llvm-project/clang/test/SemaCXX/return-stack-addr.cpp

// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s

int* ret_local() {
  int x = 1;
  return &x; // expected-warning {{address of stack memory}}
}

int* ret_local_array() {
  int x[10];
  return x; // expected-warning {{address of stack memory}}
}

int* ret_local_array_element(int i) {
  int x[10];
  return &x[i]; // expected-warning {{address of stack memory}}
}

int *ret_local_array_element_reversed(int i) {
  int x[10];
  return &i[x]; // expected-warning {{address of stack memory}}
}

int* ret_local_array_element_const_index() {
  int x[10];
  return &x[2];  // expected-warning {{address of stack memory}}
}

int& ret_local_ref() {
  int x = 1;
  return x;  // expected-warning {{reference to stack memory}}
}

int* ret_local_addrOf() {
  int x = 1;
  return &*&x; // expected-warning {{address of stack memory}}
}

int* ret_local_addrOf_paren() {
  int x = 1;
  return (&(*(&x))); // expected-warning {{address of stack memory}}
}

int* ret_local_addrOf_ptr_arith() {
  int x = 1;
  return &*(&x+1); // expected-warning {{address of stack memory}}
}

int* ret_local_addrOf_ptr_arith2() {
  int x = 1;
  return &*(&x+1); // expected-warning {{address of stack memory}}
}

int* ret_local_field() {
  struct { int x; } a;
  return &a.x; // expected-warning {{address of stack memory}}
}

int& ret_local_field_ref() {
  struct { int x; } a;
  return a.x; // expected-warning {{reference to stack memory}}
}

int* ret_conditional(bool cond) {
  int x = 1;
  int y = 2;
  return cond ? &x : &y; // expected-warning {{address of stack memory}}
}

int* ret_conditional_rhs(int *x, bool cond) {
  int y = 1;
  return cond ? x : &y;  // expected-warning {{address of stack memory}}
}

void* ret_c_cast() {
  int x = 1;
  return (void*) &x;  // expected-warning {{address of stack memory}}
}

int* ret_static_var() {
  static int x = 1;
  return &x;  // no warning.
}

int z = 1;

int* ret_global() {
  return &z;  // no warning.
}

int* ret_parameter(int x) {
  return &x;  // expected-warning {{address of stack memory}}
}


void* ret_cpp_static_cast(short x) {
  return static_cast<void*>(&x); // expected-warning {{address of stack memory}}
}

int* ret_cpp_reinterpret_cast(double x) {
  return reinterpret_cast<int*>(&x); // expected-warning {{address of stack me}}
}

int* ret_cpp_reinterpret_cast_no_warning(long x) {
  return reinterpret_cast<int*>(x); // no-warning
}

int* ret_cpp_const_cast(const int x) {
  return const_cast<int*>(&x);  // expected-warning {{address of stack memory}}
}

struct A { virtual ~A(); }; struct B : A {};
A* ret_cpp_dynamic_cast(B b) {
  return dynamic_cast<A*>(&b); // expected-warning {{address of stack memory}}
}

// PR 7999 - handle the case where a field is itself a reference.
template <typename T> struct PR7999 {
  PR7999(T& t) : value(t) {}
  T& value;
};

struct PR7999_X {};

PR7999_X& PR7999_f(PR7999<PR7999_X> s) { return s.value; } // no-warning
void test_PR7999(PR7999_X& x) { (void)PR7999_f(x); } // no-warning

// PR 8774: Don't try to evaluate parameters with default arguments like
// variables with an initializer, especially in templates where the default
// argument may not be an expression (yet).
namespace PR8774 {
  template <typename U> struct B { };
  template <typename V> V f(typename B<V>::type const &v = B<V>::value()) {
    return v;
  }
  template <> struct B<const char *> {
    typedef const char *type;
    static const char *value();
  };
  void g() {
    const char *t;
    f<const char*>(t);
  }
}

// Don't warn about returning a local variable from a surrounding function if
// we're within a lambda-expression.
void ret_from_lambda() {
  int a;
  int &b = a;
  (void) [&]() -> int& { return a; };
  (void) [&]() -> int& { return b; };
  (void) [=]() mutable -> int& { return a; };
  (void) [=]() mutable -> int& { return b; };
  (void) [&]() -> int& { int a; return a; }; // expected-warning {{reference to stack}}
  (void) [=]() -> int& { int a; return a; }; // expected-warning {{reference to stack}}
  (void) [&]() -> int& { int &a = b; return a; };
  (void) [=]() mutable -> int& { int &a = b; return a; };
}