test_fnptrs_v1.tc

test_fnptrs_v1.tc — function pointers v1 (Phase B) probe

Source on GitHub

// =================================================================
// test_fnptrs_v1.tc — function pointers v1 (Phase B) probe
// =================================================================

// Local fn-ptr type via typedef
typedef int (*int_op)(int, int);
typedef void (*greet_fn)(char who[]);

// Some named functions to point at
int my_add(int a, int b) { return a + b; }
int my_mul(int a, int b) { return a * b; }

void hello(char who[]) {
    addLog("Hello, %s!", who);
}

void hi(char who[]) {
    addLog("Hi %s.", who);
}

// Test 1: local fn-ptr, assigned + called
void test_local_int_op() {
    int_op op;
    op = my_add;
    int s = op(3, 4);
    int_op op2;
    op2 = my_mul;
    int p = op2(3, 4);
    addLog("test_local_int_op: 3+4=%d (expect 7), 3*4=%d (expect 12)", s, p);
}

// Test 2: reassign + dispatch by enum
int OP_ADD = 0;
int OP_MUL = 1;

int dispatch(int op_id, int a, int b) {
    int_op fn;
    if (op_id == OP_ADD) fn = my_add;
    else                 fn = my_mul;
    return fn(a, b);
}

void test_dispatch() {
    addLog("test_dispatch: add=%d mul=%d (expect 9, 20)", dispatch(OP_ADD, 4, 5), dispatch(OP_MUL, 4, 5));
}

// Test 3: global fn-ptr
greet_fn g_greeter;

void test_global_fnptr() {
    g_greeter = hello;
    g_greeter("world");
    g_greeter = hi;
    g_greeter("Tasmota");
}

// Test 4: pass fn-ptr-valued expression as arg via dispatch helper
int run_op(int_op f, int a, int b) {
    return f(a, b);
}

void test_fnptr_as_arg() {
    int s = run_op(my_add, 10, 20);
    int p = run_op(my_mul, 10, 20);
    addLog("test_fnptr_as_arg: add=%d mul=%d (expect 30, 200)", s, p);
}

int main() {
    addLog("=== fnptrs v1 probe start ===");
    test_local_int_op();
    test_dispatch();
    test_global_fnptr();
    test_fnptr_as_arg();
    addLog("=== fnptrs v1 probe end ===");
    return 0;
}