[v4,11/14] log: add a per line log helper
Checks
Commit Message
gcc builtin __builtin_strchr can be used as a static assertion to check
whether passed format strings contain a \n.
This can be useful to detect double \n in log messages.
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Chengwen Feng <fengchengwen@huawei.com>
---
Changes since v3:
- fixed some checkpatch complaints,
Changes since RFC v1:
- added a check in checkpatches.sh,
---
devtools/checkpatches.sh | 8 ++++++++
lib/log/rte_log.h | 21 +++++++++++++++++++++
2 files changed, 29 insertions(+)
Comments
18/12/2023 15:38, David Marchand:
> +#ifdef RTE_TOOLCHAIN_GCC
> +#define RTE_LOG_CHECK_NO_NEWLINE(fmt) \
> + static_assert(!__builtin_strchr(fmt, '\n'), \
> + "This log format string contains a \\n")
> +#else
> +#define RTE_LOG_CHECK_NO_NEWLINE(...)
> +#endif
No support in clang?
> +#define RTE_LOG_LINE(l, t, ...) do { \
> + RTE_LOG_CHECK_NO_NEWLINE(RTE_FMT_HEAD(__VA_ARGS__ ,)); \
> + RTE_LOG(l, t, RTE_FMT(RTE_FMT_HEAD(__VA_ARGS__ ,) "\n", \
> + RTE_FMT_TAIL(__VA_ARGS__ ,))); \
> +} while (0)
> +
> +#define RTE_LOG_DP_LINE(l, t, ...) do { \
> + RTE_LOG_CHECK_NO_NEWLINE(RTE_FMT_HEAD(__VA_ARGS__ ,)); \
> + RTE_LOG_DP(l, t, RTE_FMT(RTE_FMT_HEAD(__VA_ARGS__ ,) "\n", \
> + RTE_FMT_TAIL(__VA_ARGS__ ,))); \
> +} while (0)
I don't think we need a space between __VA_ARGS__ and the comma.
On Tue, 19 Dec 2023 16:45:19 +0100
Thomas Monjalon <thomas@monjalon.net> wrote:
> 18/12/2023 15:38, David Marchand:
> > +#ifdef RTE_TOOLCHAIN_GCC
> > +#define RTE_LOG_CHECK_NO_NEWLINE(fmt) \
> > + static_assert(!__builtin_strchr(fmt, '\n'), \
> > + "This log format string contains a \\n")
> > +#else
> > +#define RTE_LOG_CHECK_NO_NEWLINE(...)
> > +#endif
>
> No support in clang?
clang has static assert, but probably not builtin_strchr
On Tue, Dec 19, 2023 at 6:16 PM Stephen Hemminger
<stephen@networkplumber.org> wrote:
>
> On Tue, 19 Dec 2023 16:45:19 +0100
> Thomas Monjalon <thomas@monjalon.net> wrote:
>
> > 18/12/2023 15:38, David Marchand:
> > > +#ifdef RTE_TOOLCHAIN_GCC
> > > +#define RTE_LOG_CHECK_NO_NEWLINE(fmt) \
> > > + static_assert(!__builtin_strchr(fmt, '\n'), \
> > > + "This log format string contains a \\n")
> > > +#else
> > > +#define RTE_LOG_CHECK_NO_NEWLINE(...)
> > > +#endif
> >
> > No support in clang?
>
> clang has static assert, but probably not builtin_strchr
clang seems to have support for __builtin_strchr (which was not
obvious to me when I first looked at it).
Testing with clang ("thanks" to net/mlx4), I realised that this check
relies on some gnu extension (constant folding) which breaks
compilation with -pedantic.
An additional check on PEDANTIC is needed, and I can then add support for clang.
@@ -53,6 +53,14 @@ print_usage () {
check_forbidden_additions() { # <patch>
res=0
+ # refrain from new calls to RTE_LOG
+ awk -v FOLDERS="lib" \
+ -v EXPRESSIONS="RTE_LOG\\\(" \
+ -v RET_ON_FAIL=1 \
+ -v MESSAGE='Prefer RTE_LOG_LINE' \
+ -f $(dirname $(readlink -f $0))/check-forbidden-tokens.awk \
+ "$1" || res=1
+
# refrain from new additions of rte_panic() and rte_exit()
# multiple folders and expressions are separated by spaces
awk -v FOLDERS="lib drivers" \
@@ -17,6 +17,7 @@
extern "C" {
#endif
+#include <assert.h>
#include <stdint.h>
#include <stdio.h>
#include <stdarg.h>
@@ -358,6 +359,26 @@ int rte_vlog(uint32_t level, uint32_t logtype, const char *format, va_list ap)
RTE_LOGTYPE_ ## t, # t ": " __VA_ARGS__) : \
0)
+#ifdef RTE_TOOLCHAIN_GCC
+#define RTE_LOG_CHECK_NO_NEWLINE(fmt) \
+ static_assert(!__builtin_strchr(fmt, '\n'), \
+ "This log format string contains a \\n")
+#else
+#define RTE_LOG_CHECK_NO_NEWLINE(...)
+#endif
+
+#define RTE_LOG_LINE(l, t, ...) do { \
+ RTE_LOG_CHECK_NO_NEWLINE(RTE_FMT_HEAD(__VA_ARGS__ ,)); \
+ RTE_LOG(l, t, RTE_FMT(RTE_FMT_HEAD(__VA_ARGS__ ,) "\n", \
+ RTE_FMT_TAIL(__VA_ARGS__ ,))); \
+} while (0)
+
+#define RTE_LOG_DP_LINE(l, t, ...) do { \
+ RTE_LOG_CHECK_NO_NEWLINE(RTE_FMT_HEAD(__VA_ARGS__ ,)); \
+ RTE_LOG_DP(l, t, RTE_FMT(RTE_FMT_HEAD(__VA_ARGS__ ,) "\n", \
+ RTE_FMT_TAIL(__VA_ARGS__ ,))); \
+} while (0)
+
#define RTE_LOG_REGISTER_IMPL(type, name, level) \
int type; \
RTE_INIT(__##type) \