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=(*dataOfReference).payload.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]

On May 2, 12:53*pm, Alexander Mahone <[e-mail]>
wrote:

void method(void* parameter)
{
1: * *struct Data* dataOfReference=(struct Data*)parameter;
2: * *Info tmpInfo=(*dataOfReference).payload.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]

Alexander Mahone wrote:

OK, I have this piece of code:

void method(void* parameter)
{
1: struct Data* dataOfReference=(struct Data*)parameter;
2: Info tmpInfo=(*dataOfReference).payload.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]

In article <f9**********************************@x41g2000hsb. googlegroups.com>,
Alexander Mahone <sa******************@gmail.comwrote:

>void method(void* parameter)
{
1: struct Data* dataOfReference=(struct Data*)parameter;
2: Info tmpInfo=(*dataOfReference).payload.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]

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=(*dataOfReference).payload.data;

Easier on the eye is...

Info tmpInfo = dataOfReference->payload.data;

--
Peter

[Igmar Palsenberg]

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

This cast is bogus, and hides real bugs.

2: Info tmpInfo=(*dataOfReference).payload.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.