arm-none-eabi-g++

arm-none-eabi-objcopy -O binary .pioenvs/lpc1114fn28/firmware.elf .pioenvs/lpc1114fn28/firmware.bin
text       data     bss     dec     hex filename
22948       124     340   23412    5b74 .pioenvs/lpc1114fn28/firmware.elf

arm-none-eabi-g++ --version
arm-none-eabi-g++ (GNU Tools for ARM Embedded Processors) 4.8.4 20140725 (release) [ARM/embedded-4_8-branch revision 213147]
Copyright (C) 2013 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

main.cpp

#include "mbed.h"

DigitalOut myled(LED1);
AnalogIn adc(dp1);

int main() {
    float foobar = adc.read();
    foobar = pow(foobar, 2);
    while(1) {
        myled = 1;
        wait(0.2);
        myled = 0;
        wait(0.2);
    }
}

mbed-onlinecompiler.md