numam-dpdk/lib/librte_compat/rte_compat.h
Neil Horman 7317af97f9 compat: relicense some files
Received a note the other day from the Linux Foundation governance board
for DPDK indicating that several files I have copyright on need to be
relicensed to be compliant with the DPDK licensing guidelines.  I have
some concerns with some parts of the request, but am not opposed to
other parts.  So, for those pieces that we are in consensus on, I'm
proposing that we change their license from BSD 2 clause to 3 clause.
I'm also updating the files to use the SPDX licensing scheme

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>
2018-02-06 23:13:47 +01:00

93 lines
3.0 KiB
C

/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2015 Neil Horman <nhorman@tuxdriver.com>.
* All rights reserved.
*/
#ifndef _RTE_COMPAT_H_
#define _RTE_COMPAT_H_
#include <rte_common.h>
#ifdef RTE_BUILD_SHARED_LIB
/*
* Provides backwards compatibility when updating exported functions.
* When a symol 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. To support that, the __vsym and
* VERSION_SYMBOL macros are created. They, in conjunction with the
* <library>_version.map file for a given library allow for multiple versions of
* a symbol to exist in a shared library so that older binaries need not be
* immediately recompiled.
*
* Refer to the guidelines document in the docs subdirectory for details on the
* use of these macros
*/
/*
* Macro Parameters:
* b - function base name
* e - function version extension, to be concatenated with base name
* n - function symbol version string to be applied
* f - function prototype
* p - full function symbol name
*/
/*
* VERSION_SYMBOL
* Creates a symbol version table entry binding symbol <b>@DPDK_<n> to the internal
* function name <b>_<e>
*/
#define VERSION_SYMBOL(b, e, n) __asm__(".symver " RTE_STR(b) RTE_STR(e) ", " RTE_STR(b) "@DPDK_" RTE_STR(n))
/*
* BIND_DEFAULT_SYMBOL
* Creates a symbol version entry instructing the linker to bind references to
* symbol <b> to the internal symbol <b>_<e>
*/
#define BIND_DEFAULT_SYMBOL(b, e, n) __asm__(".symver " RTE_STR(b) RTE_STR(e) ", " RTE_STR(b) "@@DPDK_" RTE_STR(n))
#define __vsym __attribute__((used))
/*
* MAP_STATIC_SYMBOL
* If a function has been bifurcated into multiple versions, none of which
* are defined as the exported symbol name in the map file, this macro can be
* used to alias a specific version of the symbol to its exported name. For
* example, if you have 2 versions of a function foo_v1 and foo_v2, where the
* former is mapped to foo@DPDK_1 and the latter is mapped to foo@DPDK_2 when
* building a shared library, this macro can be used to map either foo_v1 or
* foo_v2 to the symbol foo when building a static library, e.g.:
* MAP_STATIC_SYMBOL(void foo(), foo_v2);
*/
#define MAP_STATIC_SYMBOL(f, p)
#else
/*
* No symbol versioning in use
*/
#define VERSION_SYMBOL(b, e, n)
#define __vsym
#define BIND_DEFAULT_SYMBOL(b, e, n)
#define MAP_STATIC_SYMBOL(f, p) f __attribute__((alias(RTE_STR(p))))
/*
* RTE_BUILD_SHARED_LIB=n
*/
#endif
#ifndef ALLOW_EXPERIMENTAL_API
#define __rte_experimental \
__attribute__((deprecated("Symbol is not yet part of stable ABI"), \
section(".text.experimental")))
#else
#define __rte_experimental \
__attribute__((section(".text.experimental")))
#endif
#endif /* _RTE_COMPAT_H_ */