[Strings] string.as (#4797)

1 files changed, 19 insertions, 0 deletions

diff --git a/src/wasm/wasm-binary.cpp b/src/wasm/wasm-binary.cpp
index 0ae17f47c..ee1f4929b 100644
--- a/src/wasm/wasm-binary.cpp
+++ b/src/wasm/wasm-binary.cpp
@@ -3936,6 +3936,9 @@ BinaryConsts::ASTNodes WasmBinaryBuilder::readExpression(Expression*& curr) {
       if (maybeVisitStringEq(curr, opcode)) {
         break;
       }
+      if (maybeVisitStringAs(curr, opcode)) {
+        break;
+      }
       if (opcode == BinaryConsts::RefIsFunc ||
           opcode == BinaryConsts::RefIsData ||
           opcode == BinaryConsts::RefIsI31) {
@@ -7249,6 +7252,22 @@ bool WasmBinaryBuilder::maybeVisitStringEq(Expression*& out, uint32_t code) {
   return true;
 }
 
+bool WasmBinaryBuilder::maybeVisitStringAs(Expression*& out, uint32_t code) {
+  StringAsOp op;
+  if (code == BinaryConsts::StringAsWTF8) {
+    op = StringAsWTF8;
+  } else if (code == BinaryConsts::StringAsWTF16) {
+    op = StringAsWTF16;
+  } else if (code == BinaryConsts::StringAsIter) {
+    op = StringAsIter;
+  } else {
+    return false;
+  }
+  auto* ref = popNonVoidExpression();
+  out = Builder(wasm).makeStringAs(op, ref);
+  return true;
+}
+
 void WasmBinaryBuilder::visitRefAs(RefAs* curr, uint8_t code) {
   BYN_TRACE("zz node: RefAs\n");
   switch (code) {