# \[PATCH\] include/uapi/linux/swab.h: define a silent macro to avoid sparse error

- Subsystems: THE REST
- Maintainers: Linus Torvalds
- List: linux-api
- 2 messages, 2 authors
- Page: https://ratatoskr.run/linux-api/2015/06/4515633/t

## \[PATCH\] include/uapi/linux/swab.h: define a silent macro to avoid sparse error

- From: Bilel DRIRA \<hidden\>
- Date: 2015-06-14 22:24:21 
- Message: https://ratatoskr.run/linux-api/2015/06/4515633.md

```text
define a silent macro when _CHECKER_ is defined.
This change fixes the following sparse errors:

include/uapi/linux/swab.h:60:16: error: undefined identifier '__builtin_bswap32'
include/uapi/linux/swab.h:60:33: error: not a function <noident>
include/uapi/linux/swab.h:71:16: error: undefined identifier '__builtin_bswap64'
include/uapi/linux/swab.h:71:33: error: not a function <noident>
include/uapi/linux/swab.h:60:33: error: not a function <noident>

Signed-off-by: Bilel DRIRA <redacted>
---
 include/uapi/linux/swab.h |   12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/include/uapi/linux/swab.h b/include/uapi/linux/swab.h
index 0e011eb..c04de49 100644
--- a/include/uapi/linux/swab.h
+++ b/include/uapi/linux/swab.h
@@ -5,6 +5,18 @@
 #include <linux/compiler.h>
 #include <asm/swab.h>
 
+#ifdef __CHECKER__
+
+#ifdef __HAVE_BUILTIN_BSWAP64__
+#define __builtin_bswap64(val) (0)
+#endif
+
+#ifdef __HAVE_BUILTIN_BSWAP32__
+#define __builtin_bswap32(val) (0)
+#endif
+
+#endif	/* __CHECKER__ */
+
 /*
  * casts are necessary for constants, because we never know how for sure
  * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way.
-- 
1.7.9.5
```

## Re: \[PATCH\] include/uapi/linux/swab.h: define a silent macro to avoid sparse error

- From: Greg KH \<hidden\>
- Date: 2015-06-15 23:06:43 
- Message: https://ratatoskr.run/linux-api/2015/06/4516322.md

```text
On Sun, Jun 14, 2015 at 11:23:32PM +0100, Bilel DRIRA wrote:
> define a silent macro when _CHECKER_ is defined.
> This change fixes the following sparse errors:
> 
> include/uapi/linux/swab.h:60:16: error: undefined identifier '__builtin_bswap32'
> include/uapi/linux/swab.h:60:33: error: not a function <noident>
> include/uapi/linux/swab.h:71:16: error: undefined identifier '__builtin_bswap64'
> include/uapi/linux/swab.h:71:33: error: not a function <noident>
> include/uapi/linux/swab.h:60:33: error: not a function <noident>
> 
> Signed-off-by: Bilel DRIRA <redacted>
> ---
>  include/uapi/linux/swab.h |   12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/include/uapi/linux/swab.h b/include/uapi/linux/swab.h
> index 0e011eb..c04de49 100644
> --- a/include/uapi/linux/swab.h
> +++ b/include/uapi/linux/swab.h
> @@ -5,6 +5,18 @@
>  #include <linux/compiler.h>
>  #include <asm/swab.h>
>  
> +#ifdef __CHECKER__
> +
> +#ifdef __HAVE_BUILTIN_BSWAP64__
> +#define __builtin_bswap64(val) (0)
> +#endif
> +
> +#ifdef __HAVE_BUILTIN_BSWAP32__
> +#define __builtin_bswap32(val) (0)
> +#endif
> +
> +#endif	/* __CHECKER__ */

Shouldn't the tool be fixed instead of papering over the issue with
random defines like this?

thanks,

greg k-h
```