llvm-project/clang/test/AST/ByteCode/new-delete.cpp

// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -verify=expected,both %s
// RUN: %clang_cc1 -std=c++20 -fexperimental-new-constant-interpreter -verify=expected,both %s
// RUN: %clang_cc1 -triple=i686-linux-gnu -std=c++20 -fexperimental-new-constant-interpreter -verify=expected,both %s
// RUN: %clang_cc1 -verify=ref,both %s
// RUN: %clang_cc1 -std=c++20 -verify=ref,both %s
// RUN: %clang_cc1 -triple=i686-linux-gnu -std=c++20 -verify=ref,both %s

#if __cplusplus >= 202002L

constexpr int *Global = new int(12); // both-error {{must be initialized by a constant expression}} \
                                     // both-note {{pointer to heap-allocated object}} \
                                     // both-note {{heap allocation performed here}}

static_assert(*(new int(12)) == 12); // both-error {{not an integral constant expression}} \
                                     // both-note {{allocation performed here was not deallocated}}


constexpr int a() {
  new int(12); // both-note {{allocation performed here was not deallocated}}
  return 1;
}
static_assert(a() == 1, ""); // both-error {{not an integral constant expression}}

constexpr int b() {
  int *i = new int(12);
  int m = *i;
  delete(i);
  return m;
}
static_assert(b() == 12, "");


struct S {
  int a;
  int b;

  static constexpr S *create(int a, int b) {
    return new S(a, b);
  }
};

constexpr int c() {
  S *s = new S(12, 13);

  int i = s->a;
  delete s;

  return i;
}
static_assert(c() == 12, "");

/// Dynamic allocation in function ::create(), freed in function d().
constexpr int d() {
  S* s = S::create(12, 14);

  int sum = s->a + s->b;
  delete s;
  return sum;
}
static_assert(d() == 26);


/// Test we emit the right diagnostic for several allocations done on
/// the same site.
constexpr int loop() {
  for (int i = 0; i < 10; ++i) {
    int *a = new int[10]; // both-note {{not deallocated (along with 9 other memory leaks)}}
  }

  return 1;
}
static_assert(loop() == 1, ""); // both-error {{not an integral constant expression}}

/// No initializer.
constexpr int noInit() {
  int *i = new int;
  delete i;
  return 0;
}
static_assert(noInit() == 0, "");

/// Try to delete a pointer that hasn't been heap allocated.
constexpr int notHeapAllocated() { // both-error {{never produces a constant expression}}
  int A = 0; // both-note 2{{declared here}}
  delete &A; // ref-note 2{{delete of pointer '&A' that does not point to a heap-allocated object}} \
             // expected-note 2{{delete of pointer '&A' that does not point to a heap-allocated object}}

  return 1;
}
static_assert(notHeapAllocated() == 1, ""); // both-error {{not an integral constant expression}} \
                                            // both-note {{in call to 'notHeapAllocated()'}}

consteval int deleteNull() {
  int *A = nullptr;
  delete A;
  return 1;
}
static_assert(deleteNull() == 1, "");

consteval int doubleDelete() { // both-error {{never produces a constant expression}}
  int *A = new int;
  delete A;
  delete A; // both-note 2{{delete of pointer that has already been deleted}}
  return 1;
}
static_assert(doubleDelete() == 1); // both-error {{not an integral constant expression}} \
                                    // both-note {{in call to 'doubleDelete()'}}

constexpr int AutoArray() {
  auto array = new int[]{0, 1, 2, 3};
  int ret = array[3];
  delete [] array;
  return ret;
}

static_assert(AutoArray() == 3);

#if 0
consteval int largeArray1(bool b) {
  if (b) {
    int *a = new int[1ull<<32]; // both-note {{cannot allocate array; evaluated array bound 4294967296 is too large}}
    delete[] a;
  }
  return 1;
}
static_assert(largeArray1(false) == 1, "");
static_assert(largeArray1(true) == 1, ""); // both-error {{not an integral constant expression}} \
                                           // both-note {{in call to 'largeArray1(true)'}}

consteval int largeArray2(bool b) {
  if (b) {
    S *a = new S[1ull<<32]; // both-note {{cannot allocate array; evaluated array bound 4294967296 is too large}}
    delete[] a;
  }
  return 1;
}
static_assert(largeArray2(false) == 1, "");
static_assert(largeArray2(true) == 1, ""); // both-error {{not an integral constant expression}} \
                                           // both-note {{in call to 'largeArray2(true)'}}
#endif
namespace Arrays {
  constexpr int d() {
    int *Arr = new int[12];

