Modernize the build system so it builds on current toolchains

The autotools setup could not bootstrap with modern autoconf/libtool:
`autoreconf -fi` failed with "possibly undefined macro: AC_PROG_LIBTOOL",
and several other macros used here were removed or deprecated long ago.

configure.ac:
  - AC_PROG_LIBTOOL -> LT_INIT (with AC_CONFIG_MACRO_DIRS/AC_CONFIG_AUX_DIR);
    add AM_PROG_AR required by newer libtool/automake.
  - AM_CONFIG_HEADER -> AC_CONFIG_HEADERS; AC_OUTPUT(files...) -> AC_OUTPUT
    with an explicit AC_CONFIG_FILES list.
  - AC_TRY_COMPILE -> AC_COMPILE_IFELSE; drop AC_HEADER_STDC,
    AC_PROG_GCC_TRADITIONAL, AC_STRUCT_ST_RDEV, AC_C_CONST and AC_C_INLINE
    (all obsolete or unconditionally available).
  - Drop AC_FUNC_MEMCMP/STRFTIME/VPRINTF; the corresponding HAVE_* macros
    were never referenced. Keep the register_printf_* check but test the
    ac_cv_func_* names that AC_CHECK_FUNCS actually sets.
  - Pin -std=gnu11 (the sources predate C99 and rely on implicit-int-era
    behaviour that newer C standards reject) and fix the -Wuninitialized
    probe, which never set its cache variable.
  - off_t/blkcnt_t sizeof fallbacks 64 -> 8 (bytes, not bits).

reiserfscore.pc.in: substitute @PACKAGE_VERSION@; REISERFSPROGS_VERSION was
never defined, so the generated .pc always carried an empty Version.

lib/parse_time.c: define _GNU_SOURCE, not _XOPEN_SOURCE. The valueless
_XOPEN_SOURCE disables _DEFAULT_SOURCE, which hides loff_t in <sys/types.h>
and broke the build. Every other translation unit already uses _GNU_SOURCE.

reiserfscore/xattr.c: drop the unused <sys/acl.h> include; no libacl symbol
is used (the reiserfs_acl_* structs come from reiserfs_fs.h), and the header
is not a declared build dependency.

Add autogen.sh to regenerate the build system after a fresh clone, and
update .gitignore for the build-aux/m4 layout and generated artifacts.

Verified: ./autogen.sh && ./configure && make completes on gcc 16 /
automake 1.18 / autoconf 2.72. mkreiserfs, reiserfsck --check,
debugreiserfs -S and reiserfstune all run against a freshly formatted
64 MiB image.

.gitignore

@@ -1,32 +1,54 @@
+# Editor / OS cruft
 *~
-*.[ao]
-*.8
+core
+tags
 
+# Autotools generated files (run ./autogen.sh to regenerate)
 INSTALL
 Makefile.in
 aclocal.m4
+autom4te.cache/
+compile
 config.guess
 config.sub
+config.h.in
 configure
 depcomp
-config.h.in
 install-sh
 missing
-aclocal.m4
-autom4te.cache
-tags
-.pc
+ltmain.sh
+ar-lib
+/build-aux/
+/m4/
+
+# configure / make output
 Makefile
-.deps
+.deps/
+.libs/
+*.o
+*.a
+*.lo
+*.la
 config.log
 config.status
+config.h
 include/config.h
 include/credits.h
 include/stamp-h1
+libtool
+reiserfscore/reiserfs_err.c
+reiserfscore/reiserfs_err.h
+reiserfscore/reiserfscore.pc
 
-reiserfsprogs-*.tar.*
+# Generated man pages (from *.8.in)
+*.8
+
+# Built programs
 /debugreiserfs/debugreiserfs
 /fsck/reiserfsck
 /mkreiserfs/mkreiserfs
 /resize_reiserfs/resize_reiserfs
 /tune/reiserfstune
+
+# Release tarballs
+reiserfsprogs-*.tar.*

autogen.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+# Regenerate the autotools build system (configure, Makefile.in, ...).
+# Run this after a fresh clone; release tarballs ship the generated files.
+set -e
+
+srcdir=$(dirname "$0")
+cd "$srcdir"
+
+mkdir -p m4 build-aux
+
+autoreconf -fi
+
+echo
+echo "Now run ./configure && make"

configure.ac

@@ -1,68 +1,79 @@
 dnl Process this file with autoconf to produce a configure script.
 AC_INIT([reiserfsprogs], [3.6.25], [reiserfs-devel@vger.kernel.org])
 AC_CANONICAL_HOST
-AC_PREREQ(2.50)
+AC_PREREQ([2.64])
+
+AC_CONFIG_MACRO_DIRS([m4])
+AC_CONFIG_AUX_DIR([build-aux])
 
 AH_TEMPLATE([HAVE_LIBUUID], [Define for enable libuuid using.])
 
