binutils-gdb/libctf/configure.ac
Nick Alcock edc27e2d90 libctf: do not include undefined functions in libctf.ver
libctf's version script is applied to two libraries: libctf.so,
and libctf-nobfd.so.  The latter library is a subset of the former
which does not link to libbfd and does not include a few public
entry points that use it (found in libctf-open-bfd.c).  This means
that some of the symbols in this version script only exist in one
of the libraries it's applied to.

A number of linkers dislike this: before now, only Solaris's linker
caused serious problems, introducing NOTYPE-typed symbols when such
things were found, but now LLD has started to complain as well:

ld: error: version script assignment of 'LIBCTF_1.0' to symbol 'ctf_arc_open' failed: symbol not defined
ld: error: version script assignment of 'LIBCTF_1.0' to symbol 'ctf_fdopen' failed: symbol not defined
ld: error: version script assignment of 'LIBCTF_1.0' to symbol 'ctf_open' failed: symbol not defined
ld: error: version script assignment of 'LIBCTF_1.0' to symbol 'ctf_bfdopen' failed: symbol not defined
ld: error: version script assignment of 'LIBCTF_1.0' to symbol 'ctf_bfdopen_ctfsect' failed: symbol not defined

Rather than adding more and more whack-a-mole fixes for every
linker we encounter that does this, simply exclude such symbols
unconditionally, using the same trick we used to use for Solaris.
(Well, unconditionally if we can use version scripts with this
linker at all, which is not always the case.)

Thanks to Nicholas Vinson for the original report and a fix very
similar to this one (but not quite identical).

libctf/

	* configure.ac: Always exclude libctf symbols from
	libctf-nobfd's version script.
	* configure: Regenerated.
2024-04-19 16:14:48 +01:00

