configure.ac

##
## Configure template file for FRRouting.
## autoconf will generate a configure script.
##
##  Copyright (c) 1996, 97, 98, 99, 2000 Kunihiro Ishiguro <kunihiro@zebra.org>
##  Portions Copyright (c) 2003 Paul Jakma <paul@dishone.st>
##
AC_PREREQ([2.69])

AC_INIT([frr], [10.6-dev], [https://github.com/frrouting/frr/issues])
PACKAGE_URL="https://frrouting.org/"
AC_SUBST([PACKAGE_URL])
PACKAGE_FULLNAME="FRRouting"
AC_SUBST([PACKAGE_FULLNAME])

CONFIG_ARGS="`echo $ac_configure_args | sed -e \"s% '[[A-Z]]*FLAGS=[[^']]\+'%%g\"`"
AC_SUBST([CONFIG_ARGS])

AC_CONFIG_SRCDIR([lib/zebra.h])
AC_CONFIG_MACRO_DIR([m4])
AC_CONFIG_AUX_DIR([m4/ac])

dnl ------------------------------
dnl system paths
dnl ------------------------------
dnl Versions of FRR (or Quagga, or Zebra) before ca. 9.2 used sysconfdir and
dnl localstatedir as-is, without appending /frr.  The /frr was expected to be
dnl given on ./configure invocations.
dnl
dnl This does not match standard behavior by other packages and makes FRR
dnl specific packaging changes necessary to add these options.  localstatedir
dnl was also misused to include the /run part (it normally is only /var),
dnl leaving no path configuration option that references /var itself.  This
dnl is because runstatedir did not exist in ancient autoconf.
dnl
dnl The path options have been changed to expect plain / system prefix
dnl directories.  As a temporary workaround to not break packaging, eventual
dnl /frr suffixes are stripped and a warning is printed.

path_warn_banner=false

AC_MSG_CHECKING([whether --sysconfdir option is FRR-specific])
case "$sysconfdir" in
  */frr)
    AC_MSG_RESULT([yes, ends in /frr - removing suffix])
    AC_MSG_WARN([Please remove /frr suffix from --sysconfdir="${sysconfdir}" (it should be /etc in 99% of cases)])
    sysconfdir="${sysconfdir%/frr}"
    path_warn_banner=true
    ;;
  *)
    AC_MSG_RESULT([no, as expected])
    ;;
esac

frr_sysconfdir="\${sysconfdir}/frr"

AC_MSG_CHECKING([whether --localstatedir option is FRR-specific])
case "$localstatedir" in
  */run/frr)
    AC_MSG_RESULT([yes, ends in /run/frr - removing suffix])
    AC_MSG_WARN([Please remove /run/frr suffix from --localstatedir=${localstatedir} (it should be /var in 99% of cases)])
    localstatedir="${localstatedir%/run/frr}"
    path_warn_banner=true
    ;;
  */frr)
    AC_MSG_RESULT([yes, ends in /frr - removing suffix])
    AC_MSG_WARN([The --localstatedir=${localstatedir} option seems to include /frr but not /run, this is unexpected.  Please check for consistency.)])
    localstatedir="${localstatedir%/frr}"
    path_warn_banner=true
    ;;
  *)
    AC_MSG_RESULT([no, as expected])
    ;;
esac

dnl runstatedir is either ${localstatedir}/run or plain /run
dnl the change of localstatedir above may impact this
dnl
dnl note runstatedir was never used with /frr as the other two above, so does
dnl not need the same cleanup hack
: "${runstatedir:=\${localstatedir\}/run}"
frr_runstatedir="\${runstatedir}/frr"

if $path_warn_banner; then
  AC_MSG_WARN([^])
  AC_MSG_WARN([^])
  AC_MSG_WARN([^ warnings regarding system path configuration were printed above])
  AC_MSG_WARN([^ paths have been adjusted by temporary workarounds])
  AC_MSG_WARN([^ please fix your ./configure invocation (remove /frr) so it will work without the workarounds])
  AC_MSG_WARN([^])
  AC_MSG_WARN([^])
fi

frr_libstatedir="\${localstatedir}/lib/frr"

dnl -----------------------------------
dnl Get hostname and other information.
dnl -----------------------------------
AC_CANONICAL_BUILD()
AC_CANONICAL_HOST()

AC_ARG_VAR([AR],[archiver command])
AC_ARG_VAR([LD],[linker command])
AC_ARG_VAR([OBJCOPY],[objcopy command])
AC_ARG_VAR([OBJDUMP],[objdump command])
AC_ARG_VAR([RANLIB],[ranlib command])
AC_ARG_VAR([STRIP],[strip command])

hosttools_clippy="false"
build_clippy="true"

dnl case 1: external clippy
if test -n "$with_clippy" -a "$with_clippy" != "no" -a "$with_clippy" != "yes"; then
  if test "$enable_clippy_only" = "yes"; then
    AC_MSG_ERROR([--enable-clippy-only does not make sense with --with-clippy])
  fi

  CLIPPY="$with_clippy"
  build_clippy="false"
  if test ! -x "$with_clippy"; then
    AC_MSG_ERROR([clippy tool ($with_clippy) is not executable])
  fi

dnl case 2: cross-compiling internal clippy
elif test "$host" != "$build"; then
  if test "$srcdir" = "."; then
    AC_MSG_ERROR([cross-compilation is only possible with builddir separate from srcdir or by building clippy separately and using the --with-clippy option.  create a separate directory and run as .../path-to-frr/configure.])
  fi
  test -d hosttools || mkdir hosttools
  abssrc="`cd \"${srcdir}\"; pwd`"

  AC_MSG_NOTICE([...])
  AC_MSG_NOTICE([... cross-compilation: creating hosttools directory and self-configuring for build platform tools])
  AC_MSG_NOTICE([... use HOST_CPPFLAGS / HOST_CFLAGS / HOST_LDFLAGS if necessary])
  AC_MSG_NOTICE([...])

  (
    for var in $ac_precious_vars; do
      dnl special cases
      case "$var" in
      YACC|YFLAGS) continue;;
      PYTHON*)     retain=true;;
      *)           retain=false;
      esac

      eval "hostvar=\"\${HOST_$var}\""
      eval "targetvar=\"\${$var}\""
      if test -n "$hostvar"; then
        eval "$var='$hostvar'"
        _AS_ECHO_LOG([host $var='$hostvar'])
      elif $retain; then
        _AS_ECHO_LOG([host retain $var='$targetvar'])
      else
        eval "unset $var"
        _AS_ECHO_LOG([host unset $var])
      fi
    done
    cd hosttools
    "${abssrc}/configure" "--host=$build" "--build=$build" "--enable-clippy-only" "--disable-nhrpd" "--disable-vtysh"
  ) || exit 1

  AC_MSG_NOTICE([...])
  AC_MSG_NOTICE([... cross-compilation: finished self-configuring for build platform tools])
  AC_MSG_NOTICE([...])

  build_clippy="false"
  hosttools_clippy="true"
  CLIPPY="hosttools/lib/clippy"

dnl case 3: normal build internal clippy
else
  CLIPPY="lib/clippy\$(EXEEXT)"
fi
AC_SUBST([CLIPPY])
AM_CONDITIONAL([BUILD_CLIPPY], [$build_clippy])
AM_CONDITIONAL([HOSTTOOLS_CLIPPY], [$hosttools_clippy])
AM_CONDITIONAL([ONLY_CLIPPY], [test "$enable_clippy_only" = "yes"])

# Disable portability warnings -- our automake code (in particular
# common.am) uses some constructs specific to gmake.
AM_INIT_AUTOMAKE([1.12 -Wno-portability foreign])
m4_ifndef([AM_SILENT_RULES], [m4_define([AM_SILENT_RULES],[])])
AM_SILENT_RULES([yes])
AC_CONFIG_HEADERS([config.h])

AC_PATH_PROG([PERL], [perl])
PKG_PROG_PKG_CONFIG

dnl default is to match previous behavior
pkgsrcrcdir=""
AC_ARG_ENABLE([pkgsrcrcdir],
	  AS_HELP_STRING([--enable-pkgsrcrcdir],
			 [specify directory for rc.d scripts]),
			 pkgsrcrcdir="$enableval",)
dnl XXX add --pkgsrcrcdir to autoconf standard directory list somehow
AC_SUBST([pkgsrcrcdir])
AM_CONDITIONAL([PKGSRC], [test "$pkgsrcrcdir" != ""])

AC_ARG_WITH([moduledir], [AS_HELP_STRING([--with-moduledir=DIR], [module directory (${libdir}/frr/modules)])], [
	moduledir="$withval"
], [
	moduledir="\${libdir}/frr/modules"
])
AC_SUBST([moduledir], [$moduledir])

AC_ARG_WITH([pkgconfigdir], [AS_HELP_STRING([--with-pkgconfigdir=DIR], [pkg-config directory (${libdir}/pkgconfig)])], [
	pkgconfigdir="$withval"
], [
	pkgconfigdir="\${libdir}/pkgconfig"
])
AC_SUBST([pkgconfigdir], [$pkgconfigdir])

AC_ARG_WITH([scriptdir], [AS_HELP_STRING([--with-scriptdir=DIR], [script directory (${sysconfdir}/frr/scripts)])], [
	scriptdir="$withval"
], [
	scriptdir="\${frr_sysconfdir}/scripts"
])
AC_SUBST([scriptdir], [$scriptdir])

AC_ARG_WITH([yangmodelsdir], [AS_HELP_STRING([--with-yangmodelsdir=DIR], [yang models directory (${datarootdir}/yang)])], [
	yangmodelsdir="$withval"
], [
	yangmodelsdir="\${datarootdir}/yang"
])
AC_SUBST([yangmodelsdir])

AC_ARG_WITH([vici-socket], [AS_HELP_STRING([--with-vici-socket=PATH], [vici-socket (/var/run/charon.vici)])], [
	vici_socket="$withval"
], [
	vici_socket="/var/run/charon.vici"
])
AC_DEFINE_UNQUOTED([VICI_SOCKET], ["$vici_socket"], [StrongSWAN vici socket path])

AC_ARG_ENABLE(tcmalloc,
	AS_HELP_STRING([--enable-tcmalloc], [Turn on tcmalloc]),
[case "${enableval}" in
  yes) tcmalloc_enabled=true
LIBS="$LIBS -ltcmalloc_minimal"
 ;;
  no)  tcmalloc_enabled=false ;;
  *) AC_MSG_ERROR([bad value ${enableval} for --enable-tcmalloc]) ;;
esac],[tcmalloc_enabled=false])


dnl Thanks autoconf, but we don't want a default -g -O2.  We have our own
dnl flag determination logic.
CFLAGS="${CFLAGS:-}"

dnl --------------------
dnl Check CC and friends
dnl --------------------
dnl note orig_cflags is also used further down
orig_cflags="$CFLAGS"
orig_cxxflags="$CXXFLAGS"
AC_LANG([C])
AC_PROG_CC
AC_PROG_CPP
AC_PROG_CXX
AM_PROG_CC_C_O
dnl remove autoconf default "-g -O2"
CFLAGS="$orig_cflags"
CXXFLAGS="$orig_cxxflags"

dnl Some special handling for ICC later on
if test "$CC" = "icc"; then
    cc_is_icc="yes"
fi

PKG_PROG_PKG_CONFIG

dnl it's 2019, sed is sed.
SED=sed
AC_SUBST([SED])

dnl try and enable CFLAGS that are useful for FRR
dnl - specifically, options to control warnings

AC_SUBST([AC_CFLAGS])
AC_USE_SYSTEM_EXTENSIONS
AC_DEFUN([AC_C_FLAG], [{
    m4_pushdef([cachename],[m4_translit([frr_cv_$1],[ =-+/{}$],[________])])
    AC_CACHE_CHECK([[whether $CC supports $1]], cachename, [
	AC_LANG_PUSH([C])
	ac_c_flag_save="$CFLAGS"
	dnl GCC ignores unknown -Wno-whatever flags, but errors on -Wwhatever
	dnl except when it ignores them it prints:
	dnl   cc1: note: unrecognized command-line option ‘-Wno-whatever’ may have been intended to silence earlier diagnostics
	dnl which is annoying as hell.  So check for the positive flag instead.
	flag_add="$1"
	if test "$flag_add" != "${flag_add#-Wno-}"; then
	    CFLAGS="$CFLAGS -W${flag_add#-Wno-}"
	else
	    CFLAGS="$CFLAGS $flag_add"
	fi
	AC_COMPILE_IFELSE(
		[AC_LANG_PROGRAM([[$4]])],
		[
			cachename=yes
		], [
			cachename=no
		])
	CFLAGS="$ac_c_flag_save"
	AC_LANG_POP([C])
    ])
    if test "$cachename" = "yes"; then
	m4_if([$3], [], [AC_CFLAGS="$AC_CFLAGS $1"], [$3])
    else
	:
	$2
    fi
    m4_popdef([cachename])
}])

AC_DEFUN([AC_LINK_IFELSE_FLAGS], [{
	AC_LANG_PUSH([C])
	ac_cflags_save="$CFLAGS"
	ac_libs_save="$LIBS"
	CFLAGS="$CFLAGS $1"
	LIBS="$LIBS $2"
	AC_LINK_IFELSE(
		[$3],
		[
			CFLAGS="$ac_cflags_save"
			LIBS="$ac_libs_save"
			m4_default([$5], [
				AC_MSG_RESULT([yes])
			])
		], [
			CFLAGS="$ac_cflags_save"
			LIBS="$ac_libs_save"
			m4_default([$4], [
				AC_MSG_RESULT([no])
			])
		])
	AC_LANG_POP([C])
	}])

dnl ICC won't bail on unknown options without -diag-error 10006
dnl need to do this first so we get useful results for the other options
if test "$cc_is_icc" = "yes"; then
    AC_C_FLAG([-diag-error 10006])
fi

dnl autoconf 2.69 AC_PROG_CC_C99 is "state of the art"
dnl autoconf 2.70 AC_PROG_CC_C99 is deprecated and AC_PROC_CC tries to do C11
m4_if(m4_version_compare(m4_defn([AC_AUTOCONF_VERSION]), [2.70]), [-1], [dnl
  dnl autoconf < 2.70
  AC_PROG_CC_C99

  dnl AC_PROG_CC_C99 may change CC to include -std=gnu99 or something
  ac_cc="$CC"
  CC="${CC% -std=gnu99}"
  CC="${CC% -std=c99}"

  AC_C_FLAG([-std=gnu11], [CC="$ac_cc"], [CC="$CC -std=gnu11"])
], [
  dnl autoconf >= 2.70
  if test "$ac_cv_prog_cc_c11" = "no"; then
    AC_MSG_ERROR([ISO C11 compiler support (with GNU extensions) is required.])
  fi
])

dnl if the user has specified any CFLAGS, override our settings
if test "$enable_gcov" = "yes"; then
   if test "$orig_cflags" = ""; then
      AC_C_FLAG([--coverage])
      AC_C_FLAG([-O0])
   fi

