Add event section (#2151)

This adds support for the event and the event section, as specified in
https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md#changes-to-the-binary-model.

Wasm events are features that suspend the current execution and transfer
the control flow to a corresponding handler. Currently the only
supported event kind is exceptions.

For events, this includes support for
- Binary file reading/writing
- Wast file reading/writing
- Binaryen.js API
- Fuzzer
- Validation
- Metadce
- Passes: metrics, minify-imports-and-exports,
  remove-unused-module-elements

1 files changed, 32 insertions, 0 deletions

diff --git a/test/binaryen.js/event.js b/test/binaryen.js/event.js
new file mode 100644
index 000000000..ec7a0f3b1
--- /dev/null
+++ b/test/binaryen.js/event.js
@@ -0,0 +1,32 @@
+function cleanInfo(info) {
+  var ret = {};
+  for (var x in info) {
+    ret[x] = info[x];
+  }
+  return ret;
+}
+
+var module = new Binaryen.Module();
+module.setFeatures(Binaryen.Features.ExceptionHandling);
+
+var vi = module.addFunctionType("vi", Binaryen.none, [Binaryen.i32]);
+var vif = module.addFunctionType("vif", Binaryen.none, [Binaryen.i32, Binaryen.f32]);
+
+var event_ = module.addEvent("a-event", 0, vi);
+
+console.log("GetEvent is equal: " + (event_ === module.getEvent("a-event")));
+
+var eventInfo = Binaryen.getEventInfo(event_);
+console.log("getEventInfo=" + JSON.stringify(cleanInfo(eventInfo)));
+
+module.addEventExport("a-event", "a-event-exp");
+module.addEventImport("a-event-imp", "module", "base", 0, vif);
+
+module.validate();
+console.log(module.emitText());
+
+module.removeExport("a-event-exp");
+module.removeEvent("a-event");
+
+module.validate();
+console.log(module.emitText());