clang/test/C/C11/n1285.c

   1 // RUN: %clang_cc1 -verify=wrong -std=c99 %s
   2 // RUN: %clang_cc1 -verify=wrong -std=c11 %s
   3 // RUN: %clang_cc1 -verify=cpp -std=c++11 -x c++ %s
   4
   5 /* WG14 N1285: No
   6  * Extending the lifetime of temporary objects (factored approach)
   7  *
   8  * NB: we do not properly materialize temporary expressions in situations where
   9  * it would be expected; that is why the "no-diagnostics" marking is named
  10  * "wrong". We do issue the expected diagnostic in C++ mode.
  11  */
  12
  13 // wrong-no-diagnostics
  14
  15 struct X { int a[5]; };
  16 struct X f(void);
  17
  18 int foo(void) {
  19   // FIXME: This diagnostic should be issued in C11 as well (though not in C99,
  20   // as this paper was a breaking change between C99 and C11).
  21   int *p = f().a; // cpp-warning {{temporary whose address is used as value of local variable 'p' will be destroyed at the end of the full-expression}}
  22   return *p;
  23 }
  24