Add support for ref.test instruction

Work in progress

Author: hoodmane

include/wabt/binary-reader-logging.h

@@ -221,6 +221,7 @@ class BinaryReaderLogging : public BinaryReaderDelegate {
   Result OnRefFuncExpr(Index index) override;
   Result OnRefNullExpr(Type type) override;
   Result OnRefIsNullExpr() override;
+  Result OnRefTestExpr(Type type) override;
   Result OnNopExpr() override;
   Result OnRethrowExpr(Index depth) override;
   Result OnReturnCallExpr(Index func_index) override;

include/wabt/binary-reader-nop.h

@@ -302,6 +302,7 @@ class BinaryReaderNop : public BinaryReaderDelegate {
   Result OnRefFuncExpr(Index func_index) override { return Result::Ok; }
   Result OnRefNullExpr(Type type) override { return Result::Ok; }
   Result OnRefIsNullExpr() override { return Result::Ok; }
+  Result OnRefTestExpr(Type type) override { return Result::Ok; }
   Result OnNopExpr() override { return Result::Ok; }
   Result OnRethrowExpr(Index depth) override { return Result::Ok; }
   Result OnReturnCallExpr(Index sig_index) override { return Result::Ok; }

include/wabt/binary-reader.h

@@ -297,6 +297,7 @@ class BinaryReaderDelegate {
   virtual Result OnRefFuncExpr(Index func_index) = 0;
   virtual Result OnRefNullExpr(Type type) = 0;
   virtual Result OnRefIsNullExpr() = 0;
+  virtual Result OnRefTestExpr(Type check_type) = 0;
   virtual Result OnNopExpr() = 0;
   virtual Result OnRethrowExpr(Index depth) = 0;
   virtual Result OnReturnExpr() = 0;

include/wabt/expr-visitor.h

@@ -112,6 +112,7 @@ class ExprVisitor::Delegate {
   virtual Result OnRefFuncExpr(RefFuncExpr*) = 0;
   virtual Result OnRefNullExpr(RefNullExpr*) = 0;
   virtual Result OnRefIsNullExpr(RefIsNullExpr*) = 0;
+  virtual Result OnRefTestExpr(RefTestExpr*) = 0;
   virtual Result OnNopExpr(NopExpr*) = 0;
   virtual Result OnReturnExpr(ReturnExpr*) = 0;
   virtual Result OnReturnCallExpr(ReturnCallExpr*) = 0;
@@ -189,6 +190,7 @@ class ExprVisitor::DelegateNop : public ExprVisitor::Delegate {
   Result OnRefFuncExpr(RefFuncExpr*) override { return Result::Ok; }
   Result OnRefNullExpr(RefNullExpr*) override { return Result::Ok; }
   Result OnRefIsNullExpr(RefIsNullExpr*) override { return Result::Ok; }
+  Result OnRefTestExpr(RefTestExpr*) override { return Result::Ok; }
   Result OnNopExpr(NopExpr*) override { return Result::Ok; }
   Result OnReturnExpr(ReturnExpr*) override { return Result::Ok; }
   Result OnReturnCallExpr(ReturnCallExpr*) override { return Result::Ok; }

include/wabt/ir.h

@@ -400,6 +400,7 @@ enum class ExprType {
   RefIsNull,
   RefFunc,
   RefNull,
+  RefTest,
   Rethrow,
   Return,
   ReturnCall,
@@ -553,6 +554,14 @@ class RefTypeExpr : public ExprMixin<TypeEnum> {
 using RefNullExpr = RefTypeExpr<ExprType::RefNull>;
 using RefIsNullExpr = ExprMixin<ExprType::RefIsNull>;
 
