Add weak implementations of xxx_free() functions

Author: mprse

hal/mbed_compat.c

@@ -0,0 +1,43 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2019 ARM Limited
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "analogin_api.h"
+#include "i2c_api.h"
+#include "gpio_api.h"
+#include "mbed_toolchain.h"
+
+// To be re-implemented in the target layer if required
+MBED_WEAK void gpio_free(gpio_t *obj)
+{
+    // Do nothing
+}
+
+#if DEVICE_I2C
+// To be re-implemented in the target layer if required
+MBED_WEAK void i2c_free(i2c_t *obj)
+{
+    // Do nothing
+}
+#endif
+
+#if DEVICE_ANALOGIN
+// To be re-implemented in the target layer if required
+MBED_WEAK void analogin_free(analogin_t *obj)
+{
+    // Do nothing
+}
+#endif