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.

2 files changed, 28 insertions, 1 deletions

diff --git a/src/wasm/wasm-type.cpp b/src/wasm/wasm-type.cpp
index ba38231b6..4ce72582c 100644
--- a/src/wasm/wasm-type.cpp
+++ b/src/wasm/wasm-type.cpp
@@ -2580,6 +2580,29 @@ void TypeBuilder::dump() {
   }
 }
 
+std::unordered_set<HeapType> getIgnorablePublicTypes() {
+  auto array8 = Array(Field(Field::i8, Mutable));
+  auto array16 = Array(Field(Field::i16, Mutable));
+  TypeBuilder builder(4);
+  // We handle final and non-final here, but should remove one of them
+  // eventually TODO
+  builder[0] = array8;
+  builder[0].setOpen(false);
+  builder[1] = array16;
+  builder[1].setOpen(false);
+  builder[2] = array8;
+  builder[2].setOpen(true);
+  builder[3] = array16;
+  builder[3].setOpen(true);
+  auto result = builder.build();
+  assert(result);
+  std::unordered_set<HeapType> ret;
+  for (auto type : *result) {
+    ret.insert(type);
+  }
+  return ret;
+}
+
 } // namespace wasm
 
 namespace std {
diff --git a/src/wasm/wasm-validator.cpp b/src/wasm/wasm-validator.cpp
index 2d00c4b67..3baaacb16 100644
--- a/src/wasm/wasm-validator.cpp
+++ b/src/wasm/wasm-validator.cpp
@@ -3726,8 +3726,12 @@ static void validateClosedWorldInterface(Module& module, ValidationInfo& info) {
     }
   }
 
+  // Ignorable public types are public, but we can ignore them for purposes of
+  // erroring here: It is always ok that they are public.
+  auto ignorable = getIgnorablePublicTypes();
+
   for (auto type : ModuleUtils::getPublicHeapTypes(module)) {
-    if (!publicFuncTypes.count(type)) {
+    if (!publicFuncTypes.count(type) && !ignorable.count(type)) {
       auto name = type.toString();
       if (auto it = module.typeNames.find(type); it != module.typeNames.end()) {
         name = it->second.name.toString();