-AM_INIT_AUTOMAKE([1.11.1 dist-xz silent-rules])
+AM_INIT_AUTOMAKE([1.11.1 foreign dist-xz silent-rules subdir-objects])
 AM_SILENT_RULES([yes])
 AM_MAINTAINER_MODE
 
 dnl We install in /sbin, the utils are to be available on boot
 dnl AC_PREFIX(/)
 
-AM_CONFIG_HEADER(include/config.h)
+AC_CONFIG_HEADERS([include/config.h])
 
 dnl Checks for programs.
 AC_PROG_CC
-AC_PROG_AWK 
+AC_PROG_AWK
 AC_PROG_INSTALL
 AC_PROG_LN_S
 AC_PROG_MAKE_SET
-AC_PROG_LIBTOOL
+AM_PROG_AR
+
+dnl libtool, replaces the long-obsolete AC_PROG_LIBTOOL
+LT_INIT
 
 dnl Checks for libraries.
 
 # Check for LIBUUID
-AC_CHECK_LIB(uuid, uuid_generate, , AC_MSG_WARN(libuuid could not be found))
+AC_CHECK_LIB([uuid], [uuid_generate], [], [AC_MSG_WARN([libuuid could not be found])])
 UUID_LIBS="$LIBS"
-AC_SUBST(UUID_LIBS)
+AC_SUBST([UUID_LIBS])
 
-AC_CHECK_LIB(com_err, _et_list, , AC_MSG_ERROR(libcom_err could not be found))
+AC_CHECK_LIB([com_err], [_et_list], [], [AC_MSG_ERROR([libcom_err could not be found])])
 COM_ERR_LIBS="$LIBS"
-AC_SUBST(COM_ERR_LIBS)
+AC_SUBST([COM_ERR_LIBS])
 
 dnl Checks for header files.
-AC_HEADER_STDC
-AC_CHECK_HEADERS(fcntl.h limits.h malloc.h sys/ioctl.h unistd.h uuid/uuid.h)
+AC_CHECK_HEADERS([fcntl.h limits.h malloc.h sys/ioctl.h unistd.h uuid/uuid.h])
 AC_HEADER_MAJOR
 
 dnl Checks for typedefs, structures, and compiler characteristics.
-AC_C_CONST
-AC_C_INLINE
 AC_TYPE_SIZE_T
-AC_STRUCT_ST_RDEV
+
+dnl Use a deterministic language level: the code predates C99 and C23
+dnl removes constructs (e.g. implicit int in some spots) it relies on.
+AC_MSG_CHECKING([whether $CC accepts -std=gnu11])
+saved_CFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS -std=gnu11"
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
+	[AC_MSG_RESULT([yes])],
+	[AC_MSG_RESULT([no]); CFLAGS="$saved_CFLAGS"])
 
 # Checking for compiler warning options
 AC_CACHE_CHECK([whether -Wuninitialized works], [ac_cv_wuninitialized_flag], [
-	saved_CPPFLAGS="$CPPFLAGS"
-	CPPFLAGS="-O1 -Wuninitialized"
-	AC_TRY_COMPILE(, , [ac_cv_wuninitialized_flag=yes], [ac_cv_wuninitialized_flag=no])
-	CPPFLAGS="$saved_CPPFLAGS"
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
+		[ac_cv_wuninitialized_flag=yes], [ac_cv_wuninitialized_flag=no])
 ])
 
 AC_CACHE_CHECK([whether -Wno-unused-parameter works], [ac_cv_wno_unused_parameter_flag], [
 	saved_CPPFLAGS="$CPPFLAGS"
-	CPPFLAGS="-Wno-unused-parameter"
-	AC_TRY_COMPILE(, , [ac_cv_wno_unused_parameter_flag=yes], [ac_cv_wno_unused_parameter_flag=no])
+	CPPFLAGS="$CPPFLAGS -Wno-unused-parameter"
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
+		[ac_cv_wno_unused_parameter_flag=yes], [ac_cv_wno_unused_parameter_flag=no])
 	CPPFLAGS="$saved_CPPFLAGS"
 ])
 
 AC_CACHE_CHECK([whether -Wredundant-decls works], [ac_cv_wredundant_decls_flag], [
 	saved_CPPFLAGS="$CPPFLAGS"
-	CPPFLAGS="-Wredundant-decls"
-	AC_TRY_COMPILE(, , [ac_cv_wredundant_decls_flag=yes], [ac_cv_wredundant_decls_flag=no])
+	CPPFLAGS="$CPPFLAGS -Wredundant-decls"
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
+		[ac_cv_wredundant_decls_flag=yes], [ac_cv_wredundant_decls_flag=no])
 	CPPFLAGS="$saved_CPPFLAGS"
 ])
 
@@ -70,77 +81,74 @@ AC_CACHE_CHECK([whether -Wredundant-decls works], [ac_cv_wredundant_decls_flag],
 AC_SYS_LARGEFILE
 
 if test -z "${ac_cv_sys_file_offset_bits}"; then
-	AC_MSG_WARN(Can't detect right _FILE_OFFSET_BITS. Will be forced to 64bit.)
+	AC_MSG_WARN([Can't detect right _FILE_OFFSET_BITS. Will be forced to 64bit.])
 	ac_cv_sys_file_offset_bits=64
 fi
 
