llvm-project/clang/test/SemaCXX/default2.cpp

// RUN: %clang_cc1 -fsyntax-only -verify=expected,precxx17 %std_cxx11-14 %s
// RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx17 %std_cxx17- %s

void f(int i, int j, int k = 3);
void f(int i, int j, int k);
void f(int i, int j = 2, int k);
void f(int i, int j, int k);
void f(int i = 1, int j, int k);
void f(int i, int j, int k);

void i()
{
  f();
  f(0);
  f(0, 1);
  f(0, 1, 2);
}


int f1(int i,          // expected-note {{previous declaration is here}}
       int i, int j) { // expected-error {{redefinition of parameter 'i'}}
  i = 17;
  return j;
} 

int x;
void g(int x, int y = x); // expected-error {{default argument references parameter 'x'}}

void g2(int x, int y, int z = x + y); // expected-error {{default argument references parameter 'x'}} expected-error {{default argument references parameter 'y'}}

class X {
  void f(X* x = this); // expected-error{{invalid use of 'this' outside of a non-static member function}}

  void g() { 
    int f(X* x = this); // expected-error{{default argument references 'this'}}
  }
};

// C++ [dcl.fct.default]p6
class C { 
  static int x;
  void f(int i = 3); // expected-note{{previous definition is here}}
  void g(int i, int j = x); 

  void h();
}; 
void C::f(int i = 3) // expected-error{{redefinition of default argument}}
{ } 

void C::g(int i = 88, int j) {}

void C::h() {
  g(); // okay
}

// C++ [dcl.fct.default]p9
struct Y { 
  int a; 
  int mem1(int i = a); // expected-error{{invalid use of non-static data member 'a'}}
  int mem2(int i = b); // OK; use Y::b 
  int mem3(int i);
  int mem4(int i);

  struct Nested {
    int mem5(int i = b, // OK; use Y::b
             int j = c, // OK; use Y::Nested::c
             int k = j, // expected-error{{default argument references parameter 'j'}}
             int l = a,  // expected-error{{invalid use of non-static data member 'a'}}
             Nested* self = this, // expected-error{{invalid use of 'this' outside of a non-static member function}}
             int m); // expected-error{{missing default argument on parameter 'm'}}
    static int c;
    Nested(int i = 42);
  };

  int mem7(Nested n = Nested());

  static int b; 
}; 

int Y::mem3(int i = b) { return i; } // OK; use X::b

int Y::mem4(int i = a) // expected-error{{invalid use of non-static data member 'a'}}
{ return i; }


// Try to verify that default arguments interact properly with copy
// constructors.
class Z {
public:
  Z(Z&, int i = 17); // expected-note 3 {{candidate constructor}}

  void f(Z& z) { 
    Z z2;    // expected-error{{no matching constructor for initialization}}
    Z z3(z);
  }

  void test_Z(const Z& z) {
    Z z2(z); // expected-error{{no matching constructor for initialization of 'Z'}}
  }
};

void test_Z(const Z& z) {
  Z z2(z); // expected-error{{no matching constructor for initialization of 'Z'}}
}

struct ZZ {
  static ZZ g(int = 17);

  void f(ZZ z = g()); // precxx17-error{{no matching constructor for initialization}} \
  // precxx17-note{{passing argument to parameter 'z' here}}

  ZZ(ZZ&, int = 17); // precxx17-note{{candidate constructor}}
};

// http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#325
class C2 {
  static void g(int = f()); // expected-error{{use of default argument to function 'f' that is declared later in class 'C2'}}
  static int f(int = 10); // expected-note{{default argument declared here}}
};

template <typename T> class C3;
template <> class C3<int> {
  static void g(int = f()); // expected-error {{use of default argument to function 'f' that is declared later in class 'C3<int>'}}
  static int f(int = 10); // expected-note {{default argument declared here}}
};

// Make sure we actually parse the default argument for an inline definition
class XX {
  void A(int length = -1 ) {  } 
  void B() { A(); }
};

template <int I = (1 * I)> struct S {};  // expected-error-re {{use of undeclared identifier 'I'{{$}}}}
S<1> s;

template <int I1 = I2, int I2 = 1> struct T {};  // expected-error-re {{use of undeclared identifier 'I2'{{$}}}}
T<0, 1> t;

struct PR28105 {
  PR28105 (int = 0, int = 0,
      PR28105  // expected-error{{recursive evaluation of default argument}}
      =
      0); // expected-note {{default argument used here}}
};