Create Declaration / Definition in current file

Discussed in https://github.com/microsoft/vscode-cpptools/discussions/10642

^{Originally posted by FernandoGarcia March 7, 2023}
Hi!

I would to know how to create function prototype in an Arduino code while using Platformio.

I'm talking about this type of code:

main.cpp

#include <Arduino.h>
#include <Bounce2.h>

#define NUM_RELAYS 3
#define INITIAL_STATE LOW  // Initial state = HIGH to active LOW relay model.

struct INFOS
{
  const byte relayPin;
  bool relayState;
  const byte buttonPin;
};

INFOS info[NUM_RELAYS] =
{
  {2, INITIAL_STATE, 18}, // Relay 0 pin, relay 0 state, button 0 pin
  {4, INITIAL_STATE, 19},
  {5, INITIAL_STATE, 21}
};

Bounce2::Button button[NUM_RELAYS] = {Bounce2::Button()};

void setup()
{
  Serial.begin(9600);

  for (byte i = 0; i < NUM_RELAYS; i++)
  {
    button[i].attach(info[i].buttonPin, INPUT_PULLUP);
    button[i].setPressedState(LOW);
    button[i].interval(5);

    pinMode(info[i].relayPin, OUTPUT);
    digitalWrite(info[i].relayPin, info[i].relayState);
  }
}

void loop()
{
  for (byte i = 0; i < NUM_RELAYS; i++)
  {
    button[i].update();

    if (button[i].pressed())
    {
      info[i].relayState = !info[i].relayState;
      digitalWrite(info[i].relayPin, info[i].relayState);
      printDebug(i);
      break;
    }
  }
}

void printDebug(byte i)
{
  Serial.print("Button ");
  Serial.print(i);
  Serial.print(" pressed, relayState ");
  Serial.print(i);
  Serial.print(": ");
  Serial.println(info[i].relayState);
}

The compiling error for this code is:

src/main.cpp: In function 'void loop()':
src/main.cpp:47:7: error: 'printDebug' was not declared in this scope
       printDebug(i);
       ^~~~~~~~~~
src/main.cpp:47:7: note: suggested alternative: 'Printable'
       printDebug(i);
       ^~~~~~~~~~
       Printable
*** [.pio/build/uno/src/main.cpp.o] Error 1

So I have always to create manually all functions prototypes on top of my code in this way:

void printDebug(byte i);

I have tried the new feature of C++ extension but it doesn't works well for this type of code.

The declaration is being placed in Arduino.h header file what is not correct for this case.

Thanks in advance.

Best regards.

Reproduce el problema utilizando el ejemplo main.cpp proporcionado en un proyecto Arduino de PlatformIO, centrándote en la función Create Definitions and Declarations. Compara la ubicación de la declaración generada con Arduino.h y con el contexto actual del archivo. Se considera completado cuando el prototipo de la función se coloca en el archivo fuente actual en lugar de en Arduino.h.