review feedback

crates/wasmparser/src/readers/core/types.rs

@@ -941,6 +941,33 @@ impl RefType {
     /// `externref`.
     pub const EXTERNREF: Self = RefType::EXTERN.nullable();
 
+    /// A nullable reference to any object aka `(ref null any)` aka `anyref`.
+    pub const ANYREF: Self = RefType::ANY.nullable();
+
+    /// A nullable reference to no object aka `(ref null none)` aka `nullref`.
+    pub const NULLREF: Self = RefType::NONE.nullable();
+
+    /// A nullable reference to a noextern object aka `(ref null noextern)` aka
+    /// `nullexternref`.
+    pub const NULLEXTERNREF: Self = RefType::NOEXTERN.nullable();
+
+    /// A nullable reference to a nofunc object aka `(ref null nofunc)` aka
+    /// `nullfuncref`.
+    pub const NULLFUNCREF: Self = RefType::NOFUNC.nullable();
+
+    /// A nullable reference to an eq object aka `(ref null eq)` aka `eqref`.
+    pub const EQREF: Self = RefType::EQ.nullable();
+
+    /// A nullable reference to a struct aka `(ref null struct)` aka
+    /// `structref`.
+    pub const STRUCTREF: Self = RefType::STRUCT.nullable();
+
+    /// A nullable reference to an array aka `(ref null array)` aka `arrayref`.
+    pub const ARRAYREF: Self = RefType::ARRAY.nullable();
+
+    /// A nullable reference to an i31 object aka `(ref null i31)` aka `i31ref`.
+    pub const I31REF: Self = RefType::I31.nullable();
+
     /// A nullable reference to an exception object aka `(ref null exn)` aka
     /// `exnref`.
     pub const EXNREF: Self = RefType::EXN.nullable();

crates/wasmparser/src/validator/operators.rs

@@ -1072,10 +1072,13 @@ where
                 BinaryReaderError::new("implementation limit: type index too large", self.offset)
             })?;
 
-        let sup_ty = self
-            .pop_ref()?
-            .unwrap_or_else(|| sub_ty.as_reference_type().unwrap());
-        let sup_ty = RefType::new(true, self.resources.top_type(&sup_ty.heap_type())).unwrap();
+        let sup_ty = self.pop_ref()?.unwrap_or_else(|| {
+            sub_ty
+                .as_reference_type()
+                .expect("we created this as a reference just above")
+        });
+        let sup_ty = RefType::new(true, self.resources.top_type(&sup_ty.heap_type()))
+            .expect("can't panic with non-concrete heap types");
 
         if !self.resources.is_subtype(sub_ty, sup_ty.into()) {
             bail!(
@@ -3990,15 +3993,11 @@ where
         self.push_operand(ValType::Ref(RefType::I31))
     }
     fn visit_i31_get_s(&mut self) -> Self::Output {
-        self.pop_operand(Some(ValType::Ref(
-            RefType::new(true, HeapType::I31).unwrap(),
-        )))?;
+        self.pop_operand(Some(ValType::Ref(RefType::I31REF)))?;
         self.push_operand(ValType::I32)
     }
     fn visit_i31_get_u(&mut self) -> Self::Output {
-        self.pop_operand(Some(ValType::Ref(
-            RefType::new(true, HeapType::I31).unwrap(),
-        )))?;
+        self.pop_operand(Some(ValType::Ref(RefType::I31REF)))?;
         self.push_operand(ValType::I32)
     }
 }