#------------------------------------------------------------------------
# SC_PATH_TCLCONFIG --
#
#	Locate the tclConfig.sh file and perform a sanity check on
#	the Tcl compile flags
#	Currently a no-op for Windows
#
# Arguments:
#	none
#
# Results:
#
#	Adds the following arguments to configure:
#		--with-tcl=...
#
#	Defines the following vars:
#		TCLCONFIG	Full path to the tclConfig.sh file
#------------------------------------------------------------------------

AC_DEFUN(SC_PATH_TCLCONFIG, [
])

#------------------------------------------------------------------------
# SC_PATH_TKCONFIG --
#
#	Locate the tkConfig.sh file
#	Currently a no-op for Windows
#
# Arguments:
#	none
#
# Results:
#
#	Adds the following arguments to configure:
#		--with-tk=...
#
#	Defines the following vars:
#		TKCONFIG	Full path to the tkConfig.sh file
#------------------------------------------------------------------------

AC_DEFUN(SC_PATH_TKCONFIG, [
])

#------------------------------------------------------------------------
# SC_LOAD_TCLCONFIG --
#
#	Load the tclConfig.sh file
#	Currently a no-op for Windows
#
# Arguments:
#	
#	Requires the following vars to be set:
#		TCLCONFIG
#
# Results:
#
#	Subst's the following vars:
#		TCL_CC
#		TCL_DEFS
#		TCL_CFLAGS
#		TCL_DBGX
#		TCL_LIBS
#		TCL_SHLIB_LD
#		SHLIB_SUFFIX
#		TCL_LD_FLAGS
#		TCL_BUILD_LIB_SPEC
#		TCL_LIB_SPEC
#		TCL_SHARED_LIB_SUFFIX
#------------------------------------------------------------------------

AC_DEFUN(SC_LOAD_TCLCONFIG, [
])

#------------------------------------------------------------------------
# SC_LOAD_TKCONFIG --
#
#	Load the tkConfig.sh file
#	Currently a no-op for Windows
#
# Arguments:
#	
#	Requires the following vars to be set:
#		TKCONFIG
#
# Results:
#
#	Subst's the following vars:
#		TK_VERSION
#		TK_DEFS
#		TK_DBGX
#		TK_LIBS
#		TK_XINCLUDES
#		TK_XLIBSW
#		TK_BUILD_LIB_SPEC
#		TK_LIB_SPEC
#------------------------------------------------------------------------

AC_DEFUN(SC_LOAD_TKCONFIG, [
])

#------------------------------------------------------------------------
# SC_ENABLE_GCC --
#
#	Allows the use of GCC if available
#
# Arguments:
#	none
#	
# Results:
#
#	Adds the following arguments to configure:
#		--enable-gcc
#
#	Defines the following vars:
#		CC	Command to use for the compiler
#------------------------------------------------------------------------

AC_DEFUN(SC_ENABLE_GCC, [
    AC_ARG_ENABLE(gcc, [  --enable-gcc            allow use of gcc if available [--disable-gcc]],
	[ok=$enableval], [ok=no])
    if test "$ok" = "yes"; then
	CC=gcc
    else
	CC=cl
    fi
])

#------------------------------------------------------------------------
# SC_ENABLE_SHARED --
#
#	Allows the building of shared libraries
#
# Arguments:
#	none
#	
# Results:
#
#	Adds the following arguments to configure:
#		--enable-shared=yes|no
#
#	Defines the following vars:
#		TCL_SHARED_BUILD	Value of 1 or 0
#		STATIC_BUILD
#------------------------------------------------------------------------

AC_DEFUN(SC_ENABLE_SHARED, [
    AC_ARG_ENABLE(shared,
	[  --enable-shared         build and link with shared libraries [--enable-shared]],
    [tcl_ok=$enableval], [tcl_ok=yes])

    if test "${enable_shared+set}" = set; then
    enableval="$enable_shared"
    tcl_ok=$enableval
    else
    tcl_ok=yes
    fi

    if test "$tcl_ok" = "yes" ; then
	TCL_SHARED_BUILD=1
    else
	TCL_SHARED_BUILD=0
	AC_DEFINE(STATIC_BUILD)
    fi

