configure.ac

   1 dnl Process this file with autoconf to produce a configure script.
   2 dnl Note we do not use AC_PREREQ here!  See aclocal.m4 for what we use instead.
   3 AC_INIT([GNU C Library], [(see version.h)], [https://sourceware.org/bugzilla/],
   4   [glibc], [https://www.gnu.org/software/glibc/])
   5 AC_CONFIG_SRCDIR([include/features.h])
   6 AC_CONFIG_HEADERS([config.h])
   7 AC_CONFIG_AUX_DIR([scripts])
   8
   9 ACX_PKGVERSION([GNU libc])
  10 ACX_BUGURL([https://www.gnu.org/software/libc/bugs.html])
  11 AC_DEFINE_UNQUOTED([PKGVERSION], ["$PKGVERSION"],
  12                    [Package description])
  13 AC_DEFINE_UNQUOTED([REPORT_BUGS_TO], ["$REPORT_BUGS_TO"],
  14                    [Bug reporting address])
  15
  16 # Glibc should not depend on any header files
  17 AC_DEFUN([_AC_INCLUDES_DEFAULT_REQUIREMENTS],
  18   [m4_divert_text([DEFAULTS],
  19     [ac_includes_default='/* none */'])])
  20
  21 # We require GCC, and by default use its preprocessor.  Override AC_PROG_CPP
  22 # here to work around the Autoconf issue discussed in
  23 # <https://sourceware.org/ml/libc-alpha/2013-01/msg00721.html>.
  24 AC_DEFUN([AC_PROG_CPP],
  25 [AC_REQUIRE([AC_PROG_CC])dnl
  26 AC_ARG_VAR([CPP],      [C preprocessor])dnl
  27 _AC_ARG_VAR_CPPFLAGS()dnl
  28 # On Suns, sometimes $CPP names a directory.
  29 if test -n "$CPP" && test -d "$CPP"; then
  30   CPP=
  31 fi
  32 if test -z "$CPP"; then
  33   CPP="$CC -E"
  34 fi
  35 AC_SUBST(CPP)dnl
  36 ])# AC_PROG_CPP
  37
  38 # We require GCC.  Override _AC_PROG_CC_C89 here to work around the Autoconf
  39 # issue discussed in
  40 # <https://sourceware.org/ml/libc-alpha/2013-01/msg00757.html>.
  41 AC_DEFUN([_AC_PROG_CC_C89], [[$1]])
  42
  43 dnl This is here so we can set $subdirs directly based on configure fragments.
  44 AC_CONFIG_SUBDIRS()
  45
  46 AC_CANONICAL_HOST
  47
  48 AC_PROG_CC
  49 if test $host != $build; then
  50   AC_CHECK_PROGS(BUILD_CC, gcc cc)
  51 fi
  52 AC_SUBST(cross_compiling)
  53 AC_PROG_CPP
  54 AC_CHECK_TOOL(READELF, readelf, false)
  55
  56 # We need the C++ compiler only for testing.
  57 AC_PROG_CXX
  58 # It's useless to us if it can't link programs (e.g. missing -lstdc++).
  59 AC_CACHE_CHECK([whether $CXX can link programs], libc_cv_cxx_link_ok, [dnl
  60 AC_LANG_PUSH([C++])
  61 # Default, dynamic case.
  62 AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])],
  63                [libc_cv_cxx_link_ok=yes],
  64                [libc_cv_cxx_link_ok=no])
  65 # Static case.
  66 old_LDFLAGS="$LDFLAGS"
  67 LDFLAGS="$LDFLAGS -static"
  68 AC_LINK_IFELSE([AC_LANG_SOURCE([
  69 #include <iostream>
  70
  71 int
  72 main()
  73 {
  74   std::cout << "Hello, world!";
  75   return 0;
  76 }
  77 ])],
  78                [],
  79                [libc_cv_cxx_link_ok=no])
  80 LDFLAGS="$old_LDFLAGS"
  81 AC_LANG_POP([C++])])
  82 AS_IF([test $libc_cv_cxx_link_ok != yes], [CXX=])
  83
  84 if test "`cd $srcdir; pwd -P`" = "`pwd -P`"; then
  85   AC_MSG_ERROR([you must configure in a separate build directory])
  86 fi
  87
  88 # This will get text that should go into config.make.
  89 config_vars=
  90
  91 # Check for a --with-gd argument and set libgd-LDFLAGS in config.make.
  92 AC_ARG_WITH([gd],
  93             AS_HELP_STRING([--with-gd=DIR],
  94                            [find libgd include dir and library with prefix DIR]),
  95             [dnl
  96 case "$with_gd" in
  97 yes|''|no) ;;
  98 *) libgd_include="-I$withval/include"
  99    libgd_ldflags="-L$withval/lib" ;;
 100 esac
 101 ])
 102 AC_ARG_WITH([gd-include],
 103             AS_HELP_STRING([--with-gd-include=DIR],
 104                            [find libgd include files in DIR]),
 105             [dnl
 106 case "$with_gd_include" in
 107 ''|no) ;;
 108 *) libgd_include="-I$withval" ;;
 109 esac
 110 ])
 111 AC_ARG_WITH([gd-lib],
 112             AS_HELP_STRING([--with-gd-lib=DIR],
 113                            [find libgd library files in DIR]),
 114             [dnl
 115 case "$with_gd_lib" in
 116 ''|no) ;;
 117 *) libgd_ldflags="-L$withval" ;;
 118 esac
 119 ])
 120
 121 if test -n "$libgd_include"; then
 122   config_vars="$config_vars
 123 CFLAGS-memusagestat.c = $libgd_include"
 124 fi
 125 if test -n "$libgd_ldflags"; then
 126   config_vars="$config_vars
 127 libgd-LDFLAGS = $libgd_ldflags"
 128 fi
 129
 130 dnl Arguments to specify presence of other packages/features.
 131 AC_ARG_WITH([binutils],
 132             AS_HELP_STRING([--with-binutils=PATH],
 133                            [specify location of binutils (as and ld)]),
 134             [path_binutils=$withval],
 135             [path_binutils=''])
 136 AC_ARG_WITH([selinux],
 137             AS_HELP_STRING([--with-selinux],
 138                            [if building with SELinux support]),
 139             [with_selinux=$withval],
 140             [with_selinux=auto])
 141
 142 AC_ARG_WITH([headers],
 143             AS_HELP_STRING([--with-headers=PATH],
 144                            [location of system headers to use
 145                             (for example /usr/src/linux/include)
 146                             @<:@default=compiler default@:>@]),
 147             [sysheaders=$withval],
 148             [sysheaders=''])
 149 AC_SUBST(sysheaders)
 150
 151 AC_SUBST(use_default_link)
 152 AC_ARG_WITH([default-link],
 153             AS_HELP_STRING([--with-default-link],
 154                            [do not use explicit linker scripts]),
 155             [use_default_link=$withval],
 156             [use_default_link=default])
 157
 158 dnl Additional build flags injection.
 159 AC_ARG_WITH([nonshared-cflags],
 160             AS_HELP_STRING([--with-nonshared-cflags=CFLAGS],
 161                            [build nonshared libraries with additional CFLAGS]),
 162             [extra_nonshared_cflags=$withval],
 163             [extra_nonshared_cflags=])
 164 AC_SUBST(extra_nonshared_cflags)
 165
 166 AC_ARG_ENABLE([sanity-checks],
 167               AS_HELP_STRING([--disable-sanity-checks],
 168                              [really do not use threads (should not be used except in special situations) @<:@default=yes@:>@]),
 169               [enable_sanity=$enableval],
 170               [enable_sanity=yes])
 171
 172 AC_ARG_ENABLE([shared],
 173               AS_HELP_STRING([--enable-shared],
 174                              [build shared library @<:@default=yes if GNU ld@:>@]),
 175               [shared=$enableval],
 176               [shared=yes])
 177 AC_ARG_ENABLE([profile],
 178               AS_HELP_STRING([--enable-profile],
 179                              [build profiled library @<:@default=no@:>@]),
 180               [profile=$enableval],
 181               [profile=no])
 182 AC_ARG_ENABLE([static-pie],
 183               AS_HELP_STRING([--enable-static-pie],
 184                              [enable static PIE support and use it in the testsuite @<:@default=no@:>@]),
 185               [static_pie=$enableval],
 186               [static_pie=no])
 187 AC_ARG_ENABLE([timezone-tools],
 188               AS_HELP_STRING([--disable-timezone-tools],
 189                              [do not install timezone tools @<:@default=install@:>@]),
 190               [enable_timezone_tools=$enableval],
 191               [enable_timezone_tools=yes])
 192 AC_SUBST(enable_timezone_tools)
 193
 194 AC_ARG_ENABLE([hardcoded-path-in-tests],
 195               AS_HELP_STRING([--enable-hardcoded-path-in-tests],
 196                              [hardcode newly built glibc path in tests @<:@default=no@:>@]),
 197               [hardcoded_path_in_tests=$enableval],
 198               [hardcoded_path_in_tests=no])
 199 AC_SUBST(hardcoded_path_in_tests)
 200
 201 AC_ARG_ENABLE([stackguard-randomization],
 202               AS_HELP_STRING([--enable-stackguard-randomization],
 203                              [initialize __stack_chk_guard canary with a random number at program start]),
 204               [enable_stackguard_randomize=$enableval],
 205               [enable_stackguard_randomize=no])
 206 if test "$enable_stackguard_randomize" = yes; then
 207   AC_DEFINE(ENABLE_STACKGUARD_RANDOMIZE)
 208 fi
 209
 210 AC_ARG_ENABLE([hidden-plt],
 211               AS_HELP_STRING([--disable-hidden-plt],
 212                              [do not hide internal function calls to avoid PLT]),
 213               [hidden=$enableval],
 214               [hidden=yes])
 215 if test "x$hidden" = xno; then
 216   AC_DEFINE(NO_HIDDEN)
 217 fi
 218
 219 AC_ARG_ENABLE([bind-now],
 220               AS_HELP_STRING([--enable-bind-now],
 221                              [disable lazy relocations in DSOs]),
 222               [bindnow=$enableval],
 223               [bindnow=no])
 224 AC_SUBST(bindnow)
 225 if test "x$bindnow" = xyes; then
 226   AC_DEFINE(BIND_NOW)
 227 fi
 228
 229 dnl Build glibc with -fstack-protector, -fstack-protector-all, or
 230 dnl -fstack-protector-strong.
 231 AC_ARG_ENABLE([stack-protector],
 232               AS_HELP_STRING([--enable-stack-protector=@<:@yes|no|all|strong@:>@],
 233                              [Use -fstack-protector[-all|-strong] to detect glibc buffer overflows]),
 234               [enable_stack_protector=$enableval],
 235               [enable_stack_protector=no])
 236 case "$enable_stack_protector" in
 237 all|yes|no|strong) ;;
 238 *) AC_MSG_ERROR([Not a valid argument for --enable-stack-protector: \"$enable_stack_protector\"]);;
 239 esac
 240
 241 dnl On some platforms we cannot use dynamic loading.  We must provide
 242 dnl static NSS modules.
