gold/configure.ac

   1 dnl Process this file with autoconf to produce a configure script.
   2 dnl
   3 dnl   Copyright (C) 2006-2020 Free Software Foundation, Inc.
   4 dnl
   5 dnl This file is free software; you can redistribute it and/or modify
   6 dnl it under the terms of the GNU General Public License as published by
   7 dnl the Free Software Foundation; either version 3 of the License, or
   8 dnl (at your option) any later version.
   9 dnl
  10 dnl This program is distributed in the hope that it will be useful,
  11 dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 dnl GNU General Public License for more details.
  14 dnl
  15 dnl You should have received a copy of the GNU General Public License
  16 dnl along with this program; see the file COPYING3.  If not see
  17 dnl <http://www.gnu.org/licenses/>.
  18 dnl
  19
  20 AC_INIT(gold, 0.1)
  21 AC_CONFIG_SRCDIR(gold.cc)
  22
  23 AC_CANONICAL_TARGET
  24
  25 AM_INIT_AUTOMAKE([no-dist parallel-tests])
  26
  27 AM_CONFIG_HEADER(config.h:config.in)
  28
  29 AC_USE_SYSTEM_EXTENSIONS
  30
  31 # PR 14072
  32 AH_VERBATIM([00_CONFIG_H_CHECK],
  33 [/* Check that config.h is #included before system headers
  34    (this works only for glibc, but that should be enough).  */
  35 #if defined(__GLIBC__) && !defined(__FreeBSD_kernel__) && !defined(__CONFIG_H__)
  36 #  error config.h must be #included before system headers
  37 #endif
  38 #define __CONFIG_H__ 1])
  39
  40 AC_ARG_WITH(sysroot,
  41 [  --with-sysroot[=DIR]    search for usr/lib et al within DIR],
  42 [sysroot=$withval], [sysroot=no])
  43
  44 if test "$sysroot" = "yes"; then
  45   sysroot='${exec_prefix}/${target_alias}/sys-root'
  46 elif test "$sysroot" = "no"; then
  47   sysroot=
  48 fi
  49
  50 sysroot_relocatable=0
  51 if test -n "$sysroot"; then
  52   case "$sysroot" in
  53     "${prefix}" | "${prefix}/"* | \
  54     "${exec_prefix}" | "${exec_prefix}/"* | \
  55     '${prefix}' | '${prefix}/'*| \
  56     '${exec_prefix}' | '${exec_prefix}/'*)
  57       sysroot_relocatable=1
  58       ;;
  59   esac
  60 fi
  61
  62 AC_DEFINE_UNQUOTED(TARGET_SYSTEM_ROOT, "$sysroot",
  63   [System root for target files])
  64 AC_DEFINE_UNQUOTED(TARGET_SYSTEM_ROOT_RELOCATABLE, $sysroot_relocatable,
  65   [Whether the system root can be relocated])
  66
  67 dnl "install_as_default" is true if the linker to be installed as the
  68 dnl default linker, ld.
  69 dnl "installed_linker" is the installed gold linker name.
  70
  71 installed_linker=ld.gold
  72 AC_ARG_ENABLE(gold,
  73 [[  --enable-gold[=ARG]     build gold [ARG={default,yes,no}]]],
  74 [case "${enableval}" in
  75  default)
  76    install_as_default=yes
  77    ;;
  78  yes)
  79    if test x${enable_ld} = xno; then
  80      install_as_default=yes
  81    fi
  82    ;;
  83  esac],
  84 [install_as_default=no])
  85 AC_SUBST(install_as_default)
  86 AC_SUBST(installed_linker)
  87
  88 AC_PLUGINS
  89 if test "$plugins" = "yes"; then
  90   AC_DEFINE(ENABLE_PLUGINS, 1,
  91             [Define to enable linker plugins])
  92 fi
  93 AM_CONDITIONAL(PLUGINS, test "$plugins" = "yes")
  94
  95 # Decide if -z relro should be enabled in ELF linker by default.
  96 ac_default_ld_z_relro=unset
  97 # Provide a configure time option to override our default.