+class RefTestExpr : public ExprMixin<ExprType::RefTest> {
+ public:
+  RefTestExpr(Var type, const Location& loc = Location())
+      : ExprMixin<ExprType::RefTest>(loc), type(type) {}
+
+  Var type;
+};
+
 template <ExprType TypeEnum>
 class OpcodeExpr : public ExprMixin<TypeEnum> {
  public:

include/wabt/opcode.def

@@ -264,6 +264,7 @@ WABT_OPCODE(___,  I32,  ___,  I32,  0,  0xfc, 0x11, TableFill, "table.fill", "")
 WABT_OPCODE(___,  ___,  ___,  ___,  0,  0,    0xd0, RefNull, "ref.null", "")
 WABT_OPCODE(___,  ___,  ___,  ___,  0,  0,    0xd1, RefIsNull, "ref.is_null", "")
 WABT_OPCODE(___,  ___,  ___,  ___,  0,  0,    0xd2, RefFunc, "ref.func", "")
+WABT_OPCODE(I32,  ___,  ___,  ___,  0,  0xfb, 0x14, RefTest, "ref.test", "")
 
 /* Simd opcodes */
 WABT_OPCODE(V128, I32,  ___,  ___,  16, 0xfd, 0x00, V128Load, "v128.load", "")

include/wabt/opcode.h

@@ -84,16 +84,17 @@ struct Opcode {
   Address GetAlignment(Address alignment) const;
 
   static bool IsPrefixByte(uint8_t byte) {
-    return byte == kMathPrefix || byte == kThreadsPrefix || byte == kSimdPrefix;
+    return byte == kMathPrefix || byte == kThreadsPrefix || byte == kSimdPrefix || byte == kReferencePrefix;
   }
 
   bool IsEnabled(const Features& features) const;
   bool IsInvalid() const { return enum_ >= Invalid; }
 
  private:
+  static constexpr uint32_t kReferencePrefix = 0xfb;
   static constexpr uint32_t kMathPrefix = 0xfc;
-  static constexpr uint32_t kThreadsPrefix = 0xfe;
   static constexpr uint32_t kSimdPrefix = 0xfd;
+  static constexpr uint32_t kThreadsPrefix = 0xfe;
 
   struct Info {
     const char* name;

include/wabt/shared-validator.h

@@ -178,6 +178,7 @@ class SharedValidator {
   Result OnRefFunc(const Location&, Var func_var);
   Result OnRefIsNull(const Location&);
   Result OnRefNull(const Location&, Type type);
+  Result OnRefTest(const Location&, Var type);
   Result OnRethrow(const Location&, Var depth);
   Result OnReturnCall(const Location&, Var func_var);
   Result OnReturnCallIndirect(const Location&, Var sig_var, Var table_var);

include/wabt/token.def

@@ -133,6 +133,7 @@ WABT_TOKEN(RefExtern, "ref.extern")
 WABT_TOKEN(RefFunc, "ref.func")
 WABT_TOKEN(RefIsNull, "ref.is_null")
 WABT_TOKEN(RefNull, "ref.null")
+WABT_TOKEN(RefTest, "ref.test")
 WABT_TOKEN(Rethrow, "rethrow")
 WABT_TOKEN(ReturnCallIndirect, "return_call_indirect")
 WABT_TOKEN(ReturnCall, "return_call")

include/wabt/type-checker.h

@@ -118,6 +118,7 @@ class TypeChecker {
   Result OnRefFuncExpr(Index func_type, bool force_generic_funcref);
   Result OnRefNullExpr(Type type);
   Result OnRefIsNullExpr();
+  Result OnRefTestExpr();
   Result OnRethrow(Index depth);
   Result OnReturn();
   Result OnSelect(const TypeVector& result_types);

src/apply-names.cc

@@ -43,6 +43,7 @@ class NameApplier : public ExprVisitor::DelegateNop {
   Result OnBrTableExpr(BrTableExpr*) override;
   Result OnCallExpr(CallExpr*) override;
   Result OnRefFuncExpr(RefFuncExpr*) override;
+  Result OnRefTestExpr(RefTestExpr*) override;
   Result OnCallIndirectExpr(CallIndirectExpr*) override;
   Result OnReturnCallExpr(ReturnCallExpr*) override;
   Result OnReturnCallIndirectExpr(ReturnCallIndirectExpr*) override;
@@ -423,6 +424,11 @@ Result NameApplier::OnRefFuncExpr(RefFuncExpr* expr) {
   return Result::Ok;
 }
 
