DISABLED macro may conflict with sketches

[ewasscher]

Basic Infos

The macro DISABLED as defined in Arduino.h may conflict with some sketches.

Hardware

Hardware: All ESP8266
Core Version: 2.2.0

Description

The macro DISABLED as defined in Arduino.h may conflict with some sketches when DISABLED is defined in the sketch or library. Changing from a generic name like "DISABLED" to a more specific name like "ESP8266_INT_DISABLED" would help to avoid collisions like this. Would this be an option?

Sketch

#include <Arduino.h>

enum class State : uint8_t {
  DISABLED,
  WAITING,
  READING,
  CHECKSUM,
};

void setup() {

}

void loop() {

}

Debug Messages

Build options changed, rebuilding all
In file included from /tmp/arduino_modified_sketch_437587/sketch_may30b.ino:1:0:
/home/ewasscher/.arduino15/packages/esp8266/hardware/esp8266/2.2.0/cores/esp8266/Arduino.h:76:19: error: expected identifier before numeric constant
 #define DISABLED  0x00
                   ^
/tmp/arduino_modified_sketch_437587/sketch_may30b.ino:4:3: note: in expansion of macro 'DISABLED'
   DISABLED,
   ^
/home/ewasscher/.arduino15/packages/esp8266/hardware/esp8266/2.2.0/cores/esp8266/Arduino.h:76:19: error: expected '}' before numeric constant
 #define DISABLED  0x00
                   ^
/tmp/arduino_modified_sketch_437587/sketch_may30b.ino:4:3: note: in expansion of macro 'DISABLED'
   DISABLED,
   ^
/home/ewasscher/.arduino15/packages/esp8266/hardware/esp8266/2.2.0/cores/esp8266/Arduino.h:76:19: error: expected unqualified-id before numeric constant
 #define DISABLED  0x00
                   ^
/tmp/arduino_modified_sketch_437587/sketch_may30b.ino:4:3: note: in expansion of macro 'DISABLED'
   DISABLED,
   ^
sketch_may30b:8: error: expected declaration before '}' token
 };
 ^
exit status 1
expected declaration before '}' token

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[matthijskooijman]

Alternatively, using a global constant will reduce the impact of this:

const uint8_t DISABLED = 0;

This will still conflict with global variables or constants, but will allow using DISABLED as an identifier in other places (parameter names, member names, etc.). Using a constant instead of a define in this way should not influence performance (generated code is typically identical).