  98 AC_ARG_ENABLE(relro,
  99               AS_HELP_STRING([--enable-relro],
 100               [enable -z relro in ELF linker by default]),
 101 [case "${enableval}" in
 102   yes)  ac_default_ld_z_relro=1 ;;
 103   no)  ac_default_ld_z_relro=0 ;;
 104 esac])dnl
 105 if test "${ac_default_ld_z_relro}" = unset; then
 106   ac_default_ld_z_relro=1
 107 fi
 108 AC_DEFINE_UNQUOTED(DEFAULT_LD_Z_RELRO,
 109   $ac_default_ld_z_relro,
 110   [Define to 1 if you want to enable -z relro in ELF linker by default.])
 111
 112 AC_ARG_ENABLE([targets],
 113 [  --enable-targets        alternative target configurations],
 114 [case "${enableval}" in
 115   yes | "")
 116     AC_MSG_ERROR([--enable-targets option must specify target names or 'all'])
 117     ;;
 118   no)
 119     enable_targets=
 120     ;;
 121   *)
 122     enable_targets=$enableval
 123     ;;
 124 esac],
 125 [# For now, enable all targets by default
 126  enable_targets=all
 127 ])
 128
 129 # Canonicalize the enabled targets.
 130 if test -n "$enable_targets"; then
 131   for targ in `echo $enable_targets | sed -e 's/,/ /g'`; do
 132     result=`$ac_config_sub $targ 2>/dev/null`
 133     if test -n "$result"; then
 134       canon_targets="$canon_targets $result"
 135     else
 136       # Permit unrecognized target names, like "all".
 137       canon_targets="$canon_targets $targ"
 138     fi
 139   done
 140 fi
 141
 142 # Decide which "--hash-style" to use by default
 143 # Provide a configure time option to override our default.
 144 AC_ARG_ENABLE([default-hash-style],
 145 AS_HELP_STRING([--enable-default-hash-style={sysv,gnu,both}],
 146                [use this default hash style]),
 147 [case "${enable_default_hash_style}" in
 148   sysv | gnu | both) ;;
 149   *) AC_MSG_ERROR([bad value ${enable_default_hash_style} for enable-default-hash-style option]) ;;
 150 esac],
 151 [case "${target}" in
 152   # Enable gnu hash only on GNU targets, but not mips
 153   mips*-*-*) enable_default_hash_style=sysv ;;
 154   *-*-gnu* | *-*-linux* | *-*-nacl*) enable_default_hash_style=both ;;
 155   *) enable_default_hash_style=sysv ;;
 156 esac])
 157
 158 AC_DEFINE_UNQUOTED([DEFAULT_HASH_STYLE],
 159   ["${enable_default_hash_style}"],
 160   [Set the default --hash-style value])
 161
 162 # See which specific instantiations we need.
 163 targetobjs=
 164 all_targets=
 165 default_machine=
 166 default_size=
 167 default_big_endian=
 168 default_osabi=ELFOSABI_NONE
 169 targ_32_little=
 170 targ_32_big=
 171 targ_64_little=
 172 targ_64_big=
 173 for targ in $target $canon_targets; do
 174   if test "$targ" = "all"; then
 175     targ_32_little=yes
 176     targ_32_big=yes
 177     targ_64_little=yes
 178     targ_64_big=yes
 179     all_targets=yes
 180   else
 181     . ${srcdir}/configure.tgt
 182
 183     if test "$targ_obj" = "UNKNOWN"; then
 184       AC_MSG_ERROR("unsupported target $targ")
 185     else
 186       targetobjs="$targetobjs ${targ_obj}.\$(OBJEXT)"
 187       if test "$targ_extra_obj" != ""; then
 188         targetobjs="$targetobjs ${targ_extra_obj}.\$(OBJEXT)"
 189       fi
 190       if test "$targ_size" = "32" -o "$targ_extra_size" = "32"; then
 191           if test "$targ_big_endian" = "true" \
 192               -o "$targ_extra_big_endian" = "true"; then
 193               targ_32_big=yes
 194           fi
 195           if test "$targ_big_endian" = "false" \
 196               -o "$targ_extra_big_endian" = "false"; then
 197               targ_32_little=yes
 198           fi