+Result NameApplier::OnRefTestExpr(RefTestExpr* expr) {
+  CHECK_RESULT(UseNameForFuncTypeVar(&expr->type));
+  return Result::Ok;
+}
+
 Result NameApplier::OnCallIndirectExpr(CallIndirectExpr* expr) {
   if (expr->decl.has_func_type) {
     CHECK_RESULT(UseNameForFuncTypeVar(&expr->decl.type_var));

src/binary-reader-ir.cc

@@ -249,6 +249,7 @@ class BinaryReaderIR : public BinaryReaderNop {
   Result OnRefFuncExpr(Index func_index) override;
   Result OnRefNullExpr(Type type) override;
   Result OnRefIsNullExpr() override;
+  Result OnRefTestExpr(Type type) override;
   Result OnNopExpr() override;
   Result OnRethrowExpr(Index depth) override;
   Result OnReturnExpr() override;
@@ -1160,6 +1161,13 @@ Result BinaryReaderIR::OnRefIsNullExpr() {
   return AppendExpr(std::make_unique<RefIsNullExpr>());
 }
 
+Result BinaryReaderIR::OnRefTestExpr(Type type) {
+  assert(type.IsIndex());
+  Index type_index = type.GetIndex();
+  return AppendExpr(
+      std::make_unique<RefTestExpr>(Var(type_index, GetLocation())));
+}
+
 Result BinaryReaderIR::OnNopExpr() {
   return AppendExpr(std::make_unique<NopExpr>());
 }

src/binary-reader-logging.cc

@@ -873,6 +873,7 @@ DEFINE_INDEX(OnTableSizeExpr)
 DEFINE_INDEX_DESC(OnTableFillExpr, "table index")
 DEFINE_INDEX(OnRefFuncExpr)
 DEFINE_TYPE(OnRefNullExpr)
+DEFINE_TYPE(OnRefTestExpr)
 DEFINE0(OnRefIsNullExpr)
 DEFINE0(OnNopExpr)
 DEFINE_INDEX_DESC(OnRethrowExpr, "depth");

src/binary-reader.cc

@@ -1925,6 +1925,13 @@ Result BinaryReader::ReadInstructions(Offset end_offset, const char* context) {
         CALLBACK(OnOpcodeBare);
         break;
 
+      case Opcode::RefTest:
+        Type type;
+        CHECK_RESULT(ReadType(&type, "ref.test type"));
+        CALLBACK(OnRefTestExpr, type);
+        CALLBACK(OnOpcodeBare);
+        break;
+
       case Opcode::CallRef:
         CALLBACK(OnCallRefExpr);
         CALLBACK(OnOpcodeBare);

src/binary-writer.cc

@@ -1009,6 +1009,13 @@ void BinaryWriter::WriteExpr(const Func* func, const Expr* expr) {
       WriteU32Leb128WithReloc(index, "function index", RelocType::FuncIndexLEB);
       break;
     }
+    case ExprType::RefTest: {
+      WriteOpcode(stream_, Opcode::RefTest);
+      WriteType(stream_,
+                module_->GetFuncTypeIndex(cast<RefTestExpr>(expr)->type),
+                "ref.test type");
+      break;
+    }
     case ExprType::RefNull: {
       WriteOpcode(stream_, Opcode::RefNull);
       WriteType(stream_, cast<RefNullExpr>(expr)->type, "ref.null type");

src/c-writer.cc

@@ -4148,6 +4148,7 @@ void CWriter::Write(const ExprList& exprs) {
       case ExprType::CallRef:
       case ExprType::ThrowRef:
       case ExprType::TryTable:
+      case ExprType::RefTest:
         UNIMPLEMENTED("...");
         break;
     }

src/expr-visitor.cc

@@ -365,6 +365,10 @@ Result ExprVisitor::HandleDefaultState(Expr* expr) {
       CHECK_RESULT(delegate_->OnRefIsNullExpr(cast<RefIsNullExpr>(expr)));
       break;
 
