Remove basic reference types (#4802)

Basic reference types like `Type::funcref`, `Type::anyref`, etc. made it easy to
accidentally forget to handle reference types with the same basic HeapTypes but
the opposite nullability. In principle there is nothing special about the types
with shorthands except in the binary and text formats. Removing these shorthands
from the internal type representation by removing all basic reference types
makes some code more complicated locally, but simplifies code globally and
encourages properly handling both nullable and non-nullable reference types.

1 files changed, 15 insertions, 61 deletions

diff --git a/src/tools/fuzzing/fuzzing.cpp b/src/tools/fuzzing/fuzzing.cpp
index 5489e7638..59c9dca45 100644
--- a/src/tools/fuzzing/fuzzing.cpp
+++ b/src/tools/fuzzing/fuzzing.cpp
@@ -260,15 +260,15 @@ void TranslateToFuzzReader::setupTables() {
   // Ensure a funcref element segment and table exist. Segments with more
   // specific function types may have a smaller chance of getting functions.
   Table* table = nullptr;
-  auto iter =
-    std::find_if(wasm.tables.begin(), wasm.tables.end(), [&](auto& table) {
-      return table->type == Type::funcref;
-    });
+  Type funcref = Type(HeapType::func, Nullable);
+  auto iter = std::find_if(wasm.tables.begin(),
+                           wasm.tables.end(),
+                           [&](auto& table) { return table->type == funcref; });
   if (iter != wasm.tables.end()) {
     table = iter->get();
   } else {
     auto tablePtr = builder.makeTable(
-      Names::getValidTableName(wasm, "fuzzing_table"), Type::funcref, 0, 0);
+      Names::getValidTableName(wasm, "fuzzing_table"), funcref, 0, 0);
     tablePtr->hasExplicitName = true;
     table = wasm.addTable(std::move(tablePtr));
   }
@@ -277,7 +277,7 @@ void TranslateToFuzzReader::setupTables() {
     std::any_of(wasm.elementSegments.begin(),
                 wasm.elementSegments.end(),
                 [&](auto& segment) {
-                  return segment->table.is() && segment->type == Type::funcref;
+                  return segment->table.is() && segment->type == funcref;
                 });
   if (!hasFuncrefElemSegment) {
     // TODO: use a random table
@@ -934,7 +934,7 @@ Expression* TranslateToFuzzReader::_makeConcrete(Type type) {
   if (type.isTuple()) {
     options.add(FeatureSet::Multivalue, &Self::makeTupleMake);
   }
-  if (type == Type::i31ref) {
+  if (type.isRef() && type.getHeapType() == HeapType::i31) {
     options.add(FeatureSet::ReferenceTypes | FeatureSet::GC, &Self::makeI31New);
   }
   // TODO: struct.get and other GC things
@@ -1463,11 +1463,6 @@ Expression* TranslateToFuzzReader::makeNonAtomicLoad(Type type) {
       return builder.makeLoad(
         16, false, offset, pick(1, 2, 4, 8, 16), ptr, type);
     }
-    case Type::funcref:
-    case Type::anyref:
-    case Type::eqref:
-    case Type::i31ref:
-    case Type::dataref:
     case Type::none:
     case Type::unreachable:
       WASM_UNREACHABLE("invalid type");
@@ -1566,11 +1561,6 @@ Expression* TranslateToFuzzReader::makeNonAtomicStore(Type type) {
       return builder.makeStore(
         16, offset, pick(1, 2, 4, 8, 16), ptr, value, type);
     }
-    case Type::funcref:
-    case Type::anyref:
-    case Type::eqref:
-    case Type::i31ref:
-    case Type::dataref:
     case Type::none:
     case Type::unreachable:
       WASM_UNREACHABLE("invalid type");
@@ -1701,11 +1691,6 @@ Literal TranslateToFuzzReader::makeLiteral(Type type) {
         case Type::f64:
           return Literal(getDouble());
         case Type::v128:
-        case Type::funcref:
-        case Type::anyref:
-        case Type::eqref:
-        case Type::i31ref:
-        case Type::dataref:
         case Type::none:
         case Type::unreachable:
           WASM_UNREACHABLE("invalid type");
@@ -1747,11 +1732,6 @@ Literal TranslateToFuzzReader::makeLiteral(Type type) {
         case Type::f64:
           return Literal(double(small));
         case Type::v128:
-        case Type::funcref:
-        case Type::anyref:
-        case Type::eqref:
-        case Type::i31ref:
-        case Type::dataref:
         case Type::none:
         case Type::unreachable:
           WASM_UNREACHABLE("unexpected type");
@@ -1816,11 +1796,6 @@ Literal TranslateToFuzzReader::makeLiteral(Type type) {
                                        std::numeric_limits<uint64_t>::max()));
           break;
         case Type::v128:
-        case Type::funcref:
-        case Type::anyref:
-        case Type::eqref:
-        case Type::i31ref:
-        case Type::dataref:
         case Type::none:
         case Type::unreachable:
           WASM_UNREACHABLE("unexpected type");
@@ -1844,11 +1819,6 @@ Literal TranslateToFuzzReader::makeLiteral(Type type) {
           value = Literal(double(int64_t(1) << upTo(64)));
           break;
         case Type::v128:
-        case Type::funcref:
-        case Type::anyref:
-        case Type::eqref:
-        case Type::i31ref:
-        case Type::dataref:
         case Type::none:
         case Type::unreachable:
           WASM_UNREACHABLE("unexpected type");
@@ -2115,11 +2085,6 @@ Expression* TranslateToFuzzReader::makeUnary(Type type) {
                                   AllTrueVecI32x4),
                              make(Type::v128)});
         }
-        case Type::funcref:
-        case Type::anyref:
-        case Type::eqref:
-        case Type::i31ref:
-        case Type::dataref:
         case Type::none:
         case Type::unreachable:
           WASM_UNREACHABLE("unexpected type");
@@ -2255,11 +2220,6 @@ Expression* TranslateToFuzzReader::makeUnary(Type type) {
       }
       WASM_UNREACHABLE("invalid value");
     }
-    case Type::funcref:
-    case Type::anyref:
-    case Type::eqref:
-    case Type::i31ref:
-    case Type::dataref:
     case Type::none:
     case Type::unreachable:
       WASM_UNREACHABLE("unexpected type");
@@ -2493,11 +2453,6 @@ Expression* TranslateToFuzzReader::makeBinary(Type type) {
                           make(Type::v128),
                           make(Type::v128)});
     }
-    case Type::funcref:
-    case Type::anyref:
-    case Type::eqref:
-    case Type::i31ref:
-    case Type::dataref:
     case Type::none:
     case Type::unreachable:
       WASM_UNREACHABLE("unexpected type");
@@ -2700,11 +2655,6 @@ Expression* TranslateToFuzzReader::makeSIMDExtract(Type type) {
       op = ExtractLaneVecF64x2;
       break;
     case Type::v128:
-    case Type::funcref:
-    case Type::anyref:
-    case Type::eqref:
-    case Type::i31ref:
-    case Type::dataref:
     case Type::none:
     case Type::unreachable:
       WASM_UNREACHABLE("unexpected type");
@@ -2892,7 +2842,7 @@ Expression* TranslateToFuzzReader::makeRefEq(Type type) {
 }
 
