general.m4

autoconf是一个产生可以自动配置源代码包

    break
  fi
done
if test -z "$ac_aux_dir"; then
  AC_MSG_ERROR([cannot find install-sh or install.sh in $1])
fi

# These three variables are undocumented and unsupported,
# and are intended to be withdrawn in a future Autoconf release.
# They can cause serious problems if a builder's source tree is in a directory
# whose full name contains unusual characters.
ac_config_guess="$SHELL $ac_aux_dir/config.guess"  # Please don't use this var.
ac_config_sub="$SHELL $ac_aux_dir/config.sub"  # Please don't use this var.
ac_configure="$SHELL $ac_aux_dir/configure"  # Please don't use this var.

AC_PROVIDE([AC_CONFIG_AUX_DIR_DEFAULT])dnl
])# AC_CONFIG_AUX_DIRS




## ------------------------ ##
## Finding aclocal macros.  ##
## ------------------------ ##


# AC_CONFIG_MACRO_DIR(DIR)
# ------------------------
# Declare directory containing additional macros for aclocal.
# DIR can be either absolute or relative to $srcdir.
AC_DEFUN([AC_CONFIG_MACRO_DIR],
[case $1 in
  [[\\/]]* | ?:[[\\/]]* ) ac_macro_dir=$1         ;;
  *)                      ac_macro_dir=$srcdir/$1 ;;
esac
test -d "$ac_macro_dir" ||
  AC_MSG_ERROR([cannot find macro directory `$1'])
])# AC_CONFIG_MACRO_DIR



## --------------------- ##
## Requiring aux files.  ##
## --------------------- ##

# AC_REQUIRE_AUX_FILE(FILE)
# -------------------------
# This macro does nothing, it's a hook to be read with `autoconf --trace'.
# It announces FILE is required in the auxdir.
m4_define([AC_REQUIRE_AUX_FILE],
[AS_LITERAL_IF([$1], [],
	       [AC_FATAL([$0: requires a literal argument])])])



## ----------------------------------- ##
## Getting the canonical system type.  ##
## ----------------------------------- ##

# The inputs are:
#    configure --host=HOST --target=TARGET --build=BUILD
#
# The rules are:
# 1. Build defaults to the current platform, as determined by config.guess.
# 2. Host defaults to build.
# 3. Target defaults to host.


# _AC_CANONICAL_SPLIT(THING)
# --------------------------
# Generate the variables THING, THING_{alias cpu vendor os}.
m4_define([_AC_CANONICAL_SPLIT],
[case $ac_cv_$1 in
*-*-*) ;;
*) AC_MSG_ERROR([invalid value of canonical $1]);;
esac
AC_SUBST([$1], [$ac_cv_$1])dnl
ac_save_IFS=$IFS; IFS='-'
set x $ac_cv_$1
shift
AC_SUBST([$1_cpu], [$[1]])dnl
AC_SUBST([$1_vendor], [$[2]])dnl
shift; shift
[# Remember, the first character of IFS is used to create $]*,
# except with old shells:
$1_os=$[*]
IFS=$ac_save_IFS
case $$1_os in *\ *) $1_os=`echo "$$1_os" | sed 's/ /-/g'`;; esac
AC_SUBST([$1_os])dnl
])# _AC_CANONICAL_SPLIT


# AC_CANONICAL_BUILD
# ------------------
AC_DEFUN([AC_CANONICAL_BUILD],
[AC_REQUIRE([AC_CONFIG_AUX_DIR_DEFAULT])dnl
AC_REQUIRE_AUX_FILE([config.sub])dnl
AC_REQUIRE_AUX_FILE([config.guess])dnl
m4_divert_once([HELP_CANON],
[[
System types:
  --build=BUILD     configure for building on BUILD [guessed]]])dnl
# Make sure we can run config.sub.
$SHELL "$ac_aux_dir/config.sub" sun4 >/dev/null 2>&1 ||
  AC_MSG_ERROR([cannot run $SHELL $ac_aux_dir/config.sub])

AC_CACHE_CHECK([build system type], [ac_cv_build],
[ac_build_alias=$build_alias
test "x$ac_build_alias" = x &&
  ac_build_alias=`$SHELL "$ac_aux_dir/config.guess"`
test "x$ac_build_alias" = x &&
  AC_MSG_ERROR([cannot guess build type; you must specify one])
ac_cv_build=`$SHELL "$ac_aux_dir/config.sub" $ac_build_alias` ||
  AC_MSG_ERROR([$SHELL $ac_aux_dir/config.sub $ac_build_alias failed])
])
_AC_CANONICAL_SPLIT(build)
])# AC_CANONICAL_BUILD


# AC_CANONICAL_HOST
# -----------------
AC_DEFUN([AC_CANONICAL_HOST],
[AC_REQUIRE([AC_CANONICAL_BUILD])dnl
m4_divert_once([HELP_CANON],
[[  --host=HOST       cross-compile to build programs to run on HOST [BUILD]]])dnl
AC_CACHE_CHECK([host system type], [ac_cv_host],
[if test "x$host_alias" = x; then
  ac_cv_host=$ac_cv_build
else
  ac_cv_host=`$SHELL "$ac_aux_dir/config.sub" $host_alias` ||
    AC_MSG_ERROR([$SHELL $ac_aux_dir/config.sub $host_alias failed])
fi
])
_AC_CANONICAL_SPLIT([host])
])# AC_CANONICAL_HOST