])

#------------------------------------------------------------------------
# SC_ENABLE_THREADS --
#
#	Specify if thread support should be enabled
#
# Arguments:
#	none
#	
# Results:
#
#	Adds the following arguments to configure:
#		--enable-threads=yes|no
#
#	Defines the following vars:
#		TCL_THREADS
#
#------------------------------------------------------------------------

AC_DEFUN(SC_ENABLE_THREADS, [
    AC_ARG_ENABLE(threads, [  --enable-threads        build with threads],
	[tcl_ok=$enableval], [tcl_ok=no])
    if test "$tcl_ok" = "yes"; then
	AC_DEFINE(TCL_THREADS)
	echo "building with threads enabled"
    else
	echo "building with threads disabled (default)"
    fi
])

#------------------------------------------------------------------------
# SC_ENABLE_SYMBOLS --
#
#	Specify if debugging symbols should be used
#
# Arguments:
#	none
#	
#	Requires the following vars to be set:
#		CFLAGS_DEBUG
#		CFLAGS_OPTIMIZE
#	
# Results:
#
#	Adds the following arguments to configure:
#		--enable-symbols
#
#	Defines the following vars:
#		CFLAGS_DEFAULT	Sets to CFLAGS_DEBUG if true
#				Sets to CFLAGS_OPTIMIZE if false
#		LD_FLAGS_DEFAULT	Sets to LDFLAGS_DEBUG if true
				Sets to LDFLAGS_OPTIMIZE if false
#		DBGX		Debug library extension
#
#------------------------------------------------------------------------

AC_DEFUN(SC_ENABLE_SYMBOLS, [
    AC_ARG_ENABLE(symbols, [  --enable-symbols        build with debugging symbols [--disable-symbols]],    [tcl_ok=$enableval], [tcl_ok=no])

    if test "$tcl_ok" = "yes"; then
	CFLAGS_DEFAULT='${CFLAGS_DEBUG}'
	LD_FLAGS_DEFAULT='${LDFLAGS_DEBUG}'
	DBGX=d
	echo "building with debug symbols"
    else
	CFLAGS_DEFAULT='${CFLAGS_OPTIMIZE}'
	LD_FLAGS_DEFAULT='${LDFLAGS_OPTIMIZE}'
	DBGX=""
	echo "building without debug symbols"
    fi
])


#--------------------------------------------------------------------
# SC_TCL_CONFIG_CFLAGS
#
#	Try to determine the proper flags to pass to the compiler
#	for building shared libraries and other such nonsense.
#
# Arguments:
#	none
#
# Results:
#
#	Defines the following vars:
#
#       DL_OBJS -       Name of the object file that implements dynamic
#                       loading for Tcl on this system.
#       DL_LIBS -       Library file(s) to include in tclsh and other base
#                       applications in order for the "load" command to work.
#       LD_FLAGS -      Flags to pass to the compiler when linking object
#                       files into an executable application binary such
#                       as tclsh.
#       LD_SEARCH_FLAGS-Flags to pass to ld, such as "-R /usr/local/tcl/lib",
#                       that tell the run-time dynamic linker where to look
#                       for shared libraries such as libtcl.so.  Depends on
#                       the variable LIB_RUNTIME_DIR in the Makefile.
#       MAKE_LIB -      Command to execute to build the Tcl library;
#                       differs depending on whether or not Tcl is being
#                       compiled as a shared library.
#       SHLIB_CFLAGS -  Flags to pass to cc when compiling the components
#                       of a shared library (may request position-independent
#                       code, among other things).
#       SHLIB_LD -      Base command to use for combining object files
#                       into a shared library.
#       SHLIB_LD_LIBS - Dependent libraries for the linker to scan when
#                       creating shared libraries.  This symbol typically
#                       goes at the end of the "ld" commands that build
#                       shared libraries. The value of the symbol is
#                       "${LIBS}" if all of the dependent libraries should
#                       be specified when creating a shared library.  If
#                       dependent libraries should not be specified (as on
#                       SunOS 4.x, where they cause the link to fail, or in
#                       general if Tcl and Tk aren't themselves shared
#                       libraries), then this symbol has an empty string
#                       as its value.
#       SHLIB_SUFFIX -  Suffix to use for the names of dynamically loadable
#                       extensions.  An empty string means we don't know how
#                       to use shared libraries on this platform.
#       TCL_LIB_FILE -  Name of the file that contains the Tcl library, such
#                       as libtcl7.8.so or libtcl7.8.a.
#       TCL_LIB_SUFFIX -Specifies everything that comes after the "libtcl"
#                       in the shared library name, using the $VERSION variable
#                       to put the version in the right place.  This is used
#                       by platforms that need non-standard library names.
#                       Examples:  ${VERSION}.so.1.1 on NetBSD, since it needs
#                       to have a version after the .so, and ${VERSION}.a
#                       on AIX, since the Tcl shared library needs to have
#                       a .a extension whereas shared objects for loadable
#                       extensions have a .so extension.  Defaults to
#                       ${VERSION}${SHLIB_SUFFIX}.
#       TCL_NEEDS_EXP_FILE -
#                       1 means that an export file is needed to link to a
#                       shared library.
#       TCL_EXP_FILE -  The name of the installed export / import file which
#                       should be used to link to the Tcl shared library.
#                       Empty if Tcl is unshared.
#       TCL_BUILD_EXP_FILE -
#                       The name of the built export / import file which
#                       should be used to link to the Tcl shared library.
#                       Empty if Tcl is unshared.
#	CFLAGS_DEBUG -
#			Flags used when running the compiler in debug mode
#	CFLAGS_OPTIMIZE -
#			Flags used when running the compiler in optimize mode
#--------------------------------------------------------------------

