On Wed, 4 Nov 2015 11:24:18 +0100
Adrien Mazarguil <adrien.mazarguil at 6wind.com> wrote:
> On Wed, Nov 04, 2015 at 02:19:36AM +0100, Thomas Monjalon wrote:
> > 2015-11-03 12:00, Bruce Richardson:
> > > Move the function ptr and port id checking macros to the header file, so
> > > that they can be used in the static inline functions there. In doxygen
> > > comments, mark them as for internal use only.
> > [...]
> > > +/**
> > > + * @internal
> > > + * Macro to print a message if in debugging mode
> > > + */
> > > +#ifdef RTE_LIBRTE_ETHDEV_DEBUG
> > > +#define RTE_PMD_DEBUG_TRACE(fmt, args...) \
> > > + RTE_LOG(ERR, PMD, "%s: " fmt, __func__, ## args)
> > > +#else
> > > +#define RTE_PMD_DEBUG_TRACE(fmt, args...)
> > > +#endif
> >
> > It does not compile because Mellanox drivers are pedantic:
> >
> > In file included from
> > /home/thomas/projects/dpdk/dpdk/drivers/net/mlx4/mlx4.c:78:0:
> > /home/thomas/projects/dpdk/dpdk/x86_64-native-linuxapp-gcc-shared-next/include/rte_ethdev.h:
> > At top level:
> > /home/thomas/projects/dpdk/dpdk/x86_64-native-linuxapp-gcc-shared-next/include/rte_ethdev.h:933:38:
> > error: ISO C does not permit named variadic macros
> > [-Werror=variadic-macros]
> > #define RTE_PMD_DEBUG_TRACE(fmt, args...) \
>
> I suggest something like the following definitions as a pedantic-proof and
> standard compliant method (one drawback being that it cannot be done with a
> single macro), see PMD_DRV_LOG() in drivers/net/mlx5/mlx5_utils.h which also
> automatically appends a line feed:
>
> #ifdef RTE_LIBRTE_ETHDEV_DEBUG
>
> #define STRIP(a, b) a
> #define OPAREN (
> #define CPAREN )
> #define COMMA ,
>
> #define RTE_PMD_DEBUG_TRACE(...) \
> RTE_PMD_DEBUG_TRACE_(__VA_ARGS__ STRIP OPAREN, CPAREN)
>
> #define RTE_PMD_DEBUG_TRACE_(fmt, ...) \
> RTE_PMD_DEBUG_TRACE__(fmt COMMA __func__, __VA_ARGS__)
>
> #define RTE_PMD_DEBUG_TRACE__(...) \
> RTE_LOG(ERR, PMD, "%s: " __VA_ARGS__)
>
> #else /* RTE_LIBRTE_ETHDEV_DEBUG */
>
> #define RTE_PMD_DEBUG_TRACE(...)
>
> #endif /* RTE_LIBRTE_ETHDEV_DEBUG */
>
> STRIP() and other helper macros are used to manage the dangling comma issue
> when __VA_ARGS__ is empty as in the first call below:
>
> RTE_PMD_DEBUG_TRACE("foo\n");
> RTE_PMD_DEBUG_TRACE("foo %u\n", 42);
That solution is really ugly.
Why not do something that keeps the expected checks.
diff --git a/lib/librte_eal/common/include/rte_log.h
b/lib/librte_eal/common/include/rte_log.h
index ede0dca..f3a3d34 100644
--- a/lib/librte_eal/common/include/rte_log.h
+++ b/lib/librte_eal/common/include/rte_log.h
@@ -99,6 +99,8 @@ extern struct rte_logs rte_logs;
#define RTE_LOG_INFO 7U /**< Informational. */
#define RTE_LOG_DEBUG 8U /**< Debug-level messages. */
+#define RTE_LOG_DISABLED 99U /**< Never printed */
+
/** The default log stream. */
extern FILE *eal_default_log_stream;
diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
index eee1194..e431f2e 100644
--- a/lib/librte_ether/rte_ethdev.h
+++ b/lib/librte_ether/rte_ethdev.h
@@ -931,6 +931,61 @@ struct rte_eth_dev_callback;
/** @internal Structure to keep track of registered callbacks */
TAILQ_HEAD(rte_eth_dev_cb_list, rte_eth_dev_callback);
+/**
+ * @internal
+ * Macro to print a message if in debugging mode
+ */
+#ifdef RTE_LIBRTE_ETHDEV_DEBUG
+#define RTE_PMD_DEBUG_TRACE(fmt, args...) \
+ RTE_LOG(ERR, PMD, "%s: " fmt, __func__, ## args)
+#else
+#define RTE_PMD_DEBUG_TRACE(fmt, args...) \
+ RTE_LOG(DISABLED, PMD, "%s: " fmt, __func__, ## args)
+#endif
