2 files changed, 11 insertions, 2 deletions
diff --git a/src/wasm/wasm-s-parser.cpp b/src/wasm/wasm-s-parser.cpp
index af77d75b6..b2ee2a2f4 100644
--- a/src/wasm/wasm-s-parser.cpp
+++ b/src/wasm/wasm-s-parser.cpp
@@ -955,6 +955,15 @@ Expression* SExpressionWasmBuilder::makeHost(Element& s, HostOp op) {
   } else {
     parseCallOperands(s, 1, s.size(), ret);
   }
+  if (ret->op == HostOp::GrowMemory) {
+    if (ret->operands.size() != 1) {
+      throw ParseException("grow_memory needs one operand");
+    }
+  } else {
+    if (ret->operands.size() != 0) {
+      throw ParseException("host needs zero operands");
+    }
+  }
   ret->finalize();
   return ret;
 }
diff --git a/src/wasm/wasm.cpp b/src/wasm/wasm.cpp
index d2bf4e75c..a879ebd05 100644
--- a/src/wasm/wasm.cpp
+++ b/src/wasm/wasm.cpp
@@ -74,7 +74,7 @@ Name GROW_WASM_MEMORY("__growWasmMemory"),
 
 const char* getExpressionName(Expression* curr) {
   switch (curr->_id) {
-    case Expression::Id::InvalidId: abort();
+    case Expression::Id::InvalidId: WASM_UNREACHABLE();
     case Expression::Id::BlockId: return "block";
     case Expression::Id::IfId: return "if";
     case Expression::Id::LoopId: return "loop";
@@ -500,7 +500,7 @@ void Host::finalize() {
       }
       break;
     }
-    default: abort();
+    default: WASM_UNREACHABLE();
   }
 }