 243 AC_ARG_ENABLE([static-nss],
 244               AS_HELP_STRING([--enable-static-nss],
 245                              [build static NSS modules @<:@default=no@:>@]),
 246               [static_nss=$enableval],
 247               [static_nss=no])
 248 dnl Enable static NSS also if we build no shared objects.
 249 if test x"$static_nss" = xyes || test x"$shared" = xno; then
 250   static_nss=yes
 251   AC_DEFINE(DO_STATIC_NSS)
 252 fi
 253
 254 AC_ARG_ENABLE([force-install],
 255               AS_HELP_STRING([--disable-force-install],
 256                              [don't force installation of files from this package, even if they are older than the installed files]),
 257               [force_install=$enableval],
 258               [force_install=yes])
 259 AC_SUBST(force_install)
 260
 261 AC_ARG_ENABLE([maintainer-mode],
 262               AS_HELP_STRING([--enable-maintainer-mode],
 263                              [enable make rules and dependencies not useful (and sometimes confusing) to the casual installer]),
 264               [maintainer=$enableval],
 265               [maintainer=no])
 266
 267 dnl On some platforms we allow dropping compatibility with all kernel
 268 dnl versions.
 269 AC_ARG_ENABLE([kernel],
 270               AS_HELP_STRING([--enable-kernel=VERSION],
 271                              [compile for compatibility with kernel not older than VERSION]),
 272               [minimum_kernel=$enableval],
 273               [])
 274 dnl Prevent unreasonable values.
 275 if test "$minimum_kernel" = yes || test "$minimum_kernel" = no; then
 276   # Better nothing than this.
 277   minimum_kernel=""
 278 else
 279   if test "$minimum_kernel" = current; then
 280     minimum_kernel=`uname -r 2>/dev/null` || minimum_kernel=
 281   fi
 282 fi
 283
 284 dnl For the development we sometimes want gcc to issue even more warnings.
 285 dnl This is not the default since many of the extra warnings are not
 286 dnl appropriate.
 287 AC_ARG_ENABLE([all-warnings],
 288               AS_HELP_STRING([--enable-all-warnings],
 289                              [enable all useful warnings gcc can issue]),
 290               [all_warnings=$enableval],
 291               [])
 292 AC_SUBST(all_warnings)
 293
 294 AC_ARG_ENABLE([werror],
 295               AS_HELP_STRING([--disable-werror],
 296                              [do not build with -Werror]),
 297               [enable_werror=$enableval],
 298               [enable_werror=yes])
 299 AC_SUBST(enable_werror)
 300
 301 AC_ARG_ENABLE([multi-arch],
 302               AS_HELP_STRING([--enable-multi-arch],
 303                              [enable single DSO with optimizations for multiple architectures]),
 304               [multi_arch=$enableval],
 305               [multi_arch=default])
 306
 307 AC_ARG_ENABLE([experimental-malloc],
 308               AS_HELP_STRING([--disable-experimental-malloc],
 309                              [disable experimental malloc features]),
 310               [experimental_malloc=$enableval],
 311               [experimental_malloc=yes])
 312 AC_SUBST(experimental_malloc)
 313
 314 AC_ARG_ENABLE([memory-tagging],
 315               AS_HELP_STRING([--enable-memory-tagging],
 316                              [enable memory tagging if supported by the architecture @<:@default=no@:>@]),
 317               [memory_tagging=$enableval],
 318               [memory_tagging=no])
 319 if test "$memory_tagging" = yes; then
 320   # Only enable this on architectures that support it.
 321   case $host_cpu in
 322     aarch64)
 323       AC_DEFINE(USE_MTAG)
 324       ;;
 325   esac
 326 fi
 327 AC_SUBST(memory_tagging)
 328
 329 AC_ARG_ENABLE([crypt],
 330               AS_HELP_STRING([--disable-crypt],
 331                              [do not build nor install the passphrase hashing library, libcrypt]),
 332               [build_crypt=$enableval],
 333               [build_crypt=yes])
 334 AC_SUBST(build_crypt)
 335
 336 AC_ARG_ENABLE([nss-crypt],
 337               AS_HELP_STRING([--enable-nss-crypt],
 338                              [enable libcrypt to use nss]),
 339               [nss_crypt=$enableval],
 340               [nss_crypt=no])
 341 if test x$build_libcrypt = xno && test x$nss_crypt = xyes; then
 342   AC_MSG_WARN([--enable-nss-crypt has no effect when libcrypt is disabled])
 343   nss_crypt=no
 344 fi
 345 if test x$nss_crypt = xyes; then
 346   nss_includes=-I$(nss-config --includedir 2>/dev/null)
 347   if test $? -ne 0; then
 348     AC_MSG_ERROR([cannot find include directory with nss-config])
 349   fi
 350   nspr_includes=-I$(nspr-config --includedir 2>/dev/null)
 351   if test $? -ne 0; then
 352     AC_MSG_ERROR([cannot find include directory with nspr-config])
 353   fi
 354   old_CFLAGS="$CFLAGS"
 355   CFLAGS="$CFLAGS $nss_includes $nspr_includes"
 356   AC_COMPILE_IFELSE([AC_LANG_PROGRAM([typedef int PRBool;
 357 #include <hasht.h>
 358 #include <nsslowhash.h>
 359 void f (void) { NSSLOW_Init (); }])],
 360              libc_cv_nss_crypt=yes,
 361              AC_MSG_ERROR([
 362 cannot find NSS headers with lowlevel hash function interfaces]))
 363   old_LIBS="$LIBS"
 364   old_LDFLAGS="$LDFLAGS"
 365   LIBS="$LIBS -lfreebl3"
 366   AC_LINK_IFELSE([AC_LANG_PROGRAM([typedef int PRBool;
 367 #include <hasht.h>
 368 #include <nsslowhash.h>],
 369                                   [NSSLOW_Init();])],
 370                  libc_cv_nss_crypt=yes,
 371                  AC_MSG_ERROR([
 372 cannot link program using lowlevel NSS hash functions]))
 373   # Check to see if there is a static NSS cryptographic library.
 374   # If there isn't then we can't link anything with libcrypt.a,
 375   # and that might mean disabling some static tests.
 376   LDFLAGS="$LDFLAGS -static"
 377   AC_LINK_IFELSE([AC_LANG_PROGRAM([typedef int PRBool;
 378 #include <hasht.h>
 379 #include <nsslowhash.h>],
 380                                   [NSSLOW_Init();])],
 381                  libc_cv_static_nss_crypt=yes,
 382                  libc_cv_static_nss_crypt=no)
 383   LDFLAGS="$old_LDFLAGS"
 384   CFLAGS="$old_CFLAGS"
 385   LIBS="$old_LIBS"
 386 else
 387   libc_cv_nss_crypt=no
 388   libc_cv_static_nss_crypt=no
 389 fi
 390 AC_SUBST(libc_cv_nss_crypt)
 391 AC_SUBST(libc_cv_static_nss_crypt)
 392
 393
 394 AC_ARG_ENABLE([systemtap],
 395               [AS_HELP_STRING([--enable-systemtap],
 396                [enable systemtap static probe points @<:@default=no@:>@])],
 397               [systemtap=$enableval],
 398               [systemtap=no])
 399 if test "x$systemtap" != xno; then
 400   AC_CACHE_CHECK([for systemtap static probe support], libc_cv_sdt, [dnl
 401   old_CFLAGS="$CFLAGS"
 402   CFLAGS="-std=gnu11 $CFLAGS"
 403   AC_COMPILE_IFELSE([AC_LANG_SOURCE([[#include <sys/sdt.h>
 404 void foo (int i, void *p)
 405 {
 406   asm ("" STAP_PROBE_ASM (foo, bar, STAP_PROBE_ASM_TEMPLATE (2)) ""
 407        :: STAP_PROBE_ASM_OPERANDS (2, i, p));
 408 }]])], [libc_cv_sdt=yes], [libc_cv_sdt=no])
 409   CFLAGS="$old_CFLAGS"])
 410   if test $libc_cv_sdt = yes; then
 411     AC_DEFINE([USE_STAP_PROBE])
 412   elif test "x$systemtap" != xauto; then
 413     AC_MSG_FAILURE([systemtap support needs sys/sdt.h with asm support])
 414   fi
 415 fi
 416
 417 AC_ARG_ENABLE([build-nscd],
 418               [AS_HELP_STRING([--disable-build-nscd],
 419                [disable building and installing the nscd daemon])],
 420               [build_nscd=$enableval],
 421               [build_nscd=default])
 422 AC_SUBST(build_nscd)
 423
 424 # Note the use of $use_nscd is near the bottom of the file.
 425 AC_ARG_ENABLE([nscd],
 426               [AS_HELP_STRING([--disable-nscd],
 427                [library functions will not contact the nscd daemon])],
 428               [use_nscd=$enableval],
 429               [use_nscd=yes])
 430
 431 AC_ARG_ENABLE([pt_chown],
 432               [AS_HELP_STRING([--enable-pt_chown],
 433                [Enable building and installing pt_chown])],
 434               [build_pt_chown=$enableval],
 435               [build_pt_chown=no])
 436 AC_SUBST(build_pt_chown)
 437 if test "$build_pt_chown" = yes; then
 438   AC_DEFINE(HAVE_PT_CHOWN)
 439 fi
 440
 441 AC_ARG_ENABLE([tunables],
 442               [AS_HELP_STRING([--enable-tunables],
 443                [Enable tunables support. Known values are 'yes', 'no' and 'valstring'])],
 444               [have_tunables=$enableval],
 445               [have_tunables=yes])
 446 AC_SUBST(have_tunables)
 447 if test "$have_tunables" = yes; then
 448   AC_DEFINE(HAVE_TUNABLES)
 449 fi
 450
 451 # The abi-tags file uses a fairly simplistic model for name recognition that
 452 # can't distinguish i486-pc-linux-gnu fully from i486-pc-gnu.  So we mutate a
 453 # $host_os of `gnu*' here to be `gnu-gnu*' just so that it can tell.
 454 # This doesn't get used much beyond that, so it's fairly safe.
 455 case "$host_os" in
 456 linux*)
 457   ;;
 458 gnu*)
 459   host_os=`echo $host_os | sed -e 's/gnu/gnu-gnu/'`
 460   ;;
 461 esac
 462
 463 AC_ARG_ENABLE([mathvec],
 464               [AS_HELP_STRING([--enable-mathvec],
 465               [Enable building and installing mathvec @<:@default depends on architecture@:>@])],
 466               [build_mathvec=$enableval],
 467               [build_mathvec=notset])
 468
 469 AC_TRY_COMPILE([], [
 470 #ifndef __CET__
 471 # error no CET compiler support
 472 #endif],
 473                [libc_cv_compiler_default_cet=yes],
 474                [libc_cv_compiler_default_cet=no])
 475
 476 AC_ARG_ENABLE([cet],
 477               AS_HELP_STRING([--enable-cet],
 478                              [enable Intel Control-flow Enforcement Technology (CET), x86 only]),
 479               [enable_cet=$enableval],
 480               [enable_cet=$libc_cv_compiler_default_cet])
 481
 482 # We keep the original values in `$config_*' and never modify them, so we
 483 # can write them unchanged into config.make.  Everything else uses
 484 # $machine, $vendor, and $os, and changes them whenever convenient.
