[dpdk-dev] [PATCH v4 1/7] eal: introduce portable format attribute

[Thomas Monjalon]

27/02/2020 05:25, Dmitry Kozlyuk:
> When using __attribute__((format(...)) on functions, GCC on Windows
> assumes MS-specific format string by default, even if the underlying
> stdio implementation is ANSI-compliant (either MS Unicersal CRT
> or MinGW implementation). Wrap attribute into a macro that forces
> GNU-specific format string when using GCC.
> 
> Use this new attribute for logging and panic messages in EAL
> and for output strings in cmdline library.
> 
> Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk at gmail.com>
> ---
> +/**
> + * Check format string and its arguments at compile-time.
> + *
> + * GCC on Windows assumes MS-specific format string by default,
> + * even if the underlying stdio implementation is ANSI-compliant,
> + * so this must be overridden.
> + */
> +#if defined(RTE_TOOLCHAIN_GCC)
> +#define __rte_format_printf(format_index, first_arg) \
> +	__attribute__((format(gnu_printf, format_index, first_arg)))
> +#else
> +#define __rte_format_printf(format_index, first_arg) \
> +	__attribute__((format(printf, format_index, first_arg)))
> +#endif

It does not work when compiling pmdinfogen with clang and drivers with gcc.

I suggest this change (I can send a patch fixing the issue in other .h files):

+/*
+ * RTE_TOOLCHAIN_GCC is true if the target is built with GCC,
+ * while a host application (like pmdinfogen) may have another compiler.
+ * RTE_CC_IS_GNU is true if the file is compiled with GCC,
+ * no matter it is a target or host application.
+ */
+#if defined __GNUC__ && !defined __clang__ && !defined __INTEL_COMPILER
+#define RTE_CC_IS_GNU
+#endif
+
+#ifdef RTE_CC_IS_GNU
-/** Define GCC_VERSION **/
-#ifdef RTE_TOOLCHAIN_GCC
 #define GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + \
                __GNUC_PATCHLEVEL__)
 #endif
@@ -96,7 +105,7 @@ typedef uint16_t unaligned_uint16_t;
  * even if the underlying stdio implementation is ANSI-compliant,
  * so this must be overridden.
  */
-#if defined(RTE_TOOLCHAIN_GCC)
+#ifdef RTE_CC_IS_GNU
 #define __rte_format_printf(format_index, first_arg) \
        __attribute__((format(gnu_printf, format_index, first_arg)))
 #else