Maintenance: update --with-heimdal-krb5 detection (#1687)

[thirdparty/squid.git] / configure.ac

## Copyright (C) 1996-2023 The Squid Software Foundation and contributors
##
## Squid software is distributed under GPLv2+ license and includes
## contributions from numerous individuals and organizations.
## Please see the COPYING and CONTRIBUTORS files for details.
##

AC_INIT([Squid Web Proxy],[7.0.0-VCS],[https://bugs.squid-cache.org/],[squid])
AC_PREREQ(2.61)
AC_CONFIG_HEADERS([include/autoconf.h])
AC_CONFIG_AUX_DIR(cfgaux)
AC_CONFIG_SRCDIR([src/main.cc])
AM_INIT_AUTOMAKE([tar-ustar nostdinc subdir-objects dist-xz])
AC_REVISION($Revision$)dnl
AC_PREFIX_DEFAULT(/usr/local/squid)
AM_MAINTAINER_MODE

m4_include([acinclude/ax_with_prog.m4])
m4_include([acinclude/init.m4])
m4_include([acinclude/squid-util.m4])
m4_include([acinclude/compiler-flags.m4])
m4_include([acinclude/os-deps.m4])
m4_include([acinclude/krb5.m4])
m4_include([acinclude/ldap.m4])
m4_include([acinclude/nettle.m4])
m4_include([acinclude/pam.m4])
m4_include([acinclude/pkg.m4])
m4_include([acinclude/tdb.m4])
m4_include([acinclude/lib-checks.m4])
m4_include([acinclude/ax_cxx_compile_stdcxx.m4])
m4_include([acinclude/win32-sspi.m4])

PRESET_CFLAGS="$CFLAGS"
PRESET_CXXFLAGS="$CXXFLAGS"
PRESET_LDFLAGS="$LDFLAGS"

dnl Set default LDFLAGS
AS_IF([test "x$LDFLAGS" = "x"],[LDFLAGS="-g"])

# check for host OS detail
AC_CANONICAL_HOST
AC_MSG_CHECKING([simplified host os])
simple_host_os=`echo $host_os|sed 's/[0-9].*//g;s/-.*//g'`
squid_host_os_version=`echo $host_os|tr -d "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-"`
AS_IF([test -n "$squid_host_os_version"],[
  squid_host_os="`echo $simple_host_os| sed s/$squid_host_os_version//g`"
],[
  squid_host_os="$simple_host_os"
])
AC_MSG_RESULT($squid_host_os (version $squid_host_os_version))
# on windows squid_host_os is either mingw or cygwin, version is 32

AC_PROG_CC
AM_PROG_CC_C_O
AC_PROG_CXX

# AC_USE_SYSTEM_EXTENSIONS should be called before any macros that run the C compiler.
AC_USE_SYSTEM_EXTENSIONS

AC_LANG([C++])

# Clang 3.2 on some CPUs requires -march-native to detect correctly.
# GCC 4.3+ can also produce faster executables when its used.
# But building inside a virtual machine environment has been found to
# cause random Illegal Instruction errors due to mis-detection of CPU.
AC_ARG_ENABLE(arch-native,
  AS_HELP_STRING([--disable-arch-native],[Some compilers offer CPU-specific
                 optimizations with the -march=native parameter.
                 This flag disables the optimization. The default is to
                 auto-detect compiler support and use where available.]), [
  SQUID_YESNO([$enableval],[--enable-arch-native])
])
AC_MSG_NOTICE([CPU arch native optimization enabled: ${enable_arch_native:=auto}])
AS_IF([test "x${enable_arch_native}" != "xno"],[
  SQUID_CC_CHECK_ARGUMENT([squid_cv_check_marchnative],[-march=native])
])

# If the user did not specify a C++ version.
user_cxx=`echo "$PRESET_CXXFLAGS" | grep -o -E "(-)std="`
AS_IF([test "x$user_cxx" = "x"],[
  # Check for C++17 compiler support
  # May change CXX.
  AX_CXX_COMPILE_STDCXX([17],[noext],[mandatory])
])

# Prerequisite: CXX has been finalized.
# BUILDCXXFLAGS are defined later, after CXXFLAGS have been finalized.
AC_ARG_VAR([BUILDCXX],[path to compiler for building compile-time tools. e.g. cf_gen])
AS_IF([test "x$HOSTCXX" != "x" -a "x$BUILDCXX" = "x"],[
  AC_MSG_WARN([Cross-compiling with HOSTCXX is deprecated. Use BUILDCXX instead.])
  BUILDCXX="$HOSTCXX"
])
AS_IF([test "x$BUILDCXX" = "x"],[
  BUILDCXX="$CXX"
  AS_IF([test "x$squid_cv_check_marchnative" = "xyes"],[
    CXXFLAGS="$CXXFLAGS -march=native"
  ])
])
AC_SUBST(BUILDCXX)

# test for programs
AC_PROG_RANLIB
AC_PROG_CPP
AC_PROG_INSTALL
AC_PROG_LN_S
AC_PROG_EGREP

AC_PATH_PROG(SH, sh, /bin/sh)
AC_PATH_PROG(FALSE, false, /usr/bin/false)
AC_PATH_PROG(TRUE, true, /usr/bin/true)
AC_PATH_PROG(MV, mv, $FALSE)
AC_PATH_PROG(MKDIR, mkdir, $FALSE)
AC_PATH_PROG(LN, ln, cp)
AC_PATH_PROG(CHMOD, chmod, $FALSE)
AC_PATH_PROG(TR, tr, $FALSE)
AC_PATH_PROG(RM, rm, $FALSE)
dnl Libtool 2.2.6 requires: rm -f
RM="$RM -f"

PKG_PROG_PKG_CONFIG

AC_PATH_PROG(PERL, perl, none)
AS_IF([test "x$ac_cv_path_PERL" = "xnone"],[
  AC_MSG_FAILURE([Perl is required to compile Squid. Please install Perl and then re-run configure ])
])
AC_PATH_PROG(POD2MAN, pod2man, $FALSE)
AM_CONDITIONAL(ENABLE_POD2MAN_DOC, test "x${ac_cv_path_POD2MAN}" != "x$FALSE")

AC_PATH_PROG(AR, ar, $FALSE)
AR_R="$AR r"
AC_SUBST(AR_R)

AC_PATH_PROG(LINUXDOC, linuxdoc, $FALSE)
AM_CONDITIONAL(ENABLE_RELEASE_DOCS, test "x${ac_cv_path_LINUXDOC}" != "x$FALSE")

SQUID_RELEASE=`echo $VERSION | cut -d. -f1`
AC_SUBST(SQUID_RELEASE)

# pre-define DEFAULT_PREFIX, some modules need it.
AS_IF([test "${prefix}" = "NONE"],[squid_prefix=$ac_default_prefix],[squid_prefix=$prefix])
AC_DEFINE_UNQUOTED(DEFAULT_PREFIX,[$squid_prefix],[The install prefix])

AC_ARG_ENABLE(strict-error-checking,
  AS_HELP_STRING([--disable-strict-error-checking],[By default squid is compiled
                 with all possible static compiler error-checks enabled.
                 This flag disables the behavior]), [
  SQUID_YESNO([$enableval],[--enable-strict-error-checking])
])
AC_MSG_NOTICE([strict error checking enabled: ${enable_strict_error_checking:=yes}])

# LT_INIT requires libtool v2, might as well state it loud
LT_PREREQ([2.2])
LT_INIT([dlopen])
AS_IF([test "x$ac_top_build_prefix" != "x"],[
  # LTDL v3-v7 macros assume the autoconf 2.62 variable top_build_prefix is defined
  # But from autoconf 2.64 its called ac_top_build_prefix and not automatically added to the Makefile
  # This fixes Linux LTDLv3-v7, and BSD LTDL v2.2
  top_build_prefix=${ac_top_build_prefix}
  AC_SUBST(top_build_prefix)
])
LTDL_INIT

dnl LibTool environment is now prepared for setup. Check that it is usable and initialize.
LT_LIB_DLLOAD

# Do we need these unconditionally for "make distcheck" to work?
AC_SUBST(INCLTDL)
AC_SUBST(LIBLTDL)

AC_MSG_CHECKING(whether to use loadable modules)
AS_IF([test "x${enable_shared:=yes}" = "xyes"],[AC_DEFINE(USE_LOADABLE_MODULES,1,[Support Loadable Modules])])
AM_CONDITIONAL(ENABLE_LOADABLE_MODULES, test "x${enable_shared:=yes}" = "xyes")
AC_MSG_RESULT([$enable_shared])

SQUID_CC_GUESS_VARIANT
SQUID_CC_GUESS_OPTIONS

dnl find out the exe extension for this platform.
dnl If it is not empty, use it for CGI as well.
AC_EXEEXT
AC_OBJEXT
AS_IF([test "x$EXEEXT" = "x"],[CGIEXT=".cgi"],[CGIEXT=""])
AC_SUBST(CGIEXT)

AM_CONDITIONAL(ENABLE_WIN32SPECIFIC,[test "x$squid_host_os" = "xmingw"])
AM_CONDITIONAL(ENABLE_WIN32_IPC,[test "x$squid_host_os" = "xmingw"])

AS_CASE(["$squid_host_os"],
  [mingw],[
    CFLAGS="$CFLAGS -mthreads"
    CXXFLAGS="$CXXFLAGS -mthreads -static-libgcc -static-libstdc++"
    dnl Check for Winsock only on MinGW
    SQUID_CHECK_WINSOCK_LIB
    AC_CHECK_HEADERS([ws2tcpip.h winsock2.h windows.h io.h],,,[
#if HAVE_WS2TCPIP_H
#include <ws2tcpip.h>
#endif
#if HAVE_WINSOCK2_H
#include <winsock2.h>
#endif
#if HAVE_WINDOWS_H
#include <windows.h>
#endif
    ])
    MINGW_LIBS="-lmingwex"
    AC_SUBST(MINGW_LIBS)
    AC_CHECK_FUNCS([fsync])
  ],

  [freebsd],[
    # FreeBSD places local libraries and packages in /usr/local
    CFLAGS="$CFLAGS -I/usr/local/include"
    CXXFLAGS="$CXXFLAGS -I/usr/local/include"
    LDFLAGS="$LDFLAGS -L/usr/local/lib -Wl,-R/usr/local/lib"
  ]
)

dnl Substitutions
AC_DEFINE_UNQUOTED(CONFIG_HOST_TYPE, "$host",[Host type from configure])

AC_DEFINE_UNQUOTED(SQUID_CONFIGURE_OPTIONS, "$ac_configure_args",
                       [configure command line used to configure Squid])

CACHE_EFFECTIVE_USER="nobody"
AC_ARG_WITH(default-user,
  AS_HELP_STRING([--with-default-user=USER],[System user account for squid permissions. Default: nobody]),
 [ CACHE_EFFECTIVE_USER="$withval" ]
)
AC_SUBST(CACHE_EFFECTIVE_USER)

DEFAULT_LOG_DIR="$localstatedir/logs"
AC_ARG_WITH(logdir,
  AS_HELP_STRING([--with-logdir=PATH],
    [Default location for squid logs. default: PREFIX/var/logs]),[
  AS_CASE([$withval],
    [yes|no],[AC_MSG_ERROR([--with-logdir requires a directory PATH. --with-logdir=PATH])],
    [DEFAULT_LOG_DIR="$withval"]
  )
])
AC_SUBST(DEFAULT_LOG_DIR)

DEFAULT_PID_FILE="$localstatedir/run/@SERVICE_NAME@.pid"
AC_ARG_WITH(pidfile,
  AS_HELP_STRING([--with-pidfile=PATH],
    [Default location for squid pid file. Default: PREFIX/var/run/squid.pid]),[
  AS_CASE([$withval],
    [yes|no],[AC_MSG_ERROR([--with-pidfile requires a file PATH. --with-pidfile=PATH])],
    [DEFAULT_PID_FILE="$withval"]
  )
])
AC_SUBST(DEFAULT_PID_FILE)

DEFAULT_SWAP_DIR="$localstatedir/cache/squid"
AC_ARG_WITH(swapdir,
  AS_HELP_STRING([--with-swapdir=PATH],
    [Default location for squid cache directories. Default: PREFIX/var/cache/squid]),[
  AS_CASE([$withval],
    [yes|no],[AC_MSG_ERROR([--with-swapdir requires a directory PATH. --with-swapdir=PATH])],
    [DEFAULT_SWAP_DIR="$withval"]
  )
])
AC_SUBST(DEFAULT_SWAP_DIR)

dnl Set Default CFLAGS
AS_IF([test "x$PRESET_CFLAGS" = "x"],[
  AS_IF([test "$squid_cv_compiler" = "gcc"],[
    # TODO check if these exceptions are still necessary
    AS_CASE(["$host"],
      [*-sun-sunos*],[
        # sunos has too many warnings for -Wall to be useful
      ],
      [CFLAGS="$squid_cv_cc_option_wall $CFLAGS"]
    )
  ],[
    AS_CASE(["$host"],
      [*mips-sgi-irix6.*],[
        # suggested by Rafael Seidl <rafaels@cthulhu.engr.sgi.com>
        CFLAGS="$squid_cv_cc_option_optimize -OPT:Olimit=0:space=OFF \
                -woff 1009,1014,1110,1116,1183,1185,1188,1204,1230,1233,1355 \
                -Wl,-woff,85,-woff,84,-woff,134 \
                -nostdinc -I/usr/include -D_BSD_SIGNALS $CFLAGS"
        CXXFLAGS="$squid_cv_cc_option_optimize -OPT:Olimit=0:space=OFF \
                  -woff 1009,1014,1110,1116,1183,1185,1188,1204,1230,1233,1355 \
                  -Wl,-woff,85,-woff,84,-woff,134 \
                  -nostdinc -I/usr/include -D_BSD_SIGNALS $CXXFLAGS"
    ])
  ])
])

AC_MSG_CHECKING([compiler name-version])
squid_cv_cc_name=`$CC --version | head -1 | cut -f1 -d" "`
AS_CASE([$squid_cv_cc_name],
  [gcc|clang],[squid_cv_cc_majversion=`$CC -dumpversion | cut -f1 -d.`],
  [squid_cv_cc_majversion="unknown"]
)
squid_cv_cc_simplified="$squid_cv_cc_name-$squid_cv_cc_majversion"
AC_MSG_RESULT($squid_cv_cc_simplified)

# warning flags

# -Wall
SQUID_CC_ADD_CXXFLAG_WARNING_IF_SUPPORTED([$squid_cv_cc_option_wall])

# -Wextra
AS_IF([test "$squid_cv_cc_simplified" = "gcc-4"],[
    AC_MSG_NOTICE([skipping -Wextra on $squid_cv_cc_simplified])
],[
    SQUID_CC_ADD_CXXFLAG_WARNING_IF_SUPPORTED([-Wextra])

    # Now disable or configure certain warnings enabled by -Wextra

    # -Wunused-private-field causes a huge number of false positives
    #    in unit tests. Disable that
    SQUID_CC_ADD_CXXFLAG_WARNING_IF_SUPPORTED([-Wno-unused-private-field])

    # ...=5: Do not trust comments about fallthrough cases (GCC).
    SQUID_CC_ADD_CXXFLAG_WARNING_IF_SUPPORTED([-Wimplicit-fallthrough=5])
    AS_IF([test "x$squid_cv_cc_arg_wimplicit_fallthrough_5" != "xyes"], [
        SQUID_CC_ADD_CXXFLAG_WARNING_IF_SUPPORTED([-Wno-implicit-fallthrough])
    ])
])

# useful warnings that may not be included in -Wall -Wextra
SQUID_CC_ADD_CXXFLAG_WARNING_IF_SUPPORTED([-Wpointer-arith])
SQUID_CC_ADD_CXXFLAG_WARNING_IF_SUPPORTED([-Wwrite-strings])
SQUID_CC_ADD_CXXFLAG_WARNING_IF_SUPPORTED([-Wcomments])
SQUID_CC_ADD_CXXFLAG_WARNING_IF_SUPPORTED([-Wshadow])
SQUID_CC_ADD_CXXFLAG_WARNING_IF_SUPPORTED([-Wmissing-declarations])
SQUID_CC_ADD_CXXFLAG_WARNING_IF_SUPPORTED([-Woverloaded-virtual])

dnl CentOS (and RHEL) still define ntohs() using deprecated C++ features
SQUID_CC_REQUIRE_ARGUMENT([ac_cv_require_wno_deprecated_register],[-Werror -Wno-deprecated-register],[[#include <arpa/inet.h>]],[[int fox=ntohs(1);]])

AS_IF([test "x$enable_strict_error_checking" != "xno"],[
  SQUID_CFLAGS="$SQUID_CFLAGS $squid_cv_cc_option_werror"
  SQUID_CXXFLAGS="$SQUID_CXXFLAGS $squid_cv_cxx_option_werror"
])

AS_IF([test "x$ac_cv_require_wno_deprecated_register" = "xyes"],[
  SQUID_CXXFLAGS="$SQUID_CXXFLAGS -Wno-deprecated-register"
])

# squid_cv_cc_arg_pipe is set by SQUID_CC_GUESS_OPTIONS
SQUID_CXXFLAGS="$SQUID_CXXFLAGS $squid_cv_cc_arg_pipe"
SQUID_CFLAGS="$SQUID_CFLAGS $squid_cv_cc_arg_pipe"

# possibly include some build info tag into squid -v
SQUID_EMBED_BUILD_INFO

AC_ARG_ENABLE(optimizations,
  AS_HELP_STRING([--disable-optimizations],
                 [Do not compile Squid with compiler optimizations enabled.
                  Optimization is good for production builds, but not
                  good for debugging. During development, use
                  --disable-optimizations to reduce compilation times
                  and allow easier debugging.]), [
  AS_IF([test "x$enableval" = "xno"],[
    AC_MSG_NOTICE([Disabling compiler optimizations (-O flag)])
    CFLAGS="`echo $CFLAGS | sed -e 's/-O[[0-9g]]*//'`"
    CXXFLAGS="`echo $CXXFLAGS | sed -e 's/-O[[0-9g]]*//'`"
  ])
])

dnl Nasty hack to get autoconf 2.64 on Linux to run.
dnl all other uses of RUN_IFELSE are wrapped inside CACHE_CHECK which breaks on 2.64
AC_RUN_IFELSE([AC_LANG_SOURCE([[ int main(int argc, char **argv) { return 0; } ]])],[],[],[:])

