ltconfig

MPEG-4编解码的实现(包括MPEG4视音频编解码)

	# Check to see if the nm accepts a BSD-compat flag.
	# Adding the `sed 1q' prevents false positives on HP-UX, which says:
	#   nm: unknown option "B" ignored
	if ($ac_dir/nm -B /dev/null 2>&1 | sed '1q'; exit 0) | egrep /dev/null >/dev/null; then
	  NM="$ac_dir/nm -B"
	  break
	elif ($ac_dir/nm -p /dev/null 2>&1 | sed '1q'; exit 0) | egrep /dev/null >/dev/null; then
	  NM="$ac_dir/nm -p"
	  break
	else
	  NM=${NM="$ac_dir/nm"} # keep the first match, but
	  continue # so that we can try to find one that supports BSD flags
	fi
      fi
    done
    IFS="$ac_save_ifs"
    test -z "$NM" && NM=nm
    ;;
  esac
  echo "$ac_t$NM" 1>&6
fi

# 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*)
  symcode='[BDT]'
  ;;
sysv4)
  symcode='[DFNSTU]'
  ;;
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/^.*[ 	]\($symcode\)[ 	][ 	]*\($ac_symprfx\)$sympat$/$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:1653: checking if global_symbol_pipe works" >&5
  if { (eval echo $progname:1654: \"$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 "$progname:1657: eval \"$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 $progname:1709: \"$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

# Check hardcoding attributes.
echo $ac_n "checking how to hardcode library paths into programs... $ac_c" 1>&6
hardcode_action=
if test -n "$hardcode_libdir_flag_spec" || \
   test -n "$runpath_var"; then

  # We can hardcode non-existant directories.
  if test "$hardcode_direct" != no &&
     # If the only mechanism to avoid hardcoding is shlibpath_var, we
     # have to relink, otherwise we might link with an installed library
     # when we should be linking with a yet-to-be-installed one
     ## test "$hardcode_shlibpath_var" != no &&
     test "$hardcode_minus_L" != no; then
    # Linking always hardcodes the temporary library directory.
    hardcode_action=relink
  else
    # We can link without hardcoding, and we can hardcode nonexisting dirs.
    hardcode_action=immediate
  fi
else
  # We cannot hardcode anything, or else we can only hardcode existing
  # directories.
  hardcode_action=unsupported
fi
echo "$ac_t$hardcode_action" 1>&6


reload_flag=
reload_cmds='$LD$reload_flag -o $output$reload_objs'
echo $ac_n "checking for $LD option to reload object files... $ac_c" 1>&6
# PORTME Some linkers may need a different reload flag.
reload_flag='-r'
echo "$ac_t$reload_flag" 1>&6
test -n "$reload_flag" && reload_flag=" $reload_flag"

# PORTME Fill in your ld.so characteristics
library_names_spec=
libname_spec='lib$name'
soname_spec=
postinstall_cmds=
postuninstall_cmds=
finish_cmds=
finish_eval=
shlibpath_var=
shlibpath_overrides_runpath=unknown
version_type=none
dynamic_linker="$host_os ld.so"
sys_lib_dlsearch_path_spec="/lib /usr/lib"
sys_lib_search_path_spec="/lib /usr/lib /usr/local/lib"
file_magic_cmd=
file_magic_test_file=
deplibs_check_method='unknown'
# Need to set the preceding variable on all platforms that support
# interlibrary dependencies.
# 'none' -- dependencies not supported.
# `unknown' -- same as none, but documents that we really don't know.
# 'pass_all' -- all dependencies passed with no checks.
# 'test_compile' -- check by making test program.
# 'file_magic [regex]' -- check by looking for files in library path
# which responds to the $file_magic_cmd with a given egrep regex.
# If you have `file' or equivalent on your system and you're not sure
# whether `pass_all' will *always* work, you probably want this one.
echo $ac_n "checking dynamic linker characteristics... $ac_c" 1>&6
case "$host_os" in
aix3*)
  version_type=linux
  library_names_spec='${libname}${release}.so$versuffix $libname.a'
  shlibpath_var=LIBPATH