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dnl -*- Autoconf -*-
dnl Process this file with autoconf to produce a configure script.
dnl
dnl Copyright (C) 2019-2024 Free Software Foundation, Inc.
dnl
dnl This file is free software; you can redistribute it and/or modify
dnl it under the terms of the GNU General Public License as published by
dnl the Free Software Foundation; either version 2 of the License, or
dnl (at your option) any later version.
dnl
dnl This program is distributed in the hope that it will be useful,
dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
dnl GNU General Public License for more details.
dnl
dnl You should have received a copy of the GNU General Public License
dnl along with this program; see the file COPYING. If not see
dnl <http://www.gnu.org/licenses/>.
dnl
AC_PREREQ(2.64)
AC_INIT([libctf], 1.2.0)
AC_CONFIG_SRCDIR(ctf-impl.h)
AC_CANONICAL_BUILD
AC_CANONICAL_HOST
AC_CANONICAL_TARGET
AC_USE_SYSTEM_EXTENSIONS
AM_INIT_AUTOMAKE
AM_SILENT_RULES([yes])
# Checks for programs.
AC_PROG_MAKE_SET
AC_PROG_CC
AC_PROG_RANLIB
AM_PROG_AR
ZW_GNU_GETTEXT_SISTER_DIR
dnl Default to a non shared library. This may be overridden by the
dnl configure option --enable-shared.
AC_DISABLE_SHARED
LT_INIT
AC_SYS_LARGEFILE
LT_OUTPUT
MISSING=`cd $ac_aux_dir && ${PWDCMD-pwd}`/missing
AC_CHECK_PROGS([ACLOCAL], [aclocal], [$MISSING aclocal])
AC_CHECK_PROGS([AUTOCONF], [autoconf], [$MISSING autoconf])
AC_CHECK_PROGS([AUTOHEADER], [autoheader], [$MISSING autoheader])
# Figure out what compiler warnings we can enable.
# See config/warnings.m4 for details.
ACX_PROG_CC_WARNING_OPTS([-W -Wall -Wno-narrowing -Wwrite-strings \
-Wmissing-format-attribute], [warn])
ACX_PROG_CC_WARNING_OPTS([-Wstrict-prototypes -Wmissing-prototypes \
-Wold-style-definition], [c_warn])
ACX_PROG_CC_WARNING_ALMOST_PEDANTIC([-Wno-long-long])
# Only enable with --enable-werror-always until existing warnings are
# corrected.
ACX_PROG_CC_WARNINGS_ARE_ERRORS([manual])
AM_MAINTAINER_MODE
AM_INSTALL_LIBBFD
ACX_PROG_CC_WARNING_OPTS([-Wall], [ac_libctf_warn_cflags])
GCC_AC_FUNC_MMAP
# Needed for BFD capability checks.
AC_SEARCH_LIBS(dlsym, dl)
AM_ZLIB
GCC_ENABLE([libctf-hash-debugging], [no], [], [Enable expensive debugging of CTF deduplication type hashing])
if test "${enable_libctf_hash_debugging}" = yes; then
AC_DEFINE(ENABLE_LIBCTF_HASH_DEBUGGING, 1, [Enable expensive debugging of CTF deduplication type hashing])
fi
AM_CONDITIONAL(ENABLE_LIBCTF_HASH_DEBUGGING, test "${enable_libctf_hash_debugging}" = yes)
# Similar to GDB_AC_CHECK_BFD.
OLD_CFLAGS=$CFLAGS
OLD_LDFLAGS=$LDFLAGS
OLD_LIBS=$LIBS
OLD_CC=$CC
# Put the old CFLAGS/LDFLAGS last, in case the user's (C|LD)FLAGS
# points somewhere with bfd, with -I/foo/lib and -L/foo/lib. We
# always want our bfd.
CC="./libtool --quiet --mode=link $OLD_CC"
CFLAGS="-I${srcdir}/../include -I../bfd -I${srcdir}/../bfd $CFLAGS"
LDFLAGS="-L../bfd -L../libiberty $LDFLAGS"
intl=`echo $LIBINTL | sed 's,${top_builddir}/,,g'`
LIBS="-lbfd -liberty $intl $LIBS"
AC_CACHE_CHECK([for ELF support in BFD], ac_cv_libctf_bfd_elf,
[AC_TRY_LINK([#include <stdlib.h>
#include <string.h>
#include "bfd.h"
#include "elf-bfd.h"],
[(void) bfd_section_from_elf_index (NULL, 0);
return 0;],
[ac_cv_libctf_bfd_elf=yes],
[ac_cv_libctf_bfd_elf=no])])
CFLAGS=$OLD_CFLAGS
LDFLAGS=$OLD_LDFLAGS
LIBS=$OLD_LIBS
CC=$OLD_CC
if test $ac_cv_libctf_bfd_elf = yes; then
