diff mbox series

[v4,11/14] log: add a per line log helper

Message ID	20231218143805.1500121-12-david.marchand@redhat.com (mailing list archive)
State	Superseded, archived
Delegated to:	Thomas Monjalon
Headers	From: David Marchand <david.marchand@redhat.com> To: dev@dpdk.org Cc: thomas@monjalon.net, ferruh.yigit@amd.com, bruce.richardson@intel.com, stephen@networkplumber.org, mb@smartsharesystems.com, Chengwen Feng <fengchengwen@huawei.com> Subject: [PATCH v4 11/14] log: add a per line log helper Date: Mon, 18 Dec 2023 15:38:00 +0100 Message-ID: <20231218143805.1500121-12-david.marchand@redhat.com> In-Reply-To: <20231218143805.1500121-1-david.marchand@redhat.com> References: <20231117131824.1977792-1-david.marchand@redhat.com> <20231218143805.1500121-1-david.marchand@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII"; x-default=true Precedence: list Errors-To: dev-bounces@dpdk.org
Series	Detect superfluous newline in logs \| [v4,00/14] Detect superfluous newline in logs [v4,01/14] hash: remove some dead code [v4,02/14] regexdev: fix logtype register [v4,03/14] lib: use dedicated logtypes and macros [v4,04/14] lib: add newline in logs [v4,05/14] lib: remove redundant newline from logs [v4,06/14] eal/linux: remove log paraphrasing the doc [v4,07/14] bpf: remove log level in internal helper [v4,08/14] lib: simplify multilines log messages [v4,09/14] rcu: introduce a logging helper [v4,10/14] vhost: improve log for memory dumping configuration [v4,11/14] log: add a per line log helper [v4,12/14] lib: convert to per line logging [v4,13/14] lib: replace logging helpers [v4,14/14] lib: use per line logging in helpers

Checks

Context	Check	Description
ci/checkpatch	success	coding style OK

Commit Message

David Marchand Dec. 18, 2023, 2:38 p.m. UTC

  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

Thomas Monjalon Dec. 19, 2023, 3:45 p.m. UTC | #1

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.

Stephen Hemminger Dec. 19, 2023, 5:16 p.m. UTC | #2

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

David Marchand Dec. 20, 2023, 8:26 a.m. UTC | #3

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.

diff mbox series

Patch

diff --git a/devtools/checkpatches.sh b/devtools/checkpatches.sh
index 10b79ca2bc..10d1bf490b 100755
--- a/devtools/checkpatches.sh
+++ b/devtools/checkpatches.sh
@@ -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" \
diff --git a/lib/log/rte_log.h b/lib/log/rte_log.h
index 3394746103..637e9dcc9a 100644
--- a/lib/log/rte_log.h
+++ b/lib/log/rte_log.h
@@ -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)							    \