AC_DEFUN(SC_TCL_CONFIG_CFLAGS, [

    # Step 1: set the variable "system" to hold the name and version number
    # for the system.  This can usually be done via the "uname" command, but
    # there are a few systems, like Next, where this doesn't work.

    AC_MSG_CHECKING([system version (for dynamic loading)])
    if test -f /usr/lib/NextStep/software_version; then
	system=NEXTSTEP-`awk '/3/,/3/' /usr/lib/NextStep/software_version`
    else
	system=`uname -s`-`uname -r`
	if test "$?" -ne 0 ; then
	    AC_MSG_RESULT([unknown (can't find uname command)])
	    system=unknown
	else
	    # Special check for weird MP-RAS system (uname returns weird
	    # results, and the version is kept in special file).
	
	    if test -r /etc/.relid -a "X`uname -n`" = "X`uname -s`" ; then
		system=MP-RAS-`awk '{print $3}' /etc/.relid'`
	    fi
	    if test "`uname -s`" = "AIX" ; then
		system=AIX-`uname -v`.`uname -r`
	    fi
	    AC_MSG_RESULT($system)
	fi
    fi

    # Step 2: check for existence of -ldl library.  This is needed because
    # Linux can use either -ldl or -ldld for dynamic loading.

    AC_CHECK_LIB(dl, dlopen, have_dl=yes, have_dl=no)