# AC_CANONICAL_TARGET
# -------------------
AC_DEFUN([AC_CANONICAL_TARGET],
[AC_REQUIRE([AC_CANONICAL_HOST])dnl
AC_BEFORE([$0], [AC_ARG_PROGRAM])dnl
m4_divert_once([HELP_CANON],
[[  --target=TARGET   configure for building compilers for TARGET [HOST]]])dnl
AC_CACHE_CHECK([target system type], [ac_cv_target],
[if test "x$target_alias" = x; then
  ac_cv_target=$ac_cv_host
else
  ac_cv_target=`$SHELL "$ac_aux_dir/config.sub" $target_alias` ||
    AC_MSG_ERROR([$SHELL $ac_aux_dir/config.sub $target_alias failed])
fi
])
_AC_CANONICAL_SPLIT([target])

# The aliases save the names the user supplied, while $host etc.
# will get canonicalized.
test -n "$target_alias" &&
  test "$program_prefix$program_suffix$program_transform_name" = \
    NONENONEs,x,x, &&
  program_prefix=${target_alias}-[]dnl
])# AC_CANONICAL_TARGET


AU_ALIAS([AC_CANONICAL_SYSTEM], [AC_CANONICAL_TARGET])


# AU::AC_VALIDATE_CACHED_SYSTEM_TUPLE([CMD])
# ------------------------------------------
# If the cache file is inconsistent with the current host,
# target and build system types, execute CMD or print a default
# error message.  Now handled via _AC_ARG_VAR_PRECIOUS.
AU_DEFUN([AC_VALIDATE_CACHED_SYSTEM_TUPLE], [])


## ---------------------- ##
## Caching test results.  ##
## ---------------------- ##


# AC_SITE_LOAD
# ------------
# Look for site or system specific initialization scripts.
m4_define([AC_SITE_LOAD],
[# Prefer explicitly selected file to automatically selected ones.
if test -n "$CONFIG_SITE"; then
  set x "$CONFIG_SITE"
elif test "x$prefix" != xNONE; then
  set x "$prefix/share/config.site" "$prefix/etc/config.site"
else
  set x "$ac_default_prefix/share/config.site" \
	"$ac_default_prefix/etc/config.site"
fi
shift
for ac_site_file
do
  if test -r "$ac_site_file"; then
    AC_MSG_NOTICE([loading site script $ac_site_file])
    sed 's/^/| /' "$ac_site_file" >&AS_MESSAGE_LOG_FD
    . "$ac_site_file"
  fi
done
])


# AC_CACHE_LOAD
# -------------
m4_define([AC_CACHE_LOAD],
[if test -r "$cache_file"; then
  # Some versions of bash will fail to source /dev/null (special
  # files actually), so we avoid doing that.
  if test -f "$cache_file"; then
    AC_MSG_NOTICE([loading cache $cache_file])
    case $cache_file in
      [[\\/]]* | ?:[[\\/]]* ) . "$cache_file";;
      *)                      . "./$cache_file";;
    esac
  fi
else
  AC_MSG_NOTICE([creating cache $cache_file])
  >$cache_file
fi
])# AC_CACHE_LOAD


# _AC_CACHE_DUMP
# --------------
# Dump the cache to stdout.  It can be in a pipe (this is a requirement).
m4_define([_AC_CACHE_DUMP],
[# The following way of writing the cache mishandles newlines in values,
# but we know of no workaround that is simple, portable, and efficient.
# So, we kill variables containing newlines.
# Ultrix sh set writes to stderr and can't be redirected directly,
# and sets the high bit in the cache file unless we assign to the vars.
(
  for ac_var in `(set) 2>&1 | sed -n ['s/^\([a-zA-Z_][a-zA-Z0-9_]*\)=.*/\1/p']`; do
    eval ac_val=\$$ac_var
    case $ac_val in #(
    *${as_nl}*)
      case $ac_var in #(
      *_cv_*) AC_MSG_WARN([Cache variable $ac_var contains a newline.]) ;;
      esac
      case $ac_var in #(
      _ | IFS | as_nl) ;; #(
      *) $as_unset $ac_var ;;
      esac ;;
    esac
  done

  (set) 2>&1 |
    case $as_nl`(ac_space=' '; set) 2>&1` in #(
    *${as_nl}ac_space=\ *)
      # `set' does not quote correctly, so add quotes (double-quote
      # substitution turns \\\\ into \\, and sed turns \\ into \).
      sed -n \
	["s/'/'\\\\''/g;
	  s/^\\([_$as_cr_alnum]*_cv_[_$as_cr_alnum]*\\)=\\(.*\\)/\\1='\\2'/p"]
      ;; #(
    *)
      # `set' quotes correctly as required by POSIX, so do not add quotes.
      sed -n ["/^[_$as_cr_alnum]*_cv_[_$as_cr_alnum]*=/p"]
      ;;
    esac |
    sort
)dnl
])# _AC_CACHE_DUMP


