[EH] Misc. fixes for EH (#6195)

- Deletes a stray whitespace after `throw_ref`
- Adds missing `makeThrowRef` to `wasm-builder.h`
- Adds a case for `TryTable` in `ControlFlowWalker`

3 files changed, 16 insertions, 6 deletions

diff --git a/src/passes/Print.cpp b/src/passes/Print.cpp
index 5ea62c9f2..5e290ebca 100644
--- a/src/passes/Print.cpp
+++ b/src/passes/Print.cpp
@@ -2018,7 +2018,7 @@ struct PrintExpressionContents
     printMedium(o, "rethrow ");
     printName(curr->target, o);
   }
-  void visitThrowRef(ThrowRef* curr) { printMedium(o, "throw_ref "); }
+  void visitThrowRef(ThrowRef* curr) { printMedium(o, "throw_ref"); }
   void visitNop(Nop* curr) { printMinor(o, "nop"); }
   void visitUnreachable(Unreachable* curr) { printMinor(o, "unreachable"); }
   void visitPop(Pop* curr) {
diff --git a/src/wasm-builder.h b/src/wasm-builder.h
index dd5b498be..a873a7309 100644
--- a/src/wasm-builder.h
+++ b/src/wasm-builder.h
@@ -836,6 +836,12 @@ public:
     ret->finalize();
     return ret;
   }
+  ThrowRef* makeThrowRef(Expression* exnref) {
+    auto* ret = wasm.allocator.alloc<ThrowRef>();
+    ret->exnref = exnref;
+    ret->finalize();
+    return ret;
+  }
   Unreachable* makeUnreachable() { return wasm.allocator.alloc<Unreachable>(); }
   Pop* makePop(Type type) {
     auto* ret = wasm.allocator.alloc<Pop>();
diff --git a/src/wasm-traversal.h b/src/wasm-traversal.h
index 1a458bdf7..f5f25dd1f 100644
--- a/src/wasm-traversal.h
+++ b/src/wasm-traversal.h
@@ -403,7 +403,8 @@ using ExpressionStack = SmallVector<Expression*, 10>;
 
 template<typename SubType, typename VisitorType = Visitor<SubType>>
 struct ControlFlowWalker : public PostWalker<SubType, VisitorType> {
-  ExpressionStack controlFlowStack; // contains blocks, loops, and ifs
+  // contains blocks, loops, ifs, trys, and try_tables
+  ExpressionStack controlFlowStack;
 
   // Uses the control flow stack to find the target of a break to a name
   Expression* findBreakTarget(Name name) {
@@ -420,8 +421,9 @@ struct ControlFlowWalker : public PostWalker<SubType, VisitorType> {
           return curr;
         }
       } else {
-        // an if or try, ignorable
-        assert(curr->template is<If>() || curr->template is<Try>());
+        // an if, try, or try_table, ignorable
+        assert(curr->template is<If>() || curr->template is<Try>() ||
+               curr->template is<TryTable>());
       }
       if (i == 0) {
         return nullptr;
@@ -447,7 +449,8 @@ struct ControlFlowWalker : public PostWalker<SubType, VisitorType> {
       case Expression::Id::BlockId:
       case Expression::Id::IfId:
       case Expression::Id::LoopId:
-      case Expression::Id::TryId: {
+      case Expression::Id::TryId:
+      case Expression::Id::TryTableId: {
         self->pushTask(SubType::doPostVisitControlFlow, currp);
         break;
       }
@@ -461,7 +464,8 @@ struct ControlFlowWalker : public PostWalker<SubType, VisitorType> {
       case Expression::Id::BlockId:
       case Expression::Id::IfId:
       case Expression::Id::LoopId:
-      case Expression::Id::TryId: {
+      case Expression::Id::TryId:
+      case Expression::Id::TryTableId: {
         self->pushTask(SubType::doPreVisitControlFlow, currp);
         break;
       }