llvm-project/clang/test/SemaCXX/scope-check.cpp

// RUN: %clang_cc1 -fsyntax-only -verify -fblocks -fcxx-exceptions -fms-extensions %s -Wno-unreachable-code
// RUN: %clang_cc1 -fsyntax-only -verify -fblocks -fcxx-exceptions -fms-extensions -std=gnu++11 %s -Wno-unreachable-code

namespace testInvalid {
Invalid inv; // expected-error {{unknown type name}}
// Make sure this doesn't assert.
void fn()
{
    int c = 0;
    if (inv)
Here: ;
    goto Here;
}
}

namespace test0 {
  struct D { ~D(); };

  int f(bool b) {
    if (b) {
      D d;
      goto end;
    }

  end:
    return 1;
  }
}

namespace test1 {
  struct C { C(); };

  int f(bool b) {
    if (b)
      goto foo; // expected-error {{cannot jump}}
    C c; // expected-note {{jump bypasses variable initialization}}
  foo:
    return 1;
  }
}

namespace test2 {
  struct C { C(); };

  int f(void **ip) {
    static void *ips[] = { &&lbl1, &&lbl2 };

    C c;
    goto *ip;
  lbl1:
    return 0;
  lbl2:
    return 1;
  }
}

namespace test3 {
  struct C { C(); };

  int f(void **ip) {
    static void *ips[] = { &&lbl1, &&lbl2 };

    goto *ip;
  lbl1: {
    C c;
    return 0;
  }
  lbl2:
    return 1;
  }
}

namespace test4 {
  struct C { C(); };
  struct D { ~D(); };

  int f(void **ip) {
    static void *ips[] = { &&lbl1, &&lbl2 };

    C c0;

    goto *ip; // expected-error {{cannot jump}}
    C c1; // expected-note {{jump bypasses variable initialization}}
  lbl1: // expected-note {{possible target of indirect goto}}
    return 0;
  lbl2:
    return 1;
  }
}

namespace test5 {
  struct C { C(); };
  struct D { ~D(); };

  int f(void **ip) {
    static void *ips[] = { &&lbl1, &&lbl2 };
    C c0;

    goto *ip;
  lbl1: // expected-note {{possible target of indirect goto}}
    return 0;
  lbl2:
    if (ip[1]) {
      D d; // expected-note {{jump exits scope of variable with non-trivial destructor}}
      ip += 2;
      goto *ip; // expected-error {{cannot jump}}
    }
    return 1;
  }
}

namespace test6 {
  struct C { C(); };

  unsigned f(unsigned s0, unsigned s1, void **ip) {
    static void *ips[] = { &&lbl1, &&lbl2, &&lbl3, &&lbl4 };
    C c0;

    goto *ip;
  lbl1:
    s0++;
    goto *++ip;
  lbl2:
    s0 -= s1;
    goto *++ip;
  lbl3: {
    unsigned tmp = s0;
    s0 = s1;
    s1 = tmp;
    goto *++ip;
  }
  lbl4:
    return s0;
  }
}

// C++0x says it's okay to skip non-trivial initializers on static
// locals, and we implement that in '03 as well.
namespace test7 {
  struct C { C(); };

  void test() {
    goto foo;
    static C c;
  foo:
    return;
  }
}

// PR7789
namespace test8 {
  void test1(int c) {
    switch (c) {
    case 0:
      int x = 56; // expected-note {{jump bypasses variable initialization}}
    case 1:       // expected-error {{cannot jump}}
      x = 10;
    }
  }

  void test2() {
    goto l2;     // expected-error {{cannot jump}}
  l1: int x = 5; // expected-note {{jump bypasses variable initialization}}
  l2: x++;
  }
}

namespace test9 {
  struct S { int i; };
  void test1() {
    goto foo;
    S s;
  foo:
    return;
  }
  unsigned test2(unsigned x, unsigned y) {
    switch (x) {
    case 2:
      S s;
      if (y > 42) return x + y;
    default:
      return x - 2;
    }
  }
}

// http://llvm.org/PR10462
namespace PR10462 {
  enum MyEnum {
    something_valid,
    something_invalid
  };

  bool recurse() {
    MyEnum K;
    switch (K) { // expected-warning {{enumeration value 'something_invalid' not handled in switch}}
    case something_valid:
    case what_am_i_thinking: // expected-error {{use of undeclared identifier}}
      int *X = 0;
      if (recurse()) {
      }

      break;
    }
  }
}

namespace test10 {
  int test() {
    static void *ps[] = { &&a0 };
    goto *&&a0; // expected-error {{cannot jump}}
    int a = 3; // expected-note {{jump bypasses variable initialization}}
  a0:
    return 0;
  }
}