    # Step 3: set configuration options based on system name and version.

    do64bit_ok=no
    fullSrcDir=`cd $srcdir; pwd`
    EXTRA_CFLAGS=""
    TCL_EXPORT_FILE_SUFFIX=""
    TCL_UNSHARED_LIB_SUFFIX=""
    TCL_TRIM_DOTS='`echo ${VERSION} | tr -d .`'
    ECHO_VERSION='`echo ${VERSION}`'
    TCL_LIB_VERSIONS_OK=ok
    CFLAGS_DEBUG=-g
    CFLAGS_OPTIMIZE=-O
    TCL_NEEDS_EXP_FILE=0
    TCL_BUILD_EXP_FILE=""
    TCL_EXP_FILE=""
    case $system in
	AIX-4.[[2-9]])
	    SHLIB_CFLAGS=""
	    SHLIB_LD="$fullSrcDir/ldAix /bin/ld -bhalt:4 -bM:SRE -bE:lib.exp -H512 -T512 -bnoentry"
	    SHLIB_LD_LIBS='${LIBS}'
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS="-ldl"
	    LD_FLAGS=""
	    LD_SEARCH_FLAGS='-L${LIB_RUNTIME_DIR}'
	    TCL_NEEDS_EXP_FILE=1
	    TCL_EXPORT_FILE_SUFFIX='${VERSION}\$\{DBGX\}.exp'
	    ;;
	AIX-*)
	    SHLIB_CFLAGS=""
	    SHLIB_LD="$fullSrcDir/ldAix /bin/ld -bhalt:4 -bM:SRE -bE:lib.exp -H512 -T512"
	    SHLIB_LD_LIBS='${LIBS}'
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    LIBOBJS="$LIBOBJS tclLoadAix.o"
	    DL_LIBS="-lld"
	    LD_FLAGS=""
	    LD_SEARCH_FLAGS='-L${LIB_RUNTIME_DIR}'
	    TCL_NEEDS_EXP_FILE=1
	    TCL_EXPORT_FILE_SUFFIX='${VERSION}\$\{DBGX\}.exp'
	    ;;
	BSD/OS-2.1*|BSD/OS-3*)
	    SHLIB_CFLAGS=""
	    SHLIB_LD="shlicc -r"
	    SHLIB_LD_LIBS='${LIBS}'
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS="-ldl"
	    LD_FLAGS=""
	    LD_SEARCH_FLAGS=""
	    ;;
	BSD/OS-4.*)
	    SHLIB_CFLAGS="-export-dynamic -fPIC"
	    SHLIB_LD="cc -shared"
	    SHLIB_LD_LIBS='${LIBS}'
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS="-ldl"
	    LD_FLAGS="-export-dynamic"
	    LD_SEARCH_FLAGS=""
	    ;;
	dgux*)
	    SHLIB_CFLAGS="-K PIC"
	    SHLIB_LD="cc -G"
	    SHLIB_LD_LIBS=""
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS="-ldl"
	    LD_FLAGS=""
	    LD_SEARCH_FLAGS=""
	    ;;
	HP-UX-*.08.*|HP-UX-*.09.*|HP-UX-*.10.*|HP-UX-*.11.*)
	    SHLIB_SUFFIX=".sl"
	    AC_CHECK_LIB(dld, shl_load, tcl_ok=yes, tcl_ok=no)
	    if test "$tcl_ok" = yes; then
		SHLIB_CFLAGS="+z"
		SHLIB_LD="ld -b"
		SHLIB_LD_LIBS=""
		DL_OBJS="tclLoadShl.o"
		DL_LIBS="-ldld"
		LD_FLAGS="-Wl,-E"
		LD_SEARCH_FLAGS='-Wl,+s,+b,${LIB_RUNTIME_DIR}:.'
	    fi
	    ;;
	IRIX-4.*)
	    SHLIB_CFLAGS="-G 0"
	    SHLIB_SUFFIX=".a"
	    SHLIB_LD="echo tclLdAout $CC \{$SHLIB_CFLAGS\} | `pwd`/tclsh -r -G 0"
	    SHLIB_LD_LIBS='${LIBS}'
	    DL_OBJS="tclLoadAout.o"
	    DL_LIBS=""
