Could someone please explain me this error?

[Alexander Mahone]

OK, I have this piece of code:

void method(void* parameter)
{
1: struct Data* dataOfReference =(struct Data*)parameter ;
2: Info tmpInfo=(*dataO fReference).pay load.data;
3: char* message;
....
}

Why does the compiler (gcc) complain about line 2?

'error: dereferencing pointer to incomplete type'

Shouldn't it be correct? I have a pointer, and I dereference it with
'*'...
Thanks

[Nick Keighley]

Re: Could someone please explain me this error?

On May 2, 12:53 pm, Alexander Mahone <salvodanilogiu ffr...@gmail.co m>
wrote:

void method(void* parameter)
{
1:    struct Data* dataOfReference =(struct Data*)parameter ;
2:    Info tmpInfo=(*dataO fReference).pay load.data;
3:    char* message;
}
>
Why does the compiler (gcc) complain about line 2?
>
'error: dereferencing pointer to incomplete type'
>
Shouldn't it be correct? I have a pointer, and I dereference it with
'*'...

what is the definition of struct Data?

--
Nick Keighley

[Ian Collins]

Re: Could someone please explain me this error?

Alexander Mahone wrote:

OK, I have this piece of code:
>
void method(void* parameter)
{
1: struct Data* dataOfReference =(struct Data*)parameter ;
2: Info tmpInfo=(*dataO fReference).pay load.data;
3: char* message;
....
}
>
Why does the compiler (gcc) complain about line 2?
>
'error: dereferencing pointer to incomplete type'
>

Is the complete definition of struct Data (not just a forward
declaration) visible to the compiler? It looks like you have left out a
header file.

--
Ian Collins.

[Richard Tobin]

Re: Could someone please explain me this error?

In article <f90e4f94-9061-42c8-b2e2-b2e8541e0d82@x4 1g2000hsb.googl egroups.com>,
Alexander Mahone <salvodanilogiu ffrida@gmail.co mwrote:

>void method(void* parameter)
>{
>1: struct Data* dataOfReference =(struct Data*)parameter ;
>2: Info tmpInfo=(*dataO fReference).pay load.data;

Where's the definition of struct Data?

>Why does the compiler (gcc) complain about line 2?
>
>'error: dereferencing pointer to incomplete type'
>
>Shouldn't it be correct? I have a pointer, and I dereference it with
>'*'...

You have a pointer to a struct Data, and to dereference it you
need a definition of that struct. Presumably you don't have one.

-- Richard
--
:wq

[Peter Nilsson]

Re: Could someone please explain me this error?

Alexander Mahone wrote:

1: struct Data* dataOfReference =(struct Data*)parameter ;

If you need the cast, then there's a chance this is wrong.

2: Info tmpInfo=(*dataO fReference).pay load.data;

Easier on the eye is...

Info tmpInfo = dataOfReference->payload.data ;

--
Peter

[Igmar Palsenberg]

Re: Could someone please explain me this error?

void method(void* parameter)
{
1: struct Data* dataOfReference =(struct Data*)parameter ;

This cast is bogus, and hides real bugs.

2: Info tmpInfo=(*dataO fReference).pay load.data;
3: char* message;
...
}
>
Why does the compiler (gcc) complain about line 2?

because it doesn't now what struct Data looks like, hence the 'incomplete'.



Igmar.