 199       fi
 200       if test "$targ_size" = "64" -o "$targ_extra_size" = "64"; then
 201           if test "$targ_big_endian" = "true" \
 202               -o "$targ_extra_big_endian" = "true"; then
 203               targ_64_big=yes
 204           fi
 205           if test "$targ_big_endian" = "false" \
 206               -o "$targ_extra_big_endian" = "false"; then
 207               targ_64_little=yes
 208           fi
 209       fi
 210
 211       if test "$target" = "$targ"; then
 212         default_machine=$targ_machine
 213         default_size=$targ_size
 214         default_big_endian=$targ_big_endian
 215         default_osabi=$targ_osabi
 216
 217         AM_CONDITIONAL(DEFAULT_TARGET_AARCH64, test "$targ_obj" = "aarch64")
 218         AM_CONDITIONAL(DEFAULT_TARGET_ARM, test "$targ_obj" = "arm")
 219         AM_CONDITIONAL(DEFAULT_TARGET_I386, test "$targ_obj" = "i386")
 220         AM_CONDITIONAL(DEFAULT_TARGET_POWERPC, test "$targ_obj" = "powerpc")
 221         AM_CONDITIONAL(DEFAULT_TARGET_SPARC, test "$targ_obj" = "sparc")
 222         AM_CONDITIONAL(DEFAULT_TARGET_S390, test "$targ_obj" = "s390")
 223         target_x86_64=no
 224         target_x32=no
 225         if test "$targ_obj" = "x86_64"; then
 226           case "$target" in
 227           x86_64*-linux-gnux32)
 228             target_x32=yes
 229             default_size=32
 230             ;;
 231           *)
 232             target_x86_64=yes
 233             ;;
 234           esac
 235         fi
 236         AM_CONDITIONAL(DEFAULT_TARGET_X86_64, test "$target_x86_64" = "yes")
 237         AM_CONDITIONAL(DEFAULT_TARGET_X32, test "$target_x32" = "yes")
 238         AM_CONDITIONAL(DEFAULT_TARGET_X86_64_OR_X32,
 239                        test "$target_x86_64" = "yes" -o "$target_x32" = "yes")
 240         AM_CONDITIONAL(DEFAULT_TARGET_TILEGX, test "$targ_obj" = "tilegx")
 241         AM_CONDITIONAL(DEFAULT_TARGET_MIPS, test "$targ_obj" = "mips")
 242         DEFAULT_TARGET=${targ_obj}
 243         AC_SUBST(DEFAULT_TARGET)
 244       fi
 245     fi
 246   fi
 247 done
 248
 249 # Remove any duplicates.
 250 to=""
 251 for t in $targetobjs; do
 252   case " $to " in
 253   *" $t "*) ;;
 254   *) to="$to $t" ;;
 255   esac
 256 done
 257 targetobjs=$to
 258
 259 if test -n "$targ_32_little"; then
 260   AC_DEFINE(HAVE_TARGET_32_LITTLE, 1,
 261               [Define to support 32-bit little-endian targets])
 262 fi
 263 if test -n "$targ_32_big"; then
 264   AC_DEFINE(HAVE_TARGET_32_BIG, 1,
 265               [Define to support 32-bit big-endian targets])
 266 fi
 267 if test -n "$targ_64_little"; then
 268   AC_DEFINE(HAVE_TARGET_64_LITTLE, 1,
 269               [Define to support 64-bit little-endian targets])
 270 fi
 271 if test -n "$targ_64_big"; then
 272   AC_DEFINE(HAVE_TARGET_64_BIG, 1,
 273               [Define to support 64-bit big-endian targets])
 274 fi
 275
 276 if test -n "$all_targets"; then
 277   TARGETOBJS='$(ALL_TARGETOBJS)'
 278 else
 279   TARGETOBJS="$targetobjs"
 280 fi
 281 AC_SUBST(TARGETOBJS)
 282
 283 AC_DEFINE_UNQUOTED(GOLD_DEFAULT_MACHINE, $default_machine,
 284                    [Default machine code])
 285 AC_DEFINE_UNQUOTED(GOLD_DEFAULT_SIZE, $default_size,
 286                    [Default size (32 or 64)])
 287 AC_DEFINE_UNQUOTED(GOLD_DEFAULT_BIG_ENDIAN, $default_big_endian,
 288                    [Default big endian (true or false)])
 289 AC_DEFINE_UNQUOTED(GOLD_DEFAULT_OSABI, $default_osabi,
 290                    [Default OSABI code])
 291