 485 config_machine=$host_cpu config_vendor=$host_vendor config_os=$host_os
 486
 487 # Don't allow vendor == "unknown"
 488 test "$config_vendor" = unknown && config_vendor=
 489 config_os="`echo $config_os | sed 's/^unknown-//'`"
 490
 491 # Some configurations imply other options.
 492 elf=yes
 493
 494 # The configure fragment of a port can modify these to supplement
 495 # or override the table in the case statement below.  No fragment should
 496 # ever change the config_* variables, however.
 497 machine=$config_machine
 498 vendor=$config_vendor
 499 os=$config_os
 500 base_os=''
 501
 502 submachine=
 503 AC_ARG_WITH([cpu],
 504             AS_HELP_STRING([--with-cpu=CPU], [select code for CPU variant]),
 505             [dnl
 506   case "$withval" in
 507   yes|'') AC_MSG_ERROR([--with-cpu requires an argument]) ;;
 508   no) ;;
 509   *) submachine="$withval" ;;
 510   esac
 511 ])
 512
 513 # An preconfigure script can set this when it wants to disable the sanity
 514 # check below.
 515 libc_config_ok=no
 516
 517 # A preconfigure script for a system that may or may not use fpu
 518 # sysdeps directories sets this to a preprocessor conditional for
 519 # whether to use such directories.
 520 with_fp_cond=1
 521
 522 dnl Let sysdeps/*/preconfigure act here.
 523 LIBC_PRECONFIGURE([$srcdir], [for sysdeps])
 524
 525
 526 ###
 527 ### By using the undocumented --enable-hacker-mode option for configure
 528 ### one can skip this test to make the configuration not fail for unsupported
 529 ### platforms.
 530 ###
 531 if test -z "$enable_hacker_mode" && test x"$libc_config_ok" != xyes; then
 532   case "$machine-$host_os" in
 533   *-linux* | *-gnu*)
 534     ;;
 535   *)
 536     AC_MSG_ERROR([
 537 *** The GNU C library is currently unavailable for this platform.
 538 *** If you are interested in seeing glibc on this platform visit
 539 *** the "How to submit a new port" in the wiki:
 540 ***   https://sourceware.org/glibc/wiki/#Development
 541 *** and join the community!])
 542     ;;
 543   esac
 544 fi
 545
 546 # Set base_machine if not set by a preconfigure fragment.
 547 test -n "$base_machine" || base_machine=$machine
 548 AC_SUBST(base_machine)
 549
 550 # Determine whether to use fpu or nofpu sysdeps directories.
 551 AC_CACHE_CHECK([for use of fpu sysdeps directories],
 552                libc_cv_with_fp, [dnl
 553 cat > conftest.c <<EOF
 554 #if $with_fp_cond
 555 int dummy;
 556 #else
 557 # error "no hardware floating point"
 558 #endif
 559 EOF
 560 libc_cv_with_fp=no
 561 if ${CC-cc} $CFLAGS $CPPFLAGS -S conftest.c -o conftest.s \
 562    1>&AS_MESSAGE_LOG_FD 2>&AS_MESSAGE_LOG_FD ; then
 563   libc_cv_with_fp=yes
 564 fi
 565 rm -f conftest*])
 566 AC_SUBST(libc_cv_with_fp)
 567
 568 AC_CACHE_CHECK(for -fstack-protector, libc_cv_ssp, [dnl
 569 LIBC_TRY_CC_OPTION([$CFLAGS $CPPFLAGS -Werror -fstack-protector],
 570                    [libc_cv_ssp=yes],
 571                    [libc_cv_ssp=no])
 572 ])
 573
 574 AC_CACHE_CHECK(for -fstack-protector-strong, libc_cv_ssp_strong, [dnl
 575 LIBC_TRY_CC_OPTION([$CFLAGS $CPPFLAGS -Werror -fstack-protector-strong],
 576                    [libc_cv_ssp_strong=yes],
 577                    [libc_cv_ssp_strong=no])
 578 ])
 579
 580 AC_CACHE_CHECK(for -fstack-protector-all, libc_cv_ssp_all, [dnl
 581 LIBC_TRY_CC_OPTION([$CFLAGS $CPPFLAGS -Werror -fstack-protector-all],
 582                    [libc_cv_ssp_all=yes],
 583                    [libc_cv_ssp_all=no])
 584 ])
 585
 586 stack_protector=
 587 no_stack_protector=
 588 if test "$libc_cv_ssp" = yes; then
 589   no_stack_protector="-fno-stack-protector -DSTACK_PROTECTOR_LEVEL=0"
 590   AC_DEFINE(HAVE_CC_NO_STACK_PROTECTOR)
 591 fi
 592
 593 if test "$enable_stack_protector" = yes && test "$libc_cv_ssp" = yes; then
 594   stack_protector="-fstack-protector"
 595   AC_DEFINE(STACK_PROTECTOR_LEVEL, 1)
 596 elif test "$enable_stack_protector" = all && test "$libc_cv_ssp_all" = yes; then
 597   stack_protector="-fstack-protector-all"
 598   AC_DEFINE(STACK_PROTECTOR_LEVEL, 2)
 599 elif test "$enable_stack_protector" = strong && test "$libc_cv_ssp_strong" = yes; then
 600   stack_protector="-fstack-protector-strong"
 601   AC_DEFINE(STACK_PROTECTOR_LEVEL, 3)
 602 else
 603   stack_protector="-fno-stack-protector"
 604   AC_DEFINE(STACK_PROTECTOR_LEVEL, 0)
 605 fi
 606 AC_SUBST(libc_cv_ssp)
 607 AC_SUBST(stack_protector)
 608 AC_SUBST(no_stack_protector)
 609
 610 if test -n "$stack_protector"; then
 611   dnl Don't run configure tests with stack-protection on, to avoid problems with
 612   dnl bootstrapping.
 613   no_ssp=-fno-stack-protector
 614 else
 615   no_ssp=
 616
 617   if test "$enable_stack_protector" != no; then
 618     AC_MSG_ERROR([--enable-stack-protector=$enable_stack_protector specified, but specified level of stack protection is not supported by the compiler.])
 619   fi
 620 fi
 621
 622 # For the multi-arch option we need support in the assembler & linker.
 623 AC_CACHE_CHECK([for assembler and linker STT_GNU_IFUNC support],
 624                libc_cv_ld_gnu_indirect_function, [dnl
 625 cat > conftest.S <<EOF
 626 .type foo,%gnu_indirect_function
 627 foo:
 628 .globl _start
 629 _start:
 630 .globl __start
 631 __start:
 632 .data
 633 #ifdef _LP64
 634 .quad foo
 635 #else
 636 .long foo
 637 #endif
 638 EOF
 639 libc_cv_ld_gnu_indirect_function=no
 640 if ${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \
 641             -nostartfiles -nostdlib $no_ssp \
 642             -o conftest conftest.S 1>&AS_MESSAGE_LOG_FD 2>&AS_MESSAGE_LOG_FD; then
 643   # Do a link to see if the backend supports IFUNC relocs.
 644   $READELF -r conftest 1>&AS_MESSAGE_LOG_FD
 645   LC_ALL=C $READELF -Wr conftest | grep -q 'IRELATIVE\|R_SPARC_JMP_IREL' && {
 646     libc_cv_ld_gnu_indirect_function=yes
 647   }
 648 fi
 649 rm -f conftest*])
 650
 651 # Check if gcc supports attribute ifunc as it is used in libc_ifunc macro.
 652 AC_CACHE_CHECK([for gcc attribute ifunc support],
 653                libc_cv_gcc_indirect_function, [dnl
 654 cat > conftest.c <<EOF
 655 extern int func (int);
 656 int used_func (int a)
 657 {
 658   return a;
 659 }
 660 static void *resolver ()
 661 {
 662   return &used_func;
 663 }
 664 extern __typeof (func) func __attribute__ ((ifunc ("resolver")));
 665 EOF
 666 libc_cv_gcc_indirect_function=no
 667 if ${CC-cc} -c conftest.c -o conftest.o 1>&AS_MESSAGE_LOG_FD \
 668    2>&AS_MESSAGE_LOG_FD ; then
 669   if $READELF -s conftest.o | grep IFUNC >/dev/null 2>&AS_MESSAGE_LOG_FD; then
 670     libc_cv_gcc_indirect_function=yes
 671   fi
 672 fi
 673 rm -f conftest*])
 674
 675 # Check if linker supports textrel relocation with ifunc (used on elf/tests).
 676 # Note that it relies on libc_cv_ld_gnu_indirect_function test above.
 677 AC_CACHE_CHECK([whether the linker supports textrels along with ifunc],
 678                libc_cv_textrel_ifunc, [dnl
 679 cat > conftest.S <<EOF
 680 .type foo,%gnu_indirect_function
 681 foo:
 682 .globl _start
 683 _start:
 684 .globl __start
 685 __start:
 686 .data
 687 #ifdef _LP64
 688 .quad foo
 689 #else
 690 .long foo
 691 #endif
 692 .text
 693 .globl address
 694 address:
 695 #ifdef _LP64
 696 .quad address
 697 #else
 698 .long address
 699 #endif
 700 EOF
 701 libc_cv_textrel_ifunc=no
 702 if test $libc_cv_ld_gnu_indirect_function = yes; then
 703    if AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -nostartfiles -nostdlib $no_ssp -pie -o conftest conftest.S); then
 704      libc_cv_textrel_ifunc=yes
 705    fi
 706 fi
 707 rm -f conftest*])
 708 AC_SUBST(libc_cv_textrel_ifunc)
 709
 710 # Check if CC supports attribute retain as it is used in attribute_used_retain macro.
 711 AC_CACHE_CHECK([for GNU attribute retain support],
 712                libc_cv_gnu_retain, [dnl
 713 cat > conftest.c <<EOF
 714 static int var  __attribute__ ((used, retain, section ("__libc_atexit")));
 715 EOF
 716 libc_cv_gnu_retain=no
 717 if ${CC-cc} -Werror -c conftest.c -o /dev/null 1>&AS_MESSAGE_LOG_FD \
 718    2>&AS_MESSAGE_LOG_FD ; then
 719   libc_cv_gnu_retain=yes
 720 fi
 721 rm -f conftest*])
 722 if test $libc_cv_gnu_retain = yes; then
 723   AC_DEFINE(HAVE_GNU_RETAIN)
 724 fi
 725 LIBC_CONFIG_VAR([have-gnu-retain], [$libc_cv_gnu_retain])
 726
 727 # Check if gcc warns about alias for function with incompatible types.
