Add support for reference types proposal (#2451)

This adds support for the reference type proposal. This includes support
for all reference types (`anyref`, `funcref`(=`anyfunc`), and `nullref`)
and four new instructions: `ref.null`, `ref.is_null`, `ref.func`, and
new typed `select`. This also adds subtype relationship support between
reference types.

This does not include table instructions yet. This also does not include
wasm2js support.

Fixes #2444 and fixes #2447.

1 files changed, 32 insertions, 0 deletions

diff --git a/src/passes/InstrumentLocals.cpp b/src/passes/InstrumentLocals.cpp
index 407903219..ae35ec2d1 100644
--- a/src/passes/InstrumentLocals.cpp
+++ b/src/passes/InstrumentLocals.cpp
@@ -56,14 +56,18 @@ Name get_i32("get_i32");
 Name get_i64("get_i64");
 Name get_f32("get_f32");
 Name get_f64("get_f64");
+Name get_funcref("get_funcref");
 Name get_anyref("get_anyref");
+Name get_nullref("get_nullref");
 Name get_exnref("get_exnref");
 
 Name set_i32("set_i32");
 Name set_i64("set_i64");
 Name set_f32("set_f32");
 Name set_f64("set_f64");
+Name set_funcref("set_funcref");
 Name set_anyref("set_anyref");
+Name set_nullref("set_nullref");
 Name set_exnref("set_exnref");
 
 struct InstrumentLocals : public WalkerPass<PostWalker<InstrumentLocals>> {
@@ -84,9 +88,15 @@ struct InstrumentLocals : public WalkerPass<PostWalker<InstrumentLocals>> {
         break;
       case v128:
         assert(false && "v128 not implemented yet");
+      case funcref:
+        import = get_funcref;
+        break;
       case anyref:
         import = get_anyref;
         break;
+      case nullref:
+        import = get_nullref;
+        break;
       case exnref:
         import = get_exnref;
         break;
@@ -126,9 +136,15 @@ struct InstrumentLocals : public WalkerPass<PostWalker<InstrumentLocals>> {
         break;
       case v128:
         assert(false && "v128 not implemented yet");
+      case funcref:
+        import = set_funcref;
+        break;
       case anyref:
         import = set_anyref;
         break;
+      case nullref:
+        import = set_nullref;
+        break;
       case exnref:
         import = set_exnref;
         break;
@@ -156,10 +172,26 @@ struct InstrumentLocals : public WalkerPass<PostWalker<InstrumentLocals>> {
     addImport(curr, set_f64, {Type::i32, Type::i32, Type::f64}, Type::f64);
 
     if (curr->features.hasReferenceTypes()) {
+      addImport(curr,
+                get_funcref,
+                {Type::i32, Type::i32, Type::funcref},
+                Type::funcref);
+      addImport(curr,
+                set_funcref,
+                {Type::i32, Type::i32, Type::funcref},
+                Type::funcref);
       addImport(
         curr, get_anyref, {Type::i32, Type::i32, Type::anyref}, Type::anyref);
       addImport(
         curr, set_anyref, {Type::i32, Type::i32, Type::anyref}, Type::anyref);
+      addImport(curr,
+                get_nullref,
+                {Type::i32, Type::i32, Type::nullref},
+                Type::nullref);
+      addImport(curr,
+                set_nullref,
+                {Type::i32, Type::i32, Type::nullref},
+                Type::nullref);
     }
     if (curr->features.hasExceptionHandling()) {
       addImport(