	    LD_FLAGS="-Wl,-D,08000000"
	    LD_SEARCH_FLAGS='-L${LIB_RUNTIME_DIR}'
	    TCL_SHARED_LIB_SUFFIX='${VERSION}\$\{DBGX\}.a'
	    ;;
	IRIX-5.*|IRIX-6.*|IRIX64-6.5*)
	    SHLIB_CFLAGS=""
	    SHLIB_LD="ld -n32 -shared -rdata_shared"
	    SHLIB_LD_LIBS=""
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS=""
	    LD_SEARCH_FLAGS='-Wl,-rpath,${LIB_RUNTIME_DIR}'
	    if test "$CC" = "gcc" -o `$CC -v 2>&1 | grep -c gcc` != "0" ; then
		EXTRA_CFLAGS="-mabi=n32"
		LD_FLAGS="-mabi=n32"
	    else
		case $system in
		    IRIX-6.3)
			# Use to build 6.2 compatible binaries on 6.3.
			EXTRA_CFLAGS="-n32 -D_OLD_TERMIOS"
			;;
		    *)
			EXTRA_CFLAGS="-n32"
			;;
		esac
		LD_FLAGS="-n32"
	    fi
	    ;;
	IRIX64-6.*)
	    SHLIB_CFLAGS=""
	    SHLIB_LD="ld -32 -shared -rdata_shared"
	    SHLIB_LD_LIBS='${LIBS}'
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS=""
	    LD_FLAGS=""
	    LD_SEARCH_FLAGS='-Wl,-rpath,${LIB_RUNTIME_DIR}'
	    ;;
	Linux*)
	    SHLIB_CFLAGS="-fPIC"
	    SHLIB_LD_LIBS='${LIBS}'
	    SHLIB_SUFFIX=".so"
	    if test "$have_dl" = yes; then
		SHLIB_LD="${CC} -shared"
		DL_OBJS="tclLoadDl.o"
		DL_LIBS="-ldl"
		LD_FLAGS="-rdynamic"
		LD_SEARCH_FLAGS='-Wl,-rpath,${LIB_RUNTIME_DIR}'
	    else
		AC_CHECK_HEADER(dld.h, [
		    SHLIB_LD="ld -shared"
		    DL_OBJS="tclLoadDld.o"
		    DL_LIBS="-ldld"
		    LD_FLAGS=""
		    LD_SEARCH_FLAGS=""])
	    fi
	    ;;
	MP-RAS-02*)
	    SHLIB_CFLAGS="-K PIC"
	    SHLIB_LD="cc -G"
	    SHLIB_LD_LIBS=""
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS="-ldl"
	    LD_FLAGS=""
	    LD_SEARCH_FLAGS=""
	    ;;
	MP-RAS-*)
	    SHLIB_CFLAGS="-K PIC"
	    SHLIB_LD="cc -G"
	    SHLIB_LD_LIBS=""
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS="-ldl"
	    LD_FLAGS="-Wl,-Bexport"
	    LD_SEARCH_FLAGS=""
	    ;;
	NetBSD-*|FreeBSD-[[12]].*|OpenBSD-*)
	    # Not available on all versions:  check for include file.
	    AC_CHECK_HEADER(dlfcn.h, [
		SHLIB_CFLAGS="-fpic"
		SHLIB_LD="ld -Bshareable -x"
		SHLIB_LD_LIBS=""
		SHLIB_SUFFIX=".so"
		DL_OBJS="tclLoadDl.o"
		DL_LIBS=""
		LD_FLAGS=""
		LD_SEARCH_FLAGS=""
		TCL_SHARED_LIB_SUFFIX='${TCL_TRIM_DOTS}\$\{DBGX\}.so.1.0'
	    ], [
		SHLIB_CFLAGS=""
		SHLIB_LD="echo tclLdAout $CC \{$SHLIB_CFLAGS\} | `pwd`/tclsh -r"
		SHLIB_LD_LIBS='${LIBS}'
		SHLIB_SUFFIX=".a"
		DL_OBJS="tclLoadAout.o"
		DL_LIBS=""
		LD_FLAGS=""
		LD_SEARCH_FLAGS='-L${LIB_RUNTIME_DIR}'
		TCL_SHARED_LIB_SUFFIX='${TCL_TRIM_DOTS}\$\{DBGX\}.a'
	    ])