AC_DEFINE([HAVE_BFD_ELF], 1,
[Whether libbfd was configured for an ELF target.])
fi
AC_C_BIGENDIAN
AC_CHECK_HEADERS(byteswap.h endian.h)
AC_CHECK_FUNCS(pread)
dnl Check for bswap_{16,32,64}
AC_CHECK_DECLS([bswap_16, bswap_32, bswap_64], [], [], [[#include <byteswap.h>]])
AC_CHECK_DECLS([asprintf, vasprintf, stpcpy])
dnl Check for qsort_r. (Taken from gnulib.)
AC_CHECK_FUNCS_ONCE([qsort_r])
if test $ac_cv_func_qsort_r = yes; then
AC_CACHE_CHECK([for qsort_r signature], [ac_cv_libctf_qsort_r_signature],
[AC_LINK_IFELSE(
[AC_LANG_PROGRAM([[#undef qsort_r
#include <stdlib.h>
void qsort_r (void *, size_t, size_t,
int (*) (void const *, void const *,
void *),
void *);
void (*p) (void *, size_t, size_t,
int (*) (void const *, void const *,
void *),
void *) = qsort_r;
]])],
[ac_cv_libctf_qsort_r_signature=GNU],
[AC_LINK_IFELSE(
[AC_LANG_PROGRAM([[#undef qsort_r
#include <stdlib.h>
void qsort_r (void *, size_t, size_t, void *,
int (*) (void *,
void const *,
void const *));
void (*p) (void *, size_t, size_t, void *,
int (*) (void *, void const *,
void const *)) = qsort_r;
]])],
[ac_cv_libctf_qsort_r_signature=BSD],
[ac_cv_libctf_qsort_r_signature=unknown])])])
fi
case x$ac_cv_libctf_qsort_r_signature in
xGNU) AC_DEFINE([HAVE_QSORT_R_ARG_LAST], 1,
[Whether a qsort_r exists with a void *arg as its last arg.]);;
xBSD) AC_DEFINE([HAVE_QSORT_R_COMPAR_LAST], 1,
[Whether a qsort_r exists with the compar function as its last arg.]);;
*) ac_cv_libctf_qsort_r_signature=unknown;;
esac
AM_CONDITIONAL(NEED_CTF_QSORT_R, test "${ac_cv_libctf_qsort_r_signature}" = unknown)
AC_CACHE_CHECK([for O_CLOEXEC], [ac_cv_libctf_macro_O_CLOEXEC],
[AC_LINK_IFELSE(
[AC_LANG_PROGRAM([[#include <fcntl.h>
#ifndef O_CLOEXEC
choke me;
#endif
]],
[[return O_CLOEXEC;]])],
[ac_cv_libctf_macro_O_CLOEXEC=yes],
[ac_cv_libctf_macro_O_CLOEXEC=no])])
if test $ac_cv_libctf_macro_O_CLOEXEC = yes; then
AC_DEFINE([HAVE_O_CLOEXEC], 1,
[Whether the platform has a definition of O_CLOEXEC.])
fi
build_info=
makeinfo_too_old=
AC_CHECK_PROGS([MAKEINFO], makeinfo, [$MISSING makeinfo])
case " $build_configdirs " in
*" texinfo "*) MAKEINFO='$$r/$(BUILD_SUBDIR)/texinfo/makeinfo/makeinfo' ;;
esac
changequote(,)
# We require texinfo to be 6.3 or later, for a working synindex
# and validatemenus: otherwise we fall back to /bin/true.
if ${MAKEINFO} --version \
| egrep 'texinfo[^0-9]*(6\.[3-9]|[7-9]|[1-6][0-9])' >/dev/null 2>&1; then
build_info=yes
else
build_info=
makeinfo_too_old=t
fi
changequote([,])
if test -n "$makeinfo_too_old"; then
AC_MSG_WARN([
*** Makeinfo is too old. Info documentation will not be built.])
fi
AC_SUBST(MAKEINFO)
AM_CONDITIONAL(BUILD_INFO, test "${build_info}" = yes)
CTF_LIBADD="-L`pwd`/../libiberty -liberty"
SHARED_LDFLAGS=
# Horrible hacks to build DLLs on Windows and a shared library elsewhere.
if test "$enable_shared" = "yes"; then
# When building a shared libctf, link against the pic version of libiberty
# so that apps that use libctf won't need libiberty just to satisfy any
# libctf references. We can't do that if a pic libiberty is unavailable
# since including non-pic # code would insert text relocations into libctf.
# Note that linking against libbfd as we do here, which is itself linked
# against libiberty, may not satisfy all the libctf libiberty references
# since libbfd may not pull in the entirety of libiberty.
# Also, jam libintl into the right place in all of this: after libiberty,
# which uses it, but before -lcygwin, which it uses.
changequote(,)dnl
