Emit heap types for call_indirect that match the table (#4221)

See #4220 - this lets us handle the common case for now of simply having
an identical heap type to the table when the signature is identical.

With this PR, #4207's optimization of call_ref + table.get into
call_indirect now leads to a binary that works in V8 in nominal mode.

1 files changed, 12 insertions, 0 deletions

diff --git a/src/wasm.h b/src/wasm.h
index fbec9247a..c87b8c197 100644
--- a/src/wasm.h
+++ b/src/wasm.h
@@ -556,6 +556,9 @@ enum BrOnOp {
   BrOnNonI31,
 };
 
+// Forward declaration for methods that receive a Module as a parameter.
+class Module;
+
 //
 // Expressions
 //
@@ -828,6 +831,15 @@ public:
   bool isReturn = false;
 
   void finalize();
+
+  // FIXME We should probably store a heap type here, and not a signature, see
+  //       https://github.com/WebAssembly/binaryen/issues/4220
+  //       For now, copy the heap type from the table if it matches - then a
+  //       nominal check will succeed too. If it does not match, then just
+  //       emit something for it like we always used to, using
+  //       HeapType(sig) (also do that if no module is provided).
+  // FIXME When we remove this, also remove the forward decl of Module, above.
+  HeapType getHeapType(Module* module = nullptr);
 };
 
 class LocalGet : public SpecificExpression<Expression::LocalGetId> {