How can I correctly assign a pointer to a call back function?-CodePudding

I try to call a function in a IRQ with C, with the next code I get it.

static void (*functionPulsacion)();

void eint2_init(void *funcPulsacion){
    functionPulsacion = funcPulsacion;
}

But when I compile in Keil the IDE show me the next message:

Button2.c(38): warning: #513-D: a value of type "void " cannot be assigned to an entity of type "void ()()"

What is the good way for do this?.

Thank you in advance

CodePudding user response：

Make sure the type of funcPulsacion matches that of functionPulsacion, like so:

static void (*functionPulsacion)(void);

void eint2_init(void (*funcPulsacion)(void)) {
    functionPulsacion = funcPulsacion;
}

It helps to use typedef to define the function pointer type so it can be reused:

typedef void (*functionPulsacion_type)(void);

static void functionPulsacion_type functionPulsacion;

void eint2_init(functionPulsacion_type funcPulsacion) {
    functionPulsacion = funcPulsacion;
}

CodePudding user response：

It's the same syntax for the parameter variable as for the static one.

static void (*functionPulsacion)(void);

void eint2_init(void (*funcPulsacion)(void)) {
    functionPulsacion = funcPulsacion;
}

Typedefs make function pointers a lot more readable, though.

typedef void (*PulsacionFunc)(void);

static PulsacionFunc pulsacion_func;

void eint2_init(PulsacionFunc a_pulsacion_func) {
   pulsacion_func = a_pulsacion_func;
}