[Qemu-devel] [PATCH for 1.7] qga: Fix compiler warnings (missing gnu_printf format attribute, wrong format string)

[Qemu-devel] [PATCH for 1.7] qga: Fix compiler warnings (missing gnu_printf format attribute, wrong format string)

[Stefan Weil]

gcc 4.8.2 reports this warning when extra warnings are enabled (-Wextra):

  CC    qga/commands.o
qga/commands.c: In function ‘slog’:
qga/commands.c:28:5: error:
 function might be possible candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format]
     g_logv("syslog", G_LOG_LEVEL_INFO, fmt, ap);
     ^

gcc 4.8.2 reports this warning when slog is declared with the
gnu_printf format attribute:

qga/commands-posix.c: In function ‘qmp_guest_file_open’:
qga/commands-posix.c:404:5: warning:
 format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘int64_t’ [-Wformat=]
     slog("guest-file-open, handle: %d", handle);
     ^

Signed-off-by: Stefan Weil <sw@weilnetz.de>
---

Note: checkpatch.pl wrongly reports an error.

 qga/commands-posix.c   |    2 +-
 qga/guest-agent-core.h |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index f453132..182279d 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -401,7 +401,7 @@ int64_t qmp_guest_file_open(const char *path, bool has_mode, const char *mode, E
         return -1;
     }
 
-    slog("guest-file-open, handle: %d", handle);
+    slog("guest-file-open, handle: %" PRId64, handle);
     return handle;
 }
 
diff --git a/qga/guest-agent-core.h b/qga/guest-agent-core.h
index 624a559..95721eb 100644
--- a/qga/guest-agent-core.h
+++ b/qga/guest-agent-core.h
@@ -29,7 +29,7 @@ GACommandState *ga_command_state_new(void);
 bool ga_logging_enabled(GAState *s);
 void ga_disable_logging(GAState *s);
 void ga_enable_logging(GAState *s);
-void slog(const gchar *fmt, ...);
+void GCC_FMT_ATTR(1, 2) slog(const gchar *fmt, ...);
 void ga_set_response_delimited(GAState *s);
 bool ga_is_frozen(GAState *s);
 void ga_set_frozen(GAState *s);
-- 
1.7.10.4

Re: [Qemu-devel] [PATCH for 1.7] qga: Fix compiler warnings (missing gnu_printf format attribute, wrong format string)

[Stefan Weil]

This patch is superseded by a new one.

v2 fixes three more format strings and is needed for 32 bit hosts.

Stefan


Am 17.11.2013 19:01, schrieb Stefan Weil:
> gcc 4.8.2 reports this warning when extra warnings are enabled (-Wextra):
>
>   CC    qga/commands.o
> qga/commands.c: In function ‘slog’:
> qga/commands.c:28:5: error:
>  function might be possible candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format]
>      g_logv("syslog", G_LOG_LEVEL_INFO, fmt, ap);
>      ^
>
> gcc 4.8.2 reports this warning when slog is declared with the
> gnu_printf format attribute:
>
> qga/commands-posix.c: In function ‘qmp_guest_file_open’:
> qga/commands-posix.c:404:5: warning:
>  format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘int64_t’ [-Wformat=]
>      slog("guest-file-open, handle: %d", handle);
>      ^
>
> Signed-off-by: Stefan Weil <sw@weilnetz.de>
> ---
>
> Note: checkpatch.pl wrongly reports an error.
>
>  qga/commands-posix.c   |    2 +-
>  qga/guest-agent-core.h |    2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
>