 728 AC_CACHE_CHECK([if compiler warns about alias for function with incompatible types],
 729                libc_cv_gcc_incompatible_alias, [dnl
 730 cat > conftest.c <<EOF
 731 int __redirect_foo (const void *s, int c);
 732
 733 __typeof (__redirect_foo) *foo_impl (void) __asm__ ("foo");
 734 __typeof (__redirect_foo) *foo_impl (void)
 735 {
 736   return 0;
 737 }
 738
 739 extern __typeof (__redirect_foo) foo_alias __attribute__ ((alias ("foo")));
 740 EOF
 741 libc_cv_gcc_incompatible_alias=yes
 742 if ${CC-cc} -Werror -c conftest.c -o conftest.o 1>&AS_MESSAGE_LOG_FD 2>&AS_MESSAGE_LOG_FD ; then
 743   libc_cv_gcc_incompatible_alias=no
 744 fi
 745 rm -f conftest*])
 746
 747 if test x"$libc_cv_ld_gnu_indirect_function" != xyes; then
 748   if test x"$multi_arch" = xyes; then
 749     AC_MSG_ERROR([--enable-multi-arch support requires assembler and linker support])
 750   else
 751     multi_arch=no
 752   fi
 753 fi
 754 if test x"$libc_cv_gcc_indirect_function" != xyes; then
 755   # GCC 8+ emits a warning for alias with incompatible types and it might
 756   # fail to build ifunc resolvers aliases to either weak or internal
 757   # symbols.  Disables multiarch build in this case.
 758   if test x"$libc_cv_gcc_incompatible_alias" == xyes; then
 759     AC_MSG_WARN([gcc emits a warning for alias between functions of incompatible types])
 760     if test x"$multi_arch" = xyes; then
 761       AC_MSG_ERROR([--enable-multi-arch support requires a gcc with gnu-indirect-function support])
 762     fi
 763     AC_MSG_WARN([Multi-arch is disabled.])
 764     multi_arch=no
 765   elif test x"$multi_arch" = xyes; then
 766     AC_MSG_WARN([--enable-multi-arch support recommends a gcc with gnu-indirect-function support.
 767 Please use a gcc which supports it by default or configure gcc with --enable-gnu-indirect-function])
 768   fi
 769 fi
 770 multi_arch_d=
 771 if test x"$multi_arch" != xno; then
 772   multi_arch_d=/multiarch
 773 fi
 774
 775 # Compute the list of sysdep directories for this configuration.
 776 # This can take a while to compute.
 777 sysdep_dir=$srcdir/sysdeps
 778 AC_MSG_CHECKING(sysdep dirs)
 779 dnl We need to use [ and ] for other purposes for a while now.
 780 changequote(,)dnl
 781 # Make sco3.2v4 become sco3.2.4 and sunos4.1.1_U1 become sunos4.1.1.U1.
 782 os="`echo $os | sed 's/\([0-9A-Z]\)[v_]\([0-9A-Z]\)/\1.\2/g'`"
 783
 784 test "x$base_os" != x || case "$os" in
 785 gnu*)
 786   base_os=mach/hurd ;;
 787 linux*)
 788   base_os=unix/sysv ;;
 789 esac
 790
 791 # For sunos4.1.1, try sunos4.1.1, then sunos4.1, then sunos4, then sunos.
 792 tail=$os
 793 ostry=$os
 794 while o=`echo $tail | sed 's/\.[^.]*$//'`; test $o != $tail; do
 795   ostry="$ostry /$o"
 796   tail=$o
 797 done
 798 o=`echo $tail | sed 's/[0-9]*$//'`
 799 if test $o != $tail; then
 800   ostry="$ostry /$o"
 801 fi
 802 # For linux-gnu, try linux-gnu, then linux.
 803 o=`echo $tail | sed 's/-.*$//'`
 804 if test $o != $tail; then
 805   ostry="$ostry /$o"
 806 fi
 807
 808 # For unix/sysv/sysv4, try unix/sysv/sysv4, then unix/sysv, then unix.
 809 base=
 810 tail=$base_os
 811 while b=`echo $tail | sed 's@^\(.*\)/\([^/]*\)$@& \1@'`; test -n "$b"; do
 812   set $b
 813   base="$base /$1"
 814   tail="$2"
 815 done
 816
 817 # For sparc/sparc32, try sparc/sparc32 and then sparc.
 818 mach=
 819 tail=$machine${submachine:+/$submachine}
 820 while m=`echo $tail | sed 's@^\(.*\)/\([^/]*\)$@& \1@'`; test -n "$m"; do
 821   set $m
 822   # Prepend the machine's FPU directory unless the architecture specific
 823   # preconfigure disables it.
 824   if test "$libc_cv_with_fp" = yes; then
 825     maybe_fpu=/fpu
 826   else
 827     maybe_fpu=/nofpu
 828   fi
 829   # For each machine term, try it with and then without /multiarch.
 830   for try_fpu in $maybe_fpu ''; do
 831     for try_multi in $multi_arch_d ''; do
 832       mach="$mach /$1$try_fpu$try_multi"
 833     done
 834   done
 835   tail="$2"
 836 done
 837
 838 dnl We are done with glob and regexp uses of [ and ]; return to autoconf.
 839 changequote([,])dnl
 840
 841 # Find what sysdep directories exist.
 842 sysnames=
 843 for b in $base ''; do
 844   for m0 in $mach ''; do
 845     for v in /$vendor ''; do
 846       test "$v" = / && continue
 847       for o in /$ostry ''; do
 848         test "$o" = / && continue
 849         for m in $mach ''; do
 850           try_suffix="$m0$b$v$o$m"
 851           if test -n "$try_suffix"; then
 852             try_srcdir="${srcdir}/"
 853             try="sysdeps$try_suffix"
 854             test -n "$enable_debug_configure" &&
 855             echo "$0 [DEBUG]: try $try" >&2
 856             if test -d "$try_srcdir$try"; then
 857               sysnames="$sysnames $try"
 858               { test -n "$o" || test -n "$b"; } && os_used=t
 859               { test -n "$m" || test -n "$m0"; } && machine_used=t
 860               case x${m0:-$m} in
 861               x*/$submachine) submachine_used=t ;;
 862               esac
 863             fi
 864           fi
 865         done
 866       done
 867     done
 868   done
 869 done
 870
 871 # If the assembler supports gnu_indirect_function symbol type and the
 872 # architecture supports multi-arch, we enable multi-arch by default.
 873 case $sysnames in
 874 *"$multi_arch_d"*)
 875   ;;
 876 *)
 877   test x"$multi_arch" = xdefault && multi_arch=no
 878   ;;
 879 esac
 880 if test x"$multi_arch" != xno; then
 881   AC_DEFINE(USE_MULTIARCH)
 882 fi
 883 AC_SUBST(multi_arch)
 884
 885 if test -z "$os_used" && test "$os" != none; then
 886   AC_MSG_ERROR(Operating system $os is not supported.)
 887 fi
 888 if test -z "$machine_used" && test "$machine" != none; then
 889   AC_MSG_ERROR(The $machine is not supported.)
 890 fi
 891 if test -z "$submachine_used" && test -n "$submachine"; then
 892   AC_MSG_ERROR(The $submachine subspecies of $host_cpu is not supported.)
 893 fi
 894 AC_SUBST(submachine)
 895
 896 # We have now validated the configuration.
 897
 898 # Expand the list of system names into a full list of directories
 899 # from each element's parent name and Implies file (if present).
 900 set $sysnames
 901 names=
 902 while test $# -gt 0; do
 903   name=$1
 904   shift
 905
 906   case " $names " in *" $name "*)
 907     # Already in the list.
 908     continue
 909   esac
 910
 911   # Report each name as we discover it, so there is no long pause in output.
 912   echo $ECHO_N "$name $ECHO_C" >&AS_MESSAGE_FD
 913
 914   name_base=`echo $name | sed -e 's@\(.*sysdeps\)/.*@\1@'`
 915
 916   case $name in
 917     /*) xsrcdir= ;;
 918     *)  xsrcdir=$srcdir/ ;;
 919   esac
 920   test -n "$enable_debug_configure" &&
 921   echo "[DEBUG]: name/Implies $xsrcdir$name/Implies" >&2
 922
 923   for implies_file in Implies Implies-before Implies-after; do
 924     implies_type=`echo $implies_file | sed s/-/_/`
 925     eval ${implies_type}=
 926     if test -f $xsrcdir$name/$implies_file; then
 927       # Collect more names from the `Implies' file (removing comments).
 928       implied_candidate="`sed 's/#.*$//' < $xsrcdir$name/$implies_file`"
 929       for x in $implied_candidate; do
 930         found=no
 931         if test -d $xsrcdir$name_base/$x; then
 932           eval "${implies_type}=\"\$${implies_type} \$name_base/\$x\""
 933           found=yes
 934         fi
 935         try="sysdeps/$x"
 936         try_srcdir=$srcdir/
 937         test -n "$enable_debug_configure" &&
 938          echo "[DEBUG]: $name $implies_file $x try() {$try_srcdir}$try" >&2
 939         if test $try != $xsrcdir$name_base/$x && test -d $try_srcdir$try;
 940         then
 941           eval "${implies_type}=\"\$${implies_type} \$try\""
 942           found=yes
 943         fi
 944         if test $found = no; then
 945           AC_MSG_WARN($name/$implies_file specifies nonexistent $x)
 946         fi
 947       done
 948     fi
 949   done
 950
 951   # Add NAME to the list of names.
 952   names="$names $name"
 953
 954   # Find the parent of NAME, using the empty string if it has none.
 955 changequote(,)dnl
 956   parent="`echo $name | sed -n -e 's=/[^/]*$==' -e '/sysdeps$/q' -e p`"
 957 changequote([,])dnl
 958
 959   test -n "$enable_debug_configure" &&
 960     echo "[DEBUG]: $name Implies='$Implies' rest='$*' parent='$parent' \
 961 Implies_before='$Implies_before' Implies_after='$Implies_after'" >&2
 962
 963   # Add the names implied by NAME, and NAME's parent (if it has one), to
 964   # the list of names to be processed (the argument list).  We prepend the
 965   # implied names to the list and append the parent.  We want implied
 966   # directories to come before further directories inferred from the
 967   # configuration components; this ensures that for sysv4, unix/common
 968   # (implied by unix/sysv/sysv4) comes before unix/sysv (in ostry (here $*)
 969   # after sysv4).
 970   sysnames="`echo $Implies $* $Implies_before $parent $Implies_after`"
 971   test -n "$sysnames" && set $sysnames
 972 done
 973
 974 # Add the default directories.
 975 default_sysnames="sysdeps/generic"
 976 sysnames="$names $default_sysnames"
 977 AC_SUBST(sysnames)
 978 # The other names were emitted during the scan.
 979 AC_MSG_RESULT($default_sysnames)
 980
 981
 982 ### Locate tools.
 983
 984 AC_PROG_INSTALL
 985 if test "$INSTALL" = "${srcdir}/scripts/install-sh -c"; then
 986   # The makefiles need to use a different form to find it in $srcdir.
 987   INSTALL='\$(..)./scripts/install-sh -c'
 988 fi
 989 AC_PROG_LN_S
 990
 991 LIBC_PROG_BINUTILS
 992
 993 # Accept binutils 2.25 or newer.
