glibc/include/shlib-compat.h
Roland McGrath 361742eda9 * shlib-versions [USE_IN_LIBIO] (.*-.*-gnu-gnu*): Set earliest
supported version for libc 0.2.90.libio to GLIBC_2.2.

	* Makeconfig (soversions.mk): Grok new third column in shlib-versions,
	and use it to emit new variable `map-firstversions'.
	* scripts/firstversions.awk: New file.
	* Makerules (Versions.all): Use scripts/firstversions.awk and
	the $(map-firstversions) value to generate a modified versions list
	that includes renames in "A = B" syntax for each version set earlier
	than the "earliest symbol version" named in shlib-versions.
	* scripts/versions.awk: Recognize "A = B" lines in the input to mean
	rename version set A to B in the output to the intermediate file.
	* scripts/abi-versions.awk: New file.
	* Makerules (abi-versions.h): New target, generated by that script.
	[$(versioning) = yes] (before-compile): Prepend abi-versions.h.
	* include/shlib-compat.h: New file, uses that generated header.
2000-03-19 20:36:44 +00:00

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C

/* 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 */