AH_TEMPLATE(XMALLOC_STATISTICS,[Define to have malloc statistics])
AC_ARG_ENABLE(xmalloc-statistics,
  AS_HELP_STRING([--enable-xmalloc-statistics],
                 [Show malloc statistics in status page]), [
  SQUID_YESNO([$enableval],[--enable-xmalloc-statistics])
])
SQUID_DEFINE_BOOL(XMALLOC_STATISTICS,${enable_xmalloc_statistics:=no},
    [Show malloc statistics in status page])
AC_MSG_NOTICE([xmalloc stats display: $enable_xmalloc_statistics])

squid_opt_aufs_threads=""
AC_ARG_WITH(aufs-threads,
  AS_HELP_STRING([--with-aufs-threads=N_THREADS],
    [Tune the number of worker threads for the aufs object store.]), [
  AS_CASE([$withval],
    [@<:@0-9@:>@*],[squid_opt_aufs_threads=$withval],
    AC_MSG_ERROR(--with-aufs-threads expects a numeric argument)
  )
])
AS_IF([test "x$squid_opt_aufs_threads" != "x"],[
  AC_MSG_NOTICE([With $squid_opt_aufs_threads aufs threads])
  AC_DEFINE_UNQUOTED(AUFS_IO_THREADS,$squid_opt_aufs_threads,
    [Defines how many threads aufs uses for I/O])
])

## TODO check if this is necessary, LT_INIT does these checks
SQUID_AUTO_LIB(dl,[dynamic linking],[LIBDL])
SQUID_CHECK_LIB_WORKS(dl,[
  LDFLAGS="$LIBDL_PATH $LDFLAGS"
  AC_CHECK_LIB(dl, dlopen,[LIBDL_LIBS="-ldl"])
  LIBS="$LIBDL_LIBS $LIBS"
])

AC_DEFUN([LIBATOMIC_CHECKER],[
  AC_MSG_CHECKING(whether linking $1 -latomic works)
  AC_LINK_IFELSE([
    AC_LANG_SOURCE([[
#include <atomic>
#include <cstdint>
      int
      main(int argc, char **) {
          return (
              std::atomic<uint8_t>(uint8_t(argc)).exchange(0) &&
              std::atomic<uint64_t>{}.is_lock_free()
              ) ? 0 : 1;
      }
  ]])],[
    AC_MSG_RESULT(yes)
    libatomic_checker_result="yes"],[
    AC_MSG_RESULT(no)
    libatomic_checker_result="no"
])])

## check for atomics library before anything that might need it
SQUID_STATE_SAVE(LIBATOMIC)
LIBATOMIC_CHECKER(without)
AS_IF([test "x$libatomic_checker_result" = "xno"],[
  LIBS="$LIBS -latomic"
  LIBATOMIC_CHECKER(with)
  AS_IF([test "x$libatomic_checker_result" = "xyes"],[
    ATOMICLIB="-latomic"],[
    AC_MSG_ERROR([Required library libatomic not found.])
])])
SQUID_STATE_ROLLBACK(LIBATOMIC)
AC_SUBST(ATOMICLIB)

SQUID_AUTO_LIB(psapi,[Windows PSAPI.dll],[LIBPSAPI])
AS_IF([test "x$with_psapi" != "xno"],[
  SQUID_STATE_SAVE(squid_psapi_state)
  CPPFLAGS="$LIBPSAPI_CFLAGS $CPPFLAGS"
  LIBS="$LIBPSAPI_PATH $LIBS"
  AC_CHECK_LIB([psapi],[K32GetProcessMemoryInfo],[LIBPSAPI_LIBS="-lpsapi"])
  AC_CHECK_HEADER([psapi.h],,,[
#if HAVE_WINDOWS_H
#include <windows.h>
#endif
  ])
  SQUID_STATE_ROLLBACK(squid_psapi_state)
  AS_IF([test "x$LIBPSAPI_LIBS" != "x"],[
    CXXFLAGS="$LIBPSAPI_CFLAGS $CXXFLAGS"
    LIBPSAPI_LIBS="$LIBPSAPI_PATH $LIBPSAPI_LIBS"
  ],[test "x$with_psapi" = "xyes"],[
    AC_MSG_ERROR([Required library PSAPI.dll not found])
  ],[
    AC_MSG_NOTICE([Library PSAPI.dll not found.])
  ])
])
AC_MSG_NOTICE([Using Windows PSAPI.dll library: ${with_psapi:=auto}])
AC_SUBST(LIBPSAPI_LIBS)

AC_SEARCH_LIBS([shm_open], [rt])
AS_IF([test "x$ac_cv_search_shm_open" != "xno"],[
  AC_DEFINE(HAVE_SHM,1,[Support shared memory features])
])

squid_disk_module_candidates=
AC_ARG_ENABLE(disk-io,
  AS_HELP_STRING([--enable-disk-io="list of modules"],
    [Build support for the list of disk I/O modules.
     Set without a value or omitted, all available modules will be built.
     See src/DiskIO for a list of available modules, or
     Programmers Guide section on DiskIO
     for details on how to build your custom disk module]),
  AS_CASE(["$enableval"],
    [yes],[],
    [no|none],[enable_disk_io="no"],
    [
      enable_disk_io="yes"
      squid_disk_module_candidates="$enableval"
  ])
)
AS_IF([test "x${enable_disk_io:=yes}" = "xyes"],[
  SQUID_LOOK_FOR_MODULES([$srcdir/src/DiskIO],[squid_disk_module_candidates])
  AS_IF([test "x$ac_cv_search_shm_open" = "xno"],[
    squid_disk_module_candidates=`echo "$squid_disk_module_candidates" | sed 's/IpcIo//g'`
  ])
])
SQUID_CLEANUP_MODULES_LIST([squid_disk_module_candidates])
SQUID_CHECK_EXISTING_MODULES([$srcdir/src/DiskIO],[squid_disk_module_candidates])
AC_MSG_NOTICE([DiskIO modules built: ${squid_disk_module_candidates:-none}])
SQUID_DEFINE_BOOL(USE_DISKIO,$enable_disk_io,[DiskIO modules are expected to be available.])

dnl Some autoconf.h defines we might enable later...
AC_ARG_WITH(pthreads,AS_HELP_STRING([--without-pthreads],[Disable POSIX Threads]))
AC_ARG_WITH(aio, AS_HELP_STRING([--without-aio],[Do not use POSIX AIO. Default: auto-detect]))
ENABLE_WIN32_AIOPS=0
squid_opt_use_aio=
squid_opt_use_diskthreads=
AIOLIB=

dnl Setup the module paths etc.
DISK_LIBS=
DISK_MODULES=
AH_TEMPLATE(HAVE_DISKIO_MODULE_AIO, [Whether POSIX AIO Disk I/O module is built])
AH_TEMPLATE(HAVE_DISKIO_MODULE_BLOCKING, [Whether Blocking Disk I/O module is built])
AH_TEMPLATE(HAVE_DISKIO_MODULE_DISKDAEMON, [Whether DiskDaemon Disk I/O module is built])
AH_TEMPLATE(HAVE_DISKIO_MODULE_DISKTHREADS, [Whether DiskThreads Disk I/O module is built])
AH_TEMPLATE(HAVE_DISKIO_MODULE_IPCIO, [Whether IpcIo Disk I/O module is built])
AH_TEMPLATE(HAVE_DISKIO_MODULE_MMAPPED, [Whether Mmapped Disk I/O module is built])
for module in $squid_disk_module_candidates none; do
  # maybe not needed
  AS_IF([test "x$module" = "xnone"],[continue])
  AS_IF([! test -d "$srcdir/src/DiskIO/$module"],[AC_MSG_ERROR([disk-io $module does not exist])])
  AS_CASE(["$module"],
    [AIO],[
      dnl Check for POSIX AIO availability
      squid_opt_use_aio="yes"
      AIOLIB=
      AS_IF([test "x$with_aio" != "xno"],[
        have_aio_header=no
        AC_CHECK_HEADERS(aio.h,[have_aio_header=yes])
        dnl On some systems POSIX AIO functions are in librt
        dnl On some systems POSIX AIO functions are in libaio
        AC_CHECK_LIB(rt,aio_read,[AIOLIB="-lrt"],AC_CHECK_LIB(aio,aio_read,[AIOLIB="-laio"],[]))
        dnl Enable AIO if the library and headers are found
        AS_IF([test "x$AIOLIB" != "x" -a "x$have_aio_header" = "xyes"],[
          AC_MSG_NOTICE([Native POSIX AIO support detected.])
          squid_opt_use_aio="yes"
        ],[
          dnl Windows does things differently. We provide wrappers.
          dnl TODO: Windows really needs its own DiskIO module or its Overlaped IO
          AS_IF([test "$squid_host_os" = "mingw"],[
            squid_opt_use_aio="yes"
            AC_MSG_NOTICE([Windows being built. Maybe-enable POSIX AIO.])
          ],[
            squid_opt_use_aio="no"
            AC_MSG_NOTICE([Native POSIX AIO support not detected. AIO automatically disabled.])
          ])
        ])
      ],[
        AC_MSG_NOTICE([POSIX AIO support manually disabled.])
        squid_opt_use_aio="no"
      ])
      dnl Use the POSIX AIO pieces if we actually need them.
      AS_IF([test "x$squid_opt_use_aio" = "xyes"],[
        DISK_MODULES="$DISK_MODULES AIO"
        AC_DEFINE([HAVE_DISKIO_MODULE_AIO],1,[POSIX AIO Disk I/O module is built])
        AS_IF([test "$squid_host_os" = "mingw"],[
          ENABLE_WIN32_AIO=1
          AC_MSG_NOTICE([Replacing AIO DiskIO module with: Windows overlapped I/O support])
        ],[
          AC_MSG_NOTICE([Enabling AIO DiskIO module])
        ])
      ],[
        AC_MSG_NOTICE([AIO DiskIO Module disabled. Missing POSIX AIO support.])
        squid_disk_module_candidates_AIO=no
      ])
    ],

    [Blocking],[
      AC_MSG_NOTICE([Enabling Blocking DiskIO module])
      DISK_MODULES="$DISK_MODULES Blocking"
      AC_DEFINE([HAVE_DISKIO_MODULE_BLOCKING],1,[Blocking Disk I/O module is built])
    ],

    [DiskDaemon],[
      AS_IF([test "$squid_host_os" = "mingw"],[
        AC_MSG_NOTICE([DiskDaemon not supported on MinGW])
        squid_disk_module_candidates_DiskDaemon=no
      ],[
        AC_MSG_NOTICE([Enabling DiskDaemon DiskIO module])
        DISK_MODULES="$DISK_MODULES DiskDaemon"
        AC_DEFINE([HAVE_DISKIO_MODULE_DISKDAEMON],1,[DiskDaemon Disk I/O module is built])
      ])
    ],

    [DiskThreads],[
      squid_opt_use_diskthreads="yes"
      LIBPTHREADS=
      SQUID_STATE_SAVE([diskthreads_state],[SQUID_CFLAGS SQUID_CXXFLAGS])
      AS_IF([test "x$with_pthreads" != "xno"],[
        dnl TODO: this needs to be extended to handle more systems and better
        dnl REF: http://www.openldap.org/lists/openldap-bugs/200006/msg00070.html
        dnl REF: http://autoconf-archive.cryp.to/acx_pthread.html
        AS_CASE(["$squid_host_os"],
          [mingw],[
            ENABLE_WIN32_AIOPS=1
            AC_MSG_NOTICE([Windows threads support automatically enabled])
          ],

          [freebsd],[
            AS_IF([test `echo "$squid_host_os_version" | tr -d .` -lt 70],[
              AC_MSG_NOTICE(pthread library requires FreeBSD 7 or later)
              squid_opt_use_diskthreads="no"
            ],[
              SQUID_CFLAGS="$SQUID_CFLAGS -D_REENTRANT"
              SQUID_CXXFLAGS="$SQUID_CXXFLAGS -D_REENTRANT"
              AS_IF([test "x$GCC" = "xyes" -a "x$PRESET_LDFLAGS" = "x"],[LDFLAGS="$LDFLAGS -pthread"])
            ])
          ],

          [openbsd],[
            AS_IF([test `echo "$squid_host_os_version" | tr -d .` -lt 52],[
              AC_MSG_NOTICE(pthread library requires OpenBSD 5.2 or later)
              squid_opt_use_diskthreads="no"
            ],[
              SQUID_CFLAGS="$SQUID_CFLAGS -D_REENTRANT"
              SQUID_CXXFLAGS="$SQUID_CXXFLAGS -D_REENTRANT"
              LDFLAGS="$LDFLAGS -lpthread"
            ])
          ],

          [solaris],[
            AS_IF([test "x$GCC" = "xyes"],[
              SQUID_CFLAGS="$SQUID_CFLAGS -D_REENTRANT -pthreads"
              SQUID_CXXFLAGS="$SQUID_CXXFLAGS -D_REENTRANT -pthreads"
              AC_CHECK_LIB(pthread, pthread_create ,[LIBPTHREADS="-lpthread"], [
                AC_MSG_NOTICE(pthread library required but cannot be found.)
                squid_opt_use_diskthreads="no"
               ])
            ],[
              dnl test for -lpthread first. libc version is a stub apparently on Solaris.
              SQUID_CFLAGS="$SQUID_CFLAGS -D_REENTRANT -lpthread"
              SQUID_CXXFLAGS="$SQUID_CXXFLAGS -D_REENTRANT -lpthread"
              AC_SEARCH_LIBS([pthread_create],[pthread thread],[
                LIBPTHREADS="" #in LIBS
              ],[
                AC_MSG_NOTICE(pthread library required but cannot be found.)
                squid_opt_use_diskthreads="no"
              ])
            ])
          ],

          [
            SQUID_CFLAGS="$SQUID_CFLAGS -D_REENTRANT"
            SQUID_CXXFLAGS="$SQUID_CXXFLAGS -D_REENTRANT"
            AC_CHECK_LIB(pthread, pthread_create ,[LIBPTHREADS="-lpthread"], [
              AC_MSG_NOTICE(pthread library required but cannot be found.)
              squid_opt_use_diskthreads="no"
            ])
          ]
        )
      ],[
        AC_MSG_NOTICE([Native pthreads support manually disabled.])
        squid_opt_use_diskthreads="no"
      ])
      AS_IF([test "x$squid_opt_use_diskthreads" = "xyes"],[
        AC_MSG_NOTICE([Enabling DiskThreads DiskIO module])
        DISK_MODULES="$DISK_MODULES DiskThreads"
        AC_DEFINE([HAVE_DISKIO_MODULE_DISKTHREADS],1,[DiskThreads Disk I/O module is built])
      ],[
        AC_MSG_NOTICE([Native pthreads support disabled. DiskThreads module automaticaly disabled.])
        SQUID_STATE_ROLLBACK([diskthreads_state])
        squid_disk_module_candidates_DiskThreads=no
      ])
    ],

    [IpcIo],[
      AS_IF([test "x$ac_cv_search_shm_open" = "xno"],[
        AC_MSG_NOTICE([DiskIO IpcIo module requires shared memory support])
        squid_disk_module_candidates_IpcIo=no
      ],[
        AC_MSG_NOTICE([Enabling IpcIo DiskIO module])
        DISK_MODULES="$DISK_MODULES IpcIo"
        AC_DEFINE([HAVE_DISKIO_MODULE_IPCIO],1,[IpcIo Disk I/O module is built])
      ])
    ],

    [Mmapped],[
      dnl TODO: use availability of sys/mman.h and/or mmap to define
      dnl  OR support windows mmap functions
      AS_IF([test "x$squid_host_os" = "xmingw"],[
        AC_MSG_NOTICE([Mmapped DiskIO is not available on Mingw])
        squid_disk_module_candidates_Mmapped=no
      ],[
        AC_MSG_NOTICE([Enabling Mmapped DiskIO module])
        DISK_MODULES="$DISK_MODULES Mmapped"
        AC_DEFINE([HAVE_DISKIO_MODULE_MMAPPED],1,[Mmapped Disk I/O module is built])
      ])
    ],