-AC_CHECK_SIZEOF(off_t, 64, [ 
+AC_CHECK_SIZEOF([off_t], [8], [
 	#include <stdio.h>
 	#include <sys/types.h>
-	#include <unistd.h> 
+	#include <unistd.h>
 ])
 
-AC_CHECK_SIZEOF(blkcnt_t, 64, [ 
+AC_CHECK_SIZEOF([blkcnt_t], [8], [
 	#include <stdio.h>
 	#include <sys/types.h>
-	#include <unistd.h> 
+	#include <unistd.h>
 ])
 
 dnl Checks for library functions.
-AC_PROG_GCC_TRADITIONAL
-AC_FUNC_MEMCMP
-AC_FUNC_STRFTIME
-AC_FUNC_VPRINTF
-AC_CHECK_FUNCS(strerror strstr strtol statfs getmntent hasmntopt memset time \
-	       uname strptime ctime_r register_printf_modifier \
-	       register_printf_specifier)
+AC_CHECK_FUNCS([strerror strstr strtol statfs getmntent hasmntopt memset time \
+		uname strptime ctime_r register_printf_modifier \
+		register_printf_specifier])
 
-if test -z "${ac_cv_func_register_printf_function}" -a -z "${ac_cv_func_register_printf_specifier}"; then
-	AC_MSG_ERROR(reiserfsprogs requires a method to add printf modifiers)
+if test "x$ac_cv_func_register_printf_specifier" != xyes -a \
+	"x$ac_cv_func_register_printf_modifier" != xyes; then
+	AC_MSG_ERROR([reiserfsprogs requires a method to add printf modifiers])
 fi
 
 
 dnl Never enable this. It is for debugging only
-AC_ARG_ENABLE(io-failure-emulation,
+AC_ARG_ENABLE([io-failure-emulation],
 	[AS_HELP_STRING([--enable-io-failure-emulation], [Never use this. It is for debugging only])])
 if test "$enable_io_failure_emulation" = "yes" ; then
 	AC_MSG_WARN([Careful! IO failure emulation is ON])
-	AC_DEFINE(IO_FAILURE_EMULATION, 1, [gets set when configure --enable-io-failure-emulation])
+	AC_DEFINE([IO_FAILURE_EMULATION], [1], [gets set when configure --enable-io-failure-emulation])
 fi
 
 if test "x$ac_cv_wno_unused_parameter_flag" = xyes; then
 	CFLAGS="$CFLAGS -Wno-unused-parameter"
-else
-	CFLAGS="$CFLAGS -Wno-unused"
 fi
-	
+
 if test "x$ac_cv_wredundant_decls_flag" = xyes; then
 	CFLAGS="$CFLAGS -Wredundant-decls"
 fi
-	
+
 if test "x$ac_cv_wuninitialized_flag" = xyes; then
 	CFLAGS="$CFLAGS -Wuninitialized"
 fi
 
 CPPFLAGS="-I\$(top_srcdir)/include $CPPFLAGS"
 
-AC_OUTPUT(
-    include/Makefile 
-    mkreiserfs/Makefile 
-    mkreiserfs/mkreiserfs.8
-    resize_reiserfs/Makefile 
-    resize_reiserfs/resize_reiserfs.8
-    fsck/Makefile 
-    fsck/reiserfsck.8
-    lib/Makefile 
-    Makefile 
-    reiserfscore/Makefile 
-    reiserfscore/reiserfscore.pc
-    debugreiserfs/Makefile 
-    debugreiserfs/debugreiserfs.8
-    tune/Makefile
-    tune/reiserfstune.8
-    )
+AC_CONFIG_FILES([
+	Makefile
+	include/Makefile
+	lib/Makefile
+	reiserfscore/Makefile
+	reiserfscore/reiserfscore.pc
+	fsck/Makefile
+	fsck/reiserfsck.8
+	mkreiserfs/Makefile
+	mkreiserfs/mkreiserfs.8
+	debugreiserfs/Makefile
+	debugreiserfs/debugreiserfs.8
+	resize_reiserfs/Makefile
+	resize_reiserfs/resize_reiserfs.8
+	tune/Makefile
+	tune/reiserfstune.8
+])
+
+AC_OUTPUT
 
 AC_MSG_NOTICE([
 

lib/parse_time.c

@@ -1,4 +1,4 @@
-#define _XOPEN_SOURCE
+#define _GNU_SOURCE
 #ifdef HAVE_CONFIG_H
 #include <config.h>
 #endif

reiserfscore/reiserfscore.pc.in

@@ -5,6 +5,6 @@ includedir=@includedir@
 
 Name: reiserfscore
 Description: ReiserFS Core Library
-Version: @REISERFSPROGS_VERSION@
+Version: @PACKAGE_VERSION@
 Cflags: -I${includedir}/reiserfs -I${includedir}
 Libs: -L${libdir} -lreiserfscore

reiserfscore/xattr.c

@@ -1,7 +1,6 @@
 #include <sys/types.h>
 #include <stdio.h>
 #include <errno.h>
-#include <sys/acl.h>
 #include "reiserfs_lib.h"
 
 static inline unsigned short from32to16(unsigned int x)