# AC_CACHE_SAVE
# -------------
# Save the cache.
# Allow a site initialization script to override cache values.
m4_define([AC_CACHE_SAVE],
[cat >confcache <<\_ACEOF
# This file is a shell script that caches the results of configure
# tests run on this system so they can be shared between configure
# scripts and configure runs, see configure's option --config-cache.
# It is not useful on other systems.  If it contains results you don't
# want to keep, you may remove or edit it.
#
# config.status only pays attention to the cache file if you give it
# the --recheck option to rerun configure.
#
# `ac_cv_env_foo' variables (set or unset) will be overridden when
# loading this file, other *unset* `ac_cv_foo' will be assigned the
# following values.

_ACEOF

_AC_CACHE_DUMP() |
  sed ['
     /^ac_cv_env_/b end
     t clear
     :clear
     s/^\([^=]*\)=\(.*[{}].*\)$/test "${\1+set}" = set || &/
     t end
     s/^\([^=]*\)=\(.*\)$/\1=${\1=\2}/
     :end'] >>confcache
if diff "$cache_file" confcache >/dev/null 2>&1; then :; else
  if test -w "$cache_file"; then
    test "x$cache_file" != "x/dev/null" &&
      AC_MSG_NOTICE([updating cache $cache_file])
    cat confcache >$cache_file
  else
    AC_MSG_NOTICE([not updating unwritable cache $cache_file])
  fi
fi
rm -f confcache[]dnl
])# AC_CACHE_SAVE


# AC_CACHE_VAL(CACHE-ID, COMMANDS-TO-SET-IT)
# ------------------------------------------
# The name of shell var CACHE-ID must contain `_cv_' in order to get saved.
# Should be dnl'ed.  Try to catch common mistakes.
m4_defun([AC_CACHE_VAL],
[m4_bmatch([$2], [AC_DEFINE],
	   [AC_DIAGNOSE([syntax],
[$0($1, ...): suspicious presence of an AC_DEFINE in the second argument, ]dnl
[where no actions should be taken])])dnl
AS_VAR_SET_IF([$1],
	      [_AS_ECHO_N([(cached) ])],
	      [$2])])


# AC_CACHE_CHECK(MESSAGE, CACHE-ID, COMMANDS)
# -------------------------------------------
# Do not call this macro with a dnl right behind.
m4_defun([AC_CACHE_CHECK],
[AC_MSG_CHECKING([$1])
AC_CACHE_VAL([$2], [$3])dnl
AS_LITERAL_IF([$2],
	      [AC_MSG_RESULT([$$2])],
	      [ac_res=AS_VAR_GET([$2])
	       AC_MSG_RESULT([$ac_res])])dnl
])



## ---------------------- ##
## Defining CPP symbols.  ##
## ---------------------- ##


# AC_DEFINE_TRACE_LITERAL(LITERAL-CPP-SYMBOL)
# -------------------------------------------
# Used by --trace to collect the list of AC_DEFINEd macros.
m4_define([AC_DEFINE_TRACE_LITERAL],
[m4_pattern_allow([^$1$])])


# AC_DEFINE_TRACE(CPP-SYMBOL)
# ---------------------------
# This macro is a wrapper around AC_DEFINE_TRACE_LITERAL which filters
# out non literal symbols.
m4_define([AC_DEFINE_TRACE],
[AS_LITERAL_IF([$1], [AC_DEFINE_TRACE_LITERAL([$1])])])


# AC_DEFINE(VARIABLE, [VALUE], [DESCRIPTION])
# -------------------------------------------
# Set VARIABLE to VALUE, verbatim, or 1.  Remember the value
# and if VARIABLE is affected the same VALUE, do nothing, else
# die.  The third argument is used by autoheader.
m4_define([AC_DEFINE], [_AC_DEFINE_Q([\], $@)])


# AC_DEFINE_UNQUOTED(VARIABLE, [VALUE], [DESCRIPTION])
# ----------------------------------------------------
# Similar, but perform shell substitutions $ ` \ once on VALUE.
m4_define([AC_DEFINE_UNQUOTED], [_AC_DEFINE_Q([], $@)])


# _AC_DEFINE_Q(QUOTE, VARIABLE, [VALUE], [DESCRIPTION])
# -----------------------------------------------------
m4_define([_AC_DEFINE_Q],
[AC_DEFINE_TRACE([$2])dnl
m4_ifval([$4], [AH_TEMPLATE(m4_bpatsubst([[$2]], [(.*)]), [$4])])dnl
cat >>confdefs.h <<$1_ACEOF
[@%:@define] $2 m4_if($#, 2, 1, [$3])
_ACEOF
])



## -------------------------- ##
## Setting output variables.  ##
## -------------------------- ##


# AC_SUBST_TRACE(VARIABLE)
# ------------------------
# This macro is used with --trace to collect the list of substituted variables.
m4_define([AC_SUBST_TRACE])


# AC_SUBST(VARIABLE, [VALUE])
# ---------------------------
# Create an output variable from