ltconfig

PPP协议的实现演示

    hardcode_into_libs=yes
    ;;
  esac
  ;;

gnu*)
  version_type=linux
  need_lib_prefix=no
  need_version=no
  library_names_spec='${libname}${release}.so$versuffix ${libname}${release}.so${major} ${libname}.so'
  soname_spec='${libname}${release}.so$major'
  shlibpath_var=LD_LIBRARY_PATH
  hardcode_into_libs=yes
  ;;

hpux9* | hpux10* | hpux11*)
  # Give a soname corresponding to the major version so that dld.sl refuses to
  # link against other versions.
  dynamic_linker="$host_os dld.sl"
  version_type=sunos
  need_lib_prefix=no
  need_version=no
  shlibpath_var=SHLIB_PATH
  shlibpath_overrides_runpath=no # +s is required to enable SHLIB_PATH
  library_names_spec='${libname}${release}.sl$versuffix ${libname}${release}.sl$major $libname.sl'
  soname_spec='${libname}${release}.sl$major'
  # HP-UX runs *really* slowly unless shared libraries are mode 555.
  postinstall_cmds='chmod 555 $lib'
  ;;

irix5* | irix6*)
  version_type=irix
  need_lib_prefix=no
  need_version=no
  soname_spec='${libname}${release}.so.$major'
  library_names_spec='${libname}${release}.so.$versuffix ${libname}${release}.so.$major ${libname}${release}.so $libname.so'
  case "$host_os" in
  irix5*)
    libsuff= shlibsuff=
    ;;
  *)
    case "$LD" in # libtool.m4 will add one of these switches to LD
    *-32|*"-32 ") libsuff= shlibsuff= libmagic=32-bit;;
    *-n32|*"-n32 ") libsuff=32 shlibsuff=N32 libmagic=N32;;
    *-64|*"-64 ") libsuff=64 shlibsuff=64 libmagic=64-bit;;
    *) libsuff= shlibsuff= libmagic=never-match;;
    esac
    ;;
  esac
  shlibpath_var=LD_LIBRARY${shlibsuff}_PATH
  shlibpath_overrides_runpath=no
  sys_lib_search_path_spec="/usr/lib${libsuff} /lib${libsuff} /usr/local/lib${libsuff}"
  sys_lib_dlsearch_path_spec="/usr/lib${libsuff} /lib${libsuff}"
  ;;

# No shared lib support for Linux oldld, aout, or coff.
linux-gnuoldld* | linux-gnuaout* | linux-gnucoff*)
  dynamic_linker=no
  ;;

# This must be Linux ELF.
linux-gnu*)
  version_type=linux
  need_lib_prefix=no
  need_version=no
  library_names_spec='${libname}${release}.so$versuffix ${libname}${release}.so$major $libname.so'
  soname_spec='${libname}${release}.so$major'
  finish_cmds='PATH="\$PATH:/sbin" ldconfig -n $libdir'
  shlibpath_var=LD_LIBRARY_PATH
  shlibpath_overrides_runpath=no
  # This implies no fast_install, which is unacceptable.
  # Some rework will be needed to allow for fast_install
  # before this can be enabled.
  hardcode_into_libs=yes

  if test -f /lib/ld.so.1; then
    dynamic_linker='GNU ld.so'
  else
    # Only the GNU ld.so supports shared libraries on MkLinux.
    case "$host_cpu" in
    powerpc*) dynamic_linker=no ;;
    *) dynamic_linker='Linux ld.so' ;;
    esac
  fi
  ;;

netbsd*)
  version_type=sunos
  if echo __ELF__ | $CC -E - | grep __ELF__ >/dev/null; then
    library_names_spec='${libname}${release}.so$versuffix ${libname}.so$versuffix'
    finish_cmds='PATH="\$PATH:/sbin" ldconfig -m $libdir'
    dynamic_linker='NetBSD (a.out) ld.so'
  else
    library_names_spec='${libname}${release}.so$versuffix ${libname}${release}.so$major ${libname}${release}.so ${libname}.so'
    soname_spec='${libname}${release}.so$major'
    dynamic_linker='NetBSD ld.elf_so'
  fi
  shlibpath_var=LD_LIBRARY_PATH
  ;;

openbsd*)
  version_type=sunos
  if test "$with_gnu_ld" = yes; then
    need_lib_prefix=no
    need_version=no
  fi
  library_names_spec='${libname}${release}.so$versuffix ${libname}.so$versuffix'
  finish_cmds='PATH="\$PATH:/sbin" ldconfig -m $libdir'
  shlibpath_var=LD_LIBRARY_PATH
  ;;

os2*)
  libname_spec='$name'
  need_lib_prefix=no
  library_names_spec='$libname.dll $libname.a'
  dynamic_linker='OS/2 ld.exe'
  shlibpath_var=LIBPATH
  ;;

