Add table.size operation (#4224)

1 files changed, 22 insertions, 2 deletions

diff --git a/src/wasm/wasm-binary.cpp b/src/wasm/wasm-binary.cpp
index 7e72b056f..9aa18f270 100644
--- a/src/wasm/wasm-binary.cpp
+++ b/src/wasm/wasm-binary.cpp
@@ -2793,6 +2793,8 @@ void WasmBinaryBuilder::processNames() {
         get->table = getTableName(index);
       } else if (auto* set = ref->dynCast<TableSet>()) {
         set->table = getTableName(index);
+      } else if (auto* size = ref->dynCast<TableSize>()) {
+        size->table = getTableName(index);
       } else {
         WASM_UNREACHABLE("Invalid type in table references");
       }
@@ -3613,8 +3615,10 @@ BinaryConsts::ASTNodes WasmBinaryBuilder::readExpression(Expression*& curr) {
       if (maybeVisitMemoryFill(curr, opcode)) {
         break;
       }
-      throwError("invalid code after nontrapping float-to-int prefix: " +
-                 std::to_string(opcode));
+      if (maybeVisitTableSize(curr, opcode)) {
+        break;
+      }
+      throwError("invalid code after misc prefix: " + std::to_string(opcode));
       break;
     }
     case BinaryConsts::SIMDPrefix: {
@@ -4918,6 +4922,22 @@ bool WasmBinaryBuilder::maybeVisitMemoryFill(Expression*& out, uint32_t code) {
   return true;
 }
 
+bool WasmBinaryBuilder::maybeVisitTableSize(Expression*& out, uint32_t code) {
+  if (code != BinaryConsts::TableSize) {
+    return false;
+  }
+  Index tableIdx = getU32LEB();
+  if (tableIdx >= tables.size()) {
+    throwError("bad table index");
+  }
+  auto* curr = allocator.alloc<TableSize>();
+  curr->finalize();
+  // Defer setting the table name for later, when we know it.
+  tableRefs[tableIdx].push_back(curr);
+  out = curr;
+  return true;
+}
+
 bool WasmBinaryBuilder::maybeVisitBinary(Expression*& out, uint8_t code) {
   Binary* curr;
 #define INT_TYPED_CODE(code)                                                   \