exceptions.cpp

// RUN: %clang_cc1 -fcxx-exceptions -fexceptions -fsyntax-only -verify=expected,precxx17 %std_cxx98-14 %s
// RUN: %clang_cc1 -fcxx-exceptions -fexceptions -fsyntax-only -verify %std_cxx17- %s

struct A; // expected-note 4 {{forward declaration of 'A'}}

struct Abstract { virtual void f() = 0; }; // expected-note {{unimplemented pure virtual method 'f'}}

void trys() {
  int k = 42;
  try {
  } catch(int i) { // expected-note {{previous definition}}
    int j = i;
    int i; // expected-error {{redefinition of 'i'}}
  } catch(float i) {
  } catch(void v) { // expected-error {{cannot catch incomplete type 'void'}}
  } catch(A a) { // expected-error {{cannot catch incomplete type 'A'}}
  } catch(A *a) { // expected-error {{cannot catch pointer to incomplete type 'A'}}
  } catch(A &a) { // expected-error {{cannot catch reference to incomplete type 'A'}}
  } catch(Abstract) { // expected-error {{variable type 'Abstract' is an abstract class}}
  } catch(...) {
    int ref = k;
    {
      int ref = k;
    }
    int j = i; // expected-error {{use of undeclared identifier 'i'}}
  }

  try {
  } catch(...) { // expected-error {{catch-all handler must come last}}
  } catch(int) {
  }
}

void throws() {
  throw;
  throw 0;
  throw throw; // expected-error {{cannot throw object of incomplete type 'void'}}
  throw (A*)0; // expected-error {{cannot throw pointer to object of incomplete type 'A'}}
}

void jumps() {
l1:
  goto l5;
  goto l4; // expected-error {{cannot jump}}
  goto l3; // expected-error {{cannot jump}}
  goto l2; // expected-error {{cannot jump}}
  goto l1;
  try { // expected-note 4 {{jump bypasses initialization of try block}}
  l2:
    goto l5;
    goto l4; // expected-error {{cannot jump}}
    goto l3; // expected-error {{cannot jump}}
    goto l2;
    goto l1;
  } catch(int) { // expected-note 4 {{jump bypasses initialization of catch block}}
  l3:
    goto l5;
    goto l4; // expected-error {{cannot jump}}
    goto l3;
    goto l2; // expected-error {{cannot jump}}
    goto l1;
  } catch(...) { // expected-note 4 {{jump bypasses initialization of catch block}}
  l4:
    goto l5;
    goto l4;
    goto l3; // expected-error {{cannot jump}}
    goto l2; // expected-error {{cannot jump}}
    goto l1;
  }
l5:
  goto l5;
  goto l4; // expected-error {{cannot jump}}
  goto l3; // expected-error {{cannot jump}}
  goto l2; // expected-error {{cannot jump}}
  goto l1;
}

struct BadReturn {
  BadReturn() try {
  } catch(...) {
    // Try to hide
    try {
    } catch(...) {
      {
        if (0)
          return; // expected-error {{return in the catch of a function try block of a constructor is illegal}}
      }
    }
  }
  BadReturn(int);
};

BadReturn::BadReturn(int) try {
} catch(...) {
  // Try to hide
  try {
  } catch(int) {
    return; // expected-error {{return in the catch of a function try block of a constructor is illegal}}
  } catch(...) {
    {
      if (0)
        return; // expected-error {{return in the catch of a function try block of a constructor is illegal}}
    }
  }
}

// Cannot throw an abstract type.
class foo {
public:
  foo() {}
  void bar () {
    throw *this; // expected-error{{cannot throw an object of abstract type 'foo'}}
  }
  virtual void test () = 0; // expected-note{{unimplemented pure virtual method 'test'}}
};

namespace PR6831 {
  namespace NA { struct S; }
  namespace NB { struct S; }
  
  void f() {
    using namespace NA;
    using namespace NB;
    try {
    } catch (int S) { 
    }
  }
}

