Re: [Qemu-devel] [PATCH v2] HACKING: Document 'struct' keyword usage

[Thomas Huth]

On 8/13/19 1:46 AM, Eduardo Habkost wrote:
> Sometimes we use the 'struct' keyword in headers to help us
> reduce dependencies between header files.  Document that
> practice.
> 
> Signed-off-by: Paolo Bonzini <address@hidden>
> Signed-off-by: Eduardo Habkost <address@hidden>
> ---
> Changes v1 -> v2:
> * Use paragraphs written by Paolo Bonzini at
>   https://www.mail-archive.com/address@hidden/msg586214.html
> * Fix typos spotted by Thomas Huth
> ---
>  HACKING | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/HACKING b/HACKING
> index 0fc3e0fc04..035276e668 100644
> --- a/HACKING
> +++ b/HACKING
> @@ -100,7 +100,19 @@ pointer, you're guaranteed that it is used to modify the 
> storage
>  it points to, or it is aliased to another pointer that is.
>  
>  2.3. Typedefs
> -Typedefs are used to eliminate the redundant 'struct' keyword.
> +
> +Typedefs are used to eliminate the redundant 'struct' keyword, since type
> +names have a different style than other identifiers ("CamelCase" versus
> +"snake_case").  Each struct should have a CamelCase name and a

Maybe s/Each struct/Each global struct/ ? Or "non-local" or something
similar? Sometimes, you also define a struct just within a function, and
in that case we don't require the typedef, do we?

> +corresponding typedef.
> +
> +Since certain C compilers choke on duplicated typedefs, you should avoid
> +them and declare a typedef only in one header file.  For common types,
> +you can use "include/qemu/typedefs.h" for example.  However, as a matter
> +of convenience it is also perfectly fine to use forward struct
> +definitions instead of typedefs in headers and function prototypes; this
> +avoids problems with duplicated typedefs and reduces the need to include
> +headers from other headers.

Reviewed-by: Thomas Huth <address@hidden>