Implement changes of function reference proposal

Author: Zoltan Herczeg

include/wabt/ir.h

@@ -36,7 +36,7 @@ namespace wabt {
 
 struct Module;
 
-enum class VarType {
+enum class VarType : uint16_t {
   Index,
   Name,
 };
@@ -54,6 +54,7 @@ struct Var {
   VarType type() const { return type_; }
   bool is_index() const { return type_ == VarType::Index; }
   bool is_name() const { return type_ == VarType::Name; }
+  bool has_opt_type() const { return opt_type_ < 0; }
 
   Index index() const {
     assert(is_index());
@@ -63,17 +64,24 @@ struct Var {
     assert(is_name());
     return name_;
   }
+  Type::Enum opt_type() const {
+    assert(has_opt_type());
+    return static_cast<Type::Enum>(opt_type_);
+  }
 
   void set_index(Index);
   void set_name(std::string&&);
   void set_name(std::string_view);
+  void set_opt_type(Type::Enum);
 
   Location loc;
 
  private:
   void Destroy();
 
   VarType type_;
+  // Can be set to Type::Enum types, 0 represent no optional type.
+  int16_t opt_type_;
   union {
     Index index_;
     std::string name_;
@@ -734,9 +742,7 @@ class CallRefExpr : public ExprMixin<ExprType::CallRef> {
   explicit CallRefExpr(const Location& loc = Location())
       : ExprMixin<ExprType::CallRef>(loc) {}
 
-  // This field is setup only during Validate phase,
-  // so keep that in mind when you use it.
-  Var function_type_index;
+  Var function_type;
 };
 
 template <ExprType TypeEnum>

include/wabt/shared-validator.h

@@ -140,7 +140,7 @@ class SharedValidator {
   Result EndBrTable(const Location&);
   Result OnCall(const Location&, Var func_var);
   Result OnCallIndirect(const Location&, Var sig_var, Var table_var);
-  Result OnCallRef(const Location&, Index* function_type_index);
+  Result OnCallRef(const Location&, Var function_type_var);
   Result OnCatch(const Location&, Var tag_var, bool is_catch_all);
   Result OnCompare(const Location&, Opcode);
   Result OnConst(const Location&, Type);

include/wabt/token.def

@@ -55,6 +55,7 @@ WABT_TOKEN(Module, "module")
 WABT_TOKEN(Mut, "mut")
 WABT_TOKEN(NanArithmetic, "nan:arithmetic")
 WABT_TOKEN(NanCanonical, "nan:canonical")
+WABT_TOKEN(Null, "null")
 WABT_TOKEN(Offset, "offset")
 WABT_TOKEN(Output, "output")
 WABT_TOKEN(PageSize, "pagesize")

include/wabt/type.h

@@ -46,6 +46,8 @@ class Type {
     FuncRef = -0x10,    // 0x70
     ExternRef = -0x11,  // 0x6f
     Reference = -0x15,  // 0x6b
+    HeapRef = -0x1c,    // 0x64
+    HeapNullRef = -0x1d, // 0x63
     Func = -0x20,       // 0x60
     Struct = -0x21,     // 0x5f
     Array = -0x22,      // 0x5e
@@ -63,7 +65,8 @@ class Type {
       : enum_(static_cast<Enum>(code)), type_index_(kInvalidIndex) {}
   Type(Enum e) : enum_(e), type_index_(kInvalidIndex) {}
   Type(Enum e, Index type_index) : enum_(e), type_index_(type_index) {
-    assert(e == Enum::Reference);
+    assert(e == Enum::Reference || e == Enum::HeapRef ||
+           e == Enum::HeapNullRef || type_index == kInvalidIndex);
   }
   constexpr operator Enum() const { return enum_; }
 

src/ir-util.cc

@@ -140,7 +140,7 @@ ModuleContext::Arities ModuleContext::GetExprArity(const Expr& expr) const {
     }
 
     case ExprType::CallRef: {
-      const Var& var = cast<CallRefExpr>(&expr)->function_type_index;
+      const Var& var = cast<CallRefExpr>(&expr)->function_type;
       return {GetFuncParamCount(var) + 1, GetFuncResultCount(var)};
     }
 

src/ir.cc

@@ -591,10 +591,10 @@ void MakeTypeBindingReverseMapping(
 Var::Var() : Var(kInvalidIndex, Location()) {}
 
 Var::Var(Index index, const Location& loc)
-    : loc(loc), type_(VarType::Index), index_(index) {}
+    : loc(loc), type_(VarType::Index), opt_type_(0), index_(index) {}
 
 Var::Var(std::string_view name, const Location& loc)
-    : loc(loc), type_(VarType::Name), name_(name) {}
+    : loc(loc), type_(VarType::Name), opt_type_(0), name_(name) {}
 
 Var::Var(Var&& rhs) : Var() {
   *this = std::move(rhs);
@@ -644,6 +644,12 @@ void Var::set_name(std::string_view name) {
   set_name(std::string(name));
 }
 
+void Var::set_opt_type(Type::Enum type) {
+  assert(static_cast<int32_t>(type) < 0 &&
+         static_cast<int32_t>(type) >= INT16_MIN);
+  opt_type_ = static_cast<int16_t>(type);
+}
+
 void Var::Destroy() {
   if (is_name()) {
     Destruct(name_);

src/lexer-keywords.txt

@@ -556,6 +556,7 @@ mut, TokenType::Mut
 nan:arithmetic, TokenType::NanArithmetic
 nan:canonical, TokenType::NanCanonical
 nop, TokenType::Nop, Opcode::Nop
+null, TokenType::Null
 offset, TokenType::Offset
 output, TokenType::Output
 pagesize, TokenType::PageSize