Support anyref variable declarations as Wasm locals

Author: jayphelps

NOTICE

@@ -78,6 +78,7 @@ the following terms:
   Hauke Mehrtens
   Hiltjo Posthuma
   Isaac Dunham
+  Jay Phelps
   Jaydeep Patil
   Jens Gustedt
   Jeremy Huntwork

src/flow.ts

@@ -324,6 +324,7 @@ export class Flow {
       case NativeType.F32: { temps = parentFunction.tempF32s; break; }
       case NativeType.F64: { temps = parentFunction.tempF64s; break; }
       case NativeType.V128: { temps = parentFunction.tempV128s; break; }
+      case NativeType.Anyref: { temps = parentFunction.tempAnyrefs; break; }
       default: throw new Error("concrete type expected");
     }
     var local: Local;
@@ -395,6 +396,10 @@ export class Flow {
         temps = parentFunction.tempV128s || (parentFunction.tempV128s = []);
         break;
       }
+      case NativeType.Anyref: {
+        temps = parentFunction.tempAnyrefs || (parentFunction.tempAnyrefs = []);
+        break;
+      }
       default: throw new Error("concrete type expected");
     }
     assert(local.index >= 0);

src/module.ts

@@ -1423,6 +1423,10 @@ export class Module {
             // TODO
             return 0;
           }
+          // Not possible to clone an anyref as it is opaque
+          case NativeType.Anyref: {
+            return 0;
+          }
           default: {
             throw new Error("concrete type expected");
           }

src/program.ts

@@ -2900,6 +2900,7 @@ export class Function extends TypedElement {
   tempF32s: Local[] | null = null;
   tempF64s: Local[] | null = null;
   tempV128s: Local[] | null = null;
+  tempAnyrefs: Local[] | null = null;
 
   // used by flows to keep track of break labels
   nextBreakId: i32 = 0;

tests/compiler/features/reference-types.ts

@@ -3,7 +3,8 @@
 export declare function external(a: anyref): anyref;
 
 export function internal(a: anyref): anyref {
-  return a;
+  const b = external(a);
+  return b;
 }
 
 // can use reflection to work with anyref values