    [
      AC_MSG_NOTICE([Enabling $module DiskIO module])
      DISK_LIBS="$DISK_LIBS lib${module}.la"
      DISK_MODULES="$DISK_MODULES ${module}"
    ])
done
AC_MSG_NOTICE([IO Modules built: $DISK_MODULES])
AC_SUBST(DISK_MODULES)
AC_SUBST(DISK_LIBS)
AM_CONDITIONAL(ENABLE_DISKIO_AIO, test "x$squid_disk_module_candidates_AIO" = "xyes")
AC_SUBST(AIOLIB)
AM_CONDITIONAL(ENABLE_WIN32_AIO, test "x$squid_disk_module_candidates_AIO" = "xyes" -a "x$ENABLE_WIN32_AIO" = "x1")
AM_CONDITIONAL(ENABLE_DISKIO_BLOCKING, test "x$squid_disk_module_candidates_Blocking" = "xyes")
AM_CONDITIONAL(ENABLE_DISKIO_DISKDAEMON, test "x$squid_disk_module_candidates_DiskDaemon" = "xyes")
AM_CONDITIONAL(ENABLE_DISKIO_DISKTHREADS, test "x$squid_disk_module_candidates_DiskThreads" = "xyes")
AC_SUBST(LIBPTHREADS)
AM_CONDITIONAL(ENABLE_WIN32_AIOPS, test "x$squid_disk_module_candidates_DiskThreads" = "xyes" -a "x$ENABLE_WIN32_AIOPS" = "x1")
AM_CONDITIONAL(ENABLE_DISKIO_IPCIO, test "x$squid_disk_module_candidates_IpcIo" = "xyes")
AM_CONDITIONAL(ENABLE_DISKIO_MMAPPED, test "x$squid_disk_module_candidates_Mmapped" = "xyes")

dnl Check what Storage formats are wanted.
dnl This version will error out with a message saying why if a required DiskIO is missing.
AC_ARG_ENABLE([storeio],
  AS_HELP_STRING([--enable-storeio="list of modules"],
                 [Build support for the list of store I/O modules.
                  The default is only to build the "ufs" module.
                  See src/fs for a list of available modules, or
                  Programmers Guide section <not yet written>
                  for details on how to build your custom store module]), [
  AS_CASE(["$enableval"],
    [yes],[],
    [no|none],[enable_storeio="no"],
    [
      enable_storeio="yes"
      # ufs is really always needed as it has low-level routines
      # if it is a dupe it will be cleaned-up later
      squid_storeio_module_candidates="$enableval ufs"
  ])
])
AS_IF([test "x${enable_storeio:=yes}" = "xyes"],[
  SQUID_LOOK_FOR_MODULES([$srcdir/src/fs],[squid_storeio_module_candidates])
])
SQUID_CLEANUP_MODULES_LIST([squid_storeio_module_candidates])
SQUID_CHECK_EXISTING_MODULES([$srcdir/src/fs],[squid_storeio_module_candidates])
AC_MSG_NOTICE([Store modules built: ${squid_storeio_module_candidates:-none}])

for fs in ${squid_storeio_module_candidates:-none}; do
  AS_CASE([$fs],
    [diskd],[
      AS_IF([test "x$squid_disk_module_candidates_Blocking" != "xyes" -a \
        "x$squid_disk_module_candidates_DiskDaemon" != "xyes"],[
        AC_MSG_ERROR([Storage diskd module requires DiskIO module: Blocking or DiskDaemon])
      ])
    ],
    [aufs],[
      AS_IF([test "x$squid_disk_module_candidates_Blocking" != "xyes" -a \
        "x$squid_disk_module_candidates_DiskThreads" != "xyes"],[
        AC_MSG_ERROR([Storage module aufs requires DiskIO module: Blocking or DiskThreads])
      ])
    ],
    [rock],[
      AS_IF([test "x$squid_disk_module_candidates_IpcIo" != "xyes" -a \
        "x$squid_disk_module_candidates_Blocking" != "xyes"],[
         AC_MSG_ERROR([Storage module Rock requires DiskIO module: Blocking or IpcIo])
      ])
      squid_do_build_rock=true
    ],
    [ufs],[
      AS_IF([test "x$squid_disk_module_candidates_Blocking" != "xyes"],[
        AC_MSG_ERROR([Storage module ufs requires DiskIO module: Blocking])
      ])
      squid_do_build_ufs=true
    ]
  )
done

AM_CONDITIONAL(ENABLE_FS_UFS, test "x$squid_do_build_ufs" = "xtrue")
AM_CONDITIONAL(ENABLE_FS_ROCK, test "x$squid_do_build_rock" = "xtrue")
dnl hack: need to define those even if not used in the build system to
dnl make sure that global FS objects are linked to the squid binary.
AH_TEMPLATE(HAVE_FS_UFS, "Define to 1 if ufs filesystem module is build")
AH_TEMPLATE(HAVE_FS_AUFS, "Define to 1 if aufs filesystem module is build")
AH_TEMPLATE(HAVE_FS_DISKD, "Define to 1 if diskd filesystem module is build")
AH_TEMPLATE(HAVE_FS_ROCK, "Define to 1 if rock filesystem module is build")


dnl got final squid_storeio_module_candidates, build library lists
dnl This list will not be needed when each fs library has its own Makefile
STORE_LIBS_TO_BUILD=
dnl File system libraries to link executables with.
dnl These are the same as STORE_LIBS_TO_BUILD, but with a path
STORE_LIBS_TO_ADD=
for fs in $squid_storeio_module_candidates; do
    STORE_LIBS_TO_BUILD="$STORE_LIBS_TO_BUILD lib${fs}.la"
    STORE_LIBS_TO_ADD="$STORE_LIBS_TO_ADD fs/lib${fs}.la"
    SQUID_TOUPPER_VAR_CONTENTS([fs])
    AC_DEFINE_UNQUOTED(HAVE_FS_${fs}, 1)
done

AC_SUBST(STORE_LIBS_TO_BUILD)
AC_SUBST(STORE_LIBS_TO_ADD)
AC_SUBST(STORE_TESTS)


dnl At lest one removal policy is always needed.
dnl 'lru' removal policy is currently hard-coded by name for tests
dnl so we must set it as default.
REPL_POLICIES="lru"
AC_ARG_ENABLE(removal-policies,
  AS_HELP_STRING([--enable-removal-policies="list of policies"],
                 [Build support for the list of removal policies.
                  The default is only to build the "lru" module.
                  See src/repl for a list of available modules, or
                  Programmers Guide section 9.9 for details on how
                  to build your custom policy]), [
  AS_CASE(["$enableval"],
    [yes],[ SQUID_LOOK_FOR_MODULES([$srcdir/src/repl],[REPL_POLICIES]) ],
    [no],[],
    [ REPL_POLICIES="$enableval" ]
  )
])
SQUID_CLEANUP_MODULES_LIST([REPL_POLICIES])
SQUID_CHECK_EXISTING_MODULES([$srcdir/src/repl],[REPL_POLICIES])
AC_MSG_NOTICE([Removal policies to build: $REPL_POLICIES])
REPL_OBJS="repl/lib`echo \"$REPL_POLICIES\" | sed -e 's% %.a repl/lib%g'`.a"
REPL_LIBS=`echo "$REPL_OBJS" | sed -e 's%repl/%%g'`
AC_SUBST(REPL_POLICIES)
AC_SUBST(REPL_OBJS)
AC_SUBST(REPL_LIBS)

AM_CONDITIONAL(ENABLE_PINGER, false)
AC_ARG_ENABLE(icmp,
  AS_HELP_STRING([--enable-icmp],[Enable ICMP pinging and Network Measurement]),[
  AS_IF([test "x$enableval" = "xyes"],[
    AC_MSG_NOTICE([ICMP enabled])
    AC_DEFINE(USE_ICMP,1,[Define to use Squid ICMP and Network Measurement features (highly recommended!)])
    AM_CONDITIONAL(ENABLE_PINGER, true)
  ])
])

AM_CONDITIONAL(ENABLE_DELAY_POOLS, false)
AC_ARG_ENABLE(delay-pools,
  AS_HELP_STRING([--enable-delay-pools],[Enable delay pools to limit bandwidth usage]),[
  AS_IF([test "x$enableval" = "xyes"],[
    AC_MSG_NOTICE([Delay pools enabled])
    AC_DEFINE([USE_DELAY_POOLS],1,[Traffic management via "delay pools".])
    AM_CONDITIONAL(ENABLE_DELAY_POOLS, true)
  ])
])

dnl disable generic/common adaptation support by default
squid_opt_use_adaptation=no

squid_opt_use_esi=auto
AH_TEMPLATE([USE_SQUID_ESI],[Define to enable the ESI processor])
AC_ARG_ENABLE(esi,
  AS_HELP_STRING([--disable-esi],
                 [Disable ESI for accelerators. ESI requires expat or xml2 library.
                  Enabling ESI will cause squid reverse proxies to be capable
                  of the Edge Acceleration Specification (www.esi.org).]),
                 [squid_opt_use_esi=$enableval],[])

# ESI support libraries: expat
AH_TEMPLATE(HAVE_LIBEXPAT,[Define to 1 if you have the expat library])
SQUID_AUTO_LIB(expat,[ESI expat library],[LIBEXPAT])
AS_IF([test "x$squid_opt_use_esi" != "xno" -a "x$with_expat" != "xno"],[
  SQUID_STATE_SAVE(squid_expat_state)
  PKG_CHECK_MODULES([LIBEXPAT],[expat],[],[
    AC_CHECK_LIB([expat],[main],[LIBEXPAT_LIBS="-lexpat"])
  ])
  CPPFLAGS="$LIBEXPAT_CFLAGS $CPPFLAGS"
  AC_CHECK_HEADERS(expat.h)
  SQUID_STATE_ROLLBACK(squid_expat_state)
  AS_IF([test "x$LIBEXPAT_LIBS" != "x"],[
      squid_opt_use_esi=yes
      LIBEXPAT_LIBS="$LIBEXPAT_PATH $LIBEXPAT_LIBS"
      AC_DEFINE(HAVE_LIBEXPAT,1,[Define to 1 if you have the expat library])
    ],
    [test "x$with_expat" = "xyes"],[AC_MSG_ERROR([Required library expat not found.])],
    [AC_MSG_NOTICE([Library expat not found.])]
  )
])
AM_CONDITIONAL(ENABLE_LIBEXPAT,[test "x$LIBEXPAT_LIBS" != "x"])
AC_SUBST(LIBEXPAT_LIBS)

# ESI support libraries: xml2
AH_TEMPLATE(HAVE_LIBXML2,[Define to 1 if you have the xml2 library])
SQUID_AUTO_LIB(xml2,[ESI xml2 library],[LIBXML2])
AS_IF([test "x$squid_opt_use_esi" != "xno" -a "x$with_xml2" != "xno"],[
  SQUID_STATE_SAVE([squid_libxml2_save])
  PKG_CHECK_MODULES([LIBXML2],[libxml-2.0],[],[
    AC_CHECK_LIB([xml2],[main],[LIBXML2_LIBS="$LIBXML2_PATH -lxml2"])
  ])
  CPPFLAGS="$LIBXML2_CFLAGS $CPPFLAGS"
  AC_CHECK_HEADERS(libxml/parser.h libxml/HTMLparser.h libxml/HTMLtree.h)
  SQUID_STATE_ROLLBACK([squid_libxml2_save])

  AS_IF([test "x$LIBXML2_LIBS" != "x"],[
    squid_opt_use_esi=yes
    CPPFLAGS="$LIBXML2_CFLAGS $CPPFLAGS"
    LIBXML2_LIBS="$LIBXML2_PATH $LIBXML2_LIBS"
    AC_DEFINE(HAVE_LIBXML2,1,[Define to 1 if you have the xml2 library])
  ],[test "x$with_xml2" = "xyes"],[
    AC_MSG_ERROR([Required library xml2 not found])
  ],[
    AC_MSG_NOTICE([Library xml2 not found.])
  ])
])
AM_CONDITIONAL(ENABLE_LIBXML2,[test "x$LIBXML2_LIBS" != "x"])
AC_SUBST(LIBXML2_LIBS)

AS_IF([test "x$squid_opt_use_esi" = "xyes"],[
  AS_IF([test "x$LIBXML2_LIBS" = "x" -a "x$LIBEXPAT_LIBS" = "x"],[
    AC_MSG_ERROR([ESI processor requires libxml2 or libexpat])
  ])
  AC_MSG_NOTICE([Enabling ESI processor: $LIBEXPAT_LIBS $LIBXML2_LIBS])
  AC_DEFINE(USE_SQUID_ESI,1,[Compile the ESI processor])
],[
  AS_IF(test "x$squid_opt_use_esi" = "xno",[
    AC_MSG_NOTICE([Disabling ESI processor.])
  ],[
    AC_MSG_NOTICE([Disabling ESI processor. libxml2 and libexpat not found.])
  ])
])
AM_CONDITIONAL(ENABLE_ESI, test "x$squid_opt_use_esi" = "xyes")

AC_ARG_ENABLE(icap-client,
  AS_HELP_STRING([--disable-icap-client],[Disable the ICAP client.]),[
  SQUID_YESNO([$enableval],[--enable-icap-client])
])
SQUID_DEFINE_BOOL(ICAP_CLIENT,${enable_icap_client:=yes}, [Enable ICAP client features in Squid])
AS_IF(test "x$enable_icap_client" != "xno", squid_opt_use_adaptation="yes")
AM_CONDITIONAL(ENABLE_ICAP_CLIENT, test "x$enable_icap_client" != "xno")

AC_ARG_ENABLE(ecap,
  AS_HELP_STRING([--enable-ecap],[support loadable content adaptation modules]),[
  SQUID_YESNO([$enableval],[--enable-ecap])],[
  enable_ecap="no"
])
dnl Perform configuration consistency checks for eCAP
AS_IF([test "x$enable_ecap" != "xno"],[
  AS_IF([test "x$enable_shared" != "xyes"],[
    AC_MSG_ERROR([eCAP support requires loadable modules. Please do not use --disable-shared with --enable-ecap.])
  ])

  AS_IF([test -n "$PKG_CONFIG"],[
    dnl eCAP support requires libecap.
    dnl This Squid supports libecap v1.0.x.
    dnl Use EXT_ prefix to distinguish external libecap (that we check for
    dnl here) from our own convenience ecap library in Makefiles.
    PKG_CHECK_MODULES([EXT_LIBECAP],[libecap >= 1.0 libecap < 1.1])
  ],[
    AC_MSG_NOTICE([eCAP support requires pkg-config to verify the correct library version. Trouble may follow.])
  ])

  SQUID_STATE_SAVE(squid_ecap_state)
  AC_MSG_CHECKING([whether -lecap will link])
  CXXFLAGS="$CXXFLAGS $EXT_LIBECAP_CFLAGS"
  LIBS="$LIBS $EXT_LIBECAP_LIBS"
  AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <libecap/common/names.h>]],[[
    const libecap::Name test("test", libecap::Name::NextId());
  ]])],[
    AC_MSG_RESULT(yes)
    squid_opt_use_adaptation=yes
  ],[
    AC_MSG_RESULT(no)
    AS_IF([test "x$enable_ecap" = "xyes"],[
      AC_MSG_ERROR([eCAP library will not link.
                  You may need to rebuild libecap using the same version of GCC as Squid.
                  There have been breaking ABI changes in the libstdc++ STL with GCC 5.])
    ],[
      AC_MSG_NOTICE([eCAP library will not link.
                  You may need to rebuild libecap using the same version of GCC as Squid.
                  There have been breaking ABI changes in the libstdc++ STL with GCC 5.])
      enable_ecap="no"
    ])
  ])
  SQUID_STATE_ROLLBACK(squid_ecap_state)
])
SQUID_DEFINE_BOOL(USE_ECAP,${enable_ecap:=no},[Whether to use eCAP support])
AM_CONDITIONAL(ENABLE_ECAP, test "x$enable_ecap" = "xyes")

dnl enable adaptation if requested by specific adaptation mechanisms
ADAPTATION_LIBS=""
AS_IF([test "x$squid_opt_use_adaptation" = "xyes"],[ADAPTATION_LIBS="adaptation/libadaptation.la"])
SQUID_DEFINE_BOOL(USE_ADAPTATION,${squid_opt_use_adaptation:=no}, [common adaptation support])
AM_CONDITIONAL(ENABLE_ADAPTATION, test "x$squid_opt_use_adaptation" = "xyes")
AC_SUBST(ADAPTATION_LIBS)

AS_IF([test "x$squid_host_os" = "xmingw"],[enable_wccp=no])
AC_ARG_ENABLE(wccp,
  AS_HELP_STRING([--disable-wccp],[Disable Web Cache Coordination Protocol]),[
  SQUID_YESNO([$enableval],[--enable-wccp])
])
SQUID_DEFINE_BOOL(USE_WCCP, ${enable_wccp:=yes}, [Define to enable WCCP])
AC_MSG_NOTICE([Web Cache Coordination Protocol enabled: $enable_wccp])

AS_IF([test "x$squid_host_os" = "xmingw"],[enable_wccpv2=no])
AC_ARG_ENABLE(wccpv2,
  AS_HELP_STRING([--disable-wccpv2],
                 [Disable Web Cache Coordination V2 Protocol]), [
  SQUID_YESNO([$enableval],[--enable-wccpv2])
])
SQUID_DEFINE_BOOL(USE_WCCPv2,${enable_wccpv2:=yes},
            [Define to enable WCCP V2])
AC_MSG_NOTICE([Web Cache Coordination V2 Protocol enabled: $enable_wccpv2])

AC_ARG_ENABLE(snmp,
  AS_HELP_STRING([--disable-snmp],[Disable SNMP monitoring support]), [
  SQUID_YESNO([$enableval],[--enable-snmp])
])
SQUID_DEFINE_BOOL(SQUID_SNMP,${enable_snmp:=yes},
   [Define to enable SNMP monitoring of Squid])
AM_CONDITIONAL(ENABLE_SNMP, [test "x$enable_snmp" = "xyes"])
AS_IF([test "x$enable_snmp" = "xyes"],[SNMPLIB="../lib/snmplib/libsnmplib.la"])
AC_MSG_NOTICE([SNMP support enabled: $enable_snmp])
AC_SUBST(SNMPLIB)

AC_ARG_ENABLE(eui,
  AS_HELP_STRING([--disable-eui],
                 [Disable use of ARP / MAC/ EUI (ether address)]), [
  SQUID_YESNO([$enableval],[--enable-eui])
])
AS_IF([test "x${enable_eui:=yes}" = "xyes"],[
  SQUID_STATE_SAVE(LIBEUI)
  # GLIBC 2.30 deprecates sysctl.h. Test with the same flags that (may) break includes later.
  CFLAGS=$SQUID_CFLAGS
  CXXFLAGS=$SQUID_CXXFLAGS
  AS_CASE(["$squid_host_os"],
    [linux|solaris|freebsd|openbsd|netbsd|cygwin],[:],
    [mingw],[EUILIB="-liphlpapi"],
    [AC_MSG_WARN([EUI support probably will not work on host $host.])]
  )
  # iphlpapi.h check delayed after winsock2.h
  AC_CHECK_HEADERS( \
    windows.h \
    sys/sockio.h \
    sys/param.h,
  [], [], [[
#if HAVE_WINDOWS_H
include <windows.h>
#endif
]]
  )
  AC_CHECK_HEADERS( \
    net/if_arp.h \
    net/route.h,
  [], [], [[
#include <sys/types.h>
#include <sys/socket.h>
]])