 994 AC_CHECK_PROG_VER(AS, $AS, --version,
 995                   [GNU assembler.* \([0-9]*\.[0-9.]*\)],
 996                   [2.1[0-9][0-9]*|2.2[5-9]*|2.[3-9][0-9]*|[3-9].*|[1-9][0-9]*],
 997                   AS=: critic_missing="$critic_missing as")
 998
 999 if test -n "`$LD --version | sed -n 's/^GNU \(gold\).*$/\1/p'`"; then
1000   # Accept gold 1.14 or higher
1001   AC_CHECK_PROG_VER(LD, $LD, --version,
1002                     [GNU gold.* \([0-9][0-9]*\.[0-9.]*\)],
1003                     [1.1[4-9]*|1.[2-9][0-9]*|1.1[0-9][0-9]*|[2-9].*|[1-9][0-9]*],
1004                     LD=: critic_missing="$critic_missing GNU gold")
1005 else
1006   AC_CHECK_PROG_VER(LD, $LD, --version,
1007                     [GNU ld.* \([0-9][0-9]*\.[0-9.]*\)],
1008                     [2.1[0-9][0-9]*|2.2[5-9]*|2.[3-9][0-9]*|[3-9].*|[1-9][0-9]*],
1009                     LD=: critic_missing="$critic_missing GNU ld")
1010 fi
1011
1012 # These programs are version sensitive.
1013 AC_CHECK_PROG_VER(MAKE, gnumake gmake make, --version,
1014   [GNU Make[^0-9]*\([0-9][0-9.]*\)],
1015   [[4-9].* | [1-9][0-9]*], critic_missing="$critic_missing make")
1016
1017 AC_CHECK_PROG_VER(MSGFMT, gnumsgfmt gmsgfmt msgfmt, --version,
1018   [GNU gettext.* \([0-9]*\.[0-9.]*\)],
1019   [0.10.3[6-9]* | 0.10.[4-9][0-9]* | 0.1[1-9]* | 0.[2-9][0-9]* | [1-9].*],
1020   MSGFMT=: aux_missing="$aux_missing msgfmt")
1021 AC_CHECK_PROG_VER(MAKEINFO, makeinfo, --version,
1022   [GNU texinfo.* \([0-9][0-9.]*\)],
1023   [4.[7-9]*|4.[1-9][0-9]*|[5-9].*],
1024   MAKEINFO=: aux_missing="$aux_missing makeinfo")
1025 AC_CHECK_PROG_VER(SED, sed, --version,
1026   [GNU sed[^0-9]* \([0-9]*\.[0-9.]*\)],
1027   [3.0[2-9]*|3.[1-9]*|[4-9]*],
1028   SED=: aux_missing="$aux_missing sed")
1029 AC_CHECK_PROG_VER(AWK, gawk, --version,
1030   [GNU Awk[^0-9]*\([0-9][0-9.]*\)],
1031   [3.1.[2-9]*|3.[2-9]*|[4-9]*], critic_missing="$critic_missing gawk")
1032 AC_CHECK_PROG_VER(BISON, bison, --version,
1033   [bison (GNU Bison) \([0-9]*\.[0-9.]*\)],
1034   [2.7*|[3-9].*|[1-9][0-9]*], critic_missing="$critic_missing bison")
1035
1036 AC_CACHE_CHECK([if $CC is sufficient to build libc], libc_cv_compiler_ok, [
1037 AC_TRY_COMPILE([], [
1038 #if !defined __GNUC__ || __GNUC__ < 6 || (__GNUC__ == 6 && __GNUC_MINOR__ < 2)
1039 #error insufficient compiler
1040 #endif],
1041                [libc_cv_compiler_ok=yes],
1042                [libc_cv_compiler_ok=no])])
1043 AS_IF([test $libc_cv_compiler_ok != yes],
1044       [critic_missing="$critic_missing compiler"])
1045
1046 AC_CHECK_TOOL(NM, nm, false)
1047
1048 if test "x$maintainer" = "xyes"; then
1049   AC_CHECK_PROGS(AUTOCONF, autoconf, no)
1050   case "x$AUTOCONF" in
1051   xno|x|x:) AUTOCONF=no ;;
1052   *)
1053     AC_CACHE_CHECK(dnl
1054   whether $AUTOCONF${ACFLAGS:+ }$ACFLAGS works, libc_cv_autoconf_works, [dnl
1055     if (cd $srcdir; $AUTOCONF $ACFLAGS configure.ac > /dev/null 2>&1); then
1056       libc_cv_autoconf_works=yes
1057     else
1058       libc_cv_autoconf_works=no
1059     fi])
1060     test $libc_cv_autoconf_works = yes || AUTOCONF=no
1061     ;;
1062   esac
1063   if test "x$AUTOCONF" = xno; then
1064     aux_missing="$aux_missing autoconf"
1065   fi
1066 else
1067   AUTOCONF=no
1068 fi
1069
1070 # Check for python3 if available, or else python.
1071 AC_CHECK_PROG_VER(PYTHON_PROG, python3 python, --version,
1072   [Python \([0-9][0-9.]*\)],
1073   [3.[4-9]*|3.[1-9][0-9]*|[4-9].*|[1-9][0-9]*],
1074   critic_missing="$critic_missing python")
1075 PYTHON="$PYTHON_PROG -B"
1076 AC_SUBST(PYTHON)
1077
1078 test -n "$critic_missing" && AC_MSG_ERROR([
1079 *** These critical programs are missing or too old:$critic_missing
1080 *** Check the INSTALL file for required versions.])
1081
1082 test -n "$aux_missing" && AC_MSG_WARN([
1083 *** These auxiliary programs are missing or incompatible versions:$aux_missing
1084 *** some features or tests will be disabled.
1085 *** Check the INSTALL file for required versions.])
1086
1087 # if using special system headers, find out the compiler's sekrit
1088 # header directory and add that to the list.  NOTE: Only does the right
1089 # thing on a system that doesn't need fixincludes.  (Not presently a problem.)
1090 if test -n "$sysheaders"; then
1091   SYSINCLUDES=-nostdinc
1092   for d in include include-fixed; do
1093     i=`$CC -print-file-name="$d"` && test "x$i" != x && test "x$i" != "x$d" &&
1094     SYSINCLUDES="$SYSINCLUDES -isystem $i"
1095   done
1096   SYSINCLUDES="$SYSINCLUDES \
1097 -isystem `echo $sysheaders | sed 's/:/ -isystem /g'`"
1098   if test -n "$CXX"; then
1099     CXX_SYSINCLUDES=
1100     for cxxheaders in `$CXX -v -S -x c++ /dev/null -o /dev/null 2>&1 \
1101     | sed -n -e '1,/#include/d' -e 's/^ \(\/.*\/[cg]++\)/\1/p'`; do
1102       test "x$cxxheaders" != x &&
1103       CXX_SYSINCLUDES="$CXX_SYSINCLUDES -isystem $cxxheaders"
1104     done
1105   fi
1106 fi
1107 AC_SUBST(SYSINCLUDES)
1108 AC_SUBST(CXX_SYSINCLUDES)
1109
1110 # Obtain some C++ header file paths.  This is used to make a local
1111 # copy of those headers in Makerules.
1112 if test -n "$CXX"; then
1113   find_cxx_header () {
1114     echo "#include <$1>" | $CXX -M -MP -x c++ - 2>/dev/null \
1115          | sed -n "\,$1:,{s/:\$//;p}"
1116   }
1117   CXX_CSTDLIB_HEADER="$(find_cxx_header cstdlib)"
1118   CXX_CMATH_HEADER="$(find_cxx_header cmath)"
1119   CXX_BITS_STD_ABS_H="$(find_cxx_header bits/std_abs.h)"
1120 fi
1121 AC_SUBST(CXX_CSTDLIB_HEADER)
1122 AC_SUBST(CXX_CMATH_HEADER)
1123 AC_SUBST(CXX_BITS_STD_ABS_H)
1124
1125 # Test if LD_LIBRARY_PATH contains the notation for the current directory
1126 # since this would lead to problems installing/building glibc.
1127 # LD_LIBRARY_PATH contains the current directory if one of the following
1128 # is true:
1129 # - one of the terminals (":" and ";") is the first or last sign
1130 # - two terminals occur directly after each other
1131 # - the path contains an element with a dot in it
1132 AC_MSG_CHECKING(LD_LIBRARY_PATH variable)
1133 changequote(,)dnl
1134 case ${LD_LIBRARY_PATH} in
1135   [:\;]* | *[:\;] | *[:\;][:\;]* |  *[:\;]. | .[:\;]*| . | *[:\;].[:\;]* )
1136     ld_library_path_setting="contains current directory"
1137     ;;
1138   *)
1139     ld_library_path_setting="ok"
1140     ;;
1141 esac
1142 changequote([,])dnl
1143 AC_MSG_RESULT($ld_library_path_setting)
1144 if test "$ld_library_path_setting" != "ok"; then
1145 AC_MSG_ERROR([
1146 *** LD_LIBRARY_PATH shouldn't contain the current directory when
1147 *** building glibc. Please change the environment variable
1148 *** and run configure again.])
1149 fi
1150
1151 AC_PATH_PROG(BASH_SHELL, bash, no)
1152
1153 AC_PATH_PROG(PERL, perl, no)
1154 if test "$PERL" != no &&
1155    (eval `$PERL -V:apiversion`; test `expr "$apiversion" \< 5` -ne 0); then
1156   PERL=no
1157 fi
1158 AC_PATH_PROG(INSTALL_INFO, install-info, no,
1159              $PATH:/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin)
1160
1161 AC_CACHE_CHECK(for .set assembler directive, libc_cv_asm_set_directive, [dnl
1162 cat > conftest.s <<EOF
1163 .text
1164 foo:
1165 .set glibc_conftest_frobozz,foo
1166 .globl glibc_conftest_frobozz
1167 EOF
1168 # The alpha-dec-osf1 assembler gives only a warning for `.set'
1169 # (but it doesn't work), so we must do a linking check to be sure.
