[hl] Support taking reference to fields of Dynamic.

src/generators/genhl.ml

@@ -2076,12 +2076,13 @@ and eval_expr ctx e =
 				op ctx (ORef (r,rv));
 				r
 			| TField (obj, access) ->
-				let r = alloc_tmp ctx (HRef (to_type ctx (field_type ctx access e.epos))) in
+				let r = alloc_tmp ctx (to_type ctx e.etype) in
 				(match get_access ctx v with
 				| AStaticVar (g,t,fid) ->
 					let o = alloc_tmp ctx t in
 					op ctx (OGetGlobal (o,g));
 					op ctx (OFieldRef (r,o,fid));
+				| ADynamic (ethis, fid)
 				| AInstanceField (ethis,fid) ->
 					let robj = eval_null_check ctx ethis in
 					op ctx (OFieldRef (r,robj,fid));

src/generators/hl2c.ml

@@ -1115,17 +1115,18 @@ let generate_function ctx f =
 		| OAsm _ ->
 			sexpr "UNSUPPORTED ASM OPCODE";
 		| OFieldRef (r, obj, fid) ->
+			let val_type = (match (rtype r) with HRef t -> t | _ -> Globals.die "" __LOC__) in
 			match rtype obj with
 			| HObj o | HStruct o ->
 				let name, t = resolve_field o fid in
 				sexpr "%s &%s->%s" (rassign r (HRef t)) (reg obj) (obj_field fid name)
 			| HVirtual v ->
 				let name, nid, t = v.vfields.(fid) in
-				let dget = sprintf "hl_dyn_get_ref(%s->value,%ld/*%s*/)" (reg obj) (hash ctx nid) name in
+				let dget = sprintf "hl_dyn_get_ref(%s->value,%ld/*%s*/,%s)" (reg obj) (hash ctx nid) name (type_value val_type) in
 				sexpr "%shl_vfields(%s)[%d] ? ((%s*)(hl_vfields(%s)[%d])) : %s" (rassign r (HRef t)) (reg obj) fid (ctype t) (reg obj) fid dget
 			| HDyn ->
 				let h = hash ctx fid in
-				sexpr "%s = hl_dyn_get_ref((vdynamic*)%s,%ld/*%s*/)" (reg r) (reg obj) h code.strings.(fid)
+				sexpr "%s = hl_dyn_get_ref((vdynamic*)%s,%ld/*%s*/,%s)" (reg r) (reg obj) h code.strings.(fid) (type_value val_type)
 			| _ ->
 				Globals.die "" __LOC__
 	) f.code;

std/hl/Ref.macro.hx

@@ -21,10 +21,26 @@ import haxe.macro.Expr;
 
 		final pos:Position = Context.currentPos();
 		final typedFieldExpr:TypedExpr = Context.typeExpr(expr);
-		final valType:Type = typedFieldExpr.t;
-		final refType:Type = switch Context.getType("hl.Ref") {
+
+		var valType:Type = typedFieldExpr.t;
+		var refType:Type = switch Context.getType("hl.Ref") {
 			case TAbstract(t, _): TAbstract(t, [valType]);
 			case _: Context.error("hl.Ref is not an abstract", pos);
+		};
+
+		switch typedFieldExpr.expr {
+			case TField(e, FDynamic(s)):
+				final expectedType = Context.getExpectedType();
+				switch expectedType {
+					case TAbstract(_.get() => {pack: ["hl"], name: "Ref"}, [param]):
+						refType = expectedType;
+						valType = param;
+					case null, TMono(_):
+						Context.error("Taking reference to a field of a dynamic requires an explicit type hint", pos);
+					case _:
+						// this case will fail later
+				}
+			case _:
 		}
 
 		final typedExpr:TypedExpr = {