Validate heap types

src/wasm/wasm-type.cpp

@@ -1087,9 +1087,6 @@ FeatureSet Type::getFeatures() const {
       // A reference type implies we need that feature. Some also require more,
       // such as GC or exceptions.
       auto heapType = t.getHeapType();
-      if (heapType.isStruct() || heapType.isArray()) {
-        return FeatureSet::ReferenceTypes | FeatureSet::GC;
-      }
       if (heapType.isBasic()) {
         switch (heapType.getBasic()) {
           case HeapType::ext:
@@ -1114,11 +1111,16 @@ FeatureSet Type::getFeatures() const {
             return FeatureSet::ReferenceTypes;
         }
       }
-      // Note: Technically typed function references also require the typed
-      // function references feature, however, we use these types internally
-      // regardless of the presence of features (in particular, since during
-      // load of the wasm we don't know the features yet, so we apply the more
-      // refined types), so we don't add that in any case here.
+      if (heapType.isStruct() || heapType.isArray() ||
+          heapType.getRecGroup().size() > 1 || heapType.getSuperType()) {
+        return FeatureSet::ReferenceTypes | FeatureSet::GC;
+      }
+      // Note: Technically typed function references also require GC, however,
+      // we use these types internally regardless of the presence of GC (in
+      // particular, since during load of the wasm we don't know the features
+      // yet, so we apply the more refined types), so we don't add that in any
+      // case here.
+      assert(heapType.isSignature());
       return FeatureSet::ReferenceTypes;
     }
     TODO_SINGLE_COMPOUND(t);

src/wasm/wasm-validator.cpp

@@ -2903,6 +2903,9 @@ void FunctionValidator::visitFunction(Function* curr) {
                  "Multivalue function results (multivalue is not enabled)");
   }
   FeatureSet features;
+  // Check for things like having a rec group with GC enabled.
+  features |=
+    (Type(curr->type, Nullable).getFeatures() & ~FeatureSet::ReferenceTypes);
   for (const auto& param : curr->getParams()) {
     features |= param.getFeatures();
     shouldBeTrue(param.isConcrete(), curr, "params must be concretely typed");

test/lit/validation/rec-groups-no-gc.wast

@@ -0,0 +1,16 @@
+;; Test that using rec groups types without GC is a validation error.
+
+;; RUN:  not wasm-opt %s --hybrid -all --disable-gc 2>&1 | filecheck %s
+
+;; CHECK: all used types should be allowed
+
+(module
+  (rec
+    (type $f1 (func))
+    (type $f2 (func))
+  )
+
+  (func $test (type $f1)
+    (unreachable)
+  )
+)

test/lit/validation/supertypes-no-gc.wast

@@ -0,0 +1,14 @@
+;; Test that declaring supertypes without GC is a validation error.
+
+;; RUN:  not wasm-opt %s --hybrid -all --disable-gc 2>&1 | filecheck %s
+
+;; CHECK: all used types should be allowed
+
+(module
+  (type $f1 (func_subtype func))
+  (type $f2 (func_subtype $f1))
+
+  (func $test (type $f2)
+    (unreachable)
+  )
+ )