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Subject[PATCH] iavf: Use printf instead of gnu_printf for iavf_debug_d
Date
Clang warns:

In file included from drivers/net/ethernet/intel/iavf/iavf_main.c:4:
In file included from drivers/net/ethernet/intel/iavf/iavf.h:37:
In file included from drivers/net/ethernet/intel/iavf/iavf_type.h:8:
drivers/net/ethernet/intel/iavf/iavf_osdep.h:49:18: warning: 'format' attribute argument not supported: gnu_printf [-Wignored-attributes]
__attribute__ ((format(gnu_printf, 3, 4)));
^
1 warning generated.

We can convert from gnu_printf to printf without any side effects for
two reasons:

1. All iavf_debug instances use standard printf formats, as pointed out
by Miguel Ojeda at the below link, meaning gnu_printf is not strictly
required.

2. However, GCC has aliased printf to gnu_printf on Linux since at least
2010 based on git history.

From gcc/c-family/c-format.c:

/* Attributes such as "printf" are equivalent to those such as
"gnu_printf" unless this is overridden by a target. */
static const target_ovr_attr gnu_target_overrides_format_attributes[] =
{
{ "gnu_printf", "printf" },
{ "gnu_scanf", "scanf" },
{ "gnu_strftime", "strftime" },
{ "gnu_strfmon", "strfmon" },
{ NULL, NULL }
};

The mentioned override only happens on Windows (mingw32). Changing from
gnu_printf to printf is a no-op for GCC and stops Clang from warning.

Link: https://github.com/ClangBuiltLinux/linux/issues/111
Suggested-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
drivers/net/ethernet/intel/iavf/iavf_osdep.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/iavf/iavf_osdep.h b/drivers/net/ethernet/intel/iavf/iavf_osdep.h
index e6e0b0328706..c90cafb526d0 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_osdep.h
+++ b/drivers/net/ethernet/intel/iavf/iavf_osdep.h
@@ -46,7 +46,7 @@ struct iavf_virt_mem {

#define iavf_debug(h, m, s, ...) iavf_debug_d(h, m, s, ##__VA_ARGS__)
extern void iavf_debug_d(void *hw, u32 mask, char *fmt_str, ...)
- __attribute__ ((format(gnu_printf, 3, 4)));
+ __printf(3, 4);

typedef enum iavf_status_code iavf_status;
#endif /* _IAVF_OSDEP_H_ */
--
2.20.1
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