Compile error: invalid type modifier within pointer declarator

[Per Johansson]

Compiling code using GCC 3.2.2 with the following function declaration
give this error.

extern void APIENTRY glutDisplayFunc (void (* APIENTRY)(void) );

Changing to:

extern void APIENTRY glutDisplayFunc (void (*)(void));

fixes the error.

APIENTRY is a macro defined as "_SYSTEM".

What is wrong with the original declaration?

--
Per Johansson
Systems developer

http://per.johansson.name/

[Mike Wahler]

Re: Compile error: invalid type modifier within pointer declarator


"Per Johansson" <remove-per-this@johansson. name> wrote in message
news:TGZvFVipR1 cm-pn2-Gnvo9l99zR74@ra navalona...[color=blue]
> Compiling code using GCC 3.2.2 with the following function declaration
> give this error.
>
> extern void APIENTRY glutDisplayFunc (void (* APIENTRY)(void) );
>
> Changing to:
>
> extern void APIENTRY glutDisplayFunc (void (*)(void));
>
> fixes the error.
>
> APIENTRY is a macro defined as "_SYSTEM".
>
> What is wrong with the original declaration?[/color]

We cannot say, since '_SYSTEM' is not defined by the C++
language. Perhaps it's an implemenation-specific
keyword. If it's simply another macro that resolves
to a valid C++ construct, post it and we'll take a look.

IOW the best thing is probably to see your documentation
about 'APIENTRY' and '_SYSTEM'.

-Mike

[Per Johansson]

Re: Compile error: invalid type modifier within pointer declarator

On Sun, 31 Oct 2004 20:17:33 UTC, "Mike Wahler"
<mkwahler@mkwah ler.net> wrote:
[color=blue]
>
> "Per Johansson" <remove-per-this@johansson. name> wrote in message
> news:TGZvFVipR1 cm-pn2-Gnvo9l99zR74@ra navalona...[color=green]
> > Compiling code using GCC 3.2.2 with the following function declaration
> > give this error.
> >
> > extern void APIENTRY glutDisplayFunc (void (* APIENTRY)(void) );
> >
> > Changing to:
> >
> > extern void APIENTRY glutDisplayFunc (void (*)(void));
> >
> > fixes the error.
> >
> > APIENTRY is a macro defined as "_SYSTEM".
> >
> > What is wrong with the original declaration?[/color]
>
> We cannot say, since '_SYSTEM' is not defined by the C++
> language. Perhaps it's an implemenation-specific
> keyword. If it's simply another macro that resolves
> to a valid C++ construct, post it and we'll take a look.
>
> IOW the best thing is probably to see your documentation
> about 'APIENTRY' and '_SYSTEM'.
>[/color]

I know it's system dependent, a calling convention I suppose. It's
written like this with gcc -E

extern void __attribute__(( __system__)) glutDisplayFunc (void (*
__attribute__(( __system__)))(v oid));

This is a callback function, taking another function as its parameter.
I was thinking that this kind of modifier is perhaps against the C++
standard?

--
Per Johansson
Systems developer

http://per.johansson.name/

[Mike Wahler]

Re: Compile error: invalid type modifier within pointer declarator


"Per Johansson" <remove-per-this@johansson. name> wrote in message
news:TGZvFVipR1 cm-pn2-IP44og5Y1Tg8@ra navalona...[color=blue]
> On Sun, 31 Oct 2004 20:17:33 UTC, "Mike Wahler"
> <mkwahler@mkwah ler.net> wrote:
>[color=green]
> >
> > "Per Johansson" <remove-per-this@johansson. name> wrote in message
> > news:TGZvFVipR1 cm-pn2-Gnvo9l99zR74@ra navalona...[color=darkred]
> > > Compiling code using GCC 3.2.2 with the following function declaration
> > > give this error.
> > >
> > > extern void APIENTRY glutDisplayFunc (void (* APIENTRY)(void) );
> > >
> > > Changing to:
> > >
> > > extern void APIENTRY glutDisplayFunc (void (*)(void));
> > >
> > > fixes the error.
> > >
> > > APIENTRY is a macro defined as "_SYSTEM".
> > >
> > > What is wrong with the original declaration?[/color]
> >
> > We cannot say, since '_SYSTEM' is not defined by the C++
> > language. Perhaps it's an implemenation-specific
> > keyword. If it's simply another macro that resolves
> > to a valid C++ construct, post it and we'll take a look.
> >
> > IOW the best thing is probably to see your documentation
> > about 'APIENTRY' and '_SYSTEM'.
> >[/color]
>
> I know it's system dependent, a calling convention I suppose. It's
> written like this with gcc -E
>
> extern void __attribute__(( __system__)) glutDisplayFunc (void (*
> __attribute__(( __system__)))(v oid));
>
> This is a callback function, taking another function as its parameter.
> I was thinking that this kind of modifier is perhaps against the C++
> standard?[/color]

I wouldn't say it's "against" it, but it's not part of it. It's
an "extension" to it. Check the gcc documentation for its proper
use.

-Mike