[PATCH 01/19] xmon: Use __printf markup to silence compiler

[Mathieu Malaterre]

Update also the other prototype declaration in asm/xmon.h.

Silence warnings (triggered at W=1) by adding relevant __printf attribute.
Move #define at bottom of the file to prevent conflict with gcc attribute.

  CC      arch/powerpc/xmon/nonstdio.o
arch/powerpc/xmon/nonstdio.c: In function ‘xmon_printf’:
arch/powerpc/xmon/nonstdio.c:178:2: error: function might be possible candidate 
for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format]
  n = vsnprintf(xmon_outbuf, sizeof(xmon_outbuf), format, args);
  ^
cc1: all warnings being treated as errors

Signed-off-by: Mathieu Malaterre <ma...@debian.org>
---
 arch/powerpc/include/asm/xmon.h | 2 +-
 arch/powerpc/xmon/nonstdio.h    | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/xmon.h b/arch/powerpc/include/asm/xmon.h
index eb42a0c6e1d9..30ff69bd8f43 100644
--- a/arch/powerpc/include/asm/xmon.h
+++ b/arch/powerpc/include/asm/xmon.h
@@ -29,7 +29,7 @@ static inline void xmon_register_spus(struct list_head *list) 
{ };
 extern int cpus_are_in_xmon(void);
 #endif
 
-extern void xmon_printf(const char *format, ...);
+extern __printf(1, 2) void xmon_printf(const char *format, ...);
 
 #endif /* __KERNEL __ */
 #endif /* __ASM_POWERPC_XMON_H */
diff --git a/arch/powerpc/xmon/nonstdio.h b/arch/powerpc/xmon/nonstdio.h
index 2202ec61972c..e8deac6c84e2 100644
--- a/arch/powerpc/xmon/nonstdio.h
+++ b/arch/powerpc/xmon/nonstdio.h
@@ -1,13 +1,13 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #define EOF    (-1)
 
-#define printf xmon_printf
-#define putchar        xmon_putchar
-
 extern void xmon_set_pagination_lpp(unsigned long lpp);
 extern void xmon_start_pagination(void);
 extern void xmon_end_pagination(void);
 extern int xmon_putchar(int c);
 extern void xmon_puts(const char *);
 extern char *xmon_gets(char *, int);
-extern void xmon_printf(const char *, ...);
+extern __printf(1, 2) void xmon_printf(const char *fmt, ...);
+
+#define printf xmon_printf
+#define putchar        xmon_putchar
-- 
2.11.0