	    # FreeBSD doesn't handle version numbers with dots.

	    TCL_UNSHARED_LIB_SUFFIX='${TCL_TRIM_DOTS}\$\{DBGX\}.a'
	    TCL_LIB_VERSIONS_OK=nodots
	    ;;
	FreeBSD-*)
	    # FreeBSD 3.* and greater have ELF.
	    SHLIB_CFLAGS="-fpic"
	    SHLIB_LD="ld -Bshareable -x"
	    SHLIB_LD_LIBS=""
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS=""
	    LD_FLAGS=""
	    LD_SEARCH_FLAGS=""
	    ;;
	NEXTSTEP-*)
	    SHLIB_CFLAGS=""
	    SHLIB_LD="cc -nostdlib -r"
	    SHLIB_LD_LIBS=""
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadNext.o"
	    DL_LIBS=""
	    LD_FLAGS=""
	    LD_SEARCH_FLAGS=""
	    ;;
	OS/390-*)
	    CFLAGS_OPTIMIZE=""      # Optimizer is buggy
	    AC_DEFINE(_OE_SOCKETS)  # needed in sys/socket.h
	    ;;      
	OSF1-1.0|OSF1-1.1|OSF1-1.2)
	    # OSF/1 1.[012] from OSF, and derivatives, including Paragon OSF/1
	    SHLIB_CFLAGS=""
	    # Hack: make package name same as library name
	    SHLIB_LD='ld -R -export $@:'
	    SHLIB_LD_LIBS=""
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadOSF.o"
	    DL_LIBS=""
	    LD_FLAGS=""
	    LD_SEARCH_FLAGS=""
	    ;;
	OSF1-1.*)
	    # OSF/1 1.3 from OSF using ELF, and derivatives, including AD2
	    SHLIB_CFLAGS="-fpic"
	    SHLIB_LD="ld -shared"
	    SHLIB_LD_LIBS=""
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS=""
	    LD_FLAGS=""
	    LD_SEARCH_FLAGS=""
	    ;;
	OSF1-V*)
	    # Digital OSF/1
	    SHLIB_CFLAGS=""
	    SHLIB_LD='ld -shared -expect_unresolved "*"'
	    SHLIB_LD_LIBS=""
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS=""
	    LD_FLAGS=""
	    LD_SEARCH_FLAGS='-Wl,-rpath,${LIB_RUNTIME_DIR}'
	    ;;
	RISCos-*)
	    SHLIB_CFLAGS="-G 0"
	    SHLIB_LD="echo tclLdAout $CC \{$SHLIB_CFLAGS\} | `pwd`/tclsh -r -G 0"
	    SHLIB_LD_LIBS='${LIBS}'
	    SHLIB_SUFFIX=".a"
	    DL_OBJS="tclLoadAout.o"
	    DL_LIBS=""
	    LD_FLAGS="-Wl,-D,08000000"
	    LD_SEARCH_FLAGS='-L${LIB_RUNTIME_DIR}'
	    ;;
	SCO_SV-3.2*)
	    # Note, dlopen is available only on SCO 3.2.5 and greater.  However,
	    # this test works, since "uname -s" was non-standard in 3.2.4 and
	    # below.
	    SHLIB_CFLAGS="-Kpic -belf"
	    SHLIB_LD="ld -G"
	    SHLIB_LD_LIBS=""
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS=""
	    LD_FLAGS="-belf -Wl,-Bexport"
	    LD_SEARCH_FLAGS=""
	    ;;
	SINIX*5.4*)
	    SHLIB_CFLAGS="-K PIC"
	    SHLIB_LD="cc -G"
	    SHLIB_LD_LIBS=""
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS="-ldl"
	    LD_FLAGS=""
	    LD_SEARCH_FLAGS=""
	    ;;
	SunOS-4*)
	    SHLIB_CFLAGS="-PIC"
	    SHLIB_LD="ld"
	    SHLIB_LD_LIBS=""
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS="-ldl"
	    LD_FLAGS=""
	    LD_SEARCH_FLAGS='-L${LIB_RUNTIME_DIR}'

	    # SunOS can't handle version numbers with dots in them in library
	    # specs, like -ltcl7.5, so use -ltcl75 instead.  Also, it
	    # requires an extra version number at the end of .so file names.
	    # So, the library has to have a name like libtcl75.so.1.0

	    TCL_SHARED_LIB_SUFFIX='${TCL_TRIM_DOTS}\$\{DBGX\}.so.1.0'
	    TCL_UNSHARED_LIB_SUFFIX='${TCL_TRIM_DOTS}\$\{DBGX\}.a'
	    TCL_LIB_VERSIONS_OK=nodots
	    ;;
	SunOS-5.[[0-6]]*)
	    SHLIB_CFLAGS="-KPIC"
	    SHLIB_LD="/usr/ccs/bin/ld -G -z text"