  # AIX has no versioning support, so we append a major version to the name.
  soname_spec='${libname}${release}.so$major'
  ;;

aix4*)
  version_type=linux
  # AIX has no versioning support, so currently we can not hardcode correct
  # soname into executable. Probably we can add versioning support to
  # collect2, so additional links can be useful in future.
  # We preserve .a as extension for shared libraries though AIX4.2
  # and later linker supports .so
  library_names_spec='${libname}${release}.so$versuffix ${libname}${release}.so$major $libname.a'
  shlibpath_var=LIBPATH
  deplibs_check_method=pass_all
  ;;

amigaos*)
  library_names_spec='$libname.ixlibrary $libname.a'
  # Create ${libname}_ixlibrary.a entries in /sys/libs.
  finish_eval='for lib in `ls $libdir/*.ixlibrary 2>/dev/null`; do libname=`$echo "X$lib" | $Xsed -e '\''s%^.*/\([^/]*\)\.ixlibrary$%\1%'\''`; test $rm /sys/libs/${libname}_ixlibrary.a; $show "(cd /sys/libs && $LN_S $lib ${libname}_ixlibrary.a)"; (cd /sys/libs && $LN_S $lib ${libname}_ixlibrary.a) || exit 1; done'
  ;;

beos*)
  library_names_spec='${libname}.so'
  dynamic_linker="$host_os ld.so"
  shlibpath_var=LIBRARY_PATH
  deplibs_check_method=pass_all
  lt_cv_dlopen="load_add_on"
  lt_cv_dlopen_libs=
  lt_cv_dlopen_self=yes
  ;;

bsdi4*)
  version_type=linux
  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 $libdir'
  shlibpath_var=LD_LIBRARY_PATH
  deplibs_check_method='file_magic ELF [0-9][0-9]*-bit [ML]SB (shared object|dynamic lib)'
  file_magic_cmd=/usr/bin/file
  file_magic_test_file=/shlib/libc.so
  sys_lib_search_path_spec="/shlib /usr/lib /usr/X11/lib /usr/contrib/lib /lib /usr/local/lib"
  sys_lib_dlsearch_path_spec="/shlib /usr/lib /usr/local/lib"
  export_dynamic_flag_spec=-rdynamic
  # the default ld.so.conf also contains /usr/contrib/lib and
  # /usr/X11R6/lib (/usr/X11 is a link to /usr/X11R6), but let us allow
  # libtool to hard-code these into programs
  ;;

cygwin* | mingw*)
  version_type=windows
  need_version=no
  need_lib_prefix=no
  if test "$with_gcc" = yes; then
    library_names_spec='${libname}`echo ${release} | sed -e 's/[.]/-/g'`${versuffix}.dll $libname.a'
  else
    library_names_spec='${libname}`echo ${release} | sed -e 's/[.]/-/g'`${versuffix}.dll $libname.lib'
  fi
  dynamic_linker='Win32 ld.exe'
  deplibs_check_method='file_magic file format pei*-i386(.*architecture: i386)?'
  file_magic_cmd='${OBJDUMP} -f'
  # FIXME: first we should search . and the directory the executable is in
  shlibpath_var=PATH
  lt_cv_dlopen="LoadLibrary"
  lt_cv_dlopen_libs=
  ;;

freebsd1*)
  dynamic_linker=no
  ;;
  
freebsd*)
  objformat=`test -x /usr/bin/objformat && /usr/bin/objformat || echo aout`
  version_type=freebsd-$objformat
  case "$version_type" in
    freebsd-elf*)
      deplibs_check_method='file_magic ELF [0-9][0-9]*-bit [LM]SB shared object'
      file_magic_cmd=/usr/bin/file
      file_magic_test_file=`echo /usr/lib/libc.so*`
      library_names_spec='${libname}${release}.so$versuffix ${libname}${release}.so $libname.so'
      need_version=no
      need_lib_prefix=no
      ;;
    freebsd-*)
      deplibs_check_method=unknown
      library_names_spec='${libname}${release}.so$versuffix $libname.so$versuffix'
      need_version=yes
      ;;
  esac
  shlibpath_var=LD_LIBRARY_PATH
  case "$host_os" in
  freebsd2* | freebsd3.[01]* | freebsdelf3.[01]*)
    shlibpath_overrides_runpath=yes
    ;;
  *) # from 3.2 on
    shlibpath_overrides_runpath=no
    ;;
  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
  ;;

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 $lib'
  case "$host_os" in
  hpux10.20*)
    # TODO:  Does this work for hpux-11 too?
    deplibs_check_method='file_magic (s[0-9][0-9][0-9]|PA-RISC[0-9].[0-9]) shared library'
    file_magic_cmd=/usr/bin/file
    file_magic_test_file=/usr/lib/libc.sl
    ;;
  esac
  ;;

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 $lib