28/03/2025 11:52, David Marchand:
> --- a/lib/eal/common/eal_symbol_exports.h
> +++ b/lib/eal/common/eal_symbol_exports.h
> @@ -5,6 +5,8 @@
> #ifndef EAL_SYMBOL_EXPORTS_H
> #define EAL_SYMBOL_EXPORTS_H
>
> +#include <rte_common.h>
> +
> /* Internal macros for exporting symbols, used by the build system.
> * For RTE_EXPORT_EXPERIMENTAL_SYMBOL, ver indicates the
> * version this symbol was introduced in.
> @@ -13,4 +15,68 @@
> #define RTE_EXPORT_INTERNAL_SYMBOL(a)
> #define RTE_EXPORT_SYMBOL(a)
>
> +#if !defined(RTE_USE_FUNCTION_VERSIONING) && (defined(RTE_CC_GCC) ||
> defined(RTE_CC_CLANG))
> +#define VERSIONING_WARN RTE_PRAGMA_WARNING(Use of function versioning
> disabled. \
> + Is "use_function_versioning=true" in meson.build?)
> +#else
> +#define VERSIONING_WARN
> +#endif
Why no warning for other compilers?
Why not warn at Meson level?
> +
> +/*
> + * Provides backwards compatibility when updating exported functions.
I feel a word is missing. What "provides" it?
> + * When a symbol is exported from a library to provide an API, it also
> provides a
> + * calling convention (ABI) that is embodied in its name, return type,
> + * arguments, etc. On occasion that function may need to change to
> accommodate
> + * new functionality, behavior, etc. When that occurs, it is desirable to
> + * allow for backwards compatibility for a time with older binaries that are
> + * dynamically linked to the dpdk.
> + */
> +
> +#ifdef RTE_BUILD_SHARED_LIB
> +
> +/*
Why not Doxygen style?
> + * RTE_VERSION_SYMBOL
No need to repeat the macro name here.
> + * Creates a symbol version table entry binding symbol <name>@DPDK_<ver> to
> the internal
Imperative form is more usual.
> + * function name <name>_v<ver>.
> + */
> +#define RTE_VERSION_SYMBOL(ver, type, name, args) VERSIONING_WARN \
> +__asm__(".symver " RTE_STR(name) "_v" RTE_STR(ver) ", " RTE_STR(name)
> "@DPDK_" RTE_STR(ver)); \
> +__rte_used type name ## _v ## ver args; \
> +type name ## _v ## ver args
This is only GNU style. It should be highlighted both in this file and the
commit log.
> +
> +/*
> + * RTE_VERSION_EXPERIMENTAL_SYMBOL
> + * Similar to RTE_VERSION_SYMBOL but for experimental API symbols.
> + * This is mainly used for keeping compatibility for symbols that get
> promoted to stable ABI.
> + */
> +#define RTE_VERSION_EXPERIMENTAL_SYMBOL(type, name, args) VERSIONING_WARN \
> +__asm__(".symver " RTE_STR(name) "_exp, " RTE_STR(name) "@EXPERIMENTAL") \
> +__rte_used type name ## _exp args; \
> +type name ## _exp args
> +
> +/*
> + * RTE_DEFAULT_SYMBOL
> + * Creates a symbol version entry instructing the linker to bind references
> to
> + * symbol <name> to the internal symbol <name>_v<ver>.
> + */
> +#define RTE_DEFAULT_SYMBOL(ver, type, name, args) VERSIONING_WARN \
> +__asm__(".symver " RTE_STR(name) "_v" RTE_STR(ver) ", " RTE_STR(name)
> "@@DPDK_" RTE_STR(ver)); \
> +__rte_used type name ## _v ## ver args; \
> +type name ## _v ## ver args
Only 3 macros, that's simple and clean, thank you.