+    case ExprType::RefTest:
+      CHECK_RESULT(delegate_->OnRefTestExpr(cast<RefTestExpr>(expr)));
+      break;
+
     case ExprType::Nop:
       CHECK_RESULT(delegate_->OnNopExpr(cast<NopExpr>(expr)));
       break;

src/interp/binary-reader-interp.cc

@@ -222,6 +222,7 @@ class BinaryReaderInterp : public BinaryReaderNop {
   Result OnRefFuncExpr(Index func_index) override;
   Result OnRefNullExpr(Type type) override;
   Result OnRefIsNullExpr() override;
+  Result OnRefTestExpr(Type type) override;
   Result OnNopExpr() override;
   Result OnRethrowExpr(Index depth) override;
   Result OnReturnExpr() override;
@@ -1393,6 +1394,17 @@ Result BinaryReaderInterp::OnRefIsNullExpr() {
   return Result::Ok;
 }
 
+Result BinaryReaderInterp::OnRefTestExpr(Type type) {
+  int type_index = 0;
+  if (type.IsIndex()) {
+    type_index = type.GetIndex();
+  }
+  CHECK_RESULT(
+      validator_.OnRefTest(GetLocation(), Var(type_index, GetLocation())));
+  istream_.Emit(Opcode::RefTest);
+  return Result::Ok;
+}
+
 Result BinaryReaderInterp::OnNopExpr() {
   CHECK_RESULT(validator_.OnNop(GetLocation()));
   return Result::Ok;

src/interp/interp.cc

@@ -1877,6 +1877,7 @@ RunResult Thread::StepInternal(Trap::Ptr* out_trap) {
     case O::MemoryAtomicNotify:
     case O::MemoryAtomicWait32:
     case O::MemoryAtomicWait64:
+    case O::RefTest:
       return TRAP("not implemented");
 
     case O::I32AtomicLoad:       return DoAtomicLoad<u32>(instr, out_trap);

src/interp/istream.cc

@@ -532,6 +532,7 @@ Instr Istream::Read(Offset* offset) const {
     case Opcode::LocalTee:
     case Opcode::MemoryGrow:
     case Opcode::TableGet:
+    case Opcode::RefTest:
       // Index immediate, 1 operand.
       instr.kind = InstrKind::Imm_Index_Op_1;
       instr.imm_u32 = ReadAt<u32>(offset);

src/ir-util.cc

@@ -186,6 +186,7 @@ ModuleContext::Arities ModuleContext::GetExprArity(const Expr& expr) const {
     case ExprType::RefIsNull:
     case ExprType::LoadSplat:
     case ExprType::LoadZero:
+    case ExprType::RefTest:
       return {1, 1};
 
     case ExprType::Drop:

src/ir.cc

@@ -63,6 +63,7 @@ const char* ExprTypeName[] = {
     "RefIsNull",
     "RefFunc",
     "RefNull",
+    "RefTest",
     "Rethrow",
     "Return",
     "ReturnCall",

src/lexer-keywords.txt

@@ -566,6 +566,7 @@ ref.extern, TokenType::RefExtern
 ref.func, TokenType::RefFunc, Opcode::RefFunc
 ref.is_null, TokenType::RefIsNull, Opcode::RefIsNull
 ref.null, TokenType::RefNull, Opcode::RefNull
+ref.test, TokenType::RefTest, Opcode::RefTest
 register, TokenType::Register
 result, TokenType::Result
 rethrow, TokenType::Rethrow, Opcode::Rethrow