/src/tools/fuzzing/fuzzing.cpp
index d9e0f6baf..07464af9d 100644
--- a/src/tools/fuzzing/fuzzing.cpp
+++ b/src/tools/fuzzing/fuzzing.cpp
@@ -2429,6 +2429,14 @@ Expression* TranslateToFuzzReader::makeBasicRef(Type type) {
         HeapType(Array(Field(Field::PackedType::i8, Immutable)));
       return builder.makeArrayNewFixed(trivialArray, {});
     }
+    case HeapType::exn: {
+      auto null = builder.makeRefNull(HeapType::ext);
+      if (!type.isNullable()) {
+        assert(funcContext);
+        return builder.makeRefAs(RefAsNonNull, null);
+      }
+      return null;
+    }
     case HeapType::string:
       return builder.makeStringConst(std::to_string(upTo(1024)));
     case HeapType::stringview_wtf8:
@@ -2437,7 +2445,8 @@ Expression* TranslateToFuzzReader::makeBasicRef(Type type) {
       WASM_UNREACHABLE("TODO: strings");
     case HeapType::none:
     case HeapType::noext:
-    case HeapType::nofunc: {
+    case HeapType::nofunc:
+    case HeapType::noexn: {
       auto null = builder.makeRefNull(heapType);
       if (!type.isNullable()) {
         assert(funcContext);
@@ -3888,6 +3897,8 @@ HeapType TranslateToFuzzReader::getSubType(HeapType type) {
         return pick(HeapType::struct_, HeapType::none);
       case HeapType::array:
         return pick(HeapType::array, HeapType::none);
+      case HeapType::exn:
+        return HeapType::exn;
       case HeapType::string:
         return HeapType::string;
       case HeapType::stringview_wtf8:
@@ -3897,6 +3908,7 @@ HeapType TranslateToFuzzReader::getSubType(HeapType type) {
       case HeapType::none:
       case HeapType::noext:
       case HeapType::nofunc:
+      case HeapType::noexn:
         break;
     }
   }
diff --git a/src/tools/fuzzing/heap-types.cpp b/src/tools/fuzzing/heap-types.cpp
index 32a3fd960..13ad01474 100644
--- a/src/tools/fuzzing/heap-types.cpp
+++ b/src/tools/fuzzing/heap-types.cpp
@@ -378,8 +378,6 @@ struct HeapTypeGeneratorImpl {
         return type.getBottom();
       }
       switch (type.getBasic()) {
-        case HeapType::ext:
-          return HeapType::ext;
         case HeapType::func:
           return pickSubFunc();
         case HeapType::any:
@@ -392,6 +390,8 @@ struct HeapTypeGeneratorImpl {
           return pickSubStruct();
         case HeapType::array:
           return pickSubArray();
+        case HeapType::ext:
+        case HeapType::exn:
         case HeapType::string:
         case HeapType::stringview_wtf8:
         case HeapType::stringview_wtf16:
@@ -399,6 +399,7 @@ struct HeapTypeGeneratorImpl {
         case HeapType::none:
         case HeapType::noext:
         case HeapType::nofunc:
+        case HeapType::noexn:
           return type;
       }
       WASM_UNREACHABLE("unexpected type");
@@ -440,6 +441,7 @@ struct HeapTypeGeneratorImpl {
     switch (type.getBasic()) {
       case HeapType::ext:
       case HeapType::func:
+      case HeapType::exn:
       case HeapType::any:
         break;
       case HeapType::eq:
@@ -464,6 +466,9 @@ struct HeapTypeGeneratorImpl {
       case HeapType::noext:
         candidates.push_back(HeapType::ext);
         break;
+      case HeapType::noexn:
+        candidates.push_back(HeapType::exn);
+        break;
     }
     assert(!candidates.empty());
     return rand.pick(candidates);