 292 AC_ARG_WITH(lib-path,
 293 [  --with-lib-path=dir1:dir2...  set default LIB_PATH],
 294 [case "$withval" in
 295  yes) LIB_PATH='"/lib:/usr/lib"' ;;
 296  no) LIB_PATH='""' ;;
 297  *) LIB_PATH='"'"$withval"'"' ;;
 298  esac],
 299 [LIB_PATH='"::DEFAULT::"'])
 300 AC_DEFINE_UNQUOTED(LIB_PATH, $LIB_PATH,
 301                    [Default library search path])
 302 if test "x$target_alias" = "x" -o "x$host_alias" = "x$target_alias"; then
 303   AC_DEFINE(NATIVE_LINKER, 1, [Whether configured as a native linker])
 304 fi
 305
 306 AC_CHECK_TOOL(NM, nm)
 307
 308 AC_PROG_CC
 309 AC_PROG_CXX
 310 AC_PROG_YACC
 311 AC_PROG_RANLIB
 312 AC_PROG_INSTALL
 313 AC_PROG_LN_S
 314
 315 AC_GNU_SOURCE
 316
 317 ZW_GNU_GETTEXT_SISTER_DIR
 318 AM_PO_SUBDIRS
 319
 320 AC_C_BIGENDIAN
 321
 322 AC_EXEEXT
 323
 324 AM_CONDITIONAL(NATIVE_LINKER,
 325   test "x$target_alias" = "x" -o "x$host_alias" = "x$target_alias")
 326 AM_CONDITIONAL(GCC, test "$GCC" = yes)
 327
 328 AM_CONDITIONAL(NATIVE_OR_CROSS_LINKER,
 329   test "x$target_alias" = "x" -o "x$host_alias" = "x$target_alias" -o "x$host_alias" = "x$build_alias")
 330
 331 dnl Test for whether static linking is supported.  Some systems do not
 332 dnl install static libraries.  This only affects the set of tests that
 333 dnl we run.
 334 AC_CACHE_CHECK([whether static linking works], [gold_cv_lib_static],
 335 [LDFLAGS_hold=$LDFLAGS
 336 LDFLAGS="$LDFLAGS -static"
 337 AC_LINK_IFELSE([
 338 AC_LANG_PROGRAM([[void f() { }]])],
 339 [gold_cv_lib_static=yes], [gold_cv_lib_static=no])
 340 LDFLAGS=$LDFLAGS_hold])
 341 AM_CONDITIONAL(HAVE_STATIC, test "$gold_cv_lib_static" = "yes")
 342
 343 dnl Some architectures do not support taking pointers of functions
 344 dnl defined in shared libraries except in -fPIC mode.  We need to
 345 dnl tell the unittest framework if we're compiling for one of those
 346 dnl targets, so it doesn't try to run the tests that do that.
 347 AM_CONDITIONAL(FN_PTRS_IN_SO_WITHOUT_PIC, [
 348   case $target_cpu in
 349     powerpc*) false;;
 350     x86_64) false;;
 351     sparc64) false;;
 352     s390x) false;;
 353     *) true;;
 354   esac])
 355
 356 dnl Test for gcc 4.1 or later.  Full support for -mcmodel=medium is
 357 dnl only available in gcc 4.1.
 358 AC_CACHE_CHECK([for gcc >= 4.1], [gold_cv_prog_gcc41],
 359 [AC_COMPILE_IFELSE([AC_LANG_SOURCE([
 360 #if !defined __GNUC__
 361 error
 362 #elif __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1)
 363 error
 364 #endif
 365 ])], [gold_cv_prog_gcc41=yes], [gold_cv_prog_gcc41=no])])
 366
 367 save_CFLAGS="$CFLAGS"
 368 CFLAGS="$CFLAGS -mcmodel=medium"
 369 AC_COMPILE_IFELSE([AC_LANG_SOURCE([int i;])], [have_mcmodel_medium=yes], [have_mcmodel_medium=no])
 370 CFLAGS="$save_CFLAGS"
 371 dnl Whether we can test -mcmodel=medium.
 372 AM_CONDITIONAL(MCMODEL_MEDIUM,
 373 [test "$target_cpu" = "x86_64" -a "$have_mcmodel_medium" = "yes" -a "$gold_cv_prog_gcc41" = "yes"])
 374
 375 AC_CACHE_CHECK([whether $CC supports -fmerge-constants],
 376                [gold_cv_merge_constants], [
 377 save_CFLAGS="$CFLAGS"
 378 CFLAGS="$CFLAGS -fmerge-constants"
 379 AC_COMPILE_IFELSE([AC_LANG_SOURCE([const char *s = "foo";])],
 380                   [gold_cv_merge_constants=yes],
 381                   [gold_cv_merge_constants=no])
 382 CFLAGS="$save_CFLAGS"])
 383 AC_SUBST([MERGE_CONSTANTS_FLAG])
 384 AS_IF([test "$gold_cv_merge_constants" = yes],
 385       [MERGE_CONSTANTS_FLAG=-fmerge-constants],
 386       [MERGE_CONSTANTS_FLAG=])
 387
 388 dnl Test for __thread support.