	    # Note: need the LIBS below, otherwise Tk won't find Tcl's
	    # symbols when dynamically loaded into tclsh.

	    SHLIB_LD_LIBS='${LIBS}'
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS="-ldl"
	    LD_FLAGS=""
	    LD_SEARCH_FLAGS='-Wl,-R,${LIB_RUNTIME_DIR}'
	    ;;
	SunOS-5*)
	    SHLIB_CFLAGS="-KPIC"
	    SHLIB_LD="/usr/ccs/bin/ld -G -z text"
	    LD_FLAGS=""
    
	    do64bit_ok=no
	    if test "$do64bit" = "yes" ; then
	    arch=`isainfo`
	    if test "$arch" = "sparcv9 sparc" ; then
		if test "$CC" != "gcc" -a `$CC -v 2>&1 | grep -c gcc` = "0" ; then
		do64bit_ok=yes
		EXTRA_CFLAGS="-xarch=v9"
		LD_FLAGS="-xarch=v9"
		else 
		AC_MSG_WARN("64bit mode not supported using GCC on $system")
		fi
	    else
		AC_MSG_WARN("64bit mode only supported sparcv9 system")
	    fi
	    fi
	    
	    # Note: need the LIBS below, otherwise Tk won't find Tcl's
	    # symbols when dynamically loaded into tclsh.

	    SHLIB_LD_LIBS='${LIBS}'
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS="-ldl"
	    if test "$CC" = "gcc" -o `$CC -v 2>&1 | grep -c gcc` != "0" ; then
		LD_SEARCH_FLAGS='-Wl,-R,${LIB_RUNTIME_DIR}'
	    else
		LD_SEARCH_FLAGS='-R ${LIB_RUNTIME_DIR}'
	    fi
	    ;;
	ULTRIX-4.*)
	    SHLIB_CFLAGS="-G 0"
	    SHLIB_SUFFIX=".a"
	    SHLIB_LD="echo tclLdAout $CC \{$SHLIB_CFLAGS\} | `pwd`/tclsh -r -G 0"
	    SHLIB_LD_LIBS='${LIBS}'
	    DL_OBJS="tclLoadAout.o"
	    DL_LIBS=""
	    LD_FLAGS="-Wl,-D,08000000"
	    LD_SEARCH_FLAGS='-L${LIB_RUNTIME_DIR}'
	    ;;
	UNIX_SV* | UnixWare-5*)
	    SHLIB_CFLAGS="-KPIC"
	    SHLIB_LD="cc -G"
	    SHLIB_LD_LIBS=""
	    SHLIB_SUFFIX=".so"
	    DL_OBJS="tclLoadDl.o"
	    DL_LIBS="-ldl"
	    # Some UNIX_SV* systems (unixware 1.1.2 for example) have linkers
	    # that don't grok the -Bexport option.  Test that it does.
	    hold_ldflags=$LDFLAGS
	    AC_MSG_CHECKING(for ld accepts -Bexport flag)
	    LDFLAGS="${LDFLAGS} -Wl,-Bexport"
	    AC_TRY_LINK(, [int i;], found=yes, found=no)
	    LDFLAGS=$hold_ldflags
	    AC_MSG_RESULT($found)
	    if test $found = yes; then
	    LD_FLAGS="-Wl,-Bexport"
	    else
	    LD_FLAGS=""
	    fi
	    LD_SEARCH_FLAGS=""
	    ;;
    esac

    if test "$do64bit" = "yes" -a "$do64bit_ok" = "no" ; then
    AC_MSG_WARN("64bit support being disabled -- not supported on this platform")
    fi

    # Step 4: If pseudo-static linking is in use (see K. B. Kenny, "Dynamic
    # Loading for Tcl -- What Became of It?".  Proc. 2nd Tcl/Tk Workshop,
    # New Orleans, LA, Computerized Processes Unlimited, 1994), then we need
    # to determine which of several header files defines the a.out file
    # format (a.out.h, sys/exec.h, or sys/exec_aout.h).  At present, we
    # support only a file format that is more or less version-7-compatible. 
    # In particular,
    #	- a.out files must begin with `struct exec'.
    #	- the N_TXTOFF on the `struct exec' must compute the seek address
    #	  of the text segment
    #	- The `struct exec' must contain a_magic, a_text, a_data, a_bss
    #	  and a_entry fields.
    # The following compilation should succeed if and only if either sys/exec.h
    # or a.out.h is usable for the purpose.
    #
    # Note that the modified COFF format used on MIPS Ultrix 4.x is usable; the
    # `struct exec' includes a second header that contains information that
    # duplicates the v7 fields that are needed.

