function doThis(address id) returns (int) {
    // This is allwoed
    return bar1.this_is_external{program_id: id}(1, 2);
}

contract bar1 {
    constructor() {}

    function this_is_external(int a, int b) external pure returns (int) {
        return a-b;
    }
}


contract bar2 is bar1 {
    constructor() {}

    function hello(int a, int b) external pure returns (int) {
        return a - b;
    }

    function test2(int c, int d) external returns (int) {
        // Not allowed
        return hello(c, d);
    }

    function test3(int f, int g) external returns (int) {
        // Not allowed
        return hello({b: g, a: f});
    }

    function test4(int c, int d) external returns (int) {
        // This is allowed
        return this.this_is_external(c, d) + this.hello(d, c);
    }

    function test5(int f, int g) external returns (int) {
        // Not allowed
        return this_is_external(f, g);
    }
}

// ---- Expect: diagnostics ----
// error: 4:12-55: accounts are required for calling a contract. You can either provide the accounts with the {accounts: ...} call argument or change this function's visibility to external
// error: 25:16-27: functions declared external cannot be called via an internal function call
// 	note 19:5-61: declaration of function 'hello'
// error: 30:16-35: functions declared external cannot be called via an internal function call
// 	note 19:5-61: declaration of function 'hello'
// error: 35:16-43: a contract needs a program id to be called. Either a '@program_id' must be declared above a contract or the {program_id: ...} call argument must be present
// error: 40:16-38: functions declared external cannot be called via an internal function call
// 	note 10:5-72: declaration of function 'this_is_external'