GCC Bugzilla Bug 33911

In the following example, class "foo" gets a deprecated warning, but a similar
class template "goo" does not. Typedefs constructed with foo or goo get an
error.

What up?


struct foo
{
  int i;
} __attribute__ ((__deprecated__));

template<typename _Tp>
struct goo
{
  int i;
} __attribute__ ((__deprecated__));

typedef foo foo_type __attribute__ ((__deprecated__));
typedef goo<int> goo_type __attribute__ ((__deprecated__));


int main()
{
  foo f1;
  goo<int> f2;

  foo_type f3;
  goo_type f4;

  return 0;
}


I have a patch to mark the C++0x bits deprecated, but it's not working because
of this issue.

*** Bug 33912 has been marked as a duplicate of this bug. ***

I can second that problem for template member functions - in contrast to
non-template member functions, where the attribute works.

This gives a warning about deprecation as expected:
-----------------------------------------------------------------
struct T { } ;

struct A {
        inline void foo(T & ) __attribute__((deprecated));
};

inline void A::foo(T & ) { }

void test(T & t) {
        A a;
        a.foo(t);
}
-------------------------------------------------------------

... while this is not causing a warning as it should:
-------------------------------------------------------------
struct A {
        template <class T> inline void foo(T & ) __attribute__((deprecated));
};

template <class T> inline void A::foo(T & ) { }

void test(A & t) {
        A a;
        a.foo(t);
}
-------------------------------------------------------------

Subject: Re:  attribute deprecated vs. templates

niemayer at isg dot de wrote:
> I can second that problem for template member functions - in contrast to
> non-template member functions, where the attribute works.

This is a parser bug: parsing the member template declaration winds up 
in cp_parser_init_declarator, which ignores attributes at the end of a 
declaration.  A normal member function goes through 
cp_parser_member_declaration, which handles the attributes properly. 
You can work around this bug by moving the attribute into the 
decl-specifier-seq, i.e. "void __attribute ((deprecated)) foo(T&)".

Jason

*** Bug 36307 has been marked as a duplicate of this bug. ***

Not planning to work on this soon since there's a reasonable workaround.