commit 9f9503b56a8c7566c91d486a67be5d41792a87ca

Author: Florian Weimer <fweimer@redhat.com>

Date:   Wed Jul 13 14:06:00 2016 +0200

    sln: Install as a hard link to ldconfig

    Implementing and sln and ldconfig with the same binary saves

    around 850 KiB from a glibc installation.

    The sln program is implicitly tested during the build, so no test

    case is needed.

Index: b/elf/Makefile

===================================================================

--- a/elf/Makefile

+++ b/elf/Makefile

@@ -97,12 +97,8 @@ install-others	= $(inst_rtlddir)/$(rtld-

 install-bin-script = ldd

 endif

-others		= sprof sln

+others		= sprof

 install-bin	= sprof

-others-static   = sln

-install-rootsbin = sln

-sln-modules	:= static-stubs

-extra-objs	+= $(sln-modules:=.o)

 ifeq (yes,$(use-ldconfig))

 ifeq (yes,$(build-shared))

@@ -110,9 +106,17 @@ others-static	+= ldconfig

 others		+= ldconfig

 install-rootsbin += ldconfig

-ldconfig-modules := cache readlib xmalloc xstrdup chroot_canon static-stubs

+ldconfig-modules := cache readlib xmalloc xstrdup chroot_canon static-stubs sln

 extra-objs	+= $(ldconfig-modules:=.o)

 others-extras   = $(ldconfig-modules)

+

+# Install sln as a hard link to ldconfig.

+install-others-programs += $(inst_rootsbindir)/sln

+others: $(objpfx)sln

+$(objpfx)sln: $(objpfx)ldconfig

+	ln -f $< $@

+$(inst_rootsbindir)/sln: $(inst_rootsbindir)/ldconfig

+	ln -f $< $@

 endif

 endif

@@ -548,8 +552,6 @@ $(objpfx)ldd: ldd.bash.in $(common-objpf

 $(objpfx)sprof: $(libdl)

-$(objpfx)sln: $(sln-modules:%=$(objpfx)%.o)

-

 $(objpfx)ldconfig: $(ldconfig-modules:%=$(objpfx)%.o)

 SYSCONF-FLAGS := -D'SYSCONFDIR="$(sysconfdir)"'

Index: b/elf/ldconfig.c

===================================================================

--- a/elf/ldconfig.c

+++ b/elf/ldconfig.c

@@ -44,6 +44,8 @@

 #include <dl-procinfo.h>

+#include "sln.h"

+

 #ifdef _DL_FIRST_PLATFORM

 # define _DL_FIRST_EXTRA (_DL_FIRST_PLATFORM + _DL_PLATFORMS_COUNT)

 #else

@@ -1285,6 +1287,9 @@ main (int argc, char **argv)

   /* Set the text message domain.  */

   textdomain (_libc_intl_domainname);

+  if (run_sln (argv[0]))

+    return sln_main (argc, argv);

+

   /* Parse and process arguments.  */

   int remaining;

   argp_parse (&argp, argc, argv, 0, &remaining, NULL);

Index: b/elf/sln.c

===================================================================

--- a/elf/sln.c

+++ b/elf/sln.c

@@ -1,4 +1,4 @@

-/* `sln' program to create symbolic links between files.

+/* sln helper to create symbolic links between files, invoked from ldconfig.

    Copyright (C) 1998-2017 Free Software Foundation, Inc.

    This file is part of the GNU C Library.

@@ -31,21 +31,29 @@

 #include "../version.h"

-#define PACKAGE _libc_intl_domainname

+#include "sln.h"

 static int makesymlink (const char *src, const char *dest);

 static int makesymlinks (const char *file);

 static void usage (void);

-int

-main (int argc, char **argv)

+/* Check if we have to run sln.  */

+bool

+run_sln (const char *argv0)

 {

-  /* Set locale via LC_ALL.  */

-  setlocale (LC_ALL, "");

-

-  /* Set the text message domain.  */

-  textdomain (PACKAGE);

+  const char *slash = strrchr (argv0, '/');

+  const char *progname;

+  if (slash == NULL)

+    progname = argv0;

+  else

+    progname = slash + 1;

+  return strcmp (progname, "sln") == 0;

+}

+/* Invoked from ldconfig.  */

+int

+sln_main (int argc, char **argv)

+{

   switch (argc)

     {

     case 2:

Index: b/elf/sln.h

===================================================================

--- /dev/null

+++ b/elf/sln.h

@@ -0,0 +1,30 @@

+/* Interface of the sln command-line tool.

+   Copyright (C) 2016 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 Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 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

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <http://www.gnu.org/licenses/>.  */

+

+#ifndef SLN_H

+#define SLN_H

+

+#include <stdbool.h>

+

+/* Return true if main should invoke sln_main.  */

+bool run_sln (const char *argv0);

+

+/* Main routine of the sln command.  */

+int sln_main (int argc, char **argv);

+

+#endif  /* SLN_H */