Where is setup() defined in the Arduino code tree?

Using Arduino Programming Questions
1

A recursive grep shows that there exists the declaration "extern void setup( void ) ;" in the Arduino.h file. Other files have the same declaration. But nowhere can I find where setup() actually exists as lines of code. Any clues?

2

???
You create the setup() function, There are no lines of code until you create the function in your .ino.

3

Arduino supplies the main() function.
Have a look at main.cpp down in the cores directory.
You will find the main() function that calls you setup() function then has a for loop
that calls your loop() function.

--- bill

4

setup and loop are in "arduino/hardware/arduino/cores/arduino/main.c"

#include <Arduino.h>

int main(void)
{
	init();

#if defined(USBCON)
	USBDevice.attach();
#endif

	setup();

	for (;;) {
		loop();
		if (serialEventRun) serialEventRun();
	}

	return 0;
}

If you want to avoid the "setup" and "loop" foolishness, simply use this as a code skeleton:

int main (void)
{
    init (); // setup timers, interrupts, etc... (necessary)
    Serial.begin (baudrate); // if needed
//----------------------------------
    normal C and C++ code goes here as usual
//----------------------------------
    while (1); // last line of your code - necessary
}

Or if your code needs to run in an endless loop:

int main (void)
{
    init (); // setup timers, interrupts, etc... (necessary)
    while (1) {
//----------------------------------
    Serial.begin (baudrate); // if needed
    normal C and C++ code goes here as usual
//----------------------------------
    }
}

Hope this helps.