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* [Bug c/17573] New: redefinition of builtin generates error when K&R fn def used
@ 2004-09-20 22:00 bowdidge at apple dot com
  2004-09-20 22:39 ` [Bug c/17573] " pinskia at gcc dot gnu dot org
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: bowdidge at apple dot com @ 2004-09-20 22:00 UTC (permalink / raw)
  To: gcc-bugs

The following code generates an error if a function is defined in K&R style, but not if the function is 
defined in ANSI C style:

extern float dremf ( float, float );

float
dremf(x, y)
        float x;
        float y;
{
  return 1.0;
}

On Apple's gcc-3.5-based compilers, the code generates an error or warning with the K&R C definition, 
but generates no error with the ANSI C function declaration.  The problem is reproducible on at least 
the 9/2 mainline, also with powerpc-apple-darwin.

-- 
           Summary: redefinition of builtin generates error when K&R fn def
                    used
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: bowdidge at apple dot com
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: powerpc-apple-darwin
  GCC host triplet: powerpc-apple-darwin
GCC target triplet: powerpc-apple-darwin


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17573


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [Bug c/17573] redefinition of builtin generates error when K&R fn def used
  2004-09-20 22:00 [Bug c/17573] New: redefinition of builtin generates error when K&R fn def used bowdidge at apple dot com
@ 2004-09-20 22:39 ` pinskia at gcc dot gnu dot org
  2004-09-20 22:44 ` schwab at suse dot de
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-09-20 22:39 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From pinskia at gcc dot gnu dot org  2004-09-20 22:39 -------
: Search converges between 2004-02-01-trunk (#445) and 2004-03-01-trunk (#446).

I think the code is invalid but I don't know the C standard that well.
Zack I think one of your patches which went in during that time changed the behavior of the C front-
end, what do you think of this bug.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |zack at gcc dot gnu dot org
   Target Milestone|---                         |4.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17573


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [Bug c/17573] redefinition of builtin generates error when K&R fn def used
  2004-09-20 22:00 [Bug c/17573] New: redefinition of builtin generates error when K&R fn def used bowdidge at apple dot com
  2004-09-20 22:39 ` [Bug c/17573] " pinskia at gcc dot gnu dot org
@ 2004-09-20 22:44 ` schwab at suse dot de
  2004-09-20 23:11 ` jsm at polyomino dot org dot uk
  2004-09-20 23:38 ` pinskia at gcc dot gnu dot org
  3 siblings, 0 replies; 5+ messages in thread
From: schwab at suse dot de @ 2004-09-20 22:44 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From schwab at suse dot de  2004-09-20 22:44 -------
The definition is not compatible with the declaration.  In K&R style a  
function parameter that is defined as float is actually a double due to  
default promotion. 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17573


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [Bug c/17573] redefinition of builtin generates error when K&R fn def used
  2004-09-20 22:00 [Bug c/17573] New: redefinition of builtin generates error when K&R fn def used bowdidge at apple dot com
  2004-09-20 22:39 ` [Bug c/17573] " pinskia at gcc dot gnu dot org
  2004-09-20 22:44 ` schwab at suse dot de
@ 2004-09-20 23:11 ` jsm at polyomino dot org dot uk
  2004-09-20 23:38 ` pinskia at gcc dot gnu dot org
  3 siblings, 0 replies; 5+ messages in thread
From: jsm at polyomino dot org dot uk @ 2004-09-20 23:11 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From jsm at polyomino dot org dot uk  2004-09-20 23:11 -------
Subject: Re:  New: redefinition of builtin generates error when
 K&R fn def used

On Mon, 20 Sep 2004, bowdidge at apple dot com wrote:

> The following code generates an error if a function is defined in K&R 
> style, but not if the function is defined in ANSI C style:
> 
> extern float dremf ( float, float );
> 
> float
> dremf(x, y)
>         float x;
>         float y;
> {
>   return 1.0;
> }

This seems the same as bug 16666.  The code is invalid (prototypes for a 
function with an old-style definition must contain the argument types 
after default promotions), but is a documented GNU extension.



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17573


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [Bug c/17573] redefinition of builtin generates error when K&R fn def used
  2004-09-20 22:00 [Bug c/17573] New: redefinition of builtin generates error when K&R fn def used bowdidge at apple dot com
                   ` (2 preceding siblings ...)
  2004-09-20 23:11 ` jsm at polyomino dot org dot uk
@ 2004-09-20 23:38 ` pinskia at gcc dot gnu dot org
  3 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-09-20 23:38 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From pinskia at gcc dot gnu dot org  2004-09-20 23:38 -------
It is a dup of 16666 (an almost evil number:) ). 

*** This bug has been marked as a duplicate of 16666 ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |DUPLICATE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17573


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2004-09-20 23:38 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-09-20 22:00 [Bug c/17573] New: redefinition of builtin generates error when K&R fn def used bowdidge at apple dot com
2004-09-20 22:39 ` [Bug c/17573] " pinskia at gcc dot gnu dot org
2004-09-20 22:44 ` schwab at suse dot de
2004-09-20 23:11 ` jsm at polyomino dot org dot uk
2004-09-20 23:38 ` pinskia at gcc dot gnu dot org

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