1170 cat > conftest1.c <<\EOF
1171 extern int glibc_conftest_frobozz;
1172 void _start() { glibc_conftest_frobozz = 1; }
1173 EOF
1174 if ${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \
1175             -nostartfiles -nostdlib $no_ssp \
1176             -o conftest conftest.s conftest1.c 1>&AS_MESSAGE_LOG_FD 2>&AS_MESSAGE_LOG_FD; then
1177   libc_cv_asm_set_directive=yes
1178 else
1179   libc_cv_asm_set_directive=no
1180 fi
1181 rm -f conftest*])
1182 if test $libc_cv_asm_set_directive = yes; then
1183   AC_DEFINE(HAVE_ASM_SET_DIRECTIVE)
1184 fi
1185
1186 AC_CACHE_CHECK(linker support for protected data symbol,
1187                libc_cv_protected_data,
1188                [cat > conftest.c <<EOF
1189                 int bar __attribute__ ((visibility ("protected"))) = 1;
1190 EOF
1191                 libc_cv_protected_data=no
1192                 if AC_TRY_COMMAND(${CC-cc} -nostdlib -nostartfiles $no_ssp -fPIC -shared conftest.c -o conftest.so); then
1193                   cat > conftest.c <<EOF
1194                   extern int bar;
1195                   int main (void) { return bar; }
1196 EOF
1197                   if AC_TRY_COMMAND(${CC-cc} -nostdlib -nostartfiles $no_ssp conftest.c -o conftest conftest.so); then
1198                     libc_cv_protected_data=yes
1199                   fi
1200                 fi
1201                 rm -f conftest.*
1202                ])
1203 AC_SUBST(libc_cv_protected_data)
1204
1205 AC_CACHE_CHECK(linker support for INSERT in linker script,
1206                libc_cv_insert,
1207                [cat > conftest.c <<EOF
1208                 const int __attribute__ ((section(".bar"))) bar = 0x12345678;
1209                 int test (void) { return bar; }
1210 EOF
1211                 cat > conftest.t <<EOF
1212                 SECTIONS
1213                 {
1214                   .bar : { *(.bar) }
1215                 }
1216                 INSERT AFTER .rela.dyn;
1217 EOF
1218                 libc_cv_insert=no
1219                 if AC_TRY_COMMAND([${CC-cc} -nostdlib -nostartfiles $no_ssp -fPIC -shared conftest.c -Wl,-T,conftest.t -o conftest.so]); then
1220                   libc_cv_insert=yes
1221                 fi
1222                 rm -f conftest.*
1223                ])
1224 AC_SUBST(libc_cv_insert)
1225
1226 AC_CACHE_CHECK(for broken __attribute__((alias())),
1227                libc_cv_broken_alias_attribute,
1228                [cat > conftest.c <<EOF
1229                extern int foo (int x) __asm ("xyzzy");
1230                int bar (int x) { return x; }
1231                extern __typeof (bar) foo __attribute ((weak, alias ("bar")));
1232                extern int dfoo;
1233                extern __typeof (dfoo) dfoo __asm ("abccb");
1234                int dfoo = 1;
1235 EOF
1236                libc_cv_broken_alias_attribute=yes
1237                if AC_TRY_COMMAND(${CC-cc} -Werror -S conftest.c -o conftest.s 1>&AS_MESSAGE_LOG_FD); then
1238                  if grep 'xyzzy' conftest.s >/dev/null &&
1239                     grep 'abccb' conftest.s >/dev/null; then
1240                    libc_cv_broken_alias_attribute=no
1241                  fi
1242                fi
1243                rm -f conftest.c conftest.s
1244                ])
1245 if test $libc_cv_broken_alias_attribute = yes; then
1246   AC_MSG_ERROR(working alias attribute support required)
1247 fi
1248
1249 AC_CACHE_CHECK(whether to put _rtld_local into .sdata section,
1250                libc_cv_have_sdata_section,
1251                [echo "int i;" > conftest.c
1252                 libc_cv_have_sdata_section=no
1253                 if ${CC-cc} $LDFLAGS -fPIC -shared -Wl,--verbose conftest.c -o conftest.so 2>&1 \
1254                    | grep '\.sdata' >/dev/null; then
1255                   libc_cv_have_sdata_section=yes
1256                 fi
1257                 rm -f conftest.c conftest.so
1258                ])
1259 if test $libc_cv_have_sdata_section = yes; then
1260   AC_DEFINE(HAVE_SDATA_SECTION)
1261 fi
1262
1263 AC_CACHE_CHECK(for libunwind-support in compiler,
1264                libc_cv_cc_with_libunwind, [
1265   cat > conftest.c <<EOF
1266 int main (void) { return 0; }
1267 EOF
1268   if ${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -static -o conftest \
1269      conftest.c -v 2>&1 >/dev/null | grep ' -lunwind ' >/dev/null; then
1270     libc_cv_cc_with_libunwind=yes
1271   else
1272     libc_cv_cc_with_libunwind=no
1273   fi
1274   rm -f conftest*])
1275 AC_SUBST(libc_cv_cc_with_libunwind)
1276 if test $libc_cv_cc_with_libunwind = yes; then
1277   AC_DEFINE(HAVE_CC_WITH_LIBUNWIND)
1278 fi
1279
1280 ASFLAGS_config=
1281 AC_CACHE_CHECK(whether --noexecstack is desirable for .S files,
1282                libc_cv_as_noexecstack, [dnl
1283 cat > conftest.c <<EOF
1284 void foo (void) { }
1285 EOF
1286 if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS
1287                    -S -o conftest.s conftest.c 1>&AS_MESSAGE_LOG_FD]) \
1288    && grep .note.GNU-stack conftest.s >/dev/null \
1289    && AC_TRY_COMMAND([${CC-cc} $ASFLAGS -Wa,--noexecstack
1290                       -c -o conftest.o conftest.s 1>&AS_MESSAGE_LOG_FD])
1291 then
1292   libc_cv_as_noexecstack=yes
1293 else
1294   libc_cv_as_noexecstack=no
1295 fi
1296 rm -f conftest*])
1297 if test $libc_cv_as_noexecstack = yes; then
1298   ASFLAGS_config="$ASFLAGS_config -Wa,--noexecstack"
1299 fi
1300 AC_SUBST(ASFLAGS_config)
1301
1302 AC_CACHE_CHECK(for -z combreloc,
1303                libc_cv_z_combreloc, [dnl
1304 cat > conftest.c <<EOF
1305 extern int bar (int);
1306 extern int mumble;
1307 int foo (void) { return bar (mumble); }
1308 EOF
1309 if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS
1310                         -fPIC -shared $no_ssp -o conftest.so conftest.c
1311                         -nostdlib -nostartfiles
1312                         -Wl,-z,combreloc 1>&AS_MESSAGE_LOG_FD])
1313 then
1314 dnl The following test is a bit weak.  We must use a tool which can test
1315 dnl cross-platform since the gcc used can be a cross compiler.  Without
1316 dnl introducing new options this is not easily doable.  Instead use a tool
1317 dnl which always is cross-platform: readelf.  To detect whether -z combreloc
1318 dnl look for a section named .rel.dyn or .rela.dyn.
1319   if $READELF -S conftest.so | grep -E '.rela?.dyn' > /dev/null; then
1320     libc_cv_z_combreloc=yes
1321   else
1322     libc_cv_z_combreloc=no
1323   fi
1324 else
1325   libc_cv_z_combreloc=no
1326 fi
1327 rm -f conftest*])
1328 if test "$libc_cv_z_combreloc" = yes; then
1329   AC_DEFINE(HAVE_Z_COMBRELOC)
1330 fi
1331 AC_SUBST(libc_cv_z_combreloc)
1332
1333 LIBC_LINKER_FEATURE([-z execstack], [-Wl,-z,execstack],
1334                     [libc_cv_z_execstack=yes], [libc_cv_z_execstack=no])
1335 AC_SUBST(libc_cv_z_execstack)
1336
1337 LIBC_LINKER_FEATURE([-z start-stop-gc], [-Wl,-z,start-stop-gc],
1338                     [libc_cv_z_start_stop_gc=yes], [libc_cv_z_start_stop_gc=no])
1339 LIBC_CONFIG_VAR([have-z-start-stop-gc], [$libc_cv_z_start_stop_gc])
1340
1341 LIBC_LINKER_FEATURE([--no-dynamic-linker],
1342                     [-Wl,--no-dynamic-linker],
1343                     [libc_cv_no_dynamic_linker=yes],
1344                     [libc_cv_no_dynamic_linker=no])
1345 LIBC_CONFIG_VAR([have-no-dynamic-linker], [$libc_cv_no_dynamic_linker])
1346
1347 AC_CACHE_CHECK(for -static-pie, libc_cv_static_pie, [dnl
1348 LIBC_TRY_CC_OPTION([-static-pie],
1349                    [libc_cv_static_pie=yes],
1350                    [libc_cv_static_pie=no])
1351 ])
1352 LIBC_CONFIG_VAR([have-static-pie], [$libc_cv_static_pie])
1353
1354 AC_CACHE_CHECK(for -fpie, libc_cv_fpie, [dnl
1355 LIBC_TRY_CC_OPTION([-fpie], [libc_cv_fpie=yes], [libc_cv_fpie=no])
1356 ])
1357
1358 AC_SUBST(libc_cv_fpie)
1359
1360 AC_CACHE_CHECK(for --hash-style option,
1361                libc_cv_hashstyle, [dnl
1362 cat > conftest.c <<EOF
1363 int _start (void) { return 42; }
1364 EOF
1365 if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS $no_ssp
1366                             -fPIC -shared -o conftest.so conftest.c
1367                             -Wl,--hash-style=both -nostdlib 1>&AS_MESSAGE_LOG_FD])
1368 then
1369   libc_cv_hashstyle=yes
1370 else
1371   libc_cv_hashstyle=no
1372 fi
1373 rm -f conftest*])
1374 AC_SUBST(libc_cv_hashstyle)
1375
1376 # The linker's default -shared behavior is good enough if it
1377 # does these things that our custom linker scripts ensure that
1378 # all allocated NOTE sections come first.
1379 if test "$use_default_link" = default; then
1380   AC_CACHE_CHECK([for sufficient default -shared layout],
1381                   libc_cv_use_default_link, [dnl
1382   libc_cv_use_default_link=no
1383   cat > conftest.s <<\EOF
1384           .section .note.a,"a",%note
1385           .balign 4
1386           .long 4,4,9
1387           .string "GNU"
1388           .string "foo"
1389           .section .note.b,"a",%note
1390           .balign 4
1391           .long 4,4,9
1392           .string "GNU"
1393           .string "bar"
1394 EOF
1395   if AC_TRY_COMMAND([dnl
1396   ${CC-cc} $ASFLAGS -shared -o conftest.so conftest.s 1>&AS_MESSAGE_LOG_FD]) &&
1397        ac_try=`$READELF -S conftest.so | sed -n \
1398          ['${x;p;}
1399           s/^ *\[ *[1-9][0-9]*\]  *\([^ ][^ ]*\)  *\([^ ][^ ]*\) .*$/\2 \1/
1400           t a
1401           b
1402           : a
1403           H']`
1404   then
1405     libc_seen_a=no libc_seen_b=no
1406     set -- $ac_try
1407     while test $# -ge 2 -a "$1" = NOTE; do
1408       case "$2" in
1409       .note.a) libc_seen_a=yes ;;
1410       .note.b) libc_seen_b=yes ;;
1411       esac
1412       shift 2
1413     done
1414     case "$libc_seen_a$libc_seen_b" in
1415     yesyes)
1416       libc_cv_use_default_link=yes
1417       ;;
1418     *)
1419       echo >&AS_MESSAGE_LOG_FD "\
1420 $libc_seen_a$libc_seen_b from:
1421 $ac_try"
1422       ;;
1423     esac
1424   fi
1425   rm -f conftest*])
1426   use_default_link=$libc_cv_use_default_link
1427 fi
1428
1429 AC_CACHE_CHECK(for GLOB_DAT reloc,
1430                libc_cv_has_glob_dat, [dnl
1431 cat > conftest.c <<EOF
1432 extern int mumble;
1433 int foo (void) { return mumble; }
1434 EOF
1435 if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS
1436                         -fPIC -shared -o conftest.so conftest.c
1437                         -nostdlib -nostartfiles $no_ssp
1438                         1>&AS_MESSAGE_LOG_FD])
1439 then
1440 dnl look for GLOB_DAT relocation.