 389 AC_CACHE_CHECK([for thread support], [gold_cv_c_thread],
 390 [AC_COMPILE_IFELSE([AC_LANG_SOURCE([__thread int i = 1;])],
 391 [gold_cv_c_thread=yes], [gold_cv_c_thread=no])])
 392
 393 AM_CONDITIONAL(TLS, test "$gold_cv_c_thread" = "yes")
 394
 395 dnl On GNU/Linux TLS in static programs only works when using glibc
 396 dnl 2.4 or later.
 397 AC_CACHE_CHECK([for glibc >= 2.4], [gold_cv_lib_glibc24],
 398 [AC_COMPILE_IFELSE([AC_LANG_SOURCE([
 399 #include <features.h>
 400 #if !defined __GLIBC__
 401 error
 402 #elif __GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ < 4)
 403 error
 404 #endif
 405 ])], [gold_cv_lib_glibc24=yes], [gold_cv_lib_glibc24=no])])
 406
 407 AM_CONDITIONAL(STATIC_TLS, test "$gold_cv_lib_glibc24" = "yes")
 408
 409 dnl Test for #pragma omp threadprivate
 410 AC_CACHE_CHECK([for omp support], [gold_cv_c_threadprivate],
 411 [save_CFLAGS="$CFLAGS"
 412 CFLAGS="$CFLAGS -fopenmp"
 413 AC_COMPILE_IFELSE([AC_LANG_SOURCE([
 414 #include <omp.h>
 415 int i;
 416 #pragma omp threadprivate (i)
 417 ])], [gold_cv_c_threadprivate=yes], [gold_cv_c_threadprivate=no])
 418 CFLAGS="$save_CFLAGS"])
 419 if test "$gold_cv_c_threadprivate" = "yes"; then
 420   AC_DEFINE(HAVE_OMP_SUPPORT, 1,
 421             [Define if compiler supports #pragma omp threadprivate])
 422 fi
 423 AM_CONDITIONAL(OMP_SUPPORT, test "$gold_cv_c_threadprivate" = "yes")
 424
 425 dnl Test for the -ftls-dialect=gnu2 option.
 426 dnl Use -Werror in case of compilers that make unknown -m options warnings.
 427 dnl They would pass the test here, but fail in actual use when $WARN_CFLAGS
 428 dnl gets set later by default Autoconf magic to include -Werror.  (We are
 429 dnl assuming here that there is no compiler that groks -mtls-dialect=gnu2
 430 dnl but does not grok -Werror.)
 431 save_CFLAGS="$CFLAGS"
 432 CFLAGS="$CFLAGS -Werror -fpic -mtls-dialect=gnu2"
 433 AC_COMPILE_IFELSE([AC_LANG_SOURCE([
 434 __thread int i;
 435 void foo (void)
 436 {
 437   i = 10;
 438 }
 439 ])], [have_tls_gnu2=yes], [have_tls_gnu2=no])
 440 CFLAGS="$save_CFLAGS"
 441 AM_CONDITIONAL(TLS_GNU2_DIALECT, test "$have_tls_gnu2" = "yes")
 442
 443 dnl On GNU/Linux TLS descriptors are supported by the dynamic loader
 444 dnl only with glibc 2.9 or later.
 445 AC_CACHE_CHECK([for glibc >= 2.9], [gold_cv_lib_glibc29],
 446 [AC_COMPILE_IFELSE([AC_LANG_SOURCE([
 447 #include <features.h>
 448 #if !defined __GLIBC__
 449 error
 450 #elif __GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ < 9)
 451 error
 452 #endif
 453 ])], [gold_cv_lib_glibc29=yes], [gold_cv_lib_glibc29=no])])
 454
 455 AM_CONDITIONAL(TLS_DESCRIPTORS, test "$gold_cv_lib_glibc29" = "yes")
 456
 457 dnl Test for the -frandom-seed option.
