add FFI::isNull() to check whether a FFI\CData is a null pointer

Author: pilif

ext/ffi/ffi.c

@@ -4361,6 +4361,35 @@ ZEND_METHOD(FFI, string) /* {{{ */
 }
 /* }}} */
 
+ZEND_METHOD(FFI, isNull) /* {{{ */
+{
+	zval *zv;
+	zend_ffi_type *type;
+	void *ptr = NULL;
+
+	ZEND_FFI_VALIDATE_API_RESTRICTION();
+	ZEND_PARSE_PARAMETERS_START(1, 1)
+		Z_PARAM_ZVAL(zv);
+	ZEND_PARSE_PARAMETERS_END();
+
+	ZVAL_DEREF(zv);
+	if (Z_TYPE_P(zv) == IS_OBJECT && Z_OBJCE_P(zv) == zend_ffi_cdata_ce) {
+		zend_ffi_cdata *cdata = (zend_ffi_cdata*)Z_OBJ_P(zv);
+		type = ZEND_FFI_TYPE(cdata->type);
+		ptr = cdata->ptr;
+	} else {
+		zend_wrong_parameter_class_error(1, "FFI\\CData", zv);
+		return;
+	}
+
+	if (type->kind != ZEND_FFI_TYPE_POINTER){
+		zend_throw_error(zend_ffi_exception_ce, "FFI\\Cdata is not a pointer");
+	}
+
+	RETURN_BOOL(*(void**)ptr == NULL);
+}
+/* }}} */
+
 ZEND_BEGIN_ARG_INFO_EX(arginfo_func_cdef, 0, 0, 0)
 	ZEND_ARG_INFO(0, code)
 	ZEND_ARG_INFO(0, lib)
@@ -4437,6 +4466,10 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_func_string, 0, 0, 1)
 	ZEND_ARG_INFO(0, size)
 ZEND_END_ARG_INFO()
 
+ZEND_BEGIN_ARG_INFO_EX(arginfo_func_isnull, 0, 0, 1)
+	ZEND_ARG_INFO(ZEND_SEND_PREFER_REF, ptr)
+ZEND_END_ARG_INFO()
+
 static const zend_function_entry zend_ffi_functions[] = {
 	ZEND_ME(FFI, cdef,        arginfo_func_cdef,    ZEND_ACC_PUBLIC|ZEND_ACC_STATIC)
 	ZEND_ME(FFI, load,        arginfo_func_load,    ZEND_ACC_PUBLIC|ZEND_ACC_STATIC)
@@ -4454,6 +4487,7 @@ static const zend_function_entry zend_ffi_functions[] = {
 	ZEND_ME(FFI, memcmp,      arginfo_func_memcmp,  ZEND_ACC_PUBLIC|ZEND_ACC_STATIC)
 	ZEND_ME(FFI, memset,      arginfo_func_memset,  ZEND_ACC_PUBLIC|ZEND_ACC_STATIC)
 	ZEND_ME(FFI, string,      arginfo_func_string,  ZEND_ACC_PUBLIC|ZEND_ACC_STATIC)
+	ZEND_ME(FFI, isNull,      arginfo_func_isnull,  ZEND_ACC_PUBLIC|ZEND_ACC_STATIC)
 	ZEND_FE_END
 };