Add anyref feature and type (#3109)

Adds `anyref` type, which is enabled by a new feature `--enable-anyref`. This type is primarily used for testing that passes correctly handle subtype relationships so that the codebase will continue to be prepared for future subtyping. Since `--enable-anyref` is meaningless without also using `--enable-reference-types`, this PR also makes it a validation error to pass only the former (and similarly makes it a validation error to enable exception handling without enabling reference types).

1 files changed, 17 insertions, 0 deletions

diff --git a/src/wasm/wasm-validator.cpp b/src/wasm/wasm-validator.cpp
index c6d679a24..80c54abed 100644
--- a/src/wasm/wasm-validator.cpp
+++ b/src/wasm/wasm-validator.cpp
@@ -1363,6 +1363,7 @@ void FunctionValidator::validateMemBytes(uint8_t bytes,
     case Type::funcref:
     case Type::externref:
     case Type::exnref:
+    case Type::anyref:
     case Type::none:
       WASM_UNREACHABLE("unexpected type");
   }
@@ -2176,6 +2177,7 @@ void FunctionValidator::validateAlignment(
     case Type::funcref:
     case Type::externref:
     case Type::exnref:
+    case Type::anyref:
     case Type::none:
       WASM_UNREACHABLE("invalid type");
   }
@@ -2475,6 +2477,20 @@ static void validateModule(Module& module, ValidationInfo& info) {
   }
 }
 
+static void validateFeatures(Module& module, ValidationInfo& info) {
+  if (module.features.hasAnyref()) {
+    info.shouldBeTrue(module.features.hasReferenceTypes(),
+                      module.features,
+                      "--enable-anyref requires --enable-reference-types");
+  }
+  if (module.features.hasExceptionHandling()) { // implies exnref
+    info.shouldBeTrue(
+      module.features.hasReferenceTypes(),
+      module.features,
+      "--enable-exception-handling requires --enable-reference-types");
+  }
+}
+
 // TODO: If we want the validator to be part of libwasm rather than libpasses,
 // then Using PassRunner::getPassDebug causes a circular dependence. We should
 // fix that, perhaps by moving some of the pass infrastructure into libsupport.
@@ -2495,6 +2511,7 @@ bool WasmValidator::validate(Module& module, Flags flags) {
     validateTable(module, info);
     validateEvents(module, info);
     validateModule(module, info);
+    validateFeatures(module, info);
   }
   // validate additional internal IR details when in pass-debug mode
   if (PassRunner::getPassDebug()) {