[Bug c++/12246] New: __attribute__ not able to be placed on inline ctors

[Bug c++/12246] New: __attribute__ not able to be placed on inline ctors

[Bruce at Fitzsimons dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12246

           Summary: __attribute__ not able to be placed on inline ctors
           Product: gcc
           Version: 3.2.3
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: Bruce at Fitzsimons dot org
                CC: gcc-bugs at gcc dot gnu dot org

__attribute__ attributes are not able to be placed on inline ctors, which is a
bit frustrating.

Sometimes inline ctors are used in header files, esp. when doing a thin layer of
inheritance around an existing object ie only the base class needs
initialisation, there are no new member variables. 

This is often the case for deriving exceptions, where a new type is desired (for
specific catch'es) but no new methods or members are defined.

A simple example (not the inheritance case)

class A
{
public:
    A(int _anInt)  __attribute__ ((deprecated)) { anInt = _anInt; }
private:
    int anInt;
};

int main(void) {
    A aInstance(42);
}

Fails to parse:
g++ test.cc
test.cc:4: syntax error before `{' token
test.cc:5: semicolon missing after declaration of `A'
test.cc: In function `int main()':
test.cc:10: no matching function for call to `A::A(int)'
test.cc:2: candidates are: A::A(const A&)

[Bug c++/12246] __attribute__ not able to be placed on inline ctors

[Bruce at Fitzsimons dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12246



------- Additional Comments From Bruce at Fitzsimons dot org  2003-09-11 07:02 -------
I can provide a more realistic example, if required, or attach the test.cc if
copy/paste from the bug text is unacceptable.

[Bug c++/12246] __attribute__ not allowed in member function definition

[bangerth at dealii dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12246


bangerth at dealii dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |diagnostic
   Last reconfirmed|0000-00-00 00:00:00         |2003-09-11 14:06:28
               date|                            |
            Summary|__attribute__ not able to be|__attribute__ not allowed in
                   |placed on inline ctors      |member function definition


------- Additional Comments From bangerth at dealii dot org  2003-09-11 14:06 -------
Indeed, but this has nothing to do with constructors, as this example shows: 
------------------------------------------------------ 
struct A { 
    int f()  __attribute__ ((deprecated)) {} 
}; 
 
int f()  __attribute__ ((deprecated)) {} 
------------------------------------------------------- 
Compiled with 3.3, we get 
mp/g> ~/bin/gcc-3.3/bin/c++ -c x.cc 
x.cc:2: error: parse error before `{' token 
x.cc:2: error: missing ';' before right brace 
x.cc:5: error: parse error before `{' token 
 
That's not very enlightening. Present mainline tells us more, at least for the 
non-member case: 
mp/g> c++ -c x.cc 
x.cc:2: error: expected function-definition 
x.cc:5: error: attributes are not allowed on a function-definition 
 
So the point is really that attributes are not allowed at function _definitions_ (though it's 
easy to check that they are of course allowed at _declarations_), but that this is only 
properly diagnosed for the non-member case. 
 
W. 
 
PS: A workaround for the original problem is this: 
-------------------- 
struct A { 
    A()  __attribute__ ((deprecated)); 
}; 
 
inline A::A () {} 
---------------------

[Bug c++/12246] __attribute__ not allowed in member function definition

[Bruce at Fitzsimons dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12246



------- Additional Comments From Bruce at Fitzsimons dot org  2003-09-12 02:13 -------
Yes, you're right Wolfgang, sorry I hadn't burrowed that far into it.

I've now seen some references to a patch for this
(http://gcc.gnu.org/ml/gcc-patches/2002-01/msg00223.html) but no indication that
it was accepted or went any further.

It is annoying that it doesn't always work, as this is a very useful feature in
mature software projects.

[Bug c++/12246] __attribute__ not allowed in member function definition

[Bruce at Fitzsimons dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12246



------- Additional Comments From Bruce at Fitzsimons dot org  2003-09-12 02:16 -------
(sorry for the spam)

In fact it does look like it was accepted (there is a followup) and the original
problem was slightly different, in that it parsed "...They [deprecated attribs]
were being properly handled by the grammar...".

[Bug c++/12246] __attribute__ not allowed in member function definition

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-01-01 01:42 -------
Fixed for 3.4.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |3.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12246