* 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.

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 */