   AC_LDFLAGS="${AC_LDFLAGS} --coverage"
fi

if test "$enable_clang_coverage" = "yes"; then
   AC_C_FLAG([-fprofile-instr-generate], [
     AC_MSG_ERROR([$CC does not support -fprofile-instr-generate.])
   ])
   AC_C_FLAG([-fcoverage-mapping], [
     AC_MSG_ERROR([$CC does not support -fcoverage-mapping.])
   ])
fi

AM_CONDITIONAL([SCRIPTING], [test "$enable_scripting" = "yes"])

if test "$enable_scripting" = "yes"; then
   AX_PROG_LUA([5.3], [], [], [
     AC_MSG_ERROR([Lua >= 5.3 is required to build with Lua support. No other version is supported.])
   ])
   AX_LUA_HEADERS([], [
     AC_MSG_ERROR([Lua >= 5.3 headers are required to build with Lua support. No other version is supported.])
   ])
  
   for version in 5.3 5.4; do
     PKG_CHECK_MODULES([LUA], [lua >= $version], [
       AC_DEFINE([HAVE_SCRIPTING], [1], [Have support for scripting])
         LIBS="$LIBS $LUA_LIBS"
         SCRIPTING=true
         break
     ], [
       PKG_CHECK_MODULES([LUA], [lua$version], [
         AC_DEFINE([HAVE_SCRIPTING], [1], [Have support for scripting])
           LIBS="$LIBS $LUA_LIBS"
           SCRIPTING=true
           break
       ], [
         PKG_CHECK_MODULES([LUA], [lua-$version], [
           AC_DEFINE([HAVE_SCRIPTING], [1], [Have support for scripting])
             LIBS="$LIBS $LUA_LIBS"
             SCRIPTING=true
             break
         ], [])
       ])
     ])
   done

   if [ "$SCRIPTING" != "true" ]; then
     AX_LUA_LIBS([
       AC_DEFINE([HAVE_SCRIPTING], [1], [Have support for scripting])
         LIBS="$LIBS $LUA_LIB"
         SCRIPTING=true
     ], [
       AC_MSG_ERROR([Lua >= 5.3 libraries are required to build with Lua support. No other version is supported.])
     ])
   fi
fi

dnl the following flags go in CFLAGS rather than AC_CFLAGS since they make
dnl sense to be overridden by the user
if test "$enable_dev_build" = "yes"; then
   AC_DEFINE([DEV_BUILD], [1], [Build for development])
   if test "$orig_cflags" = ""; then
      AC_C_FLAG([-O0],,[CFLAGS="$CFLAGS -O0"])
      AC_C_FLAG([-g3],,[CFLAGS="$CFLAGS -g3"])
      AC_C_FLAG([-ggdb3],,[CFLAGS="$CFLAGS -ggdb3"])
   fi
else
   if test "$orig_cflags" = ""; then
      AC_C_FLAG([-g],,[CFLAGS="$CFLAGS -g"])
      AC_C_FLAG([-O2],,[CFLAGS="$CFLAGS -O2"])
   fi
fi

dnl just stick -g into LDFLAGS, if we don't have it in CFLAGS it won't do much
LDFLAGS="$LDFLAGS -g"

AM_CONDITIONAL([DEV_BUILD], [test "$enable_dev_build" = "yes"])

dnl -fms-extensions causes clang to have a built-in __wchar_t on OpenBSD,
dnl which just straight up breaks compiling any code.
dnl (2022-04-04 / OpenBSD 7 / clang 11.1.0)
AH_VERBATIM([OpenBSD], [
#ifdef __OpenBSD__
#define __wchar_t __wchar_t_ignore
#include <stdint.h>
#undef __wchar_t
#endif
])

dnl always want these CFLAGS
AC_C_FLAG([-fms-extensions], [
  AC_MSG_ERROR([$CC does not support unnamed struct fields (-fms-extensions)])
])
AC_C_FLAG([-fno-omit-frame-pointer])
AC_C_FLAG([-funwind-tables])
AC_C_FLAG([-Wall])
AC_C_FLAG([-Wextra])
AC_C_FLAG([-Wformat-nonliteral])
AC_C_FLAG([-Wformat-security])
AC_C_FLAG([-Wswitch-enum])
AC_C_FLAG([-Wstrict-prototypes])
AC_C_FLAG([-Wmissing-prototypes])
AC_C_FLAG([-Wmissing-declarations])
AC_C_FLAG([-Wpointer-arith])
AC_C_FLAG([-Wbad-function-cast])
AC_C_FLAG([-Wwrite-strings])
AC_C_FLAG([-Wundef])
AC_C_FLAG([-Wimplicit-fallthrough])
AC_C_FLAG([-Wshadow])
AC_C_FLAG([-Wmissing-noreturn])
AC_C_FLAG([-Wformat-extra-args])
if test "$enable_gcc_ultra_verbose" = "yes" ; then
  AC_C_FLAG([-Wcast-qual])
  AC_C_FLAG([-Wmissing-format-attribute])
  AC_C_FLAG([-Wunreachable-code])
  AC_C_FLAG([-Wpacked])
  AC_C_FLAG([-Wpadded])
else
  AC_C_FLAG([-Wno-unused-result])
fi
AC_C_FLAG([-Wno-unused-parameter])
AC_C_FLAG([-Wno-missing-field-initializers])
AC_C_FLAG([-Wno-microsoft-anon-tag])
AC_C_FLAG([-Wno-error=deprecated-declarations])
AC_C_FLAG([-Waddress-of-packed-member])

AC_C_FLAG([-Wc++-compat], [], [CXX_COMPAT_CFLAGS="-Wc++-compat"])
AC_SUBST([CXX_COMPAT_CFLAGS])

dnl ICC emits a broken warning for const char *x = a ? "b" : "c";
dnl for some reason the string consts get 'promoted' to char *,
dnl triggering a const to non-const conversion warning.
if test "$cc_is_icc" = "yes"; then
    AC_C_FLAG([-diag-disable 3179])
fi

if test "$enable_werror" = "yes" ; then
  WERROR="-Werror"
fi
AC_SUBST([WERROR])

SAN_FLAGS=""
if test "$enable_address_sanitizer" = "yes"; then
  AC_C_FLAG([-fsanitize=address], [
    AC_MSG_ERROR([$CC does not support Address Sanitizer.])
  ], [
    SAN_FLAGS="$SAN_FLAGS -fsanitize=address"
  ])
fi
if test "$enable_thread_sanitizer" = "yes"; then
  AC_C_FLAG([-fsanitize=thread], [
    AC_MSG_ERROR([$CC does not support Thread Sanitizer.])
  ], [
    SAN_FLAGS="$SAN_FLAGS -fsanitize=thread"
  ])
fi
if test "$enable_memory_sanitizer" = "yes"; then
  AC_C_FLAG([-fsanitize=memory -fPIE -pie], [
    AC_MSG_ERROR([$CC does not support Memory Sanitizer.])
  ], [
    SAN_FLAGS="$SAN_FLAGS -fsanitize=memory -fPIE -pie"
  ])
fi
if test "$enable_undefined_sanitizer" = "yes"; then
  AC_C_FLAG([-fsanitize=undefined], [
    AC_MSG_ERROR([$CC does not support UndefinedBehaviorSanitizer.])
  ], [
    SAN_FLAGS="$SAN_FLAGS -fsanitize=undefined"
  ])
fi
AC_SUBST([SAN_FLAGS])

dnl frr-format.so
if test "$with_frr_format" != "no" -a "$with_frr_format" != "yes" -a -n "$with_frr_format"; then
  AC_C_FLAG([-fplugin=${with_frr_format}], [
    AC_MSG_ERROR([specified frr-format plugin ($with_frr_format) does not work])
  ],,[
#ifndef _FRR_ATTRIBUTE_PRINTFRR
#error plugin not loaded
#endif
#if _FRR_ATTRIBUTE_PRINTFRR < 0x10000
#error plugin too old
#endif
  ])
elif test "$with_frr_format" = "no"; then
  : #nothing
else
  AC_C_FLAG([-fplugin=tools/gcc-plugins/frr-format.so],[
    AC_C_FLAG([-fplugin=frr-format],[
      if test "$with_frr_format" = "yes"; then
        AC_MSG_ERROR([frr-format plugin requested but not found])
      fi
    ],,[
#ifndef _FRR_ATTRIBUTE_PRINTFRR
#error plugin not loaded
#endif
#if _FRR_ATTRIBUTE_PRINTFRR < 0x10000
#error plugin too old
#endif
    ])
  ],,[
#ifndef _FRR_ATTRIBUTE_PRINTFRR
#error plugin not loaded
#endif
#if _FRR_ATTRIBUTE_PRINTFRR < 0x10000
#error plugin too old
#endif
  ])
fi

AC_MSG_CHECKING([whether linker supports __start/stop_section symbols])
AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <stdio.h>
int __attribute__((section("secttest"))) var = 1;
extern int __start_secttest, __stop_secttest;
]], [[
  void *a = &var, *b = &__start_secttest, *c = &__stop_secttest;
  printf("%p %p %p\n", a, b, c);
]])], [
  AC_MSG_RESULT(yes)
], [
  AC_MSG_RESULT(no)
  AC_MSG_ERROR([Toolchain issue: ELF __start/stop_section symbols seem to not work.  Please open configure.ac and search for this message for further information.])
dnl
dnl if you have arrived here, well, you might be about to have a rather bad day
dnl since the above issue will be caused by one of the following things:
dnl
dnl (1) the test above broke.  This is the best case; just comment it out and
dnl     try building anyway.  If it works, you're lucky, but please open an
dnl     issue on the FRR bugtracker.
dnl
dnl (2) you're trying to build for Linux or *BSD.  All non-necromantic versions
dnl     of those support this feature, so start looking at what might be wrong
dnl     with your compiler toolchain.  Is "ld" not installed correctly or
dnl     something like that?  Some weird LTO thing going on?  Weird mix of GNU
dnl     and LLVM toolchains?  Maybe try a fresh install in a container/VM?
dnl
dnl (3) you're trying to build for Solaris.  Support for Solaris has been
dnl     removed due to lack of maintainers and testing.  For this specific
dnl     problem, use GNU ld and you're good, but you'll hit walls elsewhere.
dnl
dnl (4) you're trying to build for Apple OSX.  You in for a world of pain, with
dnl     OSX using Mach-O for its binaries rather than ELF.  FRR contains code
dnl     that uses libelf to open its own binaries and fish out things.  For
dnl     obvious reasons of Mach-O not being ELF, this won't work.  There is no
dnl     easy workaround, disabling this code results in a non-working FRR
dnl     build even if you somehow get it to pass.  Good luck!
dnl
dnl IN ALL CASES: open config.log, scroll to the very bottom, then back up to
dnl     before the kilometer long dumps of internal autoconf variables.  There
dnl     should be a compiler/linker error there.  You absolutely need that
dnl     error message, otherwise you're completely lost in the dark.
])

dnl ----------
dnl Essentials
dnl ----------

AX_PTHREAD([
  CC="$PTHREAD_CC"
  AC_CFLAGS="$AC_CFLAGS $PTHREAD_CFLAGS"
  LIBS="$PTHREAD_LIBS $LIBS"
], [
  AC_MSG_FAILURE([This FRR version needs pthreads])
])

orig_cflags="$CFLAGS"
CFLAGS="$CFLAGS $PTHREAD_CFLAGS"

AC_CHECK_HEADERS([pthread_np.h],,, [
#include <pthread.h>
])
AC_CHECK_FUNCS([pthread_setname_np pthread_set_name_np pthread_getthreadid_np])

CFLAGS="$orig_cflags"

dnl --------------
dnl Check programs
dnl --------------
AC_PROG_INSTALL
AC_PROG_LN_S
AC_CHECK_TOOL([AR], [ar])

dnl -------
dnl libtool
dnl -------
AC_ARG_ENABLE([static-bin],
  AS_HELP_STRING([--enable-static-bin], [link binaries statically]))
LT_INIT
_LT_CONFIG_LIBTOOL([
  patch -N -i "${srcdir}/m4/libtool-whole-archive.patch" libtool >&AS_MESSAGE_LOG_FD || \
    AC_MSG_WARN([Could not patch libtool for static linking support.  Loading modules into a statically linked daemon will fail.])
dnl the -i option is not POSIX sed and the BSDs implement it differently
dnl cat'ing the output back instead of mv/cp keeps permissions on libtool intact
  sed -e 's%func_warning "relinking%true #\0%'                   libtool > libtool.sed && cat libtool.sed > libtool
  sed -e 's%func_warning "remember to run%true #\0%'             libtool > libtool.sed && cat libtool.sed > libtool
  sed -e 's%func_warning ".*has not been installed in%true #\0%' libtool > libtool.sed && cat libtool.sed > libtool
  test -f libtool.sed && rm libtool.sed
])
if test "$enable_static_bin" = "yes"; then
  AC_LDFLAGS_EXEC="-static"
  if test "$enable_static" != "yes"; then
    AC_MSG_ERROR([The --enable-static-bin option must be combined with --enable-static.])
  fi
fi
if test "$enable_shared" != "yes"; then
  AC_MSG_ERROR([FRR cannot be built with --disable-shared.  If you want statically linked daemons, use --enable-shared --enable-static --enable-static-bin])
fi
AC_SUBST([AC_LDFLAGS])
AC_SUBST([AC_LDFLAGS_EXEC])
AM_CONDITIONAL([STATIC_BIN], [test "$enable_static_bin" = "yes"])

dnl libtool, the repository of all knowledge related linkers, is too stupid to
dnl correctly tell the linker how to build modules.
if test -z "$module_cmds"; then
  module_cmds="`echo \"$archive_cmds\" | sed -e 's%$wl-soname $wl$soname%%'`"
fi
if test -z "$module_expsym_cmds"; then
  module_expsym_cmds="`echo \"$archive_expsym_cmds\" | sed -e 's%$wl-soname $wl$soname%%'`"
fi

AC_ARG_ENABLE([rpath],
  [AS_HELP_STRING([--enable-rpath], [set hardcoded rpaths in the executable @<:@default=yes@:>@])],
  [],
  [enable_rpath=yes])

dnl $AR and $RANLIB are set by LT_INIT above
AC_MSG_CHECKING([whether $AR supports D option])
if $AR crD conftest.a >/dev/null 2>/dev/null; then
  AC_MSG_RESULT([yes])
  dnl ARFLAGS is for automake, AR_FLAGS for libtool m-(
  ARFLAGS="crD"
  AR_FLAGS="crD"
else
  AC_MSG_RESULT([no])
  ARFLAGS="cru"
  AR_FLAGS="cru"
fi
AC_SUBST([ARFLAGS])
AC_SUBST([AR_FLAGS])