 458 AC_CACHE_CHECK([for -frandom-seed support], [gold_cv_c_random_seed],
 459 [save_CFLAGS="$CFLAGS"
 460 CFLAGS="$CFLAGS -frandom-seed=foo"
 461 AC_COMPILE_IFELSE([AC_LANG_SOURCE([int i;])], [gold_cv_c_random_seed=yes],
 462 [gold_cv_c_random_seed=no])
 463 CFLAGS="$save_CFLAGS"])
 464 if test "$gold_cv_c_random_seed" = "yes"; then
 465   # In Makefile, '$@' will be expanded to be the name of the file
 466   # being built, providing a unique seed for each file.
 467   RANDOM_SEED_CFLAGS=-frandom-seed=\$@
 468 fi
 469 AC_SUBST(RANDOM_SEED_CFLAGS)
 470
 471 dnl On GNU/Linux ifunc is supported by the dynamic linker in glibc
 472 dnl 2.11 or later, and by binutils 2.20.1 or later.
 473 AC_CACHE_CHECK([for glibc ifunc support], [gold_cv_lib_glibc_ifunc],
 474 [save_LDFLAGS="$LDFLAGS"
 475 LDFLAGS="$LDFLAGS -static"
 476 AC_LINK_IFELSE([AC_LANG_PROGRAM([[
 477 #include <features.h>
 478 #if !defined __GLIBC__
 479 error
 480 #elif __GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ < 11)
 481 error
 482 #endif
 483 void func (void) { }
 484 void invoke (void);
 485 __asm__(".type invoke, %gnu_indirect_function");
 486 typedef void (*funcptr) (void);
 487 funcptr dispatch (void) __asm__ ("invoke");
 488 funcptr dispatch (void) { return &func; }]],
 489 [[invoke();]])
 490 ], [
 491 if ${NM} conftest$EXEEXT | grep "__rela\?_iplt_start" >/dev/null 2>&1; then
 492   gold_cv_lib_glibc_ifunc=both
 493 else
 494   gold_cv_lib_glibc_ifunc=dyn
 495 fi], [gold_cv_lib_glibc_ifunc=no])
 496 LDFLAGS="$save_LDFLAGS"])
 497
 498 AM_CONDITIONAL(IFUNC, test "$gold_cv_lib_glibc_ifunc" != "no")
 499 AM_CONDITIONAL(IFUNC_STATIC, test "$gold_cv_lib_glibc_ifunc" = "both")
 500
 501 AM_BINUTILS_WARNINGS
 502
 503 WARN_CXXFLAGS=`echo ${WARN_CFLAGS} | sed -e 's/-Wstrict-prototypes//' -e 's/-Wmissing-prototypes//' -e 's/-Wshadow//'`
 504 AC_SUBST(WARN_CXXFLAGS)
 505
 506 AC_ARG_WITH(gold-ldflags,
 507 [  --with-gold-ldflags=FLAGS  additional link flags for gold],
 508 [if test "$withval" = "no" -o "$withval" = "yes"; then
 509    GOLD_LDFLAGS=
 510  else
 511    GOLD_LDFLAGS=$withval
 512  fi],
 513 [GOLD_LDFLAGS=])
 514 AC_SUBST(GOLD_LDFLAGS)
 515
 516 AC_ARG_WITH(gold-ldadd,
 517 [  --with-gold-ldadd=LIBS     additional libraries for gold],
 518 [if test "$withval" = "no" -o "$withval" = "yes"; then
 519    GOLD_LDADD=
 520  else
 521    GOLD_LDADD=$withval
 522  fi],
 523 [GOLD_LDADD=])
 524 AC_SUBST(GOLD_LDADD)
 525
 526 dnl Force support for large files by default.  This may need to be
 527 dnl host dependent.  If build == host, we can check getconf LFS_CFLAGS.
 528 LFS_CFLAGS="-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"
 529 AC_SUBST(LFS_CFLAGS)
 530
 531 AC_CHECK_HEADERS(sys/mman.h)
 532 AC_CHECK_FUNCS(chsize mmap link)
 533 AC_REPLACE_FUNCS(pread ftruncate ffsll)
 534
 535 AC_CACHE_CHECK([mremap with MREMAP_MAYMOVE], [gold_cv_lib_mremap_maymove],
 536 [AC_LINK_IFELSE([
 537 AC_LANG_PROGRAM([[
 538 #include <sys/mman.h>
 539 void f() { mremap (0, 0, 0, MREMAP_MAYMOVE); }
 540 ]])], [gold_cv_lib_mremap_maymove=yes], [gold_cv_lib_mremap_maymove=no])])
 541 if test "$gold_cv_lib_mremap_maymove" = "yes"; then
 542   AC_DEFINE(HAVE_MREMAP, 1,
 543     [Define to 1 if you have the mremap function with MREMAP_MAYMOVE support])
 544 else
 545   AC_LIBOBJ(mremap)
 546 fi
 547
 548 # Link in zlib if we can.  This allows us to write compressed sections.
