Merge pull request #103 from vpetrigo/issue/89-configurable_PAL

mqttc: Add an option to specify own MQTT-C PAL header file

include/mqtt.h

@@ -29,7 +29,19 @@ SOFTWARE.
 extern "C" {
 #endif
 
+// Users can override mqtt_pal.h with their own configuration by defining
+// MQTTC_PAL_FILE as a header file to include (-DMQTTC_PAL_FILE=my_mqtt_pal.h).
+//
+// If MQTTC_PAL_FILE is used, none of the default utils will be emitted and must be
+// provided by the config file. To start, I would suggest copying mqtt_pal.h
+// and modifying as needed.
+#ifdef MQTTC_PAL_FILE
+#define MQTTC_STR2(x) #x
+#define MQTTC_STR(x) MQTTC_STR2(x)
+#include MQTTC_STR(MQTTC_PAL_FILE)
+#else
 #include <mqtt_pal.h>
+#endif /* MQTT_PAL_FILE */
 
 /**
  * @file