Add support for the reference types proposal (#938)

* Add support for the reference types proposal

This commit adds support for the reference types proposal to wabt.
Namely it adds new opcodes like `table.{get,set,grow}` as well as adds a
new `anyref` type. These are plumbed throughout for various operations
in relatively simple fashions, no support was added for a subtyping
relationship between `anyref` and `anyfunc` just yet.

This also raises the restriction that multiple tables are disallowed,
allowing multiple tables to exist when `--enable-reference-types` is
passed.

* Allow nonzero table indices in `call_indirect`

Plumb support throughout for the `call_indirect` instruction (and
`return_call_indirect`) to work with multi-table modules according to
the reference types proposal.

1 files changed, 12 insertions, 0 deletions

diff --git a/src/expr-visitor.h b/src/expr-visitor.h
index e42c36ad..a27357ad 100644
--- a/src/expr-visitor.h
+++ b/src/expr-visitor.h
@@ -97,6 +97,12 @@ class ExprVisitor::Delegate {
   virtual Result OnTableCopyExpr(TableCopyExpr*) = 0;
   virtual Result OnElemDropExpr(ElemDropExpr*) = 0;
   virtual Result OnTableInitExpr(TableInitExpr*) = 0;
+  virtual Result OnTableGetExpr(TableGetExpr*) = 0;
+  virtual Result OnTableSetExpr(TableSetExpr*) = 0;
+  virtual Result OnTableGrowExpr(TableGrowExpr*) = 0;
+  virtual Result OnTableSizeExpr(TableSizeExpr*) = 0;
+  virtual Result OnRefNullExpr(RefNullExpr*) = 0;
+  virtual Result OnRefIsNullExpr(RefIsNullExpr*) = 0;
   virtual Result OnNopExpr(NopExpr*) = 0;
   virtual Result OnReturnExpr(ReturnExpr*) = 0;
   virtual Result OnReturnCallExpr(ReturnCallExpr*) = 0;
@@ -156,6 +162,12 @@ class ExprVisitor::DelegateNop : public ExprVisitor::Delegate {
   Result OnTableCopyExpr(TableCopyExpr*) override { return Result::Ok; }
   Result OnElemDropExpr(ElemDropExpr*) override { return Result::Ok; }
   Result OnTableInitExpr(TableInitExpr*) override { return Result::Ok; }
+  Result OnTableGetExpr(TableGetExpr*) override { return Result::Ok; }
+  Result OnTableSetExpr(TableSetExpr*) override { return Result::Ok; }
+  Result OnTableGrowExpr(TableGrowExpr*) override { return Result::Ok; }
+  Result OnTableSizeExpr(TableSizeExpr*) override { return Result::Ok; }
+  Result OnRefNullExpr(RefNullExpr*) override { return Result::Ok; }
+  Result OnRefIsNullExpr(RefIsNullExpr*) override { return Result::Ok; }
   Result OnNopExpr(NopExpr*) override { return Result::Ok; }
   Result OnReturnExpr(ReturnExpr*) override { return Result::Ok; }
   Result OnReturnCallExpr(ReturnCallExpr*) override { return Result::Ok; }