#if __cplusplus < 201703L
namespace Decay {
  struct A {
    void f() throw (A[10]);
  };

  template<typename T> struct B {
    void f() throw (B[10]);
  };
  template struct B<int>;

  void f() throw (int[10], int(*)());
  void f() throw (int*, int());

  template<typename T> struct C {
    void f() throw (T);
#if __cplusplus <= 199711L
    // expected-error@-2 {{pointer to incomplete type 'Decay::E' is not allowed in exception specification}}
#endif
  };
  struct D {
    C<D[10]> c;
  };
  struct E;
#if __cplusplus <= 199711L
  // expected-note@-2 {{forward declaration of 'Decay::E'}}
#endif

  C<E[10]> e;
#if __cplusplus <= 199711L
  // expected-note@-2 {{in instantiation of template class 'Decay::C<Decay::E[10]>' requested here}}
#endif
}

void rval_ref() throw (int &&); // expected-error {{rvalue reference type 'int &&' is not allowed in exception specification}}
#if __cplusplus <= 199711L
// expected-warning@-2 {{rvalue references are a C++11 extension}}
#endif
#endif

namespace HandlerInversion {
struct B {};
struct D : B {};
struct D2 : D {};

void f1() {
  try {
  } catch (B &b) { // expected-note {{for type 'B &'}}
  } catch (D &d) { // expected-warning {{exception of type 'D &' will be caught by earlier handler}}
  }
}

void f2() {
  try {
  } catch (B *b) { // expected-note {{for type 'B *'}}
  } catch (D *d) { // expected-warning {{exception of type 'D *' will be caught by earlier handler}}
  }
}

void f3() {
  try {
  } catch (D &d) { // Ok
  } catch (B &b) {
  }
}

void f4() {
  try {
  } catch (B &b) { // Ok
  }
}

void f5() {
  try {
  } catch (int) {
  } catch (float) {
  }
}

void f6() {
  try {
  } catch (B &b) {  // expected-note {{for type 'B &'}}
  } catch (D2 &d) {  // expected-warning {{exception of type 'D2 &' will be caught by earlier handler}}
  }
}

void f7() {
  try {
  } catch (B *b) { // Ok
  } catch (D &d) { // Ok
  }

  try {
  } catch (B b) { // Ok
  } catch (D *d) { // Ok
  }
}

void f8() {
  try {
  } catch (const B &b) {  // expected-note {{for type 'const B &'}}
  } catch (D2 &d) {  // expected-warning {{exception of type 'D2 &' will be caught by earlier handler}}
  }

  try {
  } catch (B &b) {  // expected-note {{for type 'B &'}}
  } catch (const D2 &d) {  // expected-warning {{exception of type 'const D2 &' will be caught by earlier handler}}
  }

  try {
  } catch (B b) { // expected-note {{for type 'B'}}
  } catch (D &d) { // expected-warning {{exception of type 'D &' will be caught by earlier handler}}
  }
}
}

namespace ConstVolatileThrow {
struct S {
  S() {}         // precxx17-note{{candidate constructor not viable}}
  S(const S &s); // precxx17-note{{candidate constructor not viable}}
};

typedef const volatile S CVS;

void f() {
  throw CVS(); // precxx17-error{{no matching constructor for initialization}}
}
}

namespace ConstVolatileCatch {
struct S {
  S() {}
  S(const volatile S &s);

private:
  S(const S &s); // expected-note {{declared private here}}
};

void f();

void g() {
  try {
    f();
  } catch (volatile S s) { // expected-error {{calling a private constructor}}
  }
}
}

namespace PR28047 {
void test1(int i) {
  try {
  } catch (int(*)[i]) { // expected-error{{cannot catch variably modified type}}
  }
}
void test2() {
  int i;
  try {
  } catch (int(*)[i]) { // expected-error{{cannot catch variably modified type}}
  }
}
}