Support i8/i16 mutable arrays as public types for string interop (#5814)

Probably any array of non-reference data can be allowed to be public and sent
out of the module, as it is just data. For now, however, just special case the i8
and i16 array types which are useful already for string interop.

1 files changed, 14 insertions, 0 deletions

diff --git a/src/wasm-type.h b/src/wasm-type.h
index 927e37845..d97bdeba3 100644
--- a/src/wasm-type.h
+++ b/src/wasm-type.h
@@ -661,6 +661,20 @@ struct TypeBuilder {
   void dump();
 };
 
+// We consider certain specific types to always be public, to allow closed-
+// world to operate even if they escape. Specifically, "plain old data" types
+// like array of i8 and i16, which are used to represent strings, may cross
+// the boundary in Web environments.
+//
+// These are "ignorable as public", because we do not error on them being
+// public. That is, we
+//
+//  1. Consider them public, so that passes that do not operate on public types
+//     do not in fact operate on them, and
+//  2. Are ok with them being public in the validator.
+//
+std::unordered_set<HeapType> getIgnorablePublicTypes();
+
 std::ostream& operator<<(std::ostream&, Type);
 std::ostream& operator<<(std::ostream&, Type::Printed);
 std::ostream& operator<<(std::ostream&, HeapType);