 Expression* TranslateToFuzzReader::makeI31New(Type type) {
-  assert(type == Type::i31ref);
+  assert(type.isRef() && type.getHeapType() == HeapType::i31);
   assert(wasm.features.hasReferenceTypes() && wasm.features.hasGC());
   auto* value = make(Type::i32);
   return builder.makeI31New(value);
@@ -2901,7 +2851,9 @@ Expression* TranslateToFuzzReader::makeI31New(Type type) {
 Expression* TranslateToFuzzReader::makeI31Get(Type type) {
   assert(type == Type::i32);
   assert(wasm.features.hasReferenceTypes() && wasm.features.hasGC());
-  auto* i31 = make(Type::i31ref);
+  // TODO: Maybe this should be nullable?
+  // https://github.com/WebAssembly/gc/issues/312
+  auto* i31 = make(Type(HeapType::i31, NonNullable));
   return builder.makeI31Get(i31, bool(oneIn(2)));
 }
 
@@ -2958,7 +2910,9 @@ Type TranslateToFuzzReader::getSingleConcreteType() {
                      WeightedOption{Type::f32, VeryImportant},
                      WeightedOption{Type::f64, VeryImportant})
                 .add(FeatureSet::SIMD, WeightedOption{Type::v128, Important})
-                .add(FeatureSet::ReferenceTypes, Type::funcref, Type::anyref)
+                .add(FeatureSet::ReferenceTypes,
+                     Type(HeapType::func, Nullable),
+                     Type(HeapType::any, Nullable))
                 .add(FeatureSet::ReferenceTypes | FeatureSet::GC,
                      // Type(HeapType::func, NonNullable),
                      // Type(HeapType::any, NonNullable),
@@ -2974,7 +2928,7 @@ Type TranslateToFuzzReader::getReferenceType() {
   return pick(FeatureOptions<Type>()
                 // Avoid Type::anyref without GC enabled, see
                 // TranslateToFuzzReader::getSingleConcreteType.
-                .add(FeatureSet::ReferenceTypes, Type::funcref)
+                .add(FeatureSet::ReferenceTypes, Type(HeapType::func, Nullable))
                 .add(FeatureSet::ReferenceTypes | FeatureSet::GC,
                      Type(HeapType::func, NonNullable),
                      Type(HeapType::any, NonNullable),