  # OpenBSD, FreeBSD and NetBSD requires sys/param.h to be included before sysctl.h and net/if_dl.h
  AC_CHECK_HEADERS( \
    net/if_dl.h \
    sys/sysctl.h,
  [], [], [[
#if HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
  ]])
  SQUID_STATE_ROLLBACK(LIBEUI)
])
AC_SUBST(EUILIB)
AC_MSG_NOTICE([EUI (MAC address) controls enabled: $enable_eui])
SQUID_DEFINE_BOOL(USE_SQUID_EUI,$enable_eui,
   [Define this to include code which lets you use ethernet addresses. This code uses API initially defined in 4.4-BSD.])
AM_CONDITIONAL(ENABLE_EUI, [test "x$enable_eui" = "xyes" ])


AC_ARG_ENABLE(htcp,
  AS_HELP_STRING([--disable-htcp],[Disable HTCP protocol support]), [
  SQUID_YESNO([$enableval],[--enable-htcp])
])
SQUID_DEFINE_BOOL(USE_HTCP,${enable_htcp:=yes},
   [Define this to include code for the Hypertext Cache Protocol (HTCP)])
AM_CONDITIONAL(ENABLE_HTCP, [test "x$enable_htcp" = "xyes"])
AC_MSG_NOTICE([HTCP support enabled: $enable_htcp])

# Cryptograhic libraries
SQUID_AUTO_LIB(nettle,[Nettle crypto],[LIBNETTLE])
SQUID_CHECK_LIB_WORKS(nettle,[
  SQUID_STATE_SAVE(squid_nettle_state)
  PKG_CHECK_MODULES([LIBNETTLE],[nettle >= 3.4],[],[
    CPPFLAGS="$LIBNETTLE_CFLAGS $CPPFLAGS"
    AC_CHECK_LIB(nettle,[nettle_md5_init],[LIBNETTLE_LIBS="-lnettle"])
  ])
  AC_CHECK_HEADERS(nettle/base64.h nettle/md5.h)
  SQUID_CHECK_NETTLE_BASE64
  SQUID_STATE_ROLLBACK(squid_nettle_state)
])

dnl Check for libcrypt
CRYPTLIB=
dnl Some of our helpers use crypt(3) which may be in libc, or in
dnl libcrypt (eg FreeBSD)
AC_CHECK_LIB(crypt, crypt, [CRYPTLIB="-lcrypt"])
dnl Solaris10 provides MD5 natively through libmd5
AC_CHECK_LIB(md5, MD5Init, [CRYPTLIB="$CRYPTLIB -lmd5"])
AC_SUBST(CRYPTLIB)

SSLLIB=""

SQUID_AUTO_LIB(gnutls,[GnuTLS crypto],[LIBGNUTLS])
AH_TEMPLATE(USE_GNUTLS,[GnuTLS support is available])
SQUID_CHECK_LIB_WORKS(gnutls,[
  SQUID_STATE_SAVE(squid_gnutls_state)

  # User may have provided a custom location for GnuTLS. Otherwise...
  CPPFLAGS="$LIBGNUTLS_CFLAGS $CPPFLAGS"
  LIBS="$LIBS $LIBGNUTLS_PATH"

  # auto-detect using pkg-config
  PKG_CHECK_MODULES([LIBGNUTLS],[gnutls >= 3.4.0],[
    CPPFLAGS="$CPPFLAGS $LIBGNUTLS_CFLAGS"
    ],[
    ## find the package without pkg-config
    ## check that the library is actually new enough.
    ## by testing for a 3.4.0+ function which we use
    AC_CHECK_LIB(gnutls,gnutls_pcert_export_x509,[LIBGNUTLS_LIBS="-lgnutls"])
  ])
  # if any of the required headers is not found, signal we can't support gnutls
  AC_CHECK_HEADERS([gnutls/gnutls.h gnutls/x509.h gnutls/abstract.h], [], [LIBGNUTLS_LIBS=""])

  SQUID_STATE_ROLLBACK(squid_gnutls_state) #de-pollute LIBS

  AS_IF([test "x$LIBGNUTLS_LIBS" != "x"],[
    SSLLIB="$LIBGNUTLS_PATH $LIBGNUTLS_LIBS $SSLLIB"
    AC_DEFINE(USE_GNUTLS,1,[GnuTLS support is available])
  ])
])

dnl User may specify OpenSSL is needed from a non-standard location
SQUID_OPTIONAL_LIB(openssl,[OpenSSL],[LIBOPENSSL])
AH_TEMPLATE(USE_OPENSSL,[OpenSSL support is available])
## OpenSSL is default disable due to licensing issues on some OS
AS_IF([test "x$with_openssl" = "xyes"],[
  CPPFLAGS="$LIBOPENSSL_CFLAGS $CPPFLAGS"
  AC_CHECK_HEADERS( \
    openssl/asn1.h \
    openssl/bio.h \
    openssl/bn.h \
    openssl/crypto.h \
    openssl/decoder.h \
    openssl/dh.h \
    openssl/err.h \
    openssl/evp.h \
    openssl/lhash.h \
    openssl/md5.h \
    openssl/opensslv.h \
    openssl/rsa.h \
    openssl/ssl.h \
    openssl/x509.h \
    openssl/x509v3.h \
    openssl/engine.h \
    openssl/txt_db.h \
    openssl/pem.h \
  )

  # User may have provided a custom location for OpenSSL. Otherwise...
  SQUID_STATE_SAVE(squid_openssl_state)
  LIBS="$LIBS $LIBOPENSSL_PATH"

  # auto-detect using pkg-config
  PKG_CHECK_MODULES([LIBOPENSSL],[openssl],,[
    ## For some OS pkg-config is broken or unavailable.
    ## Detect libraries the hard way.

    # Windows MinGW has some special libraries ...
    AS_IF([test "x$squid_host_os" = "xmingw"],[
      LIBOPENSSL_LIBS='-lssleay32 -leay32 -lgdi32 $LIBOPENSSL_LIBS'
      AC_MSG_NOTICE([Windows OpenSSL library support: yes -lssleay32 -leay32 -lgdi32])
    ])

    AC_CHECK_LIB(crypto,[CRYPTO_new_ex_data],[LIBOPENSSL_LIBS="-lcrypto $LIBOPENSSL_LIBS"],[
      AC_MSG_ERROR([library 'crypto' is required for OpenSSL])
    ],$LIBOPENSSL_LIBS)
    AC_CHECK_LIB(ssl,[SSL_CTX_new],[LIBOPENSSL_LIBS="-lssl $LIBOPENSSL_LIBS"],[
      AC_MSG_ERROR([library 'ssl' is required for OpenSSL])
    ],$LIBOPENSSL_LIBS)
  ])

  SQUID_STATE_ROLLBACK(squid_openssl_state) #de-pollute LIBS

  AS_IF([test "x$LIBOPENSSL_LIBS" != "x"],[
    CXXFLAGS="$LIBOPENSSL_CFLAGS $CXXFLAGS"
    SSLLIB="$LIBOPENSSL_PATH $LIBOPENSSL_LIBS $SSLLIB"
    AC_DEFINE(USE_OPENSSL,1,[OpenSSL support is available])

    # check for API functions
    SQUID_CHECK_LIBCRYPTO_API
    SQUID_CHECK_LIBSSL_API
    SQUID_CHECK_OPENSSL_TLS_METHODS
    SQUID_STATE_SAVE(check_SSL_CTX_get0_certificate)
    LIBS="$LIBS $SSLLIB"
    AC_CHECK_LIB(ssl, SSL_CTX_get0_certificate, [
      AC_DEFINE(HAVE_SSL_CTX_GET0_CERTIFICATE, 1, [SSL_CTX_get0_certificate is available])
      ], [
          missing_SSL_CTX_get0_certificate=yes
      ])
    SQUID_STATE_ROLLBACK(check_SSL_CTX_get0_certificate)

    # check for other specific broken implementations
    AS_IF([test "x$missing_SSL_CTX_get0_certificate" = "xyes"],SQUID_CHECK_OPENSSL_GETCERTIFICATE_WORKS)
    SQUID_CHECK_OPENSSL_CONST_SSL_METHOD
    SQUID_CHECK_OPENSSL_CONST_CRYPTO_EX_DATA
    SQUID_CHECK_OPENSSL_CONST_SSL_SESSION_CB_ARG
    SQUID_CHECK_OPENSSL_CONST_X509_GET0_SIGNATURE_ARGS
    SQUID_CHECK_OPENSSL_TXTDB
  ])
  AS_IF([test "x$SSLLIB" = "x"],[AC_MSG_ERROR([Required OpenSSL library not found])])
])
AC_MSG_NOTICE([OpenSSL library support: ${with_openssl:=no} ${LIBOPENSSL_PATH} ${LIBOPENSSL_LIBS}])
AM_CONDITIONAL(ENABLE_SSL,[ test "x$with_openssl" = "xyes" ])
AC_SUBST(SSLLIB)

dnl User may specify MIT Kerberos is needed from a non-standard location
SQUID_AUTO_LIB(mit-krb5,[MIT Kerberos],[LIB_KRB5])
AH_TEMPLATE(USE_APPLE_KRB5,[Apple Kerberos support is available])
AH_TEMPLATE(USE_MIT_KRB5,[MIT Kerberos support is available])
AH_TEMPLATE(USE_SOLARIS_KRB5,[Solaris Kerberos support is available])

## find out if pkg-config or krb5-config will work
AS_IF([test "x$with_mit_krb5" != "xno"],[
  CXXFLAGS="$LIB_KRB5_CFLAGS $CXXFLAGS"
  krb5confpath="$with_mit_krb5/bin"
  # find installed libs via pkg-config or krb5-config
  squid_pc_krb5_name=
  PKG_CHECK_EXISTS(mit-krb5-gssapi mit-krb5, [squid_pc_krb5_name="mit-krb5-gssapi mit-krb5"],[
    PKG_CHECK_EXISTS(gssapi-krb5 krb5, [squid_pc_krb5_name="gssapi-krb5 krb5"])
  ])
  AS_IF([test "x$squid_pc_krb5_name" = "x" -a "$cross_compiling" = "no"],[
    # Look for krb5-config (unless cross-compiling)
    AC_PATH_PROG(krb5_config,krb5-config,no,$krb5confpath)
    AS_IF([test "x$ac_cv_path_krb5_config" != "xno"],[
      krb5confpath="`dirname $ac_cv_path_krb5_config`"
      ac_heimdal="`$ac_cv_path_krb5_config --version 2>/dev/null | grep -c -i heimdal`"
      ac_solaris="`$ac_cv_path_krb5_config --version 2>/dev/null | grep -c -i solaris`"
      ac_apple="`$ac_cv_path_krb5_config --vendor 2>/dev/null | grep -c -i apple`"
      AS_IF([test $ac_solaris -gt 0],[with_solaris_krb5=yes],
        [test $ac_apple -gt 0],[with_apple_krb5=yes],
        [test $ac_heimdal -gt 0],[with_mit_krb5=no]
      )
    ],[
      AS_IF([test "x$with_mit_krb5" = "xyes"],[
        AC_MSG_ERROR([Could not find krb5-config in path])
      ],[
        with_mit_krb5=no
      ])
    ])
  ])
])

# detect MIT Kerberos dependencies (except on Solaris)
AS_IF([test "x$with_mit_krb5" != "xno" -a "x$with_solaris_krb5" != "xyes"],[
  SQUID_STATE_SAVE([squid_krb5_save])
  LIBS="$LIBS $LIB_KRB5_PATH"

  # auto-detect using pkg-config
  PKG_CHECK_MODULES([LIB_KRB5], $squid_pc_krb5_name,,[
    # look for krb5-config (unless cross-compiling)
    AS_IF([test "$cross_compiling" = "no"],[
      AS_IF([test "x$krb5confpath" = "x"],[
        AC_PATH_PROG(krb5_config,krb5-config,no)
        AS_IF([test "x$ac_cv_path_krb5_config" != "xno"],[ac_krb5_config="$ac_cv_path_krb5_config"])
      ],[
        ac_krb5_config="$krb5confpath/krb5-config"
      ])
    ])
    AS_IF([test "x$ac_krb5_config" != "x" -a -x "$ac_krb5_config"],[
      # Get libs, etc
      AC_MSG_NOTICE([Use krb5-config to get CXXFLAGS and LIBS])
      LIB_KRB5_CFLAGS="`$ac_krb5_config --cflags krb5 2>/dev/null`"
      LIB_KRB5_LIBS="`$ac_krb5_config --libs krb5 2>/dev/null`"
      LIB_KRB5_CFLAGS="`$ac_krb5_config --cflags gssapi 2>/dev/null` $LIB_KRB5_CFLAGS"
      LIB_KRB5_LIBS="`$ac_krb5_config --libs gssapi 2>/dev/null` $LIB_KRB5_LIBS"
    ],[
      ## For some OS pkg-config is broken or unavailable.
      ## Detect libraries the hard way.

      SQUID_STATE_SAVE([squid_mit_save])
      missing_required=
      AC_MSG_NOTICE([Try to find Kerberos libraries in given path])
      AC_CHECK_LIB(com_err, [main], [LIB_KRB5_LIBS="-lcom_err $LIB_KRB5_LIBS"],[
        AC_MSG_WARN([library 'com_err' is required for MIT Kerberos])
        missing_required=yes
      ])
      LIBS=$LIB_KRB5_LIBS
      AC_CHECK_LIB(k5crypto, [main], [LIB_KRB5_LIBS="-lk5crypto $LIB_KRB5_LIBS"],[
        AC_MSG_WARN([library 'k5crypto' is required for MIT Kerberos])
        missing_required=yes
      ])
      LIBS=$LIB_KRB5_LIBS
      AC_CHECK_LIB(krb5, [main], [LIB_KRB5_LIBS="-lkrb5 $LIB_KRB5_LIBS"],[
        AC_MSG_WARN([library 'krb5' is required for MIT Kerberos])
        missing_required=yes
      ])
      LIBS=$LIB_KRB5_LIBS
      AC_CHECK_LIB(gssapi_krb5, [main], [LIB_KRB5_LIBS="-lgssapi_krb5 $LIB_KRB5_LIBS"],[
        AC_MSG_WARN([library 'gssapi_krb5' is required for MIT Kerberos])
        missing_required=yes
      ])
      SQUID_STATE_ROLLBACK([squid_mit_save])
      AS_IF([test "x$missing_required" = "xyes"],[LIB_KRB5_LIBS=""])
    ])
  ])

  AS_IF([test "x$LIB_KRB5_LIBS" != "x"],[
    AS_IF([test "x$with_apple_krb5" = "xyes"],[
      AC_DEFINE(USE_APPLE_KRB5,1,[Apple Kerberos support is available])
      KRB5_FLAVOUR="Apple"
    ],[
      AC_DEFINE(USE_MIT_KRB5,1,[MIT Kerberos support is available])
      KRB5_FLAVOUR="MIT"
    ])
    KRB5LIBS="$LIB_KRB5_PATH $LIB_KRB5_LIBS $KRB5LIBS"
    KRB5INCS="$LIB_KRB5_CFLAGS"

    # check for other specific broken implementations
    CXXFLAGS="$CXXFLAGS $KRB5INCS"
    LIBS="$LIBS $KRB5LIBS"

    AC_MSG_NOTICE([Try to find Kerberos headers in given path])
    AC_CHECK_HEADERS(gssapi.h gssapi/gssapi.h gssapi/gssapi_krb5.h)
    AC_CHECK_HEADERS(gssapi/gssapi_generic.h)
    AC_CHECK_HEADERS(krb5.h com_err.h et/com_err.h)
    AC_CHECK_HEADERS(profile.h)

    SQUID_CHECK_KRB5_FUNCS
  ])
  AS_IF([test "x$with_mit_krb5" = "xyes" -a "x$KRB5LIBS" = "x"],[
    AC_MSG_ERROR([Required Kerberos library not found])
  ],[test "x$KRB5LIBS" = "x"],[
    with_mit_krb5=no
    with_apple_krb5=no
  ])
  SQUID_STATE_ROLLBACK([squid_krb5_save])
])

# detect Solaris Kerberos dependencies
AS_IF([test "x$with_solaris_krb5" = "xyes" -a "x$KRB5LIBS" = "x"],[
  SQUID_STATE_SAVE([squid_krb5_save])
  LIBS="$LIBS $LIB_KRB5_PATH"

  # no pkg-config for solaris native Kerberos
  # look for krb5-config (unless cross-compiling)
  AS_IF([test "$cross_compiling" = "no"],[
    AS_IF([test "x$krb5confpath" = "x"],[
      AC_PATH_PROG(krb5_config,krb5-config,no)
      AS_IF([test "x$ac_cv_path_krb5_config" != "xno"],[ac_krb5_config="$ac_cv_path_krb5_config"])
    ],[
      ac_krb5_config="$krb5confpath/krb5-config"
    ])
  ])
  AS_IF([test "x$ac_krb5_config" != "x" -a -x "$ac_krb5_config"],[
    # Get libs, etc
    AC_MSG_NOTICE([Use krb5-config to get CXXFLAGS and LIBS])
    LIB_KRB5_CFLAGS="`$ac_krb5_config --cflags krb5 2>/dev/null`"
    LIB_KRB5_LIBS="`$ac_krb5_config --libs krb5 2>/dev/null`"
    # Solaris 10 Update 11 patches the krb5-config tool to produce stderr messages on stdout.
    SOLARIS_BROKEN_KRB5CONFIG_GSSAPI="`$ac_krb5_config --libs gssapi 2>/dev/null | grep "krb5-config"`"
    AS_IF([test "x$SOLARIS_BROKEN_KRB5CONFIG_GSSAPI" = "x"],[
      LIB_KRB5_CFLAGS="`$ac_krb5_config --cflags gssapi 2>/dev/null` $LIB_KRB5_CFLAGS"
      LIB_KRB5_LIBS="`$ac_krb5_config --libs gssapi 2>/dev/null` $LIB_KRB5_LIBS"
    ])
  ],[
    ## For some OS pkg-config is broken or unavailable.
    ## Detect libraries the hard way.

