[Bug c/39026] New: Gcc accepts invalid code

[Bug c/39026] New: Gcc accepts invalid code

[hjl dot tools at gmail dot com]

+++ This bug was initially created as a clone of Bug #39013 +++

[hjl@gnu-6 gcc]$ cat /tmp/i.i
inline void foo ();

int
main ()
{
  foo ();
  return 0;
}
[hjl@gnu-6 gcc]$ gcc  /tmp/i.i  -S

Is this valid C code? From

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39013#c10

--
IMHO this is invalid.  6.7.4/6

"... If a function is declared with an inline function specifier, then it
shall also be defined in the same translation unit."
--


-- 
           Summary: Gcc accepts invalid code
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: hjl dot tools at gmail dot com
 BugsThisDependsOn: 39013


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39026

[Bug c/39026] Gcc accepts invalid code

[hjl dot tools at gmail dot com]

------- Comment #1 from hjl dot tools at gmail dot com  2009-01-29 18:34 -------
Icc 11.0 gave:

[hjl@gnu-6 tmp]$ /opt/intel/cce/11.0/bin/icc -S i.i    -Wall
i.i(1): remark #1419: external declaration in primary source file
  inline void foo ();
              ^

[hjl@gnu-6 tmp]$ /opt/intel/cce/11.0/bin/icc -S i.i 
[hjl@gnu-6 tmp]$ 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39026

[Bug c/39026] Gcc accepts invalid code

[joseph at codesourcery dot com]

------- Comment #2 from joseph at codesourcery dot com  2009-01-29 20:02 -------
Subject: Re:   New: Gcc accepts invalid code

On Thu, 29 Jan 2009, hjl dot tools at gmail dot com wrote:

> inline void foo ();
> 
> int
> main ()
> {
>   foo ();
>   return 0;
> }
> [hjl@gnu-6 gcc]$ gcc  /tmp/i.i  -S

If you use -std=c99 -pedantic-errors you get an error, as expected.  
You're compiling in gnu89 mode.

If you use -std=c99 without -pedantic-errors you get a duplicate warning:

t.c:1: warning: inline function 'foo' declared but never defined
t.c:1: warning: inline function 'foo' declared but never defined


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39026

Re: [Bug c/39026] New: Gcc accepts invalid code

[Joseph S. Myers]

On Thu, 29 Jan 2009, hjl dot tools at gmail dot com wrote:

> inline void foo ();
> 
> int
> main ()
> {
>   foo ();
>   return 0;
> }
> [hjl@gnu-6 gcc]$ gcc  /tmp/i.i  -S

If you use -std=c99 -pedantic-errors you get an error, as expected.  
You're compiling in gnu89 mode.

If you use -std=c99 without -pedantic-errors you get a duplicate warning:

t.c:1: warning: inline function 'foo' declared but never defined
t.c:1: warning: inline function 'foo' declared but never defined

-- 
Joseph S. Myers
joseph@codesourcery.com

[Bug c/39026] Gcc accepts invalid code

[hjl dot tools at gmail dot com]

------- Comment #3 from hjl dot tools at gmail dot com  2009-01-29 20:09 -------
(In reply to comment #2)
> If you use -std=c99 -pedantic-errors you get an error, as expected.  
> You're compiling in gnu89 mode.
> 
> If you use -std=c99 without -pedantic-errors you get a duplicate warning:
> 
> t.c:1: warning: inline function 'foo' declared but never defined
> t.c:1: warning: inline function 'foo' declared but never defined
> 

So the code is valid in gnu89 mode, which is the default. With -std=c99
and without -pedantic-errors, shouldn't we generate working binary?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39026

[Bug c/39026] Gcc accepts invalid code

[rguenther at suse dot de]

------- Comment #4 from rguenther at suse dot de  2009-01-29 21:24 -------
Subject: Re:  Gcc accepts invalid code

On Thu, 29 Jan 2009, joseph at codesourcery dot com wrote:

> 
> 
> ------- Comment #2 from joseph at codesourcery dot com  2009-01-29 20:02 -------
> Subject: Re:   New: Gcc accepts invalid code
> 
> On Thu, 29 Jan 2009, hjl dot tools at gmail dot com wrote:
> 
> > inline void foo ();
> > 
> > int
> > main ()
> > {
> >   foo ();
> >   return 0;
> > }
> > [hjl@gnu-6 gcc]$ gcc  /tmp/i.i  -S
> 
> If you use -std=c99 -pedantic-errors you get an error, as expected.  
> You're compiling in gnu89 mode.
> 
> If you use -std=c99 without -pedantic-errors you get a duplicate warning:
> 
> t.c:1: warning: inline function 'foo' declared but never defined
> t.c:1: warning: inline function 'foo' declared but never defined

I think the frontend should, in C89 mode and if just issueing a warning,
set DECL_EXTERNAL properly on the decl.

Richard.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39026

[Bug c/39026] Gcc accepts invalid code

[hjl dot tools at gmail dot com]

------- Comment #5 from hjl dot tools at gmail dot com  2009-01-30 01:17 -------
(In reply to comment #4)
> 
> I think the frontend should, in C89 mode and if just issueing a warning,
> set DECL_EXTERNAL properly on the decl.
> 

Do we want to make such a change, especially for 4.3 branch?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39026

[Bug c/39026] Gcc accepts invalid code

[rguenther at suse dot de]

------- Comment #6 from rguenther at suse dot de  2009-01-30 06:52 -------
Subject: Re:  Gcc accepts invalid code

On Fri, 30 Jan 2009, hjl dot tools at gmail dot com wrote:

> ------- Comment #5 from hjl dot tools at gmail dot com  2009-01-30 01:17 -------
> (In reply to comment #4)
> > 
> > I think the frontend should, in C89 mode and if just issueing a warning,
> > set DECL_EXTERNAL properly on the decl.
> > 
> 
> Do we want to make such a change, especially for 4.3 branch?

It would be a way more local change than changing what binds local
(which also affects other languages).  Did you try to track down which
change broke this in the first place?

Richard.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39026

[Bug c/39026] Gcc accepts invalid code

[hjl dot tools at gmail dot com]

------- Comment #7 from hjl dot tools at gmail dot com  2009-01-30 16:04 -------
I think it is caused by revision 118356:

http://gcc.gnu.org/ml/gcc-cvs/2006-11/msg00007.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39026

[Bug c/39026] Gcc accepts invalid code

[hjl dot tools at gmail dot com]

------- Comment #8 from hjl dot tools at gmail dot com  2009-01-30 16:44 -------
(In reply to comment #6)
> 
> It would be a way more local change than changing what binds local
> (which also affects other languages).

My proposal patch will bind undefined functions global, instead of
local. It sounds safe to me. We can put it on trunk and wait a while
before backporting it to 4.3 branch.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39026

[Bug c/39026] Gcc accepts invalid code

[hjl dot tools at gmail dot com]

------- Comment #9 from hjl dot tools at gmail dot com  2009-01-31 17:43 -------
The code is valid in gnu89 mode.


-- 

hjl dot tools at gmail dot com changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39026