AC_MSG_CHECKING([whether $RANLIB supports D option])
if $RANLIB -D conftest.a >conftest.err 2>&1; then
  if grep -q -- '-D' conftest.err; then
    AC_MSG_RESULT([no])
  else
    AC_MSG_RESULT([yes])
    RANLIB="$RANLIB -D"
  fi
else
  AC_MSG_RESULT([no])
fi
AC_SUBST([RANLIB])

test -f conftest.err && rm conftest.err
test -f conftest.a && rm conftest.a

dnl ----------------------
dnl Packages configuration
dnl ----------------------
if test -f config.version; then
  . ./config.version
elif test -f "${srcdir}/config.version"; then
  . "${srcdir}/config.version"
fi
AC_ARG_WITH([pkg-extra-version],
  AS_HELP_STRING([--with-pkg-extra-version=VER], [add extra version field, for packagers/distributions]), [
  if test "$withval" = "no"; then
    EXTRAVERSION=
  else
    EXTRAVERSION=$withval
  fi
], [])
AC_ARG_WITH([pkg-git-version],
	AS_HELP_STRING([--with-pkg-git-version], [add git information to MOTD and build version string]),
	[ test "$withval" != "no" && with_pkg_git_version="yes" ])
AC_ARG_WITH([clippy],
  AS_HELP_STRING([--with-clippy=PATH], [use external clippy helper program]))
AC_ARG_WITH([vtysh_pager],
	AS_HELP_STRING([--with-vtysh-pager=PAGER], [control what pager is compiled in as default]),
	VTYSH_PAGER=$withval, VTYSH_PAGER="more")
AC_ARG_ENABLE([vtysh],
  AS_HELP_STRING([--disable-vtysh], [do not build integrated vty shell for FRR]))
AC_ARG_ENABLE([doc],
  AS_HELP_STRING([--disable-doc], [do not build docs]))
AC_ARG_ENABLE([doc-html],
  AS_HELP_STRING([--enable-doc-html], [build HTML docs]))
AC_ARG_ENABLE([zebra],
  AS_HELP_STRING([--disable-zebra], [do not build zebra daemon]))
AC_ARG_ENABLE([bgpd],
  AS_HELP_STRING([--disable-bgpd], [do not build bgpd]))
AC_ARG_ENABLE([mgmtd],
  AS_HELP_STRING([--disable-mgmtd], [do not build mgmtd]))
AC_ARG_ENABLE([mgmtd_local_validations],
  AS_HELP_STRING([--enable-mgmtd-local-validations], [dev: unimplemented local validation]))
AC_ARG_ENABLE([mgmtd_test_be_client],
  AS_HELP_STRING([--enable-mgmtd-test-be-client], [build test backend client]))
AC_ARG_ENABLE([fpm_listener],
  AS_HELP_STRING([--enable-fpm-listener], [build fpm listener test program]))
AC_ARG_ENABLE([ripd],
  AS_HELP_STRING([--disable-ripd], [do not build ripd]))
AC_ARG_ENABLE([ripngd],
  AS_HELP_STRING([--disable-ripngd], [do not build ripngd]))
AC_ARG_ENABLE([ospfd],
  AS_HELP_STRING([--disable-ospfd], [do not build ospfd]))
AC_ARG_ENABLE([ospf6d],
  AS_HELP_STRING([--disable-ospf6d], [do not build ospf6d]))
AC_ARG_ENABLE([ldpd],
  AS_HELP_STRING([--disable-ldpd], [do not build ldpd]))
AC_ARG_ENABLE([nhrpd],
  AS_HELP_STRING([--disable-nhrpd], [do not build nhrpd]))
AC_ARG_ENABLE([eigrpd],
  AS_HELP_STRING([--disable-eigrpd], [do not build eigrpd]))
AC_ARG_ENABLE([babeld],
  AS_HELP_STRING([--disable-babeld], [do not build babeld]))
AC_ARG_ENABLE([watchfrr],
  AS_HELP_STRING([--disable-watchfrr], [do not build watchfrr]))
AC_ARG_ENABLE([isisd],
  AS_HELP_STRING([--disable-isisd], [do not build isisd]))
AC_ARG_ENABLE([pimd],
  AS_HELP_STRING([--disable-pimd], [do not build pimd]))
AC_ARG_ENABLE([pim6d],
  AS_HELP_STRING([--disable-pim6d], [do not build pim6d]))
AC_ARG_ENABLE([pbrd],
  AS_HELP_STRING([--disable-pbrd], [do not build pbrd]))
AC_ARG_ENABLE([sharpd],
  AS_HELP_STRING([--enable-sharpd], [build sharpd]))
AC_ARG_ENABLE([staticd],
  AS_HELP_STRING([--disable-staticd], [do not build staticd]))
AC_ARG_ENABLE([fabricd],
  AS_HELP_STRING([--disable-fabricd], [do not build fabricd]))
AC_ARG_ENABLE([vrrpd],
  AS_HELP_STRING([--disable-vrrpd], [do not build vrrpd]))
AC_ARG_ENABLE([pathd],
  AS_HELP_STRING([--disable-pathd], [do not build pathd]))
AC_ARG_ENABLE([bgp-announce],
  AS_HELP_STRING([--disable-bgp-announce], [turn off BGP route announcement]))
AC_ARG_ENABLE([bgp-vnc],
  AS_HELP_STRING([--disable-bgp-vnc],[turn off BGP VNC support]))
AC_ARG_ENABLE([bgp-bmp],
  AS_HELP_STRING([--disable-bgp-bmp],[turn off BGP BMP support]))
AC_ARG_ENABLE([snmp],
  AS_HELP_STRING([--enable-snmp], [enable SNMP support for agentx]))
AC_ARG_ENABLE([config_rollbacks],
  AS_HELP_STRING([--enable-config-rollbacks], [enable configuration rollbacks (requires sqlite3)]))
AC_ARG_ENABLE([sysrepo],
  AS_HELP_STRING([--enable-sysrepo], [enable sysrepo integration]))
AC_ARG_ENABLE([grpc],
  AS_HELP_STRING([--enable-grpc], [enable the gRPC northbound plugin]))
AC_ARG_ENABLE([zeromq],
  AS_HELP_STRING([--enable-zeromq], [enable ZeroMQ handler (libfrrzmq)]))
AC_ARG_ENABLE([lttng],
  AS_HELP_STRING([--enable-lttng], [enable LTTng tracing]))
AC_ARG_ENABLE([usdt],
  AS_HELP_STRING([--enable-usdt], [enable USDT probes]))
AC_ARG_WITH([libpam],
  AS_HELP_STRING([--with-libpam], [use libpam for PAM support in vtysh]))
AC_ARG_ENABLE([ospfapi],
  AS_HELP_STRING([--disable-ospfapi], [do not build OSPFAPI to access the OSPF LSA Database]))
AC_ARG_ENABLE([ospfclient],
  AS_HELP_STRING([--disable-ospfclient], [do not build OSPFAPI client for OSPFAPI,
                          (this is the default if --disable-ospfapi is set)]))
AC_ARG_WITH([log_timestamp_precision],
  AS_HELP_STRING([--with-log-timestamp-precision=ARG], [set startup log timestamp precision, ARG must be 0-12]))
AC_ARG_ENABLE([multipath],
  AS_HELP_STRING([--enable-multipath=ARG], [enable multipath function, ARG must be digit]))
AC_ARG_WITH([service_timeout],
  AS_HELP_STRING([--with-service-timeout=ARG], [set service timeout value (2 minutes by default), ARG must be digit]))
AC_ARG_ENABLE([user],
  AS_HELP_STRING([--enable-user=USER], [user to run FRR suite as (default frr)]))
AC_ARG_ENABLE([group],
  AS_HELP_STRING([--enable-group=GROUP], [group to run FRR suite as (default frr)]))
AC_ARG_ENABLE([vty_group],
  AS_HELP_STRING([--enable-vty-group=ARG], [set vty sockets to have specified group as owner]))
AC_ARG_ENABLE([configfile_mask],
  AS_HELP_STRING([--enable-configfile-mask=ARG], [set mask for config files]))
AC_ARG_ENABLE([logfile_mask],
  AS_HELP_STRING([--enable-logfile-mask=ARG], [set mask for log files]))
AC_ARG_ENABLE([realms],
  AS_HELP_STRING([--enable-realms], [enable REALMS support under Linux]))
AC_ARG_ENABLE([capabilities],
  AS_HELP_STRING([--disable-capabilities], [disable using POSIX capabilities]))
AC_ARG_ENABLE([gcc_ultra_verbose],
  AS_HELP_STRING([--enable-gcc-ultra-verbose], [enable ultra verbose GCC warnings]))
AC_ARG_ENABLE([backtrace],
  AS_HELP_STRING([--disable-backtrace], [disable crash backtraces (default autodetect)])
AS_HELP_STRING([--enable-backtrace=<execinfo|libunwind>], [select specific backtrace library])
)
AC_ARG_ENABLE([pcreposix],
  AS_HELP_STRING([--enable-pcreposix], [enable using PCRE Posix libs for regex functions]))
AC_ARG_ENABLE([pcre2posix],
  AS_HELP_STRING([--enable-pcre2posix], [enable using PCRE2 Posix libs for regex functions]))
AC_ARG_ENABLE([fpm],
  AS_HELP_STRING([--enable-fpm], [enable Forwarding Plane Manager support]))
AC_ARG_ENABLE([werror],
  AS_HELP_STRING([--enable-werror], [enable -Werror (recommended for developers only)]))
AC_ARG_ENABLE([cumulus],
  AS_HELP_STRING([--enable-cumulus], [enable Cumulus Switch Special Extensions]))
AC_ARG_ENABLE([datacenter],
  AS_HELP_STRING([--enable-datacenter], [enable Compilation for Data Center Extensions]))
AC_ARG_ENABLE([protobuf],
  AS_HELP_STRING([--enable-protobuf], [Enable experimental protobuf support]))
AC_ARG_ENABLE([oldvpn_commands],
  AS_HELP_STRING([--enable-oldvpn-commands], [Keep old vpn commands]))
AC_ARG_ENABLE([rpki],
  AS_HELP_STRING([--enable-rpki], [enable RPKI prefix validation support]))
AC_ARG_ENABLE([clippy-only],
  AS_HELP_STRING([--enable-clippy-only], [Only build clippy]))
AC_ARG_ENABLE([numeric_version],
  AS_HELP_STRING([--enable-numeric-version], [Only numeric digits allowed in version (for Alpine)]))
AC_ARG_ENABLE([gcov],
  AS_HELP_STRING([--enable-gcov], [Collect coverage information with gcov]))
AC_ARG_ENABLE([clang_coverage],
  AS_HELP_STRING([--enable-clang-coverage], [Collect coverage information with Clang Coverage]))
AC_ARG_ENABLE([bfdd],
  AS_HELP_STRING([--disable-bfdd], [do not build bfdd]))
AC_ARG_ENABLE([address-sanitizer],
  AS_HELP_STRING([--enable-address-sanitizer], [enable AddressSanitizer support for detecting a wide variety of memory allocation and deallocation errors]))
AC_ARG_ENABLE([thread-sanitizer],
  AS_HELP_STRING([--enable-thread-sanitizer], [enable ThreadSanitizer support for detecting data races]))
AC_ARG_ENABLE([memory-sanitizer],
  AS_HELP_STRING([--enable-memory-sanitizer], [enable MemorySanitizer support for detecting uninitialized memory reads]))
AC_ARG_ENABLE([undefined-sanitizer],
  AS_HELP_STRING([--enable-undefined-sanitizer], [enable UndefinedBehaviorSanitizer support for detecting undefined behavior]))
AC_ARG_WITH([crypto],
  AS_HELP_STRING([--with-crypto=<internal|openssl>], [choose between different implementations of cryptographic functions(default value is --with-crypto=internal)]))
AC_ARG_WITH([frr-format],
  AS_HELP_STRING([--with-frr-format[=<.../frr-format.so>]], [use frr-format GCC plugin]))

AC_ARG_ENABLE([version_build_config],
  AS_HELP_STRING([--disable-version-build-config], [do not include build configs in show version command]))

AC_ARG_ENABLE([python_runtime],
  AS_HELP_STRING([--disable-python-runtime], [do not install python scripts or have python runtime dependency]))

##
## gperftools tcmalloc version, more complete than "minimal"
##
AC_ARG_ENABLE(gperf-tcmalloc,
	AS_HELP_STRING([--enable-gperf-tcmalloc], [Use gperftools tcmalloc]),
[case "${enableval}" in
  yes)
  AC_MSG_CHECKING([for gperftools tcmalloc])
  AC_CHECK_LIB([tcmalloc], [MallocExtension_ReleaseToSystem], [
gperf_tcmalloc_enabled=true
LIBS="$LIBS -ltcmalloc"
AC_DEFINE([HAVE_TCMALLOC], [1], [Enable tcmalloc])
  ], [AC_MSG_ERROR([tcmalloc specified but libtcmalloc not found, or missing apis])])
 ;;
  no)  gperf_tcmalloc_enabled=false ;;
  *) AC_MSG_ERROR([bad value ${enableval} for --enable-gperf-tcmalloc]) ;;
esac],[gperf_tcmalloc_enabled=false])

#if openssl, else use the internal
AS_IF([test "$with_crypto" = "openssl"], [
AC_CHECK_LIB([crypto], [EVP_DigestInit], [LIBS="$LIBS -lcrypto"], [], [])
if test "$ac_cv_lib_crypto_EVP_DigestInit" = "no"; then
  AC_MSG_ERROR([build with openssl has been specified but openssl library was not found on your system])
else
  AC_DEFINE([CRYPTO_OPENSSL], [1], [Compile with openssl support])
fi
], [test "$with_crypto" = "internal" || test "$with_crypto" = "" ], [AC_DEFINE([CRYPTO_INTERNAL], [1], [Compile with internal cryptographic implementation])
], [AC_MSG_ERROR([Unknown value for --with-crypto])]
)

AS_IF([test "$enable_clippy_only" != "yes"], [
AC_CHECK_HEADERS([json-c/json.h])
AC_CHECK_LIB([json-c], [json_object_get], [LIBS="$LIBS -ljson-c"], [], [-lm])
if test "$ac_cv_lib_json_c_json_object_get" = "no"; then
  AC_CHECK_LIB([json], [json_object_get], [LIBS="$LIBS -ljson"])
  if test "$ac_cv_lib_json_json_object_get" = "no"; then
      AC_MSG_ERROR([libjson is needed to compile])
  fi
fi
])

AC_ARG_ENABLE([ccls],
AS_HELP_STRING([--enable-ccls], [Write .ccls config for this build]))

AC_ARG_ENABLE([dev_build],
    AS_HELP_STRING([--enable-dev-build], [build for development]))

AC_ARG_ENABLE([scripting],
    AS_HELP_STRING([--enable-scripting], [Build with scripting support]))

AC_ARG_ENABLE([netlink-debug],
  AS_HELP_STRING([--disable-netlink-debug], [don't pretty print netlink debug messages]))

if test "$enable_netlink_debug" != "no" ; then
  AC_DEFINE([NETLINK_DEBUG], [1], [Netlink extra debugging code])
fi

AM_CONDITIONAL([NETLINK_DEBUG], [test "$enable_netlink_debug" != "no"])

if test "$enable_datacenter" = "yes" ; then
  AC_DEFINE([HAVE_DATACENTER], [1], [Compile extensions for a DataCenter])
  DFLT_NAME="datacenter"
else
  DFLT_NAME="traditional"
fi

if test "$enable_cumulus" = "yes" ; then
  AC_DEFINE([HAVE_CUMULUS], [1], [Compile Special Cumulus Code in])
fi

AC_SUBST([DFLT_NAME])
AC_DEFINE_UNQUOTED([DFLT_NAME], ["$DFLT_NAME"], [Name of the configuration default set])

