[Spice-devel] [PATCH] RFC: Allow multiple typedefs

[Frediano Ziglio]

> 
> Since recent version of GCC allow multiple typedefs of the same name as
> long as it refers to the same type, we can avoid some of the
> typedef/header issues if we just decide to require a version of gcc that
> allows this behavior. This is also valid according ot the C11 standard.
> I don't know exactly what version of gcc started to support this, and
> it's likely that it won't be backward compatible to e.g. RHEL6. If we
> want to support older compilers we'd have to find a different solution,
> but I present this here for discussion.

I supposed this patch would be better looking than other solutions
however the other solution were all based on not having multiple
type definitions.

Could we use a backported gcc on rhel6 ?
I remember for rhel5 there was an official gcc44 package you
could install to get a newer compiler, maybe we can use it
to support multiple typedefs on rhel6.

Frediano


> ---
>  server/dcc-encoders.h        | 1 +
>  server/display-channel.h     | 2 ++
>  server/image-cache.h         | 2 --
>  server/main-channel-client.h | 1 -
>  server/stream.h              | 3 +--
>  5 files changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/server/dcc-encoders.h b/server/dcc-encoders.h
> index 84f9f93..07effa2 100644
> --- a/server/dcc-encoders.h
> +++ b/server/dcc-encoders.h
> @@ -32,6 +32,7 @@
>  #endif
>  #include "zlib-encoder.h"
>  
> +typedef struct DisplayChannelClient DisplayChannelClient;
>  typedef struct RedCompressBuf RedCompressBuf;
>  typedef struct GlzDrawableInstanceItem GlzDrawableInstanceItem;
>  typedef struct RedGlzDrawable RedGlzDrawable;
> diff --git a/server/display-channel.h b/server/display-channel.h
> index 647d8c0..2332acf 100644
> --- a/server/display-channel.h
> +++ b/server/display-channel.h
> @@ -52,6 +52,7 @@ typedef struct DependItem {
>      RingItem ring_item;
>  } DependItem;
>  
> +typedef struct Drawable Drawable;
>  struct Drawable {
>      uint8_t refs;
>      RingItem surface_list_link;
> @@ -166,6 +167,7 @@ struct _Drawable {
>      } u;
>  };
>  
> +typedef struct DisplayChannel DisplayChannel;
>  struct DisplayChannel {
>      CommonGraphicsChannel common; // Must be the first thing
>      uint32_t bits_unique;
> diff --git a/server/image-cache.h b/server/image-cache.h
> index 38a318e..4a828d0 100644
> --- a/server/image-cache.h
> +++ b/server/image-cache.h
> @@ -23,9 +23,7 @@
>  #include <common/canvas_base.h>
>  #include <common/ring.h>
>  
> -/* FIXME: move back to display-channel.h (once structs are private) */
>  typedef struct Drawable Drawable;
> -typedef struct DisplayChannelClient DisplayChannelClient;
>  
>  typedef struct ImageCacheItem {
>      RingItem lru_link;
> diff --git a/server/main-channel-client.h b/server/main-channel-client.h
> index e65a2fb..53b1b98 100644
> --- a/server/main-channel-client.h
> +++ b/server/main-channel-client.h
> @@ -19,7 +19,6 @@
>  
>  #include "red-channel.h"
>  
> -/* FIXME: remove extra MainChannel typedef when possible */
>  typedef struct MainChannel MainChannel;
>  typedef struct MainChannelClient MainChannelClient;
>  
> diff --git a/server/stream.h b/server/stream.h
> index 511d752..b6009bf 100644
> --- a/server/stream.h
> +++ b/server/stream.h
> @@ -42,9 +42,8 @@
>  #define RED_STREAM_DEFAULT_LOW_START_BIT_RATE (2.5 * 1024 * 1024) // 2.5Mbps
>  #define MAX_FPS 30
>  
> -/* move back to display_channel once struct private */
>  typedef struct DisplayChannel DisplayChannel;
> -
> +typedef struct DisplayChannelClient DisplayChannelClient;
>  typedef struct Stream Stream;
>  
>  typedef struct RedStreamActivateReportItem {
> --
> 2.4.11
> 
> _______________________________________________
> Spice-devel mailing list
> Spice-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/spice-devel
>