// pr13812
namespace test11 {
  struct C {
    C(int x);
    ~C();
  };
  void f(void **ip) {
    static void *ips[] = { &&l0 };
  l0:  // expected-note {{possible target of indirect goto}}
    C c0 = 42; // expected-note {{jump exits scope of variable with non-trivial destructor}}
    goto *ip; // expected-error {{cannot jump}}
  }
}

namespace test12 {
  struct C {
    C(int x);
    ~C();
  };
  void f(void **ip) {
    static void *ips[] = { &&l0 };
    const C c0 = 17;
  l0: // expected-note {{possible target of indirect goto}}
    const C &c1 = 42; // expected-note {{jump exits scope of lifetime-extended temporary with non-trivial destructor}}
    const C &c2 = c0;
    goto *ip; // expected-error {{cannot jump}}
  }
}

namespace test13 {
  struct C {
    C(int x);
    ~C();
    int i;
  };
  void f(void **ip) {
    static void *ips[] = { &&l0 };
  l0: // expected-note {{possible target of indirect goto}}
    const int &c1 = C(1).i; // expected-note {{jump exits scope of lifetime-extended temporary with non-trivial destructor}}
    goto *ip;  // expected-error {{cannot jump}}
  }
}

namespace test14 {
  struct C {
    C(int x);
    ~C();
    operator int&() const;
  };
  void f(void **ip) {
    static void *ips[] = { &&l0 };
  l0:
    // no warning since the C temporary is destructed before the goto.
    const int &c1 = C(1);
    goto *ip;
  }
}

// PR14225
namespace test15 {
  void f1() try {
    goto x; // expected-error {{cannot jump}}
  } catch(...) {  // expected-note {{jump bypasses initialization of catch block}}
    x: ;
  }
  void f2() try {  // expected-note {{jump bypasses initialization of try block}}
    x: ;
  } catch(...) {
    goto x; // expected-error {{cannot jump}}
  }
}

namespace test16 {
  struct S { int n; };
  int f() {
    goto x; // expected-error {{cannot jump}}
    const S &s = S(); // expected-note {{jump bypasses variable initialization}}
x:  return s.n;
  }
}

#if __cplusplus >= 201103L
namespace test17 {
  struct S { int get(); private: int n; };
  int f() {
    goto x; // expected-error {{cannot jump}}
    S s = {}; // expected-note {{jump bypasses variable initialization}}
x:  return s.get();
  }
}
#endif

namespace test18 {
  struct A { ~A(); };
  struct B { const int &r; const A &a; };
  int f() {
    void *p = &&x;
    const A a = A();
  x:
    B b = { 0, a }; // ok
    goto *p;
  }
  int g() {
    void *p = &&x;
  x: // expected-note {{possible target of indirect goto}}
    B b = { 0, A() }; // expected-note {{jump exits scope of lifetime-extended temporary with non-trivial destructor}}
    goto *p; // expected-error {{cannot jump}}
  }
}

#if __cplusplus >= 201103L
namespace std {
  typedef decltype(sizeof(int)) size_t;
  template<typename T> struct initializer_list {
    const T *begin;
    size_t size;
    initializer_list(const T *, size_t);
  };
}
namespace test19 {
  struct A { ~A(); };

  int f() {
    void *p = &&x;
    A a;
  x: // expected-note {{possible target of indirect goto}}
    std::initializer_list<A> il = { a }; // expected-note {{jump exits scope of lifetime-extended temporary with non-trivial destructor}}
    goto *p; // expected-error {{cannot jump}}
  }
}

namespace test20 {
  struct A { ~A(); };
  struct B {
    const A &a;
  };

  int f() {
    void *p = &&x;
    A a;
  x:
    std::initializer_list<B> il = {
      a,
      a
    };
    goto *p;
  }
  int g() {
    void *p = &&x;
    A a;
  x: // expected-note {{possible target of indirect goto}}
    std::initializer_list<B> il = {
      a,
      { A() } // expected-note {{jump exits scope of lifetime-extended temporary with non-trivial destructor}}
    };
    goto *p; // expected-error {{cannot jump}}
  }
}
#endif

namespace test21 {
  template<typename T> void f() {
  goto x; // expected-error {{cannot jump}}
    T t; // expected-note {{bypasses}}
 x: return;
  }

  template void f<int>();
  struct X { ~X(); };
  template void f<X>(); // expected-note {{instantiation of}}
}

namespace PR18217 {
  typedef int *X;

  template <typename T>
  class MyCl {
    T mem;
  };

  class Source {
    MyCl<X> m;
  public:
    int getKind() const;
  };

  bool b;
  template<typename TT>
  static void foo(const Source &SF, MyCl<TT *> Source::*m) {
    switch (SF.getKind()) {
      case 1: return;
      case 2: break;
      case 3:
      case 4: return;
    };
    if (b) {
      auto &y = const_cast<MyCl<TT *> &>(SF.*m); // expected-warning 0-1{{extension}}
    }
  }

  int Source::getKind() const {
    foo(*this, &Source::m);
    return 0;
  }
}

namespace test_recovery {
  // Test that jump scope checking recovers when there are unspecified errors
  // in the function declaration or body.

  void test(nexist, int c) { // expected-error {{}}
    nexist_fn(); // expected-error {{}}
    goto nexist_label; // expected-error {{use of undeclared label}}
    goto a0; // expected-error {{cannot jump}}
    int a = 0; // expected-note {{jump bypasses variable initialization}}
    a0:;

    switch (c) {
    case $: // expected-error {{}}
    case 0:
      int x = 56; // expected-note {{jump bypasses variable initialization}}
    case 1: // expected-error {{cannot jump}}
      x = 10;
    }
  }
}

namespace seh {

// Jumping into SEH try blocks is not permitted.