#
# Python for clippy
#

AS_IF([test "$host" = "$build"], [
  AM_PATH_PYTHON([3])
  AC_CHECK_HEADER([gelf.h], [], [
    AC_MSG_ERROR([libelf headers are required for building clippy.  (Host only when cross-compiling.)])
  ])

  LIBS_save="$LIBS"
  AC_CHECK_LIB([elf], [elf_memory], [], [
    AC_MSG_ERROR([libelf is required for building clippy.  (Host only when cross-compiling.)])
  ])

  AC_CHECK_LIB([elf], [elf_getdata_rawchunk], [
    AC_DEFINE([HAVE_ELF_GETDATA_RAWCHUNK], [1], [Have elf_getdata_rawchunk()])
  ])
  AC_CHECK_LIB([elf], [gelf_getnote], [
    AC_DEFINE([HAVE_GELF_GETNOTE], [1], [Have gelf_getnote()])
  ])
  LIBS="$LIBS_save"
  unset LIBS_save

  FRR_PYTHON_DEV
], [
  FRR_PYTHON
])

FRR_PYTHON_MODULES([pytest])

if test "$enable_doc" != "no"; then
  FRR_PYTHON_MODULES([sphinx], , [
    if test "$enable_doc" = "yes"; then
      AC_MSG_ERROR([Documentation was explicitly requested with --enable-doc but sphinx is not available for $PYTHON. Please disable docs or install sphinx.])
    fi
  ])
fi
AM_CONDITIONAL([DOC], [test "$enable_doc" != "no" -a "$frr_py_mod_sphinx" != "false"])
AM_CONDITIONAL([DOC_HTML], [test "$enable_doc_html" = "yes"])

FRR_PYTHON_MOD_EXEC([sphinx], [--version], [
  PYSPHINX="-m sphinx"
], [
  PYSPHINX="-c 'import sys; from sphinx import main; sys.exit(main(sys.argv))'"
])
AC_SUBST([PYSPHINX])

#
# Logic for old vpn commands support.
#
if test "$enable_oldvpn_commands" = "yes"; then
   AC_DEFINE([KEEP_OLD_VPN_COMMANDS], [1], [Define for compiling with old vpn commands])
fi

if test "$enable_user" = "no"; then
  enable_user=""
else
  if test "$enable_user" = "yes" || test "$enable_user" = ""; then
    enable_user="frr"
  fi
  AC_DEFINE_UNQUOTED([FRR_USER], ["${enable_user}"], [frr User])
fi

if test "$enable_group" = "no"; then
  enable_group=""
else
  if test "$enable_group" = "yes" || test "$enable_group" = ""; then
    enable_group="frr"
  fi
  AC_DEFINE_UNQUOTED([FRR_GROUP], ["${enable_group}"], [frr Group])
fi

if test "$enable_vty_group" = "yes" ; then
  AC_MSG_ERROR([--enable-vty-group requires a group as argument, not yes])
elif test "$enable_vty_group" != ""; then
  if test "$enable_vty_group" != "no"; then
    AC_DEFINE_UNQUOTED([VTY_GROUP], ["${enable_vty_group}"], [VTY Sockets Group])
  fi
fi
AC_SUBST([enable_user])
AC_SUBST([enable_group])
AC_SUBST([enable_vty_group])

enable_configfile_mask=${enable_configfile_mask:-0600}
AC_DEFINE_UNQUOTED([CONFIGFILE_MASK], [${enable_configfile_mask}], [Mask for config files])
AC_SUBST([enable_configfile_mask])

enable_logfile_mask=${enable_logfile_mask:-0600}
AC_DEFINE_UNQUOTED([LOGFILE_MASK], [${enable_logfile_mask}], [Mask for log files])

MPATH_NUM=16

case "${enable_multipath}" in
  0)
    MPATH_NUM=64
    ;;
  [[1-9]|[1-9][0-9]|[1-9][0-9][0-9]])
    MPATH_NUM="${enable_multipath}"
    ;;
  "")
    ;;
  *)
    AC_MSG_FAILURE([Please specify digit to enable multipath ARG])
    ;;
esac

AC_DEFINE_UNQUOTED([MULTIPATH_NUM], [$MPATH_NUM], [Maximum number of paths for a route])
AC_SUBST([MULTIPATH_NUM], [$MPATH_NUM])

case "${with_log_timestamp_precision}" in
[[0-9]|1[012]])
;;
"")
;;
*)
AC_MSG_FAILURE([Please specify a number from 0-12 for log precision ARG])
;;
esac
with_log_timestamp_precision=${with_log_timestamp_precision:-0}
AC_DEFINE_UNQUOTED([LOG_TIMESTAMP_PRECISION], [${with_log_timestamp_precision}], [Startup zlog timestamp precision])

AC_DEFINE_UNQUOTED([VTYSH_PAGER], ["$VTYSH_PAGER"], [What pager to use])

TIMEOUT_MIN=2
case "${with_service_timeout}" in
  [[1-9]|[1-9][0-9]|[1-9][0-9][0-9]])
    TIMEOUT_MIN="${with_service_timeout}"
    ;;
  0|"")
    ;;
  *)
    AC_MSG_FAILURE([Please specify digit for timeout ARG])
    ;;
esac
AC_SUBST([TIMEOUT_MIN])

dnl --------------------
dnl Enable code coverage
dnl --------------------
AM_CONDITIONAL([HAVE_GCOV], [test "$enable_gcov" != "no"])

dnl ------------------------------------
dnl Alpine only accepts numeric versions
dnl ------------------------------------
if test "$enable_numeric_version" != "" ; then
  VERSION="`echo ${VERSION} | tr -c -d '[[.0-9]]'`"
  PACKAGE_VERSION="`echo ${PACKAGE_VERSION} | tr -c -d '[[.0-9]]'`"
fi

dnl -----------------------------------
dnl Add extra version string to package
dnl name, string and version fields.
dnl -----------------------------------
if test "$EXTRAVERSION" != "" ; then
  VERSION="${VERSION}${EXTRAVERSION}"
  PACKAGE_VERSION="${PACKAGE_VERSION}${EXTRAVERSION}"
  AC_SUBST(PACKAGE_EXTRAVERSION, ["${EXTRAVERSION}"])
  PACKAGE_STRING="${PACKAGE_STRING}${EXTRAVERSION}"
fi
AC_SUBST([EXTRAVERSION])

if test "$with_pkg_git_version" = "yes"; then
	if test -e "${srcdir}/.git"; then
		AC_DEFINE([GIT_VERSION], [1], [include git version info])
	else	with_pkg_git_version="no"
		AC_MSG_WARN([--with-pkg-git-version given, but this is not a git checkout])
	fi
fi
AM_CONDITIONAL([GIT_VERSION], [test "$with_pkg_git_version" = "yes"])

AC_CHECK_TOOL([OBJCOPY], [objcopy], [:])
if test "$OBJCOPY" != ":"; then
  AC_CACHE_CHECK([for .interp value to use], [frr_cv_interp], [
    frr_cv_interp=""
    AC_LINK_IFELSE([AC_LANG_SOURCE([[int main() { return 0; }]])], [
      if $OBJCOPY -j.interp -Obinary conftest conftest.interp; then
        frr_cv_interp="`xargs -0 echo < conftest.interp`"
      fi
      test -f conftest.interp && rm conftest.interp
    ])
  ])
fi
if test -n "$frr_cv_interp"; then
  AC_DEFINE_UNQUOTED([INTERP], ["$frr_cv_interp"], [.interp value])
fi

dnl -------------------------
dnl Check other header files.
dnl -------------------------
AC_CHECK_HEADERS([ \
	asm/types.h sys/endian.h])

AC_CHECK_HEADER([endian.h], [], [
  AC_MSG_ERROR([missing endian.h])
])

AC_CHECK_LIB([atomic], [main], [LIBS="$LIBS -latomic"], [], [])

AC_CHECK_HEADER([stdatomic.h],[
  AC_MSG_CHECKING([whether _Atomic qualifier works])
  AC_LINK_IFELSE([AC_LANG_SOURCE([[
#include <stdatomic.h>
int main(int argc, char **argv) {
  _Atomic int i = 0;
  return i;
}
]])], [
    AC_DEFINE([HAVE_STDATOMIC_H], [1], [found stdatomic.h])
    AC_MSG_RESULT([yes])
    ac_stdatomic_ok=true
  ], [
    AC_MSG_RESULT([no])
    AC_MSG_ERROR([building FRR requires an ISO C11 compliant compiler with atomics support])
  ])
])

needsync=true

AS_IF([$needsync], [
  dnl Linux
  AC_MSG_CHECKING([for Linux futex() support])
  AC_LINK_IFELSE([AC_LANG_PROGRAM([
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <unistd.h>
#include <limits.h>
#include <sys/time.h>
#include <sys/syscall.h>
#include <linux/futex.h>

int main(void);
],
[
{
  return syscall(SYS_futex, NULL, FUTEX_WAIT, 0, NULL, NULL, 0);
}
])], [
    AC_MSG_RESULT([yes])
    AC_DEFINE(HAVE_SYNC_LINUX_FUTEX,,Have Linux futex support)
    needsync=false
  ], [
    AC_MSG_RESULT([no])
  ])
])

AS_IF([$needsync], [
  dnl FreeBSD
  AC_MSG_CHECKING([for FreeBSD _umtx_op() support])
  AC_LINK_IFELSE([AC_LANG_PROGRAM([
#include <errno.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/umtx.h>
int main(void);
],
[
{
  return _umtx_op(NULL, UMTX_OP_WAIT_UINT, 0, NULL, NULL);
}
])], [
    AC_MSG_RESULT([yes])
    AC_DEFINE(HAVE_SYNC_UMTX_OP,,Have FreeBSD _umtx_op() support)
    needsync=false
  ], [
    AC_MSG_RESULT([no])
  ])
])

AS_IF([$needsync], [
  dnl OpenBSD patch (not upstream at the time of writing this)
  dnl https://marc.info/?l=openbsd-tech&m=147299508409549&w=2
  AC_MSG_CHECKING([for OpenBSD futex() support])
  AC_LINK_IFELSE([AC_LANG_PROGRAM([
#include <sys/futex.h>
int main(void);
],
[
{
  return futex(NULL, FUTEX_WAIT, 0, NULL, NULL, 0);
}
])], [
    AC_MSG_RESULT([yes])
    AC_DEFINE(HAVE_SYNC_OPENBSD_FUTEX,,Have OpenBSD futex support)
    needsync=false
  ], [
    AC_MSG_RESULT([no])
  ])
])

dnl Utility macro to avoid retyping includes all the time
m4_define([FRR_INCLUDES],
[#ifdef SUNOS_5
#define _POSIX_C_SOURCE 200809L
#define __EXTENSIONS__
#endif
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <sys/types.h>
#include <sys/param.h>
/* Required for MAXSIG */
#include <signal.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/time.h>
#include <time.h>
#include <net/if.h>
])dnl

AC_CHECK_HEADERS([netinet/in_var.h \
	netinet/ip_icmp.h],
	[], [], [FRR_INCLUDES])

AC_CHECK_HEADERS([ucontext.h], [], [],
[#ifndef __USE_GNU
#define __USE_GNU
#endif /* __USE_GNU */
FRR_INCLUDES
])

m4_define([UCONTEXT_INCLUDES],
[#include <ucontext.h>])dnl

AC_CHECK_MEMBERS([ucontext_t.uc_mcontext.uc_regs],
  [], [], [UCONTEXT_INCLUDES])
AC_CHECK_MEMBERS([ucontext_t.uc_mcontext.regs],
  [AC_CHECK_MEMBERS([ucontext_t.uc_mcontext.regs.nip],
   [], [], [UCONTEXT_INCLUDES])],
  [], [UCONTEXT_INCLUDES])
AC_CHECK_MEMBERS([ucontext_t.uc_mcontext.gregs],
  [], [], [UCONTEXT_INCLUDES])

m4_define([FRR_INCLUDES],
FRR_INCLUDES
[
#include <sys/un.h>
#include <netinet/in_systm.h>
#ifdef HAVE_NETINET_IN_VAR_H
# include <netinet/in_var.h>
#endif
#ifndef __linux__
# include <net/if_dl.h>
#endif
#include <net/route.h>
#include <arpa/inet.h>
/* Required for IDRP */
#ifdef HAVE_NETINET_IP_ICMP_H
# include <netinet/ip_icmp.h>
#endif
])dnl

dnl V6 headers are checked below, after we check for v6

is_linux=false

AC_MSG_CHECKING([which operating system interface to use])
case "$host_os" in
  sunos* | solaris2*)
    AC_MSG_FAILURE([Solaris support has been removed please see versions prior or equal to 7.5])
    ;;
  linux*)
    AC_MSG_RESULT([Linux])

    AC_DEFINE([GNU_LINUX], [1], [GNU Linux])
    AC_DEFINE([HAVE_NETLINK], [1], [netlink])
    AC_DEFINE([LINUX_IPV6], [1], [Linux IPv6 stack])

    dnl Linux has a compilation problem with mixing
    dnl netinet/in.h and linux/in6.h they are not
    dnl compatible.  There has been discussion on
    dnl how to fix it but no real progress on implementation
    dnl when they fix it, remove this
    AC_DEFINE([IPV6_MINHOPCOUNT], [73], [Linux ipv6 Min Hop Count])

    is_linux=true
    ;;
  openbsd*)
    AC_MSG_RESULT([OpenBSD])

    AC_DEFINE([OPEN_BSD], [1], [OpenBSD])
    AC_DEFINE([BSD_V6_SYSCTL], [1], [BSD v6 sysctl to turn on and off forwarding])
    ;;
  *)
    AC_MSG_RESULT([BSD])

    AC_DEFINE([HAVE_NET_RT_IFLIST], [1], [NET_RT_IFLIST])
    AC_DEFINE([BSD_V6_SYSCTL], [1], [BSD v6 sysctl to turn on and off forwarding])
    ;;
esac
AM_CONDITIONAL([LINUX], [${is_linux}])

AC_SYS_LARGEFILE

dnl ------------------------
dnl Integrated REALMS option
dnl ------------------------
if test "$enable_realms" = "yes"; then
    case "$host_os" in
      linux*)
       AC_DEFINE([SUPPORT_REALMS], [1], [Realms support])
       ;;
      *)
       echo "Sorry, only Linux has REALMS support"
       exit 1
       ;;
    esac
fi

dnl ---------------
dnl other functions
dnl ---------------
AC_CHECK_FUNCS([ \
	strlcat strlcpy \
	getgrouplist \
	getloadavg \
	openat \
	unlinkat \
	posix_fallocate \
	sendmmsg \
	explicit_bzero \
	])

dnl note the trailing _ in the following macros; this is neccessary since
dnl otherwise autoheader *replaces* the #define with the block...
dnl
dnl yes this might include stddef.h 3 times but who cares