osf3* | osf4* | osf5*)
  version_type=osf
  need_version=no
  soname_spec='${libname}${release}.so'
  library_names_spec='${libname}${release}.so$versuffix ${libname}${release}.so $libname.so'
  shlibpath_var=LD_LIBRARY_PATH
  sys_lib_search_path_spec="/usr/shlib /usr/ccs/lib /usr/lib/cmplrs/cc /usr/lib /usr/local/lib /var/shlib"
  sys_lib_dlsearch_path_spec="$sys_lib_search_path_spec"
  ;;

sco3.2v5*)
  version_type=osf
  soname_spec='${libname}${release}.so$major'
  library_names_spec='${libname}${release}.so$versuffix ${libname}${release}.so$major $libname.so'
  shlibpath_var=LD_LIBRARY_PATH
  ;;

solaris*)
  version_type=linux
  need_lib_prefix=no
  need_version=no
  library_names_spec='${libname}${release}.so$versuffix ${libname}${release}.so$major $libname.so'
  soname_spec='${libname}${release}.so$major'
  shlibpath_var=LD_LIBRARY_PATH
  shlibpath_overrides_runpath=yes
  hardcode_into_libs=yes
  # ldd complains unless libraries are executable
  postinstall_cmds='chmod +x $lib'
  ;;

sunos4*)
  version_type=sunos
  library_names_spec='${libname}${release}.so$versuffix ${libname}.so$versuffix'
  finish_cmds='PATH="\$PATH:/usr/etc" ldconfig $libdir'
  shlibpath_var=LD_LIBRARY_PATH
  shlibpath_overrides_runpath=yes
  if test "$with_gnu_ld" = yes; then
    need_lib_prefix=no
  fi
  need_version=yes
  ;;

sysv4 | sysv4.2uw2* | sysv4.3* | sysv5*)
  version_type=linux
  library_names_spec='${libname}${release}.so$versuffix ${libname}${release}.so$major $libname.so'
  soname_spec='${libname}${release}.so$major'
  shlibpath_var=LD_LIBRARY_PATH
  case "$host_vendor" in
    motorola)
      need_lib_prefix=no
      need_version=no
      shlibpath_overrides_runpath=no
      sys_lib_search_path_spec='/lib /usr/lib /usr/ccs/lib'
      ;;
  esac
  ;;

uts4*)
  version_type=linux
  library_names_spec='${libname}${release}.so$versuffix ${libname}${release}.so$major $libname.so'
  soname_spec='${libname}${release}.so$major'
  shlibpath_var=LD_LIBRARY_PATH
  ;;

dgux*)
  version_type=linux
  need_lib_prefix=no
  need_version=no
  library_names_spec='${libname}${release}.so$versuffix ${libname}${release}.so$major $libname.so'
  soname_spec='${libname}${release}.so$major'
  shlibpath_var=LD_LIBRARY_PATH
  ;;

sysv4*MP*)
  if test -d /usr/nec ;then
    version_type=linux
    library_names_spec='$libname.so.$versuffix $libname.so.$major $libname.so'
    soname_spec='$libname.so.$major'
    shlibpath_var=LD_LIBRARY_PATH
  fi
  ;;

*)
  dynamic_linker=no
  ;;
esac
echo "$ac_t$dynamic_linker" 1>&6
test "$dynamic_linker" = no && can_build_shared=no

# Check for command to grab the raw symbol name followed by C symbol from nm.
echo $ac_n "checking command to parse $NM output... $ac_c" 1>&6

# These are sane defaults that work on at least a few old systems.
# [They come from Ultrix.  What could be older than Ultrix?!! ;)]

# Character class describing NM global symbol codes.
symcode='[BCDEGRST]'

# Regexp to match symbols that can be accessed directly from C.
sympat='\([_A-Za-z][_A-Za-z0-9]*\)'

# Transform the above into a raw symbol and a C symbol.
symxfrm='\1 \2\3 \3'

# Transform an extracted symbol line into a proper C declaration
global_symbol_to_cdecl="sed -n -e 's/^. .* \(.*\)$/extern char \1;/p'"

# Define system-specific variables.
case "$host_os" in
aix*)
  symcode='[BCDT]'
  ;;
cygwin* | mingw*)
  symcode='[ABCDGISTW]'
  ;;
hpux*) # Its linker distinguishes data from code symbols
  global_symbol_to_cdecl="sed -n -e 's/^T .* \(.*\)$/extern char \1();/p' -e 's/^. .* \(.*\)$/extern char \1;/p'"
  ;;
irix*)
  symcode='[BCDEGRST]'
  ;;
solaris* | sysv5*)
  symcode='[BDT]'
  ;;
sysv4)
  symcode='[DFNSTU]'
  ;;
esac

