[Qemu-devel] [PATCH for 1.7 v2] qga: Fix compiler warnings (missing format attribute, wrong format strings)

[Qemu-devel] [PATCH for 1.7 v2] qga: Fix compiler warnings (missing format attribute, wrong format strings)

[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);
     ^

On 32 bit hosts there are three more warnings which are also fixed here.

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

v2: Fix three more wrong format strings for 32 bit hosts.

 qga/commands-posix.c   |    8 ++++----
 qga/guest-agent-core.h |    2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index 10682f5..8100bee 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;
 }
 
@@ -410,7 +410,7 @@ void qmp_guest_file_close(int64_t handle, Error **err)
     GuestFileHandle *gfh = guest_file_handle_find(handle, err);
     int ret;
 
-    slog("guest-file-close called, handle: %ld", handle);
+    slog("guest-file-close called, handle: %" PRId64, handle);
     if (!gfh) {
         return;
     }
@@ -451,7 +451,7 @@ struct GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,
     read_count = fread(buf, 1, count, fh);
     if (ferror(fh)) {
         error_setg_errno(err, errno, "failed to read file");
-        slog("guest-file-read failed, handle: %ld", handle);
+        slog("guest-file-read failed, handle: %" PRId64, handle);
     } else {
         buf[read_count] = 0;
         read_data = g_malloc0(sizeof(GuestFileRead));
@@ -496,7 +496,7 @@ GuestFileWrite *qmp_guest_file_write(int64_t handle, const char *buf_b64,
     write_count = fwrite(buf, 1, count, fh);
     if (ferror(fh)) {
         error_setg_errno(err, errno, "failed to write to file");
-        slog("guest-file-write failed, handle: %ld", handle);
+        slog("guest-file-write failed, handle: %" PRId64, handle);
     } else {
         write_data = g_malloc0(sizeof(GuestFileWrite));
         write_data->count = write_count;
diff --git a/qga/guest-agent-core.h b/qga/guest-agent-core.h
index 624a559..e422208 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);
-- 
1.7.9.5

Re: [Qemu-devel] [PATCH for 1.7 v2] qga: Fix compiler warnings (missing format attribute, wrong format strings)

[Stefan Weil]

Please note that this patch fixes real bugs, namely wrong format strings.

As far as I could see those bugs are only in code branches which handle
rare error conditions, so maybe they only have a low priority.
Nevertheless they can be fixed in QEMU 1.7.

Do we need a pull request, or can it be applied directly?

Stefan


Am 17.11.2013 19:19, 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);
>      ^
>
> On 32 bit hosts there are three more warnings which are also fixed here.
>
> Signed-off-by: Stefan Weil <sw@weilnetz.de>
> ---
>
> v2: Fix three more wrong format strings for 32 bit hosts.
>
>  qga/commands-posix.c   |    8 ++++----
>  qga/guest-agent-core.h |    2 +-
>  2 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/qga/commands-posix.c b/qga/commands-posix.c
> index 10682f5..8100bee 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;
>  }
>  
> @@ -410,7 +410,7 @@ void qmp_guest_file_close(int64_t handle, Error **err)
>      GuestFileHandle *gfh = guest_file_handle_find(handle, err);
>      int ret;
>  
> -    slog("guest-file-close called, handle: %ld", handle);
> +    slog("guest-file-close called, handle: %" PRId64, handle);
>      if (!gfh) {
>          return;
>      }
> @@ -451,7 +451,7 @@ struct GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,
>      read_count = fread(buf, 1, count, fh);
>      if (ferror(fh)) {
>          error_setg_errno(err, errno, "failed to read file");
> -        slog("guest-file-read failed, handle: %ld", handle);
> +        slog("guest-file-read failed, handle: %" PRId64, handle);
>      } else {
>          buf[read_count] = 0;
>          read_data = g_malloc0(sizeof(GuestFileRead));
> @@ -496,7 +496,7 @@ GuestFileWrite *qmp_guest_file_write(int64_t handle, const char *buf_b64,
>      write_count = fwrite(buf, 1, count, fh);
>      if (ferror(fh)) {
>          error_setg_errno(err, errno, "failed to write to file");
> -        slog("guest-file-write failed, handle: %ld", handle);
> +        slog("guest-file-write failed, handle: %" PRId64, handle);
>      } else {
>          write_data = g_malloc0(sizeof(GuestFileWrite));
>          write_data->count = write_count;
> diff --git a/qga/guest-agent-core.h b/qga/guest-agent-core.h
> index 624a559..e422208 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);

Re: [Qemu-devel] [Qemu-trivial] [PATCH for 1.7 v2] qga: Fix compiler warnings (missing format attribute, wrong format strings)

[Michael Tokarev]

17.11.2013 22:19, Stefan Weil wrote:
> 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);
>      ^
> 
> On 32 bit hosts there are three more warnings which are also fixed here.
> 
> Signed-off-by: Stefan Weil <sw@weilnetz.de>
> ---
> 
> v2: Fix three more wrong format strings for 32 bit hosts.

Thanks, applied to the trivial-patches queue.

/mjt