1441   if $READELF -rW conftest.so | grep '_GLOB_DAT' > /dev/null; then
1442     libc_cv_has_glob_dat=yes
1443   else
1444     libc_cv_has_glob_dat=no
1445   fi
1446 else
1447   libc_cv_has_glob_dat=no
1448 fi
1449 rm -f conftest*])
1450 AC_SUBST(libc_cv_has_glob_dat)
1451
1452 AC_CACHE_CHECK(for -fno-toplevel-reorder -fno-section-anchors, libc_cv_fno_toplevel_reorder, [dnl
1453 cat > conftest.c <<EOF
1454 int foo;
1455 EOF
1456 if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -S -fno-toplevel-reorder -fno-section-anchors
1457                             conftest.c 1>&AS_MESSAGE_LOG_FD])
1458 then
1459   libc_cv_fno_toplevel_reorder=yes
1460 else
1461   libc_cv_fno_toplevel_reorder=no
1462 fi
1463 rm -f conftest*])
1464 if test $libc_cv_fno_toplevel_reorder = yes; then
1465   fno_unit_at_a_time="-fno-toplevel-reorder -fno-section-anchors"
1466 else
1467   fno_unit_at_a_time=-fno-unit-at-a-time
1468 fi
1469 AC_SUBST(fno_unit_at_a_time)
1470
1471 AC_CACHE_CHECK([for -mtls-dialect=gnu2], libc_cv_mtls_dialect_gnu2,
1472 [dnl
1473 cat > conftest.c <<EOF
1474 __thread int i;
1475 void foo (void)
1476 {
1477   i = 10;
1478 }
1479 EOF
1480 if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -S -fPIC -mtls-dialect=gnu2
1481                    conftest.c 1>&AS_MESSAGE_LOG_FD])
1482 then
1483   libc_cv_mtls_dialect_gnu2=yes
1484 else
1485   libc_cv_mtls_dialect_gnu2=no
1486 fi
1487 rm -f conftest*])
1488 AC_SUBST(libc_cv_mtls_dialect_gnu2)
1489 LIBC_CONFIG_VAR([have-mtls-dialect-gnu2], [$libc_cv_mtls_dialect_gnu2])
1490
1491 AC_CACHE_CHECK(whether cc puts quotes around section names,
1492                libc_cv_have_section_quotes,
1493                [cat > conftest.c <<EOF
1494                 static const int foo
1495                 __attribute__ ((section ("bar"))) = 1;
1496 EOF
1497                 if ${CC-cc} -S conftest.c -o conftest.s; then
1498                   if grep '\.section.*"bar"' conftest.s >/dev/null; then
1499                     libc_cv_have_section_quotes=yes
1500                   else
1501                     libc_cv_have_section_quotes=no
1502                   fi
1503                 else
1504                   libc_cv_have_section_quotes=unknown
1505                 fi
1506                 rm -f conftest.{c,s}
1507                 ])
1508 if test $libc_cv_have_section_quotes = yes; then
1509   AC_DEFINE(HAVE_SECTION_QUOTES)
1510 fi
1511
1512 AC_CACHE_CHECK(for __builtin_memset, libc_cv_gcc_builtin_memset, [dnl
1513 cat > conftest.c <<\EOF
1514 void zero (void *x)
1515 {
1516   __builtin_memset (x, 0, 1000);
1517 }
1518 EOF
1519 dnl
1520 if AC_TRY_COMMAND([${CC-cc} -O3 -S conftest.c -o - | grep -F "memset" > /dev/null]);
1521 then
1522   libc_cv_gcc_builtin_memset=no
1523 else
1524   libc_cv_gcc_builtin_memset=yes
1525 fi
1526 rm -f conftest* ])
1527 if test "$libc_cv_gcc_builtin_memset" = yes ; then
1528   AC_DEFINE(HAVE_BUILTIN_MEMSET)
1529 fi
1530
1531 AC_CACHE_CHECK(for redirection of built-in functions, libc_cv_gcc_builtin_redirection, [dnl
1532 cat > conftest.c <<\EOF
1533 extern char *strstr (const char *, const char *) __asm ("my_strstr");
1534 char *foo (const char *a, const char *b)
1535 {
1536   return __builtin_strstr (a, b);
1537 }
1538 EOF
1539 dnl
1540 if AC_TRY_COMMAND([${CC-cc} -O3 -S conftest.c -o - | grep -F "my_strstr" > /dev/null]);
1541 then
1542   libc_cv_gcc_builtin_redirection=yes
1543 else
1544   libc_cv_gcc_builtin_redirection=no
1545 fi
1546 rm -f conftest* ])
1547 if test "$libc_cv_gcc_builtin_redirection" = no; then
1548   AC_MSG_ERROR([support for the symbol redirection needed])
1549 fi
1550
1551 dnl Determine how to disable generation of FMA instructions.
1552 AC_CACHE_CHECK([for compiler option to disable generation of FMA instructions],
1553                libc_cv_cc_nofma, [dnl
1554 libc_cv_cc_nofma=
1555 for opt in -ffp-contract=off -mno-fused-madd; do
1556   LIBC_TRY_CC_OPTION([$opt], [libc_cv_cc_nofma=$opt; break])
1557 done])
1558 AC_SUBST(libc_cv_cc_nofma)
1559
1560 if test -n "$submachine"; then
1561   AC_CACHE_CHECK([for compiler option for CPU variant],
1562                  libc_cv_cc_submachine, [dnl
1563   libc_cv_cc_submachine=no
1564   for opt in "-march=$submachine" "-mcpu=$submachine"; do
1565     LIBC_TRY_CC_OPTION([$opt], [
1566       libc_cv_cc_submachine="$opt"
1567       break], [])
1568   done])
1569   if test "x$libc_cv_cc_submachine" = xno; then
1570     AC_MSG_ERROR([${CC-cc} does not support $submachine])
1571   fi
1572 fi
1573 AC_SUBST(libc_cv_cc_submachine)
1574
1575 AC_CACHE_CHECK(if $CC accepts -fno-tree-loop-distribute-patterns with \
1576 __attribute__ ((__optimize__)), libc_cv_cc_loop_to_function, [dnl
1577 cat > conftest.c <<EOF
1578 void
1579 __attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns")))
1580 foo (void) {}
1581 EOF
1582 libc_cv_cc_loop_to_function=no
1583 if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -c conftest.c])
1584 then
1585   libc_cv_cc_loop_to_function=yes
1586 fi
1587 rm -f conftest*])
1588 if test $libc_cv_cc_loop_to_function = yes; then
1589   AC_DEFINE(HAVE_CC_INHIBIT_LOOP_TO_LIBCALL)
1590 fi
1591 AC_SUBST(libc_cv_cc_loop_to_function)
1592
1593 dnl Check whether we have the gd library available.
1594 AC_MSG_CHECKING(for libgd)
1595 if test "$with_gd" != "no"; then
1596   old_CFLAGS="$CFLAGS"
1597   CFLAGS="$CFLAGS $libgd_include"
1598   old_LDFLAGS="$LDFLAGS"
1599   LDFLAGS="$LDFLAGS $libgd_ldflags"
1600   old_LIBS="$LIBS"
1601   LIBS="$LIBS -lgd -lpng -lz -lm"
1602   AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <gd.h>]], [[gdImagePng (0, 0)]])],
1603                  [LIBGD=yes], [LIBGD=no])
1604   CFLAGS="$old_CFLAGS"
1605   LDFLAGS="$old_LDFLAGS"
1606   LIBS="$old_LIBS"
1607 else
1608   LIBGD=no
1609 fi
1610 AC_MSG_RESULT($LIBGD)
1611 AC_SUBST(LIBGD)
1612
1613 # SELinux detection
1614 if test x$with_selinux = xno ; then
1615   have_selinux=no;
1616 else
1617   # See if we have the SELinux library
1618   AC_CHECK_LIB(selinux, is_selinux_enabled,
1619                have_selinux=yes, have_selinux=no)
1620   if test x$with_selinux = xyes ; then
1621     if test x$have_selinux = xno ; then
1622       AC_MSG_ERROR([SELinux explicitly required, but SELinux library not found])
1623     fi
1624   fi
1625 fi
1626 # Check if we're building with SELinux support.
1627 if test "x$have_selinux" = xyes; then
1628   AC_DEFINE(HAVE_SELINUX, 1, [SELinux support])
1629
1630   # See if we have the libaudit library
1631   AC_CHECK_LIB(audit, audit_log_user_avc_message,
1632                have_libaudit=yes, have_libaudit=no)
1633   if test "x$have_libaudit" = xyes; then
1634     AC_DEFINE(HAVE_LIBAUDIT, 1, [SELinux libaudit support])
1635   fi
1636   AC_SUBST(have_libaudit)
1637
1638   # See if we have the libcap library
1639   AC_CHECK_LIB(cap, cap_init, have_libcap=yes, have_libcap=no)
1640   if test "x$have_libcap" = xyes; then
1641     AC_DEFINE(HAVE_LIBCAP, 1, [SELinux libcap support])
1642   fi
1643   AC_SUBST(have_libcap)
1644 fi
1645 AC_SUBST(have_selinux)
1646
1647 CPPUNDEFS=
1648 dnl Check for silly hacked compilers predefining _FORTIFY_SOURCE.
1649 dnl Since we are building the implementations of the fortified functions here,
1650 dnl having the macro defined interacts very badly.
1651 AC_CACHE_CHECK([for _FORTIFY_SOURCE predefine], libc_cv_predef_fortify_source,
1652 [AC_TRY_COMPILE([], [
1653 #ifdef _FORTIFY_SOURCE
1654 # error bogon
1655 #endif],
1656                 [libc_cv_predef_fortify_source=no],
1657                 [libc_cv_predef_fortify_source=yes])])
1658 if test $libc_cv_predef_fortify_source = yes; then
1659   CPPUNDEFS="${CPPUNDEFS:+$CPPUNDEFS }-U_FORTIFY_SOURCE"
1660 fi
1661 AC_SUBST(CPPUNDEFS)
1662
1663 # Some linkers on some architectures support __ehdr_start but with
1664 # bugs.  Make sure usage of it does not create relocations in the
1665 # output (as the linker should resolve them all for us).
