1 files changed, 21 insertions, 1 deletions
diff --git a/src/wasm-builder.h b/src/wasm-builder.h
index 04e0aa4de..42d3dfe47 100644
--- a/src/wasm-builder.h
+++ b/src/wasm-builder.h
@@ -17,7 +17,8 @@
 #ifndef wasm_wasm_builder_h
 #define wasm_wasm_builder_h
 
-#include <wasm.h>
+#include "wasm.h"
+#include "ast/manipulation.h"
 
 namespace wasm {
 
@@ -379,6 +380,25 @@ public:
     std::swap(iff->ifTrue, iff->ifFalse);
     iff->condition = makeUnary(EqZInt32, iff->condition);
   }
+
+  // returns a replacement with the precise same type, and with
+  // minimal contents. as a replacement, this may reuse the
+  // input node
+  template<typename T>
+  Expression* replaceWithIdenticalType(T* curr) {
+    Literal value;
+    // TODO: reuse node conditionally when possible for literals
+    switch (curr->type) {
+      case i32: value = Literal(int32_t(0)); break;
+      case i64: value = Literal(int64_t(0)); break;
+      case f32: value = Literal(float(0)); break;
+      case f64: value = Literal(double(0)); break;
+      case none: return ExpressionManipulator::nop(curr);
+      case unreachable: return ExpressionManipulator::convert<T, Unreachable>(curr);
+    }
+    return makeConst(value);
+  }
+
 };
 
 } // namespace wasm