 549 AM_ZLIB
 550
 551 AC_ARG_ENABLE([threads],
 552 [[  --enable-threads[=ARG]  multi-threaded linking [ARG={auto,yes,no}]]],
 553 [case "${enableval}" in
 554   yes | "") threads=yes ;;
 555   no) threads=no ;;
 556   auto) threads=auto ;;
 557   *) threads=yes ;;
 558  esac],
 559 [threads=auto])
 560
 561 if test "$threads" = "yes"; then
 562   AX_PTHREAD([threads=yes], AC_MSG_ERROR([pthread not found]))
 563 elif test "$threads" = "auto"; then
 564   AX_PTHREAD([threads=yes], [threads=no])
 565 fi
 566
 567 if test "$threads" = "yes"; then
 568   AC_DEFINE(ENABLE_THREADS, 1,
 569             [Define to do multi-threaded linking])
 570 fi
 571 AM_CONDITIONAL(THREADS, test "$threads" = "yes")
 572
 573 dnl We have to check these in C, not C++, because autoconf generates
 574 dnl tests which have no type information, and current glibc provides
 575 dnl multiple declarations of functions like basename when compiling
 576 dnl with C++.
 577 AC_CHECK_DECLS([basename, ffs, asprintf, vasprintf, snprintf, vsnprintf, strverscmp])
 578
 579 dnl Check if gcc supports the -gpubnames option.
 580 dnl Use -Werror in case of compilers that make unknown -g options warnings.
 581 dnl They would pass the test here, but fail in actual use when $WARN_CFLAGS
 582 dnl gets set later by default Autoconf magic to include -Werror.  (We are
 583 dnl assuming here that there is no compiler that groks -gpubnames
 584 dnl but does not grok -Werror.)
 585 save_CFLAGS="$CFLAGS"
 586 CFLAGS="$CFLAGS -Werror -gpubnames"
 587 AC_COMPILE_IFELSE([AC_LANG_SOURCE([int i;])], [have_pubnames=yes], [have_pubnames=no])
 588 CFLAGS="$save_CFLAGS"
 589 AM_CONDITIONAL(HAVE_PUBNAMES, test "$have_pubnames" = "yes")
 590
 591 dnl Check if gcc supports the -fno-use-linker-plugin option.
 592 save_CFLAGS="$CFLAGS"
 593 CFLAGS="$CFLAGS -Werror -fno-use-linker-plugin"
 594 AC_COMPILE_IFELSE([AC_LANG_SOURCE([int i;])], [have_no_use_linker_plugin=yes], [have_no_use_linker_plugin=no])
 595 CFLAGS="$save_CFLAGS"
 596 AM_CONDITIONAL(HAVE_NO_USE_LINKER_PLUGIN, test "$have_no_use_linker_plugin" = "yes")
 597
 598 AC_LANG_PUSH(C++)
 599
 600 AC_CHECK_HEADERS(unordered_set unordered_map)
 601 AC_CHECK_HEADERS(tr1/unordered_set tr1/unordered_map)
 602 AC_CHECK_HEADERS(ext/hash_map ext/hash_set)
 603 AC_CHECK_HEADERS(byteswap.h)
 604
 605 dnl When plugins enabled dynamic loader interface is required. Check headers
 606 dnl which may provide this interface. Add the necessary library to link.
 607 AC_CHECK_HEADERS(windows.h)
 608 AC_CHECK_HEADERS(dlfcn.h)
 609 AC_SEARCH_LIBS(dlopen, [dl dld])
 610 case "$ac_cv_search_dlopen" in
 611   no*) DLOPEN_LIBS="";;
 612   *)   DLOPEN_LIBS="$ac_cv_search_dlopen";;
 613 esac
 614 AC_SUBST(DLOPEN_LIBS)
 615
 616 AC_CHECK_FUNCS(mallinfo posix_fallocate fallocate readv sysconf times mkdtemp)
 617 AC_CHECK_DECLS([basename, ffs, asprintf, vasprintf, snprintf, vsnprintf, strverscmp, strndup, memmem])
 618
 619 # Use of ::std::tr1::unordered_map::rehash causes undefined symbols
 620 # at link time with some versions of GCC.
