[Bug c++/13717] New: duplicated parameter name not caught ?

[Bug c++/13717] New: duplicated parameter name not caught ?

[d dot binderman at virgin dot net]

The one liner

void f( int fred, char * fred);

is IMHO illegal code because fred is the name of two parameters.

I couldn't get gcc332 to find the bug in this code.
This is salted down from real code in Fedora Core 1.

-- 
           Summary: duplicated parameter name not caught ?
           Product: gcc
           Version: 3.3.2
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: d dot binderman at virgin dot net
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: linux-i386


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13717

Re: [Bug c++/13717] New: duplicated parameter name not caught ?

[Joseph S. Myers]

On Sat, 17 Jan 2004, d dot binderman at virgin dot net wrote:

> The one liner
> 
> void f( int fred, char * fred);
> 
> is IMHO illegal code because fred is the name of two parameters.
> 
> I couldn't get gcc332 to find the bug in this code.
> This is salted down from real code in Fedora Core 1.

If you give the parameters the same type, then the C front end has
acquired such a bug as well in 3.4/3.5.  Neither

void f (int fred, int fred);

nor

void f (int fred, int fred) {}

now give a diagnostic for C.  I guess Zack's patches are the most likely
cause, or at least the subsequent ones the most likely fix.

(Sent to gcc-bugs rather than gcc-bugzilla because this is a separate bug.  
Shall I open a new PR for this regression or will this be fixed shortly
(with the above testcases included) in a subsequent stage of the c-decl.c
cleanup patches?)

-- 
Joseph S. Myers
jsm@polyomino.org.uk

Re: [Bug c++/13717] New: duplicated parameter name not caught ?

[Andrew Pinski]

On Jan 17, 2004, at 04:17, Joseph S. Myers wrote:
> now give a diagnostic for C.  I guess Zack's patches are the most 
> likely
> cause, or at least the subsequent ones the most likely fix.

It was the most recent patch which broke this as it failed still on 
2004-01-01.


> (Sent to gcc-bugs rather than gcc-bugzilla because this is a separate 
> bug.
> Shall I open a new PR for this regression or will this be fixed shortly
> (with the above testcases included) in a subsequent stage of the 
> c-decl.c
> cleanup patches?)


I would open just to make sure that it gets fixed.

Thanks,
Andrew Pinski

Re: [Bug c++/13717] New: duplicated parameter name not caught ?

[Zack Weinberg]

Andrew Pinski <pinskia@physics.uc.edu> writes:

> On Jan 17, 2004, at 04:17, Joseph S. Myers wrote:
>> now give a diagnostic for C.  I guess Zack's patches are the most
>> likely
>> cause, or at least the subsequent ones the most likely fix.
>
> It was the most recent patch which broke this as it failed still on
> 2004-01-01.
>
>
>> (Sent to gcc-bugs rather than gcc-bugzilla because this is a
>> separate bug.
>> Shall I open a new PR for this regression or will this be fixed shortly
>> (with the above testcases included) in a subsequent stage of the
>> c-decl.c
>> cleanup patches?)
>
> I would open just to make sure that it gets fixed.

Please do.

zw

Re: [Bug c++/13717] New: duplicated parameter name not caught ?

[Gabriel Dos Reis]

"d dot binderman at virgin dot net" <gcc-bugzilla@gcc.gnu.org> writes:

| The one liner
| 
| void f( int fred, char * fred);
| 
| is IMHO illegal code because fred is the name of two parameters.

Yes, it invalid in C++.  This bug should be easier to fix in
GCC-3.4.x/g++ than GCC-3.3.x/g++.

-- Gaby

[Bug c++/13717] duplicated parameter name not caught ?

[dhazeghi at yahoo dot com]

------- Additional Comments From dhazeghi at yahoo dot com  2004-01-18 09:20 -------
Confirmed with mainline/3.4 branch. C frontend properly rejects this, so this is
not a duplicate of PR13728.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |accepts-invalid
   Last reconfirmed|0000-00-00 00:00:00         |2004-01-18 09:20:19
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13717

[Bug c++/13717] duplicated parameter name not caught ?

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-10-03 19:52 -------
*** Bug 17786 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rth at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13717

[Bug c++/13717] duplicated parameter name not caught ?

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-10-04 12:45 -------
As mentioned in PR 17786 by Nathan: 
 
correct. there is a related bug in that we fail to compile things like 
 
void foo (int x, int ary[sizeof(x)]); 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|3.3.2 3.4.0 4.0             |3.3.2 3.4.0 4.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13717

[Bug c++/13717] duplicated parameter name not caught ?

[dcb314 at hotmail dot com]

------- Comment #4 from dcb314 at hotmail dot com  2006-03-15 10:42 -------
(In reply to comment #0)
> The one liner
> 
> void f( int fred, char * fred);
> 
> is IMHO illegal code because fred is the name of two parameters.

I just checked gcc 4.2 and it is broken there as well.

Even adding flags -Wall -ansi -pedantic doesn't help


-- 

dcb314 at hotmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dcb314 at hotmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13717

[Bug c++/13717] duplicated parameter name not caught ?

[rguenth at gcc dot gnu dot org]

------- Comment #5 from rguenth at gcc dot gnu dot org  2006-05-29 15:13 -------
Based on 8.3.5/8 and the example from 8.3.6/9 which reads

 int f(int a, int b = a);

I think this bug is invalid and function declarations with duplicate parameter
names are not invalid.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13717

[Bug c++/13717] duplicated parameter name not caught ?

[mueller at gcc dot gnu dot org]

------- Comment #6 from mueller at gcc dot gnu dot org  2006-05-29 16:26 -------
it might not be invalid, but its certainly worth a diagnostic IMHO


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13717

[Bug c++/13717] duplicated parameter name not caught ?

[dcb314 at hotmail dot com]

------- Comment #7 from dcb314 at hotmail dot com  2006-05-29 22:34 -------
(In reply to comment #5)
> Based on 8.3.5/8 and the example from 8.3.6/9 which reads
> 
>  int f(int a, int b = a);
> 
> I think this bug is invalid and function declarations with duplicate parameter
> names are not invalid.

I don't understand how the line of code you mention helps
demonstrate your logic. Two parameters are declared, one
called a and one called b. 

In the standard, the end of paragraph 8.3.5.7 says

If a parameter name is present  in  a  function
  declaration that is not a definition, it cannot be used outside of the
  parameter-declaration-clause since it goes out of scope at the end  of
  the function declarator

So it implies that a new scope is entered at the (
and exited at the ). But we already know that a name can't 
be reused at the same scope [ except for function overloading,
but that's different]. QED.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13717

[Bug c++/13717] duplicated parameter name not caught ?

[tsarkov at cs dot man dot ac dot uk]

------- Comment #8 from tsarkov at cs dot man dot ac dot uk  2008-01-16 17:39 -------
This is fixed in current mainline GCC (as per
http://gcc.gnu.org/gcc-4.3/porting_to.html).


-- 

tsarkov at cs dot man dot ac dot uk changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tsarkov at cs dot man dot ac
                   |                            |dot uk


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13717

[Bug c++/13717] duplicated parameter name not caught ?

[bangerth at dealii dot org]

------- Comment #9 from bangerth at dealii dot org  2008-01-22 22:06 -------
Apparently fixed.


-- 

bangerth at dealii dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13717

[Bug c++/13717] duplicated parameter name not caught ?

[manu at gcc dot gnu dot org]

-- 

manu at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13717