Add support for ref.null in global initializers (#1131)

As per the reference-types spec, ref.null is a constant expression.

I did try to add support for ref.func at the same time, but I didn't
really understand the strategy of wabt and reference types; there seems
to be strong intertwingliness between func.ref and the element section,
whereas it does seem possible for a func.ref to be global.  Oh well, I
didn't need it :)

1 files changed, 7 insertions, 0 deletions

diff --git a/src/binary-reader-ir.cc b/src/binary-reader-ir.cc
index fb7b53ae..0515f660 100644
--- a/src/binary-reader-ir.cc
+++ b/src/binary-reader-ir.cc
@@ -240,6 +240,7 @@ class BinaryReaderIR : public BinaryReaderNop {
   Result OnInitExprGlobalGetExpr(Index index, Index global_index) override;
   Result OnInitExprI32ConstExpr(Index index, uint32_t value) override;
   Result OnInitExprI64ConstExpr(Index index, uint64_t value) override;
+  Result OnInitExprRefNull(Index index) override;
 
  private:
   Location GetLocation() const;
@@ -1178,6 +1179,12 @@ Result BinaryReaderIR::OnInitExprI64ConstExpr(Index index, uint64_t value) {
   return Result::Ok;
 }
 
+Result BinaryReaderIR::OnInitExprRefNull(Index index) {
+  Location loc = GetLocation();
+  current_init_expr_->push_back(MakeUnique<RefNullExpr>(loc));
+  return Result::Ok;
+}
+
 Result BinaryReaderIR::OnLocalName(Index func_index,
                                    Index local_index,
                                    string_view name) {