void jump_into_except() {
  goto into_try_except_try; // expected-error {{cannot jump from this goto statement to its label}}
  __try { // expected-note {{jump bypasses initialization of __try block}}
  into_try_except_try:
    ;
  } __except(0) {
  }

  goto into_try_except_except; // expected-error {{cannot jump from this goto statement to its label}}
  __try {
  } __except(0) { // expected-note {{jump bypasses initialization of __except block}}
  into_try_except_except:
    ;
  }
}

void jump_into_finally() {
  goto into_try_except_try; // expected-error {{cannot jump from this goto statement to its label}}
  __try { // expected-note {{jump bypasses initialization of __try block}}
  into_try_except_try:
    ;
  } __finally {
  }

  goto into_try_except_finally; // expected-error {{cannot jump from this goto statement to its label}}
  __try {
  } __finally { // expected-note {{jump bypasses initialization of __finally block}}
  into_try_except_finally:
    ;
  }
}

// Jumping out of SEH try blocks ok in general. (Jumping out of a __finally
// has undefined behavior.)

void jump_out_of_except() {
  __try {
    goto out_of_except_try;
  } __except(0) {
  }
out_of_except_try:
  ;

  __try {
  } __except(0) {
    goto out_of_except_except;
  }
out_of_except_except:
  ;
}

void jump_out_of_finally() {
  __try {
  goto out_of_finally_try;
  } __finally {
  }
out_of_finally_try:
  ;

  __try {
  } __finally {
    goto out_of_finally_finally; // expected-warning {{jump out of __finally block has undefined behavior}}
  }

  __try {
  } __finally {
    goto *&&out_of_finally_finally; // expected-warning {{jump out of __finally block has undefined behavior}}
  }
out_of_finally_finally:
  ;
}

// Jumping between protected scope and handler is not permitted.

void jump_try_except() {
  __try {
    goto from_try_to_except; // expected-error {{cannot jump from this goto statement to its label}}
  } __except(0) { // expected-note {{jump bypasses initialization of __except block}}
  from_try_to_except:
    ;
  }

  __try { // expected-note {{jump bypasses initialization of __try block}}
  from_except_to_try:
    ;
  } __except(0) {
    goto from_except_to_try; // expected-error {{cannot jump from this goto statement to its label}}
  }
}

void jump_try_finally() {
  __try {
    goto from_try_to_finally; // expected-error {{cannot jump from this goto statement to its label}}
  } __finally { // expected-note {{jump bypasses initialization of __finally block}}
  from_try_to_finally:
    ;
  }

  __try { // expected-note {{jump bypasses initialization of __try block}}
  from_finally_to_try:
    ;
  } __finally {
    goto from_finally_to_try; // expected-error {{cannot jump from this goto statement to its label}} expected-warning {{jump out of __finally block has undefined behavior}}
  }
}

void nested() {
  // These are not permitted.
  __try {
    __try {
    } __finally {
      goto outer_except; // expected-error {{cannot jump from this goto statement to its label}}
    }
  } __except(0) { // expected-note {{jump bypasses initialization of __except bloc}}
  outer_except:
    ;
  }

  __try {
    __try{
    } __except(0) {
      goto outer_finally; // expected-error {{cannot jump from this goto statement to its label}}
    }
  } __finally { // expected-note {{jump bypasses initialization of __finally bloc}}
  outer_finally:
    ;
  }

  // These are permitted.
  __try {
    __try {
    } __finally {
      goto after_outer_except; // expected-warning {{jump out of __finally block has undefined behavior}}
    }
  } __except(0) {
  }
after_outer_except:
  ;

  __try {
    __try{
    } __except(0) {
      goto after_outer_finally;
    }
  } __finally {
  }
after_outer_finally:
  ;
}

// This section is academic, as MSVC doesn't support indirect gotos.

void indirect_jumps(void **ip) {
  static void *ips[] = { &&l };

  __try { // expected-note {{jump exits __try block}}
    // FIXME: Should this be allowed? Jumping out of the guarded section of a
    // __try/__except doesn't require unwinding.
    goto *ip; // expected-error {{cannot jump from this indirect goto statement to one of its possible targets}}
  } __except(0) {
  }

  __try {
  } __except(0) { // expected-note {{jump exits __except block}}
    // FIXME: What about here?
    goto *ip; // expected-error {{cannot jump from this indirect goto statement to one of its possible targets}}
  }

  __try { // expected-note {{jump exits __try block}}
    goto *ip; // expected-error {{cannot jump from this indirect goto statement to one of its possible targets}}
  } __finally {
  }

  __try {
  } __finally { // expected-note {{jump exits __finally block}}
    goto *ip; // expected-error {{cannot jump from this indirect goto statement to one of its possible targets}}
  }
l: // expected-note 4 {{possible target of indirect goto statement}}
  ;
}

} // namespace seh