    CXXFLAGS="-I/usr/include/kerberosv5 $CXXFLAGS"

    SQUID_STATE_SAVE([squid_solaris_save])
    missing_required=
    AC_MSG_NOTICE([Try to find Kerberos libraries in given path])
    AC_CHECK_LIB(krb5, [main], [LIB_KRB5_LIBS="-lkrb5 $LIB_KRB5_LIBS"],[
      AC_MSG_WARN([library 'krb5' is required for Solaris Kerberos])
        missing_required=yes
    ])
    LIBS=$LIB_KRB5_LIBS
    AC_CHECK_LIB(gss, [main], [LIB_KRB5_LIBS="-lgss $LIB_KRB5_LIBS"],[
      AC_MSG_WARN([library 'gss' is required for Solaris Kerberos])
        missing_required=yes
    ])
    SQUID_STATE_ROLLBACK([squid_solaris_save])
    AS_IF([test "x$missing_required" = "xyes"],[LIB_KRB5_LIBS=""])
  ])

  AS_IF([test "x$LIB_KRB5_LIBS" != "x"],[
    KRB5LIBS="$LIB_KRB5_PATH $LIB_KRB5_LIBS $KRB5LIBS"
    KRB5INCS="$LIB_KRB5_CFLAGS"
    AC_DEFINE(USE_SOLARIS_KRB5,1,[Solaris Kerberos support is available])
    KRB5_FLAVOUR="Solaris"

    # check for other specific broken implementations
    CXXFLAGS="$CXXFLAGS $KRB5INCS"
    LIBS="$LIBS $KRB5LIBS"

    AC_MSG_NOTICE([Try to find Kerberos headers in given path])
    AC_CHECK_HEADERS(gssapi/gssapi.h gssapi/gssapi_ext.h)
    AC_CHECK_HEADERS(krb5.h com_err.h)

    SQUID_CHECK_KRB5_SOLARIS_BROKEN_KRB5_H
    AS_IF([test "x$squid_cv_broken_krb5_h" = "xyes"],[
      AC_DEFINE(HAVE_BROKEN_SOLARIS_KRB5_H, 1, [Define to 1 if Solaris krb5.h is broken for C++])
      AC_MSG_WARN([You have a broken Solaris <krb5.h> system include.])
      AC_MSG_WARN([Please see http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6837512])
      AC_MSG_WARN([If you need Kerberos support you will have to patch])
      AC_MSG_WARN([your system. See contrib/solaris/solaris-krb5-include.patch])
    ])
    SQUID_CHECK_KRB5_FUNCS
  ])
  AS_IF([test "x$with_mit_krb5" = "xyes" -a "x$KRB5LIBS" = "x"],[
    # Error only if Solaris flavour was detected while looking for required MIT Kerberos
    AC_MSG_ERROR([Required Kerberos library not found])
  ],[test "x$KRB5LIBS" = "x"],[
    with_solaris_krb5=no
    with_mit_krb5=no
  ])
  SQUID_STATE_ROLLBACK([squid_krb5_save])
])

# Kerberos support libraries: Heimdal
SQUID_AUTO_LIB(heimdal-krb5,[Heimdal Kerberos],[LIBHEIMDAL_KRB5])
SQUID_CHECK_LIB_WORKS(heimdal-krb5,[
  AS_IF([test "x$KRB5LIBS" = "x"],[
    SQUID_STATE_SAVE(squid_heimdal_krb5_save)
    PKG_CHECK_MODULES([LIBHEIMDAL_KRB5],[heimdal-krb5 heimdal-gssapi],[
      CPPFLAGS="$LIBHEIMDAL_KRB5_CFLAGS $CPPFLAGS"
      AC_CHECK_HEADERS(gssapi.h gssapi/gssapi.h gssapi/gssapi_krb5.h)
      AC_CHECK_HEADERS(krb5.h com_err.h et/com_err.h)

      LIBS="$LIBHEIMDAL_KRB5_PATH $LIBHEIMDAL_KRB5_LIBS $LIBS"
      SQUID_CHECK_KRB5_HEIMDAL_BROKEN_KRB5_H
      SQUID_CHECK_KRB5_FUNCS
    ],[:])
    SQUID_STATE_ROLLBACK(squid_heimdal_krb5_save)
  ])
])

# Kerberos support libraries: GNU GSS
SQUID_AUTO_LIB(gss,[GNU gss],[LIBGSS])
SQUID_CHECK_LIB_WORKS(gss,[
  AS_IF([test "x$KRB5LIBS" = "x" -a "x$LIBHEIMDAL_KRB5_LIBS" = "x"],[
    SQUID_STATE_SAVE(squid_gss_save)
    PKG_CHECK_MODULES([LIBGSS],[gss],[
      CPPFLAGS="$LIBGSS_CFLAGS $CPPFLAGS"
      AC_CHECK_HEADERS(gss.h)
      LIBS="$LIBGSS_PATH $LIBS"
      SQUID_CHECK_WORKING_GSSAPI
      SQUID_DEFINE_BOOL(HAVE_GSSAPI,$squid_cv_working_gssapi,[GSSAPI support])
      SQUID_CHECK_SPNEGO_SUPPORT
      SQUID_DEFINE_BOOL(HAVE_SPNEGO,$squid_cv_have_spnego,[SPNEGO support])
      SQUID_CHECK_WORKING_KRB5
      SQUID_DEFINE_BOOL(HAVE_KRB5,$squid_cv_working_krb5,[KRB5 support])
    ],[:])
    SQUID_STATE_ROLLBACK(squid_gss_save)
  ])
])

AS_IF([test "x$KRB5LIBS" != "x"],[with_krb5=yes])
AC_MSG_NOTICE([$KRB5_FLAVOUR Kerberos library support: ${with_krb5:=no} ${LIB_KRB5_PATH} ${LIB_KRB5_LIBS}])
AC_SUBST(KRB5INCS)
AC_SUBST(KRB5LIBS)

SQUID_AUTO_LIB(ldap,[LDAP],[LIBLDAP])
SQUID_CHECK_LIB_WORKS(ldap,[
  dnl On MinGW OpenLDAP is not available, so LDAP helpers can be linked
  dnl only with Windows LDAP libraries using -lwldap32
  AS_IF([test "$squid_host_os" = "mingw"],[
    LIBLDAP_LIBS="-lwldap32"
  ],[
    SQUID_STATE_SAVE(squid_ldap_state)
    LIBS="$LIBLDAP_PATH $LIBPTHREADS $LIBS"
    PKG_CHECK_MODULES([LIBLDAP],[ldap],[],[
      AC_CHECK_LIB(lber, ber_init, [LIBLBER="-llber"])
      AC_CHECK_LIB(ldap, ldap_init, [LIBLDAP_LIBS="-lldap $LIBLBER"])
      dnl if no ldap lib found check for mozilla version
      AS_IF([test "x$ac_cv_lib_ldap_ldap_init" != "xyes"],[
        SQUID_STATE_SAVE(squid_ldap_mozilla)
        LIBS="$LIBLDAP_PATH $LIBPTHREADS"
        AC_CHECK_LIB(ldap60, ldap_init, [LIBLDAP_LIBS="-lldap60 $LIBLBER"])
        LIBS="$LIBLDAP_PATH $LIBLDAP_LIBS $LIBPTHREADS"
        AC_CHECK_LIB(prldap60, prldap_init, [LIBLDAP_LIBS="-lprldap60 $LIBLDAP_LIBS"])
        LIBS="$LIBLDAP_PATH $LIBLDAP_LIBS $LIBPTHREADS"
        AC_CHECK_LIB(ssldap60, ldapssl_init, [LIBLDAP_LIBS="-lssldap60 $LIBLDAP_LIBS"])
        SQUID_STATE_ROLLBACK(squid_ldap_mozilla)
      ])
    ])
    AC_CHECK_HEADERS(ldap.h lber.h)
    AC_CHECK_HEADERS(mozldap/ldap.h)
    SQUID_CHECK_LDAP_API
  ])
])

SQUID_AUTO_LIB(systemd,[systemd API for start-up notification],[LIBSYSTEMD])
AH_TEMPLATE(USE_SYSTEMD,[systemd support is available])
SQUID_CHECK_LIB_WORKS(systemd,[
  SQUID_STATE_SAVE(squid_systemd_state)
  LIBS="$LIBS $LIBSYSTEMD_PATH"
  PKG_CHECK_MODULES(LIBSYSTEMD,[libsystemd],,[
    # systemd < 209
    PKG_CHECK_MODULES(LIBSYSTEMD,[libsystemd-daemon],,[:])
  ])
  AC_CHECK_HEADERS(systemd/sd-daemon.h)
  SQUID_STATE_ROLLBACK(squid_systemd_state)

  AS_IF([test "x$LIBSYSTEMD_LIBS" != "x"],[
    AC_DEFINE(USE_SYSTEMD,1,[systemd support is available])
  ])
])

AC_ARG_ENABLE(forw-via-db,
  AS_HELP_STRING([--enable-forw-via-db],[Enable Forw/Via database]), [
  SQUID_YESNO([$enableval],[--enable-forw-via-db])
])
SQUID_DEFINE_BOOL(USE_FORW_VIA_DB,${enable_forw_via_db:=no},
                      [Enable Forw/Via database])
AC_MSG_NOTICE([Forw/Via database enabled: $enable_forw_via_db])

AC_ARG_ENABLE(cache-digests,
  AS_HELP_STRING([--enable-cache-digests],
   [Use Cache Digests. See https://wiki.squid-cache.org/SquidFaq/CacheDigests]),[
  SQUID_YESNO([$enableval],[--enable-cache-digests])
])
SQUID_DEFINE_BOOL(USE_CACHE_DIGESTS,${enable_cache_digests:=no},
  [Use Cache Digests for locating objects in neighbor caches.])
AC_MSG_NOTICE([Cache Digests enabled: $enable_cache_digests])


################################
# check for netio plugin stuff #
################################
dnl order of these options handling is relevant in case the user
dnl supplies more than one --enable option. Options handled later
dnl override those handled earlier for io loop method manual override
AC_ARG_ENABLE(select,
  AS_HELP_STRING([--disable-select],[Disable select(2) support.]),[
  SQUID_YESNO([$enableval],[--enable-select])
  AS_IF([test "x$enableval" = "xyes"],[squid_opt_io_loop_engine="select"])
])
AC_MSG_NOTICE([enabling select syscall for net I/O: ${enable_select:=auto}])

AC_ARG_ENABLE(poll,
  AS_HELP_STRING([--disable-poll],[Disable poll(2) support.]),[
  SQUID_YESNO([$enableval],[--enable-poll])
  AS_IF([test "x$enableval" = "xyes"],[squid_opt_io_loop_engine="poll"])
])
AC_MSG_NOTICE([enabling poll syscall for net I/O: ${enable_poll:=auto}])

AC_ARG_ENABLE(kqueue,
  AS_HELP_STRING([--disable-kqueue],
                 [Disable kqueue(2) support.]), [
  SQUID_YESNO([$enableval],[--enable-kqueue])
])
AS_IF([test "x${enable_kqueue:=auto}" != "xno"],[
  AC_CHECK_HEADERS([sys/event.h],[],[
    AS_IF([test "x${enable_kqueue}" = "xyes"],[
      AC_MSG_ERROR([kqueue support requires sys/event.h header file.])
    ])
  ])
  AC_CHECK_FUNCS(kqueue,[],[
    AS_IF([test "x${enable_kqueue}" = "xyes"],[
      AC_MSG_ERROR([kqueue support missing in libc library.])
    ])
  ])
  AS_IF([test "x$ac_cv_func_kqueue" = "xyes" -a "x$ac_cv_header_sys_event_h" = "xyes"],[
    squid_opt_io_loop_engine="kqueue"
  ],[
    enable_kqueue="no"
  ])
])
AC_MSG_NOTICE([enabling kqueue for net I/O: ${enable_kqueue:=auto}])

dnl Enable epoll()
AC_ARG_ENABLE(epoll,
  AS_HELP_STRING([--disable-epoll],[Disable Linux epoll(2) support.]),
[
  SQUID_YESNO([$enableval],[--enable-epoll])
AS_IF([test "x$enableval" = "xyes"],[squid_opt_io_loop_engine="epoll"])
])
AC_MSG_NOTICE([enabling epoll syscall for net I/O: ${enable_epoll:=auto}])

# auto-detect and verify epoll header and library present and working
# logic mapping and loop method selection are performed later
AS_IF([test "x$enable_epoll" != "xno"],[
  # check if libs are needed to support epoll
  SQUID_STATE_SAVE(squid_epoll_state)
  AC_SEARCH_LIBS(epoll_ctl,[epoll])
  AS_IF([test "x$ac_cv_search_epoll_ctl" = "xno"],[enable_epoll=no],
    [test "x$ac_cv_search_epoll_ctl" = "xnone required"],[EPOLL_LIBS=""],
    [EPOLL_LIBS=$ac_cv_search_epoll_ctl]
  )
  AC_SUBST(EPOLL_LIBS)
  SQUID_STATE_ROLLBACK(squid_epoll_state) #de-pollute LIBS

  # epoll requires sys/epoll.h
  AC_CHECK_HEADERS([sys/epoll.h])

  dnl Verify that epoll really works
  AS_IF([test "x$ac_cv_search_epoll_ctl" != "xno"], SQUID_CHECK_EPOLL)

  AS_IF([test "x$enable_epoll" = "xyes" -a "x$squid_cv_epoll_works" = "xno"],[
    AC_MSG_ERROR([Epoll does not work. Force-enabling it is not going to help.])
  ])
])

dnl Enable /dev/poll
AC_ARG_ENABLE(devpoll,
  AS_HELP_STRING([--disable-devpoll],[Disable Solaris /dev/poll support.]),[
  SQUID_YESNO([$enableval],[--enable-devpoll])
  AS_IF([test "x$enableval" = "xyes"],[squid_opt_io_loop_engine="devpoll"])
])
AC_MSG_NOTICE([enabling /dev/poll for net I/O: ${enable_devpoll:=auto}])

## auto-detect and verify devpoll header and library present and working
AS_IF([test "x$enable_devpoll" != "xno"],[
  # /dev/poll requires ioctl() and write()
  AC_CHECK_FUNCS(ioctl)
  AC_CHECK_FUNCS(write)

  # /dev/poll requires sys/devpoll.h
  AC_CHECK_HEADERS([sys/devpoll.h],,[
    AS_IF([test "x$enable_devpoll" = "xyes"],[
      AC_MSG_ERROR([--enable-devpoll specified but /dev/poll headers not found])
    ])
    enable_devpoll=no
  ])

  # Verify that /dev/poll really works
  AS_IF([test "x$enable_devpoll" != "xno"], SQUID_CHECK_DEVPOLL)

  AS_IF([test "x$enable_devpoll" = "xyes" -a "x$squid_cv_devpoll_works" = "xno"],[
    AC_MSG_ERROR([/dev/poll does not work. Force-enabling it is not going to help.])
  ])
])

AC_ARG_ENABLE(http-violations,
  AS_HELP_STRING([--disable-http-violations],
                 [This allows you to remove code which is known to
                  violate the HTTP protocol specification.]), [
  SQUID_YESNO([$enableval],[--enable-http-violations])
])
SQUID_DEFINE_BOOL(USE_HTTP_VIOLATIONS, ${enable_http_violations:=yes},
  [Define to enable code which volates the HTTP standard specification])
AC_MSG_NOTICE([HTTP violations support enabled: $enable_http_violations])

# IPFW Transparent Proxy
AC_ARG_ENABLE(ipfw-transparent,
  AS_HELP_STRING([--enable-ipfw-transparent],
                 [Enable Transparent Proxy support for systems
                  using FreeBSD IPFW-style firewalling.]), [
  SQUID_YESNO([$enableval],[--enable-ipfw-transparent])
])
SQUID_DEFINE_BOOL(IPFW_TRANSPARENT,${enable_ipfw_transparent:=no},
  [Enable support for Transparent Proxy on systems using FreeBSD IPFW-style firewalling.])
AC_MSG_NOTICE([FreeBSD IPFW-based transparent proxying enabled: $enable_ipfw_transparent])

# IP-Filter Transparent Proxy
AC_ARG_ENABLE(ipf-transparent,
  AS_HELP_STRING([--enable-ipf-transparent],
     [Enable Transparent Proxy support using IPFilter-style firewalling]), [
  SQUID_YESNO([$enableval],[--enable-ipf-transparent])
])
#will be AC_DEFINEd later, after checking for appropriate infrastructure
#IPF currently broken. Default-disabled for now.
AC_MSG_NOTICE([IPF-based transparent proxying requested: ${enable_ipf_transparent:=no}])

dnl Enable PF Transparent Proxy
AC_ARG_ENABLE(pf-transparent,
  AS_HELP_STRING([--enable-pf-transparent],
    [Enable Transparent Proxy support for systems using PF network address redirection.]), [
  SQUID_YESNO([$enableval],[--enable-pf-transparent])
])
#will be AC_DEFINEd later, after checking for appropriate infrastructure
AC_MSG_NOTICE([PF-based transparent proxying requested: ${enable_pf_transparent:=no}])

dnl Enable /dev/pf support for older PF Transparent Proxy systems (OpenBSD 4.x and older)
AC_ARG_WITH(nat-devpf,
  AS_HELP_STRING([--with-nat-devpf],
    [Enable /dev/pf support for NAT on older OpenBSD and FreeBSD kernels.]), [
  SQUID_YESNO([$withval],[--with-nat-devpf])
])
#will be AC_DEFINEd later, after checking for appropriate infrastructure
AC_MSG_NOTICE([NAT lookups via /dev/pf: ${with_nat_devpf:=no}])

