Refactor TypeBuilder (#3728)

Makes TypeBuilders growable, adds a `getTempHeapType` method, allows the
`getTemp*Type` methods to take arbitrary temporary or canonical HeapTypes rather
than just an index, and allows BasicHeapTypes to be assigned to TypeBuilder
slots. All of these changes are necessary for the upcoming re-implementation of
equirecursive LUB calculation.

Also adds a new utility to TypeBuilder for using `operator[]` as an intuitive
and readable wrapper around the `getTempHeapType` and `setHeapType` methods.

1 files changed, 5 insertions, 5 deletions

diff --git a/src/wasm/wasm-binary.cpp b/src/wasm/wasm-binary.cpp
index 5fff58045..5bd368e17 100644
--- a/src/wasm/wasm-binary.cpp
+++ b/src/wasm/wasm-binary.cpp
@@ -1816,7 +1816,7 @@ void WasmBinaryBuilder::readTypes() {
         if (size_t(htCode) >= numTypes) {
           throwError("invalid type index: " + std::to_string(htCode));
         }
-        return builder.getTempRefType(size_t(htCode), nullability);
+        return builder.getTempRefType(builder[size_t(htCode)], nullability);
       }
       case BinaryConsts::EncodedType::rtt_n:
       case BinaryConsts::EncodedType::rtt: {
@@ -1826,7 +1826,7 @@ void WasmBinaryBuilder::readTypes() {
         if (size_t(htCode) >= numTypes) {
           throwError("invalid type index: " + std::to_string(htCode));
         }
-        return builder.getTempRttType(htCode, depth);
+        return builder.getTempRttType(Rtt(depth, builder[htCode]));
       }
       default:
         throwError("unexpected type index: " + std::to_string(typeCode));
@@ -1896,11 +1896,11 @@ void WasmBinaryBuilder::readTypes() {
     BYN_TRACE("read one\n");
     auto form = getS32LEB();
     if (form == BinaryConsts::EncodedType::Func) {
-      builder.setHeapType(i, readSignatureDef());
+      builder[i] = readSignatureDef();
     } else if (form == BinaryConsts::EncodedType::Struct) {
-      builder.setHeapType(i, readStructDef());
+      builder[i] = readStructDef();
     } else if (form == BinaryConsts::EncodedType::Array) {
-      builder.setHeapType(i, Array(readFieldDef()));
+      builder[i] = Array(readFieldDef());
     } else {
       throwError("bad type form " + std::to_string(form));
     }