x=`sed -n -e 's/^[ ]*PICFLAG[ ]*=[ ]*//p' < ../libiberty/Makefile | sed -n '$p'`
changequote([,])dnl
if test -n "$x"; then
CTF_LIBADD="-L`pwd`/../libiberty/pic -liberty"
fi
fi
CTF_LIBADD="$CTF_LIBADD $LTLIBINTL"
if test "$enable_shared" = "yes"; then
case "${host}" in
# More hacks to build DLLs on Windows.
*-*-cygwin*)
SHARED_LDFLAGS="-no-undefined"
CTF_LIBADD="$CTF_LIBADD -lcygwin"
;;
esac
fi
AC_SUBST(SHARED_LDFLAGS)
AC_SUBST(CTF_LIBADD)
AC_PATH_PROG([EXPECT], [expect])
AC_CACHE_CHECK([for Tcl supporting try/catch], [ac_cv_libctf_tcl_try],
[ac_cv_libctf_tcl_try=`if test -z $EXPECT; then echo no; else $EXPECT << EOF
if @<:@llength @<:@info commands try@:>@@:>@ then { puts yes } else { puts no }
EOF
fi`
])
HAVE_TCL_TRY=false
if test "${ac_cv_libctf_tcl_try}" = "yes"; then
HAVE_TCL_TRY=true
fi
AC_SUBST(HAVE_TCL_TRY)
# Use a version script, if possible, or an -export-symbols-regex otherwise.
# First figure out the version script flag: then massage the script, if
# needed.
decommented_version_script=
no_version_script=
AC_CACHE_CHECK([for linker versioning flags], [ac_cv_libctf_version_script],
[echo 'FOO { global: mai*; local: ctf_fo*; };' > conftest.ver
old_LDFLAGS="$LDFLAGS"
old_CFLAGS="$CFLAGS"
LDFLAGS="$LDFLAGS -shared -Wl,--version-script=conftest.ver"
CFLAGS="$CFLAGS -fPIC"
AC_LINK_IFELSE([AC_LANG_SOURCE([[int ctf_foo (void) { return 0; }
int main (void) { return ctf_foo(); }]])],
[ac_cv_libctf_version_script="-Wl,--version-script"],
[])
LDFLAGS="$old_LDFLAGS"
if test -z "$ac_cv_libctf_version_script"; then
LDFLAGS="$LDFLAGS -shared -Wl,-B,local -Wl,-z,gnu-version-script=conftest.ver"
AC_LINK_IFELSE([AC_LANG_SOURCE([[int ctf_foo (void) { return 0; }
int main (void) { return ctf_foo(); }]])],
[ac_cv_libctf_version_script="-Wl,-B,local -Wl,-z,gnu-version-script"
decommented_version_script=t],
[])
LDFLAGS="$old_LDFLAGS"
fi
CFLAGS="$old_CFLAGS"
if test -z "$ac_cv_libctf_version_script"; then
ac_cv_libctf_version_script='-export-symbols-regex ctf_.*'
no_version_script=t
fi
rm -f conftest.ver])
# Ensure that no symbols exist in the version script for libctf-nobfd.so
# that do not exist in the shared library itself, since some linkers (Solaris)
# add such symbols with type NOTYPE, and others (LLVM) complain loudly
# and fail to link.
grep -v 'libctf only' $srcdir/libctf.ver > libctf-nobfd.ver
if test -n "$decommented_version_script"; then
# Solaris's version scripts use shell-style comments rather than the C-style
# used by GNU ld. Use cpp to strip the comments out. (cpp exists under this
# name on all platforms that support ld -z gnu-version-script.)
/lib/cpp < $srcdir/libctf.ver > libctf-decommented.ver
/lib/cpp < $srcdir/libctf-nobfd.ver > libctf-nobfd-decommented.ver
VERSION_FLAGS="$ac_cv_libctf_version_script='libctf-decommented.ver'"
VERSION_FLAGS_NOBFD="$ac_cv_libctf_version_script='libctf-nobfd-decommented.ver'"
elif test -z "$no_version_script"; then
VERSION_FLAGS="$ac_cv_libctf_version_script='$srcdir/libctf.ver'"
VERSION_FLAGS_NOBFD="$ac_cv_libctf_version_script='libctf-nobfd.ver'"
else
VERSION_FLAGS="$ac_cv_libctf_version_script"
VERSION_FLAGS_NOBFD="$ac_cv_libctf_version_script"
fi
AC_SUBST(VERSION_FLAGS)
AC_SUBST(VERSION_FLAGS_NOBFD)
AC_CONFIG_FILES(Makefile)
AC_CONFIG_HEADERS(config.h)
AC_OUTPUT
GNU_MAKE_JOBSERVER