# Linux Netfilter Transparent Proxy
AC_ARG_ENABLE(linux-netfilter,
  AS_HELP_STRING([--enable-linux-netfilter],
                 [Enable Transparent Proxy support for Linux (Netfilter)]), [
  SQUID_YESNO([$enableval],[--enable-linux-netfilter])
])
AC_MSG_NOTICE([Linux Netfilter support requested: ${enable_linux_netfilter:=auto}])
#will be AC_DEFINEd later, after checking for appropriate infrastructure


dnl Look for libnetfilter_conntrack options (needed for QOS netfilter marking)
SQUID_AUTO_LIB(netfilter-conntrack,[Netfilter conntrack],[LIBNETFILTER_CONNTRACK])
SQUID_CHECK_LIB_WORKS(netfilter-conntrack,[
  LDFLAGS="$LIBNETFILTER_CONNTRACK_PATH $LDFLAGS"
  CPPFLAGS="$LIBNETFILTER_CONNTRACK_CFLAGS $CPPFLAGS"
  AC_SEARCH_LIBS([nfct_query],[netfilter_conntrack],[LIBNETFILTER_CONNTRACK_LIBS="-lnetfilter_conntrack"])
  AC_CHECK_HEADERS([ \
    libnetfilter_conntrack/libnetfilter_conntrack.h \
    libnetfilter_conntrack/libnetfilter_conntrack_tcp.h
  ],,[LIBNETFILTER_CONNTRACK_LIBS=""])
])

dnl Enable Large file support
buildmodel=""

AC_ARG_WITH(large-files,
  AS_HELP_STRING([--with-large-files],[Enable support for large files (logs etc).]), [
  SQUID_YESNO([$withval],[--with-large-files])
  squid_opt_enable_large_files=$withval
])

dnl UNIX Build environment
dnl AS_HELP_STRING is not suited here because it cannot to specify newlines
AC_ARG_WITH(build-environment,
 AS_HELP_STRING([--with-build-environment=model],
     [The build environment to use. Normally one of
      POSIX_V6_ILP32_OFF32 (32 bits),
      POSIX_V6_ILP32_OFFBIG (32 bits with large file support),
      POSIX_V6_LP64_OFF64 (64 bits),
      POSIX_V6_LPBIG_OFFBIG (large pointers and files),
      XBS5_ILP32_OFF32 i(legacy, 32 bits),
      XBS5_ILP32_OFFBIG (legacy, 32 bits with large file support),
      XBS5_LP64_OFF64 (legacy, 64 bits),
      XBS5_LPBIG_OFFBIG (legacy, large pointers and files)
      or default (The default for your OS)]), [
  AS_CASE(["$withval"],
    [yes|no],[AC_MSG_FAILURE([--with-build-environment expects a build environment string as used by getconf])],
    [buildmodel="$withval"]
  )
])

#hack. Let's early-detect sizeof(long)
AC_CHECK_SIZEOF(long)

AS_IF([test "x$squid_opt_enable_large_files" = "xyes" -a "x$buildmodel" = "x"],[
  for model in POSIX_V6_LPBIG_OFFBIG XBS5_LPBIG_OFFBIG POSIX_V6_LP64_OFF64 XBS5_LP64_OFF64 POSIX_V6_ILP32_OFFBIG XBS5_ILP32_OFFBIG; do
    AS_IF([test "`getconf _$model 2>/dev/null || true`" = 1 -o "`getconf $model 2>/dev/null || true`"],[
      buildmodel=$model
      break
    ])
  done
  AS_IF([test "x$buildmodel" = "x"],[
    AC_MSG_WARN([No suitable build environment found for large files. Trying to use _FILE_OFFSET_BITS=64])
  ])
])
AS_IF([test "x$buildmodel" = "xdefault" -o "x$buildmodel" = "x"],[
  # define _FILE_OFFSET_BITS if requested and needed
  AS_IF([test "x$squid_opt_enable_large_files" = "xyes" -a $ac_cv_sizeof_long -le 4],[
    AC_MSG_NOTICE([Enabling -D_FILE_OFFSET_BITS=64])
    CFLAGS="-D_FILE_OFFSET_BITS=64 $CFLAGS"
    CXXFLAGS="-D_FILE_OFFSET_BITS=64 $CXXFLAGS"
  ])
],[
  AC_MSG_NOTICE([Using $buildmodel build environment])
  AS_IF([ ! test "`getconf _$buildmodel 2>/dev/null || true`" = 1 -o "`getconf $buildmodel 2>/dev/null || true`"],[
    AC_MSG_ERROR([Build environment $buildmodel not known to getconf.])
  ])
  CFLAGS="`getconf ${buildmodel}_CFLAGS` $CFLAGS"
  CXXFLAGS="`getconf ${buildmodel}_CFLAGS` $CXXFLAGS"
  LIBS="`getconf ${buildmodel}_LIBS` $LIBS"
  LDFLAGS="`getconf ${buildmodel}_LDFLAGS` $LDFLAGS"

  AS_IF([test "x$squid_host_os" = "xsolaris"],[
# On Solaris getconf returns for CFLAGS -xarch=generic64, -Xa and -Usun options, and
# for LDFLAGS -xarch=generic64, but:
#   "-Xa" is supported only by Sun cc, so we need to remove it when using gcc
#   For gcc "-xarch=generic64" must be replaced with "-m64"
#   The 'sun' define is needed by ipfilter includes, so we must remove "-Usun"
    AS_IF([test "x$GCC" = "xyes"],[
      AC_MSG_NOTICE([Removing -Xa for gcc/g++ on $host])
      CFLAGS="`echo $CFLAGS | sed -e 's/-Xa//'`"
      CXXFLAGS="`echo $CXXFLAGS | sed -e 's/-Xa//'`"
      AC_MSG_NOTICE([Replacing -xarch=generic64 with -m64 for gcc/g++ on $host])
      CFLAGS="`echo $CFLAGS | sed -e 's/-xarch=generic64/-m64/'`"
      CXXFLAGS="`echo $CXXFLAGS | sed -e 's/-xarch=generic64/-m64/'`"
      LDFLAGS="`echo $LDFLAGS | sed -e 's/-xarch=generic64//'`"
    ])
    AC_MSG_NOTICE([Removing -Usun on $host])
    CFLAGS="`echo $CFLAGS | sed -e 's/-Usun//'`"
    CXXFLAGS="`echo $CXXFLAGS | sed -e 's/-Usun//'`"
  ])
])

AC_ARG_ENABLE(follow-x-forwarded-for,
  AS_HELP_STRING([--disable-follow-x-forwarded-for],
                 [Do not follow the X-Forwarded-For
                 HTTP header to try to find the IP address of the
                 original or indirect client when a request has
                 been forwarded through other proxies.]), [
  SQUID_YESNO([$enableval],[--enable-follow-x-forwarded-for])
])
AC_MSG_NOTICE([Support for X-Forwarded-For enabled: ${enable_follow_x_forwarded_for:=yes}])
SQUID_DEFINE_BOOL(FOLLOW_X_FORWARDED_FOR,$enable_follow_x_forwarded_for,
  [Enable following X-Forwarded-For headers])

AC_ARG_ENABLE(ident-lookups,
  AS_HELP_STRING([--disable-ident-lookups],
                 [Remove code that supports performing Ident (RFC 931) lookups.]), [
  SQUID_YESNO([$enableval],[--enable-ident-lookups])
])
AC_MSG_NOTICE([Support for Ident lookups enabled: ${enable_ident_lookups:=yes}])
SQUID_DEFINE_BOOL(USE_IDENT,$enable_ident_lookups,[Support for Ident (RFC 931) lookups])

dnl Select Default hosts file location
AC_ARG_ENABLE(default-hostsfile,
  AS_HELP_STRING([--enable-default-hostsfile=path],
                 [Select default location for hosts file.
                  See hosts_file directive in squid.conf for details]), [
  # TODO: handle the "yes" case cleanly
  AS_CASE(["$enableval"],
    [no|none],[squid_opt_default_hosts="none"],
    [
      squid_opt_default_hosts=$enableval
      AS_IF([ ! test -f "$enableval"],[
        AC_MSG_WARN([Unable to find file $enableval. I hope you know what you are doing.])
      ])
    ])
])
AC_MSG_NOTICE([Default hosts file set to: ${squid_opt_default_hosts:=/etc/hosts}])
DEFAULT_HOSTS=$squid_opt_default_hosts
AC_SUBST(DEFAULT_HOSTS)

# Select auth schemes modules to build
AC_ARG_ENABLE(auth,
  AS_HELP_STRING([--disable-auth],
                 [Do not support authentication. When supported, the list of schemes
                  and helpers to be enabled is defined elsewhere]), [
  SQUID_YESNO([$enableval],[--enable-auth])
])
AC_MSG_NOTICE([Authentication support enabled: ${enable_auth:=yes}])
SQUID_DEFINE_BOOL(USE_AUTH,$enable_auth,[Enable support for authentication])
AM_CONDITIONAL(ENABLE_AUTH, test "x$enable_auth" != "xno")
AUTH_MODULES=""
require_smblib="no"
require_sspi="no"

AC_ARG_ENABLE(auth-basic,
  AS_HELP_STRING([--enable-auth-basic="list of helpers"],
     [Enable the basic authentication scheme, and build the specified helpers.
      Not providing an explicit list of helpers will attempt build of
      all possible helpers. Default is to do so.
      To disable the basic authentication scheme, use --disable-auth-basic.
      To enable but build no helpers, specify "none".
      To see available helpers, see the src/auth/basic/ directory. ]),[
#nothing to do really
])
m4_include([src/auth/basic/helpers.m4])

AC_ARG_ENABLE(auth-digest,
  AS_HELP_STRING([--enable-auth-digest="list of helpers"],
     [Enable the Digest authentication scheme, and build the specified helpers.
      Not providing an explicit list of helpers will attempt build of
      all possible helpers. Default is to do so.
      To disable the Digest authentication scheme, use --disable-auth-digest.
      To enable but build no helpers, specify "none".
      To see available helpers, see the src/auth/digest/ directory. ]),[
#nothing to do, really
])
m4_include([src/auth/digest/helpers.m4])

AC_ARG_ENABLE(auth-negotiate,
  AS_HELP_STRING([--enable-auth-negotiate="list of helpers"],
     [Enable the Negotiate authentication scheme, and build the specified
      helpers.
      Not providing an explicit list of helpers will attempt build of
      all possible helpers. Default is to do so.
      To disable the Negotiate authentication scheme,
      use --disable-auth-negotiate.
      To enable but build no helpers, specify "none".
      To see available helpers, see the src/auth/negotiate/ directory. ]),[
#nothing to do, really
])
m4_include([src/auth/negotiate/helpers.m4])

AC_ARG_ENABLE(auth-ntlm,
  AS_HELP_STRING([--enable-auth-ntlm="list of helpers"],
     [Enable the NTLM authentication scheme, and build the specified helpers.
      Not providing an explicit list of helpers will attempt build of
      all possible helpers. Default is to do so.
      To disable the NTLM authentication scheme, use --disable-auth-ntlm.
      To enable but build no helpers, specify "none".
      To see available helpers, see the src/auth/ntlm/ directory. ]),[
])
m4_include([src/auth/ntlm/helpers.m4])

dnl Authentication libraries to build
dnl This list will not be needed when each auth library has its own Makefile
dnl this is to be placed AFTER each auth module's handler
AUTH_LIBS_TO_BUILD=
for module in $AUTH_MODULES; do
    AUTH_LIBS_TO_BUILD="$AUTH_LIBS_TO_BUILD ${module}/lib${module}.la"
done
AC_SUBST(AUTH_MODULES)
AC_SUBST(AUTH_LIBS_TO_BUILD)
AM_CONDITIONAL(ENABLE_SMBLIB, test "x$require_smblib" = "xyes")
AM_CONDITIONAL(ENABLE_SSPI, test "x$require_sspi" = "xyes")

dnl Select logging daemon helpers to build
AC_ARG_ENABLE(log-daemon-helpers,
  AS_HELP_STRING([--enable-log-daemon-helpers="list of helpers"],
                 [This option selects which logging daemon helpers to
                  build and install as part of the normal build process
                  For a list of available helpers see the src/log/
                  directory.]),[
#nothing to do, really
])
m4_include([src/log/helpers.m4])

AC_ARG_ENABLE(external-acl-helpers,
  AS_HELP_STRING([--enable-external-acl-helpers="list of helpers"],
                 [Enable external_acl helpers support and the helpers themselves.
                  Default is to build all buildable helpers and enable support.
                  To disable support, use --disable-external-acl-helpers.
                  To build no helpers, specify "none".
                  To see available helpers, see the src/acl/external/
                  directory]), [
#nothing to do, really
])
m4_include([src/acl/external/helpers.m4])

dnl Select url_rewrite helpers to build
AC_ARG_ENABLE(url-rewrite-helpers,
  AS_HELP_STRING([--enable-url-rewrite-helpers="list of helpers"],
                 [This option selects which url_rewrite helpers to
                  build and install as part of the normal build
                  process. The default is to attempt the build of all possible
                  helpers. Use --disable-url-rewrite-helpers to build none.
                  For a list of available helpers see the
                  src/http/url_rewriters/ directory.]),[
])
m4_include([src/http/url_rewriters/helpers.m4])

dnl Select security helpers to build
AC_ARG_ENABLE(security-cert-validators,
  AS_HELP_STRING([--enable-security-cert-validators="list of helpers"],
                 [This option selects which security certificate validator
                  helpers to build and install as part of the normal build
                  process. The default is to attempt the build of all possible
                  helpers. Use --disable-security-cert-validators to
                  build none. For a list of available helpers see the
                  src/security/cert_validators/ directory.]),[
])
m4_include([src/security/cert_validators/helpers.m4])

AC_ARG_ENABLE(security-cert-generators,
  AS_HELP_STRING([--enable-security-cert-generators="list of helpers"],
                 [This option selects which security certificate validator
                  helpers to build and install as part of the normal build
                  process. The default is to attempt the build of all possible
                  helpers. Use --disable-security-cert-genrators to
                  build none. For a list of available helpers see the
                  src/security/cert_generators/ directory.]),[
])
m4_include([src/security/cert_generators/helpers.m4])

dnl Select storeid_rewrite helpers to build
AC_ARG_ENABLE(storeid-rewrite-helpers,
  AS_HELP_STRING([--enable-storeid-rewrite-helpers="list of helpers"],
                 [This option selects which Store-ID rewrite helpers to
                  build and install as part of the normal build
                  process. The default is to attempt the build of all possible
                  helpers. Use --disable-storeid-rewrite-helpers to build none.
                  For a list of available helpers see the
                  src/store/id_rewriters/ directory.]),[
])
m4_include([src/store/id_rewriters/helpers.m4])

AC_ARG_WITH(valgrind-debug,
  AS_HELP_STRING([--with-valgrind-debug],
                 [Include debug instrumentation for use with valgrind]),
[
  SQUID_YESNO([$withval],[--with-valgrind-debug])
  AS_IF([test "x$withval" != "xno"],[
    AC_CHECK_HEADERS(valgrind/memcheck.h,[],[
      AC_MSG_ERROR([Valgrind support requested, needed headers not found.])
    ])
  ])
])
SQUID_DEFINE_BOOL(WITH_VALGRIND,${with_valgrind_debug:=no},
                  [Valgrind memory debugger support])
AC_MSG_NOTICE([Valgrind debug support enabled: $with_valgrind_debug])

dnl Enable WIN32 Service compile mode
AC_ARG_ENABLE(win32-service,
  AS_HELP_STRING([--enable-win32-service],
                 [Compile Squid as a WIN32 Service.
                  Works only on MS-Windows platforms]), [
  SQUID_YESNO([$enableval],[--enable-win32-service])
])
SQUID_DEFINE_BOOL(USE_WIN32_SERVICE,${enable_win32_service:=no},
   [Enable code supporting MS Windows service mode])
AC_MSG_NOTICE([MS Windows service mode enabled: $enable_win32_service])


# Disable "unlinkd" code
AC_ARG_ENABLE(unlinkd,
  AS_HELP_STRING([--disable-unlinkd],[Do not use unlinkd]), [
  SQUID_YESNO([$enableval],[--enable-unlinkd])
])
SQUID_DEFINE_BOOL(USE_UNLINKD,${enable_unlinkd:=yes},
                      [Enable useage of unlinkd])
AM_CONDITIONAL(ENABLE_UNLINKD,test "x$enable_unlinkd" = "xyes")
AC_MSG_NOTICE([unlinkd enabled: $enable_unlinkd])

# Enable backtraces on fatal errors
AC_ARG_ENABLE(stacktraces,
  AS_HELP_STRING([--enable-stacktraces],
                 [Enable automatic call backtrace on fatal errors]), [
  SQUID_YESNO([$enableval],[--enable-stacktraces])
])
SQUID_DEFINE_BOOL(PRINT_STACK_TRACE,${enable_stacktraces:=no},
                      [Print stack traces on fatal errors])
AC_MSG_NOTICE([Automatically print stack trace on fatal errors: $enable_stacktraces])

# Enable X-Accelerator-Vary for Vary support within an accelerator setup
AC_ARG_ENABLE(x-accelerator-vary,
  AS_HELP_STRING([--enable-x-accelerator-vary],
                 [Enable support for the X-Accelerator-Vary
                  HTTP header. Can be used to indicate
                  variance within an accelerator setup.
                  Typically used together with other code
                  that adds custom HTTP headers to the requests.]), [
  SQUID_YESNO([$enableval],[--enable-x-accelerator-vary])
])
SQUID_DEFINE_BOOL(X_ACCELERATOR_VARY,${enable_x_accelerator_vary:=no},
                      [Enable support for the X-Accelerator-Vary HTTP header])
AC_MSG_NOTICE([X-Accelerator-Vary support enabled: $enable_x_accelerator_vary])

SQUID_AUTO_LIB(cppunit,[cppunit test framework],[LIBCPPUNIT])
SQUID_CHECK_LIB_WORKS(cppunit,[
  PKG_CHECK_MODULES([LIBCPPUNIT],[cppunit],[
    squid_cv_cppunit_version="`pkg-config --modversion cppunit`"
    AC_MSG_NOTICE([using system installed cppunit version $squid_cv_cppunit_version])
    AS_UNSET(squid_cv_cppunit_version)