    if test "x$DL_OBJS" = "xtclLoadAout.o" ; then
	AC_MSG_CHECKING(sys/exec.h)
	AC_TRY_COMPILE([#include <sys/exec.h>],[
	    struct exec foo;
	    unsigned long seek;
	    int flag;
#if defined(__mips) || defined(mips)
	    seek = N_TXTOFF (foo.ex_f, foo.ex_o);
#else
	    seek = N_TXTOFF (foo);
#endif
	    flag = (foo.a_magic == OMAGIC);
	    return foo.a_text + foo.a_data + foo.a_bss + foo.a_entry;
    ], tcl_ok=usable, tcl_ok=unusable)
	AC_MSG_RESULT($tcl_ok)
	if test $tcl_ok = usable; then
	    AC_DEFINE(USE_SYS_EXEC_H)
	else
	    AC_MSG_CHECKING(a.out.h)
	    AC_TRY_COMPILE([#include <a.out.h>],[
		struct exec foo;
		unsigned long seek;
		int flag;
#if defined(__mips) || defined(mips)
		seek = N_TXTOFF (foo.ex_f, foo.ex_o);
#else
		seek = N_TXTOFF (foo);
#endif
		flag = (foo.a_magic == OMAGIC);
		return foo.a_text + foo.a_data + foo.a_bss + foo.a_entry;
	    ], tcl_ok=usable, tcl_ok=unusable)
	    AC_MSG_RESULT($tcl_ok)
	    if test $tcl_ok = usable; then
		AC_DEFINE(USE_A_OUT_H)
	    else
		AC_MSG_CHECKING(sys/exec_aout.h)
		AC_TRY_COMPILE([#include <sys/exec_aout.h>],[
		    struct exec foo;
		    unsigned long seek;
		    int flag;
#if defined(__mips) || defined(mips)
		    seek = N_TXTOFF (foo.ex_f, foo.ex_o);
#else
		    seek = N_TXTOFF (foo);
#endif
		    flag = (foo.a_midmag == OMAGIC);
		    return foo.a_text + foo.a_data + foo.a_bss + foo.a_entry;
		], tcl_ok=usable, tcl_ok=unusable)
		AC_MSG_RESULT($tcl_ok)
		if test $tcl_ok = usable; then
		    AC_DEFINE(USE_SYS_EXEC_AOUT_H)
		else
		    DL_OBJS=""
		fi
	    fi
	fi
    fi

    # Step 5: disable dynamic loading if requested via a command-line switch.

    AC_ARG_ENABLE(load, [  --disable-load          disallow dynamic loading and "load" command],
	[tcl_ok=$enableval], [tcl_ok=yes])
    if test "$tcl_ok" = "no"; then
	DL_OBJS=""
    fi

    if test "x$DL_OBJS" != "x" ; then
	BUILD_DLTEST="\$(DLTEST_TARGETS)"
    else
	echo "Can't figure out how to do dynamic loading or shared libraries"
	echo "on this system."
	SHLIB_CFLAGS=""
	SHLIB_LD=""
	SHLIB_SUFFIX=""
	DL_OBJS="tclLoadNone.o"
	DL_LIBS=""
	LD_FLAGS=""
	LD_SEARCH_FLAGS=""
	BUILD_DLTEST=""
    fi

    # If we're running gcc, then change the C flags for compiling shared
    # libraries to the right flags for gcc, instead of those for the
    # standard manufacturer compiler.

    if test "$DL_OBJS" != "tclLoadNone.o" ; then
	if test "$CC" = "gcc" -o `$CC -v 2>&1 | grep -c gcc` != "0" ; then
	    case $system in
		AIX-*)
		    ;;
		BSD/OS*)
		    ;;
		IRIX*)
		    ;;
		NetBSD-*|FreeBSD-*|OpenBSD-*)
		    ;;
		RISCos-*)
		    ;;
		ULTRIX-4.*)
		    ;;
		*)
		    SHLIB_CFLAGS="-fPIC"
		    ;;
	    esac
	fi
    fi
])