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Diffstat (limited to 'include/shlib-compat.h')
-rw-r--r-- | include/shlib-compat.h | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/include/shlib-compat.h b/include/shlib-compat.h new file mode 100644 index 0000000000..50fba1b957 --- /dev/null +++ b/include/shlib-compat.h @@ -0,0 +1,61 @@ +/* Macros for managing ABI-compatibility definitions using ELF symbol versions. + Copyright (C) 2000 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#ifndef _SHLIB_COMPAT_H +#define _SHLIB_COMPAT_H 1 + +#if defined HAVE_ELF && defined PIC && defined DO_VERSIONING + +#include <abi-versions.h> /* header generated by abi-versions.awk */ + +/* The file abi-versions.h (generated by scripts/abi-versions.awk) defines + symbols like `ABI_libm_GLIBC_2_0' to either 1 or 0 indicating whether or + not we want to build binary compatibility for e.g. the GLIBC_2.0 version + set into the libm shared object. If this evaluates to zero, then there + is no need to compile in extra code to support this version set where it + has been superseded by a newer version. The compatibility code should + be conditionalized with `#if SHLIB_COMPAT (libm, GLIBC_2_0)'. */ + +#define SHLIB_COMPAT(lib, version) ABI_##lib##_##version + +/* That header also defines symbols like `VERSION_libm_GLIBC_2_1' to + the version set name to use for e.g. symbols first introduced into + libm in the GLIBC_2.1 version. Definitions of symbols with explicit + versions should look like: + versioned_symbol (libm, new_foo, foo, GLIBC_2_1); + This will define the symbol `foo' with the appropriate default version, + i.e. either GLIBC_2.1 or the "earliest version" specified in + shlib-versions if that is newer. */ + +#define versioned_symbol(lib, local, symbol, version) \ + default_symbol_version (local, symbol, VERSION_##lib##_##version) + +#else + +/* Not compiling ELF shared libraries at all, so never any old versions. */ +#define SHLIB_COMPAT(lib, version) 0 + +/* No versions to worry about, just make this the global definition. */ +#define versioned_symbol(lib, local, symbol, version) \ + weak_alias (local, symbol) + +#endif + + +#endif /* shlib-compat.h */ |