    Arr[0] = 1;
    Arr[1] = 5;

    int sum = Arr[0] + Arr[1];
    delete[] Arr;
    return sum;
  }
  static_assert(d() == 6);


  constexpr int mismatch1() { // both-error {{never produces a constant expression}}
    int *i = new int(12); // both-note {{allocated with 'new' here}} \
                          // both-note 2{{heap allocation performed here}}
    delete[] i; // both-warning {{'delete[]' applied to a pointer that was allocated with 'new'}} \
                // both-note 2{{array delete used to delete pointer to non-array object of type 'int'}}
    return 6;
  }
  static_assert(mismatch1() == 6); // both-error {{not an integral constant expression}} \
                                   // both-note {{in call to 'mismatch1()'}}

  constexpr int mismatch2() { // both-error {{never produces a constant expression}}
    int *i = new int[12]; // both-note {{allocated with 'new[]' here}} \
                          // both-note 2{{heap allocation performed here}}
    delete i; // both-warning {{'delete' applied to a pointer that was allocated with 'new[]'}} \
              // both-note 2{{non-array delete used to delete pointer to array object of type 'int[12]'}}
    return 6;
  }
  static_assert(mismatch2() == 6); // both-error {{not an integral constant expression}} \
                                   // both-note {{in call to 'mismatch2()'}}
  /// Array of composite elements.
  constexpr int foo() {
    S *ss = new S[12];

    ss[0].a = 12;

    int m = ss[0].a;

    delete[] ss;
    return m;
  }
  static_assert(foo() == 12);



  constexpr int ArrayInit() {
    auto array = new int[4]{0, 1, 2, 3};
    int ret = array[0];
    delete [] array;
    return ret;
  }
  static_assert(ArrayInit() == 0, "");

  struct S {
    float F;
  };
  constexpr float ArrayInit2() {
    auto array = new S[4]{};
    float ret = array[0].F;
    delete [] array;
    return ret;
  }
  static_assert(ArrayInit2() == 0.0f, "");
}

namespace std {
  struct type_info;
  struct destroying_delete_t {
    explicit destroying_delete_t() = default;
  } inline constexpr destroying_delete{};
  struct nothrow_t {
    explicit nothrow_t() = default;
  } inline constexpr nothrow{};
  using size_t = decltype(sizeof(0));
  enum class align_val_t : size_t {};
};

[[nodiscard]] void *operator new(std::size_t, const std::nothrow_t&) noexcept;
[[nodiscard]] void *operator new(std::size_t, std::align_val_t, const std::nothrow_t&) noexcept;
[[nodiscard]] void *operator new[](std::size_t, const std::nothrow_t&) noexcept;
[[nodiscard]] void *operator new[](std::size_t, std::align_val_t, const std::nothrow_t&) noexcept;
[[nodiscard]] void *operator new[](std::size_t, std::align_val_t);
void operator delete(void*, const std::nothrow_t&) noexcept;
void operator delete(void*, std::align_val_t, const std::nothrow_t&) noexcept;
void operator delete[](void*, const std::nothrow_t&) noexcept;
void operator delete[](void*, std::align_val_t, const std::nothrow_t&) noexcept;

struct placement_new_arg {};
void *operator new(std::size_t, placement_new_arg);
void operator delete(void*, placement_new_arg);


constexpr void *operator new(std::size_t, void *p) { return p; }
namespace std {
  template<typename T> constexpr T *construct(T *p) { return new (p) T; }
  template<typename T> constexpr void destroy(T *p) { p->~T(); }
}



