[Exceptions] Finish interpreter + optimizer support for try_table. (#6814)

* Add interpreter support for exnref values.
* Fix optimization passes to support try_table.
* Enable the interpreter (but not in V8, see code) on exceptions.

1 files changed, 16 insertions, 0 deletions

diff --git a/src/ir/possible-contents.h b/src/ir/possible-contents.h
index 5ec4f758f..7b88483cf 100644
--- a/src/ir/possible-contents.h
+++ b/src/ir/possible-contents.h
@@ -473,6 +473,15 @@ struct TagLocation {
   }
 };
 
+// The location of an exnref materialized by a catch_ref or catch_all_ref clause
+// of a try_table. No data is stored here. exnrefs contain a tag and a payload
+// at run-time, as well as potential metadata such as stack traces, but we don't
+// track that. So this is the same as NullLocation in a way: we just need *a*
+// source of contents for places that receive an exnref.
+struct CaughtExnRefLocation {
+  bool operator==(const CaughtExnRefLocation& other) const { return true; }
+};
+
 // A null value. This is used as the location of the default value of a var in a
 // function, a null written to a struct field in struct.new_with_default, etc.
 struct NullLocation {
@@ -520,6 +529,7 @@ using Location = std::variant<ExpressionLocation,
                               SignatureResultLocation,
                               DataLocation,
                               TagLocation,
+                              CaughtExnRefLocation,
                               NullLocation,
                               ConeReadLocation>;
 
@@ -608,6 +618,12 @@ template<> struct hash<wasm::TagLocation> {
   }
 };
 
+template<> struct hash<wasm::CaughtExnRefLocation> {
+  size_t operator()(const wasm::CaughtExnRefLocation& loc) const {
+    return std::hash<const char*>()("caught-exnref-location");
+  }
+};
+
 template<> struct hash<wasm::NullLocation> {
   size_t operator()(const wasm::NullLocation& loc) const {
     return std::hash<wasm::Type>{}(loc.type);