AH_VERBATIM(HAVE_STRLCAT_, [
#ifndef HAVE_STRLCAT
#include <stddef.h>
size_t strlcat(char *__restrict dest,
	       const char *__restrict src, size_t destsize);
#endif
])
AH_VERBATIM(HAVE_STRLCPY_, [
#ifndef HAVE_STRLCPY
#include <stddef.h>
size_t strlcpy(char *__restrict dest,
	       const char *__restrict src, size_t destsize);
#endif
])
AH_VERBATIM(HAVE_EXPLICIT_BZERO_, [
#ifndef HAVE_EXPLICIT_BZERO
#include <stddef.h>
void explicit_bzero(void *buf, size_t len);
#endif
])

AC_CHECK_MEMBERS([struct mmsghdr.msg_hdr], [], [], FRR_INCLUDES)

dnl ##########################################################################
dnl LARGE if block spans a lot of "configure"!
if test "$enable_clippy_only" != "yes"; then
dnl ##########################################################################

#
# Logic for protobuf support.
#
PROTO3=false
if test "$enable_protobuf" != "no"; then
  AC_CHECK_PROGS([PROTOC], [protoc], [/bin/false])
  AC_CHECK_PROGS([PROTOC_C], [protoc-c], [/bin/false])
  PKG_CHECK_MODULES([PROTOBUF_C], [libprotobuf-c >= 1.3.0], [PROTO3=true], [PROTO3=false])

  if test "$PROTOC_C" != "/bin/false" && test "$PROTO3" != "false"; then
    AC_DEFINE([HAVE_PROTOBUF], [1], [protobuf])
    dnl
    dnl The libprotobuf-c >= 1.3.0 check replaces an older check for a symbol
    dnl that shows up in libprotobuf-c 1.3.0. Also previously this check was
    dnl only done when a non-existent flag (`--enable-protobuf3`) was specified
    dnl (i.e., never).
    dnl
    dnl Finally this seems misnamed (why not PROTOBUF_C_13?), but the users of
    dnl this flag should address this.
    dnl
    AC_DEFINE([HAVE_PROTOBUF_VERSION_3], [1], [Have libprotobuf-c version 1.3])
  fi

  # Require things if the user explicitly requested protobuf
  if test "$enable_protobuf" = "yes"; then
    if test "$PROTOC_C" = "/bin/false"; then
      AC_MSG_FAILURE([protobuf requested but protoc-c not found.  Install protobuf-c])
    fi
    if test "$PROTO3" = "false"; then
      AC_MSG_FAILURE([protobuf requested but libprotobuf-c > 1.3.0 not found])
    fi
  fi
fi
#
# End of logic for protobuf support.
#


dnl ---------------------
dnl Integrated VTY option
dnl ---------------------
case "${enable_vtysh}" in
"no")
  VTYSH="";;
*)
  VTYSH="vtysh";
  AC_DEFINE([VTYSH], [1], [VTY shell])

  prev_libs="$LIBS"
  AC_CHECK_LIB([readline], [readline], [
    LIBREADLINE="-lreadline"
  ], [
    dnl readline failed - it might be incorrectly linked and missing its
    dnl termcap/tinfo/curses dependency.  see if we can fix that...
    AC_SEARCH_LIBS([tputs], [termcap tinfo curses ncurses], [
      LIBREADLINE="$ac_cv_search_tputs"
    ], [
      AC_MSG_ERROR([libreadline (needed for vtysh) not found and/or missing dependencies])
    ])

    dnl re-try with the lib we found above
    unset ac_cv_lib_readline_main
    AC_CHECK_LIB([readline], [main], [
      LIBREADLINE="-lreadline $LIBREADLINE"
    ], [
      AC_MSG_ERROR([libreadline (needed for vtysh) not found and/or missing dependencies])
    ], [$LIBREADLINE])
  ], [])
  LIBS="$LIBS -lreadline"
  AC_CHECK_FUNCS([rl_clear_visible_line])
  LIBS="$prev_libs"

  AC_CHECK_HEADER([readline/history.h])
  if test "$ac_cv_header_readline_history_h" = "no"; then
    AC_MSG_ERROR([readline is too old to have readline/history.h, please update to the latest readline library.])
  fi
  AC_CHECK_LIB([readline], [rl_completion_matches], [true], [], [$LIBREADLINE])
  if test "$ac_cv_lib_readline_rl_completion_matches" = "no"; then
    AC_DEFINE([rl_completion_matches], [completion_matches], [Old readline])
  fi
  AC_CHECK_LIB([readline], [append_history], [frr_cv_append_history=yes], [frr_cv_append_history=no], [$LIBREADLINE])
  if test "$frr_cv_append_history" = "yes"; then
    AC_DEFINE([HAVE_APPEND_HISTORY], [1], [Have history.h append_history])
  fi
  ;;
esac
AC_SUBST([LIBREADLINE])

dnl ----------
dnl PAM module
dnl
dnl FRR detects the PAM library it is built against by checking for a
dnl functional pam_misc.h (Linux-PAM) or openpam.h (OpenPAM) header. pam_misc.h
dnl is known to #include pam_appl.h, the standard header of a PAM library, and
dnl openpam.h doesn't do that, although depends on the header too. Hence a
dnl little assistance to AC_CHECK_HEADER is necessary for the proper detection
dnl of OpenPAM.
dnl ----------
if test "$with_libpam" = "yes"; then
  AC_CHECK_HEADER([security/pam_misc.h],
    [AC_DEFINE([HAVE_PAM_MISC_H], [1], [Have pam_misc.h])
     AC_DEFINE([PAM_CONV_FUNC], [misc_conv], [Have misc_conv])
     pam_conv_func="misc_conv"
    ],
    [], FRR_INCLUDES)
  AC_CHECK_HEADER([security/openpam.h],
    [AC_DEFINE([HAVE_OPENPAM_H], [1], [Have openpam.h])
     AC_DEFINE([PAM_CONV_FUNC], [openpam_ttyconv], [Have openpam_ttyconv])
     pam_conv_func="openpam_ttyconv"
    ],
    [], FRR_INCLUDES[#include <security/pam_appl.h>])
  if test -z "$ac_cv_header_security_pam_misc_h$ac_cv_header_security_openpam_h" ; then
    AC_MSG_WARN([*** pam support will not be built ***])
    with_libpam="no"
  fi
fi

if test "$with_libpam" = "yes"; then
dnl took this test from proftpds configure.in and suited to our needs
dnl -------------------------------------------------------------------------
dnl
dnl This next check looks funky due to a linker problem with some versions
dnl of the PAM library.  Prior to 0.72 release, the Linux PAM shared library
dnl omitted requiring libdl linking information. PAM-0.72 or better ships
dnl with RedHat 6.2 and Debian 2.2 or better.
AC_CHECK_LIB([pam], [pam_start],
  [AC_CHECK_LIB([pam], [$pam_conv_func],
    [AC_DEFINE([USE_PAM], [1], [Use PAM for authentication])
     LIBPAM="-lpam"],
    [AC_DEFINE([USE_PAM], [1], [Use PAM for authentication])
     LIBPAM="-lpam -lpam_misc"]
    )
  ],

  [AC_CHECK_LIB([pam], [pam_end],
    [AC_CHECK_LIB([pam], [$pam_conv_func],
      [AC_DEFINE([USE_PAM], [1], [Use PAM for authentication])
       LIBPAM="-lpam -ldl"],
      [AC_DEFINE([USE_PAM], [1], [Use PAM for authentication])
       LIBPAM="-lpam -ldl -lpam_misc"]
     )
  ],AC_MSG_WARN([*** pam support will not be built ***]),
  [-ldl])
  ]
)
fi
AC_SUBST([LIBPAM])

dnl -------------------------------
dnl bgpd needs pow() and hence libm
dnl -------------------------------
TMPLIBS="$LIBS"
LIBS=""
AC_SEARCH_LIBS([pow], [m], [
  LIBM="$LIBS"
], [
  AC_MSG_WARN([Unable to find working pow function - bgpd may not link])
])
LIBS="$TMPLIBS"
AC_SUBST([LIBM])

AC_CHECK_FUNCS([ppoll], [
  AC_DEFINE([HAVE_PPOLL], [1], [have Linux/BSD ppoll()])
])
AC_CHECK_FUNCS([pollts], [
  AC_DEFINE([HAVE_POLLTS], [1], [have NetBSD pollts()])
])

AC_CHECK_HEADER([asm-generic/unistd.h],
                [AC_CHECK_DECL(__NR_setns,
                               AC_DEFINE([HAVE_NETNS], [1], [Have netns]),,
                               FRR_INCLUDES [#include <asm-generic/unistd.h>
                               ])
                 AC_CHECK_FUNCS([setns])]
               )

dnl --------------------------
dnl Determine IS-IS I/O method
dnl --------------------------
AC_DEFINE([ISIS_METHOD_PFPACKET], [1], [constant value for isis method pfpacket])
AC_DEFINE([ISIS_METHOD_DLPI], [2], [constant value for isis method dlpi])
AC_DEFINE([ISIS_METHOD_BPF], [3], [constant value for isis method bpf])
AC_CHECK_HEADER([net/bpf.h])
AC_CHECK_HEADER([sys/dlpi.h])
AC_MSG_CHECKING([zebra IS-IS I/O method])

case "$host_os" in
  linux*)
    AC_MSG_RESULT([pfpacket])
    ISIS_METHOD_MACRO="ISIS_METHOD_PFPACKET"
    ;;
  *)
    if test "$ac_cv_header_net_bpf_h" = "no"; then
      if test "$ac_cv_header_sys_dlpi_h" = "no"; then
        AC_MSG_RESULT([none])
        if test "$enable_isisd" = "yes" -o "$enable_fabricd" = "yes"; then
          AC_MSG_FAILURE([IS-IS support requested but no packet backend found])
        fi
        AC_MSG_WARN([*** IS-IS support will not be built ***])
        enable_isisd="no"
        enable_fabricd="no"
      else
        AC_MSG_RESULT([DLPI])
      fi
      ISIS_METHOD_MACRO="ISIS_METHOD_DLPI"
    else
      AC_MSG_RESULT([BPF])
      ISIS_METHOD_MACRO="ISIS_METHOD_BPF"
    fi
    ;;
esac
AC_DEFINE_UNQUOTED([ISIS_METHOD], [$ISIS_METHOD_MACRO], [selected method for isis, == one of the constants])

dnl ---------------------------------------------------------------
dnl figure out how to specify an interface in multicast sockets API
dnl ---------------------------------------------------------------
AC_CHECK_MEMBERS([struct ip_mreqn.imr_ifindex], [], [], FRR_INCLUDES)

AC_CHECK_HEADERS([linux/mroute.h], [], [],[
	#include <sys/socket.h>
	#include <netinet/in.h>
	#define _LINUX_IN_H             /* For Linux <= 2.6.25 */
	#include <linux/types.h>
])

AC_CHECK_HEADERS([linux/mroute6.h], [], [],[
	#include <sys/socket.h>
	#include <netinet/in.h>
	#define _LINUX_IN_H             /* For Linux <= 2.6.25 */
	#include <linux/types.h>
])

m4_define([FRR_INCLUDES],
FRR_INCLUDES
[#ifdef HAVE_LINUX_MROUTE_H
# include <linux/mroute.h>
#endif
])dnl

AC_CHECK_HEADERS([netinet/ip_mroute.h], [], [],[
	#include <sys/socket.h>
	#include <sys/types.h>
	#include <netinet/in.h>
	#include <net/route.h>
])

m4_define([FRR_INCLUDES],
FRR_INCLUDES
[#ifdef HAVE_NETINET_IP_MROUTE_H
# include <netinet/ip_mroute.h>
#endif
])dnl

AC_CHECK_HEADERS([netinet6/ip6_mroute.h], [], [],[
	#include <sys/socket.h>
	#include <sys/param.h>
	#include <sys/types.h>
	#include <netinet/in.h>
	#include <net/route.h>
])

m4_define([FRR_INCLUDES],
FRR_INCLUDES
[#ifdef HAVE_NETINET_IP6_MROUTE_H
# include <netinet6/ip6_mroute.h>
#endif
])dnl

AC_MSG_CHECKING([for RFC3678 protocol-independed API])
AC_COMPILE_IFELSE(
[ AC_LANG_PROGRAM([[
      #include <sys/types.h>
      #include <netinet/in.h>
  ]], [[
      struct group_req gr;
      int sock;
      setsockopt(sock, IPPROTO_IP, MCAST_JOIN_GROUP, (void*)&gr, sizeof(gr));
  ]])
],[
  AC_MSG_RESULT([yes])
  AC_DEFINE([HAVE_RFC3678], [1], [Have RFC3678 protocol-independed API])
],[
  AC_MSG_RESULT(no)
])

dnl ---------------------------------------------------------------
dnl figure out how to check link-state
dnl ---------------------------------------------------------------
AC_CHECK_HEADER([net/if_media.h],
  [m4_define([LINK_DETECT_INCLUDES],
    FRR_INCLUDES
    [#include <net/if_media.h>
  ])
  AC_CHECK_MEMBERS([struct ifmediareq.ifm_status],
    AC_DEFINE([HAVE_BSD_LINK_DETECT], [1], [BSD link-detect]),
    [], LINK_DETECT_INCLUDES)],
  [],
  FRR_INCLUDES)

dnl ---------------------------------------------------------------
dnl Additional, newer way to check link-state using ifi_link_state.
dnl Not available in all BSD's when ifmediareq available
dnl ---------------------------------------------------------------
AC_CHECK_MEMBERS([struct if_data.ifi_link_state],
  AC_DEFINE([HAVE_BSD_IFI_LINK_STATE], [1], [BSD ifi_link_state available]),
  [], FRR_INCLUDES)

dnl ------------------------
dnl TCP_MD5SIG socket option
dnl ------------------------

AC_CHECK_HEADER([netinet/tcp.h],
   [m4_define([MD5_INCLUDES],
      FRR_INCLUDES
      [#include <netinet/tcp.h>
    ])
    AC_CHECK_DECLS([TCP_MD5SIG], [], [], MD5_INCLUDES)],
   [],
   FRR_INCLUDES)
if test "$ac_cv_have_decl_TCP_MD5SIG" = "no"; then
  AC_CHECK_HEADER([linux/tcp.h],
       [m4_define([MD5_INCLUDES],
          FRR_INCLUDES
          [#include <linux/tcp.h>
        ])
       AC_CHECK_DECLS([TCP_MD5SIG], [], [], MD5_INCLUDES)])
fi

LIBS_save="$LIBS"
AC_CHECK_LIB([crypt], [crypt], [], [
  AC_CHECK_LIB([crypto], [DES_crypt])
])
LIBCRYPT="$LIBS"
LIBCRYPT="${LIBCRYPT%$LIBS_save}"
LIBCRYPT="${LIBCRYPT#$LIBS_save}"
AC_SUBST([LIBCRYPT])
LIBS="$LIBS_save"
unset LIBS_save