/// FIXME: The new interpreter produces the wrong diagnostic.
namespace PlacementNew {
  constexpr int foo() { // both-error {{never produces a constant expression}}
    char c[sizeof(int)];
    new (c) int{12}; // ref-note {{this placement new expression is not supported in constant expressions before C++2c}} \
                     // expected-note {{subexpression not valid in a constant expression}}
    return 0;
  }
}

namespace NowThrowNew {
  constexpr bool erroneous_array_bound_nothrow(long long n) {
    int *p = new (std::nothrow) int[n];
    bool result = p != nullptr;
    delete[] p;
    return result;
  }
  static_assert(erroneous_array_bound_nothrow(3));
  static_assert(erroneous_array_bound_nothrow(0));
  static_assert(erroneous_array_bound_nothrow(-1) == 0);
  static_assert(!erroneous_array_bound_nothrow(1LL << 62));

  struct S { int a; };
  constexpr bool erroneous_array_bound_nothrow2(long long n) {
    S *p = new (std::nothrow) S[n];
    bool result = p != nullptr;
    delete[] p;
    return result;
  }
  /// This needs support for CXXConstrucExprs with non-constant array sizes.
  static_assert(erroneous_array_bound_nothrow2(3)); // expected-error {{not an integral constant expression}}
  static_assert(erroneous_array_bound_nothrow2(0));// expected-error {{not an integral constant expression}}
  static_assert(erroneous_array_bound_nothrow2(-1) == 0);// expected-error {{not an integral constant expression}}
  static_assert(!erroneous_array_bound_nothrow2(1LL << 62));// expected-error {{not an integral constant expression}}

  constexpr bool evaluate_nothrow_arg() {
    bool ok = false;
    delete new ((ok = true, std::nothrow)) int;
    return ok;
  }
  static_assert(evaluate_nothrow_arg());
}

namespace placement_new_delete {
  struct ClassSpecificNew {
    void *operator new(std::size_t);
  };
  struct ClassSpecificDelete {
    void operator delete(void*);
  };
  struct DestroyingDelete {
    void operator delete(DestroyingDelete*, std::destroying_delete_t);
  };
  struct alignas(64) Overaligned {};

  constexpr bool ok() {
    delete new Overaligned;
    delete ::new ClassSpecificNew;
    ::delete new ClassSpecificDelete;
    ::delete new DestroyingDelete;
    return true;
  }
  static_assert(ok());

  /// FIXME: Diagnosting placement new.
  constexpr bool bad(int which) {
    switch (which) {
    case 0:
      delete new (placement_new_arg{}) int; // ref-note {{this placement new expression is not supported in constant expressions}} \
                                            // expected-note {{subexpression not valid in a constant expression}}
      break;

    case 1:
      delete new ClassSpecificNew; // ref-note {{call to class-specific 'operator new'}}
      break;

    case 2:
      delete new ClassSpecificDelete; // ref-note {{call to class-specific 'operator delete'}}
      break;

    case 3:
      delete new DestroyingDelete; // ref-note {{call to class-specific 'operator delete'}}
      break;

    case 4:
      // FIXME: This technically follows the standard's rules, but it seems
      // unreasonable to expect implementations to support this.
      delete new (std::align_val_t{64}) Overaligned; // ref-note {{this placement new expression is not supported in constant expressions}} \
                                                     // expected-note {{subexpression not valid in a constant expression}}
      break;
    }

    return true;
  }
  static_assert(bad(0)); // both-error {{constant expression}} \
                         // both-note {{in call}}
  static_assert(bad(1)); // ref-error {{constant expression}} ref-note {{in call}}
  static_assert(bad(2)); // ref-error {{constant expression}} ref-note {{in call}}
  static_assert(bad(3)); // ref-error {{constant expression}} ref-note {{in call}}
  static_assert(bad(4)); // both-error {{constant expression}} \
                         // both-note {{in call}}
}




