4 files changed, 21 insertions, 10 deletions
diff --git a/src/parser/wast-parser.cpp b/src/parser/wast-parser.cpp
index a3a6c14ce..00269a577 100644
--- a/src/parser/wast-parser.cpp
+++ b/src/parser/wast-parser.cpp
@@ -25,7 +25,17 @@ using namespace std::string_view_literals;
 namespace {
 
 Result<Literal> const_(Lexer& in) {
-  // TODO: handle `ref.extern n` as well.
+  if (in.takeSExprStart("ref.extern"sv)) {
+    auto n = in.takeI32();
+    if (!n) {
+      return in.err("expected host reference payload");
+    }
+    if (!in.takeRParen()) {
+      return in.err("expected end of ref.extern");
+    }
+    // Represent host references as externalized i31s.
+    return Literal::makeI31(*n, Unshared).externalize();
+  }
   return parseConst(in);
 }
 
diff --git a/src/tools/wasm-shell.cpp b/src/tools/wasm-shell.cpp
index 651857965..eda4facc9 100644
--- a/src/tools/wasm-shell.cpp
+++ b/src/tools/wasm-shell.cpp
@@ -318,7 +318,8 @@ struct Shell {
           return Err{err.str()};
         }
       } else if (auto* ref = std::get_if<RefResult>(&expected)) {
-        if (!val.type.isRef() || val.type.getHeapType() != ref->type) {
+        if (!val.type.isRef() ||
+            !HeapType::isSubType(val.type.getHeapType(), ref->type)) {
           err << "expected " << ref->type << " reference, got " << val
               << atIndex();
           return Err{err.str()};
diff --git a/src/wasm-interpreter.h b/src/wasm-interpreter.h
index 1bf135c40..cbd2b31d6 100644
--- a/src/wasm-interpreter.h
+++ b/src/wasm-interpreter.h
@@ -3172,20 +3172,17 @@ public:
     }
     auto info = getTableInstanceInfo(curr->table);
 
-    Index tableSize = info.interface()->tableSize(info.name);
+    uint64_t tableSize = info.interface()->tableSize(info.name);
     auto* table = info.instance->wasm.getTable(info.name);
     Flow ret = Literal::makeFromInt64(tableSize, table->indexType);
     Flow fail = Literal::makeFromInt64(-1, table->indexType);
-    Index delta = deltaFlow.getSingleValue().geti32();
+    uint64_t delta = deltaFlow.getSingleValue().getUnsigned();
 
-    if (tableSize >= uint32_t(-1) - delta) {
+    uint64_t newSize;
+    if (std::ckd_add(&newSize, tableSize, delta)) {
       return fail;
     }
-    if (uint64_t(tableSize) + uint64_t(delta) > uint64_t(table->max)) {
-      return fail;
-    }
-    Index newSize = tableSize + delta;
-    if (newSize > WebLimitations::MaxTableSize) {
+    if (newSize > table->max || newSize > WebLimitations::MaxTableSize) {
       return fail;
     }
     if (!info.interface()->growTable(
diff --git a/src/wasm/literal.cpp b/src/wasm/literal.cpp
index 650318be3..d60e2f8a9 100644
--- a/src/wasm/literal.cpp
+++ b/src/wasm/literal.cpp
@@ -463,6 +463,9 @@ bool Literal::operator==(const Literal& other) const {
     if (type.getHeapType().isMaybeShared(HeapType::i31)) {
       return i32 == other.i32;
     }
+    if (type.getHeapType().isMaybeShared(HeapType::ext)) {
+      return internalize() == other.internalize();
+    }
     WASM_UNREACHABLE("unexpected type");
   }
   WASM_UNREACHABLE("unexpected type");