use Nop

3 files changed, 11 insertions, 12 deletions

diff --git a/src/asm2wasm.cpp b/src/asm2wasm.cpp
index e3fb23c4f..28ff7d563 100644
--- a/src/asm2wasm.cpp
+++ b/src/asm2wasm.cpp
@@ -77,6 +77,7 @@ struct WasmWalker {
   virtual Expression* walkCompare(Compare *curr) { return curr; };
   virtual Expression* walkConvert(Convert *curr) { return curr; };
   virtual Expression* walkHost(Host *curr) { return curr; };
+  virtual Expression* walkNop(Nop *curr) { return curr; };
 
   // children-first
   Expression *walk(Expression *curr) {
@@ -181,6 +182,10 @@ struct WasmWalker {
       }
       return walkHost(cast);
     }
+    if (Nop *cast = dynamic_cast<Nop*>(curr)) {
+      return walkNop(cast);
+    }
+    abort();
   }
 
   void startWalk(Function *func) {
@@ -1040,9 +1045,7 @@ Function* Asm2WasmModule::processFunction(Ref ast) {
       return ret;
     } else if (what == SWITCH) {
       // XXX switch is still in flux in the spec repo, just emit a placeholder
-      auto ret = allocator.alloc<Block>();
-      ret->var = IString("SWITCH_PLACEHOLDER");
-      return ret;
+      return allocator.alloc<Nop>();
 #if 0
       IString name = getNextId("switch");
       breakStack.push_back(name);
diff --git a/src/wasm.h b/src/wasm.h
index ff273e5c0..6aa568210 100644
--- a/src/wasm.h
+++ b/src/wasm.h
@@ -251,7 +251,7 @@ typedef std::vector<Expression*> ExpressionList; // TODO: optimize
 
 class Nop : public Expression {
   std::ostream& print(std::ostream &o, unsigned indent) override {
-    o << "nop";
+    printMinorOpening(o, "nop") << ')';
     return o;
   }
 };
diff --git a/test/emcc_hello_world.wast b/test/emcc_hello_world.wast
index c965c94f0..410a3b2b5 100644
--- a/test/emcc_hello_world.wast
+++ b/test/emcc_hello_world.wast
@@ -424,8 +424,7 @@
           (i32.const 2047)
         )
       )
-      (block $SWITCH_PLACEHOLDER
-      )
+      (nop)
       (break $topmost
         (convert sint32toDouble
           (get_local $$retval$0)
@@ -6049,8 +6048,7 @@
           )
           (loop $label$break$L9 $label$continue$L9
             (block
-              (block $SWITCH_PLACEHOLDER
-              )
+              (nop)
               (set_local $$incdec$ptr
                 (i32.add
                   (get_local $$incdec$ptr169274)
@@ -7911,8 +7909,7 @@
             )
           )
           (block $label$break$L75
-            (block $SWITCH_PLACEHOLDER
-            )
+            (nop)
           )
           (block $label$break$L308
             (if
@@ -9442,8 +9439,7 @@
             (i32.const 0)
           )
           (block $do-once$0
-            (block $SWITCH_PLACEHOLDER
-            )
+            (nop)
           )
         )
       )