1666 AC_CACHE_CHECK([whether the linker provides working __ehdr_start],
1667                libc_cv_ehdr_start, [
1668 old_CFLAGS="$CFLAGS"
1669 old_LDFLAGS="$LDFLAGS"
1670 old_LIBS="$LIBS"
1671 CFLAGS="$CFLAGS -fPIC"
1672 LDFLAGS="$LDFLAGS -nostdlib -nostartfiles -shared $no_ssp"
1673 LIBS=
1674 AC_LINK_IFELSE([AC_LANG_SOURCE([
1675 typedef struct {
1676   char foo;
1677   long val;
1678 } Ehdr;
1679 extern const Ehdr __ehdr_start __attribute__ ((visibility ("hidden")));
1680 long ehdr (void) { return __ehdr_start.val; }
1681 ])],
1682                [if $READELF -r conftest | grep -F __ehdr_start >/dev/null; then
1683                   libc_cv_ehdr_start=broken
1684                 else
1685                   libc_cv_ehdr_start=yes
1686                 fi], [libc_cv_ehdr_start=no])
1687 CFLAGS="$old_CFLAGS"
1688 LDFLAGS="$old_LDFLAGS"
1689 LIBS="$old_LIBS"
1690 ])
1691 if test "$libc_cv_ehdr_start" = yes; then
1692   AC_DEFINE([HAVE_EHDR_START])
1693 elif test "$libc_cv_ehdr_start" = broken; then
1694   AC_MSG_WARN([linker is broken -- you should upgrade])
1695 fi
1696
1697 dnl Starting with binutils 2.35, GAS can attach multiple symbol versions
1698 dnl to one symbol (PR 23840).
1699 AC_CACHE_CHECK(whether the assembler requires one version per symbol,
1700                libc_cv_symver_needs_alias, [dnl
1701   cat > conftest.s <<EOF
1702         .text
1703 testfunc:
1704         .globl testfunc
1705         .symver testfunc, testfunc1@VERSION1
1706         .symver testfunc, testfunc1@VERSION2
1707 EOF
1708   libc_cv_symver_needs_alias=no
1709   if ${CC-cc} $ASFLAGS -c conftest.s 2>&AS_MESSAGE_LOG_FD; then
1710     libc_cv_symver_needs_alias=no
1711   else
1712     libc_cv_symver_needs_alias=yes
1713   fi
1714   rm conftest.*
1715 ])
1716 if test "$libc_cv_symver_needs_alias" = yes; then
1717   AC_DEFINE(SYMVER_NEEDS_ALIAS)
1718 fi
1719
1720 AC_CACHE_CHECK(for __builtin_trap with no external dependencies,
1721                libc_cv_builtin_trap, [dnl
1722 libc_cv_builtin_trap=no
1723 AC_TRY_COMPILE([], [__builtin_trap ()], [
1724 libc_undefs=`$NM -u conftest.o |
1725   LC_ALL=C $AWK '$1 == "U" { print $2 | "sort -u"; next } { exit(1) }' \
1726     2>&AS_MESSAGE_LOG_FD` || {
1727   AC_MSG_ERROR([confusing output from $NM -u])
1728 }
1729 echo >&AS_MESSAGE_LOG_FD "libc_undefs='$libc_undefs'"
1730 if test -z "$libc_undefs"; then
1731   libc_cv_builtin_trap=yes
1732 fi])])
1733 if test $libc_cv_builtin_trap = yes; then
1734   AC_DEFINE([HAVE_BUILTIN_TRAP])
1735 fi
1736
1737 dnl C++ feature tests.
1738 AC_LANG_PUSH([C++])
1739
1740 AC_CACHE_CHECK([whether the C++ compiler supports thread_local],
1741                libc_cv_cxx_thread_local, [
1742 old_CXXFLAGS="$CXXFLAGS"
1743 CXXFLAGS="$CXXFLAGS -std=gnu++11"
1744 AC_COMPILE_IFELSE([AC_LANG_SOURCE([
1745 #include <thread>
1746
1747 // Compiler support.
1748 struct S
1749 {
1750   S ();
1751   ~S ();
1752 };
1753 thread_local S s;
1754 S * get () { return &s; }
1755
1756 // libstdc++ support.
1757 #ifndef _GLIBCXX_HAVE___CXA_THREAD_ATEXIT_IMPL
1758 #error __cxa_thread_atexit_impl not supported
1759 #endif
1760 ])],
1761                [libc_cv_cxx_thread_local=yes],
1762                [libc_cv_cxx_thread_local=no])
1763 CXXFLAGS="$old_CXXFLAGS"
1764 ])
1765 AC_SUBST(libc_cv_cxx_thread_local)
1766
1767 AC_LANG_POP([C++])
1768 dnl End of C++ feature tests.
1769
1770 ### End of automated tests.
1771 ### Now run sysdeps configure fragments.
1772
1773 # They also can set these variables.
1774 use_ldconfig=no
1775 ldd_rewrite_script=no
1776 libc_cv_sysconfdir=$sysconfdir
1777 libc_cv_localstatedir=$localstatedir
1778 libc_cv_gcc_unwind_find_fde=no
1779 libc_cv_idn=no
1780
1781 # Iterate over all the sysdep directories we will use, running their
1782 # configure fragments.
1783 for dir in $sysnames; do
1784   case $dir in
1785     /*) dest=$dir ;;
1786     *)  dest=$srcdir/$dir ;;
1787   esac
1788   if test -r $dest/configure; then
1789     AC_MSG_RESULT(running configure fragment for $dir)
1790     . $dest/configure
1791   fi
1792 done
1793
1794 if test x"$build_mathvec" = xnotset; then
1795   build_mathvec=no
1796 fi
1797 LIBC_CONFIG_VAR([build-mathvec], [$build_mathvec])
1798
1799 AC_SUBST(libc_extra_cflags)
1800 AC_SUBST(libc_extra_cppflags)
1801
1802 if test x$libc_cv_gcc_unwind_find_fde = xyes; then
1803   AC_DEFINE(EXPORT_UNWIND_FIND_FDE)
1804 fi
1805 AC_SUBST(libc_cv_gcc_unwind_find_fde)
1806
1807 # A sysdeps configure fragment can reset this if IFUNC is not actually
1808 # usable even though the assembler knows how to generate the symbol type.
1809 if test x"$libc_cv_ld_gnu_indirect_function" = xyes; then
1810   AC_DEFINE(HAVE_IFUNC)
1811 fi
1812 LIBC_CONFIG_VAR([have-ifunc], [$libc_cv_ld_gnu_indirect_function])
1813
1814 if test x"$libc_cv_gcc_indirect_function" = xyes; then
1815   AC_DEFINE(HAVE_GCC_IFUNC)
1816 fi
1817 LIBC_CONFIG_VAR([have-gcc-ifunc], [$libc_cv_gcc_indirect_function])
1818
1819 # This is far from the AC_ARG_ENABLE that sets it so that a sysdeps
1820 # configure fragment can override the value to prevent this AC_DEFINE.
1821 AC_SUBST(use_nscd)
1822 if test "x$use_nscd" != xno; then
1823   AC_DEFINE([USE_NSCD])
1824 fi
1825 if test "x$build_nscd" = xdefault; then
1826   build_nscd=$use_nscd
1827 fi
1828
1829 AC_SUBST(libc_cv_slibdir)
1830 AC_SUBST(libc_cv_rtlddir)
1831 AC_SUBST(libc_cv_complocaledir)
1832 AC_SUBST(libc_cv_sysconfdir)
1833 AC_SUBST(libc_cv_localstatedir)
1834 AC_SUBST(libc_cv_rootsbindir)
1835
1836 if test x$use_ldconfig = xyes; then
1837   AC_DEFINE(USE_LDCONFIG)
1838 fi
1839 AC_SUBST(use_ldconfig)
1840 AC_SUBST(ldd_rewrite_script)
1841
1842 AC_SUBST(static)
1843 AC_SUBST(shared)
1844
1845 AC_CACHE_CHECK([whether -fPIC is default], libc_cv_pic_default,
1846 [libc_cv_pic_default=yes
1847 cat > conftest.c <<EOF
1848 #if defined __PIC__ || defined __pic__ || defined PIC || defined pic
1849 # error PIC is default.
1850 #endif
1851 EOF
1852 if eval "${CC-cc} -S conftest.c 2>&AS_MESSAGE_LOG_FD 1>&AS_MESSAGE_LOG_FD"; then
1853   libc_cv_pic_default=no
1854 fi
1855 rm -f conftest.*])
1856 AC_SUBST(libc_cv_pic_default)
1857
1858 AC_CACHE_CHECK([whether -fPIE is default], libc_cv_cc_pie_default,
1859 [libc_cv_cc_pie_default=yes
1860 cat > conftest.c <<EOF
1861 #if defined __PIE__ || defined __pie__ || defined PIE || defined pie
1862 # error PIE is default.
1863 #endif
1864 EOF
1865 if eval "${CC-cc} -S conftest.c 2>&AS_MESSAGE_LOG_FD 1>&AS_MESSAGE_LOG_FD"; then
1866   libc_cv_cc_pie_default=no
1867 fi
1868 rm -f conftest.*])
1869 libc_cv_pie_default=$libc_cv_cc_pie_default
1870 AC_SUBST(libc_cv_cc_pie_default)
1871 AC_SUBST(libc_cv_pie_default)
1872
1873 # Set the `multidir' variable by grabbing the variable from the compiler.
1874 # We do it once and save the result in a generated makefile.
1875 libc_cv_multidir=`${CC-cc} $CFLAGS $CPPFLAGS -print-multi-directory`
1876 AC_SUBST(libc_cv_multidir)
1877
1878 if test "$static_pie" = yes; then
1879   # Check target support for static PIE
1880   AC_COMPILE_IFELSE([AC_LANG_SOURCE([[#ifndef SUPPORT_STATIC_PIE
1881 # error static PIE is not supported
1882 #endif]])], , AC_MSG_ERROR([the architecture does not support static PIE]))
1883   # The linker must support --no-dynamic-linker.
1884   if test "$libc_cv_no_dynamic_linker" != yes; then
1885     AC_MSG_ERROR([linker support for --no-dynamic-linker needed])
1886   fi
1887   # Default to PIE.
1888   libc_cv_pie_default=yes
1889   AC_DEFINE(ENABLE_STATIC_PIE)
1890 fi
1891 LIBC_CONFIG_VAR([enable-static-pie], [$static_pie])
1892
1893 AC_SUBST(profile)
1894 AC_SUBST(static_nss)
1895
1896 AC_SUBST(DEFINES)
1897
1898 dnl See sysdeps/mach/configure.ac for this variable.
1899 AC_SUBST(mach_interface_list)
1900
1901 VERSION=`sed -n -e 's/^#define VERSION "\([^"]*\)"/\1/p' < $srcdir/version.h`
1902 RELEASE=`sed -n -e 's/^#define RELEASE "\([^"]*\)"/\1/p' < $srcdir/version.h`
1903 AC_SUBST(VERSION)
1904 AC_SUBST(RELEASE)
1905
1906 AC_CONFIG_FILES([config.make Makefile])
1907 AC_CONFIG_COMMANDS([default],[[
1908 case $CONFIG_FILES in *config.make*)
1909 echo "$config_vars" >> config.make;;
1910 esac
1911 test -d bits || mkdir bits]],[[config_vars='$config_vars']])
1912 AC_OUTPUT