    SQUID_STATE_SAVE(squid_cppunit_state)
    CXXFLAGS="${CXXFLAGS} ${LIBCPPUNIT_CFLAGS}"
    LIBS="${LIBS} ${LIBCPPUNIT_LIBS}"
    AC_CHECK_HEADERS(cppunit/extensions/HelperMacros.h)
    SQUID_STATE_ROLLBACK(squid_cppunit_state)
  ],[
    AC_MSG_WARN([cppunit does not appear to be installed. Squid does not require this, but code testing with 'make check' will fail.])
  ])
])

dnl Check for headers
AC_CHECK_HEADERS( \
  arpa/inet.h \
  arpa/nameser.h \
  assert.h \
  bstring.h \
  crypt.h \
  ctype.h \
  direct.h \
  dirent.h \
  errno.h \
  execinfo.h \
  fcntl.h \
  fnmatch.h \
  getopt.h \
  glob.h \
  gnumalloc.h \
  grp.h \
  ipl.h \
  libc.h \
  limits.h \
  linux/posix_types.h \
  linux/types.h \
  malloc.h \
  math.h \
  memory.h \
  mount.h \
  netdb.h \
  netinet/in.h \
  netinet/in_systm.h \
  netinet/tcp.h \
  paths.h \
  poll.h \
  priv.h \
  pwd.h \
  regex.h \
  sched.h \
  siginfo.h \
  signal.h \
  stdarg.h \
  stddef.h \
  stdio.h \
  stdlib.h \
  string.h \
  strings.h \
  sys/bitypes.h \
  sys/file.h \
  sys/ioctl.h \
  sys/ipc.cc \
  sys/param.h \
  sys/prctl.h \
  sys/procctl.h \
  sys/md5.h \
  sys/mman.h \
  sys/msg.h \
  sys/resource.h \
  sys/select.h \
  sys/shm.h \
  sys/socket.h \
  sys/stat.h \
  syscall.h \
  sys/syscall.h \
  sys/time.h \
  sys/types.h \
  sys/uio.h \
  sys/un.h \
  sys/vfs.h \
  sys/wait.h \
  syslog.h \
  time.h \
  unistd.h \
  utime.h \
  varargs.h \
  byteswap.h \
  glib.h \
  stdint.h \
  inttypes.h \
  wchar.h
)

AC_CHECK_HEADERS( \
  linux/netfilter_ipv4.h \
  linux/netfilter_ipv6/ip6_tables.h \
,,,
SQUID_DEFAULT_INCLUDES
#if HAVE_LIMITS_H
#include <limits.h>
#endif
/* Netfilter ip(6)tables v1.4.0 has broken headers */
#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
)

dnl *BSD do not include the dependencies for all their net/ and netinet/ files
dnl We must include a few basic type headers for them to work.
AC_CHECK_HEADERS( \
  net/if.h \
  netinet/if_ether.h\
  netinet/icmp6.h \
  netinet/in.h \
  netinet/ip.h \
  netinet/ip6.h \
  netinet/ip_icmp.h \
  netinet/ipl.h \
  net/pf/pfvar.h \
  net/pfvar.h \
  sys/mount.h\
  resolv.h \
,,,
SQUID_BSDNET_INCLUDES)

AC_C_CONST
AC_C_BIGENDIAN

AC_CHECK_MEMBERS([struct tm.tm_gmtoff],,,[
#if HAVE_TIME_H
#include <time.h>
#endif
])

AC_CHECK_TYPE(struct rusage,AC_DEFINE(HAVE_STRUCT_RUSAGE,1,[The system provides struct rusage]),,[
#if HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#if HAVE_SYS_RESOURCE_H
#include <sys/resource.h>
#endif
])

AC_CHECK_MEMBERS([struct iphdr.ip_hl],,,[
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#if defined (__linux__) || defined (__CYGWIN__)
#define ip_hl ihl
#endif
#ifndef __linux__
#ifndef __CYGWIN__
#define iphdr ip
#endif
#endif])

dnl Check for typedefs
AC_CHECK_SIZEOF(void *)

# check for a bunch of types
AC_TYPE_INT8_T
AC_TYPE_UINT8_T
AC_TYPE_INT16_T
AC_TYPE_UINT16_T
AC_TYPE_INT32_T
AC_TYPE_UINT32_T
AC_TYPE_INT64_T
AC_TYPE_UINT64_T
AC_TYPE_PID_T
AC_TYPE_SIZE_T
AC_TYPE_SSIZE_T
AC_TYPE_OFF_T
AC_TYPE_UID_T
AC_CHECK_TYPE([bool])
#need the defines for PRId64
AC_CHECK_SIZEOF(int64_t)
AC_CHECK_SIZEOF(long)
#need the define for overflow checks
AC_CHECK_SIZEOF(off_t)
AC_CHECK_SIZEOF(size_t)

dnl On Solaris 9 x86, gcc may includes a "fixed" set of old system include files
dnl that is incompatible with the updated Solaris header files.
dnl For this reason, we must check if pad128_t and upad128_t are defined.
AC_CHECK_TYPE(pad128_t,
  AC_DEFINE(HAVE_PAD128_T,1,[pad128_t is defined in system headers]),
  ,SQUID_DEFAULT_INCLUDES)

AC_CHECK_TYPE(upad128_t,
  AC_DEFINE(HAVE_UPAD128_T,1,[upad128_t is defined in system headers]),
  ,SQUID_DEFAULT_INCLUDES)

AC_CHECK_TYPE(mode_t, AC_DEFINE(HAVE_MODE_T,1,[mode_t is defined by the system headers]),,SQUID_DEFAULT_INCLUDES)
AC_CHECK_TYPE(fd_mask,  AC_DEFINE(HAVE_FD_MASK,1,[fd_mask is defined by the system headers]),,SQUID_DEFAULT_INCLUDES)

AC_CHECK_TYPE(socklen_t,AC_DEFINE(HAVE_SOCKLEN_T,1,[socklen_t is defined by the system headers]),,[
#include <sys/types.h>
#include <sys/socket.h>
#include <stdlib.h>
#include <stddef.h>
])

AC_CHECK_TYPE(mtyp_t,AC_DEFINE(HAVE_MTYP_T,1,
   [mtyp_t is defined by the system headers]),,[#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>])

AC_CHECK_TYPE(cpu_set_t,
   AC_DEFINE(HAVE_CPU_SET_T,1,[cpu_set_t is defined by the system headers]),,[
#if HAVE_SCHED_H
#include <sched.h>
#endif
])

dnl Check for special functions
AC_FUNC_ALLOCA

SQUID_AUTO_LIB(cap,[Linux capabilities],[LIBCAP])
SQUID_CHECK_LIB_WORKS(cap,[
  SQUID_STATE_SAVE(squid_libcap_state)
  CXXFLAGS="$LIBCAP_CFLAGS $CXXFLAGS"
  LDFLAGS="$LIBCAP_PATH $LDFLAGS"
  PKG_CHECK_MODULES([LIBCAP],[libcap >= 2.09],[],[
    # cap_clear_flag is the most recent libcap function we require
    AC_CHECK_LIB([cap],[cap_clear_flag],[LIBCAP_LIBS="$LIBCAP_LIBS -lcap"])
  ])
  SQUID_CHECK_FUNCTIONAL_LIBCAP2
  AC_MSG_NOTICE([libcap headers are ok: $squid_cv_sys_capability_works])
  AS_IF([test "x$squid_cv_sys_capability_works" = "xno"],[LIBCAP_LIBS=""])
  SQUID_STATE_ROLLBACK(squid_libcap_state)

  AS_IF([test "x$LIBCAP_LIBS" != "x"],[
    AC_DEFINE(USE_LIBCAP,1,[Linux capabilities library support])
  ])
])

dnl Check for needed libraries
AC_SEARCH_LIBS([gethostbyname],[nsl resolv bind])
AC_SEARCH_LIBS([res_init],[resolv])
AC_SEARCH_LIBS([__res_search],[resolv])
AC_SEARCH_LIBS([bind],[socket])
AC_SEARCH_LIBS([opcom_stack_trace],[opcom_stack])
AC_SEARCH_LIBS([yp_match], [nsl nss_nis nss_nisplus])

# check that we have unix sockets
SQUID_CHECK_UNIX_SOCKET
SQUID_DEFINE_BOOL(HAVE_UNIXSOCKET,$squid_cv_unixsocket,[System supports unix sockets])

AC_CHECK_LIB(gnumalloc, malloc)
AS_IF([test "x$ac_cv_lib_gnumalloc_malloc" = "xyes"],[
  AC_MSG_NOTICE([Disabling extended malloc functions when using bundled gnumalloc])
  ac_cv_func_mallocblksize=no
  ac_cv_func_mallopt=no
],[
  AS_CASE(["$squid_host_os"],
    [solaris],[AC_MSG_NOTICE([skipping libmalloc check for $host])],
    [freebsd],[AC_MSG_NOTICE([skipping libmalloc check for $host])],
    [AC_CHECK_LIB(malloc, main)]
  )
])

AS_IF([test "$squid_host_os" = "mingw"],[
  AC_MSG_NOTICE([Use MSVCRT for math functions.])
],[
  dnl log() are only used in old C code for now.
  AC_LANG_PUSH([C])
  AC_SEARCH_LIBS([log],[m])
  AC_LANG_POP([C])
])

dnl --with-maxfd present for compatibility with Squid-2.
dnl undocumented in ./configure --help  to encourage using the Squid-3 directive
AC_ARG_WITH(maxfd,,[
  AS_CASE([$withval],
    [@<:@0-9@:>@*],[
      squid_filedescriptors_num=$withval
      AC_MSG_NOTICE([forcing default of $squid_filedescriptors_num filedescriptors (user-forced)])
    ],
    [AC_MSG_ERROR(--with-maxfd expects a numeric argument)]
  )
])

AC_ARG_WITH(filedescriptors,
  AS_HELP_STRING([--with-filedescriptors=NUMBER],
    [Force squid to support NUMBER filedescriptors]),[
  AS_CASE([$withval],
    [@<:@0-9@:>@*],[
      squid_filedescriptors_num=$withval
      AC_MSG_NOTICE([forcing default of $squid_filedescriptors_num filedescriptors (user-forced)])],
    [AC_MSG_ERROR([--with-filedescriptors expects a numeric argument])]
  )
])

SQUID_CHECK_DEFAULT_FD_SETSIZE
SQUID_CHECK_MAXFD


dnl Enable IPv6 support
AC_MSG_CHECKING([whether to enable IPv6])
AC_ARG_ENABLE(ipv6,
  AS_HELP_STRING([--disable-ipv6],[Disable IPv6 support. The default is to probe system capabilities on startup.]), [
  SQUID_YESNO([$enableval],[--enable-ipv6])
])
AC_MSG_RESULT(${enable_ipv6:=yes})
SQUID_DEFINE_BOOL(USE_IPV6,$enable_ipv6,[Enable support for IPv6 ])

AS_IF([test "x$enable_ipv6" = "xyes"],[SQUID_CHECK_SIN6_LEN_IN_SAI])
SQUID_CHECK_SS_LEN_IN_SOCKADDR_STORAGE
SQUID_CHECK_SIN_LEN_IN_SOCKADDR_IN

dnl System-specific library modifications
AH_TEMPLATE(GETTIMEOFDAY_NO_TZP,[Whether gettimeofday takes only one argument])
AS_CASE(["$host"],
  [*-pc-sco3.2*],[
    # -lintl is needed on SCO version 3.2v4.2 for strftime()
    # Robert Side <rside@aiinc.bc.ca>
    # Mon, 18 Jan 1999 17:48:00 GMT
    AC_CHECK_LIB(intl, strftime)
  ],

  [i386-*-solaris2.*],[
    AS_IF([test "x$GCC" = "xyes"],[
      AC_MSG_NOTICE([Removing -O for gcc on $host])
      CFLAGS="`echo $CFLAGS | sed -e 's/-O[[0-9g]]*//'`"
    ])
  ],

  [*-sgi-irix*],[
    AC_MSG_NOTICE([Removing -lsocket for IRIX...])
    LIBS=`echo $LIBS | sed -e s/-lsocket//`
    AC_MSG_NOTICE([Removing -lnsl for IRIX...])
    LIBS=`echo $LIBS | sed -e s/-lnsl//`
    ac_cv_lib_nsl_main=no
  ],

  [*-ibm-aix*],[
    SQUID_CC_REQUIRE_ARGUMENT([ac_cv_require_rtti],[-rtti],[[
#include <assert.h>
#ifndef NULL
#define NULL 0
#endif
class Foo{
public:virtual ~Foo(){}
};
class Bar:public Foo{
public:Bar():Foo(){}
};
      ]],[[
Foo * myFoo=new Bar();
Bar * myBar=dynamic_cast<Bar *>(myFoo);
assert(myBar != NULL);
      ]])
    AS_IF([test "$ac_cv_require_rtti" = "yes"],[
      SQUID_CFLAGS="-rtti $SQUID_CFLAGS"
      SQUID_CXXFLAGS="-rtti $SQUID_CXXFLAGS"
    ])

    AC_LANG_PUSH([C])
    SQUID_CC_REQUIRE_ARGUMENT([ac_cv_require_qcpluscmt],[-qcpluscmt],[[]],[[//c++ cmt]])
    AC_LANG_POP([C])
    AS_IF([test "$ac_cv_require_qcpluscmt" = "yes"],[
      SQUID_CFLAGS="-qcpluscmt $SQUID_CFLAGS"
    ])
  ],

  [*-*-solaris2.[[0-4]]],[AC_DEFINE(GETTIMEOFDAY_NO_TZP,1)],

  [*-sony-newsos[[56]]*],[AC_DEFINE(GETTIMEOFDAY_NO_TZP,1)]
)

dnl This has to be before AC_CHECK_FUNCS
# Disable poll() on certain platforms. Override by setting ac_cv_func_poll
# when running configure.
AS_IF([test "x$ac_cv_func_poll" = "x"],[
  AS_CASE(["$host"],
    [*-hp-hpux*.*],[
      # Duane Wessels
      AC_MSG_NOTICE([disabling poll for $host...])
      ac_cv_func_poll='no'
    ],

    [*-linux-*],[
      # Henrik Nordstrom (hno@squid-cache.org) 19980817
      # poll is problematic on Linux.  We disable it
      # by default until Linux gets it right.
      rev=`uname -r | awk -F. '{printf "%03d%03d",$1,$2}'`
      AS_IF([test $rev -lt 002002],[
          AC_MSG_NOTICE([disabling poll for $host < 2.2...])
          ac_cv_func_poll='no'
      ])
    ],

    [powerpc-ibm-aix4.1.*],[
      # Mike Laster (mlaster@metavillage.com) 19981021
      AC_MSG_NOTICE([disabling poll for $host...])
      ac_cv_func_poll='no'
    ]
  )
])

dnl Check for library functions
AC_CHECK_FUNCS(\
	backtrace_symbols_fd \
	bcopy \
	eui64_aton \
	fchmod \
	getdtablesize \
	getpagesize \
	getpass \
	getrusage \
	getspnam \
	gettimeofday \
	glob \
	mallocblksize \
	mallopt \
	memcpy \
	memmove \
	memrchr \
	memset \
	mkstemp \
	mktime \
	mstats \
	poll \
	prctl \
	procctl \
	pthread_attr_setschedparam \
	pthread_attr_setscope \
	pthread_setschedparam \
	pthread_sigmask \
	putenv \
	regcomp \
	regexec \
	regfree \
	res_init \
	__res_init \
	rint \
	sched_getaffinity \
	sched_setaffinity \
	select \
	seteuid \
	setgroups \
	setpflags \
	setpgrp \
	setsid \
	setresuid \
	sigaction \
	snprintf \
	socketpair \
	sysconf \
	syslog \
	timegm \
	vsnprintf \
)
dnl ... and some we provide local replacements for
AC_REPLACE_FUNCS(\
	initgroups \
	psignal \
	strerror \
	strtoll \
	tempnam \
)

# Magic which checks whether we are forcing a type of comm loop we
# are actually going to (ab)use.
# Mostly ripped from squid-commloops, thanks to adrian and benno

AS_IF([test "x$squid_opt_io_loop_engine" != "x"],
  AC_MSG_NOTICE([choosing user-specified net I/O API $squid_opt_io_loop_engine]),
  [test "x$enable_epoll" != "xno" -a "x$squid_cv_epoll_works" = "xyes"],
  squid_opt_io_loop_engine="epoll",
  [test "x$enable_kqueue" != "xno"],
  squid_opt_io_loop_engine="kqueue",
  [test "x$enable_devpoll" != "xno"],
  squid_opt_io_loop_engine="devpoll",
  [test "x$enable_poll" != "xno" -a "x$ac_cv_func_poll" = "xyes"],
  squid_opt_io_loop_engine="poll",
  [test "x$enable_select" != "xno" -a "x$ac_cv_func_select" = "xyes"],
  squid_opt_io_loop_engine="select",
  [
    AC_MSG_WARN([Eep!  Cannot find epoll, kqueue, /dev/poll, poll or select!])
    AC_MSG_WARN([Will try select and hope for the best.])
    squid_opt_io_loop_engine="select"
  ]
)

AC_MSG_NOTICE([Using ${squid_opt_io_loop_engine} for the IO loop.])