namespace delete_random_things {
  static_assert((delete new int, true));
  static_assert((delete (int*)0, true));
  int n; // both-note {{declared here}}
  static_assert((delete &n, true)); // both-error {{}} \
                                    // both-note {{delete of pointer '&n' that does not point to a heap-allocated object}}
  struct A { int n; };
  static_assert((delete &(new A)->n, true)); // both-error {{}} \
                                             // both-note {{delete of pointer to subobject }}
  static_assert((delete (new int + 1), true)); // both-error {{}} \
                                               // ref-note {{delete of pointer '&{*new int#0} + 1' that does not point to complete object}} \
                                               // expected-note {{delete of pointer '&{*new int#1} + 1' that does not point to complete object}}
  static_assert((delete[] (new int[3] + 1), true)); // both-error {{}} \
                                                    // both-note {{delete of pointer to subobject}}
  static_assert((delete &(int&)(int&&)0, true)); // both-error {{}} \
                                                 // both-note {{delete of pointer '&0' that does not point to a heap-allocated object}} \
                                                 // both-note {{temporary created here}}
}

namespace value_dependent_delete {
  template<typename T> void f(T *p) {
    int arr[(delete p, 0)];
  }
}

namespace memory_leaks {
  static_assert(*new bool(true)); // both-error {{}} both-note {{allocation performed here was not deallocated}}

  constexpr bool *f() { return new bool(true); } // both-note {{allocation performed here was not deallocated}}
  static_assert(*f()); // both-error {{}}

  struct UP {
    bool *p;
    constexpr ~UP() { delete p; }
    constexpr bool &operator*() { return *p; }
  };
  constexpr UP g() { return {new bool(true)}; }
  static_assert(*g()); // ok

  constexpr bool h(UP p) { return *p; }
  static_assert(h({new bool(true)})); // ok
}

/// From test/SemaCXX/cxx2a-consteval.cpp

namespace std {
template <typename T> struct remove_reference { using type = T; };
template <typename T> struct remove_reference<T &> { using type = T; };
template <typename T> struct remove_reference<T &&> { using type = T; };
template <typename T>
constexpr typename std::remove_reference<T>::type&& move(T &&t) noexcept {
  return static_cast<typename std::remove_reference<T>::type &&>(t);
}
}

namespace cxx2a {
struct A {
  int* p = new int(42); // both-note 3{{heap allocation performed here}}
  consteval int ret_i() const { return p ? *p : 0; }
  consteval A ret_a() const { return A{}; }
  constexpr ~A() { delete p; }
};

consteval int by_value_a(A a) { return a.ret_i(); }

consteval int const_a_ref(const A &a) {
  return a.ret_i();
}

consteval int rvalue_ref(const A &&a) {
  return a.ret_i();
}

consteval const A &to_lvalue_ref(const A &&a) {
  return a;
}

void test() {
  constexpr A a{ nullptr };
  { int k = A().ret_i(); }

  { A k = A().ret_a(); } // both-error {{'cxx2a::A::ret_a' is not a constant expression}} \
                         // both-note {{heap-allocated object is not a constant expression}}
  { A k = to_lvalue_ref(A()); } // both-error {{'cxx2a::to_lvalue_ref' is not a constant expression}} \
                                // both-note {{reference to temporary is not a constant expression}} \
                                // both-note {{temporary created here}}
  { A k = to_lvalue_ref(A().ret_a()); } // both-error {{'cxx2a::to_lvalue_ref' is not a constant expression}} \
                                        // both-note {{reference to temporary is not a constant expression}} \
                                        // both-note {{temporary created here}}
  { int k = A().ret_a().ret_i(); } // both-error {{'cxx2a::A::ret_a' is not a constant expression}} \
                                   // both-note {{heap-allocated object is not a constant expression}}
  { int k = by_value_a(A()); }
  { int k = const_a_ref(A()); }
  { int k = const_a_ref(a); }
  { int k = rvalue_ref(A()); }
  { int k = rvalue_ref(std::move(a)); }
  { int k = const_a_ref(A().ret_a()); }
  { int k = const_a_ref(to_lvalue_ref(A().ret_a())); }
  { int k = const_a_ref(to_lvalue_ref(std::move(a))); }
  { int k = by_value_a(A().ret_a()); }
  { int k = by_value_a(to_lvalue_ref(static_cast<const A&&>(a))); }
  { int k = (A().ret_a(), A().ret_i()); } // both-error {{'cxx2a::A::ret_a' is not a constant expression}} \
                                          // both-note {{is not a constant expression}} \
                                          // both-warning {{left operand of comma operator has no effect}}
  { int k = (const_a_ref(A().ret_a()), A().ret_i()); } // both-warning {{left operand of comma operator has no effect}}
}
}