AC_CHECK_LIB([resolv], [res_init])

dnl ---------------------------
dnl check system has PCRE regexp
dnl ---------------------------
if test "$enable_pcreposix" = "yes"; then
  AC_CHECK_LIB([pcreposix], [regexec], [], [
    AC_MSG_ERROR([--enable-pcreposix given but unable to find libpcreposix])
  ])
fi
AC_SUBST([HAVE_LIBPCREPOSIX])

dnl ---------------------------
dnl check system has PCRE2 regexp
dnl ---------------------------
if test "$enable_pcre2posix" = "yes"; then
  AC_CHECK_LIB([pcre2-posix], [regexec], [], [
    AC_MSG_ERROR([--enable-pcre2posix given but unable to find libpcre2-posix])
  ])
fi
AC_SUBST([HAVE_LIBPCRE2_POSIX])

dnl ##########################################################################
dnl test "$enable_clippy_only" != "yes"
fi
dnl END OF LARGE if block
dnl ##########################################################################

dnl ------------------
dnl check C-Ares library
dnl ------------------
PKG_CHECK_MODULES([CARES], [libcares], [
  c_ares_found=true
],[
  c_ares_found=false
])
AM_CONDITIONAL([CARES], [$c_ares_found])


dnl ----------------------------------------------------------------------------
dnl figure out if domainname is available in the utsname struct (GNU extension).
dnl ----------------------------------------------------------------------------
AC_CHECK_MEMBERS([struct utsname.domainname], [], [], [#include <sys/utsname.h>])

dnl ------------------
dnl IPv6 header checks
dnl ------------------
AC_CHECK_HEADERS([ \
	netinet6/nd6.h], [], [],
	FRR_INCLUDES)

m4_define([FRR_INCLUDES],dnl
FRR_INCLUDES
[#include <netinet/icmp6.h>
#ifdef HAVE_NETINET6_ND6_H
# include <netinet6/nd6.h>
#endif
])dnl

dnl --------------------
dnl Daemon disable check
dnl --------------------

AS_IF([test "$enable_bgpd" != "no"], [
  AC_DEFINE([HAVE_BGPD], [1], [bgpd])
])

AS_IF([test "$enable_mgmtd" != "no"], [
  AC_DEFINE([HAVE_MGMTD], [1], [mgmtd])
])

AS_IF([test "$enable_mgmtd_test_be_client" = "yes"], [
  AC_DEFINE([HAVE_MGMTD_TESTC], [1], [mgmtd_testc])
])

AS_IF([test "$enable_fpm_listener" = "yes"], [
  AC_DEFINE([HAVE_FPM_LISTENER], [1], [fpm_listener])
])

AS_IF([test "$enable_ripd" != "no"], [
  AC_DEFINE([HAVE_RIPD], [1], [ripd])
])

AS_IF([test "$enable_ripngd" != "no"], [
  AC_DEFINE([HAVE_RIPNGD], [1], [ripngd])
])

AS_IF([test "$enable_ospfd" != "no"], [
  AC_DEFINE([HAVE_OSPFD], [1], [ospfd])
])

AS_IF([test "$enable_ospf6d" != "no"], [
  AC_DEFINE([HAVE_OSPF6D], [1], [ospf6d])
])

AS_IF([test "$enable_ldpd" != "no"], [
  AC_DEFINE([HAVE_LDPD], [1], [ldpd])
])

AS_IF([test "$enable_nhrpd" != "no"], [
  AC_DEFINE([HAVE_NHRPD], [1], [nhrpd])
])

AS_IF([test "$enable_eigrpd" != "no"], [
  AC_DEFINE([HAVE_EIGRPD], [1], [eigrpd])
])

AS_IF([test "$enable_babeld" != "no"], [
  AC_DEFINE([HAVE_BABELD], [1], [babeld])
])

AS_IF([test "$enable_isisd" != "no"], [
  AC_DEFINE([HAVE_ISISD], [1], [isisd])
])

AS_IF([test "$enable_pimd" != "no"], [
  AC_DEFINE([HAVE_PIMD], [1], [pimd])
])

AS_IF([test "$enable_pim6d" != "no"], [
  AC_DEFINE([HAVE_PIM6D], [1], [pim6d])
])

AS_IF([test "$enable_pbrd" != "no"], [
  AC_DEFINE([HAVE_PBRD], [1], [pbrd])
])

AS_IF([test "$enable_sharpd" = "yes"], [
  AC_DEFINE([HAVE_SHARPD], [1], [sharpd])
])

AS_IF([test "$enable_staticd" != "no"], [
  AC_DEFINE([HAVE_STATICD], [1], [staticd])
])

AS_IF([test "$enable_fabricd" != "no"], [
  AC_DEFINE([HAVE_FABRICD], [1], [fabricd])
])

AS_IF([test "$enable_vrrpd" != "no"], [
  AC_DEFINE([HAVE_VRRPD], [1], [vrrpd])
])

if test "$enable_bfdd" = "no"; then
  AC_DEFINE([HAVE_BFDD], [0], [bfdd])
  BFDD=""
else
  AC_DEFINE([HAVE_BFDD], [1], [bfdd])
  BFDD="bfdd"

  case $host_os in
    linux*)
      AC_DEFINE([BFD_LINUX], [1], [bfdd])
      ;;

    *)
      AC_DEFINE([BFD_BSD], [1], [bfdd])
      ;;
  esac
fi

AS_IF([test "$enable_pathd" != "no"], [
  AC_DEFINE([HAVE_PATHD], [1], [pathd])
])

if test "$ac_cv_lib_json_c_json_object_get" = "no" -a "$BFDD" = "bfdd"; then
  AC_MSG_ERROR(["you must use json-c library to use bfdd"])
fi

NHRPD=""
case "$host_os" in
  linux*)
    case "${enable_nhrpd}" in
      no)
        ;;
      yes)
	if test "$enable_clippy_only" != "yes"; then
        if test "$c_ares_found" != "true" ; then
          AC_MSG_ERROR([nhrpd requires libcares.  Please install c-ares and its -dev headers.])
        fi
	fi
        NHRPD="nhrpd"
        ;;
      *)
        if test "$c_ares_found" = "true" ; then
          NHRPD="nhrpd"
        fi
        ;;
    esac
    ;;
  *)
    if test "$enable_nhrpd" = "yes"; then
      AC_MSG_ERROR([nhrpd requires kernel APIs that are only present on Linux.])
    fi
    ;;
esac

if test "$enable_watchfrr" = "no";then
  WATCHFRR=""
else
  WATCHFRR="watchfrr"
fi

OSPFCLIENT=""
if test "$enable_ospfapi" != "no";then
    AC_DEFINE([SUPPORT_OSPF_API], [1], [OSPFAPI])

  if test "$enable_ospfclient" != "no";then
      OSPFCLIENT="ospfclient"
  fi
fi

if test "$enable_bgp_announce" = "no";then
  AC_DEFINE([DISABLE_BGP_ANNOUNCE], [1], [Disable BGP installation to zebra])
else
  AC_DEFINE([DISABLE_BGP_ANNOUNCE], [0], [Disable BGP installation to zebra])
fi

if test "$enable_bgp_vnc" != "no";then
  AC_DEFINE([ENABLE_BGP_VNC], [1], [Enable BGP VNC support])
fi

bgpd_bmp=false
case "${enable_bgp_bmp}" in
  no)
    ;;
  yes)
    if test "$c_ares_found" != "true" ; then
      AC_MSG_ERROR([BMP support requires libcares.  Please install c-ares and its -dev headers.])
    fi
    bgpd_bmp=true
    ;;
  *)
    if test "$c_ares_found" = "true" ; then
      bgpd_bmp=true
    fi
    ;;
esac

if test "$enable_version_build_config" != "no";then
  AC_DEFINE([ENABLE_VERSION_BUILD_CONFIG], [1], [Report build configs in show version])
fi

dnl ##########################################################################
dnl LARGE if block
if test "$enable_clippy_only" != "yes"; then
dnl ##########################################################################

dnl ------------------
dnl check Net-SNMP library
dnl ------------------
SNMP=false
if test "$enable_snmp" != "" -a "$enable_snmp" != "no"; then
  PKG_CHECK_MODULES([SNMP], [netsnmp-agent], [
    dnl all set, nothing to do
  ], [
    AC_PATH_TOOL([NETSNMP_CONFIG], [net-snmp-config], [no])
    if test "$NETSNMP_CONFIG" = "no"; then
      AC_MSG_ERROR([--enable-snmp given but unable to find netsnmp-agent pkgconfig or net-snmp-config])
    fi
    SNMP_LIBS="`${NETSNMP_CONFIG} --agent-libs`"
    SNMP_CFLAGS="`${NETSNMP_CONFIG} --base-cflags`"
    # net-snmp lists all of its own dependencies.  we absolutely do not want that
    # among other things we avoid a GPL vs. OpenSSL license conflict here
    for removelib in crypto ssl sensors pci wrap; do
      SNMP_LIBS="`echo $SNMP_LIBS | sed -e 's/-l'$removelib'/ /g'`"
    done
    AC_MSG_CHECKING([whether we can link to Net-SNMP])
    AC_LINK_IFELSE_FLAGS([$SNMP_CFLAGS], [$SNMP_LIBS], [
      AC_LANG_PROGRAM([
int main(void);
], [
{
  return 0;
}
])
    ], [
      AC_MSG_RESULT([no])
      AC_MSG_ERROR([SNMP libraries found but failed to link])
    ])
  ])
  SNMP=true
  AC_DEFINE([SNMP_AGENTX], [1], [Enable AgentX SNMP modules])
fi
AC_SUBST([SNMP_LIBS])
AC_SUBST([SNMP_CFLAGS])

dnl ---------------
dnl libyang
dnl ---------------
PKG_CHECK_MODULES([LIBYANG], [libyang >= 2.1.128], , [
AC_MSG_ERROR([m4_normalize([libyang >= 2.1.128 is required, and was not found on your system.
Please consult doc/developer/building-libyang.rst for instructions on installing or building libyang.])])])
ac_cflags_save="$CFLAGS"
CFLAGS="$CFLAGS $LIBYANG_CFLAGS"
AC_CHECK_MEMBER([struct lyd_node.priv], [], [
  AC_MSG_ERROR([m4_normalize([
    libyang needs to be compiled with ENABLE_LYD_PRIV=ON.
    Instructions for this are included in the build documentation for your platform at http://docs.frrouting.org/projects/dev-guide/en/latest/building.html])
  ])
], [[#include <libyang/libyang.h>]])

AC_CHECK_LIB([yang],[lyd_find_xpath3],[],[AC_MSG_ERROR([m4_normalize([
libyang missing lyd_find_xpath3])])])
dnl -- don't add lyd_new_list3 to this list unless bug is fixed upstream
dnl -- https://github.com/CESNET/libyang/issues/2149
AC_CHECK_FUNCS([ly_strerrcode ly_strvecode lyd_trim_xpath])

CFLAGS="$ac_cflags_save"

dnl ---------------
dnl configuration rollbacks
dnl ---------------
SQLITE3=false
if test "$enable_config_rollbacks" = "yes"; then
  PKG_CHECK_MODULES([SQLITE3], [sqlite3], [
    AC_DEFINE([HAVE_CONFIG_ROLLBACKS], [1], [Enable configuration rollbacks])
    AC_DEFINE([HAVE_SQLITE3], [1], [Enable sqlite3 database])
    SQLITE3=true
  ], [
    AC_MSG_ERROR([--enable-config-rollbacks given but sqlite3 was not found on your system.])
  ])
fi

dnl ---------------
dnl sysrepo
dnl ---------------
if test "$enable_sysrepo" = "yes"; then
  PKG_CHECK_MODULES([SYSREPO], [sysrepo >= 2.1.42],
      [AC_DEFINE([HAVE_SYSREPO], [1], [Enable sysrepo integration])
      SYSREPO=true],
      [SYSREPO=false
      AC_MSG_ERROR([sysrepo was not found on your system.])]
  )
fi

dnl ---------------
dnl gRPC
dnl ---------------
if test "$enable_grpc" = "yes"; then
  AC_LANG_PUSH([C++])
  PKG_CHECK_MODULES([GRPC], [grpc >= 6.0.0 grpc++ >= 1.16.1 protobuf >= 3.6.1 ], [
    AC_CHECK_PROGS([PROTOC], [protoc], [/bin/false])
    if test "$PROTOC" = "/bin/false"; then
      AC_MSG_FAILURE([grpc requested but protoc not found.])
    fi

    AC_DEFINE([HAVE_GRPC], [1], [Enable the gRPC northbound plugin])
    GRPC=true
  ], [
    GRPC=false
    AC_MSG_ERROR([grpc/grpc++ were not found on your system.])
  ])
  AC_LANG_POP([C++])
fi

dnl ---------
dnl DPDK
dnl ---------
if test "$enable_dp_dpdk" = "yes"; then
  PKG_CHECK_MODULES([DPDK], [libdpdk], [
    AC_DEFINE([HAVE_DPDK], [1], [Enable DPDK backend])
    DPDK=true
  ], [
    AC_MSG_ERROR([configuration specifies --enable-dp-dpdk but DPDK libs were not found])
  ])
fi

dnl -----
dnl LTTng
dnl -----
if test "$enable_lttng" = "yes"; then
  PKG_CHECK_MODULES([UST], [lttng-ust >= 2.9.0], [
    AC_DEFINE([HAVE_LTTNG], [1], [Enable LTTng support])
    LTTNG=true
  ], [
    AC_MSG_ERROR([configuration specifies --enable-lttng but lttng-ust was not found])
  ])
fi

dnl ----
dnl USDT
dnl ----
if test "$enable_usdt" = "yes"; then
  AC_CHECK_HEADERS([sys/sdt.h], [
    AC_DEFINE([HAVE_USDT], [1], [Enable USDT probes])
    USDT=true
  ], [
    AC_MSG_ERROR([configuration specifies --enable-usdt but no USDT kernel headers (sys/sdt.h) found])
  ])
fi

dnl ------
dnl ZeroMQ
dnl ------
if test "$enable_zeromq" != "no"; then
  PKG_CHECK_MODULES([ZEROMQ], [libzmq >= 4.0.0], [
    AC_DEFINE([HAVE_ZEROMQ], [1], [Enable ZeroMQ support])
    ZEROMQ=true
  ], [
    if test "$enable_zeromq" = "yes"; then
      AC_MSG_ERROR([configuration specifies --enable-zeromq but libzmq was not found])
    fi
  ])
fi

dnl ------------------------------------
dnl Enable RPKI and add librtr to libs
dnl ------------------------------------
if test "$enable_rpki" = "yes"; then
  PKG_CHECK_MODULES([RTRLIB], [rtrlib >= 0.8.0],
      [RPKI=true],
      [RPKI=false
      AC_MSG_ERROR([rtrlib was not found on your system or is too old.])]
  )
fi

dnl ------------------------------------
dnl pimd and pim6d not supported on OpenBSD and MacOS
dnl ------------------------------------
if test "$enable_pimd" != "no"; then
AC_MSG_CHECKING([for pimd OS support])
case "$host_os" in
  darwin*)
    AC_MSG_RESULT([no])
    enable_pimd="no"
    ;;
  openbsd*)
    AC_MSG_RESULT([no])
    enable_pimd="no"
    ;;
  *)
    AC_MSG_RESULT([yes])
    ;;
esac
fi

if test "$enable_pim6d" != "no"; then
AC_MSG_CHECKING([for pim6d OS support])
case "$host_os" in
  linux*)
    AC_MSG_RESULT([yes])
    ;;
  *)
    AC_MSG_RESULT([no])
    enable_pim6d="no"
    ;;
esac
fi

dnl -------------------------------------
dnl VRRP is only supported on linux
dnl -------------------------------------
if test "$enable_vrrpd" != "no"; then
AC_MSG_CHECKING([for VRRP OS support])
case "$host_os" in
  linux*)
    AC_MSG_RESULT([yes])
    ;;
  *)
    AC_MSG_RESULT([no])
    enable_vrrpd="no"
    ;;
esac
fi

dnl ------------------------------------------
dnl Check whether rtrlib was build with ssh support
dnl ------------------------------------------
AC_MSG_CHECKING([whether the RTR Library is compiled with SSH])
AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include "rtrlib/rtrlib.h"]],
			[[struct tr_ssh_config config;]])],
	[AC_MSG_RESULT([yes])
	AC_DEFINE([FOUND_SSH], [1], [found_ssh])],
	AC_MSG_RESULT([no])
)

dnl ---------------
dnl dlopen & dlinfo
dnl ---------------
LIBS_save="$LIBS"
AC_SEARCH_LIBS([dlopen], [dl dld], [], [
  AC_MSG_ERROR([unable to find the dlopen()])
])