AM_CONDITIONAL(ENABLE_POLL, test "x$squid_opt_io_loop_engine" = "xpoll")
AM_CONDITIONAL(ENABLE_EPOLL, test "x$squid_opt_io_loop_engine" = "xepoll")
AM_CONDITIONAL(ENABLE_SELECT, test "x$squid_opt_io_loop_engine" = "xselect")
AM_CONDITIONAL(ENABLE_KQUEUE, test "x$squid_opt_io_loop_engine" = "xkqueue")
AM_CONDITIONAL(ENABLE_DEVPOLL, test "x$squid_opt_io_loop_engine" = "xdevpoll")

AS_CASE([$squid_opt_io_loop_engine],
  [epoll],[AC_DEFINE(USE_EPOLL,1,[Use epoll() for the IO loop])],
  [devpoll],[AC_DEFINE(USE_DEVPOLL,1,[Use /dev/poll for the IO loop])],
  [poll],[AC_DEFINE(USE_POLL,1,[Use poll() for the IO loop])],
  [kqueue],[AC_DEFINE(USE_KQUEUE,1,[Use kqueue() for the IO loop])],
  [select],[AC_DEFINE(USE_SELECT,1,[Use select() for the IO loop])],
)

AS_IF([test "x$ac_cv_func_sched_getaffinity" = "xyes" -a "x$ac_cv_func_sched_setaffinity" = "xyes"],[
  AC_DEFINE(HAVE_CPU_AFFINITY,1,[Support setting CPU affinity for workers])
])

AC_CHECK_HEADERS(mswsock.h)
AC_MSG_CHECKING([for constant CMSG_SPACE])
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
  #if HAVE_SYS_SOCKET_H
  #include <sys/socket.h>
  #endif
  #if HAVE_MSWSOCK_H
  #include <mswsock.h>
  #endif

  int a[CMSG_SPACE(int)];
]])], [
  AC_MSG_RESULT(yes)
  AC_DEFINE(HAVE_CONSTANT_CMSG_SPACE, 1, [Define to 1 if CMSG_SPACE is constant])
], [
  AC_MSG_RESULT(no)
])

AC_CHECK_TYPE(struct cmsghdr,AC_DEFINE(HAVE_CMSGHDR,1,[The system provides struct cmsghdr]),,[
  #if HAVE_SYS_SOCKET_H
  #include <sys/socket.h>
  #endif
  #if HAVE_MSWSOCK_H
  #include <mswsock.h>
  #endif
  #if HAVE_WINSOCK2_H
  #include <winsock2.h>
  #endif
])

AC_CHECK_TYPE(struct iovec,AC_DEFINE(HAVE_IOVEC,1,[The system provides struct iovec]),,[
  #if HAVE_SYS_SOCKET_H
  #include <sys/socket.h>
  #endif
  #if HAVE_WINSOCK2_H
  #include <winsock2.h>
  #endif
  #if HAVE_SYS_UIO_H
  #include <sys/uio.h>
  #endif
])

AC_CHECK_TYPE(struct msghdr,AC_DEFINE(HAVE_MSGHDR,1,[The system provides struct msghdr]),,[
  #if HAVE_SYS_SOCKET_H
  #include <sys/socket.h>
  #endif
  #if HAVE_MSWSOCK_H
  #include <mswsock.h>
  #endif
  #if HAVE_WINSOCK2_H
  #include <winsock2.h>
  #endif
])

AC_CHECK_TYPE(struct sockaddr_un,AC_DEFINE(HAVE_SOCKADDR_UN,1,[The system provides sockaddr_un]),,[
  #if HAVE_SYS_UN_H
  #include <sys/un.h>
  #endif
  #if HAVE_SYS_SOCKET_H
  #include <sys/socket.h>
  #endif
  #if HAVE_WINSOCK2_H
  #include <winsock2.h>
  #endif
])

SQUID_CHECK_FUNC_STRNSTR

dnl IP-Filter support requires ipf header files. These aren't
dnl installed by default, so we need to check for them
AS_IF([test "x$enable_ipf_transparent" != "xno"],[
  SQUID_CHECK_BROKEN_SOLARIS_IPFILTER
  AC_MSG_CHECKING(for availability of IP-Filter header files)
  # hold on to your hats...
  AS_IF(
  [test "x$ac_cv_header_ip_compat_h" = "xyes" -o \
    "x$ac_cv_header_ip_fil_compat_h" = "xyes" -o \
    "x$ac_cv_header_netinet_ip_compat_h" = "xyes" -o \
    "x$ac_cv_header_netinet_ip_fil_compat_h" = "xyes"],
  [have_ipfilter_compat_header="yes"])

  AS_IF(
  [test "x$have_ipfilter_compat_header" = "xyes" -a \
    "x$ac_cv_header_ip_fil_h" = "xyes" -a \
    "x$ac_cv_header_ip_nat_h" = "xyes"],[enable_ipf_transparent="yes"],

  [test "x$have_ipfilter_compat_header" = "xyes" -a \
    "x$ac_cv_header_netinet_ip_fil_h" = "xyes" -a \
    "x$ac_cv_header_netinet_ip_nat_h" = "xyes"],[enable_ipf_transparent="yes"],
  [enable_ipf_transparent="no"])

  AC_MSG_RESULT($IPF_TRANSPARENT)

## On Solaris Ipfilter includes expect that SOLARIS2 is defined with the
## Solaris minor version (8, 9, 10, ...)
  AS_IF([test "x$enable_ipf_transparent" = "xyes" -a "x$squid_host_os" = "xsolaris"],[
    solrev=`uname -r | sh -c 'IFS=. read j n x; echo $n'`
    CFLAGS="-DSOLARIS2=$solrev $CFLAGS"
    CXXFLAGS="-DSOLARIS2=$solrev $CXXFLAGS"
  ])
])
AC_MSG_NOTICE([IPF-based transparent proxying enabled: $enable_ipf_transparent])
SQUID_DEFINE_BOOL(IPF_TRANSPARENT,$enable_ipf_transparent,
    [Enable support for IPF-style transparent proxying])

dnl PF /dev/pf support requires a header file.
AS_IF([test "x$with_nat_devpf" != "xno"],[
  AS_IF([test "x$ac_cv_header_net_pfvar_h" = "xyes" -o \
    "x$ac_cv_header_net_pf_pfvar_h" = "xyes"],[
    AS_IF([test "x$with_nat_devpf" = "xauto"],[with_nat_devpf="no"])
  ],[
    AS_IF([test "x$with_nat_devpf" = "xyes"],[
      AC_MSG_ERROR([PF /dev/pf based NAT requested but needed header not found])
    ])
    with_nat_devpf="no"
  ])
])
SQUID_DEFINE_BOOL(PF_TRANSPARENT,${enable_pf_transparent:=no},
  [Enable support for PF-style transparent proxying])
SQUID_DEFINE_BOOL(USE_NAT_DEVPF,${with_nat_devpf:=no},
  [Enable support for /dev/pf NAT lookups])

AS_IF([test "x$enable_linux_netfilter" != "xno"],[
  AS_IF([test "x$ac_cv_header_linux_netfilter_ipv4_h" = "xyes"],[
    AS_IF([test "x$enable_linux_netfilter" = "xauto"],[enable_linux_netfilter=yes])
  ],[
    AS_IF([test "x$enable_linux_netfilter" = "xauto"],[
      enable_linux_netfilter=no
    ],[
      AC_MSG_ERROR([Linux Netfilter support requested but needed headers not found])
    ])
  ])
])
SQUID_DEFINE_BOOL(LINUX_NETFILTER,$enable_linux_netfilter,
  [Enable support for Transparent Proxy on Linux via Netfilter])

dnl Netfilter TPROXY depends on libcap but the NAT parts can still work.
AC_MSG_NOTICE([Support for Netfilter-based interception proxy requested: $enable_linux_netfilter])
AS_IF([test "x$enable_linux_netfilter" = "xyes" -a "x$with_cap" != "xyes"],[
  AC_MSG_WARN([Missing needed capabilities (libcap 2.09+) for TPROXY])
  AC_MSG_WARN([Linux Transparent Proxy (version 4+) support WILL NOT be enabled])
  AC_MSG_WARN([Reduced support to NAT Interception Proxy])
  # AC_DEFINEd later
])
AS_IF([test "x$with_netfilter_conntrack" = "xyes" -a "x$with_cap" != "xyes"],[
  AC_MSG_WARN([Missing needed capabilities (libcap 2.09+) for netfilter mark support])
  AC_MSG_WARN([Linux netfilter marking support WILL NOT be enabled])
  with_netfilter_conntrack=no
])
AC_MSG_NOTICE([Linux Netfilter Conntrack support enabled: ${with_netfilter_conntrack}])


AC_ARG_ENABLE(zph-qos,
  AS_HELP_STRING([--disable-zph-qos],[Disable ZPH QOS support]), [
  SQUID_YESNO([$enableval],[--enable-zph-qos])
])
SQUID_DEFINE_BOOL(USE_QOS_TOS,${enable_zph_qos:=yes},
          [Enable Zero Penalty Hit QOS. When set, Squid will alter the
           TOS field of HIT responses to help policing network traffic])
AC_MSG_NOTICE([ZPH QOS enabled: $enable_zph_qos])
AS_IF([test "x$enable_zph_qos" = "xyes"],[
  AC_MSG_NOTICE([QOS netfilter mark preservation enabled: $with_netfilter_conntrack])
  SQUID_DEFINE_BOOL(USE_LIBNETFILTERCONNTRACK,${with_netfilter_conntrack:=no},
    [Enable support for QOS netfilter mark preservation])
])

AC_CHECK_LIB(regex, regexec, [REGEXLIB="-lregex"],[REGEXLIB=''])
AC_SUBST(REGEXLIB)

SQUID_DETECT_UDP_SND_BUFSIZE
SQUID_DETECT_UDP_RECV_BUFSIZE
SQUID_DETECT_TCP_SND_BUFSIZE
SQUID_DETECT_TCP_RECV_BUFSIZE

SQUID_CHECK_NEED_SYS_ERRLIST
SQUID_CHECK_MAXPATHLEN

SQUID_CHECK_LIBRESOLV_DNS_TTL_HACK
SQUID_CHECK_RESOLVER_FIELDS

AC_CHECK_HEADERS(sys/statvfs.h)
AS_IF([test "x$ac_cv_header_sys_statvfs_h" = "xyes"],[SQUID_CHECK_WORKING_STATVFS])
AS_IF([test "x$ac_cv_func_statvfs" != "xyes"],[
  AC_CHECK_HEADERS(sys/param.h sys/mount.h sys/vfs.h sys/statfs.h)
  AC_CHECK_FUNCS(statfs)
  SQUID_CHECK_F_FRSIZE_IN_STATFS
])

dnl Squid will not usually attempt to translate templates when building
AC_ARG_ENABLE(translation,
 AS_HELP_STRING([--enable-translation],[Generate the localized error page templates and manuals.
		 Which can also be downloaded from http://www.squid-cache.org/Versions/langpack/.]), [
  SQUID_YESNO([$enableval],[--enable-translation])
])
AS_IF([test "x${enable_translation:=no}" = "xyes"],[
  AX_WITH_PROG([PO2HTML],[po2html])
  AX_WITH_PROG([PO2TEXT],[po2txt])
],[
  PO2HTML="off"
  PO2TEXT="off"
])
AC_SUBST(PO2HTML)
AC_SUBST(PO2TEXT)
AM_CONDITIONAL(ENABLE_TRANSLATION, test "x${enable_translation:=no}" = "xyes")

dnl Squid now has limited locale handling ...
dnl on error pages
AC_ARG_ENABLE(auto-locale,
 AS_HELP_STRING([--disable-auto-locale],[This prevents Squid providing localized error pages based on the
		 clients request headers.
		 When disabled Squid requires explicit language configuration.]), [
  SQUID_YESNO([$enableval],[--enable-auto-locale])
])
AC_MSG_NOTICE([Multi-Language support enabled: ${enable_auto_locale:=yes}])
SQUID_DEFINE_BOOL(USE_ERR_LOCALES,$enable_auto_locale,
   [Use multi-language support on error pages])


dnl Need the debugging version of malloc if available
XTRA_OBJS=''
AS_IF([test "x$ac_cv_lib_malloc_main" = "xyes"],[
  AS_IF([test -r /usr/lib/debug/malloc.o],[XTRA_OBJS="$XTRA_OBJS /usr/lib/debug/malloc.o"])
  AS_IF([test -r /usr/lib/debug/mallocmap.o],[XTRA_OBJS="$XTRA_OBJS /usr/lib/debug/mallocmap.o"]);
])
AC_SUBST(XTRA_OBJS)

AS_IF([test "x$XTRA_LIBS" = "x"],[
  XTRA_LIBS="$LIBS"
  dnl minor cleanup
  XTRA_LIBS=`echo $XTRA_LIBS | sed -e "s/  */ /g"`
  LIBS=''
])
AC_SUBST(XTRA_LIBS)

AC_SUBST(SQUID_CFLAGS)
AC_SUBST(SQUID_CXXFLAGS)

# Prerequisite: CXXFLAGS have been finalized.
AC_ARG_VAR([BUILDCXXFLAGS],[C++ compiler flags for building compile-time tools. e.g. cf_gen])
AS_IF([test "x$BUILDCXXFLAGS" = "x"],[
  # if we are NOT cross-compiling, use the default build flags for cf_gen and friends
  # otherwise rely on the user-provided value
  AS_IF([test "x$squid_cv_check_marchnative" = "xyes"],[
    # always valid for the Build compiler.
    BUILDCXXFLAGS="-march=native"
  ])
  BUILDCXXFLAGS="$BUILDCXXFLAGS $CXXFLAGS"
])
AC_SUBST(BUILDCXXFLAGS)

AC_MSG_NOTICE([BUILD LIBRARIES: $LIBS])
AC_MSG_NOTICE([BUILD EXTRA LIBRARIES: $XTRA_LIBS])
AC_MSG_NOTICE([BUILD OBJECTS: $OBJS])
AC_MSG_NOTICE([BUILD EXTRA OBJECTS: $XTRA_OBJS])
AC_MSG_NOTICE([BUILD C FLAGS: $CFLAGS])
AC_MSG_NOTICE([BUILD EXTRA C FLAGS: $SQUID_CFLAGS])
AC_MSG_NOTICE([BUILD C++ FLAGS: $CXXFLAGS])
AC_MSG_NOTICE([BUILD EXTRA C++ FLAGS: $SQUID_CXXFLAGS])
AC_MSG_NOTICE([BUILD Tools C++ FLAGS: $BUILDCXXFLAGS])

dnl Clean up after OSF/1 core dump bug
rm -f core

AC_CONFIG_FILES([
	Makefile
	compat/Makefile
	contrib/Makefile
	doc/Makefile
	doc/manuals/Makefile
	doc/release-notes/Makefile
	errors/Makefile
	icons/Makefile
	lib/Makefile
	lib/libTrie/Makefile
	lib/libTrie/test/Makefile
	lib/ntlmauth/Makefile
	lib/rfcnb/Makefile
	lib/smblib/Makefile
	lib/snmplib/Makefile
	lib/sspi/Makefile
	scripts/Makefile
	src/Makefile
	src/acl/Makefile
	src/acl/external/Makefile
	src/acl/external/AD_group/Makefile
	src/acl/external/delayer/Makefile
	src/acl/external/eDirectory_userip/Makefile
	src/acl/external/file_userip/Makefile
	src/acl/external/kerberos_ldap_group/Makefile
	src/acl/external/kerberos_sid_group/Makefile
	src/acl/external/LDAP_group/Makefile
	src/acl/external/LM_group/Makefile
	src/acl/external/session/Makefile
	src/acl/external/SQL_session/Makefile
	src/acl/external/unix_group/Makefile
	src/acl/external/wbinfo_group/Makefile
	src/acl/external/time_quota/Makefile
	src/adaptation/Makefile
	src/adaptation/icap/Makefile
	src/adaptation/ecap/Makefile
	src/anyp/Makefile
	src/auth/Makefile
	src/auth/basic/Makefile
	src/auth/basic/DB/Makefile
	src/auth/basic/fake/Makefile
	src/auth/basic/getpwnam/Makefile
	src/auth/basic/LDAP/Makefile
	src/auth/basic/NCSA/Makefile
	src/auth/basic/NIS/Makefile
	src/auth/basic/PAM/Makefile
	src/auth/basic/POP3/Makefile
	src/auth/basic/RADIUS/Makefile
	src/auth/basic/SASL/Makefile
	src/auth/basic/SMB/Makefile
	src/auth/basic/SMB_LM/Makefile
	src/auth/basic/SSPI/Makefile
	src/auth/digest/Makefile
	src/auth/digest/eDirectory/Makefile
	src/auth/digest/file/Makefile
	src/auth/digest/LDAP/Makefile
	src/auth/negotiate/Makefile
	src/auth/negotiate/kerberos/Makefile
	src/auth/negotiate/SSPI/Makefile
	src/auth/negotiate/wrapper/Makefile
	src/auth/ntlm/Makefile
	src/auth/ntlm/fake/Makefile
	src/auth/ntlm/SMB_LM/Makefile
	src/auth/ntlm/SSPI/Makefile
	src/base/Makefile
	src/clients/Makefile
	src/comm/Makefile
	src/debug/Makefile
	src/dns/Makefile
	src/DiskIO/Makefile
	src/DiskIO/AIO/Makefile
	src/DiskIO/Blocking/Makefile
	src/DiskIO/DiskDaemon/Makefile
	src/DiskIO/DiskThreads/Makefile
	src/DiskIO/IpcIo/Makefile
	src/DiskIO/Mmapped/Makefile
	src/error/Makefile
	src/esi/Makefile
	src/eui/Makefile
	src/format/Makefile
	src/fs/Makefile
	src/ftp/Makefile
	src/helper/Makefile
	src/html/Makefile
	src/http/Makefile
	src/http/one/Makefile
	src/http/url_rewriters/Makefile
	src/http/url_rewriters/fake/Makefile
	src/http/url_rewriters/LFS/Makefile
	src/icmp/Makefile
	src/ident/Makefile
	src/ip/Makefile
	src/ipc/Makefile
	src/log/Makefile
	src/log/DB/Makefile
	src/log/file/Makefile
	src/mem/Makefile
	src/mgr/Makefile
	src/parser/Makefile
	src/proxyp/Makefile
	src/repl/Makefile
	src/sbuf/Makefile
	src/security/Makefile
	src/security/cert_generators/Makefile
	src/security/cert_generators/file/Makefile
	src/security/cert_validators/Makefile
	src/security/cert_validators/fake/Makefile
	src/servers/Makefile
	src/snmp/Makefile
	src/ssl/Makefile
	src/store/Makefile
	src/store/id_rewriters/Makefile
	src/store/id_rewriters/file/Makefile
	src/time/Makefile
	test-suite/Makefile
	tools/Makefile
	tools/apparmor/Makefile
	tools/helper-mux/Makefile
	tools/systemd/Makefile
	tools/sysvinit/Makefile
])

# must configure libltdl subdir unconditionally for "make distcheck" to work
#AC_CONFIG_SUBDIRS(libltdl)

AC_OUTPUT