constexpr int *const &p = new int; // both-error {{must be initialized by a constant expression}} \
                                   // both-note {{pointer to heap-allocated object}} \
                                   // both-note {{allocation performed here}}

constexpr const int *A[] = {nullptr, nullptr, new int{12}}; // both-error {{must be initialized by a constant expression}} \
                                                            // both-note {{pointer to heap-allocated object}} \
                                                            // both-note {{allocation performed here}}

struct Sp {
  const int *p;
};
constexpr Sp ss[] = {Sp{new int{154}}}; // both-error {{must be initialized by a constant expression}} \
                                        // both-note {{pointer to heap-allocated object}} \
                                        // both-note {{allocation performed here}}

namespace DeleteRunsDtors {
  struct InnerFoo {
    int *mem;
    constexpr ~InnerFoo() {
      delete mem;
    }
  };

  struct Foo {
    int *a;
    InnerFoo IF;

    constexpr Foo() {
      a = new int(13);
      IF.mem = new int(100);
    }
    constexpr ~Foo() { delete a; }
  };

  constexpr int abc() {
    Foo *F = new Foo();
    int n = *F->a;
    delete F;

    return n;
  }
  static_assert(abc() == 13);

  constexpr int abc2() {
    Foo *f = new Foo[3];

    delete[] f;

    return 1;
  }
  static_assert(abc2() == 1);
}

/// FIXME: There is a slight difference in diagnostics here.
namespace FaultyDtorCalledByDelete {
  struct InnerFoo {
    int *mem;
    constexpr ~InnerFoo() {
      if (mem) {
        (void)(1/0); // both-warning {{division by zero is undefined}} \
                     // both-note {{division by zero}}
      }
      delete mem;
    }
  };

  struct Foo {
    int *a;
    InnerFoo IF;

    constexpr Foo() {
      a = new int(13);
      IF.mem = new int(100);
    }
    constexpr ~Foo() { delete a; } // expected-note {{in call to}}
  };

  constexpr int abc() {
    Foo *F = new Foo();
    int n = *F->a;
    delete F; // both-note {{in call to}} \
              // ref-note {{in call to}}

    return n;
  }
  static_assert(abc() == 13); // both-error {{not an integral constant expression}} \
                              // both-note {{in call to 'abc()'}}
}

namespace DeleteThis {
  constexpr bool super_secret_double_delete() {
    struct A {
      constexpr ~A() { delete this; } // both-note {{destruction of object that is already being destroyed}} \
                                      // ref-note {{in call to}}
    };
    delete new A; // both-note {{in call to}}
    return true;
  }
  static_assert(super_secret_double_delete()); // both-error {{not an integral constant expression}} \
                                               // both-note {{in call to 'super_secret_double_delete()'}}
}

/// FIXME: This is currently diagnosed, but should work.
/// If the destructor for S is _not_ virtual however, it should fail.
namespace CastedDelete {
  struct S {
    constexpr S(int *p) : p(p) {}
    constexpr virtual ~S() { *p = 1; }
    int *p;
  };
  struct T: S {
    // implicit destructor defined eagerly because it is constexpr and virtual
    using S::S;
  };

  constexpr int vdtor_1() {
    int a;
    delete (S*)new T(&a); // expected-note {{delete of pointer to subobject}}
    return a;
  }
  static_assert(vdtor_1() == 1); // expected-error {{not an integral constant expression}} \
                                 // expected-note {{in call to}}
}

#else
/// Make sure we reject this prior to C++20
constexpr int a() { // both-error {{never produces a constant expression}}
  delete new int(12); // both-note 2{{dynamic memory allocation is not permitted in constant expressions until C++20}}
  return 1;
}
static_assert(a() == 1, ""); // both-error {{not an integral constant expression}} \
                             // both-note {{in call to 'a()'}}


static_assert(true ? *new int : 4, ""); // both-error {{expression is not an integral constant expression}} \
                                        // both-note {{read of uninitialized object is not allowed in a constant expression}}

#endif