AC_CHECK_HEADERS([link.h])

AC_CACHE_CHECK([for dlinfo(RTLD_DI_ORIGIN)], [frr_cv_rtld_di_origin], [
  AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <stdlib.h>
#ifdef HAVE_LINK_H
#include <link.h>
#endif
#include <dlfcn.h>
]], [[
  char origin[1];
  dlinfo (NULL, RTLD_DI_ORIGIN, &origin);
]])], [
    frr_cv_rtld_di_origin=yes
  ], [
    frr_cv_rtld_di_origin=no
  ])
])
if test "$frr_cv_rtld_di_origin" = "yes"; then
  AC_DEFINE([HAVE_DLINFO_ORIGIN], [1], [Have dlinfo RTLD_DI_ORIGIN])
fi

AC_CACHE_CHECK([for dlinfo(RTLD_DI_LINKMAP)], [frr_cv_rtld_di_linkmap], [
  AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <stdlib.h>
#ifdef HAVE_LINK_H
#include <link.h>
#endif
#include <dlfcn.h>
]], [[
  struct link_map *lm = NULL;
  dlinfo (NULL, RTLD_DI_LINKMAP, &lm);
]])], [
    frr_cv_rtld_di_linkmap=yes
  ], [
    frr_cv_rtld_di_linkmap=no
  ])
])
if test "$frr_cv_rtld_di_linkmap" = "yes"; then
  AC_DEFINE([HAVE_DLINFO_LINKMAP], [1], [Have dlinfo RTLD_DI_LINKMAP])
fi

LIBDL="$LIBS"
LIBDL="${LIBDL%$LIBS_save}"
LIBDL="${LIBDL#$LIBS_save}"
AC_SUBST([LIBDL])
LIBS="$LIBS_save"
unset LIBS_save

dnl ##########################################################################
dnl test "$enable_clippy_only" != "yes"
fi
dnl END OF LARGE if block
dnl ##########################################################################

dnl ---------------------------
dnl sockaddr and netinet checks
dnl ---------------------------
AC_CHECK_TYPES([
	struct sockaddr_dl,
	struct vifctl, struct mfcctl, struct sioc_sg_req,
	vifi_t, struct sioc_vif_req, struct igmpmsg,
	struct ifaliasreq,
	struct nd_opt_adv_interval,
	struct nd_opt_homeagent_info, struct nd_opt_adv_interval,
	struct nd_opt_rdnss, struct nd_opt_dnssl],
	[], [], FRR_INCLUDES)

AC_CHECK_MEMBERS([struct sockaddr.sa_len,
	struct sockaddr_in.sin_len, struct sockaddr_un.sun_len,
	struct sockaddr_dl.sdl_len,
	struct nd_opt_adv_interval.nd_opt_ai_type],
	[], [], FRR_INCLUDES)


dnl -----------------------
dnl checking for IP_PKTINFO
dnl -----------------------
AC_MSG_CHECKING([for IP_PKTINFO])
AC_COMPILE_IFELSE(
[ AC_LANG_PROGRAM([[
        #include <netdb.h>
   ]], [[
        int opt = IP_PKTINFO;
   ]])
],[
  AC_MSG_RESULT([yes])
  AC_DEFINE([HAVE_IP_PKTINFO], [1], [Have IP_PKTINFO])
],[
  AC_MSG_RESULT([no])
])

dnl ---------------------------
dnl checking for IP_RECVDSTADDR
dnl ---------------------------
AC_MSG_CHECKING([for IP_RECVDSTADDR])
AC_COMPILE_IFELSE(
[ AC_LANG_PROGRAM([[
        #include <netinet/in.h>
  ]], [[
        int opt = IP_RECVDSTADDR;
  ]])
],[
  AC_MSG_RESULT([yes])
  AC_DEFINE([HAVE_IP_RECVDSTADDR], [1], [Have IP_RECVDSTADDR])
],[
  AC_MSG_RESULT([no])
])

dnl ----------------------
dnl checking for IP_RECVIF
dnl ----------------------
AC_MSG_CHECKING([for IP_RECVIF])
AC_COMPILE_IFELSE(
[ AC_LANG_PROGRAM([[
        #include <netinet/in.h>
  ]], [[
        int opt = IP_RECVIF;
  ]])
],[
  AC_MSG_RESULT([yes])
  AC_DEFINE([HAVE_IP_RECVIF], [1], [Have IP_RECVIF])
],[
  AC_MSG_RESULT([no])
])

dnl ----------------------
dnl checking for SO_BINDANY
dnl ----------------------
AC_MSG_CHECKING([for SO_BINDANY])
AC_COMPILE_IFELSE(
[ AC_LANG_PROGRAM([[
        #include <sys/socket.h>
  ]], [[
        int opt = SO_BINDANY;
  ]])
],[
  AC_MSG_RESULT([yes])
  AC_DEFINE([HAVE_SO_BINDANY], [1], [Have SO_BINDANY])
],[
  AC_MSG_RESULT([no])
])

dnl ----------------------
dnl checking for IP_FREEBIND
dnl ----------------------
AC_MSG_CHECKING([for IP_FREEBIND])
AC_COMPILE_IFELSE(
[ AC_LANG_PROGRAM([[
        #include <netinet/in.h>
  ]], [[
        int opt = IP_FREEBIND;
  ]])
],[
  AC_MSG_RESULT([yes])
  AC_DEFINE([HAVE_IP_FREEBIND], [1], [Have IP_FREEBIND])
],[
  AC_MSG_RESULT([no])
])

dnl --------------------------------------
dnl checking for be32dec existence or not
dnl --------------------------------------
AC_CHECK_DECLS([be32enc, be32dec], [], [], [
        #ifdef HAVE_SYS_ENDIAN_H
        #include <sys/endian.h>
        #endif
        #include <endian.h>
])

dnl --------------------------------------
dnl checking for clock_time monotonic struct and call
dnl --------------------------------------
AC_CHECK_LIB([rt], [clock_gettime], [LIBS="$LIBS -lrt"])

AC_SEARCH_LIBS([clock_nanosleep], [rt], [
  AC_DEFINE([HAVE_CLOCK_NANOSLEEP], [1], [Have clock_nanosleep()])
])

dnl --------------------------------------
dnl checking for flex and bison
dnl --------------------------------------

dnl autoconf 2.69 AC_PROG_LEX has no parameters
dnl autoconf 2.70 AC_PROG_LEX prints a deprecation warning without params
m4_if(m4_version_compare(m4_defn([AC_AUTOCONF_VERSION]), [2.70]), [-1], [dnl
  dnl autoconf < 2.70
  AC_PROG_LEX
], [
  dnl autoconf >= 2.70
  AC_PROG_LEX([noyywrap])
])

AC_MSG_CHECKING([version of flex])
frr_ac_flex_version="$(eval $LEX -V | grep flex | head -n 1)"
frr_ac_flex_version="${frr_ac_flex_version##* }"
AC_MSG_RESULT([$frr_ac_flex_version])
AX_COMPARE_VERSION([$frr_ac_flex_version], [lt], [2.5.20], [
  LEX="$SHELL $missing_dir/missing flex"
  if test -f "${srcdir}/lib/command_lex.c" -a -f "${srcdir}/lib/command_lex.h"; then
    AC_MSG_WARN([using pregenerated flex output files])
  else
    AC_MSG_ERROR([flex failure and pregenerated files not included (probably a git build)])
  fi
  AC_SUBST([LEX_OUTPUT_ROOT], [lex.yy])
  AC_SUBST([LEXLIB], [''])
])

AC_PROG_YACC
dnl thanks GNU bison for this b*llshit...
AC_MSG_CHECKING([version of bison])
frr_ac_bison_version="$(eval $YACC -V | grep bison | head -n 1)"
frr_ac_bison_version="${frr_ac_bison_version##* }"
frr_ac_bison_missing="false"
case "x${frr_ac_bison_version}x" in
  x2.7*)
    BISON_OPENBRACE='"'
    BISON_CLOSEBRACE='"'
    BISON_VERBOSE=''
    AC_MSG_RESULT([$frr_ac_bison_version - 2.7 or older])
    ;;
  x2.*|x1.*)
    AC_MSG_RESULT([$frr_ac_bison_version])
    AC_MSG_WARN([installed bison is too old.  Please install GNU bison 2.7.x or newer.])
    frr_ac_bison_missing="true"
    ;;
  x)
    AC_MSG_RESULT([none])
    AC_MSG_WARN([could not determine bison version.  Please install GNU bison 2.7.x or newer.])
    frr_ac_bison_missing="true"
    ;;
  x3.[012][^0-9]*)
    BISON_OPENBRACE='{'
    BISON_CLOSEBRACE='}'
    BISON_VERBOSE='-Dparse.error=verbose'
    AC_MSG_RESULT([$frr_ac_bison_version - 3.0 to 3.2])
    ;;
  *)
    BISON_OPENBRACE='{'
    BISON_CLOSEBRACE='}'
    BISON_VERBOSE='-Dparse.error=verbose -Wno-yacc'
    AC_MSG_RESULT([$frr_ac_bison_version - 3.3 or newer])
    ;;
esac
AC_SUBST([BISON_OPENBRACE])
AC_SUBST([BISON_CLOSEBRACE])
AC_SUBST([BISON_VERBOSE])

if $frr_ac_bison_missing; then
  YACC="$SHELL $missing_dir/missing bison -y"
  if test -f "${srcdir}/lib/command_parse.c" -a -f "${srcdir}/lib/command_parse.h"; then
    AC_MSG_WARN([using pregenerated bison output files])
  else
    AC_MSG_ERROR([bison failure and pregenerated files not included (probably a git build)])
  fi
fi

dnl -------------------
dnl capabilities checks
dnl -------------------
if test "$enable_capabilities" != "no"; then
  AC_MSG_CHECKING([whether prctl PR_SET_KEEPCAPS is available])
  AC_COMPILE_IFELSE(
  [ AC_LANG_PROGRAM([[
        #include <sys/prctl.h>
    ]], [[
        prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0);
    ]])
  ],[AC_MSG_RESULT([yes])
     AC_DEFINE([HAVE_PR_SET_KEEPCAPS], [1], [prctl])
     frr_ac_keepcaps="yes"
  ],[AC_MSG_RESULT(no)
  ])
  if test "$frr_ac_keepcaps" = "yes"; then
    AC_CHECK_HEADERS([sys/capability.h])
  fi
  if test "$ac_cv_header_sys_capability_h" = "yes"; then
    AC_CHECK_LIB([cap], [cap_init],
      [AC_DEFINE([HAVE_LCAPS], [1], [Capabilities])
       LIBCAP="-lcap"
       frr_ac_lcaps="yes"]
    )
  fi
  if test "$frr_ac_scaps" = "yes" \
       -o "$frr_ac_lcaps" = "yes"; then
    AC_DEFINE([HAVE_CAPABILITIES], [1], [capabilities])
  fi

  case "$host_os" in
  linux*)
    if test "$enable_clippy_only" != "yes"; then
    if test "$frr_ac_lcaps" != "yes"; then
      AC_MSG_ERROR([libcap and/or its headers were not found.  Running FRR without libcap support built in causes a huge performance penalty.])
    fi
    fi
    ;;
  esac
else
  case "$host_os" in
  linux*)
    AC_MSG_WARN([Running FRR without libcap support built in causes a huge performance penalty.])
    ;;
  esac
fi
AC_SUBST([LIBCAP])

dnl ---------------------------
dnl check for glibc 'backtrace'
dnl ---------------------------
backtrace_ok=false
if test "$enable_backtrace" != "no" ; then
  case "x$enable_backtrace" in
  x|xyes|xexecinfo|xlibunwind)
    ;;
  *)
    AC_MSG_FAILURE([invalid argument ${enable_backtrace} for --enable-backtrace])
    ;;
  esac
  if test "$enable_backtrace" != "execinfo"; then
    PKG_CHECK_MODULES([UNWIND], [libunwind], [
      AC_DEFINE([HAVE_LIBUNWIND], [1], [libunwind])
      backtrace_ok=true
    ], [
      AC_CHECK_HEADER([libunwind.h], [
        AC_SEARCH_LIBS([unw_getcontext], [unwind], [
          AC_DEFINE([HAVE_LIBUNWIND], [1], [libunwind])
          backtrace_ok=true
        ])
      ])
    ])
    if test "$enable_backtrace" = "libunwind" -a "$backtrace_ok" = "false"; then
      AC_MSG_FAILURE([libunwind backtraces explicitly requested but not found])
    fi
  fi

  if test "$backtrace_ok" = "false"; then
    AC_CHECK_HEADER([execinfo.h], [
      AC_SEARCH_LIBS([backtrace], [execinfo], [
        AC_DEFINE([HAVE_GLIBC_BACKTRACE], [1], [Glibc backtrace])
        backtrace_ok=true
      ], [], [-lm])
    ])
    if test "$enable_backtrace" = "execinfo" -a "$backtrace_ok" = "false"; then
      AC_MSG_FAILURE([glibc/execinfo backtraces explicitly requested but not found])
    fi
  fi

  if test "$enable_backtrace" != "" -a "$backtrace_ok" = "false"; then
    dnl user explicitly requested backtrace but we failed to find support
    AC_MSG_FAILURE([failed to find glibc/execinfo backtrace or libunwind])
  fi
fi

dnl -----------------------------------------
dnl check for malloc mallinfo struct and call
dnl this must try and link using LIBS, in
dnl order to check no alternative allocator
dnl has been specified, which might not provide
dnl mallinfo
dnl -----------------------------------------
AC_CHECK_HEADERS([malloc.h malloc_np.h malloc/malloc.h],,, [FRR_INCLUDES])

AC_CACHE_CHECK([whether mallinfo is available], [frr_cv_mallinfo], [
  AC_LINK_IFELSE([AC_LANG_PROGRAM([FRR_INCLUDES [
#ifdef HAVE_MALLOC_H
#include <malloc.h>
#endif
#ifdef HAVE_MALLOC_NP_H
#include <malloc_np.h>
#endif
#ifdef HAVE_MALLOC_MALLOC_H
#include <malloc/malloc.h>
#endif
]], [[
struct mallinfo ac_x; ac_x = mallinfo ();
]])], [
    frr_cv_mallinfo=yes
  ], [
    frr_cv_mallinfo=no
  ])
])
if test "$frr_cv_mallinfo" = "yes"; then
  AC_DEFINE([HAVE_MALLINFO], [1], [mallinfo])
fi

