tools: bpftool: move "__printf()" attributes to header file

Some functions in bpftool have a "__printf()" format attributes to tell
the compiler they should expect printf()-like arguments. But because
these attributes are not used for the function prototypes in the header
files, the compiler does not run the checks everywhere the functions are
used, and some mistakes on format string and corresponding arguments
slipped in over time.

Let's move the __printf() attributes to the correct places.

Note: We add guards around the definition of GCC_VERSION in
tools/include/linux/compiler-gcc.h to prevent a conflict in jit_disasm.c
on GCC_VERSION from headers pulled via libbfd.

Fixes: c101189bc968 ("tools: bpftool: fix -Wmissing declaration warnings")
Reported-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index 5215e0870bcbaf84e97db8c241260989ed74318f..a7036c70db4858f42ef15bc62981d44a2c87abbc 100644 (file)
--- a/tools/bpf/bpftool/common.c
+++ b/tools/bpf/bpftool/common.c
@@ -29,7 +29,7 @@
 #define BPF_FS_MAGIC           0xcafe4a11
 #endif
 
-void __printf(1, 2) p_err(const char *fmt, ...)
+void p_err(const char *fmt, ...)
 {
        va_list ap;
 
@@ -47,7 +47,7 @@ void __printf(1, 2) p_err(const char *fmt, ...)
        va_end(ap);
 }
 
-void __printf(1, 2) p_info(const char *fmt, ...)
+void p_info(const char *fmt, ...)
 {
        va_list ap;
 

diff --git a/tools/bpf/bpftool/json_writer.c b/tools/bpf/bpftool/json_writer.c
index 6046dcab51cc538b679428def22ff377a6fada7c..86501cd3c763e7fbaff97f1944da70f8b7d67183 100644 (file)
--- a/tools/bpf/bpftool/json_writer.c
+++ b/tools/bpf/bpftool/json_writer.c
@@ -15,7 +15,6 @@
 #include <malloc.h>
 #include <inttypes.h>
 #include <stdint.h>
-#include <linux/compiler.h>
 
 #include "json_writer.h"
 
@@ -153,8 +152,7 @@ void jsonw_name(json_writer_t *self, const char *name)
                putc(' ', self->out);
 }
 
-void __printf(2, 0)
-jsonw_vprintf_enquote(json_writer_t *self, const char *fmt, va_list ap)
+void jsonw_vprintf_enquote(json_writer_t *self, const char *fmt, va_list ap)
 {
        jsonw_eor(self);
        putc('"', self->out);
@@ -162,7 +160,7 @@ jsonw_vprintf_enquote(json_writer_t *self, const char *fmt, va_list ap)
        putc('"', self->out);
 }
 
-void __printf(2, 3) jsonw_printf(json_writer_t *self, const char *fmt, ...)
+void jsonw_printf(json_writer_t *self, const char *fmt, ...)
 {
        va_list ap;
 

diff --git a/tools/bpf/bpftool/json_writer.h b/tools/bpf/bpftool/json_writer.h
index cb9a1993681c6e3997e07343b3d5c9a4a68b9e6e..35cf1f00f96cadb463ad65c725df2d314bfd866c 100644 (file)
--- a/tools/bpf/bpftool/json_writer.h
+++ b/tools/bpf/bpftool/json_writer.h
@@ -14,6 +14,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdarg.h>
+#include <linux/compiler.h>
 
 /* Opaque class structure */
 typedef struct json_writer json_writer_t;
@@ -30,8 +31,9 @@ void jsonw_pretty(json_writer_t *self, bool on);
 void jsonw_name(json_writer_t *self, const char *name);
 
 /* Add value  */
-void jsonw_vprintf_enquote(json_writer_t *self, const char *fmt, va_list ap);
-void jsonw_printf(json_writer_t *self, const char *fmt, ...);
+void __printf(2, 0) jsonw_vprintf_enquote(json_writer_t *self, const char *fmt,
+                                         va_list ap);
+void __printf(2, 3) jsonw_printf(json_writer_t *self, const char *fmt, ...);
 void jsonw_string(json_writer_t *self, const char *value);
 void jsonw_bool(json_writer_t *self, bool value);
 void jsonw_float(json_writer_t *self, double number);

diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index 7031a4bf87a020716df5eb20fa0c641c423de9d7..af9ad56c303a1dff6359c6af2530fcdbf60e6fb4 100644 (file)
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -98,8 +98,8 @@ extern int bpf_flags;
 extern struct pinned_obj_table prog_table;
 extern struct pinned_obj_table map_table;
 
-void p_err(const char *fmt, ...);
-void p_info(const char *fmt, ...);
+void __printf(1, 2) p_err(const char *fmt, ...);
+void __printf(1, 2) p_info(const char *fmt, ...);
 
 bool is_prefix(const char *pfx, const char *str);
 int detect_common_prefix(const char *arg, ...);

diff --git a/tools/include/linux/compiler-gcc.h b/tools/include/linux/compiler-gcc.h
index 0d35f18006a136b4578f2298243e3728a067c272..95c072b70d0e832f70a4ac07470bcd0d1ed46deb 100644 (file)
--- a/tools/include/linux/compiler-gcc.h
+++ b/tools/include/linux/compiler-gcc.h
@@ -6,9 +6,11 @@
 /*
  * Common definitions for all gcc versions go here.
  */
+#ifndef GCC_VERSION
 #define GCC_VERSION (__GNUC__ * 10000          \
                     + __GNUC_MINOR__ * 100     \
                     + __GNUC_PATCHLEVEL__)
+#endif
 
 #if GCC_VERSION >= 70000 && !defined(__CHECKER__)
 # define __fallthrough __attribute__ ((fallthrough))