clang/test/Parser/expressions.cpp

   1 // RUN: %clang_cc1 -std=c++2a -verify %s
   2
   3 void *operator new(__SIZE_TYPE__, void*);
   4
   5 // Check that we give a good diagnostic for an attempt to use a postfix
   6 // operator after a unary-expression.
   7 namespace postfix_after_unary {
   8   struct A { int n; };
   9   int &a = new A->n; // expected-error {{expression cannot be followed by a postfix '->' operator; add parentheses}}
  10
  11   struct B { B(int); int operator()(int); };
  12   int n = new (0) (B) (int()) (int()); // expected-error {{cannot be followed by a postfix '(}} expected-error {{not a function or function pointer}}
  13
  14   char x = sizeof(int)["hello"]; // expected-error {{cannot be followed by a postfix '[}}
  15   char y = alignof(int)["hello"]; // expected-error {{cannot be followed by a postfix '[}}
  16   char z = noexcept(0)["hello"]; // expected-error {{cannot be followed by a postfix '[}}
  17   char w = requires { x == x; }["ny"]; // expected-error {{cannot be followed by a postfix '[}}
  18
  19   int f() {
  20   label:
  21     return &&label->n; // expected-error {{cannot be followed by a postfix}} expected-error {{not a structure or union}}
  22   }
  23
  24   char k = sizeof(int) // expected-error {{expected ';'}}
  25   [[noreturn]] void g();
  26 }
  27
  28 // Check that we do parse postfix-expression suffixes after some more unusual
  29 // kinds of postfix-expressions (null literals and builtin calls).
  30 namespace unusual_primary_exprs {
  31   int a = nullptr["foo"]; // expected-error {{array subscript is not an integer}}
  32   int b = __builtin_COLUMN()["sufficiently long string constant"];
  33   int c = __builtin_available(*)["ny"];
  34   static_assert(__null["foo"] == 'f'); // FIXME: Warn about converting __null to integer in array subscripting.
  35   static_assert(__is_standard_layout(int)["ny"] == 'y');
  36   static_assert(__array_rank(int[1][2])["0123"] == '2');
  37   static_assert(__is_lvalue_expr(a)["ny"] == 'y');
  38 }