AC_CACHE_CHECK([whether mallinfo2 is available], [frr_cv_mallinfo2], [
  AC_LINK_IFELSE([AC_LANG_PROGRAM([FRR_INCLUDES [
#ifdef HAVE_MALLOC_H
#include <malloc.h>
#endif
#ifdef HAVE_MALLOC_NP_H
#include <malloc_np.h>
#endif
#ifdef HAVE_MALLOC_MALLOC_H
#include <malloc/malloc.h>
#endif
]], [[
struct mallinfo2 ac_x; ac_x = mallinfo2 ();
]])], [
    frr_cv_mallinfo2=yes
  ], [
    frr_cv_mallinfo2=no
  ])
])
if test "$frr_cv_mallinfo2" = "yes"; then
  AC_DEFINE([HAVE_MALLINFO2], [1], [mallinfo2])
fi

AC_MSG_CHECKING([whether malloc_usable_size is available])
AC_LINK_IFELSE([AC_LANG_PROGRAM([FRR_INCLUDES [
#ifdef HAVE_MALLOC_H
#include <malloc.h>
#endif
#ifdef HAVE_MALLOC_MALLOC_H
#include <malloc/malloc.h>
#endif
]], [[
size_t ac_x; ac_x = malloc_usable_size(NULL);
]])], [
  AC_MSG_RESULT([yes])
  AC_DEFINE([HAVE_MALLOC_USABLE_SIZE], [1], [malloc_usable_size])
], [
  AC_MSG_RESULT([no])

  AC_MSG_CHECKING([whether malloc_size is available])
  AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#ifdef HAVE_MALLOC_H
#include <malloc.h>
#endif
#ifdef HAVE_MALLOC_MALLOC_H
#include <malloc/malloc.h>
#endif
]], [[
size_t ac_x; ac_x = malloc_size(NULL);
]])], [
    AC_MSG_RESULT([yes])
    AC_DEFINE([HAVE_MALLOC_SIZE], [1], [malloc_size])
  ], [
    AC_MSG_RESULT([no])
  ])
])

dnl ----------
dnl configure date
dnl ----------
dev_version=`echo $VERSION | grep dev`
#don't expire deprecated code in non 'dev' branch
if test "$dev_version" = ""; then
   CONFDATE=0
else
   CONFDATE=`date '+%Y%m%d'`
fi
AC_SUBST([CONFDATE])

dnl get the full path, recursing through variables...
AC_DEFUN([AX_SUBST_EXPANDED], [
  AX_RECURSIVE_EVAL([[$]$1], [e_$1])
  AC_SUBST([e_$1])
])

AX_SUBST_EXPANDED([bindir])
AX_SUBST_EXPANDED([sbindir])
AX_SUBST_EXPANDED([frr_sysconfdir])
AX_SUBST_EXPANDED([frr_runstatedir])
AX_SUBST_EXPANDED([frr_libstatedir])
AX_SUBST_EXPANDED([moduledir])
AX_SUBST_EXPANDED([pkgconfigdir])
AX_SUBST_EXPANDED([yangmodelsdir])
AX_SUBST_EXPANDED([scriptdir])

dnl strip duplicate trailing slashes if necessary
dnl note this uses e_bindir / e_sbindir created above
watchfrr_sh="\${e_sbindir%/}/watchfrr.sh"
AX_SUBST_EXPANDED([watchfrr_sh])
vtysh_bin="\${e_bindir%/}/vtysh"
AX_SUBST_EXPANDED([vtysh_bin])

dnl various features
AM_CONDITIONAL([SUPPORT_REALMS], [test "$enable_realms" = "yes"])
AM_CONDITIONAL([ENABLE_BGP_VNC], [test "$enable_bgp_vnc" != "no"])
AM_CONDITIONAL([BGP_BMP], [$bgpd_bmp])
dnl northbound
AM_CONDITIONAL([SQLITE3], [$SQLITE3])
AM_CONDITIONAL([SYSREPO], [test "$enable_sysrepo" = "yes"])
AM_CONDITIONAL([GRPC], [test "$enable_grpc" = "yes"])
AM_CONDITIONAL([ZEROMQ], [test "$ZEROMQ" = "true"])
dnl plugins
AM_CONDITIONAL([RPKI], [test "$RPKI" = "true"])
AM_CONDITIONAL([SNMP], [$SNMP])
AM_CONDITIONAL([FPM], [test "$enable_fpm" = "yes"])
AM_CONDITIONAL([HAVE_PROTOBUF], [test "$enable_protobuf" != "no"])
AM_CONDITIONAL([HAVE_PROTOBUF3], [$PROTO3])

dnl PCEP plugin
AS_IF([test "$enable_pathd" != "no"], [
       AC_SUBST([PATHD_PCEP_LIBS], ["pceplib/libpcep_pcc.la"])
       AC_SUBST([PATHD_PCEP_INCL], ["-I./pceplib "])
       ])
AC_CHECK_LIB([cunit], [CU_initialize_registry], [pcep_cunit=yes],[pcep_cunit=no])
AM_CONDITIONAL([PATHD_PCEP_TEST], [test "x${pcep_cunit}" = xyes])
AC_CHECK_PROG(VALGRIND_CHECK, valgrind, yes)
AM_CONDITIONAL([HAVE_VALGRIND_PCEP], [test "$VALGRIND_CHECK" = "yes"])

dnl daemons
AM_CONDITIONAL([VTYSH], [test "$VTYSH" = "vtysh"])
AM_CONDITIONAL([ZEBRA], [test "$enable_zebra" != "no"])
AM_CONDITIONAL([BGPD], [test "$enable_bgpd" != "no"])
AM_CONDITIONAL([MGMTD], [test "$enable_mgmtd" != "no"])
AM_CONDITIONAL([MGMTD_TESTC], [test "$enable_mgmtd_test_be_client" = "yes"])
AM_CONDITIONAL([FPM_LISTENER], [test "enable_fpm_listener" = "yes"])
AM_CONDITIONAL([RIPD], [test "$enable_ripd" != "no"])
AM_CONDITIONAL([OSPFD], [test "$enable_ospfd" != "no"])
AM_CONDITIONAL([LDPD], [test "$enable_ldpd" != "no"])
AM_CONDITIONAL([BFDD], [test "$BFDD" = "bfdd"])
AM_CONDITIONAL([NHRPD], [test "$NHRPD" = "nhrpd"])
AM_CONDITIONAL([EIGRPD], [test "$enable_eigrpd" != "no"])
AM_CONDITIONAL([WATCHFRR], [test "$WATCHFRR" = "watchfrr"])
AM_CONDITIONAL([OSPFCLIENT], [test "$OSPFCLIENT" = "ospfclient"])
AM_CONDITIONAL([RIPNGD], [test "$enable_ripngd" != "no"])
AM_CONDITIONAL([BABELD], [test "$enable_babeld" != "no"])
AM_CONDITIONAL([OSPF6D], [test "$enable_ospf6d" != "no"])
AM_CONDITIONAL([ISISD], [test "$enable_isisd" != "no"])
AM_CONDITIONAL([PIMD], [test "$enable_pimd" != "no"])
AM_CONDITIONAL([PIM6D], [test "$enable_pim6d" != "no"])
AM_CONDITIONAL([PBRD], [test "$enable_pbrd" != "no"])
AM_CONDITIONAL([SHARPD], [test "$enable_sharpd" = "yes"])
AM_CONDITIONAL([STATICD], [test "$enable_staticd" != "no"])
AM_CONDITIONAL([FABRICD], [test "$enable_fabricd" != "no"])
AM_CONDITIONAL([VRRPD], [test "$enable_vrrpd" != "no"])
AM_CONDITIONAL([PATHD], [test "$enable_pathd" != "no"])
AM_CONDITIONAL([PATHD_PCEP], [test "$enable_pathd" != "no"])
AM_CONDITIONAL([DP_DPDK], [test "$enable_dp_dpdk" = "yes"])


AM_CONDITIONAL([PYTHON_RUNTIME_DEPENDENCY], [test "$enable_python_runtime" != "no"])

AC_CONFIG_FILES([Makefile],[
	test "$enable_dev_build" = "yes" && makefile_devbuild="--dev-build"
	${PYTHON} "${ac_abs_top_srcdir}/python/makefile.py" ${makefile_devbuild} || exit 1
], [
	PYTHON="$PYTHON"
	enable_dev_build="$enable_dev_build"
])

AC_CONFIG_FILES([
	  config.version
	  redhat/frr.spec
	  alpine/APKBUILD
	  snapcraft/snapcraft.yaml
	  lib/version.h
	  lib/config_paths.h
	  tests/lib/cli/test_cli.refout pkgsrc/mgmtd.sh
	  pkgsrc/bgpd.sh pkgsrc/ospf6d.sh pkgsrc/ospfd.sh
	  pkgsrc/ripd.sh pkgsrc/ripngd.sh pkgsrc/zebra.sh
	  pkgsrc/eigrpd.sh])

AC_CONFIG_FILES([tools/frr], [chmod +x tools/frr])
AC_CONFIG_FILES([tools/watchfrr.sh], [chmod +x tools/watchfrr.sh])
AC_CONFIG_FILES([tools/frrinit.sh], [chmod +x tools/frrinit.sh])
AC_CONFIG_FILES([tools/frrcommon.sh])
AC_CONFIG_FILES([tools/frr.service])
AC_CONFIG_FILES([tools/frr@.service])
AC_CONFIG_FILES([tools/frr.pc])

# dnl write out a ccls file with our compile configuration
# dnl have to add -Wno-unused-function otherwise foobar_cmd_magic causes
# dnl all DEFPY(), et al., macros to flag as errors.
AS_IF([test "$enable_ccls" = "yes"], [
    AC_CONFIG_COMMANDS([gen-dot-ccls], [
        cat > "${srcdir}/.ccls" <<EOF
clang
-DHAVE_CONFIG_H
-I.
-I./include
-I./lib
-I./lib/assert
-DSYSCONFDIR="${ac_frr_sysconfdir}"
-DCONFDATE=${ac_frr_confdate}
EOF
        if test "$ac_abs_top_builddir" != "$ac_abs_top_srcdir"; then
            echo "-I${ac_abs_top_builddir}" >> "${srcdir}/.ccls"
        fi
        if test -n "$FRR_ALL_CCLS_FLAGS"; then
            echo ${FRR_ALL_CCLS_FLAGS} | tr ' ' '\n' >> "${srcdir}/.ccls"
        fi
        if test -n "$FRR_ALL_CCLS_CFLAGS"; then
            cat >> "${srcdir}/.ccls" <<EOF
%c $(echo ${FRR_ALL_CCLS_CFLAGS} | sed -e 's/  */\n%c /g')
%c -Wno-unused-function
%c -Wno-microsoft
EOF
fi
    ], [
    FRR_ALL_CCLS_FLAGS="$(echo ${LIBYANG_CFLAGS} ${LUA_INCLUDE} ${SQLITE3_CFLAGS} | sed -e 's/  */ /g')"
    FRR_ALL_CCLS_CFLAGS="$(echo ${CFLAGS} ${WERROR} ${AC_CFLAGS} ${SAN_FLAGS} | sed -e 's/  */ /g')"
    ac_frr_confdate="${CONFDATE}"
    ac_frr_sysconfdir="${frr_sysconfdir}/"
    ])
])


AS_IF([test "$with_pkg_git_version" = "yes"], [
    AC_CONFIG_COMMANDS([lib/gitversion.h], [
	dst="${ac_abs_top_builddir}/lib/gitversion.h"
	${PERL} "${ac_abs_top_srcdir}/lib/gitversion.pl" \
		"${ac_abs_top_srcdir}" \
		> "${dst}.tmp"
	test -f "$dst" \
		&& diff "${dst}.tmp" "${dst}" >/dev/null 2>/dev/null \
		&& rm "${dst}.tmp" \
		|| mv "${dst}.tmp" "${dst}"
    ], [
	PERL="$PERL"
    ])
])

## Hack, but working solution to avoid rebuilding of frr.info.
## It's already in CVS until texinfo 4.7 is more common.
AC_OUTPUT

if test "$enable_rpath" = "yes" ; then
	true
else
	# See https://old-en.opensuse.org/openSUSE:Packaging_Guidelines#Removing_Rpath
	sed -e 's|^hardcode_libdir_flag_spec=.*|hardcode_libdir_flag_spec=""|g' libtool > libtool.sed && cat libtool.sed > libtool
	sed -e 's|^runpath_var=LD_RUN_PATH|runpath_var=DIE_RPATH_DIE|g'         libtool > libtool.sed && cat libtool.sed > libtool
	test -f libtool.sed && rm libtool.sed
fi

echo "
FRRouting configuration
------------------------------
FRR version             : ${PACKAGE_VERSION}
host operating system   : ${host_os}
source code location    : ${srcdir}
compiler                : ${CC}
compiler flags          : ${CFLAGS} ${WERROR} ${AC_CFLAGS} ${SAN_FLAGS}
make                    : ${MAKE-make}
linker flags            : ${LDFLAGS} ${SAN_FLAGS} ${LIBS} ${LIBCAP} ${LIBREADLINE} ${LIBM}
local state file dir    : ${e_frr_libstatedir}
run state file dir      : ${e_frr_runstatedir}
config file directory   : ${e_frr_sysconfdir}
module directory        : ${e_moduledir}
pkgconfig directory     : ${e_pkgconfigdir}
script directory        : ${e_scriptdir}
user to run as          : ${enable_user}
group to run as         : ${enable_group}
group for vty sockets   : ${enable_vty_group}
config file mask        : ${enable_configfile_mask}
log file mask           : ${enable_logfile_mask}
zebra protobuf enabled  : ${enable_protobuf:-yes}
vici socket path        : ${vici_socket}

The above user and group must have read/write access to the state file
directory and to the config files in the config file directory."

if test -n "$enable_datacenter"; then
  AC_MSG_WARN([The --enable-datacenter compile time option is deprecated.  Please modify the init script to pass -F datacenter to the daemons instead.])
fi

if test "$enable_doc" != "no" -a "$frr_py_mod_sphinx" = "false"; then
  AC_MSG_WARN([sphinx is missing but required to build documentation])
fi
if test "$frr_py_mod_pytest" = "false"; then
  AC_MSG_WARN([pytest is missing, unit tests cannot be performed])
fi
if test "$backtrace_ok" = "false"; then
  AC_MSG_WARN([^])
  AC_MSG_WARN([building FRR without crash/assert backtraces. This is NOT RECOMMENDED.])
fi

if $path_warn_banner; then
  AC_MSG_WARN([^])
  AC_MSG_WARN([^])
  AC_MSG_WARN([^ warnings regarding system path configuration were printed at the very top of output])
  AC_MSG_WARN([^ paths have been adjusted by temporary workarounds])
  AC_MSG_WARN([^ please fix your ./configure invocation (remove /frr) so it will work without the workarounds])
fi