 621 AC_CACHE_CHECK([whether ::std::tr1::unordered_map::rehash is usable.],
 622 [gold_cv_unordered_map_rehash],
 623 [AC_LINK_IFELSE([AC_LANG_PROGRAM([[
 624 #include <tr1/unordered_map>
 625 void bar() { ::std::tr1::unordered_map<int, int> x; x.rehash(10); }
 626 ]])], [gold_cv_unordered_map_rehash=yes], [gold_cv_unordered_map_rehash=no])])
 627 if test "$gold_cv_unordered_map_rehash" = "yes"; then
 628   AC_DEFINE(HAVE_TR1_UNORDERED_MAP_REHASH, 1,
 629             [Define if ::std::tr1::unordered_map::rehash is usable])
 630 fi
 631
 632 # Use of tr1/unordered_map with off_t as a key is not supported on GCC
 633 # 4.1.xx when compiling in 32-bit mode with a 64-bit off_t type.
 634 AC_CACHE_CHECK([whether std::tr1::hash<off_t> is defined],
 635 [gold_cv_hash_off_t],
 636 [CXXFLAGS_hold=$CXXFLAGS
 637 CXXFLAGS="$CXXFLAGS $LFS_CFLAGS"
 638 AC_COMPILE_IFELSE([AC_LANG_SOURCE([
 639 #include <sys/types.h>
 640 #include <tr1/unordered_map>
 641 std::tr1::hash<off_t> h;
 642 ])],
 643 [gold_cv_hash_off_t=yes],
 644 [gold_cv_hash_off_t=no])
 645 CXXFLAGS=$CXXFLAGS_hold])
 646 if test "$gold_cv_hash_off_t" = "yes"; then
 647    AC_DEFINE(HAVE_TR1_HASH_OFF_T, 1,
 648              [Define if std::tr1::hash<off_t> is usable])
 649 fi
 650
 651 # gcc 4.3.0 doesn't recognize the printf attribute on a template
 652 # function.  Check for that.  This is gcc bug 35546.  This test can
 653 # probably be removed after the bug has been fixed for a while.
 654 AC_CACHE_CHECK([whether we can use attributes with template functions],
 655 [gold_cv_template_attribute],
 656 [AC_COMPILE_IFELSE([AC_LANG_SOURCE([
 657 template<typename T> extern void foo(const char*, ...)
 658   __attribute__ ((__format__ (__printf__, 1, 2)));
 659 template<typename T> void foo(const char* format, ...) {}
 660 void bar() { foo<int>("%s\n", "foo"); }
 661 ])], [gold_cv_template_attribute=yes], [gold_cv_template_attribute=no])])
 662 if test "$gold_cv_template_attribute" = "yes"; then
 663   AC_DEFINE(HAVE_TEMPLATE_ATTRIBUTES, 1,
 664             [Define if attributes work on C++ templates])
 665 fi
 666
 667 dnl Check if the system has struct stat::st_mtim.
 668 AC_CACHE_CHECK([for struct stat::st_mtim.],
 669 [gold_cv_stat_st_mtim],
 670 [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 671 #include <sys/stat.h>
 672 long bar() { struct stat s; return (long)(s.st_mtim.tv_sec + s.st_mtim.tv_sec);}
 673 ]])], [gold_cv_stat_st_mtim=yes], [gold_cv_stat_st_mtim=no])])
 674 if test "$gold_cv_stat_st_mtim" = "yes"; then
 675   AC_DEFINE(HAVE_STAT_ST_MTIM, 1,
 676             [Define if struct stat has a field st_mtim with timespec for mtime])
 677 fi
 678
 679 AC_LANG_POP(C++)
 680
 681 AC_CHECK_HEADERS(locale.h)
 682 AC_CHECK_FUNCS(setlocale)
 683 AM_LC_MESSAGES
 684
 685 AM_MAINTAINER_MODE
 686
 687 AC_OUTPUT(Makefile testsuite/Makefile po/Makefile.in:po/Make-in)