# Handle CRLF in mingw too chain
opt_cr=
case "$host_os" in
mingw*)
  opt_cr=`echo 'x\{0,1\}' | tr x '\015'` # option cr in regexp
  ;;
esac

# If we're using GNU nm, then use its standard symbol codes.
if $NM -V 2>&1 | egrep '(GNU|with BFD)' > /dev/null; then
  symcode='[ABCDGISTW]'
fi

# Try without a prefix undercore, then with it.
for ac_symprfx in "" "_"; do

  # Write the raw and C identifiers.
global_symbol_pipe="sed -n -e 's/^.*[ 	]\($symcode\)[ 	][ 	]*\($ac_symprfx\)$sympat$opt_cr$/$symxfrm/p'"

  # Check to see that the pipe works correctly.
  pipe_works=no
  $rm conftest*
  cat > conftest.c <<EOF
#ifdef __cplusplus
extern "C" {
#endif
char nm_test_var;
void nm_test_func(){}
#ifdef __cplusplus
}
#endif
main(){nm_test_var='a';nm_test_func();return(0);}
EOF

  echo "$progname:1867: checking if global_symbol_pipe works" >&5
  if { (eval echo $progname:1868: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; } && test -s conftest.$objext; then
    # Now try to grab the symbols.
    nlist=conftest.nm
    if { echo "$progname:1871: eval \"$NM conftest.$objext | $global_symbol_pipe > $nlist\"" >&5; eval "$NM conftest.$objext | $global_symbol_pipe > $nlist 2>&5"; } && test -s "$nlist"; then

      # Try sorting and uniquifying the output.
      if sort "$nlist" | uniq > "$nlist"T; then
	mv -f "$nlist"T "$nlist"
      else
	rm -f "$nlist"T
      fi

      # Make sure that we snagged all the symbols we need.
      if egrep ' nm_test_var$' "$nlist" >/dev/null; then
	if egrep ' nm_test_func$' "$nlist" >/dev/null; then
	  cat <<EOF > conftest.c
#ifdef __cplusplus
extern "C" {
#endif

EOF
	  # Now generate the symbol file.
	  eval "$global_symbol_to_cdecl"' < "$nlist" >> conftest.c'

	  cat <<EOF >> conftest.c
#if defined (__STDC__) && __STDC__
# define lt_ptr_t void *
#else
# define lt_ptr_t char *
# define const
#endif

/* The mapping between symbol names and symbols. */
const struct {
  const char *name;
  lt_ptr_t address;
}
lt_preloaded_symbols[] =
{
EOF
	  sed 's/^. \(.*\) \(.*\)$/  {"\2", (lt_ptr_t) \&\2},/' < "$nlist" >> conftest.c
	  cat <<\EOF >> conftest.c
  {0, (lt_ptr_t) 0}
};

#ifdef __cplusplus
}
#endif
EOF
	  # Now try linking the two files.
	  mv conftest.$objext conftstm.$objext
	  save_LIBS="$LIBS"
	  save_CFLAGS="$CFLAGS"
	  LIBS="conftstm.$objext"
	  CFLAGS="$CFLAGS$no_builtin_flag"
	  if { (eval echo $progname:1923: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
	    pipe_works=yes
	  else
	    echo "$progname: failed program was:" >&5
	    cat conftest.c >&5
	  fi
	  LIBS="$save_LIBS"
	else
	  echo "cannot find nm_test_func in $nlist" >&5
	fi
      else
	echo "cannot find nm_test_var in $nlist" >&5
      fi
    else
      echo "cannot run $global_symbol_pipe" >&5
    fi
  else
    echo "$progname: failed program was:" >&5
    cat conftest.c >&5
  fi
  $rm conftest* conftst*

  # Do not use the global_symbol_pipe unless it works.
  if test "$pipe_works" = yes; then
    break
  else
    global_symbol_pipe=
  fi
done
if test "$pipe_works" = yes; then
  echo "${ac_t}ok" 1>&6
else
  echo "${ac_t}failed" 1>&6
fi

if test -z "$global_symbol_pipe"; then
  global_symbol_to_cdecl=
fi

# Report the final consequences.
echo "checking if libtool supports shared libraries... $can_build_shared" 1>&6

# Only try to build win32 dlls if AC_LIBTOOL_WIN32_DLL was used in
# configure.in, otherwise build static only libraries.
case "$host_os" in
cygwin* | mingw* | os2*)
  if test x$can_build_shared = xyes; then
    test x$enable_win32_dll = xno && can_build_shared=no
    echo "checking if package supports dlls... $can_build_shared" 1>&6
  fi
;;
esac

echo $ac_n "checki