Add initial support for anyref as an opaque type (#2294)

Another round of trying to push upstream things from my fork.

This PR only adds support for anyref itself as an opaque type. It does NOT implement the full [reference types proposal](https://github.com/WebAssembly/reference-types/blob/master/proposals/reference-types/Overview.md)--so no table.get/set/grow/etc or ref.null, ref.func, etc.

Figured it was easier to review and merge as we go, especially if I did something fundamentally wrong.

***

I did put it under the `--enable-reference-types` flag as I imagine that even though this PR doesn't complete the full feature set, it probably is the right home. Lmk if not.

I'll also be adding a few github comments to places I want to point out/question.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/wasm/literal.cpp b/src/wasm/literal.cpp
index 68268d366..43adec6f6 100644
--- a/src/wasm/literal.cpp
+++ b/src/wasm/literal.cpp
@@ -137,6 +137,7 @@ void Literal::getBits(uint8_t (&buf)[16]) const {
     case Type::v128:
       memcpy(buf, &v128, sizeof(v128));
       break;
+    case Type::anyref: // anyref type is opaque
     case Type::exnref: // exnref type is opaque
     case Type::none:
     case Type::unreachable:
@@ -272,6 +273,7 @@ std::ostream& operator<<(std::ostream& o, Literal literal) {
       o << "i32x4 ";
       literal.printVec128(o, literal.getv128());
       break;
+    case Type::anyref: // anyref type is opaque
     case Type::exnref: // exnref type is opaque
     case Type::unreachable:
       WASM_UNREACHABLE();
@@ -475,6 +477,7 @@ Literal Literal::eqz() const {
     case Type::f64:
       return eq(Literal(double(0)));
     case Type::v128:
+    case Type::anyref:
     case Type::exnref:
     case Type::none:
     case Type::unreachable:
@@ -494,6 +497,7 @@ Literal Literal::neg() const {
     case Type::f64:
       return Literal(int64_t(i64 ^ 0x8000000000000000ULL)).castToF64();
     case Type::v128:
+    case Type::anyref:
     case Type::exnref:
     case Type::none:
     case Type::unreachable:
@@ -513,6 +517,7 @@ Literal Literal::abs() const {
     case Type::f64:
       return Literal(int64_t(i64 & 0x7fffffffffffffffULL)).castToF64();
     case Type::v128:
+    case Type::anyref:
     case Type::exnref:
     case Type::none:
     case Type::unreachable:
@@ -615,6 +620,7 @@ Literal Literal::add(const Literal& other) const {
     case Type::f64:
       return Literal(getf64() + other.getf64());
     case Type::v128:
+    case Type::anyref:
     case Type::exnref:
     case Type::none:
     case Type::unreachable:
@@ -634,6 +640,7 @@ Literal Literal::sub(const Literal& other) const {
     case Type::f64:
       return Literal(getf64() - other.getf64());
     case Type::v128:
+    case Type::anyref:
     case Type::exnref:
     case Type::none:
     case Type::unreachable:
@@ -724,6 +731,7 @@ Literal Literal::mul(const Literal& other) const {
     case Type::f64:
       return Literal(getf64() * other.getf64());
     case Type::v128:
+    case Type::anyref:
     case Type::exnref:
     case Type::none:
     case Type::unreachable:
@@ -942,6 +950,7 @@ Literal Literal::eq(const Literal& other) const {
     case Type::f64:
       return Literal(getf64() == other.getf64());
     case Type::v128:
+    case Type::anyref:
     case Type::exnref:
     case Type::none:
     case Type::unreachable:
@@ -961,6 +970,7 @@ Literal Literal::ne(const Literal& other) const {
     case Type::f64:
       return Literal(getf64() != other.getf64());
     case Type::v128:
+    case Type::anyref:
     case Type::exnref:
     case Type::none:
     case Type::unreachable: