Update rb_check_typeddata to check inherited types

Author: bjfish

spec/ruby/optional/capi/ext/typed_data_spec.c

@@ -148,6 +148,18 @@ VALUE sws_typed_change_struct(VALUE self, VALUE obj, VALUE new_val) {
   return Qnil;
 }
 
+VALUE sws_typed_rb_check_typeddata_same_type(VALUE self, VALUE obj) {
+  return rb_check_typeddata(obj, &sample_typed_wrapped_struct_data_type) == DATA_PTR(obj) ? Qtrue : Qfalse;
+}
+
+VALUE sws_typed_rb_check_typeddata_same_type_parent(VALUE self, VALUE obj) {
+  return rb_check_typeddata(obj, &sample_typed_wrapped_struct_parent_data_type) == DATA_PTR(obj) ? Qtrue : Qfalse;
+}
+
+VALUE sws_typed_rb_check_typeddata_different_type(VALUE self, VALUE obj) {
+  return rb_check_typeddata(obj, &sample_typed_wrapped_struct_other_data_type) == DATA_PTR(obj) ? Qtrue : Qfalse;
+}
+
 void Init_typed_data_spec(void) {
   VALUE cls = rb_define_class("CApiAllocTypedSpecs", rb_cObject);
   rb_define_alloc_func(cls, sdaf_alloc_typed_func);
@@ -160,6 +172,9 @@ void Init_typed_data_spec(void) {
   rb_define_method(cls, "typed_get_struct_rdata", sws_typed_get_struct_rdata, 1);
   rb_define_method(cls, "typed_get_struct_data_ptr", sws_typed_get_struct_data_ptr, 1);
   rb_define_method(cls, "typed_change_struct", sws_typed_change_struct, 2);
+  rb_define_method(cls, "rb_check_typeddata_same_type", sws_typed_rb_check_typeddata_same_type, 1);
+  rb_define_method(cls, "rb_check_typeddata_same_type_parent", sws_typed_rb_check_typeddata_same_type_parent, 1);
+  rb_define_method(cls, "rb_check_typeddata_different_type", sws_typed_rb_check_typeddata_different_type, 1);
 }
 
 #ifdef __cplusplus

spec/ruby/optional/capi/typed_data_spec.rb

@@ -57,4 +57,21 @@
       @s.typed_get_struct_data_ptr(a).should == 1024
     end
   end
+
+  describe "rb_check_typeddata" do
+    it "returns data pointer when the struct has the given type" do
+      a = @s.typed_wrap_struct(1024)
+      @s.rb_check_typeddata_same_type(a).should == true
+    end
+
+    it "returns data pointer when the parent struct has the given type" do
+      a = @s.typed_wrap_struct(1024)
+      @s.rb_check_typeddata_same_type_parent(a).should == true
+    end
+
+    it "raises an error for different types" do
+      a = @s.typed_wrap_struct(1024)
+      -> { @s.rb_check_typeddata_different_type(a) }.should raise_error(TypeError)
+    end
+  end
 end

src/main/c/cext/data.c

@@ -36,8 +36,11 @@ VALUE rb_data_typed_object_make(VALUE ruby_class, const rb_data_type_t *type, vo
 
 void *rb_check_typeddata(VALUE value, const rb_data_type_t *data_type) {
   struct RTypedData* typed_data = RTYPEDDATA(value);
-  if (typed_data->type != data_type) {
-    rb_raise(rb_eTypeError, "wrong argument type");
+  // NOTE: this function is used on every access to typed data so it should remain fast.
+  // RB_TYPE_P(value, T_DATA) is already checked by `RTYPEDDATA(value)`, see Truffle::CExt.RDATA().
+  // RTYPEDDATA_P(value) is already checked implicitly by `typed_data->type` which would return `nil` if not `RTYPEDDATA_P`.
+  if (!rb_typeddata_inherited_p(typed_data->type, data_type)) {
+    rb_raise(rb_eTypeError, "wrong argument type %"PRIsVALUE" (expected %s)", rb_obj_class(value), data_type->wrap_struct_name);
   }
   return typed_data->data;
 }